Mold Structure for Improving the Life of the Mold Core

Abstract

The present invention relates to the technical field of cold heading and stamping, and discloses a die structure for improving the life of a die core. Through the setting of a separate alloy forming disc and an assembled die body, the die of the present invention can not only meet the life requirements, but also save a large amount of costs. At the same time, the cold heading oil filled in the die pad can be injected into the gap between the dies through the movement of the cylindrical module during stamping and the reciprocating movement of the ejector rod, so that an oil film with a protective buffering effect can be formed between the workpiece and the alloy forming disc and between the die gaps, cooling and bufferingly protecting the die, reducing the wear of the die, and improving the service life.

Description

Technical Field

[0001] The present invention relates to the technical field of cold heading and stamping, and specifically to a die structure for improving the life of a die core. Background Art

[0002] The processing of screw heads usually adopts the method of cold heading and stamping. Cold heading and stamping can carry out continuous automated production at high speed, and can quickly complete the forming and processing of screw heads. Compared with other traditional processing methods, cold heading and stamping can improve production efficiency and productivity, and meet the needs of mass manufacturing.

[0003] However, since the die used for cold heading and stamping needs to continuously apply high-speed pressure impacts, the life of the die core of the cold heading and stamping die is greatly tested. Existing high-strength alloys can effectively meet the needs of cold heading dies, but traditional integral dies require a large amount of alloy, resulting in increased costs. Moreover, traditional cold heading and stamping oils are usually directly applied to the stamping surface, which can only protect the stamping surface and cannot protect other impacted parts. Summary of the Invention

[0004] The purpose of the present invention is to provide a die structure for improving the life of a die core, so as to solve the problem of the relatively low life of the die core of the current traditional cold heading and stamping die proposed in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A die structure for improving the life of a die core, including a fixed die sleeve. A tapered groove is opened above the inner part of the fixed die sleeve. A tapered ring sleeve is arranged in the tapered groove. A cylindrical module is arranged in the tapered ring sleeve. A stepped groove is opened at the upper end of the cylindrical module. An alloy forming disk is arranged in the stepped groove. A forming groove is opened in the alloy forming disk. A thimble groove is opened at the center of the cylindrical module. A die pad is inserted into the lower end of the fixed die sleeve. A first oil injection groove is opened at the center of the die pad. Second oil injection grooves are opened around the lower part of the cylindrical module. Buffer springs are arranged in the second oil injection grooves. A one-way valve is arranged between the second oil injection groove and the first oil injection groove. A push thimble penetrates through the thimble groove and the first oil injection groove.

[0006] Further, an open ring gasket is arranged between the tapered groove and the tapered ring sleeve. The open ring gasket is made of brass and has an opening on one side.

[0007] Further, the alloy forming disk is made of tungsten titanium alloy, and a hard coating is deposited on the inner wall of the forming groove on the alloy forming disk. The coating is selected from one or more of titanium nitride coating, titanium aluminum nitride coating or thorium carbide coating.

[0008] Further, four pin holes are processed at equal intervals around the die cushion, threaded through holes are processed at corresponding positions on the fixed die sleeve, a threaded pin penetrates through the pin holes and the threaded through holes, and the threaded pin is threadedly connected to the threaded through hole.

[0009] Further, three threaded pins are provided, corresponding to three groups of pin holes and threaded through holes respectively. The fourth group of pin holes is communicated with the first oil injection groove through an oil injection hole, and a tubing joint is threadedly connected in the fourth group of pin holes and the threaded through holes. The middle section of the tubing joint is processed with threads, the outer end is processed with a flare fitting, the flare fitting is communicated with an oil delivery pipeline, and a rubber washer is arranged at one end in contact with the pin hole.

[0010] Further, a pressure stop valve is arranged above the oil injection hole. The pressure stop valve includes a telescopic groove. A telescopic groove communicating the second oil injection groove with the oil injection hole is opened in the die cushion. A telescopic valve rod is arranged in the telescopic groove. A return spring is arranged around the telescopic valve rod. A pressure relief hole is processed at the lower end of the telescopic valve rod.

[0011] Further, a second grid groove communicated with the second oil injection groove is processed on the upper end face of the die cushion. A third grid groove communicated with the second grid groove is processed on the side face of the die cushion. A fourth grid groove communicated with the second grid groove is processed on the outer wall of the conical ring sleeve. A fifth grid groove communicated with the second grid groove is processed on the inner wall of the fixed die sleeve.

[0012] Further, the upper end of the ejector rod is connected with a first plum blossom rod. The upper end of the first plum blossom rod is threadedly connected with an oil pushing valve. The upper end of the oil pushing valve is threadedly connected with a second plum blossom rod. The top end of the second plum blossom rod is threadedly connected with a rubber ejector rod cap.

[0013] Further, an oil passing groove is opened in the oil pushing valve. Six groups of annularly distributed oil inlet holes are opened at the lower part of the oil passing groove. Six groups of annularly distributed oil outlet holes are opened at the upper part of the oil passing groove. A movable metal valve plate is arranged in the oil passing groove. A pressure spring is arranged above the metal valve plate. A first oil passing groove is processed around the first plum blossom rod. The first oil passing groove is matched with the oil inlet holes. A second oil passing groove is processed around the second plum blossom rod. The second oil passing groove is matched with the oil outlet holes.

[0014] Further, a first grid groove is processed on the inner wall of the stepped groove on the cylindrical module. The lower end of the first grid groove is communicated with the ejector rod groove. The upper end of the first grid groove extends out from the gap between the cylindrical module and the alloy forming disc, and the upper plane of the alloy forming disc is lower than the alloy forming disc.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. By providing a separate alloy forming disk and an assembled die body, the stamping surface of the die is made of high-strength tungsten-titanium alloy material, which is sufficient to meet the service life requirement of more than 200,000 stampings. At the same time, the split die body can be made of ordinary carbon steel material, which can save a large amount of material costs.

[0017] 2. The present invention abandons the method of directly applying or spraying cold heading oil on the forming surface during the stamping gap in the traditional stamping process, and instead introduces the cold heading oil into the inside of the die cushion through a pipeline. The cold heading oil can be pushed into the second grid groove, the third grid groove, the fourth grid groove and the fifth grid groove by the reduction of the volume of the second oil injection groove during stamping, so as to form an oil film protection in the gap between the fixed die sleeve, the conical ring sleeve, the open ring gasket and the die cushion, improve the compression resistance and shock absorption and extend the service life. At the same time, the reciprocating movement of the existing ejector rod can also inject the cold heading oil into the gap between the alloy forming disk and the cylindrical module and flow into the forming groove of the alloy forming disk, so as to form an oil film with a protective and buffering effect between the workpiece and the alloy forming disk and between the alloy forming disk and the cylindrical module, buffer and protect the alloy forming disk, reduce the wear of the alloy forming disk and improve the service life.

[0018] 3. The present invention distributes the cold heading oil onto the alloy forming disk by pushing it out from the ejector rod groove. When the ejector rod is pushed outwards, the cold heading oil under pressure is used to push out the workpiece embedded in the forming groove, and the ejector rod itself will not come into direct contact with the workpiece, so that the wear of the ejector rod is greatly reduced and the service life of the ejector rod is extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic cross-sectional structure diagram of the present invention;

[0020] Figure 2 is a schematic external structure diagram of the present invention;

[0021] Figure 3 is a schematic three-dimensional cross-sectional structure diagram of the present invention;

[0022] Figure 4 is a schematic structure diagram of the stepped groove and the alloy forming disk of the present invention;

[0023] Figure 5 is a schematic structure diagram of the conical ring sleeve and the die cushion of the present invention;

[0024] Figure 6 is a schematic cross-sectional structure diagram of the fixed die sleeve of the present invention;

[0025] Figure 7 is the present invention Figure 1 magnified schematic structure diagram at A in;

[0026] Figure 8 Schematic diagram of the ejector rod structure for the present invention;

[0027] Figure 9 For the present invention Figure 8 Enlarged schematic diagram of the structure at position B in the present invention;

[0028] Figure 10 Schematic diagram of the oil pushing valve structure for the present invention.

[0029] Reference numerals in the figure: 1, fixed die sleeve; 2, tapered groove; 3, tapered ring sleeve; 4, split ring gasket; 5, cylindrical module; 6, stepped groove; 601, first grid groove; 7, alloy forming disc; 8, forming groove; 9, ejector rod groove; 10, die cushion; 11, pin hole; 12, threaded through hole; 13, threaded pin; 14, first oil injection groove; 15, second oil injection groove; 16, buffer spring; 17, one-way valve; 18, oil injection hole; 19, oil pipe joint; 20, pressure stop valve; 2001, telescopic groove; 2002, telescopic valve rod; 2003, return spring; 2004, pressure relief hole; 21, second grid groove; 22, third grid groove; 23, fourth grid groove; 24, fifth grid groove; 25, ejector rod; 26, first plum blossom rod; 2601, first oil passage groove; 27, oil pushing valve; 2701, oil passage groove; 2702, oil inlet hole; 2703, oil outlet hole; 2704, metal valve disc; 2705, pressure spring; 28, second plum blossom rod; 2801, second oil passage groove; 29, rubber ejector rod cap. Detailed implementation manners

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] To further understand the content of the present invention, the present invention will be described in detail in conjunction with the accompanying drawings.

[0032] Please refer to Figure 1 - Figure 3, A mold structure for improving the core life, including a fixed mold sleeve 1. A conical groove 2 is opened above the interior of the fixed mold sleeve 1. A conical ring sleeve 3 is arranged in the conical groove 2. A cylindrical module 5 is arranged in the conical ring sleeve 3. A ejector rod groove 9 is opened at the center of the cylindrical module 5. A mold pad 10 is inserted into the lower end of the fixed mold sleeve 1. Four pin holes 11 are equally spaced and machined around the mold pad 10. Threaded through holes 12 are machined at corresponding positions on the fixed mold sleeve 1. A threaded pin 13 passes through the pin holes 11 and the threaded through holes 12. The threaded pin 13 is threadedly connected to the threaded through hole 12. Thus, when the mold pad 10 is pushed into the fixed mold sleeve 1, a thrust can be applied to the conical ring sleeve 3, pushing the conical ring sleeve 3 into the conical groove 2. Thus, the conical ring sleeve 3 is squeezed by the conical groove 2, clamping the cylindrical module 5, and the cylindrical module 5 can in turn clamp the alloy forming disk 7 to achieve pre-tightening. An open ring gasket 4 is arranged between the conical groove 2 and the conical ring sleeve 3. The open ring gasket 4 is made of brass and has an opening on one side. It has good elasticity and extrusion deformation space, and can play a good filling support and buffering effect between the conical groove 2 and the conical ring sleeve 3. Through experiments, when the inner wall angle of the conical groove 2 in the conical groove 2 is 4 - 5 degrees, the pre-tightening force exerted by the conical groove 2 on the cylindrical module 5 can better achieve the fastening effect. Four pin holes 11 are equally spaced and machined around the mold pad 10. Threaded through holes 12 are machined at corresponding positions on the fixed mold sleeve 1. A threaded pin 13 passes through the pin holes 11 and the threaded through holes 12. The threaded pin 13 is threadedly connected to the threaded through hole 12. The mold pad 10 is positioned by inserting the threaded pin 13.

[0033] Please refer to Figure 3 , A stepped groove 6 is opened at the upper end of the cylindrical module 5. An alloy forming disk 7 is arranged in the stepped groove 6. A forming groove 8 is opened in the alloy forming disk 7. The alloy forming disk 7 is made of tungsten titanium alloy and has good high-pressure resistance and impact resistance. A hard coating is deposited and adhered to the inner wall of the forming groove 8 on the alloy forming disk 7. The coating is selected from one or more of titanium nitride coating, aluminum titanium nitride coating, or thorium carbide coating. The hard coating can protect the surface of the forming groove 8 and prevent the forming surface from collapsing or wearing due to long-term high-pressure contact with the workpiece, and can greatly improve the life of the alloy forming disk 7.

[0034] Please refer to Figure 1 - Figure 10, a first oil injection groove 14 is provided in the center of the die cushion 10. There are three threaded pins 13 in total, corresponding to three groups of pin holes 11 and threaded through holes 12 respectively. A tubing joint 19 is provided in the fourth group of pin holes 11 and threaded through holes 12. The fourth group of pin holes 11 is communicated with the first oil injection groove 14. The middle section of the tubing joint 19 is connected to the threaded through hole 12 by threads. The outer end is machined with a flare fitting to communicate with the oil delivery pipeline. A rubber washer is provided at one end in contact with the pin hole 11 for sealing. Thus, cold heading oil can be injected into the first oil injection groove 14 and flow into the second oil injection groove 15 through the one-way valve 17. During stamping, the cylindrical module 5 is compressed and retracted under pressure, compressing the buffer spring 16. At this time, the one-way valve 17 is closed. Therefore, the oil in the first oil injection groove 14 can only overflow through the second grid groove 21 and flow into the gap between the fixed die sleeve 1, the tapered ring sleeve 3 and the die cushion 10, and enter the gap between the fixed die sleeve 1 and the die cushion 10 through the third grid groove 22, enter the gap between the tapered ring sleeve 3 and the split ring gasket 4 through the fourth grid groove 23, enter the gap between the fixed die sleeve 1 and the split ring gasket 4 through the fifth grid groove 24, and form a protective oil film to reduce the impact force and wear. At the same time, it dissipates heat for the fixed die sleeve 1, the tapered ring sleeve 3, the split ring gasket 4 and the die cushion 10, which can greatly improve the service life of the die.

[0035] Please refer to Figure 8 - Figure 10, a ejector rod groove 9 and a first oil injection groove 14 are penetrated by an ejector rod 25. The ejector rod 25 is connected to a transmission device on a cold heading and stamping device, and is used to eject the stamped screw workpiece from the forming groove 8. The upper end of the ejector rod 25 is connected to a first plum blossom rod 26. The upper end of the first plum blossom rod 26 is threadedly connected to an oil pushing valve 27. The upper end of the oil pushing valve 27 is threadedly connected to a second plum blossom rod 28. The top end of the second plum blossom rod 28 is threadedly connected to a rubber ejector rod cap 29. An oil passing groove 2701 is formed in the oil pushing valve 27. Six groups of annularly distributed oil inlet holes 2702 are formed in the lower part of the oil passing groove 2701. Six groups of annularly distributed oil outlet holes 2703 are formed in the upper part of the oil passing groove 2701. A movable metal valve plate 2704 is arranged in the oil passing groove 2701. A pressure spring 2705 is arranged above the metal valve plate 2704. A first oil passing groove 2601 is machined around the first plum blossom rod 26. The first oil passing groove 2601 is matched with the oil inlet hole 2702. A second oil passing groove 2801 is machined around the second plum blossom rod 28. The second oil passing groove 2801 is matched with the oil outlet hole 2703. Thus, during stamping, the pressure in the first oil injection groove 14 increases, pushing the pressure stop valve 20 downward, and pushing the expansion valve rod 2002 in the expansion groove 2001 to compress the return spring 2003 and move downward, so as to insert into the oil injection hole 18, making the oil fluid can only flow through the narrow pressure relief hole 2004 at the lower end of the expansion valve rod 2002, increasing the pressure in the second oil injection groove 15. Thus, the cold heading oil will compress the pressure spring 2705 and push open the metal valve plate 2704, and enter the oil passing groove 2701 through the first oil passing groove 2601 and the oil inlet hole 2702, then enter the second oil passing groove 2801 through the oil outlet hole 2703, and thus flow above the rubber ejector rod cap 29. Then, with the ejection of the ejector rod 25, the metal valve plate 2704 blocks the oil injection hole 18 under the push of the pressure spring 2705. Thus, the pressure of the cold heading oil above the rubber ejector rod cap 29 increases to eject the workpiece, avoiding direct contact between the ejector rod 25 and the workpiece and causing wear.

[0036] Please refer to Figure 4 , a first grid groove 601 is machined on the inner wall of the stepped groove 6 on the cylindrical module 5. The lower end of the first grid groove 601 is communicated with the ejector rod groove 9. The upper end of the first grid groove 601 extends out from the gap between the cylindrical module 5 and the alloy forming disc 7, and the upper plane of the alloy forming disc 7 is lower than the alloy forming disc 7. Thus, when the rubber ejector rod cap 29 approaches the screw workpiece in the stepped groove 6, the cold heading oil in the ejector rod groove 9 will be squeezed into the first grid groove 601 and overflow from the upper end through the first grid groove 601. The cold heading oil at the upper end of the ejector rod groove 9 will infiltrate the gap between the alloy forming disc 7 and the stepped groove 6 through capillary action, and the cold heading oil overflowing from the opening of the first grid groove 601 will also flow back into the forming groove 8 from above, realizing the protection of the forming groove 8 and effectively improving the service life of the alloy forming disc 7.

[0037] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. The die structure for improving the core life, including a fixed die sleeve (1), is characterized in that: Above the inside of the fixed die sleeve (1), a conical groove (2) is provided. Inside the conical groove (2), a conical ring sleeve (3) is arranged. Inside the conical ring sleeve (3), a cylindrical module (5) is arranged. At the upper end of the cylindrical module (5), a stepped groove (6) is provided. Inside the stepped groove (6), an alloy forming disc (7) is arranged. Inside the alloy forming disc (7), a forming groove (8) is provided. In the center of the cylindrical module (5), a ejector rod groove (9) is provided. A die cushion (10) is inserted into the lower end of the fixed die sleeve (1). In the center of the die cushion (10), a first oil injection groove (14) is provided. Around the lower part of the cylindrical module (5), a second oil injection groove (15) is provided. Inside the second oil injection groove (15), a buffer spring (16) is arranged. A one-way valve (17) is arranged between the second oil injection groove (15) and the first oil injection groove (14). An ejector rod (25) penetrates through the ejector rod groove (9) and the first oil injection groove (14). On the upper end face of the die cushion (10), a second grid groove (21) communicating with the second oil injection groove (15) is machined. On the side face of the die cushion (10), a third grid groove (22) communicating with the second grid groove (21) is machined. On the outer wall of the conical ring sleeve (3), a fourth grid groove (23) communicating with the second grid groove (21) is machined. On the inner wall of the fixed die sleeve (1), a fifth grid groove (24) communicating with the second grid groove (21) is machined.

2. The mold structure for improving the core life according to claim 1, wherein: An open ring gasket (4) is arranged between the conical groove (2) and the conical ring sleeve (3). The open ring gasket (4) is made of brass and has an opening on one side.

3. The mold structure for improving the core life according to claim 1, characterized in that: The alloy forming disc (7) is made of tungsten titanium alloy. On the inner wall of the forming groove (8) on the alloy forming disc (7), a hard coating is deposited. The coating is selected from one or more of titanium nitride coating, titanium aluminum nitride coating, or thorium carbide coating.

4. The mold structure for improving the life of the lifting die core according to claim 1, characterized in that: Four pin holes (11) are machined equidistantly around the die cushion (10). At the corresponding positions on the fixed die sleeve (1), threaded through holes (12) are machined. A threaded pin (13) penetrates through the pin holes (11) and the threaded through holes (12). The threaded pin (13) is threadedly connected to the threaded through hole (12).

5. The mold structure for improving the core life according to claim 4, wherein: There are three threaded pins (13) in total, corresponding to three groups of pin holes (11) and threaded through holes (12) respectively. The fourth group of pin holes (11) is communicated with the first oil injection groove (14) through an oil injection hole (18). And a tubing joint (19) is threadedly connected in the fourth group of pin holes (11) and the threaded through hole (12). The middle section of the tubing joint (19) is machined with threads, and the outer end is machined with a flare fitting. The flare fitting is communicated with the oil delivery pipeline. A rubber gasket is arranged at the end in contact with the pin hole (11).

6. The mold structure for improving the core life according to claim 5, characterized in that: A pressure stop valve (20) is provided above the oil injection hole (18). The pressure stop valve (20) includes a telescopic groove (2001). A telescopic groove (2001) communicating the second oil injection groove (15) with the oil injection hole (18) is formed in the die pad (10). A telescopic valve rod (2002) is arranged in the telescopic groove (2001). A return spring (2003) is arranged around the telescopic valve rod (2002). A pressure relief hole (2004) is machined at the lower end of the telescopic valve rod (2002).

7. The mold structure for improving the core life according to claim 1, characterized in that: The upper end of the ejector rod (25) is connected with a first plum blossom rod (26). The upper end of the first plum blossom rod (26) is threadedly connected with an oil pushing valve (27). The upper end of the oil pushing valve (27) is threadedly connected with a second plum blossom rod (28). The top end of the second plum blossom rod (28) is threadedly connected with a rubber ejector rod cap (29).

8. The mold structure for improving the core life according to claim 7, characterized in that: An oil passing groove (2701) is formed in the oil pushing valve (27). Six groups of annularly distributed oil inlet holes (2702) are formed in the lower part of the oil passing groove (2701). Six groups of annularly distributed oil outlet holes (2703) are formed in the upper part of the oil passing groove (2701). A movable metal valve plate (2704) is arranged in the oil passing groove (2701). A pressure spring (2705) is arranged above the metal valve plate (2704). A first oil passing groove (2601) is machined around the first plum blossom rod (26). The first oil passing groove (2601) is matched with the oil inlet holes (2702). A second oil passing groove (2801) is machined around the second plum blossom rod (28). The second oil passing groove (2801) is matched with the oil outlet holes (2703).

9. The mold structure for improving the life of the lifting die core according to claim 1, characterized in that: A first grid groove (601) is machined on the inner wall of the stepped groove (6) on the cylindrical module (5). The lower end of the first grid groove (601) communicates with the ejector rod groove (9). The upper end of the first grid groove (601) extends out from the gap between the cylindrical module (5) and the alloy forming disc (7), and the upper plane of the alloy forming disc (7) is lower than the alloy forming disc (7).

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