Punch structure

Abstract

The utility model relates to a punch structure which comprises a cylindrical punch body. A plurality of groove bodies extending in the circumferential direction are formed in the outer circumferential side face of the punch body, copper alloy layers are fully laid in the groove bodies in an embedded mode, and the outer side faces, in the radial direction of the punch body, of the copper alloy layers are flush with the outer circumferential side face of the punch body. The groove bodies can be closed-ring-shaped groove bodies, all the groove bodies are arranged at intervals in the axial direction of the punch body, and the groove bodies extending in the circumferential direction can be integrally and spirally communicated with one another. According to the punch structure, the punch body made of cast iron can still be adopted, the copper alloy layer is overlaid in the groove body, the outer side face is processed to be flush and smooth, the abrasion resistance of the cylindrical face of the punch body in the using process can be greatly improved, the copper alloy layer is embedded in the groove body and restrained by the groove body, and the connection stability is good and the shape retention degree is high in the using process. According to the punch structure, the manufacturing cost is relatively low, the wear resistance of the punch is effectively improved, and the service life of the punch is prolonged.

Description

Technical Field

[0001] This utility model belongs to the technical field of pressure casting or jet casting in metal casting, and specifically relates to a punch structure. Background Technology

[0002] The injection punch is a key component in metal die casting production. During use, the injection punch pushes the molten alloy liquid into the melting cup, similar to the action of a piston. The gap between the injection punch and the inner wall of the melting cup is very small. The cylindrical surface of the injection punch is subjected to high temperature and flow impact, making it the part that wears the most. When the wear exceeds the allowable gap, the injection punch needs to be replaced.

[0003] Regarding how to improve wear resistance, some existing technologies have provided methods for improving the wear resistance of bearings, bushings, and bearing shells, such as the solutions disclosed in CN201344205Y, CN200982349Y, and CN210461403U. The common approach is to use a steel-based substrate and add a copper alloy layer on the steel substrate using methods such as metal molecular chain infiltration, atomic exchange, and powder metallurgy to improve wear resistance. The disadvantages are that the cost is high and the connection stability of the copper alloy layer is not good.

[0004] Injection punches are usually made of ductile iron, which is cheaper. However, ductile iron injection punches have a short lifespan due to wear. There are some solutions in the existing technology, such as CN209006644U and CN108746559A, which propose structural improvements on how to improve the wear resistance of the cylindrical surface of the injection punch and how to form a wear-resistant surface. However, the structural improvements are relatively complex and the manufacturing and use costs are not low. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the prior art, the technical problem to be solved by this utility model is to provide a punch structure that avoids the problem of poor wear resistance of the punch and achieves the effect of improving the service life of the punch.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A punch structure includes a cylindrical punch body; a plurality of circumferentially extending grooves are formed on the outer circumferential side of the punch body, and a copper alloy layer is fully embedded in the grooves, wherein the outer side of the copper alloy layer in the radial direction of the punch body is flush with the outer circumferential side of the punch body.

[0008] To further improve the above technical solution, the groove is a closed-loop annular groove, and all grooves are spaced apart along the axial direction of the punch body.

[0009] Alternatively, the plurality of circumferentially extending grooves may be integrally spirally connected grooves.

[0010] Furthermore, the punch body is made of cast iron, and the copper alloy layer fully covered in the tank is a copper alloy layer formed by copper welding. The copper alloy layer formed by copper welding is a copper alloy layer formed by welding in the tank. During manufacturing, gas welding, tungsten inert gas welding, thermal spraying welding, manual arc welding, etc. are used. The manual arc welding method with lower cost is preferred. The manual arc welding method is also a common iron-copper welding method. During the welding process, an appropriate electrode diameter and welding current intensity are selected, and the high temperature generated by the arc is used to melt the copper material and bond it with the cast iron matrix.

[0011] Furthermore, a recessed internal threaded hole is provided in the middle of one end face of the punch body, and the internal threaded hole is coaxial with the outer circumferential side surface of the punch body.

[0012] Furthermore, a recessed platform coaxial with the internal threaded hole is also recessed on the end face of the punch body, and the bottom wall of the recessed platform is perpendicular to the axis of the punch body.

[0013] Furthermore, a grinding tool is connected through the internal threaded hole. The grinding tool is cylindrical, with one end face adhering to the bottom wall of the countersink and an external threaded section protruding from the middle of the end face. The external threaded section is threadedly engaged with the internal threaded hole and tightened so that the end face of the grinding tool is adhering to the bottom wall of the countersink. A second center hole coaxial with the external threaded section is machined on the other end face of the grinding tool.

[0014] The other end face of the punch body is machined with a first center hole coaxial with the internal thread hole.

[0015] Furthermore, on the outer circumferential side of the punch body, near the end of the internal threaded hole, there is a flat rectangular section that facilitates screwing.

[0016] Furthermore, the flat rectangular segment is an outer hexagonal shape coaxial with the outer circumferential side surface of the punch body, and each vertex of the outer hexagon is lower than the outer circumferential side surface of the punch body.

[0017] Furthermore, several axially extending connecting grooves are opened on the outer circumferential side of the punch body. Each connecting groove corresponds to an adjacent groove in the axial direction, and the connecting grooves are staggered in the circumferential direction.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The punch structure of this utility model can still use a cast iron punch body. During manufacturing, a circular groove is directly formed or machined on the outer circumferential side. Then, a copper alloy layer is soldered into the groove. The outer side is treated to be flat and smooth, which can greatly improve the wear resistance of the cylindrical surface of the punch body during use. Furthermore, the copper alloy layer is embedded in the groove and constrained by the groove, resulting in good connection stability and high shape retention during use.

[0020] 2. The punch structure of this utility model is easy to manufacture, has a relatively low manufacturing cost, and effectively improves the wear resistance of the punch and extends its service life. Attached Figure Description

[0021] Figure 1 This is a cross-sectional schematic diagram of a punch structure according to Embodiment 1;

[0022] Figure 2 for Figure 1 The right view;

[0023] Figure 3 This is a schematic diagram of a punch structure according to Embodiment 1;

[0024] Figure 4 This is a cross-sectional schematic diagram of the punch structure in Embodiment 1, which is connected to a grinding tool and has a central hole.

[0025] Figure 5 This is a schematic diagram of a punch structure according to Embodiment 2;

[0026] Figure 6 This is a schematic diagram of a punch structure according to Embodiment 3;

[0027] Figure 7 A schematic diagram showing the addition of a connecting groove to a punch structure in Embodiment 3;

[0028] The punch body 1, annular groove 11, spiral connecting groove 12, internal threaded hole 13, countersunk platform 14, first center hole 15, flat square section 16, connecting groove 17, copper alloy layer 18, weight reduction groove 19, grinding tool 2, external threaded section 21, and second center hole 22. Detailed Implementation

[0029] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings.

[0030] Example 1

[0031] Please see Figures 1-3 A punch structure according to a specific embodiment includes a cylindrical punch body 1; a plurality of grooves extending circumferentially are provided on the outer circumferential side surface of the punch body 1, and a copper alloy layer 18 is fully embedded in the grooves, with the outer side surface of the copper alloy layer 18 in the radial direction of the punch body 1 being flush with the outer circumferential side surface of the punch body 1.

[0032] The groove is a closed-loop annular groove 11, and all grooves are spaced apart along the axial direction of the punch body 1. The punch body 1 is made of cast iron, and the copper alloy layer 18 that is fully covered in the groove is a copper alloy layer 18 that is brazed into the groove.

[0033] The punch structure in Embodiment 1 still uses a cast iron punch body 1. During manufacturing, a circular groove 11 is directly formed or machined into the outer circumferential side. Then, a copper alloy layer 18 is deposited and welded into the groove. The outer side is finished to be flush and smooth, which can greatly improve the wear resistance of the cylindrical surface of the punch body 1 during use. Furthermore, the copper alloy layer 18 is embedded in the groove and constrained by the groove, resulting in good connection stability and high shape retention during use. This punch structure has a relatively low manufacturing cost and effectively improves the wear resistance of the punch, extending its service life.

[0034] To facilitate manufacturing and use, a recessed internal threaded hole 13 is provided in the middle of one end face of the punch body 1, and the internal threaded hole 13 is coaxial with the outer circumferential side surface of the punch body 1.

[0035] This facilitates the connection of the actuating rod (not shown in the figure) of the push-pull punch body 1, and the detachable connection makes it easy to replace. During manufacturing, a weight-reducing groove 19 is also provided at the inner end of the internal threaded hole 13 inside the punch body 1. The diameter of the weight-reducing groove 19 is larger than the major diameter of the thread of the internal threaded hole 13, which facilitates the machining of the thread and reduces the material cost of the punch body 1.

[0036] Please see again. Figure 1 and Figure 4 The punch body 1 also has a recessed countersunk plate 14 coaxial with the internal threaded hole 13 on its end face. The bottom wall of the countersunk plate 14 is perpendicular to the axis of the punch body 1. A grinding tool 2 is connected through the internal threaded hole 13. The grinding tool 2 is cylindrical, with one end face adhering to the bottom wall of the countersunk plate 14 and an external thread section 21 protruding from the middle of the end face. The external thread section 21 is threaded into the internal threaded hole 13 and tightened so that the end face of the grinding tool 2 is adhering to the bottom wall of the countersunk plate 14. The other end face of the grinding tool is machined with a second center hole 22 coaxial with the external thread section 21. The other end face of the punch body 1 is machined with a first center hole 15 coaxial with the internal threaded hole 13.

[0037] In this way, the bottom wall of the sinker 14 is perpendicular to the axis of the punch body 1. After the grinding tool 2 is threadedly connected to the internal thread hole 13 of the punch body 1 through the external thread section 21 and tightened, the end face of the grinding tool 2 is completely and tightly attached to the bottom wall of the sinker 14, which can ensure the coaxiality of the second center hole 22 and the first center hole 15, and facilitate the implementation of the manufacturing process.

[0038] During manufacturing, in order to ensure that the copper alloy layer 18 is fully covered in the annular groove 11, the copper alloy layer 18, after being welded into the groove, is usually higher than (overflowing) the groove. It can be processed by grinding, with the two ends supporting the first center hole 15 and the second center hole 22 respectively, and the radial height of the copper alloy layer 18 is ground to be flush with the outer circumferential side of the punch body 1, while also ensuring the surface finish.

[0039] Please continue reading Figure 1 and Figure 2 On the outer circumferential side of the punch body 1, near the end of the internal threaded hole 13, there is a flat rectangular section 16 that facilitates screwing. In this way, when threadedly connecting the grinding tool 2 or the actuating rod, the flat rectangular section 16 can easily exert force to tighten the connection.

[0040] The flat rectangular segment 16 is an external hexagonal shape coaxial with the outer circumferential side surface of the punch body 1, with each vertex of the external hexagon lower than the outer circumferential side surface of the punch body 1. This not only facilitates tightening, but also allows the flat rectangular segment 16 of the external hexagonal shape to be clamped with a lathe's three-jaw chuck before grinding after the copper alloy layer 18 is deposited in the groove. This allows for the removal of excess copper alloy layer 18 that is higher than the groove, leaving a small amount (approximately 0.5 mm per side) of grinding allowance. This high turning efficiency avoids the problem of excessive grinding during the grinding process, improves manufacturing efficiency, and ensures surface quality.

[0041] Example 2

[0042] Please see Figure 5 The difference between Embodiment 2 and Embodiment 1 is that several axially extending connecting grooves 17 are also formed on the outer circumferential side of the punch body 1. Each connecting groove 17 corresponds to two adjacent annular grooves 11 connected axially, and the connecting grooves 17 are staggered in the circumferential direction. In this way, while ensuring the good shape and connection stability of the copper alloy layer 18, the wear resistance can be made more uniform. In this embodiment, there are two connecting grooves 17 symmetrically arranged at 180° between adjacent annular grooves 11, and the connecting grooves 17 on both sides of the annular groove 11 are staggered at 90°. During manufacturing, the connecting grooves 17 are formed at the same time or after the annular grooves 11 are formed. During copper soldering, the copper alloy layer 18 is deposited on each annular groove 11 and the connecting groove 17. Then, it is turned and ground until the outer side is flush with the outer circumferential side of the punch body 1.

[0043] Example 3

[0044] Please see Figure 6 The difference between Embodiment 3 and Embodiment 1 is that the plurality of circumferentially extending grooves are integrally spirally connected groove 12. This provides better continuity, facilitates the forming of the grooves through continuous turning, and ensures continuity when welding the copper alloy layer 18, allowing for uninterrupted welding in one go. This is highly suitable for automated mechanical processing, further improving manufacturing efficiency. The wear resistance is the same as described above.

[0045] During implementation, the overall spiral-shaped connecting groove 12 can also be as follows: Figure 7 As shown, connecting slots 17 are added and staggered in all directions around the perimeter. The same effect will not be described again here.

[0046] Finally, it should be noted that 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 preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A punch structure, comprising a cylindrical punch body; characterized in that: The outer circumferential side of the punch body has several grooves extending in the circumferential direction. The grooves are fully filled with a copper alloy layer. The outer side of the copper alloy layer in the radial direction of the punch body is flush with the outer circumferential side of the punch body.

2. The punch structure according to claim 1, characterized in that: The groove is a closed-loop annular groove, and all grooves are spaced apart along the axial direction of the punch body.

3. The punch structure according to claim 1, characterized in that: The plurality of circumferentially extending grooves form an integral spiral interconnected groove.

4. The punch structure according to claim 1, characterized in that: The copper alloy layer that fills the tank is a copper-welded copper alloy layer, and the punch body is made of cast iron.

5. The punch structure according to claim 1, characterized in that: A recessed internal threaded hole is provided in the middle of one end face of the punch body, and the internal threaded hole is coaxial with the outer circumferential side of the punch body.

6. The punch structure according to claim 5, characterized in that: The punch body also has a recessed countersunk plate that is coaxial with the internal threaded hole on this end face, and the bottom wall of the countersunk plate is perpendicular to the axis of the punch body.

7. The punch structure according to claim 6, characterized in that: A grinding tool is connected through the internal threaded hole. The grinding tool is cylindrical, with one end face adhering to the bottom wall of the countersink and an external thread section protruding from the middle of the end face. The external thread section is threaded into the internal threaded hole and tightened so that the end face of the grinding tool is adhering to the bottom wall of the countersink. A second center hole coaxial with the external thread section is machined on the other end face of the grinding tool. The other end face of the punch body is machined with a first center hole coaxial with the internal thread hole.

8. The punch structure according to claim 5, characterized in that: On the outer circumferential side of the punch body, near the end of the internal threaded hole, there is a flat rectangular section that is easy to screw.

9. The punch structure according to claim 8, characterized in that: The flat rectangular segment is an outer hexagonal shape coaxial with the outer circumferential side surface of the punch body, and each vertex of the outer hexagon is lower than the outer circumferential side surface of the punch body.

10. A punch structure according to any one of claims 1-9, characterized in that: Several axially extending connecting grooves are opened on the outer circumferential side of the punch body. Each connecting groove corresponds to two adjacent grooves in the axial direction, and the connecting grooves are staggered in the circumferential direction.

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