Cold heading forming process of conical forge piece

Abstract

According to the cold heading forming process of the conical forge piece, the forming procedures of the forge piece are reasonably designed, in the first step, a raw material piece is cut and formed, in the second step and the third step, the raw material piece is subjected to chamfering and first shrinkage rod section preforming, and in the fourth step, a second step rod section is formed so that follow-up clamp stress clamping can be facilitated; in the fifth step, an inner hole is formed firstly, a convex shoulder and the like are formed in the follow-up steps, the situation that when the inner hole is formed, size deformation of other parts is caused, a first shrinkage rod section needs to be clamped and moved by a clamp, and finally forming is carried out is avoided, clamping is not needed at the moment, the influence on the size or shape of a product in the clamping process is reduced, and under the forming technology, the yield of the forge piece is high.

Description

Technical Field

[0001] The invention relates to the technical field of cold heading, in particular to a cold heading process for a tapered forging. Background Art

[0002] like Figure 1 The forging shown is mainly used in the receiving parts of drill bit excavation equipment. It is mainly formed by cold heading process. However, due to the problem of the corresponding structure forming sequence on the forging, the yield of the forging is not high and needs to be improved. Summary of the Invention

[0003] To solve at least one of the above technical deficiencies, the present invention provides the following technical solutions:

[0004] This application document discloses a cold heading forming process for a tapered forging, comprising the following steps:

[0005] The first step is to cut out the raw material of the required size for forging;

[0006] The second step is to chamfer the tail of the raw material, i.e. preformed part 1;

[0007] Step 3: Using a cold heading process, the lower shaft diameter of the preformed part 1 is reduced to form a first shrinkage section, i.e., the preformed part 2;

[0008] Step 4: Using a cold heading process, the diameter of the shaft above the first shrinkage section in the preformed part 2 is reduced to form a second step section, i.e., the preformed part 3;

[0009] Step 5: forming an inner hole on the end face of the first end of the preformed part 3 and reducing the shaft diameter of the first end of the preformed part 3, i.e., preformed part 4;

[0010] Step 6: Using a cold heading process, the overall length of the preformed part 4 is shortened, and the shaft between the upper part of the second step rod section and the head end where the inner hole is located is expanded and a shoulder is formed at intervals. Simultaneously, the taper of the upper peripheral wall of the shoulder at the upper part is made consistent with the taper of the lower part of the head end where the inner hole is located, and the second step rod section is tapered, i.e., the preformed part 5.

[0011] Step 7: Through the cold forging process, the first shrinkage rod section and the second step rod section in the preformed part 5 are connected to form a cone shape, so that the length of the preformed part 5 is shortened and the tail end of the preformed part 5 is expanded to be larger than the diameter of the tail end of the cone, that is, the required forging.

[0012] In this scheme, the forming process of forgings is reasonably designed. In the first step, the raw material is cut and formed. In the second and third steps, the raw material is pre-formed with chamfers and the first reduced rod section is pre-formed. In the fourth step, the second step rod section is formed to facilitate the subsequent clamping. In the fifth step, the inner hole is first formed and the boss is formed in the subsequent steps to avoid dimensional deformation of other parts when forming the inner hole. The first reduced rod section needs to be clamped and moved by the clamp, which is left to the last forming. At this time, clamping is no longer required, reducing the impact of the clamping process on the size or shape of the product. Under this forming process, the yield rate of forgings is high.

[0013] Furthermore, in the second step, the bottom end of the raw material is extruded and chamfered by the impact of the punch, which is convenient for operation through the cold heading die and does not require the installation of other chamfering devices in the workshop.

[0014] Furthermore, in the fifth step, an inner hole is formed on the top of the preform three by a punch, which is convenient for operation through a cold heading die, and no other hole-making device is required in the workshop.

[0015] Furthermore, the mold used in the cold heading process includes a bottom mold and a movable mold. The bottom mold includes a lower mold outer sleeve, a lower mold middle sleeve, a mold pad, a mold core, and a punch rod. A mold pad is provided at the bottom opening of the lower mold outer sleeve. The lower mold middle sleeve is elastically and telescopically connected to the lower mold outer sleeve cavity. The lower mold middle sleeve has a tapered hole cavity and the hole cavity is axially slidably connected to the mold core. The mold core is composed of multiple mold pieces, and the adjacent mold pieces are elastically connected to reset to an open state. The mold pad is provided with a mold cavity and an alloy sleeve is provided at the head end cavity of the mold cavity. The punch rod is in the mold cavity of the mold pad and its end extends into the cavity of the alloy sleeve. A thick push pad is provided at the tail end of the punch rod. The mold is reasonably designed to facilitate the forming of the first shrinkage section.

[0016] Furthermore, the movable mold includes an upper mold sleeve, an ejector pin, a sleeve, a second punch rod, a positioning plate, a fixed ring, and a thick pad. The positioning plate, the fixed ring, and the thick pad are fixed in the upper mold sleeve cavity. The fixed ring is sleeved on the sleeve and the two are slidably matched. The positioning plate is located between the thick pad and the fixed ring. The sleeve is sleeved on the second punch rod and the two are slidably matched. An ejector pin is provided at the tail end of the sleeve, and a second thick pusher pad is provided at the tail end of the second punch rod to facilitate the forming of the inner hole of the forging head.

[0017] Furthermore, the middle interval of the forging is provided with a shoulder, a groove is formed between the two shoulders, the forging is in the shape of a contracted rod above the upper shoulder, and the forging is in the shape of a contracted rod below the lower shoulder. The tail of the forging is expanded outward, and the head end face of the forging forms an inner hole.

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

[0019] 1. The present invention rationally designs the forming process of forgings, which can improve the yield rate of forgings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 It is a structural diagram of this forging;

[0022] Figure 2 It is a structural diagram of the cold heading die;

[0023] Figure 3 It is a structural diagram of the raw material part and the preformed part;

[0024] Figure 4 Schematic diagram of the structure of preform 2 and preform 3;

[0025] Figure 5 1 is a schematic diagram of the structure of preform four and preform five;

[0026] Figure 6 It is a structural diagram of this forging;

[0027] Wherein, the accompanying drawings are marked as follows:

[0028] 1. Moving mold; 2. Bottom mold; 3. Boss; 4. Inner hole; 11. Upper mold outer sleeve; 12. Fixing ring; 13. Ejector pin; 14. Punch rod 2; 15. Sleeve; 16. Positioning plate; 17. Thick pad; 18. Pusher thick pad 2; 21. Lower mold outer sleeve; 22. Lower mold middle sleeve; 23. Lower mold cover; 24. Mold core; 25. Spring; 26. Punch rod 1; 27. Mold pad; 28. Alloy sleeve; 29. ​​Pusher thick pad 1. DETAILED DESCRIPTION

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

[0030] Example 1

[0031] The structure of the forging is as follows Figure 1 As shown, the middle interval of the forging is provided with a shoulder 3, and a groove is formed between the two shoulders 3. The forging is in the shape of a contracted rod above the upper shoulder and in the shape of a contracted rod below the lower shoulder. The tail of the forging is expanded outward, and the head end face of the forging is formed with an inner hole.

[0032] The basic configuration of the cold heading die used is as follows Figure 2As shown, it includes a bottom mold 2 and a movable mold 1. The bottom mold 2 includes a lower mold outer sleeve 21, a lower mold middle sleeve 22, a mold pad 27, a mold core 24, and a punch 26. The mold pad 27 is fixed at the bottom opening of the lower mold outer sleeve 21, and the lower mold middle sleeve 22 is elastically and telescopically connected to the head end cavity of the lower mold outer sleeve 21 through a spring. The lower mold middle sleeve 22 has a tapered hole and the hole is axially slidably connected to the mold core 24. The mold core is composed of four common mold petals. Adjacent mold petals are also elastically connected by springs. The springs are used to reset the mold petals to the open state (for the connection structure of the spring, please refer to the solution described in CN102248109A patent).

[0033] The die pad 27 is provided with a die cavity and an alloy sleeve 28 is fixed at the head end of the die cavity. A punch rod 26 is in the die cavity of the die pad 27 and its head end extends into the cavity of the alloy sleeve 28. A thick pusher pad 29 is placed at the tail end of the punch rod 26. The configuration of the die flap in the die core can be changed to make the corresponding part of the forging have the required configuration.

[0034] The movable die 1 includes an upper die sleeve 11, an ejector pin 13, a sleeve 15, a second punch 14, a positioning plate 16, a fixing ring 12, and a thick pad 17. The positioning plate 16, the fixing ring 12, and the thick pad 17 are fixed in the cavity of the upper die sleeve 11. The fixing ring 12 is sleeved on the sleeve 15 and the two are slidably matched. The positioning plate 16 is located between the thick pad 17 and the fixing ring 12, and the thick pad is supported by the positioning plate. The sleeve 15 is sleeved on the second punch 14 and the two are slidably matched. The tail end of the sleeve 15 is equipped with an ejector pin 13, such as three ejectors, which push the sleeve forward to facilitate the removal of the forging. The tail end of the second punch is equipped with a second thick pad 18 for pushing the material.

[0035] The cold heading process of tapered forgings includes the following steps:

[0036] The first step is to cut out the raw material of the required size of the forging through the knife die, such as Figure 3 shown.

[0037] The second step is to place the raw material on the corresponding cold heading die, press down with the punch rod 2, and make the tail of the raw material be extruded and chamfered with the cooperation of the corresponding die core, that is, preformed part 1, such as Figure 3 shown.

[0038] The third step is to place the preform 1 on the corresponding cold heading die, press down with the punch 2, and reduce the lower shaft diameter of the preform 1 with the cooperation of the corresponding die core to preform the first shrinkage section, i.e., the preform 2. Figure 4 shown.

[0039] The fourth step is to reduce the diameter of the shaft above the first shrinkage section in the preform 2 by cold heading process to form the second step section, that is, the preform 3. Figure 4 shown.

[0040] The fifth step is to place the preform part 3 on the corresponding cold heading die, and use the punch 2 to press down to impact the end face of the preform part 3 to form a concave hole. The inner hole is formed and the shaft diameter of the head end of the preform part 3 is reduced, that is, the preform part 4. Figure 5 shown.

[0041] The sixth step is to place the preformed part 4 at the corresponding cold heading die, press down with the punch 2, and shorten the overall length of the preformed part 4 through the cold heading process with the cooperation of the corresponding die core, and expand the shaft between the head end of the second step rod section and the inner hole to form a shoulder at intervals, and form a groove between the two shoulders. At the same time, the upper peripheral wall of the upper shoulder is made consistent with the taper of the lower part of the head end of the inner hole, and the second step rod section is tapered, that is, the preformed part 5. Figure 5 shown.

[0042] The seventh step is to place the preform 5 at the corresponding cold heading die, press down with the punch 2, and connect the first shrinkage rod section and the second step rod section of the preform 5 to form a cone shape through the cold heading process with the cooperation of the corresponding die core, so that the length of the preform 5 is shortened and the tail end of the preform 5 is expanded to be larger than the tail diameter of the cone, that is, the required forging, such as Figure 1 、 Figure 6 shown.

[0043] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions based on the principles of the present invention are within the scope of protection of the present invention. It should be noted that improvements and modifications that do not depart from the principles of the present invention are within the scope of protection of the present invention.

Claims

1. The cold heading process of tapered forgings is characterized by: The following steps are involved: The first step is to cut out the raw material of the required size for forging; The second step is to chamfer the tail of the raw material, i.e. preformed part 1; Step 3: Using a cold heading process, the lower shaft diameter of the preformed part 1 is reduced to form a first shrinkage section, i.e., the preformed part 2; Step 4: Using a cold heading process, the diameter of the shaft above the first shrinkage section in the preformed part 2 is reduced to form a second step section, i.e., the preformed part 3; Step 5: forming an inner hole on the end face of the first end of the preformed part 3 and reducing the shaft diameter of the first end of the preformed part 3, i.e., preformed part 4; Step 6: Using a cold heading process, the overall length of the preformed part 4 is shortened, and the shaft between the upper part of the second step rod section and the head end where the inner hole is located is expanded and a shoulder is formed at intervals. Simultaneously, the taper of the upper peripheral wall of the shoulder at the upper part is made consistent with the taper of the lower part of the head end where the inner hole is located, and the second step rod section is tapered, i.e., the preformed part 5. Step 7: Through the cold forging process, the first shrinkage rod section and the second step rod section in the preformed part 5 are connected to form a cone shape, so that the length of the preformed part 5 is shortened and the tail end of the preformed part 5 is expanded to be larger than the diameter of the tail end of the cone, that is, the required forging.

2. The cold heading forming process for a tapered forging according to claim 1, wherein: In the second step, the bottom end of the raw material is extruded and chamfered by the impact of the punch.

3. The cold heading forming process for a tapered forging according to claim 1, wherein: In the fifth step, an inner hole is formed on the top of the preform three by a punch.

4. The cold heading forming process for a tapered forging according to claim 1, wherein: The mold used in the cold heading process includes a bottom mold (2) and a movable mold (1), the bottom mold (2) includes a lower mold outer shell (21), a lower mold middle shell (22), a mold pad (27), a mold core (24), and a punch rod (26), a mold pad (27) is set at the bottom opening of the lower mold outer shell, the lower mold middle shell (22) is elastically and telescopically connected to the cavity of the lower mold outer shell (21), the lower mold middle shell (22) has a tapered hole cavity and the hole cavity is axially slidably connected to the mold core (24), the mold core is composed of multiple mold halves, and the adjacent mold halves are elastically connected to reset to an open state, the mold pad (27) has a mold cavity and an alloy sleeve (28) is set at the head end of the mold cavity, the punch rod (26) is in the mold cavity of the mold pad and its end extends into the cavity of the alloy sleeve, and a thick push pad (29) is set at the tail end of the punch rod.

5. The cold heading forming process for a tapered forging according to claim 4, wherein: The movable mold (1) includes an upper mold outer shell (11), an ejector pin (13), a sleeve (15), a second punch rod (14), a positioning plate (16), a fixing ring (12), and a thick pad (17). The positioning plate (16), the fixing ring (12), and the thick pad (17) are fixed in the cavity of the upper mold outer shell (11). The fixing ring (12) is sleeved on the sleeve (15) and the two are slidably matched. The positioning plate (16) is located between the thick pad (17) and the fixing ring (12). The sleeve (15) is sleeved on the second punch rod (14) and the two are slidably matched. The tail end of the sleeve (15) is provided with an ejector pin (13), and the tail end of the second punch rod is provided with a second pusher thick pad (18).

6. The cold heading forming process for a tapered forging according to claim 1, wherein: The middle interval of the forging is provided with a shoulder (3), a groove is formed between the two shoulders, the forging is in a contracted rod shape above the upper shoulder, and the forging is in a contracted rod shape below the lower shoulder, the tail of the forging is expanded outward, and the head end face of the forging forms an inner hole (4).

Images