Continuous self-ejection cold press forming device for gear manufacturing

Abstract

The invention discloses a continuous self-ejection cold press forming device for gear manufacturing, relates to the technical field of gear machining, and aims at the ejection process of a cold-pressed gear blank in a gear blank powder metallurgy process, which is different from a conventional upper ejection mode, adopts a lower stripping action mode. Firstly, an oil pressure detection mode composed of a fixed sleeve and a pressure conical cap is additionally arranged at the center point position of a forming pressing core, and the oil pressure detection mode can be applied to the forming pressure detection process in the forming stage and can also be used as the pressure detection process in the stripping process. In the stripping process, the contact area between a gear blank and the inner wall of a forming cavity is reduced by moving a dynamic arc-shaped block, in this way, the damage degree of the gear blank in the stripping process is reduced, and a set material conical head is additionally arranged in cooperation with a stripping base and used for stabilizing the structural strength of the gear blank in the stripping process.

Description

Technical Field

[0001] This invention relates to the field of gear processing technology, and specifically to a continuous self-ejecting cold pressing forming apparatus for gear manufacturing. Background Technology

[0002] To meet the requirements of complex structural shapes or mass production, powder metallurgy / casting processes can be used to complete the automated manufacturing process of gears. Taking powder metallurgy as an example, the mixed powder in the mold cavity is continuously extruded under high pressure to form a gear blank with a density of 85% to 95%, and finally the shape is completed by sintering.

[0003] The forming quality of gear blanks is one of the key factors affecting product quality. Therefore, the blank ejection process needs to be explained: Because the compression rate of the mixed powder needs to be ensured, the cavity during the extrusion process is in a relatively sealed state, which can be indirectly understood as the gear blank being in "close contact" with the inner wall of the cavity. If a conventional material feeding method is used (such as the ejection structure involved in CN107335739A), then the blank will suffer varying degrees of damage during ejection, such as local collapse or material shortage. If the semi-finished gear formed from this blank is a defective or unqualified product, this invention proposes a solution. Summary of the Invention

[0004] The purpose of this invention is to provide a continuous self-ejecting cold pressing forming device for gear manufacturing. In the powder metallurgy process of gear parts, when the gear blank is ejected from the cavity, it will cause secondary damage to the blank, such as local collapse, material shortage, etc., which will affect the subsequent gear shaping quality.

[0005] The objective of this invention can be achieved through the following technical solution: a continuous self-ejecting cold pressing forming device for gear manufacturing, comprising a tower and a working seat, wherein the working seat and the tower are fixedly connected, and a forming core and a forming cavity with a corresponding forming core are provided in the center area of ​​the working seat;

[0006] The work seat is provided with a material support seat directly below the forming cavity, the center point of the forming core is provided with a fixed sleeve and a pressure cone cap, and the material support seat is provided with a fixed cone head corresponding to the pressure cone cap;

[0007] Multiple sets of dynamic arc-shaped blocks are arranged on the inner wall of the forming cavity, and annular oil passages corresponding to the dynamic arc-shaped blocks are opened in the working seat.

[0008] Further configuration: a connecting seat is installed on the forming core, and power components two and one corresponding to the connecting seat and the material support seat are respectively installed at the upper and lower ends of the tower, and power component three corresponding to the material support cone is installed in the material support seat.

[0009] The configuration is further defined as follows: the fixed sleeve, the pressure cone cap, and the forming core are respectively connected in a fixed manner and in a sliding manner, and the fixed sleeve and the pressure cone cap are combined to form an oil pressure detection structure.

[0010] The connection seat is further configured to include an oil pressure detection assembly corresponding to the fixed sleeve and pressure cone cap.

[0011] Further configuration: an air-avoiding annular groove is formed on the inner wall position of the forming cavity corresponding to the dynamic arc block, the dynamic arc block is arranged in a ring array along the center point area of ​​the forming cavity, and a spring piston assembly is arranged on the outer wall center point area of ​​one side of the annular oil passage corresponding to the dynamic arc block.

[0012] The design further includes: the cross-section of the lower end of the pressure cone is a concave cone shape, and the upper end of the material-fixing cone matches the contour surface of the lower end of the pressure cone.

[0013] A further configuration is provided: a vertically downward directional rod is installed at the center point of the pressure cone cap, the directional rod extends to the interior of the material-fixing cone head and maintains a sliding connection with the material-fixing cone head.

[0014] A further setting is made so that when the cold pressing action is performed by the forming core, the lower end of the pressure cone cap and the upper end of the material-fixing cone cap do not directly contact each other.

[0015] The present invention has the following beneficial effects:

[0016] 1. Regarding the gear blank ejection process in gear powder metallurgy, the forming core is first improved by adding a hydraulic detection method consisting of a pressure sleeve and a pressure cone cap in its center area. In the overall powder metallurgy process, this can be used as a pressure detection process during cold pressing to provide feedback on the forming quality of the gear blank, and also as a pressure feedback process during the unloading process after the gear blank is formed, thus avoiding the risk of damage caused by pressure fluctuations during the overall unloading process.

[0017] 2. The blank ejection process is explained as follows: Unlike the conventional top ejection method, a bottom ejection action is adopted. The key is the forming cavity formed by the combination of dynamic arc blocks. By limiting the arc length and the number of dynamic arc blocks, a complete ring shape is formed. The key point is that after the gear blank is formed, the dynamic arc blocks are used to reset and separate from the outer wall of the gear blank. The purpose is to reduce the contact area between the gear blank and the inner wall of the forming cavity (dynamic arc blocks), so as to avoid the quality risk of the outer wall of the gear blank collapsing due to stress changes during the ejection process. Finally, a movable fixed cone is added at the center point of the support seat. On the one hand, it works with the fixed sleeve and pressure cone to form a lower support structure. On the other hand, when the gear blank is ejected downwards, the movement of the fixed cone relative to the support seat is restricted. On the basis of achieving the purpose of ejection, the fixed cone stabilizes the structural strength of the gear blank on the support seat. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a continuous self-ejecting cold pressing forming device for gear manufacturing proposed in this invention;

[0020] Figure 2 For the present invention Figure 1 Cross-sectional view of the central tower;

[0021] Figure 3 This is a horizontal cross-sectional view of the annular oil passage corresponding to the working seat in this invention;

[0022] Figure 4 In this invention Figure 4 Top view;

[0023] Figure 5 This is a cross-sectional view of the working seat in this invention corresponding to its center point;

[0024] Figure 6 For the present invention Figure 5 The front view.

[0025] In the diagram: 1. Tower; 2. Working seat; 3. Material support seat; 4. Power component one; 5. Power component two; 6. Forming core; 7. Hydraulic pressure detection assembly; 8. Power component three; 9. Connecting seat; 10. Annular oil passage; 11. Dynamic arc block; 12. Spring piston assembly; 13. Fixed sleeve; 14. Pressure cone cap; 15. Fixed material cone head; 16. Directional rod. Detailed Implementation

[0026] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1: In the powder metallurgy process of gear parts, secondary damage can occur to the gear blank when it is ejected from the cavity, such as local collapse or material shortage, which affects the subsequent gear shaping quality. The following technology is proposed to address this issue:

[0028] Reference Figures 1-6 The gear manufacturing continuous self-ejecting cold pressing forming device in this embodiment includes a tower 1 and a working seat 2. The working seat 2 is fixedly connected to the tower 1, and a forming core 6 and a forming cavity with a corresponding forming core 6 are provided in the center area of ​​the working seat 2.

[0029] The work seat 2 is provided with a material support seat 3 directly below the forming cavity. The center point of the forming core 6 is provided with a fixed sleeve 13 and a pressure cone cap 14. The material support seat 3 is provided with a fixed material cone head 15 corresponding to the pressure cone cap 14.

[0030] Multiple sets of dynamic arc blocks 11 are arranged on the inner wall of the forming cavity. The working seat 2 has an annular oil passage 10 corresponding to the dynamic arc blocks 11. A connecting seat 9 is installed on the forming core 6. The upper and lower ends of the tower 1 are respectively equipped with the power component 2 5 and the power component 1 4 corresponding to the connecting seat 9 and the material support seat 3. The material support seat 3 is equipped with the power component 3 8 corresponding to the fixed cone head 15.

[0031] Basic working principle: Refer to powder metallurgy process in gear manufacturing. Figure 6 The process involves introducing a fixed amount of alloy powder into the forming cavity. After the forming core 6 moves downward and squeezes the alloy powder in the forming cavity, a gear blank is formed under high pressure. This is the basic process of gear powder forming. After forming, the gear blank can also be ejected by the material support 3. However, the difference in this invention is that the material support 3 moves downward instead of upward, and the forming core 6 does not need to provide downward pressure on the gear blank.

[0032] Key contents of this invention refer to Figure 4 The inner wall position of each dynamic arc-shaped block 11 is perfectly matched with the gear component. In the initial state, by pumping high-pressure hydraulic oil into the annular oil passage 10, each dynamic arc-shaped block 11 simultaneously moves towards the center point region of the forming cavity. Figure 4 It can be understood that the arc length of each dynamic arc block 11 needs to be determined according to its quantity. If the number of dynamic arc blocks 11 is n and the maximum arc length of the forming cavity is K, then the arc length of each dynamic arc block 11 is K / n. The purpose is to ensure the maximum displacement distance of each dynamic arc block 11.

[0033] Thus, when the gear blank is being supported, the high-pressure hydraulic oil in the annular oil passage 10 is pumped out, and the elastic potential energy of the spring piston assembly 12 can be used to reset the dynamic arc block 11 to the outside. Specifically, a clearance is opened in a local position in the forming cavity to maintain the spatial mobility of the dynamic arc block 11 during the sliding process, so as to avoid damage to the gear blank due to the contact force between the gear blank and the inner wall of the forming cavity when the gear blank is ejected.

[0034] Example 2: The following technical solution is provided to supplement the overall material ejection process regarding the movement of the material support:

[0035] The fixed sleeve 13, pressure cone cap 14, and forming core 6 are respectively connected in a fixed manner and in a sliding manner. The fixed sleeve 13 and pressure cone cap 14 are combined to form a hydraulic pressure detection structure 7. The connecting seat 9 is provided with hydraulic pressure detection components corresponding to the fixed sleeve 13 and pressure cone cap 14. An anti-cavity annular groove is formed on the inner wall of the forming cavity corresponding to the dynamic arc block 11. The dynamic arc block 11 is arranged in a ring array along the center point area of ​​the forming cavity, and the dynamic arc block 11 is provided with a corresponding feature on the outer wall center point area of ​​one side of the annular oil passage 10. The spring piston assembly 12 has a cross-section at the lower end of the pressure cone cap 14 that is concave upwards. The upper end of the fixed cone head 15 matches the contour surface of the lower end of the pressure cone cap 14. A vertically downward directional rod 16 is installed at the center point of the pressure cone cap 14. The directional rod 16 extends into the interior of the fixed cone head 15 and maintains a sliding connection with the fixed cone head 15. When the cold pressing action is performed by the forming core 6, the lower end of the pressure cone cap 14 and the upper end of the fixed cone head 15 do not directly contact each other.

[0036] Improvement Scheme 1: First, add a pressure sleeve 13 and a pressure cone cap 14 to the forming core 6. According to the thickness requirements in the gear forming process, limit the relative position of the pressure cone cap 14 to the fixed cone head 15. It is required that there is always a gap between the pressure cone cap 14 and the fixed cone head 15. Specifically, the position of the fixed cone head 15 is actively adjusted by the power component 3 8.

[0037] Because the center point area of ​​the gear parts mostly needs to be drilled to form roller holes, the pressure sleeve 13 and the pressure cone cap 14 will not directly affect the forming specifications of the gear parts, and can save alloy powder material. The gap between the pressure sleeve 13 and the pressure cone cap 14 is mainly used to feed back the pressure changes during the forming process. Specifically, the alloy powder is squeezed against each other under high pressure, and the lower structure of the pressure cone cap 14 makes it more susceptible to the extrusion force from the alloy powder and tends to move upward. The upper part of the pressure cone cap 14 and the fixed sleeve 13 form a hydraulic cylinder structure, and the hydraulic pressure change can be obtained in real time through the hydraulic pressure detection component 7 to indirectly feed back the high pressure compression degree of the alloy powder.

[0038] Improvement Scheme 2: Explanation of the structure of dynamic arc block 11: The height of dynamic arc block 11 determines the thickness of the gear blank after high pressure forming. After each dynamic arc block 11 is fully close together, a complete ring is formed. After the hydraulic pressure of high pressure hydraulic oil is lost, it can be reset under the action of spring piston assembly 12. Its key purpose is to eliminate the contact force between the outer wall of the gear blank and the dynamic arc block 11, and avoid the problem of the outer wall of the gear blank collapsing due to uneven force distribution during the unloading process.

[0039] Improvement Scheme 3: As shown in Embodiment 1, the key content of this invention lies in the unloading method of the gear blank during the unloading process. The gear blank is moved downwards by the active downward movement of the support seat 3 until it is completely detached from the forming cavity. Finally, the power component 3 8 drives the fixed cone 15 to move completely downwards in conjunction with the support seat 3 until the upper part of the fixed cone 15 is lower than the upper surface of the support seat 3. However, in actual practice, the following actions are also included:

[0040] S1: After the high-pressure forming process of the gear blank is completed, the dynamic arc block 11 does not directly return to the clearance area. Instead, the forming core 6 and the material support 3 continue to move downwards, and the downward movement distance is less than or equal to one-third of the thickness of the gear blank. Figure 6 As shown, the lower third of the gear blank will completely detach from the forming cavity and will not come into contact with other structures. The purpose is to reduce the degree of stress difference that the outer wall of the gear blank may be subjected to by reducing the contact area between the gear blank and the dynamic arc block 11, thereby reducing the degree of damage to the outer wall of the gear blank.

[0041] S2: Combined with S1, when the forming core 6 and the material support 3 move down synchronously, the fixed sleeve 13, pressure cone cap 14 and fixed material cone head 15 will also move down synchronously. The hydraulic pressure detection component 7 is used for this purpose. Its essence is to provide feedback on the damage that may occur when the gear blank is initially ejected based on the hydraulic pressure change. If the gear blank and the dynamic arc block 11 are damaged due to the large contact force, the hydraulic pressure in the hydraulic pressure detection component 7 will fluctuate significantly. This method can be used to initially judge the quality status of the gear blank when it is unloaded.

[0042] S3: The key is that after the gear blank moves down by one-third of its thickness, the forming core 6 stops moving, and multiple dynamic arc blocks 11 synchronously reset to the outside after losing hydraulic pressure, so that the outer wall of the entire gear blank will not come into contact with any structure. However, when the forming core 6 resets upward, the power component 3 8 is needed to actively drive the fixed cone 15 to move down and the power component 1 4 to drive the support seat 3 to move down. During this process, the gear blank moves down synchronously with the support seat 3 until the gear blank is completely separated from the forming cavity.

[0043] However, when the gear blank and the material support 3 move down synchronously, the fixed cone 15 moves further relative to the material support 3. It can be understood that the fixed cone 15 is completely separated from the gear blank before the coating seat 3.

[0044] In summary, the ejection process of cold-pressed gear blanks in powder metallurgy is different from the conventional top ejection method, instead employing a bottom ejection action. Firstly, a hydraulic detection method consisting of a fixed sleeve and a pressure cone cap is added to the center point of the forming core. This method can be used for pressure detection during the forming stage and also for pressure detection during the ejection process. The key aspect is that the movement of multiple dynamic arc blocks changes the annular diameter of the forming cavity. During the ejection process, the contact area between the gear blank and the inner wall of the forming cavity is reduced by moving the dynamic arc blocks, thereby reducing the damage to the gear blank during ejection. Furthermore, a setting cone is added to the ejection seat to stabilize the structural strength of the gear blank during ejection.

[0045] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A continuous self-ejecting cold pressing forming apparatus for gear manufacturing, comprising a tower (1) and a work stand (2), characterized in that, The work base (2) is fixedly connected to the tower (1), and the center point area of ​​the work base (2) is provided with a forming core (6) and a forming cavity with a corresponding forming core (6); The work seat (2) is provided with a material support seat (3) directly below the forming cavity. The center point of the forming core (6) is provided with a fixed sleeve (13) and a pressure cone cap (14). The material support seat (3) is provided with a fixed cone head (15) corresponding to the pressure cone cap (14). Multiple sets of dynamic arc blocks (11) are provided on the inner wall of the molding cavity, and annular oil passages (10) corresponding to the dynamic arc blocks (11) are opened in the working seat (2).

2. The gear manufacturing continuous self-ejecting cold pressing forming apparatus according to claim 1, characterized in that, The forming core (6) is equipped with a connecting seat (9), and the upper and lower ends of the tower (1) are respectively equipped with the power component two (5) and the power component one (4) of the corresponding connecting seat (9) and the material support seat (3). The material support seat (3) is equipped with the power component three (8) of the corresponding fixed cone head (15).

3. The gear manufacturing continuous self-ejecting cold pressing forming apparatus according to claim 1, characterized in that, The fixed sleeve (13), pressure cone cap (14) and forming core (6) are respectively connected in a fixed manner and in a sliding manner, and the fixed sleeve (13) and pressure cone cap (14) are combined to form an oil pressure detection structure (7).

4. The gear manufacturing continuous self-ejecting cold pressing forming apparatus according to claim 3, characterized in that, The connecting seat (9) is equipped with a corresponding oil pressure detection component for the fixed sleeve (13) and pressure cone cap (14).

5. The gear manufacturing continuous self-ejecting cold pressing forming apparatus according to claim 1, characterized in that, The forming cavity forms an air-avoiding annular groove on the inner wall of the dynamic arc block (11). The dynamic arc block (11) is arranged in a ring array along the center point area of ​​the forming cavity, and a spring piston assembly (12) is provided on the outer wall center point area of ​​one side of the annular oil passage (10) corresponding to the dynamic arc block (11).

6. The gear manufacturing continuous self-ejecting cold pressing forming apparatus according to claim 1, characterized in that, The cross-section of the lower end of the pressure cone cap (14) is a concave cone shape, and the upper end of the material-fixing cone (15) matches the contour surface of the lower end of the pressure cone cap (14).

7. A continuous self-ejecting cold pressing forming apparatus for gear manufacturing according to claim 6, characterized in that, A vertically downward directional rod (16) is installed at the center point of the pressure cone cap (14). The directional rod (16) extends to the interior of the material-fixing cone head (15) and maintains a sliding connection with the material-fixing cone head (15).

8. The gear manufacturing continuous self-ejecting cold pressing forming apparatus according to claim 7, characterized in that, When the cold pressing action is performed by the forming core (6), the lower end of the pressure cone cap (14) and the upper end of the material-fixing cone head (15) do not directly contact each other.

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