An accumulator extreme working condition durability test system

Abstract

The present invention discloses an accumulator extreme working condition durability test system, comprising a normal temperature oil source, a main pump source, a main accumulator module, a servo control system, a pressurized thermal isolation system, a supplementary oil pump source, a supplementary oil accumulator module, a heat exchange device, a test bench, and a temperature-controlled oil source. The normal temperature oil source provides normal temperature oil, the main pump source provides the normal temperature oil of the normal temperature oil source to the pressurized thermal isolation system through the servo control system, the main accumulator module can stabilize the outlet pressure of the main pump source, the supplementary oil pump source can replenish leaked oil, the supplementary oil accumulator module can stabilize the outlet pressure of the supplementary oil pump source, the test bench is used to place the test piece and the high and low temperature alternating test chamber, the high and low temperature alternating test chamber provides a high and low temperature environment for the test piece, and the temperature-controlled oil source is used to control the oil temperature of the heat exchange device. The present invention breaks the limitation of extreme working conditions on the hydraulic components of the accumulator test system, realizes the simulation of extreme working conditions, and completes the accumulator durability test.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic component inspection and detection, and in particular to an accumulator extreme working condition durability testing system. Background Art

[0002] Accumulators are crucial energy storage devices in hydraulic systems. They convert system energy into compressed or potential energy at the appropriate time and store it. When needed, they convert the compressed or potential energy into hydraulic energy and release it to replenish the system. They store energy, absorb hydraulic shock, eliminate pressure pulsation, reduce noise, provide vehicle shock absorption, compensate for pressure, and recover energy. They are widely used in aviation, aerospace, the automotive industry, deep-sea operations, and other fields. However, the extreme operating conditions of these fields, such as high pressure, high temperature, low temperature, high power, and high frequency, pose severe challenges to the performance and durability of accumulators. To ensure the service life of accumulators in these critical areas, they must simulate these extreme conditions, performing long-term, multiple-cycle oil filling and discharging fatigue tests to verify their durability.

[0003] At present, servo valve-controlled hydraulic systems are generally used to achieve high-frequency testing. However, the rated pressure and medium temperature range of general servo valves cannot meet the operating requirements of the accumulator's high pressure (75MPa), high temperature (150℃), and low temperature (-55℃). For example, the maximum pressure resistance of a commonly used servo valve is only 35MPa, and the allowable medium temperature is only -20℃ to 80℃. At the same time, the hydraulic pump's tolerance to high temperatures is only up to 100℃. Above this temperature, the life span is drastically shortened and it is easy to fail. If the traditional solution is adopted to heat the oil tank temperature to 150℃, the hydraulic components will not be able to support the long-term accumulator durability test. If the 80℃ oil source + pipeline heater solution commonly used in the aviation field is adopted, due to the high frequency charging and discharging of the accumulator, the instantaneous flow rate is very large, and the heating and cooling power is huge, which will also greatly increase the floor space and cost.

[0004] Therefore, how to achieve innovation in testing principles and test configurations and complete the simulation of extreme working conditions such as high pressure, high temperature, low temperature, and high frequency is the key and difficulty in realizing the durability test of accumulators under extreme working conditions. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide an accumulator extreme working condition durability test system, break the limitations of extreme working conditions on the hydraulic components of the accumulator test system, realize the simulation of extreme working conditions, and complete the accumulator durability test.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] An accumulator extreme working condition durability test system includes a normal temperature oil source, a main pump source, a main accumulator module, a servo control system, a pressurized thermal isolation system, an oil replenishment pump source, an oil replenishment accumulator module, a heat exchange device, a test bench, and a temperature-controlled oil source. The normal temperature oil source provides normal temperature oil, and the main pump source provides the normal temperature oil of the normal temperature oil source to the pressurized thermal isolation system through the servo control system. The main accumulator module can stabilize the outlet pressure of the main pump source, the oil replenishment pump source can replenish the leaked oil, and the oil replenishment accumulator module can stabilize the outlet pressure of the oil replenishment pump source. The test bench is used to place the test piece and the high and low temperature alternating test box. The high and low temperature alternating test box provides a high and low temperature environment for the test piece. The temperature-controlled oil source is used to control the oil temperature of the heat exchange device. The servo control system includes a servo valve, and the pressurized thermal isolation system includes a servo booster cylinder, a first hydraulically controlled one-way valve, and a proportional throttle valve. When the servo valve is in the parallel position, the P port of the servo valve is connected to the A port, and the high-pressure oil enters the input chamber V1 of the servo booster cylinder from P→A→A1, pressurizes the oil in the output chamber V2, and enters the test piece through the A3 port of the heat exchange device; when the servo valve is in the cross position, the P port of the servo valve is connected to the B port, and the high-pressure oil enters the pressurized thermal isolation system from P→B through the B1 port, opens the first hydraulically controlled one-way valve, and the oil in the input chamber V1 of the servo booster cylinder enters the normal temperature oil source through the first hydraulically controlled one-way valve and the T2 port of the proportional throttle valve, completing the unloading of the input chamber V1 of the servo booster cylinder, and at the same time, the oil in the test piece enters the output chamber V2.

[0008] The pressurized thermal isolation system also includes a second hydraulically controlled one-way valve, an enabling solenoid valve, and a throttle valve. When the enabling solenoid valve is in a de-energized state and the servo valve is in a cross position, the oil at port B1 opens the second hydraulically controlled one-way valve through the enabling solenoid valve, allowing the oil in the output chamber V2, the heat exchange device, and the measured component to flow through the throttle valve and T1 into the normal temperature oil source. When the enabling solenoid valve is in an energized state, the oil in the output chamber V2, the heat exchange device, and the measured component cannot be released.

[0009] The main pump source includes a first motor, a proportional pump, a first proportional relief valve and a first one-way valve. The first motor drives the proportional pump. The input port of the proportional pump is connected to the normal temperature oil source. The output port of the proportional pump is connected to the normal temperature oil source through the first proportional relief valve. The output port of the proportional pump is connected to the P port of the servo valve through the first one-way valve.

[0010] The main accumulator module includes a main accumulator, a first oil discharge switching valve, a first safety valve and a first oil discharge buffer valve. The main accumulator is connected to a normal temperature oil source through the first oil discharge buffer valve and the first oil discharge switching valve, and the main accumulator is connected to a normal temperature oil source through the first safety valve. The main accumulator is connected to the outlet of the main pump source.

[0011] The pressurized thermal isolation system further includes a second one-way valve and a liquid discharge ball valve, both of which are connected to the output chamber V2.

[0012] The oil charge pump source includes a second motor, an oil charge pump, a second proportional relief valve, and a third one-way valve. The second motor drives the oil charge pump. The input port of the oil charge pump is connected to the normal temperature oil source. The output port of the oil charge pump is connected to the normal temperature oil source through the second proportional relief valve. The output port of the oil charge pump is connected to the output chamber V2 through the third one-way valve and the second one-way valve.

[0013] The oil-making accumulator module includes an oil-making accumulator, a second oil-discharge switching valve, a second safety valve, and a second oil-discharge buffer valve. The oil-making accumulator is connected to a normal-temperature oil source through the second oil-discharge buffer valve and the second oil-discharge switching valve, and the oil-making accumulator is connected to a normal-temperature oil source through the second safety valve. The oil-making accumulator is connected to the outlet of the oil-making pump source.

[0014] The heat exchange device includes a heat exchange liner, a heating coil, a cooling coil and a heat-insulating and cold-insulating shell. The heating coil and the cooling coil are wound around the heat exchange liner and the outermost layer is covered by the heat-insulating and cold-insulating shell.

[0015] The temperature-controlled oil source includes a first servo motor, a magnetic high-temperature pump, a high-temperature oil tank, a first ball valve, a high-temperature electric heater, a second servo motor, a magnetic low-temperature pump, a low-temperature oil tank, a second ball valve, and a liquid nitrogen cooler. The high-temperature electric heater heats the medium in the high-temperature oil tank to a required high temperature, and the liquid nitrogen cooler cools the medium in the low-temperature oil tank to a required low temperature. The medium is respectively transported to the heating coil and the cooling coil by the magnetic high-temperature pump and the magnetic low-temperature pump for heat exchange. The magnetic high-temperature pump is driven by the first servo motor, and the magnetic low-temperature pump is driven by the second servo motor.

[0016] Its flow requirements are calculated using the following steps:

[0017] A total of n DUTs are tested simultaneously, the pulsation test frequency is fHz, and the maximum pressure is P max , the minimum pressure is P min , when filling, from the lowest pressure P min To the maximum pressure P max The filling volume is V0, and the pressure level of the servo valve is P v ;

[0018] The main pump source and the main accumulator module set pressure are determined, and the main pump source and the main accumulator module set pressure P p The same pressure rating as the servo valve, i.e. P p =P v ;

[0019] The boost ratio of the servo booster cylinder is determined, and the servo valve outlet pressure should not be higher than The boost ratio of the servo booster cylinder is:

[0020] System flow determination: Assuming that the filling and draining times of the tested component are the same, the pressure rise time at fHz is: The pressure rise rate requirement is

[0021] The oil compression flow rate on the side of the input chamber V1 is:

[0022]

[0023] Where, is the pressure rise rate, E is the elastic modulus of the oil, V1 is the volume of the input chamber V1, and V6 is the volume of the pipeline on the side of the input chamber V1;

[0024] The oil compression flow rate on the side of the output chamber V2 is:

[0025]

[0026] Where V2 is the volume of the output chamber V2, V4 is the volume of the heat exchange tank of the heat exchange device, and V5 is the volume of the pipeline on the output chamber V2 side;

[0027] The flow requirement of the extreme working condition endurance test system of the tested piece is: r =2λfnV0+Δq1+λΔq2.

[0028] The beneficial effects of the present invention are as follows: a servo valve control system is used to realize high-frequency endurance testing; a pressurized thermal isolation system is designed to overcome the limitation of the maximum pressure of an ordinary servo valve to 35 MPa, so that the maximum loading pressure of the accumulator under test is increased to 75 MPa, and at the same time, the hydraulic source medium is separated from the medium of the accumulator under test, which can overcome the limitation that the operating temperature of the core hydraulic components (hydraulic pump, servo valve, proportional relief valve, etc.) is generally below 100°C, so that the test temperature of the accumulator under test can reach 150°C and as low as -55°C. At the same time, the pressurized thermal isolation system also greatly reduces the power of high-temperature heating and low-temperature cooling, reducing the cost and space occupation of high-power heating / cooling equipment; through the high-frequency reversing of the servo valve, a high-frequency working condition of 20Hz is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a block diagram of the accumulator extreme working condition endurance test system of the present invention;

[0030] Figure 2 This is a hydraulic principle diagram of the accumulator extreme working condition endurance test system of the present invention;

[0031] Figure 3 This is a schematic structural diagram of the pressurized thermal isolation system of the accumulator extreme working condition endurance test system of the present invention;

[0032] Figure 4This is a schematic diagram of the installation structure of the servo booster cylinder of the accumulator extreme working condition endurance test system of the present invention.

[0033] In the figure: 1-normal temperature oil source, 2-main pump source, 3-main accumulator module, 4-servo control system, 5-boost thermal isolation system, 6-supply oil pump source, 7-supply oil accumulator module, 8-heat exchange device, 9-test bench, 10-temperature controlled oil source, 2.1-first motor, 2.2-proportional pump, 2.3-first proportional relief valve, 2.4-first check valve, 3.1-main accumulator, 3.2-first oil discharge switching valve, 3.3-first safety valve, 3.4-first oil discharge buffer valve, 4.1-servo valve , 4.2-unloading buffer valve, 4.3-first pressure sensor, 5.1-servo booster cylinder, 5.2-first hydraulically controlled one-way valve, 5.3-second hydraulically controlled one-way valve, 5.4-proportional throttle valve, 5.5-enabling solenoid valve, 5.6-throttle valve, 5.7-second one-way valve, 5.8-liquid discharge ball valve, 6.1-second motor, 6.2-oil supply pump, 6.3-second proportional relief valve, 6.4-third one-way valve, 7.1-oil supply accumulator, 7.2-second oil discharge switch valve, 7.3-second safety Valve, 7.4-Second oil discharge buffer valve, 8.1-Heat exchange liner, 8.2-Heating coil, 8.3-Cooling coil, 8.4-Insulation shell, 9.1-Temperature sensor, 9.2-Second pressure sensor, 9.3-High and low temperature alternating test chamber, 10.1-First servo motor, 10.2-Magnetic high temperature pump, 10.3-High temperature oil tank, 10.4-First ball valve, 10.5-High temperature electric heater, 10.6-Second servo motor, 10.7-Magnetic low temperature pump, 10.8-Low temperature Oil tank, 10.9-second ball valve, 10.10-liquid nitrogen cooler, 5.1.1-input chamber cylinder, 5.1.2-output chamber cylinder, 5.1.3-third pressure sensor, 5.1.4-fourth pressure sensor, 5.1.5-piston, 5.1.6-piston rod, 5.1.7-magnetostrictive displacement sensor, 5.1.8-magnetic ring, 5.1.9-piston grid ring, 5.1.10-piston guide ring, 5.1.11-piston rod grid ring, 5.1.12-piston rod guide ring. DETAILED DESCRIPTION

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0035] like Figure 1 As shown, an accumulator extreme working condition durability test system includes a normal temperature oil source 1, a main pump source 2, a main accumulator module 3, a servo control system 4, a pressurization thermal isolation system 5, a supplementary oil pump source 6, a supplementary oil accumulator module 7, a heat exchange device 8, a test bench 9, and a temperature-controlled oil source 10.

[0036] like Figure 2As shown, the normal temperature oil source 1 provides normal temperature oil for the entire endurance test system. It has its own cooling and circulation oil circuits, which can ensure that the oil temperature is at normal temperature and the oil cleanliness is good.

[0037] The main pump source 2 provides high-pressure oil for the accumulator extreme working condition endurance test system, and includes a first motor 2.1, a proportional pump 2.2 driven by the motor, a first proportional relief valve 2.3 for adjusting the output pressure of the main pump source 2, and a first one-way valve 2.4 to prevent oil backflow.

[0038] The main accumulator module 3 can stabilize the outlet pressure of the main pump source 2, and includes a main accumulator 3.1 for charging and discharging oil, a first oil discharge switching valve 3.2, a first safety valve 3.3 and a first oil discharge buffer valve 3.4.

[0039] The servo control system 4 is used to perform cyclic loading on the accumulator under test, and comprises a servo valve 4.1, an unloading buffer valve 4.2, and a first pressure sensor 4.3 for detecting the inlet pressure of the servo valve 4.1.

[0040] The boost thermal isolation system 5 includes a servo booster cylinder 5.1, a first hydraulically controlled one-way valve 5.2 for unloading the input chamber of servo booster cylinder 5.1, a second hydraulically controlled one-way valve 5.3 for unloading the output chamber of servo booster cylinder 5.1, a proportional throttle valve 5.4 for controlling the unloading speed of the input chamber of servo booster cylinder 5.1, an enabling solenoid valve 5.5 for the accumulator under test, a throttle valve 5.6 for controlling the unloading speed of the output chamber of servo booster cylinder 5.1, a second one-way valve 5.7 to prevent backflow of oil in the output chamber of servo booster cylinder 5.1, and a drain ball valve 5.8 for the output chamber of servo booster cylinder 5.1.

[0041] The oil replenishment pump source 6 replenishes leaked oil for the accumulator extreme operating condition endurance test system, and includes a second motor 6.1, an oil replenishment pump 6.2 driven by the motor, a second proportional relief valve 6.3 for adjusting the output pressure of the oil replenishment pump source 6, and a third one-way valve 6.4 to prevent oil backflow.

[0042] The oil replenishment accumulator module 7 can stabilize the outlet pressure of the oil replenishment pump source 6, and includes an oil replenishment accumulator 7.1 for charging and discharging oil, a second oil discharge switching valve 7.2, a second safety valve 7.3 and a second oil discharge buffer valve 7.4.

[0043] The heat exchange device 8 comprises a heat exchange liner 8.1 for storing high and low temperature oils, a heating coil 8.2, a cooling coil 8.3 and a heat-insulating and cold-insulating outer shell 8.4.

[0044] The test bench 9 is used to place the test piece and the high and low temperature alternating test box 9.3, including a temperature sensor 9.1 for detecting the inlet temperature of the test piece, a second pressure sensor 9.2 for detecting the inlet pressure of the test piece, and the high and low temperature alternating test box 9.3 providing a high and low temperature environment for the test piece.

[0045] The temperature-controlled oil source 10 is used to control the oil temperature of the heat exchange device 8 and includes a first servo motor 10.1 with adjustable speed, a magnetic high-temperature pump 10.2, a high-temperature oil tank 10.3, a first ball valve 10.4, a high-temperature electric heater 10.5, a second servo motor 10.6 with adjustable speed, a magnetic low-temperature pump 10.7, a low-temperature oil tank 10.8, a second ball valve 10.9, and a liquid nitrogen cooler 10.10.

[0046] like Figure 3 As shown, the boost thermal isolation system 5 is integrated into a single unit. A first hydraulically controlled check valve 5.2, a proportional throttle valve 5.4, and an enabling solenoid valve 5.5 are integrated into the input chamber of the servo booster cylinder 5.1 via a valve block. Servo valve 4.1 is also integrated into the input chamber of the servo booster cylinder 5.1, eliminating the need for long control lines and significantly improving the responsiveness of the servo valve control system. A second hydraulically controlled check valve 5.3, which unloads the output chamber, a throttle valve 5.6 for controlling the discharge rate of the output chamber V2, and a second check valve 5.7 are integrated into the output chamber of the servo booster cylinder 5.1.

[0047] like Figure 4 As shown, the servo booster cylinder 5.1 includes an input chamber cylinder 5.1.1, an output chamber cylinder 5.1.2, a third pressure sensor 5.1.3 for measuring the input chamber pressure, a fourth pressure sensor 5.1.4 for measuring the output chamber pressure, a piston 5.1.5, a piston rod 5.1.6, a magnetostrictive displacement sensor 5.1.7 for measuring the displacement and speed of the piston cylinder, a magnetic ring 5.1.8 of the magnetostrictive displacement sensor, a piston grid ring 5.1.9, a piston guide ring 5.1.10, a piston rod grid ring 5.1.11 and a piston rod guide ring 5.1.12.

[0048] like Figure 2 As shown, the main accumulator module 3 is filled with oil to a set pressure by the main pump source 2. When a pressure spike occurs at the outlet of the main pump source 2, the main accumulator 3.1 can absorb the pressure spike by filling with oil. If the oil from the main pump source 2 is not replenished in time, the stored high-pressure oil can be released to replenish the system and maintain the stability of the pressure at the P port of the servo valve 4.1.

[0049] like Figure 2As shown, servo valve 4.1 is used to control the high-frequency charging and discharging of the accumulator under test. When servo valve 4.1 is in the parallel position, port P of servo valve 4.1 is connected to port A, and high-pressure oil enters the input chamber V1 of servo booster cylinder 5.1 from P→A→A1, pushing piston 5.1.5 and piston rod 5.1.6 of servo booster cylinder 5.1 to increase the pressure of the oil in output chamber V2, and then enters the accumulator under test (i.e., the test piece) through port A3 of heat exchange device 8; when servo valve 4.1 is in the cross position, port P of servo valve 4.1 is connected to port B, and high-pressure oil flows from P→B, and the flow rate is adjusted by unloading buffer valve 4.2. The oil then enters the pressurized thermal isolation system 5 through port B1, opening the first hydraulically controlled check valve 5.2. The oil in the input chamber V1 of the servo booster cylinder 5.1 flows through the first hydraulically controlled check valve 5.2 and port T2 of the proportional throttle valve 5.4 into the normal-temperature oil source 1, unloading the input chamber V1 of the servo booster cylinder 5.1. Simultaneously, the piston 5.1.5 and piston rod 5.1.6 retract under the high pressure in the output chamber V2, allowing the oil in the accumulator under test to enter the output chamber V2, unloading the output chamber V2, the heat exchange liner 8.1, and the accumulator under test. The discharge and unloading speed of the accumulator under test are determined by the opening size of the proportional throttle valve 5.4.

[0050] like Figure 2 As shown, when the enabling solenoid valve 5.5 is de-energized and the servo valve 4.1 is in the crossover position, oil at port B1 flows through the enabling solenoid valve 5.5, opening the second hydraulically controlled check valve 5.3. This allows the oil in the output chamber V2, the heat exchange liner 8.1, and the accumulator under test to flow through throttle valve 5.6, through T1, and into the normal-temperature oil source 1. The draining and unloading rates are determined by the opening size of throttle valve 5.6. When the enabling solenoid valve 5.5 is energized, the oil in the output chamber V2, the heat exchange liner 8.1, and the accumulator under test cannot be released, facilitating a reciprocating cycle to perform pressurized endurance testing on the accumulator under test. The accumulator under test's manual drain ball valve 5.8 allows for manual draining of the accumulator. However, due to the hazardous nature of high and low-temperature oils, this operation should only be performed in emergency situations.

[0051] like Figure 4 As shown, the input chamber V1 is formed between the input chamber cylinder 5.1.1 and the piston 5.1.5 of the servo booster cylinder 5.1, the output chamber V2 is formed between the output chamber cylinder 5.1.2 and the piston rod 5.1.6, and the drain chamber V3 is formed between the input chamber cylinder 5.1.1 and the piston rod 5.1.6. The pressure of the input chamber V1 is P1 and the diameter is D. The pressure of the output chamber V2 is P2 and the diameter is d. Since the force on the piston rod is balanced, that is, P1*D 2 =P2*d 2 , we can get P2 / P1=D 2 / d 2The ratio of the pressure in output chamber V2 to the pressure in input chamber V1 is the ratio of the piston diameter D to the square of the piston rod diameter d, allowing servo booster cylinder 5.1 to achieve boosting. Furthermore, due to the isolation between piston 5.1.5, piston rod 5.1.6, and drain chamber V3, the oil in input chamber V1 and output chamber V2 are isolated from each other, resulting in virtually no heat exchange. Heat exchange device 8 can heat and cool only the oil in output chamber V2, heat exchange liner 8.1, the accumulator under test, and a small amount of piping, unaffected by the ambient temperature oil in input chamber V1. This significantly reduces heating and cooling power. Drain chamber V3 is connected to ambient temperature oil source 1 via port S1 to accommodate changes in V3's volume. The ambient temperature oil in source 1 can also be used to reduce the temperature of the piston and piston rod, enhancing the thermal isolation of servo booster cylinder 5.1.

[0052] like Figure 2 As shown, the oil replenishment pump source 6 and the oil replenishment accumulator module 7 cooperate to replenish the leakage of the output chamber V2 of the servo booster cylinder 5.1, the heat exchange device 8 and the accumulator under test, and can maintain the minimum pressure at the inlet of the accumulator under test.

[0053] like Figure 2 As shown, the charge accumulator module 7 is charged with oil by the charge pump source 6 according to the minimum pressure requirement at the inlet of the accumulator under test. When leakage occurs in the output chamber V2 of the servo booster cylinder 5.1, the heat exchange device 8, or the accumulator under test, causing a pressure drop, the oil in the charge accumulator 7.1 is replenished to the system to maintain a stable minimum pressure at the inlet of the accumulator under test.

[0054] like Figure 2 As shown, heat exchange device 8 performs heat exchange between the output chamber V2 of servo booster cylinder 5.1 and the oil in the accumulator under test to control the oil temperature. Heat exchange liner 8.1 is made of high- and low-temperature alloy steel and is customized according to the test conditions. It can withstand high pressures up to 70 MPa and high and low temperatures of -55°C to 150°C. A heating coil 8.2 and a cooling coil 8.3 are wrapped around the outside for heating and cooling, respectively. The outermost layer is covered with a thermal insulation shell 8.4 to reduce heat exchange with the outside world.

[0055] like Figure 2 As shown, a temperature-controlled oil source 10 provides high and low-temperature media to the heat exchange device 8, with the media temperature ranging from -55°C to 150°C. A high-temperature electric heater 10.5 heats the media in the high-temperature oil tank 10.3 to the desired high temperature, while a liquid nitrogen cooler 10.10 cools the media in the low-temperature oil tank 10.8 to the desired low temperature. This fluid is then transported to the heating coil 8.2 and cooling coil 8.3 by a magnetic high-temperature pump 10.2 and a magnetic low-temperature pump 10.7, respectively, for heat exchange. A first servo motor 10.1 and a second servo motor 10.6, both with adjustable speeds, control the flow rates of the high and low-temperature cooling media, enabling precise control of the heat exchange rate and achieving accurate temperature control.

[0056] like Figure 2 As shown, a total of n accumulators are tested simultaneously, the pulsation test frequency is fHz, and the maximum pressure is P max , the minimum pressure is P min , when filling, from the lowest pressure P min To the maximum pressure P max The filling volume is V0, and the pressure level of the servo valve 4.1 is P v The following methods are used to determine the system parameters of the present invention:

[0057] (1) The set pressure of the main pump source 2 and the main accumulator module 3 is determined. The set pressure P of the main pump source 2 and the main accumulator module 3 is determined. p The pressure level can be the same as that of servo valve 4.1, that is, P p =P v ;

[0058] (2) Determine the boost ratio of the servo booster cylinder 5.1. In order to achieve the best control effect, the outlet pressure of the servo valve 4.1 should not be higher than Then the boost ratio of the servo booster cylinder 5.1 should be:

[0059]

[0060] (3) Determination of system flow.

[0061] When determining the system flow, in addition to the accumulator's oil filling requirements, it is also necessary to consider the oil compression in the chamber and make corrections to the flow requirements.

[0062] Assuming that the charging and discharging time of the accumulator is the same, the pressure rise time at fHz is: The pressure rise rate requirement is

[0063] The oil compression flow rate on the upstream side of piston 5.1.5 and piston rod 5.1.6 (i.e., the side where input chamber V1 is located) is:

[0064]

[0065] Where, is the pressure rise rate (MPa / s), E is the elastic modulus of the oil (MPa), V1 is the volume of the input chamber V1, and V6 is the volume of the upstream pipeline.

[0066] The oil compression flow rate on the downstream side of the piston 5.1.5 and the piston rod 5.1.6 (i.e., the side where the output chamber V2 is located) is:

[0067]

[0068] Where V2 is the volume of the output chamber V2, V4 is the volume of the heat exchange liner 8.1, and V5 is the volume of the downstream side pipeline.

[0069] Therefore, the flow requirement of the accumulator extreme working condition endurance test system is:

[0070] q r =2λfnV0+Δq1+λΔq2

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An accumulator extreme working condition durability test system, characterized in that: The invention comprises a normal temperature oil source (1), a main pump source (2), a main accumulator module (3), a servo control system (4), a pressurized thermal isolation system (5), an oil replenishment pump source (6), an oil replenishment accumulator module (7), a heat exchange device (8), a test bench (9), and a temperature control oil source (10). The normal temperature oil source (1) provides normal temperature oil, the main pump source (2) provides the normal temperature oil of the normal temperature oil source (1) to the pressurized thermal isolation system (5) through the servo control system (4), and the main accumulator The oil supply module (3) can stabilize the outlet pressure of the main pump source (2), the oil supply pump source (6) can replenish the leaked oil, the oil supply accumulator module (7) can stabilize the outlet pressure of the oil supply pump source (6), the test bench (9) is used to place the test piece and the high and low temperature alternating test box (9.3), the high and low temperature alternating test box (9.3) provides a high and low temperature environment for the test piece, the temperature control oil source (10) is used to control the oil temperature of the heat exchange device (8), and the servo control system (4) includes Servo valve (4.1), the pressurized thermal isolation system (5) includes a servo booster cylinder (5.1), a first hydraulically controlled one-way valve (5.2), and a proportional throttle valve (5.4). When the servo valve (4.1) is in the parallel position, the P port of the servo valve (4.1) is connected to the A port, and the high-pressure oil enters the input chamber V1 of the servo booster cylinder (5.1) from P→A→A1, pressurizes the oil in the output chamber V2, and enters the measured object through the A3 port of the heat exchange device (8); when ... 1) When in the cross position, the P port of the servo valve (4.1) is connected to the B port, and the high-pressure oil flows from P to B and enters the booster thermal isolation system (5) from the B1 port, opening the first hydraulic-controlled one-way valve (5.2). The oil in the input chamber V1 of the servo booster cylinder (5.1) enters the normal temperature oil source (1) through the first hydraulic-controlled one-way valve (5.2) and the T2 port of the proportional throttle valve (5.4), completing the unloading of the input chamber V1 of the servo booster cylinder (5.1). At the same time, the oil in the measured part enters the output chamber V2.

2. The accumulator extreme working condition durability testing system according to claim 1, characterized in that: The pressurized thermal isolation system (5) further comprises a second hydraulically controlled one-way valve (5.3), an enabling electromagnetic valve (5.5), and a throttle valve (5.6). When the enabling electromagnetic valve (5.5) is in a non-energized state and the servo valve (4.1) is in a cross position, the oil at port B1 opens the second hydraulically controlled one-way valve (5.3) through the enabling electromagnetic valve (5.5), allowing the oil in the output chamber V2, the heat exchange device (8), and the measured component to flow through T1 through the throttle valve (5.6) and enter the normal temperature oil source (1). When the enabling electromagnetic valve (5.5) is in an energized state, the oil in the output chamber V2, the heat exchange device (8), and the measured component cannot be released.

3. The accumulator extreme working condition durability testing system according to claim 1, characterized in that: The main pump source (2) comprises a first motor (2.1), a proportional pump (2.2), a first proportional relief valve (2.3) and a first one-way valve (2.4); the first motor (2.1) drives the proportional pump (2.2); the input port of the proportional pump (2.2) is connected to the normal temperature oil source (1); the output port of the proportional pump (2.2) is connected to the normal temperature oil source (1) via the first proportional relief valve (2.3); and the output port of the proportional pump (2.2) is connected to the P port of the servo valve (4.1) via the first one-way valve (2.4).

4. The accumulator extreme working condition durability testing system according to claim 1, characterized in that: The main accumulator module (3) comprises a main accumulator (3.1), a first oil discharge switching valve (3.2), a first safety valve (3.3) and a first oil discharge buffer valve (3.4); the main accumulator (3.1) is connected to a normal temperature oil source (1) via the first oil discharge buffer valve (3.4) and the first oil discharge switching valve (3.2); the main accumulator (3.1) is connected to the normal temperature oil source (1) via the first safety valve (3.3); and the main accumulator (3.1) is connected to the outlet of a main pump source (2).

5. The accumulator extreme working condition durability testing system according to claim 1, characterized in that: The pressurized thermal isolation system (5) further comprises a second one-way valve (5.7) and a liquid discharge ball valve (5.8), and both the second one-way valve (5.7) and the liquid discharge ball valve (5.8) are connected to the output chamber V2.

6. The accumulator extreme working condition durability testing system according to claim 5, characterized in that: The oil replenishment pump source (6) comprises a second motor (6.1), an oil replenishment pump (6.2), a second proportional relief valve (6.3), and a third one-way valve (6.4). The second motor (6.1) drives the oil replenishment pump (6.2). The input port of the oil replenishment pump (6.2) is connected to the normal temperature oil source (1). The output port of the oil replenishment pump (6.2) is connected to the normal temperature oil source (1) via the second proportional relief valve (6.3). The output port of the oil replenishment pump (6.2) is connected to the output chamber V2 via the third one-way valve (6.4) and the second one-way valve (5.7).

7. The accumulator extreme working condition durability testing system according to claim 1, characterized in that: The oil replenishment accumulator module (7) comprises an oil replenishment accumulator (7.1), a second oil discharge switching valve (7.2), a second safety valve (7.3) and a second oil discharge buffer valve (7.4); the oil replenishment accumulator (7.1) is connected to a normal temperature oil source (1) via the second oil discharge buffer valve (7.4) and the second oil discharge switching valve (7.2); the oil replenishment accumulator (7.1) is connected to the normal temperature oil source (1) via the second safety valve (7.3); and the oil replenishment accumulator (7.1) is connected to the outlet of an oil replenishment pump source (6).

8. The accumulator extreme working condition durability testing system according to claim 1, characterized in that: The heat exchange device (8) comprises a heat exchange liner (8.1), a heating coil (8.2), a cooling coil (8.3) and a heat-insulating and cold-insulating outer shell (8.4); the heat exchange liner (8.1) is externally wound with the heating coil (8.2) and the cooling coil (8.3) and is covered on the outermost layer by the heat-insulating and cold-insulating outer shell (8.4).

9. The accumulator extreme working condition durability testing system according to claim 8, characterized in that: The temperature-controlled oil source (10) comprises a first servo motor (10.1), a magnetic high-temperature pump (10.2), a high-temperature oil tank (10.3), a first ball valve (10.4), a high-temperature electric heater (10.5), a second servo motor (10.6), a magnetic low-temperature pump (10.7), a low-temperature oil tank (10.8), a second ball valve (10.9), and a liquid nitrogen cooler (10.10). The high-temperature electric heater (10.5) connects the high-temperature oil tank (10.3) to the liquid nitrogen cooler (10.11). The medium in the low-temperature oil tank (10.8) is heated to a desired high temperature, and the liquid nitrogen cooler (10.10) cools the medium in the low-temperature oil tank (10.8) to a desired low temperature. The medium is respectively transported to the heating coil (8.2) and the cooling coil (8.3) by the magnetic high-temperature pump (10.2) and the magnetic low-temperature pump (10.7) for heat exchange. The magnetic high-temperature pump (10.2) is driven by the first servo motor (10.1), and the magnetic low-temperature pump (10.7) is driven by the second servo motor (10.6).

10. The accumulator extreme working condition durability testing system according to claim 1, characterized in that: Its flow requirements are calculated using the following steps: A total of n DUTs are tested simultaneously, the pulsation test frequency is fHz, and the maximum pressure is P max , the minimum pressure is P min , when filling, from the lowest pressure P min To the maximum pressure P max The filling volume is V0, and the pressure level of the servo valve (4.1) is P v ; The main pump source (2) and the main accumulator module (3) set pressure to determine the main pump source (2) and the main accumulator module (3) set pressure P p The same pressure level as the servo valve (4.1), that is, P p =P v ; The boost ratio of the servo booster cylinder (5.1) is determined, and the outlet pressure of the servo valve (4.1) should not be higher than Then the boost ratio of the servo booster cylinder (5.1) is: System flow determination: Assuming that the filling and draining times of the tested component are the same, the pressure rise time at fHz is: The pressure rise rate requirement is The oil compression flow rate on the side of the input chamber V1 is: Where, is the pressure rise rate, E is the elastic modulus of the oil, V1 is the volume of the input chamber V1, and V6 is the volume of the pipeline on the side of the input chamber V1; The oil compression flow rate on the side of the output chamber V2 is: Wherein, V2 is the volume of the output chamber V2, V4 is the volume of the heat exchange liner (8.1) of the heat exchange device (8), and V5 is the volume of the pipeline on the side of the output chamber V2; The flow requirement of the extreme working condition endurance test system of the tested piece is: r =2λfnV0+Δq1+λΔq2.

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