Machining die for straight-tooth and helical-tooth duplicate gear for powder metallurgy

Abstract

The utility model discloses a powder metallurgy straight tooth and helical tooth duplicate gear machining die which comprises a middle die with a cavity formed inside, and the middle die is provided with an upper punch and a lower punch which can be screwed into the cavity to form a first-stage helical gear part during die assembly in the die assembly direction. The second lower punch can axially penetrate through the first lower punch and extend into the cavity to form a second-stage straight gear part, and the forming core rod can axially penetrate through the second lower punch and extend into the cavity to be matched with the upper punch to form a shaft hole. According to the utility model, the straight and helical duplicate gears can be machined by one-time mold closing, so that the production efficiency is improved, and the machined gear is of an integrally formed structure, thereby being beneficial to improving the overall strength of the gear.

Description

Technical Field

[0001] The utility model relates to the technical field of powder metallurgy double gear processing dies, in particular to a powder metallurgy straight and helical double gear processing die. Background Art

[0002] The double gear has two stages of teeth with different numbers of teeth, and is mainly used for speed transmission of the transmission; in the prior art, the two stages of teeth of the double gear can be two stages of spur teeth, or one stage of helical teeth and the other stage of spur teeth; when processing the spur and helical double gears, due to the existence of helical gear parts and spur gear parts, in order to facilitate processing, the two stages of teeth are generally first processed separately using corresponding molds, and then the two stages of teeth are assembled to form a combined structure. In order to ensure the matching accuracy of the two stages of teeth, this processing method has high requirements on processing accuracy, resulting in low processing efficiency, and the combined structure will reduce the overall strength of the gear. Utility Model Content

[0003] The utility model aims to provide a powder metallurgy straight and helical double gear processing die, which can integrally form the straight and helical double gears, thereby improving the overall strength and processing efficiency of the gears.

[0004] The purpose of this utility model is achieved through the following technical solutions:

[0005] A powder metallurgy spur and helical double gear processing mold includes a middle mold with a cavity formed therein, the middle mold is provided with an upper punch and a lower punch in the mold closing direction, which can be screwed into the mold cavity to form a first-level helical gear part when the mold is closed, a lower second punch can be axially inserted through the lower punch and extended into the mold cavity to form a second-level spur gear part, and a forming core rod can be axially inserted through the lower second punch and extended into the mold cavity to cooperate with the upper punch to form an axial hole.

[0006] On the basis of the above technical solution, the present invention can be improved as follows:

[0007] Furthermore, the inner wall of the cavity of the middle die is provided with internal helical teeth for guiding the upper punch and the lower punch to be screwed into the cavity along the axis of the middle die.

[0008] Furthermore, the upper punch includes an upper outer punch, the outer peripheral surface of which is provided with outer spiral teeth that can cooperate with the inner spiral teeth on the inner wall of the cavity of the middle mold; an upper inner punch is movably inserted into the upper outer punch, and the upper inner punch is provided with a first core rod insertion hole that can be plugged and cooperated with the forming core rod inserted into the cavity.

[0009] Furthermore, the outer peripheral surface of the next punch is provided with external helical teeth that can cooperate with the internal helical teeth on the inner wall of the cavity of the middle mold; the next punch is provided with a through hole for the insertion of the lower second punch.

[0010] Furthermore, the inner wall of the through hole on the next punch is provided with inner straight teeth for guiding the lower second punch to axially penetrate through the next punch and extend into the cavity of the middle die.

[0011] Furthermore, the outer peripheral surface of the lower second punch is provided with external straight teeth that can cooperate with the internal straight teeth on the inner wall of the through hole of the lower punch.

[0012] Furthermore, the lower second punch is provided with a second core rod insertion hole for the forming core rod to be inserted.

[0013] Furthermore, the outer peripheral surface of the forming mandrel is a smooth surface that can fit with the inner wall of the second mandrel insertion hole.

[0014] Furthermore, the upper punch, the lower punch, the lower second punch and the forming core rod are provided with connecting parts at the connecting ends for connecting to the ejection mechanism of the press, and the upper punch, the lower punch, the lower second punch and the forming core rod can rotate around the axis through the connecting parts when the mold is closed.

[0015] Furthermore, the connecting part includes a sleeve with a barrel cavity formed inside, a barrel mouth is provided on the sleeve, and a sleeve is provided with a sleeve hole on the barrel wall opposite to the barrel mouth. The upper punch, the next punch, the lower second punch or the forming core rod is inserted into the sleeve through the barrel mouth and passes through the sleeve hole on the sleeve. The connecting end of the upper punch, the next punch, the lower second punch or the forming core rod can be rotatably sleeved in the barrel cavity, and the sleeve is provided with a barrel cover at the barrel mouth to close the barrel cavity.

[0016] Compared with the existing technology, the technology of this utility model has the following advantages:

[0017] In this embodiment, an upper punch, a middle die, a lower punch, a lower second punch and a forming core rod are provided. When the mold is closed, the upper punch and the lower punch can be rotated into the cavity of the middle die, driving the lower second punch and the forming core rod to rotate accordingly, and the lower second punch and the forming core rod can axially extend into the cavity of the middle die relative to the lower punch, so that the straight and helical double gears can be processed by closing the mold once, which not only improves production efficiency, but also the processed gears are an integrated molding structure, which is beneficial to improving the overall strength of the gears. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Figure 1 Schematic diagram of the straight and helical double gear structure processed for the utility model;

[0020] Figure 2 This is a schematic diagram of the structure of a utility model powder metallurgy straight and helical double gear processing die;

[0021] Figure 3It is a structural schematic diagram of the utility model friction plate.

[0022] Markings on the accompanying drawings: 1-straight and helical double gears, 101-first-stage helical gear part, 102-second-stage spur gear part, 103-axis hole, 2-upper punch, 201-upper outer punch, 202-upper inner punch, 3-middle die, 301-die sleeve, 302-die core, 4-next punch, 5-lower second punch, 6-forming mandrel, 7-upper punch sleeve, 8-upper punch cylinder cover, 9-next punch sleeve, 10-next punch cylinder cover, 11-lower second punch sleeve, 12-lower second punch cylinder cover, 13-forming mandrel sleeve, 14-forming mandrel cylinder cover, 15-friction plate, 16-stop screw hole, 17-reset rod, 18-reset spring. DETAILED DESCRIPTION

[0023] The following further describes the specific embodiments of the present invention in conjunction with the accompanying drawings. The description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] See also Figure 1 and Figure 3 The utility model relates to a powder metallurgy spur and helical double gear processing die, which is used in conjunction with a vertical press to longitudinally clamp and integrally form a spur and helical double gear 1. The pressed spur and helical double gear 1 includes a primary helical gear portion 101, a secondary spur gear portion 102, and an axial hole 103 passing through the primary helical gear portion 101 and the secondary spur gear portion 102.

[0025] The processing mold includes an upper punch 2, a middle mold 3, a lower punch 4, a lower second punch 5 and a forming core rod 6 arranged in sequence along the mold closing direction; the upper punch 2 is rotatably arranged on the upper ejection mechanism of the press; the middle mold 3 is fixedly arranged on the workbench of the press, and a cavity for forming the gear is formed inside the middle mold 3; the lower punch 4, the lower second punch 5 and the forming core rod 6 are rotatably arranged on the lower ejection mechanism of the press mechanism, and are interspersed in sequence from the outside to the inside.

[0026] When the mold is closed, the upper punch 2 and the lower punch 4 can be screwed into the cavity of the middle mold 3 along the axis of the middle mold 3 to form the first-level helical gear part 101, the lower second punch 5 is inserted through the lower punch 4 and extends into the cavity of the middle mold 3 to form the second-level spur gear part 102, and the forming core rod 6 is inserted through the lower second punch 5 and extends into the cavity of the middle mold 3 to cooperate with the upper punch 2 to form the shaft hole 103.

[0027] Specifically, the middle mold 3 includes a mold sleeve 301 that can be fixed on the workbench of the press together with the middle mold 3 pressure cover, and a mold core 302 arranged in the mold sleeve 301; the mold sleeve 301 is provided with a matching hole in the middle that matches the mold core 302, and the mold core 302 is interference fit in the matching hole of the mold sleeve 301. After matching, the end faces of the mold core 302 and the mold sleeve 301 are flush; the mold core 302 is a cylindrical structure, and a cavity for forming gears is formed inside the mold core 302. The mold core 302 is provided with internal helical teeth on the inner wall of the cavity, and the upper punch 2 and the lower punch 4 are guided by the internal helical teeth to be screwed into the cavity of the middle mold 3 along the axis of the middle mold 3 to form the first-stage helical gear part 101.

[0028] The upper punch 2 includes an upper outer punch 201 and an upper inner punch 202 which is movably inserted into the upper outer punch 201. The top of the upper outer punch 201 is a connecting end, and the connecting end of the upper outer punch 201 is rotatably connected to the upper ejection mechanism of the press through a first connecting member. The upper outer punch 201 and the inner and outer punches are all cylindrical structures, wherein the upper outer punch 201 is provided with a through hole in the middle for the upper inner punch 202 to penetrate, and the outer peripheral surface of the upper outer punch 201 is provided with external spiral teeth. The external spiral teeth on the outer circumference cooperate with the internal spiral teeth on the inner wall of the mold cavity of the mold core 302, so that the upper outer punch 201 can be screwed into the mold cavity inside the mold core 302 when the mold is closed; the upper inner punch 202 has a smooth outer circumference, so that the upper inner punch 202 can smoothly pass through the upper outer punch 201 and extend into the mold cavity; the upper inner punch 202 is provided with a first core rod insertion hole in the middle, and the first core rod insertion hole has a smooth inner wall, so that the forming core rod 6 inserted into the mold cavity can be plugged into the upper inner punch 202.

[0029] The first connecting member includes a detachably connected upper punch sleeve 7 and an upper punch cover 8; the upper punch sleeve 7 is a hollow cylindrical structure with an annular side wall and a bottom wall. The top of the upper punch sleeve 7 forms a barrel mouth opposite to the bottom wall, and a barrel cavity is formed inside the upper punch sleeve 7. The upper punch sleeve 7 is provided with a sleeve hole connected to the barrel cavity on the bottom wall; the upper punch cover 8 is detachably arranged at the barrel mouth of the upper punch sleeve 7, and the upper punch cover 8 is provided with an insertion hole in the middle; during assembly, the upper outer punch 201 is inserted into the upper punch sleeve 7 from the barrel mouth of the upper punch sleeve 7, and passes through the sleeve hole on the bottom wall of the upper punch sleeve 7. The connecting end sleeve part of the upper outer punch 201 is sleeved in the upper punch sleeve 7 and can rotate around the axis in the barrel cavity. The upper inner punch 202 enters the upper punch sleeve 7 through the insertion hole on the upper punch cover 8 and inserts the upper outer punch 201.

[0030] It should be noted that the connecting end of the upper outer punch 201 forms a circular boss, and the diameter of the connecting end of the upper outer punch 201 should be slightly smaller than the diameter of the upper punch sleeve cavity inside the upper punch sleeve 7 to ensure that the top connecting part of the upper outer punch 201 can rotate smoothly around the axis in the cylinder cavity.

[0031] A reset guide groove is provided on the annular side wall of the upper punch sleeve 7, and a return screw hole 16 and a reset rod 17 perpendicular to the axis of the upper punch 2 are provided on the circumferential side of the upper punch 2. The return screw enters the upper punch sleeve 7 through the return guide groove and is threadedly engaged with the return screw hole 16 on the upper punch 2 to limit the rotation range of the upper punch 2; the reset rod 17 extends out of the upper punch sleeve 7 through the return guide groove and is provided with a return spring 18 at the extended end, and the end of the return spring 18 is fixedly connected to the mold frame; when the mold is closed, the reset rod 17 follows the rotation of the upper punch 2 and rotates accordingly along the reset guide groove, and the reset spring 18 is stretched to form an elastic force; in the open mode, under the action of the elastic force of the reset spring 18, the reset rod 17 drives the upper punch 2 to rotate and reset, thereby ensuring that the rotation angle of the upper punch 2 is consistent each time the mold is closed, avoiding damage to the mold due to inconsistent angles of the upper punch 2 entering the middle mold.

[0032] The bottom end of the next punch 4 is the connecting end, and the connecting end of the next punch 4 is rotatably connected to the lower ejection mechanism of the press through a second connecting piece; the next punch 4 is a cylindrical structure, and the outer circumference of the next punch 4 is provided with external helical teeth, and the external helical teeth on the outer circumference of the next punch 4 cooperate with the internal helical teeth on the inner wall of the cavity of the mold core 302, so that the next punch 4 can be screwed into the cavity inside the mold core 302 when the mold is closed to complete the molding of the first-stage helical gear part 101.

[0033] The second connecting member includes a detachably connected next punch sleeve 9 and a next punch cylinder cover 10; the next punch sleeve 9 is a hollow cylindrical structure with an annular side wall and a top wall. The bottom of the next punch sleeve 9 forms a barrel mouth opposite to the top wall, and a barrel cavity is formed inside the next punch sleeve 9. The next punch sleeve 9 is provided with a socket hole connected to the barrel cavity on the top wall; the next punch cylinder cover 10 is detachably arranged at the barrel mouth of the next punch sleeve 9, and the next punch cylinder cover 10 is provided with an insertion hole in the middle; during assembly, the next punch 4 is inserted into the next punch sleeve 9 from the barrel mouth of the next punch sleeve 9 and passes through the socket hole on the top wall of the next punch sleeve 9. The connecting end of the next punch 4 is sleeved in the next punch sleeve 9 and can rotate around the axis in the barrel cavity. The next two punches 5 enter the next punch sleeve 9 through the insertion hole on the next punch cylinder cover 10 and insert the next punch 4.

[0034] It should be noted that the connecting end of the next punch 4 forms a circular boss, and the diameter of the connecting end of the next punch 4 should be slightly smaller than the diameter of the next punch sleeve cavity inside the next punch sleeve 9 to ensure that the bottom end connecting part of the next punch 4 can rotate smoothly around the axis in the cylinder cavity.

[0035] The lower punch 4 is provided with a through hole in the middle for the lower second punch 5 to penetrate. The inner wall of the through hole on the lower punch 4 is provided with internal straight teeth, which guide the lower second punch 5 to axially penetrate through the next punch 4 and extend into the cavity of the middle mold 3 to form the secondary straight gear part 102.

[0036] The bottom end of the lower second punch 5 is the connecting end, and the connecting end of the lower second punch 5 is rotatably connected to the lower ejection mechanism of the press through a third connecting piece; the lower second punch 5 is a cylindrical structure, and the outer circumferential surface of the lower second punch 5 is provided with external spur teeth, and the external spur teeth on the outer circumferential surface of the lower second punch 5 cooperate with the internal spur teeth on the inner wall of the through hole of the lower punch 4, so that when the mold is closed, the lower second punch 5 can axially penetrate through the lower punch 4 and extend into the cavity inside the mold core 302 to complete the molding of the secondary spur gear part 102.

[0037] The third connecting member includes a detachably connected lower second punch sleeve 11 and a lower second punch cylinder cover 12; the lower second punch sleeve 11 is a hollow cylindrical structure with an annular side wall and a top wall. The bottom of the lower secondary punch sleeve forms a barrel mouth opposite to the top wall, and a barrel cavity is formed inside the lower second punch sleeve 11. The lower second punch sleeve 11 is provided with a socket hole connected to the barrel cavity on the top wall; the lower second punch cylinder cover 12 is detachably arranged at the barrel mouth of the lower second punch sleeve 11, and the lower second punch cylinder cover 12 is provided with an insertion hole in the middle; during assembly, the lower second punch 5 is inserted into the lower second punch sleeve 11 from the barrel mouth of the lower second punch sleeve 11, and passes through the socket hole on the top wall of the lower second punch sleeve 11. The connecting end of the lower second punch 5 is sleeved in the lower second punch sleeve 11 and can rotate around the axis in the barrel cavity. The forming core rod 6 enters the lower second punch sleeve 11 through the insertion hole on the lower second punch cylinder cover 12 and inserts the lower second punch 5.

[0038] It should be noted that the connecting end of the lower second punch 5 forms a circular boss, and the diameter of the connecting end of the lower second punch 5 should be slightly smaller than the diameter of the lower second punch sleeve cavity inside the lower second punch sleeve 11 to ensure that the bottom end connecting part of the lower second punch 5 can rotate smoothly around the axis in the cylinder cavity.

[0039] The lower second punch 5 is provided with a second core rod insertion hole in the middle for the forming core rod 6 to be inserted. The second core rod insertion hole has a smooth inner wall so that the forming core rod 6 can axially pass through the lower second punch 5 and extend into the cavity of the middle mold 3, and be connected with the upper inner punch 202 to complete the forming of the axial hole 103.

[0040] The bottom end of the forming mandrel 6 is the connecting end, and the connecting end of the forming mandrel 6 is rotatably connected to the lower ejection mechanism of the press through the fourth connecting piece; the forming mandrel 6 is a round rod-shaped structure, and the outer peripheral surface of the forming mandrel 6 is smooth. When the mold is closed, the forming mandrel 6 can axially penetrate through the lower second punch 5 and extend into the cavity inside the mold core 302, and be connected with the upper inner punch 202 to complete the forming of the axial hole 103.

[0041] The fourth connecting member includes a detachably connected forming mandrel sleeve 13 and a forming mandrel cover 14; the forming mandrel sleeve 13 is a hollow cylindrical structure with an annular side wall and a top wall, and the bottom of the forming mandrel sleeve 13 forms a barrel mouth opposite to the top wall, and a barrel cavity is formed inside the forming mandrel sleeve 13. The forming mandrel sleeve 13 is provided with a socket hole connected to the lower barrel cavity on the top wall; the forming mandrel cover 14 is detachably arranged at the barrel mouth of the forming mandrel sleeve 13; during assembly, the forming mandrel 6 is inserted into the forming mandrel sleeve 13 from the barrel mouth of the forming mandrel sleeve 13, and passes through the socket hole on the top wall of the forming mandrel sleeve 13. The connecting end of the forming mandrel 6 is sleeved in the forming mandrel sleeve 13 and can rotate around the axis in the barrel cavity.

[0042] It should be noted that the connecting end of the forming mandrel 6 forms a circular boss, and the diameter of the connecting end of the forming mandrel 6 should be slightly smaller than the diameter of the barrel cavity inside the forming mandrel sleeve 13 to ensure that the bottom end connecting part of the forming mandrel 6 can rotate smoothly around the axis in the barrel cavity.

[0043] In this embodiment, sleeves and cylinder covers are provided at the connecting ends of the upper punch 2, the lower punch 4, the lower second punch 5 and the forming core rod 6, so that the upper punch 2 and the lower punch 4 can be screwed into the cavity of the middle mold 3 in a rotational manner when the mold is closed, driving the lower second punch 5 and the forming core rod 6 to rotate accordingly, and the lower second punch 5 and the forming core rod 6 can axially extend into the cavity of the middle mold 3 relative to the lower punch 4, so that the straight and helical double gears can be processed by one mold closing, which not only improves production efficiency, but also the processed gears are an integrated molding structure, which is beneficial to improving the overall strength of the gears.

[0044] According to actual conditions, other connecting parts may be used instead of the sleeve and cover in this embodiment, so that the upper punch, the lower punch, the lower second punch and the forming core rod can rotate around the axis during mold closing.

[0045] At least one friction plate 15 is provided on the inner side of the bottom wall of the upper punch sleeve 7, the inner side of the cover of the upper punch sleeve 7, the inner side of the top wall of the next punch sleeve 9, the inner side of the next punch cover 10, the inner side of the top wall of the lower second punch sleeve 11, the inner side of the lower second punch cover 12, the inner side of the top wall of the forming mandrel sleeve 13, and the inner side of the forming mandrel cover 14. The friction plate 15 can absorb the impact force during mold closing and pressing, thereby preventing the formed gear from being affected by the impact force and cracking, thereby effectively ensuring the quality of the gear.

[0046] The friction plate 15 is a conventional friction plate in the prior art with a spiral oil groove on the end surface. Lubricating oil is stored in the spiral oil groove to reduce friction and ensure smooth rotation of the upper punch 2, the lower punch 4, the lower second punch 5 and the forming core rod 6.

[0047] The above embodiments of the present invention are not intended to limit the scope of protection of the present invention, and the implementation methods of the present invention are not limited thereto. All other modifications, replacements or changes made to the above structure of the present invention based on the above contents of the present invention, in accordance with common technical knowledge and customary means in this field, without departing from the above basic technical ideas of the present invention, should fall within the scope of protection of the present invention.

Claims

1. A powder metallurgy straight and helical double gear processing mold, comprising a middle mold with a cavity formed inside, characterized in that: The middle mold is provided with an upper punch and a lower punch in the mold closing direction, which can be screwed into the mold cavity to form the first-stage helical gear part when the mold is closed, a lower second punch that can be axially inserted through the lower punch and extended into the mold cavity to form the second-stage spur gear part, and a forming core rod that can axially insert through the lower second punch and extend into the mold cavity to cooperate with the upper punch to form the shaft hole.

2. The powder metallurgy straight and helical double gear processing die according to claim 1, characterized in that: The inner wall of the cavity of the middle die is provided with internal spiral teeth for guiding the upper punch and the lower punch to be screwed into the cavity along the axis of the middle die.

3. The powder metallurgy straight and helical double gear processing die according to claim 2, characterized in that: The upper punch includes an upper outer punch, the outer peripheral surface of which is provided with outer spiral teeth that can cooperate with the inner spiral teeth on the inner wall of the cavity of the middle mold; an upper inner punch is movably inserted into the upper outer punch, and the upper inner punch is provided with a first core rod insertion hole that can be plugged and cooperated with the forming core rod inserted into the cavity.

4. The powder metallurgy straight and helical double gear processing die according to claim 3, characterized in that: The outer peripheral surface of the next punch is provided with external helical teeth that can cooperate with the internal helical teeth on the inner wall of the cavity of the middle die; the next punch is provided with a through hole for the insertion of the second lower punch.

5. The powder metallurgy straight and helical double gear processing die according to claim 4, characterized in that: The inner wall of the through hole on the next punch is provided with inner straight teeth for guiding the lower second punch to axially penetrate through the next punch and extend into the cavity of the middle die.

6. The powder metallurgy straight and helical double gear processing die according to claim 5, characterized in that: The outer peripheral surface of the lower second punch is provided with external straight teeth that can cooperate with the internal straight teeth on the inner wall of the through hole of the lower punch.

7. The powder metallurgy straight and helical double gear processing die according to claim 6, characterized in that: The lower second punch is provided with a second core rod insertion hole for the forming core rod to be inserted.

8. The powder metallurgy straight and helical double gear processing die according to claim 7, characterized in that: The outer peripheral surface of the forming core rod is a smooth surface that can be fitted with the inner wall of the second core rod insertion hole.

9. The powder metallurgy straight and helical double gear processing die according to any one of claims 1 to 8, characterized in that: The upper punch, the lower punch, the lower second punch and the forming core rod are provided with connecting parts for connecting to the ejection mechanism of the press at the connecting ends, and the upper punch, the lower punch, the lower second punch and the forming core rod can rotate around the axis through the connecting parts when the mold is closed.

10. The powder metallurgy straight and helical double gear processing die according to claim 9, characterized in that: The connecting part includes a sleeve with a barrel cavity formed inside, a barrel mouth is provided on the sleeve, and a sleeve is provided with a sleeve hole on the barrel wall opposite to the barrel mouth. The upper punch, the next punch, the lower second punch or the forming core rod are inserted into the sleeve through the barrel mouth and pass out through the sleeve hole on the sleeve. The connecting end of the upper punch, the next punch, the lower second punch or the forming core rod can be rotatably sleeved in the barrel cavity, and the sleeve is provided with a barrel cover at the barrel mouth to close the barrel cavity.

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