Compression resistance detection device for PVC (Polyvinyl Chloride) pipe

Abstract

The invention relates to the technical field of PVC pipe detection, in particular to a PVC pipe compression resistance detection device which comprises a detection machine table, a lifting plate is slidably connected to the detection machine table, a pressure applying plate is installed on the lifting plate, a trigger plate is installed on the lower side of the pressure applying plate, and a bearing table used for bearing a plastic pipe is fixedly arranged on the detection machine table. A supporting rod is fixedly connected to the detection machine table, a contraction plate is connected to the supporting rod in a sliding mode, a lower spring is further arranged on the supporting rod in a sleeving mode, a positioning seat is fixedly connected to the contraction plate, the positioning seat upwards penetrates through a contraction hole in the bearing table, and a positioning rod used for limiting the plastic pipe is installed on the positioning seat. According to the device, the plastic pipe can be limited before detection, the plastic pipe is prevented from rolling during placement, the plastic pipe can be accurately placed in the middle position, the limiting of the plastic pipe can be canceled in time when detection is started, the natural change rule of the plastic pipe in the radial compression state is prevented from being influenced, and the detection accuracy is improved. And the accuracy of detection data is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of PVC pipe detection, and in particular to a pressure resistance detection device for PVC pipes. Background Art

[0002] The flattening test is a test method used to evaluate the deformation resistance and compressive performance of pipes when subjected to external radial pressure. During the experiment, the PVC pipe needs to be placed horizontally between two flat and parallel pressure plates, ensuring that the PVC pipe is in close contact with the pressure plates and is centered. Then, pressure is applied uniformly at a certain rate to cause the PVC pipe to deform radially. The compressive performance and deformation capacity of the PVC pipe are obtained by measuring the deformation and recording the failure pressure.

[0003] At present, in order to enable PVC pipes to change according to their natural deformation laws under pressure and ensure the accuracy of the detection structure, the pressure plate of the detection equipment is usually not provided with a clamp or support structure for fixing the PVC pipe. However, due to the cylindrical shape of the PVC pipe, the PVC pipe is easy to roll on the pressure plate when it is placed on the pressure plate, and it is difficult to place the PVC pipe accurately in the center position, which causes inconvenience to the detection of the PVC pipe and may affect the detection accuracy. Therefore, it is necessary to design a detection device that can limit the PVC pipe before pressure is applied without affecting the deformation law of the PVC pipe during the pressure application process. Summary of the Invention

[0004] In order to overcome the shortcomings of PVC pipes that are prone to rolling during placement and difficult to accurately place in the center, but the provision of fixtures and support structures may affect the natural change pattern of PVC pipes, the present invention provides a pressure resistance detection device suitable for PVC pipes of different diameters. The device can limit the position of the PVC pipe before pressure is applied, and automatically cancel the limit on the PVC pipe when pressure begins to be applied, and can automatically adapt to the timing of canceling the limit according to the different diameters of the PVC pipe.

[0005] The technical solution is: a pressure resistance testing device for PVC pipes, including a testing machine, a lifting plate slidably connected to the testing machine, a pressure plate installed on the lifting plate, a trigger plate installed on the lower side of the pressure plate, a bearing platform for supporting the plastic pipe fixedly arranged on the testing machine, and a support rod fixedly connected to the testing machine, a contraction plate slidably connected to the support rod, a lower spring is also sleeved on the support rod, a positioning seat is fixedly connected to the contraction plate, the positioning seat passes upward through the contraction hole on the bearing platform, a positioning rod for limiting the plastic pipe is installed on the positioning seat, a contraction mechanism is connected to the trigger plate, and when the trigger plate is resisted by the plastic pipe, the contraction mechanism will push the contraction plate to move downward.

[0006] Furthermore, the retraction mechanism includes a pushing rack, which is slidably arranged on the lifting plate, a pushing spring is sleeved on the pushing rack, a locking rod is fixed to the pushing rack, a locking hole is opened on the locking rod, and a locking head is slidably connected to the pressure plate. The locking head is used to be inserted into the locking hole to limit the locking rod from descending, and one end of the locking spring is respectively connected to the locking head and the pressure plate. A locking assembly is connected to the trigger plate. When the trigger plate is contacted by the plastic tube, the locking assembly will drive the locking head to gradually withdraw from the locking hole.

[0007] Furthermore, the locking assembly includes a trigger rod, which is fixed to the trigger plate, and the trigger rod passes upward through the pressure plate and is slidably connected thereto, the trigger rod is fixed to a reset plate, the reset plate is fixed to a retraction rod, the locking head is fixed to a retraction plate, the retraction rod and the retraction plate are squeezed together to drive the locking head to exit the locking hole, and a reset rod is fixed to the detection machine for pressing the reset plate to push the pressure plate to reset downward.

[0008] Furthermore, both the upper and lower sides of the retractable plate are inclined plate-like structures, and the horizontal extension length of the lower side of the retractable plate is greater than that of the upper side, and the horizontal extension direction is towards the direction away from the locking head.

[0009] Furthermore, the middle portion of the retractable plate is a vertical plate-shaped structure, a plurality of locking holes are provided on the locking rod, and inclined surfaces are provided on the locking holes and the locking head.

[0010] Furthermore, it also includes a magnetic attraction component for fixing the pressure plate, the magnetic attraction component includes a second magnetic block, the two second magnetic blocks are respectively fixed to the upper and lower ends of the reset plate, the pressure plate is fixed to the first magnetic block and the support, the support is also fixed to the first magnetic block, the reset plate is located between the upper and lower first magnetic blocks, and the first magnetic block and the second magnetic block attract each other.

[0011] Furthermore, it also includes an adjustment component for adjusting the angle of the positioning rod, the adjustment component includes an adjustment plate, the adjustment plate is rotatably connected to the positioning seat, the positioning rod is fixed to the adjustment plate, an adjustment hole is opened at one end of the adjustment plate, an adjustment rod is slidably inserted in the adjustment hole, an adjustment wheel is fixed to the adjustment rod, and a clamping rod for limiting the rotation of the adjustment wheel is fixed to the positioning seat.

[0012] Furthermore, a blocking plate is also included. The blocking plate is slidably arranged on the bearing platform. When the positioning seat moves downward, the blocking plate will gradually move toward the upper side of the shrinkage hole.

[0013] Furthermore, it also includes a guide frame and a sliding shaft. The guide frame is fixed on the blocking plate. The sliding shaft is rotatably arranged on the retracting plate, and the sliding shaft is slidably connected to the guide frame on the same side.

[0014] Furthermore, it also includes a support assembly that facilitates the adjustment of the pressure plate and the supporting platform. The support assembly includes a fixed seat, a threaded rod and a threaded seat. There are two groups of support assemblies, which are arranged opposite to each other. One group is used to connect the lifting plate and the pressure plate, and the other group is used to connect the detection machine and the supporting platform.

[0015] The beneficial effects of the present invention are as follows: the device can limit the plastic tube before testing to prevent the plastic tube from rolling when placed, and enable the plastic tube to be accurately placed in the center position; when starting the test, the limit on the plastic tube will be cancelled in time to avoid affecting the natural change law of the plastic tube under radial pressure, thereby ensuring the accuracy of the test data; and through the cooperation of the trigger plate and the locking assembly, the timing of canceling the limit can be automatically adjusted according to the different diameters of the plastic tube, thereby preventing the positioning rod from shrinking early or late, thereby affecting the normal operation of the pressure resistance test, so that the device can be applied to the pressure resistance test of plastic tubes of various diameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0017] Figure 2 Schematic diagram of the position relationship of the pressure plate of the present invention.

[0018] Figure 3 Schematic diagram of the position relationship of the trigger plate of the present invention.

[0019] Figure 4 It is a schematic diagram of the retractable plate structure of the present invention.

[0020] Figure 5 Schematic diagram of the position relationship of the contraction plate of the present invention.

[0021] Figure 6 It is a schematic diagram of the cross-sectional structure of the adjustment plate of the present invention.

[0022] Figure 7 It is a schematic diagram of the cross-sectional structure of the threaded seat of the present invention.

[0023] Figure 8 It is a schematic diagram of the deformation state of the plastic tube of the present invention.

[0024] Figure numbers: 10: Detection machine, 11: Lifting plate, 12: Pressure plate, 13: Trigger plate, 14: Support rod, 15: Carrying platform, 16: Retraction plate, 17: Lower spring, 18: Electric push rod, 20: Pushing frame, 21: Pushing spring, 22: Locking rod, 23: Locking hole, 24: Locking head, 25: Locking spring, 26: Limit seat, 30: Retraction plate, 31: Reset plate, 32: Retraction Rod, 33: Reset rod, 34: Trigger rod, 40: Support, 41: First magnetic block, 42: Second magnetic block, 50: Positioning seat, 51: Positioning rod, 52: Card rod, 53: Adjustment plate, 54: Adjustment hole, 55: Adjustment rod, 56: Adjustment wheel, 60: Sealing plate, 61: Guide frame, 62: Sliding shaft, 70: Fixed seat, 71: Threaded rod, 72: Threaded seat, 73: Shrinkage hole, 80: Plastic tube. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] Example 1: A compression testing device for PVC pipes, such as Figure 1 、 Figure 2 、 Figure 3 and Figure 5 As shown, it includes a detection machine 10, a lifting plate 11, a pressure plate 12, a trigger plate 13, a support rod 14, a bearing platform 15, a retracting plate 16, a lower spring 17, an electric push rod 18, a positioning seat 50, a positioning rod 51 and a retracting mechanism. The lifting plate 11 is slidably connected to the detection machine 10 in the vertical direction, and the electric push rod 18 is fixed to the detection machine 10. The telescopic axis of the electric push rod 18 is fixed to the upper end of the lifting plate 11. The pressure plate 12 is installed at the lower end of the lifting plate 11, and the trigger plate 13 is installed on the lower side of the pressure plate 12. Figure 3It can be seen that the lower end of the pressure plate 12 is provided with a groove for accommodating the trigger plate 13, and a bearing platform 15 is fixedly provided on the base of the detection machine 10. The bearing platform 15 is located directly below the pressure plate 12, and two support rods 14 are fixedly connected to the base of the detection machine 10 in a front-to-back symmetrical manner. The support rods 14 are located on the lower side of the bearing platform 15. A retraction plate 16 is connected to the two support rods 14 in a vertical sliding manner. A lower spring 17 is also provided on the support rod 14. The lower spring 17 is located on the lower side of the retraction plate 16. Two positioning seats 50 are fixedly connected to the top of the retraction plate 16 in a symmetrical manner. Two retraction holes 73 are symmetrically opened on the supporting platform 15 and pass through the supporting platform 15 upward through the retraction holes 73. A positioning rod 51 for limiting the plastic tube 80 is installed on the upper side of the positioning seat 50. A retraction mechanism is connected to the trigger plate 13. When the trigger plate 13 is resisted by the plastic tube 80, the retraction mechanism will push the retraction plate 16 to move downward, so that the positioning rod 51 is away from the plastic tube 80 to avoid affecting the detection.

[0027] The retraction mechanism includes a pushing frame 20, a pushing spring 21, a locking rod 22, a locking head 24, a locking spring 25, a limit seat 26 and a locking assembly. There are two pushing frames 20 symmetrically connected to the lifting plate 11 for sliding connection. The two pushing frames 20 move in the vertical direction. A pushing spring 21 is provided on the pushing frame 20, and the pushing spring 21 is located on the lower side of the lifting plate 11. A locking rod 22 is fixed to the pushing frame 20. The locking rod 22 extends upward and passes through the lifting plate 11. A locking hole 23 is provided at the opposite end of the two sets of locking rods 22. Two brackets are symmetrically provided on the upper end of the pressure plate 12. The locking heads 24 are slidably connected to the two brackets. The fixed heads 24 are symmetrically arranged on the left and right and slide in the horizontal direction. The locking heads 24 are used to be inserted into the locking holes 23 to limit the locking rod 22 from descending. A locking spring 25 is sleeved on the guide rod to which the locking head 24 and the bracket are slidably connected, and one end of the locking spring 25 is fixed to the locking head 24, and the other end is fixed to the bracket arranged on the upper end of the pressure plate 12. Two limit seats 26 for limiting the descending height of the retraction plate 16 are fixed on the base of the detection machine 10 symmetrically on the left and right. The limit seats 26 are located on the lower side of the retraction plate 16. A locking assembly is connected to the trigger plate 13. When the trigger plate 13 is contacted by the plastic tube 80, the locking assembly will drive the locking head 24 to gradually withdraw from the locking hole 23.

[0028] The locking assembly includes a retraction plate 30, a reset plate 31, a retraction rod 32, a reset rod 33 and a trigger rod 34. Four trigger rods 34 are fixedly connected to the upper end of the trigger plate 13 in a front-to-back symmetrical manner. The trigger rods 34 pass upward through the pressure plate 12. The trigger plate 13 is slidably connected to the pressure plate 12 through the trigger rods 34. The two trigger rods 34 on the same side are fixedly connected to the reset plate 31. The reset plate 31 is located on the upper side of the pressure plate 12. The retraction rod 32 is fixedly connected to the reset plate 31. The retraction rod 32 is located on the side adjacent to the two reset plates 31. A retraction plate 30 is fixedly connected to the adjacent end of the two locking heads 24. The upper and lower sides of the retraction plate 30 are inclined plate-like structures, and the horizontal extension length of the lower side of the retraction plate 30 is greater than that of the upper side. The horizontal extension direction refers to the direction away from the locking head 24. When the trigger plate 13 moves upward, the retraction rod 32 will squeeze the retraction plate 30 in the direction away from the locking rod 22 on the same side. Two reset rods 33 are fixedly connected to the upper side of the detection machine 10 symmetrically. The reset rod 33 is used to press the reset plate 31 to push the pressure plate 12 to reset downward.

[0029] A plastic tube 80 of appropriate length is cut in advance, and then the cut plastic tube 80 is placed on the supporting platform 15 in a manner that the axial direction is parallel to the two positioning rods 51, and the plastic tube 80 is located between the two positioning rods 51, and the lower end of the plastic tube 80 contacts the supporting platform 15. The experimental parameters such as extrusion speed, applied pressure and extrusion height are set through the computer control system, and then the electric push rod 18 is controlled to extend, and the lifting plate 11 and the pressure plate 12 will move downward. When the trigger plate 13 contacts the plastic tube 80, they will be resisted. At this time, it proves that pressure has begun to be applied to the plastic tube 80. The trigger plate 13 will first move upward relative to the pressure plate 12 under the resistance of the plastic tube 80. The trigger plate 13 will drive the retraction rod 32 and the reset plate 31 upward. When the retraction rod 32 moves upward, it will first squeeze the retraction plate 30 away from the locking head 24, and the locking spring 25 will be compressed, thereby driving the locking head 24 to move out of the locking hole 23. The push spring 21 shown in the figure is at When the locking rod 22 is released from the locking hole 23, the locking head 24 is located at the upper side of the locking hole 23, and the locking head 24 cannot be reset due to the obstruction of the locking rod 22. The locking spring 25 will remain in the compressed state. When the pushing frame 20 moves downward, it will press the retraction plate 16 downward, and the retraction plate 16 will drive the positioning rod 51 downward away from the plastic tube 80. Because the plastic tube 80 will deform during the pressure test, first changing from a circular shape to an elliptical shape, by actively moving the positioning rod 51 away from the downward movement, it can prevent it from affecting the natural deformation law of the plastic tube 80, thereby ensuring the accuracy of the test. Moreover, since pressure has been applied to the plastic tube 80, a radial clamping force on the plastic tube 80 is formed between the trigger plate 13 and the supporting platform 15. Even if the positioning rod 51 has moved away from the plastic tube 80, the plastic tube 80 will not roll.When the trigger plate 13 retracts into the groove at the lower end of the pressure plate 12, the pressure plate 12 will drive the trigger plate 13 to move downward synchronously to start the pressure test on the plastic tube 80. A pressure sensor is provided on the trigger plate 13. The specific structure of the pressure sensor is not shown in the figure. The pressure sensor is used to monitor the applied pressure. During the test process, the lifting plate 11 can be controlled to stop intermittently, so that technicians can observe, measure and record the deformation of the plastic tube 80 in time, and observe whether the plastic tube 80 has cracks, ruptures, etc. In addition, technicians can also add deformation detection equipment to detect the deformation of the plastic tube 80 in real time. During the downward movement of the lifting plate 11, the locking head 24 will gradually move downward close to the locking hole 23. When the plastic tube 80 is Inspection is complete when the deformation of the material tube 80 reaches a certain proportion of its diameter, and the locking head 24 precisely enters the locking hole 23. For example, if the plastic tube 80 has a diameter of 30 cm, when the plastic tube 80 is compressed and deformed to a height of only 10 cm, the locking head 24 moves to the same height as the locking hole 23. The locking spring 25 then pushes the locking head 24 into the locking hole 23, and the electric push rod 18 is then controlled to retract, causing the lifting plate 11 and pressure plate 12 to return upward. The pressure plate 12, through the locking head 24, drives the locking rod 22 and the pushing frame 20 upward. The pushing spring 21 is compressed upward, and the lower spring 17 also pushes the retracting plate 16 upward to facilitate the placement of the next plastic tube 80 to be inspected on the support platform 15.

[0030] When the trigger plate 13 follows the pressure plate 12 to reset upward to the set height, the reset rod 33 will contact the reset plate 31, so that the reset plate 31 drives the trigger plate 13 to move downward relative to the pressure plate 12 through the trigger rod 34, that is, the trigger plate 13 moves out of the groove at the lower end of the pressure plate 12, and the reset plate 31 drives the retraction rod 32 to move downward relatively. Since the lower side of the retraction plate 30 extends longer in the horizontal direction than the upper side, the retraction rod 32 will first squeeze the retraction plate 30 a short distance toward the locking rod 22. When the retraction plate 30 is reset a short distance away from the positioning rod 51, the locking head 24 will not be driven out of the locking hole 23, and the push spring 21 is still in a compressed state.

[0031] Example 2: Based on Example 1, Figure 3 As shown, the middle portion of the retracting plate 30 is a vertical plate-like structure, and five locking holes 23 are equidistantly provided on the locking rod 22 in the vertical direction, and both the locking holes 23 and the locking head 24 are provided with inclined surfaces.

[0032] In order to make the device applicable to the detection of plastic tubes 80 with different diameters, five positioning holes are opened at equal intervals on the locking rod 22, corresponding to the plastic tubes 80 with different diameters. Figure 3 and Figure 4 It can be seen that the locking hole 23 and the locking head 24 are both provided with inclined surfaces. This design is to enable the locking head 24 to retract under the squeezing effect of the inclined surface during the downward movement, so that the locking head 24 can continue to move into the locking hole 23 below. Figure 4As can be seen in the figure, the middle part of the retraction plate 30 is a vertical plate-like structure. This design is to enable the retraction rod 32 to maintain the compression of the retraction plate 30 first, so that the push spring 21 has enough time to push the push frame 20 to move downward, and prevent the locking head 24 from being directly reset under the push of the locking spring 25, resulting in being stuck in the locking hole 23 on the upper side; in order to facilitate further understanding of this embodiment, assuming that the diameter of the plastic tube 80 tested last time is 30 cm, the test can be completed when the plastic tube 80 is compressed and deformed to a height of only 10 cm, that is, when it is compressed to one-third of the diameter of the plastic tube 80, the pressure plate 12 does not need to continue to press down, and at this time the locking head 24 The push spring 21 is further compressed, and the retracting plate 16 is pushed upward by the lower spring 17. At this time, the distance between the trigger plate 13 and the pressure plate 12 and the top of the carrier 15 is 10 cm, and the push frame 20 will push the retracting plate 16 down 8 cm. The retracting plate 16 will be blocked by the limit seat 26 and cannot continue to fall. In order to convert the minimum diameter of the plastic tube 80 that can be detected, the pressure plate 12 and the trigger plate 13 are first controlled to reset upward by 8 cm. Since the locking head 24 has been stuck in the locking hole 23, the pushing frame 20 will also move upward by 8 cm. The pushing spring 21 is further compressed, and the retracting plate 16 will be reset upward by 8 cm under the push of the lower spring 17. At this time, the distance between the trigger plate 13 and the pressure plate 12 and the top of the carrier 15 is 10 cm. 18 cm. Since the retracting plate 16 has completed its upward reset at this time, the pushing rack 20 will be out of contact with the retracting plate 16 when the trigger plate 13 continues to move upward. Therefore, when the pressure plate 12 drops again and the pressure plate 12 is 18 cm away from the load-bearing platform 15, the pushing rack 20 will contact the retracting plate 16. It should be noted that since the trigger plate 13 will move downward relative to the pressure plate 12 during the upward reset process, that is, the trigger plate 13 moves out of the groove at the lower end of the pressure plate 12. Assuming that the trigger plate 13 will move downward by 3 cm, when the pressure plate 12 is 18 cm away from the load-bearing platform 15, the trigger plate 13 is 15 cm away from the load-bearing platform 15. If If the diameter of the plastic tube 80 is less than 15 cm, the trigger plate 13 will continue to move downward before it starts to contact the plastic tube 80, that is, the trigger plate 13 will continue to move downward before it starts to apply pressure to the plastic tube 80, and the pushing frame 20 will push the retraction plate 16 downward in advance, that is, drive the positioning rod 51 to cancel the positioning of the plastic tube 80 in advance, causing the plastic tube 80 to roll. Therefore, the minimum diameter of the plastic tube 80 to be tested next time needs to be greater than or equal to 15 cm to prevent the positioning of the plastic tube 80 from being released in advance; it should be noted that when actually producing this device, the actual stroke of the retraction plate 16, trigger plate 13 and other structures can be set according to actual needs.

[0033] like Figure 2 and Figure 3As shown, it also includes a magnetic attraction component for fixing the pressure plate 12, the magnetic attraction component is connected to the reset plate 31, and the magnetic attraction component includes a support 40, a first magnetic block 41 and a second magnetic block 42. Two first magnetic blocks 41 are symmetrically fixed to the top of the pressure plate 12 in the front and back directions, and two supports 40 are also symmetrically fixed to the top of the pressure plate 12. The first magnetic block 41 is also fixed to the support 40. The pressure plate 12 and the first magnetic blocks 41 on the support 40 are arranged opposite to each other in the upper and lower directions. The reset plate 31 is located between the upper and lower first magnetic blocks 41 on the same side. The upper and lower ends of the reset plate 31 are fixed with the second magnetic blocks 42, and the first magnetic block 41 and the second magnetic block 42 attract each other.

[0034] The magnetic attraction effect of the first magnetic block 41 and the second magnetic block 42 can fix the trigger plate 13, thereby preventing the trigger plate 13 from moving freely and affecting the normal operation of the device.

[0035] like Figure 5 and Figure 6 As shown, it also includes an adjustment component for adjusting the angle of the positioning rod 51. The adjustment component is connected to the positioning seat 50. The adjustment component includes a clamping rod 52, an adjustment plate 53, an adjustment rod 55 and an adjustment wheel 56. The positioning seat 50 is rotatably connected to the adjustment plate 53. The lower end of the positioning rod 51 is fixed to the adjustment plate 53, that is, the positioning rod 51 is installed on the positioning seat 50 through the adjustment plate 53. An adjustment hole 54 is provided at one end of the adjustment plate 53. The adjustment rod 55 is slidably inserted in the adjustment hole 54. It should be noted that the adjustment rod 55 can only slide axially but cannot rotate. An adjustment wheel 56 is fixed to the adjustment rod 55. The adjustment wheel 56 is in the shape of a gear. A clamping rod 52 is fixed to the positioning seat 50. The clamping rod 52 is used to clamp the teeth of the adjustment wheel 56 to limit its rotation.

[0036] When the diameter of the plastic tube 80 becomes smaller, in order to make the positioning rod 51 contact the left and right sides of the small diameter plastic tube 80, it is necessary to swing the positioning rod 51 and the adjustment plate 53 inwards. Figure 5 Taking the adjustment plate 53 on the middle left as an example, first pull the adjustment rod 55 out one end away from the adjustment plate 53 so that the adjustment wheel 56 and the adjustment rod 55 are out of contact, then rotate the adjustment plate 53 clockwise so that the positioning rod 51 can contact the side wall of the small-diameter plastic tube 80 placed in the center, and then insert the adjustment rod 55 into the adjustment hole 54 so that the adjustment rod 55 can limit the rotation of the adjustment plate 53 through the adjustment wheel 56 to prevent the plastic tube 80 from rolling on the supporting platform 15.

[0037] Example 3: Based on Example 2, Figure 5As shown, it also includes a blocking plate 60, and a guide frame 61 and a sliding shaft 62 for driving the blocking plate 60. The blocking plate 60 is used to block the shrinkage hole 73 during the pressure resistance test to improve the detection accuracy. The two blocking plates 60 are symmetrically arranged horizontally on the supporting platform 15. The lower end of the blocking plate 60 is fixed with a guide frame 61, and the guide frames 61 on the two blocking plates 60 are symmetrically arranged. An inclined slide is provided on the guide frame 61, and the shrinkage plate 16 is rotatably connected with a sliding shaft 62. The sliding shaft 62 is located in the slide provided on the guide frame 61 on the same side. During the downward movement of the positioning seat 50, the blocking plate 60 will gradually move toward the upper side of the shrinkage hole 73 under the action of the sliding shaft 62 and the guide frame 61.

[0038] When some plastic tubes 80 are compressed to a certain extent, the lower side thereof will be in a W shape, such as Figure 8 The schematic shape at the bottom is shown in the figure. The present device is designed with a liftable structure of the positioning seat 50 and the positioning rod 51. Therefore, two shrinkage holes 73 are symmetrically opened on the supporting platform 15. In order to prevent the plastic tube 80 from contacting the shrinkage hole 73 during the radial compression deformation process, resulting in a change in the force direction, affecting the normal deformation of the plastic tube 80, and increasing the difficulty and accuracy of detection, a structure that can block the shrinkage hole 73 is further designed, so that the device can always support the plastic tube 80 through the plane to ensure that the plastic tube 80 can change according to its natural change law under the radial compression state; when the shrinkage plate 16 moves downward, it will drive the sliding shaft 62 to slide in the guide frame 61. Since the sliding shaft 62 moves in the vertical direction and the slideway on the guide frame 61 is inclined, the sliding shaft 62 will drive the blocking plates 60 on both sides to move relative to each other through the guide frame 61, so as to cover the upper side of the shrinkage hole 73 through the blocking plate 60. Conversely, when the shrinkage plate 16 moves upward, the two blocking plates 60 will move in opposite directions.

[0039] like Figure 1 、 Figure 2 and Figure 7 As shown, it also includes a support assembly that is convenient for adjusting the pressure plate 12 and the supporting platform 15. The support assembly includes a fixed seat 70, a threaded rod 71 and a threaded seat 72. There are two groups of support assemblies, and the two groups of support assemblies are arranged opposite to each other. One group is used to connect the lifting plate 11 and the pressure plate 12. The specific arrangement is that a fixed seat 70 is fixedly connected to the lower end surface of the lifting plate 11, and a threaded rod 71 is fixedly connected to the lower end surface of the fixed seat 70. The lower side of the threaded rod 71 is threadedly connected to the threaded seat 72, and the lower end of the threaded seat 72 is fixed to the top of the pressure plate 12; the other group is used to connect the detection machine 10 and the supporting platform 15. The specific arrangement is that a fixed seat 70 is fixedly connected to the base of the detection machine 10, and a threaded rod 71 is fixedly connected to the upper end surface of the fixed seat 70. The threaded seat 72 is threadedly connected to the upper side of the threaded rod 71, and the upper end of the threaded seat 72 is fixed to the supporting platform 15.

[0040] By rotating the threaded seat 72 , the corresponding pressure plate 12 or the supporting platform 15 can be driven to move up and down, so as to adjust the height of the pressure plate 12 and the supporting platform 15 according to actual conditions.

[0041] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A compression testing device for PVC pipes, comprising a testing machine (10), characterized in that: A lifting plate (11) is slidably connected to the detection machine (10), a pressure plate (12) is installed on the lifting plate (11), and a trigger plate (13) is installed on the lower side of the pressure plate (12). A bearing platform (15) for supporting the plastic tube (80) is fixedly provided on the detection machine (10), and a support rod (14) is fixedly connected to the detection machine (10), a shrinking plate (16) is slidably connected to the support rod (14), and a lower spring (17) is also sleeved on the support rod (14). A positioning seat (50) is fixedly connected to the shrinking plate (16), and the positioning seat (50) passes upward through the shrinking hole (73) on the bearing platform (15). A positioning rod (51) for limiting the plastic tube (80) is installed on the positioning seat (50). A shrinking mechanism is connected to the trigger plate (13). When the trigger plate (13) is abutted by the plastic tube (80), the shrinking mechanism pushes the shrinking plate (16) to move downward.

2. A compression testing device for PVC pipes according to claim 1, characterized in that: The retraction mechanism includes a pushing frame (20), the pushing frame (20) is slidably arranged on the lifting plate (11), a pushing spring (21) is sleeved on the pushing frame (20), a locking rod (22) is fixedly connected to the pushing frame (20), a locking hole (23) is opened on the locking rod (22), a locking head (24) is slidably connected to the pressure plate (12), the locking head (24) is used to be inserted into the locking hole (23) to limit the locking rod (22) from descending, one end of the locking spring (25) is connected to the locking head (24) and the pressure plate (12) respectively, and a locking assembly is connected to the trigger plate (13), and when the trigger plate (13) is abutted by the plastic tube (80), the locking assembly drives the locking head (24) to gradually withdraw from the locking hole (23).

3. A compression testing device for PVC pipes according to claim 2, characterized in that: The locking assembly includes a trigger rod (34), the trigger rod (34) is fixed on the trigger plate (13), and the trigger rod (34) passes through the pressure plate (12) upward and is slidably connected thereto, a reset plate (31) is fixed on the trigger rod (34), a retraction rod (32) is fixed on the reset plate (31), a retraction plate (30) is fixed on the locking head (24), the retraction rod (32) and the retraction plate (30) are squeezed together to drive the locking head (24) to exit the locking hole (23), and a reset rod (33) is fixed on the detection machine (10) for pressing the reset plate (31) to push the pressure plate (12) to reset downward.

4. A compression testing device for PVC pipes according to claim 3, characterized in that: The upper and lower sides of the retraction plate (30) are both inclined plate-shaped structures, and the lower side of the retraction plate (30) extends longer in the horizontal direction than the upper side, and the horizontal extension direction is in the direction away from the locking head (24).

5. A compression testing device for PVC pipes according to claim 4, characterized in that: The middle portion of the retracting plate (30) is a vertical plate-shaped structure, a plurality of locking holes (23) are provided on the locking rod (22), and inclined surfaces are provided on the locking holes (23) and the locking head (24).

6. A compression testing device for PVC pipes according to claim 3, characterized in that: The magnetic attraction assembly further includes a magnetic attraction assembly for fixing the pressure plate (12), the magnetic attraction assembly includes a second magnetic block (42), the two second magnetic blocks (42) are respectively fixed to the upper and lower ends of the reset plate (31), the pressure plate (12) is fixed to the first magnetic block (41) and the support (40), the support (40) is also fixed to the first magnetic block (41), the reset plate (31) is located between the upper and lower first magnetic blocks (41), and the first magnetic block (41) and the second magnetic block (42) are attracted to each other.

7. The compression testing device for PVC pipes according to claim 1, characterized in that: The invention also includes an adjustment component for adjusting the angle of the positioning rod (51), the adjustment component including an adjustment plate (53), the adjustment plate (53) being rotatably connected to the positioning seat (50), the positioning rod (51) being fixed to the adjustment plate (53), an adjustment hole (54) being provided at one end of the adjustment plate (53), an adjustment rod (55) being slidably inserted into the adjustment hole (54), an adjustment wheel (56) being fixed to the adjustment rod (55), and a clamping rod (52) for limiting the rotation of the adjustment wheel (56) being fixed to the positioning seat (50).

8. The compression testing device for PVC pipes according to claim 3, characterized in that: It also includes a blocking plate (60), which is slidably arranged on the bearing platform (15). When the positioning seat (50) moves downward, the blocking plate (60) will gradually move toward the upper side of the shrinkage hole (73).

9. A compression testing device for PVC pipes according to claim 8, characterized in that: It also includes a guide frame (61) and a sliding shaft (62), wherein the guide frame (61) is fixedly connected to the blocking plate (60), the sliding shaft (62) is rotatably arranged on the contraction plate (16), and the sliding shaft (62) is slidably connected to the guide frame (61) on the same side.

10. The compression testing device for PVC pipes according to claim 1, characterized in that: The invention also includes a support assembly for facilitating the adjustment of the pressure plate (12) and the supporting platform (15), wherein the support assembly includes a fixing seat (70), a threaded rod (71) and a threaded seat (72). Two groups of support assemblies are provided, and the two groups of support assemblies are arranged opposite to each other, one group is used to connect the lifting plate (11) and the pressure plate (12), and the other group is used to connect the detection machine (10) and the supporting platform (15).

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