Stress counteracting structure of split type combined special-shaped cold heading die

Abstract

The invention discloses a stress counteracting structure of a split type combined special-shaped cold heading die, and relates to the technical field of cold heading dies. Comprising a fixing structure, a first half mold and a second half mold, the first half die and the second half die are spliced to form a complete special-shaped cold heading die mounting cavity, and the mounting cavity is integrally inserted into the fixing structure and is in rigid contact fit with the fixing structure to offset initial stress; the first half mold comprises a first mold body, pull rods are fixedly arranged on the two sides of the first mold body, abutting blocks are fixedly arranged at the ends, away from the first mold body, of the pull rods, and first protruding blocks are fixedly arranged on the sides, facing the second half mold, of the abutting blocks. Through the arrangement of the fixing structure, the first half die and the second half die, triple stress elimination is achieved, the problems that an existing special-shaped cold heading die is concentrated in stress, prone to cracking and short in service life during working are effectively solved, die fatigue failure caused by long-term action of residual stress is avoided, and the service cycle of the die is prolonged.

Description

Technical Field

[0001] This invention relates to the field of cold heading mold technology, specifically to a stress-relief structure for a split-type combined irregular cold heading mold. Background Technology

[0002] During operation, irregularly shaped cold heading dies are subjected to instantaneous impact compressive stress, radial expansion force, and shear stress of hundreds to thousands of MPa, accompanied by local thermal stress of 200~400℃, assembly stress, and springback internal stress after repeated impacts. These stresses are prone to concentration in areas such as sharp corners, thin walls, and deep grooves of irregularly shaped cavities, leading to failure modes such as mold cracking, plastic deformation, and excessively rapid cavity wear. The mold life is usually only 1 / 3 to 1 / 2 of that of conventional cold heading dies, which seriously restricts the production efficiency and cost control of irregularly shaped cold heading parts. Therefore, a stress-compensating structure for split-type combined irregularly shaped cold heading dies is proposed to solve these problems. Summary of the Invention

[0003] Technical problems to be solved

[0004] To address the shortcomings of existing technologies, this invention provides a stress-relief structure for a split-type combined irregular-shaped cold heading die, thus solving the problems mentioned in the background art.

[0005] Technical solution

[0006] To achieve the above objectives, the present invention provides the following technical solution: a stress-relief structure for a split-type combined irregular cold heading die, comprising: a fixing structure, a first half-die, and a second half-die;

[0007] The first half-mold and the second half-mold are assembled to form a complete irregular cold heading mold mounting cavity. The mounting cavity is inserted into the fixed structure as a whole and is in rigid contact with the fixed structure to offset the initial stress.

[0008] The first half-mold includes a first mold body, with pull rods fixed on both sides of the first mold body. An abutment block is fixed on the end of the pull rod away from the first mold body, and a first protrusion is fixed on the side of the abutment block facing the second half-mold.

[0009] The second half mold includes a second mold body. Two symmetrically arranged fixing frames are fixed on the side of the second mold body facing the first half mold. A bidirectional screw is rotatably connected between the two fixing frames. An adjusting wheel is fixed in the middle of the bidirectional screw. Two limiting claws are movably connected on the bidirectional screw. A second protrusion is fixed on the side of the limiting claw facing the abutment block. The limiting claw abuts against the abutment block to offset secondary stress.

[0010] Preferably, the fixing structure includes a base, a support column, and a top seat. The base and the top seat are arranged in parallel, and the support column is connected between the base and the top seat. The inner sides of the base and the top seat are provided with limiting grooves.

[0011] Preferably, the support column is a telescopic support column, and both ends of the support column are rigidly connected to the base and the top seat, respectively.

[0012] Preferably, a limiting strip is fixed between the two fixing frames, and the limiting strip and the two fixing frames together form a limiting groove. Part of the structure of the limiting claw is embedded in the limiting groove and slides in cooperation with the limiting groove.

[0013] Preferably, the limiting claw has a limiting groove, and a bearing is movably connected in the limiting groove. The bearing is connected to a bidirectional screw.

[0014] Preferably, an elastic element is fixed between the bearing seat and the inner wall of the limiting groove, and the elastic element is used to offset residual stress.

[0015] Preferably, the first protrusion and the second protrusion are interlocked, and their mating surfaces are wedge-shaped.

[0016] Preferably, the limiting groove on the base is a blind groove, and the limiting groove on the top seat is coaxially aligned with the limiting groove on the base.

[0017] Preferably, the two sections of the bidirectional screw have opposite thread directions, and the two limiting claws are respectively connected to the bidirectional screw thread sections on both sides of the adjusting wheel.

[0018] Beneficial effects

[0019] The present invention has the following beneficial effects:

[0020] This stress-relief structure for a split-type combined irregular-shaped cold heading die achieves triple stress relief through a fixed structure, a first half-die, and a second half-die. This effectively solves the problems of stress concentration, easy cracking, and short service life of existing irregular-shaped cold heading dies during operation, preventing fatigue failure caused by long-term residual stress and extending the die's service life. The fixed structure achieves initial stress relief, preventing impact stress from directly acting on the half-die mating surface and causing damage, thus improving the overall rigidity and load-bearing capacity of the die. Secondary stress relief is achieved through the cooperation of the first protrusion of the first half-die and the second protrusion of the second half-die, as well as the limiting claw and the abutment block, preventing die cracking caused by half-die mating surface movement and localized stress concentration, ensuring die positioning accuracy. Residual stress is eliminated through the limiting claw, shaft seat, and elastic element, preventing fatigue failure caused by long-term residual stress and extending the die's service life.

[0021] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a stress-relief structure for a split-type combined irregular-shaped cold heading die according to the present invention.

[0023] Figure 2 This is a schematic diagram of the fixed structure in an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the structure of the first half-mold, the second half-mold, and the fixing structure in an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the structure of the first half-mold in an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the structure of the second half-mold in an embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of the limiting claw in an embodiment of the present invention.

[0028] In the diagram: 1. Fixed structure; 101. Base; 102. Support column; 103. Top seat; 104. Limiting groove; 2. First half mold; 201. First mold body; 202. Tie rod; 203. Abutting block; 204. First protrusion; 3. Second half mold; 301. Second mold body; 302. Fixed frame; 303. Limiting strip; 304. Bidirectional screw; 305. Adjusting wheel; 306. Limiting claw; 307. Second protrusion; 308. Limiting groove; 309. Shaft seat; 310. Elastic element. Detailed Implementation

[0029] 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, and 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.

[0030] This invention provides a technical solution: a stress-relief structure for a split-type combined irregular-shaped cold heading die, such as... Figures 1-6 As shown, it includes: a fixed structure 1, a first half mold 2, and a second half mold 3.

[0031] The fixed structure 1 consists of a base 101, a telescopic support column 102, a top seat 103, and a limiting groove 104. The base 101 and the top seat 103 are arranged in parallel. The telescopic support column 102 is connected around the base 101 and the top seat 103. Both ends of the telescopic support column 102 are rigidly fixed to the base 101 and the top seat 103, respectively, so as to realize the support and adjustable spacing of the base 101 and the top seat 103, which facilitates the installation and disassembly of the mold. The inner sides of the base 101 and the top seat 103 are provided with limiting grooves 104. The limiting groove 104 on the base 101 is a blind groove and does not penetrate the bottom of the base 101. The limiting groove 104 on the top seat 103 is coaxially aligned with the limiting groove 104 on the base 101, and together they form the upper and lower positioning constraint cavities for mold installation, which are used to position and rigidly support the combination of the first half mold 2 and the second half mold 3.

[0032] The first half mold 2 includes a first mold body 201, a pull rod 202, an abutment block 203, and a first protrusion 204. The first mold body 201 is the left half mounting base of the irregular cold heading mold. Pull rods 202 are fixed to both sides of the first mold body 201. An abutment block 203 is vertically fixed to the end of the pull rod 202 away from the first mold body 201. The first protrusion 204 is fixed to the side of the abutment block 203 facing the second half mold 3, which is used to cooperate with the second half mold 3 to achieve stress relief and half mold locking.

[0033] The second half mold 3 includes a second mold body 301, a fixing frame 302, a limiting strip 303, a bidirectional screw 304, an adjusting wheel 305, a limiting claw 306, a second protrusion 307, a limiting groove 308, a shaft seat 309, and an elastic element 310. The second mold body 301 is the right half mounting base of the irregular cold heading mold, and two symmetrically arranged fixing frames 302 are fixedly connected to its side facing the first half mold 2. A bidirectional screw 304 is rotatably connected between the two fixing frames 302. A manual adjusting wheel 305 is fixedly connected to the middle of the bidirectional screw 304. The adjusting wheel 305 is located between the two fixing frames 302 and serves as the power input component for manually driving the bidirectional screw 304 to rotate. The two sections of the bidirectional screw 304 have opposite threads, and two limiting claws 306 are respectively connected to the threaded sections of the bidirectional screw 304 on both sides of the adjusting wheel 305, realizing the relative or opposite displacement of the two limiting claws 306.

[0034] A limiting strip 303 is fixedly connected between two fixed frames 302. The limiting strip 303 and the two fixed frames 302 together form a limiting groove. Part of the limiting claw 306 is embedded in the limiting groove and slides within it, providing horizontal guidance for the limiting claw 306 and preventing it from shifting during movement. A limiting groove 308 is formed on the limiting claw 306. A bearing 309 is movably connected within the limiting groove 308. The bearing 309 is connected to a bidirectional screw 304 to convert the rotational motion of the bidirectional screw 304 into the linear displacement of the limiting claw 306. An elastic element 310 is fixedly connected between the bearing 309 and the inner wall of the limiting groove 308. The elastic element 310 is used to offset the residual stress during cold heading, achieving triple stress buffering. The limiting claw 306 is fixed to the side of the contact block 203 with a second protrusion 307. The first protrusion 204 and the second protrusion 307 are interlocked, and the mating surface of the two is a wedge-shaped surface. The secondary stress is offset by the surface contact of the wedge-shaped surface.

[0035] The first half mold 2 and the second half mold 3 are assembled to form a complete irregular cold heading mold mounting cavity. The mounting cavity is inserted into the limiting groove 104 of the fixed structure 1 and is in rigid contact with the fixed structure 1 to offset the initial stress. The limiting claw 306 and the abutting block 203 abut to offset the secondary stress. The elastic element 310 is used to offset the residual stress. The three work together to achieve three-level stress offset and ensure the stability of the mold.

[0036] Working principle

[0037] Fixed structure adjustment and adaptation assembly: Based on the overall height of the first half mold 2 and the second half mold 3 after assembly, manually adjust the telescopic support column 102 to change the distance between the base 101 and the top seat 103, so that the distance between the upper and lower limit grooves 104 matches the height of the mold assembly, complete the positioning adjustment before assembly, and improve the convenience of mold installation; after the adjustment is completed, the telescopic support column 102 is locked in a rigid support state to ensure the structural stability during use and provide a rigid foundation for subsequent stress compensation.

[0038] The first half mold 2 and the second half mold 3 are manually assembled along the mating surface, so that the first protrusion 204 and the second protrusion 307 of the second half mold 3 are initially engaged to form a complete irregular cold heading mold installation cavity, thus completing the assembly of the mold base and providing a carrier for the installation of the cold heading mold.

[0039] The overall insertion achieves initial stress cancellation: the first half mold 2 and the second half mold 3 are horizontally inserted along the upper and lower limiting grooves 104 of the fixed structure 1, so that the upper and lower outer walls of the assembly are in rigid contact with the inner wall of the limiting groove 104; during cold heading, the axial impact stress on the mold is transmitted to the base 101 and the top seat 103 through the outer wall of the assembly, and is distributed and borne by the rigid frame of the fixed structure 1, thus achieving initial stress cancellation, avoiding the impact stress from acting directly on the half mold assembly surface, and preventing early damage to the half mold assembly surface.

[0040] Manual drive achieves half-mold locking: Manually rotate the adjusting wheel 305, which drives the bidirectional screw 304 to rotate around its own axis. Since the two threads of the bidirectional screw 304 rotate in opposite directions, and the bearing seat 309 is connected to the bidirectional screw 304 and the limiting claw 306 is guided and constrained by the limiting groove, when the bidirectional screw 304 rotates, it drives the two bearing seats 309 to make relative horizontal displacement along the bidirectional screw 304, thereby driving the two limiting claws 306 to move towards the middle synchronously until the limiting claw 306 is tightly abutted against the contact block 203 of the first half-mold 2, completing the rigid locking of the first half-mold 2 and the second half-mold 3, preventing the half-mold from separating during the cold heading process.

[0041] The wedge-shaped surface engagement achieves secondary stress cancellation: while the limiting claw 306 abuts against the contact block 203, the wedge-shaped surfaces of the first protrusion 204 and the second protrusion 307 are embedded into each other's grooves, forming a large-area surface contact fit; during cold heading, the radial expansion stress on the mold pushes the first half mold 2 and the second half mold 3 to tend to separate. This tendency will drive the wedge-shaped surfaces to further fit tightly, forming a self-driven lock. The reverse support stress of the wedge-shaped surface and the radial expansion stress cancel each other out. At the same time, the surface contact fit disperses the local concentrated stress to the entire wedge-shaped surface, achieving secondary stress cancellation and avoiding mold cracking caused by the movement of the half mold splicing surface and local stress concentration.

[0042] The elastic element buffers and offsets residual stress: After the initial and secondary offsetting of the instantaneous impact stress during cold heading, a small amount of residual stress remains. When this residual stress is transmitted to the bearing seat 309, it will push the bearing seat 309 to slide slightly along the limiting groove 308 of the limiting claw 306, thereby compressing the elastic element 310. The elastic element 310 absorbs the residual impact energy through its own elastic deformation, converts the residual stress into elastic potential energy and releases it slowly, thereby offsetting the residual stress. After the stress is released, the elastic rebound force of the elastic element 310 drives the bearing seat 309 to reset, ensuring the locking accuracy of the limiting claw 306 and extending the service life of the mold.

[0043] Mold disassembly and maintenance: When it is necessary to replace or maintain the cold heading mold, rotate the adjusting wheel 305 in the opposite direction. The bidirectional screw 304 drives the two limiting claws 306 to move away from each other, releasing the abutment constraint between the limiting claws 306 and the contact block 203, so that the first half mold 2 and the second half mold 3 can be separated. If the height of the mold assembly does not match the limiting groove 104, the telescopic support column 102 can be adjusted again to achieve quick mold disassembly, reduce maintenance difficulty, and improve production efficiency.

[0044] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0045] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A stress-relief structure for a split-type combined irregular-shaped cold heading die, characterized in that, include: Fixed structure (1), first half mold (2), second half mold (3); The first half mold (2) and the second half mold (3) are assembled to form a complete irregular cold heading mold mounting cavity. The mounting cavity is inserted into the fixed structure (1) and is rigidly contacted with the fixed structure (1) to offset the initial stress. The first half mold (2) includes a first mold body (201), and pull rods (202) are fixed on both sides of the first mold body (201). An abutment block (203) is fixed on one end of the pull rod (202) away from the first mold body (201), and a first protrusion (204) is fixed on the side of the abutment block (203) facing the second half mold (3). The second half mold (3) includes a second mold body (301). Two symmetrically arranged fixing frames (302) are fixed on the side of the second mold body (301) facing the first half mold (2). A bidirectional screw (304) is rotatably connected between the two fixing frames (302). An adjusting wheel (305) is fixed in the middle of the bidirectional screw (304). Two limiting claws (306) are movably connected on the bidirectional screw (304). A second protrusion (307) is fixed on the side of the limiting claw (306) facing the abutting block (203). The limiting claw (306) abuts against the abutting block (203) to offset the secondary stress.

2. The stress-relief structure of the split-type combined irregular-shaped cold heading die according to claim 1, characterized in that, The fixed structure (1) includes a base (101), a support column (102), and a top seat (103). The base (101) and the top seat (103) are arranged in parallel. The support column (102) is connected between the base (101) and the top seat (103). The inner sides of the base (101) and the top seat (103) are provided with limiting grooves (104).

3. The stress-relief structure of the split-type combined irregular-shaped cold heading die according to claim 2, characterized in that, The support column (102) is a telescopic support column, and the two ends of the support column (102) are rigidly connected to the base (101) and the top seat (103) respectively.

4. The stress-relief structure of the split-type combined irregular-shaped cold heading die according to claim 1, characterized in that, A limiting strip (303) is fixed between the two fixed frames (302). The limiting strip (303) and the two fixed frames (302) together form a limiting groove. Part of the structure of the limiting claw (306) is embedded in the limiting groove and slides in cooperation with the limiting groove.

5. The stress-relief structure of the split-type combined irregular-shaped cold heading die according to claim 1, characterized in that, The limiting claw (306) has a limiting groove (308), and a bearing seat (309) is movably connected in the limiting groove (308). The bearing seat (309) is connected to the bidirectional screw (304).

6. The stress-relief structure of the split-type combined irregular-shaped cold heading die according to claim 5, characterized in that, An elastic element (310) is fixed between the bearing seat (309) and the inner wall of the limiting groove (308), and the elastic element (310) is used to offset residual stress.

7. The stress-relief structure of the split-type combined irregular-shaped cold heading die according to claim 1, characterized in that, The first protrusion (204) and the second protrusion (307) are interlocked, and their mating surfaces are wedge-shaped.

8. The stress-relief structure of the split-type combined irregular-shaped cold heading die according to claim 2, characterized in that, The limiting groove (104) on the base (101) is a blind groove, and the limiting groove (104) on the top seat (103) is coaxially aligned with the limiting groove (104) on the base (101).

9. The stress-relief structure of the split-type combined irregular-shaped cold heading die according to claim 1, characterized in that, The two sections of the bidirectional screw (304) have opposite threads, and the two limiting claws (306) are respectively connected to the threaded sections of the bidirectional screw (304) on both sides of the adjusting wheel (305).

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