CN108317112B - Fork truck duplex pump turns to parking braking and releases hydraulic system - Google Patents
Fork truck duplex pump turns to parking braking and releases hydraulic system Download PDFInfo
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- CN108317112B CN108317112B CN201810236847.8A CN201810236847A CN108317112B CN 108317112 B CN108317112 B CN 108317112B CN 201810236847 A CN201810236847 A CN 201810236847A CN 108317112 B CN108317112 B CN 108317112B
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- pump
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Classifications
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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
- F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
- F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more pumps
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
- B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
- B60T13/66—Electrical control in fluid-pressure brake systems
- B60T13/68—Electrical control in fluid-pressure brake systems by electrically-controlled valves
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D5/00—Power-assisted or power-driven steering
- B62D5/06—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle
- B62D5/062—Details, component parts
- B62D5/064—Pump driven independently from vehicle engine, e.g. electric driven pump
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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
- B66F9/20—Means for actuating or controlling masts, platforms, or forks
- B66F9/22—Hydraulic devices or systems
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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
-
- 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
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
- F15B13/06—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with two or more servomotors
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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
- F15B2211/80—Other types of control related to particular problems or conditions
- F15B2211/88—Control measures for saving energy
Abstract
The invention relates to a forklift duplex pump steering parking brake release hydraulic system. The hydraulic oil pump comprises a duplex pump formed by connecting a steering gear pump and a braking gear pump in series, wherein an oil outlet of the braking gear pump is connected with an oil inlet of a first two-position three-way electromagnetic reversing valve, a first working oil port of the first two-position three-way electromagnetic reversing valve is connected with an oil inlet of a first one-way valve, a second working oil port of the first two-position three-way electromagnetic reversing valve is respectively connected with an oil inlet of a braking overflow valve and an oil inlet of a second one-way valve, an oil outlet of the second one-way valve is respectively connected with an energy accumulator, a low-pressure switch and an oil inlet of the second two-position three-way electromagnetic reversing valve, a working oil port of the second two-position three-way electromagnetic reversing valve is respectively connected with a high-pressure alarm switch and a braking release oil cylinder, and an oil return port of the second two-position three-way electromagnetic reversing valve is connected with a hydraulic oil tank. The invention not only can ensure the continuous and reliable operation of the steering system, but also can ensure the realization of brake release.
Description
Technical Field
The invention relates to a forklift duplex pump steering parking brake release hydraulic system.
Background
Because the negative brake can realize the advantage of automatic braking when the vehicle parks, the application on fork truck is more and more wide at present, and for adopting the negative brake to carry out the vehicle parking braking system and just need carry out the negative brake release when driving, the release pressure working range that the negative brake released needs is narrower, and required flow is less, so generally adopt independent gear pump oil feed to carry out the parking negative brake release, and adopt independent motor and controller to control the parking brake and release, and the flow that fork truck's steering hydraulic system used equally is little, low-pressure independent hydraulic system also uses independent gear pump independent motor and controller to control, and steering system is in order to guarantee response and the reliability of turning to, need fork truck start back steering pump keep certain rotational speed, two sets of independent hydraulic systems cause the cost higher, spare part arrangement difficulty, and the energy consumption is also great, its principle block diagram is as shown in figure 3.
Disclosure of Invention
The invention aims to provide a forklift duplex pump steering parking brake release hydraulic system which is an integrated hydraulic system with forklift negative brake and steering functions, solves the problems of high cost, difficult arrangement of parts and the like caused by the fact that the existing forklift steering and braking are two independent hydraulic systems, and has the advantage of low energy consumption.
In order to achieve the above purpose, the present invention adopts the following technical scheme: the hydraulic pump comprises a duplex pump formed by serially connecting a steering gear pump and a braking gear pump, wherein an oil suction port of the duplex pump is connected with a hydraulic oil tank, and the duplex pump is driven by a motor to work; an oil outlet of the steering gear pump is respectively connected with an oil inlet of the steering overflow valve, an oil inlet of the hydraulic steering device and an oil outlet of the first one-way valve, the oil outlet of the steering overflow valve and an oil return port of the hydraulic steering device are respectively connected with a hydraulic oil tank, and a working oil port of the hydraulic steering device is connected with the steering oil cylinder; an oil outlet of the brake gear pump is connected with an oil inlet of a first two-position three-way electromagnetic directional valve, a first working oil port of the first two-position three-way electromagnetic directional valve is connected with an oil inlet of a first one-way valve, a second working oil port of the first two-position three-way electromagnetic directional valve is respectively connected with an oil inlet of a brake overflow valve and an oil inlet of a second one-way valve, an oil outlet of the second one-way valve is respectively connected with an accumulator, a low-voltage switch and an oil inlet of a second two-position three-way electromagnetic directional valve, and a working oil port of the second two-position three-way electromagnetic directional valve is respectively connected with a high-voltage alarm switch and a brake release oil cylinder;
the second working oil port of the second two-position three-way electromagnetic reversing valve is connected with the oil inlet of the brake overflow valve and the oil inlet of the second one-way valve through a first tee joint, the oil outlet of the second one-way valve is connected with the energy accumulator, the low-voltage switch and the oil inlet of the second two-position three-way electromagnetic reversing valve through a four-way joint, the working oil port of the second two-position three-way electromagnetic reversing valve is connected with the high-voltage alarm switch and the brake release oil cylinder through a second tee joint, and the oil return port of the second two-position three-way electromagnetic reversing valve is connected with the oil return port of the brake overflow valve and the hydraulic oil tank through a third tee joint;
a fourth tee joint is arranged between the oil outlet of the steering gear pump and the oil inlet of the steering overflow valve, the other port of the fourth tee joint is connected with a fifth tee joint, the other two ports of the fifth tee joint are respectively connected with the oil inlet of the hydraulic steering gear and the oil outlet of the first one-way valve, and the oil return port of the hydraulic steering gear is connected with the oil outlet of the steering overflow valve and the hydraulic oil tank through a sixth tee joint;
the motor is connected with the steering brake electrical control system, and the steering gear pump and the brake gear pump are respectively connected with the steering brake hydraulic system.
The braking gear pump adopts a small-displacement gear pump with the displacement of 1-3 ml/r.
The low-voltage switch is a normally open pressure switch, and the pressure set value of the low-voltage switch is 0.5MPa higher than the lowest release pressure of the brake release oil cylinder.
The high-pressure alarm switch is a normally closed pressure switch, and the pressure set value of the high-pressure alarm switch is 0.5MPa higher than the highest release pressure of the brake release oil cylinder.
And the overflow pressure of the steering overflow valve is 2 MPa higher than the highest working pressure of the steering oil cylinder.
The overflow pressure of the brake overflow valve is equal to the highest working pressure of the brake release cylinder.
According to the technical scheme, the double pump is controlled to timely switch oil supply through the two-position three-way electromagnetic reversing valve, so that continuous and reliable operation of the steering system can be ensured, and brake release is realized; the sum of the displacements of the duplex pumps adopted is equal to the single pump displacement used by the original independent steering hydraulic system, so that the displacement of the original independent braking hydraulic system pump is reduced, the flow of the whole hydraulic system is reduced, the total power of a loading motor is reduced, and the energy conservation of the hydraulic system is realized; the steering function and the braking function are provided with independent safety overflow, so that the steering and braking safety and reliability are ensured.
Drawings
FIG. 1 is a schematic diagram of the structure of the present invention;
FIG. 2 is a functional block diagram of the present invention;
fig. 3 is a schematic block diagram of the background art.
Detailed Description
The invention is further described below with reference to the accompanying drawings:
the hydraulic system for releasing the parking brake of the forklift dual pump steering as shown in fig. 1 comprises a dual pump formed by serially connecting a steering gear pump 1 and a brake gear pump 2, namely the steering gear pump 1 and the brake gear pump 2 are serially connected to form the dual pump, wherein the sum of the displacement of the steering gear pump 1 and the displacement of the brake gear pump 2 can meet the output flow of the fastest steering action, namely the displacement of the dual pump is equal to the displacement of the steering pump of the independent steering hydraulic system; the brake gear pump 2 adopts a small-displacement gear pump with the displacement of 1-3 ml/r.
The oil suction port of the duplex pump is connected with the hydraulic oil tank 3, and the duplex pump is driven by the motor 4 to work; an oil outlet of the steering gear pump 1 is respectively connected with an oil inlet of the steering overflow valve 5, an oil inlet P2 of the hydraulic steering device 6 and an oil outlet of the first one-way valve 7, the oil outlet of the steering overflow valve 5 and an oil return port T2 of the hydraulic steering device 6 are respectively connected with the hydraulic oil tank 3, a working oil port of the hydraulic steering device 6 is connected with the steering oil cylinder 8, the hydraulic steering device 6 is provided with two working oil ports B2 and A2, and the two working oil ports B2 and A2 are respectively connected with the steering oil cylinder 8; specifically, a fourth tee joint 21 is arranged between the oil outlet of the steering gear pump 1 and the oil inlet of the steering overflow valve 5, the other port of the fourth tee joint 21 is connected with a fifth tee joint 22, the other two ports of the fifth tee joint 22 are respectively connected with the oil inlet P2 of the hydraulic steering device 6 and the oil outlet of the first one-way valve 7, and the oil return port T2 of the hydraulic steering device 6 is connected with the oil outlet of the steering overflow valve 5 and the hydraulic oil tank 3 through a sixth tee joint 23.
The oil outlet of the brake gear pump 2 is connected with the oil inlet P of the first two-position three-way electromagnetic directional valve 9, the first working oil port A of the first two-position three-way electromagnetic directional valve 9 is connected with the oil inlet of the first one-way valve 7, the second working oil port B of the first two-position three-way electromagnetic directional valve 9 is respectively connected with the oil inlet of the brake overflow valve 10 and the oil inlet of the second one-way valve 11, the oil outlet of the second one-way valve 11 is respectively connected with the accumulator 12, the low-pressure switch 13 and the oil inlet C of the second two-position three-way electromagnetic directional valve 14, the working oil port D of the second two-position three-way electromagnetic directional valve 14 is respectively connected with the high-pressure alarm switch 15 and the brake release oil cylinder 16, and the oil return port T of the second two-position three-way electromagnetic directional valve 14 and the oil return port of the brake overflow valve 10 are connected with the hydraulic oil tank 3. Specifically, the second working oil port of the first two-position three-way electromagnetic directional valve 9 is connected with the oil inlet of the brake overflow valve 10 and the oil inlet of the second one-way valve 11 through a first tee joint 17, the oil outlet of the second one-way valve 11 is connected with the energy accumulator 12, the low-pressure switch 13 and the oil inlet of the second two-position three-way electromagnetic directional valve 14 through a four-way 18, the working oil port of the second two-position three-way electromagnetic directional valve 14 is connected with the high-pressure alarm switch 15 and the brake release cylinder 16 through a second tee joint 19, and the oil return port of the second two-position three-way electromagnetic directional valve 14 is connected with the oil return port of the brake overflow valve 10 and the hydraulic oil tank 3 through a third tee joint 20.
Further, the first two-position three-way electromagnetic directional valve 9 has two working positions, when the electromagnet of the electromagnetic valve is powered on, the electromagnetic directional valve works in the right position shown in fig. 1, at the moment, the oil inlet P is communicated with the working oil port B, and the working oil port A is disconnected; when the electromagnet is powered off, the electromagnet works at the left position shown in fig. 1, at the moment, the oil inlet P is communicated with the first working oil port A, and the second working oil port B is disconnected.
Further, the second two-position three-way electromagnetic directional valve 14 has two working positions, when the electromagnet of the electromagnetic valve is powered on, the electromagnetic directional valve works in the lower position shown in fig. 1, at this time, the oil return port T is communicated with the working oil port D, and the oil inlet C is disconnected; when the electromagnet is powered off, the electromagnet works in the upper position shown in fig. 1, at the moment, the oil inlet C is communicated with the working oil port D, and the oil return port D is disconnected.
Further, the low-pressure switch 13 is a normally open pressure switch, and the pressure set value is 0.5MPa higher than the lowest release pressure of the brake release cylinder 16; the high-pressure warning switch 15 is a normally closed pressure switch, and its pressure set value is 0.5MPa higher than the highest release pressure of the brake release cylinder 16.
Further, the overflow pressure set by the steering overflow valve 5 is 2 MPa higher than the highest working pressure of the steering oil cylinder 8; the relief pressure set by the brake relief valve 10 is equal to the highest operating pressure of the brake release cylinder 16.
Further, as shown in fig. 2, the motor 4 is connected to a steering brake electric control system 24, the output end of the motor 4 is connected to a steering gear pump 1 and a brake gear pump 2, the oil suction ports of the steering gear pump 1 and the brake gear pump 2 are connected to a hydraulic oil tank 3, and the steering gear pump 1 and the brake gear pump 2 are connected to a steering brake hydraulic system 25.
The working principle and working process of the invention are as follows:
when the vehicle is in a parking state, the electromagnet of the second two-position three-way electromagnetic directional valve is in a power-off state, the working cavity of the brake release oil cylinder is connected with a hydraulic oil tank through the second three-way, the working oil port D of the second two-position three-way electromagnetic directional valve, the oil return port T of the second two-position three-way electromagnetic directional valve and the third three-way, and the brake release oil cylinder is reset under the action of a spring force and is in a parking brake state;
when the vehicle is started, the first two-position three-way electromagnetic directional valve is in a power-off state, the motor starts to work, the duplex pump is driven to absorb oil from the hydraulic oil tank, oil discharged from the brake gear pump flows through the first one-way valve through the oil inlet P of the first two-position three-way electromagnetic directional valve and the first working oil port A, is converged with oil discharged from the steering gear pump at the fifth three-way valve, and is provided to the oil inlet P2 of the hydraulic steering gear, so that sufficient oil is provided for the hydraulic steering gear;
pressing a parking brake release button, and powering an electromagnet of a second two-position three-way electromagnetic reversing valve, wherein a steering brake electrical control system detects the working position of a low-voltage switch; if the low-voltage switch works at a normal pressure working position S2, the stored pressure oil in the energy accumulator can be directly used for stopping braking release, the first two-position three-way electromagnetic directional valve maintains a power-off state, hydraulic oil in the energy accumulator enters the braking release oil cylinder through the four-way valve, the oil inlet C of the second two-position three-way electromagnetic directional valve and the working oil port D of the second two-position three-way electromagnetic directional valve through the second three-way valve, the pressure of a rodless cavity of the braking release oil cylinder rises, the piston is pushed to overcome the spring force, the piston rod stretches out, and stopping braking is released; if the low-voltage switch works at the low-voltage alarm position S1, the vehicle electrical control system controls the first two-position three-way electromagnetic directional valve to be electrified and sends out liquid filling warning sound through the vehicle buzzer, at the moment, oil discharged from the steering gear pump is independently supplied to the hydraulic steering gear, hydraulic oil provided by the braking gear pump flows through the first three-way valve, the second one-way valve and the four-way valve through the oil inlet P of the first two-position three-way electromagnetic directional valve and the working oil port B of the first two-position three-way electromagnetic directional valve, liquid is filled into the energy accumulator through one of the four-way oil passages, the other of the four-way oil passage enters the brake release oil cylinder 22 through the oil inlet C and the working oil port D of the second two-position three-way electromagnetic directional valve, at the moment, the pressure of the energy accumulator starts to rise, the time delay is controlled through the steering brake electrical control system, the first two-position three-way electromagnetic directional valve loses electricity after the first two-way electromagnetic directional valve is electrified for 3 seconds, the liquid filling warning sound stops, the double pump in the double pump continues to supply, the hydraulic steering gear works, and at the moment, the brake release pressure of the energy accumulator is maintained by the energy accumulator.
In summary, the invention controls the duplex pump to switch oil supply timely through the two-position three-way electromagnetic reversing valve, thereby ensuring continuous and reliable operation of the steering system and realizing brake release; the sum of the displacements of the duplex pumps adopted is equal to the single pump displacement used by the original independent steering hydraulic system, so that the displacement of the original independent braking hydraulic system pump is reduced, the flow of the whole hydraulic system is reduced, the total power of a loading motor is reduced, and the energy conservation of the hydraulic system is realized; the steering function and the braking function are provided with independent safety overflow, so that the steering and braking safety and reliability are ensured. When the electric control steering device is used, the original steering pump motor and the original controller can be used for controlling steering and parking brake release simultaneously, so that the electric control of the brake pump motor and the brake pump is reduced, the cost is reduced, and the problem of difficult arrangement of parts is solved.
The above examples are only illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solution of the present invention should fall within the scope of protection defined by the claims of the present invention without departing from the spirit of the present invention.
Claims (6)
1. A fork truck duplex pump turns to parking brake and releases hydraulic system, its characterized in that: the hydraulic pump comprises a duplex pump formed by connecting a steering gear pump (1) and a braking gear pump (2) in series, wherein an oil suction port of the duplex pump is connected with a hydraulic oil tank (3), and the duplex pump is driven by a motor (4) to work; an oil outlet of the steering gear pump (1) is respectively connected with an oil inlet of the steering overflow valve (5), an oil inlet of the hydraulic steering device (6) and an oil outlet of the first one-way valve (7), an oil outlet of the steering overflow valve (5) and an oil return port of the hydraulic steering device (6) are respectively connected with the hydraulic oil tank (3), and a working oil port of the hydraulic steering device (6) is connected with the steering oil cylinder (8); an oil outlet of the brake gear pump (2) is connected with an oil inlet of a first two-position three-way electromagnetic directional valve (9), a first working oil port of the first two-position three-way electromagnetic directional valve (9) is connected with an oil inlet of a first one-way valve (7), a second working oil port of the first two-position three-way electromagnetic directional valve (9) is respectively connected with an oil inlet of a brake overflow valve (10) and an oil inlet of a second one-way valve (11), an oil outlet of the second one-way valve (11) is respectively connected with an accumulator (12), a low-pressure switch (13) and an oil inlet of a second two-position three-way electromagnetic directional valve (14), and a working oil port of the second two-position three-way electromagnetic directional valve (14) is respectively connected with a high-pressure alarm switch (15) and a brake release oil cylinder (16), and an oil return port of the second two-position three-way electromagnetic directional valve (14) and an oil return port of the brake overflow valve (10) are connected with a hydraulic oil tank (3);
the second working oil port of the first two-position three-way electromagnetic directional valve (9) is connected with the oil inlet of the brake overflow valve (10) and the oil inlet of the second one-way valve (11) through a first tee joint (17), the oil outlet of the second one-way valve (11) is connected with the energy accumulator (12), the low-voltage switch (13) and the oil inlet of the second two-position three-way electromagnetic directional valve (14) through a four-way joint (18), the working oil port of the second two-position three-way electromagnetic directional valve (14) is connected with the high-voltage alarm switch (15) and the brake release oil cylinder (16) through a second tee joint (19), and the oil return port of the second two-position three-way electromagnetic directional valve (14) is connected with the oil return port of the brake overflow valve (10) and the hydraulic oil tank (3) through a third tee joint (20);
a fourth tee joint (21) is arranged between an oil outlet of the steering gear pump (1) and an oil inlet of the steering overflow valve (5), the other port of the fourth tee joint (21) is connected with a fifth tee joint (22), the other two ports of the fifth tee joint (22) are respectively connected with an oil inlet of the hydraulic steering gear (6) and an oil outlet of the first one-way valve (7), and an oil return port of the hydraulic steering gear (6) is connected with the oil outlet of the steering overflow valve (5) and the hydraulic oil tank (3) through a sixth tee joint (23);
the motor (4) is connected with a steering brake electrical control system (24), and the steering gear pump (1) and the brake gear pump (2) are respectively connected with a steering brake hydraulic system (25).
2. The forklift tandem pump steering parking brake release hydraulic system according to claim 1, wherein: the braking gear pump (2) adopts a small-displacement gear pump with the displacement of 1-3 ml/r.
3. The forklift tandem pump steering parking brake release hydraulic system according to claim 1, wherein: the low-voltage switch (13) is a normally open pressure switch, and the pressure set value of the low-voltage switch is 0.5MPa higher than the lowest release pressure of the brake release oil cylinder (16).
4. The forklift tandem pump steering parking brake release hydraulic system according to claim 1, wherein: the high-pressure alarm switch (15) is a normally closed pressure switch, and the pressure set value of the high-pressure alarm switch is 0.5MPa higher than the highest release pressure of the brake release oil cylinder (16).
5. The forklift tandem pump steering parking brake release hydraulic system according to claim 1, wherein: the overflow pressure of the steering overflow valve (5) is 2 MPa higher than the highest working pressure of the steering oil cylinder (8).
6. The forklift tandem pump steering parking brake release hydraulic system according to claim 1, wherein: the relief pressure set by the brake relief valve (10) is equal to the highest operating pressure of the brake release cylinder (16).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810236847.8A CN108317112B (en) | 2018-03-21 | 2018-03-21 | Fork truck duplex pump turns to parking braking and releases hydraulic system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810236847.8A CN108317112B (en) | 2018-03-21 | 2018-03-21 | Fork truck duplex pump turns to parking braking and releases hydraulic system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108317112A CN108317112A (en) | 2018-07-24 |
| CN108317112B true CN108317112B (en) | 2023-08-04 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201810236847.8A Active CN108317112B (en) | 2018-03-21 | 2018-03-21 | Fork truck duplex pump turns to parking braking and releases hydraulic system |
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| CN111720369B (en) * | 2020-06-30 | 2022-08-05 | 潍柴动力股份有限公司 | Liquid filling system and engineering machinery |
| CN111810478A (en) * | 2020-08-12 | 2020-10-23 | 徐州徐工环境技术有限公司 | Priority flow control system based on feeding device of compression vehicle |
| CN113404730B (en) * | 2021-07-30 | 2023-05-05 | 华侨大学 | Steering system of electric loader based on hydraulic accumulator and variable motor |
| CN114179907B (en) * | 2022-01-06 | 2022-11-01 | 安徽合力股份有限公司 | Hydraulic steering and parking braking control system for electric industrial vehicle |
| CN115681232B (en) * | 2022-11-04 | 2023-09-01 | 阿特拉斯叉车(杭州)有限公司 | Hydraulic system and four-way forklift with same |
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| JP2004019806A (en) * | 2002-06-17 | 2004-01-22 | Hitachi Constr Mach Co Ltd | Hydraulic circuit of working vehicle |
| WO2014082530A1 (en) * | 2012-11-27 | 2014-06-05 | 徐州重型机械有限公司 | Electric-control multimode steering valve, steering hydraulic control system, and wheel type crane |
| CN203496984U (en) * | 2013-08-19 | 2014-03-26 | 北京安期生技术有限公司 | Underground wheeled vehicle emergency steering system |
| CN203820402U (en) * | 2014-04-23 | 2014-09-10 | 福建晋工机械有限公司 | Hydraulic system of forklift |
| WO2015165344A1 (en) * | 2014-04-29 | 2015-11-05 | 三一汽车制造有限公司 | Rotary hydraulic system and concrete conveying pump apparatus |
| WO2016041115A1 (en) * | 2014-09-15 | 2016-03-24 | 南京迈瑞生物医疗电子有限公司 | Hydraulic drive system for operation table |
| CN206860567U (en) * | 2017-06-06 | 2018-01-09 | 吉林大学 | A kind of loading machine joint energy supply hydraulic system |
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|---|---|
| CN108317112A (en) | 2018-07-24 |
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