JP2000016798A - Support device of working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a support device of a working vehicle such that even if jacks are to be grounded by an automatic jack grounding device under conditions where jack bases are needed, as on soft ground, the jack bases can easily be displaced to proper positions between the jacks and the ground. SOLUTION: When each jack 15 or the like is extended by operating an automatic overhanging switch 17a and the grounding of each jack 15 or the like is detected by a grounding detecting sensor, then a jack contracting device stops the expansion of each jack 15 or the like and contracts each jack 15 or the like until the grounding of each jack 15 or the like is not detected. Thus when jack bases B, B... are laid below the jacks 15 or the like during grounding of the jacks 15 or the like, the jack base B can be displaced easily if shifted from its proper position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support device for supporting a vehicle body by grounding a jack provided on the vehicle body of a working vehicle at the time of work, and further uses a jack base when supporting the vehicle body with the jack. The present invention relates to a work vehicle support device that can easily and reliably ground a jack even in such a case.

[0002]

2. Description of the Related Art Jacks are attached to the front, rear, left and right of a working vehicle having a boom that can freely move up and down on a vehicle body, such as an aerial working vehicle. Then, by appropriately extending these jacks and grounding the grounding plate attached to the lower end thereof, a moment acting on the vehicle body in the direction of tipping over based on the weight of the boom and the load at the tip (hereinafter referred to as a “falling moment”) ) Can be supported stably.

[0003] As a jack operating device for grounding a jack as described above, an automatic jack grounding device is conventionally known. This automatic jack grounding device automatically extends all jacks when the operator operates the automatic jack switch, grounds the jacks, and stably supports the vehicle body against the falling moment. In addition, the amount of extension of each jack is controlled so that the vehicle body is horizontal while the vehicle body is supported.

[0004] When performing a high-altitude operation using an aerial vehicle equipped with such a jack, it is necessary to extend the ground plate until a sufficient ground reaction force acts on the jack. Here, when grounding the jack as described above, if the ground to be grounded is unstable (so-called “soft ground”), it is possible to obtain a large grounding area between the jack and the ground. In addition, a plate material called a jack base is sandwiched between a ground plate provided at the lower end of the jack and the ground.

[0005]

However, when the jack is grounded by an automatic jack grounding device using a jack base on such a soft ground, the jack base may move with the extension operation of the jack depending on the condition of the ground. May be done. If the jack base moves and the jack deviates from the center of the jack base in this manner, there is a problem that a sufficient ground reaction force cannot be obtained.

The present invention has been made in view of such a problem, and even when the jack is grounded by an automatic jack grounding device in a situation where a jack base such as a soft ground is required, the distance between the jack and the ground can be reduced. It is an object of the present invention to provide a work vehicle support device that can easily move a jack base to an appropriate position.

[0007]

To achieve the above object, a work vehicle support device according to the present invention includes a plurality of jacks that stably support a vehicle body by contacting the vehicle body by performing an extension operation from a stowed state. Installed on the vehicle body. Each of these jacks is expanded and contracted by jack expansion and contraction means (for example, the left front control valve 25 described in the embodiment). The extension operation of each jack by the jack expansion and contraction means is performed by extension operation means (for example, in the embodiment). The extension operation control operation of the automatic extension switch 17a) described above is performed. As described above, the detection of whether or not the extended jack is in contact with the ground by performing the extension operation control operation of the extension operation means is performed by the ground detection means. Then, when the extension operation means is operated to extend each jack, when the grounding of each jack is detected by the ground detection means, the extension operation of each jack by the jack extension means is stopped by the ground release means. Let each jack release the ground.

According to the jack support device for a working vehicle constructed as described above, when the jack is extended in order to ground the jack, the extension operation is stopped while the jack is in contact with the ground and the jack is grounded. To be released
The ground reaction force does not act on the jack. For this reason, when grounding the jack, the jack base may be laid under the jack, but even if the jack base has shifted due to the grounding of the jack, the grounding of the jack after the jack has once grounded Since the jack base is released, the jack base can be moved to a desired position.

In the work vehicle support device according to the present invention, the ground release means is used as a jack reduction means (for example, in the embodiment) for reducing the jack until the ground contact of the jack is no longer detected by the ground detection means. The jack reduction device 20a) described is preferred. With such a configuration, the ground reaction force can be reliably prevented from acting, and the jack base and the like can be easily moved.

Further, in the work vehicle support device according to the present invention, when the extension operating means is operated again after the grounding of the jack is released by the grounding releasing means, the installation and release operation of the jack by the grounding releasing means is performed. It is preferable to adopt a configuration in which a release preventing means for preventing is provided. With such a configuration, when the jack base shifts due to the initial grounding operation, etc., the jack ground can be performed by operating the extension operation means again after correcting the jack base shift. Therefore, it is not necessary to separately provide an operation means, and the jack can be grounded by a simple operation.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. First, an aerial work vehicle 10 including a work vehicle support device according to the present invention will be described with reference to FIG. The aerial work vehicle 10 includes a body 11
, Front and rear wheels R and R for road traveling, and a turntable 12 at the rear of the vehicle body 11 that can freely turn horizontally with respect to the vehicle body 11. A boom 13 which is telescopically (in a telescopic manner) configured to be extendable and retractable is attached to the upper portion of the swivel table 12 so as to be able to rise and fall. Further, a work table 14 is attached to the tip of the boom 13, and the worker who gets on the work table 14 can move to an arbitrary height through the operation of the swivel table 12 and the boom 13.

When the boom 13 is operated, a tipping moment acts on the vehicle body 11, so that the left front jack 15 and the right front jack 15 'are provided on the left and right of the front part of the vehicle body 11 in order to support the vehicle body 11 against the ground. Is provided, the vehicle body 1
A left rear jack 16 and a right rear jack 16 'are provided on the left and right of the rear portion of the unit 1. The configuration of the jack will be described by taking the front left jack 15 as an example. The jack 15 includes a cylinder tube 15a attached to the vehicle body 11, a rod 15b which is vertically expandable and contractible with respect to the cylinder tube 15a, and a lower end of the rod. And a grounding plate 15c attached to the vehicle body 11. The rod 15b expands and contracts with respect to the cylinder tube 15a by controlling supply and discharge of hydraulic oil supplied by a hydraulic pump (not shown) provided on the vehicle body 11. It operates.

The four jacks 15 constructed as described above
As shown in FIG. 2, the expansion and contraction operation can be controlled individually by controlling the supply and discharge of hydraulic oil by control valves 25, 25 ', 26 and 26' provided corresponding to each jack 15 and the like. It has become. Therefore, in the aerial work vehicle 10, even when the aerial vehicle 10 is stopped on the ground inclined in the front-rear direction or on the ground inclined in the left-right direction, the amount of extension of each jack 15 or the like is adjusted. Thereby, the aerial work vehicle 10 can be installed horizontally. The operation of the control valves 24, 24 ', 25, 25' is controlled by the vehicle body 11
The operation is performed by operating the operation device 17 provided at the rear of the vehicle. The operation device 17 includes an automatic extension switch 17a.
When the automatic extension switch 17a is operated, the front wheel F and the rear wheel R
Are extended so that the jacks 15 are grounded.

When the automatic extension switch 17a is operated, the extension operation of the jacks 15 and the like described above is performed after the extension operation of the jacks 15 and the like is controlled by the work vehicle support device 1 according to the present invention. You. Work vehicle support device 1
Is a controller 20 in addition to the jacks 15 and the like, the control valve 24 and the like, and the automatic extension switch 17a.
Left ground contact detection sensor 1 for detecting whether or not each of the ground plates 15c, 15c ', 16c, 16c' has contacted the ground.
5d, a right front contact detection sensor 15d ', a left rear contact detection sensor 16d, and a right rear contact detection sensor 16d'. Then, when the grounding of the grounding plate 15 c and the like is detected by performing the extension operation of the jack 15 and the like, a grounding detection signal is transmitted to the controller 20.

The grounding of the jacks here means not only that the jacks 15 support the vehicle body 11 (in a state where a predetermined ground reaction force is obtained), but also the front wheels of the aerial work vehicle 10. The state in which the vehicle body 11 is supported also by the F and the rear wheel R (the state in which the wheels F and R are not floating above the ground and the so-called wheels are not grounded). Ground detection sensor 1 for performing such ground detection
5d and the like are configured to determine the grounding of the grounding plate 15c or the like by detecting the hydraulic pressure in each jack 15 or the like, or to operate a limit switch or a load cell provided between the rod 15b and the grounding plate 15c. The detection is performed so that the grounding of the jack 15 and the like is detected.

Therefore, when the jacks 15 are grounded using the jack bases B on a soft ground as described above, the jack bases B sink into the ground when the jacks 15 are extended depending on the condition of the ground. Sometimes. In such a case, in the jack in which the jack base B sinks, a predetermined ground reaction force cannot be received unless the extension amount of the rod is longer than that of the other jacks.

When the automatic extension switch 17a is operated after each jack 15 is in the retracted state, the supply / discharge control of hydraulic oil is performed by the control valves 25, 25 ', 26, 26'. The extension operation of each jack 15 and the like is performed. As described above, when the extension operation is performed and any of the jacks 15 or the like is grounded by any of the grounding detection sensors 15d or the like, a detection signal is transmitted to the controller 20. The controller 20 that has received the detection signal controls the operation of the control valve 25 and the like corresponding to the grounded jack 15 and the like, and stops the extension operation of the grounded jack 15 and the like. The extension operation is continuously performed for the jack 16 and the like that are not grounded. Such extension operation of the jack 15 is performed until all four jacks 15, 15 ', 16, 16' are grounded.

All jacks 15, 15 ', 16, 16
Is detected, a detection signal is transmitted to the jack reducing device 20a provided in the controller 20. The jack reducing device 20a that has received the detection signal controls the operation of the control valves 24, 24 ', 25, 25' so as to reduce all the jacks 15, 15 ', 16, 16'. Such a reduction operation of the jack 15 and the like is performed until the ground detection is not performed by the ground detection sensor 15d and the like, and the reduction operation is sequentially stopped from the jack 15 and the like that are no longer grounded. Then, the operation of the jacks 15 and the like is stopped in a state where all the four jacks 15, 15 ', 16, 16' are not grounded.

Therefore, in such a state, the jack 15 and the like have all four rods 15b and the like extending downward, but the load of the vehicle body 11 is supported only by the front wheel F and the rear wheel R. Becomes Therefore, even when the jack bases B are held between the ground and the grounding plate 15c, the load of the vehicle body 11 is not applied to the jack bases B. B ... can be moved.

That is, in the aerial work vehicle 10 as described above, when the automatic extension switch 17a is operated, each jack 15 and the like perform a grounding operation.
If the jack base B is displaced by the pressing of the grounding plate 15c at this time, the jack base B is moved in a state where the jacks 15 and the like are once grounded as described above and then once reduced. Good. Therefore, it is possible to prevent each jack 15 and the like from being grounded while the jack base B is displaced from the ground plate 15c.

Then, the shifted jack base B
After the position is corrected, the automatic extension switch 17a is operated again. In this way, when the automatic extension switch 17a is operated again after the jack is detected once and the jack contraction device 20a performs the contraction operation, the operation signal is transmitted from the jack re-extension device 20b to the control valve 25 or the like. Is sent.

The jack re-expansion device 20
b, whether the operation signal is transmitted to the control valve 25 or the like, that is, whether the operation of the automatic extension switch 17a is the first operation or the re-operation after once touching the ground is determined by the controller. Automatic extension switch 17 at 20
This is performed by storing the number of times of operation a. That is, when the operation of the automatic extension switch 17a is performed for the second time, an operation signal is transmitted from the jack re-expansion device 20b to the control valve 25 or the like. Then, after it is confirmed that the extension operation of each jack 15 or the like capable of stably supporting the vehicle body 11 is performed, the stored number of operations is reset (returned to 0). The operation of the jack 15 or the like is confirmed by detecting that the wheels F and R are grounded by a ground detection sensor (not shown), or by detecting a jack storage sensor (not shown). Z)
This is done by detecting that all jacks 15 and the like have been stored.

The determination as to whether or not the operation has been performed once after touching the ground may be performed by detecting whether or not each jack 15 or the like is in the retracted state. That is, when the automatic extension switch 17a is operated when the respective jacks 15 and the like are detected to be in the storage state, it is determined that this is the first operation, and it is detected that the respective jacks 15 and the like are not in the storage state. When the automatic extension switch 17a is operated at this time, it may be determined that the operation is a re-operation.

Thus, the jack re-expansion device 20
b, the control valves 25, 25 'receiving the operation signal from b.
Reference numerals 26 and 26 'control the supply and discharge of hydraulic oil. The front wheel F and the rear wheel R are ground and the load of the vehicle body 11 is supported only by the four jacks 15 and the like. The jack 15 and the like are extended. That is, when the automatic extension switch 17a is operated again, even if the ground detection is performed by the front left ground detection sensor 15d or the like, the jack is not reduced. Thereby, even on soft ground, the aerial work vehicle 10 can be firmly supported against the overturning moment via the jack bases B, B.

In the above-described embodiment, the jack bases B, B
Are moved once to reduce the size of each jack 15, etc., but it is not always necessary to adopt such a configuration in the present invention. For example, when the grounding is detected by the grounding detection sensor 15d or the like, the operation of the control valve 24 or the like or a control valve provided separately from the control valve 24 or the like is controlled so that the grounding by the grounding detection sensor 15d or the like is performed. Jack 1 that was detected
The bottom-side oil chamber and the rod-side oil chamber such as 5 may be configured to be released to the tank, and the hydraulic pressure may not act on the rod 15b or the like. In such a configuration, the weight of the rod 15b, the ground plate 15c, and the like acts on the jack base B, but the jack base B can be moved.
Can be corrected.

[0026]

As described above, the work vehicle support device according to the present invention is capable of operating the extension operation means to extend each jack, and detects that each of the jacks is grounded by the ground detection means. Is configured to stop the extension operation of each jack by the jack extension means by the ground release means and release the ground of each jack. According to the jack support device for a work vehicle configured as described above, when the jack is extended in order to ground the jack, the extension operation is stopped while the jack is grounded, and the ground of the jack is released. Therefore, no ground reaction force acts on the jack. Therefore, when the jack is grounded by laying a jack base under the jack, such as when the ground on which the jack is grounded is a soft ground, the jack base may be displaced with the grounding of the jack. In such a case, the jack is released from the ground after the jack has once touched the ground, so that the displaced jack base can be easily returned to the original position without performing a complicated jack operation.

In the work vehicle support device according to the present invention, it is preferable that the ground release means is jack reducing means for performing a jack reducing operation until the ground contact of the jack is no longer detected by the ground detecting means. With this configuration, even when the jack base is laid under the jack, the ground reaction force can be prevented from acting on the jack base, so that the shifted jack base can be moved more easily. It can be carried out.

In the work vehicle support device according to the present invention, when the extension operation means is operated again after the jack is released from the ground by the ground release means, the jack installation release operation by the ground release means is performed. It is preferable to adopt a configuration in which a release preventing means for preventing is provided. With such a configuration, when the jack base shifts due to the initial grounding operation, etc., the jack ground can be performed by operating the extension operation means again after correcting the jack base shift. Therefore, there is no need to separately provide an operating means, so that the configuration of the operating device can be simplified and the jack extension operation control operation can be easily performed.

[Brief description of the drawings]

FIG. 1 is a perspective view of an aerial work vehicle provided with a work vehicle support device according to the present invention.

FIG. 2 is a block diagram illustrating a configuration of a support device for the work vehicle.

[Explanation of symbols]

 Reference Signs List 10 aerial work platform 11 body 15 left front jack 15 'right front jack 16 left rear jack 16' right rear jack 17 operating device 17a automatic extension switch

Continued on the front page F term (reference) 3F205 AA06 AA20 BA10 FA09 3F333 AA08 AB04 BD02 CA15 FA17 FA21 FD03 FD20 FE03

Claims (3)

[Claims] 1. A plurality of jacks arranged on a vehicle body and stably supporting the vehicle body by touching the ground by performing an extension operation from a stowed state, jack expansion / contraction means for performing expansion / contraction operation of each of these jacks, Extension operation means for performing an extension operation control operation of each jack by means; ground detection means for detecting the ground of each jack; extending each jack by operating the extension operation means; Grounding release means for stopping the extension operation of each jack by the jack extension means and releasing the grounding of each jack when the grounding of each jack is detected. apparatus. 2. The work according to claim 1, wherein the ground release means is a jack reducing means for reducing the jack until the ground of the jack is no longer detected by the ground detecting means. Car support device. 3. When the extension operation means is operated again after the grounding of the jack is released by the grounding release means, a release preventing means for preventing the jack from releasing the grounding operation of the jack by the grounding releasing means is provided. The support device for a working vehicle according to claim 1 or 2, wherein: