TRANSVERSE HAIRLINES FORMING APPARATUS FOR STAINLESS COIL AND STAINLESS COIL FORMED BY THE SAME

Abstract

A transverse hairline forming apparatus includes a coil supporting unit to which a stainless steel coil is rotatably disposed; a coil winding unit spaced apart from the coil supporting unit, the coil winding unit holding and winding an end of the stainless steel coil; and at least one pair of surface treatment units disposed between the coil supporting unit and the coil winding unit, the at least one pair of surface treatment units configured to form transverse hairlines on a surface of the stainless steel coil perpendicular to a winding direction of the stainless steel coil. While the stainless steel coil is unwound and rewound on the coil winding unit, when the stainless steel coil passes below the at least one pair of surface treatment units, the at least one pair of surface treatment units form the transverse hairlines on the surface of the stainless steel coil.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) AND CLAIM OF PRIORITY

This application claims priority from Korean Patent Application No. 10-2015-0123494 filed Sep. 1, 2015 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a stainless steel sheet having transverse hairlines that is used in a refrigerator. More particularly, the present disclosure relates to a transverse hairline forming apparatus for a stainless coil that can form transverse hairlines on a surface of a stainless steel sheet in a coil unit and a stainless steel coil formed by the transverse hairline forming apparatus.

BACKGROUND

The refrigerators have been widely used as a home appliance for storing food in a frozen state or chilled state.

In general, a refrigerator is provided with a main body that is formed in a substantially rectangular parallelepiped shape and a front surface of which is opened so that food can be stored, and a door formed to open and close a front opening of the main body.

These days, the refrigerators being used in households are recognized as a prop in the interior and are required to differentiate the exterior design of the refrigerator. In particular, when the refrigerator is installed, the door of the refrigerator is exposed to the outside so that it is important to differentiate the design of the door of the refrigerator.

As an example of such a design, refrigerators the doors of which are formed of a stainless steel sheet so that unique sheen and texture of the stainless steel appear have been widely sold. In particular, recently, stainless steel sheets which are surface-treated so that hairlines appear on the surface thereof are used for the production of the refrigerator door.

Stainless steel sheets having vertical hairlines are widely used to manufacture the refrigerator door. Here, the vertical hairlines refer to a surface treatment pattern formed in the height direction of the refrigerator.

In FIG. 1, a refrigerator 100 having a door 110 that is produced using a stainless steel sheet with the vertical hairlines 111 is illustrated.

In the refrigerator door 110 that is produced of the stainless steel sheet with the vertical hairlines as illustrated in FIG. 1, the brightness decreases and the irregular reflection occurs. In particular, as illustrated in FIG. 2, there is a problem that an irregular reflection phenomenon that is called as wave or smile occurs in the upper end portion of the refrigerator door.

This problem may be solved if the refrigerator door 110 is formed so that transverse hairlines appear on the front surface of the refrigerator door 110. Here, the transverse hairlines refer to a surface treatment pattern formed in the width direction of the refrigerator 100. Accordingly, the transverse hairlines form a right angle with the vertical hairlines 111 as described above.

An example of a conventional hairline forming apparatus 200 for forming hairlines on the stainless steel sheet is illustrated in FIG. 3.

Referring to FIG. 3, a stainless steel coil 201 is rotatably mounted on a coil supporting unit 210, and an end of the stainless steel coil 201 is fixed to a coil winding unit 220 that is disposed a predetermined distance away from the coil supporting unit 210. Accordingly, when the coil winding unit 220 is rotated, a strip-shaped stainless steel sheet constituting the stainless steel coil 201 mounted on the coil supporting unit 210 is unwound, and rewound on the coil winding unit 220.

At this time, three grinding belts 230 are provided above a portion 203 of the stainless steel coil 201 that extends between the coil supporting unit 210 and the coil winding unit 220. The three grinding belts 230 are disposed perpendicular to a winding direction (the direction of arrow A) of the stainless steel coil 201, and each of the three grinding belts 230 is rotatably supported by a pair of rollers. In detail, each of the three grinding belts 230 is disposed so that the rotating direction (the direction of arrow D) of the grinding belt 230 is parallel to the winding direction (the direction of arrow A) of the stainless steel coil 201.

Each of the grinding belts 230 is formed to have a width W1 corresponding to a width W2 of the stainless steel coil 201. Accordingly, when the grinding belts 230 are rotated, hairlines are formed over the entire width of a portion 205 of the stainless steel coil 201 that is in contact with the grinding belts 230. At this time, since the stainless steel coil 201 is continuously moved by the coil supporting unit 210 and the coil winding unit 220, continuous hairlines 207 are formed on the surface of the stainless steel coil 201 in the winding direction (the direction of arrow A) of the stainless steel coil 201. At this time, the hairlines 207 are formed parallel to the winding direction (the direction of arrow A) of the stainless steel coil 201.

Accordingly, if the height H of the refrigerator door 110 is less than the width W2 of the stainless steel coil 201, it is possible to form the refrigerator door 110 by using the stainless steel coil 201 with the hairlines 207 formed in this way so that the transverse hairlines appear on the surface of the refrigerator door 110.

Side-by-side type of refrigerators, one-door type of refrigerators, built-in refrigerators, etc. that are widely used nowadays have a door the height of which is greater than 1250 mm.

However, since the maximum width of the stainless steel coil 201 that is commonly used is 1250 mm, when the height H of the refrigerator door 110 is greater than 1250 mm, the refrigerator door having the transverse hairlines cannot be created by using the stainless steel coil 201 provided with the hairlines 207 that are formed by using the hairline forming apparatus 200 as illustrated in FIG. 3.

As a way to solve this problem, a method for manufacturing a steel sheet for a refrigerator door (patent number; No. 10-0860645, Filing date; 2007.05.04. Invention Title; a refrigerator, a steel sheet for a refrigerator door, and a method for manufacturing the same) has been proposed.

In the method of manufacturing a steel sheet for a refrigerator door, a stainless steel coil is cut to a length corresponding to the height of the refrigerator door, and then the transverse hairlines is formed by polishing the surface of the cut stainless steel sheet.

However, when the transverse hairlines are formed on the stainless steel sheet provided by cutting the stainless steel coil to a predetermined length, the stainless steel sheets that are cut to a predetermined length need to be transported to post processes for manufacturing the refrigerator door. Accordingly, the feeding of the stainless steel sheets having the transverse hairlines into the post processes for making the refrigerator door is expensive and the handling of the stainless steel sheets is difficult. This problem may be solved if the transverse hairlines are formed on the stainless steel sheet in a coil state and the stainless steel sheet having the transverse hairlines is transported in the coil state.

Accordingly, the development of a hairline forming apparatus which can form transverse hairlines in the coil state without cutting the stainless steel coil has been required.

SUMMARY

The present disclosure has been developed in order to overcome the above drawbacks and other problems associated with the conventional arrangement. An aspect of the present disclosure relates to a transverse hairline forming apparatus for a stainless steel coil that can form transverse hairlines in a coil state without cutting a stainless steel coil, and a stainless steel coil formed by the same.

According to an aspect of the present disclosure, a transverse hairline forming apparatus for a stainless steel coil may include a coil supporting unit to which a stainless steel coil is rotatably disposed; a coil winding unit spaced apart from the coil supporting unit, the coil winding unit holding and winding an end of the stainless steel coil; and at least one pair of surface treatment units disposed between the coil supporting unit and the coil winding unit, the at least one pair of surface treatment units configured to form transverse hairlines on a surface of the stainless steel coil perpendicular to a winding direction of the stainless steel coil, wherein, while the stainless steel coil is unwound from the coil supporting unit and then is rewound on the coil winding unit, when the stainless steel coil passes below the at least one pair of surface treatment units, the at least one pair of surface treatment units form the transverse hairlines on the surface of the stainless steel coil.

Each of the at least one pair of surface treatment units may include a grinding belt of a caterpillar shape; a drive roller disposed at an end of an inner side of the grinding belt, the drive roller to rotate the grinding belt; a driven roller disposed at another end of the inner side of the grinding belt, the driven roller to support the grinding belt to be moved endlessly by the drive roller; and a working roller to cause a portion of the grinding belt to be in line contact with the surface of the stainless steel coil, the working roller to move between the drive roller and the driven roller to form the transverse hairlines.

The working roller may be disposed to reciprocate between a first position adjacent to the drive roller and a second position adjacent to the driven roller.

The working roller may allow the portion of the grinding belt to be in line contact with the surface of the stainless steel coil when the working roller moves from the first position to the second position.

The working roller of each of the at least one pair of surface treatment units may be disposed to move in opposite directions.

An abrasive grain size of the grinding belt of each of the at least one pair of surface treatment units may be different from each other.

The at least one pair of surface treatment units may include four pairs of surface treatment units, each of the four pairs of surface treatment units may include the grinding belt, and an abrasive grain size of the grinding belt of at least one pair of the surface treatment units among the four pairs of surface treatment units may be different from the abrasive grain sizes of the grinding belts of other surface treatment units.

The stainless steel coil may include a stainless steel coil on a surface of which vertical hairlines are formed.

The stainless steel coil may include a stainless steel coil on a surface of which is embossing processed.

Other objects, advantages and salient features of the present disclosure will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the present disclosure will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a front view illustrating a refrigerator provided with a door manufactured by using a stainless steel sheet having vertical hairlines;

FIG. 2 is a partially front view illustrating wave that appears on an upper end portion of the door of the refrigerator of FIG. 1;

FIG. 3 is a perspective view conceptually illustrating a conventional hairline forming apparatus for a stainless steel coil;

FIG. 4 is a perspective view schematically illustrating a transverse hairline forming apparatus for a stainless steel coil according to an embodiment of the present disclosure;

FIG. 5 is a partially perspective view illustrating a surface treatment unit of the transverse hairline forming apparatus for a stainless steel coil of FIG. 4;

FIGS. 6A, 6B, and 6C are partially cross-sectional views illustrating operations of a working roller of a surface treatment unit of a transverse hairline forming apparatus for a stainless steel coil according to an embodiment of the present disclosure;

FIG. 7 is a perspective view illustrating a stainless steel coil manufactured by a transverse hairline forming apparatus for a stainless steel coil according to an embodiment of the present disclosure;

FIG. 8 is a view illustrating a refrigerator including a door that is manufactured by using a stainless steel sheet produced by a transverse hairline forming apparatus for a stainless steel coil according to an embodiment of the present disclosure;

FIG. 9 is a partial view illustrating a refrigerator door that is manufactured by using a stainless steel sheet produced by a transverse hairline forming apparatus for a stainless steel coil according to an embodiment of the present disclosure; and

FIG. 10 is a partial view illustrating a refrigerator door that is manufactured by using a stainless steel sheet produced by a transverse hairline forming apparatus for a stainless steel coil according to an embodiment of the present disclosure.

Throughout the drawings, like reference numerals will be understood to refer to like parts, components and structures.

DETAILED DESCRIPTION

Hereinafter, certain exemplary embodiments of a transverse hairline forming apparatus for a stainless steel coil according to the present disclosure and a stainless steel coil manufactured by this transverse hairline forming apparatus will be described in detail with reference to the accompanying drawings.

The matters defined herein, such as a detailed construction and elements thereof, are provided to assist in a comprehensive understanding of this description. Thus, it is apparent that exemplary embodiments may be carried out without those defined matters. Also, well-known functions or constructions are omitted to provide a clear and concise description of exemplary embodiments. Further, dimensions of various elements in the accompanying drawings may be arbitrarily increased or decreased for assisting in a comprehensive understanding.

The terms “first”, “second”, etc. may be used to describe diverse components, but the components are not limited by the terms. The terms are only used to distinguish one component from the others.

The terms used in the present application are only used to describe the exemplary embodiments, but are not intended to limit the scope of the disclosure. The singular expression also includes the plural meaning as long as it does not differently mean in the context. In the present application, the terms “include” and “consist of” designate the presence of features, numbers, steps, operations, components, elements, or a combination thereof that are written in the specification, but do not exclude the presence or possibility of addition of one or more other features, numbers, steps, operations, components, elements, or a combination thereof.

FIG. 4 is a perspective view schematically illustrating a transverse hairline forming apparatus for a stainless steel coil according to an embodiment of the present disclosure, and FIG. 5 is a partially perspective view illustrating a surface treatment unit of the transverse hairline forming apparatus for a stainless steel coil of FIG. 4. FIGS. 6A, 6B, and 6C are partially cross-sectional views illustrating operations of a working roller of a surface treatment unit of a transverse hairline forming apparatus for a stainless steel coil according to an embodiment of the present disclosure.

Referring to FIGS. 4 and 5, a transverse hairline forming apparatus for a stainless steel coil 1 according to an embodiment of the present disclosure may include a coil supporting unit 10, a coil winding unit 20, and four pairs of surface treatment units 30-1, 30-2, 30-3, and 30-4.

The coil supporting unit 10 is formed so that a stainless steel coil 11 is rotatably mounted to the coil supporting unit 10. Here, the stainless steel coil 11 refers to a predetermined length of strip-shaped stainless steel sheet that is wound as illustrated in FIG. 7 and is used to produce refrigerator doors. Accordingly, a single stainless steel coil 11 is used to manufacture a plurality of refrigerator doors.

The coil winding unit 20 is disposed to be spaced apart a predetermined distance from the coil supporting unit 10, and is formed to grasp and wind an end of the stainless steel coil 11 mounted to the coil supporting unit 10. Accordingly, the coil winding unit 20 is provided with a rotational shaft (not illustrated) that can grasp and rotate the end of the stainless steel coil 11. When the rotational shaft of the coil winding unit 20 is rotated, the stainless steel coil 11 mounted to the coil supporting unit 10 is unwound, and then is rewound on the coil winding unit 20.

The coil supporting unit 10 and the coil winding unit 20 are formed as the same as or similar to the coil supporting unit 210 and the coil winding unit 220 of the conventional hairline forming apparatus 200; therefore, the detailed configuration thereof is omitted.

The four pairs of surface treatment units 30-1, 30-2, 30-3, and 30-4 are disposed between the coil supporting unit 10 and the coil winding unit 20, and form transverse hairlines 12 on the surface of the stainless steel coil 11 at right angles to a moving direction of the stainless steel coil 11, that is, in the winding direction (the direction of arrow A) of the stainless steel coil 11. In detail, while the stainless steel coil 11 mounted to the coil supporting unit 10 is being unwound and then is being rewound by the coil winding unit 20, the four pairs of surface treatment units 30-1, 30-2, 30-3, and 30-4 form the transverse hairlines 12 on portions of the surface of the stainless steel coil 11 with which the four pairs of surface treatment units 30-1, 30-2, 30-3, and 30-4 are in contact, respectively. When the stainless steel coil 11 has passed through all of the four pairs of surface treatment units 30-1, 30-2, 30-3, and 30-4, the transverse hairlines 12 are completed on the surface of the stainless steel coil 11.

Since each of the four pairs of surface treatment units 30-1, 30-2, 30-3, and 30-4 includes two surface treatment units, the transverse hairline forming apparatus for a stainless steel coil 1 according to an embodiment of the present disclosure as illustrated in FIG. 4 includes a total of eight surface treatment units 31, 32, 33, 34, 35, 36, 37, and 38. Hereinafter, for convenience of description, a surface treatment unit that is closest to the coil supporting unit 10 among the eight surface treatment units 31, 32, 33, 34, 35, 36, 37, and 38 is referred to as a first surface treatment unit 31, and the remaining surface treatment units are sequentially referred to as a second surface treatment unit 32, a third surface treatment unit 33, a fourth surface treatment unit 34, a fifth surface treatment unit 35, a sixth surface treatment unit 36, a seventh surface treatment unit 37, and an eighth surface treatment unit 38 in the winding direction of the stainless steel coil 11. Accordingly, the surface treatment unit closest to the coil winding unit 20 is the eighth surface treatment unit 38.

Also, the first and second surface treatment units 31 and 32 constitute a first pair of surface treatment units 30-1. The third and fourth surface treatment units 33 and 34 constitute a second pair of surface treatment units 30-2. The fifth and sixth surface treatment units 35 and 36 constitute a third pair of surface treatment units 30-3. The seventh and eighth surface treatment units 37 and 38 constitute a fourth pair of surface treatment units 30-4.

Since the eight surface treatment units 31, 32, 33, 34, 35, 36, 37, and 38 are formed in the same structure, in the following, the structure of the eighth surface treatment unit 38 will be described in detail with reference to FIG. 5. The structure of each of the first to seventh surface treatment units 31, 32, 33, 34, 35, 36, and 37 is the same as the structure of the eighth surface treatment unit 38.

The eighth surface treatment unit 38 (hereinafter, referred to as a surface treatment unit) may include a grinding belt 41, a drive roller 42, a driven roller 43, and a working roller 45.

The grinding belt 41 is formed in a caterpillar shape forming a closed curve. The drive roller 42 and the drive roller 42 are disposed in the inner side of the grinding belt 41. The grinding belt 41 is disposed perpendicular to the winding direction (the direction of arrow A) of the stainless steel coil 11. Accordingly, the rotational direction (the direction of arrow B) of the grinding belt 41 forms a right angle with the winding direction (the direction of arrow A) of the stainless steel coil 11.

The outer surface of the grinding belt 41 is provided with an abrasive which can process the surface of the stainless steel coil 11 so as to form the transverse hairlines 12. The grain size of the abrasive of the grinding belt 41 may be approximate 80˜400 mesh.

The drive roller 42 is disposed at an end of the inner side of the grinding belt 41, and generates a driving force to rotate the grinding belt 41. The drive roller 42 may be formed as a built-in motor structure. Alternatively, the drive roller 42 may be formed to be rotated by receiving power from an outside motor as not illustrated.

The driven roller 43 is disposed at the other end of the inner side of the grinding belt 41, and supports the grinding belt 41 to be rotated by the drive roller 42. Accordingly, when the drive roller 42 rotates, the grinding belt 41 is supported and endlessly moved by the drive roller 42 and the driven roller 43.

The working roller 45 is disposed between the drive roller 42 and the driven roller 43 in the inner side of the grinding belt 41. The working roller 45 is formed to cause a portion of the grinding belt 41 to be in line contact with the surface of the stainless steel coil 11 that passes below the grinding belt 41, thereby forming the transverse hairlines 12 on the surface of the stainless steel coil 11. Accordingly, the entire surface 41-1 (see FIGS. 6A, 6B, and 6C) of the grinding belt 41 facing the stainless steel coil 11 is not in contact with the stainless steel coil 11, but a portion 41-2 (see FIGS. 6A, 6B, and 6C) of the grinding belt 41 which is pressed by the working roller 45 is in contact with the surface of the stainless steel coil 11.

The working roller 45 is disposed to reciprocately move between the drive roller 42 and the driven roller 43. In detail, if a position of the working roller 45 that is close to one side end of the stainless steel coil 11 adjacent to the drive roller 42 is referred to as a first position P1 and a position of the working roller 45 that is close to the other side end of the stainless steel coil 11 adjacent to the driven roller 43 is referred to as a second position P2, the working roller 45 is disposed to reciprocately move between the first position P1 and the second position P2. In other words, the working roller 45 is disposed to reciprocate linearly between the first position P1 adjacent to the drive roller 42 and the second position P2 adjacent to the driven roller 43. Accordingly, the moving direction (the direction of arrow C) of the working roller 45 forms a right angle with the winding direction (the direction of arrow A) of the stainless steel coil 11.

The working roller 45 may be disposed to be inclined by a predetermined angle with respect to a virtual axis (hereinafter, referred to as a vertical axis) parallel to the moving direction (the direction of arrow C) of the working roller 45 that is perpendicular to the winding direction (the direction of arrow A) of the stainless steel coil 11 so as to form the transverse hairlines 12 perpendicular to the winding direction (the direction of arrow A) of the stainless steel coil 11 on a portion of the moving stainless steel coil 11. An inclination angle of the working roller 45 with respect to the vertical axis may be appropriately determined according to a moving speed of the stainless steel coil 11, that is, a winding speed of the stainless steel coil 11, a moving speed of the working roller 45, etc. To this end, the working roller 45 may be disposed so that a user can adjust the inclination angle with respect to the vertical axis.

In the case that the working roller 45 is moved to form the transverse hairlines 12 while the stainless steel coil 11 is moving, both when the working roller 45 is moved from the first position P1 to the second position P2 and when the working roller 45 is moved from the second position P2 to the first position P1, the working roller 45 may be moved to cause the grinding belt 41 to maintain contact with the stainless steel coil 11.

At this time, the working roller 45 of each of the two surface treatment units 31-32, 33-34, 35-36, and 37-38 in the pair may be configured to perform a surface treatment operation while moving in the same direction.

As another example, the working roller 45 of each of the two surface treatment units 31-32, 33-34, 35-36, and 37-38 in the pair may be configured to perform the surface treatment operation while moving in opposite directions to each other. For example, when the working roller 45 of the eighth surface treatment unit 38 is positioned in the first position P1, the seventh surface treatment unit 37 that forms a pair with the eighth surface treatment unit 38 is configured to be positioned in the second position P2. With this configuration, when the working roller 45 of the eighth surface treatment unit 38 performs the surface treatment of the stainless steel coil 11 while moving from the first position P1 to the second position P2, the working roller 45 of the seventh surface treatment unit 37 performs the surface treatment while moving from the second position P2 to the first position P1. Accordingly, the working roller 45 of the seventh surface treatment unit 37 and the working roller 45 of the eighth surface treatment unit 38 perform the surface treatment moving in opposite directions to each other, thereby forming the transverse hairlines 12.

The abrasive grain size of the grinding belt 41 of each of the eight surface treatment units 31, 32, 33, 34, 35, 36, 37, and 38 may be formed differently. Alternatively, the abrasive grain size of the grinding belt 41 of some of the eight surface treatment units 31, 32, 33, 34, 35, 36, 37, and 38 may be formed identically.

Also, the abrasive grain sizes of the grinding belts 41 of the two surface treatment units 31-32, 33-34, 35-36, and 37-38 in the pair may be identically formed. For example, the grinding belts 41 of the first and second surface treatment units 31 and 32 included in the first pair 30-1 may be configured to have the same abrasive grain size. Further, the grinding belts 41 of the third and fourth surface treatment units 33 and 34 included in the second pair 30-2, the grinding belts 41 of the fifth and sixth surface treatment units 35 and 36 included in the third pair 30-3, and the grinding belts 41 of the seventh and eighth surface treatment units 37 and 38 included in the fourth pair 30-4 may have the same abrasive grain size, respectively.

The abrasive grain size of the grinding belt 41 of each of the four pairs of surface treatment units 30-1, 30-2, 30-3, and 30-4 may be defined within a certain range so that the transverse hairlines 12 are completed on the surface of the stainless steel coil 11 after passing through all of the four pairs of surface treatment units 30-1, 30-2, 30-3, and 30-4.

For example, in the embodiment as illustrated in FIG. 4, the grinding belts 41 of the first pair of surface treatment units 30-1 may have the abrasive grain size of about 80 to 120 mesh. The grinding belts 41 of the second pair of surface treatment units 30-2 may have the abrasive grain size of about 80 to 120 mesh. The grinding belts 41 of the third pair of surface treatment units 30-3 may have the abrasive grain size of about 80 to 150 mesh. The grinding belts 41 of the fourth pair of surface treatment units 30-4 may have the abrasive grain size of about 120 to 400 mesh.

At this time, the four pairs of surface treatment units 30-1, 30-2, 30-3, and 30-4 may be configured to have a higher abrasive grain size sequentially in the winding direction (the direction of arrow A) of the stainless steel coil 11. For example, the abrasive grain size of the grinding belt 41 of the first pair of surface treatment units 30-1 may be determined to be 90 mesh, the abrasive grain size of the grinding belt 41 of the second pair of surface treatment units 30-2 may be determined to be 100 mesh, the abrasive grain size of the grinding belt 41 of the third pair of surface treatment units 30-3 may be determined to be 120 mesh, and the abrasive grain size of the grinding belt 41 of the fourth pair of surface treatment units 30-4 may be determined to be 140 mesh.

Also, at least one pair of the four pairs of surface treatment units 30-1, 30-2, 30-3, and 30-4 may be formed to have the abrasive grain size different from the abrasive grain size of the grinding belt 41 of the other pairs of surface treatment units. For example, the grinding belts 41 of the first pair, the second pair, and third pair of surface treatment units 30-1, 30-2, and 30-3 may be configured to have the same abrasive grain size, and only the grinding belt 41 of the fourth pair of surface treatment units 30-4 may be configured to have the abrasive grain size higher than those of the grinding belts 41 of the three pairs of surface treatment units 30-1, 30-2, and 30-3.

The abrasive grain sizes of the grinding belts 41 of the four pairs of surface treatment units 30-1, 30-2, 30-3, and 30-4 may be properly determined depending on a kind of the stainless steel coil 11, a desired state of the transverse hairlines 12, a winding speed of the stainless steel coil 11, a moving speed of the working roller 45, a rotation speed of the grinding belt 41, etc.

The controller 50 controls the coil winding unit 20, and the drive roller 42 and working roller 45 of each of the eight surface treatment units 31, 32, 33, 34, 35, 36, 37, and 38. Accordingly, the controller 50 may be configured to control the speed at which the coil winding unit 20 winds the stainless steel coil 11, and the moving speed and the moving direction of the working roller 45 and the rotation speed of the drive roller 42 of each of the eight surface treatment units 31, 32, 33, 34, 35, 36, 37, and 38.

Although not illustrated in FIG. 4, a support member that supports a portion 13 of the stainless steel coil 11 which is located between the coil supporting unit 10 and the coil winding unit 20 may be disposed below the stainless steel coil 11 between the coil supporting unit 10 and the coil winding unit 20. The support member may be formed to support a force which is applied to the stainless steel coil 11 when the transverse hairlines 12 are formed on the surface of the stainless steel coil 11 by the working rollers 45 of the four pairs of surface treatment units 30-1, 30-2, 30-3, and 30-4, thereby preventing the stainless steel coil 11 from sagging.

Hereinafter, operation of the transverse hairline forming apparatus for stainless steel coil 1 according to an embodiment of the present disclosure having the above-described structure will be described in detail with reference to FIGS. 4, 5, 6A, 6B, and 6C.

First, a stainless steel coil 11 to be processed is mounted to the coil supporting unit 10, and an end of the stainless steel coil 11 mounted to the coil supporting unit 10 is fixed to the coil winding unit 20. When operating the coil winding unit 20 in this state, the stainless steel coil 11 mounted to the coil supporting unit 10 is unwound, and then rewound on the coil winding unit 20.

At this time, the transverse hairlines 12 are formed on the surface of the stainless steel coil 11′ being wound on the coil winding unit 20 by the eight grinding belts 41 and working rollers 45 while the stainless steel coil 11 is passing below the four pairs of surface treatment units 30-1, 30-2, 30-3, and 30-4.

In detail, after the working roller 45 presses the grinding belt 41 in the first position P1 as illustrated in FIG. 6A so that a portion 41-2 of the grinding belt 41 is in line contact with the stainless steel coil 11, the working roller 45 is moved to the second position P2 as illustrated in FIG. 6C in a state in which the grinding belt 41 is in line contact with the stainless steel coil 11, and thus the transverse hairlines 12 are formed on the surface of the stainless steel coil 11. FIG. 6B illustrates a state in which the working roller 45 is being moved, and the working roller 45 is located in approximately midway between the first position P1 and the second position P2.

When the working roller 45 forms the transverse hairlines 12 while moving from the first position P1 to the second position P2, the grinding belt 41 is rotated in one direction by the drive roller 42 so that the grinding belt 41 which is positioned between the working roller 45 and the stainless steel coil 11 also is moved. Accordingly, while the working roller 45 is moving from the first position P1 to the second position P2, a portion 41-2 of the grinding belt 41 that is in contact with the stainless steel coil 11 is continuously changed to form the transverse hairlines 12 on the surface of the stainless steel coil 11. Accordingly, since the surface treatment of the stainless steel coil 11 is performed by the portion 41-2 of the grinding belt 41 which is continuously changed, the transverse hairlines 12 may be effectively formed.

After the working roller 45 arrives at the second position P2, the working roller 45 moves back to the first position P1, and causes the grinding belt 41 to be in line contact with the stainless steel coil 11, thereby forming the transverse hairlines 12.

As illustrated in FIG. 4, since the transverse hairline forming apparatus for a stainless steel coil 1 according to an embodiment of the present disclosure is configured so that the four pairs of surface treatment units 30-1, 30-2, 30-3, and 30-4 are provided with the grinding belts 41 the abrasive grain sizes of which are higher in sequence, the desired transverse hairlines 12 are completed after the stainless steel coil 11 is moved in the winding direction (the direction of arrow A) and passes by the fourth pair of surface treatment units 30-4.

Accordingly, in the transverse hairline forming apparatus for a stainless steel coil 1 according to an embodiment of the present disclosure, while the coil winding unit 20 is winding the stainless steel coil 11, the transverse hairlines 12 are continuously formed on the surface of the stainless steel coil 11 by the eight surface treatment units 31, 32, 33, 34, 35, 36, 37, and 38.

In the transverse hairline forming apparatus for a stainless steel coil 1 according to an embodiment of the present disclosure, when rewinding the stainless steel coil 11 mounted on the coil supporting unit 10 on the coil winding unit 20 is completed, the processing of the transverse hairlines 12 on the surface of the strip-shaped stainless steel sheet to form the stainless steel coil 11 is completed. Accordingly, the stainless steel coil 11′ provided with the transverse hairlines 12 as illustrated in FIG. 7 may be obtained.

In the above description, the eight surface treatment units 31, 32, 33, 34, 35, 36, 37, and 38 form the transverse hairlines 12 on the surface of the stainless steel coil 11 while the stainless steel coil 11 is still wound. However, as another embodiment, the transverse hairlines 12 may be formed in a state in which the stainless steel coil 11 is stopped.

In the case of the present embodiment, the configuration of a transverse hairline forming apparatus for a stainless steel coil is the same as that of the transverse hairline forming apparatus for a stainless steel coil 1 as illustrated in FIG. 4, but the control method thereof is different. Also, in the case of this embodiment, because the transverse hairlines 12 are formed in a state in which the stainless steel coil 11 is stationary, the working roller 45 is disposed parallel to the winding direction (the direction of arrow A) of the stainless steel coil 11.

The controller 50 controls the coil winding unit 20 so that the coil winding unit 20 intermittently operates to wind a predetermined length of the stainless steel coil 11 and then stops.

For example, in the state in which the stainless steel coil 11 is stationary, the controller 50 controls the eight surface treatment units 31, 32, 33, 34, 35, 36, 37, and 38 so that the drive rollers 42 are rotated to cause the grinding belts 41 to perform the endless movement and the working rollers 45 are moved from the first position P1 to the second position P2. Thus, the grinding belt 41 is in line contact with the surface of the stainless steel coil 11 by the working roller 45, thereby forming the transverse hairlines 12 on the surface of the stainless steel coil 11.

When the working roller 45 arrives at the second position P2, the controller 50 stops the rotation of the drive roller 42, and then returns the working roller 45 to the first position P1. At this time, the working roller 45 is lifted a certain distance to be prevented from pressing the grinding belt 41 against the stainless steel coil 11. Accordingly, when the working roller 45 is returned from the second position P2 to the first position P1, the transverse hairlines 12 are not formed.

When the working roller 45 is moved from the second position P2 to the first position P1, the controller 50 controls the coil winding unit 20 to wind the stainless steel coil 11 a predetermined length. At this time, the predetermined length of the wound stainless steel coil 11 is a length of the stainless steel coil 11 on which the transverse hairlines 12 are formed by the eighth surface treatment unit 38. The length may be approximately equal to the width W3 of the grinding belt 41.

After winding the stainless steel coil 11 the predetermined length by controlling the coil winding unit 20, the controller 50 stops the coil winding unit 20 so that the stainless steel coil 11 is not moved. After that, the controller 50 again controls the drive rollers 42 and the working rollers 45 to form the transverse hairlines 12 on the surface of the stainless steel coil 11.

The controller 50 may repeat the surface treatment operation and the winding operation of the stainless steel coil 11 as described above to continuously form the transverse hairlines 12 on the surface of the stainless steel coil 11.

In the above description, the transverse hairlines 12 are processed on the surface of the stainless steel coil 11 by using the four pairs of surface treatment units 30-1, 30-2, 30-3, and 30-4, that is, the eight surface treatment units 31, 32, 33, 34, 35, 36, 37, and 38. However, this is only one example. The transverse hairline forming apparatus for a stainless steel coil 1 according to an embodiment of the present disclosure may be configured to form the transverse hairlines 12 using at least one pair of surface treatment unit, that is, at least two surface treatment units or five or more pairs of surface treatment units, that is, ten or more surface treatment units.

With the transverse hairline forming apparatus for a stainless steel coil 1 according to an embodiment of the present disclosure as described above, because the transverse hairlines 12 can be formed on the strip-shaped stainless steel sheet without cutting the stainless steel coil 11, it is possible to obtain a stainless steel coil 11′ on the surface of which the transverse hairlines 12 are formed. Accordingly, because the stainless steel sheet to be a basic plate of the refrigerator door can be moved in a coil unit for the post processes for manufacturing the refrigerator door, for example, an additional surface treatment process, a molding process, etc., the transportation is more convenient, the handling is easier, and the logistics cost is reduced compared to the prior art in which the cut stainless steel sheets with the transverse hairlines are transported.

A side by side type of refrigerator 300 provided with a door 310 which is manufactured using the stainless steel coil 11′ as illustrated in FIG. 7 on which the transverse hairlines 12 are formed by the transverse hairline forming apparatus for a stainless steel coil 1 according to an embodiment of the present disclosure is illustrated in FIG. 8.

Referring to FIG. 8, on the surface of the door 310 of the refrigerator 300, the transverse hairlines 12 are formed in a width direction of the refrigerator 300. When the transverse hairlines 12 are formed on the surface of the door 310 of the refrigerator 300 as described above, the irregular reflection phenomenon, which is called as wave, smile, and the like, may not occur in the upper end portion of the door 310 differently from the refrigerator door 110 having the vertical hairlines 111 as illustrated in FIG. 1.

In the above description, the transverse hairline forming apparatus for a stainless steel coil 1 according to an embodiment of the present disclosure forms the transverse hairlines 12 on the surface of the stainless steel coil 11 in which there is no pattern.

However, the transverse hairline forming apparatus for a stainless steel coil 1 according to an embodiment of the present disclosure may form the transverse hairlines on the surface of the stainless steel coil on which a pattern is formed.

For example, the transverse hairlines may be formed on the stainless steel coil 201 on which the vertical hairlines 207 are formed by the conventional hairline forming apparatus 200 of FIG. 3 using the transverse hairline forming apparatus for a stainless steel coil 1 according to an embodiment of the present disclosure. So, a pattern in which the vertical hairlines and the transverse hairlines cross each other may be obtained.

An example of a refrigerator door 310′ having the pattern in which the transverse hairlines and the vertical hairlines cross is illustrated in FIG. 9.

As another example, the transverse hairline forming apparatus for a stainless steel coil 1 according to an embodiment of the present disclosure may form the transverse hairlines on the surface of a stainless steel coil on which an embossing pattern is formed by an embossing process. Thus, a pattern in which the embossing pattern is combined with the transverse hairlines may be obtained.

An example of a refrigerator door 310″ having the pattern in which the embossing pattern is combined with the transverse hairlines is illustrated in FIG. 10. However, the embossing pattern as illustrated in FIG. 10 is only one example. A variety of embossing patterns may be applied to the refrigerator door.

While the embodiments of the present disclosure have been described, additional variations and modifications of the embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims shall be construed to include both the above embodiments and all such variations and modifications that fall within the spirit and scope of the inventive concepts.

Claims

1. A transverse hairline forming apparatus for a stainless steel coil, the transverse hairline forming apparatus comprising:

a coil supporting unit to which a stainless steel coil is rotatably disposed;

a coil winding unit spaced apart from the coil supporting unit, the coil winding unit holding and winding an end of the stainless steel coil; and

at least one pair of surface treatment units disposed between the coil supporting unit and the coil winding unit, the at least one pair of surface treatment units configured to form transverse hairlines on a surface of the stainless steel coil perpendicular to a winding direction of the stainless steel coil,

wherein, while the stainless steel coil is unwound from the coil supporting unit and then is rewound on the coil winding unit, when the stainless steel coil passes below the at least one pair of surface treatment units, the at least one pair of surface treatment units form the transverse hairlines on the surface of the stainless steel coil.

2. The transverse hairline forming apparatus of claim 1, wherein

each of the at least one pair of surface treatment units comprises,

a grinding belt of a caterpillar shape;

a drive roller disposed at an end of an inner side of the grinding belt, the drive roller to rotate the grinding belt;

a driven roller disposed at another end of the inner side of the grinding belt, the driven roller to support the grinding belt to be moved endlessly by the drive roller; and

a working roller to cause a portion of the grinding belt to be in line contact with the surface of the stainless steel coil, the working roller to move between the drive roller and the driven roller to form the transverse hairlines.

3. The transverse hairline forming apparatus of claim 2, wherein

the working roller is disposed to reciprocate between a first position adjacent to the drive roller and a second position adjacent to the driven roller.

4. The transverse hairline forming apparatus of claim 3, wherein

the working roller allows the portion of the grinding belt to be in line contact with the surface of the stainless steel coil when the working roller moves from the first position to the second position.

5. The transverse hairline forming apparatus of claim 3, wherein

the working roller of each of the at least one pair of surface treatment units is disposed to move in opposite directions.

6. The transverse hairline forming apparatus of claim 2, wherein

an abrasive grain size of the grinding belt of each of the at least one pair of surface treatment units is different from each other.

7. The transverse hairline forming apparatus of claim 1, wherein

the at least one pair of surface treatment units comprises four pairs of surface treatment units,

each of the four pairs of surface treatment units comprises a grinding belt, and

an abrasive grain size of the grinding belt of at least one pair of the surface treatment units among the four pairs of surface treatment units is different from the abrasive grain sizes of the grinding belts of other surface treatment units.

8. The transverse hairline forming apparatus of claim 1, wherein

the stainless steel coil comprises a stainless steel coil on a surface of which vertical hairlines are formed.

9. The transverse hairline forming apparatus of claim 1, wherein

the stainless steel coil comprises a stainless steel coil on a surface of which is embossing processed.

10. A stainless steel coil comprising:

a surface on which transverse hairlines are processed by a transverse hairline forming apparatus for a stainless steel coil,

wherein the transverse hairline forming apparatus for a stainless steel coil comprises,

a coil supporting unit to which a stainless steel coil is rotatably disposed;

a coil winding unit spaced apart from the coil supporting unit, the coil winding unit holding and winding an end of the stainless steel coil; and

at least one pair of surface treatment units disposed between the coil supporting unit and the coil winding unit, the at least one pair of surface treatment units configured to form transverse hairlines on a surface of the stainless steel coil perpendicular to a winding direction of the stainless steel coil,

wherein, while the stainless steel coil is unwound from the coil supporting unit and then is rewound on the coil winding unit, when the stainless steel coil passes below the at least one pair of surface treatment units, the at least one pair of surface treatment units form the transverse hairlines on the surface of the stainless steel coil.