Double-pin friction accurate loading test device for simulating deep sea environment

Abstract

The invention discloses a double-pin friction precise loading test device for simulating a deep sea environment. The double-pin friction precise loading test device mainly comprises an autoclave body, a rotary loading assembly, a pressure loading assembly, a friction sample and a data acquisition unit, high-pressure low-temperature water for simulating deep sea water is injected into the autoclave body to simulate a deep sea environment; the rotary loading assembly is used for driving the friction sample to rotate; the upper and lower surfaces of the friction sample are respectively connected with an upper friction pin and a lower friction pin; the pressure loading assembly is used for driving the lower friction pin to vertically move and loading pressure to the friction sample; the pressure loading assembly comprises a loading spring, a pressurizing rod, a load sensor and a stepping motor driver which are sequentially connected from top to bottom. And the stepping motor driver provides vertical pressure and drives the lower friction pin to apply vertically upward pressure to the friction sample through the pressure loading assembly. In addition, a PID controller is adopted between the load sensor and the stepping motor for feedback control, so that the accuracy and the stability of the system are ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of friction equipment, and in particular relates to a double-pin friction precision loading test device for simulating a deep-sea environment. Background Art

[0002] When deep-sea equipment is serving in the deep-sea environment, the friction and wear performance of deep-sea structural materials is crucial to the safety and reliability of deep-sea equipment. It is necessary to simulate the deep-sea environment in the laboratory to test the friction and wear performance of structural materials. The friction and wear performance test is carried out by preparing artificial seawater or taking seawater samples. Because of its advantages of low cost, simple loading and detection, it has been successfully used in various forms of seawater friction and wear test equipment, such as vertical universal friction and wear testers, high-speed ring block friction and wear testers, etc. Compared with the shallow sea normal pressure environment, the research on deep-sea high-pressure environment started later. It has obvious advantages to simulate the high-pressure seawater environment at different ocean depths and conduct friction and wear tests in high-pressure seawater environment.

[0003] However, the current friction equipment that simulates deep-sea environments can only perform single-sided friction tests, and cannot test double-sided friction and wear performance. In addition, the existing equipment cannot accurately load the load during the friction test, and the data deviation is large due to the influence of equipment vibration. Summary of the invention

[0004] The invention provides a double-pin friction precise loading test device for simulating a deep-sea environment, the purpose of which is to perform double-sided friction and precise loading on a friction sample in a simulated deep-sea environment to obtain double-sided friction test data under a precise loading state.

[0005] To this end, the present invention adopts the following technical solutions: A double-pin friction precision loading test device for simulating a deep-sea environment comprises a high-pressure kettle body, a rotation loading component, a pressure loading component, a friction specimen and a data acquisition unit.

[0006] The autoclave body is fixedly arranged, and an autoclave cover is connected to the top of the autoclave body; a water inlet is arranged at the bottom of the autoclave body, and a water outlet is arranged on the autoclave cover. High-pressure and low-temperature seawater simulating a deep-sea environment is injected into the autoclave body through the water inlet, and the water in the autoclave body is discharged through the water outlet to realize water circulation.

[0007] The rotary loading assembly comprises a magnetic motor rotator located above the autoclave body, the motor shaft of the magnetic motor rotator vertically penetrates into the autoclave body through the autoclave cover, and the motor shaft and the autoclave cover are connected by a seal; the disc-shaped friction sample is detachably connected to the head end of the motor shaft, the center of the friction sample is coaxial with the center of the motor shaft, and the magnetic motor rotator drives the friction sample to rotate when it is running.

[0008] The autoclave body is provided with an upper friction pin and a lower friction pin which are vertical and opposite to each other, and the upper friction pin and the lower friction pin respectively abut against the friction sample to provide friction force; the upper friction pin is located above the friction sample and abuts against the upper surface of the friction sample, and the lower friction pin is located below the friction sample and close to the lower surface of the friction sample; the lower friction pin is connected with a pressure loading assembly, and the pressure loading assembly is used to drive the lower friction pin to move vertically and load pressure to the friction sample.

[0009] The pressure loading assembly includes a loading spring, a pressure rod, a load sensor and a stepper motor driver connected in sequence from top to bottom. The loading spring is vertically connected to the bottom of the lower friction pin, the pressure rod is vertically connected to the bottom of the loading spring, the lower end of the pressure rod passes through the outside of the autoclave body, and the pressure rod and the autoclave body are connected by a seal; the load sensor is connected to the bottom of the pressure rod, the stepper motor driver is connected to the load sensor, and the stepper motor driver is fixed to the bottom of the autoclave body through a bracket; the vertical pressure and displacement provided by the stepper motor driver act on the load sensor, and are transmitted to the lower friction pin through the pressure rod and the loading spring, so that the lower friction pin applies vertical upward pressure to the friction sample; the load sensor and the stepper motor are feedback controlled using (through) a PID controller.

[0010] The data acquisition unit acquires the pressure value detected by the load sensor in real time, and acquires the torque value of the magnetic motor rotator in real time, and uploads the acquired pressure value and torque value to the host computer for storage.

[0011] The beneficial effects of the present invention are: 1. The autoclave of the present invention is injected with high-pressure and low-temperature water simulating deep sea water to simulate the deep sea environment in the autoclave. The deep sea environment can be simulated in the laboratory to further study the friction loss problem of the friction sample in the deep sea environment.

[0012] 2. The pressure loading assembly is used to apply load to the friction pin more accurately. The pressure rod is a rigid structure, and a small displacement will produce a large (significant) load. In practical applications, a displacement of about 5um can reach a load force of 300N, which is similar to the maximum friction load of the friction sample. In a rigid structure, vibrations during the friction process will produce (may cause) a displacement deviation of not less than 1um, thereby introducing a load deviation of more than 60N. In order to effectively reduce the system error caused by the rigid connection structure, the present invention increases the load stroke by adding a loading spring structure, and selects a spring with an elastic coefficient in the range of 100~300N / mm, so that the equivalent load deviation of 1 micron displacement deviation is reduced to 0.1~0.3N.

[0013] 3. An upper friction pin and a lower friction pin facing each other are arranged in the autoclave body. The upper friction pin and the lower friction pin respectively abut against the friction sample to provide friction force. The friction condition under the double-sided friction is studied by the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the test device of the present invention; Figure 2 The present invention Figure 1 A partial schematic diagram of the medium pressure loading component; Figure 3 It is a schematic diagram of the structure of the upper pressing plate and the lower pressing plate of the present invention; In the figure: 1-autoclave body, 2-autoclave cover, 3-water inlet, 4-water outlet, 5-magnetic motor rotator, 6-motor shaft, 7-friction sample, 8-upper clamping plate, 9-lower clamping plate, 10-upper friction pin, 11-lower friction pin, 12-loading spring, 13-pressure rod, 14-load sensor, 15-stepping motor driver, 16-support plate, 17-upper support block, 18-middle support block, 19-lower support block. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments: like Figure 1 As shown, a double-pin friction precision loading test device for simulating deep-sea environment includes a high-pressure autoclave body 1, a rotation loading component, a pressure loading component, a friction specimen 7 and a data acquisition unit.

[0016] The autoclave body 1 is fixedly arranged. The autoclave is made of duplex stainless steel with a compressive strength of not less than 20 MPa. The top of the autoclave body 1 is connected with an autoclave cover 2. A water inlet 3 is provided at the bottom of the autoclave body 1, and a water outlet 4 is provided on the autoclave cover 2. High-pressure and low-temperature water simulating deep-sea water is injected into the autoclave body 1 through the water inlet 3, and the water in the autoclave body 1 is discharged through the water outlet 4 to realize water circulation, simulate the deep-sea environment in the autoclave body 1, and thus simulate the friction test in the deep-sea environment.

[0017] The rotating loading assembly includes a magnetic motor rotator 5 located above the autoclave body 1. The motor shaft 6 of the magnetic motor rotator 5 vertically penetrates into the autoclave body 1 through the autoclave cover 2. The motor shaft 6 and the autoclave cover 2 are connected by a seal. The disc-shaped friction sample 7 is detachably connected to the head end of the motor shaft 6. The center of the friction sample 7 is coaxial with the center of the motor shaft 6. When the magnetic motor rotator 5 rotates, the friction sample 7 is driven to rotate. Figure 3As shown, it also includes an upper clamping plate 8 and a lower clamping plate 9 for clamping and fixing the friction sample 7. The upper clamping plate 8 and the lower clamping plate 9 are disc-shaped; the upper clamping plate 8 is close to the upper surface of the friction sample 7, and the lower clamping plate 9 is close to the lower surface of the friction sample 7. The surfaces of the upper clamping plate 8 and the lower clamping plate 9 are provided with circumferential through holes, and the surface of the friction sample 7 is also provided with corresponding through holes. Fastening bolts are installed in the through holes, and the friction sample 7 is fixed to the motor shaft 6 by the fastening bolts, the upper clamping plate 8 and the lower clamping plate 9; the upper clamping plate 8 and the lower clamping plate 9 are PTFE insulating gaskets.

[0018] like Figure 2 As shown, an upper friction pin 10 and a lower friction pin 11 are vertically disposed in the autoclave body 1 and are opposite to each other. The upper friction pin 10 and the lower friction pin 11 respectively abut against the friction sample 7 to provide friction force. The upper friction pin 10 is located above the friction sample 7 and abuts against the upper surface of the friction sample 7, and the lower friction pin 11 is located below the friction sample 7 and is close to the lower surface of the friction sample 7. A pressure loading assembly is connected to the lower friction pin 11, and the pressure loading assembly is used to drive the lower friction pin 11 to move vertically and load pressure on the friction sample 7.

[0019] The pressure loading assembly includes a loading spring 12, a pressure rod 13, a load sensor 14 and a stepper motor driver 15 which are connected in sequence from top to bottom. The loading spring 12 is vertically connected to the bottom of the lower friction pin 11, the pressure rod 13 is vertically connected to the bottom of the loading spring 12, the lower end of the pressure rod 13 passes through the outside of the autoclave body 1, and the pressure rod 13 and the autoclave body 1 are connected through a seal; the load sensor 14 is connected to the bottom of the pressure rod 13, the stepper motor driver 15 is connected to the load sensor 14, and the stepper motor driver 15 is fixed to the bottom of the autoclave body 1 through a bracket; after the stepper motor driver 15 provides vertical pressure and displacement to act on the load sensor 14, the vertical pressure and displacement are transmitted to the lower friction pin 11 after passing through the pressure rod 13 and the loading spring 12, and the lower friction pin 11 applies vertical upward pressure to the friction sample 7.

[0020] It also includes a vertical support plate 16 located in the autoclave, the support plate 16 is located on one side of the autoclave and the upper end is fixedly connected to the autoclave cover 2, and three support blocks arranged at intervals are welded on one side of the support plate 16, which are respectively an upper support block 17, a middle support block 18 and a lower support block 19 from top to bottom; the edge of the friction sample 7 is located between the upper support block 17 and the middle support block 18; the upper support block 17, the middle support block 18 and the lower support block 19 provide a guide for the pressure loading assembly. A positioning hole is provided at the bottom of the upper support block 17, and the upper friction pin 10 is fixed in the positioning hole of the upper support block 17; through holes are provided at corresponding positions of the middle support block 18 and the lower support block 19, and the lower friction pin 11 is penetrated in the through hole of the middle support block 18, the loading spring 12 is located between the middle support block 18 and the lower support block 19, and the upper end of the pressure rod 13 penetrates into the through hole of the lower support block 19.

[0021] The data acquisition unit acquires the pressure value detected by the load sensor 14 in real time, and acquires the torque value of the magnetic motor rotator 5 in real time, and uploads the acquired pressure value and torque value to the host computer for storage.

[0022] The working principle of the test device of the present invention is as follows: a. The autoclave body 1 is used to simulate the deep sea environment. The autoclave body 1 is designed and manufactured according to the operating pressure of 20MPa. It is made of duplex stainless steel, which can resist the corrosion of seawater medium. The autoclave body 1 and the autoclave cover 2 are both processed by forging to avoid the risk of cracking under high pressure conditions.

[0023] b. The magnetic motor rotator 5 is used to drive the friction sample 7 to perform circular rotation. The motor shaft 6 and the motor of the magnetic motor rotator 5 are driven by magnetic force, and the two parts do not contact each other. The rotation speed can reach 1200rpm. The magnetic shaft is immersed in the autoclave body 1, and the driver of the magnetic motor rotator 5 is installed outside the autoclave body 1. The motor shaft 6 is sealed and connected to the autoclave cover 2 to avoid the risk of medium leakage under high-pressure test conditions. The motor shaft 6 is made of corrosion-resistant alloy and is suitable for the corrosion test environment of seawater medium.

[0024] c. The upper clamping plate 8 and the lower clamping plate 9 are used to fix the friction sample 7. The upper clamping plate 8 and the lower clamping plate 9 are threadedly connected to the motor shaft 6. PTFE insulating gaskets are provided on the two clamping plates. The insulating gaskets fix the sample in the middle through four symmetrically arranged bolts. The lower insulating gasket has a boss to prevent galvanic corrosion caused by contact between the bolts and the friction sample 7.

[0025] d. The upper friction pin 10 and the lower friction pin 11 rub the front and back sides of the friction sample 7 at the same time. The two friction pins are made of the same or different materials such as polymers or ceramics, and the two friction pins can use cylindrical or spherical friction heads. When the lower friction pin 11 is loaded, the friction sample 7 is tightened between the upper and lower friction pins 11 under the extrusion effect, and the friction test is carried out on the front and back sides of the sample at the same time.

[0026] e. The pressure loading assembly is used to apply load force to the friction pin more accurately. The pressure rod 13 is a rigid structure, and a small displacement will produce a large load. In practical applications, a displacement of about 5um can reach a load force of 300N, which is similar to the maximum friction load of the friction sample 7. In a rigid structure, the vibration during the friction process will produce a displacement deviation of not less than 1um, resulting in a load deviation of more than 60N. By increasing the load stroke by adding a loading spring 12 structure and selecting a spring with an elastic coefficient of 100~300N / mm, the equivalent load deviation of a 1um displacement deviation is 0.1~0.3N, which can effectively reduce the system error caused by the rigid connection structure.

[0027] f. The pressure rod 13 is installed at the bottom of the pressure loading assembly. Before the test begins, the pressure rod 13 will move upward to apply load to the friction pin and the friction sample 7. During the test, it will move up and down to compensate for the load effect caused by friction vibration. The pressure rod 13 and the bottom of the autoclave body 1 will move relative to each other, and a pan-seal seal ring is used to achieve the movable seal between the rod and the autoclave body 1. The pan-seal seal ring is a slotted seal ring with an embedded spring, which is widely used in the movable seal of bearings and hydraulic rods.

[0028] g. The load sensor and the stepper motor driver 15 are installed at the end of the pressure rod 13 outside the autoclave. A PID controller is used for feedback control between the load sensor and the stepper motor. Before the friction test, the stepper motor driver 15 drives the pressure rod 13 to move upward to apply a load to the lower friction pin 11. When the rated load of the test is reached, the load sensor sends a feedback signal to the stepper motor, and the stepper motor stops moving. During the friction test, the load sensor measures the load force between the friction pin and the friction sample 7 in real time. When the load force deviates from the set load, the load sensor sends a signal to the stepper motor, and the stepper motor drives the pressure rod 13 to move up and down to compensate for the load between the friction pin and the friction sample 7 in real time.

[0029] h. Measurement of friction coefficient. The friction coefficient between the friction sample 7 and the friction pin is related to the load force and the friction force. The load force is measured and output by the load sensor, and the friction force is calculated by the output power and output speed of the motor.

[0030] Where: f – friction; r – radius of the central axis of the pin and the friction specimen 7; T – torque; ΔP - change in output power of magnetic motor before and after friction; n 1 – Motor speed.

Claims

1. A double-pin friction precision loading test device simulating a deep-sea environment, characterized in that: It comprises an autoclave body (1), a rotation loading assembly, a pressure loading assembly, a friction specimen (7) and a data acquisition unit; The autoclave body (1) is fixedly arranged, and the top of the autoclave body (1) is connected to an autoclave cover (2); a water inlet (3) is provided at the bottom of the autoclave body (1), and a water outlet (4) is provided on the autoclave cover (2); high-pressure and low-temperature water simulating deep-sea water is injected into the autoclave body (1) through the water inlet (3), and the water in the autoclave body (1) is discharged through the water outlet (4), so as to realize water circulation; The rotary loading assembly comprises a magnetic motor rotator (5) located above the autoclave body (1), the motor shaft (6) of the magnetic motor rotator (5) vertically penetrates into the autoclave body (1) through the autoclave cover (2), and the motor shaft (6) and the autoclave cover (2) are connected via a sealing member; a disc-shaped friction sample (7) is detachably connected to the head end of the motor shaft (6), the center of the friction sample (7) is coaxial with the center of the motor shaft (6), and the magnetic motor rotator (5) drives the friction sample (7) to rotate when it is in operation; An upper friction pin (10) and a lower friction pin (11) are arranged vertically and facing each other in a positive direction in the autoclave body (1). The upper friction pin (10) and the lower friction pin (11) respectively abut against the friction sample (7) to provide friction force. The upper friction pin (10) is located above the friction sample (7) and abuts against the upper surface of the friction sample (7), and the lower friction pin (11) is located below the friction sample (7) and close to the lower surface of the friction sample (7). The lower friction pin (11) is connected to a pressure loading component, which is used to drive the lower friction pin (11) to move vertically and load pressure on the friction sample (7). The pressure loading assembly comprises a loading spring (12), a pressure rod (13), a load sensor (14) and a stepper motor driver (15) which are connected in sequence from top to bottom. The loading spring (12) is vertically connected to the bottom of the lower friction pin (11). The pressure rod (13) is vertically connected to the bottom of the loading spring (12). The lower end of the pressure rod (13) extends out of the autoclave body (1). The pressure rod (13) and the autoclave body (1) are connected via a sealing member. The load sensor (14) is connected to the bottom of the pressure rod (13). The stepper motor driver (15) is connected to the load sensor (14), and the stepper motor driver (15) is fixed to the bottom of the autoclave body (1) through a bracket; after the stepper motor driver (15) provides vertical pressure and displacement to act on the load sensor (14), the vertical pressure and displacement are transmitted to the lower friction pin (11) through the pressure rod (13) and the loading spring (12), and the lower friction pin (11) applies vertical upward pressure to the friction sample (7); a PID controller is used between the load sensor and the stepper motor for feedback control; The data acquisition unit acquires the pressure value detected by the load sensor (14) in real time, and acquires the torque value of the magnetic motor rotator (5) in real time, and uploads the acquired pressure value and torque value to the host computer for storage.

2. The double-pin friction precision loading test device for simulating deep sea environment according to claim 1 is characterized in that: It also includes an upper clamping plate (8) and a lower clamping plate (9) for clamping and fixing the friction sample (7), the upper clamping plate (8) and the lower clamping plate (9) being in the shape of a disc; the upper clamping plate (8) is in close contact with the upper surface of the friction sample (7), and the lower clamping plate (9) is in close contact with the lower surface of the friction sample (7); the surfaces of the upper clamping plate (8) and the lower clamping plate (9) are provided with circumferential through holes, and the surface of the friction sample (7) is also provided with corresponding through holes, and fastening bolts are installed in the through holes, and the friction sample (7) is fixed to the motor shaft (6) by means of the fastening bolts, the upper clamping plate (8) and the lower clamping plate (9).

3. The double-pin friction precision loading test device for simulating deep-sea environment according to claim 1 is characterized in that: It also includes a vertical support plate (16) located in the autoclave, the support plate (16) being located on one side of the autoclave and having its upper end fixedly connected to the autoclave cover (2), and three support blocks arranged at intervals being welded on one side of the support plate (16), which are respectively an upper support block (17), a middle support block (18) and a lower support block (19) from top to bottom; the edge of the friction specimen (7) is located between the upper support block (17) and the middle support block (18); the upper support block (17), the middle support block (18) and the lower support block (19) provide a guide for the pressure loading assembly; A positioning hole is provided at the bottom of the upper support block (17), and the upper friction pin (10) is fixed in the positioning hole of the upper support block (17); through holes are provided at corresponding positions of the middle support block (18) and the lower support block (19), and the lower friction pin (11) is inserted into the through hole of the middle support block (18); the loading spring (12) is located between the middle support block (18) and the lower support block (19), and the upper end of the pressure rod (13) is inserted into the through hole of the lower support block (19).

4. The double-pin friction precision loading test device for simulating deep-sea environment according to claim 1 is characterized in that: The autoclave body (1) is made of duplex stainless steel and has a compressive strength of not less than 20 MPa.

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