JP3579587B2 - Work vehicle support device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a support device that supports a vehicle body by grounding a jack provided on a vehicle body of a work vehicle at the time of work, and furthermore, even when using a jack base when supporting a vehicle body with this jack, and The present invention relates to a work vehicle support device capable of reliably grounding a jack.
[0002]
[Prior art]
Jacks are attached to the front, rear, left and right of a work vehicle equipped with a boom that can swing up and down on the vehicle body like a high work vehicle. By appropriately extending these jacks and grounding the grounding plate attached to the lower end thereof, a moment acting on the body in the direction of tipping over based on the weight of the boom and the load at the tip (hereinafter referred to as the “falling moment”) ) Can be supported stably.
[0003]
Here, an automatic jack grounding device is conventionally known as a jack operating device for grounding the jack as described above. 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 supporting the vehicle body.
[0004]
When working at heights with an aerial vehicle equipped with such a jack, it is necessary to extend the grounding plate until a sufficient ground reaction force acts on the jack. Here, when the jack is grounded 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. Further, 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]
[Problems to be solved by the invention]
However, when the jack is grounded by the automatic jack grounding device using the 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. When 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.
[0006]
The present invention has been made in view of such a problem, and even in a case where the jack is grounded by an automatic jack grounding device in a situation where a jack base such as a soft ground is required, an appropriate gap between the jack and the ground can be obtained. It is an object of the present invention to provide a support device for a working vehicle that can easily move a jack base to a position.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the work vehicle support device according to the present invention has a plurality of jacks arranged on the vehicle body to stably support the vehicle body by performing an extension operation from a stowed state to ground. Each of these jacks is expanded and contracted by jack expansion and contraction means (for example, the left front control valve 25 and the like described in the embodiment). The expansion 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 contact detection means. Then, when each jack is extended by operating the extension operating means, 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.
[0008]
According to the jack support device of the work vehicle configured as described above, when the jack is extended to ground the jack, the extension operation is stopped while the jack is grounded, and the ground of the jack is released. Therefore, 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 jack grounding will occur once the jack has been grounded. Since the jack base is released, the jack base can be moved to a desired position.
[0009]
In the support device for a working vehicle according to the present invention, the ground release means is a jack reducing means for performing the jack reducing operation until the ground of the jack is no longer detected by the ground detecting means (for example, the jack described in the embodiment). Preference is given to a reduction device 20a). With such a configuration, the ground reaction force can be reliably prevented from acting, so that the jack base and the like can be easily moved.
[0010]
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 release for preventing the jack installation / release operation by the grounding releasing means. It is preferable to adopt a configuration provided with a blocking means. With this configuration, when the jack base is misaligned due to the initial grounding operation, the jack can be earthed by operating the extension operating means again after correcting the misalignment of the jack base. Therefore, it is not necessary to separately provide an operation means, and the jack can be grounded by a simple operation.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described 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 has a front wheel F and a rear wheel R for traveling on the road before and after the vehicle body 11, and has a swivel 12 at a rear portion of the vehicle body 11 that can freely turn horizontally with respect to the vehicle body 11. I have. 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 move up and down. Further, a work table 14 is attached to the tip of the boom 13, and an operator 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.
[0012]
When the boom 13 is actuated, a tipping moment acts on the vehicle body 11, so that a left front jack 15 and a right front jack 15 'are provided on the left and right front portions of the vehicle body 11 in order to support the vehicle body 11 with respect to the ground. A left rear jack 16 and a right rear jack 16 'are provided on the right and left rear portions of the vehicle body 11, respectively. The configuration of the jack will be described with reference to the left front 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 the supply and discharge of hydraulic oil supplied by a hydraulic pump (not shown) provided on the vehicle body 11. It operates.
[0013]
As shown in FIG. 2, the four jacks 15 and the like configured as described above control supply and discharge of hydraulic oil by control valves 25, 25 ', 26, and 26' provided corresponding to the jacks 15 and the like. , The expansion and contraction operation can be individually controlled. 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 operating an operating device 17 provided at the rear of the vehicle body 11. The operating device 17 is provided with an automatic extension switch 17a. When the automatic extension switch 17a is operated, the jacks 15 and the like are arranged so that the front wheel F and the rear wheel R are grounded in a grounded state. Is performed.
[0014]
When the automatic extension switch 17a is operated, the extension operation of the jacks 15 and the like as described above is performed after the extension operation of each jack 15 and the like is controlled by the work vehicle support device 1 according to the present invention. In the support device 1 for the working vehicle, in addition to the jacks 15 and the like, the control valve 24 and the like, and the automatic extension switch 17a, the controller 20 and the grounding plates 15c, 15c ', 16c and 16c' are grounded to the ground. It is configured to include a left front contact detection sensor 15d, a right front contact detection sensor 15d ', a left rear contact detection sensor 16d, and a right rear contact detection sensor 16d' for detecting whether or not this is the case. Then, when the grounding of the ground plate 15 c or the like is detected by performing the extension operation of the jack 15 or the like, the ground detection signal is transmitted to the controller 20.
[0015]
Here, the grounding of the jack 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 F and the rear of the aerial work vehicle 10. The wheel R also supports the vehicle body 11 (the state in which the wheels F and R are not floating above the ground and the so-called wheels are not grounded). The grounding detection sensor 15d for detecting such grounding is 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 determine the grounding of the rod 15b and the grounding plate 15c. The grounding of the jack 15 and the like is detected by detecting the operation of a limit switch or a load cell provided therebetween.
[0016]
Accordingly, when grounding the jack 15 or the like using the jack bases B on a soft ground as described above, the jack base B may sink into the ground when the jack 15 or the like is extended depending on the condition of the ground. is there. 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.
[0017]
When the automatic extension switch 17a is operated from the state where each jack 15 is in the retracted state, the supply / discharge control of hydraulic oil by the control valves 25, 25 ', 26, 26' is performed, and each jack is controlled. An extension operation such as 15 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 the four jacks 15, 15 ', 16, 16' are grounded.
[0018]
When the grounding of all the 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, and 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.
[0019]
Accordingly, 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. Therefore, even when the jack bases B are sandwiched 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.
[0020]
That is, in the aerial work vehicle 10 as described above, when the automatic extension switch 17a is operated, the jacks 15 and the like perform a grounding operation. At this time, the jacks 15 are pressed by the grounding plate 15c. When the base B is displaced, the jack base B may be moved in a state where the jacks 15 and the like are once grounded as described above and then temporarily reduced. 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.
[0021]
Then, after correcting the shifted position of the jack base B, 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 is reduced by the jack reduction device 20a, the operation signal is sent from the jack re-extension device 20b to the control valve 25 or the like. Is sent.
[0022]
In this manner, whether or not the operation signal is transmitted from the jack re-extension device 20b to the control valve 25 or the like is determined, that is, whether the operation of the automatic extension switch 17a is the first operation, or the The determination of the operation is performed by storing the number of times of operation of the automatic extension switch 17a in the controller 20. 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-extension device 20b to the control valve 25 or the like. Then, after it is confirmed that the extension operation of each jack 15 and 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 and the like is confirmed by detecting that each of the wheels F and R is ground by a ground detection sensor (not shown), or by detecting a jack storage sensor (not shown). This is done by detecting that all jacks 15 and the like have been stored.
[0023]
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 stowed state. That is, when the automatic extension switch 17a is operated when it is detected that each jack 15 or the like is in the storage state, it is determined that this is the first operation, and it is detected that each jack 15 or the like is 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.
[0024]
In this way, the control valves 25, 25 ', 26, 26', which have received the operation signal from the jack re-extension device 20b, control the supply and discharge of the hydraulic oil, and the front wheel F and the rear wheel R are grounded and the vehicle body is cut off. The load 11 is supported only by the four jacks 15 and the like, and each jack 15 and the like is extended until the vehicle body 11 becomes horizontal. That is, when the automatic extension switch 17a is operated again, even if the ground detection is performed by the left front ground detection sensor 15d or the like, the jack is not reduced. Thereby, even on a soft ground, the aerial work vehicle 10 can be firmly supported via the jack bases B, B... Against the overturning moment.
[0025]
In the above-described embodiment, the jack bases B, B,... Are moved once after the jacks 15 are grounded, so that the jacks 15 are once reduced. Need not necessarily have such a configuration. For example, when the ground detection is performed by the ground 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 ground is detected by the ground detection sensor 15d or the like. The bottom-side oil chamber and the rod-side oil chamber of the detected jack 15 and the like may be configured to be released to the tank, and the hydraulic pressure may not be applied to the rod 15b and the like. In such a configuration, the own 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. It can be performed.
[0026]
【The invention's effect】
As described above, the work vehicle support device according to the present invention includes the ground release means when the extension operation means is operated to extend each jack, and when the ground detection of each jack is detected by the ground detection means. As a result, the extension operation of each jack by the jack extension means is stopped, and the grounding of each jack is released. According to the jack support device of the work vehicle configured as described above, when the jack is extended to ground the jack, the extension operation is stopped while the jack is grounded, and the ground of the jack is released. Therefore, the ground reaction force does not act on the jack. For this reason, when the jack is grounded by laying the 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 is once grounded, so that the displaced jack base can be easily returned to the original position without performing a complicated jack operation.
[0027]
In the work vehicle support device according to the present invention, it is preferable that the ground release means is jack reduction means for performing a jack reduction operation until the ground detection of the jack is no longer detected by the ground detection means. With this configuration, even if 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.
[0028]
Further, in the work vehicle support device according to the present invention, when the extension operation means is operated again after the grounding of the jack is released by the grounding release means, the release for preventing the jack installation release operation by the grounding release means. It is preferable to adopt a configuration provided with a blocking means. With this configuration, when the jack base is misaligned due to the initial grounding operation, the jack can be earthed by operating the extension operating means again after correcting the misalignment of the jack base. Therefore, there is no need to provide an additional 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 vehicle 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

Claims (3)

A plurality of jacks disposed on the vehicle body and stably supporting the vehicle body by touching the ground by performing an extension operation from the 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 the jack expansion / contraction means,
Ground detection means for detecting the ground of each jack,
When the jacks are extended by operating the extension operation means, and when the ground detection of the jacks is detected by the grounding detection means, the extension operation of the jacks by the jack extension means is stopped and the respective jacks are stopped. And a ground release means for releasing the ground of the work vehicle. The work vehicle support device according to claim 1, wherein the ground release unit is a jack reducing unit that performs the jack reducing operation until the ground detection of the jack is no longer detected by the ground detection unit. When the extension operating means is operated again after the grounding of the jack is released by the grounding releasing 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

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