Open-loop controlled multifunctional hydraulic pulse test bench

Abstract

The utility model provides an open-loop controlled multifunctional hydraulic pulse test bench, which comprises a storage oil tank, an oil supply pump machine, a reversing valve, a pressurizing oil cylinder and an oil supplementing overflow valve, according to the test bed, a large amount of oil flows into a system at the moment that an oil way is opened by a reversing valve, and due to the fact that an overflow valve has a lag phenomenon in response, oil pressure instantaneously generates an overshoot peak value, pressure in a pipeline rapidly rises and a pressure peak appears, then the overflow valve is conducted, the oil is guided out along the overflow valve, and the pressure in the system is reduced to the set pressure of the overflow valve; water hammer waves and rectangular waves of various waveforms and frequency bands can be generated by adjusting the diameter of a variable damping hole of the one-way throttle valve and the rotating speed of the motor, so that the hydraulic pulse test bed can form hydraulic pulse waveforms of various waveforms and frequency bands; the set pressure of the overflow valve is increased, meanwhile, the travel switch loses efficacy, and when the reversing valve is located at the right position all the time, a damage test can be conducted on the hydraulic pipeline to measure the maximum pressure value capable of being borne by a tested piece.

Description

Technical Field

[0001] The utility model relates to hydraulic test equipment, in particular to a multi-functional hydraulic pulse test bench with open-loop control. Background Technique

[0002] In the hydraulic systems in various engineering fields, two kinds of hydraulic accessories, namely hydraulic pipe fittings and pipe joints, are indispensable. From the design to the production of hydraulic pipe fittings and pipe joints, risk verification is required during this period, including vibration tests, hydraulic pulse tests, pressure resistance tests, burst pressure tests, etc. of the pipe fittings. Their qualification determines the safety, reliability and service life of the entire hydraulic system. Generally, the damage of pipe fittings and pipe joints in a hydraulic system is often caused by structural fatigue caused by pulse cyclic loading far lower than the burst pressure. Therefore, it is necessary to conduct pulse pressure tests on pipe fittings and pipe joints, that is, to conduct fatigue strength life tests on pipe fittings and pipe joints with specified pressure pulses. Such pulse pressure tests need to form pressure pulses through the hydraulic system inside the hydraulic pulse generating device. In order to obtain higher pressure pulses, the commonly used pressure pulse test equipment usually adopts a complex oil circuit structure, which will greatly increase the equipment cost. Therefore, it is necessary to optimize its structure to overcome the above defects. Content of the Utility Model

[0003] The purpose of the utility model is to provide a multi-functional hydraulic pulse test bench with open-loop control.

[0004] The technical solution adopted by the utility model to solve its technical problems is:

[0005] A multi-functional hydraulic pulse test bench with open-loop control, comprising:

[0006] A storage oil tank, which has a storage space for accommodating oil inside;

[0007] An oil supply pump, the inlet end of which is communicated with the storage oil tank, and the oil supply pump conveys the oil in the storage oil tank outward to form hydraulic oil with a certain working pressure;

[0008] It further comprises:

[0009] A reversing valve, which is a three-position four-way electromagnetic reversing valve. Its oil inlet is communicated with the outlet end of the oil supply pump, and its oil return port is communicated with the storage oil tank. This reversing valve has a neutral unloading state, a forward through state and a reverse through state;

[0010] A booster cylinder, which has a rod chamber, a low-pressure chamber and a high-pressure chamber. The first working oil port of the reversing valve is communicated with the low-pressure chamber, the second working oil port is communicated with the rod chamber, and the high-pressure chamber of the booster cylinder is communicated with the workpiece to be measured. When the reversing valve switches between the neutral unloading state, the forward through state and the reverse through state, it drives the booster cylinder to switch between the free floating state, the forward pressurization state and the reverse pressure reduction state, so that the workpiece to be measured bears a pulse pressure;

[0011] An oil replenishing overflow valve, which is communicated with the workpiece to be measured and the storage fuel tank. When the pulse pressure borne by the workpiece to be measured exceeds the limit value, the oil in the high-pressure chamber can overflow outward through the oil replenishing overflow valve. When the pulse pressure borne by the workpiece to be measured decreases, the oil in the storage fuel tank can be replenished into the high-pressure chamber through the oil replenishing overflow valve.

[0012] In an embodiment of the present invention, a one-way throttle valve is provided between the low-pressure chamber of the booster cylinder and the first working oil port of the reversing valve, and the one-way throttle valve controls the flow rate of the oil entering the low-pressure chamber; a travel switch is provided at the limit position of the high-pressure chamber of the booster cylinder, and the travel switch is electrically connected to the driving end of the reversing valve through a circuit. When the piston in the booster cylinder abuts against the travel switch, the travel switch sends a signal to the reversing valve to switch it from the forward through state to the reverse through state, so as to control the extension and contraction strokes of the hydraulic rod and ensure the safety and accuracy of the working process.

[0013] In an embodiment of the present invention, the high-pressure chamber of the booster cylinder is communicated with the workpiece to be measured through a normally open valve; a test pressure sensor is provided in the pipeline between the normally open valve and the workpiece to be measured, and the test pressure sensor detects the test pressure of the workpiece to be measured. When the workpiece to be measured reaches the limit pressure and is damaged, the test pressure sensor records and collects it.

[0014] In an embodiment of the present invention, the oil replenishing overflow valve includes a one-way valve and an overflow valve connected in parallel, and the flow direction of the one-way valve is opposite to that of the overflow valve.

[0015] In an embodiment of the present invention, a temperature sensor is provided in the storage fuel tank to detect the temperature of the oil in the storage fuel tank; the oil outlet end of the oil supply pump is connected to the oil inlet of the reversing valve through a pipeline with an oil supply overflow valve. When the hydraulic oil pressure formed by the oil supply pump exceeds the limit value, it can overflow outward through the oil supply overflow valve; the oil supply overflow valve is communicated with the storage fuel tank through a radiator, and the oil overflowed through the oil supply overflow valve flows back to the storage fuel tank through the radiator. The temperature sensor is electrically connected to the radiator through a circuit. When the oil temperature reaches the set value, the radiator is started through the temperature sensor to dissipate heat from the oil flowing through the radiator. In an embodiment of the present invention, the radiator is a forced-air radiator.

[0016] In an embodiment of the present utility model, the driving end of the oil supply pump machine is engaged with a variable-frequency motor, and the oil supply pump machine is driven by the variable-frequency motor to operate; the oil inlet end of the oil supply pump machine is communicated with the storage oil tank through a filter, and the filter filters and purifies the oil output by the oil supply pump machine; a fuel supply pressure sensor is connected between the oil outlet end of the oil supply pump machine and the oil inlet of the reversing valve through a pipeline, and the fuel supply pressure sensor detects the hydraulic oil pressure formed by the oil supply pump machine. In an embodiment of the present utility model, the oil supply pump machine is a fixed-displacement oil pump.

[0017] In an embodiment of the present utility model, the driving ends of the one-way throttle valve, the variable-frequency motor, and the reversing valve are respectively electrically connected to the control system through lines, and the flow rate of the one-way throttle valve, the operating state of the variable-frequency motor, and the operating state of the reversing valve can be controlled through the control system.

[0018] The advantages of the present utility model are as follows:

[0019] At the moment when the reversing valve opens the oil circuit, a large amount of oil flows into the system. Due to the lag phenomenon of the overflow valve response, the oil pressure in the system instantaneously generates an overshoot peak value, the pressure in the pipeline rapidly rises, and a pressure spike appears. Subsequently, the overflow valve conducts, and the oil is discharged along the overflow valve, and the pressure in the system drops to the set pressure of the overflow valve;

[0020] By adjusting the variable damping hole diameter of the one-way throttle valve and the rotational speed of the motor, water hammer waves and rectangular waves of various waveforms and frequency bands can be generated, enabling the hydraulic pulse test bench to form hydraulic pulse waveforms of various waveforms and frequency bands;

[0021] Increase the set pressure of the overflow valve and simultaneously make the travel switch ineffective. When the reversing valve is always in the right position, a destructive test can be performed on the hydraulic pipeline to measure the maximum pressure value that the test piece can withstand;

[0022] The test bench selects a travel switch to limit the position of the piston of the booster cylinder, which can accurately control the extension and contraction strokes of the hydraulic rod, ensuring the safety and accuracy of the working process, and the stroke limiting device has a simple structure and is relatively easy to maintain and replace. Description of the Drawings

[0023] Figure 1 is a schematic structural diagram of an open-loop control multi-functional hydraulic pulse test bench proposed by the present utility model;

[0024] Figure 2 is the pressure waveform requirement in the water hammer wave test standard specified by ISO. Detailed Embodiments

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. The components of the embodiments of the present utility model usually described and illustrated in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present utility model provided in the drawings is not intended to limit the scope of the claimed present utility model, but merely represents the selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts fall within the protection scope of the present utility model.

[0026] As Figure 1 shown, the open-loop controlled multi-functional hydraulic pulse test bench proposed by the present utility model includes a storage oil tank 100, an oil supply pump 200, a reversing valve 300, a booster cylinder 400, and a make-up oil overflow valve 500. The storage oil tank has an internal storage space for containing oil. The inlet end of the oil supply pump is connected to the storage oil tank, and the oil supply pump transports the oil in the storage oil tank outward to form hydraulic oil with a certain working pressure. The reversing valve is a three-position four-way electromagnetic reversing valve. Its inlet port is connected to the outlet end of the oil supply pump, and its return port is connected to the storage oil tank. This reversing valve has a neutral unloading state, a forward through state, and a reverse through state. The booster cylinder has a rod chamber, a low-pressure chamber, and a high-pressure chamber. The first working oil port of the reversing valve is connected to the low-pressure chamber, and its second working oil port is connected to the rod chamber. The high-pressure chamber of the booster cylinder is connected to the workpiece A to be tested. When the reversing valve switches between the neutral unloading state, the forward through state, and the reverse through state, it drives the booster cylinder to switch between the free floating state, the forward pressurization state, and the reverse pressure reduction state, so that the workpiece to be tested bears a pulse pressure. The make-up oil overflow valve is connected to the workpiece to be tested and the storage oil tank. When the pulse pressure borne by the workpiece to be tested exceeds the limit value, the oil in the high-pressure chamber can overflow outward through the make-up oil overflow valve. When the pulse pressure borne by the workpiece to be tested decreases, the oil in the storage oil tank can be supplemented into the high-pressure chamber through the make-up oil overflow valve.

[0027] In this embodiment, a one-way throttle valve 410 is provided between the low-pressure chamber of the booster cylinder and the first working oil port of the reversing valve to control the flow rate of the oil entering the low-pressure chamber. A travel switch 420 is provided at the extreme position of the high-pressure chamber of the booster cylinder. This travel switch is electrically connected to the drive end of the reversing valve through a circuit. When the piston in the booster cylinder abuts against the travel switch, the travel switch sends a signal to the reversing valve to switch it from the forward through state to the reverse through state, so as to control the extension and contraction strokes of the hydraulic rod and ensure the safety and accuracy of the working process.

[0028] In this embodiment, the high-pressure chamber of the booster cylinder is connected to the workpiece to be measured through a normally open valve 430; a test pressure sensor 440 is provided in the pipeline between the normally open valve and the workpiece to be measured. The test pressure sensor detects the test pressure of the workpiece to be measured. When the workpiece to be measured reaches the limit pressure and is damaged, the test pressure sensor records and collects it.

[0029] In this embodiment, the oil replenishing overflow valve includes a check valve and an overflow valve connected in parallel with each other. The flow direction of the check valve is opposite to the flow direction of the overflow valve.

[0030] In this embodiment, a temperature sensor 110 is provided in the storage fuel tank to detect the temperature of the oil in the storage fuel tank through the temperature sensor; a supply oil overflow valve 210 is connected between the oil outlet end of the supply oil pump and the oil inlet of the reversing valve through a pipeline. When the hydraulic oil pressure formed by the supply oil pump exceeds the limit value, it can overflow outward through the supply oil overflow valve; the supply oil overflow valve is connected to the storage fuel tank through a radiator 220. The oil after overflowing through the supply oil overflow valve flows back to the storage fuel tank through the radiator. The temperature sensor is electrically connected to the radiator through a wire. When the oil temperature reaches the set value, the radiator is started through the temperature sensor to dissipate heat from the oil flowing through the radiator. In this embodiment, the radiator is an air-cooled radiator.

[0031] In this embodiment, the driving end of the supply oil pump is engaged with a variable-frequency motor 230, and the supply oil pump is driven to operate by the variable-frequency motor; the oil inlet end of the supply oil pump is connected to the storage fuel tank through a filter 240, and the filter purifies the oil output by the supply oil pump; a supply oil pressure sensor 250 is connected between the oil outlet end of the supply oil pump and the oil inlet of the reversing valve through a pipeline, and the supply oil pressure sensor detects the hydraulic oil pressure formed by the supply oil pump. In this embodiment, the supply oil pump is a fixed-displacement oil pump.

[0032] In this embodiment, the driving ends of the one-way throttle valve, the variable-frequency motor, and the reversing valve are respectively electrically connected to a control system 600 through wires, and the flow rate of the one-way throttle valve, the operating state of the variable-frequency motor, and the operating state of the reversing valve can be controlled through the control system.

[0033] When the test bench is conducting a hydraulic pulse test, the frequency conversion motor is started to drive the quantitative oil pump to operate. At this time, the three-position four-way solenoid reversing valve is in the middle position and the pump port is unloaded; when hydraulic impact is required, the three-position four-way solenoid reversing valve enters the left position, and the oil flows into the low-pressure chamber of the booster cylinder through the one-way throttle valve, instantly pushing the piston of the booster cylinder to move rapidly. Due to the lag in the response of the relief valve, the pressure in the pipeline instantly produces an overshoot peak, and then the relief valve is turned on to overflow the set pressure. The workpiece under test obtains a pressure waveform proportional to the low-pressure chamber through the booster cylinder; the waveform When descending, the three-position four-way electromagnetic reversing valve is switched to the middle position, so that the low-pressure chamber of the booster cylinder is connected to the oil return circuit, the oil returns to the oil tank, and the pressure at the workpiece under test also drops to near zero, and this cycle is repeated; in order to prevent the booster cylinder piston from reaching the right limit position after multiple cycles, a travel switch is arranged in the system. When the travel switch sends a signal, the reversing valve is switched to the right position, pushing the booster cylinder back to the left limit position and repeating the above cycle process; therefore, the control system controls the energization and de-energization of the reversing valve electromagnetic coil, and the tested piece can be subjected to a hydraulic pulse test.

[0034] In the description of the present utility model, it should be noted that when terms such as "upper", "lower", "inner", "outer", "left", "right" and the like indicating orientation or positional relationship appear, it should be understood that the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed when in use, or the orientation or positional relationship commonly understood by those skilled in the art, is only for the convenience of describing the present utility model and simplifying the description, and does not indicate or imply that the equipment or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, when terms such as "first" and "second" appear, they are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In the description of the present utility model, it should also be noted that, unless otherwise clearly specified and limited, terms such as "installation", "setting", and "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements. For those skilled in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

Claims

1. A multi-functional hydraulic pulse test bench with open-loop control, comprising: A storage fuel tank, which has a storage space inside for containing hydraulic oil; An oil supply pump, the inlet end of which is connected to the storage fuel tank. The oil supply pump transports the hydraulic oil in the storage fuel tank outward to form hydraulic oil with a certain working pressure; It is characterized in that it further comprises: A reversing valve, which is a three-position four-way electromagnetic reversing valve. Its oil inlet is connected to the outlet end of the oil supply pump, and its oil return port is connected to the storage fuel tank. This reversing valve has a neutral unloading state, a forward through state, and a reverse through state; A booster cylinder, which has a rod chamber, a low-pressure chamber, and a high-pressure chamber. The first working oil port of the reversing valve is connected to the low-pressure chamber, and its second working oil port is connected to the rod chamber. The high-pressure chamber of the booster cylinder is connected to the workpiece to be tested. When the reversing valve switches between the neutral unloading state, the forward through state, and the reverse through state, it drives the booster cylinder to switch between the free floating state, the forward pressurization state, and the reverse pressure reduction state, so that the workpiece to be tested bears pulse pressure; A make-up oil overflow valve, which is connected to the workpiece to be tested and the storage fuel tank. When the pulse pressure borne by the workpiece to be tested exceeds the limit value, the hydraulic oil in the high-pressure chamber can overflow outward through the make-up oil overflow valve. When the pulse pressure borne by the workpiece to be tested decreases, the hydraulic oil in the storage fuel tank can be supplemented into the high-pressure chamber through the make-up oil overflow valve.

2. The multi-functional hydraulic pulse test bench with open-loop control according to claim 1, characterized in that: A one-way throttle valve is provided between the low-pressure chamber of the booster cylinder and the first working oil port of the reversing valve to control the flow rate of the hydraulic oil entering the low-pressure chamber; A travel switch is provided at the limit position of the high-pressure chamber of the booster cylinder. The travel switch is electrically connected to the drive end of the reversing valve through a circuit. When the piston in the booster cylinder abuts against the travel switch, the travel switch sends a signal to the reversing valve to switch it from the forward through state to the reverse through state, so as to control the extension and contraction strokes of the hydraulic rod and ensure the safety and accuracy of the working process.

3. The multi-functional hydraulic pulse test bench with open-loop control according to claim 1, characterized in that: The high-pressure chamber of the booster cylinder is connected to the workpiece to be tested through a normally open valve; A test pressure sensor is provided in the pipeline between the normally open valve and the workpiece to be tested to detect the test pressure of the workpiece to be tested. When the workpiece to be tested reaches the limit pressure and is damaged, the test pressure sensor records and collects it.

4. The multi-functional hydraulic pulse test bench with open-loop control according to claim 1, characterized in that: The make-up oil overflow valve includes a one-way valve and an overflow valve connected in parallel, and the flow direction of the one-way valve is opposite to that of the overflow valve.

5. The multi-functional hydraulic pulse test bench with open-loop control according to claim 1, characterized in that: A temperature sensor is provided in the storage fuel tank to detect the temperature of the hydraulic oil in the storage fuel tank; A supply oil overflow valve is connected by a pipeline between the outlet end of the oil supply pump and the oil inlet of the reversing valve. When the pressure of the hydraulic oil formed by the oil supply pump exceeds the limit value, it can overflow outward through the supply oil overflow valve; The oil supply overflow valve is connected to the storage tank through the radiator. The oil after overflowing through the oil supply overflow valve flows back to the storage tank through the radiator. The temperature sensor is electrically connected to the radiator through a wire. When the oil temperature reaches the set value, the radiator is started through the temperature sensor to dissipate heat from the oil flowing through the radiator.

6. The multifunctional hydraulic pulse test bench with open-loop control according to claim 1, characterized in that: The driving end of the oil supply pump is engaged with the variable-frequency motor, and the oil supply pump is driven to operate by the variable-frequency motor; The oil inlet end of the oil supply pump is connected to the storage tank through a filter, and the filter filters and purifies the oil output by the oil supply pump; A pipeline is connected with an oil supply pressure sensor between the oil outlet end of the oil supply pump and the oil inlet of the reversing valve, and the oil supply pressure sensor detects the hydraulic oil pressure formed by the oil supply pump.

7. The multifunctional hydraulic pulse test bench with open-loop control according to any one of claims 1 to 6, characterized in that: The driving ends of the one-way throttle valve, the variable-frequency motor and the reversing valve are respectively electrically connected to the control system through wires, and the flow rate of the one-way throttle valve, the operating state of the variable-frequency motor and the operating state of the reversing valve can be controlled through the control system.

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