CN114658777B - Control method of hydraulic system - Google Patents
Control method of hydraulic system Download PDFInfo
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- CN114658777B CN114658777B CN202210227355.9A CN202210227355A CN114658777B CN 114658777 B CN114658777 B CN 114658777B CN 202210227355 A CN202210227355 A CN 202210227355A CN 114658777 B CN114658777 B CN 114658777B
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- oil
- pressure
- valve
- accumulator
- hydraulic system
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D65/00—Parts or details
- F16D65/14—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position
- F16D65/16—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
- B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
- B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
- B66F9/075—Constructional features or details
- B66F9/07509—Braking
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
- F15B1/02—Installations or systems with accumulators
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
- F15B11/028—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the actuating force
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/21—Systems with pressure sources other than pumps, e.g. with a pyrotechnical charge
- F15B2211/212—Systems with pressure sources other than pumps, e.g. with a pyrotechnical charge the pressure sources being accumulators
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D2121/00—Type of actuator operation force
- F16D2121/02—Fluid pressure
- F16D2121/12—Fluid pressure for releasing a normally applied brake, the type of actuator being irrelevant or not provided for in groups F16D2121/04 - F16D2121/10
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Transportation (AREA)
- Structural Engineering (AREA)
- Civil Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Forklifts And Lifting Vehicles (AREA)
Abstract
The application relates to a control method of a hydraulic system, which comprises the following steps: when the liquid pump pumps pressure oil into the accumulator, the first electromagnetic valve is kept in a closed state, and when the hydraulic value of the pressure oil at the oil inlet of the accumulator is larger than or equal to a first preset pressure value, the first pressure switch can control the first electromagnetic valve to be opened so as to be communicated with the liquid pump and the oil return device. When the energy accumulator pumps pressure oil into the driving device, the first electromagnetic valve is kept in an open state, and when the hydraulic value of the pressure oil at the oil inlet of the energy accumulator is smaller than or equal to a second preset pressure value, the second pressure switch can control the first electromagnetic valve to be closed so as to isolate the liquid pump from the oil return device. The first preset pressure value is greater than the second preset pressure value. The control method of the hydraulic system solves the problem that the conventional control method of the hydraulic system causes frequent switching of the electromagnetic valve, and further influences the service life of the forklift.
Description
Technical Field
The application relates to the technical field of engineering machinery, in particular to a control method of a hydraulic system.
Background
Fork trucks are an indispensable feature of modern industrial development as industrial handling vehicles. Industrial transport vehicles are widely used in ports, stations, airports, cargo yards, factory workshops, warehouses, distribution centers and the like, and forklift trucks can enter cabins, carriages and containers to carry out loading, unloading and transporting operations of pallet cargoes, which are indispensable equipment in pallet transportation and container transportation.
Forklifts typically have a hydraulic system for releasing the brakes, in particular a hydraulic system comprising an electric motor, a liquid pump, an accumulator, a drive, an oil return, a solenoid valve and a pressure switch. The liquid pump is communicated with the oil return device through the electromagnetic valve, or the liquid pump is communicated with the energy accumulator, and the motor is electrically connected with the liquid pump so as to drive the liquid pump to pump pressure oil to the energy accumulator or to pump pressure oil to the oil return device. The pressure switch is arranged at the oil inlet of the energy accumulator and used for detecting the hydraulic value of the pressure oil at the oil inlet of the energy accumulator, and the pressure switch is electrically connected with the electromagnetic valve and used for controlling the on-off of the electromagnetic valve. The energy accumulator is connected with the driving device and is used for pumping pressure oil into the driving device.
The control method of the existing hydraulic system comprises the following steps: when the liquid pump pumps pressure oil into the accumulator, the electromagnetic valve is kept in a closed state, and when the hydraulic value of the pressure oil at the oil inlet of the accumulator is larger than or equal to a preset pressure value, the pressure switch can control the electromagnetic valve to be opened so as to communicate the liquid pump with the oil return device. When the pressure oil is pumped into the driving device by the energy accumulator, the electromagnetic valve is kept in an open state, and when the hydraulic value of the pressure oil at the oil inlet of the energy accumulator is smaller than or equal to a preset pressure value, the pressure switch can control the electromagnetic valve to be closed so as to isolate the liquid pump and the oil return device. In general, when the hydraulic value of the pressure oil at the oil inlet of the energy accumulator exceeds a preset pressure value, the pressure switch controls the electromagnetic valve to be opened, the liquid pump directly returns oil to the oil return device, the energy accumulator pumps the pressure oil into the driving device so that the driving device releases the brake of the forklift, the hydraulic value of the pressure oil at the oil inlet of the energy accumulator can be caused to drop below the preset pressure value, when the pressure switch detects that the hydraulic value of the pressure oil at the oil inlet of the energy accumulator is smaller than the preset pressure value, the pressure switch controls the electromagnetic valve to be closed, and the liquid pump pumps the pressure oil into the energy accumulator. According to the above, the hydraulic value of the pressure oil at the oil inlet of the energy accumulator frequently fluctuates around the preset pressure value, so that the electromagnetic valve is frequently opened and closed, and the service life of the forklift is further affected.
Disclosure of Invention
Based on this, it is necessary to provide a control method of a hydraulic system, which solves the problem that the conventional control method of the hydraulic system causes frequent switching of the electromagnetic valve, thereby affecting the service life of the forklift.
The application provides a control method of a hydraulic system, wherein the hydraulic system comprises a motor, a liquid pump, an energy accumulator, a driving device, an oil return device, a first electromagnetic valve, a first pressure switch and a second pressure switch. The liquid pump is communicated with the oil return device through a first electromagnetic valve, or the liquid pump is communicated with the energy accumulator, and the motor is electrically connected with the liquid pump so as to drive the liquid pump to pump pressure oil to the energy accumulator or the oil return device. The first pressure switch and the second pressure switch are respectively arranged at the oil inlet of the energy accumulator and used for detecting the hydraulic value of the pressure oil at the oil inlet of the energy accumulator, and are respectively and electrically connected with the first electromagnetic valve and used for controlling the on-off of the first electromagnetic valve. The energy accumulator is connected with the driving device and is used for pumping pressure oil into the driving device. The control method of the hydraulic system comprises the following steps: when the liquid pump pumps pressure oil into the accumulator, the first electromagnetic valve is kept in a closed state, and when the hydraulic value of the pressure oil at the oil inlet of the accumulator is larger than or equal to a first preset pressure value, the first pressure switch can control the first electromagnetic valve to be opened so as to be communicated with the liquid pump and the oil return device. When the energy accumulator pumps pressure oil into the driving device, the first electromagnetic valve is kept in an open state, and when the hydraulic value of the pressure oil at the oil inlet of the energy accumulator is smaller than or equal to a second preset pressure value, the second pressure switch can control the first electromagnetic valve to be closed so as to isolate the liquid pump from the oil return device. The first preset pressure value is greater than the second preset pressure value.
In one embodiment, the first preset pressure value is greater than or equal to 5MPa and the second preset pressure value is less than or equal to 3.3MPa.
In one embodiment, the hydraulic system further includes a third pressure switch and an indicator light, the third pressure switch is electrically connected to the indicator light, the third pressure switch is disposed at an oil inlet of the driving device, and when a hydraulic value at the oil inlet of the driving device is greater than or equal to a third preset pressure value, the third pressure switch controls the indicator light to change an indication state. It will be appreciated that such an arrangement is advantageous for accurately indicating whether the hydraulic pressure value at the oil inlet of the drive device has reached a third preset pressure value.
In one embodiment, the hydraulic system further comprises a second solenoid valve, through which the drive device can communicate with the oil return device or the accumulator. It can be appreciated that such arrangement is beneficial to facilitate the return of the oil in the pressure in the drive device.
In one embodiment, the hydraulic system further comprises a diverter valve and a hydraulic steering device, the fluid pump being in communication with the hydraulic steering device and the accumulator, respectively, via the diverter valve. It will be appreciated that such an arrangement is advantageous in reducing noise during operation of the hydraulic system.
In one embodiment, the diverter valve is a fixed flow diverter valve.
In one embodiment, the hydraulic system further comprises a relief valve, which is capable of directly communicating the diverter valve with the oil return device. It will be appreciated that such an arrangement is advantageous for improving the operational safety of the hydraulic system.
In one embodiment, the hydraulic system further comprises a control valve block, a main oil inlet channel, a first oil distribution channel, a second oil distribution channel, an oil return channel and an oil outlet channel are arranged in the control valve block, the main oil inlet channel is communicated with the first oil distribution channel and the second oil distribution channel through the distribution valve, one end of the main oil inlet channel, which is far away from the distribution valve, is connected with the liquid pump, one end of the first oil distribution channel, which is far away from the distribution valve, is connected with the hydraulic steering device, one end of the second oil distribution channel, which is far away from the distribution valve, is connected with the energy accumulator and the driving device, the oil outlet channel is connected with the oil return device and the second oil distribution channel, or the oil return channel is connected with the oil return device and the oil outlet channel. It will be appreciated that such an arrangement is advantageous for improving the integration of the overall hydraulic system.
In one embodiment, the control valve block is further provided with a first branch channel and a second branch channel which are respectively communicated with the second oil distribution channel, the first pressure switch is arranged on the first branch channel, and the second pressure switch is arranged on the second branch channel. It will be appreciated that this arrangement facilitates the installation of the first and second pressure switches.
In one embodiment, the hydraulic system further includes a check valve disposed in the second oil distribution passage to allow one-way flow of pressurized oil from the distribution valve to the accumulator.
Compared with the prior art, the control method of the hydraulic system has the advantages that when the hydraulic value of the pressure oil at the oil inlet of the energy accumulator exceeds the first preset pressure value, the pressure switch controls the first electromagnetic valve to be opened, the liquid pump directly returns oil to the oil return device, and the pressure oil is pumped into the driving device by the energy accumulator, so that the braking of the forklift is relieved by the driving device. Therefore, the pressure switch can control the electromagnetic valve to be closed until the hydraulic value of the pressure oil at the oil inlet of the energy accumulator is reduced below a second preset pressure value, and the liquid pump pumps the pressure oil into the energy accumulator. Because the first preset pressure value is larger than the second preset pressure value, a certain time is needed for the hydraulic value of the pressure oil at the oil inlet of the energy accumulator to drop from the first preset pressure value to the second preset pressure value, namely, the hydraulic value of the pressure oil at the oil inlet of the energy accumulator cannot frequently fluctuate near the same preset pressure value, the first electromagnetic valve cannot frequently switch, and further the service life of the forklift is remarkably prolonged.
Drawings
In order to more clearly illustrate the technical solutions of embodiments or conventional techniques of the present application, the drawings that are required to be used in the description of the embodiments or conventional techniques will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.
FIG. 1 is a line diagram of a hydraulic system provided herein;
fig. 2 is a schematic partial structure of the hydraulic system provided in the present application.
Reference numerals: 111. a motor; 112. a liquid pump; 120. a diverter valve; 130. an accumulator; 140. a driving device; 150. an oil return device; 161. a first electromagnetic valve; 162. a second electromagnetic valve; 171. a first pressure switch; 172. a second pressure switch; 173. a third pressure switch; 180. a hydraulic steering device; 200. an overflow valve; 300. a one-way valve; 400. and a control valve block.
Detailed Description
In the description of the present application, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," etc. indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be configured and operated in a particular orientation, and therefore should not be construed as limiting the present application.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless explicitly defined otherwise.
In this application, unless specifically stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.
In this application, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.
It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.
Fork trucks are an indispensable feature of modern industrial development as industrial handling vehicles. Industrial transport vehicles are widely used in ports, stations, airports, cargo yards, factory workshops, warehouses, distribution centers and the like, and forklift trucks can enter cabins, carriages and containers to carry out loading, unloading and transporting operations of pallet cargoes, which are indispensable equipment in pallet transportation and container transportation.
Forklifts typically have a hydraulic system for releasing the brakes, in particular a hydraulic system comprising an electric motor, a liquid pump, an accumulator, a drive, an oil return, a solenoid valve and a pressure switch. The liquid pump is communicated with the oil return device through the electromagnetic valve, or the liquid pump is communicated with the energy accumulator, and the motor is electrically connected with the liquid pump so as to drive the liquid pump to pump pressure oil to the energy accumulator or to pump pressure oil to the oil return device. The pressure switch is arranged at the oil inlet of the energy accumulator and used for detecting the hydraulic value of the pressure oil at the oil inlet of the energy accumulator, and the pressure switch is electrically connected with the electromagnetic valve and used for controlling the on-off of the electromagnetic valve. The energy accumulator is connected with the driving device and is used for pumping pressure oil into the driving device.
The control method of the existing hydraulic system comprises the following steps: when the liquid pump pumps pressure oil into the accumulator, the electromagnetic valve is kept in a closed state, and when the hydraulic value of the pressure oil at the oil inlet of the accumulator is larger than or equal to a preset pressure value, the pressure switch can control the electromagnetic valve to be opened so as to communicate the liquid pump with the oil return device. When the pressure oil is pumped into the driving device by the energy accumulator, the electromagnetic valve is kept in an open state, and when the hydraulic value of the pressure oil at the oil inlet of the energy accumulator is smaller than or equal to a preset pressure value, the pressure switch can control the electromagnetic valve to be closed so as to isolate the liquid pump and the oil return device. In general, when the hydraulic value of the pressure oil at the oil inlet of the energy accumulator exceeds a preset pressure value, the pressure switch controls the electromagnetic valve to be opened, the liquid pump directly returns oil to the oil return device, the energy accumulator pumps the pressure oil into the driving device so that the driving device releases the brake of the forklift, the hydraulic value of the pressure oil at the oil inlet of the energy accumulator can be caused to drop below the preset pressure value, when the pressure switch detects that the hydraulic value of the pressure oil at the oil inlet of the energy accumulator is smaller than the preset pressure value, the pressure switch controls the electromagnetic valve to be closed, and the liquid pump pumps the pressure oil into the energy accumulator. According to the above, the hydraulic value of the pressure oil at the oil inlet of the energy accumulator frequently fluctuates around the preset pressure value, so that the electromagnetic valve is frequently opened and closed, and the service life of the forklift is further affected.
Referring to fig. 1, in order to solve the problem that the service life of a forklift is affected due to frequent switching of an electromagnetic valve caused by the control method of the existing hydraulic system. The application provides a control method of a hydraulic system, wherein the hydraulic system comprises a motor 111, a liquid pump 112, an accumulator 130, a driving device 140, an oil return device 150, a first electromagnetic valve 161, a first pressure switch 171 and a second pressure switch 172. The liquid pump 112 is communicated with the oil return device 150 through a first electromagnetic valve 161, or the liquid pump 112 is communicated with the accumulator 130, and the motor 111 is electrically connected with the liquid pump 112 for driving the liquid pump 112 to pump pressure oil into the accumulator 130 or the oil return device 150. The first pressure switch 171 and the second pressure switch 172 are respectively arranged at the oil inlet of the accumulator 130 and used for detecting the hydraulic value of the pressure oil at the oil inlet of the accumulator 130, and the first pressure switch 171 and the second pressure switch 172 are respectively electrically connected with the first electromagnetic valve 161 and used for controlling the on-off of the first electromagnetic valve 161. The accumulator 130 is connected to the drive 140 for pumping pressurized oil into the drive 140.
The control method of the hydraulic system comprises the following steps: when the liquid pump 112 pumps pressure oil into the accumulator 130, the first electromagnetic valve 161 is kept in a closed state, and when the hydraulic value of the pressure oil at the oil inlet of the accumulator 130 is greater than or equal to a first preset pressure value, the first pressure switch 171 can control the first electromagnetic valve 161 to be opened so as to communicate the liquid pump 112 with the oil return device 150. When the accumulator 130 pumps pressure oil into the driving device 140, the first electromagnetic valve 161 is kept in an open state, and when the hydraulic value of the pressure oil at the oil inlet of the accumulator 130 is smaller than or equal to a second preset pressure value, the second pressure switch 172 can control the first electromagnetic valve 161 to be closed so as to isolate the liquid pump 112 from the oil return device 150. The first preset pressure value is greater than the second preset pressure value.
In this way, when the hydraulic pressure of the pressure oil at the oil inlet of the accumulator 130 exceeds the first preset pressure value, the pressure switch controls the first solenoid valve 161 to open, the liquid pump 112 directly returns to the oil return device 150, and the accumulator 130 pumps the pressure oil into the driving device 140, so that the driving device 140 releases the brake of the forklift. In this way, the pressure switch will not control the solenoid valve to close until the hydraulic pressure of the pressure oil at the oil inlet of the accumulator 130 drops below the second preset pressure value, and the liquid pump 112 pumps the pressure oil into the accumulator 130. Because the first preset pressure value is larger than the second preset pressure value, a certain time is required for the hydraulic value of the pressure oil at the oil inlet of the accumulator 130 to drop from the first preset pressure value to the second preset pressure value, that is, the hydraulic value of the pressure oil at the oil inlet of the accumulator 130 cannot frequently fluctuate near the same preset pressure value, and the first electromagnetic valve 161 cannot frequently switch, so that the service life of the forklift is remarkably prolonged.
It should be noted that, in the actual operation process of the forklift, the first preset pressure value is greater than or equal to 5MPa, and the second preset pressure value is less than or equal to 3.3MPa. However, the present invention is not limited thereto, and the first preset pressure value and the second preset pressure value may be other values according to actual needs, specifically, the first preset pressure value may be 5.5MPa, and the second preset pressure value may be 3MPa, which is not specifically shown herein.
In order to accurately indicate whether the hydraulic pressure value at the oil inlet of the driving device 140 reaches the third preset pressure value, it should be noted that, in an embodiment, as shown in fig. 1, the hydraulic system further includes a third pressure switch 173 and an indicator lamp (not shown), the third pressure switch 173 is electrically connected to the indicator lamp, the third pressure switch 173 is disposed at the oil inlet of the driving device 140, and when the hydraulic pressure value at the oil inlet of the driving device 140 is greater than or equal to the third preset pressure value, the third pressure switch 173 controls the indicator lamp to change the indication state. Further, the indicator light may indicate whether the hydraulic pressure value at the oil inlet of the driving device 140 reaches the third preset pressure value by means of on/off or by means of changing color.
Further, to facilitate the return of the oil in the driving device 140, in an embodiment, as shown in fig. 1, the hydraulic system further includes a second solenoid valve 162, and the driving device 140 can be connected to the oil return device 150 or the accumulator 130 through the second solenoid valve 162. It is understood that the second solenoid valve 162 is a three-way valve. Specifically, the second solenoid valve 162 corresponds to a parking brake switch, when the driving device 140 is connected to the accumulator 130, the pressure oil in the accumulator 130 pushes the spring in the driving device 140 to release the brake, and when the driving device 140 is connected to the oil return device 150, the driving device 140 maintains the parking brake state.
In general, the hydraulic steering device 180 and the parking brake device of a forklift are controlled by hydraulic systems, and existing hydraulic systems mostly adopt dual pumps, specifically, a large displacement pump is supplied to the hydraulic steering device 180, a small displacement pump is supplied to the parking brake device, when the forklift adopts a dual pump scheme, the manufacturing cost of the dual pump is high, and noise of the dual pump is high during operation. To solve the above technical problem, in one embodiment, as shown in fig. 1, the hydraulic system further includes a diverter valve 120 and a hydraulic steering device 180, and the liquid pump 112 is respectively connected to the hydraulic steering device 180 and the accumulator 130 through the diverter valve 120. That is, the hydraulic system uses the diverter valve 120 to divert pressurized oil instead of a dual pump. By providing the diverter valve 120, the simultaneous oil feed of the hydraulic steering device 180 and the accumulator 130 can be accomplished with only a single liquid pump 112, and the noise generated by the single liquid pump 112 during operation is significantly lower than that of a duplex pump.
Further, the diverter valve 120 is a fixed flow diverter valve 120. That is, the amount of pressurized oil that the fluid pump 112 distributes to the hydraulic steering device 180 and the accumulator 130, respectively, via the flow divider valve 120 is fixed. However, in other embodiments, the diverter valve 120 may be a variable flow diverter valve 120, specifically, a feedback oil path is provided in the diverter valve 120, a detection sensor is provided in the feedback oil path, and dynamic control of the diversion of the diverter valve 120 is achieved by detecting the hydraulic pressure value in the feedback oil path detected by the detection sensor.
To improve the operational safety of the hydraulic system, in one embodiment, as shown in fig. 1, the hydraulic system further includes a relief valve 200, and the relief valve 200 can directly communicate the diverter valve 120 with the oil return device 150. When the hydraulic pressure of the pressure oil from the diverter valve 120 exceeds a certain value, the pressure oil can be directly returned through the overflow valve 200, so as to avoid further rising of the hydraulic pressure of the pressure oil from the diverter valve 120.
In order to reduce the use of pipelines and improve the integration level of the whole hydraulic system, in an embodiment, as shown in fig. 1 and 2, the hydraulic system further includes a control valve block 400, and a main oil inlet channel (not shown), a first oil separating channel (not shown), a second oil separating channel (not shown), an oil return channel (not shown) and an oil outlet channel (not shown) are arranged in the control valve block 400. Specifically, the main oil inlet channel is communicated with the first oil distribution channel and the second oil distribution channel through the flow distribution valve 120, one end of the main oil inlet channel, which is far away from the flow distribution valve 120, is connected with the liquid pump 112, one end of the first oil distribution channel, which is far away from the flow distribution valve 120, is connected with the hydraulic steering device 180, one end of the second oil distribution channel, which is far away from the flow distribution valve 120, is connected with the accumulator 130, the oil outlet channel is connected with the accumulator 130 and the driving device 140, the oil return channel is connected with the oil return device 150 and the second oil distribution channel, or the oil return channel is connected with the oil return device 150 and the oil outlet channel. Further, the hydraulic system further includes a check valve 300, wherein the check valve 300 is disposed in the second oil distribution passage to enable the pressure oil to flow unidirectionally from the distribution valve 120 to the accumulator 130.
In order to facilitate the installation of the first pressure switch 171 and the second pressure switch 172, the control valve block 400 is further provided with a first branch passage (not shown) and a second branch passage (not shown) respectively communicating with the second oil distribution passage, the first pressure switch 171 is provided in the first branch passage, and the second pressure switch 172 is provided in the second branch passage.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the claims. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of the present application is to be determined by the following claims.
Claims (9)
1. A control method of a hydraulic system, characterized in that the hydraulic system comprises a motor (111), a liquid pump (112), an accumulator (130), a driving device (140), an oil return device (150), a first electromagnetic valve (161), a first pressure switch (171) and a second pressure switch (172); the liquid pump (112) is communicated with the oil return device (150) through the first electromagnetic valve (161), or the liquid pump (112) is communicated with the energy accumulator (130), and the motor (111) is electrically connected with the liquid pump (112) so as to be used for driving the liquid pump (112) to pump pressure oil to the energy accumulator (130) or to pump pressure oil to the oil return device (150); the first pressure switch (171) and the second pressure switch (172) are respectively arranged at the oil inlet of the energy accumulator (130) and used for detecting the hydraulic value of pressure oil at the oil inlet of the energy accumulator (130), and the first pressure switch (171) and the second pressure switch (172) are respectively and electrically connected with the first electromagnetic valve (161) and used for controlling the on-off of the first electromagnetic valve (161); the energy accumulator (130) is connected with the driving device (140) and is used for pumping pressure oil into the driving device (140);
the control method of the hydraulic system comprises the following steps: when the liquid pump (112) pumps pressure oil into the accumulator (130), the first electromagnetic valve (161) is kept in a closed state, and when the hydraulic value of the pressure oil at the oil inlet of the accumulator (130) is greater than or equal to a first preset pressure value, the first pressure switch (171) can control the first electromagnetic valve (161) to be opened so as to communicate the liquid pump (112) with the oil return device (150);
when the accumulator (130) pumps pressure oil into the driving device (140), the first electromagnetic valve (161) is kept in an open state, and when the hydraulic value of the pressure oil at the oil inlet of the accumulator (130) is smaller than or equal to a second preset pressure value, the second pressure switch (172) can control the first electromagnetic valve (161) to be closed so as to separate the liquid pump (112) from the oil return device (150);
the first preset pressure value is greater than the second preset pressure value;
the hydraulic system further comprises a second solenoid valve (162), and the driving device (140) can be communicated with the oil return device (150) or the energy accumulator (130) through the second solenoid valve (162).
2. The control method of a hydraulic system according to claim 1, wherein the first preset pressure value is greater than or equal to 5MPa and the second preset pressure value is less than or equal to 3.3MPa.
3. The control method of a hydraulic system according to claim 1, further comprising a third pressure switch (173) and an indicator lamp, wherein the third pressure switch (173) is electrically connected to the indicator lamp, the third pressure switch (173) is provided at an oil inlet of the driving device (140), and when a hydraulic pressure value at the oil inlet of the driving device (140) is greater than or equal to a third preset pressure value, the third pressure switch (173) controls the indicator lamp to change an indication state.
4. The control method of a hydraulic system according to claim 1, characterized in that the hydraulic system further comprises a flow dividing valve (120) and a hydraulic steering device (180), the liquid pump (112) being in communication with the hydraulic steering device (180) and the accumulator (130), respectively, through the flow dividing valve (120).
5. The method of controlling a hydraulic system according to claim 4, wherein the diverter valve (120) is a fixed flow diverter valve (120).
6. The method of controlling a hydraulic system according to claim 4, characterized in that the hydraulic system further comprises a relief valve (200), the relief valve (200) being capable of directly communicating the diverter valve (120) with the oil return device (150).
7. The control method of a hydraulic system according to claim 4, further comprising a control valve block (400), wherein a main oil inlet channel, a first oil distribution channel, a second oil distribution channel, an oil return channel and an oil outlet channel are arranged in the control valve block (400), the main oil inlet channel is communicated with the first oil distribution channel and the second oil distribution channel through the distribution valve (120), one end of the main oil inlet channel, which is far away from the distribution valve (120), is connected with the liquid pump (112), one end of the first oil distribution channel, which is far away from the distribution valve (120), is connected with the hydraulic steering device (180), one end of the second oil distribution channel, which is far away from the distribution valve (120), is connected with the accumulator (130), the oil outlet channel is connected with the accumulator (130) and the driving device (140), and the oil return channel is connected with the oil return device (150) and the second oil distribution channel, or the oil return channel is connected with the oil return device (150) and the oil outlet channel.
8. The control method of a hydraulic system according to claim 7, wherein the control valve block (400) is further provided with a first branch passage and a second branch passage that communicate with the second oil distribution passage, respectively, the first pressure switch (171) being provided to the first branch passage, and the second pressure switch (172) being provided to the second branch passage.
9. The method of controlling a hydraulic system according to claim 7, further comprising a check valve (300), the check valve (300) being provided in the second oil distribution passage to allow pressure oil to flow unidirectionally from the distribution valve (120) to the accumulator (130).
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311427740.9A CN117469323A (en) | 2022-03-08 | 2022-03-08 | Control method of hydraulic system |
| CN202210227355.9A CN114658777B (en) | 2022-03-08 | 2022-03-08 | Control method of hydraulic system |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210227355.9A CN114658777B (en) | 2022-03-08 | 2022-03-08 | Control method of hydraulic system |
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| CN202311427740.9A Division CN117469323A (en) | 2022-03-08 | 2022-03-08 | Control method of hydraulic system |
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| CN114658777A CN114658777A (en) | 2022-06-24 |
| CN114658777B true CN114658777B (en) | 2023-12-26 |
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| CN202311427740.9A Pending CN117469323A (en) | 2022-03-08 | 2022-03-08 | Control method of hydraulic system |
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| CN102632922A (en) * | 2011-12-06 | 2012-08-15 | 三一重型装备有限公司 | Dump truck for mine and steering brake control device thereof |
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| CN112696389A (en) * | 2020-12-31 | 2021-04-23 | 上海立新液压有限公司 | Cantilever balance control valve group |
| CN113389761A (en) * | 2021-07-20 | 2021-09-14 | 湖南星邦智能装备股份有限公司 | Scissor-fork type aerial work platform and floating control system thereof |
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2022
- 2022-03-08 CN CN202210227355.9A patent/CN114658777B/en active Active
- 2022-03-08 CN CN202311427740.9A patent/CN117469323A/en active Pending
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102114833A (en) * | 2009-12-31 | 2011-07-06 | 中国神华能源股份有限公司 | Hydraulic control system for brakes |
| CN102425580A (en) * | 2011-08-16 | 2012-04-25 | 中联重科股份有限公司 | Brake valve group, hydraulic system with brake valve group and concrete spreader |
| CN102632922A (en) * | 2011-12-06 | 2012-08-15 | 三一重型装备有限公司 | Dump truck for mine and steering brake control device thereof |
| CN102758813A (en) * | 2012-08-01 | 2012-10-31 | 三一重工股份有限公司 | Energy-recovery hydraulic system and engineering machinery |
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Also Published As
| Publication number | Publication date |
|---|---|
| CN117469323A (en) | 2024-01-30 |
| CN114658777A (en) | 2022-06-24 |
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