JP2002079874A - Wheel traveling device for work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always ground four wheels even on a recess-projection road surface by providing a fixed axle device and a rocking axle device. SOLUTION: This vehicular wheel traveling device is constituted by arranging the rocking axle device 10 and the fixed axle device 20 having left and right wheels 15 and 25 in front and in rear of a traveling body 2. The rocking axle device 10 has a rocking axle device 11 rockably installed on the traveling body 2 and rocking regulating cylinders 16 and 17 for regulating this rocking, and has a gravity center position detector 34 for determining a vehicle gravity center position of a vehicle except for the rocking axle device 11 and a rocking angle detector 39 for detecting a rocking angle of the rocking axle device 11, and determines a triangular rockable area formed by connecting a grounding point and a rocking midpoint of the left and right wheels of the fixed axle device, and regulates operation of a work device such as moving the vehicle gravity center position outside the rockable area in a state of being a prescribed angle or more in the rocking angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel traveling device for a work vehicle having traveling wheels at four positions in front, rear, left and right of a traveling body and having a working device on the traveling body.

[0002]

2. Description of the Related Art A work vehicle having such a wheel traveling device is, for example, a self-propelled wheel-type aerial work vehicle. The self-propelled wheel-type aerial work vehicle is composed of a vehicle wheel traveling device having traveling wheels at four front, rear, left, and right sides of a traveling body, and an aerial working device provided on the traveling body. Is configured to perform high-altitude work using a high-altitude work device while the ground is in contact with the traveling body. Since the wheels directly support the traveling body, all the members that rotatably support the wheels are directly attached to the traveling body (that is, without using a suspension device or the like) and rigidly attached,
It is configured to be able to stably support the aerial work apparatus on the traveling body while the wheels are in contact with the ground.

However, simply attaching the wheel support members that rotatably support the four front, rear, left and right wheels to the traveling body as it is, when the vehicle travels on an uneven road surface,
There is a problem that the three wheels contact the ground and support the traveling body, and the remaining one wheel floats up, resulting in unstable traveling body support. For this reason, two sets of axle devices each having a pair of left and right wheels are provided before and after the traveling body, and one of these axle devices is fixed to the traveling body (this is referred to as a fixed axle device). It is known to constitute a traveling device by swingably attaching the other axle device to a traveling body in a vertical plane extending left and right (this is referred to as a pivoting axle device).

As such a traveling device, for example, as disclosed in US Pat. No. 5,447,331,
The front axle device is mounted on the traveling body so as to swing freely and a hydraulic cylinder for controlling the swing position is provided. The rear axle device is mounted on the traveling body so as to be slightly swingable and the hydraulic cylinder is operated in accordance with the slight swing. There is a wheel traveling device configured to control the operation of the vehicle and always contact four wheels. According to such a wheel traveling device, even when traveling on an uneven road surface, it is possible to travel while constantly contacting all four wheels by the swing control of the front axle device, and the traveling body is stably supported. Is done.

[0005]

By the way, in the above-mentioned wheel traveling device, the rear axle device is mounted on the traveling body so as to be slightly swingable, and based on this slight swing change,
A state where any one of the four wheels is lifted is detected, and the front axle device is rocked by operating a hydraulic cylinder so that all wheels are grounded so as to prevent such wheel lifting. For this reason, not only the front axle device but also the rear axle device need to be swingably attached to the traveling body, and there is a problem that the traveling device configuration is complicated and the manufacturing cost is increased. Further, in the wheel traveling device, since the swing control of the front axle device is performed based on the slight swing of the rear axle device, the swing control device configuration becomes complicated and expensive. There is a problem.

It is also possible to adopt a configuration in which one axle device is fixed to a traveling body and the other axle device is simply attached to the traveling body so as to be able to swing, but the swing control of the swingable axle device is not performed. Yes, this can simplify the device configuration. However, in such a configuration, the vehicle center of gravity including the aerial work apparatus moves when performing the aerial work by the aerial work apparatus on the traveling body, and the center of the swinging part (the swing center and the fixed axle) There is a problem that the traveling body swings (about a line connecting the grounding point of one of the wheels of the device), and the support of the traveling body and the working device may become unstable.

The present invention has been made in view of the above-described problems, and has a wheel for a work vehicle in which one axle device is fixed to a traveling body and only the other axle device is swingably attached to the traveling body. More specifically, it is an object of the present invention to provide a traveling apparatus, and more specifically, a work vehicle having a configuration capable of easily performing swing control of an axle device that is swingably attached to a traveling body and capable of constantly supporting the traveling body. It is an object to provide a wheel traveling device for vehicles.

[0008]

In order to achieve the above object, according to the present invention, two sets of axle devices each having a pair of left and right wheels are provided before and after the traveling body, and a working device is mounted on the traveling body. And a wheel traveling device for a work vehicle is configured, one of these axle devices is fixed to a traveling body to form a fixed axle device, and the other of the axle devices is mounted on the traveling body in a vehicle width direction (lateral direction). The swing axle device is configured to be swingably mounted in a substantially vertical plane extending to the swing axle device. The swing axle device is mounted on a traveling body so as to be able to swing in a substantially vertical plane extending in the vehicle width direction and has wheels at left and right ends, and a swing axle device for the traveling body of the swing axle device. And a swing detector for detecting a swing amount. Further, the vehicle has a center-of-gravity position detecting means for determining a vehicle center-of-gravity position in plan view of the traveling body and the working device excluding the swinging axle device. A triangular swingable area formed in a plan view is obtained by connecting the swing center point with the swing center point. If the swing amount of the swing axle device detected by the swing detector is larger than a predetermined value, the position of the center of gravity is determined. The operation of the working device such that the position of the center of gravity of the vehicle determined by the detecting means moves outward beyond the swingable region is restricted.

The fixed axle device in the present invention means a device in which wheels are rotatable with respect to a vehicle body but are fixed so as not to be able to move vertically relative to each other, and has an axle connecting left and right wheels. Instead, a configuration in which the left and right wheels are directly rotatably attached to a vehicle body (traveling body) is also included.

When the working vehicle wheel traveling device having the fixed axle device and the swinging axle device travels on an uneven road surface, the swinging axle device in the swinging axle device swings. As a result, traveling can be performed in a state where all four wheels are in contact with the ground, stable traveling is possible, and the vehicle is stopped on an uneven road surface and the traveling body is reliably and stably supported by the four wheels. Is possible.

However, when the swinging axle device is allowed to swing freely, the working device on the traveling body is operated to perform work (for example, work at a high place). Accordingly, the position of the center of gravity of the vehicle moves, and the center of the swinging part of the swinging axle device (centering on the line connecting the swinging center point of the swinging axle device and the grounding point of one of the wheels of the fixed axle device). The traveling body swings. Such swing of the running body
This occurs when the vehicle center of gravity is located outside the vehicle from a line connecting the swing center point and the ground contact point of one of the wheels of the fixed axle device.

If such swinging occurs, the work by the working device cannot be performed stably. Therefore, the swinging point is located outside the vehicle from the line connecting the swinging center point and the grounding point of one of the wheels of the fixed axle device. When the center of gravity of the vehicle is present, it is conceivable that the swinging axle device is fixedly held so as not to be able to swing, thereby enabling work by the working device. However, when such a swing axle device is fixedly held in a state where the swing amount is large, there is a problem that one wheel floats and stability is impaired.

From the above, in the present invention,
As described above, when the swing amount of the swing axle device detected by the swing detector is larger than a predetermined value, the center of gravity of the vehicle obtained by the center of gravity position detecting means is determined by a pair of left and right wheels provided on the fixed axle device. The operation of the working device that moves outward beyond the triangular swingable area formed in plan view by connecting the ground contact point of the wheel and the swing center point of the swing axle device is regulated. ing. Thus, the swing axle device is not fixedly held in a state where the swing amount is larger than the predetermined value, and the vehicle can travel with all four wheels in contact with the ground.

A swing regulating means for regulating the swing of the swing axle device is provided, and when the swing amount of the swing axle device is equal to or less than a predetermined value, the position of the center of gravity of the vehicle exceeds the swingable area and moves outward. The operation of the working device that moves to the right may be allowed in a state where the swing of the swing axle device is regulated by the swing regulating means. When the rocking of the rocking axle device is small, there is little problem that the above-mentioned stability is impaired.Therefore, after restricting the rocking of the rocking axle device, operate the working device whose center of gravity exceeds the rockable range. This allows the working range of the working device to be increased.

In this case, when the center of gravity of the vehicle is in the working state located outside the swingable region and the swinging axle device is restrained from swinging by the swinging restraining means, the travel is restricted. It is preferred to do so. If traveling is allowed while the swing of the swinging axle device is regulated, there is a risk that some of the wheels will rise and the vehicle support will become unstable when traveling on uneven road surfaces. The purpose of the present invention is to restrict traveling and prevent a situation in which vehicle support becomes unstable.

When the operation of the working device is permitted, the operable range of the working device in a state where the position of the center of gravity is within the swingable region is determined in advance, and the swing amount of the swing axle device is larger than a predetermined value. In this case, by restricting the operation of the working device beyond the operable range, the operation of the working device such that the position of the center of gravity of the vehicle determined by the center-of-gravity position detecting means moves outward beyond the swingable region. It can be configured to regulate. In this way, the operation of the working device can be regulated only by monitoring the operating position of the working device without monitoring the position of the center of gravity of the vehicle, and the control is simplified.

For the same reason, the maximum permissible moment with respect to the overturning moment generated by the operation of the working device in a state where the position of the center of gravity is within the swingable area is determined in advance, and the swing amount of the swing axle device is determined by a predetermined amount. If the value is larger than the maximum value, the operation of the working device such that the overturning moment exceeding the maximum allowable moment is generated is restricted, so that the operation of the working device such that the center of gravity of the vehicle moves outward beyond the swingable region. May be configured to be restricted.

[0018]

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 (work vehicle) 1 having a wheel traveling device according to the present invention will be described with reference to FIG. The aerial work vehicle 1 includes a lower traveling body 2 having front and rear axle devices 10 and a rear axle device 20 having a pair of left and right wheels 15 and 25, respectively, and a swing provided on the lower traveling body 2. Device 3
And an upper traveling body 4 that is horizontally rotatable on the lower traveling body 2 by the turning device 3.
And a high-altitude working device is arranged on the upper surface.

The high-altitude working device includes a boom 5 arranged on the upper traveling body 4 so as to be able to move up and down, an arm 6 arranged at the end of the boom 5 so as to be able to move up and down, and a work attached to the end of the arm 6. And a worktable 7 for passengers. Boom 5
Is raised and lowered by a lifting cylinder 5a. The boom 5 is composed of a plurality of telescopic booms which are telescopic and extend and contract by a built-in telescopic cylinder (not shown). The arm 6 is constituted by a parallel link mechanism, and is raised and lowered by an arm raising and lowering cylinder (not shown). The work table 7 has a leveling mechanism (not shown) and is attached to the tip of the arm 6, and is always kept horizontal regardless of the ups and downs of the boom 5. The worktable 7 is attached to the tip of the arm 7 so as to be able to turn horizontally (swing).

In the high-altitude working device having such a configuration,
By driving the upper traveling body 3 with respect to the lower traveling body 2 by driving a rotating motor in the rotating device 3, the boom 5 is raised and lowered by the raising and lowering cylinder 5a, and the boom 5 is expanded and contracted by the telescopic cylinder. 7 is moved to a desired altitude to perform altitude work. The swing motor, the up / down cylinder, the telescopic cylinder, and the like for performing such an operation are collectively referred to as an operation actuator 55. As shown in FIG. 1, the operation control of the operation actuator 55 is performed by the operation control device 52 based on the operation of the operation lever 51 provided on the work table 7 and operated by the worker who boarded the work table 7. .

The rear axle device 20 is fixed to the undercarriage 2 to form a fixed axle device.
As shown in FIG. 1, the swinging axle device is configured to be swingable in a vertical plane extending left and right and attached to the lower traveling body 2. This front axle device 10 is shown in FIG.
This will be described in detail with reference to FIG.

The front axle device 10 includes a swing axle device 11 pivotally connected to the lower traveling body 2 by a first pivot pin 12 and capable of swinging in a vertical plane extending left and right, and a swing axle device 11. Left and right front wheels 15a, 15b disposed on the left and right of
Left and right swing regulating cylinders 16 and 17 for regulating swing
It is composed of The first pivot pin 12 is provided with a swing detector 39 which is constituted by a potentiometer or the like and detects a swing angle of the swing axle device 11 with respect to the lower traveling body 2. The swing detector 39 is not limited to such a type, and may be one that detects the swing angle by detecting the amount of vertical movement at the end of the swing axle device.

Although the detailed configuration of the swinging axle device 11 is not shown, for example, an axle connected to the left and right front wheels 15 and
An axle housing rotatably supports the axle. The axle housing is swingably supported by the lower traveling body 2 by the first pivot pins 12. Also,
The swing axle device 11 may be provided with a steering device for steering the left and right front wheels 15 or may be configured to rotate the front wheels 15. However, since the rear axle device 20 is fixed to the lower traveling body 2, generally, a steering device is provided in the rear axle device 20, and the rear wheels 25 are driven.

As described above, the left-right swing regulation for regulating or allowing the swing of the swing axle device 11 that can swing with respect to the lower traveling body 2 about the first pivot pin 12 is provided. The cylinders 16 and 17 are pivotally connected to the lower traveling body 2 as shown. The left and right swing restriction cylinders 16 and 17 have downwardly projecting pistons 16a and 17a, and the lower ends of the pistons 16a and 17a are in contact with the swing axle device 11. For this reason, the left and right swing restriction cylinders 16 and 1
By restricting the expansion and contraction of the pistons 16a and 17a by enclosing the hydraulic oil inside 7, the rocking of the rocking axle device 11 can be restricted and fixedly held at a predetermined rocking position, and the hydraulic oil can freely enter and leave. By allowing the pistons 16a and 17a to freely expand and contract, the swing of the swing axle device 11 can be allowed.

For such swing regulation control, a swing regulation control circuit 30 is provided as shown in FIG. The swing regulation control circuit 30 includes a high-pressure supply source 31 and a low-pressure supply source 3 configured using hydraulic pressure from a hydraulic pump driven by an engine (not shown) mounted on the upper traveling body 2.
5, an electromagnetic switching valve 32 for controlling the supply switching of the high-pressure hydraulic pressure from the high-pressure supply source 31, a swing regulation controller 33 for controlling the operation of the electromagnetic switching valve 32, a low-pressure supply source 35 and a left-right swing regulation cylinder. Left and right connection control circuits 37 and 38 for controlling connection with the oil chambers 16 and 17 and a resistance valve 36 disposed in an oil passage for draining the hydraulic pressure supplied from the low pressure supply source 35 are provided. Note that a detection signal from the center-of-gravity position detector 34 and a detection signal from the fluctuation detector 39 are sent to the fluctuation control controller 33.

The left and right connection control circuits 37 and 38 are respectively
It is composed of a pair of relief valves 37a, 38a and a pair of check valves 37b, 38b. The relief pressure of the relief valves 37a and 38a is variably set in response to the hydraulic pressure from the high-pressure supply source 31, and the hydraulic pressure supply from the high-pressure supply source 31 is controlled by the electromagnetic switching valve 32.
Is controlled by Here, when the electromagnetic switching valve 32 is opened and the high pressure oil pressure from the high pressure supply source 31 acts on the relief valves 37a, 38a, the relief valves 37a, 38a are actuated.
38a is zero, that is, the relief valve 37
a, 38a are opened. On the other hand, when the electromagnetic switching valve 32 is closed and the operating pressure on the relief valves 37a, 38a becomes zero, the relief valves 37a, 38a
Is released at a relief pressure set to a predetermined high pressure.

The low-voltage supply source 35 includes a left-right connection control circuit 3
A pair of relief valves 37a, 38 forming the parts 7, 38
a and a pair of check valves 37b, 38b, and is connected to left and right swing restriction cylinders 16, 17 as shown in the figure. The hydraulic oil supplied from the low-pressure supply source 35 is connected to a drain via a resistance valve 36, and the low-pressure hydraulic oil determined by the resistance valve 36 is supplied to the relief valve 3.
7a and 38a and the check valves 37b and 38b.

In the swing regulation control circuit 30 having such a configuration, the electromagnetic switching valve 32 is opened by the swing regulation controller 33, and the high-pressure oil pressure from the high-pressure supply source 31 acts on the relief valves 37a and 38a. When the valves 37a and 38a are opened, the oil chambers (rod-side oil chamber and bottom-side oil chamber) of the left and right swing restriction cylinders 16 and 17 are all in communication with the low-pressure supply source 35. For this reason, the left and right swing restriction cylinders 16 and 17 are controlled by a light external force defined by the low pressure hydraulic pressure determined by the resistance valve 36.
The pistons 16a and 17a are in a state of being expanded and contracted.

On the other hand, the electromagnetic switching valve 32 is closed by the swing regulation controller 33 and the relief valve 37a,
38a becomes zero and the relief valve 37
When the relief pressures a and 38a reach a predetermined high pressure, the hydraulic oil in the oil chambers (rod-side oil chamber and bottom-side oil chamber) of the left and right swing regulating cylinders 16 and 17 is discharged unless the relief pressure is higher than the predetermined high pressure relief pressure. In this state, the hydraulic pressure cannot be supplied from the low-pressure supply source 35. That is, the oil chambers of the left and right swing restriction cylinders 16 and 17 are closed, and the pistons 16a and 17a are hydraulically locked.

The swing regulation control in the aerial work vehicle having the above configuration will be described. The swing regulation control circuit 3
In the center-of-gravity position detector 34, the weight of the entire vehicle excluding the swing axle device 11 of the front axle device 10 and the left and right front wheels 15a and 15b attached to both ends thereof (that is, the rear axle device 25, the lower The center of gravity of the traveling body 2, the turning device 3, the upper traveling body 4, and the aerial work apparatus provided on the upper traveling body 4) is calculated in plan view. For this reason, in the aerial work apparatus, the turning angle of the turning device 3, the undulation angle and extension of the boom 5,
And the horizontal turning angle of the worktable 7 are detected to determine the position of the center of gravity. The swing detector 39 detects the swing angle of the axle swing device 11 with respect to the lower traveling body 2,
The detection signal is sent to the swing regulation control circuit 30.

FIG. 3 shows the positional relationship of the lower traveling body 2 and the front and rear wheels 15 and 25 in the aerial work vehicle 1 in a plan view. The position of the center of gravity in the plan view is a center of gravity position detector. 34. On the other hand, in the swing controller 33, as shown in FIG. 3, the ground points P2 and P3 of the left and right rear wheels 25a and 25b of the rear axle device 25 and the swing of the swing axle device 11 by the first pivot pin 12. A triangular swingable area A formed by connecting to the center point P1 is determined, and it is determined whether the position of the center of gravity determined by the center-of-gravity position detector 34 is within the swingable area A.

When the swinging axle device 11 of the front axle device 10 can swing around the first pivot pin 12,
As shown by reference numeral G2 in FIG. 3, when the center of gravity position G2 is outside the swingable area A, the lower traveling body 2 swings around a line L1 connecting the points P1 and P2, and the left rear wheel 25b Emerges. When the position of the center of gravity is located at the position indicated by reference sign G3, a line L2 connecting the points P1 and P3
, The lower traveling body 2 swings, and the right rear wheel 25a rises. Further, when the position of the center of gravity of the total weight of the vehicle (the total weight including the oscillating axle device 11 and the front wheels 15) is at the position indicated by the reference symbol G4, the lower traveling body 2 is centered on the line L3 connecting the points P2 and P3. Swings and the front wheel 15
Rises and falls backwards. On the other hand, when the center of gravity position G1 is within the swingable area A as shown by reference numeral G1, the lower traveling body 2 is stably supported without swinging while the left and right rear wheels 25a and 25b are in contact with the ground.

For this reason, the swing regulation controller 33
When it is determined that the position of the center of gravity detected by the center-of-gravity position detector 34 is within the swingable area A, the electromagnetic switching valve 32 is opened to apply the high-pressure oil pressure from the high-pressure supply source 31 to the relief valves 37a and 38a. Then, these relief valves are opened. As a result, all the oil chambers (rod-side oil chamber and bottom-side oil chamber) of the left and right swing restriction cylinders 16 and 17 communicate with the low-pressure supply source 35, and the pistons 16a and
17a is expanded and contracted by a light external force, and the rocking axle device 11 of the front axle device 10 becomes rockable. As described above, if the position of the center of gravity is within the swingable area A, there is no possibility that the lower traveling body 2 swings about the lines L1 and L2, and thus the swing axle device 11 can swing. If you drive on uneven road surface,
The oscillating axle device 11 oscillates according to the unevenness, and can run stably with all four wheels in contact with the ground. At this time, since the low-pressure hydraulic pressure is supplied from the low-pressure supply source 35 into the oil chambers of the left and right swing restriction cylinders 16 and 17, the pistons 16 a and 16 a follow the swing of the swing axle device 11.
17a is telescopically moved.

On the other hand, from the state where the position of the center of gravity detected by the position of center of gravity detector 34 is in the swingable area A, the boom 5 is rotated, raised and lowered, and expanded and contracted by the operation actuator, and the position of the center of gravity is moved. When trying to move to the outside of the possible area A, the following control is performed according to the swing angle detected by the swing detector 12.

First, when the swing angle is a small angle smaller than a predetermined angle, the swing regulation controller 33 closes the electromagnetic switching valve 32 and releases the relief valves 37a, 38.
The relief pressure of a is changed to a predetermined high pressure. As a result, the oil chambers (rod-side oil chamber and bottom-side oil chamber) of the left and right swing restricting cylinders 16 and 17 are each hydraulically confined, and the pistons 16a and 17a are locked and held. The swing axle device 11 is fixedly held at the current swing position. Then, in such a fixed state, the operation of the aerial work apparatus in which the position of the center of gravity moves to the outside of the swingable area A is permitted.

In the state where the swing axle device 11 is fixedly held as described above, the lower traveling body 2 swings about the lines L1 and L2 even if the center of gravity moves outside the swingable area A. There is no fear and the lower traveling body is stably supported with all four wheels in contact with the ground. For this reason, the aerial work apparatus is also stably supported, and the aerial work using the aerial work apparatus can be performed safely. In the state where the swing of the swing axle device 11 is regulated by the left and right swing regulation cylinders 16 and 17 as described above, the traveling of the aerial work vehicle 1 is prohibited.

On the other hand, when the swing angle is a large angle exceeding a predetermined angle, the swing regulation controller 33 outputs an operation regulation signal to the operation control device 52, and regardless of the operation of the operation lever 51, The operation of the boom or the like by the operation actuator 55 in such a direction that the position of the center of gravity moves outside the swingable area A is restricted. That is, when the swing angle exceeds the predetermined angle, the operation of the high-altitude working device is restricted so that the position of the center of gravity is kept within the swingable area A. This allows
It restricts the running of the swing axle device while the swing amount is larger than the predetermined value while the swing axle device is fixedly held.

As described above, the aerial work vehicle 1 according to the present invention
When the center of gravity is within the swingable area A, the swing is allowed regardless of the swing angle of the swing axle device 11. However, when the swing angle exceeds a predetermined angle, the center of gravity can swing. The operation of the aerial work apparatus that moves outside the area A is restricted, and when the swing angle is equal to or smaller than a predetermined angle, the swing of the swing axle device 11 is controlled by the left and right swing limiting cylinders 16 and 17. With a simple control that permits the operation of the aerial work apparatus such that the position of the center of gravity moves to the outside of the swingable area A, the vehicle always travels while keeping the four wheels in contact with the ground, and The vehicle body can be stably supported.

In the above embodiment, it was determined whether or not the position of the center of gravity of the vehicle was within the swingable area A.
As shown in the figure, the movable range B of the worktable 7 is set in advance so that the position of the center of gravity of the vehicle falls within the swingable area A, and the work moved in accordance with the actual operation of the altitude working device It may be determined whether or not the position of the center of gravity is within the swingable area A based on whether or not the table 7 is within the movable range B set as described above. It is difficult to calculate the position of the center of gravity that changes according to the operation of the work equipment at height,
With this configuration, the determination can be made based on the detection of the position of the workbench, and the determination becomes easy.

For the same reason, an allowable moment in the overturning direction acting on the vehicle body from the working device when the position of the center of gravity of the vehicle enters the swingable area A is set in advance, and the actual working device It may be determined whether or not the swing restriction is to be performed based on whether or not the actual moment in the overturning direction acting on the vehicle body in accordance with the operation is equal to or less than the allowable moment. In this case, the allowable moment is different for each turning position of the boom 5, so the allowable moment is preset for each turning position.

[0041]

As described above, according to the present invention,
Since the working vehicle wheel travel device is configured to include the fixed axle device and the swing axle device, when the work vehicle wheel travel device travels on an uneven road surface, the swing axle in the swing axle device is used. By swinging the device, traveling is performed with all four wheels in contact with the ground, and stable traveling is possible. Further, as for the fixed axle device, the fixed axle device used in the conventional traveling device is used as it is, and only the swing axle device is replaced with one of the fixed axle devices in the conventional traveling device, the traveling according to the present invention. The device can be easily obtained.

Further, in the present invention, a triangular swing formed in a plan view by connecting a ground point of a pair of left and right wheels provided on the fixed axle device and a swing center point of the swing axle device. When the swing area of the swing axle device detected by the swing detector is larger than a predetermined value, the area of the vehicle center of gravity determined by the center of gravity position detecting means moves outward beyond the swingable area. In such a state, the center of gravity of the vehicle moves out of the swingable area in a state where the swinging axle device swings greatly, and the swinging axle device swings. The problem is that the traveling body swings around the part (centering on the line connecting the swing center point of the swinging axle device and the grounding point of one of the wheels of the fixed axle device) and the stability is impaired. Can be prevented.

When the swing of the swing axle device is small, there is little problem that the stability is impaired as described above.
A swing regulating means for regulating the swing of the swing axle device is provided, and when the swing amount of the swing axle device is equal to or less than a predetermined value, the position of the center of gravity of the vehicle moves outward beyond the swingable area. The operation of the working device may be allowed in a state where the swing of the swing axle device is regulated by the swing regulating means.

In this case, when the center of gravity of the vehicle is in the working state located outside the swingable area and the swinging axle device is restrained from swinging by the swinging restraining means, the travel is restricted. It is preferred to do so. If traveling is allowed while the swing of the swinging axle device is regulated, there is a risk that some of the wheels will rise and the vehicle support will become unstable when traveling on uneven road surfaces. It is possible to restrict traveling and prevent a situation in which the support of the vehicle becomes unstable.

When the operation of the working device is permitted, the operable range of the working device in a state where the position of the center of gravity is within the swingable region is determined in advance, and the swing amount of the swing axle device is larger than a predetermined value. In this case, by restricting the operation of the working device beyond the operable range, the operation of the working device such that the position of the center of gravity of the vehicle determined by the center-of-gravity position detecting means moves outward beyond the swingable region. It can be configured to regulate. In this way, the operation of the working device can be regulated only by monitoring the operating position of the working device without monitoring the position of the center of gravity of the vehicle, and the control is simplified.

For the same reason, the maximum permissible moment with respect to the overturning moment generated by the operation of the working device in a state where the position of the center of gravity is within the swingable region is determined in advance, and the swing amount of the swing axle device is determined by a predetermined amount. If the value is larger than the maximum value, the operation of the working device such that the overturning moment exceeding the maximum allowable moment is generated is restricted, so that the operation of the working device such that the center of gravity of the vehicle moves outward beyond the swingable region. May be configured to be restricted.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a front axle device and a swing regulation control system thereof in a wheel traveling device according to the present invention.

FIG. 2 is a front view showing a self-propelled aerial work vehicle having the wheel traveling device according to the present invention.

FIG. 3 is a plan view showing a positional relationship between a lower traveling body and left and right front and rear wheels according to the present invention.

FIG. 4 shows a lower traveling body and left and right front and rear wheels according to the present invention;
It is a top view which shows the relationship with the operation | movement control range of a working device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Self-propelled aerial work platform 2 Undercarriage 5 Boom 6 Arm 7 Workbench 10 Front axle device 11 Swing axle device 15 Front wheel 16, 17 Swing regulating cylinder 20 Rear axle device 25 Rear wheel 31 High pressure supply source 32 Electromagnetic Switching valve 33 Swing regulation controller 34 Center-of-gravity position detector 35 Low-pressure supply source 36 Resistance valve 37, 38 Connection control circuit 36 Swing detector 51 Operation lever 52 Operation controller 55 Operation actuator (slewing motor, undulating cylinder, telescopic cylinder)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Makatsu Maeda 414-1 Higashimine Sukawa, Shinji-mura, Tone-gun, Gunma F-term in Aichi Corporation Shinji Works (reference) 3D001 AA01 BA54 CA08 DA17 EA42 EB08 ED04 3F333 AA08 AB04 CA12 FA09 FA17 FA20 FA34 FD04 FD07 FE04 FE09

Claims (5)

[Claims] 1. A work vehicle wheel travel device comprising two sets of axle devices each having a pair of left and right wheels provided before and after a traveling body, wherein a working device is disposed on the traveling body. One of the axle devices is fixed to the traveling body to form a fixed axle device, and the other of the axle devices is swingably attached to the traveling body in a substantially vertical plane extending in a vehicle width direction. A swing axle device, wherein the swing axle device is swingably attached to the traveling body in a substantially vertical plane extending in the vehicle width direction and has the wheels at left and right end portions in the vehicle width direction. A swing detector that is configured to include an axle device, and that detects a swing amount of the swing axle device with respect to the traveling body; and a plan view combining the traveling body and the working device excluding the swing axle device. vehicle A center-of-gravity position detecting means for determining a center position; a triangular shape formed in a plan view connecting a ground point of the pair of left and right wheels provided on the fixed axle device and a rocking center point of the rocking axle device. A swingable area is determined, and if the swing amount of the swing axle device detected by the swing detector is larger than a predetermined value, the vehicle center of gravity determined by the center of gravity position detecting means is determined by the swing A wheel traveling device for a work vehicle, wherein the operation of the work device so as to move outward beyond a possible area is restricted. 2. The apparatus according to claim 1, further comprising: a swing restricting unit that regulates the swing of the swing axle device, wherein the swing amount of the swing axle device detected by the swing detector is equal to or less than the predetermined value. The operation of the working device such that the position of the center of gravity of the vehicle determined by the position detection unit moves outward beyond the swingable area, and the swing control unit swings the swing axle device. The wheel traveling device for a work vehicle according to claim 1, wherein the traveling vehicle wheel is configured to regulate and tolerate. 3. The swinging axle device according to claim 1, wherein the vehicle center of gravity position determined by the center of gravity position detecting means is in a working state of the working device located outside the swingable area, and the swinging axle device is swung by the swing restraining means. When movement is regulated,
The wheel traveling device for a work vehicle according to claim 2, wherein traveling regulation is performed. 4. The operable range of the working device in a state where the position of the center of gravity is within the oscillating range is determined in advance, and the swing amount of the oscillating axle device detected by the sway detector is determined. If the predetermined value is larger than the predetermined value, the operation of the working device exceeding the operable range is restricted, so that the vehicle center of gravity position obtained by the center of gravity position detecting means moves outward beyond the swingable area. The wheel traveling device for a work vehicle according to claim 1, wherein the operation of the work device is restricted. 5. A maximum permissible moment with respect to a tipping direction moment generated with the operation of the work device in a state where the position of the center of gravity is within the swingable region, and the maximum allowable moment is detected by the swing detector. When the swinging amount of the swinging axle device is larger than a predetermined value, the operation of the working device such that the overturning moment exceeding the maximum allowable moment is generated is restricted, and the swinging axle device is determined by the center-of-gravity position detecting means. The wheel traveling device for a work vehicle according to claim 1, wherein the operation of the work device such that the position of the center of gravity of the vehicle moves outward beyond the swingable region is regulated.