A rotary cushion valve, hydraulic system and working machine

Abstract

The application discloses a rotary buffering valve, a hydraulic system and engineering machinery, and relates to the technical field of hydraulic systems.The rotary buffering valve comprises the following: valve body oil ports P connected with the oil port P1 of a reversing control valve, the oil port P2 of the reversing control valve and the inlet of a bypass control valve; the working oil ports A and B of the reversing control valve connected with two ends of a rotary motor; the oil port P3 of the reversing control valve connected with a valve body return oil port T; the return oil port T of the reversing control valve connected with the valve body return oil port T through a back pressure valve; the outlet of the bypass control valve connected with the valve body return oil port T; and the control end of the bypass control valve connected with the return oil port T of the reversing control valve; the bypass control valve is used for reducing the impact of a rotary system during startup through bypass shunt control.The application avoids the rotary speed impact caused by excessively large flow entering the rotary motor during startup, guarantees that the maximum flow demand of the rotary motor after startup is not affected, improves the startup stability, and has the characteristics of simple valve core structure, fast response speed and the like.

Description

Technical Field

[0001] This invention belongs to the field of engineering machinery technology, specifically relating to a rotary buffer valve, a hydraulic system, and engineering machinery. Background Technology

[0002] When operating an engineering crane, the slewing mechanism needs to rotate left and right to adjust the position of the suspended load. A slewing control valve is typically used to control the direction and speed of the slewing mechanism. Due to variations in boom length and load weight under different operating conditions, the moment of inertia during slewing startup and shutdown is inconsistent, resulting in significant start-stop shocks and slewing wobbling. This is particularly problematic during rapid starts, leading to large startup shocks and instability of the suspended load, severely impacting the overall operability and safety of the crane.

[0003] Some existing technologies employ pressure compensation to adjust the oil inlet proportionally to the valve opening, minimizing load-related impacts. However, because the inlet control valve's orifice area is designed for maximum flow, even with rapid operation, the valve opens fully instantaneously, resulting in significant flow surges and unstable rotary starts. This makes it difficult to achieve smooth start control under various operating conditions. Some existing technologies use a dual-valve-core series configuration, controlling the response delay of the second valve core to achieve smooth start and stop control. However, the dual-main-valve-core structure is complex, costly, and compromises response speed. Furthermore, in different usage scenarios, operator speed varies. Under light or no-load conditions, the operating handle is typically operated quickly, resulting in a larger flow rate controlled by the rotary control valve into the rotary motor, leading to a significant flow gain. This results in large start-up shocks, sudden changes in rotary speed, and significant shaking of heavy loads and the entire machine. Especially under high-speed engine operation, the start-up shock is pronounced, severely impacting user experience and overall machine safety. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a rotary buffer valve, a hydraulic system, and engineering machinery. It avoids the impact on rotary speed caused by excessive flow into the rotary motor during startup, while ensuring that the maximum flow requirement of the rotary motor after startup is not affected, thus improving startup stability. At the same time, it features a simple valve core structure and fast response speed.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, a rotary damping valve is provided, comprising: a valve body port P for connecting to the outlet of a hydraulic pump and a valve body return port T for connecting to an oil tank; ports P1 and P2 of a directional control valve and the inlet of a bypass control valve are respectively connected to the valve body port P; the working ports A and B of the directional control valve are respectively connected to the two ends of a rotary motor; port P3 of the directional control valve is connected to the valve body return port T; the return port T of the directional control valve is connected to the valve body return port T via a back pressure valve; the outlet of the bypass control valve is connected to the valve body return port T; the control end of the bypass control valve is connected to the return port T of the directional control valve; the bypass control valve is used to reduce the impact during startup of the rotary system through bypass diversion control.

[0007] Furthermore, it also includes damping, which is connected between the return port T of the directional control valve and the control end of the bypass control valve.

[0008] Furthermore, when the slewing system is not in operation, the directional control valve is in the neutral position, and the oil ports P2 and P3 of the directional control valve are connected. Part of the hydraulic oil flowing into the valve body oil port P flows into the oil tank through the oil ports P2 and P3 of the directional control valve and the valve body return oil port T, while the other part flows into the oil tank through the bypass control valve and the valve body return oil port T.

[0009] Furthermore, when the slewing system is running and the directional control valve is switched to the left position, ports P2 and P3 of the directional control valve are not connected, while port P1 of the directional control valve is connected to the working port A. Part of the hydraulic oil flowing into port P of the valve body enters the working port A of the slewing motor via port P1 and the working port A of the directional control valve, driving the slewing motor to rotate. The other part flows into the oil tank via the bypass control valve and the valve body return port T, used for flow diversion. Before the slewing motor starts, there is no return flow, and the control pressure at the control end of the bypass control valve is zero. Under the action of the spring force in the spring chamber, the control valve is in the right-hand connected state. When the rotary motor starts, the return oil in the working port B of the rotary motor passes through the working port B of the reversing control valve, the return port T of the reversing control valve, the back pressure valve 13, and the valve body return port T in sequence into the oil tank. As the return oil flow increases, the return oil pressure rises, the pressure at the control end of the bypass control valve increases, the bypass control valve gradually reverses to the cut-off position, the bypass control valve closes, and all the hydraulic oil flowing into the valve body port P enters the rotary motor through the reversing control valve to achieve high-speed rotation of the rotary system.

[0010] Furthermore, when the slewing system is running and the directional control valve is switched to the right position, ports P2 and P3 of the directional control valve are not connected, while port P1 of the directional control valve is connected to the working port B. Part of the hydraulic oil flowing into port P of the valve body enters the working port B of the slewing motor via port P1 and the working port B of the directional control valve, driving the slewing motor to rotate. The other part flows into the oil tank via the bypass control valve and the valve body return port T, used for flow diversion. Before the slewing motor starts, there is no return flow, and the control pressure at the control end of the bypass control valve is zero. Under the action of the spring force in the spring chamber, the control valve is in the right-hand connected state. When the rotary motor starts, the return oil in the working port A of the rotary motor passes through the working port A of the reversing control valve, the return port T of the reversing control valve, the back pressure valve 13, and the valve body return port T in sequence into the oil tank. As the return oil flow increases, the return oil pressure rises, the pressure at the control end of the bypass control valve increases, the bypass control valve gradually reverses to the cut-off position, the bypass control valve closes, and all the hydraulic oil flowing into the valve body port P enters the rotary motor through the reversing control valve to achieve high-speed rotation of the rotary system.

[0011] Furthermore, it also includes a replenishing oil check valve one and a replenishing oil check valve two. The inlet of replenishing oil check valve one and the inlet of replenishing oil check valve two are respectively connected to the valve body return oil port T; the outlet of replenishing oil check valve one is connected to the working oil port A of the rotary motor; and the outlet of replenishing oil check valve two is connected to the working oil port B of the rotary motor.

[0012] Furthermore, it also includes relief valve one and relief valve two. The inlet of relief valve one is connected to the working oil port A of the rotary motor, and the inlet of relief valve two is connected to the working oil port B of the rotary motor. The outlets of relief valve one and relief valve two are respectively connected to the valve body return oil port T.

[0013] Furthermore, it also includes a shuttle valve and a solenoid directional valve. The first inlet of the shuttle valve is connected to the working oil port A of the rotary motor, the second inlet of the shuttle valve is connected to the working oil port B of the rotary motor, and a solenoid directional valve is installed between the outlet of the shuttle valve and the oil port P of the valve body.

[0014] In a second aspect, a rotary hydraulic system is provided, wherein the rotary hydraulic system is equipped with the rotary buffer valve described in the first aspect.

[0015] Thirdly, a rotary engineering machine is provided, wherein the rotary engineering machine is equipped with the rotary buffer valve described in the first aspect.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention uses a valve body oil port P for connecting the outlet of the hydraulic pump and a valve body return oil port T for connecting the oil tank; the oil ports P1 and P2 of the directional control valve and the inlet of the bypass control valve are respectively connected to oil port P; the working oil ports A and B of the directional control valve are respectively connected to the two ends of the rotary motor; the oil port P3 of the directional control valve is connected to the valve body return oil port T, and the return oil port T of the directional control valve is connected to the valve body return oil port T through a back pressure valve; the outlet of the bypass control valve is connected to the valve body return oil port T; the control end of the bypass control valve is connected to the return oil port T of the directional control valve; the bypass control valve reduces the impact during the start-up of the rotary system through bypass diversion control; it avoids the impact on the rotary speed caused by excessive flow entering the rotary motor during start-up, and ensures that the maximum flow requirement of the rotary motor after start-up is not affected, thus improving the start-up stability. At the same time, it has the characteristics of simple valve core structure and fast response speed. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the principle of a rotary buffer valve provided in an embodiment of the present invention;

[0018] In the diagram: 1. Hydraulic pump; 2. Reversing control valve; 3. Bypass control valve; 4. Damping; 5. Replenishing check valve one; 6. Replenishing check valve two; 7. Relief valve one; 8. Relief valve two; 9. Shuttle valve; 10. Solenoid directional valve; 11. Rotary motor; 12. Oil tank; 13. Back pressure valve. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0020] Example 1

[0021] like Figure 1 As shown, a rotary buffer valve includes: a valve body oil port P for connecting to the outlet of a hydraulic pump 1, a valve body return oil port T for connecting to an oil tank 12, a reversing control valve 2, a bypass control valve 3, a damping valve 4, a first replenishing check valve 5, a second replenishing check valve 6, a first overflow valve 7, a second overflow valve 8, a shuttle valve 9, a solenoid reversing valve 10, and a back pressure valve 13.

[0022] The oil ports P1 and P2 of the directional control valve 2 and the inlet of the bypass control valve 3 are respectively connected to the valve body oil port P; the working oil ports A and B of the directional control valve 2 are respectively connected to the two ends of the rotary motor 11; the oil port P3 of the directional control valve 2 is connected to the valve body return oil port T; the return oil port T of the directional control valve 2 is connected to the valve body return oil port T through the back pressure valve 13; the outlet of the bypass control valve 3 is connected to the valve body return oil port T; the control end of the bypass control valve 3 is connected to the return oil port T of the directional control valve 2; the bypass control valve 3 is used to reduce the impact when the rotary system starts by bypass diversion control.

[0023] Damping 4 is connected between the return port T of the directional control valve 2 and the control end of the bypass control valve 3.

[0024] The inlet of oil replenishing check valve 5 and the inlet of oil replenishing check valve 6 are respectively connected to the return oil port T of the valve body; the outlet of oil replenishing check valve 5 is connected to the working oil port A of the rotary motor 11; the outlet of oil replenishing check valve 6 is connected to the working oil port B of the rotary motor 11.

[0025] The inlet of relief valve 7 is connected to the working oil port A of rotary motor 11, and the inlet of relief valve 8 is connected to the working oil port B of rotary motor 11; the outlets of relief valve 7 and relief valve 8 are respectively connected to the valve body return oil port T.

[0026] The first inlet of the shuttle valve 9 is connected to the working oil port A of the rotary motor 11, the second inlet of the shuttle valve 9 is connected to the working oil port B of the rotary motor 11, and an electromagnetic directional valve 10 is installed between the outlet of the shuttle valve 9 and the oil port P of the valve body.

[0027] Standby unloading state: When the slewing system is in standby mode, the directional control valve 2 is in the neutral position, and the large openings of port P2 and port P3 of the directional control valve 2 are connected. Part of the hydraulic oil flowing into port P of the valve body flows into the oil tank 12 through port P2, port P3 of the directional control valve 2, and the valve body return port T, achieving low-pressure unloading. The other part of the flow flows back to the oil tank 12 through the bypass control valve 3 and the valve body return port T.

[0028] Rotational Operation Status: When the rotational system is running and the directional control valve 2 is switched to the left position, ports P2 and P3 of the directional control valve 2 are closed and not connected. Port P1 of the directional control valve 2 is connected to the large opening of the working port A. Part of the hydraulic oil output from the hydraulic pump 1 enters port A of the rotary motor 11 through port P of the valve body, port P1 of the directional control valve 2, and working port A, gradually building pressure to drive the rotary motor 11 to rotate and start the rotational system. The other part of the hydraulic oil enters the oil tank 12 through the bypass control valve 3 and the valve body return port T, achieving flow diversion. Since chamber c (control end) of the bypass control valve 3 is connected to the return oil circuit of the rotary motor 11, there is no return oil flow before the rotary motor 11 starts. The control pressure of chamber c of the bypass control valve 3 is zero, so it is in the right-hand connected state under the spring force of chamber d (spring chamber).

[0029] When the rotary motor 11 starts running, the return oil in the working port B of the rotary motor 11 enters the oil tank 12 in sequence through the working port B of the reversing control valve 2, the return oil port T, and the back pressure valve 13. As the return oil flow increases, the return oil pressure rises, the pressure in chamber c of the bypass control valve 3 increases, and the bypass control valve 3 is pushed to gradually switch to the left position, close the valve port, cut off the diversion flow, and all the hydraulic oil flowing into the valve body port P enters the rotary motor 11 through the reversing control valve 2, realizing high-speed rotation of the rotary system.

[0030] By rationally designing the maximum flow area of ​​the bypass control valve 3, the smooth start-up control of the rotary system can be achieved, and the greater the load pressure and the greater the diversion flow, the smaller the start-up impact.

[0031] When the slewing system is running and the directional control valve 2 is switched to the right position, its working principle is the same as when the directional control valve 2 is switched to the left position.

[0032] This invention employs inlet bypass flow control technology. By installing a hydraulically controlled bypass valve in the inlet circuit, the flow rate into the rotary motor is controlled based on the return oil pressure. This limits the maximum flow rate into the directional valve at the moment of rotary system startup. After rotary operation begins, the bypass valve is gradually closed, increasing the flow rate into the rotary motor, thus achieving smooth start-up and speed regulation. By monitoring changes in the return oil pressure of the rotary motor, the flow demand of the rotary system is identified, enabling reasonable control of the flow diversion. This avoids the startup speed surge caused by excessive flow supply during rapid operation, while ensuring that the rotary speed does not decrease due to flow diversion at high speeds. Smooth start-up with minimal impact and good maneuverability are achieved at various operating speeds.

[0033] Example 2

[0034] Based on the rotary buffer valve described in Embodiment 1, this embodiment provides a rotary hydraulic system, wherein the rotary hydraulic system is equipped with the rotary buffer valve described in Embodiment 1.

[0035] Example 3

[0036] Based on the rotary buffer valve described in Embodiment 1 and the rotary hydraulic system described in Embodiment 2, this embodiment provides a rotary engineering machinery, including cranes, excavators, etc., wherein the rotary engineering machinery is equipped with the rotary buffer valve described in Embodiment 1 or the rotary hydraulic system described in Embodiment 2.

[0037] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A rotary buffer valve, characterized in that, include: The valve body oil port P is used to connect the outlet of the hydraulic pump (1) and the valve body return port T is used to connect the oil tank (12); The oil port P1 of the reversing control valve (2), the oil port P2 of the reversing control valve (2), and the inlet of the bypass control valve (3) are respectively connected to the valve body oil port P; the working oil ports A and B of the reversing control valve (2) are respectively connected to the two ends of the rotary motor (11); the oil port P3 of the reversing control valve (2) is connected to the valve body return oil port T; the return oil port T of the reversing control valve (2) is connected to the valve body return oil port T through the back pressure valve (13); the outlet of the bypass control valve (3) is connected to the valve body return oil port T; the control end of the bypass control valve (3) is connected to the return oil port T of the reversing control valve (2); the bypass control valve (3) is used to reduce the impact when the rotary system starts by bypass diversion control; It also includes a damper (4), which is connected between the return port T of the reversing control valve (2) and the control end of the bypass control valve (3); When the slewing system is not in operation, the reversing control valve (2) is in the neutral position, and the oil port P2 and oil port P3 of the reversing control valve (2) are connected. Part of the hydraulic oil flowing into the valve body oil port P flows into the oil tank (12) through the oil port P2, oil port P3 and valve body return oil port T of the reversing control valve (2), and the other part flows into the oil tank (12) through the bypass control valve (3) and valve body return oil port T. When the slewing system is running, and the reversing control valve (2) is switched to the left / right position, the oil ports P2 and P3 of the reversing control valve (2) are not connected, and the oil port P1 of the reversing control valve (2) is connected to the working oil ports A / B. A portion of the hydraulic oil flowing into the valve body port P passes through the port P1 of the reversing control valve (2) and the working port A / B of the reversing control valve (2) to enter the working port A / B of the rotary motor (11) and drive the rotary motor (11) to rotate. The other portion flows into the oil tank (12) through the bypass control valve (3) and the valve body return port T to achieve flow diversion. Before the rotary motor (11) is started, there is no return oil flow. The control pressure at the control end of the bypass control valve (3) is zero. Under the action of the spring force in the spring chamber, the bypass control valve (3) is in the right-hand connected state. When the rotary motor (11) is started, the return oil in the working port B / A of the rotary motor (11) enters the oil tank (12) in sequence through the working port B / A of the reversing control valve (2), the return oil port T of the reversing control valve (2), the back pressure valve (13), and the valve body return oil port T. As the return oil flow increases, the return oil pressure rises. Under the action of the damping (4), the pressure at the control end of the bypass control valve (3) increases. The bypass control valve (3) gradually reverses to the cut-off position and closes. All the hydraulic oil flowing into the valve body port P enters the rotary motor (11) through the reversing control valve (2) to realize the high-speed rotation of the rotary system.

2. The rotary buffer valve according to claim 1, characterized in that, It also includes a replenishing oil check valve one (5) and a replenishing oil check valve two (6). The inlet of the replenishing oil check valve one (5) and the inlet of the replenishing oil check valve two (6) are respectively connected to the valve body return port T; the outlet of the replenishing oil check valve one (5) is connected to the working oil port A of the rotary motor (11); and the outlet of the replenishing oil check valve two (6) is connected to the working oil port B of the rotary motor (11).

3. The rotary buffer valve according to claim 1, characterized in that, It also includes relief valve one (7) and relief valve two (8). The inlet of relief valve one (7) is connected to the working oil port A of the rotary motor (11), and the inlet of relief valve two (8) is connected to the working oil port B of the rotary motor (11). The outlet of relief valve one (7) and the outlet of relief valve two (8) are respectively connected to the valve body return oil port T.

4. The rotary buffer valve according to claim 1, characterized in that, It also includes a shuttle valve (9) and a solenoid directional valve (10). The first inlet of the shuttle valve (9) is connected to the working port A of the rotary motor (11), the second inlet of the shuttle valve (9) is connected to the working port B of the rotary motor (11), and the solenoid directional valve (10) is provided between the outlet of the shuttle valve (9) and the valve body port P.

5. A rotary hydraulic system, characterized in that, The rotary hydraulic system is equipped with a rotary buffer valve as described in any one of claims 1 to 4.

6. A rotary engineering machine, characterized in that, The rotary engineering machinery is equipped with a rotary buffer valve as described in any one of claims 1 to 4.

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