A boom cylinder pressure control system and method for an excavator

Abstract

A boom cylinder supercharging control system for excavators and a method of use, comprising a main pump, the oil outlet end of the main pump being connected to a pilot end, a main valve end and a supercharging valve group respectively, the pilot hydraulic oil of the pilot end being connected to both ends of the main valve, the main valve being connected to a boom cylinder, a logic control valve group being provided between the main valve and the large cavity of the boom cylinder, the logic control valve group being used to control the on-off of the oil circuit between the main valve and the large cavity of the boom cylinder, the output end of the supercharging valve group being connected together with the large cavity of the boom cylinder. The boom cylinder supercharging control system for excavators and the control method improve the lifting capacity of the boom cylinder of the excavator by providing a supercharging system in the large cavity of the boom cylinder, and at the same time, a continuous supercharging device is provided in the supercharging system, which is used in cooperation with a travel switch to realize the output of sustained high pressure, meet the work requirements, in addition, the hydraulic systems for non-large weight lifting actions and large weight lifting actions are independent of each other while being related to each other, improving the safety of the use of the whole system.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, specifically to a boom cylinder booster control system and control method for excavators. Background Technology

[0002] As customers demand higher performance from excavators, new requirements are being placed on the lifting capacity of the excavator's working device. Currently, the lifting capacity of the excavator's boom lifting cylinder is generally achieved by either increasing the size of the boom cylinder or increasing the relief pressure of the main valve in the boom linkage. However, existing technologies have certain drawbacks. Firstly, adjustments to internal parameters such as the cylinder are currently nearing their limits. Secondly, adjusting the relief valve's overflow size affects the main valve's own relief pressure. Furthermore, the development cycle for larger cylinders is long, and other operating conditions still cannot be fully met. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a convenient and effective excavator boom cylinder booster control system and control method.

[0004] This invention is achieved through the following technical solution: a boom cylinder boosting control system for an excavator, comprising a main pump, an oil tank connected to the oil inlet of the main pump, a pilot end, a main valve end, and a boosting valve group connected to the oil outlet of the main pump, pilot hydraulic oil connected to both ends of the pilot end, a boom cylinder connected to the main valve, a logic control valve group provided between the main valve and the large chamber of the boom cylinder, the logic control valve group being used to control the opening and closing of the oil circuit between the main valve and the large chamber of the boom cylinder, and the output end of the boosting valve group being connected to the large chamber of the boom cylinder; A logic control valve assembly, including a two-way logic cartridge valve and a cartridge valve control assembly, wherein the cartridge valve control assembly is used to control the on / off state of the two-way logic cartridge valve; The booster valve assembly includes a double-acting booster cylinder. The two ends of the double-acting booster cylinder are respectively provided with limit switch I and limit switch II. The two oil inlet ends of the double-acting booster cylinder are connected to an oil inlet control valve assembly, which is used to control the alternating continuous oil inlet of the two oil inlet ends of the double-acting booster cylinder. It also includes a controller and a control handle. The control handle, limit switch I, limit switch II and pilot terminal are connected to the input terminal of the controller. The output terminal of the controller is connected to the logic control valve group and the oil inlet control valve group.

[0005] Furthermore, the main valve is a three-position six-way hydraulic directional valve, and the pilot end outputs two pilot oil paths, namely pa and pb. Pa and pb are applied to the two control ends of the main valve and control the main valve to switch.

[0006] The Pa terminal is equipped with a pressure sensor, which is connected to the input terminal of the controller.

[0007] The cartridge valve control valve group includes a two-position three-way solenoid valve I and a shuttle valve. The two-position three-way solenoid valve I is located at the control end of the two-way logic cartridge valve. The shuttle valve is connected to the two-position three-way solenoid valve I and the large chamber of the boom cylinder. One end of the shuttle valve with a check valve is connected to the end of the main valve that is connected to the large chamber of the boom cylinder. The control end of the two-position three-way solenoid valve I is connected to the output end of the controller.

[0008] The cross-sectional area of ​​the oil outlet chamber of the double-acting booster cylinder is smaller than that of the oil inlet chamber.

[0009] One-way valve II and one-way valve III are respectively connected between the two oil outlet chambers of the double-acting booster cylinder and the large chamber of the boom cylinder.

[0010] The oil inlet control valve assembly includes a two-position three-way hydraulic control valve I and a two-position three-way hydraulic control valve II, respectively installed at the two oil inlet ends of the double-acting booster cylinder. The hydraulic control end of the two-position three-way hydraulic control valve I is connected to a hydraulic control check valve II and an accumulator I. The hydraulic control end of the two-position three-way hydraulic control valve II is connected to a hydraulic control check valve I and an accumulator II. The oil inlet ends of the hydraulic control check valve II and the hydraulic control check valve I are respectively connected to the main pump through a two-position three-way solenoid valve II and a two-position three-way solenoid valve III. The control port of the hydraulic control check valve II is connected to the oil inlet end of the hydraulic control check valve I, and the control port of the hydraulic control check valve I is connected to the oil inlet end of the hydraulic control check valve II. The assembly also includes a two-position two-way solenoid valve, the oil outlet end of which is connected to the control ports of the hydraulic control check valve II and the hydraulic control check valve I.

[0011] The two-position three-way solenoid valve II, the two-position three-way solenoid valve III, and the two-position two-way solenoid valve are connected to the output terminal of the controller.

[0012] A method for using a boom cylinder booster control system for an excavator, including two working states: non-heavy lifting and heavy lifting. The specific steps are as follows: When performing non-heavy lifting operations, the main pump outputs pressurized oil, one path of which goes to the pilot pressure reducing and handle control section, and the other path goes to the main valve. At this time, the two-position three-way solenoid valve is not energized, the two-way logic cartridge valve is open, and the pressurized oil enters the boom cylinder from the main valve, driving the working device to move. In this state, the large chamber of the boom cylinder is not connected to the booster valve group, and the extension and retraction of the boom cylinder are not related to the booster section. When performing heavy lifting operations, the control handle moves. When there is pressurized oil in the pressure chamber (PA), the controller detects the pressure signal and sends electrical signals to the two-position three-way solenoid valve I, two-position three-way solenoid valve II, and two-position two-way solenoid valve for reversal. After the two-position three-way solenoid valve I is energized, the two-way logic cartridge valve is closed. After the two-position three-way solenoid valve II and the two-position two-way solenoid valve are energized, the booster system starts to work. At this time, the two-position three-way hydraulic control valve I reverses under the action of the pressurized oil at the control end, and the pressurized oil reaches the double-acting booster cylinder. When the double-acting booster cylinder... After the hydraulic cylinder touches the limit switch II, the two-position three-way solenoid valve III is energized, and the two-position three-way solenoid valve II is de-energized. The two-position three-way hydraulic control valve II is switched under the action of the pressure oil at the control end. The pressure oil reaches the double-acting booster cylinder through the two-position three-way hydraulic control valve II. When the double-acting booster cylinder touches the limit switch I, the two-position three-way solenoid valve II is energized and switched. This cycle repeats until the control handle sends an end signal. When there is no pressure signal at pa, the two-position three-way solenoid valve I, the two-position three-way solenoid valve II, and the two-position two-way solenoid valve are de-energized and switched.

[0013] The two-position three-way solenoid valve III is energized or de-energized by the limit switch II trigger signal. The two-position three-way solenoid valve II is jointly controlled by the control handle pressure signal and the limit switch I trigger signal. The first start signal of the two-position three-way solenoid valve II is controlled by the control handle pressure signal. The high-pressure process is controlled by the limit switch I trigger signal. When the high-pressure mode is stopped, it is controlled by the control handle pressure signal. The control handle pressure signal has the highest priority.

[0014] The present invention has the following advantages: The excavator boom cylinder booster control system and control method of the present invention improve the lifting capacity of the excavator boom cylinder by setting a booster system in the large cavity of the boom cylinder. At the same time, a continuous booster device is set in the booster system, which is used in conjunction with the limit switch to achieve a continuous high pressure output to meet the work requirements. In addition, the hydraulic systems for non-heavy lifting actions and heavy lifting actions are independent of each other but interconnected, which improves the safety of the system. Attached Figure Description

[0015] The accompanying drawings, as part of this invention, are provided to further illustrate the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation thereof. Clearly, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0016] In the attached diagram: Figure 1 This is a hydraulic schematic diagram of the present invention.

[0017] In the diagram: 1. Main pump, 2. Hydraulic oil tank, 3. Boom cylinder, 4. Shuttle valve, 5. Two-position three-way solenoid valve I, 6. Two-way logic cartridge valve, 7. Main valve, 8. Relief valve, 9. Double-acting booster cylinder, 10. Check valve I, 11. Check valve II, 12. Check valve III, 13. Check valve IV, 14. Limit switch I, 15. Limit switch II, 16. Accumulator I, 17. Accumulator II, 18. Two-position three-way hydraulic control valve I, 19. Two-position three-way hydraulic control valve II, 20. Hydraulic control check valve I, 21. Hydraulic control check valve II, 22. Two-position three-way solenoid valve II, 23. Two-position three-way solenoid valve III, 24. Two-position two-way solenoid valve.

[0018] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0020] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] like Figure 1The diagram illustrates a boom cylinder booster control system for an excavator, comprising a main pump 1. The inlet of the main pump 1 is connected to a hydraulic oil tank 2. The outlet of the main pump 1 is connected to a pilot end, a main valve end, and a booster valve assembly. Pilot hydraulic oil from the pilot end is connected to both ends of a main valve 7. The main valve 7 is connected to a boom cylinder 3. A logic control valve assembly is provided between the main valve 7 and the large chamber of the boom cylinder 3. The logic control valve assembly controls the flow of oil between the main valve 7 and the large chamber of the boom cylinder 3. The output end of the booster valve assembly is connected to the large chamber of the boom cylinder 3. The logic control valve assembly includes a two-way logic cartridge valve 6 and a cartridge valve control... The valve assembly includes a cartridge valve control valve assembly for controlling the on / off state of the two-way logic cartridge valve 6; a booster valve assembly including a double-acting booster cylinder 9, with limit switches I14 and II15 respectively at both ends of the double-acting booster cylinder 9, and an inlet control valve assembly connected to the two inlet ends of the double-acting booster cylinder 9 for controlling the alternating continuous oil intake at the two inlet ends of the double-acting booster cylinder 9; it also includes a controller and a control handle, with the control handle, limit switches I14, II15 and the pilot end connected to the input end of the controller, and the output end of the controller connected to the logic control valve assembly and the inlet control valve assembly. The excavator boom cylinder booster control system of the present invention includes a conventional system and a booster system between the main pump and the boom cylinder. The main pump outlet is connected to three oil circuits: a pilot circuit, the conventional system, and the booster system. The pilot circuit provides control pressure oil to the main valve for controlling its operation. The conventional system includes a main valve, and a logic control valve assembly is provided between the main valve and the large chamber of the boom cylinder. The main component of the logic control valve assembly is a two-way logic cartridge valve. By controlling the oil at the control end of the two-way logic cartridge valve, the connection between the main valve and the large chamber of the boom cylinder is switched on and off. When the connection between the main valve and the large chamber of the boom cylinder is established, the conventional system drives the boom cylinder. The boom cylinder operates simultaneously with the booster system inactive. Conversely, when the main valve is disconnected from the large chamber of the boom cylinder, the boom cylinder is driven by the booster system. The booster system primarily achieves its boosting function through a double-acting booster cylinder. Each end of the double-acting booster cylinder is equipped with a limit switch, and the two inlet chambers are connected to inlet control valve assemblies. These inlet control valve assemblies, in conjunction with the limit switches, indicate that the two inlet chambers of the double-acting booster cylinder are continuously and alternately supplied with oil to meet operational requirements. Additionally, the entire system includes a control device, primarily consisting of a controller and a control handle. The controller, based on received signals, controls the actions of different valves in the system to achieve the required operation.

[0023] like Figure 1The diagram illustrates a boom cylinder booster control system for an excavator. The main valve 7 is a three-position, six-way hydraulic directional valve. The pilot end outputs two pilot oil circuits, pa and pb, which are applied to the two control terminals of the main valve 7 and control its directional switching. A pressure sensor is installed at the pa end and connected to the input terminal of the controller. The two control terminals of the main valve are connected to the pilot oil circuits pa and pb, respectively. When the pilot oil circuit pa outputs pressurized oil, the boom cylinder performs a lifting action. When the booster system is needed, the control handle is activated, and the system detects pressurized oil output from the pilot oil circuit pa. The controller makes a judgment based on the control handle and the pressure sensor at the pilot oil circuit pa, controlling the conventional system to remain inactive while simultaneously activating the booster system.

[0024] like Figure 1 The diagram illustrates a boom cylinder booster control system for an excavator. The cartridge valve control group includes a two-position three-way solenoid valve I5 and a shuttle valve 4. The two-position three-way solenoid valve I5 is located at the control end of a two-way logic cartridge valve 6. The shuttle valve 4 connects the two-position three-way solenoid valve I5 and the large chamber of the boom cylinder 3. One end of the shuttle valve 4, equipped with a check valve, is connected to the end of the main valve 7 that connects to the large chamber of the boom cylinder 3. The control end of the two-position three-way solenoid valve I is connected to the output end of the controller. In this invention, the control end of the two-way logic cartridge valve is connected to the two-position three-way solenoid valve I, and the conduction of the two-way logic cartridge valve is related to whether the two-position three-way solenoid valve I is conductive.

[0025] like Figure 1 The diagram illustrates a boom cylinder booster control system for an excavator, wherein the cross-sectional area of ​​the outlet chamber of the double-acting booster cylinder 9 is smaller than the cross-sectional area of ​​the inlet chamber. One-way valves II 11 and III 12 are respectively connected between the two outlet chambers of the double-acting booster cylinder 9 and the large chamber of the boom cylinder 3. The smaller cross-sectional area of ​​the outlet chamber of the double-acting booster cylinder compared to the inlet chamber allows for better visualization of the boosting effect.

[0026] like Figure 1The diagram illustrates a boom cylinder booster control system for an excavator. The oil inlet control valve group includes a two-position three-way hydraulic control valve I18 and a two-position three-way hydraulic control valve II19, respectively located at the two oil inlet ends of a double-acting booster cylinder 9. The hydraulic control end of the two-position three-way hydraulic control valve I18 is connected to a hydraulic control check valve II21 and an accumulator I16. The hydraulic control end of the two-position three-way hydraulic control valve II19 is connected to a hydraulic control check valve I20 and an accumulator II17. The hydraulic control check valves II21 and I20... The oil inlet of valve 0 is connected to the main pump 1 via two-position three-way solenoid valves II 22 and III 23. The control port of the hydraulic check valve II 21 is connected to the oil inlet of the hydraulic check valve I 20, and the control port of the hydraulic check valve I 20 is connected to the oil inlet of the hydraulic check valve II 21. The system also includes a two-position two-way solenoid valve 24, the oil outlet of which is connected to the control ports of the hydraulic check valves II 21 and I 20. The two-position three-way solenoid valves II 22, III 23, and 24 are connected to the output of the controller. The double-acting booster cylinder of this invention has two oil inlet ends connected to a two-position three-way hydraulic control valve I18 and a two-position three-way hydraulic control valve II19, respectively. The hydraulic control ports of both valves I18 and II19 are connected to a hydraulic control check valve and an accumulator. Hydraulic control check valve II21 has two hydraulic control ports, connected to a two-position two-way solenoid valve 24 and a two-position three-way solenoid valve III23, respectively. Hydraulic control check valve I20 has two hydraulic control ports, connected to a two-position two-way solenoid valve 24 and a two-position three-way solenoid valve II22, respectively. During non-heavy lifting operations, the two-position two-way solenoid valve 24 is de-energized and conducts, allowing pressurized oil to enter the hydraulic control ports of hydraulic control check valves II21 and I20. Hydraulic control check valves II21 and I20 do not conduct under the action of the pressurized oil. Therefore, the two-position three-way hydraulic control... Valve I18 and the two-position three-way hydraulic control valve II19 do not operate, and the double-acting booster cylinder has no high-pressure oil output. When in heavy lifting operation, the two-position two-way solenoid valve 24 is de-energized, and the pressure oil cannot enter the hydraulic control ports of hydraulic control check valve II21 and hydraulic control check valve I20 through the two-position two-way solenoid valve 24. If the two-position three-way solenoid valve II22 is switched under the action of the controller, the hydraulic control check valve II21 is energized, and the pressure oil passes through the control terminal of the two-position three-way solenoid valve II22 to the hydraulic control check valve I20, which is then de-energized. Conversely, if the two-position three-way solenoid valve III23 is energized and switched, the hydraulic control check valve I20 is energized and de-energized. The subsequent operation of the two-position three-way hydraulic control valve I18 and the two-position three-way hydraulic control valve II19 can be referred to the steps for heavy lifting operation below.

[0027] A method for using a boom cylinder booster control system for an excavator, including two working states: non-heavy lifting and heavy lifting. The specific steps are as follows: When performing non-heavy lifting operations, the main pump 1 outputs pressurized oil. One path goes to the pilot pressure reducing and handle control section, acting as the pilot oil source. That is, when the handle is operated, pa / pb can output pressurized oil. The other path goes to the main valve 7, acting as the main working oil, driving the working device to move. When the handle is operated, when pa has pressurized oil, it pushes the valve core down (as shown in the diagram). Since the two-position three-way solenoid valve 5 is not in the right position at this time, that is, the control port X of the two-way logic cartridge valve 6 is connected to the oil tank, and A1 and B1 are connected. The pressurized oil enters the boom cylinder 3 from the main valve 7. The large chamber returns oil to the main valve through the two-way logic cartridge valve, realizing the shortening of the cylinder. Due to the presence of check valves II 11 and III 12, the hydraulic oil in the large chamber of the boom cylinder 3 cannot flow into the booster section. In this state, the large chamber of the boom cylinder 3 is not connected to the booster valve group, and the extension and shortening of the boom cylinder are unrelated to the booster section.

[0028] When performing heavy lifting operations, which cannot be achieved under normal conditions, the corresponding high-pressure mode can be selected. In this mode, when the control handle is moved and there is pressurized oil in PA, the controller detects the pressure signal and sends an electrical signal to the two-position three-way solenoid valve I5, the two-position three-way solenoid valve II22, and the two-position two-way solenoid valve 24 to switch directions. Since the oil outlet of shuttle valve 4 is connected to port A2 of two-position three-way solenoid valve I5, the control oil port X of the two-way logic cartridge valve 6 is connected to pressurized oil at this time, and its ports A1 and B1 are not connected. The two-way solenoid valve 24 is connected to the control ports of hydraulic check valve I20 and hydraulic check valve II21, and it is in a reverse non-conducting state at this time.Two-position three-way solenoid valve II22 connects the main pump output oil circuit to hydraulic control check valve II21. At this time, the pressurized oil reaches the accumulator I16 and the control port of two-position three-way hydraulic control valve I18 through two-position three-way solenoid valve II22 and hydraulic control check valve II21. After the two-position three-way hydraulic control valve I18 reverses, the pressurized oil reaches the B chamber of the double-acting booster cylinder through the two-position three-way hydraulic control valve I18. Since its C chamber returns to the oil tank through two-position three-way hydraulic control valve II19, the piston rod of the double-acting booster cylinder 9 moves to the right. Due to the area difference, high-pressure oil is output from the D chamber. This high-pressure oil is delivered to the large chamber of the cylinder through check valve III12, pushing the cylinder to extend. A limit switch II15 is installed. When the piston rod reaches its maximum stroke, the limit switch II15 is triggered, outputting an electrical signal to energize the two-position three-way solenoid valve III23. This allows pressurized oil to reach the inlet of the hydraulic check valve I20 via the two-position three-way solenoid valve III23. At this time, the two-position three-way solenoid valve II22 is de-energized. Since the hydraulic control port of the hydraulic check valve II21 is connected to the outlet of the two-position three-way solenoid valve III23, the hydraulic check valve II21 can be reversed. The accumulator I16 releases pressure, and due to the spring force, the two-position three-way hydraulic control valve I18 switches to the right position, allowing pressurized oil to pass through the hydraulic check valve I20. The pressurized oil reaches the control port of accumulator II17 and two-position three-way hydraulic control valve II19, that is, the pressurized oil reaches the C chamber of the double-acting booster cylinder through the two-position three-way hydraulic control valve II19. Since its B chamber returns to the oil tank through the two-position three-way hydraulic control valve I18, the piston rod of the double-acting booster cylinder 9 moves to the left. Due to the area difference, the high-pressure oil output from the A chamber passes through the one-way valve II11 and is sent to the large chamber of the boom cylinder 3. When the piston rod of the double-acting booster cylinder 9 moves to the leftmost position, it triggers the limit switch I14, outputs an electrical signal, and controls the two-position three-way solenoid valve II22 to switch. Its working mechanism is the same as described above, that is, it continuously outputs high-pressure oil. When Pa is at this high pressure... When there is no pressure signal in the mode, the two-position three-way solenoid valves II5 and II2, and the two-position two-way solenoid valve 24 are switched to the right, right, and left positions respectively due to spring force. At this time, the hydraulic control check valves I20 and II21 are reversed, that is, the accumulators I16 and II17 release pressure. The two-position three-way hydraulic control valves I18 and II19 are switched to the right and left positions respectively due to spring force. That is, the B and C chambers of the double-acting booster cylinder 9 return to the oil tank. The state at this time is the same as that described in the case of non-heavy lifting operation. The relief valve 8 is connected to the booster output hydraulic oil and plays a safety protection role.

[0029] During heavy lifting operations, the two-position three-way solenoid valve III23 is energized or de-energized by the trigger signal of limit switch II15; the two-position three-way solenoid valve II22 is jointly controlled by the control handle pressure signal and the trigger signal of limit switch I14. The first start signal of the two-position three-way solenoid valve II22 is controlled by the control handle pressure signal, the high-pressure process is controlled by the trigger signal of limit switch I14, and the high-pressure mode is stopped by the control handle pressure signal, which has the highest priority.

[0030] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0031] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features found in other embodiments but not others, combinations of features from different embodiments are also within the scope of protection of this invention and form different embodiments. For example, in the embodiments described above, those skilled in the art can use them in combination based on known technical solutions and the technical problems to be solved by this application.

[0032] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for using a boom cylinder booster control system for an excavator, characterized in that: The control system includes a main pump (1), a main valve (7), a boom cylinder (3), a logic control valve group, a booster valve group, a controller, and a control handle; The oil outlet of the main pump (1) is connected to the pilot end, the main valve end and the booster valve group respectively; The pilot outputs pa and pb pilot oil circuit control the main valve (7) to switch, and the pa end is equipped with a pressure sensor that inputs signals to the controller; The logic control valve group is used to control the connection and disconnection of the main valve (7) and the large chamber oil circuit of the boom cylinder (3), including a two-way logic cartridge valve (6) and a two-position three-way solenoid valve I (5). The booster valve assembly includes a double-acting booster cylinder (9) with limit switches I (14) and limit switches II (15) at both ends. The output end of the double-acting booster cylinder (9) is connected to the large chamber of the boom cylinder (3), and the inlet end is connected to an inlet control valve assembly. The oil inlet control valve group includes a two-position two-way solenoid valve (24), a two-position three-way hydraulic control valve I (18), a two-position three-way hydraulic control valve II (19), a two-position three-way solenoid valve II (22), and a two-position three-way solenoid valve III (23). The two-position three-way hydraulic control valve I (18) and the two-position three-way hydraulic control valve II (19) are respectively located at the two oil inlet ends of the double-acting booster cylinder (9). The oil inlet control valve group is used to control the alternating continuous oil inlet of the two oil inlet ends of the double-acting booster cylinder (9). The control handle, limit switch I (14), limit switch II (15) and the pressure sensor at the pa end are connected to the input end of the controller, and the output end of the controller controls the valve group and the oil inlet control valve group. The usage method includes two working states: non-heavy lifting and heavy lifting. The specific steps are as follows: When performing non-heavy lifting operations, the main pump (1) outputs pressure oil, one of which goes to the pilot pressure reducing and handle control part, and the other goes to the main valve (7). At this time, the two-position three-way solenoid valve I (5) is not energized, the two-way logic cartridge valve (6) is open, and the pressure oil enters the boom cylinder (3) from the main valve (7) to drive the working device to move. In this state, the large chamber of the boom cylinder (3) is not connected to the pressure boosting valve group, and the extension and retraction of the boom cylinder are not related to the pressure boosting part. When performing a heavy lifting operation, the control handle moves. When there is pressurized oil in pa, the controller detects the pressure signal and sends an electrical signal to the two-position three-way solenoid valve I (5), the two-position three-way solenoid valve II (22), and the two-position two-way solenoid valve (24) to switch directions. After the two-position three-way solenoid valve I (5) is energized, the two-way logic cartridge valve (6) is closed. After the two-position three-way solenoid valve II (22) and the two-position two-way solenoid valve (24) are energized, the booster system starts to work. At this time, the two-position three-way hydraulic control valve I (18) switches directions under the action of the pressure oil at the control end. The pressure oil reaches the double-acting booster cylinder (9). When the double-acting booster cylinder (9) touches... After the limit switch II (15) is activated, the two-position three-way solenoid valve III (23) is energized and the two-position three-way solenoid valve II (22) is de-energized. The two-position three-way hydraulic control valve II (19) is switched under the action of the pressure oil at the control end. The pressure oil reaches the double-acting booster cylinder (9) through the two-position three-way hydraulic control valve II (19). When the double-acting booster cylinder (9) touches the limit switch I (14), the two-position three-way solenoid valve II (22) is energized and switched. This cycle repeats until the control handle gives the end signal. When there is no pressure signal at pa, the two-position three-way solenoid valve I (5), the two-position three-way solenoid valve II (22) and the two-position two-way solenoid valve (24) are de-energized and switched.

2. The method of using the boom cylinder booster control system for excavators as described in claim 1, characterized in that: The gain and loss of power of the two-position three-way solenoid valve III (23) is controlled by the trigger signal of the limit switch II (15); the two-position three-way solenoid valve II (22) is jointly controlled by the control handle pressure signal and the limit switch I (14) trigger signal. The first start signal of the two-position three-way solenoid valve II (22) is controlled by the control handle pressure signal. The high pressure process is controlled by the limit switch I (14) trigger signal. When the high pressure mode is stopped, it is controlled by the control handle pressure signal. The control handle pressure signal has the highest priority.

3. A boom cylinder booster control system for an excavator, characterized in that: A method for using a boom cylinder booster control system for an excavator as described in any one of claims 1-2, the system comprising a main pump (1), the inlet end of the main pump (1) being connected to a hydraulic oil tank (2), the outlet end of the main pump (1) being connected to a pilot end, a main valve end and a booster valve group respectively, the pilot hydraulic oil of the pilot end being connected to both ends of the main valve (7), the main valve (7) being connected to a boom cylinder (3), a logic control valve group being provided between the main valve (7) and the large cavity of the boom cylinder (3), the logic control valve group being used to control the opening and closing of the oil circuit between the main valve (7) and the large cavity of the boom cylinder (3), and the output end of the booster valve group being connected to the large cavity of the boom cylinder (3); The logic control valve group includes a two-way logic cartridge valve (6) and a cartridge valve control valve group, which is used to control the on / off state of the two-way logic cartridge valve (6). The booster valve assembly includes a double-acting booster cylinder (9), with limit switch I (14) and limit switch II (15) respectively at both ends of the double-acting booster cylinder (9). The two oil inlet ends of the double-acting booster cylinder (9) are connected to an oil inlet control valve assembly, which is used to control the two oil inlet ends of the double-acting booster cylinder (9) to alternately and continuously supply oil. It also includes a controller and a control handle, wherein the control handle, limit switch I (14), limit switch II (15) and pilot terminal are connected to the input terminal of the controller, and the output terminal of the controller is connected to the logic control valve group and the oil inlet control valve group.

4. The boom cylinder booster control system for excavators as described in claim 3, characterized in that: The main valve (7) is a three-position six-way hydraulic control directional valve. The pilot end outputs two pilot oil paths, pa and pb, respectively. Pa and pb are loaded on the two control ends of the main valve (7) and control the main valve (7) to switch.

5. The boom cylinder booster control system for excavators as described in claim 4, characterized in that: The Pa terminal is equipped with a pressure sensor, which is connected to the input terminal of the controller.

6. The boom cylinder booster control system for excavators as described in claim 3, characterized in that: The cartridge valve control valve group includes a two-position three-way solenoid valve I (5) and a shuttle valve (4). The two-position three-way solenoid valve I (5) is located at the control end of the two-way logic cartridge valve (6). The shuttle valve (4) is connected to the two-position three-way solenoid valve I (5) and the large chamber of the boom cylinder (3). One end of the shuttle valve (4) with a check valve is connected to the end of the main valve (7) that is connected to the large chamber of the boom cylinder (3). The control end of the two-position three-way solenoid valve I (5) is connected to the output end of the controller.

7. The boom cylinder booster control system for excavators as described in claim 3, characterized in that: The cross-section of the oil outlet chamber of the double-acting booster cylinder (9) is smaller than the cross-section of the oil inlet chamber.

8. The boom cylinder booster control system for excavators as described in claim 3, characterized in that: The two oil outlet chambers of the double-acting booster cylinder (9) are connected to the large chamber of the boom cylinder (3) by one-way valve II (11) and one-way valve III (12), respectively.

9. The boom cylinder booster control system for excavators as described in claim 3, characterized in that: The oil inlet control valve assembly includes a two-position three-way hydraulic control valve I (18) and a two-position three-way hydraulic control valve II (19) respectively installed at the two oil inlet ends of the double-acting booster cylinder (9). The hydraulic control end of the two-position three-way hydraulic control valve I (18) is connected to a hydraulic control check valve II (21) and an accumulator I (16). The hydraulic control end of the two-position three-way hydraulic control valve II (19) is connected to a hydraulic control check valve I (20) and an accumulator II (17). The oil inlet ends of the hydraulic control check valve II (21) and the hydraulic control check valve I (20) are respectively connected to two... Two-position three-way solenoid valve II (22) and two-position three-way solenoid valve III (23) are connected to the main pump (1). The control port of the hydraulic control check valve II (21) is connected to the oil inlet of the hydraulic control check valve I (20). The control port of the hydraulic control check valve I (20) is connected to the oil inlet of the hydraulic control check valve II (21). It also includes a two-position two-way solenoid valve (24). The oil outlet of the two-position two-way solenoid valve (24) is connected to the control ports of the hydraulic control check valve II (21) and the hydraulic control check valve I (20).

10. The boom cylinder booster control system for excavators as described in claim 9, characterized in that: The two-position three-way solenoid valve II (22), the two-position three-way solenoid valve III (23), and the two-position two-way solenoid valve (24) are connected to the output terminal of the controller.

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