CNC (computer numerical control) punch for preventing tensile failure of high-strength steel

Abstract

The utility model relates to the technical field of metal stamping processing, in particular to a high-strength steel anti-snap CNC (computer numerical control) punch which comprises an upper die holder and an upper backing plate fixedly mounted at the bottom of the upper die holder, the punch adopts a circular truncated cone structure with an inclination angle of 2 degrees, micro taper is formed in the punching process, the contact area between the punch and a hole wall is reduced, and the punching quality is improved. The lateral tension brought by material resilience is reduced, the punch is effectively prevented from being snapped, stress distribution is optimized through the inclination angle, the fracture risk caused by stress concentration is avoided, the annular groove is matched with the oil discharging groove, lubricating oil evenly covers the surface of the punch and permeates into the hole wall during punching, friction resistance is greatly reduced, automatic oil supply is achieved through the built-in lubricating oil pump, and the service life of the punch is prolonged. Continuous and stable lubrication is ensured, manual maintenance requirements are reduced, a lubricating system reduces punch abrasion, the service life is prolonged, meanwhile, material adhesion caused by overheat friction is avoided, the punching precision and the surface smoothness are improved, an oil discharge groove is designed to assist the punch to exit smoothly, and die clamping or strain caused by insufficient lubrication is prevented.

Description

Technical Field

[0001] This utility model relates to the field of metal stamping technology, specifically to a high-strength steel CNC punch designed to prevent breakage. Background Technology

[0002] CNC punches are core components in computer numerical control (CNC) stamping processes, mainly used to punch holes, grooves, or other shapes on sheet metal (such as metal, plastic, etc.).

[0003] In the CNC stamping process of high-strength steel (such as automotive structural steel, mold steel, etc.), the punch is prone to breakage or tearing under high-speed impact due to material springback, high frictional resistance, or insufficient lubrication. Traditional punches are mostly cylindrical shoulder designs, with the punch held in place by countersunk holes in the clamping plate and the diameter of the shank fixing the position of the punch. During the punching process, due to the large frictional resistance between the punch and the sheet metal, especially when stamping high-strength steel, the material springback effect is obvious, which causes the punch to be subjected to a large lateral tensile force when it retracts, making it prone to breakage or accelerated wear. Ultimately, the punch may fall into the lower die and damage the die.

[0004] In addition, existing punch lubrication methods mostly involve external oil dripping or spraying of lubricant, which makes it difficult to form a stable oil film during the punching process. This results in a high coefficient of friction between the punch and the wall of the hole being punched, which not only affects the punching accuracy but also shortens the service life of the punch. Utility Model Content

[0005] In view of the above-mentioned shortcomings of the existing technology, the present invention provides a high-strength steel anti-fracture CNC punch, which can effectively solve the problems mentioned in the background technology.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] This utility model provides a high-strength steel anti-tensile breakage CNC punch, including an upper die base and an upper pad plate fixedly installed at the bottom of the upper die base, and further including: an upper pressure plate detachably installed at the bottom of the upper pad plate, the top of the upper pressure plate having an insertion hole extending through the bottom, the punch being detachably inserted into the insertion hole, and the bottom extending to the bottom of the upper pressure plate, the punch having a frustum-shaped design, and the inclination angle of the punch being 2°, the surface of the punch having an annular groove, and the bottom of the punch having several oil drain grooves extending through the annular groove, the lubrication assembly including a lubricating oil pump fixed to the outer wall of the upper pressure plate, the output end of the lubricating oil pump being connected to an oil drain pipe disposed inside the upper pressure plate and opposite to the position of the annular groove.

[0008] Furthermore, a limiting strip is vertically fixedly installed on the bottom of the upper pad, and two limiting grooves are opened on the top of the upper pressure plate, with the two limiting strips respectively inserted into the corresponding limiting grooves in a matching manner.

[0009] Furthermore, a first mating plate is fixedly installed on both sides of the upper pad, and bolts can be detachably installed on all four first mating plates.

[0010] Furthermore, a second mating plate is fixedly installed on both sides of the upper pressure plate, and the two second mating plates are connected to the corresponding first mating plates by bolts.

[0011] Furthermore, the bottom of the punch with the oil drain groove passes through the insertion hole and extends to the bottom of the upper pressure plate.

[0012] Furthermore, an annular oil cavity is formed between the insertion hole and the annular groove, and the annular oil cavity is connected to several oil drain grooves.

[0013] The technical solution provided by this utility model has the following advantages compared with the known prior art:

[0014] 1. The punch adopts a truncated cone structure with a 2° tilt angle, which forms a micro-taper during the punching process, reducing the contact area between the punch and the hole wall, reducing the lateral tensile force caused by material springback, effectively preventing the punch from breaking. The tilt angle optimizes the stress distribution and avoids the risk of fracture caused by stress concentration.

[0015] 2. The annular groove and the oil drain groove work together to make the lubricating oil evenly cover the surface of the punch and penetrate into the hole wall during punching to form a lubricating film, which greatly reduces frictional resistance. The built-in lubricating oil pump realizes automatic oil supply, ensuring continuous and stable lubrication and reducing the need for manual maintenance.

[0016] 3. The lubrication system reduces punch wear and extends service life. It also prevents material adhesion caused by excessive friction and heat, improves punching accuracy and surface finish. The oil drain groove design assists in the smooth withdrawal of the punch and prevents jamming or tearing caused by insufficient lubrication. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall assembly structure of this utility model;

[0019] Figure 2 This is a schematic diagram of the overall disassembled structure of this utility model;

[0020] Figure 3This is a schematic diagram of the upper pressure plate structure of this utility model;

[0021] Figure 4 This is a schematic diagram of the punch and lubrication assembly structure of this utility model.

[0022] The labels in the diagram represent:

[0023] 1. Upper mold base;

[0024] 2. Upper pad; 21. Limiting strip; 22. First mating plate; 23. Bolt;

[0025] 3. Upper pressure plate; 31. Limiting groove; 32. Second mating plate; 33. Insertion hole;

[0026] 4. Punch; 41. Annular groove; 42. Oil drain groove;

[0027] 51. Lubricating oil pump; 52. Oil drain pipe. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0029] The present invention will be further described below with reference to the embodiments.

[0030] Example 1:

[0031] Reference Figure 1-4 This is the first embodiment of the present utility model, which discloses a high-strength steel anti-tear-break CNC punch, including an upper die base 1 and an upper pad 2 fixedly installed at the bottom of the upper die base 1. It also includes an upper pressure plate 3 detachably installed at the bottom of the upper pad 2. The top of the upper pressure plate 3 has an insertion hole 33 through the bottom. The punch 4 is detachably inserted into the insertion hole 33. The punch 4 is designed to be compatible with the insertion hole 33. When the punch 4 is fully inserted into the insertion hole 33, the top of the punch 4 is flush with the upper opening of the insertion hole 33. At the same time, the top of the punch 4 abuts against the bottom of the upper pad 2, and the bottom extends to the bottom of the upper pressure plate 3.

[0032] The punch 4 is a frustum-shaped design with an inclination angle of 2°. A ring groove 41 is formed on the surface of the punch 4, and several oil drain grooves 42 are formed through the ring groove 41 at the bottom. The lubrication assembly includes a lubricating oil pump 51 fixed to the outer wall of the upper pressure plate 3. The output end of the lubricating oil pump 51 is connected to an oil drain pipe 52 located inside the upper pressure plate 3 and opposite to the ring groove 41. The discharged lubricating oil is directly sprayed into the lubricating oil chamber and evenly distributed on the workpiece surface due to gravity.

[0033] Example 2:

[0034] Reference Figure 1-4 This is the second embodiment of the present invention. The difference between this embodiment and the first embodiment is that: a limiting strip 21 is vertically fixedly installed on the bottom of the upper pad 2, and two limiting grooves 31 are opened on the top of the upper pressure plate 3. The two limiting strips 21 are respectively inserted into the corresponding limiting grooves 31 to facilitate the quick docking between the upper pad 2 and the upper pressure plate. First docking plates 22 are fixedly installed on both sides of the upper pad 2. Bolts 23 can be detachably installed on all four first docking plates 22. Second docking plates 32 are fixedly installed on both sides of the upper pressure plate 3. The two second docking plates 32 are docked with the corresponding first docking plates 22 by bolts 23. Through holes are opened on both second docking plates 32. After the bolts 23 pass through the first docking plates 22 and the through holes, they are locked and fixed, thus completing the temporary fixation between the first docking plates 22 and the second docking plates 32, and thus completing the temporary fixation between the upper pad 2 and the upper pressure plate 3.

[0035] The bottom of the punch 4, which is equipped with an oil drain groove 42, passes through the insertion hole 33 and extends to the bottom of the upper pressure plate 3. An annular oil cavity is formed between the insertion hole 33 and the annular groove 41. The annular oil cavity is connected to several oil drain grooves 42. The injection of lubricating oil realizes low-resistance punching and safe withdrawal during the high-strength steel punching process.

[0036] The remaining structure is the same as that in Example 1.

[0037] The working process of the high-strength steel anti-pull-out CNC punch of the present invention can be divided into a punching stage and a return stage. Combined with the synergistic effect of the lubrication components, it ensures the stable operation of the punch during high-strength punching and reduces the risk of pull-out.

[0038] 1. Stamping stage (downward stamping process)

[0039] When the CNC machine tool drives the upper die holder 1 to move downwards, the punch 4 impacts the high-strength steel plate downwards. The specific process is as follows:

[0040] a: Punch contacts the plate

[0041] The frustum design of punch 4 makes its bottom contact the plate first. Due to the 2° tilt angle of the punch, a small gap is formed between its side wall and the hole wall of the plate, reducing the initial contact stress. This tilt angle optimizes the force distribution and avoids the instantaneous high frictional resistance caused by the full circumferential contact of the traditional cylindrical shoulder punch.

[0042] b: Punching process

[0043] As the punch 4 continues to press down, the sheet metal is sheared to form a hole. Due to the tapered design of the punch 4, the sheet metal gradually adapts to the shape of the punch during plastic deformation, reducing the pressure of material springback on the side wall. The lubricating oil in the annular groove 41 is squeezed during the punching process, and some of the lubricating oil seeps out through the oil drain groove 42, forming a lubricating film between the punch 4 and the hole wall, reducing the coefficient of friction.

[0044] c. The punch is completely penetrated.

[0045] After punch 4 completely penetrates the plate, the contact area between the plate hole wall and the punch side wall is reduced due to the 2° tilt angle, avoiding the clamping phenomenon caused by material rebound.

[0046] 2. Return phase: the process of the thruster exiting the circuit.

[0047] After punching is completed, the CNC machine tool drives the upper die holder 1 to rise, and the punch 4 exits from the hole in the sheet metal. The key at this stage is to reduce the draft resistance and prevent it from breaking.

[0048] a: Lubrication assistance disengagement

[0049] During the return stroke, the lubricating oil pump 51 continues to supply oil. The lubricating oil enters the annular groove 41 through the oil drain pipe 52 and is evenly distributed along the oil drain groove 42 to the contact surface between the punch and the hole wall. The continuous supply of lubricating oil ensures that the punch 4 always maintains a low friction state during the withdrawal process, avoiding jamming or scoring caused by dry friction.

[0050] b: Taper-optimized stress distribution

[0051] Because punch 4 has a 2° tilt angle, during the return stroke, the clamping force of the hole wall on punch 4 is gradually released as the punch rises, rather than applying all the tension instantly, which greatly reduces the risk of breakage. Compared with the traditional cylindrical shoulder punch head, this design can reduce the draft resistance by about 30% and significantly improve the punch life.

[0052] c. Chip removal and lubrication cycle

[0053] Metal shavings generated during the stamping process may affect the lubrication effect, but due to the distribution design of the oil drain groove 42, the lubricating oil can carry the shavings out, avoiding the accumulation of shavings and causing secondary friction. The lubrication system adopts a circulating oil supply mode to ensure continuous and effective lubrication during long-term processing.

[0054] 3. Synergistic effect of lubrication components

[0055] a: Automatic oil supply: The lubricating oil pump 51 adjusts the oil supply according to the stamping frequency to ensure that an appropriate amount of lubricating oil enters the annular groove 41 for each stamping.

[0056] b: Uniform lubrication: The oil drain grooves 42 are radially distributed, so that the lubricating oil can cover the entire punching area and avoid friction hot spots caused by insufficient local lubrication;

[0057] c: Anti-dry friction protection: During continuous stamping, the lubrication system can prevent the oil film from breaking due to temperature rise, ensuring that the punch 4 always works in a low friction state.

[0058] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model 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. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of this utility model.

Claims

1. A high-strength steel anti-fracture CNC punch, characterized in that, Including an upper mold base (1) and an upper pad (2) fixedly installed at the bottom of the upper mold base (1), and also including: The upper pressure plate (3) is detachably installed at the bottom of the upper pad plate (2); The punch (4) is detachably inserted into the upper pressure plate (3) and its bottom extends to the bottom of the upper pressure plate (3). A ring groove (41) is formed on the surface of the punch (4), and a number of oil drain grooves (42) are formed through the ring groove (41) at the bottom of the punch (4). The lubrication assembly includes a lubricating oil pump (51) fixed to the outer wall of the upper pressure plate (3), and the output end of the lubricating oil pump (51) is connected to an oil drain pipe (52) disposed in the upper pressure plate (3) and opposite to the position of the annular groove (41).

2. The high-strength steel anti-tensile fracture CNC punch according to claim 1, characterized in that, The bottom of the upper pad (2) is vertically fixed with a limiting strip (21), and the top of the upper pressure plate (3) is provided with two limiting grooves (31).

3. A high-strength steel anti-tensile fracture CNC punch according to claim 2, characterized in that, The two limiting strips (21) are respectively inserted into the corresponding limiting grooves (31) in a matching manner.

4. A high-strength steel anti-tensile fracture CNC punch according to claim 3, characterized in that, Both sides of the upper pad (2) are fixedly installed with first docking plates (22), and bolts (23) can be detachably installed on each of the four first docking plates (22).

5. A high-strength steel anti-tensile fracture CNC punch according to claim 1, characterized in that, The upper pressure plate (3) is fixedly installed with a second docking plate (32) on both sides.

6. A high-strength steel anti-tensile fracture CNC punch according to claim 5, characterized in that, The two second docking plates (32) are connected to the corresponding first docking plates (22) by bolts (23).

7. A high-strength steel anti-tensile fracture CNC punch according to claim 1, characterized in that, The top of the upper pressure plate (3) has a through hole (33) extending to the bottom, and the punch (4) can be detachably inserted into the through hole (33).

8. A high-strength steel anti-tensile fracture CNC punch according to claim 7, characterized in that, An annular oil cavity is formed between the insertion hole (33) and the annular groove (41), and the annular oil cavity is connected to several oil drain grooves (42).

9. A high-strength steel anti-tensile fracture CNC punch according to claim 8, characterized in that, The bottom of the punch (4) with the oil drain groove (42) passes through the insertion hole (33) and extends to the bottom of the upper pressure plate (3).

10. A high-strength steel anti-tensile fracture CNC punch according to claim 1, characterized in that, The punch (4) is a frustum-shaped design, and the inclination angle of the punch (4) is 2°.

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