A powder metallurgical method for preparing helical gears with asymmetric bosses and a mold for producing helical gears.

Abstract

This utility model relates to the field of powder metallurgy preparation of helical gears, specifically to a powder metallurgy preparation of a helical gear with asymmetric bosses and a helical gear production mold. The helical gear includes a helical gear body, a first cam boss, and a second cam boss. The center of the helical gear body is provided with a circular hole. The right side of the helical gear body is integrally formed and connected to the first cam boss. The left side of the helical gear body is integrally formed with the helical gear body with a mounting groove. The second cam boss is inserted into the mounting groove. The second cam boss is welded to the helical gear body through circumferentially arranged welding blocks. The first cam boss and the second cam boss are provided with through holes coaxial with the circular hole. The helical gear production mold includes a helical gear body, a first cam boss forming mold, a second cam boss forming mold, and a welding block forming mold. It has the advantages of simple structure, material saving, low cost, and good forming effect.

Description

Technical Field

[0001] This utility model relates to the field of powder metallurgy preparation of helical gears, specifically to a powder metallurgy preparation of helical gears with asymmetric bosses and a helical gear production mold. Background Technology

[0002] As is well known, powder metallurgy helical gears are a standard product in powder metallurgy parts, accounting for more than 30% of the total usage in the reciprocating saw industry, and their design directly affects product quality. Therefore, a reasonable design is crucial for service life.

[0003] When helical gears are used in harsh working conditions of high temperature and high speed, wear resistance is the main factor affecting the life of reciprocating saws. The larger the helix angle of the helical gear, the better the durability of the reciprocating saw under the same conditions. From the perspective of helical gear manufacturing, the larger the helix angle, the shorter the mold life and the higher the product manufacturing cost.

[0004] Currently, the structure of asymmetrical helical gears includes a helical gear body, with cam-structured bosses on both sides of the helical gear body. The cam-structured bosses on both sides of the helical gear body are asymmetrical. The current production method is to design symmetrical cylindrical bosses on both sides of the helical gear body. After molding, the cylindrical bosses on both sides are cut into asymmetrical bosses by mechanical cutting. This process results in serious material waste, high cost, and low cutting precision, leading to poor gear structure molding effect. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a powder metallurgy method for preparing helical gears with asymmetric bosses and a helical gear production mold that is simple in structure, saves materials, has low cost and good forming effect.

[0006] The technical solution adopted by this utility model to solve its technical problem is: A helical gear with asymmetric bosses prepared by powder metallurgy is characterized in that the helical gear includes a helical gear body, a first cam boss, and a second cam boss. The center of the helical gear body is provided with a circular hole. The right side of the helical gear body is integrally formed and connected with the first cam boss. The left side of the helical gear body is integrally formed with the helical gear body with a mounting groove. The second cam boss is inserted into the mounting groove. The second cam boss is welded to the helical gear body through circumferentially arranged welding blocks. The first cam boss and the second cam boss are provided with through holes coaxial with the circular hole.

[0007] The helical gear body of this utility model has a positioning groove on the side of the mounting groove on the left side, and a positioning protrusion on the second cam protrusion that corresponds to the position of the positioning groove. The second cam protrusion is fixed to the bottom of the mounting groove by the cooperation of the positioning protrusion and the positioning groove, thereby realizing the precise positioning and installation of the second cam protrusion.

[0008] A powder metallurgical die for producing helical gears with asymmetric bosses is characterized in that the die comprises a helical gear body, a first cam boss forming die, a second cam boss forming die, and a weld block forming die. The helical gear body and the first cam boss forming die include an upper punch die, a middle die, a lower punch die, a lower second punch die, and a mandrel die. The upper punch die is located above the middle die, and the lower punch die, the lower second punch die, and the mandrel die are sequentially located below the middle die. The upper punch die includes an upper punch template and an upper punch head, which are rotatably connected. The lower end face of the upper punch head has an upper pressure head offset from the center, and the lower end face of the upper pressure head has an upper mandrel insertion hole concentric with the upper punch head. The middle die has a helical gear forming hole in its center. The lower punch die includes a lower punch template and a lower punch head. The lower second punch die includes a lower... The two-punch template and the lower two-punch head, the mandrel mold includes the mandrel template and the mandrel punch, the lower punch template is rotatably connected to the lower punch, the lower punch and the lower punch template are provided with through lower two-punch insertion holes, the lower two-punch insertion holes are eccentrically arranged with the upper pressure head, the lower two punch template and the lower two punch are rotatably connected, the lower two punch is inserted into the lower two punch insertion hole, the lower two punch template and the lower two punch are provided with a lower mandrel insertion hole in the middle, the mandrel template and the mandrel punch are rotatably connected, the mandrel punch is inserted through the lower mandrel insertion hole and passes through the upper mandrel insertion hole, the upper end face of the lower two punch and the lower two punch insertion hole of the lower punch form a lower forming cavity, after the upper punch, the lower punch, the lower two punch and the mandrel punch are closed, the lower forming cavity, the upper pressure head and the forming helical gear forming cavity of the middle mold are formed between the upper punch and the forming helical gear hole, the outer wall of the upper punch and the lower punch is provided with an external helical gear groove that mates with the forming helical gear of the middle mold.

[0009] The lower two punches of this invention have an upper limit boss on their outer wall and an upper limit groove on the inner wall of the lower two punch insertion hole of the lower punch. The upper limit boss of the lower two punches cooperates with the upper limit groove to limit the movement. When the lower punch rotates during demolding, it drives the lower two punches to rotate, thus preventing the boss of the formed cam structure from breaking hard.

[0010] The upper end face of the upper limit boss and the lower end face of the upper limit groove of the present invention are provided with a clearance after mold closing. The clearance ensures that the upper punch and the lower punch can move up and down relative to each other during demolding, thus ensuring the product can be ejected.

[0011] The upper punch template and the upper punch head described in this utility model are connected by a first rotating component and an upper punch cover. The upper punch head is T-shaped, and the upper punch cover is provided with a T-shaped slot. After the upper punch cover passes through the upper punch head, it is fixedly connected to the upper punch template. The upper end of the upper punch head is rotatably connected to the lower end face of the upper punch template via the first rotating component.

[0012] The next punch template and the next punch head are connected by a second rotating component and a next punch cover in this utility model. The next punch head is T-shaped, and the next punch cover is provided with a T-shaped slot. After the next punch head passes through the next punch head, it is fixedly connected to the next punch template. The lower end of the next punch head is rotatably connected to the upper end face of the next punch template via the second rotating component.

[0013] The lower two-punch template and the lower two-punch head of this utility model are connected by a third rotating component and a lower two-punch pressure cover. The lower two-punch head is T-shaped, and the lower two-punch pressure cover is provided with a T-shaped slot. After passing through the lower two-punch head, the lower two-punch pressure cover is fixedly connected to the lower two-punch template. The lower end of the lower two-punch head is rotatably connected to the upper end face of the lower two-punch template via the third rotating component.

[0014] The mandrel template and the mandrel punch of this utility model are connected by a fourth rotating component and a mandrel cover. The mandrel punch is T-shaped, and the mandrel cover is provided with a T-shaped slot. After the mandrel cover passes through the mandrel punch, it is fixedly connected to the mandrel template. The lower end of the mandrel punch is rotatably connected to the upper end face of the mandrel template via the fourth rotating component.

[0015] The first rotating component, second rotating component, third rotating component, and fourth rotating component described in this utility model are bearings or spiral plates capable of rotation.

[0016] The second cam protrusion forming mold of this utility model includes a first upper punch mold, a first middle mold, a first lower punch mold, and a first mandrel mold. The first upper punch mold is located above the first middle mold, and the first lower punch mold and the first mandrel mold are located below the first middle mold. The first upper punch mold includes a first upper punch body and a first upper punch plate, which are fixedly connected. The first upper punch body has an eccentric first upper mandrel insertion hole. The first middle mold has a second cam protrusion forming hole. The first lower punch mold includes a first lower punch template and a first lower punch body, which are fixedly connected. The first lower punch body and the first lower punch template have an eccentric first lower mandrel insertion hole concentric with the first upper mandrel insertion hole. The first mandrel mold includes a first mandrel template and a first lower mandrel insertion hole. The first mandrel punch body and the first mandrel template are fixedly connected. The first mandrel punch body is inserted through the first lower mandrel insertion hole and into the first upper mandrel insertion hole. The first lower punch body and the first upper punch body are respectively inserted into the second cam protrusion forming hole of the first middle mold to form the second cam protrusion forming cavity. The welding block forming mold includes a second upper punch mold, a second middle mold, and a second lower punch mold. The second upper punch mold and the second lower punch mold are respectively arranged on the upper and lower sides of the second middle mold. The second upper punch mold includes a second upper punch plate and a second upper punch body. The second middle mold is provided with welding block forming holes. The second lower punch mold includes a second lower punch plate and a second lower punch body. The second lower punch body and the second lower punch plate are fixedly connected. The first lower punch body and the second lower punch body are respectively inserted into the welding block forming hole of the second middle mold to form the welding block forming cavity.

[0017] This utility model, due to the above-mentioned structure, has the advantages of simple structure, material saving, low cost and good molding effect. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the helical gear structure of this utility model.

[0019] Figure 2 yes Figure 1 AA sectional view.

[0020] Figure 3 This is a schematic diagram of the structure of the helical gear body and the first cam protrusion forming mold.

[0021] Figure 4 yes Figure 3 A schematic diagram of the integrated structure of the helical gear body and the first cam protrusion after molding.

[0022] Figure 5 yes Figure 4 BB cross-sectional view.

[0023] Figure 6 yes Figure 4 A structural diagram of the other side.

[0024] Figure 7 This is a schematic diagram of the structure of the second cam protrusion forming mold.

[0025] Figure 8 yes Figure 7 A schematic diagram of the second cam protrusion structure after molding.

[0026] Figure 9 yes Figure 8 CC section view.

[0027] Figure 10 yes Figure 8 The main view.

[0028] Figure 11 This is a schematic diagram of the welding block forming mold.

[0029] Figure 12 yes Figure 11 A schematic diagram of the formed weld block structure.

[0030] Figure 13 yes Figure 11 The main view. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings: As shown in the attached figure, a helical gear with asymmetric bosses prepared by powder metallurgy is characterized in that the helical gear includes a helical gear body 1, a first cam protrusion 2, and a second cam protrusion 3. The center of the helical gear body 1 is provided with a circular hole 4. The right side of the helical gear body 1 is integrally formed and connected with the first cam protrusion 2. The left side of the helical gear body 1 is integrally formed with a mounting groove 5. The second cam protrusion 3 is inserted into the mounting groove 5. The second cam protrusion 3 is welded to the helical gear body 1 through circumferentially arranged welding blocks 6. The first cam protrusion 2 and the second cam protrusion 3 are provided with through holes 7 coaxial with the circular hole 4.

[0032] Furthermore, the mounting groove 5 on the left side of the helical gear body 1 is provided with a positioning groove 8, and the second cam protrusion 3 is provided with a positioning protrusion 9 corresponding to the position of the positioning groove 8. The second cam protrusion 3 is fixed to the bottom of the mounting groove 5 by the cooperation of the positioning protrusion 9 and the positioning groove 8, thereby realizing the precise positioning and installation of the second cam protrusion 3.

[0033] A powder metallurgical mold for producing helical gears with asymmetric bosses is characterized in that the mold comprises a helical gear body 1, a first cam boss 2 forming mold, a second cam boss 3 forming mold, and a weld block 6 forming mold. The helical gear body 1 and the first cam boss 2 forming mold comprise an upper punch mold, a middle mold 10, a lower punch mold, a lower second punch mold, and a mandrel mold. The upper punch mold is located above the middle mold 10, and the lower punch mold and the lower second punch mold are sequentially located below the middle mold 10. The system includes a mandrel mold and a core mold. The upper punch mold includes an upper punch template 11 and an upper punch head 12, which are rotatably connected. The lower end face of the upper punch head 12 has an upper pressure head 13 offset from the center, and the lower end face of the upper pressure head 13 has an upper mandrel insertion hole 14 concentric with the upper punch head 12. The middle mold 10 has a forming oblique tooth hole in its center. The lower punch mold includes a lower punch template 15 and a lower punch head 16. The lower second punch mold includes a lower second punch template 17 and a lower second punch head 18. The device includes a mandrel template 19 and a mandrel punch 20. A lower punch template 15 is rotatably connected to a lower punch 16. Both the lower punch 16 and the lower punch template 15 have through-holes 21 for the lower second punch. The lower second punch holes 21 are eccentrically arranged with the upper pressure head 13. A lower second punch template 17 is rotatably connected to a lower second punch 18. The lower second punch 18 is inserted into the lower second punch hole 21. A lower mandrel insertion hole 22 is located in the middle of the lower second punch template 17 and the lower second punch 18. The mandrel template 19 is rotatably connected to the mandrel punch 20. The punch 20 is inserted through the lower mandrel insertion hole 22 and passes through the upper mandrel insertion hole 14. The upper end face of the lower second punch 18 and the lower second punch insertion hole of the lower punch 16 form a lower forming cavity. After the upper punch 12, the lower punch 16, the lower second punch 18, and the mandrel punch 20 are closed, an asymmetrical boss helical gear forming cavity 23 is formed between the lower forming cavity, the upper pressure head 13 and the forming helical gear hole of the middle mold 10. The outer walls of the upper punch 12 and the lower punch 16 are provided with external helical gear grooves that cooperate with the forming helical gear of the middle mold 10.

[0034] Furthermore, the lower second punch 18 is provided with an upper limit boss 24 on its outer wall, and the lower second punch insertion hole 21 of the lower punch 16 is provided with an upper limit groove 25 on its inner wall. The upper limit boss 24 of the lower second punch 18 and the upper limit groove 25 cooperate to limit the movement. When the lower punch 16 rotates during demolding, it drives the lower second punch 18 to rotate, thus preventing the boss of the formed cam structure from breaking hard.

[0035] Furthermore, after mold closing, a clearance 26 is provided between the upper end face of the upper limit boss 24 and the lower end face of the upper limit groove 25. The clearance 26 ensures that the upper punch and the lower punch 18 can move up and down relative to each other during demolding, thus ensuring the product can be ejected.

[0036] Furthermore, the upper punch template 11 and the upper punch head 12 are connected by the first rotating member 27 and the upper punch cover 28. The upper punch head 12 is T-shaped, and the upper punch cover 28 is provided with a T-shaped slot. The upper punch cover 28 passes through the upper punch head 12 and is fixedly connected to the upper punch template 11. The upper end of the upper punch head 12 is rotatably connected to the lower end face of the upper punch template 11 via the first rotating member 27.

[0037] Furthermore, the next punch template 15 and the next punch 16 are connected by the second rotating member 29 and the next punch cover 30. The next punch 16 is T-shaped, and the next punch cover 30 is provided with a T-shaped slot. The next punch cover 30 passes through the next punch 16 and is fixedly connected to the next punch template 15. The lower end of the next punch 16 is rotatably connected to the upper end face of the next punch template 15 via the second rotating member 29.

[0038] Furthermore, the lower second punch template 17 and the lower second punch 18 are connected by a third rotating member 31 and a lower second punch cover 32. The lower second punch 18 is T-shaped, and the lower second punch cover 32 is provided with a T-shaped slot. After passing through the lower second punch 18, the lower second punch cover 32 is fixedly connected to the lower second punch template 17. The lower end of the lower second punch 18 is rotatably connected to the upper end face of the lower second punch template 17 via the third rotating member 31.

[0039] Furthermore, the mandrel template 19 and the mandrel punch 20 are connected by a fourth rotating member 33 and a mandrel cover 34. The mandrel punch 20 is T-shaped, and the mandrel cover 34 is provided with a T-shaped slot. The mandrel cover 34 passes through the mandrel punch 20 and is fixedly connected to the mandrel template 19. The lower end of the mandrel punch 20 is rotatably connected to the upper end face of the mandrel template 19 via the fourth rotating member 33.

[0040] Furthermore, the first rotating component 27, the second rotating component 29, the third rotating component 31, and the fourth rotating component 33 are bearings or spiral plates capable of rotation.

[0041] Furthermore, the second cam protrusion 3 forming mold includes a first upper punch mold, a first middle mold 35, a first lower punch mold, and a first mandrel mold. The first upper punch mold is located above the first middle mold 35, and the first lower punch mold and the first mandrel mold are located below the first middle mold 35. The first upper punch mold includes a first upper punch body 36 and a first upper punch plate 37, which are fixedly connected. The first upper punch body 36 has an eccentric first upper mandrel insertion hole 38. The first middle mold 35 has a second cam protrusion 3 forming hole. The first lower punch mold includes a first lower punch template 39 and a first lower punch body 40, which are fixedly connected. The first lower punch body 40 and the first lower punch template 39 have an eccentric first lower mandrel insertion hole 41 that is concentric with the first upper mandrel insertion hole 38. The first mandrel mold includes a first mandrel template 42 and a first mandrel punch body. 43. The first mandrel template 42 is fixedly connected to the first mandrel punch 43. The first mandrel punch 43 is inserted through the first lower mandrel insertion hole 41 and into the first upper mandrel insertion hole 38. The first lower punch 40 and the first upper punch 36 are respectively inserted into the second cam protrusion 3 forming hole of the first middle mold 35 to form the second cam protrusion forming cavity 44. The welding block 6 forming mold includes a second upper punch mold, a second middle mold 45, and a second lower punch mold. The second upper punch mold and the second lower punch mold are respectively arranged on the upper and lower sides of the second middle mold 45. The second upper punch mold includes a second upper punch plate 46 and a second upper punch body 47. The second middle mold 45 is provided with welding block 6 forming holes. The second lower punch mold includes a second lower punch plate 48 and a second lower punch body 49. The second lower punch body 49 and the second lower punch plate 48 are fixedly connected. The first lower punch body 40 and the second lower punch body 49 are respectively inserted into the welding block 6 forming hole of the second middle mold 45 to form the welding block forming cavity 50.

[0042] The first upper punch 36 and the first upper punch plate 37 are connected by a first upper pressure cover 51. The first upper punch 36 is T-shaped, and the first upper pressure cover 51 has a T-shaped slot. The first upper pressure cover 51 passes through the first upper punch 36 and is fixedly connected to the first upper punch plate 37. The first lower punch 40 and the first lower punch template 39 are connected by a first lower pressure cover 52. The first lower punch 40 is T-shaped, and the first lower pressure cover 52 has a T-shaped slot. The first lower pressure cover 52 passes through the first lower punch 40 and is fixedly connected to the first lower punch plate. The first mandrel punch 43 and the first mandrel template are connected by a first mandrel pressure cover 53. The first mandrel punch 43 is T-shaped. The mandrel cover 53 has a T-shaped slot. The first mandrel cover 53 passes through the first mandrel punch 43 and is fixedly connected to the first mandrel template 42. The second upper punch 47 and the second upper punch plate 46 are connected by the second upper cover 54. The second upper punch 47 is T-shaped. The second upper cover 54 has a T-shaped slot. The second upper cover 54 passes through the second upper punch 47 and is fixedly connected to the second upper punch plate 46. The second lower punch 49 and the second lower punch plate 48 are connected by the second lower cover 55. The second lower punch 49 is T-shaped. The second lower cover 55 has a T-shaped slot. The second upper cover 54 passes through the second lower punch 49 and is fixedly connected to the second lower punch 49.

[0043] In use, this utility model firstly uses a helical gear body 1 and a first cam protrusion 2 forming mold to prepare an integral structure of the helical gear body 1 and the first cam protrusion 2, respectively; a second cam protrusion 3 forming mold to prepare a second cam protrusion 3 structure; and a welding block 6 forming mold to prepare a welding block 6 structure.

[0044] The fabrication process of the aforementioned integrated structure of helical gear body 1 and first cam protrusion 2 is as follows: The middle mold 10 is fixed on the machine base. The mandrel template 19, lower punch template 15, lower second punch template 17, and upper punch template 11 are respectively fixed to the output arm end of the machine base. The mandrel punch 20, lower punch 16, and lower second punch 18 are inserted into the forming helical gear hole of the middle mold 10 under the action of the output arm. Then, powder is filled into the forming helical gear hole of the middle mold 10. The upper punch template 111 moves downward under the action of the machine base output arm. The upper end of the mandrel punch 20 is inserted into the upper mandrel insertion hole 14. The powder is pressed in the upper punch 12, upper pressure head 13, lower forming cavity, and forming helical gear hole of the middle mold 10, thereby forming an integrated structure of helical gear body 1 and first cam protrusion 2. Demolding process... The process involves the upper punch plate 11 driving the upper punch 12 to move upward, the upper punch 12 rotating and dislodging above the middle mold 10, the lower punch 16, the lower second punch 18 and the mandrel punch 20 moving upward and rotating under the action of the lower punch plate 15, the lower second punch plate 17 and the mandrel plate 19, and after the product is dislodged from the middle mold, the lower punch plate 15 drives the lower punch 16 to move upward, the lower second punch 18 and the mandrel punch 20 rotating under the action of friction, and the lower punch 16 ejects the formed product, thus completing the demolding process, or the middle mold 10 and the mandrel plate 19 drive the mandrel punch 20 to move downward, during the downward movement the lower punch 16 drives the lower second punch 18 to rotate, and then the lower punch 16 also moves downward, the formed product is directly an integral structure of the helical gear body 1 and the first cam protrusion 2.

[0045] Figure 3 In the structural schematic diagram of the helical gear body 1 and the first cam protrusion 2 forming mold, the side of the upper pressure head 13 is provided with a pressing protrusion with a positioning groove 8, and the bottom view of the upper punch 12 is the same as... Figure 6 The view Figure 1 To.

[0046] The above-mentioned second cam protrusion 3 structure is prepared as follows: the first lower punch 40 and the first mandrel punch 43 are inserted into the first middle mold 35, the first upper punch 36 moves down and is inserted into the first middle mold 35, the first mandrel punch 43 is inserted into the first upper mandrel insertion hole 38, the powder is pressed into the second cam protrusion forming cavity 44, after forming, the first upper punch 36 moves up, the first lower punch 40 moves up and is ejected, and the first mandrel punch 43 moves down, or the first upper punch 36 moves up, the first middle mold 35 moves down, and the first mandrel punch 43 moves down, thereby realizing the demolding of the second cam protrusion 3 structure.

[0047] Figure 7In the structural schematic diagram of the second cam protrusion 3 forming mold, the side of the first upper punch 36 is provided with a pressing protrusion corresponding to the positioning groove 8. The upper side of the forming hole of the second cam protrusion 3 in the first middle mold 35 is provided with a pressing groove that mates with the forming hole of the second cam protrusion 3. The positioning protrusion 9 structure is formed by pressing and shaping the pressing protrusion in the pressing groove. The bottom view of the first upper punch 36 is shown in the diagram. Figure 8 The view Figure 1 To.

[0048] The above-mentioned welding block 6 structure preparation process is as follows: the second lower punch 49 is inserted into the second middle mold 45, the second upper punch 47 moves down and is inserted into the second middle mold 45, the powder is pressed into shape in the welding block forming cavity 50, after forming, the second upper punch 47 moves up and the second lower punch 49 moves up and is ejected, or the second upper punch 47 moves up and the second mold moves down, thereby realizing the demolding of the welding block 6 structure.

[0049] Figure 11 In the structural schematic diagram of the forming mold for welding block 6, welding block 6 has an arc-shaped structure, and the arc-shaped structure is consistent with... Figure 12 Furthermore, the width of the aforementioned positioning groove 8 can be set as the sum of the width of the welding block 6 and the width of the positioning protrusion 9. After the positioning protrusion 9 is inserted into the positioning groove 8, the welding block 6 is inserted into the positioning groove 8. In this way, the welding block 6 can be welded between the bottom of the second cam protrusion 3 and the mounting groove 5 after being heated, thereby increasing the connection strength between the helical gear body 1 and the second cam protrusion 3 after welding.

[0050] The process of forming an asymmetrical helical gear with an integrated structure of the helical gear body 1 and the first cam protrusion 2, combined with the second cam protrusion 3 and the welding block 6, is as follows: The positioning protrusion 9 of the second cam protrusion 3 is inserted into the positioning groove 8 of the integrated structure of the helical gear body 1 and the first cam protrusion 2. The second cam protrusion 3 is inserted into the mounting groove 5. The welding block 6 is evenly distributed at the contact position between the second cam protrusion 3 and the mounting groove 5. Finally, high-temperature welding is performed. The welding block 6 enters along the gap between the second cam protrusion 3 and the mounting groove 5 and realizes the welding of the second cam protrusion 3 and the helical gear body 1, thereby completing the preparation of the asymmetrical helical gear. The protrusions of the cam structure on both sides of the helical gear body 1 do not need to be cut, saving a lot of materials. At the same time, the processing cost is low, the forming effect is good, and the forming efficiency is high. Due to the above structure, this utility model has the advantages of simple structure, material saving, low cost and good forming effect.

Claims

1. A method for preparing helical gears with asymmetric bosses using powder metallurgy, characterized in that... The helical gear includes a helical gear body, a first cam protrusion, and a second cam protrusion. The helical gear body has a circular hole at its center. The right side of the helical gear body is integrally formed and connected to the first cam protrusion. The left side of the helical gear body has an integrally formed mounting groove. The second cam protrusion is inserted into the mounting groove. The second cam protrusion is welded to the helical gear body via circumferentially arranged welding blocks. The first cam protrusion and the second cam protrusion have through holes coaxial with the circular hole.

2. The method for preparing helical gears with asymmetric bosses using powder metallurgy according to claim 1, characterized in that... The mounting groove on the left side of the helical gear body is provided with a positioning groove, and the second cam protrusion is provided with a positioning protrusion corresponding to the position of the positioning groove. The second cam protrusion is fixed to the bottom of the mounting groove by the cooperation of the positioning protrusion and the positioning groove, thereby realizing the precise positioning and installation of the second cam protrusion.

3. A powder metallurgy mold for manufacturing helical gears with asymmetric bosses, characterized in that... The helical gear production mold includes a helical gear body, a first cam protrusion forming mold, a second cam protrusion forming mold, and a weld block forming mold. The helical gear body and the first cam protrusion forming mold include an upper punch mold, a middle mold, a lower punch mold, a lower second punch mold, and a mandrel mold. The upper punch mold is located above the middle mold, and the lower punch mold, lower second punch mold, and mandrel mold are sequentially located below the middle mold. The upper punch mold includes an upper punch template and an upper punch head. The upper punch template and the upper punch head are rotatably connected. The lower end face of the upper punch head has an upper pressure head offset from the center, and the lower end face of the upper pressure head has an upper mandrel insertion hole concentric with the upper punch head. The middle mold has a helical gear forming hole in its center. The lower punch mold includes a lower punch template and a lower punch head. The lower second punch mold includes a lower second punch template and a lower second punch head. The mandrel mold... The device includes a mandrel template and a mandrel punch. The lower punch template is rotatably connected to the lower punch. The lower punch and the lower punch template are provided with through holes for the second lower punch. The holes for the second lower punch are eccentrically arranged with the upper pressure head. The lower punch template is rotatably connected to the second lower punch. The second lower punch is inserted into the holes for the second lower punch. The lower punch template and the second lower punch are provided with holes for the lower mandrel. The mandrel template is rotatably connected to the mandrel punch. The mandrel punch is inserted through the holes for the lower mandrel and passes through the holes for the upper mandrel. The upper end face of the second lower punch and the holes for the second lower punch of the lower punch form a lower forming cavity. After the upper punch, the lower punch, the second lower punch, and the mandrel punch are closed, an asymmetrical boss helical gear forming cavity is formed between the lower forming cavity, the upper pressure head, and the forming helical gear hole of the middle mold. The outer walls of the upper punch and the lower punch are provided with external helical gear grooves that cooperate with the forming helical gear of the middle mold.

4. A powder metallurgy mold for preparing helical gears with asymmetric bosses according to claim 3, characterized in that... The lower two punches are provided with an upper limit boss on their outer wall and an upper limit groove on the inner wall of the lower two punch insertion hole of the lower punch. The upper limit boss of the lower two punches cooperates with the upper limit groove to limit the movement. When the lower punch rotates during demolding, it drives the lower two punches to rotate, thus preventing the boss of the formed cam structure from breaking hard.

5. A powder metallurgy mold for preparing helical gears with asymmetric bosses according to claim 3, characterized in that... The upper punch template and the upper punch head are connected by a first rotating component and an upper punch cover. The upper punch head is T-shaped, and the upper punch cover is provided with a T-shaped slot. The upper punch cover passes through the upper punch head and is fixedly connected to the upper punch template. The upper end of the upper punch head is rotatably connected to the lower end face of the upper punch template via the first rotating component.

6. A powder metallurgy mold for preparing helical gears with asymmetric bosses according to claim 3, characterized in that... The next punch template and the next punch are connected by a second rotating component and a next punch cover. The next punch is T-shaped, and the next punch cover has a T-shaped slot. The next punch cover passes through the next punch and is fixedly connected to the next punch template. The lower end of the next punch is rotatably connected to the upper surface of the next punch template via the second rotating component.

7. A powder metallurgy mold for preparing helical gears with asymmetric bosses according to claim 3, characterized in that... The lower two-punch template and the lower two-punch head are connected by a third rotating component and a lower two-punch pressure cover. The lower two-punch head is T-shaped, and the lower two-punch pressure cover has a T-shaped slot. After passing through the lower two-punch head, the lower two-punch pressure cover is fixedly connected to the lower two-punch template. The lower end of the lower two-punch head is rotatably connected to the upper end face of the lower two-punch template via the third rotating component.

8. A powder metallurgy mold for preparing helical gears with asymmetric bosses according to claim 3, characterized in that... The mandrel template and the mandrel punch are connected by a fourth rotating component and a mandrel cover. The mandrel punch is T-shaped, and the mandrel cover has a T-shaped slot. After passing through the mandrel punch, the mandrel cover is fixedly connected to the mandrel template. The lower end of the mandrel punch is rotatably connected to the upper end face of the mandrel template via the fourth rotating component.

9. A powder metallurgy mold for preparing helical gears with asymmetric bosses according to claim 3, characterized in that... The first rotating component, the second rotating component, the third rotating component, and the fourth rotating component are bearings or spiral blades capable of rotation.

10. A powder metallurgy mold for preparing helical gears with asymmetric bosses according to claim 3, characterized in that... The second cam protrusion forming die includes a first upper punch die, a first middle die, a first lower punch die, and a first mandrel die. The first upper punch die is located above the first middle die, and the first lower punch die and the first mandrel die are located below the first middle die. The first upper punch die includes a first upper punch body and a first upper punch plate, which are fixedly connected. The first upper punch body has an eccentric first upper mandrel insertion hole. The first middle die has a second cam protrusion forming hole. The first lower punch die includes a first lower punch template and a first lower punch body, which are fixedly connected. The first lower punch body and the first lower punch template have an eccentric first lower mandrel insertion hole concentric with the first upper mandrel insertion hole. The first mandrel die includes a first mandrel template and a first mandrel die. The first mandrel template is fixedly connected to the first mandrel punch body. The first mandrel punch body is inserted through the first lower mandrel insertion hole and into the first upper mandrel insertion hole. The first lower punch body and the first upper punch body are respectively inserted into the second cam protrusion forming hole of the first middle mold to form the second cam protrusion forming cavity. The welding block forming mold includes a second upper punch mold, a second middle mold, and a second lower punch mold. The second upper punch mold and the second lower punch mold are respectively arranged on the upper and lower sides of the second middle mold. The second upper punch mold includes a second upper punch plate and a second upper punch body. The second middle mold is provided with a welding block forming hole. The second lower punch mold includes a second lower punch plate and a second lower punch body. The second lower punch body and the second lower punch plate are fixedly connected. The first lower punch body and the second lower punch body are respectively inserted into the welding block forming hole of the second middle mold to form the welding block forming cavity.

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