Bending machining method and forming die for leaf spring

Abstract

The invention discloses a bending machining method of a spring piece and a forming die. The machining method comprises the following steps that S1, materials are prepared; s2, blanking is conducted; s3, deburring is conducted; s4, bending and forming; and S5, demolding and surface treatment are carried out, finally, inspection is carried out, after inspection is qualified, packaging is carried out according to requirements, warehousing is carried out, and a spring piece finished product is obtained. According to the machining method and the forming die, the bending forming machining method is adopted through the forming die, the technological method is simple, die positioning is controllable, the product size is good, the appearance quality is high, the production efficiency is greatly improved, the machining requirement of batch products is met, meanwhile, the forming die is low in production cost, and the production cost is low. The die is simple in structure, easy to manufacture and convenient to maintain, not only saves production cost, but also reduces die manufacturing cost and period, and is suitable for mass production and processing.

Description

Technical Field

[0001] The invention relates to the technical field of spring sheet processing, and in particular to a bending processing method and a forming die for a spring sheet. Background Art

[0002] With the continuous development of science and technology, conventional parts such as spring sheets are widely used in various aspects of the aerospace field, such as aerospace aircraft parts, missile parts, and ship parts. They play a connecting or fastening role. Spring sheets are a special part with different shapes and structures due to their different uses, such as Figure 1 The spring sheet shown is made of T9A carbon steel, with a thickness of only 0.3mm. From the perspective of its structural appearance, it is a star-shaped structure as a whole. It is a special-shaped part with a special structure. Due to its unique shape and high bending forming requirements, it is difficult to process and is a part prone to failure. Therefore, its manufacturing and processing has always been a key link for various production and processing companies. For the bending processing of spring sheets, the commonly used process method is to use a guide column mold for bending, and then use mechanical processing methods to process the expansion port. When using a mold for processing, due to the unique shape of the spring sheet, a special bending processing mold needs to be made. In the case of large processing batches, it is necessary to ensure the unique bending size, which is particularly important for the wear of the mold.

[0003] After searching, the patent document with application publication number CN102327955A discloses a stamping method for improving the elasticity of the spring sheet, the patent document with authorization announcement number CN207205034U discloses a spring sheet bending die, and the patent document with authorization announcement number CN206455075U discloses a fire smoke exhaust valve spring sheet forming die. From the contents disclosed in the three retrieved patent documents, it can be seen that a die and a stamping method that meet the bending forming of the spring sheet are provided from different perspectives. Figure 1 The star-shaped spring leaf shown is provided with a forming die having a structure disclosed in the prior art to meet the bending forming requirements of the spring leaf in order to ensure timely delivery of the product and reduce processing costs. Summary of the invention

[0004] The technical problem to be solved by the present invention is to solve the problems existing in the background technology. In order to meet the bending forming of spring sheets, a forming mold with a simple structure and easy operation is provided. By using the forming mold, one-time bending forming is performed without the need for subsequent mechanical processing. While meeting the requirements of batch processing, the bending size must be guaranteed and the product quality must be improved to meet the use requirements. Specifically, a bending processing method and a forming mold for a spring sheet are provided.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a bending processing method of a spring sheet, the processing method comprising the following steps: S1. Material preparation: Select the corresponding metal plate according to the size and material specifications of the spring piece to be processed; S2. Blanking: Select a blanking die corresponding to the spring sheet to be processed, install it in the punching machine, then place the metal sheet on the punching machine, and use the blanking die to punch the pre-processed metal sheet to obtain a blanking product; S3. Deburring: Use a grinding tool to grind the finished blank to remove the burrs generated by the blanking to prevent product appearance defects during bending; S4. Bending: The finished product after burrs are removed is bent by a forming die to form a spring sheet; S5. Demolding and surface treatment: The spring sheet is taken out from the forming mold, and then the spring sheet is corrected by benchwork. After the correction, the spring sheet is subjected to cadmium plating and passivation treatment. Finally, the surface-treated spring sheet is inspected according to the size requirements of the design drawing. If the spring sheet passes the inspection, it is packaged as required and put into storage, and the finished spring sheet is obtained.

[0006] Furthermore, in the bending processing method of a spring sheet described in the present invention, during the blanking process in step S2, it is required that the metal flow line direction of the pre-processed metal sheet be perpendicular to the bending direction of the blanked product or be punched at a 45-degree direction.

[0007] Furthermore, a spring sheet bending method according to the present invention is adopted. During the bending process in step S4, a forming die is used to punch downward along the middle of the blank product so that both sides of the blank product are symmetrically bent toward the forming die. The spring sheet is formed through one-time bending.

[0008] The present invention also discloses a forming mold used in the bending processing method of the above-mentioned spring sheet, wherein the forming mold comprises a bottom plate, a concave mold frame, a concave mold, a convex mold, a guide pin and a positioning pin, wherein the concave mold frame has a accommodating cavity matched with the concave mold, the concave mold has a concave mold cavity, and the convex mold has a convex module matched with the concave mold cavity, the concave mold frame is arranged on the bottom plate, the concave mold is arranged in the accommodating cavity in the concave mold frame, the convex mold is located directly above the concave mold, and coaxially arranged guide holes are arranged in the convex mold, the diameter of the guide hole is axially parallel to the diameter of the guide hole, and the diameter of the guide hole is axially parallel to the diameter of the guide hole. The outer diameter of the locating pin matches that of the locating pin, and the guide pin passes through the guide holes in the punch and the die frame from top to bottom in turn, and is inserted downward into the guide hole in the bottom plate; and coaxially arranged locating holes are respectively provided in the centers of the punch, the die and the die frame, and the aperture of the locating hole matches the outer diameter of the locating pin, and the locating pin passes through the locating holes in the punch and the die in turn from top to bottom, and is inserted downward into the locating hole in the die frame; under the action of external force, the punch can reciprocate up and down along the guide pin and the locating pin toward the die frame to realize the clamping or separation between the punch and the die.

[0009] Furthermore, using the molding die described in the present invention, the die cavity in the die is an inwardly recessed arc-shaped structure and matches the spring sheet to be formed, and the convex module in the punch includes a plane segment and an arc segment, wherein the arc segment matches the die cavity, and the plane segments are located on both sides of the bottom surface of the punch, and the plane segments on both sides are connected by the arc segment to form an outwardly protruding arc structure; the convex module in the punch forms a molding cavity for the spring sheet between the arc segment and the die cavity in the die.

[0010] Furthermore, using the molding die of the present invention, two guide pins are provided, and two groups of guide holes are provided to match the guide pins, and the two groups of guide holes are symmetrically arranged on both sides of the positioning hole.

[0011] Furthermore, the forming mold described in the present invention is used, and the forming mold also includes a material withdrawal spring, coaxially arranged material withdrawal blind holes are provided in the base plate and the die, and a material withdrawal through hole coaxially arranged with the material withdrawal blind hole is provided in the die frame, the lower end of the material withdrawal spring is arranged in the material withdrawal blind hole in the base plate, and the upper end thereof passes through the material withdrawal through hole in the die frame and extends upward into the material withdrawal blind hole in the die.

[0012] Furthermore, using the molding die described in the present invention, the material withdrawal spring is a reset spring, and two groups of the reset springs are provided. The material withdrawal blind holes and the material withdrawal through holes are each provided with two groups and matched with the reset springs. The two groups of material withdrawal blind holes and material withdrawal through holes are symmetrically arranged on both sides of the positioning hole.

[0013] Compared with the prior art, the bending processing method and forming mold of a spring sheet described in the present invention have the following beneficial effects: for the configured convex mold and concave mold, the existing mechanical processing method of the expansion port of the guide column mold is changed to an extrusion bending forming method of the spring sheet with a unique shape through the mold, and the spring sheet is bent and formed once by the forming mold without the problem of strain on the bending head. The configured stripping spring facilitates demolding of the bent spring sheet, effectively solving the problem of a single bending number and low efficiency in the traditional processing method. The spring sheet processed by the bending forming method not only has good surface quality, but also has high efficiency, good product consistency, stable processing and high reliability.

[0014] It can be seen that the processing method and molding mold described in the present invention have simple process methods, controllable mold positioning, good product size, and high appearance quality, which greatly improves production efficiency and meets the needs of batch product processing. At the same time, the molding mold has low production cost, is easy to make and convenient to maintain, which not only saves production costs, but also reduces the mold production cost and cycle, and is suitable for mass production and processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0016] Figure 1 is a schematic diagram of the structure of the spring sheet to be processed; Figure 2 It is a structural schematic diagram of the molding die of the present invention; Figure 3 It is a three-dimensional structural schematic diagram of the molding die of the present invention; Figure 4 It is a schematic diagram of the three-dimensional structure after the spring sheet is bent and formed by the forming mold of the present invention; Figure 5 It is a schematic diagram of the planar structure after the spring sheet is bent and formed by the forming mold of the present invention; Figure 6 It is a schematic diagram of the cross-sectional structure after the spring sheet is bent and formed by using the forming mold of the present invention.

[0017] As shown in the figure: 1-base plate, 2-die frame, 3-die, 4-punch, 5-guide pin, 6-locating pin, 7-removal spring, 8-spring sheet. DETAILED DESCRIPTION

[0018] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0019] It should be noted that the structures, proportions, sizes, etc. drawn in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", etc. quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0020] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "provided with" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] It should be noted that the term "comprise" or any other variation is intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus. Example 1

[0022] like Figure 2 and Figure 3As shown, this embodiment provides a molding die, which includes a base plate 1, a die frame 2, a die 3, a punch 4, a guide pin 5 and a positioning pin 6. The die frame 2 has a receiving cavity matched with the die 3, the die 3 has a die cavity, and the punch 4 has a convex module matched with the die cavity. The die frame 2 is arranged on the base plate 1, the die 3 is arranged in the receiving cavity in the die frame 2, and the punch 4 is located directly above the die 3. Coaxially arranged guide holes are provided in the punch 4, the die frame 2 and the base plate 1, and the aperture of the guide hole matches the outer diameter of the guide pin 5; and in the centers of the punch 4, the die 3 and the die frame 2, respectively, The positioning holes are coaxially arranged, and the aperture of the positioning holes matches the outer diameter of the positioning pin 6; the guide pins 5 are provided with two, and the guide holes are provided with two groups and match the guide pins 5, and the two groups of guide holes are symmetrically arranged on both sides of the positioning holes; the guide pins 5 pass through the guide holes in the punch 4 and the die frame 2 from top to bottom, and are inserted downward into the guide holes in the base plate 1; and the positioning pins 6 pass through the positioning holes in the punch 4 and the die 3 from top to bottom, and are inserted downward into the positioning holes in the die frame 2; under the action of external force, the punch can reciprocate up and down along the guide pins 5 and the positioning pins 6 toward the die frame 2 to achieve the clamping or separation between the punch 4 and the die 3.

[0023] Furthermore, using the molding mold described in this embodiment, the die cavity in the die 3 is an inwardly recessed arc-shaped structure and matches the spring sheet to be formed, and the convex module in the punch 4 includes a plane segment and an arc segment, wherein the arc segment matches the die cavity, and the plane segment is located on both sides of the bottom surface of the punch 4, and the plane segments on both sides are connected by the arc segment to form an outwardly protruding arc structure; the convex module in the punch 4 forms a molding cavity for the spring sheet between the arc segment and the die cavity in the die 3.

[0024] Furthermore, the forming mold described in this embodiment is adopted, and the forming mold further includes a material withdrawal spring 7, a coaxially arranged material withdrawal blind hole is provided in the base plate 1 and the die 3, and a material withdrawal through hole is provided in the die frame 2 and coaxially arranged with the material withdrawal blind hole, and the lower end of the material withdrawal spring 7 is arranged in the material withdrawal blind hole in the base plate 1, and the upper end thereof passes through the material withdrawal through hole in the die frame 2 and extends upward to the material withdrawal blind hole in the die 3. Among them, the material withdrawal spring 7 is a reset spring, and the reset spring is provided with two groups, and the material withdrawal blind hole and the material withdrawal through hole are both provided with two groups, and matched with the reset spring, and the two groups of material withdrawal blind holes and the material withdrawal through holes are symmetrically arranged on both sides of the positioning hole. Example 2

[0025] This embodiment provides a bending method for a spring sheet, the method comprising the following steps: S1. Material preparation: Select the corresponding metal plate according to the size and material specifications of the spring piece to be processed; S2. Blanking: Select a blanking die corresponding to the spring sheet to be processed, install it in the punching machine, then place the metal sheet on the punching machine, and use the blanking die to punch the pre-processed metal sheet to obtain a blanking product; S3. Deburring: Use a grinding tool to grind the finished blank to remove the burrs generated by the blanking to prevent product appearance defects during bending; S4. Bending: The finished product after burrs are removed is bent by a forming die to form a spring sheet; S5. Demolding and surface treatment: The spring sheet is taken out from the forming mold, and then the spring sheet is corrected by benchwork. After the correction, the spring sheet is subjected to cadmium plating and passivation treatment. Finally, the surface-treated spring sheet is inspected according to the size requirements of the design drawing. If the spring sheet passes the inspection, it is packaged as required and put into storage, and the finished spring sheet is obtained.

[0026] Furthermore, using the bending processing method described in this embodiment, in the blanking process of step S2, it is required that the metal flow line direction of the pre-processed metal sheet is perpendicular to the bending direction of the blanked finished product or is punched at a 45-degree direction.

[0027] Furthermore, using the bending processing method described in this embodiment, during the bending forming process in step S4, a forming die is used to punch downward along the middle of the blank product so that both sides of the blank product are bent symmetrically toward the forming die, and the spring sheet is formed through one-time bending.

[0028] By adopting the bending processing method of the present invention, the spring sheet product structure obtained by bending once is as follows: Figures 4 to 6 As shown. In the specific application process, through the configured forming mold, the punch 4 is first connected to the power output end of the existing stamping equipment, and the bottom plate 1 is installed on the workbench of the stamping equipment. The finished blank after deburring is placed on the top surface of the die 3, and the stamping equipment is started to drive the punch 4 to move. Since the convex module in the punch 4 forms a forming cavity for the spring sheet between the arc surface segment and the die cavity in the die 3, the spring sheet can be stamped and bent by using the forming cavity. In the stamping and bending process, the spring sheet can be accurately positioned by the positioning pin 6 and the die frame 2, and the guide pin 5 can be used to make the punch 4 move up and down along the guide pin 5 to achieve the closing or separation between the punch 4 and the die 3, so as to ensure the accurate closing between the punch 4 and the die 3, so that the symmetry of the spring sheet meets the requirements, so that the forming mold has good positioning accuracy and constant part size. In addition, since a material removal spring 7 is also configured, the material removal spring 7 can remove the material from the die when the punch 4 is moving upward, which is convenient for operation.

[0029] It can be seen that the bending processing method described in the present invention has been applied in the actual production process, and the processed products have a very good effect. It not only solves the problem of single bending number and low efficiency in the traditional method, but also the spring sheet obtained by bending has good surface quality, good consistency, stable processing and reliable quality, so that the product quality is effectively controlled, the processing efficiency is improved, and the product delivery rate is guaranteed. At the same time, it also overcomes the technical bottleneck of high stamping scrap rate with unique structure.

[0030] To sum up, the processing method and forming mold described in the present invention adopt a bending forming processing method through the forming mold. The process method is simple, the mold positioning is controllable, the product size is good, and the appearance quality is also high, which greatly improves the production efficiency and meets the needs of batch product processing. At the same time, the forming mold has a low production cost, is easy to manufacture and convenient to maintain, which not only saves production costs, but also reduces the mold manufacturing cost and cycle, and is suitable for mass production and processing.

[0031] Other details of the present invention are conventional technologies known to those skilled in the art and are therefore not described in detail.

[0032] The protection scope of the present invention is not limited to the technical solutions disclosed in the specific implementation methods. The above description is only a preferred implementation method of the present invention and does not limit the present invention. Any minor modifications, equivalent substitutions and improvements made according to the technical solutions of the present invention should be included in the protection scope of the technical solutions of the present invention.

Claims

1. A bending method for a spring sheet, characterized in that: The processing method comprises the following steps: S1. Material preparation: Select the corresponding metal plate according to the size and material specifications of the spring piece to be processed; S2. Blanking: Select a blanking die corresponding to the spring sheet to be processed, install it in the punching machine, then place the metal sheet on the punching machine, and use the blanking die to punch the pre-processed metal sheet to obtain a blanking product; S3. Deburring: grinding the obtained blanking product with a grinding tool to remove the burrs generated by the blanking; S4. Bending: The finished product after burrs are removed is bent by a forming die to form a spring sheet; S5. Demolding and surface treatment: The spring sheet is taken out from the forming mold, and then the spring sheet is corrected by benchwork. After the correction, the spring sheet is subjected to cadmium plating and passivation treatment. Finally, the surface-treated spring sheet is inspected according to the size requirements of the design drawing. If the spring sheet passes the inspection, it is packaged as required and put into storage, and the finished spring sheet is obtained.

2. A method for bending a spring sheet according to claim 1, characterized in that: In the blanking process of step S2, it is required that the metal flow line direction of the pre-processed metal sheet is perpendicular to the bending direction of the blanked finished product or is blanked at a 45-degree direction.

3. The method for bending a spring sheet according to claim 1, characterized in that: In the bending process of step S4, a forming die is used to punch downward along the middle of the blank product so that both sides of the blank product are symmetrically bent toward the forming die. The spring sheet is formed by one-time bending.

4. A forming die used in the spring sheet bending method according to any one of claims 1 to 3, characterized in that: The molding die comprises a bottom plate, a concave die frame, a concave die, a convex die, a guide pin and a positioning pin, the concave die frame has a accommodating cavity matched with the concave die, the concave die has a concave die cavity, and the convex die has a convex module matched with the concave die cavity, the concave die frame is arranged on the bottom plate, the concave die is arranged in the accommodating cavity in the concave die frame, the convex die is located directly above the concave die, and coaxially arranged guide holes are arranged in the convex die, the diameter of the guide hole matches the outer diameter of the guide pin, and the guide pin is The locating pins are inserted into the guide holes in the punch and die frame from top to bottom, and inserted into the guide holes in the bottom plate downwards. Coaxially arranged positioning holes are provided in the centers of the punch, die and die frame respectively, and the apertures of the positioning holes match the outer diameters of the positioning pins. The positioning pins are inserted into the positioning holes in the punch and die frame from top to bottom, and inserted into the positioning holes in the die frame downwards. Under the action of external force, the punch can reciprocate up and down along the guide pins and the positioning pins toward the die frame, so as to achieve the clamping or separation between the punch and die.

5. The molding die according to claim 4, characterized in that: The die cavity in the die is an inwardly concave arc-shaped structure and matches the spring sheet to be formed, while the male module in the male die includes a plane segment and an arc segment, wherein the arc segment matches the die cavity, the plane segment is located on both sides of the bottom surface of the male die, and the plane segments on both sides are connected by the arc segment to form an outwardly protruding arc structure; the male module in the male die forms a forming cavity for the spring sheet between the arc segment and the die cavity in the die.

6. The molding die according to claim 4, characterized in that: There are two guide pins, and there are two groups of guide holes, which match the guide pins. The two groups of guide holes are symmetrically arranged on both sides of the positioning hole.

7. The molding die according to claim 4, characterized in that: The forming mold also includes a material withdrawal spring, a coaxially arranged material withdrawal blind hole is provided in the base plate and the die, and a material withdrawal through hole coaxially arranged with the material withdrawal blind hole is provided in the die frame, the lower end of the material withdrawal spring is arranged in the material withdrawal blind hole in the base plate, and the upper end thereof passes through the material withdrawal through hole in the die frame and extends upward into the material withdrawal blind hole in the die.

8. The molding die according to claim 7, characterized in that: The material withdrawal spring is a reset spring, and two groups of the reset springs are provided. The material withdrawal blind holes and the material withdrawal through holes are both provided with two groups and matched with the reset springs. The two groups of material withdrawal blind holes and the material withdrawal through holes are symmetrically arranged on both sides of the positioning hole.

Images