Method and tool for producing a flange on a bush bearing

Abstract

The invention relates to a method for producing at least one axial flange on an elastomer bush bearing. According to the invention, the axial flange(s) is/are produced by flanging one or both axial ends of the outer sleeve of the pre-assembled bearing after the bearing has been assembled. During this assembly process the inner component is inserted with the elastomer bearing body into the outer sleeve. In the tool, which is provided for this method and which can be used on a press, the force induced by the compressive force is transferred to both axially acting and radially acting deformation elements. Therefore, at least one of the axially acting deformation elements exhibits a groove, which is located on the side facing the bush bearing and by which the respective axial end of the outer sleeve of the bearing is held, whereas the radially acting deformation elements exhibit on their side that is immediately adjacent to the deformation element with the groove, a projection, which projects radially towards the inside.

Description

The invention relates to a method for producing at least one axial flange on an elastomer bush bearing. Furthermore, the subject of the invention is a tool that is appropriate for carrying out the method. The invention relates preferably to the production of a dual flange, thus to produce an axial flange on both axial ends of a bush bearing.

Elastomer bush bearings, as used in large numbers chiefly in the construction of vehicles, for example, in the area of the wheel suspension, are often equipped with an axial flange on one side or on both sides. Bearings of the type noted in the preamble of the claim comprise a substantially cylindrical inner component; an elastomer bearing body, which envelops the inner component and is connected to said inner component by means of vulcanization; and an outer sleeve, which accommodates the inner component with the bearing body. Optionally the outer sleeve is also connected by vulcanization to the elastomer bearing body. The axial flange(s) is/are formed by flanging the outer sleeve of the bearing. When the bearing is assembled at the installation site for the intended use, the axial flanges serve as a bearing surface, which results in a reduction in the axial pressure per unit area that acts on the bearing.

During the production of the bearing, its elastomer bearing body is radially compressed in order to set a predetermined radial rigidity. That is, a prestress is produced in the elastomer of the bearing body. To this end, following vulcanization of the bearing, or rather after the inner component was mounted with the bearing body in the outer sleeve, the diameter of the cylindrical outer sleeve is decreased in a deformation process. In this context one also talks about a calibration of the bearing.

To assemble the bearing at the installation site for the intended use, the bearing is generally pushed with its outer sleeve into a receiving eye, provided for the same, and is screwed through the hollow cylindrical inner component. However, to the extent that at this stage both sides of the bearing exhibit, as is often necessary and/or desired, an axial flange, there is the problem that the bearing may no longer be easily inserted into the receiving eye, intended for this purpose, because its outside diameter on both axial ends is larger, owing to the axial flanges constructed there, than the inside diameter of the receiving eye. One possibility for solving this problem lies in constructing the bearing in the axial direction in two parts, inserting each half of the bearing from the side into the bearing eye and connecting them together in the same operation. Of course, from a cost point of view it is considered a drawback that in this case the bearing point needs two parts to realize one bearing.

The DE 10 2005 029 614 describes a solution for the aforementioned problem that avoids this drawback. After the inner component and the bearing body have been assembled in the outer sleeve or rather after they are connected to the outer sleeve below the flanges constructed on the axial ends of the sleeve, a crimp is put into the outer sleeve. In the course of inserting this crimp, the outer edge of the flanging forming the flange is moved radially toward the inside, so that the outside diameter of the axial flange is reduced. If the depth of the crimp is suitably dimensioned, the outside diameter of both axial flanges is preferably decreased so far that the bearing may be easily inserted into a receiving eye.

The solution presented in the aforementioned document also assumes, like the state of the art that was known prior to the filing of this application, that the flangings on the outer sleeve for forming the axial flanges already exist before the inner component is inserted with the bearing body into the outer sleeve. Suitable outer sleeves with the already constructed flangings are purchased from the suppliers as a so-called collar bush. The supplier produces the flangings on the respective tubular segments, which are subsequently provided for forming the outer sleeves, with the use of a deep drawing process. This in turn causes the manufacturer of bush bearings to incur higher costs for the procurement of materials.

The object of the invention is to provide a solution, by means of which axial flanges may be easily constructed on a rubber bushing and the costs for the procurement of materials may be reduced. To this event a method and a suitable tool for carrying out the method shall be disclosed.

The problem is solved by means of a method having the features disclosed in the main claim. A suitable tool for solving the problem and carrying out the invention is characterized by the first claim relevant to the object. Advantageous embodiments and/or further developments are disclosed in the respective dependent claims.

The method that is proposed for producing one axial flange or two axial flanges on an elastomer bush bearing relates to a bush bearing of the conventional construction. Such a bearing comprises, as stated above in the introductory part of the specification, a substantially cylindrical inner component; an elastomer bearing body, which is connected to said inner component by means of vulcanization; and an outer sleeve, which accommodates the inner component with the elastomer bearing body. The axial flanges are formed on this bearing as a surface segment, which envelops one or both axial end(s) of the outer sleeve and projects in the outward direction. In contrast to the prior art, however, the construction of the axial flange(s) is carried out, according to the invention, after the assembly of the bearing, thus, after the inner component was inserted with the elastomer bearing body into the outer sleeve and after the bearing body was connected, if desired, to said outer sleeve by means of vulcanization. Therefore, the axial flange(s) is/are produced, according to the invention, by flanging one or both axial end(s) of the outer sleeve of the bearing that is already pre-assembled.

According to a preferred embodiment of the invention, the processing steps are arranged in such a manner that the flanging of the outer sleeve for the purpose of producing the axial flange(s) is carried out simultaneously with the calibration of the bearing. That is, the flanging of at least one of the axial ends of the outer sleeve of the bush bearing is carried out in a joint working step with the calibration, during which the diameter of the outer sleeve is reduced at least in the area of the axial end(s), on which an axial flange is produced.

The production of the bilateral axial flanges is carried out, according to a planned arrangement of the method, in such a manner that the outside diameter of the flangings forming the axial flanges is decreased in conjunction with the simultaneous calibration. To this end a crimp is put, according to the DE 10 2005 029 614, into the outer sleeve below the axial flanges.

In the course of affixing the crimp the axial flanges are pulled, in manner of speaking, radially towards the inside. In so doing, the depth of the corresponding crimps is dimensioned in such a manner that the outside diameter of the flangings is decreased to a size that is less than the inside diameter of a receiving eye that is provided for receiving the bush bearing.

The method, according to the invention, may be applied advantageously even to hydro bushings, wherein the elastomeric bearing body in the area of at least one of its axial ends exhibits at least two chambers, which are connected together by means of an overflow or throttle channel and are intended for a viscous damping agent. Therefore, the axial flanges may be produced in one working step, the bearing may be calibrated, and the radial stop abutments may be constructed in the damping agent chambers. Said chambers are used to limit in a defined manner the radial idle travel of the elastomer through the chambers in order to prevent an overstressing or even a destruction of the elastomer bearing body.

The suitable tool for solving the problem or rather for carrying out the method, according to the invention, and for producing at least one axial flange in a bush bearing is a tool for a press. Therefore, depending on the construction of the press, the tool is clamped, as a tool head, into the press and is subjected to a compressive force via a stamp of the press. Following the basic approach to the solution, the bush bearing, comprising an inner component, a bearing body and an outer sleeve, is put into a working chamber of the tool as a pre-assembled bearing or rather vulca component in order to produce one or two axial flange(s). In addition, the tool exhibits at least one force transfer element. Owing to this force transfer element, the force, induced by the compressive force acting on the tool, is transferred almost simultaneously to both the deformation element acting axially and a plurality of deformation elements acting radially on the outer sleeve of the bearing. The radially acting deformation elements are disposed around the periphery of the bush bearing accommodated by the working chamber. To produce at least one axial flange, at least one of the axially acting deformation elements, which during the pressing procedure move towards each other in the direction of the bearing axis of the processed bush bearing, thus following it, exhibits a circumferential groove on its side facing the bearing. The width of this groove is equivalent to at least the width of the flange, to be constructed on the bush bearing. In addition, the geometry of the axially acting deformation element, which is provided with the groove, is designed in such a manner that during the deformation or rather the pressing procedure, the inner edge of the groove rests against the inside wall of the outer sleeve of the bearing that projects into the groove. The radially acting deformation elements, which during the pressing procedure move radially towards each other on the bearing axis of the processed bush bearing between the axially acting deformation elements, along which said radially acting deformation elements slide, are constructed in such a manner that they exhibit a projection, projecting into the interior of the working chamber, in the areas, immediately adjacent to the axially acting deformation element(s), which are provided with the groove. During the pressing procedure, this projection is pressed, adjacent to the areas, projecting into the grooves, into the outer sleeve of the bush bearing. The result of the projections of the radially acting deformation elements that project into the outer sleeve of the bearing, on the one hand, and the force, acting simultaneously via the axially acting deformation elements, on the other hand, is that during the pressing procedure the areas projecting into the grooves are flanged radially in the outward direction so as to form a flange.

In a preferred embodiment of the tool, according to the invention, one or more spring(s) is/are disposed between the force transfer elements and an axially acting deformation element. Thus, it is achieved that the force, resulting from the compressive force, is transferred from the force transfer element at the start of the pressing procedure to the respective, axially acting deformation element, whereas the force transfer to the radially acting deformation elements does not start until later. This prevents the bush bearing from being pushed upward and tilted by the radially acting deformation elements at the start of the pressing procedure, an effect that could result in its outer sleeve being crushed.

In accordance with an optional embodiment of the inventive tool, the force transfer to the radially acting deformation elements is caused by the complementary contours of the force transfer elements and of the radially acting deformation elements sliding past one another. The inventive tool ought to exhibit at least 6 radially acting deformation elements, which are uniformly distributed on the periphery of a bush bearing accommodated by the working chamber. For an optimal calibration of the bearing and in light of an outer bearing contour that is as uniform or rather as flat as possible, the tool is equipped preferably with 12 radially acting deformation elements.

The invention shall be explained in detail below once again with the aid of an embodiment. In the associated drawings:

FIG. 1 depicts an elastomer bush bearing prior to producing the axial flanges

FIG. 2 depicts a tool used to produce the bilateral axial flanges

FIG. 3 depicts a bush bearing comparable to the bearing, according to FIG. 1, after the bilateral axial flanges have been produced by means of the tool, according to FIG. 2.

FIG. 1 depicts the standard design of an elastomer bush bearing. The bearing comprises a metallic, substantially cylindrical inner component 1; an elastomer bearing body 2, surrounding the inner component 1; and an outer sleeve 3, receiving the aforementioned components. As emphasized above, the inner component 1 of the bearing is substantially cylindrical, but exhibits in the illustrated example a varying outside diameter. Therefore, the outside diameter of the inner component 1 is slightly enlarged in the central area of its axial reach. Such a shaping is basically known for realizing specific radial characteristics. The inner component 1 is connected to the bearing body 2 by means of vulcanization and inserted into the outer sleeve 3. Depending on the intended purpose, the outer sleeve 3 may also be connected, if desired, to the bearing body 2 by means of vulcanization. As one can see, the bush bearing, depicted in FIG. 1, does not exhibit yet any of the axial flanges 4, 4′, after the components of said bush bearing have been assembled. Contrary to the prior art flanges, these flanges shall be realized with a tool, which is reproduced in FIG. 2, only after assembly.

The tool, depicted in FIG. 2, is a rotationally symmetrical tool for a press, which, depending on the construction of the press, is received, as a tool head, by the press or rather is clamped into the press and is subjected to a compressive force by means of a stamp of the press for the purpose of producing axial flanges 4, 4′ on the bush bearing placed in the tool. The tool comprises in essence a base plate 14; a bottom pressure pad 8′; a plurality of pushers 9₁-9_n, which are disposed in a circular course around a bush bearing to be placed in the working chamber 10; an upper pressure pad 8; and a bell 7, by means of which the tool can be connected to the press or rather effectively linked. Owing to the sectional view in FIG. 2, basically only two of the pushers 9₁-9_n can, in fact, be seen, whereas the spatial configuration of the rest is indicated only by dashed—dotted-lines. Within the meaning of the above presentation of the inventive tool, the bell 7 is a force transfer element, which transfers the force, corresponding to the compressive force, to the deformation elements: that is, the pressure pads 8, 8′, as the axially acting deformation elements, and the pushers 9₁-9_n, as the radially acting deformation elements. Compression springs 17, 17′ are disposed between the bell 7 and the upper pressure pad 8. In addition, there is a so-called guide plate 16 above the base plate 14. The radially external areas of the pushers 9₁-9_n are guided in said guide plate. This guide plate 16 prevents the pushers 9₁-9_n, which are constructed moveably in the radial direction, from falling out of the tool, for example, when the tool is moved.

FIG. 2 shows the tool without a bush bearing, to be processed with the aid of the tool. At the same time the position of the axis 6 of a bush bearing, to be placed in its working chamber 10, is marked for the sake of a better orientation in the drawing. The operating principle of the tool is as follows. To insert a bushing to be provided with axial flanges 4, 4′, the bell 7 is moved to the top. The pushers 9₁-9_n, which were previously held together by the bell 7 (that is, were forced radially towards the inside), are moved radially towards the outside by the force of the springs 15₁-15_n, which are only indicated here, as far as the stop abutments, which are formed by the guide plate 16. In this way they release the interior or rather the working chamber 10 of the tool for the purpose of inserting an elastomer bush bearing, according to or similar to FIG. 1.

After insertion of the bush bearing, the bell 7 is brought down again; and thereafter, compressive force is applied. At the same time the bush bearing lies in such a manner in the tool that the outer sleeve 3 of the bearing comes to rest with the insides of its axial ends against the inside edges 12, 12′ of the grooves 11, 11′ in the top and the bottom pressure pad 8, 8′. When the bell 7 is pushed down by the press, its inside contour, which slopes radially towards the outside, slides along a complementary outer contour of the pushers 9₁-9_n. Therefore, the pushers 9₁-9_n are moved gradually radially towards the inside against the spring force of their springs 15₁-15_n and thus slide with their axial outer edges along the pressure pads 8, 8′. In so doing, the projections 13₁-13_n, 13₁-13_n, which are constructed at the top and the bottom on the pushers 9₁-9_n, push at the top and the bottom into the outer sleeve 3 of the elastomer bush bearing below and/or above the axial ends, resting in the grooves 11, 11′. Thus, on the basis of the force, acting axially on the bearing simultaneously via the upper and the bottom pressure pads 8, 8′, the areas, which are located in the grooves 11, 11′ and belong to the outer sleeve 3 of the bush bearing, are bent radially towards the outside in the manner of a sharp edge or rather are flanged so as to form an axial flange 4, 4′. Owing to the projections 13₁-13_n, 13′₁-13′_n, which are constructed on the pushers 9₁-9_n, and the 5, 5′, which are affixed in the outer sleeve 3 and are adjacent to the axial flanges 4, 4′ owing to said projections, the axial flanges 4, 4′ are pulled radially towards the inside in the next phase of the pressing procedure, so that this process decreases their outside diameter D. If the flanges 4, 4′ and the projections 13₁-13_n, 13′₁-13′_n and/or the crimps 5, 5′, produced in the outer sleeve of the bearing, are suitably dimensioned, the result is a decrease in the outside diameter D of the axial flanges 4, 4′ so that despite the fact that the axial flanges 4, 4′ are produced on both sides, the bearing may be easily inserted into a receiving eye, provided for its accommodation at the installation site.

FIG. 3 shows a bush bearing comparable to the bearing, according to FIG. 1. The inner component of the bearing, the shape of which is constructed somewhat differently, is not supposed to be the subject of a closer inspection, but is also to be regarded as substantially cylindrical in the context of the above explanations. Even in the case of this bearing, the axial flanges 4, 4′ are produced only after the inner component, the bearing body and the outer sleeve have been joined together. When the deformation procedure, presented within the scope of the explanations with respect to FIG. 2, has ended, the elastomer bush bearing, which is basically comparable to the bearing, according to FIG. 1, exhibits the construction, shown in FIG. 3.

REFERENCE NUMERALS

1 inner component

2 bearing body

3 outer sleeve

4, 4′ axial flange

5, 5′ crimp

6 bearing axis

7 force transfer element (bell)

8, 8′ axially acting deformation element (pressure pad)

9₁-9_n radially acting deformation element (pusher)

10 working chamber

11, 11′ groove

12, 12′ inside edge of the groove

13₁-13_n projection

13′₁-13′_n projection

14 base plate

15₁-15_n spring

16 guide plate

17-17′ spring

Claims

1. Method for producing at least one axial flange on an elastomer bush bearing, which comprises a substantially cylindrical inner component an elastomer bearing body, which envelops the inner component and is connected to said inner component by means of vulcanization; and an outer sleeve, which accommodates the inner component with the elastomer bearing body, whereby the axial flange is/are formed as a surface segment, which envelops an axial end of the outer sleeve and project/projects radially towards the outside, characterized in that after the assembly of the bearing, during which the inner component is inserted with the elastomer bearing body into the outer sleeve, the axial flange is/are produced by flanging the axial endes of the outer sleeve of the pre-assembled bearing.

2. Method, as claimed in claim 1, characterized in that the outer sleeve of the bearing is also connected to the elastomer bearing body by means of vulcanization.

3. Method, as claimed in claim 1, characterized in that the flanging of the outer sleeve for the purpose of producing the axial flange is carried out in one joint working step, with the bearing calibration, which serves to generate a prestress in the bearing body, and during which the diameter of the outer sleeve is reduced at least in the area of the respective axial end, to be provided with an axial flange.

4. Method, as claimed in claim 1, characterized in that when the bearing is calibrated in the course of producing the axial flange, the diameter of the outer sleeve is reduced by affixing a crimp below the axial flanges, thus also decreasing the outside diameter of the flangings of the outer sleeve for forming the axial flanges.

5. Method, as claimed in claim 4, characterized in that the outside diameter of the flangings is decreased to the extent that it is less than the inside diameter of a receiving eye that is provided for receiving the bush bearing.

6. Method, as claimed in claim 3, for producing at least one axial flange for a bush bearing, whose elastomer bearing body exhibits at least two chambers, which are connected together by means of an overflow or throttle channel and which are intended for a viscous damping agent, in the area of at least one of its axial ends, characterized in that radial stop abutments are formed in the course of producing the axial flange and the simultaneous calibration of the bearing in its chambers.

7. Tool for producing at least one axial flange on a bush bearing by means of a press; said tool comprising a working chamber, which receives a bush bearing, comprising an inner component, a bearing body and an outer sleeve; axially active deformation elements and radially active deformation elements; and at least one force transfer element, by means of which a force, induced by a compressive force acting on the tool, is transferred to the axially acting deformation elements and the radially acting deformation elements, which are disposed around the periphery of a bush bearing accommodated by the working chamber, whereby at least one of the axially acting deformation elements, which during the pressing procedure move towards each other in the direction of the bearing axis of the processed bush bearing, exhibits a circumferential groove on the side facing the bush bearing, the width of this groove being equivalent to at least the width of the axial flange to be constructed on the bush bearing; and the inside edge of said groove resting on the inside wall of the outer sleeve of the bearing that projects into the groove; and whereby in the areas immediately adjacent to the axially acting deformation elements, provided with the groove, the radially acting deformation elements, which move during the pressing procedure between the axially acting deformation elements, sliding along these deformation elements, radially in the direction of the bearing axis of the processed bush bearing, exhibit a projection, which projects into the interior of the working chamber and which during the pressing procedure is pressed, adjacent to the areas, projecting into the grooves, into the outer sleeve of the bush bearing, so that the areas of the outer sleeve that project into the grooves, are flanged in the outward direction so as to form an axial flange.

8. Tool, as claimed in claim 7, characterized in that one or more springs are disposed between the force transfer element and an axially acting deformation element, whereby the compression force, is transferred from the force transfer element at the start of the pressing procedure to the respective, axially acting deformation element, and whereas the force transfer to the radially acting deformation elements does not start until later.

9. Tool, as claimed in claim 7, characterized in that the compressive force is transferred to the radially acting deformation elements by the complementary contours of the force transfer element and of the radially acting deformation elements sliding past one another.

10. Tool, as claimed in claim 7, characterized in that said tool exhibits at least 6 radially acting deformation elements, which are uniformly distributed on the periphery of a bush bearing accommodated by the working chamber.

11. Tool, as claimed in claim 10, characterized in that said tool exhibits 12 radially acting deformation elements.