Loading system for controlling oil return of loading cylinder

Abstract

A loading system for controlling oil return of a loading cylinder belongs to the field of testing devices for loading tests and comprises the loading cylinder and an oil tank. The hydraulic system is characterized by further comprising a hydraulic pump, a motor, an overflow valve, a one-way valve, a servo valve and a proportional reversing valve, the proportional reversing valve is provided with four interfaces, namely an interface P, an interface T, an interface A and an interface B; the motor is connected with the hydraulic pump; and an overflow valve is arranged between the one-way valve and the servo valve. The loading system is used for controlling the oil return of the loading cylinder to realize active loading and passive loading; the proportional directional valve is adopted to achieve switching of the loading direction of the loading cylinder, the servo valve is adopted to achieve dynamic adjustment of the load, the requirement for a control system is low, loading control can be achieved without a professional controller, and active and passive loading can be achieved; meanwhile, the hydraulic valve does not need to be close to the loading cylinder, and the valve group can be placed in a normal-temperature environment during a high-low-temperature loading test; the system is simple, low in cost and suitable for popularization and application.

Description

Technical Field

[0001] The invention belongs to the field of testing devices for loading tests, and in particular relates to a loading system for controlling oil return of a loading cylinder. Background Art

[0002] In the process of testing linear or rotary motion products, in order to simulate the actual working conditions, it is necessary to test under load. The hydraulic loading systems currently available on the market generally use servo valves to directly control the oil in the A and B ports of the loading cylinder to load, but this method requires the control system to have an extremely high response speed and generally requires a professional controller, so there are problems such as high cost and difficulty in debugging. Summary of the invention

[0003] The present invention aims to solve the above problems and provide a loading system for controlling the oil return of a loading cylinder which has low requirements on the control system and does not require a professional controller.

[0004] The loading system for controlling oil return of a loading cylinder of the present invention comprises a loading cylinder and an oil tank; and also comprises a hydraulic pump, a motor, a relief valve, a check valve, a servo valve and a proportional reversing valve; The proportional reversing valve is provided with four interfaces, namely, a P interface, a T interface, an A interface and a B interface; The A interface and the B interface are both connected to the aforementioned loading cylinder; The P interface and the T interface are both connected to the aforementioned oil tank; The P interface is connected to the aforementioned oil tank via a one-way valve and a hydraulic pump in sequence; The T interface is connected to the oil tank via the servo valve; The aforementioned motor is connected to the hydraulic pump; An overflow valve is arranged between the one-way valve and the servo valve.

[0005] Furthermore, in the loading system for controlling oil return of the loading cylinder of the present invention, both the outlet end of the one-way valve and the inlet end of the oil tank are provided with a filter valve; the filter valve is used for filtering and cleaning the oil.

[0006] Furthermore, in the loading system for controlling the oil return of the loading cylinder of the present invention, a pressure sensor and an accumulator are arranged between the one-way valve and the P interface; the pressure sensor is used to monitor the output pressure of the hydraulic pump; and the accumulator is used to stabilize the output pressure fluctuation of the hydraulic pump.

[0007] The method for controlling oil return of a loading cylinder of the present invention is based on any of the aforementioned loading systems for controlling oil return of a loading cylinder, comprising: driving a hydraulic pump by a motor to absorb oil in an oil tank and output high-pressure oil; The output high-pressure oil passes through the one-way valve to the proportional reversing valve; The proportional reversing valve controls the loading cylinder to perform forward and reverse movements respectively; The servo valve controls the loading force by adjusting the pressure at port T of the proportional reversing valve.

[0008] The loading system for controlling the oil return of the loading cylinder of the present invention realizes active loading and passive loading by controlling the oil return of the loading cylinder through the loading system; a proportional reversing valve is used to realize the switching of the loading direction of the loading cylinder, and a servo valve is used to realize dynamic adjustment of the load, and the control system has low requirements, and loading control can be realized without a professional controller, and active and passive loading can be realized; at the same time, the hydraulic valve does not need to be close to the loading cylinder, and the valve group can be placed in a normal temperature environment during high and low temperature loading tests; the system is simple, low-cost, and suitable for popularization and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a schematic diagram of the structure of a loading system for controlling oil return from a loading cylinder according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the principle of passive loading of the test piece in forward motion according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the passive loading principle of the negative motion of the test piece according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the principle of active loading of the test piece in forward motion according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the principle of active loading of the negative motion of the test piece according to an embodiment of the present invention; Among them, 1-oil tank, 2-motor, 3-hydraulic pump, 4-check valve, 51-first filter valve, 52-second filter valve, 6-overflow valve, 7-pressure sensor, 8-accumulator, 9-servo valve, 10-proportional reversing valve, 11-loading cylinder. DETAILED DESCRIPTION

[0010] The loading system for controlling the oil return of the loading cylinder 11 according to the present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0011] Embodiment 1 This embodiment discloses a loading system for controlling the oil return of the loading cylinder 11. Figure 1As shown, it includes a loading cylinder 11 and an oil tank 1; it also includes a hydraulic pump 3, a motor 2, a relief valve 6, a one-way valve 4, a servo valve 9 and a proportional reversing valve 10; the proportional reversing valve 10 is provided with four interfaces, namely a P interface, a T interface, an A interface and a B interface; the A interface and the B interface are both connected to the aforementioned loading cylinder 11; the P interface and the T interface are both connected to the aforementioned oil tank 1; the P interface is connected to the aforementioned oil tank 1 via the one-way valve 4 and the hydraulic pump 3 in turn; the T interface is connected to the aforementioned oil tank 1 via the aforementioned servo valve 9; the aforementioned motor 2 is connected to the hydraulic pump 3; and an overflow valve 6 is provided between the one-way valve 4 and the aforementioned servo valve 9.

[0012] In the disclosed embodiment, the outlet end of the one-way valve 4 and the inlet end of the oil tank 1 are both provided with filter valves, namely the first filter valve 51 and the second filter valve 52; a pressure sensor 7 and an accumulator 8 are provided between the one-way valve 4 and the P interface.

[0013] The motor 2 drives the hydraulic pump 3 to absorb the oil from the oil tank 1 and output high-pressure oil; the high-pressure oil passes through the one-way valve 4 to the proportional reversing valve 10; the proportional reversing valve 10 controls the forward and reverse movement of the loading cylinder 11; the servo valve 9 adjusts the pressure at the T port of the proportional reversing valve 10 to achieve the control of the loading force (torque); during the implementation process, the overflow valve 6 is used to control the pump output pressure; the pressure sensor 7 is used to monitor the pump output pressure; the accumulator 8 is used to stabilize the pump output pressure fluctuation; the filter valve is used to filter and clean the oil; the pressure sensor 7 is used to monitor the output pressure of the hydraulic pump 3; the accumulator 8 is used to stabilize the output pressure fluctuation of the hydraulic pump 3.

[0014] Embodiment 2 Based on the loading system for controlling the oil return of the loading cylinder 11 described in the first embodiment, this embodiment discloses a method for controlling the oil return of the loading cylinder 11 .

[0015] like Figure 1 As shown, the oil tank 1 stores the working medium (hydraulic oil), and the motor 2 drives the hydraulic pump 3 to absorb the oil from the oil tank 1 and output high-pressure oil; the high-pressure oil passes through the one-way valve 4 and the first filter valve 51 to the loading part, and the one-way valve 4 ensures that the oil can only flow out from the hydraulic pump 3 to prevent the oil from impacting the pump in the reverse direction; the first filter valve 51 filters the high-pressure oil to ensure the cleanliness of the output oil; the overflow valve 6 is used to adjust the maximum pressure of the oil source output to ensure the safe and stable operation of the system; the accumulator 8 is used to stabilize the pressure of the hydraulic oil source and reduce the interference of the external load on the pressure; the pressure sensor 7 is used to monitor the working pressure of the system; Figure 1 The middle arrow represents the flow direction of the oil source, the solid arrow represents the high-pressure oil, and the hollow arrow represents the low-pressure oil. The high pressure and low pressure here are relative, and the specific size is determined by the actual working conditions.

[0016] like Figure 2The figure is a schematic diagram of the passive loading process of the test piece in the forward motion. The oil source output P passes through the proportional reversing valve 10 to the loading cylinder 11, and the return oil of the loading cylinder 11 passes through the servo valve 9 to the oil source return oil T. The opening of the servo valve 9 determines the pressure of the proportional reversing valve 10B and T ports. The smaller the opening, the higher the pressure, and the larger the opening, the lower the pressure. The size of the pressure at the proportional reversing valve 10B port determines the size of the loading force, and the loading force is adjusted by adjusting the servo valve 9. Figure 2 The middle arrow represents the direction of oil flow, the solid arrow represents high-pressure oil, the semi-solid arrow represents medium-pressure oil, and the hollow arrow represents low-pressure oil. The high pressure, medium pressure, and low pressure here are relative, and the specific size is determined by the actual working conditions.

[0017] like Figure 3 The schematic diagram of the passive loading process of the test piece in the negative motion is as follows: the oil source output P is sent to the loading cylinder 11 through the proportional reversing valve 10, and the return oil of the loading cylinder 11 is sent to the oil source return oil T through the servo valve 9; the opening of the servo valve 9 determines the pressure of the proportional reversing valve 10A and T ports, the smaller the opening, the higher the pressure, and the larger the opening, the lower the pressure; the size of the pressure at the proportional reversing valve 10A port determines the size of the loading force, and the loading force is adjusted by adjusting the servo valve 9; Figure 3 The middle arrow represents the direction of oil flow, the solid arrow represents high-pressure oil, the semi-solid arrow represents medium-pressure oil, and the hollow arrow represents low-pressure oil. The high pressure, medium pressure, and low pressure here are relative, and the specific size is determined by the actual working conditions.

[0018] like Figure 4 The schematic diagram of the active loading process of the test piece in the forward motion is as follows: the oil source output P is sent to the loading cylinder 11 through the proportional reversing valve 10, and the return oil of the loading cylinder 11 is sent to the oil source return oil T through the servo valve 9; the loading cylinder 11 drags the test piece to move forward, and the opening of the servo valve 9 determines the pressure of the proportional reversing valve 10B and T ports. The smaller the opening, the higher the pressure, and the larger the opening, the lower the pressure; the size of the pressure at the proportional reversing valve 10B port determines the size of the loading force, and the loading force is adjusted by adjusting the servo valve 9; Figure 4 The middle arrow represents the direction of oil flow, the solid arrow represents high-pressure oil, the semi-solid arrow represents medium-pressure oil, and the hollow arrow represents low-pressure oil. The high pressure, medium pressure, and low pressure here are relative, and the specific size is determined by the actual working conditions.

[0019] like Figure 5 The schematic diagram of the active loading process of the test piece in the negative movement is as follows: the oil source output P is sent to the loading cylinder 11 through the proportional reversing valve 10, and the return oil of the loading cylinder 11 is sent to the oil source return oil T through the servo valve 9; the loading cylinder 11 drags the test piece to move negatively, and the opening of the servo valve 9 determines the pressure of the proportional reversing valve 10A and T ports. The smaller the opening, the higher the pressure, and the larger the opening, the lower the pressure; the size of the pressure at the proportional reversing valve 10A port determines the size of the loading force, and the loading force is adjusted by adjusting the servo valve 9; Figure 5The middle arrow represents the direction of oil flow, the solid arrow represents high-pressure oil, the semi-solid arrow represents medium-pressure oil, and the hollow arrow represents low-pressure oil. The high pressure, medium pressure, and low pressure here are relative, and the specific size is determined by the actual working conditions.

Claims

1. A loading system for controlling oil return of a loading cylinder, comprising a loading cylinder and an oil tank; characterized in that: It also includes a hydraulic pump, a motor, a relief valve, a check valve, a servo valve and a proportional reversing valve; The proportional reversing valve is provided with four interfaces, namely, a P interface, a T interface, an A interface and a B interface; The A interface and the B interface are both connected to the aforementioned loading cylinder; The P interface and the T interface are both connected to the aforementioned oil tank; The P interface is connected to the aforementioned oil tank via a one-way valve and a hydraulic pump in sequence; The T interface is connected to the oil tank via the servo valve; The aforementioned motor is connected to the hydraulic pump; An overflow valve is arranged between the one-way valve and the servo valve.

2. The loading system for controlling oil return of a loading cylinder according to claim 1, characterized in that: The outlet end of the one-way valve and the inlet end of the oil tank are both provided with filter valves.

3. The loading system for controlling oil return of a loading cylinder according to claim 1 or 2, characterized in that: A pressure sensor and an accumulator are arranged between the one-way valve and the P interface.

4. A method for controlling oil return of a loading cylinder, based on the loading system for controlling oil return of a loading cylinder according to any one of claims 1 to 3, characterized in that include: The motor drives the hydraulic pump to absorb the oil in the oil tank and output high-pressure oil; The output high-pressure oil passes through the one-way valve to the proportional reversing valve; The proportional reversing valve controls the loading cylinder to perform forward and reverse movements respectively; The servo valve controls the loading force by adjusting the pressure at the T port of the proportional reversing valve.

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