A confining pressure device used in Hopkinson test

Abstract

The present invention relates to the technical field of mechanical property testing equipment, and in particular to a confining pressure device used in a Hopkinson test, comprising: an equipment box, the equipment box being provided with a confining pressure groove; a confining pressure assembly, the confining pressure assembly comprising a hydraulic mechanism and an elastic confining pressure mechanism; a mechanical pressure equalizing assembly, the mechanical pressure equalizing assembly comprising a mechanical limiting mechanism and a locking mechanism; a self-compensating sealing assembly, the self-compensating sealing assembly comprising a movable sealing mechanism and a follow-up pressing mechanism; the present application ensures a wide range of pressure adjustment capability through the coordinated work of the hydraulic mechanism, the elastic confining pressure mechanism and the mechanical pressure equalizing mechanism, and buffers pressure fluctuations through the elastic element, thereby achieving uniform and stable application of radial pressure to the specimen; the locking mechanism locks the mechanical limiting mechanism during the test, eliminates the mechanism displacement caused by impact vibration, and ensures that the spatial distribution of the pressure field is constant; the movable sealing mechanism and the follow-up pressing mechanism in the self-compensating sealing assembly dynamically adjust the sealing force, effectively solving the leakage problem caused by seal wear.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical property testing equipment, in particular to a confining pressure device used in a Hopkinson test. Background Art

[0002] The Hopkinson bar test is primarily used to study the stress-strain relationship and failure mechanism of materials under impact loads. It is suitable for testing materials such as polymers, explosives, and solid propellants. This test measures the mechanical properties of materials under dynamic loads, helping to analyze their ability to withstand dynamic loads. Existing Hopkinson bar tests are primarily conducted using a Hopkinson bar and an active confining pressure device. The existing active confining pressure device uses an oil pump to pump hydraulic oil into an oil chamber, which then applies pressure around the specimen through a rubber barrier.

[0003] The existing confining pressure device has the following obvious defects when in use: during loading, the traditional confining pressure device relies on the hydraulic system to adjust the radial pressure, but the hydraulic system is easily affected by changes in the external environment, resulting in uneven circumferential pressure distribution, and during dynamic loading, the hydraulic device is prone to boundary constraint relaxation, resulting in radial pressure fluctuations on the specimen and radial vibration of the rod body, and the traditional sealing structure is prone to leakage due to seal wear or pressure fluctuations after the high-pressure dynamic impact of the Hopkinson pressure bar test, affecting the stability of the confining pressure. Summary of the Invention

[0004] The object of the present invention is to provide a confining pressure device for use in a Hopkinson test to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A confining pressure device for use in a Hopkinson test, comprising:

[0007] A device box, wherein the device box is provided with a confining pressure groove;

[0008] A confining pressure assembly, the confining pressure assembly comprising a hydraulic mechanism and an elastic confining pressure mechanism, the elastic confining pressure mechanism being disposed in the confining pressure groove, the hydraulic mechanism being used to drive the elastic confining pressure mechanism to apply radial pressure to the specimen;

[0009] A mechanical pressure balancing assembly, comprising a mechanical limiting mechanism and a locking mechanism, wherein the mechanical limiting mechanism is used to apply pressure to the elastic confining pressure mechanism through a mechanical structure, and the locking mechanism is used to lock the movement of the mechanical limiting mechanism during the test;

[0010] A self-compensating sealing assembly includes a movable sealing mechanism and a follower pressing mechanism. The movable sealing mechanism is arranged on both sides of the elastic confining and pressing mechanism. The follower pressing mechanism is used to increase the pressing force on the movable sealing mechanism when the hydraulic mechanism is in use to improve the sealing effect.

[0011] Preferably, the hydraulic mechanism includes a hydraulic cylinder, an oil pump, an oil inlet pipe, an oil return pipe, a pressure sensor and a connecting valve. The hydraulic cylinder is connected to the oil pump, the oil pump is connected to the confining pressure tank through the oil inlet pipe, and is connected to the confining pressure tank through the oil inlet pipe. The confining pressure tank is connected to the hydraulic cylinder through the oil return pipe. The confining pressure tank is provided with the pressure sensor, and the oil inlet pipe and the oil return pipe are both provided with a connecting valve.

[0012] Preferably, the elastic confining pressure mechanism includes a fluororubber ring and a metal connecting ring, the fluororubber ring is arranged in the confining pressure groove, and the metal connecting rings are symmetrically arranged on both sides of the fluororubber ring.

[0013] Preferably, the mechanical limiting mechanism includes a fixed ring, a transmission ring, a transmission gear, a transmission rack and a pressure equalizing block, the fixed ring is arranged in the confining pressure groove, the fixed ring and the confining pressure groove are coaxially arranged, the transmission ring is rotatably connected to the fixed ring, an internal tooth groove is arranged inside the transmission ring, the transmission gear is arranged around the confining pressure groove, the transmission gear and the internal tooth groove are engaged with each other, the fixed ring has a limiting groove, the transmission rack is movably connected to the limiting groove, the transmission gear and the transmission rack are engaged with each other, and each transmission rack is connected to a pressure equalizing block.

[0014] Preferably, six transmission gears are provided, and the number of the transmission racks and the pressure equalizing blocks is set corresponding to the number of the transmission gears.

[0015] Preferably, the locking mechanism includes a locking push rod, and a plurality of locking holes are opened around the transmission ring. The locking push rod is arranged in the confining pressure groove, and the movement of the transmission ring is locked by inserting the locking push rod into the locking hole.

[0016] Preferably, the pressure equalizing block is provided with a mounting groove, and the movable sealing mechanism comprises a sealing ring, which is connected to the mounting groove.

[0017] Preferably, the pressure equalizing block is also provided with a flow channel, the flow channel and the mounting groove are connected to each other, the follow-up clamping mechanism includes a pressure opening valve, a push piston and a sealing spring, the pressure opening valve is arranged in the flow channel, the push piston is arranged inside the flow channel, and the two ends of the sealing spring are respectively connected to the push piston and the sealing ring.

[0018] Compared with the prior art, the beneficial effects of the present invention are: the present application ensures a wide range of pressure adjustment capability through the coordinated work of the hydraulic mechanism, the elastic confining pressure mechanism and the mechanical pressure equalizing mechanism, and buffers the pressure fluctuations through the elastic element, thereby realizing the uniform and stable application of radial pressure on the specimen; the locking mechanism locks the mechanical limit mechanism during the test, eliminates the structural displacement caused by impact vibration, and ensures that the spatial distribution of the pressure field is constant; the mobile sealing mechanism and the follow-up clamping mechanism in the self-compensating sealing assembly dynamically adjust the sealing force, effectively solves the leakage problem caused by seal wear, and greatly improves the service life of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the three-dimensional structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the internal structure of the device box of the present invention (the device box is processed in perspective);

[0021] Figure 3 This is a schematic diagram of the position structure of the fixing ring, transmission ring and transmission gear of the present invention;

[0022] Figure 4 This is a schematic diagram of the connection structure of the transmission rack and the limiting groove of the present invention;

[0023] Figure 5 This is a schematic diagram of the connection structure between the fluororubber ring and the metal connecting ring of the present invention;

[0024] Figure 6 Schematic diagram of the position structure of the pressure equalizing block and the transmission rack of the present invention (one of the pressure equalizing blocks is shown in perspective);

[0025] Figure 7 Schematic diagram of the position structure of the pressure equalizing block and the sealing ring of the present invention (one of the pressure equalizing blocks is shown in perspective);

[0026] Figure 8 Schematic diagram of the internal structure of the pressure equalizing block of the present invention (the pressure equalizing block is processed in perspective);

[0027] Figure 9 This is a schematic diagram of the connection structure of the sealing ring, push piston and sealing spring of the present invention.

[0028] In the figure: 1 equipment box, 2 hydraulic cylinder, 3 oil pump, 4 oil inlet pipe, 5 oil return pipe, 6 pressure sensor, 7 connecting valve, 8 fluororubber ring, 9 metal connecting ring, 10 fixing ring, 11 transmission ring, 12 transmission gear, 13 transmission rack, 14 pressure equalizing block, 15 locking push rod, 16 lock hole, 17 sealing ring, 18 pressure opening valve, 19 pushing piston, 20 sealing spring, 101 confining pressure groove, 1001 limit groove, 1101 internal tooth groove, 1401 flow channel. DETAILED DESCRIPTION

[0029] 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.

[0030] See also Figure 1-9 , the present invention provides a technical solution:

[0031] A confining pressure device used in the Hopkinson test, as shown in the attached instructions. Figure 1 Shown, including:

[0032] The equipment box 1 is provided with a confining pressure groove 101, and the confining pressure groove 101 is used for placing the test piece;

[0033] The confining pressure assembly includes a hydraulic mechanism and an elastic confining pressure mechanism. The elastic confining pressure mechanism is arranged in the confining pressure groove 101. The hydraulic mechanism is used to drive the elastic confining pressure mechanism to apply radial pressure to the specimen.

[0034] Mechanical pressure equalizing assembly, which includes a mechanical limit mechanism and a locking mechanism. The mechanical limit mechanism is used to apply pressure to the elastic confining pressure mechanism through a mechanical structure, and the locking mechanism is used to lock the movement of the mechanical limit mechanism during the test;

[0035] Self-compensating sealing assembly, the self-compensating sealing assembly includes a mobile sealing mechanism and a follow-up pressing mechanism. The mobile sealing mechanism is arranged on both sides of the elastic confining pressure mechanism. The follow-up pressing mechanism is used to increase the pressing force on the mobile sealing mechanism when the hydraulic mechanism is in use to improve the sealing effect.

[0036] The hydraulic mechanism includes a hydraulic cylinder 2, an oil pump 3, an oil inlet pipe 4, an oil return pipe 5, a pressure sensor 6 and a connecting valve 7. The hydraulic cylinder 2 is used to store hydraulic oil. The hydraulic cylinder 2 is connected to the oil pump 3. The oil pump 3 is used to send the hydraulic oil in the hydraulic cylinder 2 to the oil inlet pipe 4. The oil pump 3 is connected to the confining pressure tank 101 through the oil inlet pipe 4. The confining pressure tank 101 is connected to the hydraulic cylinder 2 through the oil return pipe 5. The confining pressure tank 101 is provided with a pressure sensor 6. The pressure sensor 6 is used to detect the liquid pressure inside the confining pressure tank 101. The oil inlet pipe 4 and the oil return pipe 5 are both provided with a connecting valve 7. The connecting valve 7 is a solenoid valve. Figure 1 Only the connecting valve 7 connected to the oil return pipe 5 is marked. It is hereby explained that the connecting valve 7 is used to control the on-off of the oil inlet pipe 4 or the oil return pipe 5 connected thereto.

[0037] The elastic confining pressure mechanism includes a fluororubber ring 8 and a metal connecting ring 9. The fluororubber ring 8 is arranged in the confining pressure groove 101. The fluororubber ring 8 is used to compensate for radial runout through elastic deformation. The metal connecting rings 9 are symmetrically arranged on both sides of the fluororubber ring 8. The metal connecting rings 9 are used to install the fluororubber ring 8 in the confining pressure groove 101.

[0038] The mechanical limiting mechanism includes a fixed ring 10, a transmission ring 11, a transmission gear 12, a transmission rack 13 and a pressure equalizing block 14. The fixed ring 10 is used to install the transmission ring 11. The fixed ring 10 is fixedly connected to the confining pressure groove 101, and the fixed ring 10 and the confining pressure groove 101 are coaxially arranged. The transmission ring 11 is rotatably connected to the fixed ring 10. The transmission ring 11 is used to transmit power between the gears. An internal tooth groove 1101 is provided inside the transmission ring 11. The internal tooth groove 1101 is used to engage with the transmission gear 12. There are multiple transmission gears 12, and multiple transmission gears 12 are arranged around the confining pressure groove 101. The transmission gear 12 and the internal tooth groove 1101 are engaged with each other. The fixed ring 10 has a limiting groove 1001, and the limiting groove 1001 is used In order to limit the movement direction of the transmission rack 13, the transmission rack 13 is movably connected to the limiting groove 1001, the transmission gear 12 and the transmission rack 13 are meshed with each other, and each transmission rack 13 is connected to a pressure equalizing block 14. Therefore, after the hydraulic oil enters the confining pressure groove 101, it will first drive one of the pressure equalizing blocks 14 to move along the limiting groove 1001. When the pressure equalizing block 14 moves, it will drive the transmission rack 13 to move along the limiting groove 1001. When the transmission rack 13 moves, it will drive the transmission gear 12 to rotate. Through the meshing of the transmission gear 12 and the inner tooth groove 1101, the transmission ring 11 will be driven to rotate, and the other transmission gears 12 will be driven to rotate through the transmission ring 11, thereby driving the other pressure equalizing blocks 14 to move.

[0039] In this embodiment, six transmission gears 12 are provided, and the number of transmission racks 13 and pressure equalizing blocks 14 is provided corresponding to the number of transmission gears 12 .

[0040] The locking mechanism includes a locking push rod 15, which is an electric hydraulic push rod. The locking push rod 15 is used to lock the position of the transmission ring 11 and thus lock the mechanical limit mechanism. A number of locking holes 16 are opened around the transmission ring 11. The locking push rod 15 is set in the confining pressure groove 101. By inserting the locking push rod 15 into the locking hole 16, the movement of the transmission ring 11 is locked.

[0041] The pressure equalizing block 14 is provided with a mounting groove for connecting a sealing ring 17 . The mounting groove is used to install the sealing ring 17 . The movable sealing mechanism includes the sealing ring 17 , and the sealing ring 17 is connected to the mounting groove.

[0042] The pressure equalizing block 14 is also provided with a flow channel 1401. When the hydraulic oil flows into the flow channel 1401 and reaches the set value of the pressure opening valve 18, the pressure opening valve 18 will be triggered to open. At this time, the hydraulic oil enters the flow channel 1401 and drives the pushing piston 19 to move. When the pushing piston 19 moves, the sealing ring 17 will be pushed to move through the sealing spring 20 to further improve the sealing effect. The flow channel 1401 and the mounting groove are connected to each other. The follow-up clamping mechanism includes a pressure opening valve 18, a pushing piston 19 and a sealing spring 20. The pressure opening valve 18 is arranged in the flow channel 1401, and the pushing piston 19 is arranged inside the flow channel 1401. The two ends of the sealing spring 20 are respectively connected to the pushing piston 19 and the sealing ring 17. The sealing spring 20 is used to provide preload force. The squeezing effect of the sealing spring 20 can make the sealing ring 17 fit more closely to the side wall of the confining pressure groove 101, reducing the possible risk of hydraulic oil leakage.

[0043] Working principle:

[0044] When in use, the test piece is placed in the confining pressure tank 101, and then the connecting valve 7 connected to the oil inlet pipe 4 is opened, and the oil pump 3 is started, and the hydraulic oil enters the confining pressure tank 101 through the hydraulic cylinder 2;

[0045] After the hydraulic oil enters the confining pressure groove 101, it will first drive one of the pressure equalizing blocks 14 to move along the limiting groove 1001. When the pressure equalizing block 14 moves, it will drive the transmission rack 13 to move along the limiting groove 1001. When the transmission rack 13 moves, it will drive the transmission gear 12 to rotate. The engagement of the transmission gear 12 and the internal tooth groove 1101 will drive the transmission ring 11 to rotate, and the transmission ring 11 will drive the other transmission gears 12 to rotate, thereby driving the other pressure equalizing blocks 14 to move. After that, the locking can be completed by inserting the moving end of the locking push rod 15 into the lock hole;

[0046] As the hydraulic oil flows in, the hydraulic oil will gradually surround the pressure groove 101 and fill it. When the hydraulic oil flows into the flow channel 1401 and reaches the set value of the pressure opening valve 18, the pressure opening valve 18 will be triggered to open. At this time, the hydraulic oil enters the flow channel 1401 and drives the piston 19 to move. When the piston 19 moves, the sealing ring 17 will be pushed to move through the sealing spring 20, thereby further improving the sealing effect.

[0047] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A confining pressure device for use in a Hopkinson test, characterized in that: include: A device box, wherein the device box is provided with a confining pressure groove; A confining pressure assembly, the confining pressure assembly comprising a hydraulic mechanism and an elastic confining pressure mechanism, the elastic confining pressure mechanism being disposed in the confining pressure groove, the hydraulic mechanism being used to drive the elastic confining pressure mechanism to apply radial pressure to the specimen; A mechanical pressure balancing assembly, comprising a mechanical limiting mechanism and a locking mechanism, wherein the mechanical limiting mechanism is used to apply pressure to the elastic confining pressure mechanism through a mechanical structure, and the locking mechanism is used to lock the movement of the mechanical limiting mechanism during the test; A self-compensating sealing assembly, comprising a mobile sealing mechanism and a follower pressing mechanism, wherein the mobile sealing mechanism is arranged on both sides of the elastic confining pressure mechanism, and the follower pressing mechanism is used to increase the pressing force on the mobile sealing mechanism when the hydraulic mechanism is in use, thereby improving the sealing effect; The mechanical limiting mechanism includes a fixed ring, a transmission ring, a transmission gear, a transmission rack and a pressure equalizing block, the fixed ring is arranged in the confining pressure groove, the fixed ring and the confining pressure groove are coaxially arranged, the transmission ring is rotatably connected to the fixed ring, an internal tooth groove is provided inside the transmission ring, the transmission gear is arranged around the confining pressure groove, the transmission gear and the internal tooth groove are meshed with each other, the fixed ring is provided with a limiting groove, the transmission rack is movably connected to the limiting groove, the transmission gear and the transmission rack are meshed with each other, and each of the transmission racks is connected to a pressure equalizing block; The locking mechanism includes a locking push rod, which is provided with a plurality of locking holes around the transmission ring. The locking push rod is arranged in the confining pressure groove, and the movement of the transmission ring is locked by inserting the locking push rod into the locking hole. The pressure equalizing block is provided with a mounting groove, and the movable sealing mechanism includes a sealing ring connected to the mounting groove; The pressure equalizing block is also provided with a flow channel, and the flow channel and the mounting groove are communicated with each other. The follower clamping mechanism includes a pressure opening valve, a push piston and a sealing spring. The pressure opening valve is arranged in the flow channel, the push piston is arranged inside the flow channel, and the two ends of the sealing spring are respectively connected to the push piston and the sealing ring.

2. The confining pressure device for use in the Hopkinson test according to claim 1, characterized in that: The hydraulic mechanism includes a hydraulic cylinder, an oil pump, an oil inlet pipe, an oil return pipe, a pressure sensor and a connecting valve. The hydraulic cylinder is connected to the oil pump, and the oil pump is connected to the confining pressure tank through the oil inlet pipe. The confining pressure tank is connected to the hydraulic cylinder through the oil return pipe. The confining pressure tank is provided with the pressure sensor, and the oil inlet pipe and the oil return pipe are both provided with a connecting valve.

3. The confining pressure device for use in the Hopkinson test according to claim 1, characterized in that: The elastic confining pressure mechanism includes a fluororubber ring and a metal connecting ring. The fluororubber ring is arranged in the confining pressure groove, and the metal connecting rings are symmetrically arranged on both sides of the fluororubber ring.

4. The confining pressure device for use in a Hopkinson test according to claim 3, characterized in that: There are six transmission gears, and the number of the transmission racks and the pressure equalizing blocks is set corresponding to the number of the transmission gears.

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