JP2017223343A - Boosting device for vehicle for high-lift work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a boosting device for a vehicle for high-lift work which enables a work to be started in a state where working fluids in a booster chamber and a hydraulic tool are discharged.SOLUTION: The present invention relates to a boosting device 12 for a vehicle for high-lift work configured to supply a working fluid that is boosted by a booster cylinder 13, to a hydraulic tool 100. The boosting device comprises: a supply oil path 15 connecting a booster chamber 13a of the booster cylinder with the hydraulic tool; an electromagnetic changeover valve 17 for pre-compression for supplying a working fluid to the supply oil path; an electromagnetic changeover valve 24 for main compression configured selectively switchable between a boosted state where a working fluid is supplied to a rod-side oil chamber 13b of the booster cylinder, and a pressure reduced state where a working fluid is supplied to a head-side oil chamber 13c of the booster cylinder and a working fluid in the supply oil path is discharged; and pressure detection means 14 for detecting a pressure in the booster chamber. If a detection value of the pressure detection means before performing a work using the hydraulic tool exceeds a reference pressure, the electromagnetic changeover valve for main compression is switched to the reduced pressure state in such a manner that the detection value becomes the reference pressure.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a pressure booster. More specifically, the present invention relates to a pressure booster for an aerial work vehicle that supplies pressurized hydraulic oil to a hydraulic tool.

  2. Description of the Related Art Conventionally, there is known an aerial work vehicle provided with a bucket on which an operator gets on the tip of a telescopic boom. The aerial work vehicle is configured to be able to supply hydraulic oil to hydraulic equipment such as a hydraulic tool in a bucket. An aerial work vehicle for electrical wiring work is configured to be able to supply hydraulic oil to a hydraulic crimping tool, which is a hydraulic tool that connects power lines by crimping a sleeve for electrical wiring. The aerial work vehicle configured in this way is provided with a pressure increasing device for supplying increased hydraulic oil. For example, as described in Patent Document 1.

  The pressure increasing device for an aerial work vehicle described in Patent Document 1 controls the pressure increasing cylinder by switching between an upstream direction control valve and a downstream direction control valve to increase the hydraulic pressure of hydraulic oil. In the pressure booster, a downstream direction control valve is connected in series to an upstream direction control valve to which hydraulic oil is supplied from a hydraulic pump. The directional control valve on the upstream side selectively selects a state in which hydraulic oil is supplied to the rod side oil chamber of the pressure increasing cylinder and the hydraulic crimping tool is returned, and a state in which the hydraulic oil pressure tool is supplied to the downstream directional control valve. It is configured to switch. The directional control valve on the downstream side supplies hydraulic oil to the hydraulic pressure crimping tool without increasing the hydraulic pressure to temporarily hold the hydraulic pressure bonding tool, and supplies hydraulic oil to the head side oil chamber of the pressure increasing cylinder. Thus, the operation oil is increased and the hydraulic pressure crimping tool is selectively switched to a state where the main compression operation is performed.

  In the pressure increasing device for an aerial work vehicle described in Patent Document 1, a pressure switch is connected to the pressure increasing oil chamber of the pressure increasing cylinder, and it is determined whether or not the oil pressure in the pressure increasing oil chamber has exceeded a predetermined pressure. Can be detected. The pressure switch and the direction control valve are connected to the control means, and are configured to be switched to a state in which a return operation is performed when it is detected that the pressure switch exceeds a predetermined pressure.

JP 2014-20543 A

  When caulking work is performed in a pressure-increasing chamber (pressure-increasing oil chamber) of a pressure-increasing device for an aerial work vehicle and in a state where hydraulic oil remains in the hydraulic tool (pressure is present), In some cases, it was difficult to grip the sleeve because it was not fully contracted. Therefore, the pressure is released by switching the directional control valve so that the hydraulic fluid of the pressure increasing chamber and the hydraulic tool of the pressure increasing device is discharged when the pressure increasing device is activated.

However, the pressure switch of the pressure increasing device for an aerial work vehicle described in Patent Document 1 can only determine whether or not the pressure in the pressure increasing chamber has reached a specified pressure. Therefore, even if it is attempted to discharge the hydraulic oil in the pressure increasing chamber and the hydraulic tool before the caulking work, the pressure in the pressure increasing chamber and the hydraulic tool cannot be detected. I did not understand.
Then, this invention makes it a subject to provide the pressure increase apparatus for high-altitude work vehicles which can start work in the state which discharged | emitted the hydraulic oil of the pressure increase chamber and the hydraulic tool.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, the booster for an aerial work vehicle is a booster for an aerial work vehicle that supplies hydraulic oil, which has been boosted by a booster cylinder, to a hydraulic tool. A supply oil path for connecting a hydraulic tool, a preload electromagnetic switching valve for supplying hydraulic oil to the supply oil path, a pressure increasing state for supplying hydraulic oil to the rod side oil chamber of the pressure increasing cylinder, An electromagnetic switching valve for main pressure configured to be selectively switchable to a decompressed state in which hydraulic oil is supplied to the head side oil chamber of the pressure increasing cylinder and hydraulic oil in the supply oil passage is discharged, and the pressure increasing chamber Pressure detecting means for detecting the pressure of the pressure tool, and when the detected value of the pressure detecting means before the work with the hydraulic tool exceeds the reference pressure, the detected value becomes the reference pressure. The main pressure electromagnetic switching valve is switched to a reduced pressure state.

  The pressure booster for an aerial work vehicle detects a failure based on the detection value of the pressure detection means after the main pressure solenoid valve is in a reduced pressure state.

  The pressure booster for an aerial work vehicle issues an alarm using alarm means when detecting the failure.

  The pressure booster for an aerial work vehicle can reduce the time of the depressurization state during the operation of the hydraulic tool when the detection value of the pressure detection means before the operation with the hydraulic tool exceeds a reference value. Configured to be longer.

  According to the present invention, a smooth operation can be realized by starting the operation in a state where the hydraulic oil of the pressure increasing chamber and the hydraulic tool is discharged.

The side view which shows the whole aerial work vehicle structure concerning this invention. The figure which shows the hydraulic circuit of the pressure booster for an aerial work vehicle which concerns on this invention. The figure which shows the control structure of the pressure booster for an aerial work vehicle which concerns on this invention. The figure which shows the operation mode of the hydraulic tool connected to the pressure booster for high-altitude work vehicles which concerns on this invention. The figure which shows the operation | movement aspect of the hydraulic circuit at the time of temporary holding | maintenance operation in the intensifier for high-altitude work vehicles which concerns on this invention. The figure which shows the operation | movement aspect of the hydraulic circuit of the preload stage at the time of this compression operation in the intensifier for high work platforms which concerns on this invention. The figure which shows the operation | movement aspect of the hydraulic circuit of the main pressure stage at the time of this compression operation in the booster for high-altitude work vehicles which concerns on this invention. The figure which shows the operation | movement aspect of the hydraulic circuit at the time of the return operation in the pressure booster for an aerial work vehicle which concerns on this invention. The flowchart figure showing the control aspect of the pressure release of the hydraulic fluid of the supply oil path before the caulking operation | work in the pressure booster for high-altitude work vehicles which concerns on this invention. The flowchart figure showing the control aspect of releasing the pressure of the hydraulic fluid of the supply oil path before the caulking work in the pressure increasing device for an aerial work vehicle according to the present invention. The flowchart figure which shows the control aspect of the crimping operation | work after the pressure release in the pressure booster for high-altitude work vehicles which concerns on this invention.

  Hereinafter, an aerial work vehicle 1 according to an embodiment of the aerial work vehicle will be described with reference to FIG. 1.

  As shown in FIG. 1, an aerial work vehicle 1 is an aerial work vehicle for electric wiring work in which a power crimping tool 100 (see FIG. 2) that is a hydraulic tool is used to crimp a sleeve S to connect power lines. It is. The aerial work vehicle 1 includes a vehicle 2 and an aerial work device 6.

  The vehicle 2 conveys the aerial work device 6. The vehicle 2 is provided with a cab 2b and a plurality of wheels 3 on a frame 2a, and an engine 4 (see FIG. 2) as a power source is mounted. The vehicle 2 is configured to travel by transmitting the driving force of the engine 4 to the plurality of wheels 3 in accordance with an operation from the cab 2b. The vehicle 2 is provided with an outrigger 5. The outrigger 5 includes a projecting beam that can be extended by hydraulic pressure on both sides in the width direction of the vehicle 2 and a hydraulic jack cylinder that can extend in a direction perpendicular to the ground. The vehicle 2 can extend the workable range of the aerial work vehicle 1 by extending the outrigger 5 in the width direction of the vehicle 2 and grounding the jack cylinder.

  The high place working device 6 lifts the bucket 9 on which the worker gets to a high place. The aerial work device 6 includes a swivel base 7, a telescopic boom 8, a bucket 9, a hoisting cylinder 10, and an operating device 11.

  The swivel base 7 swivels the aerial work device 6. The swivel base 7 is provided on the frame 2a of the vehicle 2 via an annular bearing. The annular bearing is arranged so that the center of rotation is perpendicular to the installation surface of the vehicle 2. The swivel base 7 is configured to be rotatable about the center of an annular bearing as a rotation center. The swivel base 7 is configured to be rotated by a hydraulic swivel motor (not shown).

  The telescopic boom 8 supports the bucket 9. The telescopic boom 8 is composed of a plurality of boom members. Each boom member is formed in a hollow cylindrical shape having polygonal cross sections similar to each other. Each boom member is formed in a size that can be inserted thereinto in the order of the cross-sectional area. The telescopic boom 8 is configured such that each boom member is movable in the axial direction. That is, the telescopic boom 8 is configured to be telescopic by moving each boom member with a telescopic cylinder (not shown). The telescopic boom 8 is provided so that the base end of the boom member can swing on the swivel base 7. Further, the telescopic boom 8 is configured to be swingable with respect to the swivel base 7 around the base end of the boom member.

  The bucket 9 is for securing a working space for the worker. The bucket 9 is configured so that an operator can get inside. The bucket 9 is supported at the tip of the telescopic boom 8 via a support mechanism 9a. The support mechanism 9a swings the bucket 9 in the up-and-down direction and the horizontal direction by a hydraulic actuator (not shown).

  The hoisting cylinder 10 raises and lowers the telescopic boom 8 and maintains the posture of the telescopic boom 8. The hoisting cylinder 10 is composed of a hydraulic cylinder. The base of the hoisting cylinder 10 is slidably connected to the swivel base 7, and the tip of the rod is slidably connected to the telescopic boom 8. The hoisting cylinder 10 raises or lowers the telescopic boom 8 by extending and contracting the rod.

  The operating device 11 is for operating the swivel base 7, the telescopic boom 8, the bucket 9, and the like. The operating device 11 is provided inside the vehicle 2 and the bucket 9. The operating device 11 is provided with a swivel telescopic operation tool for performing a swiveling operation of the swivel base 7 and a telescopic boom 8, a hoisting operation tool for performing a hoisting operation of the telescopic boom 8, an engine start switch, and the like. Further, the operating device 11 is provided with a hydraulic pressure switching operation tool 11a (see FIG. 3) for switching the hydraulic pressure of the hydraulic oil supplied to the hydraulic crimping tool 100. The hydraulic pressure switching operation tool 11 a switches to a state in which the hydraulic fluid increased in pressure can be supplied to the hydraulic crimping tool 100, or discharges hydraulic fluid from the hydraulic crimping tool 100.

  The aerial work vehicle 1 configured as described above can move the aerial work device 6 to an arbitrary position by running the vehicle 2. Further, the aerial work vehicle 1 is configured such that the telescopic boom 8 is raised at an arbitrary hoisting angle by the hoisting cylinder 10 and the telescopic boom 8 is extended to an arbitrary boom length to move the bucket 9 of the high altitude working device 6. Can be enlarged.

  Below, the pressure booster 12 which the aerial work vehicle 1 comprises is demonstrated using FIG. 2 and FIG.

  As shown in FIG. 2, the pressure booster 12 increases the hydraulic pressure of the hydraulic oil supplied to the hydraulic crimping tool 100. The pressure booster 12 includes a pressure-increasing cylinder 13, a pressure sensor 14, a preload electromagnetic switching valve (preload switching valve 17) that is a directional control valve, a relief valve 21, and a main pressure electromagnetic switching valve (a directional control valve). The main pressure switching valve 24), a pilot check valve 27, a hydraulic pump 28, and a control device 31 (see FIG. 3) are provided.

  The pressure increasing cylinder 13 increases the hydraulic pressure of the hydraulic oil. The pressure increasing cylinder 13 is constituted by a hydraulic cylinder including a bottomed cylindrical pressure increasing chamber 13a provided on the rod side. The pressure increasing cylinder 13 is configured such that the inner diameter of the pressure increasing chamber 13a is smaller than the inner diameter of the hydraulic cylinder. A large-diameter piston 13d to which a rod 13f is connected is slidably inserted into the hydraulic cylinder. A rod-side oil chamber 13b and a head-side oil chamber 13c are formed inside the hydraulic cylinder. A small-diameter piston 13e is slidably inserted in the pressure increasing chamber 13a. In the pressure increasing cylinder 13, a small diameter piston 13e in the pressure increasing chamber 13a and a large diameter piston 13d in the hydraulic cylinder are connected via a rod 13f. When the hydraulic oil is supplied to the head side oil chamber 13c of the hydraulic cylinder, the pressure increasing cylinder 13 transmits the force generated in the large diameter piston 13d by the hydraulic pressure of the hydraulic oil to the small diameter piston 13e of the pressure increasing chamber 13a. Thereby, the pressure increase cylinder 13 pressurizes the hydraulic oil in the pressure increase chamber 13a with the force increased by the area ratio of the large diameter piston 13d and the small diameter piston 13e.

  A pressure sensor 14 is connected to the pressure increasing chamber 13 a of the pressure increasing cylinder 13. The pressure sensor 14 can detect the hydraulic pressure of the hydraulic oil in the pressure increasing chamber 13a in real time. The pressure sensor 14 is connected to the control device 31. A supply oil passage 15 is connected to the pressure increasing chamber 13 a of the pressure increasing cylinder 13. The supply oil passage 15 is provided with a joint 16 to which the hydraulic crimping tool 100 can be connected. As a result, the pressure increasing device 12 is configured to be able to supply the hydraulic pressure increased in the pressure increasing chamber 13 a of the pressure increasing cylinder 13 to the hydraulic pressure bonding tool 100 connected to the joint 16 through the supply oil passage 15. .

  An electromagnetic switching valve for preload (hereinafter simply referred to as “preload switching valve 17”) which is a directional control valve is a supply in which a pressure increasing chamber 13a of a pressure increasing cylinder 13 and a hydraulic pressure bonding tool 100 are connected to each other. The direction of the hydraulic oil supplied to the oil passage 15 is switched. A supply oil passage 15 is connected to one port of the preload switching valve 17 via a low pressure oil passage 18. A supply oil passage 15 is connected to the other port of the preload switching valve 17 via a preload oil passage 19. A hydraulic pump 28 is connected to the supply port of the preload switching valve 17 via the discharge oil passage 20. That is, hydraulic oil is supplied to the preload switching valve 17 at the discharge pressure of the hydraulic pump 28 (hereinafter simply referred to as “preload”). In the preload switching valve 17, one of the one port and the other port is communicated with the supply port by moving a spool (not shown) by an electromagnet.

  A relief valve 21 is connected to the low pressure oil passage 18 connected to one port of the preload switching valve 17 to control the hydraulic pressure of the hydraulic oil below a set value. In the relief valve 21, a branch oil passage branched from the low pressure oil passage 18 is connected to an inlet port, and a hydraulic oil tank 30 is connected to an outlet port. Further, the low-pressure oil passage 18 is provided with a throttle 22 on the upstream side of the branch oil passage of the relief valve 21 and a check valve 23 on the downstream side. When the hydraulic pressure of the hydraulic oil flowing through the low pressure oil passage 18 reaches a set value, the relief valve 21 returns a part of the hydraulic oil flowing through the low pressure oil passage 18 to the hydraulic oil tank 30 through the branch oil passage. That is, the hydraulic pressure of the hydraulic oil flowing through the low-pressure oil passage 18 is controlled by the relief valve 21 to a relief pressure lower than the preload (hereinafter simply referred to as “low pressure”). Further, the flow rate of the hydraulic oil flowing through the low pressure oil passage 18 is limited by the throttle 22 to be equal to or less than the relief flow rate of the relief valve 21. A check valve 23 is provided in the preload oil passage 19. The preload switching valve 17 is connected to the control device 31.

  The preload switching valve 17 is in a state where the low pressure oil passage 18 and the preload oil passage 19 are connected to the hydraulic oil tank 30 when the electromagnet is not excited (when no operation signal is received from the control device 31). The spool is moved to the II position. That is, the preload switching valve 17 is switched to a state where the hydraulic oil discharged from the hydraulic pump 28 is not supplied to the supply oil passage 15. As a result, the pressure increasing device 12 does not supply hydraulic oil to the pressure increasing chamber 13 a of the pressure increasing cylinder 13 and the hydraulic pressure bonding tool 100 through the supply oil passage 15.

  When the electromagnet is excited so that one port communicates with the supply port (when an operation signal for supplying low-pressure hydraulic oil is received from the control device 31), the preload switching valve 17 has a low-pressure oil passage. The spool is moved to the I position where 18 is connected to the discharge oil passage 20 and the preload oil passage 19 is connected to the hydraulic oil tank 30. That is, the preload switching valve 17 is switched to a state in which hydraulic oil is supplied to the supply oil passage 15 through the low pressure oil passage 18. As a result, the pressure booster 12 supplies low-pressure hydraulic oil to the pressure boosting chamber 13 a of the pressure boosting cylinder 13 and the hydraulic pressure bonding tool 100 through the supply oil passage 15. At this time, the flow rate of the hydraulic oil supplied to the pressure increasing chamber 13 a of the pressure increasing cylinder 13 and the hydraulic pressure bonding tool 100 is limited by the throttle 22 of the low pressure oil passage 18.

  When the electromagnet is excited so that the other port and the supply port communicate with each other, the preload switching valve 17 has a preload oil passage (when an operation signal for supplying preload hydraulic fluid is received from the control device 31). The spool is moved to a position III where 19 is connected to the discharge oil passage 20 and the low-pressure oil passage 18 is connected to the hydraulic oil tank 30. That is, the preload switching valve 17 is switched to a state in which the working oil is supplied to the supply oil passage 15 through the preload oil passage 19. Thereby, the pressure booster 12 supplies the preload hydraulic fluid to the pressure boosting chamber 13 a of the pressure boosting cylinder 13 and the hydraulic pressure bonding tool 100 through the supply oil passage 15.

  A main pressure electromagnetic switching valve (hereinafter simply referred to as “main pressure switching valve 24”), which is a directional control valve, switches the direction of hydraulic fluid supplied to the pressure increasing cylinder 13. The rod side oil chamber 13 b of the pressure increasing cylinder 13 is connected to one port of the main pressure switching valve 24 via a pressure reducing oil passage 25. A head side oil chamber 13 c of the pressure increasing cylinder 13 is connected to the other port of the main pressure switching valve 24 via a pressure increasing oil passage 26. A hydraulic pump 28 is connected to the supply port of the main pressure switching valve 24 via the discharge oil passage 20. That is, the hydraulic oil is supplied to the main pressure switching valve 24 with a preload. In the main pressure switching valve 24, one of the one port and the other port is communicated with the supply port when a spool (not shown) is moved by an electromagnet. The main pressure switching valve 24 is connected to the control device 31.

  When the electromagnet is not excited (when no operation signal is received from the control device 31), the main pressure switching valve 24 is in a state where the pressure reducing oil passage 25 and the pressure increasing oil passage 26 are connected to the hydraulic oil tank 30. The spool is moved to a certain II position. That is, the preload switching valve 17 is switched to a state where the hydraulic oil discharged from the hydraulic pump 28 is not supplied to the pressure increasing cylinder 13. Thereby, the pressure booster 12 does not increase the hydraulic pressure of the hydraulic oil by the pressure boosting cylinder 13.

  When the electromagnet is excited so that one port communicates with the supply port (when receiving an operation signal for reducing the hydraulic oil pressure from the control device 31), the main pressure switching valve 24 has a reduced pressure oil passage. The spool is moved to the I position where 25 is connected to the discharge oil passage 20 and the pressure-increasing oil passage 26 is connected to the hydraulic oil tank 30 (depressurized state). That is, the main pressure switching valve 24 is switched to a state where hydraulic oil is supplied to the rod side oil chamber 13 b of the pressure increasing cylinder 13 through the pressure reducing oil passage 25. Thereby, the pressure booster 12 moves the small-diameter piston 13e in the direction in which the volume of the pressure boosting chamber 13a increases to reduce the hydraulic pressure of the hydraulic oil.

  When the electromagnet is excited so that the other port and the supply port communicate with each other, the main pressure switching valve 24 increases pressure oil (when receiving an operation signal for increasing the hydraulic pressure of the hydraulic oil from the control device 31). The spool is moved to the position III where the passage 26 is connected to the discharge oil passage 20 and the decompression oil passage 25 is connected to the hydraulic oil tank 30 (pressure increasing state). That is, the main pressure switching valve 24 is switched to a state in which hydraulic oil is supplied to the head side oil chamber 13 c of the pressure increasing cylinder 13 through the pressure increasing oil passage 26. Thereby, the pressure booster 12 moves the small diameter piston 13e in the direction in which the volume of the pressure increasing chamber 13a decreases, and increases the hydraulic pressure of the hydraulic oil.

  The pilot type check valve 27 releases the oil passage. In the pilot type check valve 27, the supply oil passage 15 is connected to the inlet port, and the hydraulic oil tank 30 is connected to the outlet port. The pilot check valve 27 is configured so that pilot hydraulic oil is supplied from the decompression oil passage 25. When the main pressure switching valve 24 is switched to supply hydraulic oil to the rod side oil chamber 13 b of the pressure increasing cylinder 13, the pilot check valve 27 is opened when pilot hydraulic oil is supplied from the pressure reducing oil passage 25. I speak. The hydraulic oil in the pressure increasing chamber 13a connected to the supply oil passage 15 and the hydraulic oil in the hydraulic pressure bonding tool 100 are returned to the hydraulic oil tank 30 through the pilot check valve 27. Thereby, the pressure booster 12 is comprised so that the hydraulic oil in the pressure increase chamber 13a and the hydraulic oil in the hydraulic crimping tool 100 can be quickly discharged.

  The hydraulic pump 28 discharges hydraulic oil at a predetermined discharge pressure. The hydraulic pump 28 is driven by the engine 4. A preload switching valve 17 and a main pressure switching valve 24 are connected to the hydraulic pump 28 in parallel. The hydraulic oil discharged from the hydraulic pump 28 is supplied to the preload switching valve 17 and the main pressure switching valve 24 through the discharge oil passage 20. A hydraulic pump relief valve 29 is provided in the discharge oil passage 20. The hydraulic pump relief valve 29 controls the hydraulic pressure of the hydraulic oil discharged from the hydraulic pump 28 to a set value or less.

  As shown in FIG. 3, the control device 31 controls the operations of the preload switching valve 17 and the main pressure switching valve 24 of the pressure increasing device 12. The control device 31 may actually have a configuration in which a CPU, a ROM, a RAM, an HDD, and the like are connected by a bus, or may be configured by a one-chip LSI or the like. The control device 31 stores various programs and data for controlling the operations of the preload switching valve 17 and the main pressure switching valve 24. The control device 31 is provided in the vehicle 2.

  The control device 31 is connected to the hydraulic pressure switching operation tool 11a, and can acquire an operation signal from the hydraulic pressure switching operation tool 11a.

  The control device 31 is connected to the pressure sensor 14 of the pressure increasing chamber 13a, and can acquire the detected value of the hydraulic oil pressure in the pressure increasing chamber 13a detected by the pressure sensor 14.

  The control device 31 is connected to the preload switching valve 17 and can selectively excite the electromagnet of the preload switching valve 17 to change the position of the spool of the preload switching valve 17.

  The control device 31 is connected to the main pressure switching valve 24 and can selectively excite the electromagnet of the main pressure switching valve 24 to change the position of the spool of the main pressure switching valve 24.

  The control device 31 is connected to the tool operation tool 100c of the hydraulic crimping tool 100 via the connector 31a, and can obtain an operation signal from the hydraulic crimping tool 100.

  The control device 31 is connected to an alarm device 32 provided as an alarm means. When the alarm device 32 detects a failure of the pressure booster 12 or the like, the alarm device 32 notifies the worker by issuing an alarm display or an alarm sound. Note that the alarm device 32 is not limited to being configured by an alarm display or an alarm sound as long as it can notify the operator of a failure of the pressure booster 12 or the like.

  In this way, the pressure booster 12 of the aerial work vehicle 1 is configured as an oil passage in which the low-pressure oil passage whose hydraulic pressure is controlled by the relief valve 21 and the preload oil passage 19 without the relief valve 21 are independent of each other. ing. That is, the pressure booster 12 can set the hydraulic pressure and flow rate of the hydraulic oil flowing through the low pressure oil passage 18 and the hydraulic oil flowing through the preload oil passage 19 to different values. Thus, the pressure booster 12 does not provide a directional control valve for the relief valve 21 that is used for switching the hydraulic pressure, but only supplies the amount of hydraulic oil that is controlled to a hydraulic pressure equal to or lower than a predetermined value by the action of the relief valve 21. Can be suppressed. In other words, the pressure increasing device 12 can supply the hydraulic oil whose pressure has been increased to the hydraulic pressure bonding tool 100 without any flow rate limitation.

  In the present embodiment, the pressure increasing cylinder 13 of the pressure increasing device 12 of the aerial work vehicle 1, the preload switching valve 17, the relief valve 21, the main pressure switching valve 24, the pilot check valve 27, the hydraulic pump 28 and the control. The device 31 is provided in the vehicle 2 of the aerial work vehicle 1. In the pressure increasing device 12, a hydraulic hose constituting the supply oil passage 15 is piped to the bucket 9 via the telescopic boom 8. A joint 16 for connecting a hydraulic crimping tool or the like is provided at the tip of the hydraulic hose.

  Next, using FIG. 2 and FIGS. 4 to 8, the operation mode of the pressure increasing device 12 in the caulking operation of the sleeve S for electric wiring by the hydraulic crimping tool 100 will be described. In the present embodiment, the pressure increasing device 12 has a hydraulic crimping tool 100 connected to the joint 16 and a tool operating tool 100c of the hydraulic crimping tool 100 connected to the control device 31 via a connector 31a. To do.

  As shown in FIG. 4, the hydraulic crimping tool 100 connected to the pressure increasing device 12 grips and crimps a sleeve S for electrical wiring. The hydraulic crimping tool 100 is configured such that the movable part 100a moves toward the receiving part 100b by the hydraulic oil supplied from the pressure intensifying device 12. The hydraulic crimping tool 100 is in a stopped state s0 in which the movable part 100a is stopped by the operation of the tool operating tool 100c, and the movable part 100a is moved toward the receiving part 100b to move the sleeve S between the movable part 100a and the receiving part 100b. The temporary holding operation s1 gripped by the above, the preload stage s2 of the main compression operation in which the movable portion 100a is pressed with a predetermined force to preload the sleeve S, and the movable portion 100a is pressed with a predetermined force to A main pressure stage s3 of the main compression operation to be caulked and a return operation s4 in which the movable portion 100a is moved away from the receiving portion 100b to release the sleeve S can be performed.

  As shown in FIG. 2, when the operation mode of the hydraulic crimping tool 100 is switched to the stopped state by operating the tool operating tool 100 c, the control device 31 sets the spool position of the preload switching valve 17 to the low pressure oil passage 18. And the preload oil passage 19 are moved to the II position where the hydraulic oil tank 30 is connected. In addition, the control device 31 moves the spool position of the main pressure switching valve 24 to the II position where the pressure reducing oil passage 25 and the pressure increasing oil passage 26 are connected to the hydraulic oil tank 30. That is, the pressure booster 12 does not supply hydraulic oil to the hydraulic crimping tool 100. Thereby, the hydraulic crimping tool 100 stops in a state where the movable portion 100a is separated from the receiving portion 100b (a state where the sleeve S is released).

  As shown in FIG. 5, when the operation mode of the hydraulic crimping tool 100 is switched to the temporary holding operation s1 by the operation of the tool operating tool 100c, the control device 31 sets the spool position of the preload switching valve 17 to the low pressure oil. The passage 18 is connected to the discharge oil passage 20 and moved to the I position where the preload oil passage 19 is connected to the hydraulic oil tank 30. In addition, the control device 31 moves the spool position of the main pressure switching valve 24 to the II position where the pressure reducing oil passage 25 and the pressure increasing oil passage 26 are connected to the hydraulic oil tank 30. That is, the pressure booster 12 controls the hydraulic oil whose hydraulic pressure is controlled to a low pressure by the relief valve 21 and whose flow rate is controlled to be equal to or lower than the relief flow rate by the throttle 22, the pressure increasing chamber 13 a of the pressure increasing cylinder 13 and the hydraulic pressure bonding tool 100. (Refer to the thin ink section). Accordingly, in the hydraulic crimping tool 100, the movable portion 100a is moved toward the receiving portion 100b, and the sleeve S is gripped by the movable portion 100a and the receiving portion 100b (see the black arrow). At the same time, the pressure intensifying device 12 discharges air in the pressure intensifying chamber 13a, the hydraulic pressure bonding tool 100, and the supply oil passage 15 by supplying low-pressure hydraulic oil.

  As shown in FIG. 6, when the operation mode of the hydraulic crimping tool 100 is switched to the main compression operation by operating the tool operating tool 100c, the control device 31 sets the spool position of the preload switching valve 17 to the preload oil passage. 19 is connected to the discharge oil passage 20 and moved to a position III where the low-pressure oil passage 18 is connected to the hydraulic oil tank 30. In addition, the control device 31 moves the spool position of the main pressure switching valve 24 to the II position where the pressure reducing oil passage 25 and the pressure increasing oil passage 26 are connected to the hydraulic oil tank 30. That is, the pressure booster 12 supplies the preload hydraulic oil, which is the discharge pressure of the hydraulic pump 28, to the pressure increasing chamber 13a of the pressure increasing cylinder 13 and the hydraulic pressure bonding tool 100 (see the thin ink portion). Accordingly, the hydraulic crimping tool 100 applies the preload to the sleeve S by pressing the movable portion 100a with a predetermined force by the pre-pressurized hydraulic oil that has not been increased as the pre-load stage s2 of the main compression operation (black arrow) reference). At the same time, the pressure booster 12 discharges the air in the pressure increasing chamber 13a, the hydraulic pressure bonding tool 100, and the supply oil passage 15 by supplying the preload hydraulic fluid.

  As shown in FIG. 7, when the detected value of the pressure sensor 14 reaches the preload reference value in the preload stage s2 of the main compression operation, the control device 31 sets the spool position of the preload switching valve 17 to the low pressure oil passage 18. The preload oil passage 19 is moved to the II position where the hydraulic oil tank 30 is connected. At the same time, the control device 31 moves the spool position of the main pressure switching valve 24 to the position III where the pressure increasing oil passage 26 is connected to the discharge oil passage 20 and the pressure reducing oil passage 25 is connected to the hydraulic oil tank 30. Move. That is, the pressure booster 12 decreases the volume of the pressure boosting chamber 13a of the pressure boosting cylinder 13 to increase the hydraulic pressure of the hydraulic oil in the pressure boosting chamber 13a, and supplies the hydraulic pressure to the hydraulic pressure bonding tool 100 (see the thin ink portion). . As a result, the hydraulic crimping tool 100, as the main pressure stage s3 of the main compression operation, presses the movable portion 100a with a predetermined force by the hydraulic oil increased in pressure by the pressure-increasing cylinder 13 and caulks the sleeve S (black). (See painted arrow).

  As shown in FIG. 8, when the operation mode of the hydraulic crimping tool 100 is switched to the return operation s4 by the operation of the tool operating tool 100c, or the detection value of the pressure sensor 14 reaches the main pressure reference value. The control device 31 moves the spool position of the preload switching valve 17 to the II position where the low pressure oil passage 18 and the preload oil passage 19 are connected to the hydraulic oil tank 30. At the same time, the control device 31 moves the spool position of the main pressure switching valve 24 to the I position where the pressure reducing oil passage 25 is connected to the discharge oil passage 20 and the pressure increasing oil passage 26 is connected to the hydraulic oil tank 30. Move. That is, the pressure increasing device 12 increases the volume of the pressure increasing chamber 13a of the pressure increasing cylinder 13 to reduce the hydraulic pressure of the hydraulic oil in the pressure increasing chamber 13a, and opens the pilot check valve 27 to open the pressure increasing chamber. The hydraulic oil in 13a and the hydraulic oil in the hydraulic crimping tool 100 are discharged to the hydraulic oil tank 30 (see the thin ink portion). As a result, the hydraulic crimping tool 100 is moved in a direction in which the movable portion 100a is separated from the receiving portion 100b, and releases the sleeve S from the movable portion 100a and the receiving portion 100b (see black arrows).

  When the operation mode of the hydraulic crimping tool 100 is switched to the return operation s4, or when the detected value of the pressure sensor 14 reaches the main pressure reference value, the preload switching valve 17 is operated for a preset time. The spool position is switched to the II position, the spool position of the main pressure switching valve 24 is switched to the I position, and the pilot check valve 27 is opened to operate the hydraulic oil in the pressure increasing chamber 13a and the hydraulic pressure bonding tool 100. The oil is configured to be discharged to the hydraulic oil tank 30.

  Further, when the hydraulic pressure switching operation tool 11a of the aerial work vehicle 1 is operated, the control device 31 sets the spool position of the preload switching valve 17 to the low pressure oil passage 18 and the preload oil regardless of the detection value of the pressure sensor 14. The path 19 is moved to the II position where it is connected to the hydraulic oil tank 30. At the same time, the control device 31 moves the spool position of the main pressure switching valve 24 to the I position where the pressure reducing oil passage 25 is connected to the discharge oil passage 20 and the pressure increasing oil passage 26 is connected to the hydraulic oil tank 30. Move. In other words, the pressure booster 12 increases the volume of the pressure increasing chamber 13a to reduce the hydraulic pressure of the hydraulic oil in the pressure increasing chamber 13a and opens the pilot check valve 27 to open the hydraulic oil in the pressure increasing chamber 13a. And hydraulic oil in the hydraulic crimping tool 100 are discharged to the hydraulic oil tank 30. Thereby, the hydraulic crimping tool 100 is moved in a direction in which the movable portion 100a is separated from the receiving portion 100b, and releases the sleeve S from the movable portion 100a and the receiving portion 100b.

  With this configuration, the pressure increasing device 12 operates the low-pressure oil passage 18 without providing a directional control valve for the relief valve 21 when the hydraulic pressure of the hydraulic oil during the temporary holding operation s1 is controlled by the relief valve 21. Supply hydraulic oil with the oil flow rate limited to the relief flow rate or less. In other words, the pressure increase device 12 is not limited in the flow rate of the hydraulic oil supplied to the pressure increase cylinder 13 through the pressure increase oil passage 26 during the main compression operation. Therefore, in the hydraulic pressure bonding tool 100, the speed during the main compression operation is not affected by the relief flow rate of the relief valve 21. The pressure booster 12 switches between the preload switching valve 17 and the main pressure switching valve 24 based on at least one of the operation signal from the hydraulic crimping tool 100 and the detected value of the pressure sensor 14. . That is, the pressure booster 12 can selectively supply low-pressure or pre-pressure hydraulic oil to the supply oil passage 15 at different flow rates. Accordingly, the pressure booster 12 can supply the hydraulic tool to the hydraulic tool without limiting the flow rate of the hydraulic oil at the time of pressure boosting without providing a directional control valve for the relief valve.

  9 and 10, the pressure of the hydraulic oil supplied to the supply oil passage 15 (the pressure increasing chamber 13 a and the hydraulic crimping tool 100) before caulking work by the crimping hydraulic tool 100 is confirmed and the pressure is released. Will be described.

  The control device 31 is configured to be able to determine whether or not the detected value of the pressure sensor 14 before caulking work by the crimping hydraulic tool 100 is larger than the reference pressure. When it is determined that the detected value of the pressure sensor 14 is larger than the reference pressure, the operation mode of the hydraulic crimping tool 100 is switched to the return operation s4.

  The control device 13 determines the time or number of times of the return operation s4 based on the detection value of the pressure sensor 14. The control device 13 is configured to be able to determine whether or not the detection value of the pressure sensor 14 is larger than the reference pressure after the return operation s4 is performed for the time or the number of times. When it is determined that the detected value of the pressure sensor 14 is larger than the reference pressure, it is detected as a failure of the pressure booster 12 such as the hydraulic pump 28 or the pressure sensor 14 and is notified to the operator.

  A first embodiment of the pressure increasing device 12 for confirming the pressure of hydraulic oil supplied to the supply oil passage 15 before caulking work and releasing the pressure will be described with reference to FIG.

  In step S110, the control device 31 determines whether or not the pressure increasing device 12 is in a state before caulking work. Specifically, it is determined by the hydraulic pressure switching operation tool 11a whether or not the pressure increasing device 12 is being activated. When the hydraulic pressure switching operation tool 11a is switched to a state in which the hydraulic fluid increased in pressure can be supplied to the hydraulic pressure bonding tool 100, it is determined that the pressure increasing device 12 is in a starting state, and the process proceeds to step S120.

  In step S120, the control device 31 determines whether or not the spool position of the preload switching valve 17 is fixed at the II position and the spool position of the main pressure switching valve 24 is fixed at the II position. Here, the fact that the spool position is fixed at the II position refers to a state where the spool position cannot be moved to a position other than the II position. The state where the spool position is fixed at the II position is a state where a failure of the pressure booster 12 described later is detected. For this reason, even before the caulking operation, confirmation of the pressure of the hydraulic oil supplied to the supply oil passage 15 and release of the pressure are not performed. When it is determined that the spool position of the preload switching valve 17 is fixed at the II position and the spool position of the main pressure switching valve 24 is fixed at the II position, the process ends. When the spool position of the preload switching valve 17 is at the II position and the spool position of the main pressure switching valve 24 is not fixed at the II position, the routine proceeds to step S130.

  In step S <b> 130, the control device 31 determines whether or not the detected value of the pressure sensor 14 when the pressure increasing device 12 is started is greater than the reference pressure. If it is determined in step S130 that the detected value of the pressure sensor 14 is greater than the reference pressure, the process proceeds to step S140. If it is determined in step 130 that the detected value of the pressure sensor 14 is not greater than the reference pressure, the process ends.

  In step S140, the control device 31 determines the time for the return operation s4 based on the detection value of the pressure sensor 14. That is, the time for the return operation s4 is determined so that the detected value of the pressure sensor 14 becomes the reference pressure. When the time for the return operation s4 is determined, the process proceeds to step S150.

  In step S150, the control device 31 switches the operation mode of the hydraulic crimping tool 100 to the return operation s4, and proceeds to step S160. The pilot check valve 27 is opened by moving the spool position of the main pressure switching valve 24 to the I position, and the hydraulic oil in the supply oil passage 15 is discharged to the hydraulic oil tank 30.

  In step S160, the control device 31 determines whether or not the time (predetermined time) set in step S140 has elapsed after switching the operation mode of the hydraulic crimping tool 100 to the return operation s4. When the predetermined time has elapsed, the process proceeds to step S170.

  In step S170, the control device 31 determines again whether or not the detection value of the pressure sensor 14 is larger than the reference pressure. If it is determined in step S170 that the detected value of the pressure sensor 14 is greater than the reference pressure, the process proceeds to step S180. If it is determined in step S170 that the detected value of the pressure sensor 14 is not greater than the reference pressure, the pressure of the hydraulic oil in the supply oil passage 15 is released, and the process ends.

  In step S180, the control device 31 detects the failure of the pressure booster 12, informs the operator of the failure by the alarm device 32, and proceeds to step S190.

  In step S190, the control device 31 finishes after the spool position of the preload switching valve 17 is fixed at the II position and the spool position of the main pressure switching valve 24 is fixed at the II position.

  As described above, it is possible to eliminate the unnecessary return operation s4 by checking the pressure of the hydraulic oil supplied to the supply oil passage 15 before the caulking work and performing the return operation s4 only when there is pressure. it can. Further, when there is pressure, by performing the return operation s4, the movable portion 100a of the hydraulic crimping tool 100 is kept in a predetermined position, and when the sleeve S is gripped, the movable portion 100a is not hindered and is caulked smoothly. Work can be done.

  In addition, in step S170, it is determined that the detected value of the pressure sensor 14 is larger than the reference pressure, even though the pressure is released for a predetermined time so that the detected value of the pressure sensor 14 becomes the reference value. ing. That is, pressure remains in the pressure increasing chamber 13a of the pressure increasing cylinder 13 and the hydraulic pressure bonding tool 100 due to a failure of the pressure increasing device 12, such as the hydraulic pump 28, the preload switching valve 17, and the main pressure switching valve 24. A situation may be considered in which pressure is detected despite the fact that there is no actual pressure increasing chamber of the pressure increasing cylinder 13 and the pressure on the hydraulic pressure bonding tool 100 side due to a failure of the pressure sensor 14. Therefore, the operator is notified of the failure of the pressure booster 12. As described above, it is possible to prevent the sleeve S from being caulked with an inappropriate force by making it possible to detect the failure of the pressure increasing device 12 before performing the caulking work.

  In the above embodiment, the return operation is performed so that the detection value of the pressure sensor 14 becomes the reference pressure, but the present invention is not limited to this. For example, the return operation may be performed so that the detection value of the pressure sensor 14 becomes a pressure value (a pressure value slightly larger than the reference pressure) that does not hinder the gripping of the sleeve S.

  Further, in step S110, it is determined whether or not it is before the caulking work by determining whether or not the pressure increasing device 12 is activated, but the present invention is not limited to this. For example, after caulking the sleeve S using the hydraulic crimping tool 100, that is, when the operation mode of the hydraulic crimping tool 100 is switched from the return operation s4 to the stop state (waiting before caulking the next sleeve S) It is also possible to determine whether or not it is before caulking work.

  In step S140, the control device 31 sets the time for the return operation s4 according to the detection value of the pressure sensor 14 so that the detection value of the pressure sensor 14 becomes the reference pressure, but the present invention is not limited to this.

  In step S190, the control device 31 fixes the spool position of the preload switching valve 17 to the II position and the spool position of the main pressure switching valve 24 to the II position, so that the operator can Even if the failure is not recognized by the alarm device 32, the caulking operation of the hydraulic crimping tool 100 cannot be performed, so that the failure of the control device 31 can be recognized.

  A second embodiment of the pressure increasing device 12 for confirming the pressure of the hydraulic oil supplied to the supply oil passage 15 before the caulking work and releasing the pressure will be described with reference to FIG. In the second embodiment of FIG. 10, the time of the return operation s4 is set in advance regardless of the detection value of the pressure sensor 14. In the second embodiment shown in FIG. 10, steps S110 to S130 in FIG. 9 are similar steps, and thus the description starts from step S130.

  In step S <b> 130, the control device 31 determines whether or not the detected value of the pressure sensor 14 when the pressure increasing device 12 is started is greater than the reference pressure. If it is determined in step S130 that the detected value of the pressure sensor 14 is greater than the reference pressure, the process proceeds to step S240. If it is determined in step 130 that the detected value of the pressure sensor 14 is not greater than the reference pressure, the process ends.

  In step S240, the controller 31 determines the number of return operations s4 based on the detection value of the pressure sensor 14. The time of the return operation s4 is set in advance regardless of the detection value of the pressure sensor 14, and the number of return operations s4 is determined so that the detection value of the pressure sensor 14 becomes the reference pressure. When the number of return operations s4 is determined, the process proceeds to step S250.

  In step S250, the control device 31 switches the operation mode of the hydraulic crimping tool 100 to the return operation s4, and proceeds to step S260. The pilot check valve 27 is opened by moving the spool position of the main pressure switching valve 24 to the I position, and the hydraulic oil in the supply oil passage 15 is discharged to the hydraulic oil tank 30.

  In step S260, the control device 31 determines whether or not the operation mode of the hydraulic crimping tool 100 has been switched to the return operation s4 by the number of times (predetermined number of times) set in step S240. When the predetermined number of times has elapsed, the process proceeds to step S270.

  In step S270, the control device 31 determines again whether or not the detected value of the pressure sensor 14 is larger than the reference pressure. If it is determined in step S270 that the detected value of the pressure sensor 14 is greater than the reference pressure, the process proceeds to step S280. In step S270, when it is determined that the detected value of the pressure sensor 14 is not greater than the reference pressure, the pressure of the hydraulic oil in the supply oil passage 15 is released, and the process ends.

  In step S280, the control device 31 detects the failure of the pressure booster 12, informs the operator of the failure by the alarm device 32, and causes the process to proceed to step S290.

  In step S290, the control device 31 finishes with the spool position of the preload switching valve 17 being fixed at the II position and the spool position of the main pressure switching valve 24 being fixed at the II position.

  As described above, it is only necessary to perform a return operation (release pressure) according to the detection value of the pressure sensor 14 so that the detection value of the pressure sensor 14 becomes the reference pressure, and the return operation s4 sets a time in advance. Alternatively, the time may be set according to the detection value of the pressure sensor 14. In the above description, in order to increase the detection accuracy of the failure of the pressure booster 12, the time or number of the return operations s4 is determined so that the detected value of the pressure sensor 14 becomes the reference pressure. However, the present invention is not limited to this. . For example, regardless of the detection value of the sensor 14, the time of the return operation s4 may be set in advance, or the number of return operations s4 may be set in advance.

  In step S130, the control device 31 is configured to end when it is determined that the detected value of the pressure sensor 14 is not greater than the reference pressure, but is not limited thereto. For example, in step S130, when it is determined that the detection value of the pressure sensor 14 is not greater than the reference pressure, the control device 31 may perform the return operation s4 in a time shorter than a preset time.

  The operation mode of the caulking work performed after releasing the pressure will be described with reference to FIG. In FIG. 11, there is a pressure of the hydraulic oil in the supply oil passage 15 before the caulking work, and the description starts from the time when the pressure is released (step S170 in FIG. 9). Further, step S180 and step S190 are omitted because they are described in FIG.

  When it is determined that the detected value of the pressure sensor 14 is larger than the reference pressure when the pressure intensifying device 12 is activated, the control device 13 performs the return operation s4 performed during the caulking operation based on the detected value of the pressure sensor 14. Configured to increase time.

  In step S170, the control device 31 determines again whether or not the detection value of the pressure sensor 14 is larger than the reference pressure. If it is determined in step S170 that the detected value of the pressure sensor 14 is greater than the reference pressure, the process proceeds to step S180. If it is determined in step S170 that the detected value of the pressure sensor 14 is not greater than the reference pressure, the hydraulic oil pressure in the supply oil passage 15 is released, and the process proceeds to step S310.

  In step S310, the control device 31 determines whether or not the operation mode of the hydraulic crimping tool 100 has been switched to the temporary holding operation s1. When the operation mode of the hydraulic crimping tool 100 is switched to the temporary holding operation s1, the process proceeds to step S320.

  In step S320, the control device 31 moves the spool position of the preload switching valve 17 to the I position, moves the spool position of the main pressure switching valve 24 to the II position, and proceeds to step S330.

  In step S330, the control device 31 determines whether or not the operation mode of the hydraulic crimping tool 100 has been switched to the main compression operation. When the operation mode of the hydraulic crimping tool 100 is switched to the main compression operation, the process proceeds to step S340.

  In step S340, the control device 31 moves the spool position of the preload switching valve 17 to the III position, moves the spool position of the main pressure switching valve 24 to the II position, and proceeds to step S350.

  In step S350, the control device 31 determines whether or not the detection value of the pressure sensor 14 is a preload reference value. When the detected value of the pressure sensor 14 is the preload reference value, the process proceeds to step S360.

  In step S360, the control device 31 moves the spool position of the preload switching valve 17 to the II position, moves the spool position of the main pressure switching valve 24 to the III position, and proceeds to step S370.

  In step S370, the control device 31 determines whether or not the detection value of the pressure sensor 14 is the main pressure reference value. When the detected value of the pressure sensor 14 is the main pressure reference value, the process proceeds to step S380.

  In step S380, the control device 31 moves the spool position of the preload switching valve 17 to the II position, moves the spool position of the main pressure switching valve 24 to the I position, and ends when a predetermined time has elapsed. That is, the operation mode of the hydraulic crimping tool 100 is switched to the return operation s4, and the process ends when a predetermined time has elapsed. The predetermined time at this time is set longer than a preset time. Specifically, it is a time obtained by adding the time determined based on the detection value of the pressure sensor 14 in step S130 (see FIG. 9) to the preset time.

  If it is determined in step S130 that the detected value of the pressure sensor 14 is greater than the reference pressure, the previous caulking operation (if the pressure booster 12 is activated, the caulking performed when the pressure booster 12 is activated last time). When the operation mode of the hydraulic crimping tool 100 in the operation) is the return operation s4, the time for opening the pilot check valve 27 is short, so that the hydraulic oil in the supply oil passage 15 can be completely discharged to the hydraulic oil tank 30. The situation is not considered. Therefore, the control device 31 is configured to increase the time of the return operation s4 in the caulking work (the time for opening the pilot check valve 27), so that it is supplied at the end of the caulking work by the hydraulic crimping tool 100. The hydraulic oil can be discharged without remaining in the oil passage 15. Therefore, a smooth operation can be realized when, for example, continuous caulking operations are performed.

  In addition, although the operation | movement aspect of the crimping operation | work shown in FIG. 11 was demonstrated using 1st embodiment shown in FIG. 9, it can apply similarly in 2nd embodiment shown in FIG.

DESCRIPTION OF SYMBOLS 1 High-altitude work vehicle 13 Pressure increase cylinder 14 Pressure sensor 13a Pressure increase chamber 15 Supply oil path 17 Preload switching valve 18 Low pressure circuit 19 Preload circuit 21 Relief valve 25 Pressure decrease oil path 26 Pressure increase oil path 31 Control apparatus 32 Alarm apparatus

Claims (4)

A pressure increasing device for an aerial work vehicle that supplies hydraulic oil with hydraulic fluid increased by a pressure increasing cylinder,
A supply oil path connecting the pressure increasing chamber of the pressure increasing cylinder and the hydraulic tool;
An electromagnetic switching valve for preload for supplying hydraulic oil to the supply oil path;
A pressure increasing state in which hydraulic oil is supplied to the rod side oil chamber of the pressure increasing cylinder, and a pressure reducing state in which the operating oil is supplied to the head side oil chamber of the pressure increasing cylinder and the hydraulic oil in the supply oil passage is discharged. An electromagnetic switching valve for main pressure configured to be selectively switchable;
Pressure detecting means for detecting the pressure in the pressure increasing chamber;
Comprising
Work at a high place to switch the main pressure electromagnetic switching valve to a reduced pressure state so that the detected value becomes the reference pressure when the detected value of the pressure detecting means exceeds the reference pressure before the work with the hydraulic tool is performed Booster for cars.   The pressure increasing device for an aerial work vehicle according to claim 1, wherein a failure is detected based on a detection value of the pressure detection means after the main pressure solenoid valve is brought into a reduced pressure state.   The pressure increasing device for an aerial work vehicle according to claim 2, wherein when the failure is detected, an alarm is issued using an alarm means.   2. The system according to claim 1, wherein when the detected value of the pressure detecting means before the operation with the hydraulic tool exceeds a reference value, the time of the pressure-reducing state during the operation of the hydraulic tool is increased. 4. The pressure increasing device for an aerial work vehicle according to any one of 3 above.

Images