A mold for stripping thin materials and its assembly method

Abstract

This invention belongs to the field of mold structure technology, and specifically relates to a mold for thin material ejection and its assembly method, including an upper mold base, a lower mold base, a punch, and a die. The punch is located at the lower end of the upper mold base and includes a left die and a right die. The upper diameter of the left die is larger than its lower diameter. The left die is fixedly connected to the upper mold base, and the left die is slidably connected to the right die, with the right die not detached from the left die. The die is located at the upper end of the lower mold base. This invention solves the problem in the prior art that the product precision and surface quality of "U"-shaped parts made from thin materials cannot be guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of mold structure technology, and specifically relates to a mold for unloading thin materials and its assembly method. Background Technology

[0002] Existing technologies for ejecting parts typically employ spring-loaded ejector pins, spring-loaded ejector plates, and rigid ejection. For spring-loaded ejector pins, the ejector pin structure is installed inside the punch. After stamping, the ejector pin pushes the formed sheet metal, causing it to detach from the punch surface. However, due to the varying thickness of the part and the relatively high height of the formed "U" shape, during part forming, after the die and punch close, the part is ejected by the elastic ejector plate in the die. Since the part is a "U" shape, its springback is generally small and may even be negative, resulting in a very tight fit between the part and the punch. Upon completion of forming, a local vacuum is momentarily created between them. Combined with the deep sidewalls of the part, the spring-loaded ejector pin is ejected by spring force. If the spring-loaded ejector pin spring force is weak, it may fail, preventing part ejection. If the spring-loaded ejector pin spring force is strong, it may cause surface quality defects and deformation risks, and the part may still be unable to exit the punch.

[0003] For the punching and forming of U-shaped parts made of thin material less than 1mm, especially when producing large batches, production efficiency is paramount while ensuring part quality. Therefore, progressive dies are often used for producing these parts. However, in continuous high-speed production with progressive dies, if the product ejection is not smooth, the die design and manufacturing are considered unsuccessful, sometimes leading to the scrapping and failure of the entire die set, and even equipment accidents. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a mold for unloading thin materials, comprising an upper mold base, a lower mold base, a punch, and a die. The punch is characterized in that it is disposed at the lower end of the upper mold base, and includes a left die and a right die, wherein the upper diameter of the left die is larger than its lower diameter; the left die is fixedly connected to the upper mold base, and the left die is slidably connected to the right die, with the right die not detached from the left die; the die is disposed at the upper end of the lower mold base.

[0005] Furthermore, a backing plate is slidably disposed in the middle of the die cavity, and an ejector is disposed at the lower end of the backing plate.

[0006] Furthermore, a non-through groove is provided on the side of the left mold near the right mold, and a slider is fixedly connected to the side of the right mold near the left mold, and the slider is slidably and sealingly connected to the groove.

[0007] Furthermore, the upper end of the punch is connected to the upper die holder via a slider cover plate.

[0008] Furthermore, the slider cover plate is detachably connected to the upper mold base.

[0009] Furthermore, a sturdy structure is provided between the right mold and the slider cover plate.

[0010] Furthermore, the stabilizing structure includes a stabilizing groove and a stabilizing block. The stabilizing groove is formed at the lower end of the slider cover plate, and the stabilizing block is fixed to the upper end of the vertical side of the right mold. The length of the stabilizing groove is greater than the length of the stabilizing block.

[0011] Furthermore, the cross-sectional shape of the right mold is trapezoidal, and the diameter of the lower end of the right mold is larger than the diameter of the upper end.

[0012] Furthermore, the lower ends of the left mold and the right mold have the same diameter.

[0013] Furthermore, the punch includes at least one set of left and right molds.

[0014] This invention proposes an assembly method for a die for unloading thin materials. This method is applicable to the aforementioned die for unloading thin materials, and the method includes the following steps:

[0015] Insert the slider on the right mold horizontally from the upper end of the groove on the left mold; after the slider enters the groove, slide the right mold downward relative to the left mold; the right mold is embedded into the left mold, and the right mold and the left mold are slidably connected.

[0016] Then, fix the left mold onto the slider cover plate;

[0017] Then, fix the slider cover plate onto the upper mold base.

[0018] Beneficial effects

[0019] The beneficial effects of this invention are:

[0020] 1. The thin material ejection mold of the present invention divides the punch into two parts. Before stamping, the left and right molds are combined to form a complete punch to stamp the thin material. After the stamping is completed, during the separation of the punch and the die, the left and right molds are misaligned to create a gap, thereby realizing the separation between the part and the punch. Since the part is not subjected to any additional external force for ejection, the surface quality and dimensional accuracy of the part will not be affected by the ejection.

[0021] 2. The thin-material ejection mold of the present invention solves the problem of ejecting the workpiece in a limited space when it is difficult to arrange the ejection device; the ejection is completed during the rising of the punch without the need for other auxiliary external forces, which is very suitable for use in progressive dies, saving space and ensuring product quality.

[0022] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of the working state of a general mold for forming a "U"-shaped part in the prior art is shown.

[0025] Figure 2 A schematic diagram of the deformation of the ejector pin in the prior art is shown.

[0026] Figure 3 A schematic diagram of the material ejection deformation of an elastic unloading plate in the prior art is shown.

[0027] Figure 4 A schematic diagram of the structure in an embodiment of the present invention is shown.

[0028] Figure 5 A schematic diagram of the internal structure of the punch in an embodiment of the present invention is shown.

[0029] Figure 6 A schematic diagram showing the misalignment of the right mold and the left mold in an embodiment of the present invention is shown.

[0030] In the diagram, 1 is the upper mold base; 2 is the lower mold base; 3 is the punch; 4 is the die; 31 is the left mold; 32 is the right mold; 5 is the backing plate; 6 is the ejector; 7 is the slide groove; 8 is the slider; 9 is the slider cover plate; 10 is the stabilizing structure; 101 is the stabilizing groove; and 102 is the stabilizing block. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] This application provides a mold for unloading thin materials, which solves the problem in the prior art that the product precision and surface quality of the "U"-shaped parts made of thin materials cannot be guaranteed. The mold includes an upper mold base 1, a lower mold base 2, a punch 3 and a die 4. The punch 3 is located at the lower end of the upper mold base 1. The punch 3 includes a left die 31 and a right die 32. The upper diameter of the left die 31 is larger than the lower diameter. The left die 31 is fixedly connected to the upper mold base 1. The left die 31 is slidably connected to the right die 32, and the right die 32 does not detach from the left die 31. The die 4 is located at the upper end of the lower mold base 2.

[0033] In one embodiment of the present invention, a backing plate 5 is slidably disposed in the middle of the die 4, and an ejector 6 is disposed at the lower end of the backing plate 5.

[0034] In one embodiment of the present invention, a non-through groove 7 is provided on the side of the left mold 31 near the right mold 32, and a slider 8 is fixedly connected to the side of the right mold 32 near the left mold 31.

[0035] refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 , Figure 1 The diagram shows the working state of a general mold for forming a "U" shaped part in the prior art. The sheet metal is placed on the pad 5, and the upper mold presses downward to drive the sheet metal and the pad into the lower mold for forming. Figure 2 The diagram illustrates the deformation of the ejector pin during ejection in the prior art. The ejector pin is pushed out of the workpiece by the spring force, which causes surface quality defects and deformation risks in the workpiece. Figure 3 A schematic diagram of the deformation of the elastic unloading plate in the prior art is shown. The elastic unloading plate squeezes between the sides of the workpiece, causing the sides of the workpiece to deform. Figure 4 The diagram shows a structural schematic of an embodiment of the present invention. The punch 3 and the die 4 cooperate to stamp the thin material. The punch 3 is cut into two parts to realize the unloading of the material after stamping.

[0036] During the process, the thin material is placed on the backing plate 5 of the die cavity 4. The upper die holder 1 drives the punch 3 to move downward to perform the stamping operation. During the downward movement of the punch 3, the slider 8 on the right die 32 initially slides to the lower end of the slide groove 7. The right die 32 first contacts the thin material. Then the left die 31 continues to move downward. The slider 8 on the right die 32 slides upward along the slide groove 7 on the left die 31 until the slider 8 moves to the upper end of the slide groove 7. After the left die 31 and the right die 32 form a complete punch 3, the upper die holder 1 drives the punch 3 to continue to move downward, thereby driving the thin material and the backing plate 5 to move downward. The thin material enters the interior of the die cavity 4 to form a "U" shaped part. The slide groove 7 can be a "T" shaped slide groove 7. Without any other attachment, the right die 32 can slide up and down along the stable left die 31.

[0037] After molding is completed, the ejector 6 pushes the backing plate 5 out of the die 4. After the part is formed, due to the springback of the part, the part will tightly wrap around the punch 3. When the punch 3 moves upward, the punch 3 will pull the part upward together. Since the left die 31 is fixed on the slider cover plate 9, the pulling force F of the part on the punch 3 acts on the right die 32, pulling the right die 32 downward. At the same time, during the upward movement of the part, it is subjected to the downward friction force of the die 4 and the downward gravity of the right die 32 itself. Under the combined action of the pulling force F of the part on the right die 32, the downward friction force F1 of the die 4 on the part itself, and the gravity G of the right die 32 itself, the right die 32 moves downward and is misaligned with the left die 31, so that a gap Z is generated between the punch 3 and the part, breaking the local vacuum state formed between the part and the punch 3. The part is no longer attached to the punch 3, thus realizing the separation between the part and the punch 3.

[0038] Compared to existing technologies that use external force to eject material from thin parts, which can lead to surface defects and deformation, this application divides the punch 3 into two parts. Before stamping, the left die 31 and the right die 32 are combined to form a complete punch 3 to stamp the thin material. After stamping, during the separation of the punch 3 and the die 4, the left die 31 and the right die 32 are misaligned to create a gap, thereby separating the part from the punch 3. Since the part is not subjected to any additional external force for ejection, the surface quality and dimensional accuracy of the part will not be affected by the ejection. Furthermore, within the limited mold space, there is no need to set up an additional ejection structure for ejection, making it very suitable for use in high-speed progressive dies.

[0039] In one embodiment of the present invention, the upper end of the punch 3 is connected to the upper die base 1 via a slider cover plate 9.

[0040] In one embodiment of the present invention, the slider cover plate 9 is detachably connected to the upper mold base 1.

[0041] In one embodiment of the present invention, a stabilizing structure 10 is provided between the right mold 32 and the slider cover plate 9.

[0042] In one embodiment of the present invention, the stabilizing structure 10 includes a stabilizing groove 101 and a stabilizing block 102. The stabilizing groove 101 is formed at the lower end of the slider cover plate 9, and the stabilizing block 102 is fixed to the upper end of the vertical side of the right mold 32. The length of the stabilizing groove 101 is greater than the length of the stabilizing block 102.

[0043] refer to Figure 5 and Figure 6 , Figure 5The diagram shows the internal structure of the punch in an embodiment of the present invention. The slide groove 7 is opened on the left die 31, the slider 8 is set on the right die 32, the stabilizing groove 101 is opened on the slider cover plate 9, and the stabilizing block 102 is set on the right die 32. The stabilizing structure 10, the slider 8 and the slide groove 7 work together to achieve stable sliding of the right die. Figure 6 The diagram shows the misalignment of the right mold and the left mold in an embodiment of the present invention. When the right mold 32 slides downward, it drives the stabilizing block 102 to slide synchronously.

[0044] During implementation, a slider cover plate 9 is provided between the punch 3 and the upper die base 1. The slider cover plate 9 and the upper die base 1 can be connected by a detachable connection method such as threaded connection or snap-fit ​​connection. On the one hand, the slider cover plate 9 can install the punch 3 of this application onto different upper die bases 1 for use, thus expanding the application range of the mold of this application. On the other hand, the stabilizing structure 10 on the slider cover plate 9 provides a fixing function for the right die 32, improving the stability of the right die 32 in the stamping process. The left die 31 is fixed on the slider cover plate 9.

[0045] Before stamping, the stabilizing block 102 on the right die 32 is located at the lower end of the stabilizing groove 101, and the right die 32 is misaligned with the left die 31. The stabilizing groove 101 also limits the downward movement of the stabilizing block 102, ensuring that the downward misalignment distance of the right die 32 is within the range of the distance setting value for the gap Z caused by the misalignment of the left die 31 and the right die 32 in this application. After the right die 32 contacts the thin material, the slider cover plate 9 continues to move downward, driving the left die 31 and the stabilizing groove 101 to move downward. The stabilizing groove 101 moves downward along the path of the left die 321 moving downward at an incline until the left die 31 and the right die 32 form a complete punch 3. After that, the stabilizing block 102 is located at the upper end of the stabilizing groove 101, and the stabilizing groove 101 also limits the upward movement of the right die 32, ensuring that the upper end of the right die 32 is flush with the left die 31 after moving upward. Then the punch 3... The material continues to move downwards, drawing the thin material into the cavity 4 for stamping, forming a "U"-shaped part. After stamping, the upper die holder 1 moves the punch 3 upwards, causing the part to spring back and wrap around the outer surface of the punch 3. The punch 3 moves the part upwards, creating a downward pulling force F on the right die 32. The right die 32 also has its own gravity G, and the part itself is subjected to a downward frictional force F1 from the cavity 4 during its movement. Under the influence of its own gravity G and the pulling force F of the part, the right die 32 slides downwards. Under the influence of the frictional force F1 between the part and the cavity 4, the part also moves downwards relative to the left die 31. The downward movement of the right die 32 causes the stabilizing block 102 to move downwards along the stabilizing groove 101, resulting in a misalignment between the right die 32 and the left die 31, creating a gap Z. This breaks the local vacuum state formed between the part and the punch 3, preventing the part from wrapping around the punch 3 and thus achieving material removal.

[0046] The angle between the dividing line of the left mold 31 and the right mold 32 and the horizontal line, which is also the angle at the lower left corner of the right mold 32, is α. The range of angle α is 90° > α > 0°. The vertical space length L1 of the stabilizing block 102 moving in the stabilizing groove 101, and the length L2 of the slider 8 sliding in the slide groove 7, are given by L1 = L2sina. In this case, the sine value of the sliding distance of the slider 8 along the slide groove 7 is equal to the distance that the stabilizing block 102 moves in the vertical direction, thus ensuring that the slider 8 and the stabilizing block 102 slide synchronously during the sliding process of the right mold 32, thereby making the right mold 32 more stable during operation.

[0047] The stabilizing block 102 and stabilizing groove 101 cooperate with the slider 8 and slide groove 7 to achieve the stability of the right mold 32 during operation. Meanwhile, the sliding length L2 of the slider 8 within the slide groove 7 is limited. If the value of L2 is too large, the time it takes for the left mold 31 and right mold 32 to slide and form a complete punch 3 will be too long, increasing the stamping time and affecting the efficiency of the stamping process. If the value of L2 is too small, the value of the gap Z caused by the misalignment of the left mold 31 and right mold 32 will be too small, which is not conducive to the smooth demolding of the part. The range of L2 value is also related to the clamping distance at the lower left corner of the right mold 32. The length of L2 is related to the angle α. When the angle α is larger, the minimum range of L2 is also relatively larger, and when the angle α is smaller, the minimum range of L2 is also relatively smaller. This is because when the angle α is large, the gap z caused by the misalignment between the right mold 32 and the left mold 31 when the right mold 32 moves downward by a unit length L2 is relatively small. When the angle α is small, the gap Z caused by the misalignment between the right mold 32 and the left mold 31 when the right mold 32 moves downward by a unit length L2 is relatively large. According to different scenario requirements, this application can adjust the range of L2 and α based on the critical value required for the effect of the gap z.

[0048] In one embodiment of the present invention, the cross-sectional shape of the right mold 32 is trapezoidal, and the diameter of the lower end of the right mold 32 is larger than the diameter of the upper end.

[0049] In one embodiment of the present invention, the cross-sectional shape of the right mold 32 is trapezoidal, and the diameter of the lower end of the left mold 31 is the same as that of the right mold 32.

[0050] In one embodiment of the present invention, the punch 3 includes at least a set of left molds 31 and right molds 32.

[0051] In the implementation process, this application sets the cross-sectional shape of the right mold 32 to a trapezoidal shape, which, compared to a triangle, makes it easier and more accurate to set the stabilizing block 102 and the stabilizing groove 101. This avoids excessive deviation in the volume of the left mold 31 and the right mold 32, ensuring that the right mold 32 is more stable during operation and that the molding effect is more accurate.

[0052] By setting the lower diameters of the right mold 32 and the left mold 31 to be the same, so that the left mold 31 and the right mold 32 form a single punch 3, the gap between the left mold 31 and the right mold 32 is located in the middle. Since the left mold 31 is used to limit the right mold 32, the volume of the left mold 31 cannot be too small. Therefore, the bottom diameters of the left mold 31 and the right mold 32 are set to be the same. During the stamping process, when the punch 3 moves to the bottom of the die 4, under the premise of ensuring the balance of the left mold 31 and the right mold 32, the area of ​​the right mold 32 subjected to the upward force from the bottom of the die 4 is relatively large. As a result, the bottoms of the left mold 31 and the right mold 32 are easier to flatten, and the pressure of the left mold 31 and the right mold 32 on the workpiece is also more even, resulting in higher surface quality of the workpiece.

[0053] The mold in this application is mainly used for unloading thin materials less than 1mm thick into "U" shaped parts. The thinner the material, the more difficult it is to unload. In order to improve the forming quality and precision of the parts, the thin material is first placed on the upper end of the die 4. The upper die seat 1 is driven to move downward through the hydraulic mechanism. The upper die seat 1 drives the punch 3 to move downward to perform the stamping work. Since the punch 3 is composed of the left die 31 and the right die 32, during the unloading process after stamping, the right die 32 slides downward and is misaligned with the left die 31, which reduces the lateral diameter of the left die 31 and the right die 32. As a result, a gap is generated between the stamped part and the punch 3, so that the part is removed from the punch 3 and the unloading is completed. This unloading process is very smooth and is very suitable for use in the stamping process of high-speed progressive dies.

[0054] This application provides an assembly method for a thin-material ejection mold, applicable to the aforementioned thin-material ejection mold, and the method includes the following steps:

[0055] Insert the slider 8 on the right mold 32 horizontally from the upper end of the slide groove 7 on the left mold 31; after the slider 8 enters the slide groove 7, slide the right mold 32 downward relative to the left mold 31; the right mold 32 is embedded in the left mold 31, and the right mold 32 and the left mold 31 are slidably connected.

[0056] Then, fix the left mold 31 to the slider cover plate 9;

[0057] Then, fix the slider cover plate 9 onto the upper mold base 1.

[0058] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A mold for unloading thin materials, comprising an upper mold base (1), a lower mold base (2), a punch (3), and a die (4), characterized in that, The punch (3) is disposed at the lower end of the upper die holder (1). The punch (3) includes a left die (31) and a right die (32). The upper diameter of the left die (31) is larger than the lower diameter. The left die (31) is fixedly connected to the upper die holder (1). The left die (31) is slidably connected to the right die (32), and the right die (32) does not detach from the left die (31). The die (4) is disposed at the upper end of the lower die holder (2). The left mold (31) has a non-through groove (7) on the side near the right mold (32), and the right mold (32) has a slider (8) fixedly connected to the side near the left mold (31). The slider (8) is slidably and sealingly connected to the groove (7). The upper end of the punch (3) is connected to the upper die base (1) through the slider cover plate (9); A stabilizing structure (10) is provided between the right mold (32) and the slider cover plate (9); The stabilizing structure (10) includes a stabilizing groove (101) and a stabilizing block (102). The stabilizing groove (101) is opened at the lower end of the slider cover plate (9), and the stabilizing block (102) is fixed to the upper end of the vertical side of the right mold (32). The length of the stabilizing groove (101) is greater than the length of the stabilizing block (102). The cross-sectional shape of the right mold (32) is trapezoidal, and the diameter of the lower end of the right mold (32) is larger than the diameter of the upper end.

2. The mold for unloading thin materials according to claim 1, characterized in that, A pad (5) is slidably disposed in the middle of the die (4), and an ejector (6) is disposed at the lower end of the pad (5).

3. A mold for unloading thin materials according to claim 1, characterized in that, The slider cover plate (9) is detachably connected to the upper mold base (1).

4. A mold for unloading thin materials according to claim 1, characterized in that, The punch (3) includes at least one set of left die (31) and right die (32).

5. An assembly method for a thin-material ejection mold, characterized in that: This method is applicable to a mold for unloading thin materials as described in any one of claims 1-4, and the method includes the following steps: Insert the slider (8) on the right mold (32) horizontally from the upper end of the groove (7) on the left mold (31); after the slider (8) enters the groove (7), slide the right mold (32) downward relative to the left mold (31); the right mold (32) is embedded in the left mold (31), and the right mold (32) and the left mold (31) are slidably connected; Then fix the left mold (31) onto the slider cover plate (9); Then fix the slider cover plate (9) on the upper mold base (1).

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