WO2023000931A1

WO2023000931A1 - Rotary hydraulic system, engineering machinery, and rotary control method

Info

Publication number: WO2023000931A1
Application number: PCT/CN2022/101810
Authority: WO
Inventors: 丁锋; 陆晓兵; 王永衡
Original assignee: 三一汽车起重机械有限公司
Priority date: 2021-07-20
Filing date: 2022-06-28
Publication date: 2023-01-26
Also published as: CN113511601A; CN113511601B

Abstract

A rotary hydraulic system, engineering machinery, and a rotary control method. The rotary hydraulic system comprises: a first pipeline used for conveying hydraulic oil; a second pipeline used for conveying hydraulic oil; a motor (5), the motor (5) being provided with a first oil port (51) and a second oil port (52), the first oil port (51) being communicated with a first end of the first pipeline, and the second oil port (52) being communicated with a first end of the second pipeline; a proportional overflow valve (3), the proportional overflow valve (3) being provided with an inlet and an outlet, the inlet of the proportional overflow valve (3) being separately communicated with the first pipeline and the second pipeline, and the outlet of the proportional overflow valve (3) being separately communicated with the first pipeline and the second pipeline; a first one-way valve (2) provided between the outlet of the proportional overflow valve (3) and the first pipeline and used for communicating the outlet of the proportional overflow valve (3) with the first pipeline; and a second one-way valve provided between the outlet of the proportional overflow valve (3) and the second pipeline and used for communicating the outlet of the proportional overflow valve (3) with the second pipeline. According to the hydraulic system, pressure overshoot in a rotation process can be avoided, and stability in the rotation process can be improved.

Description

Rotary hydraulic system, engineering machinery and rotary control method

technical field

The present application relates to the technical field of construction machinery, in particular to a rotary hydraulic system, construction machinery and a rotary control method.

Background technique

The crane is mainly composed of four moving parts: the boom telescopic mechanism, the boom luffing mechanism, the turret slewing mechanism, and the winch lifting mechanism. The turret slewing mechanism is referred to as the slewing mechanism. The main function of the slewing mechanism of the turntable is to drive the turntable and the boom to rotate based on the center line of the turntable, so as to place the hoisted objects in the required direction. The rotary mechanism of the turntable is mainly composed of a motor and a brake, and the control of the rotary speed and direction of the rotary table is realized by controlling the speed and steering of the motor.

With the development of small and medium tonnage cranes, the requirements for the stability and comfort of its slewing system are getting higher and higher. In the prior art, the control of flow and pressure is realized through the diversion of the rotary control valve, but there is a pressure overshoot during the rotary process, which leads to the problem of unstable starting and braking.

Contents of the invention

The present application provides a rotary hydraulic system, engineering machinery and a rotary control method, which are used to solve the problem in the prior art that the pressure of the rotary hydraulic system is overregulated during the rotary process, resulting in unstable starting and braking.

The present application provides a rotary hydraulic system, construction machinery and a rotary control method, including: a first pipeline for delivering hydraulic oil; a second pipeline for delivering hydraulic oil; a motor with a first oil port and the second oil port, the first oil port communicates with the first end of the first pipeline, and the second oil port communicates with the first end of the second pipeline; the proportional relief valve, the The proportional overflow valve has an inlet and an outlet, the inlet of the proportional overflow valve communicates with the first pipeline and the second pipeline respectively, and the outlet of the proportional overflow valve communicates with the first pipeline communicate with the second pipeline respectively;

The first one-way valve is arranged between the outlet of the proportional overflow valve and the first pipeline, and is used to guide the outlet of the proportional overflow valve to the flow direction of the first pipeline; the second one-way valve A directional valve is arranged between the outlet of the proportional overflow valve and the second pipeline, and is used for conducting from the outlet of the proportional overflow valve to the second pipeline.

A rotary hydraulic system provided according to the present application further includes a rotary reversing valve and a proportional pressure reducing valve, the rotary reversing valve has a first inlet, a second inlet, a third inlet and a fourth inlet, the first The second end of the pipeline communicates with the first inlet of the rotary reversing valve, the second end of the second pipeline communicates with the second inlet of the reversing reversing valve, and the first inlet of the reversing reversing valve The third inlet is used to communicate with the oil supply pipeline, and the fourth inlet of the rotary reversing valve is used to communicate with the oil return pipeline;

The rotary reversing valve has a first control end and a second control end, and the proportional decompression is respectively connected between the first control end and the pilot oil source and between the second control end and the pilot oil source. valve, and the proportional pressure reducing valve is used to push the rotary reversing valve to reversing.

According to a rotary hydraulic system provided in the present application, it further includes a first pressure measuring pipeline, the first end of the first pressure measuring pipeline communicates with the oil supply pipeline, and the first end of the first pressure measuring pipeline The second end communicates with the outlet of the proportional relief valve.

According to a rotary hydraulic system provided in the present application, the pressure measuring port further includes a second pressure measuring pipeline, one end of the second pressure measuring pipeline is connected to the first control end of the rotary reversing valve and the pilot oil The pipelines between the sources and the pipelines between the second control end of the rotary reversing valve and the pilot oil source are in communication respectively.

According to a rotary hydraulic system provided by the present application, it further includes a shuttle valve, the outlet of the shuttle valve communicates with the inlet of the proportional relief valve, the shuttle valve has two inlets, one of the inlets of the shuttle valve It communicates with the first pipeline, and the other inlet of the shuttle valve communicates with the second pipeline.

According to a rotary hydraulic system provided by the present application, it also includes a motor brake and a brake solenoid valve, the port at one end of the brake solenoid valve communicates with the motor brake through the motor brake oil port, and the brake solenoid valve The other end is provided with a first port and a second port, the first port communicates with the two proportional pressure reducing valves respectively, and the second port communicates with the pilot oil source.

According to a rotary hydraulic system provided in the present application, it further includes an oil drain line, one end of which is in communication with the two proportional pressure reducing valves respectively.

According to the rotary hydraulic system provided by the present application, it also includes a back pressure check valve, the back pressure check valve is arranged in the oil return pipeline, and is used to lead the oil return pipeline to communicate with the rotary reversing valve One end of the fourth inlet to the other end of the oil return line.

The present application also provides a construction machine, including any one of the above-mentioned rotary hydraulic systems.

The present application also provides a slewing control method based on any of the slewing hydraulic systems described above, including: during the slewing start process, the first oil port of the motor communicates with the first pipeline, and according to the actual working conditions And the corresponding load determines the first set pressure of the proportional relief valve;

During the rotation stop process, the first pipeline stops oil intake, the second oil port of the motor communicates with the second pipeline, and the second setting of the proportional relief valve is determined according to the actual working conditions and the corresponding load. and/or, make the return oil of the second oil port of the motor flow to the first pipeline through the proportional relief valve and communicate with the first oil port of the motor again.

The application provides a rotary hydraulic system, construction machinery and rotary control method. By setting a first check valve between the outlet of the proportional overflow valve and the first pipeline, the outlet of the proportional overflow valve and the second pipeline A second one-way valve is set between the pipelines. According to the pressure in the pipeline, the proportional relief valve communicates with the first pipeline or the second pipeline, and then adjusts the first pipeline or the second pipeline during the swing process of the rotary hydraulic system. The oil pressure of the road avoids pressure overshoot during the turning process, thereby improving the stability during the turning start and braking process.

Description of drawings

In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are the For some embodiments of the present invention, those of ordinary skill in the art can also obtain other drawings based on these drawings on the premise of not paying creative efforts.

Fig. 1 is a schematic structural diagram of a rotary hydraulic system provided by the present application.

Explanation of reference signs:

1. Left-turn proportional pressure reducing valve; 2. First one-way valve; 3. Proportional overflow valve; 4. Shuttle valve; 5. Motor; 51. First oil port; 52. Second oil port; 6. Second oil port 2. One-way valve; 7. Brake solenoid valve; 8. Rotary reversing valve; 9. Right-turn proportional pressure reducing valve; 10. Back pressure one-way valve; 11. Motor brake; 12. Second pressure measuring port; 13 1. Pilot oil source; 14. Oil return port; 15. Oil supply port; 16. First pressure measuring port; 17. Motor brake oil port; 18. Oil drain port.

detailed description

In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the accompanying drawings in this application. Obviously, the described embodiments are part of the embodiments of this application , but not all examples. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of this application.

A rotary hydraulic system, engineering machinery and rotary control method of the present application will be described below with reference to FIG. 1 .

First, explain the technical terms involved in this application.

Slewing brake, when the slewing control handle returns to the neutral position, although there is no flow in the system, the motor and the crane turntable will continue to rotate due to inertia. The bit will also close in time to achieve braking. In addition, in an emergency or dangerous situation, the user can manually operate the brake to close the brake in time to realize emergency braking and prevent accidents.

Slewing buffer, when the crane stops turning, due to the heavy weight of the slewing mechanism itself and the large moment of inertia, there will be a large impact when it stops, causing the whole vehicle to shake, and in severe cases, safety accidents will occur. Therefore, the hydraulic system needs Equipped with slewing buffer function, on the one hand, the movement is as smooth as possible when the slewing stops, and on the other hand, the inertial force generated in the process can be converted into the pressure release of the hydraulic system, so as to realize the stability and safety when the slewing movement stops.

Free sliding, when the crane is lifting heavy objects, because the shape and material of the heavy objects are different, it cannot be guaranteed that the center of gravity of the heavy object is directly below the hook (that is, the center of gravity of the heavy object is consistent with the center of gravity of the crane). When the partial load is generated, when the partial load force reaches a certain value, it may cause the crane to tilt, and even rollover in severe cases. For this reason, the free sliding function is designed, that is, when the crane is hoisting, the brake is opened and the oil inlet and outlet ports of the motor are connected, so that the motor is in a free floating state and can rotate freely at this time. Under the action of eccentric load, the center of gravity of the crane will automatically coincide with the center of gravity of the heavy object on the same vertical line, thereby eliminating the eccentric load and playing a role of safety protection.

This embodiment provides a rotary hydraulic system, including a first pipeline for delivering hydraulic oil; a second pipeline for delivering hydraulic oil; a motor 5 with a first oil port 51 and a second oil port 52 , the first oil port 51 communicates with the first end of the first pipeline, and the second oil port 52 communicates with the second end of the second pipeline; the proportional relief valve 3, the proportional relief valve 3 has an inlet and an outlet, and the proportional The inlet of the overflow valve 3 communicates with the first pipeline and the second pipeline respectively, and the outlet of the proportional overflow valve 3 communicates with the first pipeline and the second pipeline respectively; the first one-way valve 2 is arranged on the Between the outlet of the proportional overflow valve 3 and the first pipeline, it is used to lead the outlet of the proportional overflow valve 3 to the first pipeline; the second one-way valve 6 is arranged at the outlet of the proportional overflow valve 3 Between and the second pipeline, it is used to lead from the outlet of the proportional relief valve to the second pipeline.

At present, small and medium-sized tonnage truck cranes generally adopt an open slewing system, which is composed of a quantitative pump, a slewing control valve, a quantitative motor and a pilot handle. The control of the flow and pressure is realized through the slewing control valve splitting method, and then the slewing speed is controlled. In the prior art, two proportional overflow valves and a remote control solenoid valve can only realize the rotary stop buffering, but cannot realize the rotary dynamic buffering.

Based on this, this embodiment provides a rotary hydraulic system. Referring to FIG. 1, the rotary hydraulic system includes a first pipeline, a second pipeline and a motor 5, and the motor 5 has a first oil port 51 and a second oil port 52. One oil port 51 communicates with the first end of the first pipeline; the second oil port 52 communicates with the first end of the second pipeline; the rotary hydraulic system also includes a proportional relief valve 3, which is connected with the first The pipeline and the second pipeline are connected respectively, that is, the inlet of the proportional relief valve 3 is connected with the first pipeline and the second pipeline respectively, that is to say, the first oil port 51 is connected with the first end of the first pipeline , the proportional relief valve 3 communicates with the first oil port 51 through the first pipeline; the second oil port 52 communicates with the first end of the second pipeline, and the proportional relief valve 3 communicates with the second oil port through the second pipeline 52 communication; among them, the proportional relief valve 3 changes the pressure setting value of the proportional relief valve 3 by changing its control current, adjusts the oil pressure of the first pipeline or the second pipeline, and realizes the buffer pressure of the proportional relief valve 3 dynamic changes.

Further, the proportional overflow valve 3 has an inlet and an outlet, and the outlet of the proportional overflow valve 3 communicates with the first pipeline and is provided with a first one-way valve 2 for leading the outlet of the proportional overflow valve 3 to the first pipeline. The flow direction of the first pipeline enables the hydraulic oil to flow from the outlet of the proportional relief valve 3 to the first pipeline; the outlet of the proportional relief valve 3 communicates with the second pipeline and is provided with a second check valve 6 for By connecting the outlet of the proportional relief valve 3 to the flow direction of the second pipeline, the hydraulic oil can flow from the outlet of the proportional relief valve 3 to the second pipeline. Among them, the check valve is used to control the hydraulic oil that can only flow in one direction and stop in the opposite direction, that is, the valve that can only flow in the positive direction and not allow the reverse direction to flow.

In the embodiment provided by this application, the first one-way valve 2 is arranged between the outlet of the proportional overflow valve 3 and the first pipeline, and the second one-way valve is arranged between the outlet of the proportional overflow valve 3 and the second pipeline. According to the pressure in the pipeline, the proportional relief valve 3 communicates with the first pipeline or the second pipeline, and then adjusts the oil pressure of the first pipeline or the second pipeline during the rotation process of the rotary hydraulic system, Avoid pressure overshoot during the swing process, thereby improving the stability during the swing start and braking process.

On the basis of the above-mentioned embodiments, the rotary hydraulic system also includes a rotary reversing valve 8 and a proportional pressure reducing valve. The rotary reversing valve 8 has a first inlet, a second inlet, a third inlet and a fourth inlet. The first pipeline The second end of the second pipeline communicates with the first inlet of the rotary reversing valve 8, the second end of the second pipeline communicates with the second inlet of the reversing reversing valve 8, and the third inlet of the reversing reversing valve 8 is connected with the oil supply The pipeline is connected, and the oil supply pipeline is provided with an oil supply port 15, which is used to connect the oil supply equipment, and then connects the rotary diverter valve 8 with the oil supply equipment; the fourth inlet of the rotary diverter valve 8 is used to communicate with the oil return pipeline , the oil return line is provided with an oil return port 14, so that the hydraulic oil in the rotary reversing valve 8 can return to the fuel tank through the fourth inlet of the rotary reversing valve 8 and the oil return port 14 on the oil return line.

Specifically, the oil supply port 15 on the oil supply pipeline passes through the reversing valve 8, and the first pipeline communicates with the first oil port 51 of the motor 5, or the oil supply port 15 on the oil supply pipeline passes through the reversing valve 8 , the second pipeline communicates with the second oil port 52 of the motor 5; the first oil port 51 of the motor communicates with the oil return port 14 on the oil return pipeline through the first pipeline, the switch valve 8, or the first oil port 51 of the motor 5 The second oil port 52 communicates with the oil return port 14 on the oil return pipeline through the second pipeline, and the rotary reversing valve 8; further, the rotary reversing valve 8 has a first control end and a second control end, and the first control end A proportional pressure reducing valve is connected with the pilot oil source 13, and a proportional pressure reducing valve is also connected between the second control end and the pilot oil source 13, and the proportional pressure reducing valve is used to push the reversing reversing valve 8 to reversing.

In this embodiment, when the rotary reversing valve 8 rotates to the left, the oil supply port 15 on the oil supply pipeline passes through the rotary reversing valve, and the first pipeline communicates with the first oil port 51 of the motor 5, realizing the oil supply on the oil supply pipeline. The delivery of hydraulic oil in the pipeline between the oil supply port 15 of the motor 5 and the first oil port 51 of the motor 5; the second oil port 52 of the motor 5 passes through the second pipeline, the return valve 8 and the return pipeline The oil port 14 communicates to realize the delivery of hydraulic oil in the pipeline between the second oil port 52 of the motor 5 and the upper oil return port of the oil return pipeline. Conversely, when the rotary reversing valve 8 rotates to the right, the oil supply port 15 on the oil supply pipeline communicates with the second oil port 52 of the motor 5 through the rotary reversing valve 8, the second pipeline, and realizes the oil supply on the oil supply pipeline. Transmission of hydraulic oil in the pipeline between the oil port 15 and the second oil port 52 of the motor; the first oil port 51 of the motor 5 communicates with the oil return port 14 on the oil return line through the first pipeline and the reversing valve 8 , to realize the delivery of pipeline hydraulic oil between the first oil port 51 of the motor 5 and the oil return port 14 on the oil return line.

Specifically, the rotary reversing valve 8 is used to control the reversing, and the two control ends of the rotary reversing valve 8 respectively control the left reversing and the right reversing; the proportional pressure reducing valve is used to reduce the pressure of the hydraulic oil in the pipeline , the proportional decompression valve is divided into a left-rotation proportional decompression valve 1 and a right-rotation proportional decompression valve 9; further, a left-rotation proportional decompression valve 1 is connected between the reversing reversing valve 8 and the pilot oil source 13, and the left-rotation The proportional pressure reducing valve 1 receives the current signal input by the controller, and the hydraulic oil from the pilot oil source 13 flows to the left-turn proportional pressure reducing valve 1. After the pressure reaches a certain requirement, the left-turn proportional pressure reducing valve 1 pushes the reversing valve to 8 directions. Left reversing; between the reversing reversing valve 8 and the pilot oil source 13, there is a right-turn proportional pressure reducing valve 9, and the hydraulic oil from the pilot oil source 13 flows to the right-turning proportional pressure reducing valve 9. After the pressure reaches a certain requirement, it will turn right The proportional decompression valve 9 pushes the reversing valve 8 to switch to the right.

Among them, the pilot oil source 13 is connected to the oil pump, and the oil pressure required between the pilot oil source 13 and the reversing valve 8 is relatively small, so a proportional pressure reducing valve is added between the pilot oil source 13 and the reversing valve 8 to use In order to reduce the oil pressure between the pilot oil source 13 and the reversing valve 8, and avoid affecting the normal operation of other systems because the oil pressure is too small.

Further, when the rotary control handle returns to the neutral position, that is, the rotary reversing valve 8 returns to the neutral position, both the first pipeline and the second pipeline are blocked, and the first oil port 51 and the second oil port of the motor 5 The pressure at port 52 drops rapidly, the proportional pressure reducing valve is closed, the oil supply port 15 on the oil supply line is connected to the oil return port 14 on the oil return line, and the pressure at the control port is slowly released according to the setting to achieve the effect of rotary buffering.

In this embodiment, by using the proportional pressure reducing valve to control the reversing of the spool of the reversing valve, the proportional pressure reducing valve can buffer and slowly release the pressure at the control port according to the setting, so as to achieve the buffering effect on the rotation stop process. , can improve the stability of rotary stop.

Further, the rotary hydraulic system also includes a first pressure measuring pipeline, the first end of the first pressure measuring pipeline communicates with the oil supply pipeline, and the second end of the first pressure measuring pipeline communicates with the outlet of the proportional overflow valve 3 connected. Specifically, the first pressure measurement pipeline is provided with a first pressure measurement port 16, and the first pressure measurement port 16 is connected to an external pressure measurement device, and the pressure measurement device is used to detect the oil pressure in the pipeline; further, the first pressure measurement The first end of the pressure pipeline communicates with the oil supply pipeline for detecting the oil pressure of the oil supply pipeline; the second end of the first pressure measurement pipeline communicates with the outlet of the proportional overflow valve 3 for detecting the proportional overflow. The oil pressure at the outlet of flow valve 3 can be the oil pressure flowing to the first pipeline, or the oil pressure flowing to the second pipeline.

Further, the slewing hydraulic system provided by this embodiment also includes a second pressure measuring pipeline, the pipeline between one end of the second pressure measuring pipeline and the first control end of the rotary reversing valve 8 and the pilot oil source 13 and the return The pipelines between the second control end of the reversing valve and the pilot oil source 13 are connected respectively. Specifically, the second pressure measuring pipeline is provided with a second pressure measuring port 12, and the second pressure measuring port 12 is connected with an external pressure measuring device for detecting the oil pressure on the second pressure measuring pipeline; A left-turn proportional pressure reducing valve 1 is connected between the first control end of the valve 8 and the pilot oil source 13, and one end of the second pressure measuring pipeline is connected to the pipeline between the left-turn proportional pressure reducing valve 1 and the pilot oil source 13. Connection, between the second control end of the rotary reversing valve 8 and the pilot oil source 13, there is a right-turn proportional pressure reducing valve 9, and one end of the second pressure measuring pipeline is also connected with the right-turn proportional pressure reducing valve 9 and the pilot oil source. The pipeline connection between 13, that is, the external pressure measuring equipment connected to the second pressure measuring port 12 on the second pressure measuring pipeline can detect the oil pressure in the pipeline between the pilot oil source 13 and the left-turn proportional pressure reducing valve 1 , It is also possible to detect the oil pressure in the pipeline between the pilot oil source 13 and the right-turn proportional pressure reducing valve 9 .

In one embodiment, the first pressure measuring port 16 on the first pressure measuring pipeline communicates with the oil supply pipeline to detect the pressure of the working oil port on the oil supply pipeline, while the first pressure measuring port 16 on the oil supply pipeline Connected with the outlet of the proportional relief valve 3, it can detect the oil pressure of the first pipeline passing through the proportional relief valve 3 and entering the second pipeline, and can also detect the oil pressure of the second pipeline passing through the proportional relief valve 3 and entering the second pipeline The oil pressure of the first pipeline; further, the second pressure measuring port 12 on the second pressure measuring pipeline communicates with the left rotary proportional pressure reducing valve 1 and communicates with the right rotary proportional pressure reducing valve 9 at the same time. When reversing to the right, it is used to detect the pressure when any proportional pressure reducing valve receives the electrical signal from the controller, starts to build up pressure and pushes back the reversing valve 8 for reversing.

Based on the above embodiment, the rotary hydraulic system further includes a shuttle valve 4, the outlet of the shuttle valve 4 communicates with the inlet of the proportional relief valve 3, the shuttle valve 4 has two inlets, one of the inlets of the shuttle valve 4 is connected to the first pipe The other inlet of the shuttle valve 4 is communicated with the second pipeline.

Specifically, referring to Fig. 1, the shuttle valve 4 has two inlets, one inlet of the shuttle valve 4 is connected to the first oil port 51 of the motor 5 through a first pipeline; the other inlet of the shuttle valve 4 is connected to the motor through a second pipeline The second oil port 52 of 5; the outlet of the shuttle valve 4 communicates with the inlet of the proportional relief valve 3, and the outlet of the proportional relief valve 3 communicates with the first pipeline and the second pipeline respectively, that is, enters into the The hydraulic oil of the proportional overflow valve 3 can return to the first pipeline through the first one-way valve 2 , and can also return to the second pipeline through the second one-way valve 6 .

In this embodiment, the structure of the shuttle valve 4 is not specifically limited, and may be composed of two one-way valves.

Further, the rotary hydraulic system also includes a motor brake 11 and a brake solenoid valve 7. The port at one end of the brake solenoid valve 7 communicates with the motor brake 11 through the motor brake oil port 17. The other end of the brake solenoid valve is provided with a first port and the second port, the first port communicates with the two proportional pressure reducing valves respectively, and the second port communicates with the pilot oil source 13.

Specifically, the first port and the second port of the brake solenoid valve 7 are respectively communicated with the proportional pressure reducing valve 1 of the left rotation and the proportional pressure reducing valve 9 of the right rotation. When the valve 9 receives the electrical signal from the controller, it starts to build up pressure and pushes the reversing valve 8 to change direction, and at the same time the brake solenoid valve 7 is energized; The working oil port and the motor brake oil port 17 communicate with the motor brake 11. When the brake solenoid valve 7 receives the electric signal, the brake of the motor 5 is pressurized, and the brake is opened to facilitate the rotation of the motor 5.

Based on the above embodiment, the rotary hydraulic system further includes an oil drain pipeline, and one end of the oil drain pipeline communicates with the two proportional pressure reducing valves respectively. Specifically, an oil drain port 18 is provided on the oil drain line. When the proportional pressure reducing valve does not receive an electric signal, the brake solenoid valve 7 is not powered. The oil drain port 18 on the oil pipeline communicates, so that the hydraulic oil in the motor oil port 17 to the proportional pressure reducing valve pipeline and the hydraulic oil in the proportional pressure reducing valve can return to the fuel tank through the oil drain port 18 on the oil drain line.

Further, the outlet of the proportional relief valve 3 communicates with the oil return pipeline. In one embodiment, the hydraulic oil at the outlet of the proportional relief valve 3 flows to the first pipeline or the second pipeline through the one-way valve, or directly returns to the oil return pipeline and returns to the oil tank through the oil return port 14 on the oil return pipeline. .

Based on the above embodiment, the slewing hydraulic system also includes a back pressure check valve 10, the back pressure check valve 10 is arranged in the oil return line, and is used to lead the oil return line to connect one end of the fourth inlet of the slewing reversing valve 8 to the return line. the other end of the oil line. The back pressure check valve 10 is mainly used for conducting the pipeline to make the hydraulic oil circulate when the oil pressure is greater than the setting value of the back pressure check valve 10 . Specifically, the back pressure check valve 10 is arranged on the oil return pipeline, and the oil outlet of the back pressure check valve 10 is connected to the oil return port 14 on the oil return pipeline, and the oil inlet of the back pressure check valve 10 is connected to the proportional overflow respectively. The outlet of the flow valve 3 is connected with the first oil port 51 of the motor 5 or the second oil port 52 of the motor 5, that is, the hydraulic oil in the pipeline must pass through the back pressure check valve 10 to flow to the oil return port 14 on the oil return line Get back to the oil tank, and also can prevent the hydraulic oil in the oil tank from flowing backward through the oil return port 14 on the oil return pipeline.

In this embodiment, there is no specific limitation on the selection of the proportional relief valve 3. It can be a positive proportional relief valve, an inverse proportional relief valve, or a proportional speed regulating valve, etc. The proportional relief valve can be adjusted according to the actual situation. pressure.

This embodiment also provides a construction machine, including the rotary hydraulic system in any one of the above embodiments. Wherein, the construction machine may be a crane, and the crane includes the slewing hydraulic system in any embodiment, and also includes a boom telescopic mechanism.

This embodiment also provides a slewing control method based on any of the above slewing hydraulic systems, including: during the slewing start process, the first oil port of the motor is connected to the first pipeline, and the ratio is determined according to the actual working conditions and the corresponding load The first setting pressure of the relief valve, the proportional relief valve is used to reduce the oil pressure of the first oil port of the motor, so as to realize the smooth turning and starting process.

When turning left or turning right, the proportional pressure reducing valve receives the current signal input by the controller, starts to build pressure according to the electrical signal, and pushes the reversing valve 8 to reversing, and the hydraulic oil enters the motor through the reversing valve 8. 5. The proportional relief valve 3 is set by the controller to set the pressure setting value according to the working condition information of the hoisting load and the corresponding load.

When the slewing is started, the slewing speed will slowly increase. When the slewing speed is lower than the slewing flow rate, the pressure will rise rapidly. At this time, the pressure set by the proportional relief valve 3 will leave the excess flow to meet the speed stability. Rising requirements make the swing start smooth.

In this embodiment, during the acceleration process of turning and starting, pressure overshoot may occur. At this time, the proportional relief valve realizes starting buffering of turning action by weakening the pressure overshoot.

During the rotation stop process, the first pipeline stops oil intake, and the second setting pressure of the proportional relief valve 3 is determined according to the actual working conditions and the corresponding load, and the return pressure of the second oil port 52 of the motor is controlled by the proportional relief valve. The oil is shunted back to the second pipeline to reduce the oil pressure of the second oil port 52 of the motor 5; and/or, the return oil of the second oil port 52 of the motor 5 flows to the first pipeline through the proportional overflow valve 3 It communicates with the first oil port 51 again, increases the oil pressure of the first oil port 51, and realizes the stability in the process of turning and stopping. When operating in the opposite direction, the first oil port 51 and the second oil port 52 adjust the direction of oil inlet and oil return.

When the slewing action stops, the current of the left-slewing proportional pressure reducing valve 1 or the right-swing proportional pressure reducing valve 9 starts to drop. When the current reaches zero, the pressure of the proportional relief valve 3 is set by the controller again according to the hoisting conditions of the crane. At this time, through the pressure set by the inverse proportional relief valve, the inertia of the turntable and the structure is buffered to achieve buffering. The working principle of the inverse proportional relief valve is that the larger the current, the smaller the voltage.

In this embodiment, when the rotation stops, the reversing valve is reset, and the pressure of the oil return port will rise. By adjusting the braking pressure of the electric proportional valve, the pressure is released to realize braking buffer.

Further, the pressure of the electric proportional relief valve can be automatically adjusted according to the load and working condition information of the crane. The greater the load, the greater the set pressure of the proportional relief valve 3. In the case of small load, the pressure setting of the electric proportional relief valve will be relatively small (1-2MPa higher than the starting pressure). As the load increases, the starting pressure will be adjusted accordingly.

During the free slipping process, the first oil port 51 of the motor 5 communicates with the second oil port 52 of the motor 5, and the proportional relief valve 3 and the brake solenoid valve 7 are opened to realize free slipping. Proportional relief valve 3 and brake solenoid valve 7 act at the same time to be able to play the role of free slip. When the electric proportional relief valve 3 does not build pressure, the first oil port 51 and the second oil port 52 of the motor 5 are connected, and the brake solenoid valve 7 is energized at the same time, and the brake of the reduction gear is opened to realize the free sliding function .

In one embodiment, during the process of hoisting heavy objects, the rotary free slip control switch is pressed, the brake solenoid valve 7 is opened, and the pilot oil source 13 is connected to the motor brake 11 through the brake solenoid valve 7 and the motor oil port 17 , the motor brake 11 is turned on, the proportional relief valve 3 is energized, but the proportional relief valve 3 does not build pressure, and the first oil port 51 and the second oil port 52 are connected. Specifically, when the heavy object is unbalanced, the hydraulic oil of the pilot oil source 13 flows to the brake solenoid valve 7, and the brake solenoid valve 7 is connected to the motor brake 11 through the motor oil port 17, and the motor brake 11 is opened to realize the motor 5. Rotation; the hydraulic oil in the first oil port 51 of the motor 5 flows to the motor 5 through the second oil port 52, the shuttle valve 4 flows to the proportional relief valve 3, and then returns to the first oil port 51 through the first check valve 2 to realize the first The communication between the pipeline and the second pipeline realizes the free sliding of the rotation.

In another embodiment, when the weight is unbalanced, the hydraulic oil in the second oil port 52 of the motor 5 flows to the first oil port 51 of the motor 5, the shuttle valve 4 flows to the proportional relief valve 3, and then passes through the second check valve 6 Return to the second oil port 52 to realize the communication between the first pipeline and the second pipeline, and then realize the free sliding of rotation.

This application provides a rotary hydraulic system, engineering machinery and rotary control method, which uses an electric proportional relief valve to connect the first oil port 51 and the second oil port 52 of the motor 5 to directly control the pressure of the working port; further, use The shuttle valve 4 is connected to the two working oil ports of the motor 5, the outlet of the shuttle valve 4 is connected to the inlet of the electric proportional relief valve, and the outlet of the electric proportional relief valve is connected to the oil return of the reversing valve 8. Specifically, the shuttle valve 4 is connected to the first oil port 51 and the second oil port 52 of the motor 5, the outlet of the shuttle valve 4 is connected to the inlet of the electric proportional relief valve, and the outlet of the electric proportional relief valve is connected to the return port of the rotary reversing valve 8. Oil. This principle can adjust the pressure or control signal of the electric proportional relief valve according to different load conditions to realize the start buffer and brake buffer of the rotary action.

The rotary hydraulic system, engineering machinery and rotary control method provided in this embodiment have fewer control components and can effectively improve the problem of overshooting of the rotary starting pressure and unstable acceleration; The pressure of the proportional relief valve can be adjusted according to the actual working condition.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

A rotary hydraulic system, characterized in that it comprises:

The first pipeline is used to transport hydraulic oil;

The second pipeline is used to transport hydraulic oil;

A motor (5), the motor (5) has a first oil port (51) and a second oil port (52), the first oil port (51) communicates with the first end of the first pipeline, The second oil port (52) communicates with the first end of the second pipeline;

A proportional overflow valve (3), the proportional overflow valve (3) has an inlet and an outlet, and the inlet of the proportional overflow valve (3) communicates with the first pipeline and the second pipeline respectively, The outlet of the proportional overflow valve (3) communicates with the first pipeline and the second pipeline respectively;

The first one-way valve (2), arranged between the outlet of the proportional overflow valve (3) and the first pipeline, is used to connect the outlet of the proportional overflow valve (3) to the first pipeline;

The second one-way valve (6) is arranged between the outlet of the proportional relief valve (3) and the second pipeline, and is used to lead from the outlet of the proportional relief valve (3) to the Describe the second pipeline.
The rotary hydraulic system according to claim 1, characterized in that it further comprises a rotary reversing valve (8) and a proportional pressure reducing valve, the rotary reversing valve (8) has a first inlet, a second inlet, a third Inlet and fourth inlet, the second end of the first pipeline communicates with the first inlet of the rotary reversing valve (8), and the second end of the second pipeline communicates with the reversing reversing valve (8), the third inlet of the rotary reversing valve (8) is used to communicate with the oil supply pipeline, and the fourth inlet of the rotary reversing valve (8) is used to communicate with the oil return pipeline;

The rotary reversing valve (8) has a first control end and a second control end, between the first control end and the pilot oil source (13) and between the second control end and the pilot oil source (13) The proportional decompression valves are respectively connected between them, and the proportional decompression valves are used to push the reversing reversing valve (8) to reversing.
The rotary hydraulic system according to claim 2, further comprising a first pressure measuring pipeline, the first end of the first pressure measuring pipeline communicates with the oil supply pipeline, and the first pressure measuring pipeline The second end of the pressure pipeline communicates with the outlet of the proportional relief valve (3).
The rotary hydraulic system according to claim 3, further comprising a second pressure measuring pipeline, one end of the second pressure measuring pipeline is connected to the first control end of the rotary reversing valve (8) and The pipeline between the pilot oil source (13) and the pipeline between the second control end of the rotary reversing valve (8) and the pilot oil source (13) are respectively connected.
The rotary hydraulic system according to claim 1, further comprising a shuttle valve (4), the outlet of the shuttle valve (4) communicates with the inlet of the proportional relief valve (3), and the shuttle valve (4) There are two inlets, one of the inlets of the shuttle valve (4) communicates with the first pipeline, and the other inlet of the shuttle valve (4) communicates with the second pipeline.
The rotary hydraulic system according to claim 2, characterized in that it also includes a motor brake (11) and a brake solenoid valve (7), and the port at one end of the brake solenoid valve (7) passes through the motor brake oil port ( 17) communicate with the motor brake (11), the other end of the brake solenoid valve (7) is provided with a first port and a second port, and the first port communicates with the two proportional pressure reducing valves respectively , the second port communicates with the pilot oil source (13).
The rotary hydraulic system according to any one of claims 2 to 6, further comprising an oil drain line, one end of the oil drain line communicates with the two proportional pressure reducing valves respectively.
The rotary hydraulic system according to claim 2, characterized in that it further comprises a back pressure check valve (10), the back pressure check valve (10) is arranged in the oil return line for conducting the The oil return pipeline connects one end of the fourth inlet of the rotary reversing valve (8) to the other end of the oil return pipeline.
An engineering machine, characterized by comprising the rotary hydraulic system described in any one of claims 1 to 8 above.
A slewing control method based on the slewing hydraulic system according to any one of claims 1 to 8, characterized in that it includes:

During the turning start process, the first oil port (51) of the motor (5) communicates with the first pipeline, and the first setting of the proportional relief valve (3) is determined according to the actual working condition and the corresponding load Pressure; during the rotation stop process, the first pipeline stops oil intake, and the second oil port (52) of the motor (5) communicates with the second pipeline, which is determined according to actual working conditions and corresponding loads The second setting pressure of the proportional relief valve (3); and/or, the return oil of the second oil port (52) of the motor (5) flows to the first oil port through the proportional relief valve (3) A pipeline communicates with the first oil port (51) of the motor (5) again.