Drawing Die With Lower Die Provided With Microstructures
A drawing die with a lower die provided with microstructures is provided, including a lower die. The lower die is secured on a lower die holder, coordinates with a blank pressing plate to clamp a board and performs drawing processing on the board by using a punch moving relative to the lower die, where a top working surface, a shoulder surface, and a die cavity side wall surface of the lower die include multiple microstructures sunken into the surfaces, or a surface, which touches the board when drawing is performed, of the lower die includes multiple microstructures sunken into the surface.
This application claims the benefit of Taiwan Patent Application No. 103119745, filed on Jun. 6, 2014, which is hereby incorporated by reference for all purposes as if fully set forth herein.
BACKGROUND1. Technical Field
The present invention relates to a drawing die provided with microstructures, and in particular, to a drawing die with a lower die of which surfaces are provided with sunken microstructures.
2. Related Art
Drawing forming is stamping a flat sheet metal (for example, a blank) by using a drawing die to form a required product shape. Please refer to
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In another aspect, during the forming, a side wall 204 of the finished product 20 is subject to a drawing force of the punch 17; therefore, the thickness of the side wall 204 of the finished product 20 gradually decreases. When the stress of the side wall 204 exceeds the strength of a material of the side wall 204, an area, close to a bottom 205, of the side wall 204 cracks.
SUMMARYAn objective of the present invention is to provide a drawing die that reduces a friction force between a lower die and a blank so that the blank is of a more uniform thickness after forming a shape and improves formability.
To achieve the foregoing objective, a technical means of a drawing die with a lower die provided with microstructures in the present invention comprises: a lower die, where the lower die is secured on a lower die base, coordinates with a blank holder to clamp a blank and performs drawing processing on the blank by using a punch moving relative to the lower die, where a top working surface, a shoulder surface, and a side wall surface of the lower die comprise multiple microstructures sunken into the surfaces.
In an embodiment, the top working surface, the shoulder surface, and the side wall surface of the lower die comprise multiple microstructures sunken into the surfaces.
In an embodiment, a configuration pattern of the microstructures comprises an irregular pattern, an array pattern, a radial pattern, or a pattern comprising multiple annuluses.
In an embodiment, shapes of sunken surfaces of the microstructures comprise an irregular shape or a geometrical shape such as a triangle, a square, a trapezoid, an ellipse, a circle, or an annulus.
In an embodiment, shapes of sunken cross sections of the microstructures comprise an irregular shape or a geometrical shape such as a triangle, a square, a trapezoid, a semiellipse, or a semicircle.
In an embodiment, sunken spaces of the microstructures may be exposed to air or may be filled with lubricating oil.
In an embodiment, a surface, which touches the blank when drawing is performed, of the lower die comprises multiple microstructures sunken into the surface.
The present invention includes the following features: different from a conventional structure of a lower die, a lower die with sunken microstructures provided in the present invention can use a blank holder and a punch to press a blank when the blank holder clamps the blank and the punch performs drawing forming processing on the blank, so that the blank is in close contact with the microstructures of the lower die and is drawn on surfaces provided with the microstructures; because the surfaces, on which the microstructures are distributed, of the lower die reduce a friction force between the blank and the lower die, a drawing force of the punch is reduced, so as to reduce variations in the thickness of a finished product formed by the blank (that is, the finished product is of a uniform thickness), thereby improving formability of a drawing die.
The disclosure will become more fully understood from the detailed description given herein below for illustration only, and thus are not limitative of the disclosure, and wherein:
Embodiments of the present invention are described as follows with reference to the accompanying drawings.
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In an embodiment, the top working surface 3121, the shoulder surface 3131, and the side wall surface 3141 of the lower die 31 include multiple sunken microstructures (40 and 40′) (as shown in
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It must be made clear that in the foregoing embodiments, contour diameters and sinking depths of the sunken “microstructures” formed on the surfaces of the lower die and provided in the present invention and intervals between the microstructures depend on a size, a structure, and precision of a to-be-formed finished product, a size, a structure, and precision of the drawing die corresponding to the finished product, a feature of a material of the used board, and the like. However, on a premise that no nick or scratch is caused on a surface of the processed board, all contour sizes, contour intervals, and sinking depths fall within the scope of the microstructures which the present invention defines and claims to protect.
Compared with the prior art, the present invention has the following advantages: a lower die with sunken microstructures provide in the present invention can use a blank holder and a punch to press a blank when the blank holder clamps the blank and the punch performs drawing forming processing on the blank, so that the blank is in close contact with the microstructures of the lower die and is drawn on surfaces provided with the microstructures; because the surfaces, on which the microstructures are distributed, of the lower die can reduce a friction force between the blank and the surfaces of the lower die, a drawing force of the punch is reduced, so as to reduce variations in the thickness of a finished product formed by the blank (that is, the finished product is of a more uniform thickness), thereby improving formability of a drawing die.
In conclusion, the foregoing is merely preferred implementation manners or embodiments presenting the technical means adopted in the present invention to solve the problem, and is not intended to limit the implementation scope of the patent of the present invention. That is, all equivalent variations and modifications in accordance with the idea in the application scope of the patent of the present invention or made according to the scope of the patent of the present invention are covered by the scope of the patent of the present invention.
Claims
1. A drawing die with a lower die provided with microstructures, comprising:
- a lower die, wherein the lower die is secured on a lower die base, coordinates with a blank holder to clamp a blank and performs drawing processing on the blank by using a punch moving relative to the lower die, and the lower die comprises a top, a shoulder adjacent to the top, and a die cavity side wall adjacent to an other side of the shoulder, wherein a top working surface of the top in an area corresponding to the blank holder and a surface of the shoulder comprise multiple sunken microstructures.
2. The drawing die with a lower die provided with microstructures according to claim 1, wherein a surface of the die cavity side wall comprises multiple sunken microstructures.
3. The drawing die with a lower die provided with microstructures according to claim 1, wherein a configuration pattern of the microstructures comprises an irregular pattern.
4. The drawing die with a lower die provided with microstructures according to claim 2, wherein a configuration pattern of the microstructures comprises an irregular pattern.
5. The drawing die with a lower die provided with microstructures according to claim 1, wherein a configuration pattern of the microstructures comprises an array pattern, a radial pattern, or a pattern comprising multiple annuluses.
6. The drawing die with a lower die provided with microstructures according to claim 2, wherein a configuration pattern of the microstructures comprises an array pattern, a radial pattern, or a pattern comprising multiple annuluses.
7. The drawing die with a lower die provided with microstructures according to claim 1, wherein shapes of sunken surfaces of the microstructures comprise an irregular shape.
8. The drawing die with a lower die provided with microstructures according to claim 2, wherein shapes of sunken surfaces of the microstructures comprise an irregular shape.
9. The drawing die with a lower die provided with microstructures according to claim 1, wherein shapes of sunken surfaces of the microstructures comprise a geometrical shape such as a triangle, a square, a trapezoid, an ellipse, a circle, or an annulus.
10. The drawing die with a lower die provided with microstructures according to claim 2, wherein shapes of sunken surfaces of the microstructures comprise a geometrical shape such as a triangle, a square, a trapezoid, an ellipse, a circle, or an annulus.
11. The drawing die with a lower die provided with microstructures according to claim 1, wherein shapes of sunken cross sections of the microstructures comprise an irregular shape.
12. The drawing die with a lower die provided with microstructures according to claim 2, wherein shapes of sunken cross sections of the microstructures comprise an irregular shape.
13. The drawing die with a lower die provided with microstructures according to claim 1, wherein shapes of sunken cross sections of the microstructures comprise a geometrical shape such as a triangle, a square, a trapezoid, a semiellipse, or a semicircle.
14. The drawing die with a lower die provided with microstructures according to claim 2, wherein shapes of sunken cross sections of the microstructures comprise a geometrical shape such as a triangle, a square, a trapezoid, a semi-ellipse, or a semi-circle.
15. The drawing die with a lower die provided with microstructures according to claim 1, wherein sunken spaces of the microstructures are exposed to air.
16. The drawing die with a lower die provided with microstructures according to claim 2, wherein sunken spaces of the microstructures are exposed to air.
17. The drawing die with a lower die provided with microstructures according to claim 1, wherein sunken spaces of the microstructures are filled with lubricating oil.
18. The drawing die with a lower die provided with microstructures according to claim 2, wherein sunken spaces of the microstructures are filled with lubricating oil.
Type: Application
Filed: Aug 29, 2014
Publication Date: Dec 10, 2015
Inventors: BOR-TSUEN LIN (TAIPEI), CHUN-CHIH KUO (KAOHSIUNG CITY), KUN-MIN HUANG (KAOHSIUNG CITY)
Application Number: 14/473,657