CN115949652A - Hydraulic load simulation active and passive and multi-working-condition loading method and hydraulic system - Google Patents
Hydraulic load simulation active and passive and multi-working-condition loading method and hydraulic system Download PDFInfo
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Abstract
The invention provides a hydraulic load simulation active-passive and multi-working-condition loading method and a hydraulic system. According to the invention, two modes of pressure reduction and overflow of the three-way proportional pressure reduction overflow valve and two modes of active loading and passive loading of hydraulic load simulation can be effectively realized by combining the loading pump and the oil supplementing pump for oil supply. In addition, under the active loading mode, active extension and active retraction of the hydraulic cylinder can be simulated by adjusting the load, and the pressure of the active extension and the active retraction can be adjusted by a three-way proportional pressure reducing overflow valve, so that simulation of four working conditions, namely positive and negative load working conditions 1, positive and negative load working conditions 2, negative load working conditions 1, negative load working conditions 2 and the like can be realized.
Description
Technical Field
The invention belongs to the field of hydraulic transmission and control, and particularly relates to a hydraulic load simulation active and passive multi-working-condition loading method and a hydraulic system.
Background
In the field of hydraulic transmission, when the response characteristics of an actuating mechanism of a test device, an electro-hydraulic control algorithm and the like are tested and verified, the actual working condition of test equipment needs to be simulated as much as possible, and the load faced by the actuating mechanism is simulated in a mechanical loading or hydraulic loading mode. The hydraulic load simulation is to simulate the load value of an actuator such as a tested hydraulic cylinder or a hydraulic motor by giving specific resistance or torque to the hydraulic cylinder or the hydraulic motor so as to simulate and verify the response and self-regulation performance of the actuator under the condition of complicated and variable external loads.
In linear motion, hydraulic load simulation is mainly realized by combining a load simulation hydraulic cylinder with a proportional overflow valve, a proportional throttle valve or a balance valve, load force is simulated by setting the opening degree of a valve port to form certain back pressure, and the set pressed magnitude can be controlled by an external electric signal. When the proportional overflow valve is used, the opening pressure of the proportional overflow valve can be set through an external electric signal, and the opening pressure can be used as load simulation force. When a proportional throttle valve is used, the opening degree of the throttle valve can be controlled through an external signal, and different opening degrees correspond to different fluid resistances so as to simulate the magnitude of an external load force.
In linear motion, the existing hydraulic load simulation modes are all passive loading modes, namely a load simulation hydraulic cylinder is combined with a proportional overflow valve, a proportional throttle valve or a balance valve, based on a hydraulic resistance control principle, load force is simulated by setting the opening degree of a valve port to form certain back pressure, and the load simulation hydraulic cylinders are all passive, namely the load simulation hydraulic cylinders cannot actively exert force to extend or retract and cannot actively generate and exert load force. Only when the main power of the external actuating mechanism is applied to the load hydraulic cylinder, the load simulation hydraulic system can form a certain load force through the proportional overflow valve, the proportional throttle valve or the balance valve, and when the external actuating mechanism does not have the main power applied to the load simulation hydraulic cylinder, the load simulation cannot reversely apply a load acting force, so that the load simulation function cannot be completed.
In general, the conventional load simulation fails when the following conditions are required:
(1) The load simulation device comprises a positive load working condition 1 and a negative load working condition 1, wherein the positive power of an external actuating mechanism is thrust, and the load simulation cylinder is required to actively extend out when a load acting force opposite to the movement direction of the external actuating mechanism needs to be actively applied, and the active load working condition 1 cannot be realized due to the fact that an active hydraulic loading power source is not available and the direction of hydraulic fluid cannot be changed in the traditional load simulation mode.
(2) The positive load working condition 2 is a positive load working condition 2, namely the main power of the external actuating mechanism is tensile force, and the load simulation cylinder is required to actively retract when a load acting force opposite to the movement direction of the external actuating mechanism needs to be actively applied, and the active load working condition 2 cannot be realized due to the fact that an active hydraulic loading power source is not available and the direction of hydraulic fluid cannot be changed in the traditional load simulation mode.
(3) The load simulation system comprises a load simulation cylinder, a load simulation power source and a load simulation power source, wherein the load simulation cylinder is used for simulating the load of the external execution mechanism, and the load simulation cylinder is used for simulating the load of the external execution mechanism.
(4) The load simulation device comprises a load simulation cylinder, a load simulation power source, a hydraulic fluid direction changing device and a load simulation control system, wherein the load simulation cylinder is driven by the external actuating mechanism to move in the same direction as the external actuating mechanism, and the load simulation cylinder is driven by the external actuating mechanism to extend out of the load simulation cylinder.
In addition, the traditional load simulation mode can only complete the loading under a single working condition, and cannot simultaneously complete the load simulation loading modes under multiple working conditions, so that the requirement of a simulation loading test under multiple working conditions is greatly limited.
Disclosure of Invention
In view of the fact that the traditional hydraulic load simulation loading system can only realize passive loading and cannot realize active loading; only the simulation of the positive load working condition can be carried out, and the simulation of the negative load working condition cannot be realized; the simulation of single working condition can only be realized, and the requirements of the simulation loading test of multiple working conditions cannot be met. The invention provides a hydraulic load simulation active and passive and multi-working condition loading method and a hydraulic system aiming at the defects of a traditional hydraulic load simulation loading system. The invention provides a hydraulic load simulation active-passive and multi-working-condition loading method which is mainly realized by a hydraulic system consisting of a loading hydraulic pump, an oil supplementing pump, a three-way proportional pressure reduction overflow valve group, a load simulation hydraulic cylinder, an execution hydraulic cylinder, a motor, a three-position four-way reversing valve, an overflow valve, an unloading valve, a one-way valve, an oil tank and the like.
The technical scheme of the invention is as follows:
the invention provides a hydraulic load simulation active and passive and multi-working-condition loading method and a hydraulic system, wherein the system comprises an oil tank, a loading pump, an oil supplementing pump, a three-position four-way reversing valve, a first three-way proportional pressure reducing overflow valve, a second three-way proportional pressure reducing overflow valve, an execution hydraulic cylinder, a load simulation hydraulic cylinder, an overflow valve and an unloading valve;
the oil suction ports of the loading pump and the oil replenishing pump are connected with an oil tank, the P port of the three-position four-way reversing valve is connected with the oil outlet of the loading pump, the T port of the three-position four-way reversing valve is connected with the oil tank, the A port and the B port of the three-position four-way reversing valve are respectively connected with the A port of the first three-way proportional pressure reducing overflow valve and the A port of the second three-way proportional pressure reducing overflow valve, the T port of the first three-way proportional pressure reducing overflow valve and the T port of the second three-way proportional pressure reducing overflow valve are connected with the oil tank,
a rod cavity oil port and a rodless cavity oil port of the load simulation hydraulic cylinder are respectively connected with a port B of the first three-way proportional pressure reduction overflow valve and a port B of the second three-way proportional pressure reduction overflow valve;
an outlet of the oil supplementing pump is respectively connected with an A port of the first three-way proportional pressure reducing overflow valve and an A port of the second three-way proportional pressure reducing overflow valve through a second one-way valve and a third one-way valve;
the execution hydraulic cylinder is connected with a piston rod of the load simulation hydraulic cylinder through a hinge mechanism; the overflow valve and the unloading valve are connected in parallel to form a safety valve group, one end of the safety valve group is connected with the oil tank, and the other end of the safety valve group is connected with the outlet of the loading pump.
The invention also provides an active and passive multi-working-condition loading method based on the hydraulic system, which realizes two modes of active loading and passive loading of hydraulic load simulation through two modes of pressure reduction and overflow of the first three-way proportional pressure reduction overflow valve and the second three-way proportional pressure reduction overflow valve and combined oil supply of a loading pump and an oil supplementing pump;
in the passive loading mode, the three-way proportional pressure reducing overflow valve is in a reverse flow state and is in an overflow mode, and the load simulation acting force is changed by adjusting the set pressure of the three-way proportional pressure reducing overflow valve to carry out passive loading; at the moment, a loading hydraulic pump of the hydraulic system is closed, the load simulation hydraulic cylinder cannot actively extend and retract, and the oil supplementing pump is started to supplement oil required by the load simulation hydraulic cylinder;
in an active loading mode, the three-way proportional pressure reducing overflow valve is in a positive flow state and is in a pressure reducing mode, the set pressure of the three-way proportional pressure reducing overflow valve is set to change the active extension and active retraction pressures of the load simulation hydraulic cylinder, active loading is realized, and further four working condition simulations of a positive load working condition 1, a positive load working condition 2, a negative load working condition 1 and a negative load working condition 2 can be realized;
further, when a positive-load working condition 1 is simulated, working condition simulation is completed by loading a hydraulic pump and adjusting the outlet pressure of a second three-way proportional pressure reducing overflow valve of a rodless cavity oil way of the load simulation hydraulic cylinder;
when the positive and negative load working condition 2 is simulated, the working condition simulation is completed by loading the hydraulic pump and adjusting the outlet pressure of the first three-way proportional pressure reducing overflow valve of the rod cavity oil way of the load simulation hydraulic cylinder.
When a negative load working condition 1 is simulated, working condition simulation is completed by loading a hydraulic pump and adjusting the pressure of a first three-way proportional pressure reducing overflow valve of a rod cavity oil way of a load simulation hydraulic cylinder;
and when the load working condition 2 is simulated, the working condition simulation is completed by loading the hydraulic pump and adjusting the pressure of the second three-way proportional pressure reducing overflow valve of the rodless cavity oil way of the load simulation hydraulic cylinder.
Compared with the prior art, the active loading mode and the passive loading mode of the hydraulic load simulation are effectively realized by the pressure reduction and overflow modes of the three-way proportional pressure reduction overflow valve and the combined oil supply of the loading pump and the oil supplementing pump. In addition, under the active loading mode, active extension and active retraction of the hydraulic cylinder can be simulated by adjusting the load, and the pressure of the active extension and the active retraction can be adjusted by a three-way proportional pressure reducing overflow valve, so that simulation of four working conditions, namely positive and negative load working conditions 1, positive and negative load working conditions 2, negative load working conditions 1, negative load working conditions 2 and the like can be realized.
Drawings
FIG. 1 is a schematic diagram of a hydraulic system of the present invention.
The hydraulic system comprises an oil tank 1, a loading pump 2, a three-phase motor I3, a first check valve 4, an unloading valve 5, an overflow valve 6, a three-position four-way reversing valve 7, an oil supplementing pump 8, a three-phase motor II 9, a second check valve 10, a third check valve 11, a first three-way proportional pressure reducing overflow valve 12, a second three-way proportional pressure reducing overflow valve 13, a hinge mechanism 14, an execution hydraulic cylinder 15 and a load simulation hydraulic cylinder 16.
Detailed Description
The invention will be further illustrated and described with reference to specific embodiments. The described embodiments are merely exemplary of the disclosure and are not intended to limit the scope thereof. The technical features of the embodiments of the present invention can be combined correspondingly without mutual conflict.
As shown in fig. 1, a hydraulic load simulation active and passive and multi-working condition loading method and a schematic diagram of a hydraulic system are provided, the hydraulic system mainly comprises an oil tank 1, a loading pump 2, a three-phase motor i 3, a first one-way valve 4, an unloading valve 5, an overflow valve 6, a three-position four-way reversing valve 7, an oil supplementing pump 8, a three-phase motor ii 9, a second one-way valve 10, a third one-way valve 11, a first three-way proportional pressure reducing overflow valve 12, a second three-way proportional pressure reducing overflow valve 13, a hinge mechanism 14, an execution hydraulic cylinder 15 and a load simulation hydraulic cylinder 16.
The oil suction ports of the loading pump 2 and the oil replenishing pump 8 are connected with the oil tank 1, the 7P port of the three-position four-way reversing valve 7 is connected with the oil outlet of the loading pump 2, the 7T port of the three-position four-way reversing valve 7 is connected with the oil tank 1, the 7A port and the 7B port of the three-position four-way reversing valve 7 are respectively connected with the 12A port of the first three-way proportional pressure reducing overflow valve 12 and the 13A port of the second three-way proportional pressure reducing overflow valve 13, the 12T port of the first three-way proportional pressure reducing overflow valve 12 and the 13T port of the second three-way proportional pressure reducing overflow valve 13 are connected with the oil tank, and the rod cavity oil port 16A and the rodless cavity oil port 16B of the load simulation hydraulic cylinder 16 are respectively connected with the 12B port of the first three-way proportional pressure reducing overflow valve 12 and the 13B port of the second three-way proportional pressure reducing overflow valve 13. And a second check valve 4 and a third check valve 11 at the outlet of the oil supplementing pump 8 are respectively connected with a port 12A of a first three-way proportional pressure reducing overflow valve 12 and a port 13A of a second three-way proportional pressure reducing overflow valve 13. The actuating cylinder 15 is connected to the piston rod of a load simulating cylinder 16 via a joint mechanism 14. A safety valve bank formed by connecting the overflow valve 6 and the unloading valve 5 in parallel is connected in parallel on a high-pressure main oil path of the loading pump 2, namely, one end of the safety valve bank is connected with an oil tank, and the other end of the safety valve bank is connected with an outlet of the loading pump. It should be noted that the set pressure of the relief valve 6 is higher than the system limit maximum pressure to protect the normal operation of the hydraulic system, the outlet pressure of the oil supply pump 2 is generally set to be not more than 2.5Mpa, and when the system is not in operation, the electromagnet 1DT of the unloading valve 5, and the left end electromagnet 2DT and the right end electromagnet 3DT of the three-position four-way reversing valve 7 are all in a power-off state.
It should be noted that the first three-way proportional pressure reducing relief valve and the second three-way proportional pressure reducing relief valve 13 used in the hydraulic system schematic diagram 1 attached to the present invention are pilot-operated three-way proportional pressure reducing relief valves, which can be replaced by direct-acting three-way proportional pressure reducing valves, and are also within the protection scope of the present invention.
The invention can realize passive loading of traditional load simulation, can also realize active loading of load simulation, and can simulate the working conditions of positive load and negative load.
According to the passive loading method and the hydraulic system for simulating the active and passive states of the hydraulic load, the load simulation acting force can be changed by adjusting the set pressure of the first three-way proportional pressure reducing overflow valve and the second three-way proportional pressure reducing overflow valve, and then the passive loading is carried out. At the moment, a loading hydraulic pump of the hydraulic system is closed, the load simulation hydraulic cylinder cannot actively extend out or retract, and the oil supplementing pump is used for supplementing oil required by the load simulation hydraulic cylinder.
The active loading method can complete the simulation of the positive load working condition and the negative load working condition. (1) And under the positive and negative load working condition 1, namely when the main power of the external actuating mechanism is thrust and the load simulation hydraulic cylinder is required to actively apply a load acting force opposite to the movement direction of the external actuating mechanism, the working condition simulation can be completed by loading the hydraulic pump and adjusting the outlet pressure of the second three-way proportional pressure reducing overflow valve of the rodless cavity oil way of the load hydraulic cylinder. (2) And under the positive and negative load working condition 2, namely when the main power of the external actuating mechanism is tensile force and the load simulation hydraulic cylinder is required to actively apply load acting force opposite to the movement direction of the external actuating mechanism, the working condition simulation can be completed by loading the hydraulic pump and adjusting the outlet pressure of the first three-way proportional pressure reducing overflow valve of the rod cavity oil way of the load hydraulic cylinder. (3) And under the working condition 1 of the load, namely the main power of the external actuating mechanism is thrust, and when the load simulation hydraulic cylinder is required to actively apply a load acting force in the same direction as the movement direction of the external actuating mechanism, the working condition simulation can be completed by loading the hydraulic pump and adjusting the pressure of the first three-way proportional pressure reducing overflow valve of the rod cavity oil way of the load hydraulic cylinder. (4) And under the working condition 2 of the load, namely the main power of the external actuating mechanism is tensile force, and when the load simulation hydraulic cylinder is required to actively apply load acting force in the same direction as the motion direction of the external actuating mechanism, the working condition simulation can be completed by loading the hydraulic pump and adjusting the pressure of a second three-way proportional pressure reducing overflow valve of a rodless cavity oil way of the load hydraulic cylinder.
The first three-way proportional pressure reducing overflow valve and the second three-way proportional pressure reducing overflow valve have an oil inlet, an oil outlet and an overflow port, and have both a pressure reducing function and an overflow function. The oil inlet is connected with a high-pressure main oil way, the oil outlet is connected with a working oil way, and the overflow port is connected with an oil tank. Through the internal adjusting device, the pressure of the inlet high-pressure main oil way is adjusted and reduced to the pressure reduction pressure required by the oil outlet, and meanwhile, the full-flow overflow function from the oil outlet to the overflow port is achieved. When the liquid flow reversely flows, if the pressure of the oil outlet is smaller than the set required pressure, the reverse flow from the oil outlet to the oil inlet is also provided. The pressure drop between the oil outlet and the overflow can be set and adjusted by an external control signal.
The hydraulic load simulation active and passive and multi-working condition loading method and the hydraulic system provided by the invention are further explained by combining a hydraulic system schematic diagram 1 as follows:
(1) Load simulation passive loading method for hydraulic system
When the active force of the actuating hydraulic cylinder 15 is thrust and acts on the piston rod of the load simulating hydraulic cylinder 16 through the hinge mechanism 14 to form a thrust force, the passive loading method provides a passive load loading force to the load simulating hydraulic cylinder 16, wherein the direction of the load loading force is opposite to the extending direction of the actuating hydraulic cylinder. Specifically, the loading pump 2 is in a closed state, the oil supplementing pump 8 is in an open state, the electromagnet 1DT of the unloading valve 5 of the hydraulic system is powered on to disconnect an oil path thereof, the electromagnet 2DT at the left end of the three-position four-way reversing valve 7 is powered off, the electromagnet 3DT at the right end of the three-position four-way reversing valve is powered on to connect a port 7P with a port 7B thereof, and a port 7A is connected with a port 7T thereof. Under the thrust action of the execution hydraulic cylinder 15, the load simulation hydraulic cylinder 16 retracts rightwards, oil in a rod cavity of the load simulation hydraulic cylinder is supplemented through the oil supplementing pump 8, oil in a rodless cavity of the load simulation hydraulic cylinder flows to the second three-way proportional pressure reducing overflow valve 13 through the port 16B, the second three-way proportional pressure reducing overflow valve 13 is in a reverse flow state at the moment, the oil flows to the port 13A through the port 13B, and the outlet of the port 13A is not connected with an oil tank, so that the pressure of the port 13A and the pressure of the port 13B are higher and higher. When the pressure of the port 13B rises to the set pressure of the second three-way proportional pressure-reducing overflow valve 13, the port 13B is communicated with the port 13T and overflows, the port 13A is disconnected from the port 13B, and the second three-way proportional pressure-reducing overflow valve 13 is in an overflow mode at the moment to form set load simulation pressure so as to achieve the purpose of passive loading. It should be noted that, with the second three-way proportional pressure reducing relief valve 13, when the pressure of the port 13B is lower than the external set pressure, the port 13B communicates with the port 13A, and when the pressure of the port 13B is higher than the external set pressure, the port 13T communicates with the open relief mode. The set pressure of the second three-way proportional pressure reducing relief valve 13 can be set by an external control signal.
When the active force of the actuating hydraulic cylinder 15 is a tensile force and acts on the piston rod of the load-simulating hydraulic cylinder 16 through the hinge mechanism 14 to form a tensile force, the passive loading method provides a passive load loading force to the load-simulating hydraulic cylinder 16, wherein the direction of the load loading force is opposite to the retracting direction of the actuating hydraulic cylinder. Specifically, the loading pump 2 is in a closed state, the oil replenishing pump 8 is in an open state, the electromagnet 1DT of the unloading valve 5 of the hydraulic system is powered on to disconnect an oil path thereof, the electromagnet 2DT at the left end of the three-position four-way reversing valve 7 is powered on, the electromagnet 3DT at the right end of the three-position four-way reversing valve is powered off to connect the port 7P with the port 7A, and the port 7B with the port 7T. Under the action of the pulling force of the execution hydraulic cylinder 15, the load simulation hydraulic cylinder 16 extends leftwards, oil in a rodless cavity of the load simulation hydraulic cylinder is supplemented by the oil supplementing pump 8, the oil in a rod cavity of the load simulation hydraulic cylinder flows to the first three-way proportional pressure reducing overflow valve 12 through the port 16A, the first three-way proportional pressure reducing overflow valve 12 is in a reverse flow state at the moment, the oil flows to the port 12A through the port 12B, and the pressure of the port 12A and the pressure of the port 12B are higher and higher at the moment due to the fact that the outlet of the port 12A is not connected with the oil tank. When the pressure of the port 12B rises to the set pressure of the three-way proportional pressure-reducing overflow valve I12, the port 12B is communicated with the port 12T and overflows, the port 12A is disconnected from the port 12B, and at the moment, the first three-way proportional pressure-reducing overflow valve 12 is in an overflow mode to form set load simulation pressure so as to achieve the purpose of passive loading. It should be noted that, with the first three-way proportional pressure reducing relief valve 12, when the pressure of the port 12B is lower than the external set pressure, the port 12B communicates with the port 12A, and when the pressure of the port 12B is higher than the external set pressure, the port 12B and the port 13T communicate with the open relief mode. The set pressure of the first three-way proportional pressure reducing relief valve 12 can be set by an external control signal.
(2) Load simulation active loading method for hydraulic system
a. Positive load condition 1
When the main force of the actuating hydraulic cylinder 15 is thrust and acts on the piston rod of the load simulation hydraulic cylinder 16 through the hinge mechanism 14 to form thrust force, the active loading method provides an active load loading force with the direction opposite to the extending direction of the actuating hydraulic cylinder for the load simulation hydraulic cylinder 16, and the positive load working condition 1 can be simulated. Specifically, the loading pump 2 is in an open state, the oil supplementing pump 8 is in an open state, the electromagnet 1DT of the unloading valve 5 of the hydraulic system is powered on to disconnect an oil path thereof, the electromagnet 2DT at the left end of the three-position four-way reversing valve 7 is powered off, the electromagnet 3DT at the right end of the three-position four-way reversing valve is powered on to connect a port 7P with a port 7B thereof, and a port 7A is connected with a port 7T thereof. High-pressure oil at the outlet of the loading pump 2 flows to a port 13A of a second three-way proportional pressure-reducing overflow valve 13 through a port 7B of a three-position four-way reversing valve 7, the high-pressure oil flows in from an inlet 13A and flows out from an outlet 13B, the second three-way proportional pressure-reducing overflow valve 13 is in a forward flow state, the outlet pressure is determined by the set pressure of the second three-way proportional pressure-reducing overflow valve 13, the reduced pressure oil flows to a rodless cavity of a load simulation hydraulic cylinder 16 through a port 16B from the port 13B, and a leftward active extension load loading force is formed for the load simulation hydraulic cylinder 16 so as to resist the active force of an execution hydraulic cylinder 15. It is to be noted that if the outlet pressure of the second three-way proportional pressure reducing relief valve 13 is greater than the main power of the implement hydraulic cylinder 15, the load simulation hydraulic cylinder 16 extends leftward, and the implement hydraulic cylinder 15 is forced to retract leftward; if the outlet pressure of the second three-way proportional pressure reducing relief valve 13 is lower than the main power of the actuator cylinder 15, the load-simulating hydraulic cylinder 16 is forced to retract rightward, and at this time, the oil replenishment pump 8 replenishes the rod chamber of the load-simulating hydraulic cylinder 16 via the second check valve 10 in order to prevent the rod chamber of the load-simulating hydraulic cylinder 16 from being evacuated.
b. Positive and negative load working condition 2
When the main force of the actuating hydraulic cylinder 15 is a pulling force, and acts on the piston rod of the load simulation hydraulic cylinder 16 through the hinge mechanism 14 to form a pulling force on the piston rod, the active loading method provides an active load loading force with a direction opposite to the retracting direction of the actuating hydraulic cylinder for the load simulation hydraulic cylinder 16, and at the moment, a positive load working condition 2 and a negative load working condition 2 can be simulated. Specifically, the loading pump 2 is in an open state, the oil replenishing pump 8 is in an open state, the electromagnet 1DT of the unloading valve 5 of the hydraulic system is powered on to disconnect an oil path thereof, the electromagnet 2DT at the left end of the three-position four-way reversing valve 7 is powered on, the electromagnet 3DT at the right end of the three-position four-way reversing valve is powered off to connect the port 7P with the port 7A, and the port 7B with the port 7T. High-pressure oil at the outlet of the loading pump 2 flows to a 12A port of a first three-way proportional pressure-reducing overflow valve 12 through a port 7P of a three-position four-way reversing valve 7 and a port 7A, the high-pressure oil flows in from a 12A inlet and flows out from a 12B outlet, at the moment, the first three-way proportional pressure-reducing overflow valve 12 is in a forward flowing state, the outlet pressure is determined by the set pressure of the first three-way proportional pressure-reducing overflow valve 12, the pressure oil after pressure reduction flows to a rod cavity of a load simulation hydraulic cylinder 16 from the port 12B through a port 16A, and a rightward active retraction load loading force is formed on the load simulation hydraulic cylinder 16 so as to resist the active force of an execution hydraulic cylinder 15. It is to be noted that if the outlet pressure of the first three-way proportional pressure reducing relief valve 12 is greater than the main power of the implement hydraulic cylinder 15, the load simulation hydraulic cylinder 16 retracts rightward, and the implement hydraulic cylinder 15 is forced to extend rightward; if the outlet pressure of the first three-way proportional pressure reducing relief valve 12 is lower than the main power of the actuator cylinder 15, the load simulation hydraulic cylinder 16 is forced to extend leftward, and at this time, the oil replenishment pump 8 replenishes oil to the rodless chamber of the load simulation hydraulic cylinder 16 through the third check valve 11 in order to prevent the rodless chamber of the load simulation hydraulic cylinder 16 from being evacuated.
c. Load condition 1
When the main force of the actuating hydraulic cylinder 15 is thrust and acts on the piston rod of the load simulation hydraulic cylinder 16 through the hinge mechanism 14 to form thrust force, the active loading method provides an active load loading force with the same direction as the retracting direction of the actuating hydraulic cylinder to the load simulation hydraulic cylinder 16, and the negative load working condition 1 can be simulated. Specifically, the loading pump 2 is in an open state, the oil replenishing pump 8 is in an open state, the electromagnet 1DT of the unloading valve 5 of the hydraulic system is powered on to disconnect an oil path thereof, the electromagnet 2DT at the left end of the three-position four-way reversing valve 7 is powered on, the electromagnet 3DT at the right end of the three-position four-way reversing valve is powered off to connect the port 7P with the port 7A, and the port 7B with the port 7T. High-pressure oil at the outlet of the loading pump 2 flows to a port 12A of a three-way proportional pressure-reducing overflow valve I12 through a port 7P of a three-position four-way reversing valve 7 through a port 7A, the high-pressure oil flows in from an inlet 12A and flows out from an outlet 12B, the first three-way proportional pressure-reducing overflow valve 12 is in a positive flow state at the moment, the outlet pressure is determined by the set pressure of the first three-way proportional pressure-reducing overflow valve 12, the pressure oil after pressure reduction flows to a rod cavity of a load simulation hydraulic cylinder 16 through a port 16A from a port 12B, a rightward active retraction loading force is formed on the load simulation hydraulic cylinder 16, and the direction of the loading force is consistent with the direction of the active force at the moment, so that a negative load working condition 1 is formed. It should be noted that, since the force directions of the active actuation cylinder 15 and the load simulation hydraulic cylinder 16 are the same, the load simulation hydraulic cylinder 16 is caused to retract to the right rapidly, and in order to prevent the load simulation hydraulic cylinder 16 from being sucked empty due to the retraction rapidly, the oil replenishment pump 8 replenishes oil to the rod chamber of the load simulation hydraulic cylinder 16 through the second check valve 10 to avoid the suction empty.
d. Load condition 2
When the main force of the actuating hydraulic cylinder 15 is a pulling force, and acts on the piston rod of the load simulation hydraulic cylinder 16 through the hinge mechanism 14 to form a pulling force on the piston rod, the active loading method provides an active load loading force with the same direction as the retracting direction of the actuating hydraulic cylinder for the load simulation hydraulic cylinder 16, and at the moment, the positive and negative load working condition 2 can be simulated. Specifically, the loading pump 2 is in an open state, the oil replenishing pump 8 is in an open state, the electromagnet 1DT of the unloading valve 5 of the hydraulic system is powered on to disconnect an oil path thereof, the electromagnet 2DT at the left end of the three-position four-way reversing valve 7 is powered off, the electromagnet 3DT at the right end of the three-position four-way reversing valve is powered on to connect a port 7P with a port 7B, and a port 7A is connected with a port 7T. High-pressure oil at the outlet of the loading pump 2 flows to a port 13A of a second three-way proportional pressure-reducing overflow valve 13 through a port 7P of a three-position four-way reversing valve 7 and a port 7B, the high-pressure oil flows in from a port 13A and flows out from a port 13B, the second three-way proportional pressure-reducing overflow valve 13 is in a positive flow state, the outlet pressure is determined by the set pressure of the second three-way proportional pressure-reducing overflow valve 13, the pressure oil after pressure reduction flows to a rodless cavity of a load simulation hydraulic cylinder 16 through a port 16B from the port 13B, a leftward active extending load loading force is formed on the load simulation hydraulic cylinder 16, and the load loading force direction is consistent with the active force direction at the moment, so that the negative load working condition 2 is formed. It should be noted that, since the force directions of the active actuation cylinder 15 and the load simulation hydraulic cylinder 16 are the same, the load simulation hydraulic cylinder 16 is extended to the left suddenly, and in order to prevent the load simulation hydraulic cylinder 16 from being emptied due to the sudden extension, the oil supplementing pump 8 supplements oil to the rodless chamber of the load simulation hydraulic cylinder 16 through the third check valve 11 to avoid emptying.
As can be seen from the introduction, the three-way proportional pressure reducing overflow valve provided by the invention has an oil inlet, an oil outlet and an overflow port, and has both a pressure reducing function and an overflow function. The oil inlet is connected with a high-pressure main oil way, the oil outlet is connected with a working oil way, and the overflow port is connected with an oil tank. Through the internal adjusting device, the pressure of the inlet high-pressure main oil way is adjusted to be reduced to the pressure reducing pressure required by the oil outlet, and meanwhile, the full-flow overflow function from the oil outlet to the overflow port is achieved. When the liquid flow reversely flows, if the pressure of the oil outlet is smaller than the set required pressure, the reverse flow from the oil outlet to the oil inlet is also provided. The pressure drop between the oil outlet and the overflow can be set and regulated by an external control signal.
The two tee proportional pressure reducing overflow valves are respectively connected with a rod cavity and a rodless cavity oil circuit of the load simulation hydraulic cylinder, and can be respectively subjected to pressure setting so as to control the active extension force and the active retraction force of the load simulation hydraulic cylinder.
The invention provides a combination of a loading pump and an oil supplementing pump, and the opening and the closing of the loading pump and the oil supplementing pump can be freely switched according to the requirements of working conditions. When active loading is performed, the loading pump needs to be started, and when passive loading is performed, the loading pump needs to be stopped. The oil supplementing pump is additionally arranged to prevent the load simulation hydraulic cylinder from being empty, the oil supplementing pump is arranged on oil paths of the working oil port of the three-position four-way reversing valve and the oil inlet of the three-way proportional pressure reducing valve, and the oil supplementing pump is timely started according to the working condition mode of the load simulation hydraulic cylinder to prevent the load simulation hydraulic cylinder from being empty.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is specific and detailed, but not to be understood as limiting the scope of the present invention. It will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit of the invention, and these are within the scope of the invention.
Claims (10)
1. A hydraulic load simulation active and passive and multi-working-condition loading method and a hydraulic system are characterized in that the system comprises an oil tank, a loading pump, an oil supplementing pump, a three-position four-way reversing valve, a first three-way proportional pressure reducing overflow valve, a second three-way proportional pressure reducing overflow valve, an execution hydraulic cylinder, a load simulation hydraulic cylinder, an overflow valve and an unloading valve;
the oil suction ports of the loading pump and the oil replenishing pump are connected with an oil tank, the P port of the three-position four-way reversing valve is connected with the oil outlet of the loading pump, the T port of the three-position four-way reversing valve is connected with the oil tank, the A port and the B port of the three-position four-way reversing valve are respectively connected with the A port of the first three-way proportional pressure reducing overflow valve and the A port of the second three-way proportional pressure reducing overflow valve, the T port of the first three-way proportional pressure reducing overflow valve and the T port of the second three-way proportional pressure reducing overflow valve are connected with the oil tank,
a rod cavity oil port and a rodless cavity oil port of the load simulation hydraulic cylinder are respectively connected with a port B of the first three-way proportional pressure reduction overflow valve and a port B of the second three-way proportional pressure reduction overflow valve;
an outlet of the oil supplementing pump is respectively connected with an A port of the first three-way proportional pressure reducing overflow valve and an A port of the second three-way proportional pressure reducing overflow valve through a second one-way valve and a third one-way valve;
the execution hydraulic cylinder is connected with a piston rod of the load simulation hydraulic cylinder through a hinge mechanism; the overflow valve and the unloading valve are connected in parallel to form a safety valve group, one end of the safety valve group is connected with the oil tank, and the other end of the safety valve group is connected with the outlet of the loading pump.
2. The hydraulic load simulation active and passive multi-working-condition loading method and the hydraulic system according to claim 1, wherein the set pressure of the overflow valve is higher than the system limit maximum pressure to protect the normal operation of the hydraulic system, the outlet pressure of the oil replenishing pump is set to be not more than 2.5Mpa, and when the system is not in operation, the electromagnets of the unloading valve and the electromagnets at two ends of the three-position four-way reversing valve are in a power-off state.
3. The hydraulic load simulation active and passive multi-working-condition loading method and the hydraulic system based on the claim 1 are characterized in that two modes of pressure reduction and overflow of a first three-way proportional pressure reduction overflow valve and a second three-way proportional pressure reduction overflow valve and oil supply of a loading pump and an oil supply pump are combined for supplying oil, so that two modes of active loading and passive loading of hydraulic load simulation are realized;
in the passive loading mode, the three-way proportional pressure reducing overflow valve is in a reverse flow state and is in an overflow mode, and the load simulation acting force is changed by adjusting the set pressure of the three-way proportional pressure reducing overflow valve to carry out passive loading; at the moment, a loading hydraulic pump of the hydraulic system is closed, the load simulation hydraulic cylinder cannot actively extend and retract, and the oil supplementing pump is started to supplement oil required by the load simulation hydraulic cylinder;
in an active loading mode, the three-way proportional pressure reducing overflow valve is in a positive flow state and is in a pressure reducing mode, the set pressure of the three-way proportional pressure reducing overflow valve is set to change the active extension and active retraction pressures of the load simulation hydraulic cylinder, active loading is realized, and further four working condition simulations of a positive load working condition 1, a positive load working condition 2, a negative load working condition 1 and a negative load working condition 2 can be realized;
the load simulation hydraulic cylinder is required to actively apply a load acting force opposite to the movement direction of the external actuating mechanism under the working condition of positive load and negative load 1, namely the working condition that the main force of the external actuating mechanism is thrust;
a positive load working condition 2, namely a working condition that the main force of the external actuating mechanism is tensile force and the load simulation hydraulic cylinder is required to actively apply a load acting force opposite to the movement direction of the external actuating mechanism;
the load simulation hydraulic cylinder is under a negative load working condition 1, namely the working condition that the main force of the external actuating mechanism is thrust and the load simulation hydraulic cylinder is required to actively apply a load acting force in the same direction as the movement direction of the external actuating mechanism;
and the load-bearing working condition 2 is a working condition that the main force of the external actuating mechanism is tensile force and the load-bearing simulation hydraulic cylinder is required to actively apply a load acting force in the same direction as the movement direction of the external actuating mechanism.
4. The method of claim 3, wherein:
when a positive load working condition 1 is simulated, the working condition simulation is completed by loading a hydraulic pump and adjusting the outlet pressure of a second three-way proportional pressure reducing overflow valve of a rodless cavity oil way of a load simulation hydraulic cylinder;
when the positive and negative load working condition 2 is simulated, the working condition simulation is completed by loading the hydraulic pump and adjusting the outlet pressure of the first three-way proportional pressure reducing overflow valve of the rod cavity oil way of the load simulation hydraulic cylinder.
When a load working condition 1 is simulated, working condition simulation is completed by loading a hydraulic pump and adjusting the pressure of a first three-way proportional pressure reduction overflow valve of a rod cavity oil way of a load simulation hydraulic cylinder;
and when the working condition 2 of the load is simulated, the working condition simulation is completed by loading the hydraulic pump and adjusting the pressure of the second three-way proportional pressure reducing overflow valve of the rodless cavity oil way of the load simulation hydraulic cylinder.
5. The method of claim 3, wherein: when the load simulation of the hydraulic system is in a passive loading mode, and when the active force of the execution hydraulic cylinder is thrust, the active force acts on a piston rod of the load simulation hydraulic cylinder through the hinge mechanism and forms a thrust force on the piston rod, the passive loading method provides a passive load loading force with the direction opposite to the extending direction of the execution hydraulic cylinder for the load simulation hydraulic cylinder;
at the moment, the loading pump is in a closed state, the load simulation hydraulic cylinder cannot actively extend and retract, the oil supplementing pump is in an open state, the 1DT of the unloading valve of the hydraulic system is powered on to disconnect an oil path of the unloading valve, the left end electromagnet 2DT of the three-position four-way reversing valve is powered off, the right end electromagnet 3DT of the three-position four-way reversing valve is powered on to connect a port P with a port B, and the port A is connected with the port T; under the thrust action of the execution hydraulic cylinder, the load simulation hydraulic cylinder retracts rightwards, oil in a rod cavity of the load simulation hydraulic cylinder is supplemented by an oil supplementing pump, the oil in a rodless cavity flows to a second three-way proportional pressure reducing overflow valve, the second three-way proportional pressure reducing overflow valve is in a reverse flow state, the oil flows to an A port of the second three-way proportional pressure reducing overflow valve through a B port of the second three-way proportional pressure reducing overflow valve, because an outlet of the A port is not connected with an oil tank, the pressure of the A port and the pressure of the B port of the second three-way proportional pressure reducing overflow valve are higher and higher, when the pressure of the B port is increased to the set pressure of the second three-way proportional pressure reducing overflow valve, the B port of the second three-way proportional pressure reducing overflow valve is connected with a T port and overflows, the A port and the B port are disconnected, and the second three-way proportional pressure reducing overflow valve is in an overflow mode to form set load simulation pressure so as to achieve the purpose of passive loading; the set pressure of the second three-way proportional pressure reducing overflow valve can be set by an external control signal.
6. The method of claim 4, wherein: when the load simulation of the hydraulic system is in a passive loading mode, and when the active force of the executing hydraulic cylinder is pulling force, the active force acts on a piston rod of the load simulating hydraulic cylinder through a hinge mechanism and forms a pulling acting force on the piston rod, the passive loading method provides a passive load loading force with the direction opposite to the retracting direction of the executing hydraulic cylinder for the load simulating hydraulic cylinder;
at the moment, the loading pump is in a closed state, the load simulation hydraulic cylinder cannot actively extend and retract, the oil supplementing pump is in an open state, the electromagnet 1DT of the unloading valve of the hydraulic system is electrified to disconnect the oil path, the electromagnet 2DT at the left end of the three-position four-way reversing valve is electrified, the electromagnet 3DT at the right end of the three-position four-way reversing valve is electrified to disconnect the oil path, the P port of the three-position four-way reversing valve is communicated with the A port, and the B port of the three-position four-way reversing valve is communicated with the T port; under the action of the tensile force of the execution hydraulic cylinder, the load simulation hydraulic cylinder extends leftwards, oil in a rodless cavity of the load simulation hydraulic cylinder is supplemented by an oil supplementing pump, the oil in a rod cavity of the load simulation hydraulic cylinder flows to a first three-way proportional pressure reducing overflow valve, the first three-way proportional pressure reducing overflow valve is in a reverse flow state, the oil flows to an A port of the load simulation hydraulic cylinder through a B port of the load simulation hydraulic cylinder, and the pressure of the A port and the pressure of the B port of the load simulation hydraulic cylinder are higher and higher at the moment because the outlet of the A port is not connected with an oil tank; when the pressure of the port B is increased to the set pressure of the first three-way proportional pressure-reducing overflow valve, the port B of the first three-way proportional pressure-reducing overflow valve is communicated with the port T and overflows, the port A and the port B are disconnected, and the first three-way proportional pressure-reducing overflow valve is in an overflow mode at the moment to form set load simulation pressure so as to achieve the purpose of passive loading; the set pressure of the first three-way proportional pressure reducing overflow valve can be set by an external control signal.
7. The method of claim 4, wherein: when a positive load working condition 1 is simulated, the loading pump is in an open state, the oil supplementing pump is in an open state, the electromagnet 1DT of the unloading valve of the hydraulic system is electrified to disconnect an oil path thereof, the electromagnet at the left end of the three-position four-way reversing valve is electrified to disconnect 2DT, the electromagnet at the right end of the three-position four-way reversing valve is electrified to connect 3DT, a port P and a port B are connected, and a port A and a port T are connected;
high-pressure oil at the outlet of the loading pump flows to the port A of the second three-way proportional pressure-reducing overflow valve 3 through the port B through the port P of the three-position four-way reversing valve, the high-pressure oil flows in from the inlet A and flows out from the outlet B, at the moment, the second three-way proportional pressure-reducing overflow valve is in a positive flow state, the outlet pressure is determined by the set pressure of the second three-way proportional pressure-reducing overflow valve, the reduced pressure oil flows to a rodless cavity of the load simulation hydraulic cylinder from the port B, and a leftward active extension load loading force is formed on the load simulation hydraulic cylinder so as to resist the active force of the execution hydraulic cylinder 15.
8. The method of claim 4, wherein: when a positive-negative load working condition 2 is simulated, the loading pump is in an open state, the oil supplementing pump is in an open state, the electromagnet 1DT of the unloading valve of the hydraulic system is electrified to disconnect an oil path, the electromagnet 2DT at the left end of the three-position four-way reversing valve and the electromagnet 3DT at the right end of the three-position four-way reversing valve are electrified to connect a port P with a port A, and a port B is connected with a port T;
high-pressure oil at the outlet of the loading pump flows to the port A of the first three-way proportional pressure-reducing overflow valve through the port P of the three-position four-way reversing valve and the port A, the high-pressure oil flows in from the inlet A and flows out from the outlet B, at the moment, the first three-way proportional pressure-reducing overflow valve is in a forward flowing state, the outlet pressure is determined by the set pressure of the first three-way proportional pressure-reducing overflow valve, the pressure oil after pressure reduction flows to a rod cavity of the load simulation hydraulic cylinder from the port B, and a rightward active retraction load loading force is formed on the load simulation hydraulic cylinder so as to resist the active force of the execution hydraulic cylinder 15.
9. The method of claim 4, wherein: when a load working condition 1 is simulated, the loading pump is in an open state, the oil supplementing pump is in an open state, the electromagnet 1DT of the unloading valve of the hydraulic system is electrified to disconnect an oil path thereof, the electromagnet at the left end of the three-position four-way reversing valve is electrified 2DT, the electromagnet at the right end is electrified 3DT to connect a port P with a port A, and a port B is connected with a port T;
high-pressure oil at the outlet of the loading pump flows to the port A of the first three-way proportional pressure-reducing overflow valve through the port A of the three-position four-way reversing valve, the high-pressure oil flows in from the inlet A and flows out from the outlet B, at the moment, the first three-way proportional pressure-reducing overflow valve is in a positive flow state, the outlet pressure is determined by the set pressure of the first three-way proportional pressure-reducing overflow valve, the pressure oil after pressure reduction flows to a rod cavity of the load simulation hydraulic cylinder from the port B, a rightward active retraction load loading force is formed on the load simulation hydraulic cylinder, and the load loading force direction is consistent with the active force direction at the moment, so that a negative load working condition 1 is formed.
10. The method of claim 4, wherein: when the load working condition 2 is simulated, the loading pump is in an open state, the oil supplementing pump is in an open state, the electromagnet 1DT of the unloading valve of the hydraulic system is electrified to disconnect an oil way, the electromagnet 2DT at the left end of the three-position four-way reversing valve is powered off, the electromagnet 3DT at the right end of the three-position four-way reversing valve is electrified to connect the port P with the port B, and the port A is connected with the port T;
high-pressure oil at the outlet of the loading pump flows to a port A of a second three-way proportional pressure-reducing overflow valve through a port P of a three-position four-way reversing valve and a port B, the high-pressure oil flows in from the inlet A and flows out from an outlet B, the second three-way proportional pressure-reducing overflow valve is in a positive flow state, the outlet pressure is determined by the set pressure of the second three-way proportional pressure-reducing overflow valve, the reduced pressure oil flows to a rodless cavity of a load simulation hydraulic cylinder from the port B, a leftward active extension load loading force is formed on the load simulation hydraulic cylinder, and the load loading force direction is consistent with the active force direction at the moment, so that a negative load working condition 2 is formed.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116428173A (en) * | 2023-04-17 | 2023-07-14 | 浙江大学 | Engineering machinery overrunning load simulation device and control method thereof |
| CN116557371A (en) * | 2023-07-10 | 2023-08-08 | 中国空气动力研究与发展中心设备设计与测试技术研究所 | Hydraulic servo adjusting device of large-load mechanism and control method thereof |
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2022
- 2022-12-01 CN CN202211536685.2A patent/CN115949652A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116428173A (en) * | 2023-04-17 | 2023-07-14 | 浙江大学 | Engineering machinery overrunning load simulation device and control method thereof |
| CN116428173B (en) * | 2023-04-17 | 2024-03-22 | 浙江大学 | Engineering machinery overrunning load simulation device and control method thereof |
| CN116557371A (en) * | 2023-07-10 | 2023-08-08 | 中国空气动力研究与发展中心设备设计与测试技术研究所 | Hydraulic servo adjusting device of large-load mechanism and control method thereof |
| CN116557371B (en) * | 2023-07-10 | 2023-09-01 | 中国空气动力研究与发展中心设备设计与测试技术研究所 | Hydraulic servo adjusting device of large-load mechanism and control method thereof |
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