Hydraulic control valve, vibration motor hydraulic system and engineering machinery

Abstract

The utility model relates to the technical field of hydraulic pressure, and provides a hydraulic control valve, a vibrating motor hydraulic system and engineering machinery to solve the problem that the vibration frequency of a vibrating hydraulic motor in the engineering machinery is changed due to flow change. The hydraulic control system is provided with a working oil inlet used for being connected with a working pressure oil source, a working oil outlet used for being connected with a hydraulic execution piece, a main control valve and a fixed differential pressure reducing valve. An oil inlet of the fixed differential pressure reducing valve is communicated with a working oil inlet, an oil outlet of the fixed differential pressure reducing valve is communicated with an oil inlet of the control main valve, an oil outlet of the control main valve is communicated with a working oil outlet, and a spring cavity of the fixed differential pressure reducing valve is communicated with an oil outlet of the control main valve. In the hydraulic control valve, the opposite ends of the spring cavity and the spring cavity of the fixed differential pressure reducing valve are respectively communicated with the oil outlet and the oil inlet of the control main valve, so that the flow is automatically adjusted, and the stable flow is realized.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic technology, and more specifically, to a hydraulic control valve, a vibration motor hydraulic system, and engineering machinery. Background Technology

[0002] Construction machinery such as loaders are usually equipped with corresponding attachments or auxiliary devices to achieve certain functions, including vibratory pushers generated by the rotation of hydraulic motors. The vibration frequency of the vibratory pusher is determined by the rotation speed of the hydraulic motor, which is connected to the working pump on the construction machinery through a control valve.

[0003] In construction machinery, the working pump not only supplies pressurized oil to attachments and auxiliary devices, but also supplies oil to other hydraulic actuators within the working device. The working pump, providing the pressurized oil source, is typically engine-driven. If the hydraulic system of construction machinery is a fixed-displacement system, its working pump is usually a fixed-displacement pump, such as a gear pump. Changes in engine speed will cause changes in the output flow of the working pump. Therefore, in construction machinery equipped with vibratory pushers, when the engine speed decreases or other hydraulic actuators operate, the oil flow to the hydraulic motor that generates vibration decreases, resulting in a decrease in the vibration frequency of the vibratory pusher. Utility Model Content

[0004] The technical problem to be solved by this utility model is the problem of the vibration frequency change of the hydraulic motor that generates vibration in engineering machinery due to the change of flow rate, and provides a hydraulic control valve, a vibration motor hydraulic system and engineering machinery.

[0005] The technical solution of this utility model to achieve its purpose is: a hydraulic control valve, which has a working oil inlet for connecting to a working pressure oil source, a working oil outlet for connecting to a hydraulic actuator, and also includes a control main valve and a differential pressure reducing valve.

[0006] The oil inlet of the differential pressure reducing valve is connected to the working oil inlet, the oil outlet of the differential pressure reducing valve is connected to the oil inlet of the control main valve, the oil outlet of the control main valve is connected to the working oil outlet, and the spring chamber of the differential pressure reducing valve is connected to the oil outlet of the control main valve.

[0007] In the hydraulic control valve of this utility model, the opposite end of the spring cavity of the differential pressure reducing valve is connected to the oil outlet of the differential pressure reducing valve.

[0008] In the hydraulic control valve of this utility model, a damping orifice is provided on the oil connection line between the spring cavity of the differential pressure reducing valve and the oil outlet of the control main valve and / or on the oil connection line between the opposite end of the spring cavity of the differential pressure reducing valve and the oil outlet of the differential pressure reducing valve.

[0009] In the hydraulic control valve of this utility model, the hydraulic control valve also has a return oil port for communicating with the hydraulic oil tank and includes an overflow valve, wherein the inlet and outlet ports of the overflow valve are connected to the working oil inlet and the return oil port respectively.

[0010] In the hydraulic control valve of this utility model, the hydraulic control valve also includes a replenishing oil check valve, the inlet and outlet ports of which are connected to the outlet and return ports of the control main valve respectively.

[0011] In the hydraulic control valve of this utility model, the hydraulic control valve also includes an electro-proportional valve, the oil inlet of which is connected to the working oil inlet, and the oil outlet of which is connected to the hydraulic control end of the control main valve.

[0012] In the hydraulic control valve of this utility model, a damping orifice is provided in the oil connection line between the oil inlet end of the electro-proportional valve and the working oil inlet, and / or in the oil connection line between the oil outlet end of the electro-proportional valve and the hydraulic control end of the control main valve.

[0013] In the hydraulic control valve of this utility model, the return oil end of the electro-proportional valve is connected to the return oil port.

[0014] The technical solution of this utility model to achieve its purpose is: a vibration motor hydraulic system, including a fixed-displacement working pump, a vibration hydraulic motor, and the aforementioned hydraulic control valve. The working oil inlet is connected to the fixed-displacement working pump, and the oil inlet of the vibration hydraulic motor is connected to the working oil outlet of the hydraulic control valve.

[0015] The technical solution of this utility model to achieve its purpose is: an engineering machine that has the aforementioned hydraulic control valve or the aforementioned vibratory motor hydraulic system. This engineering machine can be a loader, road roller, paver, etc., and the quantitative working pump can be a gear pump.

[0016] Compared with the prior art, in the hydraulic control valve, the spring chamber and the opposite end of the spring chamber of the differential pressure reducing valve are connected to the oil outlet and oil inlet of the control main valve respectively to automatically adjust the flow rate and achieve flow stability. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the hydraulic control valve of this utility model.

[0018] Figure 2 This is a schematic diagram of the hydraulic system of the vibration motor of this utility model.

[0019] Component names and serial numbers in the diagram:

[0020] 1. Quantitative working pump; 2. Differential pressure valve; 3. Electro-proportional valve; 4. Control main valve; 5. Vibratory hydraulic motor; 6. Fluid replenishment check valve; 7. Hydraulic oil tank; 8. Relief valve; 9. Other hydraulic actuators; 10. Hydraulic control valve. Detailed Implementation

[0021] The specific implementation plan is described below with reference to the attached diagram.

[0022] like Figure 1 As shown, the hydraulic control valve 10 has a working oil inlet (P port) for connecting to the working pressure oil source and a working oil outlet (A port) for connecting to the hydraulic actuator. It also includes a control main valve 4, a differential pressure reducing valve 2, etc.

[0023] The oil inlet of the differential pressure reducing valve 2 is connected to the working oil inlet (P port), the oil outlet of the differential pressure reducing valve 2 is connected to the oil inlet of the control main valve 4, the oil outlet of the control main valve 4 is connected to the working oil outlet (A port), the spring cavity of the differential pressure reducing valve 2 is connected to the oil outlet of the control main valve 4, and the opposite end of the spring cavity of the differential pressure reducing valve 2 is connected to the oil outlet of the differential pressure reducing valve 2.

[0024] In this embodiment, the differential pressure reducing valve 2 automatically adjusts the valve opening based on the pressure difference between the oil inlet and outlet of the control main valve 4, so that the flow output of the oil outlet of the control main valve 4 is stable and will not change significantly with the decrease of the output flow of the pressure oil source within a certain range.

[0025] Optionally, a damping orifice is provided in the oil connection line between the spring chamber of the differential pressure reducing valve 2 and the oil outlet of the control main valve 4, and / or in the oil connection line between the opposite end of the spring chamber of the differential pressure reducing valve 2 and the oil outlet of the differential pressure reducing valve 2.

[0026] Optionally, the hydraulic control valve 10 also has a return port (T port) for communication with the hydraulic oil tank 7 and includes a relief valve 8, the inlet and outlet of which are respectively connected to the working oil inlet (P port) and the return port (T port). The relief valve 8 acts as a safety valve. When the pressure of the pressure oil input to the working oil inlet (P port) is higher than the opening pressure of the relief valve 8, the relief valve 8 opens to relieve the load, thereby protecting the hydraulic actuator connected to the working oil outlet (A port) from damage caused by hydraulic oil pressure exceeding its working pressure.

[0027] Optionally, the hydraulic control valve 10 also includes a replenishing check valve 6, the inlet and outlet ports of which are connected to the outlet and return port (T port) of the control main valve 4, respectively. When the control main valve 4 is switched off, the hydraulic actuator connected to the working oil outlet (A port) may continue to operate due to inertia. At this time, the hydraulic actuator can obtain oil without driving force through the one-way replenishing valve 6, avoiding the hydraulic actuator from suddenly stopping and generating shock due to sudden oil cut-off.

[0028] Optionally, the hydraulic control valve 10 also includes an electro-proportional valve 3, the inlet of which is connected to the working oil inlet (P port), and the outlet of which is connected to the hydraulic control end of the control main valve 4. The electro-proportional valve 3 is used to control the control main valve 4, thereby controlling the speed of movement of the hydraulic actuator connected to the working oil outlet (A port).

[0029] Optionally, a damping orifice is provided in the oil connection line between the oil inlet of the electro-proportional valve 3 and the working oil inlet (P port) and / or in the oil connection line between the oil outlet of the electro-proportional valve 3 and the hydraulic control end of the main control valve 4. The damping orifice is used for pressure reduction and buffering, reducing the impact during the reversing operation of the main control valve 4. The return oil end of the electro-proportional valve 3 is connected to the return oil port (T port).

[0030] This embodiment also provides a hydraulic system for a vibration motor, such as Figure 2 As shown, it includes a fixed-displacement pump 1, a vibratory hydraulic motor 5, and the aforementioned hydraulic control valve 10. The working oil inlet (P port) is connected to the fixed-displacement pump 1, and the oil inlet of the vibratory hydraulic motor 5 is connected to the working oil outlet (A port) of the hydraulic control valve 10. The fixed-displacement pump 1 can be a gear pump. In this embodiment, in addition to supplying working pressure oil to the vibratory hydraulic motor 5, the fixed-displacement pump can also supply working pressure oil to the oil circuits 9 of other hydraulic actuators. The fixed displacement pump 1 is driven by the engine. If the hydraulic flow through the differential pressure reducing valve 2 decreases due to a reduction in the speed of the fixed displacement pump 1 or the action of other hydraulic actuators connected to the fixed displacement pump 1, the pressure at the outlet of the control main valve 4 will decrease. This pressure will be fed back to the spring chamber of the differential pressure reducing valve 2. The differential pressure reducing valve 2 will adjust and increase its opening according to the pressure difference between the inlet and outlet of the control main valve 4, thereby increasing the flow to the vibrating hydraulic motor 5. This prevents the flow through the vibrating hydraulic motor from decreasing due to a decrease in the flow of the fixed displacement pump or the action of other hydraulic actuators, thus preventing the vibration frequency from failing to meet the requirements due to a decrease in the speed of the vibrating hydraulic motor.

[0031] This embodiment also provides an engineering machine having the aforementioned hydraulic control valve or the aforementioned vibration motor hydraulic system. The engineering machine may be a loader, and the fixed displacement pump may be a gear pump.

Claims

1. A hydraulic control valve having a working oil inlet for connection to a working pressure oil source and a working oil outlet for connection to a hydraulic actuator, characterized in that, It also includes the main control valve and the differential pressure reducing valve; The oil inlet of the differential pressure reducing valve is connected to the working oil inlet, the oil outlet of the differential pressure reducing valve is connected to the oil inlet of the control main valve, the oil outlet of the control main valve is connected to the working oil outlet, and the spring chamber of the differential pressure reducing valve is connected to the oil outlet of the control main valve.

2. The hydraulic control valve according to claim 1, characterized in that, The opposite end of the spring cavity of the differential pressure reducing valve is connected to the oil outlet of the differential pressure reducing valve.

3. The hydraulic control valve according to claim 2, characterized in that, A damping orifice is provided on the oil connection line between the spring chamber of the differential pressure reducing valve and the oil outlet of the control main valve, and / or on the oil connection line between the opposite end of the spring chamber of the differential pressure reducing valve and the oil outlet of the differential pressure reducing valve.

4. The hydraulic control valve according to claim 1, characterized in that, The hydraulic control valve also has a return port for communication with a hydraulic oil tank and includes a relief valve, the inlet and outlet of which are respectively connected to the working oil inlet and the return port.

5. The hydraulic control valve according to claim 1, characterized in that, The hydraulic control valve also includes a replenishing check valve, the inlet and outlet ports of which are connected to the outlet and return ports of the main control valve, respectively.

6. The hydraulic control valve according to any one of claims 1 to 5, characterized in that, The hydraulic control valve also includes an electro-proportional valve, the inlet of which is connected to the working oil inlet, and the outlet of which is connected to the hydraulic control end of the main control valve.

7. The hydraulic control valve according to claim 6, characterized in that, A damping orifice is provided in the oil connection line between the oil inlet of the electro-proportional valve and the working oil inlet, and / or in the oil connection line between the oil outlet of the electro-proportional valve and the hydraulic control end of the main control valve.

8. The hydraulic control valve according to claim 6, characterized in that, The return oil end of the electro-proportional valve is connected to the return oil port.

9. A hydraulic system for a vibratory motor, comprising a fixed displacement pump and a vibratory hydraulic motor, characterized in that, It also includes a hydraulic control valve according to any one of claims 1 to 8, wherein the working oil inlet is connected to a fixed displacement working pump, and the oil inlet of the vibrating hydraulic motor is connected to the working oil outlet of the hydraulic control valve.

10. An engineering machinery, characterized in that, It has a hydraulic control valve as described in any one of claims 1 to 8, or a vibration motor hydraulic system as described in claim 9.

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