A powder metallurgy hydraulic press

Abstract

The present invention relates to the technical field of powder metallurgy hydraulic presses, and particularly to a powder metallurgy hydraulic press, which includes a hydraulic press body. A workbench is fixedly installed inside the hydraulic press body. A gear die is fixedly connected through the workbench. A pressurizing mechanism is rotatably connected to a moving frame. An adjusting seat is rotatably connected to the pressurizing mechanism. A powder pre-pressing plate is arranged on the lower side of the adjusting seat. When the powder metallurgy is carried out by the hydraulic press body, the powder pre-pressing plate is driven by the pressurizing mechanism to perform pre-pressurization after each layer of powder is added, which can effectively reduce the voids between each layer of powder, improve the contact degree between powder particles, and contribute to the subsequent forming process. Each layer of powder will be compacted under the pre-pressurization. This layer-by-layer compaction process helps to improve the density of the final workpiece. A higher density means that the mechanical properties (such as strength, hardness, wear resistance, etc.) of the part can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of powder metallurgy hydraulic presses, and particularly to a powder metallurgy hydraulic press. Background Art

[0002] A powder metallurgy hydraulic press is a device specifically used in the powder metallurgy forming process, mainly used to press metal powders or other powder materials into parts with specific shapes. The hydraulic press provides high pressure through a hydraulic system to compress the powder to achieve the required density, shape, and performance. Powder metallurgy hydraulic presses are widely used in the production of automotive parts, mechanical components, electronic components, tools, medical devices, etc.

[0003] The working principle of a powder metallurgy hydraulic press is based on the pressure action of the hydraulic system, and the specific steps are as follows:

[0004] Powder filling: First, metal powders or other powder materials are evenly filled into a mold, which usually consists of an upper mold and a lower mold. Hydraulic pressurization: The hydraulic system transmits high pressure to the upper mold, and compacts the powder through the action of a piston. This process usually applies a relatively large pressure (hundreds to thousands of tons), making the powder particles tightly combined and the shape fixed. Forming: During the pressing process, the powder is evenly compacted into the required shape, which can be circular, square, irregular, etc., depending on the design of the mold.

[0005] When the existing powder metallurgy hydraulic press is in use, when the powder is directly pushed into the mold, the distribution and filling of the powder are easily affected by the operation method and powder characteristics (such as particle size, shape, fluidity, etc.), resulting in uneven filling. Uneven powder filling will lead to uneven density during the forming process, forming pores, cracks, or non-dense structures, ultimately affecting the quality of the product (such as strength, wear resistance, etc.). Especially when producing gears, uneven filling will exacerbate their defect problems, thereby affecting the quality of the gears and causing safety problems and service life issues during the use of the gears.

[0006] In summary, in the prior art, there is a lack of technology for adding powder in layers and performing pre-pressurization for powder metallurgy hydraulic presses. Summary of the Invention

[0007] The purpose of the present invention is to solve the drawbacks existing in the background art, and to propose a powder metallurgy hydraulic press.

[0008] In order to achieve the above purpose, the technical solution adopted by the present invention is: a powder metallurgy hydraulic press, including a hydraulic press body, a workbench is fixedly installed on the hydraulic press body, a gear mold is fixedly connected to the workbench, a mobile frame is slidably provided on one side of the workbench, a powder feeding seat is slidably provided on the mobile frame, a knocking mechanism is rotatably connected on the powder feeding seat, a pressurizing mechanism is rotatably connected on the mobile frame, an adjusting seat is rotatably connected on the pressurizing mechanism, and a powder pre-pressing plate is provided on the lower side of the adjusting seat.

[0009] Preferably, a hydraulic rod is connected and fixedly arranged at one end of the movable frame, the hydraulic rod is connected and fixedly arranged at the workbench, and a fixed rack is connected and fixedly arranged at one side of the movable frame.

[0010] Preferably, the bottom surface of the powder loading seat is slidably matched with the top surface of the workbench, an electric push rod is fixedly connected to one side of the powder loading seat, the other end of the electric push rod is fixedly connected to the movable frame, a material guide pipe is connected and fixedly provided through the top of the powder loading seat, and an extrusion plate is fixedly provided on the material guide pipe.

[0011] Preferably, the knocking mechanism includes a universal joint, which is rotatably connected to the material guide tube, one end of the universal joint is connected and fixedly provided with a transmission wheel, the transmission wheel is meshing and transmitting with a fixed rack, the other end of the universal joint is connected and fixedly provided with an incomplete bevel gear, both sides of the incomplete bevel gear are movably meshing and transmitting with bevel gears, a knocking rod is connected and fixedly provided between the two bevel gears, the knocking rod is rotatably connected to the powder loading seat, and both ends of the knocking rod are movably contacted with the upper surface of the powder loading seat.

[0012] Preferably, the pressurizing mechanism includes two connecting rod groups, one end of the connecting rod group is rotatably connected to the movable frame, and the other end of the connecting rod group is rotatably connected to the adjustment seat, one end of the connecting rod group connected to the movable frame is connected and fixedly provided with a rotating shaft, the other end of the rotating shaft is connected and fixedly provided with an adjusting wheel, the adjusting wheel is meshingly provided with an adjusting rack, one end of the adjusting rack is slidably matched with the movable frame, one end of the adjusting rack is connected and fixedly provided with a conical rod, and the outer wall of the conical rod is slidably contacted with the extrusion plate.

[0013] Preferably, a transmission rod is rotatably connected to the adjustment seat, an adjustment groove is provided on the outer wall of the transmission rod, a worm wheel is fixedly connected to the top of the transmission rod, a worm is meshingly transmitted with a worm on one side of the worm wheel, the worm is rotatably connected to the adjustment seat, a tension spring A is fixedly connected to the adjustment seat, and the other end of the tension spring A is fixedly connected to the movable frame.

[0014] Preferably, one end of the worm is fixedly connected with a meshing wheel. A tooth rack is arranged on one side of the meshing wheel. The tooth rack is fixedly connected with the moving frame. A plurality of meshing teeth are rotatably connected to the tooth rack in a linear structure. One end of each meshing tooth is fixedly connected with a spring A, and the other end of the spring A is fixedly connected with the inner wall of the tooth rack.

[0015] Preferably, the powder pre-pressing plate is arranged in a tooth-shaped structure. The outer wall of the powder pre-pressing plate is slidably matched with the inner wall of the gear die. An adjusting frame is slidably matched on the powder pre-pressing plate. Springs B are sleeved on the outer walls of both ends on the upper side of the powder pre-pressing plate.

[0016] Preferably, one side of the upper end of the adjusting frame is slidably matched with the adjusting seat. A tension spring B is fixedly connected to the adjusting frame, and the other end of the tension spring B is fixedly connected with the adjusting seat. The other side of the upper end of the adjusting frame is fixedly connected with a guide rod, and the guide rod is slidably matched with the inner wall of the adjusting groove.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. When the hydraulic press body performs powder metallurgy, the powder pre-pressing plate is driven by the pressing mechanism to perform pre-pressing after each layer of powder is added, which can effectively reduce the voids between each layer of powder, improve the contact degree between powder particles, and contribute to the subsequent forming process. Each layer of powder will be compacted under pre-pressing, and this layer-by-layer compaction process helps to increase the density of the final workpiece. A higher density means that the mechanical properties (such as strength, hardness, wear resistance, etc.) of the part can be effectively improved;

[0019] 2. When the hydraulic press body performs powder metallurgy, the powder is added in layers through the powder feeding seat. The amount of powder added each time is relatively small, and it can be more evenly distributed in the mold, which helps to avoid voids or uneven areas during the powder filling process, ensuring a higher density of the finally pressed part. Avoid adding a large amount of powder at one time, which may lead to uneven powder filling or phenomena such as accumulation and collapse. By adding powder in layers, it can be gradually filled to reduce this risk;

[0020] 3. By arranging a knocking mechanism on the powder feeding seat, when the powder feeding seat adds powder to the gear die, the knocking rod continuously knocks on the powder feeding seat, which can make the powder in the powder feeding seat completely fall into the gear die, reduce the adhesion of the powder on the powder feeding seat, and ensure the accuracy of the feeding amount. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of a powder metallurgy hydraulic press of the present invention;

[0022] Figure 2Schematic diagram of a partial structure of a powder metallurgy hydraulic press of the present invention when not feeding materials;

[0023] Figure 3 Schematic diagram of a partial structure of a powder metallurgy hydraulic press of the present invention when feeding materials;

[0024] Figure 4 Schematic diagram of the moving frame structure of a powder metallurgy hydraulic press of the present invention;

[0025] Figure 5 Partial sectional view schematic diagram of the powder feeding seat structure of a powder metallurgy hydraulic press of the present invention;

[0026] Figure 6 Expanded schematic diagram of the knocking mechanism structure of a powder metallurgy hydraulic press of the present invention;

[0027] Figure 7 Schematic diagram of the pressurizing mechanism structure of a powder metallurgy hydraulic press of the present invention;

[0028] Figure 8 Expanded schematic diagram of the adjusting seat structure of a powder metallurgy hydraulic press of the present invention;

[0029] Figure 9 Schematic diagram of the powder pre - pressing plate structure of a powder metallurgy hydraulic press of the present invention.

[0030] In the figure, the markings are: 1. Hydraulic press body; 2. Workbench; 3. Gear die; 4. Moving frame; 5. Powder feeding seat; 6. Knocking mechanism; 7. Pressurizing mechanism; 8. Adjusting seat; 9. Powder pre - pressing plate; 401. Hydraulic rod; 402. Fixed rack; 501. Electric push rod; 502. Feeding pipe; 503. Extrusion plate; 601. Universal joint; 602. Driving wheel; 603. Incomplete bevel gear; 604. Bevel gear; 605. Knocking rod; 701. Link group; 702. Rotating shaft; 703. Adjusting wheel; 704. Adjusting rack; 705. Tapered rod; 801. Transmission rod; 802. Adjusting groove; 803. Worm gear; 804. Worm; 805. Spring A; 806. Meshing wheel; 807. Tooth rack; 808. Meshing teeth; 809. Spring A; 901. Adjusting frame; 902. Spring B; 903. Spring B; 904. Guide rod. Detailed implementation manners

[0031] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments in the following description are only examples, and those skilled in the art can think of other obvious variations.

[0032] As Figures 1 - 9A powder metallurgy hydraulic press shown in the figure includes a hydraulic press body 1. A workbench 2 is fixedly installed inside the hydraulic press body 1. A gear die 3 is fixedly connected and penetrated through the workbench 2. A moving frame 4 is slidably fitted on one side of the workbench 2. A powder feeding seat 5 is slidably fitted on the moving frame 4. A knocking mechanism 6 is rotatably connected to the powder feeding seat 5. A pressing mechanism 7 is rotatably connected to the moving frame 4. An adjusting seat 8 is rotatably connected to the pressing mechanism 7. A powder pre-pressing plate 9 is arranged on the lower side of the adjusting seat 8.

[0033] As Figure 4 shown, one end of the moving frame 4 is fixedly connected with a hydraulic rod 401, and the hydraulic rod 401 is fixedly connected with the workbench 2. A fixed rack 402 is fixedly connected to one side of the moving frame 4. The hydraulic rod 401 is used to drive the moving frame 4 to move, so that the powder pre-pressing plate 9 is located directly above the gear die 3.

[0034] As Figure 5 shown, the bottom surface of the powder feeding seat 5 is slidably fitted with the top surface of the workbench 2. One side of the powder feeding seat 5 is fixedly connected with an electric push rod 501, and the other end of the electric push rod 501 is fixedly connected with the moving frame 4. A guide pipe 502 is fixedly connected and penetrated through the top end of the powder feeding seat 5. An extrusion plate 503 is fixedly connected to the guide pipe 502. The metal powder is injected into the powder feeding seat 5 through the guide pipe 502, and then the electric push rod 501 is used to drive the powder feeding seat 5 to move above the gear die 3.

[0035] As Figure 6 shown, the knocking mechanism 6 includes a universal joint 601. The universal joint 601 is rotatably connected to the guide pipe 502. One end of the universal joint 601 is fixedly connected with a transmission wheel 602. The transmission wheel 602 is meshed and driven with the fixed rack 402. The other end of the universal joint 601 is fixedly connected with an incomplete bevel gear 603. Incomplete bevel gears 604 are movably meshed and driven on both sides of the incomplete bevel gear 603. A knocking rod 605 is fixedly connected between the two bevel gears 604. The knocking rod 605 is rotatably connected to the powder feeding seat 5. Both ends of the knocking rod 605 are movably in contact with the upper surface of the powder feeding seat 5. Under the action of the fixed rack 402, the transmission wheel 602 can be rotated, so that the transmission wheel 602 drives the connected universal joint 601 to rotate, and the universal joint 601 drives the incomplete bevel gear 603 to rotate. At this time, the incomplete bevel gear 603 will be meshed with the two bevel gears 604 in turn. At this time, the knocking rod 605 connected to the two bevel gears 604 will be rotated forward and backward, so that the knocking rod 605 knocks on the powder feeding seat 5.

[0036] As Figure 7As shown, the pressurizing mechanism 7 includes two connecting rod groups 701, one end of the connecting rod group 701 is rotatably connected to the moving frame 4, and the other end of the connecting rod group 701 is rotatably connected to the adjusting seat 8, one end of the connecting rod group 701 connected to the moving frame 4 is connected and fixedly provided with a rotating shaft 702, and the other end of the rotating shaft 702 is connected and fixedly provided with an adjusting wheel 703, and an adjusting rack 704 is meshingly provided on the adjusting wheel 703. One end of the adjusting rack 704 is slidably matched with the moving frame 4, and one end of the adjusting rack 704 is connected and fixedly provided with a tapered rod 705, and the outer wall of the tapered rod 705 is slidably contacted with the extrusion plate 503. Under the action of the fixed rack 402, the transmission wheel 602 can rotate, so that the transmission wheel 602 drives the connected universal joint 601 to rotate, and the universal joint 601 drives the incomplete bevel gear 603 to rotate. At this time, the incomplete bevel gear 603 will respectively engage with the two bevel gears 604 in turn, and at this time, the knocking rod 605 connected to the two bevel gears 604 will be driven to rotate forward and reverse, so that the knocking rod 605 knocks on the powder loading seat 5.

[0037] like Figure 8 As shown, a transmission rod 801 is rotatably connected to the adjustment seat 8, an adjustment slot 802 is provided on the outer wall of the transmission rod 801, a worm wheel 803 is fixedly connected to the top of the transmission rod 801, a worm 804 is meshingly driven on one side of the worm wheel 803, the worm 804 is rotatably connected to the adjustment seat 8, a tension spring A805 is fixedly connected to the adjustment seat 8, and the other end of the tension spring A805 is fixedly connected to the moving frame 4. When the extrusion plate 503 does not contact the tapered rod 705, the adjustment seat 8 will be driven to move upward under the action of the tension spring A805.

[0038] One end of the worm 804 is connected and fixedly provided with a meshing wheel 806, one side of the meshing wheel 806 is provided with a gear rack 807, the gear rack 807 is connected and fixedly provided with the movable frame 4, and a plurality of meshing teeth 808 are rotatably connected and provided in a linear structure on the gear rack 807, one end of the meshing tooth 808 is connected and fixedly provided with a spring A809, and the other end of the spring A809 is connected and fixedly provided with the inner wall of the gear rack 807. Under the action of spring A809, meshing teeth 808 are driven to mesh with meshing wheel 806, thereby driving worm 804 to rotate, so that worm 804 drives transmission rod 801 connected to worm wheel 803 to rotate, so that transmission rod 801 drives adjustment frame 901 connected to guide rod 904 to move up intermittently through adjustment slot 802, so that powder pre-pressing plate 9 moves up a distance after pressurization once, which is convenient for the next pressurization. When guide rod 904 moves to the linear structure position of adjustment slot 802, under the action of tension spring B903, powder pre-pressing plate 9 is driven to reset. Adjustment slot 802 is composed of two parts: a linear part and a spiral part.

[0039] like Figure 9As shown, the powder pre-pressing plate 9 is arranged in a toothed structure. The outer wall of the powder pre-pressing plate 9 is slidably fitted with the inner wall of the gear die 3. An adjusting frame 901 is slidably fitted on the powder pre-pressing plate 9. Springs B902 are sleeved on the outer walls at both ends of the upper side of the powder pre-pressing plate 9.

[0040] One side of the upper end of the adjusting frame 901 is slidably fitted with the adjusting seat 8. A tension spring B903 is fixedly connected to the adjusting frame 901. The other end of the tension spring B903 is fixedly connected to the adjusting seat 8. The other side of the upper end of the adjusting frame 901 is fixedly connected with a guide rod 904. The guide rod 904 is slidably fitted with the inner wall of the adjusting groove 802.

[0041] Working principle: When powder metallurgy of gears is required, first, the hydraulic rod 401 drives the moving frame 4 to move, so that the powder pre-pressing plate 9 is located directly above the gear die 3. Then, the metal powder is injected into the powder feeding seat 5 by the feeding pipe 502. Then, the electric push rod 501 drives the powder feeding seat 5 to move above the gear die 3, so that the powder can fall into the gear die 3.

[0042] At the same time when the powder feeding seat 5 moves above the gear die 3, under the action of the fixed rack 402, the transmission wheel 602 can be rotated, so that the transmission wheel 602 drives the connected universal joint 601 to rotate, and the universal joint 601 drives the incomplete bevel gear 603 to rotate. At this time, the incomplete bevel gear 603 will be engaged with the two bevel gears 604 in sequence respectively. At this time, the knocking rods 605 connected to the two bevel gears 604 will be rotated forward and backward, so that the knocking rods 605 knock on the powder feeding seat 5, so that the powder attached to the inner wall of the powder feeding seat 5 can completely fall into the gear die 3.

[0043] When adding a layer of powder to the powder feeding seat 5, when the powder feeding seat 5 moves, it will contact the conical rod 705 through the pressing plate 503 on the feeding pipe 502, so that the adjusting rack 704 connected to the two conical rods 705 moves. At this time, the adjusting rack 704 will drive the rotating shaft 702 connected to the adjusting wheel 703 to rotate, so that the rotating shaft 702 drives the connected connecting rod group 701 to rotate, and the connecting rod group 701 drives the adjusting seat 8 to move downward. At this time, the powder pre-pressing plate 9 can be inserted into the gear die 3 to pre-press the powder, and the powder can be compacted with a relatively small pressing force.

[0044] Then, when the extrusion plate 503 does not contact the conical rod 705, under the action of the tension spring A 805, the adjustment seat 8 will be driven to move upward, causing the powder pre-pressing plate 9 to move upward and reset. At this time, under the action of the spring A 809, the meshing teeth 808 will be driven to mesh with the meshing wheel 806, thereby driving the worm 804 to rotate. The worm 804 drives the transmission rod 801 connected to the worm wheel 803 to rotate. The transmission rod 801 drives the adjustment frame 901 connected to the guide rod 904 to move intermittently upward through the opened adjustment groove 802, causing the powder pre-pressing plate 9 to move upward a certain distance after one pressurization, facilitating the next pressurization. When the guide rod 904 moves to the linear structure position of the adjustment groove 802, under the action of the tension spring B 903, the powder pre-pressing plate 9 will be driven to reset, facilitating the powder metallurgy of the next gear;

[0045] After adding a certain amount of metal powder into the gear mold 3 in multiple layers, after the hydraulic rod 401 drives the moving frame 4 to reset, the hydraulic press body 1 is used to press and form the metal powder in the gear mold 3, thereby enabling the pressing and forming of the gear.

[0046] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A powder metallurgy hydraulic press, comprising a hydraulic press body (1), characterized in that: A workbench (2) is fixedly installed in the hydraulic press body (1), a gear mold (3) is fixedly connected to and penetrated on the workbench (2), a moving frame (4) is slidably provided on one side of the workbench (2), a powder loading seat (5) is slidably provided on the moving frame (4), a knocking mechanism (6) is rotatably connected to the powder loading seat (5), and the knocking mechanism (6) comprises a universal joint (601), the universal joint (601) is rotatably connected to the guide tube (502), one end of the universal joint (601) is connected and fixedly provided with a transmission wheel (602), the other end of the universal joint (601) is connected and fixedly provided with an incomplete bevel gear (603), both sides of the incomplete bevel gear (603) are movably meshed and transmission-equipped with bevel gears (604), a knocking rod (605) is connected and fixedly provided between the two bevel gears (604), and the knocking rod (605) is rotatably connected to the powder loading seat (502). The material seat (5) is rotatably connected, and the two ends of the knocking rod (605) are movably contacted with the upper surface of the powder loading seat (5). The movable frame (4) is rotatably connected with a pressurizing mechanism (7), and the pressurizing mechanism (7) comprises two connecting rod groups (701). One end of the connecting rod group (701) is rotatably connected with the movable frame (4), and the other end of the connecting rod group (701) is rotatably connected with an adjustment seat (8). One end of the connecting rod group (701) connected to the movable frame (4) is connected and fixedly provided with a rotating shaft (702), and the other end of the rotating shaft (702) is connected and fixedly provided with an adjustment wheel (703). An adjustment rack (704) is meshingly driven on the adjustment wheel (703), and one end of the adjustment rack (704) is slidably matched with the movable frame (4). The pressurizing mechanism (7) is rotatably connected with an adjustment seat (8), and a powder pre-pressing plate (9) is provided on the lower side of the adjustment seat (8).

2. A powder metallurgy hydraulic press according to claim 1, characterized in that: A hydraulic rod (401) is fixedly connected to one end of the movable frame (4), and the hydraulic rod (401) is fixedly connected to the workbench (2). A fixed rack (402) is fixedly connected to one side of the movable frame (4).

3. A powder metallurgy hydraulic press according to claim 1, characterized in that: The bottom surface of the powder loading seat (5) is slidably matched with the top surface of the workbench (2); an electric push rod (501) is fixedly connected to one side of the powder loading seat (5); the other end of the electric push rod (501) is fixedly connected to the movable frame (4); a material guide tube (502) is passed through the top of the powder loading seat (5) and fixedly connected; an extrusion plate (503) is fixedly connected to the material guide tube (502).

4. A powder metallurgy hydraulic press according to claim 2, characterized in that: The transmission wheel (602) is meshed with the fixed rack (402) for transmission.

5. The powder metallurgy hydraulic press according to claim 3, characterized in that: A conical rod (705) is fixedly connected to one end of the adjusting rack (704), and an outer wall of the conical rod (705) is in sliding contact with the extrusion plate (503).

6. The powder metallurgy hydraulic press according to claim 1, characterized in that: A transmission rod (801) is rotatably connected to the adjustment seat (8), an adjustment groove (802) is provided on the outer wall of the transmission rod (801), a worm wheel (803) is fixedly connected to the top of the transmission rod (801), a worm (804) is meshingly driven on one side of the worm wheel (803), the worm (804) is rotatably connected to the adjustment seat (8), a tension spring A (805) is fixedly connected to the adjustment seat (8), and the other end of the tension spring A (805) is fixedly connected to the moving frame (4).

7. A powder metallurgy hydraulic press according to claim 6, characterized in that: One end of the worm (804) is connected and fixedly provided with a meshing wheel (806), one side of the meshing wheel (806) is provided with a gear rack (807), the gear rack (807) is connected and fixedly provided with a movable frame (4), a plurality of meshing teeth (808) are rotatably connected and provided on the gear rack (807) in a linear structure, one end of the meshing teeth (808) is connected and fixedly provided with a spring A (809), and the other end of the spring A (809) is connected and fixedly provided with an inner wall of the gear rack (807).

8. The powder metallurgy hydraulic press according to claim 1, characterized in that: The powder pre-pressing plate (9) is arranged in a tooth-shaped structure, the outer wall of the powder pre-pressing plate (9) is arranged to slide with the inner wall of the gear mold (3), an adjustment frame (901) is arranged to slide on the powder pre-pressing plate (9), and springs B (902) are sleeved on the outer walls at both ends of the upper side of the powder pre-pressing plate (9).

9. The powder metallurgy hydraulic press according to claim 8, characterized in that: One side of the upper end of the adjustment frame (901) is slidably matched with the adjustment seat (8), a tension spring B (903) is connected and fixedly arranged on the adjustment frame (901), the other end of the tension spring B (903) is connected and fixedly arranged with the adjustment seat (8), and a guide rod (904) is connected and fixedly arranged on the other side of the upper end of the adjustment frame (901), and the guide rod (904) is slidably matched with the inner wall of the adjustment groove (802).

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