JP4854218B2 - Aerial work platform - Google Patents

Description

  The present invention relates to an aerial work vehicle constructed by attaching a work table to the tip of a boom that is provided on a vehicle body and is stored with the tip thereof directed rearward, and more specifically, the work table is brought close to the ground. The present invention relates to an aerial work vehicle that can be moved to the ground entry position and can enter the work table from the ground.

  An aerial work platform has a work platform for boarding an operator at the tip of a boom mounted on a swivel stand upright on the vehicle body. It is possible to move to a desired height and perform work at a height. Depending on the direction in which the boom is operated, a moment in the direction of overturning the vehicle body acts on the vehicle body, and the vehicle body becomes unstable. For this reason, an aerial work vehicle is equipped with, for example, four jacks that can be vertically expanded and contracted at the front, rear, left, and right sides of the vehicle body. The jack is extended downward to support the vehicle body in a horizontal state. It is possible to work at a high place safely by making the state stable.

  These booms and jacks are configured to operate by supplying hydraulic oil to hydraulic actuators such as hydraulic cylinders and hydraulic motors incorporated in the boom and jack, respectively. Supplied from the pump. As this hydraulic pump, there are provided a main pump configured to always operate during work and a sub pump configured to operate only at a predetermined necessity such as when the main pump is always stopped and the main pump is damaged. Also, if the boom is operated when the vehicle body is not supported in a horizontal state as described above, the vehicle body may fall over. Therefore, when allowing the supply of hydraulic oil to the jack actuator, An interlock means (interlock valve) is provided for shutting off the supply of hydraulic oil to the jack actuator when the supply of hydraulic oil to the boom actuator is permitted.

  In addition, in response to operation signals from the ground entry operation means provided on the vehicle body and the ground descent operation means provided on the work table, the jack is activated to bring the vehicle body into a predetermined vehicle body support state and extend the boom. 2. Description of the Related Art There is known an aerial work vehicle having a control unit that operates and overturns to move a workbench to a ground entry position near the ground (see, for example, Patent Document 1). In this embodiment, when starting the work, by operating the ground boarding operation means, the worktable stored on the vehicle body can be moved to the ground boarding position and boarded on the worktable from the ground. By operating the ground descent operation means when finishing the work, the work table can be moved from the high work position to the ground entry position and can be lowered from the work table to the ground.

Japanese Utility Model Publication No. 6-87397

  By the way, if the time until the work table moves to the ground entry position is short, the work can be started quickly. However, for example, when the operation of one of the boom and the jack is controlled by the action of the interlock means provided in the conventional aerial work vehicle, the operation time is long in the other mode. As a result, there is a problem that the handleability may be deteriorated.

  In view of such problems, the present invention can shorten the time required to move the work platform to the ground entry position in an aerial work vehicle that operates the jack and boom to move the work platform to the ground entry position. The purpose is to provide a high-altitude work vehicle.

In order to achieve the above object, an aerial work vehicle according to the present invention includes a vehicle body that can travel, a boom that is provided on the vehicle body and is configured to be at least extendable and retracted, and a tip portion thereof is stored toward the rear of the vehicle body. A workbench attached to the tip of the boom and stored on the vehicle body; provided on the front, rear, left and right sides of the vehicle body, and configured to be vertically extendable and retractable; Work by operating the boom and a plurality of jacks according to the operation of the jack, the ground entry operation means provided on the vehicle body, the ground descent operation means provided on the work table, and the ground entry operation means or the ground descent operation means. In an aerial work vehicle comprising a control means for moving the platform to a ground entry position located near the ground behind the vehicle body , a plurality of jacks are operated when the boom is in an activated state. Regulation The interlock means for restricting the operation of the boom when the plurality of jacks are in an operating state, and the boom and the plurality of the interlock means when the ground entry operation means or the ground descent operation means are operated. Interlocking permission means for canceling the operation restriction of the jack, and the control means activates the interlocking permission means when the operation signal from the ground entry operation means or the ground descent operation means is output, It is comprised so that the control which act | operates a several jack simultaneously may be performed .

Note that in aerial platforms having the above structure, the control means, a boom and a plurality of jacks when the boom is in the predetermined operating range to a range from near the boom storage position to near the ground Nokomi position simultaneously is activated, it is preferably configured to the causes control to regulate one of the actuating at least one of the boom and a plurality of jacks when the boom is out of the operating range.

Further, in aerial platforms having the above structure, a boom actuator for actuating the boom, and a jack actuator for actuating a plurality of jack, a main pump for supplying hydraulic fluid to the boom actuator and jack actuator, are always stopped is configured to operate at a predetermined necessary and a sub pump for supplying hydraulic fluid to the boom actuator and jacks actuators, control means, the interlocking acceptable means to actuate the controlled actuating the boom and a plurality of the jack at the same time when performing, it is preferable configured to perform control to operate the main pump and the sub-pump at the same time.

  According to such a construction of an aerial work vehicle according to the present invention, when the work table is moved to the ground entry position, simultaneous operation of the boom and the plurality of jacks is allowed by the control means. Thereby, the time for the work table to move to the ground entry position can be shortened as compared with the case where only one of them is operated.

  In addition, there are always interlock means for restricting simultaneous operation of the boom and the plurality of jacks, and interlocking permission means for releasing the restriction of simultaneous operation of the boom and jack by the interlock means. The boom and the plurality of jacks are operated at the same time. As a result, the simultaneous operation by the interlock means is restricted, and the simultaneous operation is allowed only when the ground boarding / exiting operation means is operated. Figured.

  In addition, the boom and the plurality of jacks are simultaneously operated when they are within a predetermined working range, and any one of the operations is restricted when they deviate from the predetermined operating range. In this way, by limiting the work range in which simultaneous operation is possible, it is possible to avoid the possibility of the vehicle body falling over even if the vehicle body is not in a stable state during operation of the jack.

  Further, when the boom and the jack are operated simultaneously, the sub pump that is always stopped is configured to operate together with the main pump. As a result, the flow rate of hydraulic oil increases, the flow rate of hydraulic oil necessary to operate the boom and jack simultaneously is secured, and the operating speed of the jack actuator and boom actuator is increased, further reducing the time. To be able to.

  Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show an aerial work vehicle 1 according to an embodiment of the present invention. Note that the direction of the arrow F shown in FIG. 1 is the front, the direction of the arrow R is the right, and the direction of the arrow U shown in FIG. The aerial work vehicle 1 includes front wheels 11a and 11a and rear wheels 11b and 11b, and is configured to be capable of traveling on four wheels. .. And the four jacks 40, 40,... Provided on the front, rear, left and right sides of the vehicle body 10. 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 swivel post 21 is erected on the front part of the vehicle body 10 and at the rear part of the driving cabin 12, and is configured to be swiveled by being driven by a built-in swivel motor BA3. The boom 22 is configured by nesting a proximal boom 22a and a distal boom 22b. The proximal boom 22a is pivotally connected to the turning post 21 and is turned together with the turning post 21. In addition, the boom 22 is configured to expand and contract by receiving the expansion and contraction operation of the built-in expansion cylinder BA1, and the expansion and contraction operation of the hoisting cylinder BA2 disposed between the turning post 21 and the base end boom 22a. And can be raised and lowered freely. A vertical post 23 is swingably attached to the tip of the tip boom 22b. The vertical post 23 is swung in response to an expansion / contraction operation of a leveling cylinder (not shown), and is always held in a vertical posture.

  The work table 24 is composed of a bucket 24a for boarding an operator, and a work table holding bracket 24b attached between the bucket 24a and the vertical post 23. The work table holding bracket 24b is arranged around the axis of the vertical post 23. It is attached to the neck freely. 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 so that the floor surface of the bucket 24a is in a horizontal state when the vertical post 23 is in a vertical posture, and the floor surface of the bucket 24a is always held in a horizontal state. 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 so that the notched portion can be opened and closed. The operator opens and closes the bucket 24a by opening the door 24c as indicated by a two-dot chain line.

  The working device 20 is stored on the vehicle body 10 as shown in FIGS. 1 and 2 during non-working such as traveling. In this retracted position, the telescopic cylinder BA1 is fully contracted to bring the boom 22 into the fully contracted state, and the turning angle (rightward) is such that the tip of the fully contracted boom 22 does not protrude from the vehicle body 10 in plan view. The swivel post 21 is located at the swivel position. A boom receiver 13 having a boom placement surface 13a for placing the base end boom 22a at the upper end is erected at the rear of the vehicle body 10, and the boom 22 is placed on the boom placement surface 13a. The hoisting cylinder BA2 is actuated as described above. The boom receiver 13 is disposed so that the undulation angle of the boom 22 in the retracted position is a negative angle (for example, about −10 degrees), but the undulation cylinder BA2 can be further reduced, and the boom 22 can be further tilted from the undulation angle of the retracted position. The work table 24 attached to the tip of the boom 22 stored in this way is located at the rear and upper part of the vehicle body 10 and is directed in the contraction direction of the boom 22 so as not to protrude from the vehicle body 10 in plan view. The swing angle is stored along the left side of the boom 22.

  Further, 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 placement surface 13a at the upper end. The telescopic post 13c is configured to be vertically expandable and contractable by the expansion and contraction operation of the boom receiving cylinder A2 built in 13b and 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.

  Each jack 40 is fixed to a side portion of the vehicle body 10 and extends in the vertical direction, an inner post 42 inserted in a vertically extending manner from the lower end of the outer post 41, and a lower end portion of the inner post 42. The inner post 42 can be vertically expanded and contracted by an expansion / contraction operation of a built-in jack cylinder JA (JA1, JA2, JA3, JA4). The inner posts 42, 42,... Of the four jacks 40, 40,... Extend 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. .

  The work table 24 is provided with an upper operation device 30 as shown in FIG. The upper operation device 30 is provided with a boom operation lever 31 for performing an expansion / contraction operation, a raising / lowering operation, and a turning operation of the boom 22, and a swing operation lever 32 for performing a swing operation of the work table 24. Yes. 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.

  In addition, the upper operating device 30 is provided with a work state transition switch SW2 and a ground descent switch SW3, as well as both operating levers 31 and 32. The ground descent switch SW3 is composed of an alternate switch. When the pressing operation is performed, the switch is held at the pressing position. Even if the operation is canceled, the operation on state is maintained. When the operation is canceled and the pressing operation is performed again, the operation off state is established. Become.

  A lower operation device 35 is provided at the rear of the vehicle body 10. The lower operating device 35 is provided with a ground entry switch SW1 together with a jack operating device 36 for operating the expansion and contraction operation of the jacks 40, 40,. Similarly to the ground descent switch SW3, the ground entry switch SW1 is composed of an alternate switch.

  FIG. 4 is a block diagram showing the configuration of the controller 50 of the aerial work vehicle 1. The controller 50 that controls the operation of the aerial work vehicle 1 includes a valve control unit 51, a ground entry / exit control unit 52, a work state transition control unit 53, a position calculation unit 54, an operation range storage unit 55, and a motor drive. And a control unit 56.

  Further, a grounding sensor S4 for detecting that the jack pads 43, 43,... Are grounded is provided corresponding to each jack 40, 40,. The detection signal from S4 is output to the controller 50. The vehicle body 10 is provided with a vehicle body inclination angle sensor S5 configured to be able to detect the inclination angle of the vehicle body 10 with respect to a horizontal plane, and a detection signal from the vehicle body inclination angle sensor S5 is output to the controller 50. Further, an extension amount sensor S6 for detecting the extension amount of the boom 22, an undulation angle sensor S7 for detecting the boom undulation angle, and a turning angle sensor S8 for detecting the turning angle of the boom are provided at appropriate positions of the boom 22, respectively. Each detection signal is output to the controller 50.

  The valve control unit 51 is provided corresponding to each hydraulic actuator and performs drive control of each control valve that controls supply and discharge of hydraulic oil. 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 configured to be output to the valve control unit 51, respectively. 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. When the operation signal of the jack operation sensor S3 is output to the controller 50 by the valve control unit 51, the jack control valves JV1 to JV4 are electromagnetically driven to expand and contract the corresponding jack cylinders JA1 to JA4. Thereby, the expansion / contraction operation of the inner posts 42, 42,... Is performed.

  The hydraulic oil supplied to and discharged from each hydraulic actuator is discharged by a hydraulic pump P provided in the vehicle body 10, and the hydraulic oil from the hydraulic pump P is supplied to and discharged from the corresponding hydraulic actuator via each control valve. The

  The detection signal from the vehicle body inclination angle sensor S5 is output to the position calculation unit 54, and the inclination angle of the vehicle body 10 with respect to the horizontal plane is calculated by the position calculation unit 54 based on this detection signal. Detection signals from the extension amount sensor S6, the undulation angle sensor S7, and the turning angle sensor S8 are output to the position calculation unit 54, and the position calculation unit 54 calculates the position of the boom 22 based on these detection signals. . The operating range storage unit 55 stores an operating range R of the predetermined boom 22 in advance. When the boom 22 is positioned within the operating range R, the jacks 40, 40,... Are not grounded and the vehicle body 10 is supported only by the wheels 11a, 11a, 11b, 11b, or Even if the vehicle body 10 is not in a stable state during operation of the jacks 40, 40,..., A moment that causes the vehicle body 10 to fall does not act on the vehicle body 10. In the present embodiment, the operation range R includes the vicinity of the storage position of the boom 22 to the vicinity of the ground.

  The controller 50 is provided with an interlock portion 57 that operates when a predetermined condition is met. When the interlock portion 57 is activated, an interlock valve ILV, which will be described later, is activated, and interlock control for restricting simultaneous operation of the boom 22 and the jacks 40, 40,... Is performed.

  Further, an operation signal of the ground entry switch SW1 provided on the vehicle body 10 is configured to be output to the ground boarding / alighting control unit 52, and an operation signal of the work state transition switch SW2 provided on the work table 24 and on the vehicle body 10 are configured. An inclination angle detection signal with respect to the vertical direction of the vehicle body 10 by a gravity-type vehicle body inclination angle sensor S5 provided in the vehicle is output to the work state transition control unit 53.

  In the ground entrance / exit control unit 52, the detection signal of the inclination angle of the vehicle body 10 by the vehicle body inclination angle sensor S5 is detected by the ground sensor S4 provided to each jack 40, 40,. Each signal is output.

  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. In addition to the above, the hydraulic circuit 60 includes a swing motor BA4 for vibrating the work table 24, a control valve BV4 for controlling the swing motor BA4, a boom receiving cylinder A1 for extending and retracting the boom receiver 13, and a boom receiver. The boom receiver control valve V1 that controls the operation of the cylinder A1, and further includes a filter, a joint, and the like.

  The hydraulic pump P is composed of a main pump P1 and an emergency pump P2. The main pump P1 is driven by the output of the vehicle traveling engine E, and is configured to always operate during work. The emergency pump P2 receives the output of the electric motor M and is driven. The electric power supply to the electric motor M is controlled by a motor drive control unit 56 provided in the controller 50, and is always stopped. The electric motor is only in a necessary time (emergency) such as when the main pump P1 is damaged. The emergency pump P2 is operated by driving M.

  A pump oil passage 61 extending from the hydraulic pump P is connected to the switching valve CHV. 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 receives a control signal from the ground getting on / off control unit 52 by a control signal from the valve control unit. The exciting coil can be excited and moved to the left. When the switching valve CHV is moved to the left, the pump oil passage 61 and the jack C port oil passage 64 connected to the C port of the jack operation valve JV communicate with each other. A boom-side oil passage 65 connected to the boom operation valve BV is branched from the jack C port oil passage 64. When the switching valve CHV is moved to the left, the hydraulic oil is supplied to both the jack operation valve JV and the boom operation valve BV. It is possible to supply. Further, when the exciting coil is demagnetized from the state in which the switching valve CHV is moved to the left and is moved to the right, the pump oil passage 61 and the jack P port oil passage 62 connected to the P port of the jack operation valve JV communicate with each other. 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 excitation coil by a control signal from the interlock section 57 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 jack oil passage 66 is connected to the jack P port oil passage 62 and the jack control valves JV1 to JV4 and can supply hydraulic oil to the jack cylinders JA1 to JA4. And the jack C port oil passage 64 connected to the boom side oil passage 65 communicates with the jack T port 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 through the boom side oil passage 65, but the hydraulic oil is not supplied to the boom operation valve BV side. Therefore, the operation of the boom 22 is restricted.

  On the other hand, when interlock valve ILV moves to the left from its neutral position, jack P port oil passage 62 and jack C port oil passage 64 communicate, and jack oil passage 66 and jack T port oil passage 67 communicate. 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, the hydraulic oil is supplied to the boom operation valve BV via the jack C port oil passage 64. Although the boom 22 can be operated, the hydraulic oil is not supplied to the jack cylinders JA1 to JA4 via the jack oil passage 66, so that the expansion / contraction operation of the jacks 40, 40,. Thus, when the switching valve CHV is in the right movement position, only one of the boom 22 and the jacks 40, 40,... Can be operated, and the boom 22 and the jacks 40, 40,. The operation is restricted (interlock control).

  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 expansion / contraction motion control valve BV1 is an electromagnetic switching valve that is switch-controlled based on a control signal from the valve control unit 51. 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 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 hydraulic 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 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 check valve 94. The tank side oil passage 79 is connected to the return oil passage 86.

  The undulation control valve BV <b> 2 is an electromagnetic switching valve that is switch-controlled based on a control signal from the valve control unit 51. 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 holding valve 93 is composed of a check valve 93a, a relief valve 93b, and a pilot check 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. 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

  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 shown in the figure, but the excitation coil is excited by the control signal output from the valve control unit 51 that receives the control signal from the ground getting on / off control unit 52, It moves rightward from the closed position to the open position. 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, the first shut-off valve SV1 and the check valve 96 prevent the hydraulic oil from the jack oil passage 66 from flowing into the second auxiliary oil passage 83. Yes.

  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, and, similar to the first shut-off valve SV1, it is controlled to get on and off the ground. In response to the control signal from the unit 52, the excitation coil is activated by the control signal from the valve control unit 51 to operate. The second shut-off valve SV2 is always open, and the swing motor BA3 is operated by the supply / discharge control of the hydraulic oil in the first sub oil passage 82 and the second sub oil passage 83 by the swing control valve BV3. It is possible. On the other hand, when the excitation coil of the second shut-off valve SV2 is excited by the control signal from the valve control unit 51 that receives the control signal from the ground getting on / off control unit 52, the valve spool moves up in FIG. The shutoff valve SV2 is closed.

  For this reason, the first shut-off valve SV1 is opened by the valve control unit 51 that receives the control signal from the ground getting on / off control unit 52, and hydraulic oil is supplied from the turning control valve BV3 toward the jack oil passage 66. When it is, the operation of the swing motor BA3 is blocked regardless of the operation of the swing control valve BV3.

  Next, a procedure for working at a high place using the high-altitude work vehicle 1 and operation control of the work device 20 and the jack 40 by the controller 50 will be described. Prior to the start of work, the aerial work vehicle 1 is stored with the boom 22 and the work table 24 in the retracted position and the jacks 40, 40,... First, when the ground boarding switch SW1 is operated, an operation signal of the ground boarding switch SW1 is output to the ground boarding / alighting control unit 52.

  The ground boarding / alighting control unit 52 receives this operation signal and outputs an operation control signal to the valve control unit 51. Based on the operation control signal from the ground getting on / off control unit 52, the valve control unit 51 drives and controls each control valve to operate the jack cylinder JA and the boom actuator BA. Further, the ground boarding / alighting control unit 52 receives the operation signal of the ground boarding switch SW <b> 1, and the position of the boom 22 calculated by the position calculation unit 54 is within a predetermined operation range R stored in the operation range storage unit 55. Judge whether there is. Only when within the predetermined operating range R, the interlock control signal is output from the ground boarding / alighting control unit 52 to the valve control unit 51 and the motor control signal is output to the motor drive control unit 56. As shown in FIGS. 7 and 9, the predetermined operating range R of this embodiment includes from the vicinity of the storage position of the boom 22 to near the ground. When the ground entry switch SW1 is operated, the interlock control signal And a motor control signal is output.

  When the motor control signal is output, electric power is supplied to the electric motor M by the motor drive control unit 56, and the emergency pump P2 operates simultaneously with the main pump P1 configured to always operate during work.

  When the interlock control signal is output, the control signal is output from the valve control unit 51 to the switching valve CHV, and the switching valve CHV is moved to the left. As a result, the pump oil passage 61 and the boom-side oil passage 65 communicate with each other, and hydraulic oil from the main pump P1 and the emergency pump P2 is supplied to the boom operation valve BV. Further, the valve control unit 51 that has received the interlock control signal outputs a control signal to the swing control valve BV3, the first shut-off valve SV1, and the second shut-off valve SV2, and sets the swing control valve BV3 to its 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 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 boom operation valve BV to the turning motor BA3 due to the closing of the second shut-off valve SV2, the turning movement of the boom 22 is restricted. Thus, by operating the ground entry switch SW1, hydraulic oil can be supplied to the telescopic cylinder BA1 and the hoisting cylinder BA2 and hydraulic oil can be supplied to the jacks 40, 40,... Then, the telescopic cylinder BA1 and the undulating cylinder BA2 can be operated simultaneously.

  The jack control valves JV1 to JV4 are driven and controlled by the valve control unit 51 that has received the operation control signal from the ground getting on / off control unit 52, and the jack cylinders JA1 to JA4 are extended to operate the inner posts 42 and 42 downward. The extension is activated. At this time, the front left and front right jack cylinders JA1, JA2 are extended to the maximum extendable amount, and the rear left and rear right jack cylinders JA3, JA4 are extended so that the jack pads 43, 43 are grounded. To extend.

  Further, the extension movement control valve BV1 is driven and controlled together with the extension operation of the jacks 40, 40,... By the control signal from the valve control unit 51 that receives the operation control signal from the ground boarding / alighting control unit 52. The telescopic cylinder BA1 is extended to operate the boom 22 until it reaches a predetermined extension amount.

  Further, the raising / lowering control valve BV2 is driven and controlled, and the raising / lowering cylinder BA2 is contracted to cause the boom 22 to fall down until reaching a predetermined raising / lowering angle. Further, along with this overturning operation, the valve control unit 51 drives and controls the boom receiving control valve V1 to reduce the boom receiving cylinder A1, operate the retractable post 13c to retract, and adjust the height position of the boom mounting surface 13a. The boom 22 is moved downward in accordance with the overturning operation.

  As shown in FIG. 7, the work table 24 is moved to the ground boarding position near the ground by the operation control by the ground boarding / alighting control unit 52, and the operator boardes the work table 24 by opening the door 24 c from the ground. it can. By operating the jacks 40, 40,... As described above, the vehicle body 10 is supported while the front wheels 11a, 11a are grounded and the rear wheels 11b, 11b are grounded. In such a vehicle body support state, the vehicle body 10 is tilted rearward with respect to the ground, and the rear end of the vehicle body 10 is brought close to the ground. By tilting the vehicle body 10 rearward in this way, the extension amount of the boom 22 can be reduced compared to when the vehicle body 10 is in a horizontal state, and the work table 24 can be brought closer to the ground. The space required behind the vehicle body 10 for moving to the retracted position can be made compact.

  An operator who gets on the work table 24 operates a work state transition switch SW2 provided in the upper operation device 30. An operation signal from the work state transition switch SW2 is output to a work state transition control unit 53 provided in the controller 50. The work state transition control unit 53 receives the operation signal of the work state transition switch SW2 and outputs a control signal to the valve control unit 51. In response to the 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, thereby causing the pump oil passage 61 and the interlock valve ILV to communicate with each other. At this time, the control signal from the work state transition control unit 53 is also output to the interlock unit 57, and when the interlock unit 57 receives this control signal, it outputs a control signal to the interlock valve ILV to the right from the neutral position. Move. Thereby, the operation of the jacks 40, 40,... Is permitted, and the operation of the boom 22 is restricted. Further, the valve control unit 51 outputs control signals to the first shut-off valve SV1 and the second shut-off valve SV2, closes the first shut-off valve SV1, opens the second shut-off valve SV2, and jacks. The supply of hydraulic oil from the operation valve JV to the boom operation valve BV via the branch oil passage 84 is shut off.

  In a state where the operation of the boom 22 is regulated by operating each valve in this way, an operation control signal from the work state transition control unit 53 is output to the valve control unit 51. Based on the control signal from the work state transition control unit 53, the valve control unit 51 drives and controls the rear left and rear right jack valves JV3 and JV4 to extend and operate the rear left and rear right jack cylinders JA3 and JA4. The inner posts 42, 42 of the left and right jacks 40, 40 are extended downward. The work state transition control unit 53 outputs a detection signal of an inclination angle with respect to the horizontal plane of the vehicle body 10 from the vehicle body inclination angle sensor S5, and when it is determined that the vehicle body 10 is in a horizontal state by this detection signal, the jack cylinders JA3, JA3. The extension operation of JA4 is stopped.

  By the operation control by the work state transition control unit 53, as shown in FIG. 8, the front wheels 11a and 11a and the rear wheels 11b and 11b are grounded and the vehicle body 10 is supported in a horizontal state. Then, the operator operates the boom operation lever 31 and the swing operation lever 32 of the upper operation device 30 to move the work table 24 to a desired height work position as shown in FIG. Can be done.

  When the vehicle body 10 is in the horizontal state, the output of the control signal from the work state transition control unit 53 to the interlock unit 57 is stopped. At this time, the interlock valve ILV is moved right or left from the neutral position based on the operation of the jack operation device 36 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, extended and retracted based on the operation signal from the boom operation sensor S1, and the work table 24 is moved to a desired high position, the jacks 40, 40, 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 table 24 is moved to the ground entry 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 turning movement of the boom 22 is possible.

  The worker who has finished the work at high places operates the ground descent switch SW3 provided in the upper operation device 30 to lower the work table 24. When the ground descent switch SW3 is operated, an operation signal from the ground descent switch SW3 is output to the ground boarding / alighting control unit 52, and a control signal is output from the ground boarding / alighting control unit 52 to the valve control unit 51.

  Based on the operation signal from the ground getting on / off control unit 52, the valve control unit 51 controls the extension movement control valve BV1 to cause the expansion cylinder BA1 to contract, and controls the turning movement control valve BV3 to control the turning motor BA3. Driven, the head vibration control valve BV4 is driven to drive the swing motor BA4. The extension amount and swivel angle of the boom 22 when the work table 24 in which the position of the boom 22 calculated by the position calculation unit 54 is stored in advance in the ground boarding / alighting control unit 52 is located at the ground boarding position. An operation control signal is output to the valve control unit 51 so as to operate the work device 20 so that the swing angle becomes the same. Further, the boom 22 is tilted so that the boom 22 is at the undulation angle when the working table 24 pre-stored in the ground entry / exit control unit 52 is positioned at the ground entry position by controlling the raising / lowering control valve BV2. Operate.

  When the operation signal for the ground descent switch SW3 is output to the ground boarding / alighting control unit 52, the position of the boom 22 calculated by the position calculation unit 54 is stored in the operating range storage unit 55 by the ground boarding / alighting control unit 52. It is determined whether it is within a predetermined operating range R. In the high work position shown in FIG. 9, the boom 22 is located at a position deviating from the operating range R, and at the undulation angle shown in the figure, the extension amount when it is located at the ground boarding position, Even if the boom 22 is contracted and swung until the turning angle is reached, the boom 22 is located at a position outside the operating range R.

  If the ground boarding / alighting control unit 52 determines that the boom 22 is in the working range R in the process of the overturning operation of the boom 22, a ground control signal is output from the ground boarding / alighting control unit 52 to the valve control unit, and the motor control signal is transmitted to the motor. Output to the drive controller. In the same manner as when the work table 24 is moved from the retracted position to the ground entry position by the valve control unit 51 to which the interlock control signal is output, the switching valve CHV is moved to the left and the turning control valve BV3 is moved from the neutral position. The hydraulic oil is allowed to be supplied to the undulation control valve BV2 and the jack control valves JV1 to JV4 that are moved leftward, the first shut-off valve SV1 is opened, and the second shut-off valve SV2 is closed. Further, electric power is supplied from the motor drive control unit 56 to the electric motor M, and the emergency pump P2 operates together with the main pump P1.

  As a result, the boom 22 is continuously raised and lowered, and at the same time, the rear left and rear right jack control valves JV3 and JV4 are driven and controlled, and the rear left and rear right jack cylinders JA3 and JA4 are contracted and rearward left and right. The inner posts 42, 42 of the jacks 40, 40 are contracted. This contraction operation is performed so that the rear wheels 11b and 11b reach an amount of contact with the inner posts 42 and 42 of the left and right jacks 40 and 40 extended to the maximum possible extension amount.

  In this way, when the work table 24 moves to the ground boarding position, an operator who gets on the work table 24 can easily get off the work table 24 to the ground. Upon receiving the control signal from the ground getting on / off control unit 52, the valve control unit 51 outputs a control signal to the switching valve CHV to move the switching valve CHV to the right, close the first shut-off valve SV1, and perform the second shut-off. While the valve SV2 is opened, the interlock unit 57 outputs a control signal to the interlock valve ILV to move left from the neutral position in response to a control signal from the ground getting on / off control unit 52. Thereby, the operation of the boom 22 is allowed and the operations of the jacks 40, 40,. Further, the output of the motor control signal to the motor drive control unit 56 is stopped, and the emergency pump P2 is stopped. As a result, the simultaneous operation of the jacks 40, 40,... And the boom 22 by the action of the normal interlock valve ILV is restored. Thus, in the state where the operation of the boom 22 is allowed, the boom 22 is operated, and the work table 24 is stored on the vehicle body 10 from the state where it is located at the ground entry position.

  As described above, when the operation signal from the ground entry switch SW1 or the ground descent switch SW3 is output, the boom 22 and the jacks 40, 40,. Since the operation is allowed, it takes time from the retracted position to the position where the work table 24 is located at the ground boarding position, or from the height work position to the position where the work table 24 is located at the ground boarding position. Can be shortened.

  Further, only when the position of the boom 22 is within the predetermined work range R stored in the operation range storage unit 55 in advance, an interlock control signal is output from the ground boarding / alighting control unit 52 to the valve control unit 51 and the boom 22 and When the jacks 40, 40,... Are operated simultaneously and the position of the boom 22 deviates from the operating range R, no interlock control signal is output, and only one of the jacks 40, 40,. Is now working. For this reason, the safety of the vehicle body 10 can be ensured when operating simultaneously.

  Further, an interlock valve ILV is provided so that only one of the boom 22 and the jacks 40, 40,... Is allowed depending on the operation direction of the spool, and the simultaneous operation is restricted. The restriction of the simultaneous operation by the interlock valve ILV can be released according to the operation of the provided check valve CHV, first shut-off valve SV1, and second shut-off valve SV2. The ground boarding / alighting control unit 52 drives these valves to perform simultaneous operation. This allows simultaneous operation only when the ground entry / exit operation means is operated, and during normal work or when it is necessary to operate only one of them, such as operation control by the work state transition control unit, etc. The safety of the vehicle body 10 can be ensured.

  Further, when the position of the boom 22 is within the predetermined operating range R, the ground boarding / alighting control unit 52 outputs a control signal to the motor drive control unit 56, and the emergency pump P2 that is always stopped is used as the main pump. It is comprised so that it may operate | move with P1, and the flow volume of hydraulic fluid increases. As a result, a flow rate necessary for simultaneously operating the jack actuator JA and the boom actuator BA is ensured. In addition, the operating speed of the jack actuator JA and the boom actuator BA is increased, and the time for moving the work table 24 to the ground entry position can be further shortened.

  If the operation of turning the boom 22 is required between the time when the ground entry switch SW1 or the ground descent switch SW3 is operated and before the work table 24 is moved to the ground entry position, the valve control is performed. This is possible by outputting control signals from the section 51 to the first shut-off valve SV1 and the second shut-off valve SV2. That is, by closing the first shut-off valve SV1 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 performed. In a state where the extension movement of the jacks 40, 40,... Is temporarily stopped, the boom 22 is turned by a desired amount so as to be supplied from the turning control valve BV3 to the turning motor BA3. It is possible.

  So far, the embodiment of the aerial work vehicle according to the present invention has been described, but the present invention is not necessarily limited to the above embodiment. For example, in the present embodiment, the ground entry switch SW1 and the ground descent switch SW3 are composed of alternate switches. However, a momentary-type switch that enters an operation-on state when a pressing operation is performed and enters an operation-off state when the operation is released. You may comprise with a switch.

  Further, the operation of the jacks 40, 40,... And the boom 22 is controlled by the ground getting on / off control unit 52. However, the head vibration control valve BV4 is driven to drive the swing motor BA4 and the work table 24 is swung. May be. As described above, the work table 24 is positioned along the left side with the swing angle in the retracted direction of the boom 22 in the retracted position. As the boom 22 is operated, the work table 24 is swung so that the work table 24 is directed in the extending direction of the boom 22 so that the work table 24 is positioned rearward to reduce the extension amount of the boom 22 and bring the work table 24 closer to the ground. Can do.

  Although an interlock valve is provided so that the simultaneous operation of the boom and jack is always restricted during work, etc., it is not always necessary to provide means for acting in this manner, and it is possible to control by operation control by the ground entry / exit control unit. If the boom and the jack can be operated at the same time, the time until the work table 24 moves to the ground entry position can be shortened as compared with the mode in which any one of the boom 22 and the jacks 40, 40,. .

  Further, if the boom 22 is within the predetermined operation range R, the simultaneous operation of the boom 22 and the jacks 40, 40,... Is allowed, but such an operation range may not necessarily be set. However, as described above, it is preferable that such an operating range is set in order to ensure the safety of the vehicle body 10 and the like.

  In addition, when performing control to move the work platform to the ground entry position by the ground entry / exit control unit, there is a risk of falling if the boom operation deviates from a predetermined range due to a failure or the like. You may comprise so that both a jack and a boom may be controlled. As described above, when the operation control is performed, it is preferable to perform a control in which the jack and the boom are individually operated and returned to the range without allowing the interlocking thereafter.

  Further, the working device provided on the vehicle body is not limited to the above-described configuration. For example, the working device is configured to include a bending / extending arm in which a parallel link is swingably attached between the tip of the boom 22 and the vertical post 23. Even in an aerial work vehicle provided with a device, the present invention can be similarly implemented and the same effect can be obtained.

It is a top view of the aerial work vehicle of 1st Example, 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 upper operation apparatus 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 in an aerial work vehicle according to the present invention. 1 shows a part of a hydraulic circuit in an aerial work vehicle according to the present invention. It is a side view of the aerial work vehicle, and is a side view showing when the work table is located at the ground entry 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. It is a side view of the aerial work vehicle, and is a side view showing when the work table is located at a high work position.

Explanation of symbols

P1 Main pump P2 Emergency pump BA Boom actuator JA Jack actuator ILV Interlock valve (interlock means)
CHV switching valve (interlocking permission means)
SV1, SV2 shut-off valve (interlocking permitting means)
SW1 Ground entry switch (ground entry / exit operation means)
SW3 Ground descent switch (ground entry / exit operation means)
DESCRIPTION OF SYMBOLS 1 Aerial work vehicle 10 Car body 20 Work apparatus 22 Boom 24 Work table 40 Jack 50 Controller (control means)

Claims (3)

A vehicle body that can run freely,
A boom that is provided on the vehicle body and configured to be at least telescopically movable and stored with a front end portion directed toward the rear of the vehicle body;
A workbench attached to the tip of the boom and stored on the vehicle body;
A plurality of jacks that are provided on the front, rear, left, and right sides of the vehicle body and configured to freely extend and contract vertically, and extend downward to support the vehicle body;
Ground entry operation means provided in the vehicle body;
Ground descent operating means provided on the work table,
The boom and the plurality of jacks are operated according to the operation of the ground entry operation means or the ground descent operation means, and the work table is moved to the ground entry position located near the ground behind the vehicle body. In an aerial work vehicle configured with a control means,
Interlock means for restricting the plurality of jacks from operating when the boom is in an operating state, and restricting the boom from operating when the plurality of jacks are in an operating state;
Interlocking permission means for releasing the operation restriction of the boom and the plurality of jacks by the interlock means when the ground entry operation means or the ground descent operation means is operated,
The control means is configured to activate the interlocking permission means and simultaneously actuate the boom and the plurality of jacks when an operation signal is output from the ground entry operation means or the ground descent operation means. An aerial work vehicle characterized by being configured to perform . The control means, wherein the boom is operated to the boom and the plurality of jacks when in the predetermined operation range in which a range from near the boom storage position to near the ground Nokomi position simultaneously, the boom the 2. The aerial work vehicle according to claim 1, wherein the aerial work vehicle is configured to perform control for restricting operation of at least one of the boom and the plurality of jacks when deviating from an operation range. A boom actuator for operating the boom;
A jack actuator for actuating the plurality of jacks;
A main pump for supplying hydraulic oil to the boom actuator and the jack actuator;
A sub-pump that is always stopped and configured to operate when required, and that supplies hydraulic oil to the boom actuator and the jack actuator;
Wherein, when performing control for operating the boom and the plurality of jacks simultaneously claim 1, characterized in that it is configured to perform control of actuating the said and the main pump sub pump simultaneously or The aerial work vehicle described in 2 .

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