Positioning device for piston rod shrinkage test

Abstract

The invention belongs to the technical field of piston rod testing, and particularly relates to a piston rod shrinkage test positioning device. The two supporting plates are fixedly connected to the top of the workbench; the connecting rod is rotationally connected to the inner walls of the two supporting plates through bearings; the positioning sleeve is fixedly connected between the two connecting rods; the oil cylinder is arranged in the positioning sleeve; the positioning mechanism is arranged between the oil cylinder and the positioning sleeve; through cooperation of the gear ring, the rack and the gear columns, the oil cylinder to be tested is placed in the positioning sleeve, the second motor is started, the output shaft of the second motor drives the connected rotating shaft and the gear columns to rotate, the gear rings are driven to rotate when the gear columns rotate, the other three gear columns are driven to rotate through the gear rings, and synchronous rotation of the four gear columns is achieved. The gear column drives the rack to move, the rack drives the positioning columns to move, the four positioning columns fix the oil cylinder in the positioning sleeve in the middle, and the positioning function of the oil cylinder during testing is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of piston rod testing, in particular to a piston rod contraction testing positioning device. Background Art

[0002] As a key component in an engine or hydraulic system, the contraction performance of the piston rod directly affects the stability and safety of the entire system. The piston rod contraction test is usually used to detect and evaluate the contraction performance of the piston rod during operation. It usually simulates the stress state of the piston rod in an actual working environment and evaluates its performance and reliability by accurately controlling and measuring the contraction amount of the piston rod.

[0003] A Chinese patent with publication number CN110014318A discloses a piston rod clamping tool, which has a piston rod V-block for positioning the piston rod to be assembled, and a clamping rod head for clamping the piston rod to be assembled, the piston rod V-block is placed on the bottom plate of the tooling seat, the clamping rod head is fixedly connected to the piston rod head of the oil cylinder, and the oil cylinder body is fixed on the upper support plate of the tooling seat; the oil cylinder is connected to the hydraulic pump station, and the extension and retraction of the oil cylinder piston rod are controlled by the hydraulic pump to achieve the clamping and loosening of the piston rod to be assembled. When in use, after the hydraulic station is turned on, the piston rod to be assembled is placed on the piston rod V-block, and the start button of the hydraulic pump station is pressed to make the upper chamber of the oil cylinder enter oil, and the piston rod of the oil cylinder pushes the clamping rod head to descend, clamping the piston rod to be assembled, and the anti-rotation guide mechanism is used to ensure that the clamping rod head does not rotate during use. After the assembly is completed, the button is pressed to make the lower chamber of the oil cylinder enter oil, and the piston rod of the oil cylinder drives the clamping rod head to rise, and the assembled piston rod assembly is taken out.

[0004] In the current existing technology, V-blocks are used to clamp the oil cylinder to improve the applicability of positioning oil cylinders of different sizes. However, oil cylinders usually have three shapes: cylindrical, rectangular and spherical. The V-block cannot contact the oil cylinder well. Under high pressure, the V-block may not be able to position the oil cylinder and it is easy to scratch the surface of the oil cylinder, affecting the sale of the oil cylinder.

[0005] To this end, the present invention provides a piston rod retraction test positioning device. Summary of the invention

[0006] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0007] The technical solution adopted by the present invention to solve the technical problem is: a piston rod contraction test positioning device described in the present invention comprises: Workbench; Two support plates fixedly connected to the top of the workbench; A connecting rod rotatably connected to the inner walls of the two support plates through a bearing; A positioning sleeve fixedly connected between the two connecting rods; An oil cylinder disposed inside the positioning sleeve; A positioning mechanism provided between the oil cylinder and the positioning sleeve; The positioning mechanism includes a gear ring rotatably connected to the outer wall of the positioning sleeve through a bearing, and eight fixed plates are fixedly connected to the outer wall of the positioning sleeve; two adjacent fixed plates are rotatably connected with a gear column through a rotating shaft, and the gear columns are meshed with the gear ring; four racks are slidably connected to the positioning sleeve, and the racks are arranged below the gear ring and meshed with adjacent gear columns; one end of the rack is fixedly connected to a positioning column, and the positioning column is in close contact with the oil cylinder; the other end of the rack is fixedly connected to a blocking plate; a second motor is fixedly connected to one of the fixed plates, and the output shaft of the second motor is fixedly connected to one end of the rotating shaft; anti-slip grooves are provided on the positioning columns, and the positioning columns are made of rubber.

[0008] Preferably, a piston cylinder body is installed in the oil cylinder, and the end of the piston rod body away from the oil cylinder is fixedly connected to a mounting plate, and both ends of the mounting plate are fixedly connected to sliding rods, and two limit blocks are symmetrically fixedly connected to the outer wall of the oil cylinder, and sliding openings are opened in the limit blocks, and the sliding rods slide in the sliding openings; one end of the piston rod body is fixedly connected to a connecting block.

[0009] Preferably, a displacement sensor is fixedly connected to the side wall of the mounting plate, a through opening is opened on the connecting block, pressure sensors are installed on the top inner wall and the bottom inner wall of the through opening, and the pressure sensors are electrically connected to the displacement sensor.

[0010] Preferably, the positioning sleeve is provided with two arc-shaped openings, the arc-shaped openings are slidably connected with an arc-shaped plate, the inner side walls of the top ends of the arc-shaped plates are fixedly connected with fixed tubes, the two fixed tubes are slidably connected with cross bars, the inner threads of the cross bars are connected with reciprocating screws, one end of the reciprocating screw is rotatably connected to the arc-shaped plate through a bearing, and a rotating block is fixedly connected to the outer wall extending to the arc-shaped plate; a circular plate is fixedly connected to the inner wall of the fixed tube away from the rotating block; the cross bar is inserted in the through opening.

[0011] Preferably, a load-bearing box is fixedly connected to the two arc-shaped plates, a plurality of counterweight blocks are placed in the load-bearing box, a threaded rod is rotatably connected to the load-bearing box through a bearing, a handle is fixed to one end of the threaded rod, a splint is threadedly connected to the threaded rod, the splint is in close contact with the counterweight block on the top, and the splint is slidably connected to the inside of the load-bearing box.

[0012] Preferably, a first motor is fixedly connected to the outer wall of one of the support plates, an angle sensor is fixedly connected to the outer wall of the other support plate, the output shaft of the first motor is fixedly connected to one end of a connecting rod, and the output end of the angle sensor is fixedly connected to one end of the other connecting rod.

[0013] Preferably, a controller is fixedly connected to the workbench, and the displacement sensor, angle sensor and pressure sensor are electrically connected to the controller respectively.

[0014] Preferably, both side walls of the rack are fixedly connected with limiting rods, and the limiting rods slide on the positioning sleeves.

[0015] The beneficial effects of the present invention are as follows: 1. A piston rod contraction test positioning device described in the present invention places the oil cylinder to be tested in the positioning sleeve through the cooperation of the gear ring, the rack and the gear column, and turns on the second motor, and the output shaft of the second motor drives the connected rotating shaft and the gear column to rotate. When the gear column rotates, it drives the gear ring to rotate, thereby driving the other three gear columns to rotate through the gear ring, thereby realizing the synchronous rotation of the four gear columns, and the rack is driven to move through the gear column, and the positioning column is driven to move through the rack. The four positioning columns center the oil cylinder in the positioning sleeve, thereby realizing the positioning function of the oil cylinder when it is used for testing. The arrangement of the positioning columns is suitable for different oil cylinder shapes, and the anti-skid groove is set to prevent the oil cylinder from sliding under high pressure, and the rubber material prevents the oil cylinder from being scratched during testing.

[0016] 2. The piston rod contraction test positioning device described in the present invention cooperates with a displacement sensor and a pressure sensor. When testing under different pressures, it is necessary to place counterweight blocks of different weights. After the counterweight block is placed, it is necessary to rotate the handle. The handle drives the threaded rod to rotate, and the threaded rod drives the clamp to move until the counterweight block is clamped. Then, the test of different pressures is started. Hydraulic oil is arranged in the cylinder to control the contraction movement of the piston rod body through the hydraulic system. The piston rod body drives the connecting block to move when it moves. When the pressure sensor on the connecting block contacts the cross bar, the pressure sensor transmits an electrical signal to the controller, and the displacement sensor is started through the controller. The displacement sensor starts to work. Under the same pressure conditions, it is necessary to measure the displacement changes during extension and contraction 2-3 times through the displacement sensor. When the displacement amount is always the same as the set amount, it means that the piston rod body is qualified, otherwise it is unqualified. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below in conjunction with the accompanying drawings.

[0018] Figure 1 is a stereogram of the present invention; Figure 2 It is a schematic diagram of the structure of the positioning sleeve and the positioning column in the present invention; Figure 3 It is a schematic structural diagram of the gear ring, rack and gear column in the present invention; Figure 4 It is a schematic diagram of the structure of the slide bar and the limit block in the present invention; Figure 5 It is a schematic diagram of the structure of the fixed tube and the cross bar in the present invention; Figure 6 It is a structural schematic diagram of the connection block in the present invention; Figure 7 It is a structural schematic diagram of the load-bearing box in the present invention; In the figure: 1. workbench; 11. support plate; 12. connecting rod; 13. angle sensor; 14. first motor; 15. controller; 2. positioning sleeve; 21. gear ring; 22. rack; 23. positioning column; 24. gear column; 25. blocking plate; 26. fixing plate; 27. second motor; 28. limiting rod; 29. ​​arc-shaped mouth; 210. arc-shaped plate; 3. oil cylinder; 31. limiting block; 32. sliding mouth; 33. piston rod body; 34. sliding rod; 35. mounting plate; 36. displacement sensor; 37. connecting block; 38. pressure sensor; 4. rotating block; 41. fixing tube; 42. cross bar; 43. reciprocating screw; 44. round plate; 5. load-bearing box; 51. counterweight block; 52. handle; 53. threaded rod; 54. splint. DETAILED DESCRIPTION

[0019] 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.

[0020] like Figures 1 to 7As shown, a piston rod contraction test positioning device according to an embodiment of the present invention comprises: a workbench 1; two support plates 11 fixedly connected to the top of the workbench 1; a connecting rod 12 rotatably connected to the inner walls of the two support plates 11 through bearings; a positioning sleeve 2 fixedly connected between the two connecting rods 12; an oil cylinder 3 arranged inside the positioning sleeve 2; a positioning mechanism arranged between the oil cylinder 3 and the positioning sleeve 2; the positioning mechanism comprises a gear ring 21 rotatably connected to the outer wall of the positioning sleeve 2 through bearings, eight fixing plates 26 are fixedly connected to the outer wall of the positioning sleeve 2; two adjacent fixing plates 26 are connected by a rotating shaft There are gear columns 24 rotatably connected, and the gear columns 24 are all meshed with the gear ring 21; four racks 22 are slidably connected to the positioning sleeve 2, and the racks 22 are all arranged below the gear ring 21 and meshed with adjacent gear columns 24; one end of each rack 22 is fixedly connected to a positioning column 23, and the positioning column 23 is in close contact with the oil cylinder 3; the other end of each rack 22 is fixedly connected to a blocking plate 25; a second motor 27 is fixedly connected to one of the fixing plates 26, and the output shaft of the second motor 27 is fixedly connected to one end of the rotating shaft; anti-slip grooves are provided on the positioning columns 23, and the positioning columns 23 are made of rubber.

[0021] Since the oil cylinder 3 usually has three shapes, namely cylindrical, rectangular and spherical, the V-block in the prior art cannot contact the oil cylinder 3 well. When the oil cylinder 3 is under high pressure, the V-block may not be able to position the oil cylinder 3, and it is also easy to scratch the surface of the oil cylinder 3. When the positioning mechanism provided by the present invention is used, the oil cylinder 3 to be tested is placed in the positioning sleeve 2, and the second motor 27 is turned on, and the connected rotating shaft and the gear column 24 are driven to rotate by the output shaft of the second motor 27. When the gear column 24 rotates, it drives the gear ring 21 to rotate, thereby driving the other three gear columns 24 to rotate through the gear ring 21, so as to realize the synchronous rotation of the four gear columns 24, and the rack 22 is driven to move by the gear column 24, and the positioning column 23 is driven to move by the rack 22. The four positioning columns 23 fix the oil cylinder 3 in the center of the positioning sleeve 2, so as to realize the positioning function of the oil cylinder 3 when it is used for testing. The arrangement of the positioning columns 23 is suitable for different shapes of oil cylinders 3, and the setting of the anti-skid groove prevents the oil cylinder 3 from sliding under high pressure, and the rubber material prevents the oil cylinder 3 from being scratched during testing.

[0022] like Figure 1 and Figure 4 As shown, a piston cylinder body is installed in the oil cylinder 3, and the end of the piston rod body 33 away from the oil cylinder 3 is fixedly connected to a mounting plate 35, and both ends of the mounting plate 35 are fixedly connected to sliding rods 34. Two limit blocks 31 are symmetrically fixedly connected to the outer wall of the oil cylinder 3, and sliding openings 32 are opened in the limit blocks 31. The sliding rods 34 slide in the sliding openings 32; one end of the piston rod body 33 is fixedly connected to a connecting block 37.

[0023] When the slide rod 34 and the limit block 31 provided by the present invention are in use, hydraulic oil is arranged in the oil cylinder 3 to control the contraction movement of the piston rod body 33 through the hydraulic system. When the piston rod body 33 moves, the mounting plate 35 is driven to move, and the slide rod 34 is driven to move through the mounting plate 35. The slide rod 34 slides in the limit block 31 through the sliding opening 32, and the stability of the movement of the piston rod body 33 is ensured by the slide rod 34.

[0024] like Figure 4 and Figure 6 As shown, a displacement sensor 36 is fixedly connected to the side wall of the mounting plate 35 , a through opening is opened on the connecting block 37 , and pressure sensors 38 are installed on the top inner wall and the bottom inner wall of the through opening, and the pressure sensors 38 are electrically connected to the displacement sensor 36 .

[0025] When the pressure sensor 38 and displacement sensor 36 provided by the present invention are in use, the displacement sensor 36 monitors the change in the contraction distance of the piston rod body 33, and the diameter of the cross bar 42 in the through-port is different. Therefore, when the piston rod body 33 just starts to move, it may not be connected to the pressure end, which affects the test of the piston rod body 33. By setting the pressure sensor 38, the piston rod body 33 drives the connecting block 37 to move when it moves. When the pressure sensor 38 on the connecting block 37 contacts the cross bar 42, the pressure sensor 38 transmits an electrical signal to the controller 15, and the displacement sensor 36 is started by the controller 15, and the displacement sensor 36 starts to work, thereby ensuring that the displacement sensor 36 always maintains the pressure at one end of the piston rod body 33 when it is working.

[0026] like Figure 1 and Figure 5 As shown, the positioning sleeve 2 is provided with two arc-shaped openings 29, and an arc-shaped plate 210 is slidably connected in the arc-shaped openings 29, and a fixing tube 41 is fixedly connected to the inner side wall of the top end of the arc-shaped plate 210, and a cross bar 42 is slidably connected in the two fixing tubes 41, and a reciprocating screw 43 is threadedly connected in the cross bar 42, and one end of the reciprocating screw 43 is rotatably connected to the arc-shaped plate 210 through a bearing, and a rotary block 4 is fixedly connected to the outer wall extending to the arc-shaped plate 210; a circular plate 44 is fixedly connected to the inner wall of the fixing tube 41 away from the rotary block 4; and the cross bar 42 is inserted in the through opening.

[0027] When the fixed tube 41 and the cross bar 42 provided by the present invention are in use and tested, one end of the piston rod body 33 needs to be connected to the arc plate 210, and the arc plate 210 is pulled flush with the position of the through-port, and then the rotary block 4 is rotated, the rotary block 4 drives the reciprocating screw 43 to rotate, and the cross bar 42 is driven to move by the reciprocating screw 43, and the cross bar 42 is inserted into the through-port, and then the other arc plate 210 is pulled upward, and the rotary block 4 continues to be rotated, and the cross bar 42 is screwed into the other fixed tube 41 until it moves to the circular plate 44 and stops moving, thereby connecting the piston rod body 33 to the pressure end, which is convenient for changing the conditions of the contraction test.

[0028] like Figure 7 As shown, a load-bearing box 5 is fixedly connected to the two arc-shaped plates 210, and a plurality of counterweight blocks 51 are placed in the load-bearing box 5. A threaded rod 53 is rotatably connected to the load-bearing box 5 through a bearing, and a handle 52 is fixedly connected to one end of the threaded rod 53. A splint 54 is threadedly connected to the threaded rod 53, and the splint 54 is in close contact with the counterweight block 51 on the top, and the splint 54 is slidably connected to the inside of the load-bearing box 5.

[0029] When the threaded rod 53 and the clamping plate 54 provided by the present invention are in use, when the pressure end conditions during the contraction test are changed, it is necessary to place counterweight blocks 51 of different weights. After the counterweight block 51 is placed, it is necessary to rotate the handle 52, and the handle 52 drives the threaded rod 53 to rotate, and the threaded rod 53 drives the clamping plate 54 to move until the counterweight block 51 is clamped, and then start the test of different pressures. Under the same pressure conditions, it is necessary to measure the displacement changes during extension and contraction 2-3 times through the displacement sensor 36. When the displacement amount is always the same as the set amount, it means that the piston rod body 33 is qualified, otherwise it is unqualified.

[0030] like Figure 1 As shown, a first motor 14 is fixedly connected to the outer wall of one of the support plates 11, and an angle sensor 13 is fixedly connected to the outer wall of the other support plate 11. The output shaft of the first motor 14 is fixedly connected to one end of a connecting rod 12, and the output end of the angle sensor 13 is fixedly connected to one end of the other connecting rod 12.

[0031] The angle sensor 13 provided by the present invention is used to measure the contraction of the piston rod body 33 at different angles when in use. The first motor 14 is controlled to rotate by the angle sensor 13. The first motor 14 drives the connecting rod 12 to rotate through the output shaft, and the positioning sleeve 2, the cylinder 3, the piston rod body 33 and the counterweight 51 are driven to rotate together through the connecting rod 12. When it rotates to a set angle, the counterweight 51 of the same weight is pushed by the piston rod body 33, and then the displacement sensor 36 is used to measure the displacement changes during 2-3 extensions and contractions. If the displacement is always the same as the set amount regardless of the angle it rotates to, it means that the piston rod body 33 is qualified, otherwise it is unqualified.

[0032] like Figure 1 As shown, a controller 15 is fixedly connected to the workbench 1 , and the displacement sensor 36 , the angle sensor 13 and the pressure sensor 38 are electrically connected to the controller 15 respectively.

[0033] When the controller 15 provided by the present invention is in use, the controller 15 connects the displacement sensor 36 and the pressure sensor 38 by setting a control system, so as to start the operation of the displacement sensor 36 by triggering the pressure sensor 38. The angle sensor 13 controls the first motor 14 through the controller 15 by setting different angles, so as to facilitate the adjustment of the angle.

[0034] like Figure 3 As shown, the two side walls of the rack 22 are fixedly connected with limiting rods 28 , and the limiting rods 28 slide on the positioning sleeve 2 .

[0035] When the limiting rod 28 provided by the present invention is in use, the rack 22 drives the limiting rod 28 to move during its movement, and the limiting rod 28 slides on the positioning sleeve 2, so that the limiting rod 28 ensures the stable movement of the rack 22.

[0036] Working principle: put the oil cylinder 3 to be tested in the positioning sleeve 2, turn on the second motor 27, and drive the connected rotating shaft and the gear column 24 to rotate through the output shaft of the second motor 27. When the gear column 24 rotates, it drives the gear ring 21 to rotate, thereby driving the other three gear columns 24 to rotate through the gear ring 21, so as to realize the synchronous rotation of the four gear columns 24, and drive the rack 22 to move through the gear column 24, and drive the positioning column 23 to move through the rack 22. The four positioning columns 23 fix the oil cylinder 3 in the center of the positioning sleeve 2, so as to realize the positioning function of the oil cylinder 3 when used for testing. The arrangement of the positioning columns 23 is suitable for different shapes of oil cylinders 3, and the design of the anti-slip groove is suitable for different shapes of oil cylinders 3. The arrangement prevents the oil cylinder 3 from sliding when the pressure is high, and the rubber material prevents the oil cylinder 3 from being scratched during the test; then one end of the piston rod body 33 is connected to the arc plate 210, and the arc plate 210 is pulled flush with the position of the through-port, and then the rotary block 4 is rotated, and the rotary block 4 drives the reciprocating screw 43 to rotate, and the reciprocating screw 43 drives the cross bar 42 to move, and the cross bar 42 is inserted into the through-port, and then another arc plate 210 is pulled up, and the rotary block 4 is continued to be rotated, and the cross bar 42 is screwed into another fixed tube 41 until it moves to the circular plate 44 and stops moving, thereby connecting the piston rod body 33 with the pressure end, which is convenient for changing the conditions of the contraction test; When testing at different pressures, it is necessary to place counterweights 51 of different weights. After the counterweights 51 are placed, it is necessary to rotate the handle 52, which drives the threaded rod 53 to rotate, and the threaded rod 53 drives the clamping plate 54 to move until the counterweight 51 is clamped. Then, the tests at different pressures are started. Hydraulic oil is arranged in the oil cylinder 3 to control the contraction movement of the piston rod body 33 through the hydraulic system. The piston rod body 33 drives the connecting block 37 to move when it moves. When the pressure sensor 38 on the connecting block 37 contacts the cross bar 42, the pressure sensor 38 transmits an electrical signal to the controller 15, and the displacement sensor 36 is started by the controller 15. The displacement sensor 36 starts to work. Under the same pressure condition, it is necessary to measure the displacement change during extension and contraction 2-3 times through the displacement sensor 36. When the displacement amount is always the same as the set amount, it means that the piston rod body 33 is qualified, otherwise it is unqualified. During the test at different angles, the first motor 14 is controlled to rotate by the angle sensor 13, and the first motor 14 drives the connecting rod 12 to rotate through the output shaft, and drives the positioning sleeve 2, the cylinder 3, the piston rod body 33 and the counterweight 51 to rotate together through the connecting rod 12. When it rotates to the set angle, the contraction movement of the piston rod body 33 is controlled by the hydraulic system, and the piston rod body 33 drives the connecting block 37 to move during the movement. When the pressure sensor 38 on the connecting block 37 contacts the cross bar 42, the pressure sensor 38 transmits an electrical signal to the controller 15, and the displacement sensor 36 is started by the controller 15. The displacement sensor 36 starts to work and pushes the counterweight 51 of the same weight through the piston rod body 33. Then, the displacement sensor 36 measures the displacement changes during extension and contraction 2-3 times. If the displacement is always the same as the set amount regardless of the rotation angle, it means that the piston rod body 33 is qualified, otherwise it is unqualified.

[0037] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A piston rod retraction test positioning device, comprising: Workbench (1); Two support plates (11) fixedly connected to the top of the workbench (1); A connecting rod (12) rotatably connected to the inner walls of the two support plates (11) via a bearing; A positioning sleeve (2) fixedly connected between two connecting rods (12); An oil cylinder (3) disposed inside the positioning sleeve (2); A positioning mechanism provided between the oil cylinder (3) and the positioning sleeve (2); The invention is characterized in that: the positioning mechanism comprises a toothed ring (21) rotatably connected to the outer wall of the positioning sleeve (2) through a bearing, and eight fixing plates (26) are fixedly connected to the outer wall of the positioning sleeve (2); a toothed column (24) is rotatably connected between two adjacent fixing plates (26) through a rotating shaft, and the toothed columns (24) are meshed with the toothed ring (21); four racks (22) are slidably connected to the positioning sleeve (2), and the racks (22) are arranged below the toothed ring (21), and meshing with an adjacent tooth column (24); one end of each of the racks (22) is fixedly connected to a positioning column (23), and each of the positioning columns (23) is in close contact with the oil cylinder (3); the other end of each of the racks (22) is fixedly connected to a blocking plate (25); a second motor (27) is fixedly connected to one of the fixing plates (26), and an output shaft of the second motor (27) is fixedly connected to one end of the rotating shaft; an anti-slip groove is provided on each of the positioning columns (23), and each of the positioning columns (23) is made of rubber.

2. A piston rod retraction test positioning device according to claim 1, characterized in that: A piston cylinder body is installed in the oil cylinder (3); one end of the piston rod body (33) away from the oil cylinder (3) is fixedly connected to a mounting plate (35); both ends of the mounting plate (35) are fixedly connected to sliding rods (34); two limit blocks (31) are symmetrically fixedly connected to the outer wall of the oil cylinder (3); each limit block (31) is provided with a sliding opening (32); and each sliding rod (34) slides in the sliding opening (32); one end of the piston rod body (33) is fixedly connected to a connecting block (37).

3. A piston rod retraction test positioning device according to claim 2, characterized in that: A displacement sensor (36) is fixedly connected to the side wall of the mounting plate (35), a through opening is provided on the connecting block (37), pressure sensors (38) are installed on the top inner wall and the bottom inner wall of the through opening, and the pressure sensors (38) are electrically connected to the displacement sensor (36).

4. A piston rod retraction test positioning device according to claim 3, characterized in that: The positioning sleeve (2) is provided with two arc-shaped openings (29), and an arc-shaped plate (210) is slidably connected in the arc-shaped openings (29), and a fixing tube (41) is fixedly connected to the inner side wall of the top end of the arc-shaped plate (210), and a cross bar (42) is slidably connected in the two fixing tubes (41), and a reciprocating screw (43) is internally threadedly connected in the cross bar (42), and one end of the reciprocating screw (43) is rotatably connected to the arc-shaped plate (210) through a bearing, and a rotary block (4) is fixedly connected to the outer wall of the arc-shaped plate (210); a circular plate (44) is fixedly connected to the inner wall of the fixing tube (41) away from the rotary block (4); and the cross bar (42) is inserted in the through opening.

5. A piston rod retraction test positioning device according to claim 4, characterized in that: A load-bearing box (5) is fixedly connected to the two arc-shaped plates (210), and a plurality of counterweights (51) are placed in the load-bearing box (5). A threaded rod (53) is rotatably connected to the load-bearing box (5) via a bearing, and a handle (52) is fixedly connected to one end of the threaded rod (53). A clamping plate (54) is threadedly connected to the threaded rod (53), and the clamping plate (54) is in close contact with the counterweight (51) at the top. The clamping plate (54) is slidably connected to the inside of the load-bearing box (5).

6. A piston rod contraction test positioning device according to claim 5, characterized in that: A first motor (14) is fixedly connected to the outer wall of one of the support plates (11), and an angle sensor (13) is fixedly connected to the outer wall of the other support plate (11); an output shaft of the first motor (14) is fixedly connected to one end of a connecting rod (12), and an output end of the angle sensor (13) is fixedly connected to one end of the other connecting rod (12).

7. A piston rod retraction test positioning device according to claim 6, characterized in that: A controller (15) is fixedly connected to the workbench (1), and the displacement sensor (36), the angle sensor (13) and the pressure sensor (38) are respectively electrically connected to the controller (15).

8. The piston rod retraction test positioning device according to claim 7, characterized in that: Limit rods (28) are fixedly connected to both side walls of the rack (22), and the limit rods (28) slide on the positioning sleeve (2).

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