CN203817171U - Stamping device with capacity of controlling curling resilience of side wall of stamping part - Google Patents

Abstract

The utility model discloses a stamping device for controlling the curling and springback of the side wall of a stamping part, which includes an upper die base, a die, a blank holder ring driven and connected with an air ejector rod, a punch matching the die, and a lower die from top to bottom. The upper die base is fixedly connected with the die base and moves synchronously, the punch is fixedly connected with the lower die base, and the punch includes a first punching part and a second punching part from top to bottom, and the first punching part and the second punching part There is a smooth transition between the parts through the transition curve part. The gap between the outer contour of the side wall of the first stamping part and the side wall of the die is 1.2-1.6 times the thickness of the plate to be punched. The outer contour of the side wall of the second stamping part The gap with the side wall of the die 2 is 0.8-0.9 times the thickness of the plate to be stamped, and the projected length of the transition curve in the stamping direction is 2-3 times the thickness of the plate to be stamped. The utility model reduces the stress difference between the inner and outer layers of the material by changing the mold gap during the stamping process, effectively controls the curling and springback of the side wall of the part, and improves the forming accuracy and quality of the part.

Description

Stamping device for side wall curling and springback control of stamping parts

technical field

The utility model relates to a stamping device for controlling the curling and springback of the side wall of a stamping part. By optimizing the structure of the punch, the die gap at the key part of the part changes with the stamping process, so as to achieve the purpose of controlling the curling and springback of the side wall, and belongs to the technical field of stamping forming .

Background technique

Side wall curl is a defect that is prone to occur during the bending and drawing process of parts with flanges. It is a springback phenomenon and widely exists in the forming process of automotive beam parts, stainless steel deep drawing parts and other parts. The performance is that after the forming is completed, the side wall that should have been straight is arc-shaped due to springback, which causes difficulties in subsequent welding and assembly processes, and even leads to scrapping of parts. In addition, household appliances, kitchen utensils and other household products use a large number of stainless steel parts. Due to their large yield ratio, stainless steel parts have severe springback during processing and significant work hardening. Common things such as stainless steel wash basins, gas cooktops, and mechanical equipment shells are prone to curling of the side walls during the deep drawing process.

The sidewall curling phenomenon occurs in the sidewall part, affected by the structure of the mold, the traditional springback compensation method is difficult to apply to the control of the sidewall curling phenomenon.

In order to reduce the curling and springback of the side wall of the part, after theoretical analysis and a large number of experiments, the utility model proposes a method for controlling the curling and springback of the side wall of the stamping part, which can effectively control the curling and springback of the side wall of the part and improve the durability of the part. Forming accuracy and quality.

Utility model content

The purpose of the utility model is to reduce the side wall curling and springback defects in the stamping process. By optimizing the structure of the punch, the die gap at the key part of the part changes with the stamping process, and then controls the material flow resistance of the blank during the stamping process. The principle of the utility model is illustrated below by taking a typical straight-walled U-shaped piece as an example.

The technical scheme that the utility model adopts is:

A stamping device for controlling the curling and springback of the side wall of a stamping part, comprising from top to bottom an upper die base, a die, a blank holder ring connected to an air ejector rod, a punch matching the die, and a lower die base. The upper die base is fixedly connected with the die base and moves synchronously, the punch is fixedly connected with the lower die base, and the punch includes a first punching part and a second punching part from top to bottom, and the first punching part and the second punching part There is a smooth transition between the two punching parts through the transition curve, wherein the gap between the outer contour of the side wall of the first punching part and the side wall of the die is 1.2-1.6 times the thickness of the plate to be punched, and the gap between the outer contour of the side wall of the second punching part The gap between the outer contour of the side wall and the side wall of the die is 0.8-0.9 times the thickness of the plate to be punched, and the projected length of the transition curve portion 52 in the punching direction is 2-3 times the thickness of the plate to be punched.

In the utility model, the gap between the punch and the die at the feed port becomes smaller, and the gap between the dies changes during the stamping process, and the change trend changes from large to small, so that the flow resistance of the sheet material will increase. It is difficult for the middle side wall to be supplemented by the material of the flange part, so that it is transformed from a deep-drawing state to a drawing state, reducing the stress difference between the inner and outer layers of the material, thereby reducing the curling and springback of the side wall.

Further, the stroke L after the second punching part is squeezed with the plate to be punched is 5-10% of the total punching stroke, so that the material at the extrusion point is closer to the convex and concave dies, and the positive pressure brought by the extrusion makes the The friction between the sheet and the mold increases suddenly, which prevents the sheet in the flange area from continuing to supplement the side wall. The size of the stroke L has a crucial influence on the final sidewall curl control effect: if it is less than 5% of the total stamping stroke, it is difficult to make the sidewall part enter the state of drawing, and it is impossible to make the entire sidewall fully plastic If it is more than 10% of the total stamping stroke, the plastic deformation of the side wall part will be too strong, which may cause the thinning rate Excessive size or partial rupture should be avoided as much as possible.

Further, the middle part of the punch is provided with a through-hole that penetrates up and down, and the through-hole is fixed on the convex-shaped lower mold base, and the punch and the lower mold base can be independently produced and separated from each other. When necessary, the punch can be fixed on the lower die base, and the punch can also be disassembled and separated from the lower die base, so that it is more convenient and fast to modify the outer contour of the punch during the mold trial stage, and It greatly saves the mold punch material and saves the material cost.

Compared with the prior art, in the late stage of the stamping stroke, the gap between the punch and the die at the feed inlet of the utility model becomes smaller, the flow resistance of the sheet material increases, and it is difficult to obtain the side wall in the remaining stamping stroke. The material of the flange part is supplemented, thereby changing from the deep-drawing state to the drawing state, reducing the stress difference between the inner and outer layers of the material, thereby effectively controlling the curling and springback of the side wall of the part, and improving the forming accuracy and quality of the part.

Description of drawings

Fig. 1 is a schematic structural view of the embodiment of the utility model when it is ready for stamping.

Fig. 2 is a schematic diagram of the punch structure of the utility model embodiment.

Fig. 3 is a schematic diagram of the structure of the embodiment of the utility model when the die gap starts to change during the stamping process.

FIG. 4 is an enlarged schematic diagram of point A in FIG. 3 .

Fig. 5 is a schematic diagram of the structure of the embodiment of the utility model when stamping is completed.

Fig. 6 The enlarged schematic diagram of B in Fig. 5 .

Among them, 1-upper die base; 2-die; 3-sheet material; 4-binder ring; 5-punch die; 51-first stamping part; 52-transition curve part; 53-second stamping part; 6 - air ejector rod; 7 - lower mold seat.

Detailed ways

The purpose of the utility model will be further described in detail below in conjunction with the accompanying drawings and specific examples. The examples cannot be repeated here one by one, but the implementation of the utility model is not therefore limited to the following examples. Unless otherwise specified, the materials and processing methods used in the present invention are conventional materials and processing methods in the technical field.

Example 1

As shown in Figure 1, a stamping device for controlling the curling and springback of the side wall of a stamping part includes, from top to bottom, an upper die base 1, a die 2, a blank holder 4 driven and connected to an air ejector rod 6, and a die 2. Matching punch 5 and lower mold base 7, the upper mold base 1 is fixedly connected with the die 2 and moves synchronously, the punch 5 is fixedly connected with the lower mold base 7, and the punch 5 includes from top to bottom The first stamping part 51 and the second stamping part 53, the first stamping part 51 and the second stamping part 53 are smoothly transitioned through the transition curve part 52, wherein the outer contour of the side wall of the first stamping part 51 is consistent with The gap between the side walls of the die 2 is 1.2 times the thickness of the plate to be punched, the gap between the outer contour of the side wall of the second stamping part 53 and the side wall of the die 2 is 0.9 times the thickness of the plate to be punched, and the transition curve The projected length of the portion 52 in the stamping direction is twice the thickness of the plate to be stamped.

In this embodiment, the forming of a U-shaped piece is taken as an example. The thickness of the sheet material 3 is t. The punch 5 and the lower mold base 7 are connected in a detachable manner. The profile of the side wall is not a straight straight line, but It is composed of a section of transition curve part 52 smoothly connecting straight lines at both ends, and the projection of transition curve part 52 in the stamping direction is twice the thickness of the sheet material, that is, 2t. First, the die 2 and the blank holder 4 are pressed together to fix the sheet; after the blank holder force is stabilized, the sheet moves downward under the clamping of the die 2 and the blank holder 4. At this time, the punch The gap between the outer contour of the side wall of the first stamping part 51 of 5 and the side wall of the die 2 is c=1.2t , c > t (material thickness); When L (being 5% of the total stamping stroke), the gap between the side wall of the die 2 and the outer contour of the side wall of the second stamping part 53 of the punch 5 at the feed inlet is c'=0.9t , c < t (material Thick) (as shown in Figure 3, 4), since c'<c , the resistance of the material at the feed inlet increases, and the continuous replenishment of the material is limited, and the side wall of the part undergoes stronger plastic deformation, and the inside and outside of the side wall The stress difference of layer materials will be significantly reduced until the final stamping stroke L is completed (as shown in Figures 5 and 6).

The utility model reduces the gap between the punch 5 and the die 2 at the feed inlet, so that the flow resistance of the sheet material will increase, and it is difficult for the side wall to be supplemented by the material of the flange part in the remaining stamping stroke, so that the The drawing state is transformed into a drawing state, which reduces the stress difference between the inner and outer layers of the material, thereby reducing the curling and springback of the side wall.

As shown in FIG. 2 , the middle part of the punch 5 is provided with a through hole 54 penetrating up and down, and the through hole 54 is fixed on the convex lower mold base 7 in a nested manner. The punch 5 and the lower die holder 7 can be made independently and separated from each other. During use, the punch 5 can be fixed on the lower die holder 7. When necessary, the punch 5 can also be removed from the lower die holder. 7 is disassembled and separated, so that it is more convenient and fast to modify the outer contour of the punch during the mold trial stage, and it greatly saves the material of the punch 5 and saves material costs.

Example 2

As shown in Figure 1, a stamping device for controlling the curling and springback of the side wall of a stamping part includes, from top to bottom, an upper die base 1, a die 2, a blank holder 4 driven and connected to an air ejector rod 6, and a die 2. Matching punch 5 and lower mold base 7, the upper mold base 1 is fixedly connected with the die 2 and moves synchronously, the punch 5 is fixedly connected with the lower mold base 7, and the punch 5 includes from top to bottom The first stamping part 51 and the second stamping part 53, the first stamping part 51 and the second stamping part 53 are smoothly transitioned through the transition curve part 52, wherein the outer contour of the side wall of the first stamping part 51 is consistent with The gap between the side walls of the die 2 is 1.3 times the thickness of the plate to be punched, the gap between the outer contour of the side wall of the second stamping part 53 and the side wall of the die 2 is 0.9 times the thickness of the plate to be punched, and the transition curve The projected length of the portion 52 in the punching direction is three times the thickness of the plate to be punched.

In this embodiment, the forming of a U-shaped piece is taken as an example. The thickness of the sheet material 3 is t. The punch 5 and the lower mold base 7 are connected in a detachable manner. The profile of the side wall is not a straight straight line, but It is composed of a section of transition curve 52 smoothly connecting straight lines at both ends, and the projection of transition curve 52 in the stamping direction is three times the thickness of the sheet material, that is, 3t. First, the die 2 and the blank holder 4 are pressed together to fix the sheet; after the blank holder force is stabilized, the sheet moves downward under the clamping of the die 2 and the blank holder 4. At this time, the punch The gap between the outer contour of the side wall of the first stamping part 51 of 5 and the side wall of the die 2 is c=1.3t , c > t (material thickness) (as shown in Figures 3 and 4); the die 2 and the blank holder 4 continue Downward, when there is still L left in the stamping stroke (8% of the total stamping stroke), the gap between the side wall of the die 2 and the outer contour of the side wall of the second stamping part 53 of the punch 5 at the feed port is c'=0.9 t , c < t (material thickness) (as shown in Figure 2), since c'<c , the resistance of the material at the feed inlet increases, the continued replenishment of the material is limited, and the side wall of the part undergoes stronger plasticity Deformation, the stress difference between the inner and outer materials of the side wall will be significantly reduced until the final stamping stroke L is completed (as shown in Figures 5 and 6).

In the utility model, the gap between the punch and the die at the feed port becomes smaller, so that the flow resistance of the sheet material will increase, and it is difficult for the side wall to be supplemented by the material of the flange part in the remaining stamping stroke, so that it is formed by deep drawing The state is transformed into a drawn state, which reduces the stress difference between the inner and outer layers of the material, thereby reducing the curling and springback of the side wall.

As shown in FIG. 2 , the middle part of the punch 5 is provided with a through hole 54 penetrating up and down, and the through hole 54 is fixed on the convex lower mold base 7 in a nested manner. The punch 5 and the lower die holder 7 can be made independently and separated from each other. During use, the punch 5 can be fixed on the lower die holder 7. When necessary, the punch 5 can also be removed from the lower die holder. 7 is disassembled and separated, so that it is more convenient and fast to modify the outer contour of the punch during the mold trial stage, and it greatly saves the material of the punch 5 and saves material costs.

Example 3

As shown in Figure 1, a stamping device for controlling the curling and springback of the side wall of a stamping part includes, from top to bottom, an upper die base 1, a die 2, a blank holder 4 driven and connected to an air ejector rod 6, and a die 2. Matching punch 5 and lower mold base 7, the upper mold base 1 is fixedly connected with the die 2 and moves synchronously, the punch 5 is fixedly connected with the lower mold base 7, and the punch 5 includes from top to bottom The first stamping part 51 and the second stamping part 53, the first stamping part 51 and the second stamping part 53 have a smooth transition through the transition curve part 52, wherein the outer contour of the side wall of the first stamping part 51 is consistent with The gap between the side walls of the die 2 is 1.6 times the thickness of the plate to be punched, the gap between the outer contour of the side wall of the second stamping part 53 and the side wall of the die 2 is 0.8 times the thickness of the plate to be punched, and the transition curve The projected length of the portion 52 in the punching direction is three times the thickness of the plate to be punched.

In this embodiment, the forming of a U-shaped piece is taken as an example. The thickness of the sheet material 3 is t. The punch 5 and the lower mold base 7 are connected in a detachable manner. The profile of the side wall is not a straight straight line, but It is composed of a section of transition curve 52 smoothly connecting straight lines at both ends, and the projection of transition curve 52 in the stamping direction is three times the thickness of the sheet material, that is, 3t. First, the die 2 and the blank holder 4 are pressed together to fix the sheet; after the blank holder force is stabilized, the sheet moves downward under the clamping of the die 2 and the blank holder 4. At this time, the punch The gap between the outer contour of the side wall of the first stamping part 51 of 5 and the side wall of the die 2 is c=1.6t , c > t (material thickness); When L (10% of the total stamping stroke), the gap between the side wall of the die 2 and the outer contour of the side wall of the second stamping part 53 of the punch 5 at the feed inlet is c'=0.8t , c < t (material Thick) (as shown in Figure 3, 4), since c'<c , the resistance of the material at the feed inlet increases, the continuous replenishment of the material is limited, and the side wall part of the part undergoes stronger plastic deformation, and the inside and outside of the side wall The stress difference of layer materials will be significantly reduced until the final stamping stroke L is completed (as shown in Figures 5 and 6).

The utility model reduces the gap between the punch 5 and the die 2 at the feed inlet, so that the flow resistance of the sheet material will increase, and it is difficult for the side wall to be supplemented by the material of the flange part in the remaining stamping stroke, so that the The drawing state is transformed into a drawing state, which reduces the stress difference between the inner and outer layers of the material, thereby reducing the curling and springback of the side wall.

As shown in FIG. 2 , the middle part of the punch 5 is provided with a through hole 54 penetrating up and down, and the through hole 54 is fixed on the convex lower mold base 7 in a nested manner. The punch 5 and the lower die holder 7 can be made independently and separated from each other. During use, the punch 5 can be fixed on the lower die holder 7. When necessary, the punch 5 can also be removed from the lower die holder. 7 is disassembled and separated, so that it is more convenient and fast to modify the outer contour of the punch during the mold trial stage, and it greatly saves the material of the punch 5 and saves material costs.

The above-mentioned embodiments of the present utility model are only examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. All modifications, equivalent replacements and improvements made within the spirit and principles of the utility model shall be included in the protection scope of the claims of the utility model.

Claims (3)

1. A stamping device for controlling the curling and springback of the side wall of a stamping part, comprising from top to bottom an upper mold base (1), a die (2), a blank holder (4) driven and connected to an air ejector rod (6), A punch (5) and a lower die base (7) matched with the die (2), the upper die base (1) is fixedly connected with the die (2) and moves synchronously, the punch (5) and the lower die base The mold base (7) is fixedly connected, and it is characterized in that: the punch (5) includes a first punching part (51) and a second punching part (53) from top to bottom, and the first punching part (51) and the second punching part (53) The transition between the second punching parts (53) is smooth through the transition curve part (52), wherein the gap between the outer contour of the side wall of the first punching part (51) and the side wall of the die (2) is equal to the thickness of the plate to be punched 1.2-1.6 times, the gap between the outer contour of the side wall of the second punching part (53) and the side wall of the die (2) is 0.8-0.9 times the thickness of the plate to be punched, and the transition curve part (52) The projection length in the stamping direction is 2-3 times the thickness of the plate to be stamped. 2. The stamping device according to claim 1, characterized in that: the stroke L after the second stamping part (53) is pressed against the plate to be stamped is 5 of the total stamping stroke. -10%. 3. The stamping device according to claim 1 or 2, characterized in that: the middle part of the punch (5) is provided with a through hole (54) penetrating up and down, and the through hole ( 54) set and be fixed on the convex font lower die holder (7).