WO2023207294A1

WO2023207294A1 - Hydraulic control system and operation machine

Info

Publication number: WO2023207294A1
Application number: PCT/CN2023/078072
Authority: WO
Inventors: 汤二猛; 王红昊; 张登湑
Original assignee: 三一重机有限公司
Priority date: 2022-04-25
Filing date: 2023-02-24
Publication date: 2023-11-02
Also published as: CN114704510A

Abstract

Provided in the present application are a hydraulic control system and an operation machine. The hydraulic control system comprises a hydraulic cylinder, a control valve group, a high-pressure energy accumulator and a low-pressure energy accumulator, wherein the hydraulic cylinder is connected to the high-pressure energy accumulator and the low-pressure energy accumulator by means of the control valve group; the control valve group is used for controlling a communication state between the high-pressure energy accumulator and the hydraulic cylinder and between the hydraulic cylinder and the low-pressure energy accumulator; the high-pressure energy accumulator is used for supplying oil to the hydraulic cylinder; and the low-pressure energy accumulator is used for recovering return oil of the hydraulic cylinder. By means of the structural arrangement, the energy saving of the hydraulic control system can be greatly improved.

Description

Hydraulic control system and operating machinery

Technical field

The present application relates to the technical field of hydraulic systems, and in particular to a hydraulic control system and working machinery.

Background technique

With the tremendous development of my country's construction machinery industry, excavators have become one of the important pillar industries. Excavators usually use a hydraulic system to control the boom for lifting and lowering movements. In the prior art, an engine is usually used as a power source to drive a hydraulic pump to work, and the hydraulic pump supplies oil to a hydraulic cylinder to drive the boom to lift or lower. And when the hydraulic cylinder contracts and the boom descends, the potential energy of the boom's descent will be converted into heat loss. This kind of hydraulic control system has poor energy saving.

Contents of the invention

This application provides a hydraulic control system and a working machine to solve the problem of poor energy conservation of the existing hydraulic control system.

According to a first aspect of the present application, a hydraulic control system is provided, including: a hydraulic cylinder, a control valve group, a high-pressure accumulator and a low-pressure accumulator.

The hydraulic cylinder is connected to the high-pressure accumulator and the low-pressure accumulator through the control valve group, and the control valve group is used to control the relationship between the high-pressure accumulator and the hydraulic cylinder, and the The communication state between the hydraulic cylinder and the low-pressure accumulator, the high-pressure accumulator is used to supply oil to the hydraulic cylinder, and the low-pressure accumulator is used to recover the return oil of the hydraulic cylinder.

According to a hydraulic control system provided by the present application, the hydraulic cylinder includes a plurality of hydraulic oil chambers separated from each other, the control valve group includes a high-pressure control valve and a low-pressure control valve, and each of the hydraulic oil chambers is connected to the low-pressure control valve. The low-pressure control valves are respectively provided between the accumulators. Each of the low-pressure control valves is used to control the communication state between the corresponding hydraulic oil chamber and the low-pressure accumulator. Each of the hydraulic oil chambers The high-pressure control valves are respectively arranged corresponding to the high-pressure accumulators, and each of the high-pressure control valves is used to control the communication state between the corresponding hydraulic oil chamber and the high-pressure accumulator.

According to a hydraulic control system provided by this application, the hydraulic cylinder includes a cylinder barrel, a guide rod, and a piston. and hollow piston rod.

Wherein, the cylinder tube includes a rear end cover, a front end cover and a side wall. The side wall is connected between the rear end cover and the front end cover. The side wall, the rear end cover and the front end cover together form a closed cavity structure. The guide rod is located inside the cylinder, and one end of the guide rod is connected to the rear end cover, and the other end of the guide rod is connected to the front end cover. The piston sliding sleeve is arranged on the outside of the guide rod. The hollow piston rod includes an open end and a closed end. The open end penetrates from the outside of the front end cover to the inside of the cylinder and is connected to the piston. The closed end is located outside the front end cover.

A first hydraulic oil chamber is formed between the piston and the rear end cover. A second hydraulic oil chamber is formed between the hollow piston rod and the outer surface of the front end cover. A third hydraulic oil chamber is formed between the hollow piston rod and the side wall. A fourth hydraulic oil chamber is formed between the hollow piston rod and the guide rod.

According to a hydraulic control system provided by an embodiment of the present application, a first low-pressure control valve is provided between the first hydraulic oil chamber and the low-pressure accumulator. A second low-pressure control valve is provided between the second hydraulic oil chamber and the low-pressure accumulator. A third low-pressure control valve is provided between the third hydraulic oil chamber and the low-pressure accumulator. A fourth low-pressure control valve is provided between the fourth hydraulic oil chamber and the low-pressure accumulator.

A first high-pressure control valve is provided between the first hydraulic oil chamber and the high-pressure accumulator. A second high-pressure control valve is provided between the second hydraulic oil chamber and the high-pressure accumulator. A third high-pressure control valve is provided between the third hydraulic oil chamber and the high-pressure accumulator. A fourth high-pressure control valve is provided between the fourth hydraulic oil chamber and the high-pressure accumulator.

According to a hydraulic control system provided by an embodiment of the present application, a first oil port connected to the first hydraulic oil chamber is provided on the side wall of the cylinder, and the first oil port is connected to the first hydraulic oil chamber respectively. A low-pressure control valve is connected to the first high-pressure control valve;

The guide rod, the rear end cover and the front end cover are provided with a second oil port connected to the second hydraulic oil chamber, and the second oil port is connected to the second low pressure control valve and the second hydraulic oil chamber respectively. The second high-pressure control valve is connected;

The side wall of the cylinder is also provided with a third oil port connected to the third hydraulic oil chamber, and the third oil port is connected to the third low-pressure control valve and the third high-pressure control valve respectively. ;

The guide rod and the rear end cover are also provided with a fourth oil port connected to the fourth hydraulic oil chamber, and the fourth oil port is connected to the fourth low-pressure control valve and the fourth high-pressure control valve respectively. connect.

According to a hydraulic control system provided by an embodiment of the present application, the hydraulic control system further includes a hydraulic pump, a servo motor and a fuel tank.

The servo motor is connected to the hydraulic pump. The oil inlet of the hydraulic pump is connected to the oil tank. The oil outlet of the hydraulic pump is connected to the inlet of the high-pressure accumulator and the control valve group to supply oil to the high-pressure accumulator and the hydraulic cylinder.

According to a hydraulic control system provided by an embodiment of the present application, the hydraulic control system further includes a pressure relief return valve. One side of the pressure relief return valve is connected to the oil tank. The other side of the pressure relief return valve is connected to the low-pressure accumulator and the control valve group to relieve pressure of the low-pressure accumulator or provide oil return to the hydraulic cylinder.

According to a hydraulic control system provided by an embodiment of the present application, the first low pressure control valve, the second low pressure control valve, the third low pressure control valve, the fourth low pressure control valve, the first The high-pressure control valve, the second high-pressure control valve, the third high-pressure control valve and the fourth high-pressure control valve each include a two-position, two-way electromagnetic proportional directional valve.

According to a hydraulic control system provided by an embodiment of the present application, the pressure relief return valve includes a two-position, two-way electromagnetic reversing valve.

According to a hydraulic control system provided by an embodiment of the present application, the hydraulic control system further includes a control device. The control device is respectively connected to the first low pressure control valve, the second low pressure control valve, the third low pressure control valve, the fourth low pressure control valve, the first high pressure control valve, the second The high-pressure control valve, the third high-pressure control valve, and the fourth high-pressure control valve are connected to control the first low-pressure control valve, the second low-pressure control valve, the third low-pressure control valve, and the third low-pressure control valve. The working states of the four low-pressure control valves, the first high-pressure control valve, the second high-pressure control valve, the third high-pressure control valve and the fourth high-pressure control valve.

A hydraulic control system is provided according to an embodiment of the present application. The hydraulic control system further includes a control device and a first pressure sensor. The first pressure sensor is used to detect the pressure of the low-pressure accumulator. pressure, the control device is connected to the first pressure sensor and the pressure relief return valve, and the control device is used to control the working state of the pressure relief return valve based on the detection result of the first pressure sensor.

A hydraulic control system is provided according to an embodiment of the present application. The hydraulic control system further includes a control device and a second pressure sensor. The second pressure sensor is used to detect the pressure of the high-pressure accumulator. The control device The device is connected to the second pressure sensor and the servo motor, and the control device is used to control the working state of the servo motor based on the detection result of the second pressure sensor.

According to a hydraulic control system provided by an embodiment of the present application, the hydraulic cylinder is provided with a displacement sensor for detecting the operating speed of the hydraulic cylinder.

According to a second aspect of the present application, a working machine is provided, including the hydraulic control system as described above.

In the hydraulic control system provided by this application, the hydraulic cylinder is connected to the high-pressure accumulator and the low-pressure energy storage through the control valve group, and the control valve group is used to control the high-pressure accumulator and the The communication state between the hydraulic cylinders and between the hydraulic cylinder and the low-pressure accumulator is used to supply oil to the hydraulic cylinder or recover the contraction and falling potential energy of the hydraulic cylinder.

With this structural arrangement, the high-pressure accumulator is connected to the hydraulic cylinder through the control valve group to supply oil to the hydraulic pressure, and the low-pressure accumulator is connected to the hydraulic cylinder through the control valve group to recover the contraction and falling potential energy of the hydraulic cylinder. As a result, the energy saving of the hydraulic control system can be greatly improved.

In this hydraulic control system, by adjusting the first high-pressure control valve, the second high-pressure control valve, the third high-pressure control valve, the fourth high-pressure control valve, the first low-pressure control valve, the second low-pressure control valve, and the third low-pressure control valve And the working state of the fourth low-pressure control valve can realize the supply of different pressures and flows to the hydraulic cylinder, thereby allowing the hydraulic cylinder to perform telescopic actions in different states to meet the needs of different working conditions.

The hydraulic pump can not only charge the high-pressure accumulator with oil, but also assist the high-pressure accumulator to directly supply oil to the first hydraulic oil chamber, the second hydraulic oil chamber, the third hydraulic oil chamber and the fourth hydraulic oil chamber. Furthermore, the operational reliability of the hydraulic control system can be improved.

In addition, by combining the first low pressure control valve, the second low pressure control valve, the third low pressure control valve, the fourth low pressure control valve, the first high pressure control valve, the second high pressure control valve, the third high pressure control valve and the fourth high pressure control valve, The control valve is set as a two-position two-way electromagnetic proportional reversing valve, which can reduce the throttling loss of hydraulic oil flowing through each control valve, thereby converting more boom falling potential energy into hydraulic energy and recovering it into the low-pressure accumulator. At the same time, the two-position two-way electromagnetic proportional directional valve can achieve proportional and continuous adjustment of the opening of each working position, thus greatly improving the flexibility of the hydraulic cylinder's action.

Description of the drawings

In order to more clearly explain the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are: For some embodiments of the present application, those of ordinary skill in the art can also obtain other drawings based on these drawings without exerting creative efforts.

Figure 1 is a system schematic diagram of a hydraulic control system provided according to an embodiment of the present application.

Reference signs:
100. Hydraulic cylinder; 101. Rear end cover; 102. Front end cover; 103. Side wall; 104. Guide rod; 105.
Piston; 106, hollow piston rod; 107, open end; 108, closed end; 109, first hydraulic oil chamber; 110, second hydraulic oil chamber; 111, third hydraulic oil chamber; 112, fourth hydraulic oil chamber; 200. Control valve group; 201. First low-pressure control valve; 202. Second low-pressure control valve; 203. Third low-pressure control valve; 204. Fourth low-pressure control valve; 205. First high-pressure control valve; 206. Second High-pressure control valve; 207, third high-pressure control valve; 208, fourth high-pressure control valve; 300, high-pressure accumulator; 400, low-pressure accumulator; 500, hydraulic pump; 600, servo motor; 700, fuel tank; 800, Pressure relief and return valve; 901, first pressure sensor; 902, second pressure sensor.

Detailed ways

The embodiments of the present application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present application but cannot be used to limit the scope of the present application.

In the description of the embodiments of the present application, it should be noted that the terms "center", "longitudinal", "horizontal", "upper", "lower", "front", "back", "left" and "right" The directions or positional relationships indicated by "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the drawings The orientation or positional relationship shown is only to facilitate the description of the embodiments of the present application and simplify the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as Limitations on the embodiments of this application. In addition, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance.

In the description of the embodiments of this application, it should be noted that, unless otherwise clearly stated and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. Or integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood in specific situations.

In the embodiments of this application, unless otherwise expressly provided and limited, the first feature "on" or "below" the second feature may be that the first and second features are in direct contact, or the first and second features are in intermediate contact. Indirect media contact. Furthermore, the terms "above", "above" and "above" the first feature is above the second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "below" and "beneath" the first feature to the second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature has a smaller horizontal height than the second feature.

In the description of this specification, reference to the terms "one embodiment,""someembodiments,""anexample,""specificexamples," or "some examples" or the like means that specific features are described in connection with the embodiment or example. , structures, materials or features are included in at least one embodiment or example of the embodiments of this application. In this specification, the schematic expressions of the above terms are not necessarily directed 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. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification to achieve the purpose and technical solutions of the embodiments of this application unless they are inconsistent with each other. and advantages will be more clear. The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of them. Embodiments. Based on the embodiments in this application, those of ordinary skill in the art can All other embodiments obtained below belong to the protection scope of this application.

A hydraulic control system and a working machine provided by an embodiment of the present application will be described below with reference to FIG. 1 . It should be understood that the following descriptions are only illustrative embodiments of the present application and do not constitute any special limitations to the present application.

The embodiment of the present application provides a hydraulic control system, as shown in Figure 1 . The hydraulic control system includes: a hydraulic cylinder 100, a control valve group 200, a high-pressure accumulator 300 and a low-pressure accumulator 400.

The hydraulic cylinder 100 is connected to the high-pressure accumulator 300 and the low-pressure accumulator 400 through the control valve group 200. The control valve group 200 is used to control the high-pressure accumulator 300 and the hydraulic cylinder 100, and the hydraulic cylinder 100 and the low-pressure accumulator 400. In the communication state between them, the high-pressure accumulator 300 is used to supply oil to the hydraulic cylinder 100, and the low-pressure accumulator 400 is used to recover the return oil of the hydraulic cylinder 100.

With this structural arrangement, the high-pressure accumulator 300 is connected to the hydraulic cylinder 100 through the control valve group 200 to supply hydraulic oil, and the low-pressure accumulator 400 is connected to the hydraulic cylinder 100 through the control valve group 200 to recover the contraction of the hydraulic cylinder 100 Fall potential energy. As a result, the energy saving of the hydraulic control system can be greatly improved.

In one embodiment of the present application, the hydraulic cylinder 100 includes a plurality of hydraulic oil chambers spaced apart from each other. The control valve group 200 includes a high-pressure control valve and a low-pressure control valve. A low-pressure control valve is provided between each hydraulic oil chamber and the low-pressure accumulator 400. Each low-pressure control valve is used to control the corresponding hydraulic oil chamber and low-pressure accumulator. 400 connectivity status. A high-pressure control valve is provided between each hydraulic oil chamber and the high-pressure accumulator 300, and each high-pressure control valve is used to control the communication state between the corresponding hydraulic oil chamber and the high-pressure accumulator 300.

Further, in one embodiment of the present application, the hydraulic cylinder 100 includes a cylinder barrel, a guide rod 104, a piston 105 and a hollow piston rod 106.

Among them, the cylinder tube includes a rear end cover 101, a front end cover 102 and a side wall 103. The side wall 103 is connected between the rear end cover 101 and the front end cover 102. The side wall 103, the rear end cover 101 and the front end cover 102 together form a closed cavity. The overall structure, the guide rod 104 is located inside the cylinder, and one end of the guide rod 104 is connected to the rear end cover 101, the other end of the guide rod 104 is connected to the front end cover 102, and the piston 105 is slidably sleeved on the radial outside of the guide rod 104. The hollow piston rod 106 includes an open end 107 and a closed end 108. The open end 107 is formed by the outer surface of the front end cover 102. The side is penetrated into the cylinder and connected to the piston 105 , and the closed end 108 is located outside the front end cover 102 .

A first hydraulic oil chamber 109 is formed between the piston 105 and the rear end cover 101, a second hydraulic oil chamber 110 is formed between the hollow piston rod 106 and the outer surface of the front end cover 102, and a third hydraulic oil chamber 110 is formed between the hollow piston rod 106 and the side wall 103. There are three hydraulic oil chambers 111, and a fourth hydraulic oil chamber 112 is formed between the hollow piston rod 106 and the guide rod 104.

In yet another embodiment of the present application, a first low-pressure control valve 201 is provided between the first hydraulic oil chamber 109 and the low-pressure accumulator 400 , and a second low-pressure control valve 201 is provided between the second hydraulic oil chamber 110 and the low-pressure accumulator 400 . Control valve 202, a third low-pressure control valve 203 is disposed between the third hydraulic oil chamber 111 and the low-pressure accumulator 400, and a fourth low-pressure control valve 204 is disposed between the fourth hydraulic oil chamber 112 and the low-pressure accumulator 400.

The first high-pressure control valve 205 is disposed between the first hydraulic oil chamber 109 and the high-pressure accumulator 300 , the second high-pressure control valve 206 is disposed between the second hydraulic oil chamber 110 and the high-pressure accumulator 300 , and the third hydraulic oil chamber 111 A third high-pressure control valve 207 is provided between the high-pressure accumulator 300 and a fourth high-pressure control valve 208 between the fourth hydraulic oil chamber 112 and the high-pressure accumulator 300 .

For example, as shown in Figure 1, the side wall 103 of the cylinder is provided with a first oil port connected to the first hydraulic oil chamber 109, and the first oil port is connected to the first low pressure control valve 201 and the first high pressure control valve 205 respectively. connect. The first low-pressure control valve 201 is connected to the low-pressure accumulator 400 , and the first high-pressure control valve 205 is connected to the high-pressure accumulator 300 . When the first hydraulic oil chamber 109 requires oil supply, the working state of the first high-pressure control valve 205 is adjusted so that the high-pressure accumulator 300 supplies oil to the first hydraulic oil chamber 109 . When the first hydraulic oil chamber 109 needs to return oil, the working state of the first low-pressure control valve 201 is adjusted so that this part of the oil is recovered into the low-pressure accumulator 400 .

The guide rod 104, the rear end cover 101 and the front end cover 102 are provided with a second oil port connected to the second hydraulic oil chamber 110. The second oil port is connected to the second low pressure control valve 202 and the second high pressure control valve 206 respectively. The second low-pressure control valve 202 is connected to the low-pressure accumulator 400 , and the second high-pressure control valve 206 is connected to the high-pressure accumulator 300 . When the second hydraulic oil chamber 110 requires oil supply, the working state of the second high-pressure control valve 206 is adjusted so that the high-pressure accumulator 300 supplies oil to the second hydraulic oil chamber 110 . When the second hydraulic oil chamber 110 needs to return oil, the working state of the second low-pressure control valve 202 is adjusted to recover this part of the oil. to the low-pressure accumulator 400.

The side wall 103 of the cylinder is also provided with a third oil port connected to the third hydraulic oil chamber 111, and the third oil port is connected to the third low pressure control valve 203 and the third high pressure control valve 207 respectively. The third low-pressure control valve 203 is connected to the low-pressure accumulator 400 , and the third high-pressure control valve 207 is connected to the high-pressure accumulator 300 . When the third hydraulic oil chamber 111 requires oil supply, the working state of the third high-pressure control valve 207 is adjusted so that the high-pressure accumulator 300 supplies oil to the third hydraulic oil chamber 111 . When the third hydraulic oil chamber 111 needs to return oil, the working state of the third low-pressure control valve 203 is adjusted so that this part of the oil is recovered into the low-pressure accumulator 400 .

The guide rod 104 and the rear end cover 101 are also provided with a fourth oil port connected to the fourth hydraulic oil chamber 112. The fourth oil port is connected to the fourth low pressure control valve 204 and the fourth high pressure control valve 208 respectively. The fourth low-pressure control valve 204 is connected to the low-pressure accumulator 400 , and the fourth high-pressure control valve 208 is connected to the high-pressure accumulator 300 . When the fourth hydraulic oil chamber 112 requires oil supply, the working state of the fourth high-pressure control valve 208 is adjusted so that the high-pressure accumulator 300 supplies oil to the fourth hydraulic oil chamber 112 . When the fourth hydraulic oil chamber 112 needs to return oil, the working state of the fourth low-pressure control valve 204 is adjusted so that this part of the oil is recovered into the low-pressure accumulator 400 .

As shown in FIG. 1 , when the high-pressure accumulator 300 charges high-pressure oil into the first hydraulic oil chamber 109 or/and the second hydraulic oil chamber 110 , the hollow piston rod 106 of the hydraulic cylinder 100 extends to the cylinder barrel along the Movement in external direction. When the high-pressure accumulator 300 charges high-pressure oil into the third hydraulic oil chamber 111 or/and the fourth hydraulic oil chamber 112 , the hollow piston rod 106 of the hydraulic cylinder 100 moves in the direction of shrinking into the inside of the cylinder barrel. By adjusting the first high-pressure control valve 205, the second high-pressure control valve 206, the third high-pressure control valve 207, the fourth high-pressure control valve 208, the first low-pressure control valve 201, the second low-pressure control valve 202, and the third low-pressure control valve 203 And the working state of the fourth low-pressure control valve 204 can realize the supply of different pressures and flows to the hydraulic cylinder 100, thereby allowing the hydraulic cylinder 100 to perform telescopic actions in different states to meet different working conditions. For example, the hydraulic cylinder 100 can be made to extend or retract at different speeds. For another example, the hydraulic cylinder 100 can be made to extend or retract to different lengths. In addition, by adjusting the pressure values of the low-pressure accumulator 400 and the high-pressure accumulator 300 , the operating states of the hydraulic cylinder 100 can also be enriched.

In one embodiment of the present application, the hydraulic control system also includes a hydraulic pump 500, a servo motor 600 and a fuel tank 700.

The servo motor 600 is connected to the hydraulic pump 500 . The oil inlet of the hydraulic pump 500 is connected to the oil tank 700 . The oil outlet of the hydraulic pump 500 is connected to the inlet of the high-pressure accumulator 300 and the control valve group 200 to supply oil to each hydraulic oil chamber of the high-pressure accumulator 300 or the hydraulic cylinder 100 .

Further, in one embodiment of the present application, the hydraulic control system further includes a pressure relief return valve 800 . One side of the pressure relief return valve 800 is connected to the fuel tank 700 , and the other side of the pressure relief return valve 800 is connected to the low-pressure accumulator 400 and the control valve group 200 to relieve the pressure of the low-pressure accumulator 400 or supply water to the hydraulic cylinder 100 Return oil to each hydraulic oil chamber.

For example, as shown in FIG. 1 , the servo motor 600 is used to drive the hydraulic pump 500 to operate. The oil outlet of the hydraulic pump 500 is connected to the high-pressure accumulator 300 to fill the high-pressure accumulator 300 with liquid. One side oil ports of the first high pressure control valve 205, the second high pressure control valve 206, the third high pressure control valve 207 and the fourth high pressure control valve 208 are connected to the first hydraulic oil chamber 109, the second hydraulic oil chamber 110 and the third hydraulic oil chamber 109, 110 and 110 respectively. The hydraulic oil chamber 111 and the fourth hydraulic oil chamber 112 are connected. The other side oil ports of the first high-pressure control valve 205, the second high-pressure control valve 206, the third high-pressure control valve 207 and the fourth high-pressure control valve 208 are respectively connected with the accumulator. The oil outlet of the energizer is connected with the oil outlet of the hydraulic pump 500. Therefore, the hydraulic pump 500 can not only charge the high-pressure accumulator 300 with oil, but also assist the high-pressure accumulator 300 to directly charge the first hydraulic oil chamber 109 , the second hydraulic oil chamber 110 , the third hydraulic oil chamber 111 and the fourth hydraulic oil chamber 111 . The hydraulic oil chamber 112 supplies oil. Furthermore, the operational reliability of the hydraulic control system can be improved.

As shown in Figure 1, the pressure relief and return valve 800 is connected to the low-pressure accumulator 400. The low-pressure accumulator 400 realizes pressure relief through the pressure relief and return valve 800, so as to reduce the pressure between the high-pressure accumulator 300 and the low-pressure accumulator 400. The pressure difference is adjusted to the target state. One side oil ports of the first low pressure control valve 201, the second low pressure control valve 202, the third low pressure control valve 203 and the fourth low pressure control valve 204 are respectively connected with the first hydraulic oil chamber 109, the second hydraulic oil chamber 110 and the third hydraulic oil chamber 109. The hydraulic oil chamber 111 and the fourth hydraulic oil chamber 112 are connected. The other side oil ports of the first low pressure control valve 201, the second low pressure control valve 202, the third low pressure control valve 203 and the fourth low pressure control valve 204 are respectively connected to the oil return port of the low pressure accumulator 400 and the pressure relief return valve 800. Connected. Therefore, the first hydraulic oil chamber 109 , the second hydraulic oil chamber 110 , the third hydraulic oil chamber 111 and the fourth hydraulic oil chamber 112 can transfer the oil into the chamber. The return flow is recovered into the low-pressure accumulator 400 . When the low-pressure accumulator 400 fails, by adjusting the working state of the pressure relief return valve 800, the first hydraulic oil chamber 109, the second hydraulic oil chamber 110, the third hydraulic oil chamber 111 and the fourth hydraulic oil chamber can also be adjusted. The oil inside 112 returns to the fuel tank 700 .

In one embodiment of the present application, the first low pressure control valve 201, the second low pressure control valve 202, the third low pressure control valve 203, the fourth low pressure control valve 204, the first high pressure control valve 205, the second high pressure control valve 206 , the third high-pressure control valve 207 and the fourth high-pressure control valve 208 both include two-position, two-way electromagnetic proportional directional valves. The pressure relief return valve 800 includes a two-position, two-way solenoid directional valve.

Further, in one embodiment of the present application, the hydraulic control system also includes a control device, which is respectively connected with the first low-pressure control valve 201, the second low-pressure control valve 202, the third low-pressure control valve 203, and the fourth low-pressure control valve 204. , the first high pressure control valve 205, the second high pressure control valve 206, the third high pressure control valve 207 and the fourth high pressure control valve 208 are connected to respectively control the first low pressure control valve 201, the second low pressure control valve 202, the third low pressure The working states of the control valve 203, the fourth low-pressure control valve 204, the first high-pressure control valve 205, the second high-pressure control valve 206, the third high-pressure control valve 207 and the fourth high-pressure control valve 208.

According to the embodiments described above, on the one hand, by combining the first low pressure control valve 201, the second low pressure control valve 202, the third low pressure control valve 203, the fourth low pressure control valve 204, the first high pressure control valve 205, the second The high-pressure control valve 206, the third high-pressure control valve 207 and the fourth high-pressure control valve 208 are configured as two-position, two-way electromagnetic proportional directional valves, which can reduce the throttling loss of hydraulic oil flowing through each control valve, thereby allowing more dynamic operation. The potential energy of the arm falling is converted into hydraulic energy and recovered into the low-pressure accumulator 400 . On the other hand, the two-position two-way electromagnetic proportional reversing valve can achieve proportional and continuous adjustment of the opening of each working position, thereby greatly improving the flexibility of the hydraulic cylinder 100's action.

In one embodiment of the present application, as shown in Figure 1, the hydraulic control system also includes a first pressure sensor 901. The first pressure sensor 901 is used to detect the pressure of the low-pressure accumulator 400. The control device and the first pressure sensor 901 Connected to the pressure relief and return valve 800 , the control device is used to control the working state of the pressure relief and return valve 800 based on the detection result of the first pressure sensor 901 .

In one embodiment of the present application, the hydraulic control system further includes a second pressure sensor 902. The second pressure sensor 902 is used to detect the pressure of the high-pressure accumulator 300. The control device is connected to the second pressure sensor 902 and the servo motor 600. The control device is used to control the working state of the servo motor 600 based on the detection result of the second pressure sensor 902.

For example, take the lifting and lowering of the excavator's boom as an example. The force exerted on the piston 105 of the hydraulic cylinder 100 is Ft=P1S1+P2S2+P3S3+P4S4, where S1, S2, S3, and S4 are the first hydraulic oil chamber 109, the second hydraulic oil chamber 110, and the third hydraulic oil respectively. The cross-sectional areas of the chamber 111 and the fourth hydraulic oil chamber 112; P1, P2, P3, and P4 are respectively in the first hydraulic oil chamber 109, the second hydraulic oil chamber 110, the third hydraulic oil chamber 111, and the fourth hydraulic oil chamber 112. The pressure, where P1 and P2 are the forces used to make the hollow piston rod extend, P1 and P2 are positive values, and P3 and P4 are the pressure used to make the piston rod retract, P3 and P4 are negative values. Wherein, when Ft is a positive value, the piston 105 receives a thrust force and causes the hollow piston rod 106 to extend; when Ft is a negative value, the piston 105 receives a pulling force and causes the hollow piston rod 106 to retract.

Assuming that S1:S2:S3:S4=8:2:4:1, the pressure of the low-pressure accumulator 400 is 0, and the pressure of the high-pressure accumulator 300 is P, the hydraulic control system can realize 16 groups of actions.

In combination 1: the first low-pressure control valve 201 is in the connecting position, the first high-pressure control valve 205 is in the cut-off position, the second low-pressure control valve 202 is in the connecting position, the second high-pressure control valve 206 is in the cut-off position, and the third low-pressure control valve is in the cut-off position. 203 is the cut-off position, the third high-pressure control valve 207 is the connecting position, the fourth low-pressure control valve 204 is the cut-off position, and the fourth high-pressure control valve 208 is the connecting position, then Ft=P1S1+P2S2+P3S3+P4S4=P2S2+P4S4= -5PS4;

In combination 2: the first low-pressure control valve 201 is in the connecting position, the first high-pressure control valve 205 is in the cut-off position, the second low-pressure control valve 202 is in the connecting position, the second high-pressure control valve 206 is in the cut-off position, and the third low-pressure control valve is in the cut-off position. 203 is the cut-off position, the third high-pressure control valve 207 is the connecting position, the fourth low-pressure control valve 204 is the connecting position, and the fourth high-pressure control valve 208 is the cut-off position, then Ft=P1S1+P2S2+P3S3+P4S4=-4PS4;

In combination 3: the first low-pressure control valve 201 is in the connecting position, the first high-pressure control valve 205 is in the cut-off position, the second low-pressure control valve 202 is in the cut-off position, the second high-pressure control valve 206 is in the connecting position, and the third low-pressure control valve is in the connecting position. 203 is the cut-off position, the third high-pressure control valve 207 is the connecting position, the fourth low-pressure control valve 204 is the cut-off position, and the fourth high-pressure control valve 208 is the connecting position, then Ft=P1S1+P2S2+P3S3+P4S4=-3PS4;

In combination 4: the first low-pressure control valve 201 is in the connecting position, the first high-pressure control valve 205 is in the cut-off position, the second low-pressure control valve 202 is in the cut-off position, the second high-pressure control valve 206 is in the connecting position, and the third low-pressure control valve is in the connecting position. 203 is the cut-off position, the third high-pressure control valve 207 is the connecting position, the fourth low-pressure control valve 204 is the connecting position, and the fourth high-pressure control valve 208 is the cut-off position, then Ft=P1S1+P2S2+P3S3+P4S4=-2PS4;

In combination 5: the first low-pressure control valve 201 is in the connecting position, the first high-pressure control valve 205 is in the cut-off position, the second low-pressure control valve 202 is in the connecting position, the second high-pressure control valve 206 is in the cut-off position, and the third low-pressure control valve is in the cut-off position. 203 is the connecting position, the third high-pressure control valve 207 is the cut-off position, the fourth low-pressure control valve 204 is the cut-off position, and the fourth high-pressure control valve 208 is the connecting position, then Ft=P1S1+P2S2+P3S3+P4S4=-PS4;

In combination 6: the first low-pressure control valve 201 is in the connecting position, the first high-pressure control valve 205 is in the cut-off position, the second low-pressure control valve 202 is in the connecting position, the second high-pressure control valve 206 is in the cut-off position, and the third low-pressure control valve is in the cut-off position. 203 is the connecting position, the third high-pressure control valve 207 is the cut-off position, the fourth low-pressure control valve 204 is the connecting position, and the fourth high-pressure control valve 208 is the cut-off position, then Ft=P1S1+P2S2+P3S3+P4S4=0;

In combination 7: the first low-pressure control valve 201 is in the connecting position, the first high-pressure control valve 205 is in the cut-off position, the second low-pressure control valve 202 is in the cut-off position, the second high-pressure control valve 206 is in the connecting position, and the third low-pressure control valve is in the connecting position. 203 is the connecting position, the third high-pressure control valve 207 is the cut-off position, the fourth low-pressure control valve 204 is the cut-off position, and the fourth high-pressure control valve 208 is the connecting position, then Ft=P1S1+P2S2+P3S3+P4S4=PS4;

In combination 8: the first low-pressure control valve 201 is in the connecting position, the first high-pressure control valve 205 is in the cut-off position, the second low-pressure control valve 202 is in the cut-off position, the second high-pressure control valve 206 is in the connecting position, and the third low-pressure control valve is in the connecting position. 203 is the connecting position, the third high-pressure control valve 207 is the cut-off position, the fourth low-pressure control valve 204 is the connecting position, and the fourth high-pressure control valve 208 is the cut-off position, then Ft=P1S1+P2S2+P3S3+P4S4=2PS4;

In combination 9: the first low-pressure control valve 201 is in the cut-off position, the first high-pressure control valve 205 is in the connecting position, the second low-pressure control valve 202 is in the connecting position, the second high-pressure control valve 206 is in the cut-off position, and the third low-pressure control valve 203 is the cut-off position, the third high-pressure control valve 207 is the connecting position, the fourth low-pressure control valve 204 is the cut-off position, and the fourth high-pressure control valve 208 is the connecting position, then Ft=P1S1+P2S2+P3S3+P4S4=3PS4;

In combination 10: the first low-pressure control valve 201 is in the cut-off position, the first high-pressure control valve 205 is in the communication position, the second low-pressure control valve 202 is in the communication position, the second high-pressure control valve 206 is in the cut-off position, and the third low-pressure control valve 206 is in the cut-off position. The control valve 203 is in the cut-off position, the third high-pressure control valve 207 is in the connected position, the fourth low-pressure control valve 204 is in the connected position, and the fourth high-pressure control valve 208 is in the cut-off position, then Ft=P1S1+P2S2+P3S3+P4S4=4PS4;

In combination 11: the first low-pressure control valve 201 is in the cut-off position, the first high-pressure control valve 205 is in the connecting position, the second low-pressure control valve 202 is in the cut-off position, the second high-pressure control valve 206 is in the connecting position, and the third low-pressure control valve is in the connecting position. 203 is the cut-off position, the third high-pressure control valve 207 is the connecting position, the fourth low-pressure control valve 204 is the cut-off position, and the fourth high-pressure control valve 208 is the connecting position, then Ft=P1S1+P2S2+P3S3+P4S4=5PS4;

In combination 12: the first low-pressure control valve 201 is in the cut-off position, the first high-pressure control valve 205 is in the connecting position, the second low-pressure control valve 202 is in the cut-off position, the second high-pressure control valve 206 is in the connecting position, and the third low-pressure control valve is in the connecting position. 203 is the cut-off position, the third high-pressure control valve 207 is the connecting position, the fourth low-pressure control valve 204 is the connecting position, and the fourth high-pressure control valve 208 is the cut-off position, then Ft=P1S1+P2S2+P3S3+P4S4=6PS4;

In combination 13: the first low-pressure control valve 201 is in the cut-off position, the first high-pressure control valve 205 is in the connecting position, the second low-pressure control valve 202 is in the connecting position, the second high-pressure control valve 206 is in the cut-off position, and the third low-pressure control valve 203 is the connecting position, the third high-pressure control valve 207 is the cut-off position, the fourth low-pressure control valve 204 is the cut-off position, and the fourth high-pressure control valve 208 is the connecting position, then Ft=P1S1+P2S2+P3S3+P4S4=7PS4;

In combination 14: the first low-pressure control valve 201 is in the cut-off position, the first high-pressure control valve 205 is in the connecting position, the second low-pressure control valve 202 is in the connecting position, the second high-pressure control valve 206 is in the cut-off position, and the third low-pressure control valve 203 is the connecting position, the third high-pressure control valve 207 is the cut-off position, the fourth low-pressure control valve 204 is the connecting position, and the fourth high-pressure control valve 208 is the cut-off position, then Ft=P1S1+P2S2+P3S3+P4S4=8S4;

In combination 15: the first low-pressure control valve 201 is in the cut-off position, the first high-pressure control valve 205 is in the connecting position, the second low-pressure control valve 202 is in the cut-off position, the second high-pressure control valve 206 is in the connecting position, and the third low-pressure control valve is in the connecting position. 203 is the connecting position, the third high-pressure control valve 207 is the cut-off position, the fourth low-pressure control valve 204 is the cut-off position, and the fourth high-pressure control valve 208 is the connecting position, then Ft=P1S1+P2S2+P3S3+P4S4=9PS4;

In combination 16: the first low-pressure control valve 201 is in the cut-off position, the first high-pressure control valve 205 is in the connecting position, the second low-pressure control valve 202 is in the cut-off position, the second high-pressure control valve 206 is in the connecting position, and the third low-pressure control valve is in the connecting position. 203 is the connecting position, the third high-pressure control valve 207 is the cut-off position, the fourth low-pressure control valve 204 is the connecting position, and the fourth high-pressure control valve 208 is the cut-off position, then Ft=P1S1+P2S2+P3S3+P4S4=10PS4.

It should be understood here that by adjusting the pressure values of the low-pressure accumulator 400 and the high-pressure accumulator 300, more pressure control combinations can be obtained.

This can be done in the actual working process. The operating conditions of the hydraulic control system can be artificially set before the excavator is operated. For example, the target pressure values of the low-pressure accumulator 400 and the high-pressure accumulator 300 are manually set in the control device. When the first pressure sensor 901 detects that the pressure value of the low-pressure accumulator 400 is higher than the target pressure value, the control device can control the pressure relief return valve 800 to switch to the communication position so that the low-pressure accumulator 400 communicates with the fuel tank 700 for relief. When the first pressure sensor 901 detects that the pressure value of the low-pressure accumulator 400 is equal to the target pressure value, the control device controls the pressure relief return valve 800 to switch to the cut-off position so that the low-pressure accumulator 400 stops pressure relief. When the second pressure sensor 902 detects that the pressure value of the high-pressure accumulator 300 is lower than the target pressure value, the control device controls the servo motor 600 to turn on to drive the hydraulic pump 500 to operate and store oil inside the high-pressure accumulator 300, so that Its pressure rises. When the second pressure sensor 902 detects that the pressure value of the high-pressure accumulator 300 meets the target pressure value, the control device controls the servo motor 600 to turn off so that the hydraulic pump 500 stops storing oil in the high-pressure accumulator 300 .

In addition, a displacement sensor can be installed in the hydraulic cylinder 100 to detect the operating speed of the hydraulic cylinder 100. The control device is electrically connected to the displacement sensor to receive the detection result of the displacement sensor.

The control device can control the control valve group 200 to first execute combination 16 to drive the hydraulic cylinder 100 to act. Combination 16 is the combination with the largest thrust, and this thrust must meet the thrust requirements of the current working conditions. As the high-pressure accumulator 300 continues to output oil, its flow rate gradually decreases, and accordingly, the action execution speed of the hydraulic cylinder 100 decreases. In order to reduce the change in the action execution speed of the hydraulic cylinder 100, the control device controls each control valve to jump to the directions of combination 15, combination 14,..., in sequence. During the jump along the direction of combination decrease, the speed change gradually decreases and the thrust also gradually decreases. When the control valve group 200 jumps to the first combination whose thrust does not meet the current working conditions, the control device immediately controls the control valve group 200 to jump and keep executing the action of the previous combination, so as to ensure that the thrust meets the current working conditions. , ensuring that the speed change is relatively small.

An embodiment of the second aspect of the present application provides a working machine, including the hydraulic control system as described above.

For example, the above-mentioned working machine includes a boom, and the hydraulic cylinder 100 is connected with the boom to drive the boom to perform lifting and lowering actions.

It should be noted here that the above embodiment is only an illustrative embodiment of the present application and does not constitute any limitation on the present application. That is to say, the above-mentioned working machines include but are not limited to excavators.

Furthermore, since the working machine includes the hydraulic control system as mentioned above, it also has various advantages as mentioned above.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent substitutions are made to some of the technical features; however, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions in the embodiments of the present application.

Claims

A hydraulic control system, characterized by including: a hydraulic cylinder, a control valve group, a high-pressure accumulator and a low-pressure accumulator,

The hydraulic cylinder is connected to the high-pressure accumulator and the low-pressure accumulator through the control valve group, and the control valve group is used to control the relationship between the high-pressure accumulator and the hydraulic cylinder, and the The communication state between the hydraulic cylinder and the low-pressure accumulator, the high-pressure accumulator is used to supply oil to the hydraulic cylinder, and the low-pressure accumulator is used to recover the return oil of the hydraulic cylinder.
The hydraulic control system according to claim 1, wherein the hydraulic cylinder includes a plurality of hydraulic oil chambers separated from each other, the control valve group includes a high-pressure control valve and a low-pressure control valve, and each of the hydraulic oil chambers The low-pressure control valve is provided correspondingly to the low-pressure accumulator, and each low-pressure control valve is used to control the communication state between the corresponding hydraulic oil chamber and the low-pressure accumulator. The high-pressure control valves are respectively provided between the hydraulic oil chamber and the high-pressure accumulator, and each of the high-pressure control valves is used to control the communication between the corresponding hydraulic oil chamber and the high-pressure accumulator. state.
The hydraulic control system according to claim 2, wherein the hydraulic cylinder includes a cylinder barrel, a guide rod, a piston and a hollow piston rod;

Wherein, the cylinder includes a rear end cover, a front end cover and a side wall, the side wall is connected between the rear end cover and the front end cover, the side wall, the rear end cover and the front end cover The covers together form a closed cavity structure, the guide rod is located inside the cylinder, and one end of the guide rod is connected to the rear end cover, and the other end of the guide rod is connected to the front end cover. The piston sliding sleeve is arranged on the outside of the guide rod. The hollow piston rod includes an open end and a closed end. The open end is penetrated from the outside of the front end cover to the inside of the cylinder and is connected to the piston. The closed end is located outside the front end cover;

A first hydraulic oil chamber is formed between the piston and the rear end cover, a second hydraulic oil chamber is formed between the hollow piston rod and the outer surface of the front end cover, and the hollow piston rod and the side wall A third hydraulic oil chamber is formed between them, and a fourth hydraulic oil chamber is formed between the hollow piston rod and the guide rod.
The hydraulic control system according to claim 3, characterized in that a first low-pressure control valve is provided between the first hydraulic oil chamber and the low-pressure accumulator, and the second hydraulic oil chamber and the low-pressure accumulator are A second low-pressure control valve is disposed between the energizers, a third low-pressure control valve is disposed between the third hydraulic oil chamber and the low-pressure accumulator, and a third low-pressure control valve is disposed between the fourth hydraulic oil chamber and the low-pressure accumulator. Set the fourth low-pressure control valve;

A first high-pressure control valve is disposed between the first hydraulic oil chamber and the high-pressure accumulator, a second high-pressure control valve is disposed between the second hydraulic oil chamber and the high-pressure accumulator, and the third high-pressure control valve is disposed between the second hydraulic oil chamber and the high-pressure accumulator. A third high-pressure control valve is disposed between the hydraulic oil chamber and the high-pressure accumulator, and a fourth high-pressure control valve is disposed between the fourth hydraulic oil chamber and the high-pressure accumulator.
The hydraulic control system according to claim 4, wherein a first oil port connected to the first hydraulic oil chamber is provided on the side wall of the cylinder, and the first oil port is connected to the first hydraulic oil chamber respectively. The first low-pressure control valve is connected to the first high-pressure control valve;

The guide rod, the rear end cover and the front end cover are provided with a second oil port connected to the second hydraulic oil chamber, and the second oil port is connected to the second low pressure control valve and the second hydraulic oil chamber respectively. The second high-pressure control valve is connected;

The side wall of the cylinder is also provided with a third oil port connected to the third hydraulic oil chamber, and the third oil port is connected to the third low-pressure control valve and the third high-pressure control valve respectively. ;

The guide rod and the rear end cover are also provided with a fourth oil port connected to the fourth hydraulic oil chamber, and the fourth oil port is connected to the fourth low-pressure control valve and the fourth high-pressure control valve respectively. connect.
The hydraulic control system according to any one of claims 1-5, characterized in that the hydraulic control system further includes a hydraulic pump, a servo motor and a fuel tank,

The servo motor is connected to the hydraulic pump, the oil inlet of the hydraulic pump is connected to the oil tank, and the oil outlet of the hydraulic pump is connected to the inlet of the high-pressure accumulator and the control valve group, To supply oil to the high-pressure accumulator and the hydraulic cylinder.
The hydraulic control system according to claim 6, characterized in that the hydraulic control system further includes a pressure relief return valve, one side of the pressure relief return valve is connected to the oil tank, and the other side of the pressure relief return valve One side is connected to the low-pressure accumulator and the control valve group to relieve pressure from the low-pressure accumulator or provide oil return to the hydraulic cylinder.
The hydraulic control system according to claim 7, characterized in that the pressure relief return valve package Including two-position two-way electromagnetic reversing valve.
The hydraulic control system according to claim 4, characterized in that the first low pressure control valve, the second low pressure control valve, the third low pressure control valve, the fourth low pressure control valve, the A high-pressure control valve, the second high-pressure control valve, the third high-pressure control valve and the fourth high-pressure control valve all include two-position, two-way electromagnetic proportional directional valves.
The hydraulic control system according to claim 4, characterized in that the hydraulic control system further includes a control device, the control device is respectively connected to the first low-pressure control valve, the second low-pressure control valve, and the third low-pressure control valve. Three low-pressure control valves, the fourth low-pressure control valve, the first high-pressure control valve, the second high-pressure control valve, the third high-pressure control valve and the fourth high-pressure control valve are connected to control the The first low pressure control valve, the second low pressure control valve, the third low pressure control valve, the fourth low pressure control valve, the first high pressure control valve, the second high pressure control valve, the third The working status of the high-pressure control valve and the fourth high-pressure control valve.
The hydraulic control system according to claim 7, characterized in that the hydraulic control system further includes a control device and a first pressure sensor, the first pressure sensor is used to detect the pressure of the low-pressure accumulator, and the A control device is connected to the first pressure sensor and the pressure relief backflow valve, and the control device is used to control the working state of the pressure relief backflow valve based on the detection result of the first pressure sensor.
The hydraulic control system according to claim 6, characterized in that the hydraulic control system further includes a control device and a second pressure sensor, the second pressure sensor is used to detect the pressure of the high-pressure accumulator, and the A control device is connected to the second pressure sensor and the servo motor, and the control device is used to control the working state of the servo motor based on the detection result of the second pressure sensor.
The hydraulic control system according to any one of claims 1-12, characterized in that the hydraulic cylinder is provided with a displacement sensor for detecting the operating speed of the hydraulic cylinder.
A working machine, characterized by including the hydraulic control system according to any one of claims 1 to 13.