Distribution valve, loading machine and hydraulic system of loading machine

Abstract

The utility model relates to a hydraulic valve, in particular to a distribution valve, a loading machine and a hydraulic system of the loading machine, the distribution valve comprises a valve body, at least two main valves are arranged in the valve body, a first pump source interface used for supplying working pressure oil to each main valve is arranged on the valve body, and a pilot oil supply path is arranged in the valve body. The valve body is provided with electric proportional valves used for conducting pilot control over all the main valves and a plug-in type pressure reducing valve communicated with all the electric proportional valves through pilot oil supply ways, and the valve body is provided with a second pump source connector used for being communicated with the oil inlet end of the plug-in type pressure reducing valve. According to the utility model, the valve body of the distribution valve is provided with the plug-in type electric proportional valve and the plug-in type pressure reducing valve for providing oil for pilot control, so that a pilot control oil path of the distribution valve is simplified, and the valve body of the distribution valve is provided with the two pump source interfaces for connecting the two hydraulic pumps, so that pilot control oil and working oil are separated; and the hydraulic system is controlled stably and reliably.

Description

Technical Field

[0001] The utility model relates to a hydraulic valve, and more specifically to a distribution valve, a loader and a hydraulic system thereof. Background Art

[0002] In the hydraulic system of construction machinery such as loaders, the distribution valve is a hydraulically controlled structure, and an external solenoid valve block is used as a pilot valve for electric control conversion. The pilot oil supply valve is also arranged in the form of an external valve block to reduce the high-pressure pressure oil of the working hydraulic system and convert it into low-pressure pilot oil for pilot control. In the entire system, since the pilot valve and the pilot oil supply valve are both external valve blocks relative to the distribution valve, the overall pipeline layout of the hydraulic system is relatively messy and the manufacturing cost is high.

[0003] In addition, the working conditions of the loader are changeable. When some hydraulic actuators are not in action, the main oil circuit of the hydraulic system needs to be unloaded. During unloading, the pressure in the main oil circuit is low, and a stable pressure oil source cannot be provided for the pilot oil supply valve, affecting the output of the pilot oil supply valve and thus affecting the control of the entire hydraulic system. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a distribution valve, a loader and a hydraulic system thereof, so that the oil circuit of the hydraulic system of the loader working device is simple and stable.

[0005] The utility model provides a technical solution to achieve its purpose: a distribution valve, including a valve body, at least two main valve stems arranged in the valve body, a first pump source interface for supplying working pressure oil to each main valve through a main working oil circuit, a pilot oil supply circuit arranged in the valve body, an electric proportional valve for pilot control of each main valve stem, a plug-in pressure reducing valve connected to each electric proportional valve through the pilot oil supply circuit, and a second pump source interface for connecting to an oil inlet end of the plug-in pressure reducing valve.

[0006] In the distribution valve of the utility model, an accumulator interface is arranged on the valve body, and the accumulator interface is communicated with the pilot oil supply circuit.

[0007] In the distributing valve of the utility model, the plug-in pressure reducing valve comprises a pressure reducing valve and a relief valve, the oil inlet end of the pressure reducing valve is connected to the second pump source interface, the oil outlet end is simultaneously connected to the oil inlet end of the relief valve and the oil inlet ends of each electric proportional valve, and the oil outlet end of the relief valve is connected to the main return oil circuit in the valve body.

[0008] In the distributing valve of the utility model, a plug-in main safety valve is arranged on the valve body, and the oil inlet and outlet ends of the main safety valve are correspondingly connected with the main working oil circuit and the main oil return oil circuit in the valve body.

[0009] In the distributing valve of the utility model, the valve body is provided with a first overload valve and a second overload valve of a plug-in type, the oil inlet ends of the first overload valve and the second overload valve are correspondingly connected to the two working oil ports of a main valve, and the oil outlet ends of the first overload valve and the second overload valve are connected to the main return oil circuit.

[0010] In the distribution valve of the utility model, at least one main valve is provided with a plug-in oil replenishment check valve corresponding to the main valve on the valve body; the oil inlet end of the oil replenishment check valve is connected to the main return oil circuit, and the oil outlet end is connected to a working oil port of the main valve.

[0011] The utility model provides a technical solution for achieving its purpose: a loader hydraulic system, comprising a boom cylinder, a bucket cylinder, a working pump, a steering pump, a hydraulic oil tank, and the aforementioned distribution valve, wherein the working pump is connected to a first pump source interface on the valve body, the steering pump is connected to a second pump source interface on the valve body, and the boom cylinder and the bucket cylinder are connected to cylinder interfaces on the valve body that are connected to the working oil ports of the corresponding main valves.

[0012] The utility model provides a technical solution for achieving the purpose: a loader having the above-mentioned loader hydraulic system.

[0013] Compared with the prior art, in the utility model, a cartridge-type electric proportional valve and a cartridge-type pressure reducing valve for providing pilot control oil are arranged on the valve body of the distribution valve, thereby simplifying the pilot control oil circuit of the distribution valve; two pump source interfaces are arranged on the valve body of the distribution valve for connecting two hydraulic pumps, so that the pilot control oil is separated from the working oil, and the control of the hydraulic system is stable and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a principle diagram of the distribution valve of the utility model.

[0015] Figure 2 This is a schematic diagram of the structure of the utility model distribution valve.

[0016] Figure 3 It is a schematic diagram of the hydraulic system of the utility model loader.

[0017] Parts names and serial numbers in the figure:

[0018] Distribution valve 1, bucket cylinder 2, boom cylinder 3, accumulator 4, steering pump 5, working pump 6, hydraulic oil tank 7, steering hydraulic system 8.

[0019] Valve body 10, bucket joint main valve 11, boom joint main valve 12, main working oil circuit 13, main safety valve 14, first overload valve 15, second overload valve 16, first oil replenishment check valve 17, second oil replenishment check valve 18, main return oil circuit 19, plug-in pressure reducing valve 30, pressure reducing valve 31, relief valve 32, pilot oil supply circuit 33, first electric proportional valve 41, second electric proportional valve 42, third electric proportional valve 43, fourth electric proportional valve 44. DETAILED DESCRIPTION

[0020] The specific implementation scheme is described below with reference to the accompanying drawings.

[0021] like Figure 1 Figure 2 As shown, the distribution valve in this embodiment includes a valve body 10, at least two main valve stems are arranged in the valve body 10, a first pump source interface (P1 port) for supplying working pressure oil to each main valve is arranged on the valve body 10, a pilot oil supply circuit 33 is arranged in the valve body 10, a plug-in electric proportional valve for pilot control of each main valve is arranged on the valve body 10, and a plug-in pressure reducing valve 30 connected to each electric proportional valve through the pilot oil supply circuit 33 is arranged on the valve body 10, and a second pump source interface (P2 port) for connecting to the oil inlet end of the plug-in pressure reducing valve 30 is provided on the valve body 10.

[0022] The distribution valve 1 can be used in a loader to control the boom cylinder 3 and the bucket cylinder 2 in its working device. Specifically, the main valve includes a bucket-connected main valve 11 and a boom-connected main valve 12. The boom-connected main valve 12 and the bucket-connected main valve 11 are connected to the first pump source interface (P1 port) on the valve body 10 through the main working oil circuit 13 in the valve body 10. In the hydraulic system, the first pump source interface (P1 port) is usually connected to the working pump 6, and the working pump 6 supplies oil. The return oil ports of the bucket-connected main valve 11 and the boom-connected main valve 12 are connected to the main return oil circuit 19 in the valve body 10, and the main return oil circuit 19 is connected to the hydraulic oil tank 7 through the main return oil interface (T1 port) on the valve body 10 and the return oil pipe.

[0023] Corresponding to the bucket-joined main valve 11 and the boom-joined main valve 12, four electric proportional valves are arranged on the valve body 10, namely the first electric proportional valve 41, the second electric proportional valve 42, the third electric proportional valve 43, and the fourth electric proportional valve 44. The oil outlet ends of the first electric proportional valve 41 and the second electric proportional valve 42 are connected to the hydraulic control ends at both ends of the valve stem of the bucket-joined main valve 11 to control the bucket-joined main valve 11. The oil outlet ends of the third electric proportional valve 43 and the fourth electric proportional valve 44 are connected to the hydraulic control ends at both ends of the valve stem of the boom-joined main valve 12 to control the boom-joined main valve 12. The oil inlet ends of the first electric proportional valve 41, the second electric proportional valve 42, the third electric proportional valve 43, and the fourth electric proportional valve 44 are all connected to the pilot oil supply circuit 33, and are supplied with oil by the plug-in pressure reducing valve 30. The oil return ends of the first electric proportional valve 41, the second electric proportional valve 42, the third electric proportional valve 43, and the fourth electric proportional valve 44 are connected to the pilot oil return circuit in the valve body 10, and the pilot oil return circuit is connected to the hydraulic oil tank 7 through its pilot oil return interface (T2 port) and pipeline.

[0024] The plug-in pressure reducing valve 30 includes a pressure reducing valve 31 and a relief valve 32. The oil inlet of the pressure reducing valve 31 is connected to the second pump source interface (P2 port), and the oil outlet is connected to the oil inlet of the relief valve 32 and the oil inlet of each electric proportional valve. The oil outlet of the relief valve 32 is connected to the main oil return oil circuit 19 in the valve body. The relief valve 32 acts as a safety valve to limit the maximum pressure in the pilot oil supply circuit 33.

[0025] A first overload valve 15 and a second overload valve 16 are installed on the valve body 10. The oil inlet ends of the first overload valve 15 and the second overload valve 16 are connected to the two working oil ports of the rotating bucket main valve 11, and the oil outlets are connected to the main return oil circuit 19. When the pressure at the oil inlet ends of the first overload valve 15 and the second overload valve 16 reaches their set values, the overload valves open to unload, thereby preventing the hydraulic actuator connected to the rotating bucket main valve 11 from overloading and causing damage to the device.

[0026] The valve body 10 is provided with a plug-in main safety valve 14, the oil inlet and outlet ends of the main safety valve 14 are connected to the main working oil circuit 13 and the main return oil circuit 19 in the valve body 10. The main safety valve 14 is used to limit the maximum pressure in the main working oil circuit 13.

[0027] The two-way main valve is equipped with a plug-in oil replenishment check valve on the valve body 10; the oil inlet ends of the first oil replenishment check valve 17 corresponding to the bucket-joined main valve 11 and the second oil replenishment check valve 18 corresponding to the boom-joined main valve are both connected to the main return oil circuit 19, the oil outlet end of the first oil replenishment check valve 17 is connected to a working oil port of the bucket-joined main valve, and the oil outlet end of the second oil replenishment check valve 18 is connected to a working oil port of the boom-joined main valve. When the working oil port of the corresponding joint main valve cannot meet the flow demand of the hydraulic actuator it is connected to, the oil replenishment check valve opens, and the oil flows directly from the main return oil circuit 19 to the hydraulic actuator to avoid air suction. The oil replenishment check valve can be configured as needed, and can be configured for one of the joint main valves in the valve body, or for all the joint main valves.

[0028] The valve body 10 is provided with an accumulator interface (Pc port), which is connected to the pilot oil supply circuit 33. The accumulator 4 is connected through the accumulator interface (Pc port) to stabilize the pressure in the pilot oil supply circuit 33, and to provide pilot control oil when the cartridge pressure reducing valve 30 cannot provide pilot control hydraulic oil, so as to perform a limited number of switching operations for the main valve.

[0029] The second pump source interface (P2 port) on the valve body 10 can be connected to a hydraulic pump. For example, on a loader, the second pump source interface (P2 port) is connected to the steering pump 5, so that the plug-in pressure reducing valve 30 is supplied with pilot oil for controlling the distribution valve by the steering pump 5, and the pilot oil for controlling the distribution valve is not drawn out from the main working oil circuit 13, thereby preventing the pilot oil for controlling the distribution valve from being affected by the pressure of the main working oil circuit 13.

[0030] In the valve body 10, more main valves can be configured as needed, for example, a third main valve can be configured to control the accessories. Corresponding to the third main valve, an electric proportional valve for controlling the third main valve is configured in the valve body 10, and the oil inlet end of the electric proportional valve is connected to the pilot oil supply circuit.

[0031] This embodiment provides a loader hydraulic system, such as Figure 3 As shown, the hydraulic system includes the aforementioned distribution valve 1, as well as a bucket cylinder 2, a boom cylinder 3, an accumulator 4, a steering pump 5, a working pump 6, a hydraulic oil tank 7 and a steering hydraulic system 8.

[0032] The bucket cylinder 2 is connected to the bucket cylinder interface (A1 port and B1 port) on the distribution valve 1 through a pipeline, and the bucket cylinder interface (A1 port and B1 port) on the distribution valve 1 is communicated with the working oil port of the bucket joint main valve 11 through the oil passage in the valve body 10. The boom cylinder 3 is connected to the boom cylinder interface (A2 port and B2 port) on the distribution valve 1 through a pipeline, and the boom cylinder interface (A2 port and B2 port) on the distribution valve 1 is communicated with the working oil port of the boom joint main valve 12 through the oil passage in the valve body 10.

[0033] The accumulator 4 is connected to the accumulator interface (P2 port) on the valve body 10. The pump port of the steering pump 5 is connected to the second pump source interface (P2 port) on the valve body 10 through a pipeline, and the pump port of the steering pump 5 is also connected to the steering hydraulic system 8 through a pipeline to supply oil to the steering hydraulic system 8. The working pump 6 is connected to the first pump source interface (P1 port) on the valve body 10, and is used to provide the hydraulic oil required for the action of the bucket cylinder 2 and the boom cylinder 3. The main return oil interface (T1 port) on the valve body 10 connected to the main return oil circuit 19 and the pilot return oil interface (T2 port) connected to the pilot return oil circuit are each connected to the hydraulic oil tank 7 through a pipeline. The suction ports of the steering pump 5 and the working pump 6 are connected to the hydraulic oil tank 7 through a pipeline to draw oil from the hydraulic oil tank 7.

[0034] This embodiment also provides a loader having the aforementioned loader hydraulic system.

[0035] In this embodiment, the electric proportional valves of each main valve are installed on the valve body 10 of the distribution valve using a cartridge valve, and a cartridge pressure reducing valve 30 is installed on the valve body of the distribution valve to provide pilot pressure oil for each electric proportional valve for controlling each main valve, thereby simplifying the control oil circuit of the distribution valve. The cartridge pressure reducing valve 30 is installed and connected to the second pump source interface (P1 port) on the valve body 10, so that the pilot pressure oil for control is not affected by the working oil circuit.

Claims

1. A distribution valve, comprising a valve body, at least two main valve stems arranged in the valve body, and a first pump source interface for supplying working pressure oil to each main valve through a main working oil circuit, characterized in that: A pilot oil supply circuit is arranged in the valve body, and an electric proportional valve for pilot control of the valve stems of each main valve is arranged on the valve body, and a cartridge-type pressure reducing valve is connected to each electric proportional valve through the pilot oil supply circuit. A second pump source interface is provided on the valve body for connecting to the oil inlet end of the cartridge-type pressure reducing valve.

2. The dispensing valve according to claim 1, characterized in that: An accumulator interface is provided on the valve body, and the accumulator interface is communicated with the pilot oil supply circuit.

3. The dispensing valve according to claim 1, characterized in that: The plug-in pressure reducing valve includes a pressure reducing valve and a relief valve; the oil inlet end of the pressure reducing valve is connected to the second pump source interface, and the oil outlet end is simultaneously connected to the oil inlet end of the relief valve and the oil inlet ends of each electric proportional valve; the oil outlet end of the relief valve is connected to the main return oil circuit in the valve body.

4. The dispensing valve according to claim 1, characterized in that: The valve body is provided with a plug-in main safety valve, and the oil inlet and outlet ends of the main safety valve are correspondingly connected with the main working oil circuit and the main return oil circuit in the valve body.

5. The dispensing valve according to claim 1, characterized in that: The valve body is provided with a first overload valve and a second overload valve of a plug-in type, the oil inlet ends of the first overload valve and the second overload valve are correspondingly connected to the two working oil ports of a main valve, and the oil outlet ends of the first overload valve and the second overload valve are connected to the main return oil circuit.

6. The dispensing valve according to claim 1, characterized in that: At least one main valve is provided with a plug-in oil replenishment check valve corresponding to the main valve on the valve body; the oil inlet end of the oil replenishment check valve is connected to the main return oil circuit, and the oil outlet end is connected to a working oil port of the main valve.

7. A loader hydraulic system, comprising a boom cylinder, a bucket cylinder, a working pump, a steering pump, and a hydraulic oil tank, characterized in that: It also includes the distribution valve described in any one of claims 1 to 6, the working pump is connected to the first pump source interface on the valve body, the steering pump is connected to the second pump source interface on the valve body, and the boom cylinder and bucket cylinder are connected to the cylinder interface on the valve body that is connected to the working oil port of the corresponding main valve.

8. A loader, characterized in that: The loader has the hydraulic system as claimed in claim 7.

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