A casting device for manufacturing a motor housing

Abstract

The present invention relates to the technical field of metal workpiece casting equipment, and specifically discloses a casting device for manufacturing a motor housing, including a shakeout machine body and a screen. A pushing device is arranged inside the shakeout machine body. The pushing device includes a pushing rod for pushing molding sand into the screen holes of the screen and a pushing assembly for driving the pushing rod to move. The pushing rod is slidably matched with the shakeout machine body. An extrusion device is arranged inside the shakeout machine body. The extrusion device includes an extrusion rod for pushing the molding sand and a driving assembly for driving the extrusion rod to move. The pushing rod and the extrusion rod are oppositely arranged in the horizontal direction. When the pushing rod and the extrusion rod slide towards each other, the molding sand is pushed into the screen holes of the screen, and the molding sand between the pushing rod and the extrusion rod is extruded. The casting device for manufacturing a motor housing of the present invention has the effects of being able to improve the processing quality of castings and simultaneously improving the vibration efficiency of the shakeout machine.

Description

Technical Field

[0001] The present invention relates to the technical field of metal workpiece casting equipment, and particularly relates to a casting device for manufacturing a motor housing. Background Art

[0002] An electric motor, commonly known as a motor, refers to a prime mover that converts electrical energy into mechanical energy by using the interaction between a magnetic field and a current-carrying conductor. The main types include AC motors, DC motors, stepper motors, and servo motors, etc. An electric motor mainly consists of a housing, a stator, a rotor, and other accessories.

[0003] Casting is a metal forming process. By melting metal and pouring it into a pre-prepared mold, it cools and solidifies into a component of the required shape. Among them, the manufacturing of a motor housing usually adopts casting processing. The casting of a motor housing is a process of manufacturing the housing of a motor through a casting process. When processing the casting of a motor housing, a shakeout machine is required to use vibration and impact to separate the molding sand in the mold from the casting. The vibration sources of the shakeout machine are divided into three categories: mechanical, electromagnetic, and pneumatic.

[0004] Chinese patent document with publication number CN213944841U discloses a vibration shakeout machine convenient for replacing a screen, including a housing and a conveying device. A vibration device is installed inside the housing, a spray head is installed at the top of the housing, and a servo motor is installed on one side of the housing. The output end of the servo motor is installed with an eccentric wheel, and a belt is installed at the output end of the servo motor. The conveying device is installed at the bottom of the housing, and a support frame is installed at the bottom of the housing. The usage process of this vibration shakeout machine convenient for replacing a screen is as follows: First, after the casting is poured and completed, the casting is demolded after cooling. The casting and the box body are placed on the top of the vibration shakeout machine, and the casting and the box body are made to fit with the rollers inside the vibration device. At the same time, the servo motor is started, so that the output end of the servo motor drives the eccentric wheel to rotate, and the eccentric wheel drives the vibration device to vibrate. The vibration device separates the casting and the box body, and at the same time, the sand grains in the casting are screened through the screen net and fall onto the top of the conveying device at the bottom.

[0005] In the above technology, when the molding sand falling on the vibration shakeout machine is too large, it cannot pass through the filter screen on the vibration shakeout machine in time. A large amount of molding sand vibrates with the casting on the vibration shakeout machine. The long-term common vibration of the molding sand and the casting will cause the casting to be impacted, and the surface of the casting will show wear, thereby affecting the processing quality of the casting. At the same time, a large amount of molding sand accumulates on the vibration shakeout machine, which will increase the load of the equipment and reduce the vibration efficiency. Summary of the Invention

[0006] The present invention provides a casting device for manufacturing a motor housing, aiming to solve the technical problems in the prior art that when the molding sand falling on the vibrating shakeout machine is too large, it cannot pass through the filter screen on the vibrating shakeout machine in time. A large amount of molding sand vibrates on the vibrating shakeout machine together with the casting. The long-term common vibration of the molding sand and the casting will cause the casting to be impacted, and the surface of the casting will be worn, thus affecting the processing quality of the casting. At the same time, a large amount of molding sand accumulates on the vibrating shakeout machine, which will increase the load of the equipment and reduce the vibration efficiency.

[0007] A casting device for manufacturing a motor housing according to the present invention includes a shakeout machine body and a screen mesh arranged on the shakeout machine body. A pushing device is arranged inside the shakeout machine body. The pushing device includes a pushing rod for pushing the molding sand into the screen holes of the screen mesh and a pushing assembly for driving the pushing rod to move. The pushing rod is slidably fitted to the shakeout machine body. An extrusion device is arranged inside the shakeout machine body. The extrusion device includes an extrusion rod for pushing the molding sand and a driving assembly for driving the extrusion rod to move. The pushing rod and the extrusion rod are arranged opposite to each other in the horizontal direction. When the pushing rod and the extrusion rod slide towards each other, the molding sand is pushed into the screen holes of the screen mesh, and the molding sand between the pushing rod and the extrusion rod is extruded.

[0008] Beneficial effects: Through the arrangement of the pushing device and the extrusion device, when it is necessary to process the molding sand on the screen mesh, the pushing assembly can drive the pushing rod to slide, and the driving assembly can drive the extrusion rod to slide. When the pushing rod and the extrusion rod slide towards each other, the molding sand can be pushed into the screen holes of the screen mesh, improving the filtering efficiency of the screen mesh for the molding sand, and extruding the large pieces of molding sand between the pushing rod and the extrusion rod, reducing the phenomenon of molding sand accumulation, improving the processing quality of the casting, and at the same time improving the vibration efficiency of the shakeout machine.

[0009] Preferably, a plurality of groups of the pushing rods and the extrusion rods are arranged along the length direction of the shakeout machine body.

[0010] Beneficial effects: By arranging the pushing rods and the extrusion rods in multiple groups, compared with a single group of pushing rods and extrusion rods, the adjustment stroke of the pushing rods and the extrusion rods can be shortened, thereby improving the reciprocating movement efficiency of the pushing rods and the extrusion rods, and further improving the filtering efficiency of the screen mesh for the molding sand.

[0011] Preferably, a plurality of groups of the pushing rods and the extrusion rods are arranged along the width direction of the shakeout machine body, and a fixing rod is arranged between two adjacent groups of the pushing rods along the width direction of the shakeout machine body. The pushing rods and the extrusion rods are slidably fitted to the fixing rod.

[0012] Beneficial effects: Through the arrangement of the fixing rod, the space above the screen mesh can be divided into multiple chambers for processing the molding sand, and the processing efficiency of the molding sand can be improved when processing the molding sand.

[0013] Preferably, the pushing component includes a slider slidably fitted in the sand slinger body and a driving member for pushing the slider to slide, and the slider is connected to the pushing rod.

[0014] Preferably, lifting holes are formed in both the pushing rod and the extrusion rod, and a pushing device is arranged on both the pushing rod and the extrusion rod. The pushing device includes a push rod for pushing the molding sand and the casting and a pushing mechanism for driving the push rod to move. The push rod is slidably fitted in the lifting hole along the vertical direction.

[0015] Beneficial effects: Through the arrangement of the pushing device, the pushing mechanism can drive the push rod to move, and the push rod continuously makes lifting movements, which can break the large pieces of molding sand above the pushing rod and the extrusion rod, improve the processing efficiency of the large pieces of molding sand, and at the same time can lift the casting and improve the vibration effect on the casting.

[0016] Preferably, the pushing mechanism includes a lifting component for driving the push rod to lift and a pushing component for driving the lifting component to move, and both the lifting component and the pushing component are arranged in the sand slinger body.

[0017] Beneficial effects: The pushing component drives the lifting component to move, and the lifting component can drive the push rod to make lifting movements, realizing the convenient adjustment of the push rod, and breaking the large pieces of molding sand through the push rod.

[0018] Preferably, the lifting component includes a cam for driving the push rod to lift and a rotating rod rotatably fitted in the pushing rod, and the cam is connected to the rotating rod.

[0019] Preferably, the pushing component includes a gear mounted on the rotating rod and a rack for driving the gear to rotate, and the rack meshes with the gear.

[0020] Preferably, the rack in the pushing rod is used to drive the gear in the extrusion rod to rotate, and the rack in the extrusion rod is used to drive the gear in the pushing rod to rotate.

[0021] Beneficial effects: When each group of pushing rods and extrusion rods slide relative to each other, the corresponding racks can be driven to slide, and then the gears are driven to rotate, realizing the lifting movements of the push rods in the pushing rods and the extrusion rods.

[0022] Preferably, a linkage device is arranged in both the pushing rod and the extrusion rod. The linkage device includes a linkage frame for driving a plurality of push rods to lift and an elastic member for driving the linkage frame to descend. One end of the elastic member is connected to the linkage frame, and the other end is connected to the pushing rod.

[0023] Advantageous effects: Through the setting of the linkage device, when the cam jacks up the linkage frame, multiple ejector rods can move up and down simultaneously. And through the setting of the elastic member, when the cam no longer jacks up the linkage frame, the rapid fall of the linkage frame can be achieved, and thus the rapid fall of multiple ejector rods can be realized.

[0024] The advantageous effects of the present invention are as follows:

[0025] 1. In the present invention, through the setting of the pushing device and the squeezing device, when it is necessary to process the molding sand on the sieve mesh, the pushing component can drive the pushing rod to slide, and the driving component can drive the squeezing rod to slide. When the pushing rod and the squeezing rod slide in the direction of approaching each other, the molding sand can be pushed into the sieve holes of the sieve mesh, improving the filtering efficiency of the sieve mesh for the molding sand, and squeezing the large pieces of molding sand between the pushing rod and the squeezing rod, reducing the phenomenon of molding sand accumulation, improving the processing quality of the casting, and at the same time improving the vibration efficiency of the shakeout machine.

[0026] 2. In the present invention, through the setting of the ejecting device, the ejecting mechanism can drive the ejector rod to move, and the ejector rod continuously moves up and down, which can break the large pieces of molding sand above the pushing rod and the squeezing rod, improving the processing efficiency of the large pieces of molding sand, and at the same time can jack up the casting, improving the vibration effect on the casting.

[0027] 3. In the present invention, through the setting of the linkage device, when the cam jacks up the linkage frame, multiple ejector rods can move up and down simultaneously. And through the setting of the elastic member, when the cam no longer jacks up the linkage frame, the rapid fall of the linkage frame can be achieved, and thus the rapid fall of multiple ejector rods can be realized. Description of the Drawings

[0028] Figure 1 is the overall structural schematic diagram of the present invention.

[0029] Figure 2 is the structural schematic diagram showing the positional relationship between the pushing device and the squeezing device of the present invention.

[0030] Figure 3 is the structural schematic diagram showing the connection relationship between the pushing rod and the sieve mesh of the present invention.

[0031] Figure 4 is the partial cross-sectional view of the present invention.

[0032] Figure 5 is Figure 4 the partial enlarged view of part A in

[0033] Figure 6 is the partial cross-sectional view showing the connection relationship between the ejecting device and the linkage device of the present invention.

[0034] Reference Signs:

[0035] 1. Sand shaking machine body; 2. Screen mesh; 3. Pushing device; 31. Pushing rod; 311. Lifting hole; 32. Pushing component; 321. Slide block; 322. Driving part; 4. Extrusion device; 41. Extrusion rod; 42. Driving component; 5. Fixed rod; 6. Thrusting device; 61. Thrusting rod; 62. Lifting component; 621. Cam; 622. Rotating rod; 63. Thrusting component; 631. Gear; 632. Rack; 7. Linkage device; 71. Linkage frame; 72. Elastic part. Detailed implementation mode

[0036] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention.

[0037] Refer to Figures 1-6 , a casting device for manufacturing a motor housing of the present invention includes a sand shaking machine body 1 and a screen mesh 2 fixedly arranged on the sand shaking machine body 1. A vibration mechanism, a pushing device 3 and an extrusion device 4 are arranged in the sand shaking machine body 1. The vibration mechanism is used to drive the sand shaking machine body 1 to vibrate. The pushing device 3 and the extrusion device 4 are used to push the molding sand falling on the screen mesh 2 to the screen holes of the screen mesh 2 and extrude and crush the large molding sand. When it is necessary to separate the casting from the molding sand, start the vibration mechanism to drive the sand shaking machine body 1 to vibrate, and drive the molding sand and the casting falling on the screen mesh 2 to vibrate, so that the molding sand shakes off from the casting. At the same time, start the pushing device 3 and the extrusion device 4. The pushing device 3 and the extrusion device 4 push the molding sand towards the screen holes of the screen mesh 2, and at the same time extrude and crush the large molding sand, so that the fallen molding sand can fall from the screen holes of the screen mesh 2 in time and be discharged from the sand shaking machine body 1.

[0038] Among them, refer to Figures 2-4 , the pushing device 3 includes a pushing rod 31 for pushing the molding sand into the screen holes of the screen mesh 2 and a pushing component 32 for driving the pushing rod 31 to move. The pushing rod 31 is set in an "L" shape. Multiple groups of pushing rods 31 are arranged along the length direction and the width direction of the sand shaking machine body 1. The multiple pushing rods 31 along the length direction of the sand shaking machine body 1 are fixedly connected to each other. The pushing rod 31 is slidably fitted in the sand shaking machine body 1 along the length direction of the sand shaking machine body 1; the pushing component 32 includes a slide block 321 slidably fitted in the sand shaking machine body 1 and a driving part 322 for pushing the slide block 321 to slide. The slide block 321 is a T-shaped block. A groove for the slide block 321 to slide is opened on the screen mesh 2. The slide block 321 is fixedly connected to the pushing rod 31 at one end in the length direction of the sand shaking machine body 1. The driving part 322 directly adopts a hydraulic cylinder. One end of the driving part 322 is fixedly connected to the sand shaking machine body 1, and the other end is fixedly connected to the slide block 321.

[0039] Reference Figures 2-4 As shown in Figures 2-4 , the extrusion device 4 includes an extrusion rod 41 for pushing the molding sand and a driving assembly 42 for driving the movement of the extrusion rod 41. The extrusion rod 41 is arranged in an "L" shape and is slidably fitted to the sand slinger body 1 along the length direction of the sand slinger body 1. Multiple groups of extrusion rods 41 are arranged along both the length direction and the width direction of the sand slinger body 1. The multiple extrusion rods 41 along the length direction of the sand slinger body 1 are fixedly connected to each other. The push rod 31 and the extrusion rod 41 are arranged opposite to each other along the length direction of the sand slinger body 1, and the push rod 31 and the extrusion rod 41 are arranged in sequence along the length direction of the sand slinger body 1, and the push rod 31 and the extrusion rod 41 perform relative sliding movements.

[0040] Reference Figures 2-4 As shown in Figures 2-4 , the structure of the driving assembly 42 is the same as that of the pushing assembly 32. The driving member 322 of the driving assembly 42 is fixedly connected to the slider 321 on the extrusion rod 41, and the driving member 322 of the driving assembly 42 is used to drive multiple extrusion rods 41 for sliding adjustment; by starting the driving member 322 of the driving assembly 42 and the driving member 322 of the pushing assembly 32, the extrusion rod 41 and the push rod 31 can be respectively driven to slide in the direction of approaching or moving away from each other. When the extrusion rod 41 and the push rod 31 slide in the direction of approaching each other, the molding sand in the chamber formed between the extrusion rod 41 and the push rod 31 can be pushed into the sieve holes of the sieve 2, and the molding sand between the push rod 31 and the extrusion rod 41 can be extruded; when the extrusion rod 41 and the push rod 31 slide in the direction of moving away from each other, the extrusion rod 41 and the push rod 31 can be reset.

[0041] Reference Figures 2-4 As shown in Figures 2-4 , a fixing rod 5 is arranged between two adjacent groups of push rods 31 along the width direction of the sand slinger body 1. The fixing rod 5 is fixedly connected to the sand slinger body 1, and the push rod 31 and the extrusion rod 41 are slidably fitted to the fixing rod 5.

[0042] Reference Figures 4-6 As shown in Figures 4-6 , lifting holes 311 are formed on both the push rod 31 and the extrusion rod 41. A pushing device 6 is arranged on both the push rod 31 and the extrusion rod 41. The pushing device 6 includes a push rod 61 for pushing the molding sand and the casting and a pushing mechanism for driving the movement of the push rod 61. The push rod 61 is slidably fitted to the lifting hole 311 in the vertical direction, and multiple push rods 61 are arranged at intervals along the width direction of the sand slinger body 1 on the push rod 31; the pushing mechanism includes a lifting assembly 62 for driving the lifting of the push rod 61 and a pushing assembly 63 for driving the movement of the lifting assembly 62. Both the lifting assembly 62 and the pushing assembly 63 are arranged inside the sand slinger body 1.

[0043] Among them, reference Figures 4-6The lifting assembly 62 includes a cam 621 for driving the push rod 61 to rise and fall, and a rotating rod 622 that rotates and cooperates with the push rod 31, and the cam 621 is fixedly connected to the rotating rod 622; the push assembly 63 includes a gear 631 fixedly installed on the rotating rod 622 and a rack 632 for driving the gear 631 to rotate, the rack 632 is meshed with the gear 631, the push rod 31 and the extrusion rod 41 are both fixedly connected to the rack 632, and the rack 632 in the push rod 31 is used to drive the gear 631 in the extrusion rod 41 to rotate, and the rack 632 in the extrusion rod 41 is used to drive the gear 631 in the push rod 31 to rotate.

[0044] Reference Figures 4-6 A linkage device 7 is provided in both the pushing rod 31 and the squeezing rod 41. The linkage device 7 includes a linkage frame 71 for driving the multiple pushing rods 61 to rise and fall and an elastic member 72 for driving the linkage frame 71 to descend. The linkage frame 71 is fixedly connected to the multiple pushing rods 61. The elastic member 72 directly adopts a spring. One end of the elastic member 72 is fixedly connected to the linkage frame 71, and the other end is fixedly connected to the pushing rod 31.

[0045] The implementation principle of the casting device for manufacturing a motor housing of the present invention is as follows: when it is necessary to separate the casting from the molding sand, the vibration mechanism is started to drive the sand shakeout machine body 1 to vibrate, and drive the molding sand and the casting that fall onto the screen 2 to vibrate, so that the molding sand is shaken off the casting, and part of the molding sand can fall through the sieve holes of the screen 2;

[0046] Then, the driving member 322 of the driving assembly 42 and the driving member 322 of the pushing assembly 32 are started, which can respectively drive the extrusion rod 41 and the pushing rod 31 to slide in the direction of approaching each other. During the sliding process, the extrusion rod 41 and the pushing rod 31 can push the molding sand in the chamber formed between the extrusion rod 41 and the pushing rod 31 into the sieve holes of the screen 2, so that the molding sand can quickly fall from the sieve holes of the screen 2;

[0047] When the extrusion rod 41 and the push rod 31 slide in the direction of approaching each other, the rack 632 is driven to slide, and the rack 632 on the extrusion rod 41 and the rack 632 on the push rod 31 slide in the direction of approaching each other. When the rack 632 slides, it can drive the gear 631 to rotate. When the gear 631 rotates, it drives the rotating rod 622 to rotate, and then drives the cam 621 to rotate. During the rotation of the cam 621, the linkage frame 71 is pushed, and when the elastic member 72 is stretched, the push rod 61 can be driven to lift, and the large pieces of molding sand above the push rod 31 and the extrusion rod 41 are crushed, and the casting is lifted at the same time. When the cam 621 no longer pushes the linkage frame 71, the elastic member 72 releases the elastic restoring force, drives the linkage frame 71 to descend, drives the push rod 61 to descend, and resets;

[0048] During the sliding process of the extrusion rod 41 and the pushing rod 31 towards each other, the large-sized molding sand between the extrusion rod 41 and the pushing rod 31 can be extruded and crushed. The crushed molding sand can fall through the sieve holes of the sieve 2. When the large-sized molding sand is crushed, the driving member 322 of the driving assembly 42 drives the extrusion rod 41, and the driving member 322 of the pushing assembly 32 drives the pushing rod 31 to slide away from each other. The pushing rod 31 and the extrusion rod 41 are reset. After repeating this process multiple times, the rapid processing of the molding sand is achieved. The fallen molding sand can promptly fall through the sieve holes of the sieve 2 and be discharged from the sand knockout machine body 1, completing the separation operation between the molding sand and the casting.

[0049] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0050] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0051] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations to the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A casting device for manufacturing a motor housing, comprising a shakeout machine body (1) and a screen (2) arranged on the shakeout machine body (1), characterized in that, A pushing device (3) is arranged inside the shakeout machine body (1). The pushing device (3) includes a push rod (31) for pushing molding sand into the sieve holes of the sieve mesh (2) and a pushing assembly (32) for driving the movement of the push rod (31). The push rod (31) is slidably fitted to the shakeout machine body (1). An extrusion device (4) is arranged inside the shakeout machine body (1). The extrusion device (4) includes an extrusion rod (41) for pushing the molding sand and a driving assembly (42) for driving the movement of the extrusion rod (41). The push rod (31) and the extrusion rod (41) are oppositely arranged in the horizontal direction. When the push rod (31) and the extrusion rod (41) slide towards each other, the molding sand is pushed into the sieve holes of the sieve mesh (2), and the molding sand between the push rod (31) and the extrusion rod (41) is extruded. Lifting holes (311) are formed in both the push rod (31) and the extrusion rod (41). A jacking device (6) is arranged on both the push rod (31) and the extrusion rod (41). The jacking device (6) includes a jacking rod (61) for jacking the molding sand and the casting and a jacking mechanism for driving the movement of the jacking rod (61). The jacking rod (61) is slidably fitted to the lifting hole (311) in the vertical direction.

2. The casting device for manufacturing a motor housing according to claim 1, characterized in that, A plurality of groups of the push rod (31) and the extrusion rod (41) are arranged along the length direction of the shakeout machine body (1).

3. The casting device for manufacturing a motor housing according to claim 1, wherein, A plurality of groups of the push rod (31) and the extrusion rod (41) are arranged along the width direction of the shakeout machine body (1). A fixing rod (5) is arranged between two adjacent groups of the push rods (31) along the width direction of the shakeout machine body (1). The push rod (31) and the extrusion rod (41) are slidably fitted to the fixing rod (5).

4. A casting device for manufacturing a motor housing according to claim 3, characterized in that, The pushing assembly (32) includes a slider (321) slidably fitted inside the shakeout machine body (1) and a driving member (322) for pushing the slider (321) to slide. The slider (321) is connected to the push rod (31).

5. The casting device for manufacturing a motor housing according to claim 1, characterized in that, The jacking mechanism includes a lifting assembly (62) for driving the lifting of the jacking rod (61) and a jacking component (63) for driving the movement of the lifting assembly (62). Both the lifting assembly (62) and the jacking component (63) are arranged inside the shakeout machine body (1).

6. The casting device for manufacturing a motor housing according to claim 5, characterized in that, The lifting assembly (62) includes a cam (621) for driving the lifting of the jacking rod (61) and a rotating rod (622) rotatably fitted inside the push rod (31). The cam (621) is connected to the rotating rod (622).

7. A casting device for manufacturing a motor housing according to claim 6, characterized in that, The jacking component (63) includes a gear (631) installed on the rotating rod (622) and a rack (632) for driving the rotation of the gear (631). The rack (632) meshes with the gear (631).

8. A casting device for manufacturing a motor housing according to claim 7, characterized in that, The rack (632) inside the push rod (31) is used to drive the rotation of the gear (631) inside the extrusion rod (41), and the rack (632) inside the extrusion rod (41) is used to drive the rotation of the gear (631) inside the push rod (31).

9. A casting device for manufacturing a motor housing according to claim 1, characterized in that, A linkage device (7) is provided in both the push rod (31) and the extrusion rod (41). The linkage device (7) includes a linkage frame (71) for driving a plurality of ejector rods (61) to move up and down, and an elastic member (72) for driving the linkage frame (71) to move down. One end of the elastic member (72) is connected to the linkage frame (71), and the other end is connected to the push rod (31).

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