An excavator hydraulic system and excavator

Abstract

The application provides a kind of excavator hydraulic system and excavator, belong to engineering machinery technical field, comprising: first master pump, second master pump, hydraulic oil tank, pilot oil circuit, main valve, crushing switch valve and breaking hammer;First master pump, second master pump are connected between the hydraulic oil tank and main valve respectively;Crushing switch valve adopts cone valve to realize the on-off of oil supply pipeline, it is equipped with two oil inlets, is connected first master pump and second master pump respectively, and oil outlet is connected with the oil inlet of breaking hammer;Crushing switch valve has two states of work and non-work, in its working state, the hydraulic oil of two oil inlets is combined after passing through cone valve, and oil supply is provided for breaking hammer together.This application adopts cone valve with good sealing effect to realize crushing switch, and the cone valve can automatically dissipate energy when bleeding, reduce the impact on oil supply pipeline, and avoid breaking hammer leakage caused by oil inlet pulse pressure.

Description

Technical Field

[0001] This invention relates to a hydraulic system for an excavator and an excavator, belonging to the field of engineering machinery technology. Background Technology

[0002] Existing excavators employ two hydraulic systems for crushing operations: single-pump and dual-pump hydraulic systems. The single-pump system is only suitable for smaller hydraulic breakers, resulting in low crushing efficiency and underutilization of the excavator's performance. The existing dual-pump hydraulic systems generally suffer from the following problems: (1) High pulse pressure in the oil inlet circuit causes a large overflow flow of the main relief valve, which increases the leakage of the hydraulic breaker. (2) High back pressure of return oil generates a lot of heat, causing high temperature in the hydraulic system and greatly reducing crushing efficiency. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide an excavator hydraulic system and excavator, which solves the problems of high pulse pressure in the external confluence oil inlet circuit and large overflow flow of the main relief valve.

[0004] To achieve the above objectives, the present invention is implemented using the following technical solution: In a first aspect, the present invention provides a hydraulic system for an excavator, comprising: a first main pump, a second main pump, a hydraulic oil tank, a pilot oil circuit, a main valve, a breaker switching valve, and a breaker hammer; the first main pump and the second main pump are respectively connected between the hydraulic oil tank and the main valve; the breaker switching valve uses a conical valve to realize the opening and closing of the oil supply pipeline; the breaker switching valve has two oil inlets, which are respectively connected to the first main pump and the second main pump, and its oil outlet is connected to the oil inlet of the breaker hammer; the breaker switching valve has two states, working and non-working, in which the hydraulic oil from the two oil inlets merges after passing through the conical valve to jointly supply oil to the breaker hammer.

[0005] As an optional technical solution of the present invention, the crushing switching valve adopts a two-position directional valve to control the opening and closing state of two cone valves; the two-position directional valve is connected to the return oil line of the two cone valves, and its pilot port is connected to the pilot pump through a pilot solenoid valve; when the two-position directional valve is in the first working position, the return oil line of the two cone valves is connected to the hydraulic oil tank, both cone valves are open, and the crushing switching valve enters the working state; when the two-position directional valve is in the second working position, the return oil line of the two cone valves is blocked, and oil cannot return, both cone valves are closed, and the crushing switching valve enters the non-working state.

[0006] As an optional technical solution of the present invention, the pilot oil circuit includes a first proportional solenoid valve; the first proportional solenoid valve is connected between the pilot pump and the pilot port of the main relief valve of the main valve, and is used to receive an electrical signal sent by the controller, so that the pilot oil acts on the pilot port of the main relief valve to increase the pressure value of the main relief valve.

[0007] As an optional technical solution of the present invention, it further includes: an oil diffuser installed in the return oil pipeline of the breaker; a pressure sensor and a second proportional directional valve installed on the return oil pipeline between the oil diffuser and the breaker; both the pressure sensor and the second proportional directional valve are connected to the controller signal; the pressure sensor is used to measure the return oil back pressure in real time and send the return oil back pressure to the controller.

[0008] When the return oil back pressure exceeds the preset oil pressure threshold, the controller sends a control signal to the second proportional directional valve to open the second proportional directional valve, and the hydraulic oil returns directly through the second proportional directional valve.

[0009] As an optional technical solution of the present invention, the oil cooler adopts air cooling, and its heat dissipation device includes: a fan valve group, a fan pump and a fan motor; the fan valve group is signal connected to the controller, and after receiving the control signal from the controller, the oil supply pipeline between the fan pump and the fan motor is connected, and the fan is turned on.

[0010] As an optional technical solution of the present invention, the fan valve assembly has at least a working position one, a working position two, and a working position three; when the fan valve is in working position one, the fan pump and the fan motor are not connected, and the fan is turned off; when the fan valve is in working position two, the fan pump and the fan motor are connected, and the fan rotates clockwise; when the fan valve is in working position three, the fan pump and the fan motor are connected, and the fan rotates counterclockwise.

[0011] As an optional technical solution of the present invention, it further includes: a temperature sensor for measuring the oil temperature of the hydraulic oil tank, the temperature sensor being signal-connected to the controller; when the oil temperature measured by the temperature sensor is lower than the preset lower limit of the working temperature of the hydraulic breaker, the controller sends a control signal to the second proportional directional valve to control the second proportional directional valve to open, and the hydraulic oil returns directly through the second proportional directional valve; when the oil temperature measured by the temperature sensor is higher than the preset upper limit of the working temperature of the hydraulic breaker, the controller sends a control signal to the fan pump to control the fan pump to increase its displacement, thereby increasing the speed of the fan motor.

[0012] As an optional technical solution of the present invention, the pilot solenoid valve of the pilot oil circuit adopts a four-way proportional solenoid valve group. The four groups of proportional solenoid valves are respectively used to pilot control the two-position directional valve and the main valve's main relief valve, first pressure shut-off valve and second pressure shut-off valve.

[0013] In a second aspect, the present invention provides an excavator, including the excavator hydraulic system described in the first aspect.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: (1) The hydraulic system of the excavator provided by the present invention uses a cone valve to realize the breaking switch valve. The cone valve has a good sealing effect and can automatically dissipate energy when leaking, reducing the impact on the oil supply pipeline and avoiding leakage of the breaker hammer due to the pulse pressure of the oil inlet. (2) The excavator hydraulic system provided by the present invention adjusts the pressure value of the main relief valve by adding a pilot oil circuit that directly acts on the pilot port of the main relief valve. In the non-crushing mode, the pressure value of the main relief valve is a preset value. In the crushing mode, the pressure value of the main relief valve is increased by the first proportional solenoid valve, the overflow of the main relief valve is reduced, and the crushing efficiency is improved. (3) The excavator hydraulic system provided by the present invention adds a fast return oil pipeline controlled by a second proportional solenoid valve to the return oil pipeline of the breaker. When the return oil back pressure is high or the oil temperature of the hydraulic oil tank is low, the second proportional solenoid valve is opened to perform fast return oil, quickly release the oil pressure of the return oil pipeline or bypass the oil diffuser to return oil and restore the oil temperature of the hydraulic oil tank. Attached Figure Description

[0015] Figure 1 A diagram of the hydraulic system of an excavator provided for this invention; In the diagram: 1-Triple pump, 2-Quadruple proportional solenoid valve assembly, 3-Controller, 4-Main valve, 5-Crusher hammer, 6-Pressure sensor, 7-Electro-proportional directional valve, 8-Fan motor, 9-Fan valve assembly, 10-Fan pump, 11-Temperature sensor, 12-Return oil filter, 13-Crusher switching valve. Detailed Implementation

[0016] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus. The technical solutions of the embodiments of this application will now be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them.

[0017] Example 1 This embodiment provides a hydraulic system for an excavator, such as... Figure 1 As shown, it includes: a triple pump 1, a quadruple proportional solenoid valve group 2, a controller 3, a main valve 4, a breaker hammer 5, a return oil filter 12, and a breaker switching valve 13. The triple pump 1 includes a first main pump P1, a second main pump P2, and a pilot pump P3.

[0018] In the diagram, the triple pump 1, the quadruple proportional solenoid valve group 2, the main valve 4, the breaker 5, the return oil filter 12, and the breaker switching valve 13 are connected via hydraulic pipelines. The input ports of the triple pump 1 and the quadruple proportional solenoid valve group 2 are connected to the controller 3 via electrical wiring harnesses. Specifically, Y1, Y2, Y3, and Y4 of the quadruple proportional solenoid valve group 2 are used to pilot-control the breaker switching valve 13, the main relief valve of the main valve, the first pressure shut-off valve in the main valve for controlling the first main pump P1, and the second pressure shut-off valve in the main valve for controlling the second main pump P2, respectively.

[0019] In this embodiment, the crushing switching valve 13 includes: two cone valves and a two-position directional valve. The oil inlets of the two cone valves are respectively connected to the first main pump P1 and the second main pump P2. The two-position directional valve is connected to the return oil pipeline of the two cone valves and is used to control the opening and closing state of the two cone valves. The pilot port of the two-position directional valve is connected to the pilot pump P3 through the Y1 of the four-way proportional solenoid valve group 2.

[0020] The on / off state of the two-position directional valve corresponds to the working and non-working states of the crushing switching valve 13. When the two-position directional valve is in the first working position, the return oil lines of the two cone valves are connected to the hydraulic oil tank, both cone valves are open, and the crushing switching valve is in the working state. When the two-position directional valve is in the second working position, the return oil lines of the two cone valves are blocked, and oil cannot return. Both cone valves are closed, and the crushing switching valve is in the non-working state.

[0021] In the non-working state, the breaker hammer does not work, and the excavator performs non-breaking operations. When the excavator is performing breaking operations, the controller 3 first outputs a control signal to Y1 of the four-way proportional solenoid valve group 2 according to the excavator's mode switching signal. Y1 opens, and the breaking switching valve 13 enters the working state. At this time, the pilot oil acts on the two-position directional valve of the breaking switching valve 13 through the A1 port of the four-way proportional solenoid valve group 2, making it work in the left position. The pilot oil of the two cone valves returns to the hydraulic oil tank through the two-position directional valve. The two cone valves are unlocked, and the hydraulic oil is formed by the first main pump P1 and the second main pump P2 converging through the cone valve of the breaking switching valve 13 to form high-pressure oil. The high-pressure oil enters from the P port of the breaker hammer 5, passes through the T port of the breaker hammer 5, disperses, and returns to the hydraulic oil tank through the return oil filter 12.

[0022] It should be noted that the Y2 of the four-way proportional solenoid valve group 2 is connected between the pilot pump and the pilot port of the main relief valve of the main valve. It is used to receive the electrical signal sent by the controller 3 during the crushing operation, so that the pilot oil acts on the pilot port of the main relief valve to increase the pressure value of the main relief valve. The controller 3 adjusts the electrical signal proportionally to gradually increase the pressure value of the main relief valve from the preset value to the maximum value. This design can improve the power of the breaker hammer 5 during the crushing operation and avoid the large overflow flow of the main relief valve caused by a fixed pressure value.

[0023] Example 2 Based on Example 1, this example provides an excavator hydraulic system capable of adjusting hydraulic oil temperature.

[0024] like Figure 1 As shown, the excavator hydraulic system in this embodiment also includes: a temperature sensor 11 for measuring the oil temperature of the hydraulic oil tank, an oil diffuser, a pressure sensor 6 and an electro-proportional directional valve 7 installed in the return oil line of the breaker 5, as well as a fan motor 8, a fan valve group 9 and a fan pump 10.

[0025] It should be noted that the electro-proportional directional valve 7 is installed between the return oil line of the hydraulic breaker 5 and the hydraulic oil tank, forming a fast return oil line that bypasses the oil diffuser. The controller 3 is connected to the electro-proportional directional valve 7 by signal and adjusts the flow rate of the fast return oil line proportionally according to the electrical signal.

[0026] Pressure sensor 6 is also connected to the controller signal to measure the return oil back pressure in real time and send the return oil back pressure to controller 3. When the return oil back pressure exceeds the preset oil pressure threshold, the controller sends a control signal to the electro-proportional directional valve 7 to open the electro-proportional directional valve 7. The hydraulic oil returns directly through the electro-proportional directional valve 7, quickly releasing the pressure in the return oil pipeline of the breaker 5 and avoiding the generation of a large amount of heat that could cause high temperatures in the hydraulic system.

[0027] In this embodiment, the fan motor 8, fan valve group 9, and fan pump 10 constitute an oil-cooled air-dissipating device. The fan valve group 9 is signal-connected to the controller 3. The fan valve group 9 has at least three working positions: working position one, working position two, and working position three. When the fan valve group 9 is in working position one, the fan pump 10 is not connected to the fan motor 8, and the fan is off. When the fan valve group 9 is in working position two, the fan pump 10 is connected to the fan motor 8, and the fan rotates clockwise. When the fan valve group 9 is in working position three, the fan pump 10 is connected to the fan motor 8, and the fan rotates counterclockwise.

[0028] It should be noted that one direction of the fan is used for oil cooling and heat dissipation, while the other direction is used for dust removal and cleaning.

[0029] Under the control of controller 3, the fan valve group 9 operates in the left position after being energized. The high-pressure oil output by the fan pump 10 enters the P2 port of the fan motor 8 through the P port and B port of the fan valve group 9. The hydraulic oil returns to the hydraulic oil tank through the P1 port of the fan motor 8, the A port and T port of the fan valve group 9, the oil diffuser, and the return oil filter 12.

[0030] Temperature sensor 11 is connected to controller 3 to monitor the real-time temperature of the hydraulic oil tank. When the oil temperature measured by temperature sensor 11 is lower than the preset lower limit of the hydraulic breaker's working temperature, it indicates that the hydraulic oil temperature is below the optimal working temperature range of the hydraulic breaker, and there is no need for oil cooling. At this time, controller 3 sends a control signal to electro-proportional directional valve 7 to open the electro-proportional directional valve 7, and the hydraulic oil returns directly through the electro-proportional directional valve 7. When the oil temperature measured by temperature sensor 11 is higher than the preset upper limit of the hydraulic breaker's working temperature, it indicates that the hydraulic oil temperature is above the optimal working temperature range of the hydraulic breaker, and the heat dissipation needs to be increased. At this time, controller 3 sends a control signal to fan pump 10 to increase the displacement of fan pump 10, thereby increasing the speed of fan motor 8 and increasing the heat dissipation of radiator to keep the hydraulic oil temperature within the preset optimal working temperature range of the hydraulic breaker.

[0031] Example 3 This embodiment provides an excavator, including the excavator hydraulic system described in Embodiment 1 or Embodiment 2.

[0032] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] 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 hydraulic system for an excavator, characterized in that, include: First main pump, second main pump, hydraulic oil tank, pilot oil circuit, main valve, crushing switching valve and crusher; The first main pump and the second main pump are respectively connected between the hydraulic oil tank and the main valve; The crushing switching valve uses a cone valve to switch the oil supply line on and off; The crushing switching valve has two oil inlets, which are connected to the first main pump and the second main pump respectively, and its oil outlet is connected to the oil inlet of the breaker hammer. The breaker switching valve has two states: working and non-working. In its working state, the hydraulic oil from the two inlets merges after passing through the cone valve and supplies oil to the breaker hammer. The crushing switching valve uses a two-position directional valve to control the opening and closing state of two cone valves; the two-position directional valve is connected to the return oil line of the two cone valves, and its pilot port is connected to the pilot pump through a pilot solenoid valve. When the two-position directional valve is in the first working position, the return oil lines of the two cone valves are connected to the hydraulic oil tank, both cone valves are open, and the crushing switching valve enters the working state. When the two-position directional valve is in the second working position, the return oil lines of the two cone valves are blocked and cannot return oil. Both cone valves are closed, and the crushing switching valve enters the non-working state.

2. The excavator hydraulic system according to claim 1, characterized in that, The pilot oil circuit includes a first proportional solenoid valve; the first proportional solenoid valve is connected between the pilot pump and the pilot port of the main relief valve of the main valve, and is used to receive electrical signals sent by the controller, so that the pilot oil acts on the pilot port of the main relief valve to increase the pressure value of the main relief valve.

3. The excavator hydraulic system according to claim 1, characterized in that, Also includes: An oil diffuser is installed in the oil return line of the hydraulic breaker; a pressure sensor and a second proportional directional valve are installed on the oil return line between the oil diffuser and the hydraulic breaker. The pressure sensor and the second proportional directional valve are both connected to the controller signal. The pressure sensor is used to measure the return oil back pressure in real time and send the return oil back pressure to the controller; When the return oil back pressure exceeds the preset oil pressure threshold, the controller sends a control signal to the second proportional directional valve to open the second proportional directional valve, and the hydraulic oil returns directly through the second proportional directional valve.

4. The excavator hydraulic system according to claim 3, characterized in that, The oil cooler is air-cooled, and its heat dissipation device includes: fan valve assembly, fan pump and fan motor; The fan valve assembly is connected to the controller signal. After receiving the control signal from the controller, it connects the oil supply line between the fan pump and the fan motor, and the fan starts.

5. The excavator hydraulic system according to claim 4, characterized in that, The fan valve assembly has at least three working positions: working position one, working position two, and working position three. When the fan valve is in working position one, the fan pump and fan motor are not connected, and the fan is off. When the fan valve is in working position two, the fan pump and fan motor are connected, and the fan rotates clockwise. When the fan valve is in working position three, the fan pump and fan motor are connected, and the fan rotates counterclockwise.

6. The excavator hydraulic system according to claim 4, characterized in that, Also includes: A temperature sensor is used to measure the temperature of hydraulic oil in the tank, and the temperature sensor is connected to the controller signal. When the oil temperature measured by the temperature sensor is lower than the preset lower limit of the working temperature of the hydraulic breaker, the controller sends a control signal to the second proportional directional valve to open the second proportional directional valve, and the hydraulic oil returns directly through the second proportional directional valve. When the oil temperature measured by the temperature sensor is higher than the preset upper limit of the working temperature of the hydraulic breaker, the controller sends a control signal to the fan pump to increase the displacement of the fan pump, thereby increasing the speed of the fan motor.

7. The excavator hydraulic system according to claim 2, characterized in that, The pilot solenoid valve in the pilot oil circuit adopts a four-way proportional solenoid valve group. The four groups of proportional solenoid valves are used to pilot control the two-position directional valve and the main valve's main relief valve, first pressure shut-off valve and second pressure shut-off valve.

8. An excavator, characterized in that, The excavator hydraulic system includes any one of claims 1 to 7.

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