Multi-way valve assembly, hydraulic system and motor grader

Abstract

The present invention provides a multi-way valve assembly, a hydraulic system, and a motor grader, wherein the multi-way valve assembly includes: an oil inlet passage; an oil return passage; a feedback passage; at least one valve unit, the valve unit including: a reversing valve, wherein a first oil port of the reversing valve is connected to the oil inlet passage, a second oil port of the reversing valve is connected to the oil return passage, and a working port of the reversing valve is connected to an actuator; a pressure compensating valve, wherein an inlet of the pressure compensating valve is connected to a fourth oil port of the reversing valve, an outlet of the pressure compensating valve is connected to a third oil port of the reversing valve, and a spring chamber of the pressure compensating valve is connected to the feedback passage; and an unloading valve, wherein an inlet of the unloading valve is connected to the oil inlet passage, a spring chamber of the unloading valve is connected to the feedback passage, and an outlet of the unloading valve is connected to the oil return passage. Thus, by integrating the unloading valve on the multi-way valve assembly, the proportional performance of multiple valve units is achieved, and there is no need to provide a separate control valve or variable pump, thereby effectively improving the reliability while ensuring the cost of the multi-way valve assembly.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic transmission and control, and in particular to a multi-way valve assembly, a hydraulic system and a motor grader. Background Art

[0002] Most hydraulic systems for graders utilize two types of hydraulic systems: a fixed-displacement pump + on-off multi-way valve and a load-sensing variable-displacement pump + load-sensing multi-way valve. These systems control the movements of the various cylinders in the grader's operating mechanism, such as blade raising and lowering, blade extension and retraction, articulated steering, front wheel tilt, and front bulldozer raising and lowering. The fixed-displacement pump + on-off multi-way valve solution offers lower cost, but the hydraulic valve's control accuracy is low and it cannot achieve the combined movements of multiple cylinders. The load-sensing variable-displacement pump + load-sensing multi-way valve solution allows for more precise control and combined movements of multiple cylinders, but the use of a variable-displacement pump results in higher system costs. Related technologies utilize a fixed-displacement pump + integrated control valve + load-sensing multi-way valve system, achieving the combined use of a fixed-displacement pump and load-sensing multi-way valve through a single integrated control valve. However, this solution presents a more complex hydraulic system, requiring the integration of a pressure compensation valve, solenoid reversing valve, priority valve, and relief valve into the integrated valve, resulting in significant pressure loss. Furthermore, the control lines for the load-sensing multi-way valve and integrated valve are complex and difficult to arrange. Summary of the Invention

[0003] The present invention aims to solve or improve at least one of the technical problems existing in the prior art or related art.

[0004] To this end, one aspect of the present invention provides a multi-way valve assembly.

[0005] A second aspect of the present invention provides a hydraulic system.

[0006] The third aspect of the present invention provides a motor grader.

[0007] In view of this, one aspect of the present invention proposes a multi-way valve assembly, comprising: an oil inlet channel; an oil return channel; a feedback channel; at least one connecting valve body, the connecting valve body comprising: a reversing valve, the first oil port of the reversing valve is connected to the oil inlet channel, the second oil port of the reversing valve is connected to the oil return channel, and the working port of the reversing valve is connected to the actuator; a pressure compensating valve, the inlet of the pressure compensating valve is connected to the fourth oil port of the reversing valve, the outlet of the pressure compensating valve is connected to the third oil port of the reversing valve, and the spring chamber of the pressure compensating valve is connected to the feedback oil channel; an unloading valve, the inlet of the unloading valve is connected to the oil inlet channel, the spring chamber of the unloading valve is connected to the feedback oil channel, and the outlet of the unloading valve is connected to the return oil channel.

[0008] The multi-way valve assembly provided by the present invention includes an oil inlet pipe, an oil return oil channel, a feedback oil channel, at least one joint valve body, and an unloading valve. The joint valve body includes: a reversing valve and a pressure compensating valve. Specifically, the reversing valve is a three-position six-way reversing valve, and the main valve has a total of six oil ports. The three oil ports on one side of the reversing valve are sequentially recorded as the first oil port, the second oil port, and the third oil port from bottom to top, and the three oil ports on the other side are sequentially recorded as the fourth oil port, the first working port, and the second working port from bottom to top. The first oil port of the reversing valve and the inlet of the unloading valve are connected to the oil inlet channel, the outlet of the unloading valve and the second oil port of the reversing valve are connected to the oil return channel, the working port of the reversing valve is connected to the working oil port of the actuator, the inlet and outlet of the pressure compensating valve are respectively connected to the fourth oil port and the third oil port of the reversing valve, and the spring chamber of the pressure compensating valve and the spring chamber of the unloading valve are both connected to the feedback oil channel, so that the medium can enter the reversing valve from the oil inlet channel.

[0009] Specifically, if the spool of the reversing valve does not move, that is, the spool is in the middle position, the first oil port of the reversing valve is disconnected from the fourth oil port of the reversing valve, and the actuator connected to the working port of the reversing valve does not operate. At this time, the unloading valve is opened, and the medium flows back from the return oil channel through the unloading valve. If the spool of any reversing valve in the multi-way valve assembly moves, the first oil port of the reversing valve is connected to the fourth oil port of the reversing valve, the third oil port of the reversing valve is connected to one of the working ports of the reversing valve, and the other working port of the reversing valve is connected to the second oil port of the reversing valve, so that the medium flows into the actuator through the first oil port of the reversing valve, the fourth oil port of the reversing valve, the pressure compensation valve, the third oil port of the reversing valve, and the working oil port of the reversing valve in sequence. The medium in the actuator flows into the return oil channel through the working oil port and the second oil port of the reversing valve to drive the actuator. If the reversing valves of multiple valve bodies operate simultaneously, the opening size of each pressure compensation valve is adjusted through the feedback oil channel, so that the medium can be distributed to the different reversing valve spools according to the proportion required by the actuator through the pressure compensation valve, thereby enabling the coordinated operation of the different valve bodies. At the same time, the excess medium returns from the unloading valve to perform low-pressure unloading. Integrating the unloading valve on the multi-way valve assembly thus achieves the proportional performance of the multi-way valve assembly without the need for a separate control valve (priority valve, etc.) or variable pump. The structure is simple, the oil channel distribution is simplified, and it is easy to implement. While ensuring the cost of the multi-way valve assembly, it effectively improves the reliability of the multi-way valve assembly. In addition, the components are easy to repair and replace, facilitating installation and troubleshooting of system failures.

[0010] Furthermore, the two working ports of the reversing valve switch the flow direction of the medium according to the movement direction of the valve core.

[0011] The multi-way valve assembly of the motor grader according to the present invention may also have the following additional technical features:

[0012] In the above technical solution, further, the multi-way valve assembly also includes: a relief valve connected to the oil inlet channel and the oil return channel.

[0013] In this technical solution, only overflow valves are connected to the oil inlet and return oil channels, which play an overload protection role in the system's branches. Specifically, when the hydraulic system is working normally, the overflow valve is closed. Only when the load exceeds the specified limit, that is, the system pressure exceeds the preset pressure, the overflow valve will open, so that the hydraulic system pressure no longer increases, playing a high-pressure overflow role, thereby protecting subsequent oil channels and improving the safety and reliability of the multi-way valve assembly.

[0014] In any of the above technical solutions, further, the multi-way valve assembly further includes a shuttle valve; the number of the valve bodies is N, and the number of the shuttle valves is N-1; if N is equal to 2, the first inlet of the shuttle valve is connected to the outlet of the pressure compensating valve of the first valve body, the second inlet of the first shuttle valve is connected to the outlet of the pressure compensating valve of the second valve body, and the selection oil port of the shuttle valve is connected to the feedback oil channel; if N is equal to 3; the first inlet of the first shuttle valve is connected to the outlet of the pressure compensating valve of the first valve body, the second inlet of the first shuttle valve is connected to the outlet of the pressure compensating valve of the second valve body, the selection oil port of the first shuttle valve is connected to the first inlet of the second shuttle valve, the second inlet of the second shuttle valve is connected to the outlet of the pressure compensating valve of the third valve body, and the selection oil port of the second shuttle valve is connected to the feedback oil channel; if N is greater than or equal to 4; Then the first inlet of the first shuttle valve is connected to the outlet of the pressure compensating valve of the first valve unit, the second inlet of the first shuttle valve is connected to the outlet of the pressure compensating valve of the second valve unit, and the selection oil port of the first shuttle valve is connected to the first inlet of the second shuttle valve; the first inlet of the (N-1)th shuttle valve is connected to the selection oil port of the (N-2)th shuttle valve, the second inlet of the (N-1)th shuttle valve is connected to the outlet of the pressure compensating valve of the (N)th valve unit, and the selection oil port of the (N-1)th shuttle valve is connected to the feedback oil channel; and for any value i, the first inlet of the i-th shuttle valve is connected to the selection oil port of the (i-1)th shuttle valve, the second inlet of the i-th shuttle valve is connected to the outlet of the pressure compensating valve of the (i+1)th valve unit, and the selection oil port of the i-th shuttle valve is connected to the first inlet of the (i+1)th shuttle valve, where i is an integer greater than 1 and less than N-1.

[0015] In this technical solution, a shuttle valve compares the inlet pressure of the Nth combined valve body with the inlet pressure of the N-1th combined valve body. If the two inlet pressures are unequal, the high-pressure inlet and outlet are connected. If the two inlet pressures are equal, the inlet with the higher pressure is connected to the outlet to ensure that the outlet pressure is the higher of the two inlets. The highest pressure among the multiple combined valve bodies is then selected and connected to the spring chambers of the pressure compensation valves and unloading valves of each combined valve body via a feedback oil channel connected to the outlet of the N-1th shuttle valve. This allows the pressure compensation valves and unloading valves to regulate system flow, improving system reliability. Furthermore, the shuttle valve has a minimal impact on medium pressure, enabling fast switching and low pressure loss.

[0016] In any of the above technical solutions, further, the reversing valve is a proportional reversing valve; and the unloading valve is a proportional unloading valve.

[0017] In this technical solution, both the reversing valve and the unloading valve are proportional valves. If the spool of any proportional reversing valve in the multi-way valve assembly operates, the proportional reversing valve allows the medium to be output from the corresponding valve plate working port to the actuator according to the size of the spool opening, thereby realizing the proportional function of the multi-way reversing valve. If the proportional reversing valve spool does not operate, that is, the spool is in the neutral position, the actuator connected to the proportional reversing valve working port is not operating. At this time, the proportional unloading valve opens, and the medium returns through the proportional unloading valve to the return oil channel, realizing the neutral unloading of the multi-way valve assembly.

[0018] In any of the above technical solutions, further, the multi-way valve assembly also includes: a controller connected to the reversing valve, and the controller is configured to control the reversing of the reversing valve.

[0019] In this technical solution, the multi-way valve assembly also includes a controller connected to the reversing valve. The controller controls the reversing of the reversing valve by controlling the on and off of the power to the reversing valve. If the reversing valve is a proportional reversing valve, the controller is also used to control the opening of the proportional reversing valve core to facilitate timely oil supply to the actuator, and can accurately control the oil inlet, thereby improving the adaptability and wide range of use of the product.

[0020] According to a second aspect of the present invention, a hydraulic system is proposed, comprising: an oil tank; a hydraulic pump, the inlet of the hydraulic pump being connected to the oil tank; and the multi-way valve assembly proposed in the first aspect, the oil inlet channel of the multi-way valve assembly being connected to the outlet of the hydraulic pump, and the oil return channel of the multi-way valve assembly being connected to the oil tank; and an actuator, the oil port of the actuator being connected to the working port of the multi-way valve assembly.

[0021] In this technical solution, the hydraulic system includes: an oil tank, a hydraulic pump, a multi-way valve assembly, and an actuator. The hydraulic pump outputs hydraulic oil through the oil inlet channel and enters the multi-way valve assembly. If the reversing valve spool does not move, that is, the spool is in the neutral position, the actuator connected to the reversing valve working port is not operating. At this time, the unloading valve opens, and the hydraulic oil returns through the unloading valve and the return oil channel. If the spool of any reversing valve in the multi-way valve assembly moves, the hydraulic oil flows into the actuator through the reversing valve and the pressure compensation valve to drive the actuator. If the reversing valves of multiple valve bodies operate simultaneously, the opening size of each pressure compensation valve is adjusted through the feedback oil channel, so that the hydraulic oil is distributed to the different reversing valve spools according to the actuator's demand ratio through the pressure compensation valve. The unloading valve will also close the stroke proportionally according to the required flow of the multi-way valve assembly, thereby enabling the coordinated operation of the different valve bodies. At the same time, excess hydraulic oil returns through the unloading valve. Therefore, the proportional performance of the multi-way valve assembly can be achieved without a variable pump, and the control valve between the hydraulic pump and the multi-way valve assembly is eliminated, which simplifies the hydraulic system and makes it easy to implement. While ensuring the cost of the hydraulic system, the reliability is effectively improved. In addition, the components in the hydraulic system are easy to repair and replace, and it is convenient to install and troubleshoot system failures.

[0022] In any of the above technical solutions, the hydraulic system further includes: a filter connected between the oil tank and the hydraulic pump.

[0023] In this technical solution, the first filter intercepts pollutants in the hydraulic oil, so that the hydraulic oil remains clean, ensuring that the hydraulic system can work normally and extending the service life of the hydraulic pump.

[0024] According to a third aspect of the present invention, a motor grader is provided, comprising the hydraulic system of the motor grader of the second aspect. Because the motor grader provided by the present invention includes a hydraulic system as described in any of the technical solutions of the second aspect, it possesses all the beneficial effects of the aforementioned hydraulic systems, which are not detailed here.

[0025] In any of the above technical solutions, the motor grader further includes: an engine; a transfer case connected to the engine and the hydraulic pump; and a power pump connected to the engine or the transfer case.

[0026] In this technical solution, the engine provides power for the hydraulic system, which is then distributed through the transfer case to the hydraulic pump and other components to drive the actuators. This eliminates the need for multiple engines for different components, saving costs, reducing noise, energy consumption, and overall weight. Furthermore, a power pump is added to the transfer case or engine to provide a stable power unit for the hydraulic pump, ensuring high-power output and smooth operation of the device, while minimizing mechanical efficiency losses.

[0027] Specifically, the power pump and the hydraulic pump may adopt gear pumps, which have a simple structure, small size, light weight, low price, and stable operation, which not only reduces the production cost of the product but also improves the practicality of the product.

[0028] Additional aspects and advantages of the invention will become apparent from the description which follows, or may be learned by practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0030] Figure 1 A schematic diagram showing the principle of a multi-way valve assembly according to an embodiment of the present invention is shown;

[0031] Figure 2 A schematic diagram showing the principle of a hydraulic system according to another embodiment of the present invention is shown;

[0032] Figure 3 A top view of a multi-way valve assembly according to a specific embodiment of the present invention is shown.

[0033] in, Figures 1 to 3 The corresponding relationship between the reference numerals and component names is as follows:

[0034] 100 multi-way valve assembly, 110 oil inlet channel, 120 oil return channel, 130 feedback oil channel, 140 joint valve body, 142 reversing valve, 144 pressure compensating valve, 150 unloading valve, 160 relief valve, 170 shuttle valve, 210 oil tank, 220 hydraulic pump. DETAILED DESCRIPTION

[0035] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other.

[0036] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0037] Refer to the following Figures 1 to 3 A multi-way valve assembly, a hydraulic system, and a motor grader according to some embodiments of the present invention are described.

[0038] Example 1:

[0039] like Figure 1 and Figure 2As shown, an embodiment of the first aspect of the present invention provides a multi-way valve assembly 100, comprising: an oil inlet passage 110, an oil return passage 120, a feedback passage 130, at least one joint valve body 140 and an unloading valve 150.

[0040] In detail, the valve body 140 includes a reversing valve 142 and a pressure compensating valve 144. The reversing valve is a three-position, six-way reversing valve with six main valve ports. The three ports on one side of the reversing valve are designated, from bottom to top, as the first port, the second port, and the third port. The three ports on the other side are designated, from bottom to top, as the fourth port, the first working port, and the second working port. The first port of the reversing valve 142 is connected to the oil inlet passage 110, the second port of the reversing valve 142 is connected to the oil return passage 120, and the working ports (the first working port and the second working port) of the reversing valve 142 are connected to the actuators of the hydraulic system. The inlet of the pressure compensating valve 144 is connected to the fourth port of the reversing valve 142, the outlet of the pressure compensating valve 144 is connected to the third port of the reversing valve 142, and the spring chamber of the pressure compensating valve 144 is connected to the feedback passage 130. The inlet of the unloading valve 150 is connected to the oil inlet passage 110 , the spring chamber of the unloading valve 150 is connected to the feedback oil passage 130 , and the outlet of the unloading valve 150 is connected to the oil return passage 120 .

[0041] In this embodiment, if the valve core of the reversing valve 142 does not move, that is, the valve core is in the middle position, the first oil port of the reversing valve is disconnected from the fourth oil port of the reversing valve 142, and the actuator connected to the working port of the reversing valve 142 does not operate. At this time, the unloading valve 150 is opened, and the medium flows back from the return oil channel 120 through the unloading valve 150. If the valve core of any reversing valve 142 in the multi-way valve assembly 100 is actuated, the first oil port of the reversing valve is connected to the fourth oil port of the reversing valve 142, the third oil port of the reversing valve 142 is connected to one of the working ports of the reversing valve 142, and the other working port of the working port of the reversing valve 142 is connected to the second oil port of the reversing valve 142. The medium flows into the actuator through the reversing valve 142 and the pressure compensating valve 144 and then through the reversing valve 142. That is, the medium enters the pressure compensating valve 144 through the first oil port and the fourth oil port of the reversing valve 142, and then flows into the actuator through the third oil port and the working port of the reversing valve 142. The medium in the actuator flows into the return oil channel 120 through the second oil port of the reversing valve 142 to drive the actuator. If the reversing valves 142 of multiple valve bodies 140 are actuated simultaneously, the opening size of each pressure compensation valve 144 is adjusted through the feedback oil passage 130, so that the medium can be distributed to the valve cores of different reversing valves 142 according to the proportion of the actuator requirements through the pressure compensation valve 144, thereby enabling the coordinated operation of the different valve bodies 140. At the same time, the excess medium flows back from the unloading valve 150 to perform low-pressure unloading, thereby reducing system energy consumption. Therefore, by integrating the unloading valve 150 on the multi-way valve assembly 100, the multiple valve bodies 140 of the multi-way valve assembly 100 can be operated simultaneously, with a small pressure drop. There is no need to set up a separate control valve (priority valve, etc.) or variable pump. The structure is simple and easy to implement. While ensuring the cost of the multi-way valve assembly 100, the reliability of the multi-way valve assembly 100 is effectively improved. In addition, the components are easy to repair and replace, which facilitates installation and troubleshooting of system failures.

[0042] Furthermore, the reversing valve 142 is a proportional reversing valve 142, and the unloading valve 150 is a proportional unloading valve 150. If the valve core of any proportional reversing valve 142 in the multi-way valve assembly 100 is actuated, the medium can be output from the corresponding valve plate working port to the actuator according to the size of the valve core opening through the proportional reversing valve 142. The proportional unloading valve 150 will also close the stroke proportionally according to the required flow rate of the multi-way valve assembly 100, thereby realizing the proportional function of the multi-way reversing valve 142. If the valve core of the proportional reversing valve 142 is not actuated, that is, the valve core is in the neutral position, the actuator connected to the working port of the proportional reversing valve 142 is not operating. At this time, the proportional unloading valve 150 is opened, and the medium flows back from the return oil channel 120 through the proportional unloading valve 150, realizing the neutral unloading of the multi-way valve assembly 100.

[0043] Furthermore, the multi-way valve assembly 100 also includes a controller connected to the reversing valve 142. The reversing valve 142 controller controls the reversing of the reversing valve 142 by controlling the on and off of the power of the reversing valve 142. If the reversing valve 142 is a proportional reversing valve 142, the controller is also used to control the opening of the valve core of the proportional reversing valve 142, so as to facilitate timely oil supply to the actuator, and can accurately control the oil inlet, thereby improving the adaptability and wide range of use of the product.

[0044] Specifically, the actuators include motors, cylinders, etc.

[0045] Example 2:

[0046] like Figure 2 As shown, according to one embodiment of the present invention, a multi-way valve assembly 100 is proposed, including: an oil inlet channel 110, an oil return channel 120, a feedback channel 130, at least one valve body 140, an unloading valve 150 and a relief valve 160.

[0047] In detail, valve link 140 includes a reversing valve 142 and a pressure compensating valve 144. The first oil port of reversing valve 142 is connected to the oil inlet passage 110, the second oil port of reversing valve 142 is connected to the oil return passage 120, and the working port of reversing valve 142 is connected to the actuator. The inlet of pressure compensating valve 144 is connected to the fourth oil port of reversing valve 142, the outlet of pressure compensating valve 144 is connected to the third oil port of reversing valve 142, and the spring chamber of pressure compensating valve 144 is connected to the feedback passage 130. The inlet of unloading valve 150 is connected to the oil inlet passage 110, the spring chamber of unloading valve 150 is connected to the feedback passage 130, and the outlet of unloading valve 150 is connected to the oil return passage 120. A relief valve 160 is connected to both the oil inlet passage 110 and the oil return passage 120.

[0048] In this embodiment, a relief valve 160 is connected between the oil inlet channel 110 and the oil return channel 120. The relief valve 160 serves to limit the maximum pressure and provide overload protection in the branch of the system. Specifically, when the hydraulic system is operating normally, the relief valve 160 is closed. Only when the load exceeds the specified limit, that is, the system pressure exceeds the preset pressure, the relief valve 160 will open, so that the system pressure no longer increases, thereby playing a high-pressure overflow role, thereby protecting the subsequent oil channels and improving the safety and reliability of the multi-way valve assembly 100.

[0049] Example 3:

[0050] According to one embodiment of the present invention, the present invention includes the features defined in any one of the above embodiments, and further: the multi-way valve assembly also includes a shuttle valve.

[0051] Specifically, the number of valve couplings is N, and the number of shuttle valves is N-1. If N is 2, the first inlet of the first shuttle valve is connected to the outlet of the pressure compensation valve of the first valve coupling, the second inlet of the first shuttle valve is connected to the outlet of the pressure compensation valve of the second valve coupling, and the selection oil port of the shuttle valve is connected to the feedback oil passage.

[0052] If N is equal to 3, the first inlet of the first shuttle valve is connected to the outlet of the pressure compensating valve of the first valve unit, the second inlet of the first shuttle valve is connected to the outlet of the pressure compensating valve of the second valve unit, the selection oil port of the first shuttle valve is connected to the first inlet of the second shuttle valve, the second inlet of the second shuttle valve is connected to the outlet of the pressure compensating valve of the third valve unit, and the selection oil port of the second shuttle valve is connected to the feedback oil channel;

[0053] If N is greater than or equal to 4, the first inlet of the first shuttle valve is connected to the outlet of the pressure compensating valve of the first valve unit, the second inlet of the first shuttle valve is connected to the outlet of the pressure compensating valve of the second valve unit, and the selection oil port of the first shuttle valve is connected to the first inlet of the second shuttle valve; the first inlet of the (N-1)th shuttle valve is connected to the selection oil port of the (N-2)th shuttle valve, the second inlet of the (N-1)th shuttle valve is connected to the outlet of the pressure compensating valve of the (N)th valve unit, and the selection oil port of the (N-1)th shuttle valve is connected to the feedback oil channel; and for any value i, the first inlet of the i-th shuttle valve is connected to the selection oil port of the (i-1)th shuttle valve, the second inlet of the i-th shuttle valve is connected to the outlet of the pressure compensating valve of the (i+1)th valve unit, and the selection oil port of the i-th shuttle valve is connected to the first inlet of the (i+1)th shuttle valve, where i is an integer greater than 1 and less than N-1.

[0054] In this embodiment, a shuttle valve compares the inlet pressure of the Nth combined valve body with the inlet pressure of the N-1th combined valve body. If the two inlet pressures are unequal, the high-pressure inlet and outlet are connected. If the two inlet pressures are equal, the inlet with the earlier pressure input is connected to the outlet to ensure that the outlet pressure is the higher of the two inlets. The highest load pressure among the multiple combined valve bodies is then selected and connected to the spring chambers of the pressure compensation valves and the unloading valves of each combined valve body via a feedback oil passage connected to the outlet of the N-1th shuttle valve, the last shuttle valve, thereby improving system reliability.

[0055] Specifically, if Figure 2 As shown in FIG, the number of valve bodies N=5, that is, the number of valve bodies is 5 and the number of shuttle valves is 4. The hydraulic oil flow direction along the oil inlet channel, that is, Figure 2The numbers of the combined valve bodies 140 and shuttle valves 170 are recorded in the order of the arrows in the diagram. That is, the combined valve body 140 that receives the first oil is recorded as the first combined valve body, the shuttle valve 170 that receives the first oil is recorded as the first shuttle valve, and so on. As can be seen, the first inlet of the first shuttle valve is connected to the outlet of the pressure compensating valve of the first combined valve body, the second inlet of the first shuttle valve is connected to the outlet of the pressure compensating valve of the second combined valve body, and the selector port of the first shuttle valve is connected to the first inlet of the second shuttle valve. The first inlets of the second and third shuttle valves are connected to the selector port of the previous shuttle valve, and the second inlets of the second and third shuttle valves are connected to the outlet of the pressure compensating valve of the third and fourth combined valve bodies, respectively. The selector ports of the second and third shuttle valves are connected to the first inlet of the next shuttle valve. The first inlet of the 4th shuttle valve is connected to the selection oil port of the 3rd shuttle valve, the second inlet of the 4th shuttle valve is connected to the outlet of the pressure compensation valve of the 5th valve body, and the selection oil port of the 4th shuttle valve is connected to the feedback oil channel 130.

[0056] Example 4:

[0057] like Figure 2 As shown, according to one embodiment of the present invention, a hydraulic system is proposed, including: an oil tank 210, a hydraulic pump 220, a multi-way valve assembly 100 and an actuator (not shown in the figure).

[0058] In detail, the inlet of the hydraulic pump 220 is connected to the oil tank 210, the oil inlet channel 110 of the multi-way valve assembly 100 is connected to the outlet of the hydraulic pump 220, and the oil return channel 120 of the multi-way valve assembly 100 is connected to the oil tank 210. The multi-way valve assembly 100 includes: an oil inlet channel 110, an oil return channel 120, a feedback channel 130, at least one connecting valve body 140 and an unloading valve 150, and the oil port of the actuator is connected to the working port of the multi-way valve assembly 100.

[0059] In this embodiment, hydraulic pump 220 delivers hydraulic oil through oil inlet passage 110 into multi-way valve assembly 100. If the spool of reversing valve 142 is inactive (i.e., in the neutral position), the actuator connected to the working port of reversing valve 142 is inoperative. At this point, unloading valve 150 opens, and hydraulic oil flows back through unloading valve 150 and into return oil passage 120. If the spool of any reversing valve 142 in multi-way valve assembly 100 is actuated, hydraulic oil flows through reversing valve 142 and pressure compensating valve 144 into the actuator, thereby driving the actuator. If the reversing valves 142 of multiple valve units 140 are actuated simultaneously, the opening size of each pressure compensating valve 144 is adjusted via feedback passage 130, allowing hydraulic oil to be distributed to the spools of different reversing valves 142 according to the actuator's needs. This allows coordinated operation of the different valve units 140. Excess hydraulic oil then flows back through unloading valve 150. Therefore, there is no need for a variable pump to achieve proportional flow output of multiple valve bodies in the multi-way valve assembly 100, and simultaneous operation of multiple valve bodies 140, and the control valve between the hydraulic pump 220 and the multi-way valve assembly 100 is eliminated. The structure is simple and easy to implement, and while ensuring the cost of the hydraulic system, the reliability is effectively improved. In addition, the components in the hydraulic system are easy to repair and replace, and it is convenient to install and troubleshoot system failures.

[0060] Furthermore, the oil tank 210 may be equipped with a level gauge, a thermometer, and an air filter to facilitate user monitoring of the current status of the oil tank 210. A filter is provided on the pressure supply circuit between the oil tank 210 and the hydraulic pump 220 to trap contaminants in the medium, thereby keeping the medium clean, ensuring the proper functioning of the hydraulic system, and extending the service life of the hydraulic pump 220.

[0061] In addition, the hydraulic system also includes: a filter. The first filter is arranged between the oil tank and the oil circuit of the hydraulic pump. The first filter intercepts pollutants in the hydraulic oil to keep the hydraulic oil clean, ensure that the hydraulic system can work normally, and extend the service life of the hydraulic pump.

[0062] Specifically, the hydraulic pump 220 is a gear pump, which has a simple structure, small size, light weight, low price, and stable operation, which not only reduces the production cost of the product but also improves the practicality of the product.

[0063] Example 5:

[0064] An embodiment of a third aspect of the present invention provides a motor grader, comprising: the hydraulic system, engine, transfer case and power pump provided in the embodiment of the second aspect.

[0065] In detail, the transfer case is connected to the engine and the hydraulic pump of the hydraulic system, and the power pump is connected to the engine or the transfer case.

[0066] In this embodiment, a variable displacement pump is not required to achieve proportional flow output from multiple valve bodies in a multi-way valve assembly. Furthermore, the control valve between the hydraulic pump and the multi-way valve assembly is eliminated, resulting in a simple and easy-to-implement structure. This effectively improves reliability while ensuring cost savings for the hydraulic system. Furthermore, the components in the hydraulic system are easily repaired and replaced, facilitating installation and troubleshooting. The engine provides power to the hydraulic system, which is then distributed through the transfer case to the hydraulic pump and other components to drive the actuators. This eliminates the need for multiple engines for different components, saving costs, reducing noise, and maximizing energy consumption while also reducing the overall weight of the entire device.

[0067] In addition, a power pump is added to the transfer case or engine to provide a stable power unit for the hydraulic pump, ensuring high-power output and smooth operation of the device, and reducing the loss of mechanical efficiency.

[0068] Specifically, the power pump and the hydraulic pump may adopt gear pumps, which have a simple structure, small size, light weight, low price, and stable operation, which not only reduces the production cost of the product but also improves the practicality of the product. Specific embodiment:

[0070] like Figures 2 to 3 As shown, the load-sensing hydraulic system consists of a gear pump and a load-sensing multi-way valve. The load-sensing multi-way valve includes a relief valve 160, five valve units 140, and an unloading valve 150. The valve units 140 are equipped with a reversing valve 142, a pressure compensating valve 144, and a shuttle valve 170. The reversing valve 142 is provided with working ports. The unloading valve 150 is a proportional unloading valve, and the reversing valve 142 is a manual reversing valve. Specifically, the working ports of the first valve unit are denoted as A1 and B1, the working ports of the second valve unit are denoted as A2 and B2, the working ports of the third valve unit are denoted as A3 and B3, the working ports of the fourth valve unit are denoted as A4 and B4, and the working ports of the fifth valve unit are denoted as A5 and B5.

[0071] In detail, such as Figure 2As shown, there is no control valve between the gear pump and the load-sensing multi-way valve. The gear pump outputs hydraulic oil into port P1 (the oil inlet) of the load-sensing multi-way valve. If the reversing valves 142 in the load-sensing multi-way valve are inactive, that is, all reversing valves 142 are in the neutral position, the proportional unloading valves in the load-sensing multi-way valve are all open, and the hydraulic oil flows back to the oil tank 210 through the proportional unloading valves and port T1 (the oil return port) of the load-sensing multi-way valve. When the spool of a particular link of the load-sensing multi-way valve is actuated, hydraulic oil is delivered from the corresponding valve plate working oil port to the actuator according to the size of the spool's opening stroke. The proportional unloading valve also closes proportionally to the load-sensing multi-way valve's required flow rate, achieving self-contained opening control of the proportional control reversing valve 142. When the multiple valves are actuated simultaneously, the hydraulic oil is proportionally distributed to the working spools through the compensator of the load-sensing multi-way valve, and the excess oil returns to the oil tank 210 through the proportional unloading valve.

[0072] In this embodiment, the load-sensing multi-way valve integrates a relief valve 160, a proportional reversing valve, a pressure compensating valve 144, a shuttle valve 170 and a proportional unloading valve. By adding a proportional unloading valve to the load-sensing multi-way valve group, the load-sensing multi-way valve can be unloaded in the middle position and proportional control of each reversing valve 142 can be achieved. Moreover, the metering pump is directly connected to the load-sensing multi-way valve, and the control valve between the gear pump and the load-sensing multi-way valve can be eliminated. The simultaneous operation of multiple valve bodies of the load-sensing multi-way valve can be achieved, which is simple, reliable and has a small pressure drop.

[0073] In the present invention, the term "plurality" refers to two or more, unless otherwise specified. Terms such as "installed," "connected," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean fixed, removable, or integral; and "connected" can mean directly or indirectly through an intermediary. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0074] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0075] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A multi-way valve assembly, characterized in that: include: Oil inlet passage; Oil return channel; Feedback oil channel; an unloading valve, wherein the inlet of the unloading valve is connected to the oil inlet passage, the spring chamber of the unloading valve is connected to the feedback oil passage, and the outlet of the unloading valve is connected to the oil return passage; At least one valve coupling body, the valve coupling body comprising: a reversing valve, wherein the first oil port of the reversing valve is connected to the oil inlet passage, the second oil port of the reversing valve is connected to the oil return passage, and the working port of the reversing valve is connected to the actuator; a pressure compensating valve, wherein the inlet of the pressure compensating valve is connected to the fourth oil port of the reversing valve, the outlet of the pressure compensating valve is connected to the third oil port of the reversing valve, and the spring chamber of the pressure compensating valve is connected to the feedback oil passage; The multi-way valve assembly further includes: a shuttle valve; The number of the valve coupling bodies is N, and the number of the shuttle valves is N-1; The feedback oil passage connected to the outlet of the N-1th shuttle valve is connected to the spring chamber of the pressure compensating valve and the spring chamber of the unloading valve of each valve link body, so that the pressure compensating valve and the unloading valve can regulate the system flow; If N is equal to 2, the first inlet of the shuttle valve is connected to the outlet of the pressure compensating valve of the first valve coupling body, the second inlet of the first shuttle valve is connected to the outlet of the pressure compensating valve of the second valve coupling body, and the selection oil port of the shuttle valve is connected to the feedback oil passage; If N is equal to 3, the first inlet of the first shuttle valve is connected to the outlet of the pressure compensating valve of the first valve unit, the second inlet of the first shuttle valve is connected to the outlet of the pressure compensating valve of the second valve unit, the selection oil port of the first shuttle valve is connected to the first inlet of the second shuttle valve, the second inlet of the second shuttle valve is connected to the outlet of the pressure compensating valve of the third valve unit, and the selection oil port of the second shuttle valve is connected to the feedback oil passage; If N is greater than or equal to 4, the first inlet of the first shuttle valve is connected to the outlet of the pressure compensating valve of the first valve unit, the second inlet of the first shuttle valve is connected to the outlet of the pressure compensating valve of the second valve unit, and the selection oil port of the first shuttle valve is connected to the first inlet of the second shuttle valve; the first inlet of the (N-1)th shuttle valve is connected to the selection oil port of the (N-2)th shuttle valve, the second inlet of the (N-1)th shuttle valve is connected to the outlet of the pressure compensating valve of the (N)th valve unit, and the selection oil port of the (N-1)th shuttle valve is connected to the feedback oil passage; and for any value i, the first inlet of the i-th shuttle valve is connected to the selection oil port of the (i-1)th shuttle valve, the second inlet of the i-th shuttle valve is connected to the outlet of the pressure compensating valve of the (i+1)th valve unit, and the selection oil port of the i-th shuttle valve is connected to the first inlet of the (i+1)th shuttle valve, where i is an integer greater than 1 and less than N-1; The shuttle valve is used to compare the inlet pressure of the Nth valve link body with the inlet pressure of the N-1th valve link body, and to select the highest pressure among the multiple valve links.

2. The multi-way valve assembly according to claim 1, characterized in that: Also includes: A relief valve is connected to the oil inlet passage and the oil return passage.

3. The multi-way valve assembly according to claim 1 or 2, characterized in that: The reversing valve is a proportional reversing valve; The unloading valve is a proportional unloading valve.

4. The multi-way valve assembly according to claim 1 or 2, characterized in that: Also includes: A controller is connected to the reversing valve, and the controller is configured to control the reversing of the reversing valve.

5. A hydraulic system, characterized in that: include: tank; a hydraulic pump, wherein an inlet of the hydraulic pump is connected to the oil tank; The multi-way valve assembly according to any one of claims 1 to 4, wherein the oil inlet passage of the multi-way valve assembly is connected to the outlet of the hydraulic pump, and the oil return passage of the multi-way valve assembly is connected to the oil tank; An actuator, wherein the oil port of the actuator is connected to the working port of the multi-way valve assembly.

6. The hydraulic system according to claim 5, characterized in that Also includes: A filter is connected between the oil tank and the hydraulic pump.

7. The hydraulic system according to claim 5 or 6, characterized in that: The hydraulic pump is a gear pump.

8. A motor grader, characterized in that: include: A hydraulic system as claimed in any one of claims 5 to 7.

9. The motor grader according to claim 8, wherein: Also includes: an engine connected to the hydraulic pump; a transfer case connected between the engine and the hydraulic pump; A power pump is connected to the engine or the transfer case.

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