A hydrostatic pressure pulse test bench

Abstract

The present invention discloses a hydrostatic pulse test bench, comprising: a pressurizing cylinder, the oil outlet of which is communicated with the oil inlet of the workpiece to be tested; a linear motor, the output end of which is connected to the piston rod of the pressurizing cylinder and can be used to drive the piston rod of the pressurizing cylinder to perform linear motion; a pressure sensor for measuring the pressure of the pressurizing cylinder and a thrust sensor for detecting the thrust of the linear motor; a control cabinet, which is provided with an electronic control unit, and the electronic control unit is used to receive and process the pressure of the pressurizing cylinder fed back by the pressure sensor and the thrust of the linear motor fed back by the thrust sensor; the electronic control unit controls the linear motor to drive the piston rod of the pressurizing cylinder to reciprocate, so that the pressurizing cylinder outputs a preset pressure waveform; by using the linear motor to drive the pressurizing cylinder, the pressure loss is small, the system efficiency is greatly improved, and energy is saved. And based on the data fed back by the pressure sensor and the thrust sensor, the electronic control unit controls the action of the linear motor according to the data and controls the pressurizing cylinder to output a preset pressure waveform, providing control accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of pulse test benches, and in particular, to a static pressure pulse test bench. Background Art

[0002] Pulse testing is a method for conducting shock wave fatigue life tests on various components in a fluid system, such as various pipes (rubber pipes, copper pipes, etc.), connectors, pumps, motors, and oil cylinders. The current hydraulic pulse testing machine consists of a hydraulic system, a mechanical body, and a measurement and control system. The hydraulic system is the power source of the testing machine, including a hydraulic pump, an accumulator, hydraulic valves, and other accessories. The pressure for pulse testing is provided by a pulse pressure system composed of a hydraulic pump and an accumulator, etc. The electromagnetic relief valve is used to adjust the system pressure and unload the pressure. The accumulator is mainly used to store energy, which can meet the flow demand of the servo valve during the pulse rise time. At the same time, the accumulator absorbs the flow pulsation at the outlet of the plunger pump to ensure the stability of the pressure in front of the servo valve. When the hydraulic system of the testing machine works for a long time, a large amount of heat is generated, and the alternating pressure is realized by the double closed-loop control of the servo valve.

[0003] The following four disadvantages can be seen from the working principle of the existing hydraulic pulse test bench: 1. In order to provide stable pressure, the oil pressure output by the hydraulic pump is higher than the required pressure of the test workpiece, and then the relief valve unloads the pressure to stabilize the pressure in the pipeline at the specified test pressure, resulting in a significant energy loss; 2. Regardless of how the load of the testing machine changes or the pause interval of the test process, the hydraulic pump must continuously operate at the rated power, resulting in a large power loss; 3. The measurement point and the drive adjustment of the measurement and control system are not in the same position or on the same component, and in some models, they are far apart, resulting in poor dynamic characteristics of the measurement and control system and a relatively low system frequency, generally lower than 3 Hz. Above this value, the test waveform will be severely distorted; 4. Due to the limitation of the body structure, the measurement point of the existing product is also at a relatively large distance from the test workpiece, and the actual pressure value of the workpiece cannot be obtained. Summary of the Invention

[0004] Aiming at the above deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a static pressure pulse test bench, which reduces energy loss, has a high system frequency, can improve the test accuracy, and can perform pulse tests with various pressure waveforms.

[0005] Provide a pressure wave with a preset waveform.

[0006] The technical solution adopted by the present invention to solve its technical problems is a static pressure pulse test bench, including:

[0007] A pressurizing cylinder, whose oil outlet is communicated with the oil inlet of the workpiece to be tested;

[0008] A linear motor, whose output end is connected to the piston rod of the pressure cylinder and can be used to drive the piston rod of the pressure cylinder to perform linear motion;

[0009] A pressure sensor for measuring the pressure of the pressure cylinder and a thrust sensor for detecting the thrust of the linear motor;

[0010] A control cabinet, which is provided with an electronic control unit inside. The electronic control unit is used to receive and process the pressure of the pressure cylinder feedback by the pressure sensor and the thrust of the linear motor feedback by the thrust sensor; the electronic control unit controls the linear motor to drive the piston rod of the pressure cylinder to reciprocate, so that the pressure cylinder outputs a preset pressure waveform.

[0011] A static pressure pulse test bench as described above further includes a displacement sensor for measuring the moving distance of the piston rod of the pressure cylinder. The displacement sensor is arranged on one side of the linear motor, and the displacement sensor is electrically connected to the electronic control unit.

[0012] A static pressure pulse test bench as described above, the electronic control unit includes an industrial control computer and a driver. The industrial control computer is electrically connected to the pressure sensor, the thrust sensor and the displacement sensor at the same time, and the industrial control computer can control the driver to provide a driving current to act on the linear motor.

[0013] A static pressure pulse test bench as described above, a push rod is arranged on the output end of the linear motor, and the push rod is connected to the piston rod of the pressure cylinder.

[0014] A static pressure pulse test bench as described above, a first hydraulic pipeline is arranged between the oil outlet of the pressure cylinder and the oil inlet of the workpiece to be tested, and a solenoid valve for controlling the opening or closing of the first hydraulic pipeline is arranged on the first hydraulic pipeline.

[0015] A static pressure pulse test bench as described above further includes a makeup oil pump and an oil tank. The pressure cylinder is further provided with a makeup oil port and an oil discharge port. The oil outlet of the makeup oil pump is communicated with the makeup oil port, and the oil discharge port is communicated with the oil tank.

[0016] A static pressure pulse test bench as described above, a second hydraulic pipeline is arranged between the oil discharge port and the oil tank, and a relief valve is arranged on the second hydraulic pipeline. The relief valve is provided with a preset pressure value. When the pressure in the pressure cylinder is greater than the preset pressure value of the relief valve, the relief valve opens the hydraulic pipeline.

[0017] A static pressure pulse test bench as described above further includes a support frame. The support frame includes a driving support platform frame, an oil cylinder support platform frame and a workpiece support platform frame arranged side by side. Among them, steering wheels are arranged at the bottoms of the oil cylinder support platform frame and the workpiece support platform frame.

[0018] For a hydrostatic pulse test bench as described above, the linear motor is fixed on the driving support bench, the pressurizing cylinder is fixed on the oil cylinder support bench, the workpiece to be tested is placed on the workpiece support bench, and protective fences are provided on both the pressurizing cylinder and the outside of the workpiece to be tested.

[0019] For a hydrostatic pulse test bench as described above, a filter plate is provided on the workpiece support bench, the workpiece to be tested is arranged on the filter plate, an oil sump is provided below the filter plate, and the oil sump is communicated with the oil tank through a third hydraulic pipeline.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] 1. The pressure waveform is formed by changing the thrust of the magnetic levitation motor, with small pressure loss, greatly improving the system efficiency and saving energy;

[0022] 2. The pressure of the pressurizing cylinder, the thrust of the linear motor, and the moving distance of the piston rod of the pressurizing cylinder can be fed back to the control unit through the pressure sensor, thrust sensor, and displacement sensor. The control unit can control the linear motor to output a preset driving force. At this time, the pressurizing cylinder can output a preset pressure waveform, with higher control accuracy, and the output pulse pressure waveform is closer to the preset waveform, which can improve the test accuracy;

[0023] 3. The pressurizing cylinder is directly connected to the workpiece to be tested, with a relatively short distance and a more compact overall structure;

[0024] 4. A oil filling port is provided on the pressurizing cylinder, and the oil filling pump can fill oil for the pressurizing cylinder through the oil filling port. In the case of a small amount of oil leakage, it can still work for a long time;

[0025] 5. The pressurizing cylinder is provided with an oil discharge port, which is connected to the oil tank through an overflow valve. When the oil pressure in the pressurizing cylinder is too high, the hydraulic oil will open the overflow valve for pressure relief, and the overall is relatively safe;

[0026] 6. Protective fences are provided on both the outside of the pressurizing cylinder and the workpiece to be tested, which can prevent dangerous accidents caused by high-pressure bursting. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is the front view of the overall structure of the present invention;

[0028] Figure 2 It is the schematic diagram of the overall structure of the present invention;

[0029] Figure 3 It is the top view of the overall structure of the present invention.

[0030] In the figure:

[0031] 100. Pressurizing cylinder; 110. Relief valve; 200. Linear motor; 210. Push rod; 220. Connector; 300. Workpiece to be measured; 400. Make-up oil pump; 500. Fuel tank; 510. Solenoid valve; 600. Support frame; 610. Driving support bench; 620. Oil cylinder support bench; 630. Workpiece support bench; 631. Filter plate; 632. Oil sump; 640. Steering wheel; 650. Guardrail; 700. Pressure sensor; 800. Thrust sensor; 900. Displacement sensor. Detailed implementation manners

[0032] The following are specific embodiments of the present invention in combination with the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0033] Please refer to Figures 1-3 , the present invention discloses a hydrostatic pulse test bench, including:

[0034] A pressurizing cylinder 100, whose oil outlet is communicated with the oil inlet of the workpiece 300 to be measured. The pressurizing cylinder 100 discharges hydraulic oil into the workpiece 300 to be measured through the oil outlet to provide oil pressure for the workpiece 300 to be measured, and its oil pressure can be adjusted through the pressurizing cylinder 100 so as to approach the preset pulse pressure value.

[0035] A linear motor 200, whose output end is connected to the piston rod of the pressurizing cylinder 100 and can be used to drive the piston rod of the pressurizing cylinder 100 to perform linear motion. The linear motor 200 runs relatively stably. Compared with the combined drive of a hydraulic pump, an accumulator and a valve, its drive mode is more direct, its transmission efficiency is higher, and the energy loss is less. The linear motor 200 provides a driving force acting on the piston rod of the pressurizing cylinder 100, which can drive the piston rod to reciprocate towards or away from the workpiece 300 to be measured, providing a static pulse for the workpiece 300 to be measured. Compared with the pulse test bench with a cylinder as the power in the prior art, its control accuracy is higher.

[0036] A pressure sensor 700 for measuring the pressure of the pressurizing cylinder 100 and a thrust sensor 800 for detecting the thrust of the linear motor 200, which are used to measure the pressure P in the pressurizing cylinder 100 and the thrust F of the linear motor 200 and feedback them to the electronic control unit.

[0037] Control cabinet, which is provided with an electronic control unit inside. The electronic control unit is used to receive and process the pressure of the workpiece 300 to be measured fed back by the pressure sensor 700 and the thrust of the linear motor 200 fed back by the thrust sensor 800. The electronic control unit controls the linear motor 200 to drive the piston rod of the pressure cylinder 100 to reciprocate, so that the pressure cylinder 100 outputs a preset pressure waveform. The detection principle of this device is: the linear motor 200 drives the piston rod of the pressure cylinder 100 to reciprocate, and the reciprocating motion of the piston generates a pulse pressure in the pressure cylinder 100, which is transmitted into the workpiece 300 to be measured, and a pulse pressure is applied to the inner cavity of the workpiece 300 to be measured. The waveforms of its pulse pressure include sine wave, trapezoidal wave, shock wave and random waveform, etc., which can be selected according to the actual needs of the test. Its control principle is: according to the selected pressure waveform, the algorithm calculates a series of time and pressure data. The system software calculates according to this set of time and pressure data according to the transfer function P = F / S of the system, where P is the pressure of the pressure cylinder 100, F is the motor thrust, and S is the cylinder area, and the thrust F of the linear motor 200 = K F I, where K F is the force constant of the motor, and I is the motor current. That is, the driving force of the linear motor 200 can be controlled by supplying the current to the linear motor 200, and then the pressure of the oil cylinder can be controlled. In the actual working process, the electronic control unit sends a pulse current to act on the linear motor 200, and the linear motor 200 pushes the piston rod of the pressure cylinder to move. At this time, the pressure sensor 700 and the thrust sensor 800 feed back the data to the electronic control unit. The electronic control unit can adjust the pulse current sent by the electronic control unit according to the data of the pressure sensor 700 and the thrust sensor 800 fed back, and then adjust the size of the motor driving force, so that the pulse pressure value meets the requirements of the test waveform setting. The system algorithm has the ability of self-learning to ensure that the pressure waveform output by the oil cylinder and the set waveform are highly consistent; it can improve the control accuracy and the accuracy of the test.

[0038] Preferably, it further includes a displacement sensor 900 for measuring the movement distance of the piston rod of the pressure cylinder 100. The displacement sensor 900 is arranged on one side of the output end of the linear motor 200, and the displacement sensor 900 is electrically connected to the electronic control unit. The displacement sensor 900 can feed back a movement distance of the piston rod, which is used to judge the relationship between the movement distance of the piston rod and the pressure of the pressure cylinder 100. The control system can judge whether the system is abnormal, such as oil leakage, according to the reciprocating movement distance of the piston rod, and then determine whether it is necessary to replenish oil.

[0039] Further preferably, the electronic control unit includes an industrial computer and a driver. The industrial computer is electrically connected to the pressure sensor 700, the thrust sensor 800, and the displacement sensor 900 at the same time. The industrial computer can control the driver to provide a driving current acting on the linear motor 200. The industrial computer is a control unit that can analyze the data fed back by the sensors and then control the driver to provide a preset current to the linear motor 200 to control the driving force of the linear motor 200. In this embodiment, a display is also provided on the control cabinet for real-time display of the data fed back by the sensors.

[0040] As Figure 3 described, a connector 220 is provided on one side of the linear motor 200, which can be used to connect with the integrated wiring harness of the driver.

[0041] Preferably, the linear motor 200 is a large-thrust iron-core flat linear motor or other types of large-thrust linear motors. A push rod 210 is provided at the output end of the linear motor. The push rod 210 is connected to the piston rod of the pressure cylinder 100. The linear motor drives the piston rod of the pressure cylinder 100 to perform a linear motion through the push rod 210.

[0042] Preferably, a first hydraulic pipeline is provided between the oil outlet of the pressure cylinder 100 and the oil inlet of the workpiece 300 to be tested. A solenoid valve 510 for controlling the opening or closing of the first hydraulic pipeline is provided on the first hydraulic pipeline. The solenoid valve 510 plays a role of opening and closing. Before the test, the first hydraulic pipeline can be closed through the solenoid valve 510. During the test, the first hydraulic pipeline can be opened through the solenoid valve 510 so that the oil outlet of the pressure cylinder 100 can be communicated with the oil inlet of the workpiece 300 to be tested.

[0043] Further preferably, a makeup oil pump 400 and a fuel tank 500 are further included. A makeup oil port and an oil discharge port are also provided on the pressure cylinder 100. The oil outlet of the makeup oil pump 400 is communicated with the makeup oil port, and the oil discharge port is communicated with the fuel tank 500. There may be oil leakage at the oil outlet of the pressure cylinder 100 or other connection points. Once oil leakage occurs, the position of the piston rod reciprocating movement will move forward to ensure that the output pressure of the pressure cylinder 100 reaches the specified value. Continuous oil leakage causes the piston rod to continuously move forward, and finally the piston rod is jammed at the end of the pressure cylinder 100 and cannot move forward, and the system stops running. The makeup oil pump 400 can make up oil for the pressure cylinder 100 when the piston rod slightly moves forward continuously to the limit position of the piston rod set by the system, return the reciprocating position of the piston to the original range, ensure the oil pressure stability, and ensure the test accuracy.

[0044] Further preferably, a second hydraulic pipeline is provided between the oil unloading port and the fuel tank 500. An overflow valve 110 is provided on the second hydraulic pipeline. The overflow valve 110 is provided with a preset pressure value. When the pressure in the pressure cylinder 100 is greater than the preset pressure value of the overflow valve 110, the overflow valve 110 opens the hydraulic pipeline. The preset pressure value should be set below the safety value. That is, once the oil pressure in the pressure cylinder 100 is too high and approaches the safety value, in order to avoid bursting, the overflow valve 110 can be used to relieve the pressure.

[0045] Further preferably, it further includes a support frame 600. The support frame 600 includes a driving support platform frame 610, an oil cylinder support platform frame 620, and a workpiece support platform frame 630 arranged side by side. Among them, steering wheels 640 are provided at the bottoms of the oil cylinder support platform frame 620 and the workpiece support platform frame 630. The support frame 600 is used to provide a supporting function, and the oil cylinder support platform frame 620 and the workpiece support platform frame 630 can move through the steering wheels 640.

[0046] Further preferably, the linear motor 200 is fixed on the driving support platform frame 610, the pressure cylinder 100 is fixed on the oil cylinder support platform frame 620, the workpiece to be tested 300 is placed on the workpiece support platform, and protective fences 650 are provided on both the pressure cylinder 100 and the outside of the workpiece to be tested 300. The protective fences 650 are installed with acrylic plates, which can provide good protection and prevent danger caused by the bursting of the pressure cylinder 100 and the workpiece to be tested 300.

[0047] Further preferably, a filter plate 631 is provided on the workpiece support platform. The workpiece to be tested 300 is arranged on the filter plate 631. An oil collecting tank 632 is provided below the filter plate 631. The oil collecting tank 632 is communicated with the fuel tank 500 through a third hydraulic pipeline. If the workpiece to be tested 300 leaks oil during or after the test, it can be collected into the oil collecting tank 632 through the filter plate 631 and then transferred to the fuel tank 500 by the oil collecting tank 632.

[0048] In this embodiment, the hydrostatic pulse test bench is also provided with an intelligent Internet of Things function, and the system will promptly notify the operator of the identified abnormalities and faults.

[0049] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a certain specific posture (as shown in the drawings). If this specific posture changes, then the directional indications will also change accordingly.

[0050] In addition, in the present invention, descriptions such as "first", "second", "one", etc. are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0051] In the present invention, unless otherwise clearly defined and limited, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and may be the internal connection of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

Claims

1. A hydrostatic pulse test bench, characterized in that, it includes: a pressurizing cylinder, whose oil outlet is communicated with the oil inlet of the workpiece to be tested; a linear motor, whose output end is connected to the piston rod of the pressurizing cylinder and can be used to drive the piston rod of the pressurizing cylinder to perform linear motion; a pressure sensor for measuring the pressure of the pressurizing cylinder and a thrust sensor for detecting the thrust of the linear motor; a control cabinet, which is provided with an electronic control unit inside. The electronic control unit is used to receive and process the pressure of the pressurizing cylinder fed back by the pressure sensor and the thrust of the linear motor fed back by the thrust sensor; the electronic control unit controls the linear motor to drive the piston rod of the pressurizing cylinder to reciprocate, so that the pressurizing cylinder outputs a preset pressure waveform; It further includes a displacement sensor for measuring the moving distance of the piston rod of the pressurizing cylinder. The displacement sensor is arranged on one side of the linear motor, and the displacement sensor is electrically connected to the electronic control unit; The electronic control unit includes an industrial personal computer and a driver. The industrial personal computer is electrically connected to the pressure sensor, the thrust sensor and the displacement sensor at the same time, and the industrial personal computer controls the driver to provide a driving current to act on the linear motor; Combined with the transfer function P = F / S, where P is the pressure of the pressurizing cylinder, F is the thrust of the linear motor, S is the cylinder area, and the thrust of the linear motor F = KF*I, where KF is the force constant of the DC motor and I is the motor current. The driving force of the linear motor is controlled by supplying the current to the linear motor, and then the pressure of the pressurizing cylinder is controlled; During the working process of the hydrostatic pulse test bench, the electronic control unit sends out a pulse current to act on the linear motor. The linear motor pushes the piston rod of the pressure cylinder to displace. At this time, the pressure sensor and the thrust sensor feed back the data to the electronic control unit. The electronic control unit adjusts the pulse current sent out by the electronic control unit according to the data of the pressure sensor and the thrust sensor fed back, and then adjusts the magnitude of the motor driving force.

2. A hydrostatic pulse test bench according to claim 1, characterized in that, a push rod is arranged on the output end of the linear motor, and the push rod is connected to the piston rod of the pressurizing cylinder.

3. A hydrostatic pulse test bench according to claim 1, characterized in that, a first hydraulic pipeline is arranged between the oil outlet of the pressurizing cylinder and the oil inlet of the workpiece to be tested, and a solenoid valve for controlling the opening or closing of the first hydraulic pipeline is arranged on the first hydraulic pipeline.

4. A hydrostatic pulse test bench according to claim 1 or 3, characterized in that, it further includes a makeup oil pump and an oil tank. The pressurizing cylinder is further provided with a makeup oil port and an oil discharge port. The oil outlet of the makeup oil pump is communicated with the makeup oil port, and the oil discharge port is communicated with the oil tank.

5. A hydrostatic pulse test bench according to claim 4, characterized in that, a second hydraulic pipeline is arranged between the oil discharge port and the oil tank, and a relief valve is arranged on the second hydraulic pipeline. The relief valve is provided with a preset pressure value. When the pressure in the pressurizing cylinder is greater than the preset pressure value of the relief valve, the relief valve opens the second hydraulic pipeline.

6. A hydrostatic pulse test bench according to claim 4, characterized in that, it further includes a support frame, and the support frame includes a driving support bench, an oil cylinder support bench and a workpiece support bench arranged side by side. Among them, steering wheels are provided at the bottoms of the oil cylinder support bench and the workpiece support bench.

7. A hydrostatic pulse test bench according to claim 6, characterized in that, the linear motor is fixed on the driving support bench, the pressure cylinder is fixed on the oil cylinder support bench, the workpiece to be tested is placed on the workpiece support bench, and protective fences are provided on both the pressure cylinder and the outside of the workpiece to be tested.

8. A hydrostatic pulse test bench according to claim 7, characterized in that, a filter plate is provided on the workpiece support bench, the workpiece to be tested is arranged on the filter plate, an oil collecting tank is provided below the filter plate, and the oil collecting tank is communicated with the fuel tank through a third hydraulic pipeline.

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