A powder metallurgy bevel gear mold
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-02
- Publication Date
- 2026-08-11
AI Technical Summary
[0003]首先，加工难度较高，伞齿轮齿形为空间曲面，加工过程中需精确控制刀具与工件的相对位置和运动关系，对机床精度、刚性以及刀具刃磨质量要求极为苛刻，调整过程繁琐且依赖操作人员经验，一致性难以保障；其次，工艺路线复杂，生产周期长，传统滚齿加工通常需经过粗滚、半精滚、精滚等多道工序，部分甚至还需后续剃齿或磨齿修正，不仅工艺流程繁琐，在制品周转时间长，生产效率低下，也难以适应现代多品种、小批量的柔性生产需求；再者，加工效率低下，经济性不佳，由于切削速度、进给量等参数受限，单件加工耗时较长，刀具磨损严重，换刀与调整频次高，导致生产成本增加，批量生产时的效益显著受限；在加工质量方面，传统方法易因系统刚性不足、切削振动及让刀现象导致齿形误差、齿向偏差增大，齿面粗糙度难以稳定控制，影响齿轮啮合精度与传动平稳性，同时也会引起噪声和振动，缩短使用寿命；最后，整体强度与可靠性存在不足
[0017]In this embodiment, by setting up an upper punch, a lower punch, a lower second punch, and a forming mandrel, the upper punch and the lower punch can be inserted into the cavity of the middle mold during mold closing, and the lower second punch and the forming mandrel can be inserted into the cavity of the middle mold axially relative to the lower punch. This allows the bevel gear to be processed in one mold closing operation, which is beneficial to improving the processing quality, overall strength, and processing efficiency of the bevel gear.
Smart Images
Figure CN224615150U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of powder metallurgy bevel gear mold technology, and in particular to a powder metallurgy bevel gear mold. Background Technology
[0002] Bevel gears, due to their unique conical shape and tooth structure, play an irreplaceable role in the field of mechanical transmission. Their traditional manufacturing process mainly relies on gear hobbing machines for tooth profile machining. However, with the continuous improvement of industrial requirements for gear performance, efficiency, and reliability, this machining method has increasingly revealed a series of inherent defects:
[0003] First, the machining process is quite difficult. Bevel gears have a spatial curved tooth profile, requiring precise control of the relative position and motion between the tool and the workpiece. This places extremely stringent demands on machine tool precision, rigidity, and tool grinding quality. The adjustment process is cumbersome and relies heavily on operator experience, making consistency difficult to guarantee. Second, the process route is complex and the production cycle is long. Traditional gear hobbing typically involves multiple processes such as rough hobbing, semi-finish hobbing, and finish hobbing, and some even require subsequent shaving or grinding correction. This not only results in a cumbersome process and long work-in-process turnover time, but also low production efficiency, making it unsuitable for modern high-variety, small-batch production. The traditional method suffers from several drawbacks. Firstly, it demands flexible manufacturing. Secondly, it suffers from low processing efficiency and poor economic returns. Limited parameters such as cutting speed and feed rate result in long processing times for single pieces, severe tool wear, and frequent tool changes and adjustments, leading to increased production costs and significantly limiting the profitability of mass production. Thirdly, in terms of processing quality, traditional methods are prone to insufficient system rigidity, cutting vibration, and tool deflection, leading to increased tooth profile errors and tooth direction deviations. This makes it difficult to maintain stable control of tooth surface roughness, affecting gear meshing accuracy and transmission smoothness, while also causing noise and vibration and shortening service life. Finally, it suffers from insufficient overall strength and reliability. The cutting stress and potential microcracks generated during gear hobbing reduce tooth root fatigue strength. Furthermore, traditional processing methods struggle to achieve ideal tooth surface contact area morphology and strengthening effects, further limiting the gear's load-bearing capacity and reliability. Utility Model Content
[0004] The purpose of this invention is to provide a powder metallurgy bevel gear mold that can complete the bevel gear processing in one mold closing operation, thereby improving the processing quality, overall strength and processing efficiency of the bevel gear.
[0005] The objective of this utility model is achieved through the following technical solution:
[0006] A powder metallurgy bevel gear mold includes a middle mold with an internal cavity. The middle mold is provided with an upper punch and a lower punch that can enter the cavity to form the gear body when the mold is closed in the mold-closing direction, a lower second punch that can enter the lower punch axially and form the wheel shaft in the cavity, and a forming mandrel that can pass through the lower second punch axially into the cavity and cooperate with the upper punch to form a shaft hole. The upper punch is provided with conical teeth on the forming surface for forming the bevel gear portion.
[0007] Based on the above technical solution, the present invention can be improved as follows:
[0008] Furthermore, the next punch is provided with a through hole for the next second punch to pass through, and the next second punch is provided with a second mandrel insertion hole for the forming mandrel to pass through.
[0009] Furthermore, the upper punch is provided with a first mandrel insertion hole that can be inserted and engaged with the molding mandrel entering the cavity, and the upper punch is provided with an air hole on its outer peripheral surface that communicates with the first mandrel insertion hole.
[0010] Furthermore, the forming mandrel has a guide section and a forming section. When the mold is closed, the guide section of the forming mandrel can axially pass through the lower two punches, and the forming section of the forming mandrel can enter the cavity inside the mold core and connect with the upper punch to complete the forming of the shaft hole.
[0011] Furthermore, the upper punch includes an upper outer punch that can enter the cavity to form the gear body when the mold is closed, and an upper inner punch that can enter the cavity to form a circular groove when the mold is closed is inserted inside the upper outer punch.
[0012] Furthermore, the upper outer punch has a through hole in the middle for the upper inner punch to pass through, and the upper inner punch has a first mandrel insertion hole that can be inserted and engaged with the molding mandrel that enters the cavity.
[0013] Furthermore, the upper outer punch has a first vent hole on its outer peripheral surface that connects to the through hole, and the upper inner punch has a second vent hole on its outer peripheral surface that connects to the first mandrel insertion hole.
[0014] Furthermore, the bottom surface of the upper outer punch is the forming surface, and tapered teeth are provided on the forming surface.
[0015] Furthermore, the forming mandrel has a guide section and a forming section. When the mold is closed, the guide section of the forming mandrel can axially pass through the lower second punch, and the forming section of the forming mandrel can enter the cavity inside the mold core and connect with the upper inner punch to complete the forming of the shaft hole.
[0016] Compared with the prior art, the present invention has the following advantages:
[0017] In this embodiment, by setting up an upper punch, a lower punch, a lower second punch, and a forming mandrel, the upper punch and the lower punch can be inserted into the cavity of the middle mold during mold closing, and the lower second punch and the forming mandrel can be inserted into the cavity of the middle mold axially relative to the lower punch. This allows the bevel gear to be processed in one mold closing operation, which is beneficial to improving the processing quality, overall strength, and processing efficiency of the bevel gear. Attached Figure Description
[0018] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0019] Figure 1 This is a schematic diagram of the bevel gear structure processed in Example 1;
[0020] Figure 2 This is a schematic diagram of the structure of the novel powder metallurgy bevel gear mold in Example 1;
[0021] Figure 3 for Figure 2 Enlarged view of section A in the image;
[0022] Figure 4 This is a schematic diagram of the mandrel structure.
[0023] Figure 5 This is a schematic diagram of the bevel gear structure processed in Example 2;
[0024] Figure 6 This is a schematic diagram of the structure of the novel powder metallurgy bevel gear mold in Example 2;
[0025] Figure 7 for Figure 6 A magnified view of section B in the image.
[0026] The markings on the attached diagram are as follows: 1-Bevel gear, 101-Gear body, 102-Axle, 103-Bevel tooth, 104-Shaft hole, 105-Circular groove, 2-Upper punch, 201-Upper outer punch, 2011-First air hole, 202-Upper inner punch, 2021-Second air hole, 3-Middle mold, 301-Mold sleeve, 302-Mold core, 4-Lower punch, 5-Lower second punch, 6-Forming mandrel, 601-Guide section, 602-Forming section. Detailed Implementation
[0027] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings. These descriptions are intended to aid in understanding the utility model but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.
[0028] Example 1
[0029] See Figures 1 to 4This embodiment relates to a powder metallurgy bevel gear mold, which is used in conjunction with a vertical press for longitudinally closing and integrally forming a bevel gear 1. The pressed bevel gear 1 includes a gear body 101 with a bevel tooth portion 103 formed at one end, a wheel axle 102 disposed at the other end of the gear body 101, and a shaft hole 104 axially penetrating the gear body 101 and the wheel axle 102.
[0030] The mold includes an upper punch 2, a middle die 3, a lower punch 4, a lower second punch 5, and a forming mandrel 6 arranged sequentially along the mold closing direction; the upper punch 2 is set on the upper ejection mechanism of the press; the middle die 3 is set on the worktable of the press, and a cavity for forming gears is formed inside the middle die 3; the lower punch 4, the lower second punch 5, and the forming mandrel 6 are set on the lower ejection mechanism of the press mechanism and are inserted sequentially from the outside to the inside.
[0031] When the mold is closed, the upper punch 2 and the lower punch 4 can enter the cavity of the middle mold 3 along the axis of the middle mold 3 to form the gear body 101. The lower second punch 5 passes through the lower punch 4 and enters the cavity of the middle mold 3 to form the wheel shaft 102. The forming mandrel 6 passes through the lower second punch 5 and enters the cavity of the middle mold 3 to cooperate with the upper punch 2 to form the shaft hole 104.
[0032] Specifically, the intermediate mold 3 includes a mold sleeve 301 that can be fixed on the press worktable with the pressure cover of the intermediate mold 3, and a mold core 302 disposed inside the mold sleeve 301; the mold sleeve 301 has a mating hole in the middle that mates with the mold core 302, and the mold core 302 is interference-fitted into the mating hole of the mold sleeve 301, and the end faces of the mold core 302 and the mold sleeve 301 are flush after mating; the mold core 302 has a cylindrical structure, and a cavity for forming the bevel gear 1 is formed inside the mold core 302, and the upper punch 2 and the lower punch 4 enter the cavity of the intermediate mold 3 along the axis of the intermediate mold 3 to form the gear body 101.
[0033] The top end of the upper punch 2 is a connecting end, which is connected to the upper ejection mechanism of the press. The upper punch 2 is a cylindrical structure with a smooth outer circumferential surface. The outer circumferential surface of the upper punch 2 cooperates with the inner wall of the cavity of the mold core 302 so that the upper punch 2 can enter the cavity inside the mold core 302 when the mold is closed. The upper punch 2 has a first mandrel insertion hole through the middle, and the shape of the first mandrel insertion hole corresponds to the shape of the shaft hole 104 to be formed. In this embodiment, the shaft hole 104 to be formed is a hole with a hexagonal cross section. Correspondingly, the first mandrel insertion hole is a hole with a hexagonal cross section so that the forming mandrel 6 entering the cavity can be inserted into the upper punch 2. The bottom surface of the upper punch 2 is a forming surface, and a conical tooth for forming the bevel tooth portion 103 of the bevel gear 1 is provided on the forming surface.
[0034] The upper punch 2 has air holes on its outer peripheral surface that connect to the first mandrel insertion hole, so that air can be discharged out of the first mandrel insertion hole when the forming mandrel 6 is inserted into the upper punch 2, and air can be drawn into the first mandrel insertion hole when the forming mandrel 6 is pulled out of the upper punch 2, so that the internal and external pressure of the upper punch 2 is balanced, ensuring normal mold opening and closing.
[0035] The bottom end of the next punch 4 is the connecting end, which is connected to the lower ejection mechanism of the press. The next punch 4 is a cylindrical structure, and the outer peripheral surface of the next punch 4 is provided with a smooth wall. The outer peripheral surface of the next punch 4 cooperates with the inner wall of the cavity of the mold core 302 so that the next punch 4 can enter the cavity inside the mold core 302 to complete the forming of the gear body 101 when the mold is closed.
[0036] The next punch 4 has a through hole in the middle for the next second punch 5 to pass through. The inner wall of the through hole on the next punch 4 is a smooth wall. The next second punch 5 is axially inserted into the next punch 4 and forms the wheel shaft 102 in the cavity of the middle mold 3.
[0037] The bottom end of the lower second punch 5 is the connecting end, which is connected to the lower ejection mechanism of the press. The lower second punch 5 is a cylindrical structure with a smooth outer circumferential surface. The outer circumferential surface of the lower second punch 5 cooperates with the inner wall of the through hole of the lower punch 4 so that the lower second punch 5 can enter the lower punch 4 axially during mold closing and complete the forming of the wheel axle 102 in the cavity inside the mold core 302.
[0038] The lower second punch 5 has a second core rod insertion hole through the middle for the forming core rod 6 to pass through. The inner wall of the second core rod insertion hole is a smooth wall surface, so that the forming core rod 6 can be axially inserted through the lower second punch 5 into the cavity of the middle mold 3 and connected with the upper punch 2 to complete the forming of the shaft hole 104.
[0039] The bottom end of the forming mandrel 6 is the connecting end, which is connected to the lower ejection mechanism of the press. The forming mandrel 6 is a long rod structure, consisting of a guide section 601 and a forming section 602 connected to the top of the guide section 601. The guide section 601 of the forming mandrel 6 has a circular cross-section, and the forming section 602 of the forming mandrel 6 has a hexagonal cross-section. When the mold is closed, the guide section 601 of the forming mandrel 6 can axially pass through the lower second punch 5, and the forming section 602 of the forming mandrel 6 enters the cavity inside the mold core 302 and is inserted with the upper punch 2 to complete the forming of the shaft hole 104.
[0040] In this embodiment, by setting up an upper punch 2, a lower punch 4, a lower second punch 5, and a forming mandrel 6, when the mold is closed, the upper punch 2 and the lower punch 4 can be inserted into the cavity of the middle mold 3, and the lower second punch 5 and the forming mandrel 6 can be inserted into the cavity of the middle mold 3 axially relative to the lower punch 4. This allows the bevel gear 1 to be processed in one mold closing operation, which not only improves production efficiency, but also makes the processed bevel gear 1 a one-piece molded structure, which is beneficial to improving the overall strength of the bevel gear 1.
[0041] Example 2
[0042] See Figures 5 to 7 The difference between this second embodiment and the first embodiment is that the bevel gear 1 pressed by the mold in this embodiment is also provided with a circular groove 105 on the end face where the bevel tooth part 103 is provided. The circular groove 105 is connected to the shaft hole 104 in the axle 102, and the groove diameter of the circular groove 105 is larger than the hole diameter of the shaft hole 104.
[0043] In this embodiment, the upper punch 2 includes an upper outer punch 201 and an upper inner punch 202 that is movably inserted into the upper outer punch 201. When the mold is closed, the upper outer punch 201 and the lower punch 4 enter the cavity of the middle mold 3 along the axis of the middle mold 3 to form the gear body 101, and the upper inner punch 202 passes through the upper outer punch 201 to enter the cavity of the middle mold 3 to form the circular groove 105.
[0044] Both the upper outer punch 201 and the inner and outer punches are cylindrical structures. The upper outer punch 201 has a through hole in the middle for the upper inner punch 202 to pass through. The outer peripheral surface of the upper outer punch 201 is a smooth wall surface. The outer peripheral surface of the upper outer punch 201 cooperates with the inner wall of the mold core 302 cavity so that the upper outer punch 201 can enter the cavity inside the mold core 302 when the mold is closed. The upper inner punch 202 has a smooth outer peripheral surface so that the upper inner punch 202 can smoothly pass through the upper outer punch 201 into the cavity. The upper inner punch 202 has a first mandrel insertion hole through the middle, and the shape of the first mandrel insertion hole corresponds to the shape of the shaft hole 104 to be formed. In this embodiment, the shaft hole 104 to be formed is a hole with a hexagonal cross-section. Correspondingly, the first mandrel insertion hole is a hole with a hexagonal cross-section so that the forming mandrel 6 entering the cavity can be inserted into the upper inner punch 202. The bottom surface of the upper outer punch 201 is a forming surface, and a bevel tooth for forming the bevel tooth portion 103 of the bevel gear 1 is provided on the forming surface.
[0045] The upper outer punch 201 has a first air hole 2011 on its outer peripheral surface that connects to the through hole, so that air can be discharged out of the through hole when the upper inner punch 202 is inserted into the upper outer punch 201, and air can be drawn into the through hole when the upper inner punch 202 is withdrawn from the upper outer punch 201, so that the internal and external pressure of the upper outer punch 201 is balanced; the upper inner punch 202 has a second air hole 2021 on its outer peripheral surface that connects to the first mandrel insertion hole, so that air can be discharged out of the first mandrel insertion hole when the forming mandrel 6 is inserted into the upper punch 2, and air can be drawn into the first mandrel insertion hole when the forming mandrel 6 is withdrawn from the upper punch 2, so that the internal and external pressure of the upper punch 2 is balanced; thereby ensuring normal mold opening and closing.
[0046] The bottom end of the next punch 4 is the connecting end, which is connected to the lower ejection mechanism of the press. The next punch 4 is a cylindrical structure, and the outer peripheral surface of the next punch 4 is provided with a smooth wall. The outer peripheral surface of the next punch 4 cooperates with the inner wall of the cavity of the mold core 302 so that the next punch 4 can enter the cavity inside the mold core 302 to complete the forming of the gear body 101 when the mold is closed.
[0047] The next punch 4 has a through hole in the middle for the next second punch 5 to pass through. The inner wall of the through hole on the next punch 4 is a smooth wall. The next second punch 5 is axially inserted into the next punch 4 and forms the wheel shaft 102 in the cavity of the middle mold 3.
[0048] The bottom end of the lower second punch 5 is the connecting end, which is connected to the lower ejection mechanism of the press. The lower second punch 5 is a cylindrical structure with a smooth outer circumferential surface. The outer circumferential surface of the lower second punch 5 cooperates with the inner wall of the through hole of the lower punch 4 so that the lower second punch 5 can enter the lower punch 4 axially during mold closing and complete the forming of the wheel axle 102 in the cavity inside the mold core 302.
[0049] The lower second punch 5 has a second core rod insertion hole through the middle for the forming core rod 6 to pass through. The inner wall of the second core rod insertion hole is a smooth wall surface, so that the forming core rod 6 can be axially inserted through the lower second punch 5 into the cavity of the middle mold 3, and then inserted into the upper inner punch 202 to complete the forming of the shaft hole 104.
[0050] The bottom end of the forming mandrel 6 is the connecting end, which is connected to the lower ejection mechanism of the press. The forming mandrel 6 is a long rod structure, consisting of a guide section 601 and a forming section 602 connected to the top of the guide section 601. The guide section 601 of the forming mandrel 6 has a circular cross-section, and the forming section 602 of the forming mandrel 6 has a hexagonal cross-section. When the mold is closed, the guide section 601 of the forming mandrel 6 can axially pass through the lower second punch 5, and the forming section 602 of the forming mandrel 6 enters the cavity inside the mold core 302 and is inserted with the upper inner punch 202 to complete the forming of the shaft hole 104.
[0051] In this embodiment, by setting an upper outer punch 201, an upper inner punch 202, a lower punch 4, a lower second punch 5, and a forming mandrel 6, when the mold is closed, the upper outer punch 201, the upper inner punch 202, and the lower punch 4 can be inserted into the cavity of the middle mold 3, and the lower second punch 5 and the forming mandrel 6 can be inserted into the cavity of the middle mold 3 axially relative to the lower punch 4. This allows the processing of the bevel gear 1 with the circular groove 105 to be completed in one mold closing, which not only improves production efficiency, but also makes the processed bevel gear 1 with the circular groove 105 an integrally formed structure, which is beneficial to improving the overall strength of the bevel gear 1.
[0052] The above embodiments of this utility model are not intended to limit the scope of protection of this utility model. The implementation of this utility model is not limited thereto. All other modifications, substitutions or alterations made to the above structure of this utility model based on the above content of this utility model and in accordance with the common technical knowledge and conventional means in the field, without departing from the basic technical idea of this utility model, shall fall within the scope of protection of this utility model.
Claims
1. A powder metallurgy bevel gear die comprising a middle die having a cavity formed therein, characterized by, The middle mold is provided with an upper punch and a lower punch that can enter the cavity to form the gear body when the mold is closed, a lower second punch that can enter the lower punch axially and form the wheel shaft in the cavity, and a forming mandrel that can pass through the lower second punch axially into the cavity and cooperate with the upper punch to form the shaft hole; the upper punch is provided with conical teeth on the forming surface for forming the bevel gear.
2. The powder metallurgy bevel gear die of claim 1, wherein, The next punch is provided with a through hole for the second punch to pass through, and the second punch is provided with a second mandrel insertion hole for the forming mandrel to pass through.
3. The powder metallurgy bevel gear die of claim 2, wherein, The upper punch is provided with a first mandrel insertion hole that can be inserted and engaged with the molding mandrel entering the cavity, and the upper punch is provided with an air hole on its outer peripheral surface that communicates with the first mandrel insertion hole.
4. The powder metallurgy bevel gear die of claim 3, wherein, The forming mandrel has a guide section and a forming section. When the mold is closed, the guide section of the forming mandrel can axially pass through the lower two punches, and the forming section of the forming mandrel can enter the cavity inside the mold core and connect with the upper punch to complete the forming of the shaft hole.
5. The powder metallurgy bevel gear die of claim 2 wherein, The upper punch includes an upper outer punch that can enter the cavity to form the gear body when the mold is closed, and an upper inner punch that can enter the cavity to form a circular groove when the mold is closed is inserted inside the upper outer punch.
6. The powder metallurgy bevel gear die of claim 5, wherein, The upper outer punch has a through hole in the middle for the upper inner punch to pass through, and the upper inner punch has a first mandrel insertion hole that can be inserted and engaged with the molding mandrel that enters the cavity.
7. The powder metallurgy bevel gear die of claim 6, wherein, The upper outer punch has a first vent hole on its outer peripheral surface that connects to the through hole, and the upper inner punch has a second vent hole on its outer peripheral surface that connects to the first mandrel insertion hole.
8. The powder metallurgy bevel gear mold according to claim 7, characterized in that, The bottom surface of the upper outer punch is the forming surface, and tapered teeth are provided on the forming surface.
9. The powder metallurgy bevel gear mold according to claim 8, characterized in that, The forming mandrel has a guide section and a forming section. When the mold is closed, the guide section of the forming mandrel can axially pass through the lower two punches, and the forming section of the forming mandrel can enter the cavity inside the mold core and connect with the upper inner punch to complete the forming of the shaft hole.