A flywheel housing air tightness detection device

Abstract

The invention discloses a flywheel housing air tightness detection device, which relates to the field of flywheel component production, including a first conveyor line, a clamping and positioning device, a positioning drive assembly, a second conveyor line and a sorting device. The first conveyor line is provided with a tray, in which a flywheel housing is placed, a hydraulic cylinder is provided on a frame, and an output shaft of the hydraulic cylinder is fixedly connected with a pressure plate, on which an air-filled chamber is provided, and the air-filled chamber and the internal cavity of the flywheel housing are closed to form a closed space. The sorting device in the invention uses the characteristic that if the flywheel housing has good air tightness, part of the gas filled will enter the driving air cylinder through the pressure relief valve, to judge the air tightness of the flywheel housing, and can automatically guide the flywheel housing to different areas on the second conveyor line according to the detection result, thereby eliminating the process of manual sorting, and the clamping and positioning device is driven to work by the positioning drive assembly to position the tray, without the need for an additional actuator, thereby reducing equipment costs and facilitating automation.

Description

Technical Field

[0001] The invention relates to the field of flywheel component production, and in particular to a flywheel housing air tightness detection device. Background Art

[0002] The flywheel housing is mainly used to protect the internal flywheel assembly. The internal parts of the flywheel need lubrication when working and need to avoid moisture from the external environment. Therefore, the flywheel housing needs to have qualified airtightness to avoid leakage and external moisture from rusting the flywheel components.

[0003] The existing air tightness test of the flywheel housing usually requires workers to place the flywheel on a pallet and then use professional instruments to test the air tightness. This testing method has the following disadvantages:

[0004] 1) During testing, workers are required to screen out unqualified products based on the test results. Sometimes, due to worker mistakes, classification errors may occur;

[0005] 2) The detection equipment has a single function and is difficult to combine with other manufacturing processes of the flywheel housing to achieve automated detection and sorting;

[0006] 3) The detection equipment requires professional instruments, the equipment cost is relatively high, and it is not suitable for some smaller factories. The detection process requires the use of multiple detection sensors, and sometimes electronic failures may occur. Summary of the invention

[0007] The purpose of the present invention is to provide a flywheel housing air tightness detection device to solve the problems mentioned in the above background technology.

[0008] A flywheel housing air tightness detection device, characterized in that it comprises a first conveyor line, a tray, a clamping and positioning device, a positioning drive assembly, a second conveyor line and a sorting device, wherein the first conveyor line is provided with a tray, the tray is provided with a positioning groove, a flywheel housing is placed in the positioning groove, the first conveyor line is provided with a frame, the frame is provided with a hydraulic cylinder, the output shaft of the hydraulic cylinder is fixedly connected with a pressure plate, the pressure plate is provided with an air-filled chamber, the air-filled chamber coincides with the center hole of the flywheel housing, and is closed with the internal cavity of the flywheel housing to form a closed space;

[0009] The sorting device is arranged above the second conveying line, and the sorting device divides the second conveying line into two areas, and guides the flywheel housing to different areas according to whether the air tightness is qualified or not. The excess gas in the inflation chamber enters into the driving gas cylinder in the sorting device, and is used to provide a driving gas source for the driving gas cylinder;

[0010] The clamping and positioning device is arranged below the first conveying line and is used to position and clamp the pallet just below the pressing plate;

[0011] The positioning drive assembly utilizes the change in the distance between the pressing plate and the frame to drive the clamping and positioning device to work.

[0012] Preferably, both the first conveyor line and the second conveyor line are roller conveyor lines, and the first conveyor line is provided with a photoelectric sensor for detecting the position of the tray.

[0013] Preferably, the clamping and positioning device includes a base plate and a gear 1, two slides are slidably connected to the base plate, a rack 1 is fixedly connected to the slide, and the rack 1 is also slidably connected to the base plate, the gear 1 is arranged between the two racks 1 and is rotatably connected to the base plate, the gear 1 is meshed with the two racks 1, and two symmetrical positioning columns are provided on the slide, and the positioning columns pass between the sliding rollers of the first conveyor line.

[0014] Preferably, the positioning drive assembly comprises an active piston cylinder and a driven piston cylinder, wherein two active piston cylinders are provided and are respectively located on both sides of the hydraulic cylinder, the cylinder body of the active piston cylinder is fixedly connected to the frame, and its piston rod is fixedly connected to the pressure plate; the upper port of the active piston cylinder is connected to the front port of the driven piston cylinder, the lower port of the active piston cylinder is connected to the rear port of the driven piston cylinder, and the active piston cylinder and the driven piston cylinder are filled with hydraulic oil;

[0015] The driven piston cylinder is fixedly connected to the frame, and the front end of the piston rod 2 of the driven piston cylinder is fixedly connected to a push plate. A connecting block is provided at the front end of the push plate, and the connecting block is fixedly connected to one of the slide plates. A sliding rod is provided on the connecting block, and the sliding rod is slidably connected to the push plate. A stop block is provided at the end of the sliding rod, and a spring 1 is sleeved on the sliding rod between the connecting block and the push plate.

[0016] Preferably, the sorting device includes a driving air cylinder, a fixed frame and two racks, the driving air cylinder is fixedly connected to the fixed frame, the output shaft of the driving air cylinder is fixedly connected to the two racks, a guide rod is provided at the front end of the two racks, the guide rod is slidably connected to a guide seat fixedly connected to the fixed frame, a spring is sleeved on the guide rod between the guide seat and the two racks, a rotating shaft is rotatably connected to the fixed frame, a gear two is fixedly connected to the top end of the rotating shaft, the gear two is meshed with the two racks, a rotating plate is fixedly connected to the bottom of the rotating shaft, and a number of pulleys are rotatably connected to the rotating plate.

[0017] Preferably, a partition plate is also fixedly connected to the bottom of the fixing frame, and the partition plate divides the second conveying line into a right qualified area and a left unqualified area.

[0018] Preferably, a sealing ring is provided at the bottom of the inflation chamber, an overflow port and an inflation port are provided on the inflation chamber, the inflation port is connected to the air source, the overflow port is connected to the pressure relief valve, the pressure relief valve is connected to the air inlet end of the driving air cylinder, and a normally closed electromagnetic exhaust valve is also connected to the pipeline between the pressure relief valve and the air inlet end.

[0019] The advantages of the present invention are:

[0020] The sorting device in the present invention uses the characteristic that if the air tightness of the flywheel housing is good, part of the gas will enter the driving cylinder through the pressure relief valve when the gas is filled, to judge the air tightness of the flywheel housing, and can automatically guide the flywheel housing to different areas on the second conveyor line according to the detection result, thereby eliminating the process of manual sorting, reducing errors, and no need to use professional instruments, with low cost, and suitable for some smaller factories;

[0021] The present invention utilizes the change in the distance between the pressing plate and the frame when the pressing plate is pressed down and lifted up to reset, and drives the clamping and positioning device to work through the positioning drive component, so that the pallet can be positioned before the pressing plate reaches the specified position, without the need for additional actuators, thus reducing equipment costs and avoiding the situation where electrical equipment coordination is prone to errors;

[0022] The present invention can be well combined with the production process of the flywheel housing and can be easily automated. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is the overall structural diagram of the device;

[0024] Figure 2 is a top view of the device;

[0025] Figure 3 This is a schematic diagram of the structure of the clamping and positioning device;

[0026] Figure 4 for Figure 3 A partial enlarged view of the middle A;

[0027] Figure 5 It is a structural schematic diagram of the pressure plate and the flywheel housing;

[0028] Figure 6 It is a cross-sectional view of the flywheel housing, tray and some related parts;

[0029] Figure 7 It is a schematic diagram of the fluid path of the positioning drive component;

[0030] Figure 8 It is a structural schematic diagram of a sorting device;

[0031] Fig. 9 Schematic diagram of the execution gas circuit of the drive cylinder.

[0032] In the figure: 1-first conveyor line, 11-frame, 12-photoelectric sensor, 2-tray, 21-positioning slot;

[0033] 3-clamping and positioning device, 30-bottom plate, 31-gear 1, 32-slide plate, 33-rack 1, 34-positioning column;

[0034] 4-positioning drive assembly, 41-active piston cylinder, 410-piston rod 1, 411-upper port, 412-lower port, 42-driven piston cylinder, 420-piston rod 1, 421-front port, 422-rear port, 43-push plate, 44-connecting block, 45-sliding rod, 451-stopper, 46-spring 1;

[0035] 5-second conveyor line, 51-left unqualified area, 52-right qualified area;

[0036] 6-sorting device, 60-pressure relief valve, 61-driving air cylinder, 611-air inlet end, 612-electromagnetic exhaust valve, 62-fixed frame, 621-partition plate, 63-rack 2, 64-guide rod, 65-guide seat, 66-spring 2, 67-rotating shaft, 68-gear 2, 69-rotating plate, 691-pulley;

[0037] 7-hydraulic cylinder, 8-pressure plate, 81-inflatable chamber, 811-sealing ring, 812-overflow port, 813-inflatable port, 9-flywheel housing, 91-sealing gasket. DETAILED DESCRIPTION

[0038] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0039] like Figures 1 to 9 As shown, a flywheel housing 9 air tightness detection device comprises a first conveyor line 1, a tray 2, a clamping and positioning device 3, a positioning drive assembly 4, a second conveyor line 5 and a sorting device 6, the first conveyor line 1 is provided with a tray 2, the tray 2 is provided with a positioning groove 21, the flywheel housing 9 is placed in the positioning groove 21, the first conveyor line 1 is provided with a frame 11, the frame 11 is provided with a hydraulic cylinder 7, the output shaft of the hydraulic cylinder 7 is fixedly connected with a pressing plate 8, the pressing plate 8 is provided with an air-filled chamber 81, the air-filled chamber 81 coincides with the center hole of the flywheel housing 9, and is closed with the internal cavity of the flywheel housing 9 to form a closed space;

[0040] The excess gas in the inflation chamber 81 enters the driving gas cylinder 61 in the sorting device 6 to provide a driving gas source for the driving gas cylinder 61 .

[0041] In this embodiment, the first conveyor line 1 and the second conveyor line 5 are both roller conveyor lines. The first conveyor line 1 is provided with a photoelectric sensor 12 for detecting the position of the pallet 2. When the photoelectric sensor 12 detects the pallet 2, the first conveyor line 1 suspends transportation. When the hydraulic cylinder 7 is reset, the first conveyor line 1 continues to start.

[0042] In this embodiment, the clamping and positioning device 3 is arranged below the first conveyor line 1, and is used to position and clamp the pallet 2 directly below the pressure plate 8. The specific structure includes a base plate 30 and a gear 31. Two slides 32 are slidably connected to the base plate 30, and a rack 33 is fixedly connected to the slide plate 32. The rack 33 is also slidably connected to the base plate 30. The slides 32 and the rack 33 are both slidably connected to the base plate 30 through slide rails. The gear 31 is arranged between the two racks 33 and is rotatably connected to the base plate 30. The gear 31 is meshed with the two racks 33. Two symmetrical positioning columns 34 are provided on the slide plate 32. The two fixed columns on the two slide plates 32 realize four-point positioning. The positioning columns 34 pass between the sliding rollers of the first conveyor line 1.

[0043] In this embodiment, the positioning drive assembly 4 utilizes the change in the spacing between the pressure plate 8 and the frame 11 to drive the clamping positioning device 3 to work. The specific structure includes an active piston cylinder 41 and a driven piston cylinder 42. The active piston cylinder 41 is provided with two, which are respectively located on both sides of the hydraulic cylinder 7. The cylinder body of the active piston cylinder 41 is fixedly connected to the frame 11, and its piston rod 1 410 is fixedly connected to the pressure plate 8; the upper port 411 of the active piston cylinder 41 is connected to the front port 421 of the driven piston cylinder 42, and the lower port 412 of the active piston cylinder 41 is connected to the rear port 422 of the driven piston cylinder 42, so that when the piston rod 1 410 is extended, the piston rod 2 420 is also extended. The active piston cylinder 41 and the driven piston cylinder 42 are filled with hydraulic oil;

[0044] The driven piston cylinder 42 is fixedly connected to the frame 11, and the front end of the piston rod 2 420 of the driven piston cylinder 42 is fixedly connected to the push plate 43. The front end of the push plate 43 is provided with a connecting block 44, and the connecting block 44 is fixedly connected to one of the slide plates 32. A sliding rod 45 is provided on the connecting block 44, and the sliding rod 45 is slidably connected to the push plate 43. A stopper 451 is provided at the end of the sliding rod 45, and a spring 1 46 is sleeved on the sliding rod 45 between the connecting block 44 and the push plate 43. A certain interval is reserved between the connecting block 44 and the push plate 43 by using the spring 1 46, which can ensure that when the pressure plate 8 is not pressed onto the flywheel housing 9, the positioning column 34 has already positioned the tray 2. When the pressure plate 8 continues to move down and press the flywheel housing 9, the existence of the spring 1 46 can enable the piston rod 2 420 to continue to extend a certain distance.

[0045] In this embodiment, the sorting device 6 is arranged above the second conveying line 5, the sorting device 6 divides the second conveying line 5 into two areas, and guides the flywheel housing 9 to different areas according to whether the airtightness is qualified or not. The specific structure includes a driving cylinder 61, a fixing frame 62 and a rack 63. The driving cylinder 61 is fixedly connected to the fixing frame 62, the output shaft of the driving cylinder 61 is fixedly connected to the rack 63, and the front end of the rack 63 is provided with a guide rod 64, and the guide rod 64 is slidably connected to a guide seat 65 fixedly connected to the fixing frame 62, and the guide seat 65 A spring 2 66 is sleeved on the guide rod 64 between the guide rod 64 and the rack 2 63. The spring 2 66 is used for resetting the rack 2 63 and the output shaft of the driving cylinder 61. A rotating shaft 67 is rotatably connected to the fixed frame 62. A gear 2 68 is fixedly connected to the top of the rotating shaft 67. The gear 2 68 meshes with the rack 2 63. A rotating plate 69 is fixedly connected to the bottom of the rotating shaft 67. A plurality of pulleys 691 are rotatably connected to the rotating plate 69. The rotating plate 69 and the pulley 691 combine to guide the tray 2 and close the right qualified area 52 or the left unqualified area 51.

[0046] In this embodiment, a sealing ring 811 is provided at the bottom of the inflation chamber 81, and an overflow port 812 and an inflation port 813 are provided on the inflation chamber 81. The inflation port 813 is connected to the gas source, and the overflow port 812 is connected to the pressure relief valve 60. The pressure relief valve 60 is connected to the air inlet end 611 of the driving air cylinder 61. A normally closed electromagnetic exhaust valve 612 is also connected to the pipeline between the pressure relief valve 60 and the air inlet end 611. The electromagnetic exhaust valve 612 is used to discharge the gas in the driving air cylinder 61 to meet the need to reset the output shaft of the driving air cylinder 61.

[0047] In this embodiment, a partition plate 621 is also fixedly connected to the bottom of the fixing frame 62 , and the partition plate 621 divides the second conveying line 5 into a right qualified area 52 and a left unqualified area 51 .

[0048] Working process and principle:

[0049] During the inspection, the flywheel housing 9 to be inspected is placed in the positioning groove 21 of the tray 2. A sealing gasket 91 is provided at the bottom of the flywheel housing 9. The sealing gasket 91 fits the inner bottom of the positioning groove 21. The edge of the positioning groove 21 is chamfered for easy installation. The tray 2 is placed on the first conveyor line 1 for conveying. When the photoelectric sensor 12 detects the tray 2, the first conveyor line 1 is suspended.

[0050] The hydraulic cylinder 7 is started, the output shaft is extended, the pressure plate 8 is moved downward, the piston rod 1 410 is extended, and the hydraulic oil in the cavity below the piston of the active piston cylinder 41 enters into the rear cavity of the piston of the driven piston cylinder 42 from the lower port 412 through the rear port 422 of the driven piston cylinder 42, while the hydraulic oil in the front cavity of the piston of the driven piston cylinder 42 enters into the upper cavity of the piston of the active piston cylinder 41 from the front port 421 through the upper port 411 of the active piston cylinder 41. Through the flow of the above-mentioned hydraulic oil, the piston rod 2 420 will also be extended.

[0051] The piston rod 2 420 is extended, and the connecting block 44 is pushed to move in the direction of the gear 1 31 through the push plate 43 and the spring, and the slide plate 32 moves along with it. The two slide plates 32 approach each other under the meshing action of the rack 1 33 and the gear 1 31, and the positioning column 34 acts on the tray 2, so that the tray 2 is automatically corrected to be directly below the pressure plate 8.

[0052] At this time, the pressure plate 8 has not yet contacted the flywheel housing 9, the hydraulic cylinder 7 continues to work, and the pressure plate 8 continues to move downward. The spring 1 46 arranged between the connecting block 44 and the push plate 43 can keep the piston rod 2 420 moving when the connecting block 44 does not move, thereby ensuring that the pressure plate 8 can continue to move downward.

[0053] The pressure plate 8 presses the flywheel housing 9 onto the tray 2, the inflation chamber 81 coincides with the hole in the center of the flywheel housing 9, and a fixed amount of gas is charged from the inflation port 813 into the closed space formed by the inflation chamber 81 and the flywheel housing 9 through the gas source.

[0054] If the air tightness of the flywheel housing 9 is good, the air pressure in the enclosed space will increase. When the air pressure reaches the preset value of the pressure relief valve 60, the gas will overflow from the overflow port 812 and enter the driving air cylinder 61 through the air inlet end 611, thereby pushing the output shaft of the driving air cylinder 61 to extend, and the rack 2 63 moves toward the direction of the guide seat 65. The gear 2 68 rotates counterclockwise under the meshing action, and the rotating plate 69 rotates accordingly. The roller at the front end of the rotating plate 69 contacts and abuts against part of the structure of the first conveyor line 1, supporting the rotating plate 69 and closing the left unqualified area 51.

[0055] If the flywheel housing 9 leaks, the air will leak after a fixed amount of air is filled in, and the air pressure cannot reach the preset value of the pressure relief valve 60, the driving air cylinder 61 does not work, the rotating plate 69 remains stationary, and the right qualified area 52 is closed.

[0056] After the inflation test is completed, the gas source is depressurized. Due to the unidirectional conductivity of the pressure relief valve 60, the amount of gas in the driving gas cylinder 61 remains unchanged, and the extension length of the output shaft of the driving gas cylinder 61 remains unchanged.

[0057] The hydraulic cylinder 7 drives the pressure plate 8 to rise, and the piston rod 2 420 retracts. Similarly, the piston rod 1 410 also retracts, and the two slide plates 32 move away from each other. The tray 2 is separated from the positioning and fixation of the positioning column 34, and the first conveyor line 1 is started again. When the photoelectric sensor 12 detects that the tray 2 leaves the first conveyor line 1, the control computer delays for a period of time. During the delay, the tray 2 is transported to the second conveyor line 5. The tray 2 contacts the rollers at the bottom of the rotating plate 69. The second conveyor line 5 has a forward force on the tray 2, so the tilted rollers will guide the tray 2 to the corresponding area on the second conveyor line 5, thereby sorting the flywheel shell 9 after detection.

[0058] After the delay is completed, the control computer starts the electromagnetic exhaust valve 612 to exhaust, and the gas in the driving cylinder 61 is discharged. The output shaft of the driving cylinder 61 is reset under the action of spring 2 66, rack 2 63 is reset, and the driving plate is also reset. The default initial state of the driving plate is to close the right qualified area 52.

[0059] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the above disclosed embodiments are only illustrative in all respects and are not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

Claims

1. A flywheel housing air tightness detection device, characterized in that: The invention comprises a first conveyor line (1), a tray (2), a clamping positioning device (3), a positioning drive assembly (4), a second conveyor line (5) and a sorting device (6), wherein the first conveyor line (1) is provided with a tray (2), the tray (2) is provided with a positioning groove (21), a flywheel housing (9) is placed in the positioning groove (21), the first conveyor line (1) is provided with a frame (11), the frame (11) is provided with a hydraulic cylinder (7), the output shaft of the hydraulic cylinder (7) is fixedly connected to a pressure plate (8), the pressure plate (8) is provided with an inflation chamber (81), the inflation chamber (81) coincides with the center hole of the flywheel housing (9), and is closed with the internal cavity of the flywheel housing (9) to form a closed space; The sorting device (6) is arranged above the second conveying line (5), the sorting device (6) divides the second conveying line (5) into two areas, and guides the flywheel housing (9) to different areas according to whether the air tightness is qualified or not, and the excess gas in the inflation chamber (81) enters the driving gas cylinder (61) in the sorting device (6) to provide a driving gas source for the driving gas cylinder (61); The clamping and positioning device (3) is arranged below the first conveyor line (1) and is used to position and clamp the tray (2) directly below the pressing plate (8); The positioning drive assembly (4) utilizes the change in the distance between the pressing plate (8) and the frame (11) to drive the clamping positioning device (3) to work; If the flywheel housing (9) has good air tightness, part of the gas will enter the driving gas cylinder (61) when it is filled with gas, which can be used to judge the air tightness of the flywheel housing (9). The sorting device (6) can automatically guide the flywheel housing (9) to different areas on the second conveyor line (5) according to the air tightness detection result.

2. A flywheel housing air tightness detection device according to claim 1, characterized in that: The first conveyor line (1) and the second conveyor line (5) are both roller conveyor lines, and the first conveyor line (1) is provided with a photoelectric sensor (12) for detecting the position of the tray (2).

3. A flywheel housing air tightness detection device according to claim 1, characterized in that: The clamping positioning device (3) comprises a base plate (30) and a gear one (31); two slide plates (32) are slidably connected to the base plate (30); a rack one (33) is fixedly connected to the slide plate (32); the rack one (33) is also slidably connected to the base plate (30); the gear one (31) is arranged between the two racks one (33) and is rotatably connected to the base plate (30); the gear one (31) is meshed with the two racks one (33); two symmetrical positioning columns (34) are arranged on the slide plate (32); the positioning columns (34) pass through between the rollers of the first conveyor line (1).

4. A flywheel housing air tightness detection device according to claim 1, characterized in that: The positioning drive assembly (4) comprises an active piston cylinder (41) and a driven piston cylinder (42). Two active piston cylinders (41) are provided and are respectively located on both sides of the hydraulic cylinder (7). The cylinder body of the active piston cylinder (41) is fixedly connected to the frame (11), and its piston rod (410) is fixedly connected to the pressure plate (8). The upper port (411) of the active piston cylinder (41) is connected to the front port (421) of the driven piston cylinder (42), and the lower port (412) of the active piston cylinder (41) is connected to the rear port (422) of the driven piston cylinder (42). Hydraulic oil is contained in the active piston cylinder (41) and the driven piston cylinder (42). The driven piston cylinder (42) is fixedly connected to the frame (11); the front end of the piston rod 2 (420) of the driven piston cylinder (42) is fixedly connected to a push plate (43); a connecting block (44) is provided at the front end of the push plate (43); the connecting block (44) is fixedly connected to one of the slide plates (32); a sliding rod (45) is provided on the connecting block (44); the sliding rod (45) is slidably connected to the push plate (43); a stopper (451) is provided at the end of the sliding rod (45); and a spring 1 (46) is sleeved on the sliding rod (45) between the connecting block (44) and the push plate (43).

5. A flywheel housing air tightness detection device according to claim 1, characterized in that: The sorting device (6) comprises a driving cylinder (61), a fixing frame (62) and a second rack (63), wherein the driving cylinder (61) is fixedly connected to the fixing frame (62), the output shaft of the driving cylinder (61) is fixedly connected to the second rack (63), a guide rod (64) is provided at the front end of the second rack (63), the guide rod (64) is slidably connected to a guide seat (65) fixedly connected to the fixing frame (62), a second spring (66) is sleeved on the guide rod (64) between the guide seat (65) and the second rack (63), a rotating shaft (67) is rotatably connected to the fixing frame (62), a second gear (68) is fixedly connected to the top end of the rotating shaft (67), the second gear (68) is meshed with the second rack (63), a rotating plate (69) is fixedly connected to the bottom of the rotating shaft (67), and a plurality of pulleys (691) are rotatably connected to the rotating plate (69).

6. A flywheel housing air tightness detection device according to claim 5, characterized in that: A partition plate (621) is also fixedly connected to the bottom of the fixed frame (62), and the partition plate (621) divides the second conveying line (5) into a left unqualified area (51) and a right qualified area (52).

7. A flywheel housing air tightness detection device according to claim 1, characterized in that: A sealing ring (811) is provided at the bottom of the inflation chamber (81), and an overflow port (812) and an inflation port (813) are provided on the inflation chamber (81); the inflation port (813) is connected to an air source, the overflow port (812) is connected to a pressure relief valve (60), the pressure relief valve (60) is connected to an air inlet end (611) of a driving air cylinder (61), and a normally closed electromagnetic exhaust valve (612) is also connected in a bypass manner to the pipeline between the pressure relief valve (60) and the air inlet end (611).

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