WO2020230362A1 - Soupape de commande pour véhicule industriel, et véhicule industriel - Google Patents

Soupape de commande pour véhicule industriel, et véhicule industriel Download PDF

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Publication number
WO2020230362A1
WO2020230362A1 PCT/JP2020/000225 JP2020000225W WO2020230362A1 WO 2020230362 A1 WO2020230362 A1 WO 2020230362A1 JP 2020000225 W JP2020000225 W JP 2020000225W WO 2020230362 A1 WO2020230362 A1 WO 2020230362A1
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WO
WIPO (PCT)
Prior art keywords
hydraulic oil
valve
industrial vehicle
flow path
spool
Prior art date
Application number
PCT/JP2020/000225
Other languages
English (en)
Japanese (ja)
Inventor
宏章 井垣
Original Assignee
株式会社島津製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社島津製作所 filed Critical 株式会社島津製作所
Publication of WO2020230362A1 publication Critical patent/WO2020230362A1/fr

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Classifications

    • 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
    • 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
    • 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

Definitions

  • the present invention relates to a control valve for an industrial vehicle and an industrial vehicle.
  • a forklift as an industrial vehicle
  • hydraulic oil is supplied from a common hydraulic pump to a power steering device that assists the steering operation of the forklift and a switching valve mechanism that supplies hydraulic oil to a hydraulic cylinder for cargo handling work.
  • a control valve provided with a diversion valve for diversion of hydraulic oil from the hydraulic pump into a power steering device of an industrial vehicle, a switching valve mechanism provided with a spool, and a flow dividing valve is used.
  • a priority shunt valve is used in which the hydraulic oil supplied from the hydraulic pump is preferentially supplied to the power steering device and the surplus hydraulic oil is supplied to the switching valve mechanism for cargo handling. ..
  • Patent Document 1 discloses such a priority type diversion valve.
  • Patent Document 1 discloses such a priority type diversion valve.
  • FIG. 4 is a cross-sectional view showing a main part of a priority type diversion valve as described in Patent Document 1.
  • This priority type diversion valve operates on a high-pressure port P to which high-pressure hydraulic oil is supplied from a hydraulic pump to a housing (not shown), a steering port PF connected to a power steering device, and a hydraulic cylinder for cargo handling. It has a configuration in which a cargo handling port EF connected to a switching valve mechanism for supplying oil and a load sensing port LS are formed.
  • the priority type diversion valve is configured to be slidable in the housing, and has a spool 82 in which a groove 84 is formed to guide the hydraulic oil supplied from the high pressure port P to the steering port PF and the cargo handling port EF.
  • the spool 82 is directed from the first position for guiding the hydraulic fluid from the high pressure port P to the steering port PF and the cargo handling port EF to the second position for guiding the hydraulic oil from the high pressure port P to the steering port PF.
  • a spring 83 for urging is provided.
  • the above-mentioned first position is a position where the groove portion 84 of the spool 82 faces both the steering port PF and the cargo handling port EF. At this position, the high pressure hydraulic oil supplied from the high pressure port P is supplied to both the steering port PF and the cargo handling port EF.
  • the above-mentioned second position is a position where the groove portion 84 of the spool 82 faces the steering port PF. At this position, the high pressure hydraulic oil supplied from the high pressure port P is supplied to the steering port PF.
  • a metering orifice 87 used to move the spool 82 to an appropriate position based on the pressure of hydraulic oil is provided. Further, at the end of the spool 82, a throttle check valve 89 having a function of stabilizing the moving operation of the spool 82 is provided together with a damper chamber formed in the housing.
  • the spool 82 in the state where the hydraulic oil is not supplied, the spool 82 is arranged at the second position where the groove 84 in the spool 82 faces the steering port PF by the action of the spring 83. ing. In this state, the flow path of the hydraulic oil on the steering port PF side of the spool 82 is fully open, and the flow path of the hydraulic oil on the cargo handling port EF side is fully closed. Then, when high-pressure hydraulic oil is supplied from the pump via the high-pressure port P, the hydraulic oil flows from the steering port PF of the spool 82 to the load sensing port LS through the metering orifice 87.
  • a differential pressure of the hydraulic oil is generated before and after the metering orifice 87 according to the flow rate of the hydraulic oil, and when the load applied to the spool 82 due to this differential pressure becomes larger than the urging force of the spring 83, the spool 82 The movement is started in the right direction shown in FIG.
  • the differential pressure before and after the metering orifice 87 increases, and the load due to the pressure difference applied to the spool 82 increases.
  • the spool 82 moves further to the right, and the hydraulic oil supplied from the high-pressure port P flows out to the cargo handling port EF as a surplus flow rate.
  • the spool 82 controls the opening degree of the steering port PF side and the opening degree of the cargo handling port EF side, and controls the flow rate of the hydraulic oil flowing there.
  • Patent Document 2 discloses a hydraulic control device for an industrial vehicle in which hydraulic oil discharged from a cargo handling port is throttled by a throttle valve. When the hydraulic oil discharged from the cargo handling port is throttled by the throttle valve in this way, the pressure of the hydraulic oil passing through the cargo handling port does not drop sharply, thus preventing the occurrence of kickback. It becomes possible.
  • the present invention has been made to solve the above problems, and to provide an industrial vehicle control valve and an industrial vehicle capable of preventing the occurrence of kickback while reducing the pressure loss of hydraulic oil. The purpose.
  • the first aspect of the present invention is a center bypass type industrial vehicle control provided with a diversion valve that diverts hydraulic oil from a hydraulic pump into a power steering device for an industrial vehicle, a switching valve mechanism provided with a spool, and a diversion valve.
  • a sequence valve that is arranged on the downstream side of the spool in the center bypass flow path and can switch between a state in which the flow of hydraulic oil to the tank is allowed and a state in which the flow of hydraulic oil to the tank is throttled.
  • the present invention relates to a control valve for an industrial vehicle including a pilot flow path connecting the hydraulic oil supply flow path to the switching valve mechanism and the sequence valve, and a throttle valve arranged in the pilot flow path.
  • the first aspect of the present invention it is possible to prevent the occurrence of kickback in which the steering operation becomes heavy in the power steering device while reducing the pressure loss of the hydraulic oil.
  • FIG. 1 is a schematic view of a forklift as an industrial vehicle.
  • This forklift has a main body 90 including front wheels 98 which are traveling wheels and rear wheels 99 which are steering wheels, a seat 96 for an operator to sit on, a steering 95 for operating the rear wheels 99, and a main body 90.
  • a fork 91 that moves up and down with respect to the lifting mechanism 97 arranged in the above, a lever 92 for raising and lowering the fork 91, a lever 93 for tilting the fork 91 together with the raising and lowering mechanism 97, and accessories. It is provided with a lever 94 for performing similar operations.
  • the forklift also includes a power steering device 100 for assisting the operation of the steering 95.
  • FIG. 2 and 3 are schematic views of a hydraulic circuit including a control valve for an industrial vehicle according to an embodiment of the present invention. Note that FIG. 2 shows a state in which the cargo handling operation is not performed, and FIG. 3 shows a state in which the cargo handling operation for raising the fork 91 is performed.
  • This control valve for an industrial vehicle is arranged in the main body 90 of a forklift, and includes a front cover 1, a lift switching valve mechanism 2, a tilt switching valve mechanism 3, and an accessory switching valve mechanism 4. ,
  • the rear cover 5 is stacked, and the center bypass flow path 101 is provided.
  • Reference numeral 103 in FIGS. 2 and 3 is a tank flow path.
  • the front cover 1 is connected to a hydraulic source including a pump 8 driven by the rotation of a motor 7 and a tank 6.
  • the high-pressure hydraulic oil supplied from this hydraulic source is preferentially supplied to the power steering device 100 shown in FIG. 1 via the priority type diversion valve 13, and the excess hydraulic oil is lifted via the center bypass flow path 101. It is supplied to the switching valve mechanism 2, the tilt switching valve mechanism 3, and the accessory switching valve mechanism 4.
  • the priority type diversion valve 13 has the configuration shown in FIG. 4, the arrow 11 shown in FIGS. 2 and 3 corresponds to the steering port PF, and the arrow 12 shown in FIGS. 2 and 3 is a load sensing port. Corresponds to LS.
  • the front cover 1 includes an unload valve 16 that is closed when the driver sits on the seat 96 of the forklift and activates the lift switching valve mechanism 2, the tilt switching valve mechanism 3, and the accessory switching valve mechanism 4. , A relief valve 14 for steering and a relief valve 15 for cargo handling are arranged.
  • the lift switching valve mechanism 2 is for supplying hydraulic oil to the lift cylinder 20, which is a hydraulic cylinder for raising and lowering the fork 91 in a forklift, and includes a spool 21 for controlling the flow of the hydraulic oil.
  • the lift switching valve mechanism 2 when the spool 21 moves upward in FIGS. 2 and 3 by the driver operating the lever 92, the hydraulic oil is used to raise the fork 91 with respect to the lift cylinder 20. Is supplied, and when the spool 21 moves downward in FIGS. 2 and 3, hydraulic oil is supplied so as to lower the fork 91 with respect to the lift cylinder 20.
  • the tilt switching valve mechanism 3 is for supplying hydraulic oil to the tilt cylinder 30, which is a hydraulic cylinder for tilting the fork 91 in the forklift together with the elevating mechanism 97, and is a spool for controlling the flow of the hydraulic oil. 31 and.
  • the tilt switching valve mechanism 3 when the spool 31 moves upward in FIGS. 2 and 3 by the driver operating the lever 93, the fork 91 is tilted in one direction with respect to the tilt cylinder 30.
  • the spool 31 moves downward in FIGS. 2 and 3
  • the hydraulic oil is supplied so as to tilt the fork 91 in the other direction with respect to the tilt cylinder 30.
  • the accessory switching valve mechanism 4 is for supplying hydraulic oil to the rotary drive unit 40, which is a hydraulic rotary mechanism for the rotary attachment for rotating the rotary attachment, which is an accessory in the forklift, and allows the flow of the hydraulic oil to flow.
  • a spool 41 for controlling is provided.
  • the accessory switching valve mechanism 4 when the spool 41 moves upward in FIGS. 2 and 3 by the driver operating the lever 94, the rotary attachment is rotated in one direction with respect to the rotary drive unit 40.
  • the spool 41 moves downward in FIGS. 2 and 3, the hydraulic oil is supplied to the rotary drive unit 40 so as to rotate the rotary attachment in the other direction.
  • the rear cover 5 is provided with a sequence valve 51 and a throttle valve 52.
  • the sequence valve 51 is arranged on the downstream side of the spools 21, 31, and 41 in the center bypass flow path 101 to allow the flow of hydraulic oil from the industrial vehicle control valve to the tank 6 and the industrial vehicle control. It is possible to switch between a state in which the flow of hydraulic oil from the valve to the tank 6 is throttled.
  • the sequence valve 51 is connected to a parallel flow path 102 that supplies hydraulic oil to the tilt switching valve mechanism 3 and the accessory switching valve mechanism 4 via a pilot flow path 104 and a throttle valve 52.
  • the sequence valve 51 allows the flow of hydraulic oil from the industrial vehicle control valve to the tank 6 as shown in FIG. It is in a state of doing. In this state, the excess hydraulic oil that has passed through the priority type diversion valve 13 passes through the center bypass flow path 101 and is discharged to the tank 6 without receiving pressure loss.
  • the pressure of the hydraulic oil by the lift cylinder 20 is the parallel flow path 102 and the pilot flow path 104 as shown by the thick line in FIG. And, it is supplied as a pilot pressure to the sequence valve 51 via the throttle valve 52.
  • the sequence valve 51 is in a state of restricting the flow of hydraulic oil from the control valve for industrial vehicles to the tank 6.
  • the priority type diversion valve 13 is used to secure the flow rate of hydraulic oil required for operating the power steering device.
  • the state of supplying hydraulic oil to both the power steering device 100 and the lift switching valve mechanism 2 is to be switched to the state of supplying only the power steering device 100.
  • the pressure of the hydraulic oil supplied to the power steering device 100 drops sharply, and the steering 95 by the power steering device 100 Power assist becomes temporarily impossible, and kickback occurs in which the operation of the steering 95 becomes heavy.
  • the flow of hydraulic oil from the center bypass flow path 101 of the industrial vehicle control valve to the tank 6 is throttled by the action of the sequence valve 51. Therefore, the pressure of the hydraulic oil supplied to the power steering device 100 gradually decreases, so that kickback does not occur.
  • Such an operation is executed not only when the lift switching valve mechanism 2 is operated, but also when the tilt switching valve mechanism 3 or the accessory switching valve mechanism 4 is operated.
  • the power steering is performed while reducing the pressure loss of the hydraulic oil. It is possible to prevent the occurrence of kickback in which the operation of the steering 95 becomes heavy in the device 100.
  • the priority type shunt valve 13 and the plurality of switching valve mechanisms 2, 3 and 4 are integrally configured, but the priority type shunt valve 13 and the plurality of switching valve mechanisms 2, 3 and 4 are integrated. 4 may be provided individually, and these may be connected by piping.
  • control valve for an industrial vehicle is a center bypass type equipped with a diversion valve for distributing hydraulic oil from a hydraulic pump into a power steering device of the industrial vehicle, a switching valve mechanism provided with a spool, and a diversion valve.
  • a sequence that is arranged on the downstream side of the spool in the center bypass flow path and can switch between a state that allows the flow of hydraulic oil to the tank and a state that restricts the flow of hydraulic oil to the tank. It is provided with a valve, a pilot flow path for connecting the hydraulic oil supply flow path to the switching valve mechanism and the sequence valve, and a throttle valve arranged in the pilot flow path.
  • control valve for an industrial vehicle has a configuration in which a plurality of switching valve mechanisms provided with spools are stacked, and the pilot flow path is a parallel flow for supplying hydraulic oil to the switching valve mechanism. Connect the path and the sequence valve.

Abstract

La présente soupape de commande pour un véhicule industriel de type à dérivation centrale comprend une soupape de dérivation de type prioritaire (13) qui fait dévier l'huile hydraulique d'une pompe hydraulique (8) vers un dispositif de direction assistée du véhicule industriel et vers des mécanismes de vanne de commutation (2, 3, 4) pourvus de bobines (21, 31, 41), la soupape de commande comprenant en outre : une vanne de séquence (51) qui est installée sur un canal de dérivation central (101) en aval des bobines (21, 31, 41), et qui est capable de commuter entre un état permettant un écoulement de l'huile hydraulique vers un réservoir (6) et un état de restriction de l'écoulement de l'huile hydraulique vers le réservoir (6) ; un passage d'écoulement pilote (104) qui relie un passage d'écoulement parallèle (102) de l'huile hydraulique aux mécanismes de commutation (2, 3, 4) et à la soupape de séquence (51) ; et un papillon des gaz (52) installé sur le passage d'écoulement pilote (104).
PCT/JP2020/000225 2019-05-16 2020-01-08 Soupape de commande pour véhicule industriel, et véhicule industriel WO2020230362A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2019092808 2019-05-16
JP2019-092808 2019-05-16

Publications (1)

Publication Number Publication Date
WO2020230362A1 true WO2020230362A1 (fr) 2020-11-19

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PCT/JP2020/000225 WO2020230362A1 (fr) 2019-05-16 2020-01-08 Soupape de commande pour véhicule industriel, et véhicule industriel

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09317703A (ja) * 1996-05-30 1997-12-09 Hitachi Constr Mach Co Ltd 油圧駆動回路
JP2008018846A (ja) * 2006-07-13 2008-01-31 Nissan Motor Co Ltd 産業車両の油圧制御装置
JP2010265942A (ja) * 2009-05-13 2010-11-25 Shimadzu Corp コントロールバルブ

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09317703A (ja) * 1996-05-30 1997-12-09 Hitachi Constr Mach Co Ltd 油圧駆動回路
JP2008018846A (ja) * 2006-07-13 2008-01-31 Nissan Motor Co Ltd 産業車両の油圧制御装置
JP2010265942A (ja) * 2009-05-13 2010-11-25 Shimadzu Corp コントロールバルブ

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