Rotary cushion valve, hydraulic system and engineering machinery

Abstract

The invention discloses a rotary cushion valve, a hydraulic system and engineering machinery. The rotary cushion valve is characterized in that an oil port P1 of a reversing control valve, an oil port P2 of the reversing control valve and an inlet of a bypass control valve are respectively connected with a valve body oil port P; a working oil port A and a working oil port B of the reversing control valve are connected to the two ends of the rotary motor respectively, an oil port P3 of the reversing control valve is connected with a valve body oil return port T, and an oil return port T of the reversing control valve is connected with the valve body oil return port T through a back pressure valve; an outlet of the bypass control valve is connected with a valve body oil return port T; the control end of the bypass control valve is connected with an oil return port T of the reversing control valve; and the bypass control valve is used for reducing the impact when the rotary system is started through bypass shunting control. The rotary speed impact caused by too large flow entering the rotary motor during starting is avoided, it is guaranteed that the requirement for the maximum flow of the started rotary motor is not affected, starting stability is improved, and meanwhile the rotary motor has the advantages of being simple in valve element structure, high in response speed and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of engineering machinery, and in particular relates to a rotary buffer valve, a hydraulic system and engineering machinery. Background Art

[0002] When the construction crane is mounted on the vehicle, the slewing mechanism needs to slew left and right to achieve the position adjustment of the load and other operational needs. Generally, a slewing control valve is used to control the direction and speed of the slewing mechanism. Due to the different boom lengths and load weights of the crane under different operating conditions, the inertia when the slewing starts and stops is inconsistent, resulting in large start-stop shocks and slewing shaking. Especially in the case of fast operation start-up, it will cause problems such as large slewing start-up shocks and unstable loads, which seriously affect the controllability and safety of the entire machine operation.

[0003] Some existing technologies use the principle of pressure compensation to adjust the oil inlet in proportion to the valve opening, which is less affected by the load. However, since the valve port area of ​​the oil inlet control valve is designed according to the maximum flow rate, the valve port is fully opened instantly under fast operation, and the flow impact is still large, and the swing start is not smooth. It is difficult to achieve smooth start control under different operating conditions. Some existing technologies use a dual valve core in series to achieve smooth control of start and stop by controlling the response delay of the second valve core. However, the dual main valve core has a complex structure, high cost, and the response speed is affected. However, in different usage scenarios, the operator's control speed is different. Under light load or no-load conditions, the general operating handle is faster, the swing control valve controls the flow entering the swing motor to be larger, and the flow gain is larger, resulting in a large swing start impact, a sudden change in the swing speed, and a large shaking of heavy objects and the whole machine. Especially under high-speed engine conditions, the swing start impact is obvious, which seriously affects the user experience and the safety of the whole machine. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the present invention provides a rotary buffer valve, a hydraulic system and an engineering machinery, which not only avoid the impact of the rotary speed caused by excessive flow entering the rotary motor during startup, but also ensure that the maximum flow demand of the rotary motor after startup is not affected, thereby improving the startup stability. At the same time, it has the characteristics of simple valve core structure and fast response speed.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

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

[0007] Furthermore, it also includes a damper, which is connected between the oil return port T of the reversing control valve and the control end of the bypass control valve.

[0008] Furthermore, when the rotary system is not in operation, the reversing control valve is in the middle position, the oil port P2 and the oil port P3 of the reversing control valve are connected, and a part of the hydraulic oil flowing into the oil port P of the valve body flows into the oil tank through the oil port P2, the oil port P3 and the valve body oil return port T of the reversing control valve, and the other part flows into the oil tank through the bypass control valve and the valve body oil return port T.

[0009] Furthermore, when the slewing system is running and the reversing control valve is switched to the left position, the oil ports P2 and P3 of the reversing control valve are not connected, and the oil port P1 of the reversing control valve is connected to the working oil port A; a part of the hydraulic oil flowing into the oil port P of the valve body enters the working oil port A of the slewing motor through the oil port P1 of the slewing control valve and the working oil port A of the slewing control valve to drive the slewing motor to rotate, and the other part flows into the oil tank through the bypass control valve and the oil return port T of the valve body to achieve diversion; before the slewing motor is started, there is no return oil flow, the control pressure at the control end of the bypass control valve is zero, and the bypass Under the action of the spring force in the spring chamber, the control valve is in the right-position connected state; when the swing motor is started, the return oil in the working oil port B of the swing motor enters the oil tank through the working oil port B of the reversing control valve, the return oil port T of the reversing control valve, the back pressure valve 13, and the valve body return oil port T in sequence. As the return oil flow increases, the return oil pressure rises, and the pressure at the control end of the bypass control valve increases. The bypass control valve gradually switches to the cut-off position, the bypass control valve is closed, and the hydraulic oil flowing into the valve body oil port P all enters the swing motor through the reversing control valve, which is used to realize high-speed rotation of the swing system.

[0010] Furthermore, when the slewing system is running and the reversing control valve is switched to the right position, the oil ports P2 and P3 of the reversing control valve are not connected, and the oil port P1 of the reversing control valve is connected to the working oil port B; a part of the hydraulic oil flowing into the valve body oil port P enters the working oil port B of the slewing motor through the oil port P1 of the slewing control valve and the working oil port B of the slewing control valve to drive the slewing motor to rotate, and the other part flows into the oil tank through the bypass control valve and the valve body oil return port T to achieve diversion; before the slewing motor is started, there is no return oil flow, the control pressure at the control end of the bypass control valve is zero, and the bypass Under the action of the spring force in the spring chamber, the control valve is in the right-position connected state; when the rotary motor is started, the return oil in the working oil port A of the rotary motor enters the oil tank through the working oil port A of the reversing control valve, the return oil port T of the reversing control valve, the back pressure valve 13, and the valve body return oil port T in sequence. As the return oil flow increases, the return oil pressure rises, and the pressure at the control end of the bypass control valve increases. The bypass control valve gradually switches to the cut-off position, the bypass control valve is closed, and the hydraulic oil flowing into the valve body oil port P all enters the rotary motor through the reversing control valve, which is used to realize high-speed rotation of the rotary system.

[0011] Furthermore, it also includes an oil replenishing check valve 1 and an oil replenishing check valve 2, the inlet of the oil replenishing check valve 1 and the inlet of the oil replenishing check valve 2 are respectively connected to the oil return port T of the valve body; the outlet of the oil replenishing check valve 1 is connected to the working oil port A of the rotary motor; the outlet of the oil replenishing check valve 2 is connected to the working oil port B of the rotary motor.

[0012] Furthermore, it also includes overflow valve 1 and overflow valve 2, the inlet of overflow valve 1 is connected to the working oil port A of the rotary motor, and the inlet of overflow valve 2 is connected to the working oil port B of the rotary motor; the outlet of overflow valve 1 and the outlet of overflow valve 2 are respectively connected to the valve body oil return port T.

[0013] Furthermore, it also includes a shuttle valve and an electromagnetic reversing 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 the electromagnetic reversing valve is arranged 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] According to a third aspect, a rotary engineering machine is provided, wherein the rotary engineering machine is equipped with the rotary buffer valve according to 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 oil return port T for connecting the oil tank; the oil port P1 of the reversing control valve, the oil port P2 of the reversing control valve and the inlet of the bypass control valve are respectively connected to the oil port P; the working oil port A and the working oil port B of the reversing control valve are respectively connected to the two ends of the rotary motor, the oil port P3 of the reversing control valve is connected to the valve body oil return port T, and the oil return port T of the reversing control valve is connected to the valve body oil return port T through a back pressure valve; the outlet of the bypass control valve is connected to the valve body oil return port T; the control end of the bypass control valve is connected to the oil return port T of the reversing control valve; the bypass control valve reduces the impact of the rotary system at the start-up through bypass diversion control; it not only avoids the impact of the rotary speed caused by the excessive flow entering the rotary motor at the start-up, but also ensures that the maximum flow demand of the rotary motor after the start-up is not affected, thereby improving the starting stability. At the same time, it has the characteristics of simple valve core structure and fast response speed. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0018] In the figure: 1. Hydraulic pump; 2. Reversing control valve; 3. Bypass control valve; 4. Damping; 5. Oil replenishing check valve 1; 6. Oil replenishing check valve 2; 7. Overflow valve 1; 8. Overflow valve 2; 9. Shuttle valve; 10. Solenoid reversing valve; 11. Rotary motor; 12. Oil tank; 13. Back pressure valve. DETAILED DESCRIPTION

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

[0020] Embodiment 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 oil return port T for connecting to an oil tank 12, a reversing control valve 2, a bypass control valve 3, a damper 4, an oil replenishing check valve 1 5, an oil replenishing check valve 2 6, an overflow valve 1 7, an overflow valve 2 8, a shuttle valve 9, an electromagnetic reversing valve 10, and a back pressure valve 13.

[0022] 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 port A and the working oil port 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 oil return port T, and the oil return port T of the reversing control valve 2 is connected to the valve body oil return port T through the back pressure valve 13; the outlet of the bypass control valve 3 is connected to the valve body oil return port T; the control end of the bypass control valve 3 is connected to the oil return port T of the reversing control valve 2; the bypass control valve 3 is used to reduce the impact when the rotary system is started through bypass diversion control.

[0023] The damper 4 is connected between the oil return port T of the reversing control valve 2 and the control end of the bypass control valve 3 .

[0024] The inlet of the oil replenishing check valve 1 5 and the inlet of the oil replenishing check valve 2 6 are respectively connected to the valve body oil return port T; the outlet of the oil replenishing check valve 1 5 is connected to the working oil port A of the rotary motor 11; the outlet of the oil replenishing check valve 2 6 is connected to the working oil port B of the rotary motor 11.

[0025] The inlet of the relief valve 1 7 is connected to the working oil port A of the rotary motor 11, and the inlet of the relief valve 2 8 is connected to the working oil port B of the rotary motor 11; the outlet of the relief valve 1 7 and the outlet of the relief valve 2 8 are respectively connected to the valve body oil return 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 reversing valve 10 is arranged between the outlet of the shuttle valve 9 and the oil port P of the valve body.

[0027] Standby unloading state: When the swing system is on standby and not in motion, the reversing control valve 2 is in the middle position, the oil ports P2 and P3 of the reversing control valve 2 are connected with a wide opening, and part of the hydraulic oil flowing into the valve body oil port P flows into the oil tank 12 through the oil ports P2 and P3 of the reversing control valve 2 and the valve body oil return port T, realizing 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 oil return port T.

[0028] Rotation operation state: When the rotary system is running and the reversing control valve 2 is switched to the left position, the oil ports P2 and P3 of the reversing control valve 2 are closed and not connected, and the oil port P1 of the reversing control valve 2 is connected with the working oil port A through a wide opening. A part of the hydraulic oil output by the hydraulic pump 1 enters the oil port A of the rotary motor 11 through the valve body oil port P, the oil port P1 of the reversing control valve 2, and the working oil port A, gradually builds up pressure, drives the rotary motor 11 to rotate, and starts the rotary system. The other part of the hydraulic oil enters the oil tank 12 through the bypass control valve 3 and the valve body return oil port T to achieve diversion. Since the c chamber (control end) of the bypass control valve 3 is connected to the oil return circuit of the rotary motor 11, there is no return oil flow before the rotary motor 11 is started, and the control pressure of the c chamber of the bypass control valve 3 is zero, so under the action of the spring force of the d chamber (spring chamber), it is in the right position connection state.

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

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

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

[0032] The present invention adopts the oil inlet bypass diversion control technology. By setting a hydraulically controlled bypass control valve in the oil inlet line, the flow entering the rotary motor is controlled based on the return oil pressure, so as to limit the maximum flow entering the reversing valve at the moment of starting the rotary system. After the rotation starts, the bypass control valve is gradually closed to increase the flow entering the rotary motor, so as to achieve smooth start and speed regulation of the rotation. By picking up the change of the return oil pressure of the rotary motor, the flow demand of the rotary system is identified, and the switch of the diversion flow is reasonably controlled, which not only avoids the start speed impact caused by too much flow supply during fast operation start-up, but also ensures that the rotation speed will not be reduced due to diversion at high speed. At different operating speeds, the rotation can achieve smooth start, small impact, and good controllability.

[0033] Embodiment 2

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

[0035] Embodiment 3

[0036] Based on the rotary buffer valve described in Example 1 and the rotary hydraulic system described in Example 2, this embodiment provides a rotary engineering machinery, including a crane, an excavator, etc. The rotary engineering machinery is equipped with the rotary buffer valve described in Example 1 or the rotary hydraulic system described in Example 2.

[0037] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A rotary buffer valve, characterized in that: include: A valve body oil port P for connecting to the outlet of a hydraulic pump (1) and a valve body oil return port T for connecting to an 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 port A and the working oil port 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 oil return port T; the oil return port T of the reversing control valve (2) is connected to the valve body oil return port T through the back pressure valve (13); the outlet of the bypass control valve (3) is connected to the valve body oil return port T; the control end of the bypass control valve (3) is connected to the oil return port T of the reversing control valve (2); the bypass control valve (3) is used to reduce the impact when the rotary system is started through bypass diversion control.

2. The rotary buffer valve according to claim 1, characterized in that: It also includes a damper (4), which is connected between the oil return port T of the reversing control valve (2) and the control end of the bypass control valve (3).

3. The rotary buffer valve according to claim 1, characterized in that: When the swing system is not in operation, the directional control valve (2) is in the middle position, the oil ports P2 and P3 of the directional control valve (2) are connected, and part of the hydraulic oil flowing into the valve body oil port P flows into the oil tank (12) through the oil ports P2 and P3 of the directional control valve (2) and the valve body oil return port T, while the other part flows into the oil tank (12) through the bypass control valve (3) and the valve body oil return port T.

4. The rotary buffer valve according to claim 1, characterized in that: When the rotary system is running and the directional control valve (2) is switched to the left position, the oil port P2 and the oil port P3 of the directional control valve (2) are disconnected, and the oil port P1 of the directional control valve (2) is connected to the working oil port A; A portion of the hydraulic oil flowing into the oil port P of the valve body enters the working oil port A of the rotary motor (11) through the oil port P1 of the reversing control valve (2) and the working oil port A of the reversing control valve (2), thereby driving the rotary motor (11) to rotate; the other portion flows into the oil tank (12) through the bypass control valve (3) and the oil return port T of the valve body, thereby realizing flow diversion; Before the swing 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, and the bypass control valve (3) is in a right-position connection state under the action of the spring force in the spring chamber; When the swing motor (11) is started, the return oil in the working oil port B of the swing motor (11) enters the oil tank (12) in sequence through the working oil port B 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 rate increases, the return oil pressure rises, the pressure at the control end of the bypass control valve (3) increases, the bypass control valve (3) gradually changes to the cut-off position, the bypass control valve (3) closes, and the hydraulic oil flowing into the valve body oil port P all enters the swing motor (11) through the reversing control valve (2), so as to realize high-speed swing of the swing system.

5. The rotary buffer valve according to claim 1, characterized in that: When the rotary system is running and the directional control valve (2) is switched to the right position, the oil port P2 and the oil port P3 of the directional control valve (2) are disconnected, and the oil port P1 of the directional control valve (2) is connected to the working oil port B; A portion of the hydraulic oil flowing into the oil port P of the valve body enters the working oil port B of the swing motor (11) through the oil port P1 of the reversing control valve (2) and the working oil port B of the reversing control valve (2), thereby driving the swing motor (11) to rotate; the other portion flows into the oil tank (12) through the bypass control valve (3) and the oil return port T of the valve body, thereby realizing flow diversion; Before the swing 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, and the bypass control valve (3) is in a right position connected state under the action of the spring force in the spring chamber; When the swing motor (11) is started, the return oil in the working oil port A of the swing motor (11) enters the oil tank (12) in sequence through the working oil port 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 rate increases, the return oil pressure rises, the pressure at the control end of the bypass control valve (3) increases, the bypass control valve (3) gradually changes to the cut-off position, the bypass control valve (3) closes, and the hydraulic oil flowing into the valve body oil port P all enters the swing motor (11) through the reversing control valve (2), so as to realize high-speed swing of the swing system.

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

7. The rotary buffer valve according to any one of claims 1 to 5, characterized in that: It also includes a relief valve 1 (7) and a relief valve 2 (8). The inlet of the relief valve 1 (7) is connected to the working oil port A of the rotary motor (11), and the inlet of the relief valve 2 (8) is connected to the working oil port B of the rotary motor (11); the outlet of the relief valve 1 (7) and the outlet of the relief valve 2 (8) are respectively connected to the valve body oil return port T.

8. The rotary buffer valve according to any one of claims 1 to 5, characterized in that: It also includes a shuttle valve (9) and an electromagnetic reversing valve (10), wherein a first inlet of the shuttle valve (9) is connected to a working oil port A of a rotary motor (11), a second inlet of the shuttle valve (9) is connected to a working oil port B of the rotary motor (11), and an electromagnetic reversing valve (10) is arranged between an outlet of the shuttle valve (9) and an oil port P of the valve body.

9. 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 8.

10. 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 8.

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