JP2532822Y2 - Work vehicle support state detection device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work vehicle equipped with a jack or an outrigger jack device, and more particularly to a support state detecting device for detecting a decrease in support stability of a body of the work vehicle.

[0002]

2. Description of the Related Art For example, jacks are attached to the front, rear, left and right sides of a body of a work vehicle such as an aerial work vehicle or a crane truck having a boom that can be raised and lowered and turned freely. The jack includes an outer post attached to a vehicle body, and an inner post that is inserted into the outer post so as to be able to expand and contract downward. Then, the inner post is appropriately extended and the lower end thereof is grounded, so that the vehicle body is opposed to a moment acting in the direction of overturning the vehicle body based on the weight of the boom and the tip load (hereinafter, referred to as a overturning moment). It can be stably supported. Some of the work vehicles have an outrigger jack device. The outrigger jack device includes an outrigger box attached to the vehicle body, an outrigger beam inserted into the outrigger box so as to be able to expand and contract toward the vehicle body, and a jack attached to a tip of the outrigger beam. By extending the outrigger beam and appropriately extending the jack and grounding the jack, the vehicle body can be stably supported against a considerably large overturning moment.

However, there is a limit to the overturning moment that can be supported by such a jack or outrigger jack device. For this reason, it is necessary to regulate further operation of the boom before the vehicle body becomes unstable.

Therefore, a supporting state detecting device is attached to the jack and the outrigger jack device.
In the support state detecting device attached to the jack, the mounting structure between the outer post and the inner post has vertical play. When a large overturning moment acts on the vehicle body, the outer post attached to the opposite side of the moment acting side of the vehicle body and the outer post attached thereto rises by the amount of the play above the inner post in the ground contact state. . On the other hand, in the vehicle body floating detection device attached to the outrigger jack device, the outrigger beam is inserted into the outrigger box with vertical play. Then, when a large overturning moment acts on the vehicle body, the outrigger box attached to the side opposite to the side where the moment acts on the vehicle body and attached thereto is lifted by the amount of backlash with respect to the jack and the outrigger beam in the ground contact state. Has become. For this reason, by detecting the lift using a limit switch or the like, it is possible to detect a decrease in the stability of the vehicle body at least before the jack leaves the ground. Then, safety measures such as regulation of the operation of the boom are taken based on the detection.

[0005]

However, there is a problem that the detection of a decrease in the stability of the vehicle body in such a support state detecting device is performed only after the vehicle body load is completely applied to the jack related to the detection. . That is,
When the above detection is performed, the support stability of the vehicle body has already been considerably reduced, and there is no longer enough room. For this reason, if the above-mentioned support state detecting device is used, there is a possibility that the safety of work cannot be sufficiently ensured.

In order to solve this problem, an urging means for urging the outer post upward with respect to the inner post is provided to detect a decrease in the support stability in a state where the support stability of the vehicle body has a margin. Supporting state detecting devices that can be used are also provided.However, because of the necessity of the configuration, these detecting means are mounted on the inner post side, which is a moving body, and are turned on and off by moving the inner post. It was what was done. For this reason, when this support state detecting device is used for a jack for vehicles, there is a wiring problem that the wiring must be extended from the inner post and the wiring must be stored through the outer post, and there is a problem on the movable part side. Detectors and wiring must be connected, which is not preferable from the viewpoint of reliability. The present invention has been made in view of such a problem, and it has been made possible to detect a decrease in support stability in a state where there is a margin in a support state of a vehicle body, and to make a relative position between an outer post and an inner post. The detector that detects the target movement is installed on the outer post side fixed to the vehicle body, eliminating the reciprocating movement of the wiring due to the movement of the inner post, improving the reliability of the detection device, and simplifying the storage of the wiring It is intended to be.

[0007]

Means for Solving the Problems In order to achieve the above object, a supporting state detecting device of the present invention which is attached to a jack is provided with a loose mounting for fixing an inner post to an outer post with a margin in the vertical direction. Detecting means for detecting that the outer post has been urged upward by a predetermined distance with respect to the inner post by the urging means for urging the outer post upward with respect to the inner post; Is provided on the outer post side fixed to the vehicle body.

[0008]

In such a supporting state detecting device, when the support stability of the vehicle body is reduced and the vehicle load on the jack becomes slightly smaller than the urging force of the urging means, the outer post is moved to the inner post by the urging force. It is relatively raised. For this reason, the reduction can be detected in a state where the vehicle load equivalent to the urging force is applied to the jack, that is, in a stage where the stability of the vehicle body does not decrease so much. Also, there is no need to provide any electrical contact on the inner post on the movable part side, and no load is applied to the wiring etc. due to the vertical reciprocation of the inner post, so that the reliability of the detection device can be improved as much as possible. But not
The wiring is simple and the wiring can be stored easily.

[0009]

DETAILED 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 equipped with the support state detecting device according to the present invention will be described with reference to FIG. The aerial work vehicle 30 has a boom 32 pivotally attached to a rear portion of a vehicle body 31. The boom 32 is
It is pivotally attached to the base 1 so as to be able to move up and down, and is configured to be telescopically expandable and contractible. A work table 33 is attached to the tip of the boom 32.
The operator who has boarded can control the operation of each operation of the boom 32 and can move to an arbitrary height.

By the way, the vehicle body 3 is moved so that the vehicle body 31 can be moved to a high place in a stable state.
Jacks (only those on the left side of the vehicle body 31 are shown in the figure) 1,1 are disposed at four locations on the front, rear, left, and right of the vehicle 1. Each jack 1 is composed of an outer post 2 attached to a vehicle body 31 and an inner post 3 which is fitted into the outer post 2 so as to be able to expand and contract downward.

Here, the outer post 2 of the inner post 3
As shown in detail in FIG. 1, the expansion and contraction of the jack cylinders 4 built in the posts 2 and 3 are performed. The upper end (cylinder tube side end) of the jack cylinder 4 is held by an upper end side pin 5 attached to the outer post 2. A lower end (a piston rod side end) of the jack cylinder 4 is held by a lower end pin 6 attached to a lower end of the inner post 3. A grounding plate 7 is pivotally mounted on the lower pin 6 so as to be vertically swingable. When hydraulic oil is supplied to the jack cylinder 4 attached in this manner through a hydraulic port 8 provided at the upper end thereof to extend the jack cylinder 4, the inner post 3 extends downward with respect to the outer post 2, Eventually, the ground plate 7 is grounded. When the jack cylinder 4 is further extended, the vehicle body 31 is lifted from the ground, and is supported by the four jacks 1 in a state where the full load of the vehicle body 31 (including the boom 32 and the like) is deposited.

However, depending on the operation state of the boom 32, the overturning moment generated based on the weight of the boom 32 and the mounting weight of the work table 33 becomes excessive, and the four jacks 1 cannot stably support the vehicle body 31. There is a risk. Therefore, a moment limiter (safety device) 40 as shown in FIG. The moment limiter 40 acts on the jack 1 of the vehicle body 31 by applying a falling moment.
The support state detecting device 10 which detects that the support stability has been lowered due to the above and outputs a regulation signal is attached to each jack 1. Further, a regulating device 42 is provided which regulates further operation of the boom 32 (particularly, raising / lowering operation or extension operation leading to an increase in the overturning moment) in response to a restriction signal from the support state detecting device 1. With such a moment limiter 40, work at high places can be performed safely without causing the vehicle body 31 to fall into an unstable state.

Here, the supporting state detecting device (the first embodiment) 10 will be described in detail again with reference to FIG. The support state detecting device 10 has a backlash mounting structure 1.
1, an urging device 12, and a limit switch 13. The loose mounting structure 11 is a mounting structure between the upper end of the jack cylinder 4 and the upper end pin 5. That is, an insertion hole 4a having a diameter larger than the diameter of the upper end side pin 5 is formed at the upper end of the jack cylinder 4.
When the upper end side pin 5 is inserted into the insertion hole 4a, the attachment between the two is performed in a state where there is a play of the difference between the diameters.

The biasing device 12 is mounted inside the outer post 2 and above the jack cylinder 4. The urging device 12 is closed upward (having a ceiling surface), and has a case 121 forming an inner space opened downward, and a push rod 122 inserted into the inner space so as to be movable up and down. Is provided. The case 121 is provided with an arm portion 121a extending left and right, and the distal end of the arm portion 121a is fixed to the outer post 2. Push rod 122 is case 121
And a lower end surface thereof is provided at an upper end of the jack cylinder 4 with an arm plate 14 to be described later.
Abuts through. Further, a compression plate 122a is attached to the lower side of the intermediate portion of the push rod 122. Further, a retaining nut 122 is provided at the upper end of the push rod 122 so as not to fall out of the case 121.
b is attached. A double spring (consisting of a large cylindrical spring 124 and a small cylindrical spring 125 disposed inside thereof) is attached between the ceiling surface in the inner space of the case 121 and the upper surface of the compression plate 122a.

The limit switch 13 is connected to the outer post 2
The switch rod 13a is attached to the inner side wall of the device with the switch rod 13a protruding downward. The lower end of the switch rod 13a is connected to the switch rod 1 from the upper end of the jack cylinder 4.
It is in contact with the upper surface of the head of the screw 14a attached to the tip of the arm plate 14 extending to below 3a. The limit switch 13 is turned off when the switch rod 13a is pushed upward by the head of the screw 14a, and turned on when the pushing is released, and outputs the above-mentioned regulation signal.

The support state detecting device 1 having the above-described structure.
0, when the overturning moment is small, as shown in FIG.
a is supported by the jack cylinder 4 in a state of contacting the lower portion of the inner surface. At this time, a play space 11a is formed above the upper end side pin 5. Accordingly, the lower end surface of the push rod 122 is pushed upward by the upper end of the jack cylinder 4 and is moved upward with respect to the case 121. For this reason, the double springs 124, 12
5 is compressed between the ceiling surface of the case 121 and the compression plate 122a, and the double springs 124 and 125 have the case 121, that is, the outer post 2, and the inner post 3
Is generated (hereinafter, this urging force is referred to as a floating-side urging force). However, at this time, since the vehicle body load applied to the jack 1 is larger than the above-mentioned urging force, the outer post 2 does not rise.
Further, the switch rod 13a of the limit switch 13 is also held in a state of being pushed upward.

However, when the overturning moment increases and the support stability of the vehicle body 31 decreases, the jack 1 (hereinafter referred to as a floating jack) disposed on the side of the vehicle body 31 opposite to the side on which the overturning moment acts. ) Is reduced and becomes smaller than the floating-side urging force. For this reason, the outer post 2 and the vehicle body 31 float up with respect to the inner post 3 by the vertical width of the play space 11a. Thereby, the pushing of the switch rod 13a is released, and the limit switch 13 is turned on. However, at this time, the vehicle load of a degree slightly smaller than the above-mentioned urging force is still applied to the lifting-side jack 1. Therefore, by appropriately setting the magnitude of the floating-side urging force, the moment limiter 40 can be operated in a state where the support stability of the vehicle body 31 has a margin.

In this embodiment, the double spring is used as a means for generating the lifting-side biasing force. However, the support state detecting device according to the present invention is not limited to this. That is, for example, a disc spring may be used.

Further, in the present embodiment, the support state detecting device in which the outer post 2 is incorporated in the jack 1 directly attached to the vehicle body 31 has been described. Not limited. That is, for example, the present invention can also be applied to an outrigger type jack in which the jack 1 can be extended to the side of the vehicle body 31.

When an outrigger type jack (outrigger jack device) as described above is provided, specifically, as shown in FIG. 2, the outrigger box 232 attached to the In the case where the outrigger beam 233 is inserted to extend and contract toward the side and the jack 201 is attached to the tip of the outrigger beam 233, a support state detecting device having a configuration different from that described above is provided. be able to. Hereinafter, the supporting state detecting device (described in claim 2) will be described. This support state detecting device 21
Numeral 0 is comprised of an insertion structure 211 with play, an urging device 212, and a limit switch 213. The backlash insertion structure 211 is a structure for inserting the outrigger beam 233 into the outrigger box 232. That is, the height dimension inside the outrigger box 232 is set to be larger than the height dimension of the outrigger beam 233, and the outrigger beam 233 is moved with the play of the difference between the height dimensions. Is inserted into.

The urging device 212 is attached to the upper side of the side end of the vehicle body 231. This structure is almost the same as that of the urging device 12 described above. Therefore, a detailed description of the urging device 212 is omitted. However, a roller 222a is attached to the lower end of the push rod 222, and the roller 222a is attached to the outrigger beam 233.
Is in contact with the upper surface of the

The limit switch 213 is mounted below the side end of the vehicle body 231. This switch 213
Is provided with a switch arm 213 a that is vertically swayable while being urged upward, and the tip of the arm 213 a is in contact with the lower surface of the outrigger beam 233. The switch 213 is turned off when the switch arm 213a is swinging upward, and turned on when the switch arm 213a is pushed down, and outputs a regulation signal.

The supporting state detecting device 2 configured as described above
In FIG. 10, when the overturning moment is small, as shown in FIG. 2A, the vehicle body 31 is supported in a state where the upper part of the inner tip of the outrigger box 232 is in contact with the upper surface of the outrigger beam 233. The play space 232a is provided below the outrigger beam 233 (in particular, around the switch arm 213a of the limit switch 213).
Is formed. Therefore, the roller 222 a at the lower end of the push rod 222 is pushed upward by the outrigger beam 233. Therefore, the urging device 212 includes
An urging force for raising the vehicle body 231 and the outrigger box 232 with respect to the outrigger beam 233 (hereinafter, this urging force is referred to as a floating-side urging force) is generated. However, in this case, the outrigger box 232 does not lift because the vehicle load applied to the jack 1 is larger than the lifting-side urging force. Further, the switch arm 213a is held in a state of being urged and swung upward.

However, when the overturning moment increases to some extent and the support stability of the vehicle body 231 decreases, the jack 201 disposed on the side of the vehicle body 231 opposite to the side on which the overturning moment acts and the outrigger connected to the jack 201 The vehicle body load applied to the beam 233 (hereinafter, referred to as a lifting-side beam) decreases, and becomes smaller than the lifting-side urging force. Therefore, the vehicle body 31 and the outrigger box 232 are lifted up with respect to the outrigger beam 233 by the play space 232a, as shown in FIG. 2B. Then, the switch arm 213a is pushed downward by the lower surface of the outrigger beam 233, and the limit switch 213 is turned on. However, at this time, a vehicle load of a degree slightly smaller than the above-mentioned urging force is still applied to the lifting-side beam 233. Therefore, by appropriately setting the magnitude of the floating-side urging force, the above-described moment limiter can be operated in a state where the support stability of the vehicle body 231 has a margin.

[0025]

As described above, the supporting state detecting device of the present invention includes the urging means for urging the outer post of the jack upward with respect to the inner post, and the outer post is moved by the urging means with respect to the inner post. Detecting means for detecting the upward bias is attached to the outer post. Therefore, by appropriately setting the urging force of the urging means, it is possible to detect that the outer post has lifted up with respect to the inner post before the support stability of the vehicle body decreases to the lower limit. Therefore, if this support state detection device is used for a working vehicle, there is still room for the stability of the support of the body by the jack,
A highly reliable work vehicle that can detect a decrease in support stability and can take safety measures such as work suspension at an early stage can be provided. In addition, since the detection means is attached to the outer post on the fixed portion side, there is no problem in wiring processing such that the wiring must be extended from the inner post and the wiring must be stored through the outer post. With the reciprocating movement, no load is applied to the wiring, so that the reliability of the detection device can be improved.

[Brief description of the drawings]

FIG. 1 is a side view of a supporting state detecting device according to the present invention.

FIG. 2 is a side view of the support state detecting device according to the present invention.

FIG. 3 is a perspective view of an aerial work vehicle provided with the support state detecting device.

FIG. 4 is a block diagram of a moment limiter using the support state detecting device.

[Explanation of symbols]

 1,201 Jack 2 Outer post 3 Inner post 4 Jack cylinder 5 Upper end pin 10,210 Support state detecting device 11 Mounting structure with play 12,212 Biasing device 13,213 Limit switch 40 Moment limiter 211 Insert structure with play 232 Outrigger box 233 Outrigger beam

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location B66F 11/04 B66F 11/04 E02F 9/08 E02F 9/08 A (56) References JP-A-49-108750 (JP, A) Japanese Utility Model Showa 55-17063 (JP, U) JP-B 39-4104 (JP, B1)

Claims (1)

(57) [Scope of request for utility model registration] An outer post mounted on a vehicle body;
An inner post is inserted into the outer post so as to extend and contract downward, and is provided on a working vehicle having a jack for supporting the vehicle body by grounding a lower end portion of the inner post, and the inner post is provided with the inner post. A work vehicle support state detection device that detects a decrease in support stability of the vehicle body by detecting that the outer post floats with respect to the inner post in a state where the outer post is in contact with the ground. A mounting structure with backlash for fastening the inner post to the outer post; a biasing means for biasing the outer post upwardly with respect to the inner post; and The outer post is urged upward by a predetermined distance with respect to the inner post within a range within the mounting margin. Work vehicle supporting state detecting apparatus characterized by being configured with a detecting means for detecting that the.