JP6805566B2 - Pressure booster for aerial work platforms - Google Patents

Description

The present invention relates to a pressure booster. More specifically, the present invention relates to a pressure booster for an aerial work platform that supplies boosted hydraulic oil to a flood control tool.

Conventionally, aerial work platforms are known in which a bucket on which an operator is boarded is provided at the tip of a telescopic boom. The aerial work platform is configured so that hydraulic oil can be supplied to hydraulic equipment such as hydraulic tools in the bucket. The aerial work platform 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. In the aerial work platform configured in this way, a pressure boosting device for supplying the pressure boosted hydraulic oil is provided. For example, as described in Patent Document 1.

The pressure booster for aerial work platforms described in Patent Document 1 controls the pressure boosting cylinder by switching between the directional control valve on the upstream side and the directional control valve on the downstream side to boost the oil pressure of the hydraulic oil. In the pressure booster, a downstream directional control valve is connected in series to an upstream directional control valve to which hydraulic oil is supplied from a hydraulic pump. The directional control valve on the upstream side selectively supplies hydraulic oil to the oil chamber on the rod side of the booster cylinder to return the hydraulic crimping tool, and to supply the directional control valve on the downstream side. It is configured to switch. The directional control valve on the downstream side supplies the hydraulic oil to the hydraulic crimping tool without boosting the pressure to temporarily hold the hydraulic crimping tool, and supplies the hydraulic oil to the oil chamber on the head side of the boosting cylinder. The hydraulic oil is increased in pressure to selectively switch to the state in which the main compression operation of the hydraulic crimping tool is performed.

In the pressure booster for aerial work platforms described in Patent Document 1, a pressure switch is connected to the pressure boosting oil chamber of the pressure boosting cylinder, and whether or not the oil pressure in the pressure boosting oil chamber exceeds a predetermined pressure is determined. Can be detected. The pressure switch and the directional 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 the pressure switch detects that the pressure exceeds a predetermined pressure.

Japanese Unexamined Patent Publication No. 2014-20543

The pressure switch of the pressure booster described in Patent Document 1 can only determine whether or not the pressure value in the pressure boosting chamber (pressure boosting oil chamber) has reached a predetermined pressure. Therefore, it was not possible to grasp the pressure of the hydraulic oil supplied to the hydraulic tool. Further, even in a pressure booster having a structure in which a pressure sensor is provided instead of a pressure switch in the pressure boosting chamber, the value detected by the pressure sensor is such that the hydraulic oil boosted by the pressure boosting cylinder is supplied to the flood control tool. The effects of pressure loss and changes in oil temperature will not be taken into consideration. Therefore, the pressure of the hydraulic oil supplied to the hydraulic tool cannot be accurately grasped, and the object (sleeve) may not be crimped with the set force.
Therefore, an object of the present invention is to provide a pressure booster for an aerial work platform capable of supplying hydraulic oil of an arbitrarily determined pressure to a flood control tool.

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

That is, the pressure booster for a high-place work vehicle is a pressure booster for a high-place work vehicle that supplies the hydraulic oil boosted by the pressure boost cylinder to the flood control tool, and the pressure boost chamber of the pressure boost cylinder and the above. A supply oil passage connecting a hydraulic tool, a first pressure detecting means for detecting the pressure in the pressure boosting chamber, an electromagnetic switching valve for preloading hydraulic oil to the supply oil passage, and the first pressure detection. When the detection value of the means is a predetermined value, the hydraulic oil is supplied to the head side oil chamber of the pressure boosting cylinder through the pressure boosting oil passage, and then to the rod side oil chamber of the pressure boosting cylinder through the decompression oil passage. The electromagnetic switching valve for main pressure, which is configured to be switchable in the state of supplying the flood control, the second pressure detecting means for detecting the pressure of the hydraulic oil supplied to the hydraulic tool, and the detection value of the first pressure detecting means. A display device for displaying a value obtained by multiplying is multiplied by a correction coefficient, and a predetermined value of the first pressure detecting means is adjusted so that the maximum pressure detected by the second pressure detecting means becomes a target value . the correction factor is, the maximum pressure detected by the said first pressure sensing means Ru is calculated such that the target value.

The pressure booster for aerial work platforms is based on the detection value of the first pressure detecting means after a lapse of a predetermined time from the state of supplying hydraulic oil to the head side oil chamber of the pressure boosting cylinder through the pressure boosting oil passage. Detect a failure.

According to the present invention, the predetermined value of the first pressure detecting means is set to a value in consideration of the influence of the pressure loss and the change in oil temperature that occur before the hydraulic oil boosted by the boosting cylinder is supplied to the flood control tool. Therefore, the hydraulic oil of an arbitrarily determined pressure can be supplied to the hydraulic tool.

The side view which shows the whole structure of the aerial work platform which concerns on this invention. The figure which shows the hydraulic circuit of the pressure booster for the aerial work platform which concerns on this invention. The figure which shows the control structure of the pressure booster for aerial work platforms which concerns on this invention. The figure which shows the operation mode of the hydraulic tool connected to the pressure booster for the aerial work platform which concerns on this invention. The figure which shows the operation mode of the hydraulic circuit at the time of the temporary holding operation in the pressure booster for aerial work platforms which concerns on this invention. The figure which shows the operation mode of the hydraulic circuit of the preload stage at the time of this compression operation in the pressure booster for aerial work platforms which concerns on this invention. The figure which shows the operation mode of the hydraulic circuit of the main pressure stage at the time of this compression operation in the pressure booster for aerial work platforms which concerns on this invention. The figure which shows the operation mode of the hydraulic circuit at the time of the return operation in the pressure booster for aerial work platforms which concerns on this invention. The figure which shows a part of the hydraulic circuit to which the pressure gauge is connected in the pressure booster for the aerial work platform which concerns on this invention. FIG. 5 is a flowchart showing a control mode in adjusting the pressure of hydraulic oil supplied to a hydraulic tool in the pressure booster for an aerial work platform according to the present invention. The flowchart which shows the control mode in the detection of the failure in the pressure booster for the aerial work platform which concerns on this invention.

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

As shown in FIG. 1, the aerial work platform 1 is an aerial work platform for electrical wiring work in which the sleeve S is crimped using a hydraulic crimping tool 100 (see FIG. 2), which is a hydraulic tool, to connect power lines to each other. Is. The aerial work platform 1 has a vehicle 2 and an aerial work platform 6.

The vehicle 2 conveys the aerial work platform 6. The vehicle 2 is provided with a driver's cab 2b and a plurality of wheels 3 in the frame 2a, and is equipped with an engine 4 (see FIG. 2) as a power source. The vehicle 2 is configured to travel by transmitting the driving force of the engine 4 to the plurality of wheels 3 according to the operation from the driver's cab 2b. The vehicle 2 is provided with an outrigger 5. The outrigger 5 is composed of an overhang beam that can be extended by flood control on both sides of the vehicle 2 in the width direction and a hydraulic jack cylinder that can be extended in a direction perpendicular to the ground. The vehicle 2 can expand the workable range of the aerial work platform 1 by extending the outrigger 5 in the width direction of the vehicle 2 and grounding the jack cylinder.

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

The swivel base 7 swivels the aerial work platform 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 its center of rotation is perpendicular to the installation surface of the vehicle 2. The swivel base 7 is rotatably configured with the center of the annular bearing as the center of rotation. Further, 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 into the boom member in the order of the size of the cross-sectional area. The telescopic boom 8 is configured so that each boom member can move in the axial direction. That is, the telescopic boom 8 is configured to be telescopic by moving each boom member with a telescopic cylinder or the like (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 swing around the base end of the boom member with respect to the swivel base 7.

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

The undulating cylinder 10 raises and lays down the telescopic boom 8 to maintain the posture of the telescopic boom 8. The undulating cylinder 10 is composed of a hydraulic cylinder. The base of the undulating cylinder 10 is oscillatingly connected to the swivel base 7, and the rod tip is oscillatingly connected to the telescopic boom 8. The undulating cylinder 10 erects or undulates the telescopic boom 8 by expanding and contracting the rod.

The operating device 11 operates 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 operation device 11 is provided with a swivel telescopic operation tool for swiveling the swivel base 7, a swivel telescopic operation for expanding and contracting the telescopic boom 8, an undulating operation tool for performing the undulating operation of the telescopic boom 8, an engine start switch, and the like. Further, the operating device 11 is provided with a hydraulic switching operating tool 11a (see FIG. 3) for switching the hydraulic pressure of the hydraulic oil supplied to the hydraulic crimping tool 100. The hydraulic switching operating tool 11a switches the hydraulic oil to the hydraulic crimping tool 100 in a state where the increased pressure can be supplied, and discharges the hydraulic oil from the hydraulic crimping tool 100.

The aerial work platform 1 configured in this way can move the aerial work platform 6 to an arbitrary position by running the vehicle 2. Further, in the aerial work platform 1, the telescopic boom 8 is erected at an arbitrary undulating angle by the undulating cylinder 10, the telescopic boom 8 is extended to an arbitrary boom length, and the moving range of the bucket 9 of the aerial work platform 6 is extended. Can be expanded.

Hereinafter, the pressure booster 12 included in the aerial work platform 1 will be described with reference to FIGS. 2 and 3.

As shown in FIG. 2, the pressure booster 12 boosts the oil pressure of the hydraulic oil supplied to the hydraulic crimping tool 100. The pressure boosting device 12 includes a pressure boosting cylinder 13, a pressure sensor 14, an electromagnetic switching valve for pressurization (preload switching valve 17) which is a directional control valve, a relief valve 21, and an electromagnetic switching valve for main pressure which is a directional control valve. It includes a main pressure switching valve 24), a pilot check valve 27, a hydraulic pump 28, and a control device 31 (see FIG. 3).

The pressure boosting cylinder 13 boosts the hydraulic pressure of the hydraulic oil. The pressure boosting cylinder 13 is composed of a hydraulic cylinder provided with a bottomed cylindrical pressure boosting chamber 13a provided on the rod side. The pressure boosting cylinder 13 is configured so that the inner diameter of the pressure boosting chamber 13a is smaller than the inner diameter of the hydraulic cylinder. A large-diameter piston 13d to which the rod 13f is connected is slidably inserted inside the hydraulic cylinder. Inside the hydraulic cylinder, a rod-side oil chamber 13b and a head-side oil chamber 13c are configured. A small-diameter piston 13e is slidably inserted inside the pressure boosting chamber 13a. In the pressure boosting cylinder 13, the small diameter piston 13e in the pressure boosting chamber 13a and the large diameter piston 13d in the hydraulic cylinder are connected via a rod 13f. When hydraulic oil is supplied to the oil chamber 13c on the head side of the hydraulic cylinder, the pressure boosting 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 in the pressure boosting chamber 13a. As a result, the pressure boosting cylinder 13 pressurizes the hydraulic oil in the pressure boosting chamber 13a by the force boosted 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 boosting chamber 13a of the pressure boosting cylinder 13 as a first pressure detecting means. The pressure sensor 14 can detect the oil pressure of the hydraulic oil in the pressure boosting chamber 13a in real time. The pressure sensor 14 is connected to the control device 31. Further, a supply oil passage 15 is connected to the pressure boosting chamber 13a of the pressure boosting 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 boosting device 12 is configured so that the hydraulic oil boosted in the pressure boosting chamber 13a of the pressure boosting cylinder 13 can be supplied to the hydraulic crimping tool 100 connected to the joint 16 through the supply oil passage 15. ..

The pressurizing electromagnetic switching valve (hereinafter, simply referred to as “preload switching valve 17”), which is a directional control valve, is a supply in which the boosting chamber 13a of the boosting cylinder 13 and the hydraulic crimping 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 a discharge oil passage 20. That is, the 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 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 that controls the oil pressure of the hydraulic oil to a set value or less is connected to the low-pressure oil passage 18 connected to one port of the preload switching valve 17. In the relief valve 21, a branch oil passage branched from the low pressure oil passage 18 is connected to the inlet port, and a hydraulic oil tank 30 is connected to the 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 oil 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 oil 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 hydraulic oil flowing through the low-pressure oil passage 18 is limited to the relief flow rate of the relief valve 21 or less by the throttle 22. 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 in which 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 the operation signal is not received from the control device 31). The spool is moved to position II. That is, the preload switching valve 17 is switched to a state in which the hydraulic oil discharged from the hydraulic pump 28 is not supplied to the supply oil passage 15. As a result, the pressure booster 12 does not supply hydraulic oil to the pressure boosting chamber 13a of the pressure boosting cylinder 13 and the hydraulic crimping tool 100 through the oil supply passage 15.

The preload switching valve 17 has a low-pressure oil passage when an electromagnet is excited so that one port and a supply port communicate with each other (when an operation signal for supplying low-pressure hydraulic oil is received from the control device 31). 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 the low pressure hydraulic oil to the pressure boosting chamber 13a of the pressure boosting cylinder 13 and the hydraulic crimping tool 100 through the supply oil passage 15. At this time, the flow rate of the hydraulic oil supplied to the pressure boosting chamber 13a of the pressure boosting cylinder 13 and the hydraulic crimping tool 100 is limited by the throttle 22 of the low pressure oil passage 18.

The preload switching valve 17 has a preload oil passage when the electromagnet is excited so that the other port and the supply port communicate with each other (when an operation signal for supplying the preload hydraulic oil is received from the control device 31). The spool is moved to position III in which 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 hydraulic oil is supplied to the supply oil passage 15 through the preload oil passage 19. As a result, the pressure booster 12 supplies the hydraulic oil of the preload to the pressure boosting chamber 13a of the pressure boosting cylinder 13 and the hydraulic crimping tool 100 through the supply oil passage 15.

The 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 the hydraulic oil supplied to the boosting cylinder 13. A rod-side oil chamber 13b of the pressure boosting cylinder 13 is connected to one port of the main pressure switching valve 24 via a pressure reducing oil passage 25. The head side oil chamber 13c of the pressure boosting cylinder 13 is connected to the other port of the main pressure switching valve 24 via the pressure boosting oil passage 26. A hydraulic pump 28 is connected to the supply port of the main pressure switching valve 24 via a discharge oil passage 20. That is, hydraulic oil is supplied to the main pressure switching valve 24 with a preload. In the main pressure switching valve 24, one of one port and the other port is communicated with the supply port by moving a spool (not shown) by an electromagnet. The main pressure switching valve 24 is connected to the control device 31.

The main pressure switching valve 24 is in a state where the decompression oil passage 25 and the pressure boosting oil passage 26 are connected to the hydraulic oil tank 30 when the electromagnet is not excited (when the operation signal is not received from the control device 31). The spool is moved to a certain II position. That is, the preload switching valve 17 is switched to a state in which the hydraulic oil discharged from the hydraulic pump 28 is not supplied to the boosting cylinder 13. As a result, the pressure booster 12 does not boost the hydraulic pressure of the hydraulic oil by the pressure booster cylinder 13.

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

The main pressure switching valve 24 is used when the electromagnet is excited so that the other port and the supply port communicate with each other (when an operation signal for increasing the hydraulic pressure of the hydraulic oil is received from the control device 31). The spool is moved to position III in which 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. 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 13c of the pressure boosting cylinder 13 through the pressure boosting oil passage 26. As a result, the pressure booster 12 moves the small-diameter piston 13e in the direction in which the volume of the pressure boosting chamber 13a decreases to boost the hydraulic pressure of the hydraulic oil.

The pilot check valve 27 opens 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. Further, the pilot type check valve 27 is configured so that the pilot hydraulic oil is supplied from the pressure reducing oil passage 25. When the main pressure switching valve 24 is switched to a state of supplying hydraulic oil to the rod side oil chamber 13b of the boosting cylinder 13, the pilot type check valve 27 is opened by supplying hydraulic oil for pilot from the pressure reducing oil passage 25. To speak. The hydraulic oil in the pressure boosting chamber 13a connected to the supply oil passage 15 and the hydraulic oil in the hydraulic crimping tool 100 are returned to the hydraulic oil tank 30 through the pilot check valve 27. As a result, the pressure booster 12 is configured to be able to quickly discharge the hydraulic oil in the pressure boosting chamber 13a and the hydraulic oil in the hydraulic crimping tool 100.

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 in parallel to the hydraulic pump 28. The hydraulic oil discharged from the hydraulic pump 28 is supplied to the preload switching valve 17 and the main pressure switching valve 24, respectively, through the discharge oil passage 20. A relief valve 29 for a hydraulic pump is provided in the discharge oil passage 20. The relief valve 29 for a hydraulic pump controls the oil 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 operation of the preload switching valve 17 and the main pressure switching valve 24 of the pressure boosting device 12. The control device 31 may actually have a configuration in which a CPU, ROM, RAM, HDD, etc. are connected by a bus, or may have a configuration including a one-chip LSI or the like. The control device 31 stores various programs and data for controlling the operation 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 switching operating tool 11a, and can acquire an operation signal from the hydraulic switching operating tool 11a.

The control device 31 is connected to the pressure sensor 14 of the pressure boosting chamber 13a, and can acquire the detected value of the oil pressure of the hydraulic oil in the pressure boosting 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 operating tool 100c of the hydraulic crimping tool 100 via the connector 31a, and can acquire an operation signal from the hydraulic crimping tool 100.

The control device 31 is connected to a display device 33 composed of a liquid crystal panel or the like, and displays information related to the operating status of each part of the pressure booster 12 (for example, the rotation speed of the hydraulic pump 28). The display device 33 can display a value obtained by multiplying the detected value of the pressure sensor 14 by a correction coefficient described later. The display device 33 is arranged at an arbitrary position such as the vehicle 2 or the bucket 9. The display device 33 may be configured by a tablet PC or the like.

In the present embodiment, the pressure boosting cylinder 13 of the pressure booster 12 of the aerial work platform 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 on the vehicle 2 of the aerial work platform 1. In the pressure booster 12, the 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, the operation mode of the pressure booster 12 in the caulking work of the sleeve S for electrical wiring by the hydraulic crimping tool 100 will be described with reference to FIGS. 2 and 4 to 8. In the present embodiment, the pressure booster 12 is connected to the hydraulic crimping tool 100 to the joint 16 and the tool operating tool 100c of the hydraulic crimping tool 100 to the control device 31 via the connector 31a. To do.

As shown in FIG. 4, the hydraulic crimping tool 100 connected to the pressure booster 12 grips and crimps the sleeve S for electrical wiring. The hydraulic crimping tool 100 is configured such that the movable portion 100a moves toward the receiving portion 100b by the hydraulic oil supplied from the pressure boosting device 12. In the hydraulic crimping tool 100, the movable portion 100a is stopped in the stopped state s0 by the operation of the tool operating tool 100c, the movable portion 100a is moved toward the receiving portion 100b, and the sleeve S is moved to the movable portion 100a and the receiving portion 100b. The temporary holding operation s1 to be gripped by the above, the preloading step s2 of the main compression operation in which the movable portion 100a is pressed by a predetermined force to preload the sleeve S, and the movable portion 100a is pressed by a predetermined force to press the sleeve S. It is possible to carry out the main pressure step s3 of the main compression operation of caulking and the return operation s4 in which the movable portion 100a is moved away from the receiving portion 100b to release the sleeve S.

As shown in FIG. 2, when the operation mode of the hydraulic crimping tool 100 is switched to the stopped state 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 passage 18 And the preload oil passage 19 are 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 II in which 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. As a result, the hydraulic crimping tool 100 stops in a state where the movable portion 100a is separated from the receiving portion 100b (a state in which 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 low pressure oil. The passage 18 is connected to the discharge oil passage 20, and the preload oil passage 19 is moved to the I 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 position II in which the pressure reducing oil passage 25 and the pressure increasing oil passage 26 are connected to the hydraulic oil tank 30. That is, in the pressure boosting device 12, the hydraulic pressure is controlled to a low pressure by the relief valve 21, and the hydraulic oil whose flow rate is controlled to be equal to or lower than the relief flow rate by the throttle 22 is used with the pressure boosting chamber 13a of the pressure boosting cylinder 13 and the hydraulic crimping tool 100. (See the light ink part). As a result, 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 booster 12 discharges air in the pressure boosting chamber 13a, the hydraulic crimping 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 present compression operation 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 preload oil passage. 19 is connected to the discharge oil passage 20, and the low pressure oil passage 18 is moved to the position III in which 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 II in which 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 hydraulic oil of the preload, which is the discharge pressure of the hydraulic pump 28, to the pressure boosting chamber 13a of the pressure boosting cylinder 13 and the hydraulic crimping tool 100 (see the light ink portion). As a result, in the hydraulic crimping tool 100, as the preload step s2 of the main compression operation, the movable portion 100a is pressed by a predetermined force by the hydraulic oil of the preload that is not boosted, and the preload is applied to the sleeve S (black arrow). reference). At the same time, the pressure booster 12 discharges the air in the pressure boosting chamber 13a, the hydraulic crimping tool 100, and the supply oil passage 15 by supplying the hydraulic oil of the preload.

As shown in FIG. 7, when the detected value of the pressure sensor 14 reaches the preload reference value which is a predetermined value in the preload step s2 of this compression operation, the control device 31 lowers the spool position of the preload switching valve 17 to a low pressure. The oil passage 18 and the preload oil passage 19 are moved to the II position where they are connected to the hydraulic oil tank 30. At the same time, the control device 31 sets the spool position of the main pressure switching valve 24 to the position III in which the boosting 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 boosting device 12 reduces 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 it to the hydraulic crimping tool 100 (see the light ink portion). .. As a result, in the hydraulic crimping tool 100, as the main pressure step s3 of the main compression operation, the movable portion 100a is pressed by the hydraulic oil boosted by the pressure boosting cylinder 13 with a predetermined force to crimp the sleeve S (black). See painted arrow).

As shown in FIG. 8, when the detected value of the pressure sensor 14 reaches the main pressure reference value which is a predetermined value, 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. To the position II, which is connected to the hydraulic oil tank 30. At the same time, the control device 31 sets 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 boosting device 12 increases the volume of the pressure boosting chamber 13a of the pressure boosting cylinder 13 to reduce the oil pressure of the hydraulic oil in the pressure boosting chamber 13a, and opens the pilot check valve 27 to increase the pressure 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 light ink portion). As a result, in the hydraulic crimping tool 100, the movable portion 100a is moved in the direction away from the receiving portion 100b, and the sleeve S is released from the movable portion 100a and the receiving portion 100b (see the black arrow).

Further, when the hydraulic switching operation tool 11a of the aerial work platform 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 detected value of the pressure sensor 14. The road 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 sets 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 boosting device 12 increases the volume of the pressure boosting chamber 13a to reduce the oil pressure of the hydraulic oil in the pressure boosting chamber 13a, and opens the pilot check valve 27 to open the hydraulic oil in the pressure boosting chamber 13a. And the hydraulic oil in the hydraulic crimping tool 100 are discharged to the hydraulic oil tank 30. As a result, in the hydraulic crimping tool 100, the movable portion 100a is moved in the direction away from the receiving portion 100b, and the sleeve S is released from the movable portion 100a and the receiving portion 100b.

Hereinafter, adjustment of the pressure of the hydraulic oil (force for crimping the sleeve S) supplied to the hydraulic crimping tool 100 will be described with reference to FIGS. 9 and 10. The pressure of the hydraulic oil supplied to the hydraulic crimping tool 100 is adjusted while performing this compression operation with the bucket 9 lowered to the ground.

The pressure gauge 32 is provided as a second pressure detecting means for detecting the pressure of the hydraulic oil supplied to the hydraulic crimping tool 100. The pressure gauge 32 is provided by being connected between the joints 16 and 16 to which the hydraulic crimping tool 100 and the hydraulic hose constituting the supply oil passage 15 are connected. When adjusting the pressure of the hydraulic crimping tool 100, which will be described later, the hydraulic crimping tool 100 and the hydraulic hose are temporarily removed, and the pressure gauge 32 is connected between the joints 16 and 16. The pressure gauge 32 is connected to the control device 31 via the connector 32a, and the control device 31 can acquire a signal of the detected value of the pressure gauge 32 (see FIG. 3).

As shown in FIG. 9, when adjusting the pressure of the hydraulic oil supplied to the hydraulic crimping tool 100, the joint 16 in which the hydraulic crimping tool 100 and the hydraulic hose constituting the supply oil passage 15 are connected. A pressure gauge 32 is connected between the 16. The pressure gauge 32 can measure the pressure of the hydraulic oil supplied from the pressure increasing chamber 13a to the hydraulic crimping tool 100, that is, the pressure of the hydraulic oil supplied to the hydraulic crimping tool 100.

The adjustment of the pressure of the hydraulic oil supplied to the hydraulic crimping tool 100 will be described with reference to FIG.
In step S110, the control device 31 determines whether or not it is the main pressure step s3 of the main compression operation. When it is the main pressure step s3 of the main compression operation, that is, when it is determined that the spool position of the preload switching valve 17 is in the II position and the spool position of the main pressure switching valve 24 is in the III position, the process proceeds to step S120. Let me.

In step S120, the control device 31 reduces 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 it to the hydraulic crimping tool 100. At this time, a signal about the pressure value detected by the pressure gauge 32 is acquired, and the process proceeds to step S130.

In step S130, the control device 31 determines whether or not the maximum pressure detected by the pressure gauge 32 is the target value. The target value refers to an arbitrary value within the specified pressure range of the sleeve S crimped by the hydraulic crimping tool 100. If the maximum pressure is not the target value, that is, the maximum pressure is not within the specified pressure range of the sleeve S, the process proceeds to step S140. When the maximum pressure is the target value, that is, the maximum pressure is within the specified pressure range of the sleeve S, the process proceeds to step S150. Further, the target value can be set via an input device connected to the control device 31.

In step S140, the control device 31 changes the main pressure reference value so that the maximum pressure detected by the pressure gauge 32 becomes the target value, and shifts to step S150.

In step S150, the control device 31 calculates a correction coefficient so that the maximum pressure detected by the pressure sensor 14 becomes equal to the maximum pressure (main pressure reference value) detected by the pressure gauge 32, and ends.

As described above, by providing the hydraulic hose constituting the pressure booster 12 at the side end of the hydraulic crimping tool 100, the pressure loss and the oil temperature generated while being supplied from the pressure boosting chamber 13a to the hydraulic crimping tool 100 The pressure of the hydraulic oil in consideration of the influence of the change of the above, that is, the pressure of the hydraulic oil supplied to the hydraulic crimping tool 100 can be detected. Further, by changing the main pressure reference value so that the maximum pressure detected by the pressure gauge 32 becomes the target value, the pressure of the hydraulic oil supplied to the hydraulic crimping tool 100 is adjusted to an arbitrarily determined value. , The sleeve S can be crimped with an appropriate force.

Further, the correction coefficient is calculated so that the maximum pressure detected by the pressure sensor 14 is equal to the maximum pressure detected by the pressure gauge 32, and the maximum pressure detected by the pressure sensor is multiplied by the correction coefficient to obtain the pressure gauge 32. The maximum pressure detected by can be estimated.
By displaying the estimated maximum pressure on the display device 33, when the caulking work is actually performed with the pressure gauge 32 removed, the work is performed while grasping the pressure of the hydraulic oil supplied to the hydraulic crimping tool 100. It can be carried out.

The pressure gauge 32, which is the second pressure detecting means, can be easily attached between the joints 16 and 16 to which the hydraulic hose constituting the supply oil passage 15 and the hydraulic crimping tool 100 are connected. Therefore, the pressure supplied to the hydraulic crimping tool can be easily measured. The pressure of the hydraulic oil supplied to the hydraulic crimping tool 100 can be adjusted without removing the exterior of the pressure booster 12 or using a tool.

The second pressure detecting means for measuring the pressure of the hydraulic oil supplied to the hydraulic crimping tool 100 is not limited to the pressure gauge 32, and the location is not the end of the supply oil passage 15 on the hydraulic crimping tool 100 side. May be good. For example, a pressure sensor 14 or a load cell may be used instead of the pressure gauge 32. When the pressure sensor 14 is used, the pressure sensor 14 may be provided so as to be able to detect the pressure of the hydraulic cylinders constituting the hydraulic crimping tool 100. By providing the pressure of the hydraulic cylinders constituting the hydraulic crimping tool 100 so as to be detectable, the measurement accuracy of the pressure for crimping the sleeve S of the hydraulic crimping tool 100 can be improved. When a load cell is used, the measurement accuracy of the pressure for crimping the sleeve S of the hydraulic crimping tool 100 can be further improved.

The pressure gauge 32 may be configured not to be connected to the control device 31. In this case, the control device 31 is connected to an input device composed of arbitrary input operating tools (for example, buttons, switches, etc.). The control device 31 is configured so that the preload reference value and the main pressure reference value can be changed by the operator operating the input device. In the following, the control device 31 is determined to be in the main pressure step s3 of the main compression operation, and has acquired a signal of the pressure value of the pressure gauge.

The operator confirms whether or not the maximum pressure measured by the pressure value of the pressure gauge 32 is the target value in the main pressure step s3 of the main compression operation. If the maximum pressure is higher than the target value, change it to lower the main pressure reference value via the input device, and if the maximum pressure is smaller than the target value, increase the main pressure reference value via the input device. Change to. Based on the changed main pressure reference value, the main compression operation is performed again, and the operator confirms whether or not the maximum pressure is the target value. As described above, the main pressure reference value is changed by using the input device, and the main compression operation is performed until the maximum pressure reaches the target value. When the maximum pressure reaches the target value, the operator inputs the maximum pressure via the input device, and the control device 31 uses the maximum pressure (main pressure reference value) detected by the pressure sensor 14 and the pressure gauge 32. The correction coefficient is calculated so that it is equal to the maximum pressure measured by.

Hereinafter, a method for detecting a failure of the pressure booster 12 in the main compression operation by the hydraulic crimping tool 100 will be described.

In the control device 31, the operation mode of the hydraulic crimping tool 100 is switched to the preload step s2 of the main compression operation by the operation of the tool operating tool 100c, and the detected value of the pressure sensor 14 when a predetermined time elapses is the preload reference value. It is configured so that it can be determined whether or not it is. If the detected value after a lapse of a predetermined time is not the preload reference value, it is detected as a failure of the pressure booster 12.

In the preload step s2 of the main compression operation, the control device 31 reaches the preload reference value and is switched to the main pressure step s3 of the main compression operation, and the pressure sensor 14 when a predetermined time elapses. It is configured so that it can be determined whether or not the detected value of is the main pressure reference value. If the detected value after a lapse of a predetermined time is not the main pressure reference value, it is detected as a failure of the pressure booster 12.

The failure detection control of the pressure boosting device 12 by the control device 31 will be described with reference to FIG.

In step S210, the control device 31 determines whether or not the main compression operation has been started. When the main compression operation is started by the operation of the tool operating tool 100c, the process proceeds to step S220.

In step S220, the control device 31 moves the spool position of the preload switching valve 17 to the III position and the spool position of the main pressure switching valve 24 to the II position. In the hydraulic crimping tool 100, as the preload step s2 of the main compression operation, the movable portion 100a is pressed by a predetermined force by the hydraulic oil of the preload that has not been boosted to apply the preload to the sleeve S, and the process proceeds to step S3.

In step S230, 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 then (in the preload step s2 of the main compression operation). , It is determined whether or not the detected value of the pressure sensor 14 when the predetermined time has elapsed is the preload reference value. If it is determined in step S230 that the detected value of the pressure sensor 14 is not the preload reference value, the process proceeds to step S240. If it is determined in step S230 that the detected value of the pressure sensor 14 is the preload reference value, the process proceeds to step S250.

The preload reference value in step S230 is within a predetermined range in consideration of the pressure loss due to the resistance of the hydraulic hose, the change in oil temperature, and the detection error of the pressure sensor 14 based on the preload reference value set by the control device 31. Point to a value. Similarly, the predetermined time in step S230 refers to a time within a predetermined range in consideration of the pressure loss due to the resistance of the hydraulic hose, the change in oil temperature, and the detection error of the pressure sensor 14.

In step S240, since the detected value of the pressure sensor 14 is not the preload reference value, the control device 31 notifies the operator as a failure of the pressure boosting device 12. As the notification means, the control device 31 may be provided with an alarm device, or the display device 33 may display an alarm lamp. When the control device 31 detects a failure of the pressure boosting device 12, the control device 31 shifts to step S250.

In step S250, the control device 31 moves the spool position of the preload switching valve 17 to the position II in which 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 sets 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 and end.

In step S260, the control device 31 moves 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 III position. In the hydraulic crimping tool 100, as the preload step s2 of the main compression operation, the movable portion 100a is pressed by a predetermined force by the hydraulic oil of the preload that is not boosted to apply the preload to the sleeve S, and the process proceeds to step S270.

In step S270, 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 then (in the main pressure step s3 of the main compression operation). ), It is determined whether or not the detected value of the pressure sensor 14 when the predetermined time has elapsed is the main pressure reference value. When it is determined in step S270 that the detected value of the pressure sensor 14 is the main pressure reference value, the main compression operation is terminated (shifts to the return operation). If it is determined in step S270 that the detected value of the pressure sensor 14 is not the main pressure reference value, the process proceeds to step S280.

The main pressure reference value in step S270 is a predetermined range in consideration of the pressure loss due to the resistance of the hydraulic hose, the change in oil temperature, and the detection error of the pressure sensor 14 based on the main pressure reference value set by the control device 31. Refers to the value in. Similarly, the predetermined time in step S270 refers to a time within a predetermined range in consideration of the pressure loss due to the resistance of the hydraulic hose, the change in oil temperature, and the detection error of the pressure sensor 14.

In step S280, since the detected value of the pressure sensor 14 is not the main pressure reference value, the control device 31 notifies the operator as a failure of the pressure boosting device 12. As the notification means, the control device 31 may be provided with an alarm device, or the display device 33 may display an alarm lamp. When the control device 31 detects a failure of the pressure boosting device 12, the control device 31 shifts to step S290.

In step S290, the control device 31 moves the spool position of the preload switching valve 17 to the position II in which 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 sets 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 and end.

As described above, the control device 31 determines whether or not the detected value of the pressure sensor 14 when the predetermined time elapses is the preload reference value in the preload step s2 of the main compression operation, thereby controlling the pump and the direction. It is possible to detect a failure of a component of the pressure booster 12 such as a valve. By detecting the failure of the pressure booster 12 and notifying the operator, the worker can know the failure of the pressure booster 12 during the caulking operation and can prevent the caulking operation due to an inappropriate pressure. it can.

Similarly, in the main pressure step s3 of the main compression operation, the control device 31 determines whether or not the detected value of the pressure sensor 14 when a predetermined time has elapsed is the main pressure reference value, thereby controlling the pump and the direction. It is possible to detect a failure of a component of the pressure booster 12 such as a valve. By detecting the failure of the pressure booster 12 and notifying the operator, the worker can know the failure of the pressure booster 12 during the caulking operation and can prevent the caulking operation due to an inappropriate pressure. it can.

Further, if the movable portion 100a of the hydraulic crimping tool 100 does not move and the control device 31 does not detect a failure even though the tool operating tool 100c is being operated, the flood control is applied. It can be seen that a failure of the type crimping tool 100 has occurred.

Further, in the configuration in which the pressure sensor 14 is provided in the hydraulic cylinder of the hydraulic crimping tool 100, if the maximum pressure detected by the pressure sensor 14 is not within the specified pressure of the sleeve S, the hydraulic crimping tool 100 It can be detected as a failure of.

It should be noted that a series of inspection work before the work including adjustment of the pressure of the hydraulic oil supplied to the hydraulic crimping tool 100 shown above is performed in the inspection mode before the crimping work is performed using the hydraulic crimping tool 100. The control device 31 may be configured in the above.

The control device 31 detects the failure of the pressure booster 12 from the detection value of the pressure sensor after a lapse of a predetermined time, but the control device 31 is not limited to this. For example, the control device 31 may be configured to detect a failure of the pressure booster 12 from the amount of change in the detected value of the pressure sensor 14 per predetermined time. In this case, if the amount of change per predetermined time is out of the value within the predetermined range, it is detected as a failure of the pressure booster 12.

The case where the hydraulic crimping tool 100 is connected to the pressure booster 12 of the aerial work platform 1 has been described above, but the present invention is not limited to the hydraulic crimping tool 100, and the hydraulic tool that can be attached to and detached from the pressure booster 12 It should be. The above-described embodiment only shows a typical embodiment, and can be variously modified and implemented within a range that does not deviate from the gist of one embodiment. It goes without saying that it can be carried out in various forms, and the scope of the present invention is indicated by the description of the claims, and further, the equal meaning described in the claims, and all within the scope. Including changes.

1 Aerial work platform 13 Pressure boosting cylinder 14 Pressure sensor 13a Pressure boosting chamber 15 Supply oil passage 17 Preload switching valve 18 Low pressure circuit 19 Preload circuit 21 Relief valve 25 Decompression oil passage 26 Pressure boosting oil passage 31 Control device 32 Pressure gauge 33 Display device

Claims (2)

A pressure booster for aerial work platforms that supplies hydraulic oil boosted by a pressure boost cylinder to flood control tools.
A supply oil passage connecting the pressure boosting chamber of the pressure boosting cylinder and the hydraulic tool, and
The first pressure detecting means for detecting the pressure in the pressure boosting chamber and
An electromagnetic switching valve for preload that supplies hydraulic oil to the supply oil passage,
When the detection value of the first pressure detecting means is a predetermined value, the pressure is reduced from the state where the hydraulic oil is supplied to the head side oil chamber of the pressure increasing cylinder through the pressure increasing oil passage to the rod side oil chamber of the pressure increasing cylinder. An electromagnetic switching valve for main pressure that can be switched to supply hydraulic oil through the oil passage,
A second pressure detecting means for detecting the pressure of the hydraulic oil supplied to the hydraulic tool, and
A display device that displays a value obtained by multiplying the detection value of the first pressure detecting means by a correction coefficient, and
Equipped with
A predetermined value of the first pressure detecting means is adjusted so that the maximum pressure detected by the second pressure detecting means becomes a target value .
The correction factor is, the pressure boosting device for aerial platforms that maximum pressure is Ru is calculated such that the target value for the detection of the first pressure detecting means. The high according to claim 1, wherein a failure is detected based on a value detected by the first pressure detecting means after a lapse of a predetermined time from a state in which hydraulic oil is supplied to the head side oil chamber of the pressure boosting cylinder through a pressure boosting oil passage. Pressure booster for aerial work platforms.

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