JP4757540B2 - Aerial work platform - Google Patents

Description

The present invention has a work table at the tip of a boom that is stored in a retracted posture with the tip directed rearward on the vehicle body, and includes a jack that is attached to the front, rear, left, and right of the vehicle to support the vehicle Related to aerial work vehicles.

  In general, an aerial work vehicle such as that described above is provided with a swivel base that can swivel relative to the vehicle body on a travelable vehicle body, and the swivel base can freely move up and down with respect to the vehicle body by the expansion and contraction of the hoisting cylinder. The boom is pivotally connected to each other, and the entire boom is expanded and contracted by the expansion and contraction of the telescopic cylinder inside the boom in which a plurality of boom members are nested. In addition, a work table is freely attached to the tip of the boom so that it can freely swivel (neck vibration), and an operator who gets on the work table moves the boom up and down, swivels, and expands and contracts, and swivels the work table. The workbench can be moved to a desired or arbitrary height position. In addition, the vehicle body is provided with boom receivers that support the boom by contacting the lower surface of the boom that has fallen down in a fully contracted state. A jack which can be expanded and contracted is provided below the widening and the vehicle body, and this jack can support the vehicle body when working at a high place.

  In the aerial work vehicle as described above, the boom is stored on the vehicle body in a predetermined posture during non-high work. This stowed position varies depending on the position of the swivel post, etc., and in an aerial work vehicle in which the swivel post is erected at the front part of the vehicle body, the boom is stored in a posture with its tip end directed toward the rear of the vehicle body. . In addition, the work table attached to the tip of the boom stored in the rearward direction of the vehicle body is positioned at the rear and upper parts of the vehicle body at the storage position. Further, during non-high work, jacks disposed on the left and right sides of the vehicle body are stored in a fully contracted state.

  When starting work at a high place, it is necessary for the worker to board the work table from the ground, but the work table in the retracted position as described above is located at a high position from the ground and is difficult to get in. The following control is performed so that the user can easily get on the work table. In other words, the boom is extended from the retracted position by a predetermined length so that the boom is on the ground, and the jack is extended from the retracted position so that the vehicle is grounded, and the vehicle body is inclined to the rear of the vehicle. Thus, the work table is moved to the ground getting on / off position close to the ground behind the vehicle body. When the work table is located at the ground getting-on / off position, it is close to the ground, so that it is easy to get on the work table, and the worker can safely get on the work table from the ground.

In addition, the above-described high-altitude work vehicles are provided with a safety mechanism for high-altitude work by preventing the jack from operating when the boom is not stored in the vehicle body or the boom during the operation of the jack. Further, for example, an interlock control device that restricts the simultaneous operation of the boom and the jack as described in Patent Document 1 and Patent Document 2 is provided. When moving the work platform from the retracted position of the boom and jack to the ground entry / exit position, first, the jack is extended from the retracted position to be grounded, and then the boom is extended by a predetermined length. Lock control is performed.
JP 2003-128393 A JP 2002-348099 A

  However, when the work table is moved from the retracted position of the boom and jack to the ground entry / exit position while restricting the simultaneous operation of the boom and jack by the interlock control, the jack is first moved out of the retracted position as described above. Control is performed to extend the boom by a predetermined length after that, and it is necessary to operate the jack and the boom separately, so it is necessary to move the work platform to the ground entry / exit position. There was a problem that the operation was troublesome and took time.

  In view of the above problems, the present invention provides an aerial work vehicle capable of performing in a short time from when the boom and jack are stored in the vehicle body to when the work table is moved to the ground entry / exit position. For the purpose.

  In order to solve the above problems, an aerial work vehicle according to the present invention includes a travelable vehicle body having a driving cabin in front, and a base (for example, a turning post in the embodiment) erected on the rear side of the driving cabin of the vehicle body. 21) A base end portion is attached and is configured to be at least extendable and retractable, and a boom is stored on the vehicle body in a retracted posture in which the distal end portion is directed to the rear of the vehicle body, and a predetermined retracted posture is attached to the distal end portion of the boom. A work table stored on the vehicle body, and provided on the front, rear, left, and right sides of the vehicle body, and each of which is configured to be vertically extendable and retractable. The operation control means for controlling the operation of the boom and the plurality of jacks (for example, the controller 50 in the embodiment), and the boom and the plurality of jacks are restricted from operating simultaneously. Interlock control means (for example, the interlock valve ILV in the embodiment), ground entry operation means (for example, the ground entry switch SW1 in the embodiment) that is provided on the vehicle body and can be operated by the operator, and operation control And when the ground entry operation means is operated in the retracted posture with the boom and the plurality of jacks, the boom is at least extended to be brought into the boom ground getting on / off posture, and the plurality of jacks is extended to be moved to the plurality of Ground entry control means for moving the work platform to a work platform landing position close to the ground behind the vehicle body by grounding the lower end of the jack and tilting the vehicle body backward (for example, the embodiment) The ground boarding control means 54) is configured to have a ground boarding control means when the ground boarding operation means is operated. From the retracted position of the boom and the plurality of jacks to the boom ground getting on and off posture and the vehicle body ground getting on and off posture, by releasing the restriction on the simultaneous operation of the boom and the plurality of jacks by the interlock control means, Extend and move the workbench to the platform landing position.

  Further, in the aerial work vehicle having the above-described configuration, the boom is configured to be pivotable, a hydraulic pump that discharges hydraulic oil, a pump oil passage that is connected to one end of the hydraulic pump, and the other end of the pump oil passage are connected. At the same time, the boom control oil passage (for example, the boom-side oil passage 65 in the embodiment) and one end of the first jack control oil passage (for example, the jack oil passage 66 in the embodiment) are connected and switched to switch the boom. An interlock valve that supplies hydraulic oil discharged from the hydraulic pump to either the control oil path or the first jack control oil path, and a boom control valve (for example, connected to the other end of the boom control oil path) The telescopic motion control valve BV1, the undulation motion control valve BV2, and the swing motion control valve BV3) in the embodiment are connected to the boom control valve and the swing motor that swings the boom. A swing control oil passage (for example, the first sub oil passage 82 and the second sub oil passage 83 in the embodiment) and a jack control valve to which the other end of the first jack control oil passage is connected, and pump oil Switching means (for example, switching valve CHV in the embodiment) provided in the road, bypass oil path connecting the switching means and the boom control oil path without an interlock valve, a turning control oil path, and a jack control valve And a second jack control oil passage (for example, the branch oil passage 84 in the embodiment), on which the switching means is switched to switch between the interlock valve and the bypass oil passage. It is configured to supply hydraulic oil discharged from the hydraulic pump to the ground, and when the ground entry operation means is operated, the switching means is switched to connect the pump oil path and the bypass oil path, Supply hydraulic oil discharged from the pressure pump to the boom control valve via the bypass oil passage, and supply hydraulic oil supplied to the turning control oil passage to the jack control valve via the second jack control oil passage. Thus, it is preferable to enable simultaneous operation of the boom and the plurality of jacks.

  Furthermore, in the aerial work vehicle configured as described above, a hydraulic pump that discharges hydraulic oil, a pump oil passage that is connected to the hydraulic pump at one end, and the other end of the pump oil passage are connected, and a boom control oil passage ( For example, the boom control oil passage 65 ′ and the first jack control oil passage (for example, the jack oil passage 66 in the embodiment) in the embodiment are connected and switched so that the boom control oil passage and the first jack are switched. An interlock valve that supplies hydraulic oil discharged from the hydraulic pump to any one of the control oil passages, and a boom control valve that is connected to the other end of the boom control oil passage (for example, the telescopic motion control valve BV1 in the embodiment) Undulation control valve BV2 and swivel control valve BV3), and a first jack control valve to which the other end of the first jack control oil path is connected, A second jack control valve (for example, a jack proportional control valve BV4 in the embodiment) that is connected to a branch oil path that branches from the boom control oil path and that can supply hydraulic oil from the hydraulic pump via the boom control oil path; A second jack control oil passage (for example, the jack proportional control oil passage 102 in the embodiment) having one end connected to the second jack control valve and the other end connected to the first jack control oil passage. Then, when the ground entry control means operates the interlock valve from the hydraulic pump from the retracted attitude of the boom and the plurality of jacks to the boom ground entrance / exit attitude when the ground entry operation means is operated. Switch so that oil is supplied to the boom control oil path, switch the second jack control valve and switch the first jack control via the second jack control oil path. By supplying hydraulic oil to the control valve, the boom and a plurality of jacks may be operated simultaneously.

  In the aerial work vehicle having the above-described configuration, the second jack control valve is configured by a proportional control valve that controls the amount of hydraulic oil in the second jack control oil passage in a stepwise or continuous manner. By supplying hydraulic oil to the first jack control valve via the second jack control oil passage while controlling the opening of the jack control valve, the extension amounts of a plurality of jacks can be controlled stepwise or continuously. Is preferred.

  Furthermore, in the aerial work vehicle having the above-described configuration, one end is connected to the interlock valve, and a tank oil passage (for example, the tank oil passage 67 and the return oil passage 86 in the embodiment) that discharges hydraulic oil to the tank is provided. When the interlock valve is switched, the hydraulic oil in either the boom control oil path or the first jack control oil path is discharged to the tank, and at least the first jack control oil path and the interlock valve are arranged. On one side, an oil passage closing means (for example, a check valve 110 in the embodiment) for closing the first jack control oil passage is provided, and hydraulic oil from the hydraulic pump is supplied to the boom control oil passage so that the first jack control is performed. The oil passage closing means closes the first jack control oil passage when the interlock valve is switched so that the hydraulic fluid in the oil passage is discharged to the tank. This restricts the hydraulic oil supplied from the second jack control oil passage to the first jack control oil passage from being discharged to the tank oil passage through the interlock valve regardless of the switching of the interlock valve. Is preferred.

  According to the aerial work vehicle related to the present invention, the boom and the jack are operated from their retracted positions in order to start the aerial work even if the interlock control means for restricting the simultaneous operation of the boom and the jack is provided. Until the platform is moved to the ground entry / exit position, the restriction of the simultaneous operation of the boom and the jack by the interlock control means is canceled by the control of the hydraulic circuit provided in the aerial work vehicle. For this reason, since the extension movement of the boom and the extension movement of the jack can be performed simultaneously, it is possible to move the work table to the ground entry / exit position in a short time from the start of the operation of the ground entry operation means. In comparison, it is possible to shorten the time required to move to the ground getting on / off position. Then, it is possible to easily move the work table to the ground boarding / alighting position by one operation of the ground boarding operation means. As described above, the aerial work vehicle according to the present invention is designed to improve the efficiency at the start of the aerial work while ensuring the safety of the aerial work.

  In order to enable simultaneous operation of the boom and the jack, the hydraulic circuit provided in the aerial work vehicle according to the present invention for controlling the operation of the boom and the jack supplies the hydraulic oil from the hydraulic pump to the boom control oil path. Via the jack actuator. When hydraulic oil is supplied to the jack actuator, the hydraulic oil is supplied to a swing motor that controls the swing of the boom through a proportional control valve (a swing control valve in the embodiment) that controls supply and discharge, or boom control. Supply control is performed via a proportional control valve newly provided for jack control on the oil passage. For this reason, controlling the flow rate of hydraulic oil stepwise or continuously controls the amount of jack extension stepwise or continuously while suppressing the impact caused by the flow of hydraulic oil by gradually supplying and discharging the hydraulic oil. Is possible. Further, the extension amount of the jack can be finely adjusted according to the intention of the operator according to the road surface condition where the aerial work vehicle is stopped, and the operability of the jack can be improved. Furthermore, the hydraulic oil is supplied to the jack actuator when the boom and the jack are simultaneously operated. The hydraulic oil is supplied to the boom actuator via a proportional control valve that controls the turning of the boom without newly providing an oil passage for supplying the jack actuator. Since this is performed using the same oil passage (both boom control oil passages), it is possible to immediately respond to load fluctuations in the boom actuator and jack actuator (can be supplied without delay).

  Hereinafter, a preferred embodiment of an aerial work vehicle according to the present invention will be described with reference to FIGS. 1 to 10. An example of the aerial work vehicle is shown in FIGS. The direction of arrow F shown in FIG. 1 is the front, the direction of arrow R is the right, the direction of arrow F shown in FIG. 2 is the front, and the direction of arrow U is the top.

  The aerial work vehicle 1 includes front and rear wheels 11a and 11a and rear wheels 11b and 11b. The working device 20 is provided, and four jacks 40, 40,... The working device 20 includes a turning post 21 erected on the vehicle body 10, a boom 22 having a base end attached to the turning post 21, and a work table 24 attached to the distal end of the boom 22. .

The turning post 21 is erected on the front part of the vehicle body 10 and at the rear part of the driving cabin, and is configured to be able to turn by receiving the drive of the built-in turning motor BA3. The boom 22 is configured by combining a base end boom 22 a and a front end boom 22 b in a nested manner. The base end boom 22 a is pivotally attached to the turning post 21, and is turned together with the turning post 21. The boom 22 is configured to expand and contract in response to the expansion and contraction operation of the built-in expansion cylinder BA1, and is also moved up and down in response to the expansion and contraction operation of the hoisting cylinder BA2 disposed between the swing post 21 and the proximal boom 22a. It is configured to be up and down freely. A vertical post 23 is swingably attached to the tip of the tip boom 22b, and the tip boom 22b and the vertical post 2 are attached.
3, a leveling cylinder A <b> 1 that can be expanded and contracted is disposed. The vertical post 23 is swung in response to the expansion / contraction operation of the leveling cylinder A1.

  The work table 24 is composed of a bucket 24a for boarding an operator and a work table holding bracket 24b attached to the bucket 24a. The work table holding bracket 24b is vertically movable in a state in which the neck can freely vibrate around the axis of the vertical post 23. Attached to the post 23. The worktable holding bracket 24b incorporates a swing motor BA4. When the swing motor BA4 is driven, the worktable holding bracket 24b and the bucket 24a swing around the axis of the vertical post 23. The work table 24 is attached to the vertical post 23 so that the floor surface of the bucket 24a is horizontal when the vertical post 23 is in the vertical posture. A part of one side of the bucket 24a is notched from the upper end to the lower end, and a door 24c is attached to the notched portion so as to be opened and closed. Then, the operator can get on and off the bucket 24a by opening the door 24c as shown by a two-dot chain line (see FIG. 1).

  The work device 20 is stored on the vehicle body 10 as shown in FIGS. 1 and 2 when the work vehicle 1 is not in operation, such as during travel. In this retracted position, the telescopic cylinder BA1 is fully contracted to bring the boom 22 into a fully contracted state, and the swing post is set at a swing angle such that the tip of the fully contracted boom 22 does not protrude from the vehicle body 10 in plan view. 21 is located. Further, a boom receiver 13 formed with a boom placement surface 13a for placing the base end boom 22a at the upper end is erected at the rear portion of the vehicle body 10, and the boom 22 is placed on the boom placement surface 13a in the retracted position. The hoisting cylinder BA2 is operated so as to be placed. Note that the boom receiver 13 is disposed with the height position of the boom placement surface 13a set so that the undulation angle of the boom 22 when set to the retracted position becomes a negative angle (for example, about -10 degrees). The hoisting cylinder BA2 can be further reduced, and the boom 22 can be further lowered. The work table 24 attached to the tip of the boom 22 in such a storage posture is located at the rear and upper part of the vehicle body 10, and on the left side of the boom 22 and in the contraction direction so as not to protrude from the vehicle body 10 in plan view. Stored at the swing angle toward.

  The boom receiver 13 is configured by nesting a base post 13b that extends upward and is fixed to the vehicle body 10 and an extendable post 13c that forms a boom mounting surface 13a at the upper end. The telescopic post 13c is configured to be vertically expandable and contractible by the expansion and contraction operation of the boom receiving cylinder A2 incorporated in 13c. With such a configuration, the boom receiver 13 can be moved up and down to adjust the height position of the boom placement surface 13a.

  The work table 24 includes an operation unit 30 for performing an operation for operating the boom 22 and the like. As shown in FIG. 3, the operation unit 30 includes a boom operation lever 31 for performing the expansion / contraction operation, raising / lowering operation, and turning operation of the boom 22, and a swing operation lever 32 for performing the swing operation of the work table 24. The boom 22 and the work table 24 are configured to perform predetermined operations by tilting and twisting operations in the directions indicated by the arrows. The operation unit 30 includes a work table automatic storage switch SW5 that operates the boom 22 and the work table 24 together with the operation levers 31 and 32 so that the boom 22 and the work table 24 are automatically in the stored posture, which will be described later. A work state transition switch SW2 and an automatic ground descent switch SW3 are provided.

  At the base of the boom operation lever 31, there is provided a boom operation sensor S1 including an expansion / contraction potentiometer that detects a boom expansion / contraction operation, a undulation potentiometer that detects a boom undulation operation, and a turning potentiometer that detects a boom turning operation. The base of the swing operation lever 32 is provided with a swing operation sensor S2 including a switch that is turned off at the neutral position and turned on at the left and right tilt positions.

  The jacks 40, 40, 40, 40 provided on the front, rear, left and right of the vehicle body 10 are respectively inserted in the vertical direction from the lower end of the outer post 41 and the outer post 41 fixed to the side of the vehicle body 10 and extending in the vertical direction The inner post 42 and a jack pad 43 swingably attached to the lower end of the inner post 42. The inner post 42 is moved by the expansion and contraction of the built-in jack cylinder JA1 (JA2, JA3, JA4). It can be expanded and contracted up and down. The inner posts 42, 42,... Of the four jacks 40, 40,... Are extended downward to ground the jack pads 43, 43,. At this time, by setting the vehicle body 10 in a horizontal state, the vehicle body 10 becomes stable, and the boom 22 can be operated safely against the overturning moment acting on the vehicle body 10 according to the operation of the boom 22. .

  Each of the jack cylinders JA1 to JA4 is supplied and discharged according to the opening / closing operation of the jack control valves JV1 to JV4 provided in correspondence thereto, and the jack control valves JV1 to JV4 are connected to the vehicle body 10. The jacks 40, 40,... Are opened and closed by lever operations of the jack operating levers 33, 33,... Provided corresponding to the jacks 40, 40,. In addition to the jack operation levers 33 and 33, a ground entry switch SW1 and a vehicle body automatic storage switch SW4 are provided at the rear of the vehicle body 10, respectively.

  FIG. 4 is a block diagram showing the configuration of the controller 50 for an aerial work vehicle according to the present invention. A controller 50 that controls various operations of the aerial work vehicle 1 is connected to a valve control unit 51 for driving and controlling a control valve of a hydraulic actuator provided in the boom 22, the jack 40, and the like. Leveling control unit 53, ground boarding control unit 54, and work state transition control unit 55.

  The valve control unit 51 is provided corresponding to each of the hydraulic actuators JA1 to JA4, BA1 to BA4, A1, and A2, and controls each of the control valves JV1 to JV4, BV1 to BV4, V1, and V2 that controls supply and discharge of hydraulic oil. Drive control is performed. As shown in FIG. 4, the operation signals of the boom operation sensor S1 provided on the boom operation lever 31 and the swing operation sensor S2 provided on the swing operation lever 32 are output to the valve control unit 51, respectively. Has been. Based on the operation signals output from both operation sensors S1 and S2, the valve control unit 51 electromagnetically drives the expansion / contraction movement control valve BV1 to extend / contract the expansion cylinder BA1 and electromagnetically drives the movement control valve BV2 to cause the movement. The cylinder BA2 is expanded and contracted, the swing control valve BV3 is electromagnetically driven to drive the swing motor BA3, and the neck vibration control valve BV4 is electromagnetically driven to drive the swing motor BA4. Thereby, the operation of the boom 22 according to the lever operation of the boom operation lever 31 and the swing operation of the work table 24 according to the operation of the swing operation lever 32 are performed.

  Further, the valve control unit 51 electromagnetically drives the jack control valves JV1 to JV4 to expand and contract the corresponding jack cylinders JA1 to JA4. Thereby, the expansion / contraction operation of the jacks 40, 40,... 2 according to the lever operation of the jack operation lever 33 is performed. Further, the valve control unit 51 can electromagnetically drive the leveling control valve V1 to expand and contract the leveling cylinder A1, and electromagnetically drive the boom receiving control valve V2 to expand and contract the boom receiving cylinder A2.

  The hydraulic oil supplied to and discharged from each hydraulic actuator is configured to be discharged from a hydraulic pump P provided at a predetermined position of the vehicle body 10, and the hydraulic oil discharged from the hydraulic pump P passes through the control valves. It is supplied to and discharged from the corresponding hydraulic actuator. The hydraulic pump P is driven by receiving the rotational output of an electric motor M that is operated by a battery (not shown).

  The controller 50 is provided with an interlock portion 52 that operates when the operation state of the jack 40 and the boom 22 reaches a predetermined condition. When the interlock portion 52 is operated, an interlock valve ILV described later is operated, and interlock control for restricting simultaneous operation of the boom 22 and the jacks 40, 40,... Is performed.

  The work table 24 is provided with a gravity-type work table tilt angle sensor S 3, and is configured to sequentially output a detection signal of the tilt angle with respect to the vertical direction of the work table 24 to the leveling control unit 53. Based on the detection signal output from the work table inclination angle sensor S3, the leveling control unit 53 determines the inclination state of the work table 24 and outputs a leveling control signal to the valve control unit 51. The valve control valve 51 drives and controls the leveling control valve V1 based on this leveling control signal, causes the leveling cylinder A1 to expand and contract, and swings so that the vertical post 23 is always held in a vertical posture. As a result, the work table 24 (the floor surface of the bucket 24a) is always kept in a horizontal state regardless of the state of the boom 22 being raised or lowered.

  The operation signal of the ground entry switch SW1 provided in the vehicle body 10 is configured to be output to the ground entry control unit 54, and the operation signal of the work state transition switch SW2 provided in the work table 24 and the vehicle body 10 are configured. An inclination angle detection signal with respect to the vertical direction of the vehicle body 10 by the gravity-type vehicle body inclination angle sensor S4 provided above is output to the work state transition control unit 55. The work state transition control unit 55 is connected to the interlock unit 52.

  In the ground entry control unit 54, the detection signal of the inclination angle of the vehicle body 10 by the vehicle body inclination angle sensor S4 indicates the grounding state of the jacks 40, 40,... By the ground sensor S5 provided in each jack 40, 40,. The detection signal and the detection signal of the extension amount of the boom 22 by the extension amount sensor S6 provided on the boom 22 are respectively input.

  Here, with reference to FIG. 5 and FIG. 6, the hydraulic circuit 60 comprised by each hydraulic actuator JA1-JA4, BA1-BA3, each control valve JV1-JV4, BV1-BV3, etc. is demonstrated. 5 and FIG. 6, these portions are connected to each other, circle B is connected to these portions, and circle C is connected to each other to constitute an oil passage. .

  As shown in FIGS. 5 and 6, the hydraulic circuit 60 includes an oil tank T, a hydraulic pump P, a jack operation valve JV, jack cylinders JA1 to JA4, an interlock valve ILV, a switching valve CHV, a boom operation valve BV, and a telescopic cylinder. It is configured to have BA1, hoisting cylinder BA2, swing motor BA3, first shut-off valve SV1, second shut-off valve SV2, and the like. The jack operation valve JV includes control valves JV1 to JV4 corresponding to the jack cylinders JA1 to JA4 and an interlock valve ILV, and the boom operation valve BV is an expansion and contraction control valve corresponding to the expansion cylinder BA1. BV1, a hoisting control valve BV2 corresponding to the hoisting cylinder BA2, and a swing control valve BV3 corresponding to the swing motor BA3. The hydraulic circuit 60 is configured as described above. In addition, the swing motor BA4 that vibrates the work table 24, the control valve BV4 that controls the operation of the swing motor BA4, and the work table 24 are held horizontally. The leveling cylinder A1, the leveling control valve V1 for controlling the operation of the leveling cylinder A1, and further, a filter, a joint, and the like are included. However, these are complicated and are omitted here.

  The hydraulic pump P is driven by an electric motor M that is electrically driven by a battery (not shown), and discharges hydraulic oil necessary for the operation of the jack cylinders JA1 to JA4 and the telescopic cylinder BA1. The hydraulic pump P can be driven not only by a battery but also by a vehicle running engine (not shown).

  A switching valve CHV is provided in the middle of the pump oil passage 61 whose one end is connected to the hydraulic pump P. This switching valve CHV is a 3-port 2-position directional switching valve, which is normally in the right-hand movement position (see FIG. 5), and is supplied from the controller 50 (valve control section 51) according to the operation of the ground entry switch SW1. The exciting coil can be excited by the control signal and can be moved to the left. One end of a bypass oil passage 68 is connected to the switching valve CHV, and the other end of the bypass circuit 68 is connected to a boom side oil passage 65 connected to the boom operation valve BV. When the switching valve CHV is moved to the left under such a configuration, the communication between the pump oil passage 61 and the interlock valve ILV is cut off, the pump oil passage 61 and the bypass oil passage 68 are communicated, and the hydraulic pump P The hydraulic oil discharged from the refrigerant flows through the bypass oil passage 68 so that it can be supplied to the boom-side oil passage 65 (boom operation valve BV) without passing through the interlock ILV. Further, when the exciting coil is demagnetized and moved to the right from the state in which the switching valve CHV is moved to the left, the pump oil passage 61 is opened. In this state (when the switching valve CHV is in the right movement position), the hydraulic oil from the hydraulic pump P can be supplied to the interlock valve ILV side without being supplied to the boom operation valve BV side.

  The interlock valve ILV is a four-port, three-position directional switching valve that can excite the exciting coil by a control signal from the interlock section 52 of the controller 50 and can move right or left from its neutral position. is there. Here, when the interlock valve ILV moves to the right from its neutral position, the pump oil passage 61 communicates with the jack oil passage 66 that is connected to the control valves JV1 to JV4 and can supply hydraulic oil to the jack cylinders JA1 to JA4. The boom side oil passage 65 communicates with a tank oil passage 67 connected to the tank T via the return oil passage 86.

  Therefore, when the switching valve CHV is in the right movement position and hydraulic oil can be supplied only to the interlock valve ILV side, when the interlock valve ILV moves right from its neutral position, the hydraulic oil is discharged from the jack oil passage 66. The jacks 40, 40,... Can be expanded and contracted by being supplied to the jack cylinders JA1 to JA4, but the hydraulic oil is not supplied to the boom operation valve BV side via the boom side oil passage 65. Therefore, the operation of the boom 22 is restricted.

  On the other hand, when the interlock valve ILV moves leftward from its neutral position, the pump oil passage 61 and the boom-side oil passage 65 communicate with each other, and the jack oil passage 66 and the tank oil passage 67 communicate with each other. Therefore, when the switching valve CHV is in the right movement position and the interlock valve ILV moves to the left from its neutral position, hydraulic oil is supplied to the boom operation valve BV side via the boom side oil passage 65 and the boom. 22 can be operated, but since the hydraulic oil is not supplied to the jack cylinders JA1 to JA4 via the jack oil passage 66, the expansion and contraction of the jacks 40, 40,. As described above, when the switching valve CHV is in the left movement position, only the operation of the boom 22 and the jacks 40, 40,... Is possible, and the boom 22 and the jacks 40, 40,. The operation is restricted (interlock control).

  The jack oil passage 66 is provided with a check valve 98. The check valve 98 causes the interlock valve ILV to move to the left from its neutral position so that the jack oil passage 66 communicates with the tank T. Even in the case of communicating with the path 86, the hydraulic oil supplied from the branch oil path 84 is not discharged without being supplied to the jack cylinders JA1 to JA4 as will be described later.

  The boom-side oil passage 65 includes a telescopic cylinder oil passage 70 connected to the telescopic motion control valve BV1, a hoisting cylinder oil passage 75 connected to the hoisting control valve BV2, and a swing motor connected to the swing motion control valve BV3. The oil passage 80 is branched.

  The telescopic cylinder oil passage 70 includes a pump-side oil passage 71, a tank-side oil passage 74, a bottom-side oil passage 72, and a rod-side oil passage 73. The expansion / contraction control valve BV1 and the bottom side oil chamber of the expansion cylinder BA1 communicate with each other through the bottom side oil passage 72, and the expansion / contraction control valve BV1 and the rod side oil chamber of the expansion cylinder BA1 communicate with the rod side oil passage 73. Communicate with each other.

  The telescopic motion control valve BV1 is an electromagnetic switching valve that is switch-controlled based on a control signal from the valve control unit 51 that receives an operation signal from the boom operation sensor S1. The expansion / contraction control valve BV1 is a four-port / three-position switching valve. In the neutral position, the pump-side oil passage 71 and the tank-side oil passage 74 are prevented from communicating with each other, and the bottom-side oil passage 72 and the rod-side oil passage 73 are blocked. Block communication with. In the left movement position, the port connected to the pump-side oil passage 71 and the port connected to the rod-side oil passage 73 are communicated, and the port connected to the tank-side oil passage 74 and the port connected to the bottom-side oil passage 72 are communicated. On the other hand, in the right movement position, the port connected to the pump side oil passage 71 and the port connected to the bottom side oil passage 72 are communicated, and the port connected to the tank side oil passage 74 and the port connected to the rod side oil passage 73 are communicated. The tank side oil passage 74 is connected to the return oil passage 86.

  The expansion / contraction control valve BV1 is a directional switching valve, and an electromagnetic proportional control valve capable of adjusting the flow rate of hydraulic fluid flowing through the valve by the amount of movement of the valve spool according to the magnitude of the variable current flowing through the exciting coil. It is. For this reason, the amount of expansion and contraction of the boom 22 is freely controlled by controlling the opening and closing amount of the expansion / contraction control valve BV1 and the operation amount of the expansion / contraction cylinder BA1 according to the amount of tilting operation from the neutral position of the boom operation lever 31. Can be adjusted to.

  The pump-side oil passage 71 is provided with a pressure reducing valve 90 that reduces the hydraulic pressure of the hydraulic oil discharged from the hydraulic pump P to a predetermined pressure. Further, the bottom side oil passage 72 and the rod side oil passage 73 are always allowed to allow the hydraulic oil in the bottom side oil passage 72 to flow into the bottom side oil chamber of the telescopic cylinder BA1, and the oil pressure in the rod side oil passage 73 is maintained. Only when the pressure exceeds the predetermined pressure, the hydraulic oil is allowed to flow out from the bottom side oil chamber of the expansion cylinder BA1 in the bottom side oil passage 72, and the rod side oil chamber of the expansion cylinder BA1 of the hydraulic oil in the rod side oil passage 73 is allowed. Double holding that always allows inflow into the rod side oil passage 73 and allows the hydraulic oil to flow out from the rod side oil chamber of the telescopic cylinder BA1 only when the oil pressure in the bottom side oil passage 72 exceeds a predetermined pressure. A valve 91 is provided. The double holding valve 91 is for preventing the boom 22 from expanding and contracting due to a sudden contraction or expansion of the expansion cylinder BA1 even when the hydraulic fluid leaks due to damage to the pump oil passage 61 or the like. .

  The undulating cylinder oil passage 75 has substantially the same configuration as the telescopic cylinder oil passage 70, and has a pump side oil passage 76, a tank side oil passage 79, a bottom side oil passage 77, and a rod side oil passage 78. The undulation control valve BV2 and the bottom side oil chamber of the undulation cylinder BA2 communicate with each other through the bottom side oil passage 77, and the undulation control valve BV2 and the rod side oil chamber of the undulation cylinder BA2 communicate with each other through the rod side oil passage 78. To do. The pump-side oil passage 76 is provided with a pressure reducing valve 92, the bottom-side oil passage 77 is provided with a holding valve 93, and the rod-side oil passage 78 is branched from this and connected to a return oil passage 86. The branch oil passage 97 is provided with a pilot tick valve 94. The tank side oil passage 79 is connected to the return oil passage 86.

  The raising / lowering control valve BV2 is an electromagnetic switching valve that is switch-controlled based on a control signal from the valve control unit 51 that receives the operation signal from the boom operation sensor S1. This undulation control valve BV2 is a 4-port 3-position switching valve. In the neutral position, the pump-side oil passage 76 and the tank-side oil passage 79 are prevented from communicating with each other, and the bottom-side oil passage 77 and the rod-side oil passage 78 are blocked. Block communication with. In the left movement position, the port connected to the pump side oil passage 76 and the port connected to the rod side oil passage 78 are communicated, and the port connected to the tank side oil passage 79 and the port connected to the bottom side oil passage 77 are communicated. On the other hand, in the right movement position, the port connected to the pump side oil passage 76 and the port connected to the bottom side oil passage 77 are communicated, and the port connected to the tank side oil passage 79 and the port connected to the rod side oil passage 78 are communicated.

  The undulation control valve BV2 is a direction switching valve, like the expansion / contraction control valve BV1, and the flow rate of hydraulic oil flowing through the valve according to the amount of movement of the valve spool corresponding to the magnitude of the variable current flowing through the exciting coil. It is an electromagnetic proportional control valve that can be adjusted. For this reason, the hoisting angle of the boom 22 is freely controlled by controlling the opening / closing amount of the hoisting control valve BV2 in accordance with the tilting operation amount from the neutral position of the boom operating lever 31 and the operating amount of the hoisting cylinder BA2. Can be adjusted to.

  The holding valve 93 includes a check valve 93a, a relief valve 93b, and a pilot-type tick valve 93c. Even when the pump oil passage 61 is damaged or the like and the hydraulic oil leaks, the hoisting cylinder BA2 is rapidly reduced. It is for preventing.

  The turning motor oil passage 80 has a pump side oil passage 81, a tank side oil passage 85, a first auxiliary oil passage 82, and a second auxiliary oil passage 83, and these oil passages 81 to 83 control the turning motion control valve BV3. Connected to the center. The pump side oil passage 81 is provided with a pressure reducing valve 95, and the first auxiliary oil passage 82 and the second auxiliary oil passage 83 are connected via a turning motor BA3.

  The turning control valve BV3 is an electromagnetic switching valve that is switch-controlled based on a control signal from the valve control unit 51 that has received an operation signal from the boom operation sensor S1. This turning control valve BV3 is a four-port three-position switching valve. In its neutral position, communication between the pump-side oil passage 81 and the tank-side oil passage 85 is prevented, and the first sub-oil passage 82 and the second sub-oil Block communication with the road 83. In the left movement position, the port connected to the pump side oil passage 81 and the port connected to the second auxiliary oil passage 83 are communicated, and the port connected to the tank side oil passage 85 and the port connected to the first auxiliary oil passage 82 are communicated. Let On the other hand, in the right movement position, the port connected to the pump side oil passage 81 and the port connected to the first auxiliary oil passage 82 are communicated, and the port connected to the tank side oil passage 85 and the port connected to the second auxiliary oil passage 83 are communicated. Let

  Similarly to the expansion / contraction control valve BV1, the swing control valve BV3 is a direction switching valve, and the flow rate of hydraulic oil flowing through the valve according to the amount of movement of the valve spool corresponding to the magnitude of the variable current flowing through the exciting coil. It is an electromagnetic proportional control valve that can be adjusted. For this reason, the opening / closing amount of the turning motion control valve BV3 is controlled in accordance with the amount of twisting operation from the neutral position of the boom operation lever 31, and the operation amount of the turning motor BA3 is controlled. It can be adjusted freely.

  The second sub oil passage 83 extending from the turning motor BA3 is provided with a branch oil passage 84 that branches from now on. The branch oil passage 84 communicates with the jack oil passage 66 of the jack operation valve JV connected to the jack cylinders JA1 to JA4. The branch oil passage 84 is provided with a first shutoff valve SV1 and a check valve 96. The first shut-off valve SV1 is normally in the closed position, but the excitation coil is excited by the control signal from the valve control unit 51 that receives the operation signal from the ground entry switch SW1, and the first shut-off valve SV1 is moved to the right from the closed position. It moves and opens. For this reason, when the first shut-off valve SV1 is opened, the hydraulic oil supplied from the turning control valve BV3 is supplied to the jack oil passage 66 via the branch oil passage 84 to operate the jack cylinders JA1 to JA4. The jacks 40, 40... Can be expanded and contracted. In a normal state where the ground entry switch SW1 is not operated, the hydraulic oil from the jack oil passage 66 flows into the second auxiliary oil passage 83 by the first shut-off valve SV1 and the check valve 96. Is to be blocked.

  The second sub oil passage 83 between the turning motor BA3 and the branch point where the branch oil passage 84 branches is provided with a second shut-off valve SV2. The exciting coil is activated by the control signal from the valve control unit 51 which receives the operation signal from the insertion switch SW1. The second shut-off valve SV2 is opened in a normal state where the ground entry switch SW1 is not operated, and the hydraulic oil in the first sub oil passage 82 and the second sub oil passage 83 by the turning motion control valve BV3 is opened. The turning motor BA3 can be operated by the supply / discharge control. On the other hand, when the exciting coil of the second shut-off valve SV2 is energized along with the operation of the ground entry switch SW1, the valve spool moves up in FIG. 6 and the second shut-off valve SV2 is closed.

  For this reason, when the first shut-off valve SV1 is opened by the operation of the ground entry switch SW1 and hydraulic fluid is supplied from the turning control valve BV3 toward the jack oil passage 66, the turning control valve BV3. Regardless of the operation, the operation of the turning motor BA3 is prevented.

  As mentioned above, although the structure of the controller with which the aerial work vehicle 1 was equipped, the structure of the hydraulic circuit 60, and its effect | action were demonstrated, Next, the procedure of the aerial work performed using this aerial work vehicle 1, The operation of the ground entry control unit 54 and the work state transition control unit 55 during high-altitude work will be described. Prior to the start of the aerial work, the aerial work vehicle 1 has the boom 22 and the work table 24 in the retracted position as shown in FIGS. 1 and 2, and the jacks 40, 40,. The front wheel 11a, 11a and the rear wheel 11b, 11b are in a grounded state.

  In the state as described above, first, the ground entry switch SW1 provided in the vehicle body 10 is operated. When the ground boarding switch SW1 is operated, an operation signal of the ground boarding switch SW1 is output to the ground boarding control unit 54, and a ground boarding control signal is output from the ground boarding control unit 54 to the valve control unit 51. The

  When receiving the ground boarding control signal, the valve control unit 51 outputs a control signal to the switching valve CHV to move the switching valve CHV to the left. Therefore, the pump oil passage 61 and the bypass oil passage 68 communicate with each other, and the hydraulic oil from the hydraulic pump P is supplied to the boom operation valve BV via the bypass oil passage 68.

  Further, when receiving the ground entry control signal, the valve control unit 51 outputs a control signal to the turning control valve BV3, the first shut-off valve SV1, and the second shut-off valve SV2, so that the turning control valve BV3 is turned on. By moving left from the neutral position, the first shut-off valve SV1 is opened and the second shut-off valve SV2 is closed. Therefore, the hydraulic oil supplied from the hydraulic pump P to the swing control valve BV3 of the boom operation valve BV is also supplied to the jack operation valve JV side via the branch oil passage 84. At this time, since the hydraulic oil is not supplied from the swing control valve BV3 of the boom operation valve BV to the swing motor BA3 by closing the second shut-off valve SV2, the swing motion of the boom 22 is restricted. In this way, by operating the ground entry switch SW1, it is possible to supply hydraulic oil to the telescopic cylinder BA1 and the hoisting cylinder BA2 and supply hydraulic oil to the jacks 40, 40,.

  Then, the valve control section 51 drives and controls the front left and front right jack control valves JV1 and JV2 to extend both the front left and front right jack cylinders JA1 and JA2 until the maximum extension amount is reached. The 40, 40 inner posts 42, 42 are extended downward with a maximum extension amount. Further, the rear left and rear right jack control valves JV3, JV4 are driven and controlled to extend the rear left and rear right jack cylinders JA3, JA4, and the inner posts 42, 42 of the rear left and right jacks 40, 40 are extended downward. Operate. At this time, the rear left and rear right jack control valves JV3, JV4 are driven so that the jack pads 43, 43 are extended by an extension amount that allows grounding. Thus, by operating the jacks 40, 40,..., The rear wheels 11b, 11b remain grounded, the front wheels 11a, 11a are grounded, and the vehicle body 10 has a predetermined rearward inclination angle θ1 (see FIG. 7). ), The rear end of the vehicle body 10 is brought close to the ground, and the bottom surface of the work table 24 is brought close to the ground.

  Here, the grounding sensor S5 detects the grounding of the front, rear, left and right jack pads 43, 43,..., And the vehicle body tilt angle sensor S4 provided on the vehicle body 10 causes the vehicle body 10 to tilt backward with a rearward tilt angle θ1. When detected, these detection signals are output to the ground boarding control unit 54, whereby the valve control unit 51 stops the extension operation of the jack cylinders JA1 to JA4. The ground sensor S5 may be configured by a method of detecting whether or not the ground is detected from the pressure values of the jack cylinders JA1 to JA4, or the jack cylinders JA1 to JA4 are attached to the outer posts 41, 41,. It may also be configured by a method of detecting whether or not the robot has been grounded by detecting whether or not it has moved by the amount of play set.

  As described above, along with the extension movement of the jacks 40, 40,..., The valve control unit 51 drives and controls the expansion / contraction movement control valve BV1 to extend the expansion cylinder BA1 and extend the boom 22 by a predetermined extension amount. Let Since the boom 22 has its tip portion directed rearward in the retracted posture, the work table 24 moves rearward by the extension operation of the boom 22. Further, as the vehicle body 10 approaches the rearward inclination angle θ1 due to the extension movement of the jacks 40, 40,..., The extending direction of the boom 22 is further inclined downward so that the work table 24 approaches the ground by the extension operation of the boom 22. Moving.

  When the extension operation of the boom 22 is finished, the valve control unit 51 drives and controls the raising / lowering control valve BV2 to reduce the raising / lowering cylinder BA2, and the boom 22 is lowered by a predetermined tilt angle θ2 (see FIG. 7). . As a result, the work table 24 is further brought closer to the ground as compared with the boom 22 only extending. Further, as shown in FIG. 7, the valve control unit 51 controls the boom receiving control valve V2 to reduce the boom receiving cylinder A2 simultaneously with the drive control of the raising / lowering control valve BV2, and contracts the telescopic post 13c. The height position of the boom placement surface 13a is lowered according to the fall operation of the boom 22.

  As described above, when the ground entry switch SW1 is operated, the vehicle body 10 is moved rearward as shown in FIG. 7 by the drive control of the valve control unit 51 based on the control signal output from the ground entry control unit 54. The boom 22 is tilted and the boom 22 is extended and laid down, and the work table 24 attached to the tip of the boom 22 moves to the ground boarding / alighting position. When the work table 24 is located at the ground entry / exit position, the work table 24 is close to the ground, so that the operator can easily get into the bucket 24a by opening the door 24c of the work table 24 from the ground. Become.

At this time, due to the extension operation of the jack 40 and the tilting operation of the boom 22, the work table 24 is tilted backward from the retracted position by the sum of the rearward tilt angle θ1 and the tilting angle θ2 as shown by a two-dot chain line in FIG. Will be. In this embodiment, the controller 50 is provided with a leveling control unit 53. After the operation of the ground entry switch SW1, the rear tilt angle of the vehicle body 10 and the change in the tilt angle of the boom 22 are changed from the work table tilt angle sensor S3. The detection signal shown is sequentially output to the leveling control unit 53, and the drive control of the leveling control valve V1 by the valve control unit 51 based on the control signal from the leveling control unit 53 is always performed. For this reason, the work table 24 is always held in a horizontal state as shown by a solid line in FIG. 7 regardless of the rearward tilt angle of the vehicle body 10 and the tilt angle of the boom 22.

  Next, the operator who has boarded the work table 24 operates the work state transition switch SW2 provided in the operation unit 30 of the work table 24. When the work state transition switch SW2 is operated, an operation signal of the work state transition switch SW2 is output to the work state transition control unit 55. Further, a detection signal of an inclination angle with respect to the horizontal plane of the vehicle body 10 by the vehicle body inclination angle sensor S4 is output to the work state transition control unit 55. When the operation signal of the work state transition switch SW2 is output, the work state transition control unit 55 outputs a work state transition control signal to the valve control unit 51.

  Upon receiving the work state transition control signal, the valve control unit 51 outputs a control signal to the switching valve CHV to move the switching valve CHV to the right. For this reason, the pump oil passage 61 and the interlock valve ILV communicate with each other. At this time, the work state transition control signal is also output to the interlock unit 52. When the interlock unit 52 receives the work state transition control signal, the interlock unit 52 moves the interlock valve ILV to the right from its neutral position. For this reason, the interlock control which permits the operation of the jacks 40, 40,... And restricts the operation of the boom 22 is started.

  When the valve control unit 51 receives the work state transition control signal, the valve control unit 51 outputs a control signal to the first shut-off valve SV1 and the second shut-off valve SV2, and closes the first shut-off valve SV1. The shut-off valve SV2 is opened. For this reason, the supply of hydraulic oil from the jack operation valve JV to the boom operation valve BV via the branch oil passage 84 is interrupted.

  Then, the valve control unit 51 drives and controls the rear left and rear right jack control valves JV3 and JV4 to extend the rear left and rear right jack cylinders JA3 and JA4, and the inner posts 42 of the rear left and right jacks 40 and 40 are operated. , 42 are extended. Accordingly, the vehicle body 10 is supported in a state where the rear wheels 11b and 11b are grounded. Further, the front left and front right jack valves JV1 and JV4 are driven and controlled, the front left and front right jack cylinders JA1 and JA2 are contracted, and the inner posts 42 and 42 of the front left and right jacks 40 and 40 are contracted.

  At this time, a work state shift control signal is output until the vehicle body 10 is in a horizontal state by a detection signal from the vehicle body tilt angle sensor S4, and each jack control valve JA1 of the valve control unit 51 based on the work state shift control signal is output. By the drive control of JA4, the vehicle body 10 is supported in a horizontal state as shown in FIG. Until the vehicle body 10 is supported in the horizontal state, as described above, the interlock control for restricting the operation of the boom 22 is performed, and the boom 22 moves up and down regardless of the operation signal from the boom operation sensor S1. , Telescopic movement and turning movement are restricted. Therefore, the operations of the jacks 40, 40,... Can be performed safely until the vehicle body 10 is stably supported.

  The vehicle body 10 changes from the state of being tilted rearward as shown in FIG. 7 to the horizontal state shown in FIG. 8 while changing its posture so as to lift the rear part of the vehicle body 10. , 40,..., The drive control of the leveling control valve V1 by the valve control unit 51 based on the control signal from the leveling control unit 53 is performed in the same manner as when the work table 24 is moved to the ground getting on / off position. Thus, the work table 24 is held in a horizontal state regardless of the posture of the vehicle body 10.

  When the vehicle body 10 is in the horizontal state, the output of the work state transition control signal from the work state transition control unit 55 to the interlock unit 52 is stopped. At this time, the interlock valve ILV moves right or left from its neutral position based on the operation of the jack operation lever 33 or the operation of the boom operation lever 31, and the boom 22 and the jacks 40, 40,. Simultaneous operation is restricted. For this reason, when the boom 22 is moved up and down, expanded and contracted, and swung based on the operation signal from the boom operation sensor S1, the work table 24 is moved to a desired high position. The operation 24 is regulated and the work table 24 can be moved safely in a state where the vehicle body 10 is stably supported. Since the second shut-off valve SV2 is opened when the work platform 24 moves to the ground entry / exit position, when hydraulic oil is supplied to the boom operation valve BV via the interlock valve ILV, The hydraulic oil can be supplied to the turning motor BA3, and the boom 22 can be turned.

  As described above, the worker who moves the work table 24 to a desired height position and completes the height work finishes the automatic ground descent switch SW3 provided in the operation unit 30 and the work table automatic storage. Any one of the switches SW5 is operated. When the automatic ground descent switch SW3 is operated, an automatic ground descent control signal based on this operation is input to the valve control unit 51.

  When the automatic ground descent control signal is input, the valve control unit 51 first drives and controls the expansion / contraction motion control valve BV1 and the undulation motion control valve BV2 to cause the boom 22 to perform the reduction operation and the overturn operation, and the boom 22 is moved from a high place. The vehicle body 10 is lowered to a predetermined safe state. At the same time, the swing control valve BV3 and the neck vibration control valve BV4 are driven and controlled, the swing post 21 is positioned at the swing angle in the retracted position, and the work table 24 is positioned at the swing angle in the retracted position.

  Then, the valve control unit 51 drives and controls the jack control valves JV1 to JV4 to extend and retract the inner posts 42, 42,... Tilt the vehicle body 10 rearward, and extend and retract the control valve BV1 and the undulation control valve. BV2 is driven and controlled to bring the work table 24 close to the ground. As a result, the base end boom 22a is placed on the boom placement surface 13a of the boom receiver 13 where the telescopic post 13c remains in the contracted state, and the vehicle body 10 and the boom 22 are in the ground landing posture shown in FIG. Become. When the operations of the jacks 40, 40,..., The boom 22 and the work table 24 are stopped, the worker can open the door 24c and get down from the bucket 24a to the ground.

  The worker who got off the ground operates a vehicle body automatic storage switch SW4 provided on the vehicle body 10. When the vehicle body automatic storage switch SW4 is operated, a vehicle body automatic storage control signal based on this operation is input to the valve control unit 51.

  When the vehicle body automatic storage control signal is input, the valve control unit 51 drives and controls the hoisting and moving control valve BV2 to extend the hoisting cylinder BA2 and to raise and lower the boom 22 and to move the telescopic motion control valve BV1. Drive control is performed so that the telescopic cylinder BA1 is contracted to the fully contracted state, and the boom 22 is contracted to the fully contracted state. Accordingly, the jack control valves JV1 to JV4 are driven and controlled to control the jack cylinders JA1 to JA1. The JA4 is contracted to the fully contracted state, and the inner posts 42, 42,... Of the jacks 40, 40,. In addition to the drive control of the raising / lowering control valve BV2, the boom receiving control valve V2 is driven and controlled to extend the boom receiving cylinder A2, and the extendable post 13c is extended to raise the height of the boom mounting surface 13a. Move. As a result, the front wheels 11a and 11a are grounded, and the boom 22 and the workbench 24 are in the retracted posture shown in FIGS.

  Even when the work platform automatic storage switch SW5 is operated at the end of the work at the high-altitude work position, the work platform automatic storage control signal is generated in the same manner as when the vehicle body automatic storage switch SW4 is operated as described above. Input to the valve control unit 51, the expansion control valve BV1, the undulation control valve BV2, the swing control valve BV3, the neck vibration control valve BV4, and the boom receiver control valve V2 are respectively driven and controlled. Each is operated so as to be stored on the vehicle body 10, and the height position of the boom mounting surface 13a of the boom receiver 13 is moved upward to the initial position. In this case, the jack cylinders JA1 to JA4 are not expanded and contracted, and an operator who has descended from the work table 24 stored on the vehicle body 10 manually operates the jack operation levers 33 and 33 to operate the jack control valves JV1 to JV1. JV4 is driven and operated, the jack cylinders JA1 to JA4 are contracted, the inner post is contracted, and the jacks 40, 40,. Thereby, the aerial work vehicle 1 is in a state where the front wheels 11a and 11a and the rear wheels 11b and 11b are grounded as shown in FIGS.

  From the above, in the aerial work vehicle according to the present invention, the extension movements of the jacks 40 and 40 and the extension of the boom 22 from when the ground entry switch SW1 is operated until the work table 24 moves to the ground entry / exit position. Interlock control was performed to control the operation of the boom 22 until the vehicle body 10 was supported in a horizontal state after the operation state switch SW2 was operated and the vehicle body 10 was supported in a horizontal state. Even if the boom operation lever 31 is operated by the operator, the operation of the boom 22 is restricted. After the vehicle body 10 is supported in a horizontal state, when the boom control lever 31 is operated, interlock control is performed to restrict the operation of the jacks 40, 40,. The work table 24 can be safely moved to the position.

  If the operation of turning the boom 22 between the operation of the ground entry switch SW1 and the movement of the work platform 24 to the ground entry / exit position is required, the first operation from the valve control unit 51 is performed. This is possible by outputting control signals to the shut-off valve SV1 and the second shut-off valve SV2.

  That is, when the ground entry switch SW1 is operated, as described above, the first shut-off valve SV1 is opened and the second shut-off valve SV2 is closed. At this time, the first shut-off valve SV1 is opened. By closing and opening the second shut-off valve SV2, the supply of hydraulic oil from the turning control valve BV3 to the jack oil passage 66 via the branch oil passage 84 is temporarily interrupted, and the jacks 40, 40, It is possible to turn the boom 22 by a desired amount by supplying it from the turning control valve BV3 to the turning motor BA3 side in a state where the extending movement of... Is temporarily stopped.

  The procedure of the aerial work performed by the aerial work vehicle 1 equipped with the hydraulic circuit 60 has been described above. However, the hydraulic circuit installed in the aerial work vehicle 1 is limited to the hydraulic circuit 60 described in the first embodiment. It is not something that can be done. For this reason, with reference to FIGS. 9 and 10, the configuration of the hydraulic circuit 60 ′ and the control using the hydraulic circuit 60 ′ are taken as an example of a hydraulic circuit 60 ′ that is a modified example of the hydraulic circuit 60. explain. In addition, since the structure of the aerial work vehicle 1 and the controller with which it is mounted is substantially the same as that of the first embodiment, the description will focus on the differences from the first embodiment. 9 and 10, these portions are connected to each other, circle B is connected to these portions, and circle C is connected to each other to form an oil passage. .

  In this embodiment, the jack operation lever is controlled during the drive control of the boom 22 and the jacks 40, 40,... Of the valve control unit 51 based on the control signal output from the ground boarding control unit 54 when the ground boarding switch SW1 is operated. The hydraulic circuit 60 'is configured so as to perform a proportional operation so that the expansion amount of 40, 40,... Can be freely adjusted according to the operation amount of 33.

  As shown in FIG. 9, the pump oil passage 61 is connected to the interlock valve ILV, and the hydraulic oil discharged from the hydraulic pump P is supplied to the interlock valve ILV. This interlock valve ILV is connected to one end of the boom side oil passage 65 ′ and the jack oil passage 66, and is operated to discharge from the hydraulic pump P to either the boom side oil passage 65 ′ or the jack oil passage 66 by switching. It is possible to supply oil. In addition, a check valve 110 is provided in the jack oil passage 66 connected from the interlock valve ILV to each of the jack cylinders JA1 to JA4.

  When the interlock valve ILV moves to the left from its neutral position, the pump oil passage 61 and the boom side oil passage 65 'communicate with each other, and the jack oil passage 66 and the tank oil passage 67, that is, the boom side oil passage 65'. The return oil passage 86 communicates. On the other hand, when the interlock valve ILV moves rightward from the neutral position, the pump oil passage 61 and the jack oil passage 66 communicate with each other, and the boom side oil passage 65 ′ and the tank oil passage 67, that is, the boom side oil passage 65. 'Communicates with the return oil passage 86.

  For this reason, the hydraulic oil from the hydraulic pump P is supplied to the boom operation valve BV side via the boom side oil passage 65 by the left movement from the neutral position of the interlock valve ILV, and the hydraulic oil in the jack oil passage 66 is supplied to the tank. Discharged to T. Also, hydraulic oil from the hydraulic pump P is supplied to the jack cylinders A1 to JA4 via the jack oil passage 66 by moving right from the neutral position of the interlock valve ILV, and the hydraulic oil in the boom side oil passage 65 is supplied to the tank T. Discharged.

  As shown in FIG. 10, the boom-side oil passage 65 ′ includes a telescopic cylinder oil passage 70 connected to the telescopic motion control valve BV1, a hoisting cylinder oil passage 75 connected to the hoisting control valve BV2, and a swing motion control. And a turning motor oil passage 80 connected to the valve BV3. Further, a jack proportional control oil passage 102 branched from the swing motor oil passage 80 and connected to the jack proportional control valve BV4 is provided. The jack proportional control oil passage 102 includes a pump side oil passage 101 and a tank side oil passage 103. And have. The pump side oil passage 101 is provided with a pressure reducing valve 111 for reducing the hydraulic pressure of the hydraulic oil discharged from the hydraulic pump P to a predetermined pressure. The tank side oil passage 103 is connected to a return oil passage 86.

  A jack proportional control oil passage 102 extends from the jack proportional control valve BV4 toward the jack operation valve JV and is connected to the jack oil passage 66 (see FIG. 9). The jack proportional control valve BV4 is a directional switching valve, and the flow rate of the hydraulic oil flowing through the valve can be adjusted by the amount of movement of the valve spool corresponding to the magnitude of the current flowing through the exciting coil that changes as the jack operating lever 33 is operated. This is an electromagnetic proportional control valve. For this reason, the amount of oil sent to the jack oil passage 66 is controlled by controlling the opening / closing amount of the jack proportional control valve BV4 according to the tilting operation amount from the neutral position of the jack operating lever 33, and each jack control. The hydraulic fluid supplied to the valves JV1 to JV4 can be controlled to adjust the extension amount of the jacks 40, 40,.

  When hydraulic oil is supplied to the boom side oil passage 65 ′, hydraulic oil is also supplied to the jack oil passage 66 via the jack proportional control oil passage 102 by the hydraulic circuit configuration as described above. 40, 40, ... It is necessary to regulate the operation of the jacks 40, 40, ... when working at a high place where the boom 22 is operated while the vehicle body 10 is supported and the work table 24 is moved to a desired high place. In some cases, the jacks 40, 40,... May operate.

  For this reason, when working at a high place or the like, it is necessary to restrict the flow of hydraulic oil to the jack proportional control oil path 102 even when the hydraulic oil is supplied to the boom-side oil path 65 ′. Therefore, in this embodiment, the operation of the jack proportional control valve BV4 is enabled when the ground boarding switch SW1 is operated and a ground boarding control signal is output from the ground boarding control unit 54 to the valve control unit 51. On the other hand, when the ground entry control signal is not output to the valve control unit 51, such as when moving the work platform 24 to a desired high position, the operation from the neutral position of the jack proportional control valve BV4 is restricted. To be configured.

  If comprised in this way, when hydraulic oil is supplied to boom side oil path 65 'when the ground boarding control signal is not output from the ground boarding control part 54, hydraulic oil will be extended-contraction control valve BV1, The hydraulic oil is supplied to the telescopic cylinder BA1, the hoisting cylinder BA2, and the swing motor BA3 via the hoisting control valve BV2 and the swing control valve BV3, respectively. However, the hydraulic oil does not pass through the jack proportional control valve BV4, but the jack proportional control oil path. Since it does not flow to the side of 102, the jack cylinders JA1 to JA4 do not operate. Therefore, even if the simultaneous restriction of the boom 22 and the jacks 40, 40 may be released during the output of the ground entry control signal, the operation of the jacks 40, 40 is restricted during the work at high places. Safety is ensured.

  As a method for restricting the flow of hydraulic fluid to the jack proportional control fluid passage 102 when the hydraulic fluid is supplied to the boom side fluid passage 65 ', the method according to the output of the ground entry control signal as described above. For example, the position of the tip of the boom 22 is detected by the extension amount sensor S6 or the like (the turning angle, the extension amount, and the undulation amount of the boom 22 are detected) and the jack proportional control valve according to the position of the tip of the boom 22 is detected. The BV4 may be configured to be operable. With this configuration, the jack proportional control valve BV4 can be used when the tip of the boom 22 is located within a predetermined range where there is no problem in the stability of the vehicle body 10 even if the boom 22 and the jacks 40, 40 are operated simultaneously. Is activated and hydraulic oil flows to the jack proportional control oil passage 102 side and can be supplied to the jack cylinders JA1 to JA4. When the position of the tip of the boom 22 exceeds the predetermined range, the jack By restricting the operation of the proportional control valve BV4, the supply of hydraulic oil to the JA1 to JA4 can be stopped to the jack cylinder.

  The electromagnetic proportional control in which the jack proportional control valve BV4 can adjust the flow rate of the hydraulic oil flowing through the valve according to the amount of movement of the valve spool according to the magnitude of the current flowing through the exciting coil that is changed by the operation of the jack operating lever 33. Although the description has been given on the assumption that the valve is a valve, if the jack proportional control valve BV4 is a proportional control valve capable of adjusting the flow rate of hydraulic oil by moving the valve spool by manual operation of the operation lever, the operation of the operation lever is changed. A restricting means for restricting may be provided, and the movement of the operation lever may be restricted according to the output of the ground entry control signal, the position of the tip of the boom 22, and the like as described above.

  Further, as shown in FIG. 9, since the check valve 110 is provided on the jack oil passage 66, the interlock valve ILV moves to the left from its neutral position, and the hydraulic oil flows to the boom operation valve BV side. Even if it is supplied, the hydraulic oil flowing into the jack oil passage 66 via the jack proportional control oil passage 102 is restricted from flowing into the interlock valve ILV side. For this reason, even if the jack oil passage 66 and the tank oil passage 67 are communicated with each other by the left movement of the interlock valve ILV, that is, the jack oil passage 66 and the return oil passage 86 communicate with each other, The hydraulic fluid that flows to the jack oil passage 66 via the passage 102 is not returned to the tank T.

  Therefore, since the hydraulic oil flowing through the jack proportional control oil passage 102 to the jack oil passage 66 is supplied only to the jack cylinders JA1 to JA4 without being returned to the tank T, the jacks 40, 40. It is possible to make it. In order to reliably operate the jacks 40, 40... Without returning the hydraulic oil to the tank T, the method is not limited to the method of providing the check valve 110 on the jack oil passage 66 as described above. Other methods may be used. That is, when the hydraulic oil flows into the jack oil passage 66 via the jack proportional control oil passage 102, the flow of the hydraulic oil from the jack oil passage 66 to the tank oil passage 67 (return oil passage 86) is restricted. That's fine. As a method other than the provision of the check valve 110, for example, the interlock valve ILV is configured such that the A port and the T port are blocked even when the interlock valve ILV is moved to the left from its neutral position. By configuring, the hydraulic oil flowing through the jack oil passage 66 may be configured so as not to flow through the interlock valve ILV and flow into the return oil passage 86.

  The ground boarding control under the hydraulic circuit 60 'configured as described above will be described. As shown in FIGS. 1 and 2, when the ground entry switch SW1 provided on the vehicle body 10 is turned on while the work table 24 is in the retracted position, the operation signal of the ground entry switch SW1 is changed. The ground boarding control unit 54 outputs the ground boarding control signal to the valve control unit 51.

  When receiving the ground boarding control signal, the valve control unit 51 outputs a control signal to the interlock valve ILV to move the interlock valve ILV to the left. For this reason, the pump oil passage 61 and the boom side oil passage 65 ′ communicate with each other, and the hydraulic oil from the hydraulic pump P is supplied to the boom operation valve BV side. At this time, the telescopic cylinder BA1, the raising and lowering cylinder BA2 and the swing motor BA3 can be operated, and the boom 22 is extended by a predetermined extension amount and is operated by a predetermined tilt angle.

  Further, hydraulic oil is supplied from the hydraulic pump P to the jack proportional control valve BV4 via the interlock valve ILV, but since the ground entry control signal is being output, the operation of the jack proportional control valve BV4 is performed. The hydraulic oil passes through the jack proportional control valve BV4 and is supplied to the jack oil passage 66 via the jack proportional control oil passage 102. For this reason, it is possible to extend the jacks 40, 40,... According to the tilting operation amount of the jack operating lever 33, along with the extending movement and the falling movement of the boom 22. That is, not only the front jacks 40, 40 are extended so as to reach the maximum extension amount, but also the extension amounts of the jacks 40, 40,... Are appropriately set according to the slope of the road surface on which the aerial work vehicle 1 is stopped. It is possible to adjust.

  As described above, when the ground entry switch SW1 is operated, the boom 22 is extended by a predetermined extension amount by the drive control of the valve control unit 51 based on the control signal output from the ground entry control unit 54. When the jacks 40, 40,... Are further extended by a predetermined extension amount, the work table 24 is moved to the ground boarding / alighting position.

  Thereafter, when the worker who has boarded the work table 24 operates the work state transition switch SW2, an operation signal of the work state transition switch SW2 is output to the work state transition control unit 55. Then, the work state transition control unit 55 outputs a work state transition control signal toward the valve control unit 51.

  Upon receiving the work state transition control signal, the valve control unit 51 outputs a control signal to the interlock valve ILV to move the interlock valve ILV to the right. Therefore, the pump oil passage 61 and the jack oil passage 66 communicate with each other so that the hydraulic oil from the hydraulic pump P is supplied to the jack operation valve JV side and the hydraulic oil is supplied to the boom operation valve BV side. Is interrupted, and the interlock control is started to allow the operation of the jacks 40, 40,... And restrict the operation of the boom 22.

  Then, the valve control unit 51 drives and controls the rear left and rear right jack control valves JV3 and JV4 to extend the rear left and rear right jack cylinders JA3 and JA4, and the inner posts 42 of the rear left and right jacks 40 and 40 are operated. , 42 are extended. Further, the front left and front right jack valves JV1, JV2 are driven and controlled, the front left and front right jack cylinders JA1, JA2 are contracted, and the inner posts 42, 42 of the front left and right jacks 40, 40 are contracted. In this way, control for bringing the vehicle body 10 into a horizontal state is performed. Alternatively, the front left and front right jack cylinders JA1 and JA2 may not be contracted, and the rear left and rear right jack cylinders JA3 and JA4 may only be extended to place the vehicle body 10 in a horizontal state.

  A work state transition control signal is output until the vehicle body 10 is in a horizontal state based on a detection signal from the vehicle body inclination angle sensor S4, and the vehicle body 10 is supported in the horizontal state as shown in FIG. When the vehicle body 10 is in a horizontal state, the output of the work state transition control signal from the work state transition control unit 55 to the valve control unit 51 is stopped. At this time, the interlock valve ILV temporarily returns from the right movement position to the neutral position, and moves right or left from the neutral position based on the operation of the jack operation lever 33 or the operation of the boom operation lever 31, .. And simultaneous operation of the jacks 40, 40,.

  For this reason, when the boom 22 is moved up and down, expanded and contracted, and swung based on the operation signal from the boom operation sensor S1, the work table 24 is moved to a desired high position. The operation 24 is regulated and the work table 24 can be moved safely in a state where the vehicle body 10 is stably supported. Further, when the work table 24 is moved to a desired high position, since the ground boarding control signal is not output from the ground boarding control unit 54, the operation of the jack proportional control valve BV4 is restricted, and the boom side oil passage 65 is controlled. Even when hydraulic oil is supplied to the side of ′, the hydraulic oil is not supplied to the jack oil passage 66 via the jack proportional control oil passage 102, and the operation of the jacks 40, 40,. .

  Here, the effects achieved in the present invention are summarized as follows. That is, even if the aerial work vehicle according to the present invention is equipped with the interlock control means for restricting the simultaneous operation of the boom and the jack, the boom and the jack can be moved from their retracted postures in order to start the aerial work. Until the platform is moved to the ground entry / exit position, it is configured to release the restriction of the simultaneous operation of the boom and the jack by the interlock control means by the control of the hydraulic circuit provided in the aerial work vehicle. . For this reason, since the extension movement of the boom and the extension movement of the jack can be performed simultaneously, it is possible to move the work table to the ground entry / exit position in a short time from the start of the operation of the ground entry operation means. In comparison, it is possible to shorten the time required to move to the ground getting on / off position. Then, it is possible to easily move the work table to the ground boarding / alighting position by one operation of the ground boarding operation means. As described above, the aerial work vehicle according to the present invention is designed to improve the efficiency at the start of the aerial work while ensuring the safety of the aerial work.

  In order to enable simultaneous operation of the boom and the jack, the hydraulic circuit provided in the aerial work vehicle according to the present invention for controlling the operation of the boom and the jack supplies the hydraulic oil from the hydraulic pump to the boom control oil path. Via the jack actuator. When hydraulic oil is supplied to the jack actuator, the hydraulic oil is supplied to a swing motor that controls the swing of the boom through a proportional control valve (a swing control valve in the embodiment) that controls supply and discharge, or boom control. Supply control is performed via a proportional control valve newly provided for jack control on the oil passage. For this reason, controlling the flow rate of hydraulic oil stepwise or continuously controls the amount of jack extension stepwise or continuously while suppressing the impact caused by the flow of hydraulic oil by gradually supplying and discharging the hydraulic oil. Is possible. Further, the extension amount of the jack can be finely adjusted according to the intention of the operator according to the road surface condition where the aerial work vehicle is stopped, and the operability of the jack can be improved. Furthermore, the hydraulic oil is supplied to the jack actuator when the boom and the jack are simultaneously operated. The hydraulic oil is supplied to the boom actuator via a proportional control valve that controls the turning of the boom without newly providing an oil passage for supplying the jack actuator. Since this is performed using the same oil passage (both boom control oil passages), it is possible to immediately respond to load fluctuations in the boom actuator and jack actuator (can be supplied without delay).

It is a top view of the aerial work vehicle which concerns on this invention, and is a top view which shows when a boom and a worktable are in the retracted posture. It is the side view of the said aerial work vehicle seen in the arrow II direction shown in FIG. It is a perspective view which shows the operation part of the said aerial work vehicle. It is a block diagram which shows the structure which concerns on the controller of the said aerial work vehicle. 1 shows a part of a hydraulic circuit according to an embodiment of the present invention. 1 shows a part of a hydraulic circuit according to an embodiment of the present invention. It is a side view of the aerial work vehicle, and is a side view showing when the work platform of the aerial work vehicle is located at the ground getting on / off position. It is a side view of the aerial work vehicle, and is a side view showing a state where the vehicle body is supported in a horizontal state. 1 shows a part of a hydraulic circuit according to an embodiment of the present invention. 1 shows a part of a hydraulic circuit according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aerial work vehicle 10 Car body 12 Driving cabin 21 Turning post (base)
22 Boom 24 Work table 40 Jack 50 Controller (operation control means)
51 Valve control unit (interlock control means)
52 Interlock part (interlock control means)
54 Ground boarding control part (ground boarding control means)
60, 60 'Hydraulic circuit 65, 65' Boom side oil passage (boom control oil passage)
61 Pump oil passage 66 Jack oil passage (first jack control oil passage)
67 Tank oil passage 68 Bypass oil passage 72 Bottom side oil passage 73 Rod side oil passage 77 Bottom side oil passage 78 Rod side oil passage 82 First sub oil passage (turn control oil passage)
83 Second auxiliary oil passage (turning control oil passage)
84 Branch oil passage (second jack control oil passage)
86 Return oil passage (tank oil passage)
101 Pump side oil passage (branch oil passage)
102 Jack proportional control oil passage (second jack control oil passage)
110 Check valve (oil passage closing means)
BA1 telescopic cylinder BA2 hoisting cylinder BA3 swing motor BV1 telescopic control valve (boom control valve)
BV2 undulation control valve (boom control valve)
BV3 Swiveling control valve (Boom control valve)
BV4 jack proportional control valve (second jack control valve)
CHV switching valve (switching means)
ILV interlock valve (interlock control means)
JA1 to JA4 Jack cylinders JV1 to JV4 Jack control valve (first jack control valve)
P Hydraulic pump SW1 Ground boarding switch (ground boarding operation means)
T tank

Claims (5)

A travelable vehicle body with a driving cabin in front,
A base end portion is attached to a base that stands on the rear side of the driving cabin of the vehicle body and is configured to be at least telescopically movable, and is stored on the vehicle body in a retracted posture in which a front end portion is directed toward the rear of the vehicle body. The boom,
A workbench attached to the tip of the boom and stored on the vehicle body in a predetermined storage posture;
A plurality of jacks provided on the front, rear, left and right sides of the vehicle body, each configured to be movable up and down, and extending downward from a retracted retracted posture to support the vehicle body;
Operation control means for performing operation control of the boom and the plurality of jacks;
Interlock control means for restricting simultaneous operation of the boom and the plurality of jacks;
Ground entry operation means provided on the vehicle body and operable by an operator;
Provided in the operation control means, and when the ground entry operation means is operated in the retracted posture of the boom and the plurality of jacks, the boom is at least extended to be brought into a boom ground entry / exit posture, The work table is placed on and off the work table close to the ground at the rear of the vehicle body by extending the jacks of the plurality of jacks so that the lower ends of the plurality of jacks are grounded and the vehicle body is inclined rearward. In an aerial work vehicle configured to have ground entry control means to be moved to
When the ground boarding operation means is operated, the ground boarding control means performs the interlock control from the retracted attitude of the boom and the plurality of jacks to the boom ground boarding / alighting attitude and the vehicle body ground boarding / alighting attitude. By releasing the restriction on the simultaneous operation of the boom and the plurality of jacks by means, the boom is at least extended together with the operation of the plurality of jacks, and the work table is moved to the work platform landing position. A featured aerial work platform. The boom is configured to freely pivot,
A hydraulic pump that discharges hydraulic oil;
A pump oil passage having one end connected to the hydraulic pump;
The other end of the pump oil passage is connected, and one end of the boom control oil passage and the first jack control oil passage are connected and switched, thereby switching the boom control oil passage and the first jack control oil passage. An interlock valve for supplying hydraulic oil discharged from the hydraulic pump to any one of
A boom control valve to which the other end of the boom control oil passage is connected;
A turning control oil passage connecting the boom control valve and a turning motor for turning the boom;
In an aerial work vehicle including a jack control valve to which the other end of the first jack control oil path is connected,
Switching means provided in the pump oil passage;
A bypass oil passage that connects the switching means and the boom control oil passage without going through the interlock valve;
A second jack control oil passage connecting the turning control oil passage and the jack control valve;
The switching means is configured to supply hydraulic oil discharged from the hydraulic pump to either the interlock valve or the bypass oil passage by switching,
When the ground boarding operation means is operated, the switching means is switched to communicate the pump oil passage with the bypass oil passage, and the hydraulic oil discharged from the hydraulic pump is passed through the bypass oil passage. And supplying the hydraulic oil supplied to the swivel control oil passage to the jack control valve via the second jack control oil passage, thereby the boom and the plurality of jacks. The aerial work vehicle according to claim 1, wherein simultaneous operation is possible. A hydraulic pump that discharges hydraulic oil;
A pump oil passage having one end connected to the hydraulic pump;
The other end of the pump oil passage is connected, and one end of the boom control oil passage and the first jack control oil passage are connected and switched, thereby switching the boom control oil passage and the first jack control oil passage. An interlock valve for supplying hydraulic oil discharged from the hydraulic pump to any one of
A boom control valve to which the other end of the boom control oil passage is connected;
In an aerial work vehicle including a first jack control valve to which the other end of the first jack control oil path is connected,
A second jack control valve connected to a branch oil passage branched from the boom control oil passage and capable of supplying hydraulic oil from the hydraulic pump via the boom control oil passage;
One end is connected to the second jack control valve and the other end is connected to the first jack control oil path;
When the ground boarding control means operates the ground boarding operation means from the stowed attitude of the boom and the plurality of jacks to the boom ground boarding / alighting attitude and the vehicle body ground boarding / alighting attitude, the interlock valve Is switched so that the hydraulic oil from the hydraulic pump is supplied to the boom control oil passage, the second jack control valve is switched, and the first jack control valve is switched via the second jack control oil passage. The aerial work vehicle according to claim 1, wherein the boom and the plurality of jacks can be simultaneously operated by supplying hydraulic oil to the vehicle. The second jack control valve is composed of a proportional control valve for controlling the amount of hydraulic oil in the second jack control oil passage stepwise or continuously;
By supplying hydraulic oil to the first jack control valve through the second jack control oil passage while controlling the opening degree of the second jack control valve, the extension amounts of the plurality of jacks are stepped. The aerial work vehicle according to claim 3, which can be controlled manually or continuously. One end is connected to the interlock valve, and has a tank oil passage for discharging hydraulic oil to the tank,
The hydraulic fluid of either the boom control oil passage or the first jack control oil passage is discharged to the tank by switching the interlock valve,
At least one of the first jack control oil passage and the interlock valve is provided with an oil passage closing means for closing the first jack control oil passage,
When the interlock valve is switched so that the hydraulic oil from the hydraulic pump is supplied to the boom control oil passage and the hydraulic oil in the first jack control oil passage is discharged to the tank,
The operation of supplying the first jack control oil path from the second jack control oil path regardless of the switching of the interlock valve by the oil path closing means closing the first jack control oil path. The aerial work vehicle according to any one of claims 2 to 4, wherein oil is restricted from being discharged to the tank oil passage through the interlock valve.

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