Hydraulic control system, control method of hydraulic control system, and boom

Abstract

The present invention discloses a hydraulic control system, a control method of the hydraulic control system, and a boom. The hydraulic control system includes: a first proportional valve; an electromagnetic reversing valve, the first oil port of the electromagnetic reversing valve is communicated with the first proportional valve, the second oil port of the electromagnetic reversing valve is used for communicating with the oil return tank, the third oil port of the electromagnetic reversing valve is communicated with the rod chamber of the oil cylinder through a first pipeline, and the fourth oil port of the electromagnetic reversing valve is communicated with the rodless chamber of the oil cylinder through a second pipeline; a first balance valve, the first balance valve is arranged on the first pipeline; a second balance valve, the second balance valve is arranged on the second pipeline; a second proportional valve, the second proportional valve is arranged on the second pipeline, and the second proportional valve is arranged between the second balance valve and the electromagnetic reversing valve; and a damping circuit. The above-mentioned hydraulic control system can improve the stability of the boom during startup.

Description

Technical Field

[0001] The present invention relates to the technical field of aerial work, and particularly relates to a hydraulic control system, a control method of the hydraulic control system, and a boom. Background Art

[0002] In the technical field of aerial work, an aerial work platform with a boom realizes the telescopic and luffing movements of the boom by controlling hydraulic cylinders in the boom through a hydraulic control system. A traditional hydraulic control system usually sets a proportional valve near the oil source to control the telescopic speed and luffing speed of the hydraulic cylinder, and sets a balance valve at the rod chamber and the rodless chamber of the hydraulic cylinder respectively to ensure the working stability of the hydraulic cylinder during telescopic and luffing movements. As the working height of the aerial work platform continues to increase and the length of the boom also continues to increase, the traditional hydraulic control system is prone to cause the boom to shake when the lengthened boom starts. The shaking of the boom will cause the balance valve to open and close quickly, and the rapid opening and closing of the balance valve will bring more serious jitter and shaking to the boom, resulting in poor stability of the boom. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. For this purpose, the present invention provides a hydraulic control system, which can improve the stability of the boom during startup.

[0004] The present invention also provides a control method of the hydraulic control system applied to the above-mentioned hydraulic control system.

[0005] The present invention also provides a boom having the above-mentioned hydraulic control system.

[0006] A hydraulic control system according to an embodiment of the first aspect of the present invention includes: a first proportional valve, a first oil port of the first proportional valve is used to communicate with an oil source; an electromagnetic reversing valve, a first oil port of the electromagnetic reversing valve is communicated with a second oil port of the first proportional valve, a second oil port of the electromagnetic reversing valve is used to communicate with a return oil tank, a third oil port of the electromagnetic reversing valve is communicated with a rod chamber of a cylinder through a first pipeline, a fourth oil port of the electromagnetic reversing valve is communicated with a rodless chamber of the cylinder through a second pipeline, when the electromagnetic reversing valve is in a first state, the first oil port of the electromagnetic reversing valve is communicated with the third oil port of the electromagnetic reversing valve, the fourth oil port of the electromagnetic reversing valve is communicated with the second oil port of the electromagnetic reversing valve, when the electromagnetic reversing valve is in a second state, the first oil port of the electromagnetic reversing valve is communicated with the fourth oil port of the electromagnetic reversing valve, the third oil port of the electromagnetic reversing valve is communicated with the second oil port of the electromagnetic reversing valve; a first balance valve, the first balance valve is arranged on the first pipeline, a first oil port of the first balance valve is communicated with the third oil port of the electromagnetic reversing valve, a second oil port of the first balance valve is communicated with the rod chamber of the cylinder; a second balance valve, the second balance valve is arranged on the second pipeline, a second oil port of the second balance valve is communicated with the rodless chamber of the cylinder; a second proportional valve, the second proportional valve is arranged on the second pipeline, and a first oil port of the second proportional valve is communicated with the fourth oil port of the electromagnetic reversing valve, a second oil port of the second proportional valve is communicated with a first oil port of the second balance valve; and a damping circuit, the damping circuit is used to communicate the first pipeline with the second pipeline, one end of the damping circuit communicated with the first pipeline is located between the first oil port of the first balance valve and the third oil port of the electromagnetic reversing valve, one end of the damping circuit communicated with the second pipeline is located between the first oil port of the second proportional valve and the fourth oil port of the electromagnetic reversing valve, and when the electromagnetic reversing valve is in the first state, the damping circuit is further used to guide the hydraulic oil in the first pipeline to a control oil port of the second balance valve, when the electromagnetic reversing valve is in the second state, the damping circuit is further used to guide the hydraulic oil in the second pipeline to a control oil port of the first balance valve.

[0007] The hydraulic control system according to the embodiment of the present invention has at least the following beneficial effects:

[0008] In the above hydraulic control system, when the oil cylinder contracts, the boom will contract or the luffing will lower; when the oil cylinder extends, the boom will extend or the luffing will rise. Since the first balance valve is provided on the first pipeline, the second balance valve and the second proportional valve are provided on the second pipeline, and the solenoid directional valve is connected to the rod chamber of the oil cylinder through the first pipeline, and the solenoid directional valve is connected to the rodless chamber of the oil cylinder through the second pipeline. Therefore, when the solenoid directional valve is in the first state, the hydraulic oil in the oil source can sequentially pass through the first proportional valve, the solenoid directional valve and the first balance valve and enter the rod chamber of the oil cylinder, and the hydraulic oil in the rodless chamber of the oil cylinder can sequentially pass through the second balance valve, the second proportional valve and the solenoid directional valve and return to the oil return tank. Thus, when the solenoid directional valve is in the first state, the oil cylinder can contract, so as to realize the contraction of the boom or the lowering of the luffing. In this process, the spool of the first balance valve is in the unopened state, and the hydraulic oil in the oil source can sequentially pass through the first oil port of the first proportional valve, the second oil port of the first proportional valve, the first oil port of the solenoid directional valve, the third oil port of the solenoid directional valve, the first oil port of the first balance valve and the second oil port of the first balance valve and enter the rod chamber of the oil cylinder; the spools of the second balance valve and the second proportional valve are in the opened state, and the hydraulic oil in the rodless chamber of the oil cylinder can sequentially pass through the second oil port of the second balance valve, the first oil port of the second balance valve, the second oil port of the second proportional valve, the first oil port of the second proportional valve, the fourth oil port of the solenoid directional valve and the second oil port of the solenoid directional valve and return to the oil return tank.

[0009] When the solenoid directional valve is in the first state, the first pipeline and the second pipeline can be connected through the damping circuit, so that the hydraulic oil entering the first pipeline from the third oil port of the solenoid directional valve can enter the damping circuit, and then return to the oil return tank through the damping circuit, the second pipeline and the solenoid directional valve. Thus, the pressure shock in the first pipeline can be absorbed through the damping circuit, so as to reduce the pressure shock received by the rod chamber of the oil cylinder, and thus the jitter and sway phenomena of the boom caused by the pressure shock received by the rod chamber of the oil cylinder can be suppressed.

[0010] In the above hydraulic control system, hydraulic oil can flow from the first oil port of the second balance valve to the second oil port of the second balance valve, and when the spool of the second balance valve is opened, hydraulic oil can flow from the second oil port of the second balance valve to the first oil port of the second balance valve. The spool of the second balance valve is opened when the pressure at the control oil port of the second balance valve exceeds the second preset pressure. Among them, when different sizes of second balance valves are selected, the second preset pressure has different values, and the value of the second preset pressure is generally between 250 bar and 350 bar. When the electromagnetic directional valve is in the first state, the hydraulic oil in the first pipeline can be directed to the control oil port of the second balance valve through the damping circuit. Therefore, the opening of the spool of the second balance valve is determined by the oil pressure of the hydraulic oil in the first pipeline entering the control oil port of the second balance valve. During the process of the damping circuit directing the hydraulic oil in the first pipeline to the control oil port of the second balance valve, the damping circuit can reduce the flow rate of the hydraulic oil in the first pipeline, thereby prolonging the time for the total oil pressure of the hydraulic oil in the first pipeline to reach the control oil port of the second balance valve, so as to prolong the arrival time of the pressure setting value of the second balance valve, enabling the spool of the second balance valve to be slowly opened, avoiding the phenomenon that the spool of the second balance valve is quickly opened due to the pressure impact of the hydraulic oil in the first pipeline, and further avoiding the phenomenon that the boom shakes due to the quick opening of the spool of the second balance valve. Since the second balance valve is arranged on the second pipeline and the second oil port of the second balance valve is connected to the rodless cavity of the oil cylinder, when the spool of the second balance valve is opened, the hydraulic oil in the rodless cavity of the oil cylinder can flow back to the oil return tank through the second balance valve. During this process, since the spool of the second balance valve can be slowly opened, the phenomenon that the boom shakes due to the shaking of the second balance valve can be avoided during the contraction or amplitude reduction of the boom.

[0011] When the electromagnetic directional valve is in the first state, the second proportional valve can adjust the flow rate of the hydraulic oil in the second pipeline, so that the hydraulic oil in the rodless cavity of the oil cylinder can slowly flow back to the oil return tank through the second proportional valve, and the second proportional valve can also generate back pressure in the rodless cavity of the oil cylinder to offset the sudden change of the pressure in the rodless cavity of the oil cylinder, avoiding the rapid pressure relief of the rodless cavity of the oil cylinder, and thus avoiding the phenomenon that the boom shakes due to the rapid pressure relief of the rodless cavity of the oil cylinder.

[0012] Thus, the above hydraulic control system can prevent the boom from shaking or swaying when starting to contract or reduce the amplitude.

[0013] When the electromagnetic reversing valve is in the second state, the hydraulic oil in the oil source can enter the rodless chamber of the oil cylinder through the first proportional valve, the electromagnetic reversing valve, the second proportional valve and the second balancing valve in sequence, and the hydraulic oil in the rod chamber of the oil cylinder can flow back to the return oil tank through the first balancing valve and the electromagnetic reversing valve in sequence. Therefore, when the electromagnetic reversing valve is in the second state, the oil cylinder can extend, thereby realizing the action of extending the boom or increasing the amplitude. During this process, the valve core of the second balancing valve and the valve core of the second proportional valve are in an unopened state, and the hydraulic oil in the oil source can enter the rodless chamber of the cylinder through the first oil port of the first proportional valve, the second oil port of the first proportional valve, the first oil port of the solenoid reversing valve, the fourth oil port of the solenoid reversing valve, the first oil port of the second proportional valve, the second oil port of the second balancing valve, the first oil port of the second balancing valve and the second oil port of the second balancing valve in sequence; the first balancing valve is in an open state, and the hydraulic oil in the rod chamber of the cylinder can flow back to the return oil tank through the second oil port of the first balancing valve, the first oil port of the first balancing valve, the third oil port of the solenoid reversing valve and the second oil port of the solenoid reversing valve in sequence.

[0014] When the solenoid reversing valve is in the second state, the second pipeline and the first pipeline can be connected through the damping circuit, and the hydraulic oil entering the second pipeline from the fourth oil port of the solenoid reversing valve can enter the damping circuit, and then flow back to the return oil tank through the damping circuit, the first pipeline and the solenoid reversing valve. The pressure shock in the second pipeline can be absorbed by the damping circuit, thereby reducing the pressure shock on the rodless chamber of the oil cylinder, thereby suppressing the shaking and swaying of the arm due to the pressure shock on the rodless chamber of the oil cylinder.

[0015] In the above hydraulic control system, hydraulic oil can flow from the first oil port of the first balance valve to the second oil port of the first balance valve, and when the spool of the first balance valve is opened, hydraulic oil can flow from the second oil port of the first balance valve to the first oil port of the first balance valve. The spool of the first balance valve is opened when the pressure at the control oil port of the first balance valve exceeds a first preset pressure; wherein, when different sizes of the first balance valve are selected, the first preset pressure has different values, and the value of the first preset pressure is generally between 250 bar and 350 bar. When the electromagnetic directional valve is in the second state, the hydraulic oil in the second pipeline can be directed to the control oil port of the first balance valve through the damping circuit. Therefore, the opening of the spool of the first balance valve is determined by the oil pressure of the hydraulic oil in the second pipeline entering the control oil port of the first balance valve. During the process of the damping circuit directing the hydraulic oil in the second pipeline to the control oil port of the first balance valve, the damping circuit can reduce the flow rate of the hydraulic oil in the second pipeline, thereby prolonging the time for the total oil pressure of the hydraulic oil in the second pipeline to reach the control oil port of the first balance valve, so as to prolong the arrival time of the pressure setting value of the first balance valve, enabling the spool of the first balance valve to be slowly opened, avoiding the phenomenon that the spool of the first balance valve is quickly opened due to the pressure impact of the hydraulic oil in the second pipeline, and further avoiding the phenomenon that the boom shakes due to the quick opening of the spool of the first balance valve. Since the first balance valve is arranged on the first pipeline, when the spool of the first balance valve is opened, the hydraulic oil in the rod chamber of the oil cylinder can flow back to the oil return tank through the first balance valve. During this process, since the spool of the first balance valve can be slowly opened, the phenomenon that the boom shakes due to the shaking of the first balance valve can be avoided during the extension or amplitude increase of the boom. Since the shaking phenomenon of the boom is small during the extension or amplitude increase of the boom, only by slowly opening the first balance valve can the phenomenon of shaking or wobbling of the boom be avoided during the extension or amplitude increase of the boom.

[0016] Thus, the above hydraulic control system can prevent the boom from shaking or wobbling when starting to extend or increase in amplitude.

[0017] According to some embodiments of the present invention, the damping circuit includes a first damping pipeline and a second damping pipeline. Two ends of the first damping pipeline are respectively communicated with the first pipeline and the second pipeline. One end of the second damping pipeline is communicated with the first pipeline, and the other end of the second damping pipeline is communicated with the control oil port of the second balance valve. The first damping pipeline is provided with a first damping hole and a second damping hole, and the second damping pipeline is provided with a third damping hole.

[0018] According to some embodiments of the present invention, the damping circuit further includes a third damping pipeline. One end of the third damping pipeline is communicated with the first damping pipeline, and the other end of the third damping pipeline is communicated with the control oil port of the first balance valve. The first damping hole and the second damping hole are symmetrically arranged on both sides of the third damping pipeline, and a fourth damping hole is provided on the third damping pipeline.

[0019] According to some embodiments of the present invention, the damping circuit further includes a fourth damping pipeline and a fifth damping pipeline. Both ends of the fourth damping pipeline are respectively communicated with the first pipeline and the second pipeline. One end of the fifth damping pipeline is communicated with the fourth damping pipeline, and the other end of the fifth damping pipeline is communicated with the control oil port of the second balance valve. A fifth damping hole and a sixth damping hole are provided on the fourth damping pipeline, and the fifth damping hole and the sixth damping hole are symmetrically arranged on both sides of the fifth damping pipeline. A seventh damping hole is provided on the fifth damping pipeline.

[0020] According to some embodiments of the present invention, the damping circuit further includes a sixth damping pipeline. Both ends of the sixth damping pipeline are respectively communicated with the second pipeline and the control oil port of the first balance valve, and an eighth damping hole is provided on the sixth damping pipeline.

[0021] According to some embodiments of the present invention, the damping circuit further includes a seventh damping pipeline and an eighth damping pipeline. Both ends of the seventh damping pipeline are respectively communicated with the first pipeline and the second pipeline. The first end of the eighth damping pipeline is communicated with the seventh damping pipeline, the second end of the eighth damping pipeline is communicated with the control oil port of the first balance valve, and the third end of the eighth damping pipeline is communicated with the control oil port of the second balance valve. A ninth damping hole and a tenth damping hole are provided on the seventh damping pipeline, and the ninth damping hole and the tenth damping hole are symmetrically arranged on both sides of the eighth damping pipeline. An eleventh damping hole is provided on the eighth damping pipeline.

[0022] The control method of the hydraulic control system according to the second aspect embodiment of the present invention includes: in the first case: controlling the first proportional valve to be energized so that the first oil port of the first proportional valve communicates with the second oil port of the first proportional valve; controlling the electromagnetic reversing valve to be energized to switch the electromagnetic reversing valve to the first state, so that the hydraulic oil in the oil source sequentially passes through the first proportional valve, the electromagnetic reversing valve, and the first balance valve and enters the rod chamber of the oil cylinder, and the hydraulic oil in the oil source sequentially passes through the first proportional valve, the electromagnetic reversing valve, the first pipeline, the damping circuit, the second pipeline, and the electromagnetic reversing valve and returns to the oil return tank, and the hydraulic oil in the oil source sequentially passes through the first proportional valve, the electromagnetic reversing valve, the first pipeline, and the damping circuit and enters the control oil port of the second balance valve to open the spool of the second balance valve, wherein, when the spool of the second balance valve is opened, the hydraulic oil can flow from the second oil port of the second balance valve to the first oil port of the second balance valve; within a preset time after the spool of the second balance valve is opened, controlling the second proportional valve to be energized so that the hydraulic oil can flow from the second oil port of the second proportional valve to the first oil port of the second proportional valve, so that the hydraulic oil in the rodless chamber of the oil cylinder sequentially passes through the second balance valve, the second proportional valve, and the electromagnetic reversing valve and returns to the oil return tank.

[0023] The control method of the hydraulic control system according to the embodiment of the present invention has at least the following beneficial effects:

[0024] In the above control method of the hydraulic control system, controlling the first proportional valve to be energized so that the first oil port of the first proportional valve communicates with the second oil port of the first proportional valve, and controlling the electromagnetic reversing valve to be energized to switch the electromagnetic reversing valve to the first state can make the hydraulic oil in the oil source sequentially pass through the first proportional valve, the electromagnetic reversing valve, and the first balance valve and enter the rod chamber of the oil cylinder; opening the spool of the second balance valve and controlling the second proportional valve to be energized can make the hydraulic oil in the rodless chamber of the oil cylinder sequentially pass through the second balance valve, the second proportional valve, and the electromagnetic reversing valve and return to the oil return tank. Thus, when the electromagnetic reversing valve is in the first state, the oil cylinder can contract to achieve the actions of boom retraction or amplitude reduction. In this process, the hydraulic oil in the oil source sequentially passes through the first oil port of the first proportional valve, the second oil port of the first proportional valve, the first oil port of the electromagnetic reversing valve, the third oil port of the electromagnetic reversing valve, the first oil port of the first balance valve, and the second oil port of the first balance valve and enters the rod chamber of the oil cylinder; the hydraulic oil in the rodless chamber of the oil cylinder sequentially passes through the second oil port of the second balance valve, the first oil port of the second balance valve, the second oil port of the second proportional valve, the first oil port of the second proportional valve, the fourth oil port of the electromagnetic reversing valve, and the second oil port of the electromagnetic reversing valve and returns to the oil return tank.

[0025] During this process, control the first proportional valve to be energized so that the first oil port of the first proportional valve is communicated with the second oil port of the first proportional valve, and control the electromagnetic directional valve to be energized so that the electromagnetic directional valve is switched to the first state. Then, the hydraulic oil in the oil source can sequentially pass through the first proportional valve, the electromagnetic directional valve, the first pipeline, the damping circuit, the second pipeline, and the electromagnetic directional valve and return to the oil return tank, so as to absorb the pressure impact in the first pipeline through the damping circuit, thereby reducing the pressure impact on the rod chamber of the oil cylinder and suppressing the shaking and swaying phenomena of the boom caused by the pressure impact on the rod chamber of the oil cylinder.

[0026] Control the first proportional valve to be energized so that the first oil port of the first proportional valve is communicated with the second oil port of the first proportional valve, and control the electromagnetic directional valve to be energized so that the electromagnetic directional valve is switched to the first state. Then, the hydraulic oil in the oil source can sequentially pass through the first proportional valve, the electromagnetic directional valve, the first pipeline, and the damping circuit and enter the control oil port of the second balance valve, so as to open the spool of the second balance valve. When the spool of the second balance valve is opened, the hydraulic oil can flow from the second oil port of the second balance valve to the first oil port of the second balance valve, and the second oil port of the second balance valve is communicated with the rodless chamber of the oil cylinder. Therefore, the hydraulic oil in the rodless chamber of the oil cylinder can return to the oil return tank through the second balance valve. At the same time, the damping circuit can make the spool of the second balance valve open slowly, so as to avoid the phenomenon of the second balance valve shaking due to the rapid opening of the spool of the second balance valve, and further avoid the phenomenon of the boom shaking due to the shaking of the second balance valve.

[0027] Within the preset time when the spool of the second balance valve is opened, control the second proportional valve to be energized so that the hydraulic oil can flow from the second oil port of the second proportional valve to the first oil port of the second proportional valve. Since the second oil port of the second proportional valve is communicated with the first oil port of the second balance valve, and the first oil port of the second proportional valve is communicated with the fourth oil port of the electromagnetic directional valve, the hydraulic oil in the rodless chamber of the oil cylinder can return to the oil return tank through the second balance valve, the second proportional valve, and the electromagnetic directional valve, so as to realize the contraction of the oil cylinder. During this process, the second proportional valve can adjust the flow rate of the hydraulic oil in the second pipeline, so that the hydraulic oil in the rodless chamber of the oil cylinder can slowly return to the oil return tank, avoiding the rapid pressure relief of the rodless chamber of the oil cylinder, and thus avoiding the phenomenon of the boom shaking due to the rapid pressure relief of the rodless chamber of the oil cylinder.

[0028] Thus, the control method of the above hydraulic control system can realize the contraction of the oil cylinder, so as to realize the contraction or the lowering of the amplitude of the boom, and can suppress the shaking or swaying phenomena of the boom when the boom starts to contract or the amplitude starts to lower.

[0029] According to some embodiments of the present invention, when the second proportional valve is energized, the opening from the second oil port to the first oil port of the second proportional valve gradually increases, so that the flow rate of the hydraulic oil passing through the second proportional valve gradually reaches a uniform state.

[0030] A control method for a hydraulic control system according to an embodiment of the third aspect of the present invention includes: in a second case: controlling the first proportional valve to be energized so that the first oil port of the first proportional valve communicates with the second oil port of the first proportional valve; controlling the electromagnetic reversing valve to be energized so that the electromagnetic reversing valve switches to the second state, so that the hydraulic oil in the oil source sequentially passes through the first proportional valve, the electromagnetic reversing valve, the second proportional valve, and the second balance valve and enters the rodless cavity of the oil cylinder, and the hydraulic oil in the oil source sequentially passes through the first proportional valve, the electromagnetic reversing valve, the second pipeline, the damping circuit, the first pipeline, and the electromagnetic reversing valve and returns to the oil return tank, and the hydraulic oil in the oil source sequentially passes through the first proportional valve, the electromagnetic reversing valve, the second pipeline, and the damping circuit and enters the control oil port of the first balance valve to open the spool of the first balance valve. Wherein, when the spool of the first balance valve is opened, the hydraulic oil can flow from the second oil port of the first balance valve to the first oil port of the first balance valve, so that the hydraulic oil in the rod chamber of the oil cylinder sequentially passes through the first balance valve and the electromagnetic reversing valve and returns to the oil return tank.

[0031] In the above control method of the hydraulic control system, controlling the first proportional valve to be energized so that the first oil port of the first proportional valve communicates with the second oil port of the first proportional valve, and controlling the electromagnetic reversing valve to be energized so that the electromagnetic reversing valve switches to the second state can make the hydraulic oil in the oil source sequentially pass through the first proportional valve, the electromagnetic reversing valve, the second proportional valve, and the second balance valve and enter the rodless cavity of the oil cylinder; opening the spool of the first balance valve can make the hydraulic oil in the rod chamber of the oil cylinder sequentially pass through the first balance valve and the electromagnetic reversing valve and return to the oil return tank. Thus, when the electromagnetic reversing valve is in the second state, the oil cylinder can extend to realize the actions of boom elongation or luffing up. In this process, the hydraulic oil in the oil source sequentially passes through the first oil port of the first proportional valve, the second oil port of the first proportional valve, the first oil port of the electromagnetic reversing valve, the fourth oil port of the electromagnetic reversing valve, the first oil port of the second proportional valve, the second oil port of the second proportional valve, the first oil port of the second balance valve, and the second oil port of the second balance valve and enters the rodless cavity of the oil cylinder; the hydraulic oil in the rod chamber of the oil cylinder sequentially passes through the second oil port of the first balance valve, the second oil port of the first balance valve, the third oil port of the electromagnetic reversing valve, and the second oil port of the electromagnetic reversing valve and returns to the oil return tank.

[0032] In this process, control the first proportional valve to be energized, so that the first oil port of the first proportional valve is communicated with the second oil port of the first proportional valve, and control the electromagnetic directional valve to be energized, so that the electromagnetic directional valve is switched to the second state. Then, the hydraulic oil in the oil source can sequentially pass through the first proportional valve, the electromagnetic directional valve, the second pipeline, the damping circuit, the first pipeline and the electromagnetic directional valve and flow back to the oil return tank, so as to absorb the pressure shock in the second pipeline through the damping circuit, thereby reducing the pressure shock received by the rodless cavity of the oil cylinder and suppressing the shaking and swaying phenomena of the boom due to the pressure shock received by the rodless cavity of the oil cylinder.

[0033] Control the first proportional valve to be energized, so that the first oil port of the first proportional valve is communicated with the second oil port of the first proportional valve, and control the electromagnetic directional valve to be energized, so that the electromagnetic directional valve is switched to the second state. Then, the hydraulic oil in the oil source can sequentially pass through the first proportional valve, the electromagnetic directional valve, the second pipeline and the damping circuit and enter the control oil port of the first balance valve, so as to open the spool of the first balance valve. When the spool of the first balance valve is opened, the hydraulic oil can flow from the second oil port of the first balance valve to the first oil port of the first balance valve, and the second oil port of the first balance is communicated with the rod chamber of the oil cylinder. Therefore, the hydraulic oil in the rod chamber of the oil cylinder can flow back to the oil return tank through the first balance valve. At the same time, the damping circuit can make the spool of the first balance valve be opened slowly, so as to avoid the phenomenon that the first balance valve shakes due to the rapid opening of the spool of the first balance valve, and further avoid the phenomenon that the boom shakes due to the shaking of the first balance valve.

[0034] Thus, the control method of the above hydraulic control system can realize the extension of the oil cylinder, so as to realize the elongation or amplitude increase of the boom, and can suppress the shaking or swaying phenomenon of the boom when the boom starts to elongate or the amplitude increases.

[0035] The boom according to the embodiment of the fourth aspect of the present invention includes: the above-mentioned hydraulic control system; or the control method applying the above-mentioned hydraulic control system.

[0036] In the above boom, since the above hydraulic control system can prevent the above boom from shaking or swaying when starting to contract or the amplitude decreases and when starting to elongate or the amplitude increases, the above boom can have a stable working state when starting to contract or the amplitude decreases and when starting to elongate or the amplitude increases, so as to ensure the safety of the above boom during operation. Description of the Drawings

[0037] The following further describes the present invention with reference to the drawings and embodiments, where:

[0038] Figure 1 is a schematic structural diagram of the hydraulic control system according to Embodiment 1 of the present invention;

[0039] Figure 2 It is a schematic structural diagram of the hydraulic control system according to the second embodiment of the present invention;

[0040] Figure 3 It is a schematic structural diagram of the hydraulic control system according to the third embodiment of the present invention.

[0041] Reference numerals in the drawings:

[0042] 100, the first proportional valve;

[0043] 200, the electromagnetic directional valve;

[0044] 300, the first pipeline;

[0045] 400, the second pipeline;

[0046] 500, the first balance valve;

[0047] 600, the second balance valve;

[0048] 700, the second proportional valve;

[0049] 800, the damping circuit; 810, the first damping pipeline; 811, the first damping hole; 812, the second damping hole; 820, the second damping pipeline; 821, the third damping hole; 830, the third damping pipeline; 831, the fourth damping hole; 840, the fourth damping pipeline; 841, the fifth damping hole; 842, the sixth damping hole; 850, the fifth damping pipeline; 851, the seventh damping hole; 860, the sixth damping pipeline; 861, the eighth damping hole; 870, the seventh damping pipeline; 871, the ninth damping hole; 872, the tenth damping hole; 880, the eighth damping pipeline; 881, the eleventh damping hole

[0050] 900, the oil source; 910, the oil cylinder; 920, the oil return tank. Detailed implementation manners

[0051] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0052] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as up and down, etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0053] In the description of the present invention, "a plurality of" refers to more than two. If the first and the second are described, it is only for the purpose of distinguishing technical features, and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0054] In the description of the present invention, unless otherwise clearly defined, terms such as "arrangement", "installation", "connection", etc. shall be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0055] Referring to Figures 1 to 3 As shown, a hydraulic control system according to an embodiment of the present invention includes: a first proportional valve 100, a solenoid directional valve 200, a first balance valve 500, a second balance valve 600, a second proportional valve 700, and a damping circuit 800.

[0056] Specifically, the first oil port a of the first proportional valve 100 is used to communicate with the oil source 900; the first oil port c of the electromagnetic directional valve 200 is communicated with the second oil port b of the first proportional valve 100, the second oil port d of the electromagnetic directional valve 200 is used to communicate with the oil return tank 920, a first pipeline 300 is provided between the electromagnetic directional valve 200 and the rod chamber of the oil cylinder 910, and the first pipeline 300 is used to communicate the third oil port e of the electromagnetic directional valve 200 with the rod chamber of the oil cylinder 910. A second pipeline 400 is provided between the electromagnetic directional valve 200 and the rodless chamber of the oil cylinder 910, and the second pipeline 400 is used to communicate the fourth oil port f of the electromagnetic directional valve 200 with the rodless chamber of the oil cylinder 910. When the electromagnetic directional valve 200 is in the first state, the first oil port c of the electromagnetic directional valve 200 is communicated with the third oil port e of the electromagnetic directional valve 200, and the fourth oil port f of the electromagnetic directional valve 200 is communicated with the second oil port d of the electromagnetic directional valve 200. When the electromagnetic directional valve 200 is in the second state, the first oil port c of the electromagnetic directional valve 200 is communicated with the fourth oil port f of the electromagnetic directional valve 200, and the third oil port e of the electromagnetic directional valve 200 is communicated with the second oil port d of the electromagnetic directional valve 200; the first balance valve 500 is arranged on the first pipeline 300, the first oil port g of the first balance valve 500 is communicated with the third oil port e of the electromagnetic directional valve 200, the second oil port h of the first balance valve 500 is communicated with the rod chamber of the oil cylinder 910, and hydraulic oil can flow from the first oil port g of the first balance valve 500 to the second oil port h of the first balance valve 500. When the spool of the first balance valve 500 is opened, hydraulic oil can flow from the second oil port h of the first balance valve 500 to the first oil port g of the first balance valve 500; the second balance valve 600 is arranged on the second pipeline 400, the second oil port j of the second balance valve 600 is communicated with the rodless chamber of the oil cylinder 910, and hydraulic oil can flow from the first oil port i of the second balance valve 600 to the second oil port j of the second balance valve 600. When the spool of the second balance valve 600 is opened, hydraulic oil can flow from the second oil port j of the second balance valve 600 to the first oil port i of the second balance valve 600; the second proportional valve 700 is arranged on the second pipeline 400, the first oil port k of the second proportional valve 700 is communicated with the fourth oil port f of the electromagnetic directional valve 200, the second oil port m of the second proportional valve 700 is communicated with the first oil port i of the second balance valve 600, and hydraulic oil can flow from the first oil port k of the second proportional valve 700 to the second oil port m of the second proportional valve 700. When the spool of the second balance valve 600 is opened, hydraulic oil can flow from the second oil port m of the second proportional valve 700 to the first oil port k of the second proportional valve 700;The damping circuit 800 is used to connect the first pipeline 300 and the second pipeline 400. One end of the damping circuit 800 connected to the first pipeline 300 is located between the first oil port g of the first balance valve 500 and the third oil port e of the electromagnetic directional valve 200. One end of the damping circuit 800 connected to the second pipeline 400 is located between the first oil port k of the second proportional valve 700 and the fourth oil port f of the electromagnetic directional valve 200. And when the electromagnetic directional valve 200 is in the first state, the damping circuit 800 is used to direct the hydraulic oil in the first pipeline 300 to the control oil port n of the second balance valve 600. When the electromagnetic directional valve 200 is in the second state, the damping circuit 800 is used to direct the hydraulic oil in the second pipeline 400 to the control oil port p of the first balance valve 500.;

[0057] In the above hydraulic control system, when the oil cylinder 910 contracts, the boom will perform the actions of contraction or amplitude reduction and lowering. When the oil cylinder 910 extends, the boom will perform the actions of extension or amplitude increase and rising. Since the first balance valve 500 is provided on the first pipeline 300, the second balance valve 600 and the second proportional valve 700 are provided on the second pipeline 400, and the electromagnetic directional valve 200 is connected to the rod chamber of the oil cylinder 910 through the first pipeline 300, and the electromagnetic directional valve 200 is connected to the non-rod chamber of the oil cylinder 910 through the second pipeline 400. Therefore, when the electromagnetic directional valve 200 is in the first state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic directional valve 200 and the first balance valve 500 and enter the rod chamber of the oil cylinder 910. The hydraulic oil in the non-rod chamber of the oil cylinder 910 can sequentially pass through the second balance valve 600, the second proportional valve 700 and the electromagnetic directional valve 200 and flow back to the oil return tank 920. Thus, when the electromagnetic directional valve 200 is in the first state, the oil cylinder 910 can contract, so as to realize the actions of boom contraction or amplitude reduction and lowering. In this process, the spool of the first balance valve 500 is in the unopened state. The hydraulic oil in the oil source 900 can sequentially pass through the first oil port a of the first proportional valve 100, the second oil port b of the first proportional valve 100, the first oil port c of the electromagnetic directional valve 200, the third oil port e of the electromagnetic directional valve 200, the first oil port g of the first balance valve 500 and the second oil port h of the first balance valve 500 and enter the rod chamber of the oil cylinder 910. The spools of the second balance valve 600 and the second proportional valve 700 are in the opened state. The hydraulic oil in the non-rod chamber of the oil cylinder 910 can sequentially pass through the second oil port j of the second balance valve 600, the first oil port i of the second balance valve 600, the second oil port m of the second proportional valve 700, the first oil port k of the second proportional valve 700, the fourth oil port f of the electromagnetic directional valve 200 and the second oil port d of the electromagnetic directional valve 200 and flow back into the oil return tank 920.

[0058] When the electromagnetic directional valve 200 is in the first state, the damping circuit 800 can connect the first pipeline 300 and the second pipeline 400. Then, the hydraulic oil entering the first pipeline 300 from the third oil port e of the electromagnetic directional valve 200 can enter the damping circuit 800, and then return to the oil return tank 920 through the damping circuit 800, the second pipeline 400, and the electromagnetic directional valve 200. Thus, the pressure shock in the first pipeline 300 can be absorbed through the damping circuit 800, so as to reduce the pressure shock received by the rod chamber of the oil cylinder 910, and thereby suppress the shaking and swaying phenomena of the boom due to the pressure shock received by the rod chamber of the oil cylinder 910.

[0059] In the above hydraulic control system, the hydraulic oil can flow from the first oil port i of the second balance valve 600 to the first oil port j of the second balance valve 600, and when the spool of the second balance valve 600 is opened, the hydraulic oil can flow from the second oil port j of the second balance valve 600 to the first oil port i of the second balance valve 600. The spool of the second balance valve 600 is opened when the pressure at the control oil port n of the second balance valve 600 exceeds the second preset pressure. Among them, when different sizes of the second balance valve 600 are selected, the second preset pressure has different values, and the value of the second preset pressure is generally between 250 bar and 350 bar. When the electromagnetic directional valve 200 is in the first state, the hydraulic oil in the first pipeline 300 can be directed to the control oil port n of the second balance valve 600 through the damping circuit 800. Therefore, the opening of the spool of the second balance valve 600 is determined by the oil pressure of the hydraulic oil in the first pipeline 300 entering the control oil port n of the second balance valve 600. During the process of the damping circuit 800 directing the hydraulic oil in the first pipeline 300 to the control oil port n of the second balance valve 600, the damping circuit 800 can reduce the flow rate of the hydraulic oil in the first pipeline 300, thereby prolonging the time for the total oil pressure of the hydraulic oil in the first pipeline 300 to reach the control oil port n of the second balance valve 600, so as to prolong the arrival time of the second preset pressure value of the second balance valve 600, enabling the spool of the second balance valve 600 to be slowly opened, avoiding the phenomenon that the spool of the second balance valve 600 is quickly opened due to the pressure impact of the hydraulic oil in the first pipeline 300, and further avoiding the phenomenon that the boom shakes due to the quick opening of the spool of the second balance valve 600. Since the second balance valve 600 is arranged on the second pipeline 400 and the second oil port j of the second balance valve 600 is connected to the rodless cavity of the oil cylinder 910, when the spool of the second balance valve 600 is opened, the hydraulic oil in the rodless cavity of the oil cylinder 910 can flow back to the oil return tank 920 through the second balance valve 600. During this process, since the spool of the second balance valve 600 can be slowly opened, the phenomenon that the boom shakes due to the shake of the second balance valve 600 can be avoided during the contraction or amplitude reduction of the boom.

[0060] When the electromagnetic directional valve 200 is in the first state, the second proportional valve 700 can adjust the flow rate of the hydraulic oil in the second pipeline 400, so that the hydraulic oil in the rodless cavity of the oil cylinder 910 can slowly flow back to the oil return tank 920 through the second proportional valve 700, and the second proportional valve 700 can also generate back pressure in the rodless cavity of the oil cylinder 910 to offset the sudden change of the pressure in the rodless cavity of the oil cylinder 910, avoiding the rapid pressure relief of the rodless cavity of the oil cylinder 910, and thus avoiding the phenomenon that the boom shakes due to the rapid pressure relief of the rodless cavity of the oil cylinder 910.

[0061] Thus, the above hydraulic control system can prevent the boom from jittering or swaying when starting to contract or lower in amplitude.

[0062] When the electromagnetic directional valve 200 is in the second state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic directional valve 200, the second proportional valve 700, and the second balance valve 600 and enter the rodless cavity of the oil cylinder 910. The hydraulic oil in the rod cavity of the oil cylinder 910 can sequentially pass through the first balance valve 500 and the electromagnetic directional valve 200 and flow back to the oil return tank 920. Thus, when the electromagnetic directional valve 200 is in the second state, the oil cylinder 910 can extend to achieve the actions of the boom extending or rising in amplitude. During this process, the spool of the second balance valve 600 and the spool of the second proportional valve 700 are in the unopened state. The hydraulic oil in the oil source 900 can sequentially pass through the first oil port a of the first proportional valve 100, the second oil port b of the first proportional valve 100, the first oil port c of the electromagnetic directional valve 200, the fourth oil port f of the electromagnetic directional valve 200, the first oil port k of the second proportional valve 700, the second oil port m of the second proportional valve 700, the first oil port i of the second balance valve 600, and the second oil port j of the second balance valve 600 and enter the rodless cavity of the oil cylinder 910; the first balance valve 500 is in the opened state, and the hydraulic oil in the rod cavity of the oil cylinder 910 can sequentially pass through the second oil port h of the first balance valve 500, the first oil port g of the first balance valve 500, the third oil port e of the electromagnetic directional valve 200, and the second oil port d of the electromagnetic directional valve 200 and flow back to the oil return tank 920.

[0063] When the electromagnetic directional valve 200 is in the second state, the damping circuit 800 can connect the second pipeline 400 and the first pipeline 300. Then, the hydraulic oil entering the second pipeline 400 from the fourth oil port f of the electromagnetic directional valve 200 can enter the damping circuit 800, and then flow back to the oil return tank 920 through the damping circuit 800, the first pipeline 300, and the electromagnetic directional valve 200. Thus, the pressure shock in the second pipeline 400 can be absorbed through the damping circuit 800, so as to reduce the pressure shock received by the rodless cavity of the oil cylinder 910, and thus the jittering and swaying phenomena of the boom caused by the pressure shock received by the rodless cavity of the oil cylinder 910 can be suppressed.

[0064] In the above hydraulic control system, the hydraulic oil can flow from the first oil port g of the first balance valve 500 to the second oil port h of the first balance valve 500, and when the spool of the first balance valve 500 is opened, the hydraulic oil can flow from the second oil port h of the first balance valve 500 to the first oil port g of the first balance valve 500. The spool of the first balance valve 500 is opened when the pressure at the control oil port p of the first balance valve 500 exceeds the first preset pressure. Among them, when different sizes of the first balance valve 500 are selected, the first preset pressure has different values, and the value of the first preset pressure is generally between 250 bar and 350 bar. When the electromagnetic directional valve 200 is in the second state, the hydraulic oil in the second pipeline 400 can be guided to the control oil port p of the first balance valve 500 through the damping circuit 800. Therefore, the opening of the spool of the first balance valve 500 is determined by the oil pressure of the hydraulic oil in the second pipeline 400 entering the control oil port p of the first balance valve 500. During the process that the damping circuit 800 guides the hydraulic oil in the second pipeline 400 to the control oil port p of the first balance valve 500, the damping circuit 800 can reduce the flow rate of the hydraulic oil in the second pipeline 400, thereby prolonging the time for the total oil pressure of the hydraulic oil in the second pipeline 400 to reach the control oil port p of the first balance valve 500, so as to prolong the arrival time of the first preset pressure value of the first balance valve 500, enabling the spool of the first balance valve 500 to be slowly opened, avoiding the phenomenon that the spool of the first balance valve 500 is quickly opened due to the pressure impact of the hydraulic oil in the second pipeline 400, and further avoiding the phenomenon that the boom shakes due to the shaking of the first balance valve 500. Since the first balance valve 500 is arranged on the first pipeline 300, when the spool of the first balance valve 500 is opened, the hydraulic oil in the rod chamber of the oil cylinder 910 can flow back to the oil return tank 920 through the first balance valve 500. During this process, since the spool of the first balance valve 500 can be slowly opened, during the process of the boom extending or lifting in amplitude, the phenomenon that the boom shakes due to the shaking of the first balance valve 500 can be avoided. Since the shaking phenomenon of the boom is small during the process of the boom extending or lifting in amplitude, only by enabling the first balance valve 500 to be slowly opened can the phenomenon that the boom shakes or sways during the process of the boom extending or lifting in amplitude be avoided.

[0065] Thus, the above hydraulic control system can enable the boom to avoid shaking or swaying when starting to extend or lift in amplitude.

[0066] Embodiment 1:

[0067] Refer to Figure 1As shown, in the first embodiment, the damping circuit 800 includes a first damping pipeline 810 and a second damping pipeline 820. Two ends of the first damping pipeline 810 are respectively communicated with the first pipeline 300 and the second pipeline 400. One end of the second damping pipeline 820 is communicated with the first pipeline 300, and the other end of the second damping pipeline 820 is communicated with the control oil port n of the second balance valve 600. A first damping hole 811 and a second damping hole 812 are provided on the first damping pipeline 810, and a third damping hole 821 is provided on the second damping pipeline 820.

[0068] Specifically, the first damping hole 811 is located at one end of the second damping hole 812 close to the first pipeline 300, and the second damping hole 812 is located at one end of the first damping hole 811 close to the second pipeline 400. When the aperture diameters of the first damping hole 811 and the second damping hole 812 are the same, the greater the pressure difference between one end of the first damping hole 811 close to the first pipeline 300 and one end of the second damping hole 812 close to the second pipeline 400, the greater the flow rate of the hydraulic oil passing through the first damping hole 811 and the second damping hole 812. And during the process that the hydraulic oil flows through the first damping hole 811 and the second damping hole 812, the oil pressure on the first damping pipeline 810 gradually decreases.

[0069] More specifically, the aperture diameters of the first damping hole 811, the second damping hole 812 and the third damping hole 821 are determined according to the actual working conditions.

[0070] Furthermore, the end of the second damping pipeline 820 connected to the first pipeline 300 is located between the first oil port g of the first balance valve and the third oil port e of the electromagnetic directional valve.

[0071] In this way, when the electromagnetic directional valve 200 is in the first state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic directional valve 200, the first pipeline 300, the first damping pipeline 810, the second pipeline 400 and the electromagnetic control valve and flow back into the oil return tank 920. During this process, the pressure impact in the first pipeline 300 can be absorbed by making the hydraulic oil in the first pipeline 300 flow through the first damping hole 811 and the second damping hole 812 on the first damping pipeline 810, so as to reduce the pressure impact received by the rod chamber of the oil cylinder 910, thereby being able to suppress the shaking and swaying phenomena of the boom due to the pressure impact received by the rod chamber of the oil cylinder 910.

[0072] In addition, when the electromagnetic directional valve 200 is in the first state, the hydraulic oil in the oil source 900 can flow through the first proportional valve 100, the electromagnetic directional valve 200, the first pipeline 300, and the second damping pipeline 820 in sequence and reach the control oil port n of the second balance valve 600, so that the second balance valve 600 can be opened. During this process, the hydraulic oil can pass through the third damping hole 821 on the second damping pipeline 820. Since the third damping hole 821 throttles the hydraulic oil flowing through the second damping pipeline 820, the total flow rate of the hydraulic oil flowing through the third damping hole 821 can be delayed from reaching the control oil port n of the second balance valve 600, thereby being able to extend the time for the total oil pressure of the hydraulic oil in the second damping pipeline 820 to reach the control oil port n of the second balance valve 600, so as to extend the arrival time of the second preset pressure value of the second balance valve 600, enabling the spool of the second balance valve 600 to be slowly opened, avoiding the phenomenon that the spool of the second balance valve 600 is quickly opened due to the pressure impact of the hydraulic oil in the first pipeline 300, thus avoiding the phenomenon that the second balance valve 600 shakes due to the quick opening of the spool of the second balance valve 600, and further avoiding the phenomenon that the boom shakes due to the shaking of the second balance valve 600.

[0073] Refer to Figure 1 As shown, in the first embodiment, the damping circuit 800 further includes a third damping pipeline 830. One end of the third damping pipeline 830 is communicated with the first damping pipeline 810, and the other end of the third damping pipeline 830 is communicated with the control oil port p of the first balance valve 500. The first damping hole 811 and the second damping hole 812 are symmetrically arranged on both sides of the third damping pipeline 830, and a fourth damping hole 831 is provided on the third damping pipeline 830.

[0074] Specifically, the first damping pipeline 810 and the third damping pipeline 830 form a bridge-type damping circuit. When the apertures of the first damping hole 811 and the second damping hole 812 are the same, the total oil pressure on the third damping pipeline 830 is half of that on the first damping pipeline 810.

[0075] Furthermore, the aperture size of the fourth damping hole 831 is determined according to the actual working conditions.

[0076] Thus, when the electromagnetic directional valve 200 is in the second state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic directional valve 200, the second pipeline 400, the first damping pipeline 810, the first pipeline 300, and the electromagnetic control valve and flow back into the oil return tank 920. During this process, the pressure shock in the second pipeline 400 can be absorbed by allowing the hydraulic oil in the second pipeline 400 to flow through the first damping hole 811 and the second damping hole 812 on the first damping pipeline 810, so as to reduce the pressure shock received by the rodless cavity of the oil cylinder 910, thereby suppressing the shaking and wobbling phenomena of the boom caused by the pressure shock received by the rodless cavity of the oil cylinder 910.

[0077] In addition, when the electromagnetic directional valve 200 is in the second state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic directional valve 200, the second pipeline 400, the second damping hole 812, and the third damping pipeline 830 and enter the control oil port p of the first balance valve 500 to enable the first balance valve 500 to be opened. During this process, since the total oil pressure in the third damping pipeline 830 is half of that on the first damping pipeline 810, the arrival time of the first preset pressure value of the first balance valve 500 can be extended, so that the spool of the first balance valve 500 can be slowly opened. And the hydraulic oil can also pass through the fourth damping hole 831 on the third damping pipeline 830. Since the fourth damping hole 831 throttles the hydraulic oil flowing through the third damping pipeline 830, the total flow rate of the hydraulic oil flowing through the fourth damping hole 831 can be delayed from reaching the control oil port p of the first balance valve 500, thereby extending the time for the total oil pressure of the hydraulic oil in the third damping pipeline 830 to reach the control oil port p of the first balance valve 500, so as to further extend the arrival time of the first preset pressure value of the first balance valve 500, enabling the spool of the first balance valve 500 to be slowly opened, thus avoiding the phenomenon of the first balance valve 500 shaking due to the rapid opening of the spool of the first balance valve 500, and further avoiding the phenomenon of the boom shaking due to the shaking of the first balance valve 500.

[0078] The control method of the hydraulic control system involved in the first embodiment includes: in the first case: controlling the first proportional valve 100 to be energized so that the first oil port a of the first proportional valve 100 communicates with the second oil port b of the first proportional valve 100; controlling the electromagnetic reversing valve 200 to be energized to switch the electromagnetic reversing valve 200 to the first state, so that the hydraulic oil in the oil source sequentially passes through the first proportional valve 100, the electromagnetic reversing valve 200, and the first balance valve 500 and enters the rod chamber of the oil cylinder, and the hydraulic oil in the oil source sequentially passes through the first proportional valve 100, the electromagnetic reversing valve 200, the first pipeline 300, the damping circuit 800, the second pipeline 400, and the electromagnetic reversing valve 200 and returns to the oil return tank, and the hydraulic oil in the oil source sequentially passes through the first proportional valve 100, the electromagnetic reversing valve 200, the first pipeline 300, and the damping circuit 800 and enters the control oil port p of the second balance valve 600 to open the spool of the second balance valve 600. Wherein, when the spool of the second balance valve 600 is opened, the hydraulic oil can flow from the second oil port j of the second balance valve 600 to the first oil port i of the second balance valve 600; within the preset time after the spool of the second balance valve 600 is opened, controlling the second proportional valve 700 to be energized so that the hydraulic oil can flow from the second oil port m of the second proportional valve 700 to the first oil port k of the second proportional valve 700, so that the hydraulic oil in the rodless chamber of the oil cylinder sequentially passes through the second balance valve 600, the second proportional valve 700, and the electromagnetic reversing valve 200 and returns to the oil return tank.

[0079] Specifically, the first case is the case where the oil cylinder contracts, that is, the boom contracts or the amplitude decreases.

[0080] Further, when the operation key is pressed, the operation key can be a handle or a button, and the signal is transmitted to the controller. When the controller controls S1 of the first proportional valve 100 to be energized, the first oil port a of the first proportional valve 100 communicates with the second oil port b of the first proportional valve 100.

[0081] Furthermore, when the operation key is pressed and the signal is transmitted to the controller, when the controller controls DT1 of the electromagnetic reversing valve 200 to be energized, the electromagnetic reversing valve 200 switches to the first state.

[0082] Furthermore, the preset time for the spool of the second balance valve 600 to open is within 0 s to 1 s after the spool of the second balance valve 600 is opened. Within 0 s to 1 s after the spool of the second balance valve 600 is opened, the controller controls S2 of the second proportional valve 700 to be energized so that the hydraulic oil can flow from the second oil port m of the second proportional valve 700 to the first oil port k of the second proportional valve 700.

[0083] In the control method of the hydraulic control system of the first embodiment, when the first proportional valve 100 is powered on, the first oil port a of the first proportional valve 100 is communicated with the second oil port b of the first proportional valve 100. When the electromagnetic reversing valve 200 is powered on and switched to the first state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic reversing valve 200, and the first balance valve 500 and enter the rod chamber of the oil cylinder 910. When the spool of the second balance valve 600 is opened and the second proportional valve 700 is powered on, the hydraulic oil in the rodless chamber of the oil cylinder 910 can sequentially pass through the second balance valve 600, the second proportional valve 700, and the electromagnetic reversing valve 200 and return to the oil return tank 920. Thus, when the electromagnetic reversing valve 200 is in the first state, the oil cylinder 910 can contract, so as to realize the actions of boom contraction or luffing descent. During this process, the hydraulic oil in the oil source 900 sequentially passes through the first oil port a of the first proportional valve 100, the second oil port b of the first proportional valve 100, the first oil port c of the electromagnetic reversing valve 200, the third oil port e of the electromagnetic reversing valve 200, the first oil port g of the first balance valve 500, and the second oil port h of the first balance valve 500 and enters the rod chamber of the oil cylinder 910. The hydraulic oil in the rodless chamber of the oil cylinder 910 sequentially passes through the second oil port j of the second balance valve 600, the first oil port i of the second balance valve 600, the second oil port m of the second proportional valve 700, the first oil port k of the second proportional valve 700, the fourth oil port f of the electromagnetic reversing valve 200, and the second oil port d of the electromagnetic reversing valve 200 and returns to the oil return tank 920.

[0084] During this process, when the first proportional valve 100 is powered on, the first oil port a of the first proportional valve 100 is communicated with the second oil port b of the first proportional valve 100. When the electromagnetic reversing valve 200 is powered on and switched to the first state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic reversing valve 200, the first pipeline 300, the first damping pipeline 810, the second pipeline 400, and the electromagnetic reversing valve 200 and return to the oil return tank 920, so as to absorb the pressure shock in the first pipeline 300 through the first damping hole 811 and the second damping hole 812 on the first damping pipeline 810, thereby reducing the pressure shock received by the rod chamber of the oil cylinder 910 and suppressing the shaking and swaying phenomena of the boom due to the pressure shock received by the rod chamber of the oil cylinder 910.

[0085] Energize the first proportional valve 100 to connect the first oil port a of the first proportional valve 100 to the second oil port b of the first proportional valve 100. Energize the electromagnetic directional valve 200 to switch the electromagnetic directional valve 200 to the first state. Then, the hydraulic oil in the oil source 900 can pass through the first proportional valve 100, the electromagnetic directional valve 200, the first pipeline 300, and the second damping pipeline 820 in sequence and enter the control oil port n of the second balance valve 600 to open the spool of the second balance valve 600. When the spool of the second balance valve 600 is opened, the hydraulic oil can flow from the second oil port j of the second balance valve 600 to the first oil port i of the second balance valve 600, and the second oil port j of the second balance valve 600 is connected to the rodless cavity of the oil cylinder 910. Therefore, the hydraulic oil in the rodless cavity of the oil cylinder 910 can flow back to the oil return tank 920 through the second balance valve 600. At the same time, the third damping hole 821 on the second damping pipeline 820 can slowly open the spool of the second balance valve 600, thereby avoiding the phenomenon that the second balance valve 600 shakes due to the rapid opening of the spool of the second balance valve 600, and further avoiding the phenomenon that the boom shakes due to the shaking of the second balance valve 600.

[0086] Within a preset time after the spool of the second balance valve 600 is opened, energize the second proportional valve 700 so that the hydraulic oil can flow from the second oil port m of the second proportional valve 700 to the first oil port k of the second proportional valve 700. Since the second oil port m of the second proportional valve 700 is connected to the first oil port i of the second balance valve 600, and the first oil port k of the second proportional valve 700 is connected to the fourth oil port f of the electromagnetic directional valve 200, the hydraulic oil in the rodless cavity of the oil cylinder 910 can flow back to the oil return tank 920 through the second balance valve 600, the second proportional valve 700, and the electromagnetic directional valve 200, thereby realizing the contraction of the oil cylinder 910. During this process, the second proportional valve 700 can adjust the flow rate of the hydraulic oil in the second pipeline 400, so that the hydraulic oil in the rodless cavity of the oil cylinder 910 can slowly flow back to the oil return tank 920, avoiding the rapid pressure relief of the rodless cavity of the oil cylinder 910, and thus avoiding the phenomenon that the boom shakes due to the rapid pressure relief of the rodless cavity of the oil cylinder 910.

[0087] Thus, the control method of the above hydraulic control system can realize the contraction of the oil cylinder 910, thereby realizing the contraction or amplitude reduction of the boom, and can suppress the shaking or swaying of the boom when the boom starts to contract or the amplitude decreases.

[0088] The control method of the hydraulic control system involved in the first embodiment includes: in the second case: controlling the first proportional valve 100 to be energized so that the first oil port a of the first proportional valve 100 communicates with the second oil port b of the first proportional valve 100; controlling the electromagnetic reversing valve 200 to be energized to switch the electromagnetic reversing valve 200 to the second state, so that the hydraulic oil in the oil source 900 sequentially passes through the first proportional valve 100, the electromagnetic reversing valve 200, the second proportional valve 700, and the second balance valve 600 and enters the rodless cavity of the oil cylinder 910, and making the hydraulic oil in the oil source 900 sequentially pass through the first proportional valve 100, the electromagnetic reversing valve 200, the second pipeline 400, the damping circuit 800, the first pipeline 300, and the electromagnetic reversing valve 200 and flow back to the oil return tank 920, and making the hydraulic oil in the oil source 900 sequentially pass through the first proportional valve 100, the electromagnetic reversing valve 200, the second pipeline 400, and the damping circuit 800 and enter the control oil port p of the first balance valve 500 to open the spool of the first balance valve 500. Wherein, when the spool of the first balance valve 500 is opened, the hydraulic oil can flow from the second oil port h of the first balance valve 500 to the first oil port g of the first balance valve 500, so that the hydraulic oil in the rod cavity of the oil cylinder 910 sequentially passes through the first balance valve 500 and the electromagnetic reversing valve 200 and flows back to the oil return tank 920.

[0089] Specifically, the second case is the case where the oil cylinder 910 extends, that is, the boom extends or the amplitude increases.

[0090] Further, when the operation key is pressed, the operation key can be a handle or a button, and the signal is transmitted to the controller. When the controller controls S1 of the first proportional valve 100 to be energized, the first oil port a of the first proportional valve 100 communicates with the second oil port b of the first proportional valve 100.

[0091] Furthermore, when the operation key is pressed and the signal is transmitted to the controller to control DT2 of the electromagnetic reversing valve 200 to be energized, the electromagnetic reversing valve 200 switches to the second state.

[0092] In the control method of the hydraulic control system of the first embodiment, the first proportional valve 100 is controlled to be energized so that the first oil port a of the first proportional valve 100 is connected to the second oil port b of the first proportional valve 100, and the electromagnetic reversing valve 200 is controlled to be energized so that the electromagnetic reversing valve 200 is switched to the second state, so that the hydraulic oil in the oil source 900 can pass through the first proportional valve 100, the electromagnetic reversing valve 200, the second proportional valve 700 and the second balancing valve 600 in sequence and enter the rodless chamber of the oil cylinder 910; the valve core of the first balancing valve 500 is opened, so that the hydraulic oil in the rod chamber of the oil cylinder 910 can flow back to the return oil tank 920 in sequence through the first balancing valve 500 and the electromagnetic reversing valve 200. Therefore, when the electromagnetic reversing valve 200 is in the second state, the oil cylinder 910 can be extended, so as to realize the action of extending the boom or raising the boom. During this process, the hydraulic oil in the oil source 900 enters the rodless chamber of the cylinder 910 through the first oil port a of the first proportional valve 100, the second oil port b of the first proportional valve 100, the first oil port c of the solenoid reversing valve 200, the fourth oil port f of the solenoid reversing valve 200, the first oil port k of the second proportional valve 700, the second oil port m of the second proportional valve 700, the first oil port i of the second balancing valve 600 and the second oil port j of the second balancing valve 600; the hydraulic oil in the rod chamber of the cylinder 910 flows back to the return oil tank 920 through the second oil port h of the first balancing valve 500, the second oil port h of the first balancing valve 500, the third oil port e of the solenoid reversing valve 200 and the second oil port d of the solenoid reversing valve 200.

[0093] In this process, the first proportional valve 100 is controlled to be energized so that the first oil port a of the first proportional valve 100 is connected to the second oil port b of the first proportional valve 100, and the solenoid reversing valve 200 is controlled to be energized so that the solenoid reversing valve 200 is switched to the second state, so that the hydraulic oil in the oil source 900 can flow back to the return oil tank 920 through the first proportional valve 100, the solenoid reversing valve 200, the second pipeline 400, the first damping pipeline 810, the first pipeline 300 and the solenoid reversing valve 200 in sequence, so as to absorb the pressure shock in the second pipeline 400 through the first damping hole 811 and the second damping hole 812 on the first damping pipeline 810, thereby reducing the pressure shock on the rodless chamber of the oil cylinder 910, and suppressing the shaking and swaying of the arm due to the pressure shock on the rodless chamber of the oil cylinder 910.

[0094] Energize the first proportional valve 100 to connect the first oil port a of the first proportional valve 100 to the second oil port b of the first proportional valve 100. Energize the electromagnetic reversing valve 200 to switch the electromagnetic reversing valve 200 to the second state. Then, the hydraulic oil in the oil source 900 can pass through the first proportional valve 100, the electromagnetic reversing valve 200, the second pipeline 400, the first damping pipeline 810, and the third damping pipeline 830 in sequence and enter the control oil port p of the first balance valve 500 to open the spool of the first balance valve 500. When the spool of the first balance valve 500 is opened, the hydraulic oil can flow from the second oil port h of the first balance valve 500 to the first oil port g of the first balance valve 500, and the second oil port of the first balance is connected to the rod chamber of the oil cylinder 910. Therefore, the hydraulic oil in the rod chamber of the oil cylinder 910 can flow back to the oil return tank 920 through the first balance valve 500. At the same time, the first damping pipeline 810 and the third damping pipeline 830 form a bridge damping circuit. The second damping hole 812 and the fourth damping hole 831 on the bridge damping circuit can slowly open the spool of the first balance valve 500, thereby avoiding the phenomenon that the first balance valve 500 shakes due to the rapid opening of the spool of the first balance valve 500, and further avoiding the phenomenon that the boom shakes due to the shaking of the first balance valve 500.

[0095] Thus, the control method of the above hydraulic control system can realize the extension of the oil cylinder, so as to realize the elongation or amplitude increase of the boom, and can suppress the shaking or swaying of the boom when the boom starts to elongate or increase in amplitude.

[0096] Embodiment 2:

[0097] Refer to Figure 2 As shown, in Embodiment 2, the damping circuit 800 further includes a fourth damping pipeline 840 and a fifth damping pipeline 850. The two ends of the fourth damping pipeline 840 are respectively connected to the first pipeline 300 and the second pipeline 400. One end of the fifth damping pipeline 850 is connected to the fourth damping pipeline 840, and the other end of the fifth damping pipeline 850 is connected to the control oil port n of the second balance valve 600. The fourth damping pipeline 840 is provided with a fifth damping hole 841 and a sixth damping hole 842, and the fifth damping hole 841 and the sixth damping hole 842 are symmetrically arranged on both sides of the fifth damping pipeline 850. The fifth damping pipeline 850 is provided with a seventh damping hole 851.

[0098] Specifically, the fifth damping hole 841 is located at one end of the sixth damping hole 842 close to the first pipeline 300, and the sixth damping hole 842 is located at one end of the fifth damping hole 841 close to the second pipeline 400. In the case where the fifth damping hole 841 and the sixth damping hole 842 have the same aperture, the greater the pressure difference between the end of the fifth damping hole 841 close to the first pipeline 300 and the end of the sixth damping hole 842 close to the second pipeline 400, the greater the flow rate of the hydraulic oil passing through the fifth damping hole 841 and the sixth damping hole 842, and in the process of the hydraulic oil flowing through the fifth damping hole 841 and the sixth damping hole 842, the oil pressure on the fourth damping pipeline 840 gradually decreases.

[0099] Furthermore, the fourth damping line 840 and the fifth damping line 850 form a bridge damping circuit. When the fifth damping hole 841 and the sixth damping hole 842 have the same aperture, the total oil pressure on the fifth damping line 850 is half of that on the fourth damping line 840 .

[0100] More specifically, the diameters of the fifth damping hole 841 , the sixth damping hole 842 and the seventh damping hole 851 are determined according to actual working conditions.

[0101] In this way, when the electromagnetic reversing valve 200 is in the first state, the hydraulic oil in the oil source 900 can flow back to the return oil tank 920 through the first proportional valve 100, the electromagnetic reversing valve 200, the first pipeline 300, the fourth damping pipeline 840, the second pipeline 400 and the electromagnetic control valve in sequence. In this process, the pressure shock in the first pipeline 300 can be absorbed by allowing the hydraulic oil in the first pipeline 300 to flow through the fifth damping hole 841 and the sixth damping hole 842 on the fourth damping pipeline 840, thereby reducing the pressure shock on the rod chamber of the oil cylinder 910, thereby suppressing the shaking and swaying of the boom due to the pressure shock on the rod chamber of the oil cylinder 910.

[0102] In addition, when the electromagnetic directional valve 200 is in the first state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic directional valve 200, the first pipeline 300, the fifth damping hole 841, and the fifth damping pipeline 850 and enter the control oil port n of the second balance valve 600, so that the second balance valve 600 can be opened. During this process, since the total oil pressure in the fifth damping pipeline 850 is half of that on the fourth damping pipeline 840, the arrival time of the second preset pressure value of the second balance valve 600 can be extended, so that the spool of the second balance valve 600 can be slowly opened. And the hydraulic oil can also pass through the seventh damping hole 851 on the fifth damping pipeline 850. Since the seventh damping hole 851 throttles the hydraulic oil flowing through the fifth damping pipeline 850, the total flow rate of the hydraulic oil flowing through the seventh damping hole 851 can be delayed from reaching the control oil port n of the second balance valve 600, thereby extending the time for the total oil pressure of the hydraulic oil in the fifth damping pipeline 850 to reach the control oil port n of the second balance valve 600, so as to further extend the arrival time of the second preset pressure value of the second balance valve 600, so that the spool of the second balance valve 600 can be slowly opened, thereby avoiding the phenomenon of the second balance valve 600 jittering due to the rapid opening of the spool of the second balance valve 600, and further avoiding the phenomenon of the boom jittering due to the jitter of the second balance valve 600.

[0103] Refer to Figure 2 As shown, in the second embodiment, the damping circuit 800 further includes a sixth damping pipeline 860. The two ends of the sixth damping pipeline 860 are respectively connected to the second pipeline 400 and the control oil port p of the first balance valve 500, and an eighth damping hole 861 is provided on the sixth damping pipeline 860.

[0104] Specifically, one end of the sixth damping pipeline 860 connected to the second pipeline 400 is located between the first oil port k of the second proportional valve and the fourth oil port f of the electromagnetic directional valve.

[0105] In this way, when the electromagnetic directional valve 200 is in the second state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic directional valve 200, the second pipeline 400, the fourth damping pipeline 840, the first pipeline 300, and the electromagnetic control valve and flow back to the oil return tank 920. During this process, the pressure shock in the second pipeline 400 can be absorbed by making the hydraulic oil in the second pipeline 400 flow through the fifth damping hole 841 and the sixth damping hole 842 on the fourth damping pipeline 840, so as to reduce the pressure shock received by the rodless cavity of the oil cylinder 910, thereby suppressing the jittering and swaying phenomena of the boom due to the pressure shock received by the rodless cavity of the oil cylinder 910.

[0106] In addition, when the electromagnetic directional control valve 200 is in the second state, the hydraulic oil in the oil source 900 can sequentially flow through the first proportional valve 100, the electromagnetic directional control valve 200, the second pipeline 400, and the sixth damping pipeline 860 into the control oil port p of the first balance valve 500, so that the first balance valve 500 can be opened. During this process, the hydraulic oil can pass through the eighth damping hole 861 on the sixth damping pipeline 860. Since the eighth damping hole 861 throttles the hydraulic oil flowing through the sixth damping pipeline 860, the total flow rate of the hydraulic oil flowing through the eighth damping hole 861 can be delayed from reaching the control oil port p of the first balance valve 500, thereby extending the time for the total oil pressure of the hydraulic oil in the sixth damping pipeline 860 to reach the control oil port p of the first balance valve 500. In this way, the arrival time of the first preset pressure value of the first balance valve 500 can be extended, so that the spool of the first balance valve 500 can be slowly opened, avoiding the phenomenon that the spool of the first balance valve 500 is quickly opened due to the pressure impact of the hydraulic oil in the first pipeline 300, and further avoiding the phenomenon that the first balance valve 500 shakes due to the quick opening of the spool of the first balance valve 500, and further avoiding the phenomenon that the boom shakes due to the shaking of the first balance valve 500.

[0107] The control method of the hydraulic control system involved in the second embodiment includes: in the first case: controlling the first proportional valve 100 to be energized so that the first oil port a of the first proportional valve 100 is communicated with the second oil port b of the first proportional valve 100; controlling the electromagnetic directional control valve 200 to be energized to switch the electromagnetic directional control valve 200 to the first state, so that the hydraulic oil in the oil source sequentially passes through the first proportional valve 100, the electromagnetic directional control valve 200, and the first balance valve 500 and enters the rod chamber of the oil cylinder, and the hydraulic oil in the oil source sequentially passes through the first proportional valve 100, the electromagnetic directional control valve 200, the first pipeline 300, the damping circuit 800, the second pipeline 400, and the electromagnetic directional control valve 200 and returns to the oil return tank, and the hydraulic oil in the oil source sequentially passes through the first proportional valve 100, the electromagnetic directional control valve 200, the first pipeline 300, and the damping circuit 800 and enters the control oil port p of the second balance valve 600 to open the spool of the second balance valve 600. Wherein, when the spool of the second balance valve 600 is opened, the hydraulic oil can flow from the second oil port j of the second balance valve 600 to the first oil port i of the second balance valve 600; within the preset time when the spool of the second balance valve 600 is opened, controlling the second proportional valve 700 to be energized so that the hydraulic oil can flow from the second oil port m of the second proportional valve 700 to the first oil port k of the second proportional valve 700, so that the hydraulic oil in the rodless chamber of the oil cylinder sequentially passes through the second balance valve 600, the second proportional valve 700, and the electromagnetic directional control valve 200 and returns to the oil return tank.

[0108] Specifically, the first case is when the oil cylinder contracts, that is, when the boom contracts or the luffing descends.

[0109] Further, when the operation key is pressed, the operation key can be a handle or a button, and a signal is transmitted to the controller. When the S1 of the first proportional valve 100 is powered on by the controller, the first oil port a of the first proportional valve 100 is communicated with the second oil port b of the first proportional valve 100.

[0110] Furthermore, when the operation key is pressed and a signal is transmitted to the controller, when the DT1 of the electromagnetic directional valve 200 is powered on by the controller, the electromagnetic directional valve 200 switches to the first state.

[0111] Furthermore, the preset time for the spool of the second balance valve 600 to open is within 0 s to 1 s after the spool of the second balance valve 600 opens. Within 0 s to 1 s after the spool of the second balance valve 600 opens, the controller controls the S2 of the second proportional valve 700 to be powered on, so that the hydraulic oil can flow from the second oil port m of the second proportional valve 700 to the first oil port k of the second proportional valve 700.

[0112] In the control method of the hydraulic control system of the second embodiment, when the first proportional valve 100 is powered on to communicate the first oil port a of the first proportional valve 100 with the second oil port b of the first proportional valve 100, and the electromagnetic directional valve 200 is powered on to switch the electromagnetic directional valve 200 to the first state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic directional valve 200, and the first balance valve 500 and enter the rod chamber of the oil cylinder 910; when the spool of the second balance valve 600 is opened and the second proportional valve 700 is powered on, the hydraulic oil in the rodless chamber of the oil cylinder 910 can sequentially pass through the second balance valve 600, the second proportional valve 700, and the electromagnetic directional valve 200 and return to the oil return tank 920. Thus, when the electromagnetic directional valve 200 is in the first state, the oil cylinder 910 can contract, thereby realizing the action of the boom contraction or the luffing descent. During this process, the hydraulic oil in the oil source 900 sequentially passes through the first oil port a of the first proportional valve 100, the second oil port b of the first proportional valve 100, the first oil port c of the electromagnetic directional valve 200, the third oil port e of the electromagnetic directional valve 200, the first oil port g of the first balance valve 500, and the second oil port h of the first balance valve 500 and enters the rod chamber of the oil cylinder 910; the hydraulic oil in the rodless chamber of the oil cylinder 910 sequentially passes through the second oil port j of the second balance valve 600, the first oil port i of the second balance valve 600, the second oil port m of the second proportional valve 700, the first oil port k of the second proportional valve 700, the fourth oil port f of the electromagnetic directional valve 200, and the second oil port d of the electromagnetic directional valve 200 and returns to the oil return tank 920.

[0113] In this process, control the first proportional valve 100 to be energized, so that the first oil port a of the first proportional valve 100 is communicated with the second oil port b of the first proportional valve 100, control the electromagnetic reversing valve 200 to be energized, so that the electromagnetic reversing valve 200 is switched to the first state, then the hydraulic oil in the oil source 900 can pass through the first proportional valve 100, the electromagnetic reversing valve 200, the first pipeline 300, the fourth damping pipeline 840, the second pipeline 400 and the electromagnetic reversing valve 200 in sequence and flow back into the oil return tank 920, so as to absorb the pressure shock in the first pipeline 300 through the fifth damping hole 841 and the sixth damping hole 842 on the fourth damping pipeline 840, thereby reducing the pressure shock received by the rod chamber of the oil cylinder 910 and suppressing the shaking and swaying phenomena of the boom due to the pressure shock received by the rod chamber of the oil cylinder 910.

[0114] Control the first proportional valve 100 to be energized, so that the first oil port a of the first proportional valve 100 is communicated with the second oil port b of the first proportional valve 100, control the electromagnetic reversing valve 200 to be energized, so that the electromagnetic reversing valve 200 is switched to the first state, then the hydraulic oil in the oil source 900 can pass through the first proportional valve 100, the electromagnetic reversing valve 200, the first pipeline 300 and the second damping pipeline 820 and enter the control oil port n of the second balance valve 600, so as to open the spool of the second balance valve 600. When the spool of the second balance valve 600 is opened, the hydraulic oil can flow from the second oil port j of the second balance valve 600 to the first oil port i of the second balance valve 600, and the second oil port j of the second balance valve 600 is communicated with the rodless chamber of the oil cylinder 910, so the hydraulic oil in the rodless chamber of the oil cylinder 910 can flow back into the oil return tank 920 through the second balance valve 600. At the same time, the fourth damping pipeline 840 and the fifth damping pipeline 850 form a bridge damping circuit, and the fifth damping hole 841 and the seventh damping hole 851 on the bridge damping circuit can make the spool of the second balance valve 600 be opened slowly, so as to avoid the phenomenon that the second balance valve 600 shakes due to the rapid opening of the spool of the second balance valve 600, and further avoid the phenomenon that the boom shakes due to the shaking of the second balance valve 600.

[0115] During the preset time when the valve core of the second balancing valve 600 is opened, the second proportional valve 700 is controlled to be energized so that the hydraulic oil can flow from the second oil port m of the second proportional valve 700 to the first oil port k of the second proportional valve 700. Since the second oil port m of the second proportional valve 700 is connected to the first oil port i of the second balancing valve 600, and the first oil port k of the second proportional valve 700 is connected to the fourth oil port f of the electromagnetic reversing valve 200, the hydraulic oil in the rodless chamber of the oil cylinder 910 can flow back to the return oil tank 920 through the second balancing valve 600, the second proportional valve 700 and the electromagnetic reversing valve 200, so as to achieve the contraction of the oil cylinder 910. During this process, the second proportional valve 700 can adjust the flow rate of the hydraulic oil in the second pipeline 400, so that the hydraulic oil in the rodless chamber of the oil cylinder 910 can slowly flow back to the return oil tank 920, thereby preventing the rodless chamber of the oil cylinder 910 from releasing pressure too quickly, thereby preventing the rodless chamber of the oil cylinder 910 from shaking due to excessive pressure relief.

[0116] Therefore, the control method of the hydraulic control system can realize the contraction of the oil cylinder 910, so as to realize the contraction or amplitude reduction of the boom, and can suppress the shaking or swaying of the boom when the boom starts to contract or amplitude reduce.

[0117] The control method of the hydraulic control system involved in the second embodiment includes: in the second case: controlling the first proportional valve 100 to be energized so that the first oil port a of the first proportional valve 100 is connected to the second oil port b of the first proportional valve 100; controlling the electromagnetic reversing valve 200 to be energized so that the electromagnetic reversing valve 200 is switched to the second state, so that the hydraulic oil in the oil source 900 passes through the first proportional valve 100, the electromagnetic reversing valve 200, the second proportional valve 700 and the second balancing valve 600 in sequence into the rodless chamber of the oil cylinder 910, so that the hydraulic oil in the oil source 900 passes through the first proportional valve 100, the electromagnetic reversing valve 200, the second pipeline 400, the damping circuit 800, The first pipeline 300 and the electromagnetic reversing valve 200 flow back to the return oil tank 920, and the hydraulic oil in the oil source 900 enters the control oil port p of the first balancing valve 500 through the first proportional valve 100, the electromagnetic reversing valve 200, the second pipeline 400 and the damping circuit 800 in sequence to open the valve core of the first balancing valve 500. When the valve core of the first balancing valve 500 is opened, the hydraulic oil can flow from the second oil port h of the first balancing valve 500 to the first oil port g of the first balancing valve 500, so that the hydraulic oil in the rod chamber of the cylinder 910 flows back to the return oil tank 920 through the first balancing valve 500 and the electromagnetic reversing valve 200 in sequence.

[0118] Specifically, the second situation is the situation where the oil cylinder 910 is extended, that is, the boom is extended or the boom is raised.

[0119] Further, when the operation key is pressed, the operation key can be a handle or a button, and a signal is transmitted to the controller. When the S1 of the first proportional valve 100 is powered on by the controller, the first oil port a of the first proportional valve 100 communicates with the second oil port b of the first proportional valve 100.

[0120] Furthermore, when the operation key is pressed and a signal is transmitted to the controller to make the DT2 of the electromagnetic directional valve 200 powered on by the controller, the electromagnetic directional valve 200 switches to the second state.

[0121] In the control method of the hydraulic control system of the second embodiment, when the first proportional valve 100 is powered on to make the first oil port a of the first proportional valve 100 communicate with the second oil port b of the first proportional valve 100, and the electromagnetic directional valve 200 is powered on to make the electromagnetic directional valve 200 switch to the second state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic directional valve 200, the second proportional valve 700, and the second balance valve 600 and enter the rodless cavity of the oil cylinder 910; when the spool of the first balance valve 500 is opened, the hydraulic oil in the rod chamber of the oil cylinder 910 can sequentially pass through the first balance valve 500 and the electromagnetic directional valve 200 and flow back to the oil return tank 920. Thus, when the electromagnetic directional valve 200 is in the second state, the oil cylinder 910 can extend, so as to realize the actions of boom extension or luffing up. During this process, the hydraulic oil in the oil source 900 sequentially passes through the first oil port a of the first proportional valve 100, the second oil port b of the first proportional valve 100, the first oil port c of the electromagnetic directional valve 200, the fourth oil port f of the electromagnetic directional valve 200, the first oil port k of the second proportional valve 700, the second oil port m of the second proportional valve 700, the first oil port i of the second balance valve 600, and the second oil port j of the second balance valve 600 and enters the rodless cavity of the oil cylinder 910; the hydraulic oil in the rod chamber of the oil cylinder 910 sequentially passes through the second oil port h of the first balance valve 500, the second oil port h of the first balance valve 500, the third oil port e of the electromagnetic directional valve 200, and the second oil port d of the electromagnetic directional valve 200 and flows back to the oil return tank 920.

[0122] In this process, control the first proportional valve 100 to be energized, so that the first oil port a of the first proportional valve 100 is communicated with the second oil port b of the first proportional valve 100, control the electromagnetic reversing valve 200 to be energized, so that the electromagnetic reversing valve 200 is switched to the second state, then the hydraulic oil in the oil source 900 can pass through the first proportional valve 100, the electromagnetic reversing valve 200, the second pipeline 400, the fourth damping pipeline 840, the first pipeline 300 and the electromagnetic reversing valve 200 in sequence and return to the oil return tank 920, so as to absorb the pressure shock in the second pipeline 400 through the fifth damping hole 841 and the sixth damping hole 842 on the fourth damping pipeline 840, thereby reducing the pressure shock received by the rodless cavity of the oil cylinder 910 and suppressing the shaking and swaying phenomena of the boom due to the pressure shock received by the rodless cavity of the oil cylinder 910.

[0123] Control the first proportional valve 100 to be energized, so that the first oil port a of the first proportional valve 100 is communicated with the second oil port b of the first proportional valve 100, control the electromagnetic reversing valve 200 to be energized, so that the electromagnetic reversing valve 200 is switched to the second state, then the hydraulic oil in the oil source 900 can pass through the first proportional valve 100, the electromagnetic reversing valve 200, the second pipeline 400 and the sixth damping pipeline 860 in sequence and enter the control oil port p of the first balance valve 500, so as to open the spool of the first balance valve 500. When the spool of the first balance valve 500 is opened, the hydraulic oil can flow from the second oil port h of the first balance valve 500 to the first oil port g of the first balance valve 500, and the second oil port of the first balance is communicated with the rodless cavity of the oil cylinder 910. Therefore, the hydraulic oil in the rodless cavity of the oil cylinder 910 can return to the oil return tank 920 through the first balance valve 500. At the same time, the eighth damping hole 861 on the sixth damping pipeline 860 can make the spool of the first balance valve 500 be opened slowly, so as to avoid the phenomenon that the first balance valve 500 shakes due to the rapid opening of the spool of the first balance valve 500, and further avoid the phenomenon that the boom shakes due to the shaking of the first balance valve 500.

[0124] Thus, the control method of the above hydraulic control system can realize the extension of the oil cylinder, so as to realize the elongation or amplitude increase of the boom, and can suppress the shaking or swaying phenomenon of the boom when the boom starts to elongate or the amplitude increases.

[0125] Embodiment 3:

[0126] Refer to Figure 3As shown in the figure, in the third embodiment, the damping circuit 800 further includes a seventh damping pipeline 870 and an eighth damping pipeline 880. The two ends of the seventh damping pipeline 870 are respectively communicated with the first pipeline 300 and the second pipeline 400. The first end of the eighth damping pipeline 880 is communicated with the seventh damping pipeline 870. The second end of the eighth damping pipeline 880 is communicated with the control oil port p of the first balance valve 500. The third end of the eighth damping pipeline 880 is communicated with the control oil port n of the second balance valve 600. The seventh damping pipeline 870 is provided with a ninth damping hole 871 and a tenth damping hole 872, and the ninth damping hole 871 and the tenth damping hole 872 are symmetrically arranged on both sides of the eighth damping pipeline 880. The eighth damping pipeline 880 is provided with an eleventh damping hole 881.

[0127] Specifically, the ninth damping hole 871 is located at one end of the tenth damping hole 872 close to the first pipeline 300, and the tenth damping hole 872 is located at one end of the ninth damping hole 871 close to the second pipeline 400. When the apertures of the ninth damping hole 871 and the tenth damping hole 872 are the same, the greater the pressure difference between the end of the ninth damping hole 871 close to the first pipeline 300 and the end of the tenth damping hole 872 close to the second pipeline 400, the greater the flow rate of the hydraulic oil passing through the ninth damping hole 871 and the tenth damping hole 872. And during the process of the hydraulic oil flowing through the ninth damping hole 871 and the tenth damping hole 872, the oil pressure on the seventh damping pipeline 870 gradually decreases.

[0128] Furthermore, the seventh damping pipeline 870 and the eighth damping pipeline 880 form a bridge-type damping circuit. When the apertures of the ninth damping hole 871 and the tenth damping hole 872 are the same, the total oil pressure on the eighth damping pipeline 880 is half of that on the seventh damping pipeline 870.

[0129] More specifically, the aperture sizes of the ninth damping hole 871, the tenth damping hole 872 and the eleventh damping hole 881 are determined according to the actual working conditions.

[0130] In this way, when the electromagnetic directional valve 200 is in the first state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic directional valve 200, the first pipeline 300, the seventh damping pipeline 870, the second pipeline 400 and the electromagnetic control valve and flow back into the oil return tank 920. During this process, the pressure shock in the first pipeline 300 can be absorbed by making the hydraulic oil in the first pipeline 300 flow through the ninth damping hole 871 and the tenth damping hole 872 on the seventh damping pipeline 870, so as to reduce the pressure shock received by the rod chamber of the oil cylinder 910, thereby being able to suppress the shaking and swaying phenomena of the boom due to the pressure shock received by the rod chamber of the oil cylinder 910.

[0131] In addition, when the electromagnetic directional control valve 200 is in the first state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic directional control valve 200, the first pipeline 300, the ninth damping hole 871, and the eighth damping pipeline 880 to enter the control oil port n of the second balance valve 600, so that the second balance valve 600 can be opened. During this process, since the total oil pressure in the eighth damping pipeline 880 is half of that on the seventh damping pipeline 870, the arrival time of the second preset pressure value of the second balance valve 600 can be extended, so that the spool of the second balance valve 600 can be slowly opened. And the hydraulic oil can also pass through the eleventh damping hole 881 on the eighth damping pipeline 880. Since the eleventh damping hole 881 throttles the hydraulic oil flowing through the eighth damping pipeline 880, the total flow rate of the hydraulic oil flowing through the eleventh damping hole 881 can be delayed from reaching the control oil port n of the second balance valve 600, thereby extending the time for the total oil pressure of the hydraulic oil in the eighth damping pipeline 880 to reach the control oil port n of the second balance valve 600, so as to further extend the arrival time of the second preset pressure value of the second balance valve 600, so that the spool of the second balance valve 600 can be slowly opened, thereby avoiding the phenomenon of the second balance valve 600 jittering due to the rapid opening of the spool of the second balance valve 600, and further avoiding the phenomenon of the boom jittering due to the jitter of the second balance valve 600.

[0132] When the electromagnetic directional control valve 200 is in the second state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic directional control valve 200, the second pipeline 400, the seventh damping pipeline 870, the first pipeline 300, and the electromagnetic control valve and flow back to the oil return tank 920. During this process, the pressure shock in the second pipeline 400 can be absorbed by making the hydraulic oil in the second pipeline 400 flow through the ninth damping hole 871 and the tenth damping hole 872 on the seventh damping pipeline 870, so as to reduce the pressure shock received by the rodless cavity of the oil cylinder 910, thereby suppressing the jittering and swaying phenomena of the boom due to the pressure shock received by the rodless cavity of the oil cylinder 910.

[0133] In addition, when the electromagnetic directional valve 200 is in the second state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic directional valve 200, the second pipeline 400, the tenth damping hole 872, and the eighth damping pipeline 880 and enter the control oil port p of the first balance valve 500, so that the first balance valve 500 can be opened. During this process, since the total oil pressure in the eighth damping pipeline 880 is half of that on the seventh damping pipeline 870, the arrival time of the first preset pressure value of the first balance valve 500 can be extended, so that the spool of the first balance valve 500 can be slowly opened. And the hydraulic oil can also pass through the eleventh damping hole 881 on the eighth damping pipeline 880. Since the eleventh damping hole 881 throttles the hydraulic oil flowing through the eighth damping pipeline 880, the total flow rate of the hydraulic oil flowing through the eleventh damping hole 881 can be delayed from reaching the control oil port p of the first balance valve 500, so that the time for the total oil pressure of the hydraulic oil in the eighth damping pipeline 880 to reach the control oil port p of the first balance valve 500 can be extended, thereby further extending the arrival time of the first preset pressure value of the first balance valve 500, so that the spool of the first balance valve 500 can be slowly opened, thereby avoiding the phenomenon that the first balance valve 500 shakes due to the rapid opening of the spool of the first balance valve 500, and further avoiding the phenomenon that the boom shakes due to the shaking of the first balance valve 500.

[0134] The control method of the hydraulic control system involved in the third embodiment includes: in the first case: controlling the first proportional valve 100 to be energized so that the first oil port a of the first proportional valve 100 communicates with the second oil port b of the first proportional valve 100; controlling the electromagnetic directional valve 200 to be energized to switch the electromagnetic directional valve 200 to the first state, so that the hydraulic oil in the oil source 900 sequentially passes through the first proportional valve 100, the electromagnetic directional valve 200, and the first balance valve 500 and enters the rod chamber of the oil cylinder 910, and the hydraulic oil in the oil source 900 sequentially passes through the first proportional valve 100, the electromagnetic directional valve 200, the first pipeline 300, the damping circuit 800, the second pipeline 400, and the electromagnetic directional valve 200 and returns to the oil return tank 920, and the hydraulic oil in the oil source 900 sequentially passes through the first proportional valve 100, the electromagnetic directional valve 200, the first pipeline 300, and the damping circuit 800 and enters the control oil port p of the second balance valve 600 to open the spool of the second balance valve 600. Wherein, when the spool of the second balance valve 600 is opened, the hydraulic oil can flow from the second oil port j of the second balance valve 600 to the first oil port i of the second balance valve 600; within the preset time after the spool of the second balance valve 600 is opened, control the second proportional valve 700 to be energized so that the hydraulic oil can flow from the second oil port m of the second proportional valve 700 to the first oil port k of the second proportional valve 700, so that the hydraulic oil in the rodless chamber of the oil cylinder 910 sequentially passes through the second balance valve 600, the second proportional valve 700, and the electromagnetic directional valve 200 and returns to the oil return tank 920.

[0135] Specifically, the first case is the case where the oil cylinder 910 contracts, that is, the boom contracts or the amplitude decreases.

[0136] Further, when the operation key is pressed, the operation key can be a handle or a button, and the signal is transmitted to the controller. When the controller controls S1 of the first proportional valve 100 to be energized, the first oil port a of the first proportional valve 100 communicates with the second oil port b of the first proportional valve 100.

[0137] Furthermore, when the operation key is pressed and the signal is transmitted to the controller, when the controller controls DT1 of the electromagnetic directional valve 200 to be energized, the electromagnetic directional valve 200 switches to the first state.

[0138] Furthermore, the preset time for the spool of the second balance valve 600 to open is within 0 s to 1 s after the spool of the second balance valve 600 is opened. Within 0 s to 1 s after the spool of the second balance valve 600 is opened, the controller controls S2 of the second proportional valve 700 to be energized so that the hydraulic oil can flow from the second oil port m of the second proportional valve 700 to the first oil port k of the second proportional valve 700.

[0139] In the control method of the hydraulic control system according to the third embodiment, when the first proportional valve 100 is powered on, the first oil port a of the first proportional valve 100 is communicated with the second oil port b of the first proportional valve 100. When the electromagnetic reversing valve 200 is powered on and switched to the first state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic reversing valve 200, and the first balance valve 500 and enter the rod chamber of the oil cylinder 910. When the spool of the second balance valve 600 is opened and the second proportional valve 700 is powered on, the hydraulic oil in the rodless chamber of the oil cylinder 910 can sequentially pass through the second balance valve 600, the second proportional valve 700, and the electromagnetic reversing valve 200 and return to the oil return tank 920. Thus, when the electromagnetic reversing valve 200 is in the first state, the oil cylinder 910 can contract, so as to realize the actions of boom contraction or amplitude reduction. During this process, the hydraulic oil in the oil source 900 sequentially passes through the first oil port a of the first proportional valve 100, the second oil port b of the first proportional valve 100, the first oil port c of the electromagnetic reversing valve 200, the third oil port e of the electromagnetic reversing valve 200, the first oil port g of the first balance valve 500, and the second oil port h of the first balance valve 500 and enters the rod chamber of the oil cylinder 910. The hydraulic oil in the rodless chamber of the oil cylinder 910 sequentially passes through the second oil port j of the second balance valve 600, the first oil port i of the second balance valve 600, the second oil port m of the second proportional valve 700, the first oil port k of the second proportional valve 700, the fourth oil port f of the electromagnetic reversing valve 200, and the second oil port d of the electromagnetic reversing valve 200 and returns to the oil return tank 920.

[0140] During this process, when the first proportional valve 100 is powered on, the first oil port a of the first proportional valve 100 is communicated with the second oil port b of the first proportional valve 100. When the electromagnetic reversing valve 200 is powered on and switched to the first state, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic reversing valve 200, the first pipeline 300, the seventh damping pipeline 870, the second pipeline 400, and the electromagnetic reversing valve 200 and return to the oil return tank 920, so as to absorb the pressure shock in the first pipeline 300 through the ninth damping hole 871 and the tenth damping hole 872 on the seventh damping pipeline 870, thereby reducing the pressure shock received by the rod chamber of the oil cylinder 910 and suppressing the shaking and swaying phenomena of the boom due to the pressure shock received by the rod chamber of the oil cylinder 910.

[0141] Energize the first proportional valve 100 to connect the first oil port a of the first proportional valve 100 to the second oil port b of the first proportional valve 100. Energize the electromagnetic directional valve 200 to switch the electromagnetic directional valve 200 to the first state. Then, the hydraulic oil in the oil source 900 can pass through the first proportional valve 100, the electromagnetic directional valve 200, the first pipeline 300, and the eighth damping pipeline 880 in sequence and enter the control oil port n of the second balance valve 600, so as to open the spool of the second balance valve 600. When the spool of the second balance valve 600 is opened, the hydraulic oil can flow from the second oil port j of the second balance valve 600 to the first oil port i of the second balance valve 600, and the second oil port j of the second balance valve 600 is connected to the rodless cavity of the oil cylinder 910. Therefore, the hydraulic oil in the rodless cavity of the oil cylinder 910 can flow back to the oil return tank 920 through the second balance valve 600. At the same time, the seventh damping pipeline 870 and the eighth damping pipeline 880 form a bridge damping circuit, and the ninth damping hole 871 and the eleventh damping hole 881 on the bridge damping circuit can slowly open the spool of the second balance valve 600, so as to avoid the phenomenon of the second balance valve 600 shaking due to the rapid opening of the spool of the second balance valve 600, and further avoid the phenomenon of the boom shaking due to the shaking of the second balance valve 600.

[0142] Within the preset time when the spool of the second balance valve 600 is opened, energize the second proportional valve 700 so that the hydraulic oil can flow from the second oil port m of the second proportional valve 700 to the first oil port k of the second proportional valve 700. Since the second oil port m of the second proportional valve 700 is connected to the first oil port i of the second balance valve 600, and the first oil port k of the second proportional valve 700 is connected to the fourth oil port f of the electromagnetic directional valve 200, the hydraulic oil in the rodless cavity of the oil cylinder 910 can flow back to the oil return tank 920 through the second balance valve 600, the second proportional valve 700, and the electromagnetic directional valve 200, so as to realize the contraction of the oil cylinder 910. During this process, the second proportional valve 700 can adjust the flow rate of the hydraulic oil in the second pipeline 400, so that the hydraulic oil in the rodless cavity of the oil cylinder 910 can slowly flow back to the oil return tank 920, avoiding the rapid pressure relief of the rodless cavity of the oil cylinder 910, and thus avoiding the phenomenon of the boom shaking due to the rapid pressure relief of the rodless cavity of the oil cylinder 910.

[0143] Thus, the control method of the above hydraulic control system can realize the contraction of the oil cylinder 910, so as to realize the contraction or the amplitude reduction of the boom, and can suppress the shaking or swaying phenomenon of the boom when the boom starts to contract or the amplitude reduces.

[0144] The control method of the hydraulic control system involved in the third embodiment includes: in the second case: controlling the first proportional valve 100 to be energized so that the first oil port a of the first proportional valve 100 is communicated with the second oil port b of the first proportional valve 100; controlling the electromagnetic reversing valve 200 to be energized to switch the electromagnetic reversing valve 200 to the second state, so that the hydraulic oil in the oil source 900 sequentially passes through the first proportional valve 100, the electromagnetic reversing valve 200, the second proportional valve 700, and the second balance valve 600 and enters the rodless cavity of the oil cylinder 910, and the hydraulic oil in the oil source 900 sequentially passes through the first proportional valve 100, the electromagnetic reversing valve 200, the second pipeline 400, the damping circuit 800, the first pipeline 300, and the electromagnetic reversing valve 200 and returns to the oil return tank 920, and the hydraulic oil in the oil source 900 sequentially passes through the first proportional valve 100, the electromagnetic reversing valve 200, the second pipeline 400, and the damping circuit 800 and enters the control oil port p of the first balance valve 500 to open the spool of the first balance valve 500. Wherein, when the spool of the first balance valve 500 is opened, the hydraulic oil can flow from the second oil port h of the first balance valve 500 to the first oil port g of the first balance valve 500, so that the hydraulic oil in the rod chamber of the oil cylinder 910 sequentially passes through the first balance valve 500 and the electromagnetic reversing valve 200 and returns to the oil return tank 920.

[0145] Specifically, the second case is the case where the oil cylinder 910 extends, that is, the case where the boom extends or the amplitude increases.

[0146] Further, when the operation key is pressed, the operation key can be a handle or a button, and when the signal is transmitted to the controller to control the S1 of the first proportional valve 100 to be energized, the first oil port a of the first proportional valve 100 is communicated with the second oil port b of the first proportional valve 100.

[0147] Furthermore, when the operation key is pressed and the signal is transmitted to the controller to control the DT2 of the electromagnetic reversing valve 200 to be energized, the electromagnetic reversing valve 200 switches to the second state.

[0148] Furthermore, the preset time for the spool of the second balance valve 600 to open is within 1 s to 2 s after the spool of the second balance valve 600 is opened. Within 1 s to 2 s after the spool of the second balance valve 600 is opened, the controller controls the S2 of the second proportional valve 700 to be energized so that the hydraulic oil can flow from the second oil port m of the second proportional valve 700 to the first oil port k of the second proportional valve 700.

[0149] In the control method of the hydraulic control system according to the third embodiment, the first proportional valve 100 is controlled to be energized, so that the first oil port a of the first proportional valve 100 communicates with the second oil port b of the first proportional valve 100. The electromagnetic directional valve 200 is controlled to be energized, so that the electromagnetic directional valve 200 is switched to the second state. Then, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic directional valve 200, the second proportional valve 700, and the second balance valve 600 and enter the rodless cavity of the oil cylinder 910. The spool of the first balance valve 500 is opened, so that the hydraulic oil in the rod chamber of the oil cylinder 910 can sequentially pass through the first balance valve 500 and the electromagnetic directional valve 200 and return to the oil return tank 920. Thus, when the electromagnetic directional valve 200 is in the second state, the oil cylinder 910 can extend, so as to realize the actions of the boom extension or the luffing upward. In this process, the hydraulic oil in the oil source 900 sequentially passes through the first oil port a of the first proportional valve 100, the second oil port b of the first proportional valve 100, the first oil port c of the electromagnetic directional valve 200, the fourth oil port f of the electromagnetic directional valve 200, the first oil port k of the second proportional valve 700, the second oil port m of the second proportional valve 700, the first oil port i of the second balance valve 600, and the second oil port j of the second balance valve 600 and enters the rodless cavity of the oil cylinder 910. The hydraulic oil in the rod chamber of the oil cylinder 910 sequentially passes through the second oil port h of the first balance valve 500, the second oil port h of the first balance valve 500, the third oil port e of the electromagnetic directional valve 200, and the second oil port d of the electromagnetic directional valve 200 and returns to the oil return tank 920.

[0150] In this process, the first proportional valve 100 is controlled to be energized, so that the first oil port a of the first proportional valve 100 communicates with the second oil port b of the first proportional valve 100. The electromagnetic directional valve 200 is controlled to be energized, so that the electromagnetic directional valve 200 is switched to the second state. Then, the hydraulic oil in the oil source 900 can sequentially pass through the first proportional valve 100, the electromagnetic directional valve 200, the second pipeline 400, the seventh damping pipeline 870, the first pipeline 300, and the electromagnetic directional valve 200 and return to the oil return tank 920, so as to absorb the pressure shock in the second pipeline 400 through the ninth damping hole 871 and the tenth damping hole 872 on the seventh damping pipeline 870, thereby reducing the pressure shock received by the rodless cavity of the oil cylinder 910 and suppressing the shaking and swaying phenomena of the boom due to the pressure shock received by the rodless cavity of the oil cylinder 910.

[0151] Energize the first proportional valve 100 to connect the first oil port a of the first proportional valve 100 to the second oil port b of the first proportional valve 100. Energize the electromagnetic directional valve 200 to switch the electromagnetic directional valve 200 to the second state. Then, the hydraulic oil in the oil source 900 can pass through the first proportional valve 100, the electromagnetic directional valve 200, the second pipeline 400, the seventh damping pipeline 870, and the eighth damping pipeline 880 in sequence and enter the control oil port p of the first balance valve 500 to open the spool of the first balance valve 500. When the spool of the first balance valve 500 is opened, the hydraulic oil can flow from the second oil port h of the first balance valve 500 to the first oil port g of the first balance valve 500, and the second oil port of the first balance is connected to the rod chamber of the oil cylinder 910. Therefore, the hydraulic oil in the rod chamber of the oil cylinder 910 can flow back to the oil return tank 920 through the first balance valve 500. At the same time, the seventh damping pipeline 870 and the eighth damping pipeline 880 form a bridge damping circuit. The tenth damping hole 872 and the eleventh damping hole 881 on the bridge damping circuit can slowly open the spool of the first balance valve 500, thereby avoiding the phenomenon that the first balance valve 500 shakes due to the rapid opening of the spool of the first balance valve 500, and further avoiding the phenomenon that the boom shakes due to the shaking of the first balance valve 500.

[0152] Thus, the control method of the above hydraulic control system can realize the extension of the oil cylinder, so as to realize the elongation or amplitude increase of the boom, and can suppress the shaking or swaying of the boom when the boom starts to elongate or the amplitude increases.

[0153] Refer to Figures 1 to 3 As shown, it can be understood that the hydraulic oil can flow from the first oil port k of the second proportional valve 700 to the second oil port m of the second proportional valve 700, and when the second proportional valve 700 is energized to open the spool of the second proportional valve 700, the hydraulic oil can flow from the second oil port m of the second proportional valve 700 to the first oil port k of the second proportional valve 700; wherein, when the second proportional valve 700 is energized to open the spool of the second proportional valve 700, the opening from the second oil port m to the first oil port k of the second proportional valve 700 gradually increases, so that the flow rate of the hydraulic oil passing through the second proportional valve 700 gradually reaches a uniform state.

[0154] When the second proportional valve 700 is energized, the controller adjusts the current magnitude and the working coefficient of the second proportional valve 700, so as to adjust the opening size of the second oil port m to the first oil port k of the second proportional valve 700 of the proportional valve. When the electromagnetic directional valve 200 is in the first state, the opening of the second oil port m to the first oil port k of the second proportional valve 700 is gradually increased, so that the flow rate of the hydraulic oil passing through the second proportional valve 700 gradually reaches a uniform state, so that the hydraulic oil in the rodless cavity of the oil cylinder 910 can slowly flow back to the oil return tank 920, and the second proportional valve 700 can also generate back pressure in the rodless cavity of the oil cylinder 910, so as to offset the sudden change of the pressure in the rodless cavity of the oil cylinder 910, avoid the rodless cavity of the oil cylinder 910 from discharging pressure too fast, and avoid the phenomenon of the boom shaking caused by the rodless cavity of the oil cylinder 910 discharging pressure too fast.

[0155] The boom of an embodiment of the present invention includes the hydraulic control system as described above.

[0156] In the boom described above, since the above-mentioned hydraulic control system can prevent the above-mentioned boom from shaking or swaying when starting to contract or lower the amplitude and starting to extend or raise the amplitude, the above-mentioned boom can have a stable working state when starting to contract or lower the amplitude and starting to extend or raise the amplitude, so as to ensure the safety of the above-mentioned boom during operation.

[0157] The embodiments of the present invention have been described in detail above in conjunction with the drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the art.

Claims

1. A hydraulic control system, characterized in that, Comprising: A first proportional valve, the first oil port of the first proportional valve being used for communicating with an oil source; An electromagnetic directional valve, the first oil port of the electromagnetic directional valve being communicated with the second oil port of the first proportional valve, the second oil port of the electromagnetic directional valve being used for communicating with a return oil tank, the third oil port of the electromagnetic directional valve being communicated with the rod chamber of the oil cylinder through a first pipeline, the fourth oil port of the electromagnetic directional valve being communicated with the rodless chamber of the oil cylinder through a second pipeline. When the electromagnetic directional valve is in a first state, the first oil port of the electromagnetic directional valve is communicated with the third oil port of the electromagnetic directional valve, and the fourth oil port of the electromagnetic directional valve is communicated with the second oil port of the electromagnetic directional valve. When the electromagnetic directional valve is in a second state, the first oil port of the electromagnetic directional valve is communicated with the fourth oil port of the electromagnetic directional valve, and the third oil port of the electromagnetic directional valve is communicated with the second oil port of the electromagnetic directional valve; A first balance valve, the first balance valve being arranged on the first pipeline, the first oil port of the first balance valve being communicated with the third oil port of the electromagnetic directional valve, and the second oil port of the first balance valve being communicated with the rod chamber of the oil cylinder; A second balance valve, the second balance valve being arranged on the second pipeline, and the second oil port of the second balance valve being communicated with the rodless chamber of the oil cylinder; A second proportional valve, the second proportional valve being arranged on the second pipeline, and the first oil port of the second proportional valve being communicated with the fourth oil port of the electromagnetic directional valve, and the second oil port of the second proportional valve being communicated with the first oil port of the second balance valve; and A damping circuit, the damping circuit being used for communicating the first pipeline with the second pipeline. One end of the damping circuit communicated with the first pipeline is located between the first oil port of the first balance valve and the third oil port of the electromagnetic directional valve, and one end of the damping circuit communicated with the second pipeline is located between the first oil port of the second proportional valve and the fourth oil port of the electromagnetic directional valve. When the electromagnetic directional valve is in the first state, the damping circuit is further used for guiding the hydraulic oil in the first pipeline to the control oil port of the second balance valve. When the electromagnetic directional valve is in the second state, the damping circuit is further used for guiding the hydraulic oil in the second pipeline to the control oil port of the first balance valve.

2. The hydraulic control system according to claim 1, wherein The damping circuit includes a first damping pipeline and a second damping pipeline. Two ends of the first damping pipeline are respectively communicated with the first pipeline and the second pipeline. One end of the second damping pipeline is communicated with the first pipeline, and the other end of the second damping pipeline is communicated with the control oil port of the second balance valve. A first damping hole and a second damping hole are arranged on the first damping pipeline, and a third damping hole is arranged on the second damping pipeline.

3. The hydraulic control system according to claim 2, characterized in that The damping circuit further includes a third damping pipeline. One end of the third damping pipeline is communicated with the first damping pipeline, and the other end of the third damping pipeline is communicated with the control oil port of the first balance valve. The first damping hole and the second damping hole are symmetrically arranged on two sides of the third damping pipeline, and a fourth damping hole is arranged on the third damping pipeline.

4. The hydraulic control system according to claim 1, characterized in that The damping circuit further includes a fourth damping pipeline and a fifth damping pipeline. Two ends of the fourth damping pipeline are respectively communicated with the first pipeline and the second pipeline. One end of the fifth damping pipeline is communicated with the fourth damping pipeline, and the other end of the fifth damping pipeline is communicated with a control oil port of the second balance valve. A fifth damping hole and a sixth damping hole are provided on the fourth damping pipeline, and the fifth damping hole and the sixth damping hole are symmetrically arranged on two sides of the fifth damping pipeline. A seventh damping hole is provided on the fifth damping pipeline.

5. The hydraulic control system according to claim 4, wherein, The damping circuit further includes a sixth damping pipeline. Two ends of the sixth damping pipeline are respectively communicated with the second pipeline and a control oil port of the first balance valve. An eighth damping hole is provided on the sixth damping pipeline.

6. The hydraulic control system according to claim 1, wherein, The damping circuit further includes a seventh damping pipeline and an eighth damping pipeline. Two ends of the seventh damping pipeline are respectively communicated with the first pipeline and the second pipeline. A first end of the eighth damping pipeline is communicated with the seventh damping pipeline, a second end of the eighth damping pipeline is communicated with a control oil port of the second balance valve, and a third end of the eighth damping pipeline is communicated with a control oil port of the first balance valve. A ninth damping hole and a tenth damping hole are provided on the seventh damping pipeline, and the ninth damping hole and the tenth damping hole are symmetrically arranged on two sides of the eighth damping pipeline. An eleventh damping hole is provided on the eighth damping pipeline.

7. A control method for a hydraulic control system, characterized in that, Applied to the hydraulic control system according to any one of claims 1 to 6, a control method of the hydraulic control system includes: In a first case: Control the first proportional valve to be powered on so that a first oil port of the first proportional valve is communicated with a second oil port of the first proportional valve; Control the electromagnetic directional valve to be powered on to switch the electromagnetic directional valve to the first state, so that the hydraulic oil in the oil source sequentially passes through the first proportional valve, the electromagnetic directional valve, and the first balance valve and enters a rod cavity of the oil cylinder, so that the hydraulic oil in the oil source sequentially passes through the first proportional valve, the electromagnetic directional valve, the first pipeline, the damping circuit, the second pipeline, and the electromagnetic directional valve and flows back to the oil return tank, and the hydraulic oil in the oil source sequentially passes through the first proportional valve, the electromagnetic directional valve, the first pipeline, and the damping circuit and enters a control oil port of the second balance valve to open a valve core of the second balance valve. Wherein, when the valve core of the second balance valve is opened, the hydraulic oil can flow from a second oil port of the second balance valve to a first oil port of the second balance valve; Within a preset time when the valve core of the second balance valve is opened, control the second proportional valve to be powered on so that the hydraulic oil can flow from a second oil port of the second proportional valve to a first oil port of the second proportional valve, so that the hydraulic oil in a rodless cavity of the oil cylinder sequentially passes through the second balance valve, the second proportional valve, and the electromagnetic directional valve and flows back to the oil return tank.

8. The control method of the hydraulic control system according to claim 7, characterized in that, When the second proportional valve is energized, the opening from the second oil port to the first oil port of the second proportional valve gradually increases, so that the flow rate of the hydraulic oil passing through the second proportional valve gradually reaches a uniform state.

9. A control method for a hydraulic control system, characterized in that, Applied to the hydraulic control system according to any one of claims 1 to 6, the control method of the hydraulic control system includes: In the second case: Control the first proportional valve to be energized so that the first oil port of the first proportional valve is communicated with the second oil port of the first proportional valve; Control the electromagnetic directional valve to be energized to switch the electromagnetic directional valve to the second state, so that the hydraulic oil in the oil source sequentially passes through the first proportional valve, the electromagnetic directional valve, the second proportional valve, and the second balance valve and enters the rodless cavity of the oil cylinder, and the hydraulic oil in the oil source sequentially passes through the first proportional valve, the electromagnetic directional valve, the second pipeline, the damping circuit, the first pipeline, and the electromagnetic directional valve and returns to the oil return tank, and the hydraulic oil in the oil source sequentially passes through the first proportional valve, the electromagnetic directional valve, the second pipeline, and the damping circuit and enters the control oil port of the first balance valve to open the spool of the first balance valve. Wherein, when the spool of the first balance valve is opened, the hydraulic oil can flow from the second oil port of the first balance valve to the first oil port of the first balance valve, so that the hydraulic oil in the rod chamber of the oil cylinder sequentially passes through the first balance valve and the electromagnetic directional valve and returns to the oil return tank.

10. A boom, characterized in that, Comprising: The hydraulic control system according to any one of claims 1 to 6 above; or the control method applying the hydraulic control system according to any one of claims 7 to 8 above; or the control method applying the hydraulic control system according to claim 9 above.

Images