Closed rotary cushion valve

Abstract

The application discloses a closed rotary buffer valve, comprising a closed pump, a rotary motor and a rotary buffer module, wherein the rotary buffer module comprises a stop valve group, a first electromagnetic valve, a second electromagnetic valve and a buffer valve group; the first port of the rotary motor is connected with the first port of the stop valve group and the first port of the first electromagnetic valve respectively, the second port of the rotary motor is connected with the second port of the stop valve group and the second port of the second electromagnetic valve respectively, the second port of the first electromagnetic valve is also connected with the first port of the second electromagnetic valve, the third port of the stop valve group is connected with the first port of the buffer valve group, and the second port of the buffer valve group is connected with the second port of the first electromagnetic valve. By using the above technical scheme, when the rotary action stops, the rotary buffer module is connected with both sides of the rotary motor, the instantaneous pressure difference between both sides is reduced, better buffering and impact prevention effects are achieved.

Description

Technical Field

[0001] This invention relates to the field of crane control technology, and more particularly to a closed-loop rotary buffer valve. Background Technology

[0002] A crane slewing control system is a control system used to control the left and right slewing movements of the upper part of a crane. It is mainly divided into closed-loop pump control systems and open-loop systems. A closed-loop pump control slewing system is a hydraulic system in which the inlet and outlet of a hydraulic oil pump are directly connected to the slewing motor. The speed of the slewing motor is adjusted by changing the displacement of the oil pump.

[0003] Closed-loop pump-controlled slewing systems are widely used in cranes of 100 tons and above. Their advantages include cost optimization and high reliability. However, due to the structural characteristics of the system, when the slewing motion of the crane's upper carriage stops, a large instantaneous pressure difference is generated between the two sides of the slewing motor. The slewing stop action generates a large instantaneous impact force. Even if the free slewing valve is opened for buffering, the free slewing valve is a solenoid valve, and the opening of the solenoid valve has a time delay. The system's buffering structure is not very effective in preventing such instantaneous impacts, causing the turntable to swing significantly. Summary of the Invention

[0004] Purpose of the invention: This invention provides a closed-loop rotary buffer valve. Through the addition of a rotary buffer module, when the rotary motion stops and a large instantaneous pressure difference occurs between the two sides of the rotary motor, the two sides of the rotary motor can be connected, reducing the instantaneous pressure difference. Furthermore, the solenoid valve in the rotary buffer module can remain open during the rotary motion, and its opening time delay has no impact on the buffer structure. Moreover, the rotary buffer module can be equipped with multiple one-way valves or relief valves with different opening pressures, thereby creating a pressure conduction ladder to achieve better buffering and shock prevention effects.

[0005] Technical Solution: This invention provides a closed-loop rotary buffer valve, comprising: a closed-loop pump, a rotary motor, and a rotary buffer module, wherein: a first port of the closed-loop pump is connected to a first port of the rotary motor, and a second port of the closed-loop pump is connected to a second port of the rotary motor; the rotary buffer module comprises a shut-off valve group, a first solenoid valve, a second solenoid valve, and a buffer valve group; the first port of the rotary motor is connected to the first port of the shut-off valve group and the first port of the first solenoid valve, respectively; the second port of the rotary motor is connected to the second port of the shut-off valve group and the second port of the second solenoid valve, respectively; the second port of the first solenoid valve is also connected to the first port of the second solenoid valve; the third port of the shut-off valve group is connected to the first port of the buffer valve group, and the second port of the buffer valve group is connected to the second port of the first solenoid valve; the shut-off valve group is forward-connected and reverse-connected between the first and third ports, forward-connected and reverse-connected between the second and third ports, and disconnected between the first and second ports; the buffer valve group is forward-connected and reverse-connected between the first and second ports.

[0006] Specifically, the shut-off valve assembly includes a shuttle valve.

[0007] Specifically, the shut-off valve assembly includes a first check valve and a second check valve. The oil inlet of the first check valve serves as the first port of the shut-off valve assembly, the oil inlet of the second check valve serves as the second port of the shut-off valve assembly, and the oil outlet of the first check valve and the oil outlet of the second check valve are connected to serve as the third port of the shut-off valve assembly.

[0008] Specifically, the buffer valve group includes at least one or more parallel buffer branches, and the buffer branches are equipped with a series buffer check valve or relief valve.

[0009] Specifically, the buffer valve group includes multiple parallel buffer branches, and the opening pressure of the buffer check valve or relief valve on each buffer branch is different.

[0010] Specifically, the buffer branch is equipped with a damper connected in series with a buffer check valve or an overflow valve.

[0011] Specifically, the buffer valve assembly includes multiple parallel buffer branches, each with a different damping diameter.

[0012] Specifically, the first solenoid valve and the second solenoid valve are switching solenoid valves or proportional solenoid valves.

[0013] Specifically, it also includes a closed-loop pump electro-proportional displacement control valve, used to control the pressure oil output displacement of the closed-loop pump.

[0014] Specifically, it also includes a high-pressure relief valve and a free-rotation valve, wherein: the high-pressure relief valve has a first port connected to the first port of the rotary motor and a second port connected to the second port of the rotary motor; the free-rotation valve has a first port connected to the first port of the rotary motor and a second port connected to the second port of the rotary motor.

[0015] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: When the rotary buffer module stops rotating, it connects the two sides of the rotary motor, reducing the instantaneous pressure difference between the two sides. Furthermore, the solenoid valve of the rotary buffer module can remain open during the rotary motion, and its opening time delay has no effect on the buffer structure. In addition, multiple one-way valves or relief valves with different opening pressures can be set in the rotary buffer module, thereby setting a pressure conduction step to achieve better buffering and shock prevention effects. Attached Figure Description

[0016] Figure 1 A schematic diagram of the closed rotary buffer valve provided by the present invention;

[0017] Figure 2 A schematic diagram of the route of the closed rotary buffer valve provided by the present invention in the rotary action state;

[0018] Figure 3 A schematic diagram of the circuit of the closed rotary buffer valve provided by the present invention in the buffer state when the rotary action stops;

[0019] 1-Closed-loop pump; 2-Rotary motor; 3-Rotary buffer module; 31-Stop valve assembly; 32-First solenoid valve; 33-Second solenoid valve; 34-Buffer valve assembly; 4-Closed-loop pump electro-proportional displacement control valve; 5-High-pressure relief valve; 6-Free-rotation valve. Detailed Implementation

[0020] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0021] See Figure 1 This is a schematic diagram of the closed rotary buffer valve provided by the present invention.

[0022] This invention provides a closed-loop rotary buffer valve, comprising: a closed-loop pump 1, a rotary motor 2, and a rotary buffer module 3, wherein: a first port of the closed-loop pump 1 is connected to a first port of the rotary motor 2, and a second port of the closed-loop pump 1 is connected to a second port of the rotary motor 2; the rotary buffer module 3 includes a shut-off valve assembly 31, a first solenoid valve 32, a second solenoid valve 33, and a buffer valve assembly 34; the first port of the rotary motor 2 is connected to the first port of the shut-off valve assembly 31 and the first port of the first solenoid valve 32, respectively, and the second port of the rotary motor 2 is connected to the second port of the shut-off valve assembly 31, respectively. The first solenoid valve 32 is connected to the second port of the second solenoid valve 33, and the second port of the first solenoid valve 32 is also connected to the first port of the second solenoid valve 33. The third port of the shut-off valve group 31 is connected to the first port of the buffer valve group 34, and the second port of the buffer valve group 34 is connected to the second port of the first solenoid valve 32. The shut-off valve group 31 is connected in the forward direction and shut off in the reverse direction between the first and third ports, connected in the forward direction and shut off in the reverse direction between the second and third ports, and shut off between the first and second ports. The buffer valve group 34 is connected in the forward direction and shut off in the reverse direction between the first and second ports.

[0023] In this embodiment of the invention, the shut-off valve assembly 31 includes a shuttle valve.

[0024] In this embodiment of the invention, the shut-off valve assembly 31 includes a first check valve and a second check valve. The oil inlet of the first check valve serves as the first port of the shut-off valve assembly 31, the oil inlet of the second check valve serves as the second port of the shut-off valve assembly 31, and the oil outlet of the first check valve and the oil outlet of the second check valve are connected to serve as the third port of the shut-off valve assembly 31.

[0025] In this embodiment of the invention, the buffer valve group 34 includes at least one or more parallel buffer branches, and the buffer branches are provided with a series buffer check valve or overflow valve.

[0026] In this embodiment of the invention, the buffer valve group 34 includes multiple parallel buffer branches, and the opening pressure of the buffer check valve or overflow valve on each buffer branch is different.

[0027] In this embodiment of the invention, the buffer branch is provided with a damper connected in series with a buffer check valve or an overflow valve.

[0028] In this embodiment of the invention, the buffer valve group 34 includes multiple parallel buffer branches, each with a different damping diameter.

[0029] In this embodiment of the invention, the first solenoid valve 32 and the second solenoid valve 33 are switching solenoid valves or proportional solenoid valves.

[0030] See Figure 2This is a schematic diagram of the route of a closed rotary buffer valve in the rotary action state (the route is shown in bold in the figure).

[0031] In practical implementation, when the rotational motion from direction A to direction B is initiated, the first port (port A) of the closed-loop pump 1 outputs pressurized oil, and port A is in a high-pressure state. At this time, oil enters the first port (port A) of the rotary motor 2, and oil returns from the second port (port B). The rotary motor 2 rotates from direction A to direction B. At this time, the first solenoid valve 32 is energized. However, due to the shut-off effect between the first and second ports of the shut-off valve group 31, and the shut-off effect when the second solenoid valve 33 is de-energized, the pressurized oil will not enter the B side from the A side of the rotary buffer module 3, and will not affect the start-up and normal rotation process. In addition, opening the first solenoid valve 32 at this time has the advantage over opening it when the rotation stops. When the rotation stops, there is a time delay from opening to the actual conduction of the solenoid valve. This time delay will cause a huge instantaneous pressure difference between the A side and the B side, and the resulting impact will cause the turntable to swing. However, opening it now does not have the above-mentioned time delay problem.

[0032] See Figure 3 This is a schematic diagram of the route of a closed rotary buffer valve in the buffer state when the rotary action stops (the route is the bold part in the figure).

[0033] In practice, when the rotation from direction A to direction B stops, the flow rate of the pressurized oil output from port A of closed pump 1 gradually decreases until ports A and B (second ports) of closed pump 1 are closed. Due to the inertia of the crane's rotation, the slewing motor 2 will still rotate from direction A to direction B under the action of inertial load. Since ports A and B of closed pump 1 are closed, the pressure at port B will increase, thereby generating a reverse braking torque from direction B to direction A to brake the rotating inertial load.

[0034] In practical implementation, when the pressure at port B increases, the high braking pressure at port B first opens the lower-pressure buffer check valve (relief valve) in the buffer valve assembly 34 to buffer the overflow. Through the damping effect following the low-pressure buffer check valve, the pressure flows to port A via the first solenoid valve 32, thus achieving pressure buffering. When multiple parallel buffer branches are set, if the stopping inertia is large and the pressure at port B continues to increase, it will open the higher-pressure buffer check valve (relief valve) to buffer the overflow. Through these two buffer overflows, the stopping buffering effect is strengthened. When the rotation is braked, the high pressure at port B automatically disappears, at which point the first solenoid valve 32 closes, reliably stopping the rotation.

[0035] In practice, the opening pressure of the buffer check valve (overflow valve) on different buffer branches can be set according to the actual application scenario, and the same applies to the damping diameter.

[0036] In practice, when the slewing action starts, the first solenoid valve 32 is energized. Therefore, during the buffering action, as long as the high pressure at port B reaches the opening pressure of the buffer check valve (relief valve), rapid buffering can be achieved.

[0037] In practice, the start of the rotation from direction B to direction A and the stop of the rotation from direction B to direction A can be controlled by referring to the above control method, which controls the second solenoid valve 33 to be energized and the first solenoid valve 32 to be de-energized.

[0038] In this embodiment of the invention, the closed rotary buffer valve further includes a closed pump electro-proportional displacement control valve 4, which is used to control the pressure oil output displacement of the closed pump 1.

[0039] In this embodiment of the invention, the closed rotary buffer valve further includes a high-pressure relief valve 5 and a free-rotation valve 6, wherein: the first port of the high-pressure relief valve 5 is connected to the first port of the rotary motor 2, and the second port is connected to the second port of the rotary motor 2; the first port of the free-rotation valve 6 is connected to the first port of the rotary motor 2, and the second port is connected to the second port of the rotary motor 2.

[0040] In practice, the swashplate angle of the closed pump 1 is controlled by the current of the closed pump proportional displacement control valve 4. When the current increases, the swashplate angle of the closed pump 1 increases, the output oil displacement increases, and the rotation speed of the rotary motor 2 increases. When the current decreases, the swashplate angle of the closed pump 1 decreases, the output oil displacement decreases, and the rotation speed of the rotary motor 2 decreases. When the current is 0, the swashplate angle of the closed pump 1 is 0, the oil output stops, and the rotation of the rotary motor 2 stops.

[0041] In practice, the free-swivel valve 6 is energized, which connects the inlet and outlet oil ports of the swivel motor 2, allowing the swivel motor 2 to be in a free-floating state.

[0042] In practice, when the actual rotation stops, the instantaneous high pressure difference between the two sides (side A and side B) of the rotary motor 2 is far less than the set pressure of the high-pressure relief valve 5, making it impossible to open the high-pressure relief valve 5 for buffering. However, the impact pressure is sufficient to cause significant shaking of the rotary table. If the free rotation valve 6 is opened for buffering when the rotation stops, due to the time delay of the solenoid valve opening, the instantaneous high pressure difference between the two sides of the rotary motor 2 cannot be buffered within the time delay, resulting in a high pressure impact and significant shaking when the rotation stops.

Claims

1. A closed-loop rotary buffer valve, characterized in that, include: Closed-loop pump, rotary motor, and rotary buffer module, wherein: The first port of the closed-loop pump is connected to the first port of the rotary motor, and the second port of the closed-loop pump is connected to the second port of the rotary motor. The rotary buffer module includes a shut-off valve group, a first solenoid valve, a second solenoid valve, and a buffer valve group; both the first and second solenoid valves are two-position, two-way solenoid valves; the first port of the rotary motor is connected to the first port of the shut-off valve group and the first port of the first solenoid valve, the second port of the rotary motor is connected to the second port of the shut-off valve group and the second port of the second solenoid valve, the second port of the first solenoid valve is also connected to the first port of the second solenoid valve, the third port of the shut-off valve group is connected to the first port of the buffer valve group, and the second port of the buffer valve group is connected to the second port of the first solenoid valve; the shut-off valve group has forward communication between the first and third ports and reverse shut-off between the second and third ports, and shut-off between the first and second ports; the buffer valve group has forward communication between the first and second ports and reverse shut-off between the first and second ports. When the rotational motion starts from the direction corresponding to the first port of the rotary motor to the direction corresponding to the second port, the first solenoid valve is energized and conducts, while the second solenoid valve is de-energized and cuts off. When the rotation is braked, the high voltage at the second port of the rotary motor automatically disappears, at which point the first solenoid valve closes, thus reliably stopping the rotational motion. When the rotational motion starts from the direction corresponding to the second port of the rotary motor to the direction corresponding to the first port, the second solenoid valve is energized and conducts, while the first solenoid valve is de-energized and cuts off. When the rotation is braked, the high voltage at the first port of the rotary motor automatically disappears, at which point the second solenoid valve closes, thus reliably stopping the rotational motion.

2. The closed-loop rotary buffer valve according to claim 1, characterized in that, The shut-off valve assembly includes a shuttle valve.

3. The closed rotary buffer valve according to claim 1, characterized in that, The shut-off valve assembly includes a first check valve and a second check valve. The oil inlet of the first check valve serves as the first port of the shut-off valve assembly, the oil inlet of the second check valve serves as the second port of the shut-off valve assembly, and the oil outlet of the first check valve and the oil outlet of the second check valve are connected to serve as the third port of the shut-off valve assembly.

4. The closed rotary buffer valve according to claim 2 or 3, characterized in that, The buffer valve group includes at least one or more parallel buffer branches, and a buffer check valve or an overflow valve is provided on the buffer branch.

5. The closed rotary buffer valve according to claim 4, characterized in that, The buffer valve group includes multiple parallel buffer branches, and the opening pressure of the buffer check valve or relief valve on each buffer branch is different.

6. The closed-loop rotary buffer valve according to claim 4, characterized in that, The buffer branch is equipped with a damper connected in series with a buffer check valve or an overflow valve.

7. The closed rotary buffer valve according to claim 6, characterized in that, The buffer valve assembly includes multiple parallel buffer branches, each with a different damping diameter.

8. The closed-loop rotary buffer valve according to claim 1, characterized in that, The first solenoid valve and the second solenoid valve are either on / off solenoid valves or proportional solenoid valves.

9. The closed rotary buffer valve according to claim 1, characterized in that, It also includes a closed-loop pump electro-proportional displacement control valve, used to control the pressure oil output displacement of the closed-loop pump.

10. The closed rotary buffer valve according to claim 1, characterized in that, It also includes a high-pressure relief valve and a free-spinning valve, wherein: the first port of the high-pressure relief valve is connected to the first port of the rotary motor, and the second port is connected to the second port of the rotary motor; the first port of the free-spinning valve is connected to the first port of the rotary motor, and the second port is connected to the second port of the rotary motor.

Images