A mold for stretching and forming method thereof

Abstract

The present invention discloses a mold for stretching and a molding method thereof, the mold comprises an upper mold assembly and a lower mold assembly below it, and a stripper plate arranged between the upper mold assembly and the lower mold assembly, the stripper plate is connected to the upper mold assembly and a gap is arranged between them; the upper mold assembly comprises an upper mold plate and a concave mold stripper plate arranged on the upper mold plate, an upper buffer spring is arranged between the upper mold plate and the concave mold stripper plate; the lower mold assembly comprises a lower mold plate and a convex mold pressing plate arranged on the lower mold plate, a lower buffer spring is arranged between the lower mold plate and the convex mold pressing plate; a delay assembly is arranged on the upper mold assembly and the stripper plate, a clamping assembly is arranged on the lower mold assembly, the delay assembly can push the clamping assembly to press the convex mold pressing plate, and block the clamping assembly from moving before the concave mold stripper plate is separated from the part. The present invention can avoid rebound or deformation during the part stripping process, ensure the quality of the part, and make the processing more stable, reliable and effective.

Description

Technical Field

[0001] The present invention relates to the field of moulds, and in particular to a mould for stretching and a moulding method thereof. Background Art

[0002] There is a common part in communications, new energy, and electronic products. This part is generally formed by stretching, and its top shape is non-planar. Since the material thickness is generally thin, the part has a thin-walled feature. The part material can be stainless steel, copper, steel, etc.

[0003] Conventionally, the stretching forming of parts is achieved through a mold. The mold includes a concave mold plate and a convex mold plate. During the stretching, the convex mold plate and the concave mold plate press the material to achieve forming. During the stripping process, the convex mold plate applies an upward stripping force to the product through the pressing edge of the stretching part to make the product close to the concave cavity surface in the concave mold plate. At the same time, the concave mold plate also applies a downward stripping force to the product in this process. The product is subjected to upper and lower pressures at the same time. The pressing force of the convex mold plate is greater than the stripping force of the concave mold plate. It is easy for a suspended area to exist between the top surface of the product and the convex mold plate. In other words, there is no support on the lower side of the top surface of the product during the demolding process, but at the same time, the force of the concave mold plate always acts on the top surface of the product. For such thin-walled, large-curvature stretching parts, deformation is very likely to occur when receiving top side pressure, resulting in product rebound and size changes.

[0004] Based on the above problems existing in the stretching of parts, it is necessary to develop a mold and a molding method to avoid deformation and springback of the top surface of the parts caused by the top surface force during the mold molding process. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a mold for stretching and a forming method thereof, which can avoid accidental deformation of parts during the stretching forming process, resulting in changes in the size and shape of the formed parts.

[0006] A mold for stretching, comprising an upper mold assembly and a lower mold assembly thereunder, and a stripper plate disposed between the upper mold assembly and the lower mold assembly, wherein the stripper plate is connected to the upper mold assembly, and a gap is provided between the stripper plate and the upper mold assembly;

[0007] The upper die assembly comprises an upper die plate and a die stripper plate arranged on the upper die plate, and an upper buffer spring is arranged between the upper die plate and the die stripper plate;

[0008] The lower die assembly comprises a lower die plate and a punch plate disposed on the lower die plate, a lower buffer spring is disposed between the lower die plate and the punch plate, and the punch plate and the die stripper plate cooperate with each other to stretch and form the parts located therebetween;

[0009] The upper die assembly and the stripper plate are provided with a delay assembly, and the lower die assembly is provided with a clamping assembly. The delay assembly can push the clamping assembly to press the convex film presser plate, and block the movement of the clamping assembly before the concave die stripper plate separates from the part, thereby improving the processing accuracy of the part and avoiding deformation of the part during the stripping process.

[0010] Optionally, the delay assembly includes a slider insert provided on the upper die assembly, and a limit insert provided on the stripper plate, and the distance between the lower end of the slider insert and the lower die assembly is greater than the distance between the lower end of the limit insert and the lower die assembly;

[0011] The clamping assembly comprises a sliding block arranged on the lower mold plate and a return spring connected to the sliding block, a telescopic pin is arranged on the sliding block, and the sliding block is located between the punch pressing plate and the return spring.

[0012] Optionally, the slider insert knife and the limit insert knife are provided with an inclined surface at the lower end of one side facing the punch pressing plate, and the slider is provided with a slider inclined surface matching the inclined surface of the slider insert knife.

[0013] Optionally, a protrusion is provided on the upper end of the sliding block facing the punch pressing plate, and the protrusion is used to press the surface of the punch pressing plate.

[0014] Optionally, a forming concave mold plate is provided on each side of the concave mold stripping plate, an upper mold pad connected to the upper mold plate is provided below the upper mold plate, the upper mold pad is connected to the forming concave mold plate, and the forming concave mold plate is connected to the stripping plate.

[0015] A die forming method for stretch forming comprises the following steps:

[0016] S1: Control the upper mold assembly to move downward so that the stripper plate fits with the lower mold assembly, and the stripper plate stops moving after fitting;

[0017] S2: Control the upper die assembly to continue to move downward, so that the die stripping plate and the punch pressing plate are closed, and the part is stretched and formed; during this movement, the delay assembly pushes the clamping assembly to move, and after closing, the clamping assembly presses the punch pressing plate and blocks its movement;

[0018] S3: Control the upper die assembly to move upward, so that the upper die plate moves upward. Before the die stripping plate is separated from the part, the punch pressing plate does not move because it is pressed by the clamping assembly.

[0019] S4: Control the upper die assembly to continue to move upward, so that the upper buffer spring is reset. At this time, the clamping assembly no longer presses the punch pressing plate, and the punch pressing plate moves upward driven by the reset of the lower buffer spring.

[0020] Optionally, the step S1 specifically includes: the limiting knife moves downward along with the stripping plate, the telescopic pin on the slider is pressed into the slider, and the limiting knife continues to move until the stripping plate stops moving.

[0021] Optionally, the step S2 specifically includes: during the movement process, the slider insert knife pushes the slider to move, so that after the die stripping plate and the punch pressing plate are closed, the slider presses the punch pressing plate, and the movement of the slider is blocked by the limiting insert knife.

[0022] Optionally, step S3 specifically includes: the upper mold assembly moves upward so that the slider insert leaves the surface of the slider, and the slider does not move because the telescopic pin is blocked by the limiting insert, and the punch plate does not move.

[0023] Optionally, the step S4 specifically includes: the upper buffer spring is reset to make the limit insert knife leave the telescopic pin, at which time the reset spring is reset to drive the slider to move, and the punch pressing plate moves upward driven by the lower buffer spring.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides a mold for stretching forming and a forming method thereof. During the stripping process after the part is formed, the delay component and the clamping component make the part close to the punch pressing plate and the die stripping plate, and gradually unload the force according to the forming steps to avoid rebound or deformation of the part, thereby ensuring that the shape and size of the part after stretching forming are the same as the preset ones, ensuring the quality of the part, improving the processing accuracy, and meeting the appearance requirements of the part after stretching; the mold structure and forming method of the present invention are simple, and do not require complex structures such as electric control or pneumatic control, making the processing more stable, reliable and effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The structure of the mold for stretching molding provided in the embodiment of the present application is schematically shown. Figure 1 ;

[0026] Figure 2 The structure of the mold for stretching molding provided in the embodiment of the present application is schematically shown. Figure 2 ;

[0027] Figure 3 The structure of the mold for stretching molding provided in the embodiment of the present application is schematically shown. Figure 3 ;

[0028] Figure 4 The structure of the mold for stretching molding provided in the embodiment of the present application is schematically shown. Figure 4 . DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0030] Reference Figures 1 to 4 A mold for stretching forming, including an upper mold assembly 1 and a lower mold assembly 2 thereunder, and a stripper plate 3 arranged between the upper mold assembly 1 and the lower mold assembly 2, the stripper plate 3 being connected to the upper mold assembly 1, and a gap 4 being arranged between the stripper plate 3 and the upper mold assembly 1; the upper mold assembly 1 includes an upper mold plate 11 and a concave mold stripper plate 12 arranged on the upper mold plate, and an upper buffer spring 13 is arranged between the upper mold plate 11 and the concave mold stripper plate 12; the lower mold assembly 2 includes a lower mold plate 21 and a punch pressing plate 22 arranged on the lower mold plate, and a lower buffer spring 23 is arranged between the lower mold plate 21 and the punch pressing plate 22, the punch pressing plate 22 and the concave mold stripper plate 12 cooperate with each other and stretch the part 10 located therebetween.

[0031] The upper die assembly 1 and the stripper plate 3 are provided with a delay assembly 5, and the lower die assembly is provided with a clamping assembly 6. The delay assembly 5 can push the clamping assembly 6 to press the convex film presser plate 22, and block the movement of the clamping assembly 6 before the concave die stripper plate 12 separates from the part 10. Specifically, the punch pressing plate 22 and the die stripping plate 12 cooperate with each other to stretch the part 10 into shape. After the part is formed, the upper die assembly 1 moves upward. Due to the downward force of the upper buffer spring 13, the die stripping plate 13 presses the part. At this time, the part 10 is only subjected to the downward force and is close to the punch pressing plate 22 and the die stripping plate 12. After the upper buffer spring 13 is fully reset, the punch pressing plate 22 begins to move upward under the force of the lower buffer spring 23 to reset. The punch stripping plate 22 presses the part, and the part 10 is only subjected to the upward force and is close to the punch pressing plate 22 and the die stripping plate 12. It can be understood that during the process of stripping the part 10 product, the part 10 is always close to the punch pressing plate 22 and the die stripping plate 12, and will not cause abnormal deformation of the part due to the simultaneous downward and upward forces, thereby ensuring that the shape and size of the part 10 after forming meet the requirements and the quality of the product.

[0032] In some embodiments, the delay assembly 5 includes a slider insert 51 disposed on the upper die assembly 1, and a limit insert 52 disposed on the stripper plate 3, and the distance between the lower end of the slider insert 51 and the lower die assembly 2 is greater than the distance between the lower end of the limit insert 52 and the lower die assembly 2. In some embodiments, the clamping assembly 6 includes a slider 61 disposed on the lower die plate 21 and a return spring 62 connected to the slider, and a retractable pin 63 is disposed on the slider 61, and the slider 61 is located between the punch press plate 22 and the return spring 62. The retractable pin 63 extends from the slider in a normal state, and can be retracted into the slider under a force state, and the limit insert 52 cooperates with the retractable pin 63 to enable the slider 61 to press the punch press plate 22 or leave the punch press plate 22, and the slider insert 51 cooperates with the slider 61 to push the slider 61 toward the punch press plate 22.

[0033] There are two clamping assemblies 6 and two delay assemblies 5. The two clamping assemblies 6 are respectively arranged on both sides of the die stripping plate 12, and the two delay assemblies 5 are respectively arranged on both sides of the punch pressing plate 22, which can ensure the force balance of the upper die assembly 1, the lower die assembly 2 and the stripping plate 3 during the movement process, thereby ensuring the quality of part molding.

[0034] In some embodiments, the lower end of the slider insert knife 51 and the limit insert knife 52 facing the punch plate 22 is provided with an inclined surface, and the slider 61 is provided with a slider inclined surface that matches the inclined surface of the slider insert knife 51. The upper end of the slider 61 facing the punch plate 22 is provided with a protrusion 611, and the protrusion 611 is used to press the surface of the punch plate 22. Specifically, the inclined surface on the slider insert knife 51 matches with the slider inclined surface, so that the slider 61 can be subjected to the force of moving toward the punch plate 22; the inclined surface on the limit insert knife 52 matches with the telescopic pin 63, so that the telescopic pin 63 is forced to retract into the slider 61 during the downward movement of the limit insert knife 52.

[0035] In some embodiments, a forming concave plate 14 is provided on each side of the concave die stripper plate 12, an upper die pad 15 connected to the upper die plate 11 is provided below the upper die plate 11, the upper die pad 15 is connected to the forming concave plate 14, and the forming concave plate 14 is connected to the stripper plate 3. A notch 16 is provided at the lower end of the forming concave plate 14 near the concave die stripper plate 12, and a slider insert 51 is installed on the upper die pad 15.

[0036] A stripping plate pad 7 connected to the stripping plate 3 is provided above the stripping plate 3 . The stripping plate pad 7 is connected to the upper mold assembly 1 with a gap 4 therebetween. Specifically, the stripping plate pad 7 is connected to the forming concave mold plate 14 , and the limiting insert 52 can be installed on the stripping plate pad 7 .

[0037] The present invention also provides a mold forming method for stretching forming, comprising the following steps:

[0038] S1: See attached Figure 1 , control the upper mold assembly 1 to move downward, so that the stripper plate 3 fits with the lower mold assembly 2, and the stripper plate stops moving after fitting;

[0039] Specifically, the limiting knife 52 moves downward with the stripping plate 3, the telescopic pin 63 on the slider 61 is pressed into the slider 61, and the limiting knife 52 continues to move until the stripping plate 3 stops moving. In this step, the slider knife 51 does not contact the slider.

[0040] S2: See attached Figure 2, control the upper die assembly 1 to continue to move downward, so that the concave die stripper plate 12 and the convex die pressing plate 22 are closed, at this time the upper die assembly 1, the stripper plate 3 and the lower die assembly 2 are all in contact with each other, and the part 10 is stretched and formed; during this movement, the delay assembly 5 pushes the clamping assembly 6 to move, and after closing, the clamping assembly 6 presses the convex die pressing plate 22 and blocks its movement;

[0041] Step S2 specifically includes: during the movement, the slider insert 51 pushes the slider 61 to move, so that after the die stripping plate 12 and the punch pressing plate 22 are closed, the slider 61 presses the punch pressing plate 22, and the telescopic pin 63 pops out, blocking the movement of the slider through the limiting insert 52.

[0042] S3: See attached Figure 3 , the formed part 10 begins to be stripped, the upper die assembly 1 is controlled to move upward, so that the upper die plate 11 moves upward, and before the female die stripping plate 12 is separated from the part, that is, before the upper buffer spring 13 is completely reset, the male die pressing plate 22 is pressed by the clamping assembly 5 and does not move;

[0043] Step S3 specifically includes: the upper mold assembly 1 moves upward, so that the slider insert 51 leaves the surface of the slider 61, and the retractable pin 63 is blocked by the limit insert 52 so that the slider 61 does not move. At this time, the punch pressing plate 22 does not move, and the part 10 is only subjected to the downward force of the die stripping plate 12.

[0044] S4: See Appendix Figure 4 , control the upper die assembly 1 to continue to move upward so that the upper buffer spring 13 is fully reset. At this time, the clamping assembly 6 no longer presses the punch pressing plate 22, and the punch pressing plate 22 moves upward driven by the reset of the lower buffer spring 23.

[0045] Step S4 specifically includes: the upper buffer spring 23 is reset, so that the limit insert 52 leaves the telescopic pin. At this time, the reset spring 62 is reset to drive the slider 61 to move, and the punch pressing plate 22 moves upward under the drive of the lower buffer spring 23. In this step, the part 10 is only subjected to the upward force of the punch pressing plate 22.

[0046] It is understandable that the processing material in the present invention can be steel, copper and other materials, and is also applicable to soft, thin, highly elastic materials, which are not limited here. In addition, the surface curvature of the punch pressing plate and the die stripping plate can be set according to actual processing needs.

[0047] The present invention provides a mold for stretching and a molding method thereof. In the process of stripping after the parts are formed, a delay component and a clamping component make the parts close to the male die pressing plate and the female die stripping plate, and gradually unload the force according to the molding steps to avoid the parts from rebounding or deforming, thereby ensuring that the shape and size of the parts after stretching are the same as the preset ones, ensuring the quality of the parts, improving the processing accuracy, and meeting the appearance requirements of the parts after stretching. The mold structure and molding method of the present invention are simple, and do not need to adopt complex structures such as electric control or pneumatic control, so that the processing is more stable, reliable and effective.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this implementation shall be included in the protection scope of the present invention.

Claims

1. A mold for stretching, characterized in that: It comprises an upper die assembly (1) and a lower die assembly (2) thereunder, and a stripper plate (3) arranged between the upper die assembly (1) and the lower die assembly (2), wherein the stripper plate (3) is connected to the upper die assembly (1) and a gap (4) is provided between them; The upper die assembly (1) comprises an upper die plate (11) and a die stripper plate (12) arranged on the upper die plate, and an upper buffer spring (13) is arranged between the upper die plate (11) and the die stripper plate (12); The lower die assembly (2) comprises a lower die plate (21) and a punch plate (22) arranged on the lower die plate (21); a lower buffer spring (23) is arranged between the lower die plate (21) and the punch plate (22); the punch plate (22) and the die stripping plate (12) cooperate with each other and stretch and form the part (10) located therebetween; The upper die assembly (1) and the stripper plate (3) are provided with a delay assembly (5), and the lower die assembly (2) is provided with a clamping assembly (6), wherein the delay assembly (5) is capable of pushing the clamping assembly (6) to press the convex die stripper plate (22) and blocking the movement of the clamping assembly (6) before the concave die stripper plate (12) is separated from the part (10); After the part is formed, the upper die assembly (1) moves upward and is subjected to the downward force of the upper buffer spring (13). The die stripping plate (12) presses the part. The part is subjected to only the downward force and is closely attached to the punch pressing plate (22) and the die stripping plate (12). After the upper buffer spring (13) is completely reset, the punch pressing plate (22) begins to move upward under the force of the lower buffer spring (23) to reset. The punch pressing plate (22) presses the part. The part is subjected to only the upward force and is closely attached to the punch pressing plate (22) and the die stripping plate (12). The delay assembly (5) comprises a slider insert (51) provided on the upper die assembly (1), and a limit insert (52) provided on the stripper plate (3), wherein the distance between the lower end of the slider insert (51) and the lower die assembly (2) is greater than the distance between the lower end of the limit insert (52) and the lower die assembly (2); The clamping assembly (6) comprises a slider (61) arranged on the lower mold plate (21) and a return spring (62) connected to the slider (61), a telescopic pin (63) being provided on the slider (61), and the slider (61) being located between the punch plate (22) and the return spring (62); A forming concave mold plate (14) is provided on each side of the concave mold stripping plate (12), an upper mold pad (15) connected to the upper mold plate (11) is provided below the upper mold plate (11), the upper mold pad (15) is connected to the forming concave mold plate (14), and the forming concave mold plate (14) is connected to the stripping plate (3).

2. A mold for stretching molding according to claim 1, characterized in that: The lower ends of the slider insert knife (51) and the limit insert knife (52) facing the punch pressing plate (22) are provided with inclined surfaces, and the slider (61) is provided with a slider inclined surface matching the inclined surface of the slider insert knife (51).

3. A mold for stretching according to claim 1 or 2, characterized in that: A protrusion (611) is provided at the upper end of the sliding block (61) on one side facing the punch pressing plate (22), and the protrusion (611) is used to press the surface of the punch pressing plate (22).

4. A die forming method for stretching, characterized in that: The mold comprising claim 1; The method comprises the following steps: S1: Control the upper mold assembly (1) to move downward so that the stripper plate (3) fits with the lower mold assembly (2), and the stripper plate (3) stops moving after the fitting; S2: Controlling the upper die assembly (1) to continue to move downward, so that the die stripping plate (12) and the punch pressing plate (22) are closed, and the part (10) is stretched and formed; during this movement process, the delay assembly (5) pushes the clamping assembly (6) to move, and after closing, the clamping assembly (6) presses the punch pressing plate (22) and blocks its movement; S3: Controlling the upper die assembly (1) to move upward, so that the upper die plate (11) moves upward, and before the female die stripping plate (12) is separated from the part (10), the male die pressing plate (22) does not move because it is pressed by the clamping assembly (6); S4: The upper die assembly (1) is controlled to continue to move upward, so that the upper buffer spring (13) is reset. At this time, the clamping assembly (6) no longer presses the punch pressing plate (22), and the punch pressing plate (22) moves upward under the drive of the lower buffer spring (23) to reset.

5. A mold forming method for stretching according to claim 4, characterized in that: The step S1 specifically comprises: the limiting insert (52) moves downward along with the stripping plate (3), so that the telescopic pin (63) on the slider (61) is pressed into the slider (61), and the limiting insert (52) continues to move until the stripping plate (3) stops moving.

6. A mold forming method for stretching according to claim 4, characterized in that: The step S2 specifically comprises: during the movement process, the slider insert knife (51) pushes the slider (61) to move, so that after the die stripping plate (12) and the punch pressing plate (22) are closed, the slider (61) presses the punch pressing plate (22), and blocks the movement of the slider (61) by the limiting insert knife (52).

7. A mold forming method for stretching according to claim 4, characterized in that: The step S3 specifically comprises: the upper die assembly (1) moves upwards so that the slider insert (51) leaves the surface of the slider (61), and the slider (61) does not move because the telescopic pin (63) is blocked by the limiting insert (52), and at this time, the punch plate (22) does not move.

8. A die forming method for stretching according to claim 4, characterized in that: The step S4 specifically comprises: the upper buffer spring (13) is reset so that the limit inserting knife (52) leaves the telescopic pin (63); at this time, the reset spring (62) is reset to drive the slider (61) to move, and the punch pressing plate (22) moves upward under the drive of the lower buffer spring (23).

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