CN117246950A - Fork truck electric proportion control hydraulic system - Google Patents
Fork truck electric proportion control hydraulic system Download PDFInfo
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- CN117246950A CN117246950A CN202311471090.8A CN202311471090A CN117246950A CN 117246950 A CN117246950 A CN 117246950A CN 202311471090 A CN202311471090 A CN 202311471090A CN 117246950 A CN117246950 A CN 117246950A
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- 238000013016 damping Methods 0.000 claims description 3
- 230000005611 electricity Effects 0.000 claims 10
- 239000012530 fluid Substances 0.000 claims 2
- 230000009471 action Effects 0.000 abstract description 11
- 239000003921 oil Substances 0.000 description 262
- 239000010720 hydraulic oil Substances 0.000 description 13
- 230000001276 controlling effect Effects 0.000 description 7
- 210000003813 thumb Anatomy 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- 230000008054 signal transmission Effects 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000006978 adaptation Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 1
- 230000008676 import Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
Classifications
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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
- B66F9/07568—Steering arrangements
-
- 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
-
- 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
- B66F9/07581—Remote controls
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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
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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
- F15B2211/205—Systems with pumps
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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
- F15B2211/30—Directional control
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- Engineering & Computer Science (AREA)
- Transportation (AREA)
- Structural Engineering (AREA)
- Mechanical Engineering (AREA)
- Civil Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Engineering & Computer Science (AREA)
- Forklifts And Lifting Vehicles (AREA)
Abstract
The invention discloses an electric proportional control hydraulic system of a forklift truck, which comprises an oil tank, an oil pump, an electric proportional multi-way valve, a lifting oil cylinder, an inclined oil cylinder, an accessory oil cylinder, a hydraulic steering device and a steering oil cylinder, wherein the electric proportional multi-way valve comprises a priority valve, an oil inlet of the priority valve is connected with the oil pump, one oil outlet of the priority valve is connected with an oil supply oil way of the electric proportional multi-way valve, the other oil outlet of the priority valve is connected with an oil inlet of the hydraulic steering device, a control signal input port of the priority valve is connected with a control signal output port of the hydraulic steering device, and when the hydraulic steering device controls steering action, the action of the priority valve is controlled so as to adjust the opening degrees of the two oil outlets of the priority valve. The automatic control device has the advantages that the automatic control device can realize remote control or unmanned accurate control, and the priority valve is arranged to integrate the steering priority function, so that the oil supply for other oil cylinders is reduced during steering, sufficient pressure oil is provided for steering, the smooth steering is ensured, and the safety and reliability of the system are improved.
Description
Technical Field
The invention relates to the field of forklift control systems, in particular to a forklift electric proportional control hydraulic system.
Background
The forklift is widely applied to the technical field of multiple products, and the control system comprises a lifting oil cylinder, an inclined oil cylinder, a steering oil cylinder and the like, and the lifting and inclined actions of a portal frame and normal steering are realized by controlling the extension and retraction of the oil cylinders through hydraulic pressure.
In the prior art, a mechanical valve in a control system realizes the reversing function of a multi-way valve through a mechanical control rod, and the problems of large control force, long idle stroke, poor inching performance, large opening and closing impact of the multi-way valve and the like exist, so that remote automatic control cannot be realized. Further, the whole vehicle cannot provide sufficient pressure oil for the steering gear in the steering process, so that the steering action is not smooth.
Thus, it is a technical problem that needs to be solved by those skilled in the art to provide a forklift electric proportional control hydraulic system that can be controlled remotely and automatically and is turned preferentially.
Disclosure of Invention
The invention aims to provide an electric proportional control hydraulic system of a forklift, wherein all valves in an electric proportional multi-way valve are controlled in proportion through electric signals, so that accurate control of the hydraulic system of the forklift is realized, intelligent remote control can be realized, and sufficient pressure oil is provided for steering through setting a priority valve, and smooth steering is ensured.
In order to solve the technical problems, the invention provides an electric proportional control hydraulic system of a forklift, which comprises an oil tank, an oil pump, an electric proportional multi-way valve, a lifting oil cylinder, an inclined oil cylinder, an accessory oil cylinder, a hydraulic steering device and a steering oil cylinder, wherein the oil pump is connected with an oil inlet of the electric proportional multi-way valve, an oil return port of the electric proportional multi-way valve is connected with the oil tank, a plurality of working oil ports of the electric proportional multi-way valve are respectively connected with the lifting oil cylinder, the inclined oil cylinder, the accessory oil cylinder and the hydraulic steering device, the electric proportional multi-way valve comprises a priority valve, an oil inlet of the priority valve is connected with the oil pump, one oil outlet of the priority valve is connected with an oil supply way of the electric proportional multi-way valve, the other oil outlet of the priority valve is connected with an oil inlet of the hydraulic steering device, a control signal input port of the priority valve is connected with a control signal output port of the hydraulic steering device, and when the hydraulic steering device controls steering action, the priority valve is controlled to act so as to adjust the opening degree of the two oil outlets of the priority valve.
Preferably, a steering safety valve connected with the oil tank is arranged on the control oil path of the priority valve.
Preferably, the electric proportional multi-way valve further comprises a lifting proportional electromagnetic valve and a descending proportional electromagnetic valve, wherein the lifting proportional electromagnetic valve is respectively connected with the oil supply oil way and the rodless cavity of the lifting oil cylinder, and the descending proportional electromagnetic valve is respectively connected with the rodless cavity of the lifting oil cylinder and the oil return oil way of the electric proportional multi-way valve.
Preferably, a one-way valve is arranged at the outlet of the lifting proportional electromagnetic valve, a descending compensator is arranged at the outlet of the descending proportional electromagnetic valve, and a control port of the descending compensator is connected with the inlet of the descending proportional electromagnetic valve.
Preferably, the hydraulic oil pump further comprises an unloading valve core, a lifting shuttle valve and a main safety valve, wherein the unloading valve core is respectively connected with the oil supply oil way and the oil return oil way, a first inlet of the lifting shuttle valve is connected with an inlet of the one-way valve through a damping hole, an outlet of the lifting shuttle valve is connected with a guiding port of the unloading valve core and an inlet of the main safety valve, and an outlet of the main safety valve is connected with the oil return oil way.
Preferably, the hydraulic lifting device further comprises a manual emergency descending valve, wherein the manual emergency descending valve is respectively connected with the rodless cavity of the lifting oil cylinder and the oil return oil duct.
Preferably, the electric proportional multi-way valve further comprises an inclined electric proportional reversing valve, an inclined compensator and an inclined shuttle valve, wherein an oil inlet of the inclined electric proportional reversing valve is connected with the oil supply oil way through the inclined compensator, an oil return port of the inclined electric proportional reversing valve is connected with the oil return oil way, two working oil ports of the inclined electric proportional reversing valve are respectively connected with a rodless cavity and a rod cavity of the inclined oil cylinder, a pilot port of the inclined compensator is connected with the inclined shuttle valve and a load signal port of the inclined electric proportional reversing valve, a balance valve is arranged at one working oil port of the inclined electric proportional reversing valve, and a pilot port of the balance valve is connected with the other working oil port.
Preferably, the electric proportional multi-way valve further comprises a first accessory electric proportional reversing valve and a second accessory electric proportional reversing valve which are arranged in parallel; the oil inlet of the first accessory electric proportional reversing valve is connected with the oil supply path through a first compensator, the oil return port of the first accessory electric proportional reversing valve is connected with the oil return path, the two working oil ports of the first accessory electric proportional reversing valve are respectively connected with the two ends of the first accessory oil cylinder, and the pilot port of the first compensator is connected with a first shuttle valve and a load signal port of the first accessory electric proportional reversing valve; the oil inlet of the second accessory electric proportional reversing valve is connected with the oil supply oil way through a second compensator, the oil return port of the second accessory electric proportional reversing valve is connected with the oil return oil way, the two working oil ports of the second accessory electric proportional reversing valve are respectively connected with the two ends of the second accessory oil cylinder, and the pilot port of the second compensator is connected with the second shuttle valve and the load signal port of the second accessory electric proportional reversing valve.
Preferably, the two working oil ports of the second accessory electric proportional reversing valve are connected with the oil return path through a first overload valve and a second overload valve respectively.
Preferably, the electric proportional multi-way valve is further provided with an auxiliary oil inlet and a pressure measuring port, and the auxiliary oil inlet and the pressure measuring port are connected with the oil supply oil way.
The invention provides an electric proportional control hydraulic system of a forklift, which comprises an oil tank, an oil pump, an electric proportional multi-way valve, a lifting oil cylinder, an inclined oil cylinder, an accessory oil cylinder, a hydraulic steering device and a steering oil cylinder, wherein the oil pump is connected with an oil inlet of the electric proportional multi-way valve, an oil return port of the electric proportional multi-way valve is connected with the oil tank, a plurality of working oil ports of the electric proportional multi-way valve are respectively connected with the lifting oil cylinder, the inclined oil cylinder, the accessory oil cylinder and the hydraulic steering device, the electric proportional multi-way valve comprises a priority valve, an oil inlet of the priority valve is connected with the oil pump, one oil outlet of the priority valve is connected with an oil supply oil way of the electric proportional multi-way valve, the other oil outlet of the priority valve is connected with an oil inlet of the hydraulic steering device, a control signal input port of the priority valve is connected with a control signal output port of the hydraulic steering device, and when the hydraulic steering device controls steering action, the priority valve acts to regulate the opening of two oil outlets of the priority valve.
The valves in the electric proportional multi-way valve are controlled in proportion through electric signals, mechanical control is replaced, the operating force is small, the inching performance is good, accurate automatic control during remote control or unmanned operation can be achieved, the priority valve is arranged, the steering priority function is integrated, oil supply to other oil cylinders is reduced during steering, sufficient pressure oil is provided for steering, the steering is ensured to be smooth, and the safety and reliability of the system are improved.
Drawings
FIG. 1 is a hydraulic schematic diagram of one embodiment of a truck electric proportional control hydraulic system provided by the present invention;
fig. 2 is a hydraulic schematic diagram of an electric proportional multi-way valve in an embodiment of the electric proportional control hydraulic system of a forklift provided by the invention.
The hydraulic oil pump comprises an oil tank 1, an oil suction filter 2, an oil pump 3, an electric proportional multi-way valve 4, a speed limiting valve 5, a lifting oil cylinder 6, an inclined oil cylinder 7, a hydraulic steering device 8, a steering oil cylinder 9, a priority valve 10, a steering safety valve 11, a descending compensator 12, a descending proportional electromagnetic valve 13, an unloading valve core 14, a lifting proportional electromagnetic valve 15, a one-way valve 16, a manual emergency descending valve 17, a lifting shuttle valve 18, an inclined shuttle valve 19, an inclined compensator 20, an inclined electric proportional reversing valve 21, a balance valve 22, a first shuttle valve 23, a first compensator 24, a first accessory electric proportional reversing valve 25, a second shuttle valve 26, a second compensator 27, a second accessory electric proportional reversing valve 28, a first overload valve 29, a second overload valve 30 and a main safety valve 31.
Detailed Description
The invention has the core of providing a forklift electric proportional control hydraulic system, wherein each valve in an electric proportional multi-way valve is controlled by electric signals in proportion, so that the accurate control of the forklift hydraulic system is realized, the intelligent remote control can be realized, and the priority valve is arranged to provide sufficient pressure oil for steering, so that the steering is ensured to be smooth.
In order to better understand the aspects of the present invention, the present invention will be described in further detail with reference to the accompanying drawings and detailed description.
Referring to fig. 1 and 2, fig. 1 is a hydraulic schematic diagram of an embodiment of a forklift electric proportional control hydraulic system according to the present invention; fig. 2 is a hydraulic schematic diagram of an electric proportional multi-way valve in an embodiment of the electric proportional control hydraulic system of a forklift provided by the invention.
The specific embodiment of the invention provides a forklift electric proportional control hydraulic system, which comprises an oil tank 1, an oil pump 3, an electric proportional multi-way valve 4, a lifting oil cylinder 6, an inclined oil cylinder 7, an accessory oil cylinder, a hydraulic steering device 8 and a steering oil cylinder 9, wherein the oil pump 3 can be a plurality of pump bodies such as a gear pump and the like, an oil inlet of the oil pump 3 is connected with the oil tank 1 through an oil suction filter, and hydraulic oil in the oil tank 1 is output to the electric proportional multi-way valve 4 when the oil pump 3 works. The electric proportional multi-way valve 4 is provided with a plurality of oil ports, including oil inlet P, oil return port T, turn to working port CF, signal transmission port LS and a plurality of working oil ports, oil pump 3's delivery outlet is connected electric proportional multi-way valve 4's oil inlet P, electric proportional multi-way valve 4's oil return port T connects oil tank 1, the inside oil return oil circuit of electric proportional multi-way valve 4 connects oil return port T, make oil return oil circuit connect oil tank 1, a plurality of working oil ports of electric proportional multi-way valve 4 connect respectively and rise hydro-cylinder 6, tilt cylinder 7, accessory hydro-cylinder and hydraulic steering gear 8, wherein, rise hydro-cylinder 6 import and go out and be provided with the speed limit valve, hydraulic steering gear 8 is connected with and turns to hydro-cylinder 9.
Further, the electric proportional multi-way valve 4 includes a priority valve 10, the priority valve 10 has an oil inlet, two oil outlets and a control signal input port, the oil inlet of the priority valve 10 is connected with the oil inlet P of the electric proportional multi-way valve 4, the oil pump 3 is connected through the oil inlet P, one oil outlet of the priority valve 10 is connected with an oil supply path of the electric proportional multi-way valve 4, the other oil outlet of the priority valve 10 is connected with a steering working port CF of the electric proportional multi-way valve 4, the steering working port CF is connected with the oil inlet of the hydraulic steering device 8, the control signal input port of the priority valve 10 is connected with a signal transmission port LS of the electric proportional multi-way valve 4, the signal transmission port LS is connected with a control signal output port of the hydraulic steering device 8, and the oil outlet of the hydraulic steering device 8 is connected with the oil tank 1.
When the system only does non-steering work such as lifting, the oil outlet of the priority valve 10 connected with the oil supply oil way has the maximum opening, and the hydraulic oil output by the oil pump 3 enters the oil supply oil way through the priority valve 10 to provide enough hydraulic oil for the oil supply oil way of the electric proportional multi-way valve 4. When the steering wheel is steered, a control signal output port of the hydraulic steering device 8 transmits a pressure oil signal to a signal transmission port LS of the electric proportional multi-way valve 4 through an oil pipe, the pressure signal is fed back to a control signal input port of the priority valve 10, the priority valve 10 is reversed, the opening degrees of two oil outlets of the priority valve 10 are regulated, the oil outlet connected with a steering working port CF is increased, the opening degree of the other oil outlet is further reduced, hydraulic oil output by the oil pump 3 preferentially reaches the steering working port CF through the priority valve 10, and enters the hydraulic steering device 8, so that enough hydraulic oil is provided for the steering action of the whole vehicle, and the steering priority function is realized.
Further, a steering safety valve 11 connected with the oil tank 1 is arranged on a control oil path of the priority valve 10, an inlet of the steering safety valve 11 is connected with a control signal input port of the priority valve 10, an outlet of the steering safety valve 11 is connected with an oil return oil path, and when the pressure on the control oil path is overlarge, the pressure is relieved through the steering safety valve 11, so that the maximum steering pressure is ensured.
The valves in the electric proportional multi-way valve 4 are controlled in proportion through electric signals, mechanical control is replaced, the operating force is small, the inching performance is good, accurate automatic control during remote control or unmanned operation can be achieved, the priority valve 10 is arranged, the steering priority function is integrated, oil supply to other oil cylinders is reduced during steering, sufficient pressure oil is provided for steering, smooth steering is guaranteed, and the safety and reliability of the system are improved.
In the forklift electric proportional control hydraulic system provided by the specific embodiment of the invention, in order to realize lifting and descending functions of a portal, a lifting working oil port A is arranged on an electric proportional multi-way valve 4, the electric proportional multi-way valve 4 further comprises a lifting proportional electromagnetic valve 15 and a descending proportional electromagnetic valve 13, an inlet of the lifting proportional electromagnetic valve 15 is connected with an oil supply oil way, an outlet of the lifting proportional electromagnetic valve 15 is connected with the lifting working oil port A, the lifting working oil port A is connected with a rodless cavity of a lifting oil cylinder 6 through a speed limiting valve 5, an inlet of the descending proportional electromagnetic valve 13 is connected with the lifting working oil port A, an outlet of the descending proportional electromagnetic valve 13 is connected with an oil return oil way, and the opening of the lifting proportional electromagnetic valve 15 and the opening of the descending proportional electromagnetic valve 13 can be adjusted through electric signal proportion to control lifting of the lifting oil cylinder 6.
Further, in order to improve reliability and safety of lifting operation, a check valve 16 is disposed at an outlet of the lifting proportional solenoid valve 15, an inlet of the check valve 16 is connected to an outlet of the lifting proportional solenoid valve 15, an outlet of the check valve 16 is connected to a lifting operation oil port a, hydraulic oil is allowed to flow from the lifting proportional solenoid valve 15 to the speed limiting valve 5 by the check valve 16, the check valve 16 does not affect operation of the descending proportional solenoid valve 13, a descending compensator 12 is disposed at an outlet of the descending proportional solenoid valve 13, an inlet of the descending compensator 12 is connected to an outlet of the descending proportional solenoid valve 13, an outlet of the descending compensator 12 is connected to an oil return path, and a control port of the descending compensator 12 is connected to an inlet of the descending proportional solenoid valve 13.
When the portal is lifted, an electric signal in equal proportion to the opening of the thumb switch is output to the lifting proportional electromagnetic valve 15 through the controller, the coil b is electrified to generate corresponding electromagnetic force, the valve core of the lifting proportional electromagnetic valve 15 is driven to be opened to the corresponding valve core opening, hydraulic oil provided by an oil supply circuit is output to the lifting working oil port A through the lifting proportional electromagnetic valve 15 and the one-way valve 16 to be corresponding oil flow, and the corresponding oil flow is supplied to the portal lifting oil cylinder 6, so that a lifting function capable of controlling the lifting speed in equal proportion is realized.
When the portal descends, an electric signal in equal proportion to the opening of the thumb switch is output to the descending proportional electromagnetic valve 13 through the controller, the coil a is electrified, corresponding electromagnetic force is generated, and the valve core of the descending proportional electromagnetic valve 13 is driven to open to a corresponding valve core opening. The oil in the lifting oil cylinder 6 reaches the lifting working oil port A, flows back to the oil duct through the descending proportional electromagnetic valve 13 and the descending compensator 12 in sequence, and finally returns to the oil tank 1. When the descending speed is high, the inlet outlet pressure of the descending proportional electromagnetic valve 13 is increased, the descending proportional electromagnetic valve enters the control port of the descending compensator 12, the descending compensator 12 acts, the beginning end of the descending compensator 12 is reduced, the descending speed is reduced, and the descending function of controlling the descending speed in an equal proportion is realized under the combined action of the descending proportional electromagnetic valve 13 and the descending compensator 12.
The unloading valve further comprises an unloading valve core 14, a lifting shuttle valve 18 and a main safety valve 31, wherein an inlet and an outlet of the unloading valve core 14 are respectively connected with an oil supply way and an oil return way, a first inlet of the lifting shuttle valve 18 is connected with an inlet of a one-way valve 16 through a damping hole, namely is connected with an outlet of a lifting proportional solenoid valve 15, an outlet of the lifting shuttle valve 18 is connected with a pilot port of the unloading valve core 14 and an inlet of the main safety valve 31, the other pilot port of the unloading valve core 14 is connected with an inlet of the lifting proportional solenoid valve 15, a second inlet of the lifting shuttle valve 18 is connected with a control oil way of a subsequent valve, and an outlet of the main safety valve 31 is connected with the oil return way. When lifting, the unloading valve core 14 can detect the pressure difference between the inlet and the outlet of the lifting proportional electromagnetic valve 15, the opening of the unloading valve core 14 is adjusted according to the change of the pressure difference, unloading adjustment is realized, and further, when the pressure at the outlet of the lifting proportional electromagnetic valve 15 is overlarge, hydraulic oil reaches the main safety valve 31 through the lifting shuttle valve 18 and flows back to the oil return channel.
In order to realize manual emergency descent, a manual emergency descent valve 17 can be further arranged, the manual emergency descent valve 17 is respectively connected with a rodless cavity and an oil return oil duct of the lifting oil cylinder 6, specifically, one end of the manual emergency descent valve 17 is connected with a lifting working oil port A and the oil return oil duct, when manual emergency descent is required, the manual emergency descent valve 17 is manually opened, and hydraulic oil in the rodless cavity of the lifting oil cylinder 6 flows out through the manual emergency descent valve 17 to realize manual descent.
In the forklift electric proportional control hydraulic system provided by the specific embodiment of the invention, in order to realize the tilting function of a portal, the electric proportional multi-way valve 4 further comprises a tilting electric proportional reversing valve 21, a tilting compensator 20 and a tilting shuttle valve 19, wherein an oil inlet of the tilting electric proportional reversing valve 21 is connected with an oil supply oil path through the tilting compensator 20, an oil return port of the tilting electric proportional reversing valve 21 is connected with an oil return path, two working ports of the tilting electric proportional reversing valve 21 are respectively connected with a first tilting working port A1 and a second tilting working port B1 of the electric proportional multi-way valve 4, the first tilting working port A1 and the second tilting working port B1 are respectively connected with a rodless cavity and a rod cavity of the tilting cylinder 7, a pilot port of the tilting compensator 20 is connected with a load signal port of the tilting electric proportional reversing valve 21, a first inlet of the tilting shuttle valve 19 is connected with a pilot port of the tilting compensator 20, a second inlet of the tilting shuttle valve 19 is connected with a control oil path of a subsequent valve, an outlet of the tilting shuttle valve 19 is connected with a second inlet of the lifting shuttle valve 18, and the opening of the tilting compensator 20 is controlled during load change. A balance valve 22 is arranged at one working oil port of the inclined electric proportional reversing valve 21, and a pilot port of the balance valve 22 is connected with the other working oil port.
When the system executes the portal forward tilting function, an electric signal in equal proportion to the opening degree of a thumb switch is output to the tilting electric proportional reversing valve 21 through the controller, the coil A1 is electrified to generate corresponding electromagnetic force, the valve core of the tilting electric proportional reversing valve 21 is driven to be opened to a corresponding valve core opening, the first tilting working oil port A1 outputs corresponding oil flow and is supplied to the portal tilting oil cylinder 7, meanwhile, the pressure signal of the first tilting working oil port A1 is fed back to the balance valve 22 of the second tilting working oil port B1, so that the balance valve 22 is opened, oil in the second tilting working oil port B1 returns to the oil tank 1, and the forward tilting function capable of controlling the lifting speed in equal proportion is realized.
When the system executes the mast backward tilting function, an electric signal in equal proportion to the opening degree of a thumb switch is output to the oblique electric proportional reversing valve 21 through the controller, the coil B1 is electrified to generate corresponding electromagnetic force, the valve core of the oblique electric proportional reversing valve 21 is driven to be opened to a corresponding valve core opening, and the second oblique working oil port B1 outputs corresponding oil flow and supplies the corresponding oil flow to the mast oblique oil cylinder 7, so that the backward tilting function capable of controlling backward tilting speed in equal proportion is realized.
In the forklift electric proportional control hydraulic system provided by the embodiment of the invention, the electric proportional multi-way valve 4 further comprises a first accessory electric proportional reversing valve 25 and a second accessory electric proportional reversing valve 28 which are arranged in parallel. The oil inlet of the first electric proportional reversing valve 25 is connected with an oil supply path through a first compensator 24, the oil return port of the first electric proportional reversing valve 25 is connected with an oil return path, two working oil ports of the first electric proportional reversing valve 25 are respectively connected with a first working oil port A2 and a second working oil port B2 of the electric proportional multi-way valve 4, the first working oil port A2 and the second working oil port B2 of the first electric proportional reversing valve are respectively connected with two ends of a first electric cylinder, the pilot port of the first compensator 24 is connected with a load signal port of the first electric proportional reversing valve 25, the first inlet of the first shuttle valve 23 is connected with a pilot port of the first compensator 24, the second inlet of the first shuttle valve 23 is connected with a control path of a subsequent valve, the outlet of the first shuttle valve 23 is connected with a second inlet of the inclined shuttle valve 19, and the opening of the first compensator 24 is controlled when the load changes, so that the hydraulic oil flow is controlled.
When the system executes the accessory function, an electric signal in equal proportion to the opening of the thumb switch is output to the first accessory electric proportional reversing valve 25 through the controller, the coil A2 or the coil B2 is electrified to generate corresponding electromagnetic force, the valve core of the first accessory electric proportional reversing valve 25 is driven to open to a corresponding valve core opening, and the first accessory working oil port A2 and the second accessory working oil port B2 output corresponding oil flow and are supplied to the accessory oil cylinders corresponding to the door frames, so that the action function of controlling the speed of the accessory in equal proportion is realized.
Similarly, the oil inlet of the second electric proportional reversing valve 28 is connected with an oil supply oil path through the second compensator 27, the oil return port of the second electric proportional reversing valve 28 is connected with an oil return path, the two working oil ports of the second electric proportional reversing valve 28 are respectively connected with the third and fourth working oil ports A3 and B3 of the electric proportional multi-way valve 4, the third and fourth working oil ports A3 and B3 of the second electric proportional reversing valve are respectively connected with two ends of a second electric proportional cylinder, the pilot port of the second compensator 27 is connected with the load signal port of the second electric proportional reversing valve 28, the first inlet of the second shuttle valve 26 is connected with the pilot port of the second compensator 27, the second inlet of the second shuttle valve 26 is connected with the control oil path or the oil return path of the subsequent valve, the outlet of the second shuttle valve 26 is connected with the second inlet of the first shuttle valve 23, the opening of the second compensator 27 is controlled during load change, and the hydraulic oil flow is controlled.
When the system executes the accessory function, an electric signal in equal proportion to the opening of the thumb switch is output to the second accessory electric proportional reversing valve 28 through the controller, the coil A3 or the coil B3 is electrified to generate corresponding electromagnetic force, the valve core of the second accessory electric proportional reversing valve 28 is driven to open to the corresponding valve core opening, the third accessory working oil port A3 and the fourth accessory working oil port B3 output corresponding oil flow, and the corresponding oil flow is supplied to the accessory oil cylinder corresponding to the door frame, so that the action function of controlling the speed of the accessory in equal proportion is realized.
Further, two working oil ports of the second attachment electric proportional reversing valve 28 are connected with an oil return path through a first overload valve 29 and a second overload valve 30 respectively.
In the specific embodiment, only two accessory oil cylinders are controlled, the number of the accessory oil cylinders can be increased according to the actual use requirement, and corresponding accessory electric proportional reversing valves are configured, so that the structure and the connection mode are similar, and the method is within the protection scope of the invention.
On the basis of the forklift electric proportional control hydraulic system provided by the specific embodiments, the electric proportional multi-way valve 4 is further provided with an auxiliary oil inlet P1 and a pressure measuring port M, the auxiliary oil inlet P1 is connected with an oil supply oil way, a double-pump confluence function of the system can be achieved, and the pressure measuring port M is connected with the oil supply oil way to measure pressure of a working device. The electric proportional multi-way valve 4 integrates a steering priority function, a proportional adjustment function corresponding to the action of a forklift mast, a load sensitive function, a pressure compensation function, a forward tilting self-locking function and a manual emergency descent function. The descending and lifting functions adopt independent oil ways to realize better inching performance, meanwhile, the noise vibration problem caused by a public oil way can be avoided, and the load sensitive technology is adopted, so that the system efficiency is improved, the loss is reduced, and the system is more energy-saving compared with the traditional hydraulic system.
The forklift electric proportional control hydraulic system provided by the invention is described in detail above. The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to facilitate an understanding of the method of the present invention and its core ideas. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the invention can be made without departing from the principles of the invention and these modifications and adaptations are intended to be within the scope of the invention as defined in the following claims.
Claims (10)
1. The utility model provides a fork truck electricity proportional control hydraulic system, includes oil tank (1), oil pump (3), electricity proportional multi-way valve (4), plays to rise hydro-cylinder (6), slope hydro-cylinder (7), accessory hydro-cylinder, hydraulic pressure steering (8) and steering cylinder (9), oil pump (3) are connected the oil inlet of electricity proportional multi-way valve (4), the oil return opening of electricity proportional multi-way valve (4) is connected oil tank (1), a plurality of work hydraulic fluid ports of electricity proportional multi-way valve (4) are connected respectively play hydro-cylinder (6) slope hydro-cylinder (7) accessory hydro-cylinder with hydraulic pressure steering (8), its characterized in that, the oil inlet of priority valve (10) is connected oil pump (3), one oil-out of priority valve (10) is connected the oil circuit of electricity proportional multi-way valve (4), another oil-out of priority valve (10) is connected the oil inlet of hydraulic pressure steering (8), the control signal input port of priority valve (10) is connected when controlling output port (8) turns to hydraulic pressure steering (10), the hydraulic pressure steering valve (10) are moved with priority.
2. The forklift electric proportional control hydraulic system according to claim 1, characterized in that the control oil circuit of the priority valve (10) is provided with a steering relief valve (11) connected to the oil tank (1).
3. The forklift electric proportional control hydraulic system according to claim 1, wherein the electric proportional multi-way valve (4) further comprises a lifting proportional electromagnetic valve (15) and a descending proportional electromagnetic valve (13), the lifting proportional electromagnetic valve (15) is respectively connected with the oil supply oil way and the rodless cavity of the lifting oil cylinder (6), and the descending proportional electromagnetic valve (13) is respectively connected with the rodless cavity of the lifting oil cylinder (6) and the oil return oil way of the electric proportional multi-way valve (4).
4. A forklift electric proportional control hydraulic system according to claim 3, characterized in that a one-way valve (16) is arranged at the outlet of the lifting proportional solenoid valve (15), a descending compensator (12) is arranged at the outlet of the descending proportional solenoid valve (13), and a control port of the descending compensator (12) is connected with the inlet of the descending proportional solenoid valve (13).
5. The forklift electric proportional control hydraulic system according to claim 4, further comprising an unloading valve core (14), a lifting shuttle valve (18) and a main safety valve (31), wherein the unloading valve core (14) is respectively connected with the oil supply path and the oil return path, a first inlet of the lifting shuttle valve (18) is connected with an inlet of the one-way valve (16) through a damping hole, an outlet of the lifting shuttle valve (18) is connected with a guiding port of the unloading valve core (14) and an inlet of the main safety valve (31), and an outlet of the main safety valve (31) is connected with the oil return path.
6. The forklift electric proportional control hydraulic system according to claim 5, further comprising a manual emergency lowering valve (17), wherein the manual emergency lowering valve (17) is respectively connected with the rodless cavity of the lifting cylinder (6) and the return oil duct.
7. The forklift electric proportional control hydraulic system according to claim 6, wherein the electric proportional multi-way valve (4) further comprises an inclined electric proportional reversing valve (21), an inclined compensator (20) and an inclined shuttle valve (19), an oil inlet of the inclined electric proportional reversing valve (21) is connected with the oil supply oil path through the inclined compensator (20), an oil return port of the inclined electric proportional reversing valve (21) is connected with the oil return oil path, two working oil ports of the inclined electric proportional reversing valve (21) are respectively connected with a rodless cavity and a rod-containing cavity of the inclined oil cylinder (7), a pilot port of the inclined compensator (20) is connected with load signal ports of the inclined shuttle valve (19) and the inclined electric proportional reversing valve (21), a balance valve (22) is arranged at one working oil port of the inclined electric proportional reversing valve (21), and a pilot port of the balance valve (22) is connected with the other working oil port.
8. The forklift electric proportional control hydraulic system according to claim 7, wherein the electric proportional multi-way valve (4) further comprises a first and a second accessory electric proportional reversing valve (25, 28) arranged in parallel; the oil inlet of the first accessory electric proportional reversing valve (25) is connected with the oil supply path through a first compensator (24), the oil return port of the first accessory electric proportional reversing valve (25) is connected with the oil return path, two working oil ports of the first accessory electric proportional reversing valve (25) are respectively connected with two ends of the first accessory oil cylinder, and a pilot port of the first compensator (24) is connected with a first shuttle valve (23) and a load signal port of the first accessory electric proportional reversing valve (25); the oil inlet of second accessory electricity proportion switching-over valve (28) is passed through second compensator (27) and is connected the oil feed oil circuit, the oil return mouth of second accessory electricity proportion switching-over valve (28) is connected the oil return oil circuit, two work hydraulic fluid ports of second accessory electricity proportion switching-over valve (28) are connected respectively the both ends of second accessory hydro-cylinder, the leading mouth of second compensator (27) connect second shuttle valve (26) with the load signal mouth of second accessory electricity proportion switching-over valve (28).
9. The forklift electric proportional control hydraulic system according to claim 8, wherein two working oil ports of the second attachment electric proportional reversing valve (28) are connected with the return oil path through a first overload valve (29) and a second overload valve (30), respectively.
10. The forklift electric proportional control hydraulic system according to any one of claims 1 to 9, characterized in that the electric proportional multi-way valve (4) is further provided with an auxiliary oil inlet and a pressure measuring port, which are connected to the oil supply circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311471090.8A CN117246950A (en) | 2023-11-07 | 2023-11-07 | Fork truck electric proportion control hydraulic system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311471090.8A CN117246950A (en) | 2023-11-07 | 2023-11-07 | Fork truck electric proportion control hydraulic system |
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| Publication Number | Publication Date |
|---|---|
| CN117246950A true CN117246950A (en) | 2023-12-19 |
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ID=89129697
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311471090.8A Pending CN117246950A (en) | 2023-11-07 | 2023-11-07 | Fork truck electric proportion control hydraulic system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117246950A (en) |
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2023
- 2023-11-07 CN CN202311471090.8A patent/CN117246950A/en active Pending
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