AU2022436043A1 - Multi-way valve, hydraulic system and excavator - Google Patents

Multi-way valve, hydraulic system and excavator Download PDF

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Publication number
AU2022436043A1
AU2022436043A1 AU2022436043A AU2022436043A AU2022436043A1 AU 2022436043 A1 AU2022436043 A1 AU 2022436043A1 AU 2022436043 A AU2022436043 A AU 2022436043A AU 2022436043 A AU2022436043 A AU 2022436043A AU 2022436043 A1 AU2022436043 A1 AU 2022436043A1
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Australia
Prior art keywords
oil
valve
working
port
boom
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Pending
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AU2022436043A
Inventor
Xiao CUI
Fei Huang
Shaolong Liu
Gang Xiao
Yancui XU
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Jiangsu Advanced Construction Machinery Innovation Center Ltd
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Jiangsu Advanced Construction Machinery Innovation Center Ltd
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Publication of AU2022436043A1 publication Critical patent/AU2022436043A1/en
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    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F9/00Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20Drives; Control devices
    • E02F9/22Hydraulic or pneumatic drives
    • E02F9/2264Arrangements or adaptations of elements for hydraulic drives
    • E02F9/2267Valves or distributors
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F3/00Dredgers; Soil-shifting machines
    • E02F3/04Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F3/00Dredgers; Soil-shifting machines
    • E02F3/04Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/36Component parts
    • E02F3/42Drives for dippers, buckets, dipper-arms or bucket-arms
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F3/00Dredgers; Soil-shifting machines
    • E02F3/04Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/36Component parts
    • E02F3/42Drives for dippers, buckets, dipper-arms or bucket-arms
    • E02F3/425Drive systems for dipper-arms, backhoes or the like
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F3/00Dredgers; Soil-shifting machines
    • E02F3/04Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/36Component parts
    • E02F3/42Drives for dippers, buckets, dipper-arms or bucket-arms
    • E02F3/43Control of dipper or bucket position; Control of sequence of drive operations
    • E02F3/435Control of dipper or bucket position; Control of sequence of drive operations for dipper-arms, backhoes or the like
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F9/00Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20Drives; Control devices
    • E02F9/22Hydraulic or pneumatic drives
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F9/00Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20Drives; Control devices
    • E02F9/22Hydraulic or pneumatic drives
    • E02F9/2217Hydraulic or pneumatic drives with energy recovery arrangements, e.g. using accumulators, flywheels
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F9/00Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20Drives; Control devices
    • E02F9/22Hydraulic or pneumatic drives
    • E02F9/2278Hydraulic circuits
    • E02F9/2289Closed circuit

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  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Operation Control Of Excavators (AREA)
  • Fluid-Pressure Circuits (AREA)

Abstract

OF THE DISCLOSURE Disclosed are a multi-way valve, a hydraulic system and an excavator. The multi-way valve comprises a first working unit, a second working unit and a third working unit. The first working unit comprises a travel valve group and a turning valve group. The second working unit comprises a boom group used for controlling a boom hydraulic cylinder and a bucket valve group used for controlling a bucket hydraulic cylinder. The third working unit comprises an arm valve group used for controlling an arm hydraulic cylinder and a standby valve group used for controlling a standby hydraulic cylinder. Under the condition that the size of the multi-way valve is not increased, all functions of the excavator including recycling return oil to other actuators during descending of booms of the excavator, guaranteeing the priority of arms in the case of compound actions, fulfilling overpressure-free independent regulation of bypass startup, crushing, and safety hoisting are realized, and low-power, high-efficiency and high-controllability work of the excavator is realized.

Description

MULTI-WAY VALVE, HYDRAULIC SYSTEM AND EXCAVATOR BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The invention belongs to the technical field of engineering machines, and particularly relates to a multi-way valve, a hydraulic system and an excavator.
[0003] 2. Description of Related Art
[0004] With the implementation of the green and sustainable development strategy in China and the gradual increase of environmental protection requirements, the oil consumption, working efficiency and controllability of excavators have become critical indexes for manufacturers and customers. When the booms of the excavator descend, the oil temperature of the hydraulic system rises quickly due to a large quantity of return oil and a high pressure in a boom big cavity under the weight effect, leading to an energy loss and increasing fuel consumption. According to existing solutions, return oil of the booms is recycled to other actuators to be reused through a boom recycling valve, so as to reduce fuel consumption and improve working efficiency. However, when the return oil of the booms flows through the first boom valve, a large pressure loss will be caused due to a drastic decrease of the flow area, so the utilization rate of recycled oil is low, or even the return oil cannot be recycled, indicating that the existing solutions have severe defects in principle and structure. In the aspect of controllability, especially inching controllability, a bypass oil circuit and a main oil circuit of existing excavators are regulated through one valve, the regulation of the bypass oil circuit is affected by the regulation of the main oil circuit, the impact of the excavators is large, and the overall control flexibility is unsatisfying. In addition, in some cases where the excavators are used for hoisting heavy objects, the arm big cavity of the existing excavators is not provided with a load holding structure, so when the arms retreat to an extreme position to allow the booms to be lifted for hoisting, the arms may fall during hoisting due to leakage of arm valves, which in turn affects the hoisting work. Moreover, the multi-way valve should have a standby unit when applied to of large and medium-sized excavators with a common crushing function. Existing multi-way valves that can fulfill a recycling function when the boom descend are provided with more valve trims, and by function has to be removed under the restriction of the size of the multi-way valve, so the excavators cannot fulfill the crushing function; or, the size of the multi-way valve for the excavators has to be increased to fulfill the standby function, incasing the cost and making installation inconvenient.
[0005] Existing medium or large-sized multi-way valves are based on two solutions in principle and structure. One solution has the following main features: 1, a boom recycling structure realizes recycling inside a valve and cannot recycle return oil of the booms to other actuators, so that energy loss is large; 2, the bypass oil circuit and the main oil circuit are regulated through one valve, so the impact of the whole extractor is large. The other solution has the following main features: 1, a boom recycling valve is used to realize recycling of return oil generated when the booms descend in the case of compound actions; however, when the return oil of the booms flows through the first boom valve, a large pressure loss will be caused due to a drastic decrease of the flow area, so the utilization rate of the recycled oil is low, or even the return oil cannot be recycled, indicating that this solution severe defects in principle and structure; 2. Bypass is electrically controlled and independently regulated, but due to the lack of bidirectional design, overpressure may be caused at the starting stage, or at the initial stage of starting, a main pump cannot provide a pilot oil source due to its excessively low pressure caused by a large oil return area resulting from the connection with an oil tank; 3, the arm circuit is complex, and multiple elements such as arm cut-off valves, arm recycling valves and load holding valves are used to realize the basic function of the arms, so the main valve size and the cost are increased, or the crushing function cannot be fulfilled due to size control of the multi-way valves; 4, the arm big cavity is not provided with a load holding valve in structure and principle.
[0006] The prior art has the following defects: 1, the flow of the booms cannot be recycled to other actuators, or little flow of the booms can be recycled; 2, the existing bypass solutions cannot realize independent regulation; or, bypass can be independently controlled, but overpressure may be caused at the starting stage, or at the initial stage of starting, a main pump cannot provide a pilot oil source due to its excessively low pressure caused by a large oil return area resulting from the connection with an oil tank; 3, the arm circuit of electrically controlled multi-way valves is complex, and multiple elements such as arm cut-off valves, arm recycling valves and load holding valves are used to guarantee the priority of the arms in the case of compound actions and realize oil return at low back pressure, so the main valve size and the cost are increased, or the crushing function cannot be fulfilled due to size control of the multi-way valves; 4, the arm big cavity is not provided with a load holding valve in structure and principle, so the arms may fall during hoisting work.
BRIEF SUMMARY OF THE INVENTION
[0007] Objective: In order to overcome the defects of the prior art, the invention provides a multi-way valve, a hydraulic system and an excavator, and provides a novel principle and structure of a multi-way valve for excavators.
[0008] Technical solution: To solve the aforementioned technical problems, the technical solutions adopted by the invention are as follows:
[0009] In a first aspect, the invention provides a multi-way valve, which comprises a first working unit, a second working unit, a third working unit, a first main oil inlet, a second main oil inlet and a main oil return port, and further comprises a first upper oil supply circuit communicated with the first main oil inlet, a second upper oil supply circuit communicated with the second main oil inlet, an oil return circuit communicated with the main oil return port, afirst middle oil supply passage, and a second middle oil supply passage, wherein the second working unit is disposed between the first working unit and the third working unit;
[0010] The first working unit comprises a travel valve group and a turning valve group, wherein the travel valve group comprises a linear travel valve, a left travel valve and a right travel valve, and the turning valve group comprises a turning valve used for controlling a turning hydraulic cylinder;
[0011] The second working unit comprises a boom group used for controlling a boom hydraulic cylinder and a bucket valve group used for controlling a bucket hydraulic cylinder, wherein the movable valve group comprises a first boom valve, a second boom valve, a third boom valve, a first boom load holding valve and a second boom load holding valve, and the bucket valve group comprises a bucket valve;
[0012] The third working unit comprises an arm valve group used for controlling an arm hydraulic cylinder and a standby valve group used for controlling a standby hydraulic cylinder, wherein the arm valve group comprises a first arm valve, a second arm oil inlet valve, a second arm oil return valve, an arm small cavity load holding valve and an arm big cavity load holding valve, and the standby valve group comprises a standby valve;
[0013] A first path of the first main oil inlet unidirectionally supplies oil to the first boom valve, the bucket valve, the second arm oil return valve and the standby valve through the first upper oil supply circuit;
[0014] A first path of the second main oil inlet passes through the right travel valve, sequentially passes through middle oil inlets and middle oil outlets of the turning valve, the second boom valve and the first arm valve to form the second middle oil supply passage when a middle oil inlet and a middle oil outlet of the right travel valve are communicated, and unidirectionally flows to the second upper oil supply circuit through the middle oil outlet of the right travel valve, wherein the middle oil inlets and the middle oil outlets of the turning valve, the second boom valve and the first arm valve are in a normally open state;
[0015] A second path of the first main oil inlet or the second main oil inlet is connected to the left travel valve through the linear travel valve, sequentially passes through middle oil inlets and middle oil outlets of the first boom valve, the bucket valve, the second arm oil return valve and the standby valve to form the first middle oil supply passage when a middle oil inlet and a middle oil outlet of the left travel valve are communicated, and unidirectionally flows to the first upper oil supply circuit through the middle oil outlet of the left travel valve, wherein the middle oil inlets and the middle oil outlets of the first boom valve, the bucket valve, the second arm oil return valve and the standby valve are in a normally open state;
[0016] The second path of the first main oil inlet or the second main oil inlet unidirectionally supplies oil to the turning valve, the second boom valve and the first arm valve through the second upper oil supply circuit after passing through the linear travel valve.
[0017] In some embodiments, the multi-way valve further comprises a first bypass valve, a tail end of the first middle oil supply passage is connected to an oil inlet of the first bypass valve, and an oil outlet of thefirst bypass valve is connected to the oil return passage;
[0018] The multi-way valve further comprises a second bypass valve, a tail end of the second middle oil supply passage is connected to an oil inlet of the second bypass valve, and an oil outlet of the second bypass valve is connected to the oil return passage;
[0019] The first bypass valve and the second bypass valve are four-position two-way valves and are identical in structure; when the first bypass valve or the second bypass valve is located at a first working position, the oil inlet and the oil outlet are communicated through a first damping hole; when the first bypass valve or the second bypass valve is located at a second working position, the oil inlet and the oil outlet are not communicated; when the first bypass valve or the second bypass valve is located at a third working position, the oil inlet and the oil outlet are communicated through a second damping hole; and when the first bypass valve or the second bypass valve is located at a fourth working position, the oil inlet and the oil outlet are directly communicated.
[0020] In some embodiments, the first working unit further comprises an overflow valve communicated with the main oil returnport, the first main oil inlet is connected to an oil inlet of the overflow valve through a first overflow check valve, and the second main oil inlet is connected to the oil inlet of the overflow valve through a second overflow check valve.
[0021] In some embodiments, the linear travel valve is a three-position four-way valve, and comprises a first oil inlet, a second oil inlet, a first working oil port and a second working oil port, the first oil inlet is communicated with the first main oil inlet, the second oil inlet is communicated with the second main oil inlet, the first working oil port is connected to a left travel working oil circuit which supplies oil to the left travel valve, and the second working oil port unidirectionally supplies oil to the second upper oil supply circuit;
[0022] The linear travel valve has three working positions:
[0023] When the linear travel valve is located at a first working position, the first oil inlet is communicated with the first working oil port, and the second oil inlet is communicated with the second working oil port;
[0024] When the linear travel valve is located at a second working position, the first oil inlet is communicated with the second working oil port, the second oil inlet is communicated with the first working oil port, and the first oil inlet and the second oil inlet are communicated through a first throttle hole, such that flows are combined;
[0025] When the linear travel valve is located at a third working position, the first oil inlet is communicated with the second working oil port through a third throttle hole, the first oil inlet is communicated with the second oil inlet through a check valve and a second throttle valve, and the second oil inlet is communicated with the first working oil port;
[0026] The left travel valve is a three-position six-way valve; when the left travel valve is located in a middle position, a middle oil inlet and a middle oil outlet of the left travel valve are communicated, working oil entering the first main oil inlet flows to the first middle oil supply passage through the left travel valve, working oil out of the middle oil outlet of the left travel valve unidirectionally flows to the first upper oil supply circuit, and two left travel oil ports are communicated with the oil return circuit through an oil return port of the left travel valve; when the left travel valve is located at a left working position or a right working position, the middle oil inlet and the middle oil outlet of the left travel valve are not communicated, hydraulic oil enters one of the two left travel oil ports through the left travel valve, and hydraulic oil in the other left travel oil port returns through the left travel valve, such that forward and reverse rotation of a left travel motor is realized;
[0027] The right travel valve is a three-position six-way valve; when the right travel valve is located in a middle position, a middle oil inlet and a middle oil outlet of the right travel valve are communicated, working oil entering the first main oil inlet flows to the second middle oil supply passage through the right travel valve, working oil out of the middle oil outlet of the right travel valve unidirectionally flows to the second upper oil supply circuit, and two right travel oil ports are communicated with the oil return circuit through an oil return port of the right travel valve; when the right travel valve is located at a left working position or a right working position, the middle oil inlet and the middle oil outlet of the right travel valve are not communicated, hydraulic oil enters one of the two right travel oil ports through the right travel valve, and hydraulic oil in the other oil port returns through the right travel valve, such that forward and reverse rotation of a right travel motor is realized.
[0028] In some embodiments, the turning valve is a three-position six-way valve, and has a middle position and two working positions; when the turning valve is located at the middle position, a middle oil inlet and a middle oil outlet of the turning valve are communicated, and the second upper oil supply circuit does not supplies oil to the turning hydraulic cylinder; when the turning valve is located at the two working positions, the middle oil inlet and the middle oil outlet of the turning valve are communicated, and the second upper oil supply circuit supplies oil to one of two oil ports of the turning hydraulic cylinder through the turning valve, and the other oil port is communicated with the oil return circuit through the turning valve.
[0029] In some embodiments, the first boom valve is a three-position six-way valve, and has a middle position and two working positions; when the first boom valve is located at the middle position, a middle oil inlet and a middle oil outlet of the first boom valve are communicated, the first middle oil supply passage is turned on, and the first upper oil supply circuit does not supply oil to the boom hydraulic cylinder; when the first boom valve is located at the two working positions, the first upper oil supply circuit supplies oil to one of two oil ports of the boom hydraulic cylinder through a first boom oil inlet cut-off valve, the first boom valve and a boom loading holding valve, and the other oil port is communicated with the oil return circuit through the first boom valve; an oil inlet of thefirst boom valve is communicated with the first upper oil supply circuit through a first boom oil inlet cut-off valve, and an oil return port of the first boom valve is communicated with the oil return circuit; a first working oil port is connected to a boom big cavity oil port through the boom load holding valve, a second working oil port is connected to a boom small cavity oil port, and the middle oil outlet is connected to a middle oil inlet of the bucket valve;
[0030] The second movable valve is a three-position six-way valve, an oil inlet is connected to the second upper oil supply circuit through a second boom oil inlet check valve, an oil return port is connected to the oil return passage, and a middle oil inlet is connected to the middle oil outlet of the turning valve; a first working port is connected to the boom big cavity oil port through a load holding valve; a second working port is communicated with the boom big cavity oil port through the load holding valve; a middle oil outlet is connected to a middle oil inlet of the third boom valve; the second boom valve has a middle position and two working positions; when the second boom valve is located at the middle position, the middle oil inlet is communicated with the middle oil outlet; when the second boom valve is located at a right working position, the oil inlet is communicated with the first working oil port, and the oil return port is not communicated with the second working oil port; when the second boom valve is located at a left working position, the second working oil port is communicated with the oil return port, and the oil inlet is not communicated with the first working oil port;
[0031] The third boom valve is a two-position five-way valve, an oil return port is unidirectionally communicated with the second upper oil supply circuit through a recycling check valve, and a first working oil port is communicated with the boom big cavity oil port through a load holding valve; when the third boom valve is located at a right working position, the middle oil inlet is communicated with a middle oil outlet; when the third boom valve is located at a left working position, the working oil port is communicated with the oil return port, and oil in the boom big cavity oil port is recycled to the second upper oil supply circuit;
[0032] The multi-way valve further comprises a boom big cavity recycling oil circuit which comprises a boom big cavity oil recharging check valve; when booms ascend, oil is recycled and recharged in the boom big cavity oil port from the oil return passage through the boom big cavity oil recharging check valve, such that air is prevented from being sucked into the booms;
[0033] The multi-way valve further comprises a boom small cavity recycling oil circuit which comprises a boom small cavity oil recharging check valve, and when the booms descend, oil is recycled and recharged in the boom small cavity oil port from the oil return passage through the boom small cavity oil recharging check valve, such that air is prevented from being sucked into the booms.
[0034] In some embodiments, the bucket valve is a four-position six-way valve, an oil inlet is connected to the first upper oil supply circuit through a bucket oil inlet check valve, an oil return port is connected to the oil return circuit, and two working oil ports are connected to oil ports of the bucket hydraulic cylinder; the bucket valve has a middle position and three working positions;
[0035] When the bucket valve is located at the middle position, the first upper oil supply circuit does not supply oil to the bucket hydraulic cylinder; when the bucket valve is located at the three working positions, the first upper oil supply circuit supplies oil to one cavity of the bucket valve through an arm big cavity oil port or a bucket small cavity oil port, and correspondingly, hydraulic oil in the other cavity flows out through the bucket small cavity oil port or the bucket big cavity oil port and returns to the oil return circuit through the bucket valve; when the bucket valve works at a second working position at a left end, return oil in the bucket small cavity oil port is damped, such that air is prevented from being sucked into a bucket; when the bucket retreats for excavation, the bucket valve working at a first working position at the left end, the return oil in the arm small cavity oil port is not damped, such that a back pressure of the return oil during excavation is reduced.
[0036] In some embodiments, the first arm valve is a three-position six-way valve, and has a middle position and two working positions; when the first arm valve is located at the middle position, the second middle oil supply passage is turned on, and the second upper oil supply circuit does not supply oil to a fourth actuator; when the first arm valve is located at the two working positions, the second upper oil supply circuit supplies oil to one oil port of the arm hydraulic cylinder, and the other oil port of the arm hydraulic cylinder is communicated with the oil return circuit through the first arm valve; load holding valves are disposed between the oil ports of the arm hydraulic cylinders and working oil ports of the first arm valve, and the load holding valves are of a cone valve structure and have the characteristic of zero leakage;
[0037] Further, an oil inlet of the first arm valve is connected to the second upper oil supply circuit through a first arm oil inlet check valve, a return oil port is connected to the oil return circuit, a middle oil outlet of the first arm valve is connected to a second bypass valve, a first working oil port is connected to an arm small cavity oil port through an arm small cavity load holding valve, and a second working oil port is communicated with an arm big cavity oil port through an arm big cavity load holding valve; when the first arm valve is located at a left working position, the oil inlet is communicated with the second working oil port, and a damper is disposed between the first working oil port and the oil return port; when the first arm valve is located at a right working position, the oil inlet is communicated with the first working oil port, and the second working oil port is directly communicated with the oil return port;
[0038] The second arm oil return valve is a four-position six-way valve, a middle oil outlet of the second arm oil return valve is connected to a middle oil inlet of the standby valve, an oil inlet of the second arm oil return valve is connected to thefirst upper oil supply circuit through a second arm oil inlet check valve and a second arm oil inlet valve, and an oil return port of the second arm oil return valve is connected to the oil return circuit; a first working oil port of the second arm oil return valve is connected to the arm small cavity oil port through a load holding valve; a second working oil port of the second arm oil return valve is communicated with an arm big cavity; the second arm oil return valve has a middle position and three working positions; when the second arm oil return valve is located at the middle position, the first middle oil supply passage is turned on, and the first upper oil supply circuit does not supply oil to the arm hydraulic cylinder; when the second arm oil return valve is located at the first working position, the oil inlet of the second arm oil return valve is communicated with the first working oil port, and the second working oil port is communicated with the oil inlet;
[0039] When arms retreat, if a gravity of the arms is greater than a load, the second arm oil return valve is controlled to be located at a second working position, the oil inlet is communicated with the second working oil port, the first working oil port is communicated with the second working oil port through a check valve and is communicated with the oil return port through a throttle hole, at this moment, return oil in the arms is damped by the throttle hole, and most return oil is recycled into the arm big cavity oil port through the check valve, such that quick movement of the arms is realized, and air is prevented from being sucked into the arms;
[0040] When the arms bears a drag load during excavation, the second arm oil return valve is controlled to be located at a third working position, the oil inlet is communicated with the second working oil port, the first working oil port is communicated with the second working oil port through the check valve, the first working oil port is directly communicated with the oil return port, and the return oil in the arms is not damped, such that the oil return area is large, and the back pressure during excavation is low.
[0041] In some embodiments, the standby valve is a three-position six-way valve, a middle oil outlet of the standby valve is connected to an oil inlet of a first bypass valve, and an oil outlet of the first bypass valve is connected to the main oil return passage; the first upper oil supply circuit unidirectionally supplies oil to an oil inlet, an oil return port is connected to the oil return circuit, and two working oil ports are connected to oil ports of the standby hydraulic cylinder; when the standby valve is located at a middle position, the first middle oil supply passage is turned on, and the first upper oil supply circuit does not supply oil to the standby hydraulic cylinder; and when the standby valve is located at two working positions, the first upper oil supply circuit supplies oil to one of two oil ports of the standby hydraulic cylinder through the standby valve, and the other oil port is communicated with the oil return circuit through the standby valve.
[0042] In some embodiments, the multi-way valve further comprises overload oil recharging vales, and the overload oil recharging valves are disposed between two oil ports of the boom hydraulic cylinders and the oil return circuit, between two oil ports of the bucket hydraulic cylinder and the oil return circuit, between two oil ports of the arm hydraulic cylinder and the oil return circuit, as well as between two oil ports of the standby hydraulic cylinder and the oil return circuit.
[0043] In a second aspect, the invention further provides a hydraulic system, comprising the multi-way valve described in the first aspect.
[0044] In a third aspect, the invention provides an excavator, comprising the hydraulic system described in the second aspect.
[0045] Beneficial effects: according to the multi-way valve, the hydraulic system and the excavator provided by the invention, the booms adopts two load holding valves in principle and structure, such that the flow can return through the independent oil return passage when the booms descend, the recycled flow enters the main oil circuit of a system through an independent recycling oil passage, thus greatly reducing the pressure loss of return oil, and flow recycling is realized; the system adopts bidirectional, electrically-controlled and centralized bypass regulation in principle and structure, such that the problem that an existing bypass system is complex in oil circuit and may be over-pressured when started or the main oil circuit of a main valve cannot provide a pilot oil source is solved; the arm big cavity adopts the load holding valve in structure and principle, such that the arms will not fall when retreating for hoisting; and a novel principle and structure of the multi-way valve are designed, so compared with existing multi-way valves for excavators, the size is not increased, and the system cost is reduced under the precondition that the boom recycling valve is added and independent control of oil inlet of the arms is realized. Under the condition that the size of the multi-way valve is not increased, all functions of the excavator including recycling return oil to other actuators during descending of booms of the excavator, guaranteeing the priority of arms in the case of compound actions, fulfilling overpressure-free independent regulation of bypass startup, crushing, and safety hoisting are realized, and low-power, high-efficiency and high-controllability work of the excavator is realized.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0046] FIG. 1 is a structural diagram of a multi-way valve according to one embodiment of the invention;
[0047] FIG. 2 is a structural view of the multi-way valve according to one embodiment of the invention;
[0048] FIG. 2 illustrates the working principle of a first unit of the multi-way valve according to one embodiment of the invention;
[0049] FIG. 4 illustrates the working principle of a second unit of the multi-way valve according to one embodiment of the invention;
[0050] FIG. 5 illustrates the working principle of a third unit of the multi-way valve according to one embodiment of the invention;
[0051] In the figures: 1, first working unit; 2, second working unit; 3, third working unit;
[0052] 101, right travel valve; 102, linear travel valve; 103, overflow valve; 111, left travel valve; 110, turning valve; 104, first overflow check valve; 105, second overflow check valve; 106 and 112, pump P1 circuit check valve; 107 and 109, pump P2 circuit check valve; 108, rotating oil inlet check valve; 113, second upper oil supply circuit; 114, first upper oil supply circuit; 115, first middle oil supply passage; 116, second middle oil supply passage;
[0053] 201, second boom valve; 202, first boom valve; 203, second boom oil inlet check valve; 204, boom oil inlet cut-off valve; 205, second bypass valve; 206, third movable valve; 207, boom recycling check valve; 208, boom big cavity oil recharging check valve; 209, boom big cavity overload oil recharging valve; 210, second boom load holding valve; 211, boom small cavity oil recharging check valve; 212, bucket oil inlet check valve; 213, bucket big cavity overload oil recharging valve; 214, bucket small cavity overload oil recharging valve; 215, bucket valve; 216, first boom oil inlet cut-off control valve; 217, first boom load holding valve; 218, oil passage; 219, oil passage; 220, oil passage; 221, oil passage; 222, oil passage; 223, oil passage; 226, boom small cavity overload oil recharging valve;
[0054] 301, first arm valve; 302, first arm oil inlet check valve; 303, second arm oil inlet valve; 304, second arm oil inlet check valve; 305, second arm oil return valve; 306, arm big cavity load holding valve; 307, arm small cavity overload oil recharging valve; 308, arm big cavity overload oil recharging valve; 309, standby oil inlet check valve; 310, arm small cavity load holding valve; 311, first bypass valve; 312, standby A port overload oil recharging valve; 313, standby valve; 314, standby B port overload oil recharging valve; 315, oil return passage; 316, oil passage.
DETAILED DESCRIPTION OF THE INVENTION
[0055] The technical solutions of the embodiments of the invention will be clearly and completely described below in conjunction with the accompanying drawings of these embodiments. Obviously, the embodiments in the following description are merely illustrative ones, and are not all possible ones of the invention. The following description of at least one illustrative embodiment is explanatory, and should by no means be construed as any limitations of the invention and its application or use. All other embodiments obtained by those ordinarily skilled in the art according to the following ones without creative labor should fall within the protection scope of the invention.
[0056] Unless otherwise specifically stated, relative arrangements, numerical expressions and numerical values of elements and steps expounded in the following embodiments are not intended to limit the scope of the invention. In addition, it should be understood that, for the convenience of description, the elements shown in the figures are not draw according to actual proportional relations. Techniques, methods and devices that have been known by those ordinarily skilled in related arts may not be discussed in detail. In appropriate circumstance, these techniques, methods and devices should be regarded as one part of the granted specification. In the embodiments illustrated and discussed here, all specific values should be interpreted as illustrative rather than restrictive. Other examples of the illustrative embodiments may include different values. It should be noted that similar reference signs and numerals in the following drawings denote similar items, so once one item is defined in one drawing, it will no longer be further discussed in subsequent drawings.
[0057] In the description of the invention, "a plurality of' means one or more, and "multiple" means two or more, "greater than", "less than" and "exceed" should be construed as being exclusive of said number, and "over", "below" and "within" should be construed as including said number. The description of "first" and "second", if any, is merely for distinguishing technical features, and should not be construed as indicating or implying relative importance or implicitly indicating the number or precedence relationship of technical features referred to.
[0058] In the description of the invention, the expressions of reference terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", and "some examples" are intended to indicate that specific features, structures, materials or characteristics described in conjunction with said embodiment or example are included in at least one embodiment or example of the invention. In the specification, illustrative expressions of these terms do not definitely refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics described may be combined appropriately in any one or more embodiments or examples.
[0059] Embodiment 1
[0060] In some embodiments, as shown in FIG. 1, a multi-way valve comprises a first working unit 1, a second working unit 2 and a third working unit 3, and is provided with a first main oil inlet P1, a second main oil inlet P2 and a main oil return port R3; and the multi-way valve further comprises a first upper oil supply circuit 114 communicated with the first main oil inlet P1, a second upper oil supply circuit 113 communicated with the second main oil inlet P2, an oil return circuit 315 communicated with the main oil return port R3, a first middle oil supply passage 115, and a second middle oil supply passage 116;
[0061] As shown in FIG. 1, the multi-way valve in this embodiment comprises, in principle, the first working unit 1, the second working unit 3 and the third working unit 3, wherein the first working unit 1 comprises a linear travel valve 102, a left travel valve 111, a right travel valve 101, a turning valve 110, an overflow valve 103, afirst overflow check valve 104, a second overflow check valve 105, pump P1 circuit check valves 106 and 112, pump P2 circuit check valves 107 and 109, and a rotating oil inlet check valve 108, and when the linear travel valve 102 of the first working unit is located at a middle working position, a pump 1 and a pump P2 are communicated through a throttle hole 102.1, and the flow of the pump P1 and the flow of the pump P2 are combined; the second working unit 2 comprises a first boom valve 202, a second boom valve 201, a third boom valve 206, a bucket valve 215, a second bypass valve 205, a first boom load holding valve 217, a second boom load holding valve 210, a boom small cavity oil recharging check valve 211, a boom recycling check valve 207, a first boom oil inlet cut-off valve 204, a second boom oil inlet check valve 203, and a bucket oil inlet check valve 212; and the third working unit 3 comprises a first arm valve 301, a second arm oil inlet valve 304, a second arm oil return valve 305, a standby valve 313, a first bypass valve 311, an arm small cavity load holding valve 310, an arm big cavity load holding valve 306, a first arm oil inlet check valve 302, and a standby oil inlet check valve 309.
[0062] The second working unit 2 is disposed between the first working unit 1 and the third working unit 3, and is fixedly connected to the first working unit 1 and the third working unit 3.
[0063] In some embodiments, as shown in FIG. 2, the multi-way valve is divided into three structural blocks which are a first structural block 4, a second structural block 5 and a third structural block 6 respectively, the first working unit 1 corresponds to the first structural block 4, the second working unit 1 corresponds to the second structural block 5, and the third working unit 3 corresponds to the third structural block 6.
[0064] In some embodiments, as shown in FIG. 1, the first working unit 1 comprises a travel valve group and a turning valve group, wherein the travel valve group comprises the linear travel valve 102, the left travel valve 111 and the right travel valve 101, and the turning valve group comprises the turning valve 110 used for controlling a turning hydraulic cylinder;
[0065] The second working unit 2 comprises a boom valve group used for controlling a boom hydraulic cylinder and a bucket valve group used for controlling a bucket hydraulic cylinder, wherein the boom valve group comprises the first boom valve 202, the second boom valve 201, the third boom valve 206, the first boom load holding valve 217 and the second boom load holding valve 210, and the bucket valve group comprises the bucket valve 215;
[0066] The third working unit 3 comprises an arm valve group used for controlling an arm hydraulic cylinder and a standby valve group used for controlling a standby hydraulic cylinder, wherein the arm valve group comprises the first arm valve 301, the second arm oil inlet valve 304, the second arm oil return valve 305, the arm small cavity load holding valve 310 and the arm big cavity load holding valve 306, and the standby valve group comprises the standby valve 313;
[0067] A first path of the first main oil inlet P1 unidirectionally (check valve 106) supplies oil to the first boom valve 202, the bucket valve 215, the second arm oil return valve 305 and the standby valve 313 through the first upper oil supply circuit 114;
[0068] A first path of the second main oil inlet P2 passes through the right travel valve 101, sequentially passes through middle oil inlets and middle oil outlets of the turning valve 110, the second boom valve 201 and the first arm valve 301 to form the second middle oil supply passage 116 when a middle oil inlet and a middle oil outlet of the right travel valve 101 are communicated, and unidirectionally (check valve 107) flows to the second upper oil supply circuit 113 through the middle oil outlet of the right travel valve 101; wherein, the middle oil inlets and the middle oil outlets of the turning valve 110, the second boom valve 201 and the first arm valve 301 are in a normally open state;
[0069] A second path of the first main oil inlet P1 or the second main oil inlet P2 is connected to the left travel valve 111 through the linear travel valve 102, sequentially passes through middle oil inlets and middle oil outlets of the first boom valve 202, the bucket valve 215, the second arm oil return valve 305 and the standby valve 313 to form thefirst middle oil supply passage 115 when a middle oil inlet and a middle oil outlet of the left travel valve 111 are communicated, and unidirectionally (check valve 112) flows to the first upper oil supply circuit 114 through the middle oil outlet of the left travel valve 111; wherein, the middle oil inlets and the middle oil outlets of the first boom valve 202, the bucket valve 215, the second arm oil return valve 305 and the standby valve 313 are in a normally open state;
[0070] After passing through the linear travel valve 102, the second path of the first main oil inlet P1 or the second main oil inlet P2 unidirectionally (check valve 109) supplies oil to the turning valve 110, the second boom valve 201 and the first arm valve 301 through the second upper oil supply circuit 113.
[0071] In some embodiments, as shown in FIG. 1, the multi-way valve further comprises the first bypass valve 311, wherein a tail end of the first middle oil supply passage 115 is connected to an oil inlet of the first bypass valve 311, and an oil outlet of thefirst bypass valve 311 is connected to the oil return passage 315;
[0072] And/or, the multi-way valve further comprises the second bypass valve 205, wherein a tail end of the second middle oil supply passage 116 is connected to an oil inlet of the second bypass valve 205, and an oil outlet of the second bypass valve 205 is connected to the oil return passage 315;
[0073] The first bypass valve 311 and the second bypass valve 205 are four-position two-way valve and are identical in structure; when the first bypass valve 311 or the second bypass valve 205 is located at a first working position (natural working position), the oil inlet and the oil outlet are communicated through a first damping hole; when the first bypass valve 311 or the second bypass valve 205 is located at a second working position, the oil inlet and the oil outlet are not communicated; when the first bypass valve 311 or the second bypass valve 205 is located at a third working position, the oil inlet and the oil outlet are communicated through a second damping hole; and when the first bypass valve 311 or the second bypass valve 205 is located at a fourth working position, the oil inlet and the oil outlet are directly communicated.
[0074] Further, in some embodiments, as shown in FIG. 1 and FIG. 3, the first working unit 1 further comprises the overflow valve 103 communicated with the main oil return port R3, a flow of the first main oil inlet P1 overflows back to an oil tank through thefirst overflow check valve 104 and the overflow valve 103, and a flow of the second main oil inlet P2 overflows back to the oil tank through the second overflow valve 105 and the overflow valve 103;
[0075] In some embodiments, as shown in FIG. 3 which illustrates the working principle of the first working unit 1, the pump P1 and the pump P2 fulfill a linear travel function through the linear travel valve 102, the linear travel valve 102 is a three-position four-way valve and comprises a first oil inlet, a second oil inlet, a first working oil port and a second working oil port, the first oil inlet is communicated with the hydraulic pump I P1, the second oil inlet is communicated with the hydraulic pump IIP2, the first working oil port is connected to a left travel working oil circuit which supplies oil to the left travel valve 111, and the second working oil port is communicated with the second upper oil supply circuit 113 (provided with the check valve 109);
[0076] The linear travel valve 102 has three working positions: when the linear travel valve 102 is located at a first working position (left working position), the first oil inlet is communicated with the first working oil port, and the second oil inlet is communicated with the second working oil port; when the linear travel valve 102 is located at a second working position (middle working position), the first oil inlet is communicated with the second working oil port, the second oil inlet is communicated with the first working oil port, and the first oil inlet is communicated with the second oil inlet through a first throttle hole 102.1, such that flows are combined; and when the linear travel valve 102 is located at a third working position (right working position), the first oil port is communicated with the second working oil port through a third throttle hole 102.4 and is communicated with the second oil inlet through a check valve 102.3 and a second throttle hole 102.2, and the second oil inlet is communicated with the first working oil port.
[0077] The left travel valve 111 is a three-position six-way valve; when the left travel valve 111 is located at a middle position, the middle oil inlet and the middle oil outlet of the left travel valve 111 are communicated, working oil entering the first main oil inlet P1 flows to the first middle oil supply passage 115 through the left travel valve 111, the working oil out of the middle oil outlet of the left travel valve 111 unidirectionally flows to the first upper oil supply circuit 114 (through the pump P1 circuit check valve 112), and two left travel oil ports (oil port AtL or oil port BtL) are communicated with the oil return circuit through an oil return port of the left travel valve 111; when the left travel valve 111 is located at a left working position or a right working position, the middle oil inlet and the middle oil outlet of the left travel valve 111 are not communicated, hydraulic oil enters one of the two left travel oil ports (oil port AtL or oil port BtL) through the left travel valve 111, and hydraulic oil in the other left travel oil port (oil port AtL or oil port BtL) returns through the left travel valve 111, such that forward and reverse rotation of a left travel motor is realized;
[0078] The right travel valve 101 is a three-position six-way valve; when the right travel valve 101 is located at a middle position, the middle oil inlet and the middle oil outlet of the right travel valve 101 are communicated, working oil entering the first main oil inlet P1 flows to the second middle oil supply passage 116 through the right travel valve 101, working oil out of the middle oil outlet of the right travel valve 101 unidirectionally flows to the second upper oil supply circuit 113 (through the pump P2 circuit check valve 112), and two right travel oil ports (oil port Atr or oil port Btr) are communicated with the oil return circuit through an oil return port of the right travel valve 101; when the right travel valve 101 is located at a left working position or a right working position, the middle oil inlet and the middle oil outlet of the right travel valve 101 are not communicated, hydraulic oil enters one of the two right travel oil ports (oil port Atr or oil port Btr) through the right travel valve 101, and hydraulic oil in the other right travel oil port (oil port Atr or oil port Btr) returns through the right travel valve 101, such that forward and reverse rotation of a right travel motor is realized.
[0079] When mechanical travel is not started, the linear travel valve 102 works at the left position, the first oil inlet is communicated with the first working oil port, the second oil inlet is communicated with the second working oil port, that is, the flow of the pump P2 is delivered to the second upper oil supply circuit 113 through the linear travel valve 102 and the check valve 109 to supply oil to actuators such as the turning valve 110, the second boom valve 201 and the first arm valve 301, and the flow of the pump P1 is delivered to the first middle oil supply passage 115 of the left travel valve 111, the second boom valve 202, the bucket valve 215, the arm valve 305 and the standby valve 313 through the linear travel valve 102;
[0080] When the flows of the two pumps need to be combined as required by the bucket valve 215 and the standby valve 313, the linear travel valve 102 works at the middle position, the first oil inlet is communicated with the second working oil port, the second oil inlet is communicated with the first working oil port, the first oil inlet and the second oil inlet are communicated through the first throttle hole 102.1, in this case, part of the flow of the pump P2 enters the bucket valve 215 through the first throttle hole 102.1, the check valve 106, the first upper oil supply circuit 114 and the bucket oil inlet check valve 212, and the flow of the pump P1 enters the bucket valve 215 through the check valve 106, the first upper oil supply circuit 114 and the bucket oil inlet check valve 212, such that the flows of the two pumps are combined; similarly, when the standby valve 313 works, oil of the pump P2 flows to the pump P1 through the throttle hole 102.1 of the linear travel valve 102, and then enters the standby valve 313 through the check valve 106, the first upper oil supply circuit 114 and the standby oil inlet check valve 309, such that the flows are combined for a standby purpose;
[0081] In a case where left travel, right travel and an upper part act at the same time, the linear travel valve 102 works at the right position, the first oil inlet is communicated with the second working oil port through the third throttle hole 102.4, the second oil inlet is communicated with the first working oil port, the first oil inlet is communicated with the second oil inlet through the check valve 102.3 and the second throttle hole 102.2, the pump P1 supplies oil to the actuators such as the turning valve 110, the second boom valve 201 and the first arm valve 301 via the third throttle hole 102.4 of the linear travel valve through the check valve 109 and the second upper oil supply circuit 113, such that oil is supplied to the upper part (turning gear, booms and arms), and after passing through the check valve 102.3 and the second throttle hole 102.2 of the linear travel valve, one path of oil of the pump P1 is supplied to the left travel valve 111, and the other path of the oil enters the pump P2 to be combined with oil in the pump P2 and is then supplied to the right travel valve 101; and under the throttling action of the third throttle hole 102.4, the pump P1 preferentially supplies oil to the left travel valve 111 and the right travel valve 101 to guarantee the priority of the travel function.
[0082] In some embodiments, as shown in FIG. 1 and FIG. 3, the turning valve 110 is a three-position six-way valve, and has a middle position and two working positions; when the turning valve 110 is located at the middle position, the middle oil inlet and the middle oil outlet of the turning valve 110 are communicated, the second upper oil supply circuit 113 does not supply oil to the turning hydraulic cylinder; and when the turning valve 110 is located at the two working positions, the middle oil inlet and the middle oil outlet of the turning valve 110 are communicated, the second upper oil supply circuit 113 supplies oil to one of two oil ports (As and Bs) of the turning hydraulic cylinder through the turning valve 110, and the other oil port is communicated with the return oil circuit through the turning valve 110.
[0083] As shown in FIG. 4 which illustrates the working principle of the second working unit 2, the second working unit 2 comprises the first boom valve 202, the second boom valve 201, the third boom valve 206, the bucket valve 215, the second bypass valve 205, the first boom load holding valve 217, the second boom load holding valve 210, the boom oil inlet cut-off valve 204, the boom small cavity oil recharging check valve 211, the boom recycling check valve 207, the second boom oil inlet check valve 203 and the bucket oil inlet check valve 212.
[0084] The first boom valve 202 is a three-position six-way valve, and has a middle position and two working positions; when the first boom valve 202 is located at the middle position, the middle oil inlet and the middle oil outlet of the first boom valve 202 are communicated, the first middle oil supply passage 115 is turned on, and the first upper oil supply circuit 114 does not supply oil to the boom hydraulic cylinder; and when the first boom valve 202 is located at the two working positions, the first upper oil supply circuit 114 supplies oil to one of two oil ports of the boom hydraulic cylinder (boom big cavity oil port Ab and boom small cavity oil port Bb) through the first boom oil inlet cut-off valve 204, the first boom valve 202 and the first boom load holding valve 217, and the other oil port is communicated with the oil return circuit through the first boom valve 202;
[0085] Further, an oil inlet of the first boom valve 202 is communicated with the first upper oil supply circuit 114 through the first boom oil inlet cut-off valve 204 (the first boom oil inlet cut-off control valve 216 is used for controlling on-off of the first boom oil inlet cut-off valve 204), and an oil return port of thefirst boom 202 is communicated with the oil return circuit; and a first working oil port is connected to the boom big cavity oil port Ab through the first boom load holding valve 217, a second working oil port is connected to the boom small cavity oil port Bb, and the middle oil outlet is connected to the middle oil inlet of the bucket valve 215.
[0086] In some embodiments, there are two boom big cavity oil ports which are a boom big cavity oil port Ab and a boom big cavity oil port Ab2 respectively. The second boom valve 201 is a three-position six-way valve, an oil inlet is connected to the second upper oil supply circuit 113 through the second boom oil inlet check valve 203 (such that the second upper oil supply circuit 113 can unidirectionally supply oil to the second boom oil inlet check valve 203), an oil outlet is connected to the oil return passage, and the middle oil inlet is connected to the middle oil outlet of the turning valve 110; a first working oil port is connected to the boom big cavity oil port Ab through an oil passage 221, an oil passage 224, the load holding valve 210, an oil passage 219 and an oil passage 222; a second working oil port is communicated with the boom big cavity oil port Ab through an oil passage 220, an oil passage 223 and the load holding valve 217; the middle oil outlet is connected to the middle oil inlet of the third boom valve 206; the second boom valve 210 has a middle position and two working positions; when the second boom valve 201 is located in the middle position, the middle oil inlet is communicated with the middle oil outlet (the second middle oil supply passage 116 is turned on); when the second boom valve 201 is located at a right working position, the middle oil inlet is communicated with the middle oil outlet, the oil inlet is communicated with the first working oil port (oil enters the boom big cavity Ab), and the oil return port is not communicated with the second working oil port; and when the second boom valve 201 is located at a left working position, the middle oil inlet is communicated with the middle oil outlet, the second working oil port is communicated with the oil return port (oil in the boom big cavity Ab returns), and the oil inlet is not communicated with the first working oil port.
[0087] The third boom valve 206 is a two-position five-way valve, an oil return port is unidirectionally communicated with the second upper oil supply circuit 113 through the recycling check valve 207, and the middle oil outlet is connected to the middle oil inlet of the first arm valve 301 (the middle oil outlet of the first arm valve 301 is connected to the oil return circuit through the second bypass valve 205); after passing through the load holding valve 210, a first path of the first working oil port is communicated with the boom big cavity oil port Ab2 and the other path of the first working oil port is communicated with the boom big cavity oil port Ab through the oil passage 219 and the oil passage 222; the middle oil outlet is connected to the middle oil inlet of the third boom valve 206;
[0088] When the third boom valve 206 is located at a right working position, the middle oil inlet supplies oil to the middle oil outlet and is communicated with the oil inlet (communicated with the second middle oil supply passage 116); and when the third boom valve 206 is located at a left working position, the middle oil inlet supplies oil to the middle oil outlet, and the first working oil port is communicated with the oil return port (oil in the boom big cavity oil ports Ab and Ab2 returns to the second upper oil supply passage 113).
[0089] The multi-way valve further comprises a boom big cavity recycling oil circuit, which comprises the boom big cavity oil recharging check valve 208; and when the booms ascend, oil is recycled and recharged into the boom big cavity oil port Ab from the oil return passage through the boom big cavity oil recharging check valve 208, such that air is prevented from being sucked into the booms.
[0090] The multi-way valve further comprises a boom small cavity recycling oil circuit, which comprises the boom small cavity oil recharging check valve 2111; and when the booms descend, oil is recycled and recharged into the boom small cavity oil port Bb from the oil return passage through the boom small cavity oil recharging check valve 211, such that air is prevented from being sucked into the booms.
[0091] Specifically, after passing through the boom big cavity oil recharging check valve 208, a first path of the oil return circuit is connected to the boom big cavity oil port Ab2, and a second path of the oil return circuit supplies oil to the boom big cavity oil port Ab through the oil passage 222; and the oil return circuit is connected to the boom small cavity oil port Bb through the boom small cavity oil recharging check valve 211.
[0092] The second bypass valve 205 is a four-position two-way valve; when the second bypass valve 205 is located at the first working position (natural working position) 205.1, the oil inlet and the oil outlet are communicated with the oil return circuit through a damping hole 205.5 in the second bypass valve 205; when an engine is ignited to be started, the pump 2 is connected to the oil return circuit and is in a no-load state, so the pump 2 will not be over-pressured when started, and under the action of the damping hole 205.5, the pressure of the main pump 2 will not be too low at the initial stage of starting and is slightly higher than the pilot pressure, so the pump 2 can supply oil to a pilot oil circuit through a relief valve, and this principle can be applied to a hydraulic system without a pilot pump source to reduce the system cost. In a hydraulic system with a pilot pump source, after the system is started, the second bypass valve 205 quickly moves to the right working position 205.4, the oil inlet and the oil outlet are communicated directly, the pump 2 connected to the oil return circuit is in a no-load state and has a maximum oil return area, and at this moment, the pump 2 idles at a minimum pressure. In a hydraulic system without a pilot pump source, the main pump needs to provide a pilot-pressure oil source as required by the system, the second bypass valve 205 moves to the working position 205.2 (the oil inlet and the oil outlet are not communicated) or the working position 205.3 (the oil inlet and the oil outlet are communicated through a damping hole) during operation of an excavator; and when a hand lever is operated to the maximum extent, the second bypass valve 205 moves to the working position 205.2, at this moment, the pump 2 is isolated from the oil return circuit, and all oil of the pump 2 is supplied to actuators to improve the working efficiency.
[0093] The bucket valve 215 is a four-position six-way valve, the middle oil inlet of the bucket valve 215 is communicated with the middle oil outlet of the first boom valve 202, the middle oil outlet of the bucket valve 215 is connected to the middle oil inlet of the second arm oil return valve 305, an oil inlet is connected to the first upper oil supply circuit 114 through the arm oil inlet check valve 212 (such that the first upper oil supply circuit 114 can unidirectionally supply oil to the bucket oil inlet check valve 212), an oil return port is connected to the oil return circuit, and two working oil ports are connected to the bucket hydraulic cylinder (oil port Ac and oil port Bc); when the bucket valve 215 is located at a middle position, the first upper oil supply circuit 114 does not supply oil to a third actuator (bucket); when the bucket valve 215 is located at three working positions, the first upper oil supply circuit 115 supplies oil to one cavity of the bucket valve 215 through the bucket big cavity oil port Ac or the bucket small cavity oil port Bc, and correspondingly, hydraulic oil in the other cavity flows out through the bucket small cavity oil port Bc or the bucket big cavity oil port Ac and returns to the oil return circuit through the bucket valve 215; when the bucket valve 215 works at a second working position 215.2 at the left end, return oil from a bucket small cavity AC is damped by a damper 215,1, such that air is prevented from being sucked into the bucket; and when the bucket retreats for excavation, the bucket valve 215 works at a first working position 215.3 at the left end, and return oil from the small bucket cavity AC is not damped, such that the back pressure of return oil during excavation is reduced.
[0094] P1 supplies oil to the first boom valve 202 and the bucket valve 215 through the check valve 106, P2 supplies oil to the second boom valve 201 through the check valve 107, and the third boom valve 206 and the second bypass valve 205 are arranged in parallel. The flow of the pump P2 enters the first arm valve 301, the oil passage 218 and the second bypass valve 205 of the third working unit 5 after passing through the oil passage 225, the second boom valve 201 and the third boom valve 206, and is then connected to the oil return passage R3, and the second bypass valve 205 is used for centralized regulation of the bypass flow of the pump P2.
[0095] When the booms ascend, the flow of P1 and the flow of P2 are combined, the flow of P1 enters the boom big cavity oil port Ab through the boom oil inlet cut-off valve 204, the first boom valve 202 and the boom load holding valve 217, and the flow of P2 enters the boom big cavity oil port Ab through the check valve 203, the second boom valve 201, the oil passage 224, the load holding valve 210 and the oil passage 219; and when the booms ascend, oil is recycled and recharged into the boom big cavity oil port Ab from the oil return passage R3 through the boom big cavity oil recharging check valve 208, such that air is prevented from being sucked into the booms;
[0096] When the booms descend, oil enters the boom small cavity oil port Bb, oil in the boom big cavity oil port Ab returns, P1 supplies oil to the boom small cavity oil port Bb through the first boom oil inlet cut-off valve 204 and the first boom valve 202, and in order to prevented air from being sucked into the booms, oil in the oil return passage R3 can be supplied to the boom small cavity oil port Bb through the boom small cavity oil recharging check valve 211; and after passing through the boom big cavity oil port Ab and the loading holding valve 217, one path of return oil from the boom big cavity returns through the first boom valve 202, and the other path of the return oil returns into the oil tank through the oil passage 223 and the second boom valve 201 (oil in the first boom and oil in the second boom return at the same time);
[0097] Similar to the case where the booms act along, when the booms descend and the arms act at the same time, part of return oil from the boom big cavity oil port Ab returns into the oil tank through the load holding valve 217, the oil passage 223, the first boom valve 202 and the second boom 201 (oil in the first boom and oil in the second boom return at the same time); and the other part of the return oil flows to a P2 oil circuit through the oil passage 222, the oil passage 219, the load holding valve 210, the third boom valve 206 and the recycling check valve 207, such that oil is supplied to the P2 oil circuit. So, when the booms descend and the arms act at the same time, the return oil from the boom big cavity partially returns into the oil tank through the first boom valve 202 and the second boom valve 201 and partially is recycled to the P2 oil circuit through the third boom valve 206 to be used by the arms, and the back pressure of the return oil of the boom big cavity is controlled to be higher than the pressure of P2 by controlling the oil return area of the second boom valve 201, so as to realize flow recycling.
[0098] The second working unit 2 mainly has the following five new features in principle:
[0099] 1. The second boom 201 has a middle position and two working positions; when the second movable valve 201 works at a right working position 201.2, the second upper oil supply circuit 113 of the pump P2 is connected to the boom big cavity oil port Ab through the check valve 203, the second boom valve 201, the oil passage 224, the load holding valve 210, the oil passage 219 and the oil passage 222 to supply oil to the boom big cavity, and oil in the oil port Bb cannot return through the second boom valve 201, such that independent control of oil inlet during the ascending process of the booms is realized by the second boom valve;
[00100] When the second boom valve 201 works at a left working position 201.1, the second upper oil supply circuit 113 of the pump P2 does not supply oil to the boom big cavity oil port Ab, and oil in the boom big cavity oil port Ab can return into the oil tank through the second boom valve 201, such that independent control of oil return during the descending process of the booms is realized by the second boom valve 201 at the working position 201.1;
[00101] 2. When the booms descend, oil is recycled and recharged into the boom small cavity oil port Bb from the oil return passage R3 through the check valve 211, such that air is prevented from being sucked into the booms;
[00102] 3. When the booms descend and the arms swing outwards at the same time, oil entering the booms is cut off by the boom oil inlet cut-off valve 204, the flow of P1 cannot enter the boom small cavity oil port Bb, and oil is recycled and recharged into the boom small cavity oil port Bb the check valve 211, such that air is prevented from being sucked into the booms; one part of oil in the boom big cavity oil port Ab returns into the oil tank through the load holding valve 217, the oil passage 223, the first boom valve 202 and the second boom valve 201 (oil in the first boom and oil in the second boom return at the same time), and the other part of oil is recycled to the P2 circuit after flowing through the oil passage 222, the oil passage 219, the load holding valve 210, the third boom 206 and the check valve 207, and is combined with the P2 oil circuit to be supplied to other actuators, such that return oil in the boom big cavity is recycled; the recycled oil passes through the oil passage 222, the passage 219 and the load holding valve 210, thus being parallel to the oil return passage (load holding valve 217 and passage 223) of the first boom valve 202 and the second boom valve 201; the booms adopt two load holding valves in principle and structure, so the loss of oil pressure is small, and the recycling rate is high;
[00103] 4. The second bypass valve 205 is of a distributed structure, such that the main valve size is reduced; and the flow of the pump P2 returns to the second working unit 2 after passing through the first arm valve 301 in the third working unit 3, and is connected to the second bypass valve 205 through the oil passage 218. The second bypass valve 205 has four working positions; when the second bypass valve 205 is located at the natural working position 205.1, the pump P2 is communicated with the oil return circuit through the middle passage of all valves, the oil passage 218, and the damping hole 205.5 in the second bypass valve 205; when the engine is ignited to be started, the pump P2 is connected to an oil passage T and is in a no-load state, such that the pump P2 will not be over-pressured when started; and under the action of the damping hole 205.5, the pressure of the main pump 2 will not be too low at the initial stage of starting and is slightly higher than the pilot pressure, so the pump 2 can supply oil to a pilot oil circuit through a relief valve, and this principle can be applied to a hydraulic system without a pilot pump source to reduce the system cost. In a hydraulic system with a pilot pump source, after the system is started, the second bypass valve 205 quickly moves to the right working position 205.4, the pump 2 connected to the oil return circuit is in a no-load state and has a maximum oil return area, and at this moment, the pump 2 idles at a minimum pressure. In a hydraulic system without a pilot pump source, the main pump needs to provide a pilot-pressure oil source as required by the system, the second bypass valve 205 moves to the working position 205.2 or the working position 205.3 during operation of an excavator; and when a hand lever is operated to the maximum extent, the second bypass valve 205 moves to the working position
205.2, at this moment, the pump 2 is isolated from the oil return circuit, and all oil of the pump 2 is supplied to actuators to improve the working efficiency.
[00104] 5. The bucket valve 215 has four working positions; when the bucket retreats and operates in a no-load state, the bucket valve 215 works at the second working position 215.2 at the left end, return oil from the bucket small cavity AC is damped by the damper 215.1, such that air is prevented from being sucked into the bucket; and when the bucket retreats for excavation, the bucket valve 215 works at the first working position 215.3 at the left end, and return oil from the small bucket cavity AC is not damped, such that the back pressure of return oil during excavation is reduced.
[00105] As shown in FIG. 5 which illustrates the working principle of the third working unit 3, the third working unit 3 comprises the first arm valve 301, the second arm oil inlet valve 303, the second arm oil return valve 305, the arm small cavity load holding valve 310, the arm big cavity load holding valve 306, the first bypass valve 311, the standby valve 313, the first arm oil inlet check valve 302, the second arm oil inlet check valve 304, and the standby oil inlet check valve 309.
[00106] The first arm valve 301, the first arm oil inlet check valve 302, the second arm oil inlet check valve 303, the second arm oil inlet check valve 304, the second arm oil return valve 305, the arm big cavity load holding valve 306, the arm small cavity overload oil recharging valve 307, the arm big cavity overload oil recharging valve 308, the standby oil inlet check valve 309, the arm small cavity load holding valve 310, the first bypass valve 311, the standby A port overload oil recharging valve 312, the standby valve 313, the standby B port overload oil recharging valve 314, and the oil return passage 315.
[00107] The first arm valve 301 is a three-position six-way valve, and has a middle position and two working positions; when the first arm valve 310 is located at the middle position, the second middle oil supply passage 116 is turned on, and the second upper oil supply circuit 113 does not supply oil to the arm hydraulic cylinder; when the first arm valve 301 is located at the two working positions, the second upper oil supply circuit 113 supplies oil to one oil port of the arm hydraulic cylinder (arm small cavity oil port Aa or arm big cavity oil port Ba), and the other oil port of the arm hydraulic cylinder is communicated with the oil return circuit through the first arm valve 301; and load holding valves are disposed between the oil ports of the arm hydraulic cylinder and working oil ports of the first arm valve 301. Further, the arm big cavity holding valve 306 and the arm small cavity load holding valve 310 are disposed between the arm big cavity oil port and the first arm valve 301, as well as between the arm small cavity oil port and the first arm valve 301 respectively, and the arm big cavity holding valve 306 is of a cone valve structure and has the characteristic of zero leakage.
[00108] In some embodiments, an oil inlet of the first arm valve 301 is connected to the second upper oil supply circuit 113 through the first arm oil inlet check valve 302, an oil return port is connected to the oil return circuit, a middle oil outlet of the first arm valve 301 is connected to the second bypass valve 205, one path of a first working oil port is connected to the arm small cavity oil port Aa through the load holding valve 310, and the other path of the first working oil port is connected to a first working oil port of the second arm oil return valve 305 through an oil passage 317; and a first path of a second working oil port is connected to the arm big cavity oil port Bal through the arm big cavity load holding valve 306, and a second path of the second working oil port is connected to the arm oil return port Ba2 through an oil passage 316. When the first arm valve 301 is located at a left working position, the oil inlet is communicated with the second working oil port, and a damper 301.1 is disposed between the first working oil port and the oil return port; and when the first arm valve 301 is located at a right working position, the oil inlet is communicated with the first working oil port, and the second working oil port is directly communicated with the oil return port.
[00109] The second arm oil return valve 305 is a four-position six-way valve; the middle oil outlet of the second arm oil return valve 305 is connected to the middle oil inlet of the standby valve 313, an oil inlet of the second arm oil return valve 305 is connected to the first upper oil supply circuit 114 through the second arm oil inlet valve 303 and the second arm oil inlet check valve 304, and an oil return port of the second arm oil return valve 305 is connected to the oil return circuit; a first working oil port of the second arm oil return valve 305 is connected to the arm small cavity Aa through the oil passage 317 and the load holding valve 310; and a second working oil port of the second arm oil return valve 305 is communicated with the arm big cavity Ba2.
[00110] The second arm oil return valve 305 has a middle position and three working positions; when the second arm oil return valve 305 is located at the middle position, the first middle oil supply passage 115 is turned on, and the first upper oil supply circuit 114 does not supply oil to the arm hydraulic cylinder; when the second arm oil return valve 305 is located at a first (left) working position, the oil inlet of the second arm oil return valve 305 is communicated with the first working oil port, and the second working oil port is communicated with the oil inlet;
[00111] When arms retreat, if the gravity of the arms exceeds a load, the second arm oil return valve 305 is controlled to be located at a second working position (position 305.1), the oil inlet is communicated with the second working oil port, the first working oil port is communicated with the second working oil port through a check valve 305.4, the first working oil port is communicated with the oil return port through a throttle hole 305.3, at this moment, return oil of the arms is damped by the throttle hole 305.3, and most return oil is recycled into the arm big cavity oil port Ba through the check valve 205.4, such that quick movement of the arms is realized, and air is prevented from being sucked into the arms;
[00112] When the arms bear a drag load during excavation, the second arm oil return valve 305 is controlled to be located at a third working position 305.2, the oil inlet is communicated with the second working oil port, the first working oil port is communicated with the second working oil port through the check valve and is directly communicated with the oil return port, and at this moment, return oil of the arms is not damped, the oil return area is large, and the back pressure during excavation is low.
[00113] The flow of the pump P1 is connected to the oil return passage 315 through the first bypass valve 311 after passing through the oil passage 318, the second arm oil return valve 305 and the standby valve 311, and the first bypass valve 311 is used for centralized regulation of the bypass flow of the pump P1.
[00114] When the arms retreat, oil of P1 is supplied to the arm big cavity Bal through the second arm oil inlet valve 303, the check valve 304, the second arm oil return valve 305 (the oil just passes through, and is not controlled by the second arm oil return valve 305), the oil passage 316, and the load holding valve 306; oil of P2 is supplied to the big cavity large cavity Bal through the check valve 302, the first arm valve 301, the oil passage 316 and the load holding valve 306; part of return oil of the arm small cavity Aa returns through the load holding valve 310, the oil passage 317, the first arm valve 301 and the damper 301.1, the other part of the return oil returns through the load holding valve 310, the oil passage 317 and the second arm oil return valve 305, and the second arm oil return valve 305 has a flow recycling function; when the arms retreat and the gravity of the arms is greater than the load, the second arm oil return valve works at the position 305.1, such that oil in the arm big cavity is recycled; when the arms retreat and bear a drag load, the second arm oil return valve works at the position 305.2, such that the oil return area is enlarged, and the loss of excavation pressure is reduced.
[00115] When the arms swing outwards, oil of P1 is supplied to the arm small cavity Aa through the second arm oil inlet valve 303, the check valve 304, the second arm oil return valve 305 (oil just passes through, and is not controlled by the second arm oil return valve 305), the oil passage 317 and the load holding valve 310, and oil of P2 is supplied to the arm small cavity Aa through the check valve 302, the first arm valve 301, the oil passage 317 and the load holding valve 310. Return oil of the arm big cavity Bal returns through the load holding valve 306, the oil passage 316, the first arm valve 301 and the second arm oil return valve 305.
[00116] The standby valve 313 is a three-position six-way valve, the middle oil outlet of the standby valve 313 is connected to the oil inlet of the first bypass valve 311, and the oil outlet of the first bypass valve 311 is connected to the main oil return passage; the first upper oil supply circuit 114 unidirectionally supplies oil to the oil inlet (through the standby oil inlet check valve 309), an oil return port is connected to the oil return circuit, and two working oil ports are connected to oil ports Ao and Bo of the standby hydraulic cylinder; when the standby valve 313 is located in a middle position, the first middle oil supply passage 115 is turned on, and the first upper oil supply circuit 114 does not supply oil to the standby hydraulic cylinder; when the standby valve 313 is located at two working positions, the first upper oil supply circuit 115 supplies oil to one of the two oil ports (Ao and Bo) of the standby hydraulic cylinder through the standby valve 313, and the other oil port is communicated with the oil return circuit through the standby valve 313.
[00117] The structure of the first bypass valve 311 is the same as that of the second bypass valve 205, and the working principle of the first bypass valve 311 is similar to that of the second bypass valve 205 (which will no longer be detailed), such that the pump P1 will not be over-pressured when started.
[00118] The third working unit 3 mainly has the following four new features in principle:
[00119] 1. The working principle of the first bypass valve 311 is similar to that of the second bypass valve 205, such that the pump P1 will not be over-pressured when started.
[00120] 2. Independent control of oil inlet and oil return of the arms on the pump P1 side is realized through the second arm oil inlet valve 303 and the second arm oil return valve 305; the second arm oil return valve 305 has four working positions; when the arms retreat, the arms are in an over-load state, the second arm oil return valve 305 operates at the working position 305.1, return oil of the arm small cavity Aa is damped by the damper 305.3, such that the back-pressure of the return oil of the arm small cavity is increased, and air is prevented from being sucked in the arms; when the arms retreat for excavation, the second arm oil return valve 305 operates at the working position 305.2, return oil of the arm small cavity Aa directly returns into the oil tank, such that the back pressure of return oil during excavation is reduced. When the first arm valve 301 retreats, return oil of the arm small cavity As passes through the damping hole 301.1 and determines, together with the second arm oil return valve 305, the pressure state of the arm small cavity, and air is prevented from being sucked into the arms, or the back pressure of the return oil in the arms is prevented from being too high.
[00121] 3. The standby valve 313 is disposed in the third working unit 3, and is used for being connected to a crushing actuator for a standby purpose.
[00122] 4. The arm big cavity oil port Bal adopts the load holding valve 306 in structure and principle, so when the arms retreat (the arms do not move) and the booms ascend for hoisting, the arm big cavity oil port Bal cannot return the first arm valve 301 and the second arm oil return valve 303 through the load holding valve 306, and the load holding valve 306 is of a cone valve structure and has the characteristic of zero leakage, such that the arms will not fall and safety hoisting is realized.
[00123] In addition, the multi-way valve in this embodiment adopts proportional control, and all multi-way valves with the same function obtained by changing the control method, such as by adopting hydraulic control, mechanical control or the like should fall within the protection scope of the invention. In this application, the A/B load circuit is provided with the overload oil recharging valve to limit the pressure of the load circuit and prevent air from being sucked in, and all simplifications made to the design of the invention by replacing the overload oil recharging valves with, such as, overflow valves and plugs should also fall within the protection scope of the invention.
[00124] Embodiment 2
[00125] This embodiment provides a hydraulic system, comprising the multi-way valve in Embodiment 1.
[00126] Embodiment 3
[00127] This embodiment provides an excavator, comprising the hydraulic system in Embodiment 2.
[00128] It should be noted that, in the description of the application, terms such as "center", "lengthwise", "crosswise", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner" and "outer" are used to indicate directional or positional relations based on the accompanying drawings merely for the purpose of facilitating and simplifying the description of the application, and do not indicate or imply that a device or an element referred to must be in a specific direction, or be configured and operated in a specific direction, and thus, they should not be construed as limitations of the contents protected by the application.
[00129] The above embodiments are merely preferred ones of the invention. It should be pointed out that those ordinarily skilled in the art can make some improvements and modifications without departing from the principle of the invention, and all these improvements and modifications should fall within the protection scope of the invention.

Claims (12)

What is claimed is:
1. A multi-way valve, comprising a first working unit, a second working unit, a third working unit, a first main oil inlet, a second main oil inlet and a main oil return port, and further comprising a first upper oil supply circuit communicated with the first main oil inlet, a second upper oil supply circuit communicated with the second main oil inlet, an oil return circuit communicated with the main oil return port, a first middle oil supply passage, and a second middle oil supply passage, wherein the second working unit is disposed between the first working unit and the third working unit; the first working unit comprises a travel valve group and a turning valve group, wherein the travel valve group comprises a linear travel valve, a left travel valve and a right travel valve, and the turning valve group comprises a turning valve used for controlling a turning hydraulic cylinder; the second working unit comprises a boom group used for controlling a boom hydraulic cylinder and a bucket valve group used for controlling a bucket hydraulic cylinder, wherein the movable valve group comprises a first boom valve, a second boom valve, a third boom valve, a first boom load holding valve and a second boom load holding valve, and the bucket valve group comprises a bucket valve; the third working unit comprises an arm valve group used for controlling an arm hydraulic cylinder and a standby valve group used for controlling a standby hydraulic cylinder, wherein the arm valve group comprises a first arm valve, a second arm oil inlet valve, a second arm oil return valve, an arm small cavity load holding valve and an arm big cavity load holding valve, and the standby valve group comprises a standby valve; a first path of the first main oil inlet unidirectionally supplies oil to the first boom valve, the bucket valve, the second arm oil return valve and the standby valve through the first upper oil supply circuit; a first path of the second main oil inlet passes through the right travel valve, sequentially passes through middle oil inlets and middle oil outlets of the turning valve, the second boom valve and the first arm valve to form the second middle oil supply passage when a middle oil inlet and a middle oil outlet of the right travel valve are communicated, and unidirectionally flows to the second upper oil supply circuit through the middle oil outlet of the right travel valve, wherein the middle oil inlets and the middle oil outlets of the turning valve, the second boom valve and the first arm valve are in a normally open state; a second path of the first main oil inlet or the second main oil inlet is connected to the left travel valve through the linear travel valve, sequentially passes through middle oil inlets and middle oil outlets of the first boom valve, the bucket valve, the second arm oil return valve and the standby valve to form the first middle oil supply passage when a middle oil inlet and a middle oil outlet of the left travel valve are communicated, and unidirectionally flows to the first upper oil supply circuit through the middle oil outlet of the left travel valve, wherein the middle oil inlets and the middle oil outlets of the first boom valve, the bucket valve, the second arm oil return valve and the standby valve are in a normally open state; the second path of the first main oil inlet or the second main oil inlet unidirectionally supplies oil to the turning valve, the second boom valve and the first arm valve through the second upper oil supply circuit after passing through the linear travel valve.
2. The multi-way valve according to Claim 1, wherein the multi-way valve further comprises a first bypass valve, a tail end of the first middle oil supply passage is connected to an oil inlet of the first bypass valve, and an oil outlet of the first bypass valve is connected to the oil return passage; the multi-way valve further comprises a second bypass valve, a tail end of the second middle oil supply passage is connected to an oil inlet of the second bypass valve, and an oil outlet of the second bypass valve is connected to the oil return passage; the first bypass valve and the second bypass valve are four-position two-way valves and are identical in structure; when the first bypass valve or the second bypass valve is located at a first working position, the oil inlet and the oil outlet are communicated through a first damping hole; when the first bypass valve or the second bypass valve is located at a second working position, the oil inlet and the oil outlet are not communicated; when the first bypass valve or the second bypass valve is located at a third working position, the oil inlet and the oil outlet are communicated through a second damping hole; and when the first bypass valve or the second bypass valve is located at a fourth working position, the oil inlet and the oil outlet are directly communicated.
3. The multi-way valve according to Claim 1, wherein the first working unit further comprises an overflow valve communicated with the main oil return port, the first main oil inlet is connected to an oil inlet of the overflow valve through afirst overflow check valve, and the second main oil inlet is connected to the oil inlet of the overflow valve through a second overflow check valve.
4. The multi-way valve according to Claim 1, wherein the linear travel valve is a three-position four-way valve, and comprises a first oil inlet, a second oil inlet, a first working oil port and a second working oil port, the first oil inlet is communicated with the first main oil inlet, the second oil inlet is communicated with the second main oil inlet, the first working oil port is connected to a left travel working oil circuit which supplies oil to the left travel valve, and the second working oil port unidirectionally supplies oil to the second upper oil supply circuit; the linear travel valve has three working positions: when the linear travel valve is located at a first working position, the first oil inlet is communicated with the first working oil port, and the second oil inlet is communicated with the second working oil port; when the linear travel valve is located at a second working position, the first oil inlet is communicated with the second working oil port, the second oil inlet is communicated with the first working oil port, and the first oil inlet and the second oil inlet are communicated through a first throttle hole, such that flows are combined; when the linear travel valve is located at a third working position, the first oil inlet is communicated with the second working oil port through a third throttle hole, the first oil inlet is communicated with the second oil inlet through a check valve and a second throttle valve, and the second oil inlet is communicated with the first working oil port; the left travel valve is a three-position six-way valve; when the left travel valve is located in a middle position, a middle oil inlet and a middle oil outlet of the left travel valve are communicated, working oil entering the first main oil inlet flows to the first middle oil supply passage through the left travel valve, working oil out of the middle oil outlet of the left travel valve unidirectionally flows to the first upper oil supply circuit, and two left travel oil ports are communicated with the oil return circuit through an oil return port of the left travel valve; when the left travel valve is located at a left working position or a right working position, the middle oil inlet and the middle oil outlet of the left travel valve are not communicated, hydraulic oil enters one of the two left travel oil ports through the left travel valve, and hydraulic oil in the other left travel oil port returns through the left travel valve, such that forward and reverse rotation of a left travel motor is realized; the right travel valve is a three-position six-way valve; when the right travel valve is located in a middle position, a middle oil inlet and a middle oil outlet of the right travel valve are communicated, working oil entering the first main oil inlet flows to the second middle oil supply passage through the right travel valve, working oil out of the middle oil outlet of the right travel valve unidirectionally flows to the second upper oil supply circuit, and two right travel oil ports are communicated with the oil return circuit through an oil return port of the right travel valve; when the right travel valve is located at a left working position or a right working position, the middle oil inlet and the middle oil outlet of the right travel valve are not communicated, hydraulic oil enters one of the two right travel oil ports through the right travel valve, and hydraulic oil in the other oil port returns through the right travel valve, such that forward and reverse rotation of a right travel motor is realized.
5. The multi-way valve according to Claim 1, wherein the turning valve is a three-position six-way valve, and has a middle position and two working positions; when the turning valve is located at the middle position, a middle oil inlet and a middle oil outlet of the turning valve are communicated, and the second upper oil supply circuit does not supplies oil to the turning hydraulic cylinder; when the turning valve is located at the two working positions, the middle oil inlet and the middle oil outlet of the turning valve are communicated, and the second upper oil supply circuit supplies oil to one of two oil ports of the turning hydraulic cylinder through the turning valve, and the other oil port is communicated with the oil return circuit through the turning valve.
6. The multi-way valve according to Claim 1, wherein the first boom valve is a three-position six-way valve, and has a middle position and two working positions; when the first boom valve is located at the middle position, a middle oil inlet and a middle oil outlet of the first boom valve are communicated, the first middle oil supply passage is turned on, and the first upper oil supply circuit does not supply oil to the boom hydraulic cylinder; when the first boom valve is located at the two working positions, the first upper oil supply circuit supplies oil to one of two oil ports of the boom hydraulic cylinder through a first boom oil inlet cut-off valve, the first boom valve and a boom loading holding valve, and the other oil port is communicated with the oil return circuit through the first boom valve; an oil inlet of thefirst boom valve is communicated with the first upper oil supply circuit through a first boom oil inlet cut-off valve, and an oil return port of the first boom valve is communicated with the oil return circuit; a first working oil port is connected to a boom big cavity oil port through the boom load holding valve, a second working oil port is connected to a boom small cavity oil port, and the middle oil outlet is connected to a middle oil inlet of the bucket valve; the second movable valve is a three-position six-way valve, an oil inlet is connected to the second upper oil supply circuit through a second boom oil inlet check valve, an oil return port is connected to the oil return passage, and a middle oil inlet is connected to the middle oil outlet of the turning valve; a first working port is connected to the boom big cavity oil port through a load holding valve; a second working port is communicated with the boom big cavity oil port through the load holding valve; a middle oil outlet is connected to a middle oil inlet of the third boom valve; the second boom valve has a middle position and two working positions; when the second boom valve is located at the middle position, the middle oil inlet is communicated with the middle oil outlet; when the second boom valve is located at a right working position, the oil inlet is communicated with the first working oil port, and the oil return port is not communicated with the second working oil port; when the second boom valve is located at a left working position, the second working oil port is communicated with the oil return port, and the oil inlet is not communicated with the first working oil port; the third boom valve is a two-position five-way valve, an oil return port is unidirectionally communicated with the second upper oil supply circuit through a recycling check valve, and a first working oil port is communicated with the boom big cavity oil port through a load holding valve; when the third boom valve is located at a right working position, the middle oil inlet is communicated with a middle oil outlet; when the third boom valve is located at a left working position, the first working oil port is communicated with the oil return port, and oil in the boom big cavity oil port is recycled to the second upper oil supply circuit; the multi-way valve further comprises a boom big cavity recycling oil circuit which comprises a boom big cavity oil recharging check valve; when booms ascend, oil is recycled and recharged in the boom big cavity oil port from the oil return passage through the boom big cavity oil recharging check valve, such that air is prevented from being sucked into the booms; the multi-way valve further comprises a boom small cavity recycling oil circuit which comprises a boom small cavity oil recharging check valve, and when the booms descend, oil is recycled and recharged in the boom small cavity oil port from the oil return passage through the boom small cavity oil recharging check valve, such that air is prevented from being sucked into the booms.
7. The multi-way valve according to Claim 1, wherein the bucket valve is a four-position six-way valve, an oil inlet is connected to the first upper oil supply circuit through a bucket oil inlet check valve, an oil return port is connected to the oil return circuit, and two working oil ports are connected to oil ports of the bucket hydraulic cylinder; the bucket valve has a middle position and three working positions; when the bucket valve is located at the middle position, the first upper oil supply circuit does not supply oil to the bucket hydraulic cylinder; when the bucket valve is located at the three working positions, the first upper oil supply circuit supplies oil to one cavity of the bucket valve through an arm big cavity oil port or a bucket small cavity oil port, and correspondingly, hydraulic oil in the other cavity flows out through the bucket small cavity oil port or the bucket big cavity oil port and returns to the oil return circuit through the bucket valve; when the bucket valve works at a second working position at a left end, return oil in the bucket small cavity oil port is damped, such that air is prevented from being sucked into a bucket; when the bucket retreats for excavation, the bucket valve working at a first working position at the left end, the return oil in the arm small cavity oil port is not damped, such that a back pressure of the return oil during excavation is reduced.
8. The multi-way valve according to Claim 1, wherein the first arm valve is a three-position six-way valve, and has a middle position and two working positions; when the first arm valve is located at the middle position, the second middle oil supply passage is turned on, and the second upper oil supply circuit does not supply oil to a fourth actuator; when the first arm valve is located at the two working positions, the second upper oil supply circuit supplies oil to one oil port of the arm hydraulic cylinder, and the other oil port of the arm hydraulic cylinder is communicated with the oil return circuit through the first arm valve; load holding valves are disposed between the oil ports of the arm hydraulic cylinders and working oil ports of the first arm valve, and the load holding valves are of a cone valve structure and have the characteristic of zero leakage; an oil inlet of the first arm valve is connected to the second upper oil supply circuit through a first arm oil inlet check valve, a return oil port is connected to the oil return circuit, a middle oil outlet of the first arm valve is connected to a second bypass valve, a first working oil port is connected to an arm small cavity oil port through an arm small cavity load holding valve, and a second working oil port is communicated with an arm big cavity oil port through an arm big cavity load holding valve; when the first arm valve is located at a left working position, the oil inlet is communicated with the second working oil port, and a damper is disposed between the first working oil port and the oil return port; when the first arm valve is located at a right working position, the oil inlet is communicated with the first working oil port, and the second working oil port is directly communicated with the oil return port; the second arm oil return valve is a four-position six-way valve, a middle oil outlet of the second arm oil return valve is connected to a middle oil inlet of the standby valve, an oil inlet of the second arm oil return valve is connected to the first upper oil supply circuit through a second arm oil inlet check valve and a second arm oil inlet valve, and an oil return port of the second arm oil return valve is connected to the oil return circuit; a first working oil port of the second arm oil return valve is connected to the arm small cavity oil port through a load holding valve; a second working oil port of the second arm oil return valve is communicated with an arm big cavity; the second arm oil return valve has a middle position and three working positions; when the second arm oil return valve is located at the middle position, the first middle oil supply passage is turned on, and the first upper oil supply circuit does not supply oil to the arm hydraulic cylinder; when the second arm oil return valve is located at thefirst working position, the oil inlet of the second arm oil return valve is communicated with the first working oil port, and the second working oil port is communicated with the oil inlet; when arms retreat, if a gravity of the arms is greater than a load, the second arm oil return valve is controlled to be located at a second working position, the oil inlet is communicated with the second working oil port, the first working oil port is communicated with the second working oil port through a check valve and is communicated with the oil return port through a throttle hole, at this moment, return oil in the arms is damped by the throttle hole, and most return oil is recycled into the arm big cavity oil port through the check valve, such that quick movement of the arms is realized, and air is prevented from being sucked into the arms; when the arms bears a drag load during excavation, the second arm oil return valve is controlled to be located at a third working position, the oil inlet is communicated with the second working oil port, the first working oil port is communicated with the second working oil port through the check valve, the first working oil port is directly communicated with the oil return port, and the return oil in the arms is not damped.
9. The multi-way valve according to Claim 1, wherein the standby valve is a three-position six-way valve, a middle oil outlet of the standby valve is connected to an oil inlet of a first bypass valve, and an oil outlet of the first bypass valve is connected to the main oil return passage; the first upper oil supply circuit unidirectionally supplies oil to an oil inlet, an oil return port is connected to the oil return circuit, and two working oil ports are connected to oil ports of the standby hydraulic cylinder; when the standby valve is located at a middle position, the first middle oil supply passage is turned on, and the first upper oil supply circuit does not supply oil to the standby hydraulic cylinder; and when the standby valve is located at two working positions, the first upper oil supply circuit supplies oil to one of two oil ports of the standby hydraulic cylinder through the standby valve, and the other oil port is communicated with the oil return circuit through the standby valve.
10. The multi-way valve according to Claim 1, wherein the multi-way valve further comprises overload oil recharging vales, and the overload oil recharging valves are disposed between two oil ports of the boom hydraulic cylinders and the oil return circuit, between two oil ports of the bucket hydraulic cylinder and the oil return circuit, between two oil ports of the arm hydraulic cylinder and the oil return circuit, as well as between two oil ports of the standby hydraulic cylinder and the oil return circuit.
11. A hydraulic system, comprising the multi-way valve according to any one of Claims 1-10.
12. An excavator, comprising the hydraulic system according to Claim 11.
AU2022436043A 2022-08-29 2022-12-28 Multi-way valve, hydraulic system and excavator Pending AU2022436043A1 (en)

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CN115341615B (en) * 2022-08-29 2023-09-01 江苏汇智高端工程机械创新中心有限公司 Multi-way valve, hydraulic system and excavator
CN116877519B (en) * 2023-06-30 2024-06-14 江苏汇智高端工程机械创新中心有限公司 Hydraulic main valve and system of heavy-load mining excavator

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05187042A (en) * 1992-01-08 1993-07-27 Yutani Heavy Ind Ltd Hydraulic circuit for construction machinery
JP2010047984A (en) * 2008-08-21 2010-03-04 Sumitomo (Shi) Construction Machinery Co Ltd Hydraulic circuit of hydraulic excavator
CN102518612B (en) * 2011-12-08 2014-12-03 上海三一重机有限公司 Regeneration function implementing device for bucket arm of hydraulic excavator
CN204590113U (en) * 2015-04-21 2015-08-26 山河智能装备股份有限公司 Medium-sized multi-way valve of hydraulic excavator group
CN211898661U (en) * 2017-02-27 2020-11-10 山东常林机械集团股份有限公司 Multi-way control valve for hydraulic excavator
CN108316389B (en) * 2018-04-16 2023-09-22 福建晋工机械有限公司 Multi-way valve for wheel excavator
CN209414291U (en) * 2018-12-11 2019-09-20 烟台艾迪液压科技有限公司 A kind of novel whole multi-way valve of excavator
CN211973647U (en) * 2020-01-20 2020-11-20 广西玉柴重工有限公司 Double-pump common rail multi-way valve hydraulic system
CN113882459B (en) * 2021-09-30 2023-02-17 徐州徐工挖掘机械有限公司 Excavator energy recovery system and excavator
CN115341615B (en) * 2022-08-29 2023-09-01 江苏汇智高端工程机械创新中心有限公司 Multi-way valve, hydraulic system and excavator

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