JPH11222151A - Traveling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To freely enable self-running and steering by providing a first and a second elevating frames for elevatably supporting front wheels and rear wheels on a device main body, and providing a steering mechanism for steering the device main body. SOLUTION: A first elevating frame 3 capable of freely elevating along a device main body 1 by operating a hydraulic cylinder 2 is provided on the front of a device main body 1, and driving wheels 4 are supported on both right and left sides of the lower end part of the first elevating frame 3. A second elevating frame 6 freely elevated by the operation of the hydraulic cylinder 5 is provided on the rear part of the device main body 1, a wheel side frame 8 is supported in such a manner as to freely oscillate right and left on the central part of the lower end of the second elevating frame 6 through a steering pivot shaft 7 arranged substantially in the vertical direction, and a free rotating wheel 9 is rotatably supported on the tip of the wheel side frame 8. A motor 10 as a steering mechanism is arranged on each driving wheel, and the wheels can be individually driven through a reduction gear mechanism by the motors 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a traveling device,
More specifically, the present invention relates to a traveling device capable of speedily moving by lifting an apparatus main body by a lifting wheel.

[0002]

2. Description of the Related Art Conventionally, as this type of traveling apparatus, for example, an orbital work vehicle as disclosed in Japanese Utility Model Laid-Open No. 3-81109 is known. The device described in this publication has a hydraulic shovel with traveling tires provided with wheels for track running, and a link mechanism is provided at the front and rear ends of a running frame of the hydraulic shovel, and the track mechanism is provided on the link mechanism. The link mechanism is operated by a lift cylinder to raise and lower the track wheels.

[0003] An example of a traveling device having a crawler and wheels is disclosed in Japanese Patent Application Laid-Open No. 7-257442. In the traveling device described in this publication, a wheel is provided between the contact surface and the non-contact surface of the crawler belt, and the wheel is moved up and down through an opening formed in the center portion of the crawler belt, so that the crawler travels. And wheel running.

[0004]

However, the two-way vehicle described in the former publication is intended to travel on a track for track maintenance work and the like, and has a steering function. Absent. Therefore, this traveling device cannot be used for applications in which a hydraulic shovel can travel freely at high speed on a road surface.

On the other hand, in the traveling device described in the latter publication, it is possible to switch between crawler traveling and wheel traveling, but it is configured such that wheels protrude from an opening formed in the crawler. Therefore, there is a problem that not only the strength of the crawler is weakened, but also the diameter of the wheel is restricted and the minimum ground clearance is reduced. Further, in this conventional example, since the front wheel and the rear wheel are mounted on an integral frame and the frame is raised and lowered by an X-type lifting mechanism, the lifting mechanism is complicated and a large space is required. In addition, since the left and right crawlers cannot be connected by an integrated frame, the rigidity in the left / right direction is significantly reduced.

The present invention has been made in view of such a problem, and can be additionally installed without largely changing the structure of a device main body such as a hydraulic shovel. It is an object of the present invention to provide a traveling device that can freely run and steer.

[0007]

In order to achieve the above-mentioned object, a traveling device according to the present invention comprises:
First, (a) the apparatus main body, (b) a first elevating frame which is arranged in front of the apparatus main body and supports the front wheel so as to be able to move up and down with respect to the apparatus main body, and (c) is arranged behind the apparatus main body. A second lifting frame for supporting the rear wheel so as to be able to move up and down with respect to the apparatus main body; and (d) a steering mechanism for steering the apparatus main body.

In the invention having the first feature, when the apparatus main body is run using wheels, the first elevating frame disposed in front of the apparatus main body and the second elevating frame disposed rearward of the apparatus main body are connected to each other. By operating, the front wheel and the rear wheel respectively supported by the respective lifting frames are projected downward with respect to the apparatus main body, and the apparatus main body is supported by these wheels. Then, in a state of being supported by these wheels, the wheels are appropriately driven, and the main body of the apparatus is steered by the steering mechanism, whereby self-propelling and steering are freely performed. According to the present invention, the device main body can be lifted up by wheels and self-propelled (high-speed running) / steering can be freely performed with a simple configuration in which the front and rear elevating frames are simply attached to the device main body. A complicated and large-scale device is not required as a wheel elevating mechanism, and no major modification of the device body is required.

In the present invention, the left and right wheels constituting the front wheel are driven by individual driving means,
The rear wheel may be a free-rotating wheel, and the steering mechanism may steer the apparatus body by changing the rotation speed of each of the front wheels. In the traveling device according to such an aspect, in traveling using wheels, when the device main body goes straight, the left and right wheels of the front wheels may be rotated at a constant speed, and during left / right steering, one wheel of the front wheels is turned to the other. What is necessary is just to rotate at low speed or high speed from the wheel of. In any case, the rear wheel composed of the free rotating wheels follows the traveling direction of the apparatus main body.

Further, in the present invention, one of the front wheels and the rear wheels is driven by drive means with a differential mechanism, the other wheel is a free-rotating wheel, and the steering mechanism comprises: The apparatus main body may be steered by a direction change of the free rotating wheel by a steering cylinder and the differential mechanism. In the traveling device according to such an aspect, in traveling using wheels, when the device body is traveling straight, the steering wheel cylinder may be used to direct the free rotating wheels in the direction of travel of the device body. If the free rotating wheels are caused to travel in a desired direction by the cylinder, the left and right wheels are rotated at different speeds by the differential mechanism on the driving wheel side, so that smooth steering is performed.

Preferably, each of the traveling devices is applied to a hydraulic excavator. When applied to a hydraulic excavator as described above, the front and rear elevating frames can be housed in a crawler and compactly installed. In addition, it is possible to switch between crawler traveling and wheel traveling by simple operation according to the purpose, such as running the soft rough terrain on the site with crawlers and traveling at high speed on the road with wheels by the lifting operation of these lifting frames. Becomes

As another embodiment of the traveling device according to the present invention,
The apparatus main body is a hydraulic shovel, and one of the front wheel and the rear wheel is driven by a driving mechanism with a differential mechanism, and the other wheel is freely rotatable so that it can be attached to and detached from a boom tip of the hydraulic shovel. The steering mechanism may be a wheel, and the apparatus main body may be steered by changing the direction of the free rotating wheel using a turning mechanism of the hydraulic shovel and the differential mechanism. In this aspect, when the required work by the hydraulic excavator is completed, a free rotating wheel is attached to the tip of the boom, and the free rotating wheel is stretched on the ground by using the lifting force of the boom, and is supported by the lifting frame. With the drive side wheels protruding downward with respect to the device main body, the device main body is lifted from the ground, and in a state in which the device main body is lifted off the ground, the turning mechanism of the hydraulic shovel moves the upper body to the lower body with respect to the lower body. The vehicle is steered by turning. According to this aspect, the structure of the traveling device can be simplified, and it is not necessary to provide an extra device in front of the lower part of the hydraulic excavator, so that the visibility of the worker can be kept good.

Further, the traveling device according to the present invention has a second
A traveling device capable of switching between crawler traveling and wheel traveling, provided with a switching valve capable of switching between a hydraulic circuit for driving a crawler traveling motor and a hydraulic circuit for driving a wheel traveling motor; Are controlled by a common travel control valve.

According to the invention having the second feature, the travel control valve can be commonly used for crawler traveling and wheel traveling only by switching the switching valve, thereby reducing the number of parts. As a result, the hydraulic circuit configuration can be made compact and can be adapted to both crawler traveling and wheel traveling.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a specific embodiment of a traveling device according to the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 shows a front view (a) and a bottom view (b) showing a traveling apparatus according to a first embodiment of the present invention.

In this embodiment, a first lifting frame 3 is provided at the front of the apparatus main body 1 so as to be able to move up and down along the apparatus main body 1 by operating a hydraulic cylinder 2.
Drive wheels 4 and 4 are rotatably supported on the left and right sides of the lower end of the lifting frame 1. At the rear part of the apparatus main body 1, a second elevating frame 6 which is also movable up and down along the apparatus main body by the operation of the hydraulic cylinder 5 is provided. A wheel-side frame 8 is swingably supported to the left and right via a steering pivot shaft 7 disposed on the vehicle, and free rotating wheels 9 are rotatably supported at the tip of the wheel-side frame 8. . The driving wheels 4 and 4 are motors 1 arranged for each driving wheel.
It can be driven individually via 0, 10 and a speed reduction mechanism.

In the traveling apparatus constructed as described above, when it is desired to travel the apparatus main body 1 from a state where the apparatus main body 1 is grounded, the front and rear hydraulic cylinders 2 and 5 are operated in the extension direction. The first lifting frame 3 and the second lifting frame 6 are lowered with respect to the apparatus main body 1, and the drive wheels 4, 4 and the free rotating wheels 9, 9 are grounded to ground the apparatus main body 1.
Lift. Thereafter, when it is desired to move the apparatus main body 1 straight, the left and right drive wheels 4 and 4 may be rotated at a constant speed (see FIG. 2A). The right (or left) drive wheel 4 may be rotationally driven at a low speed relative to the left (or right) drive wheel 4 (see FIG. 2B). In any of these cases, the free rotating wheels 9 move following the traveling direction of the apparatus main body 1. In the case of the traveling device according to the present embodiment, the steering direction of the free rotating wheels 9, 9 is not constant due to a variation in the traveling resistance of the left and right wheels, so that it is difficult to control the steering direction of the device main body 1 in the backward direction. Becomes Therefore, in this system, the forward direction is the main traveling direction.

(Second Embodiment) FIG. 3 is a bottom view (a) showing a traveling apparatus according to a second embodiment of the present invention, and FIG. The enlarged views (c) are shown.

In this embodiment, a first elevating frame 11 and a second elevating frame 1 which can be moved up and down by operating a hydraulic cylinder are provided at a front portion and a rear portion of the apparatus main body 1, respectively.
2 are provided, and driving wheels 13,
13 is rotatably supported, and a wheel-side frame 15 is supported on the second lifting frame 12 side via a steering pivot shaft 14 so as to freely swing left and right. 16 and 16 are rotatably supported.

In the case of this embodiment, the driving wheels 13 are driven by a driving device 17 with a differential mechanism. The drive device 17 with a differential mechanism has a structure known per se in the related art, and the input drive device (motor) 1
8 is transmitted to the bevel pinion in the bevel pinion case 19, and a rotation difference is caused between the wheels 13 and 13 in accordance with the resistance difference between the left and right wheels (tires) 13 and 13.

A steering hydraulic cylinder 21 is disposed between the second lifting frame 12 and a bracket 20 mounted on the wheel side frame 15 side. The wheel side frame 15 is connected to the second lifting frame 12 on the one side by the steering pivot shaft 14.
By turning around, the steering direction of the apparatus main body 1 is set.

In the traveling apparatus constructed as described above, similarly to the first embodiment, when it is desired to travel the apparatus main body 1 from the state where the apparatus main body 1 is grounded, the front and rear hydraulic cylinders are extended in the extending direction. The first lifting frame 1
The first and second lifting frames 12 are lowered with respect to the apparatus main body 1, and drive wheels 13, 13 and free rotating wheels 16, 16
The apparatus body 1 is lifted by the grounding. Thereafter, when the input driving device 18 is driven to move the apparatus main body 1 forward or backward, the apparatus main body 1 runs in the rotating direction of the free rotating wheels 16, 16. During the steering operation, as shown in FIG. 4, the intersection of the center lines of the front and rear wheels 13 and 16 is the center of rotation, and the inner and outer wheels of the drive wheels 13 and 13 have a constant rotation ratio r1 / r2. Although a rotation difference occurs, the driving wheels 13 are driven by the driving device 17 with a differential mechanism, so that the vehicle runs smoothly without slipping.

In the first and second embodiments, various equipment and general machinery that require self-propelled steering by wheels can be selected as the apparatus main body. It is particularly suitable if applied to a type of construction machine. In this case, it is economically advantageous when a drive source (eg, a hydraulic drive source) for driving these traveling devices is already provided on the device body side.

(Third Embodiment) FIGS. 5 and 6 show an example (third embodiment) in which the traveling apparatus of the present invention is applied to a hydraulic excavator (hydraulic excavator). This example is
The drive mechanism of the traveling device according to the first embodiment is applied to a hydraulic shovel. In the illustrated example, a mode in which the work is performed by the lifting magnet is shown.

In this embodiment, a hydraulic excavator includes a lower body 22, an upper body 23 that can rotate around a rotation axis C with respect to the lower body 22, and hydraulic cylinders 24, 25 attached to the upper body 23. , 26 and a work machine 27 for performing various work operations. The upper body 23 is equipped with an engine, a hydraulic pump, a hydraulic switching valve, and the like. The operator operates the hydraulic switching valve from the cab 28 to send hydraulic oil to various operating devices such as a hydraulic cylinder and a hydraulic pump to perform each work operation. And a running operation is performed. The lower body 22 includes the left and right crawler units 2.
9 and 30 and a track frame 31 connecting these two units 29 and 30 to each other.
1, a wheel traveling unit 32 is attached. Note that, even if the upper body 23 turns with respect to the lower body 22, a hydraulic swivel joint 61, which will be described later, is provided on the turning shaft C in order to enable the supply of pressure oil to the lower body 22. ing.

Next, the detailed structure of the wheel traveling unit 32 will be described. As shown in FIG. 7, a base end of a first lifting frame 34 is pivotally supported by the front pivot portions 33a and 33b of the track frame 31. The first lifting frame 34 is expanded and contracted by a hydraulic cylinder (two in this embodiment) 37 disposed between a bracket 35 provided on the front end side of the first lifting frame 34 and a bracket 36 provided on the track frame 31. It is rotated (moved up and down) by the operation.

At the front end of the first lifting frame 34,
Driving wheels 38 and 39 that are individually driven left and right are provided. As shown in FIG. 8, each drive wheel 38, 39
Controls the rotation of each hydraulic motor 40, 41
It is driven by transmitting it to each axle 45 via a speed reduction mechanism consisting of 2, 43 and a chain 44. In addition,
The rotational speeds of the left and right drive wheels 38 and 39 are individually controlled in proportion to the operation strokes of the left and right traveling levers.

On the other hand, as shown in FIG. 9, rear pivot portions 46a, 46
b (see FIG. 6), the base end of the second elevating frame 47 is pivotally supported, and a wheel side frame 49 is laterally mounted on the distal end side of the second elevating frame 47 via a steering pivot 48. It is swingably supported. Left and right free rotating wheels 50 and 51 are rotatably supported at the tip of the wheel side frame 49. The second elevating frame 47 is rotated (elevated) by a telescopic operation of a hydraulic cylinder 54 disposed between a bracket 52 provided on a front end side of the second elevating frame 47 and a bracket 53 provided on the track frame 31.

With this configuration, when the front and rear hydraulic cylinders 37 and 54 are extended from the state shown in FIG. 5 where the left and right crawler units 29 and 30 are in contact with the ground, the first lifting frame 34 and the Second lifting frame 4
7, the driving wheels 38, 39 and the free rotating wheels 50, 51 are lowered to the positions shown in FIG. 10, and the main body (lower body 22, upper body 23, crawler units 29, 30) of the excavator is moved to the road surface. Lifted up. At this time, the rotation axis of the steering pivot 48 is directed substantially vertically. The steering pivot 48 may be provided with a camber of about 30 °.

When it is desired to move the hydraulic excavator body straight while the drive wheels 38 and 39 and the free rotating wheels 50 and 51 are in contact with the ground, the left and right drive wheels 38 and 39 may be rotated at a constant speed. When the main body is steered left and right, the right (or left) drive wheel 39 may be rotationally driven at a low speed with respect to the left (or right) drive wheel 38. In each of these cases, the free rotating wheels 50 and 51 move following the traveling direction.

Next, in this embodiment, a traveling motor for traveling the crawler, drive wheels 38 and 39, and a lifting frame 3
A hydraulic circuit for driving the hydraulic cylinders 37, 54 for raising and lowering the 4, 47 will be described with reference to the circuit diagram of FIG.

As described above, the main hydraulic pumps 55, 56,
57 and main switching valve (first switching valve 58, left traveling control valve 6
2. Right running control valve 63 and lifting frame operating valve 64)
Are provided on the upper body 23 side.
The lower body 2 from the main hydraulic pumps 55, 56, 57, etc.
Pressure oil is supplied to hydraulic motors (the left running motor 59 and the right running motor 60) that drive the motor 2 via a hydraulic swivel joint 61. Further, a left traveling control valve 62, a right traveling control valve 63, and a lifting frame operating valve 64 are interposed in a hydraulic oil supply line extending from the hydraulic pumps 55 and 56 to the hydraulic swivel joint 61. A first switching valve 58 for supplying or shutting off a pilot pressure to a second switching valve 66 described later by operating a mode switching switch 65 is inserted in the pressure oil supply line leading to the joint 61. The crawler travels when the mode changeover switch 65 is OFF, and the wheels travel when the mode changeover switch 65 is ON.

On the other hand, a second switching valve 66 composed of six pilot switching valves is disposed on the crawler unit 29, 30 side, and the hydraulic pumps 55, 56 are connected via the second switching valve 66. From the left traveling motor 59,
Pipes are provided for supplying the right running motor 60, the left driving wheel 38, the right driving wheel 39, and the hydraulic cylinders 37 and 54, respectively.

In such a circuit configuration, when the mode changeover switch 65 is OFF, that is, when the crawler is traveling, the first switching valve 58 is at the position B (the position shown), and the second switching valve 66 is also at the position B (the position shown). Position). Therefore, when the left traveling control valve 62 is switched to the position A, the second
Pressure oil is sent to the left traveling motor 59 via the switching valve 66, and the left traveling motor 59 rotates in the forward direction. Similarly, when the left traveling control valve 62 is switched to the position B, the second
Pressure oil is sent to the left traveling motor 59 via the switching valve 66, and the left traveling motor 59 rotates in the reverse direction. Also,
When the right traveling control valve 63 is switched to the position A, pressure oil is sent to the right traveling motor 60 via the second switching valve 66, and the right traveling motor 60 rotates in the forward direction. Similarly, when the right traveling control valve 63 is switched to the B position, pressure oil is sent to the right traveling motor 60 via the second switching valve 66, and the right traveling motor 60 rotates in the reverse direction. On the other hand, no pressure oil is supplied to the hydraulic cylinders 37 and 54 even when the lifting / lowering frame operating valve 64 is switched between the A position and the B position. Further, the left driving wheel 38 and the right driving wheel 39 cannot be operated.

On the other hand, when the mode switch 65 is turned on, the first switching valve 58 is switched to the A position and the second switching valve 66 is also switched to the A position. At this time, when the raising / lowering frame operating valve 64 is switched to the position A, the pressure oil from the hydraulic pump 55 is sent to the head side of the hydraulic cylinders 37, 54 via the second switching valve 66, and the respective lifting frames 34, 47 operates in the descending direction to drive wheel 3
8, 39 and the free rotating wheels 50, 51 are grounded. When the lifting frame operating valve 64 is switched to the position B, the pressure oil from the hydraulic pump 55 is sent to the rod sides of the hydraulic cylinders 37 and 54 via the second switching valve 66, and the respective lifting frames 34 and 47 are moved. Operates in the ascending direction to drive wheel 3
8, 39 and the free rotating wheels 50, 51 are lifted. A pilot check valve 67 is interposed in the lifting circuit of the lifting frame, so that inadvertent operation of the hydraulic cylinders 37 and 54 is closed during wheel running.

The mode switch 65 is turned on.
When the left traveling control valve 62 is switched to the position A during operation, pressure oil is sent to the hydraulic motor 40 on the left drive wheel 38 side via the second switching valve 66, and the hydraulic motor 40 rotates in the forward direction. I do. Similarly, when the left traveling control valve 62 is switched to the position B, the left driving wheel 38 is switched via the second switching valve 66.
Pressure oil is sent to the hydraulic motor 40 on the
0 rotates in the reverse direction. Also, the right traveling control valve 63 is set to A
When the switching operation is performed to the position, the pressure oil is sent to the hydraulic motor 41 on the right driving wheel 39 side via the second switching valve 66, and the hydraulic motor 41 rotates in the forward direction. Similarly, when the right traveling control valve 63 is switched to the position B, pressure oil is sent to the hydraulic motor 41 on the right drive wheel 39 side via the second switching valve 66, and the hydraulic motor 41 rotates in the reverse direction. I do. However,
When the left driving wheel 38 and the right driving wheel 39 are rotated in the reverse direction, the steering direction of the free rotating wheels 50 and 51 is not constant due to the variation in the running resistance of the left and right wheels, so that the steering in the reverse direction is performed. Direction control becomes difficult. When the mode switch 65 is turned on, the left traveling motor 59
The right running motor 60 cannot be operated.

According to the traveling device of this embodiment, the first and second lifting frames 34 and 47 are moved up and down by
It is possible to switch between crawler traveling and wheel traveling by a simple operation according to the purpose, such as traveling on a soft rough terrain with a crawler and traveling at high speed on a road surface with wheels. Further, since the width of each of the front and rear elevating frames 34 and 47 can be made smaller than the width of the wheel portion, these elevating frames 34 and 47 can be housed in the crawler, and the apparatus can be made compact as a whole. Can be.
Further, the hydraulic drive source originally provided for driving the working machine or the crawler can be used to raise and lower and rotate the wheels only by switching the hydraulic circuit, so that the implementation effect is extremely high. .

In this embodiment, a description has been given of an example in which a sprocket and a chain are used as the speed reducers for the drive wheels 38 and 39. This speed reducer includes a pinion, an intermediate gear,
A gear train using an axle gear or the like may be used. If there is sufficient space in the longitudinal direction of the axle, the hydraulic motor with a speed reducer may be arranged at the center of the axle.

(Fourth Embodiment) FIGS. 12 and 13 show another example (fourth embodiment) applied to a hydraulic excavator. In this embodiment, the drive mechanism of the traveling device according to the second embodiment is applied to a hydraulic shovel. In this embodiment, portions common to the third embodiment are denoted by the same reference numerals in the drawings, detailed description thereof will be omitted, and the following description will focus on configurations specific to this embodiment. .

In this embodiment, a hydraulic motor for individually driving the left and right drive wheels 38, 39 in the third embodiment,
Instead of the speed reducer, a hydraulic motor 68, a propeller shaft 69 rotated by the hydraulic motor 68, and an axle unit 70 for transmitting the rotation of the propeller shaft 69 to the drive wheels 38 and 39 are provided on the first lifting frame 34. Is provided. The axle unit 70 incorporates a differential mechanism as in the second embodiment, and transmits the rotational driving force from the propeller shaft 69 to the left and right driving wheels 38 and 39 by bevel pinion gears, while simultaneously transmitting the left and right driving wheels. The rotation difference between the drive wheels 38 and 39 is corrected.

On the other hand, as shown in FIG. 14, a steering hydraulic cylinder 71 is added to the rear side of the track frame 31 in the third embodiment. The steering hydraulic cylinder 71 has a base end on the second lifting frame 47.
Is pivotally supported by a bracket 72 fixedly mounted on the vehicle, and a distal end side is pivotally supported by a pivotally supported portion 75 on a bracket 74 fixedly mounted on a side portion of the wheel side frame 49. Thus, the free rotating wheels 50 and 51 are connected to the steering hydraulic cylinder 7.
When the vehicle 1 is extended, it rotates about the steering pivot 48 as a rotation axis together with the wheel-side frame 49 (see FIG. 13B). When the steering hydraulic cylinder 71 is contracted, the steering hydraulic cylinder 71 is rotated in the opposite direction together with the wheel side frame 49 around the steering pivot 48 as a rotation axis. During this steering operation, a difference in rotation occurs between the left and right drive wheels 38, 39,
Since these drive wheels 38 and 39 are driven by the axle unit 70 in which the differential mechanism is incorporated, the left and right drive wheels 3
8, 39 are run smoothly without slipping.

Next, the hydraulic circuit of the traveling device of this embodiment will be described with reference to FIG. Also in this hydraulic circuit, the same parts as those in the third embodiment are denoted by the same reference numerals in the drawings, and detailed description thereof will be omitted.

In this embodiment, the crawler unit 2
The left and right traveling motors 59, 60,
In addition to the hydraulic cylinders 37 and 54, a hydraulic motor 68 for driving the drive wheels 38 and 39 and a hydraulic cylinder 71 for steering are provided, and the hydraulic oil from the hydraulic pumps 55 and 56 is passed through the second switching valve 66. It is configured to be supplied to the hydraulic motor, the hydraulic cylinder, and the like. In the case of this embodiment,
Elevating frame operating valve 64 provided on upper body 23 side
Has a function of steering operation of the free rotating wheels 50 and 51 in addition to the operation of raising and lowering the first lifting frame 34. A pilot check valve 76 is interposed in the operation circuit of the traveling hydraulic cylinder 71 so that the steering angle can be maintained.

In such a circuit configuration, when the mode changeover switch 65 is OFF, that is, when the crawler is running, the first switching valve 58 is at the position B (the position shown), and the second switching valve 66 is also at the position B (the position shown). Position). Therefore, when the left traveling control valve 62 is switched to the position A, the second
Pressure oil is sent to the left traveling motor 59 via the switching valve 66, and the left traveling motor 59 rotates in the forward direction. Similarly, when the left traveling control valve 62 is switched to the position B, the second
Pressure oil is sent to the left traveling motor 59 via the switching valve 66, and the left traveling motor 59 rotates in the reverse direction. Also,
When the right traveling control valve 63 is switched to the position A, pressure oil is sent to the right traveling motor 60 via the second switching valve 66, and the right traveling motor 60 rotates in the forward direction. Similarly, when the right traveling control valve 63 is switched to the B position, pressure oil is sent to the right traveling motor 60 via the second switching valve 66, and the right traveling motor 60 rotates in the reverse direction. On the other hand, if the lift frame operating and steering valve 64 is switched to the position A with the left traveling control valve 62 and the right traveling control valve 63 returned to the neutral position, the hydraulic oil from the hydraulic pump 55
The air is sent to the heads of the hydraulic cylinders 37 and 54 via the switching valve 66, and the lifting frames 34 and 47 operate in the downward direction, so that the driving wheels 38 and 39 and the free rotating wheels 50 and 51 are grounded. In addition, the lifting frame operation and steering valve 6
4 is switched to the B position, the pressure oil from the hydraulic pump 55 is passed through the second switching valve 66 to the hydraulic cylinders 37, 54.
And the lifting frames 34 and 47 operate in the ascending direction to drive the driving wheels 38 and 39 and the free rotating wheels 5.
0,51 is lifted. When the mode changeover switch 65 is turned off, the steering hydraulic cylinder 71 for steering cannot be operated.

When the mode switch 65 is turned on, the first switching valve 58 is switched to the position A and the second switching valve 66 is also switched to the position A. When the left traveling control valve 62 is switched to the position A in this state, the second switching valve 66 is switched.
Hydraulic motor 68 that drives the drive wheels 38 and 39 via the
And the hydraulic motor 68 rotates in the forward direction. Similarly, when the left traveling control valve 62 is switched to the position B, pressure oil is sent to the hydraulic motor 68 that drives the drive wheels 38 and 39 via the second switching valve 66, and the hydraulic motor 68 is moved in the reverse direction. To rotate. When the right traveling control valve 63 is switched to the position A, the hydraulic oil is also sent to the hydraulic motor 68 via the second switching valve 66 and the hydraulic motor
8 rotates in the forward direction. Similarly, when the right traveling control valve 63 is switched to the position B, pressure oil is sent to the hydraulic motor 68 via the second switching valve 66, and the hydraulic motor 68 rotates in the reverse direction. Further, when the left traveling control valve 62 and the right traveling control valve 63 are simultaneously operated, the vehicle speed is doubled as compared with a single operation. The mode switch 65 is turned on.
During operation, the left traveling motor 59 and the right traveling motor 60
Is inoperable.

Next, the mode changeover switch 65 is turned on.
When the lifting / lowering frame operation and steering valve 64 is switched to the position A, the hydraulic oil from the hydraulic pump 55 is sent to the rod side of the steering hydraulic cylinder 71 via the second switching valve 66, and the free rotating wheel 50 , 51 are steered in the left turning direction. Further, when the lifting / lowering frame operation and steering valve 64 is switched to the position B, the hydraulic pump 55
Is sent to the head side of the steering hydraulic cylinder 71 via the second switching valve 66, and the free rotating wheels 50 and 51 are steered in the right turning direction. At the time of this steering operation, the elevating operation of each of the elevating frames 34 and 47 is disabled.

According to the traveling device of this embodiment, similarly to the third embodiment, it is possible to switch between crawler traveling and wheel traveling by a simple operation according to the purpose. In addition, by controlling the expansion / contraction speed of the steering hydraulic cylinder 71, the steering angle can be set to a desired direction and steering can be reliably performed. In this case, the steering can be easily performed regardless of whether the traveling direction of the vehicle is the driving wheel direction or the free rotating wheel direction.

(Fifth Embodiment) FIGS. 16 to 18 show a traveling apparatus according to a fifth embodiment of the present invention. In the present embodiment, a working machine of a hydraulic shovel is used as an elevating frame, and a system is configured using a turning rotation axis as a steering pivot axis.

In this embodiment, the structure of the driving wheel side portion P is basically the same as that of the fourth embodiment. That is, the lifting frame 34 is provided with a hydraulic motor, a propeller shaft rotated by the hydraulic motor, and an axle unit that transmits the rotation of the propeller shaft to the drive wheels 38. Is incorporated. On the other hand, the work implement 27
A frame unit 78 with a free rotating wheel that can be attached to and detached from the lifting magnet 77 at the tip of the unit is provided.

As shown in FIG. 18, the frame unit 78 has a lifting magnet 77
Axles 78b, 78b that rotatably support the free rotating wheel 50 on both sides while holding the holding portion 78a for holding
(Only the left side is shown in FIG. 18). A concave portion (not shown) is formed at one end of the holding portion 78a, and a tongue piece 78c for fixing is provided at the other end. On the other hand, the lifting magnet 77 is provided with a convex portion 77a at the lower portion of the outer peripheral surface on one side and a tongue piece 77b for fixing also on the side surface on the other side. In such a configuration, in order to fix the frame unit 78 to the lifting magnet 77, the projection 77a of the lifting magnet 77 is fitted into the recess on the frame unit 78 side, and then both tongue pieces 78c and 77b are connected. Fit these tongue pieces 78c,
By passing a bolt 79 through an insertion hole formed in 77b, it is fixed by bolt and nut fastening.

In the traveling device of this embodiment, when the operation by the crawler traveling is completed and it is desired to shift to the wheel traveling, the frame unit 78 is fixed to the lifting magnet 77 as described above, The attached free rotating wheel 50 is pressed against the ground by using the lifting force of the work equipment 27, and the other drive wheel 38 is grounded by operating the hydraulic cylinder 37 in the same manner as in the fourth embodiment. The body is lifted off the road as shown in FIG. In this state, the aircraft moves straight by driving the drive wheels 38 with the aircraft oriented parallel to the traveling direction. On the other hand, when the vehicle is steered right and left, the upper body 23 is turned around the vertical axis by turning the upper body 23 with respect to the lower body 22 by the turning mechanism of the hydraulic shovel while the body is raised from the road surface. The vehicle turns to steer as a whole.

According to this embodiment, the structure of the traveling device can be simplified, and there is no need to provide an extra device in front of the lower part of the hydraulic excavator. It has the effect of being able to do so.

In each of the above embodiments, the lifting frame 3
The number of hydraulic cylinders for steering up and down and the number of hydraulic cylinders 21 and 71 for steering (second and fourth embodiments) may be one, or may be two if necessary.
Books or more may be used.

In each of the above embodiments, the drive wheels 38, 39
Each of the free rotating wheels 50 and 51 is formed of a double tire, but may be a single tire, or may be any of a pneumatic tire, a solid tire, and an iron wheel.

[Brief description of the drawings]

FIG. 1 is a view showing a traveling device according to a first embodiment, wherein (a) is a front view and (b) is a bottom view.

FIGS. 2A and 2B are diagrams illustrating a traveling state of the traveling device according to the first embodiment, wherein FIG. 2A illustrates a straight traveling state, and FIG. 2B illustrates a left and right steering state.

FIGS. 3A and 3B are views showing a traveling apparatus according to a second embodiment, in which FIG. 3A is a bottom view, FIG. 3B is an enlarged view of a portion A of FIG. 3A, and FIG. FIG.

FIG. 4 is a diagram illustrating a traveling state of a traveling device according to a second embodiment.

FIG. 5 is a front view (when a crawler is used) of a traveling device according to a third embodiment.

FIGS. 6A and 6B are bottom views of the traveling device according to the second embodiment, in which FIG. 6A shows a straight traveling state and FIG. 6B shows a left and right steering state.

FIG. 7 is a front perspective view of a traveling device according to a third embodiment.

FIG. 8 is a sectional view of a driving wheel portion of a traveling device according to a third embodiment.

FIGS. 9A and 9B are partially enlarged views of the traveling device according to the third embodiment, in which FIG. 9A shows a free rotating wheel portion, and FIG. 9B shows a second lifting frame portion.

FIG. 10 is a front view (when using wheels) of a traveling device according to a third embodiment.

FIG. 11 is a hydraulic circuit diagram of a traveling device according to a third embodiment.

FIG. 12 is a front view (when a crawler is used) of a traveling device according to a fourth embodiment.

FIGS. 13A and 13B are bottom views of the traveling device according to the fourth embodiment, in which FIG. 13A shows a straight traveling state, and FIG. 13B shows a left and right steering state.

FIGS. 14A and 14B are partially enlarged views of a traveling device according to a fourth embodiment.

FIG. 15 is a hydraulic circuit diagram of a traveling device according to a fourth embodiment.

FIG. 16 is a front view (when a crawler is used) of a traveling device according to a fifth embodiment.

FIG. 17 is a front view (when using wheels) of a traveling device according to a fifth embodiment.

FIG. 18 is an enlarged perspective view of a frame unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Device main body 2 Hydraulic cylinder 3,11,34 1st raising / lowering frame 4,13,38,39 Drive wheel 5 Hydraulic cylinder 6,12,47 2nd raising / lowering frame 7,14 Steering pivot 8,15,49 Wheel side frame 9, 16, 50, 51 Free rotating wheel 10 Motor 17 Driving device with differential mechanism 18 Input drive 19 Bevel pinion case 21 Hydraulic cylinder for steering 22 Lower body 23 Upper body 27 Work machine 29, 30 Crawler unit Reference Signs List 31 track frame 32 wheel traveling unit 33a, 33b front pivot 37 hydraulic cylinder 40, 41 hydraulic motor 46a, 46b rear pivot 48 steering pivot 54 hydraulic cylinder 55, 56, 57 hydraulic pump 58 first switching valve 59 Left traveling motor 60 Right steering motor 61 Hydraulic swivel joint 62 Left traveling control 63 right travel control valve 64 lifting frame hydraulic valve 65 mode switch 66 second switch valve 68 hydraulic motor 70 axle unit 71 hydraulic cylinders 73 and 75 pivot portion 77 lifting magnet 78 frame unit for steering

Claims (6)

[Claims] 1. An apparatus main body, (b) a first elevating frame which is disposed in front of the apparatus main body and supports a front wheel so as to be able to move up and down with respect to the apparatus main body, and (c) is disposed behind the apparatus main body. And (d) a steering mechanism for steering the device main body. 2. The left and right wheels constituting the front wheel are driven by individual driving means, the rear wheel is a free rotating wheel, and the steering mechanism controls the rotational speed of each of the front wheels. The traveling device according to claim 1, wherein the device body is steered by changing. 3. One of the front wheel and the rear wheel is driven by a drive unit with a differential mechanism, the other wheel is a free rotating wheel, and the steering mechanism is a steering cylinder. The traveling apparatus according to claim 1, wherein the apparatus main body is steered by a direction change of the free rotating wheel and the differential mechanism. 4. The traveling device according to claim 1, wherein the device main body is a hydraulic shovel. 5. The apparatus body is a hydraulic shovel, and one of the front wheel and the rear wheel is driven by a driving device with a differential mechanism, and the other wheel is provided at a tip end of a boom of the hydraulic shovel. The rotating mechanism is a detachable free rotating wheel, and the steering mechanism steers the apparatus body by changing the direction of the free rotating wheel using a turning mechanism of the hydraulic shovel and the differential mechanism. The traveling device according to claim 1. 6. A traveling device capable of switching between crawler traveling and wheel traveling, comprising a switching valve capable of switching between a hydraulic circuit for driving a crawler traveling motor and a hydraulic circuit for driving a wheel traveling motor. A traveling device, wherein both hydraulic circuits are configured to be controlled by a common traveling control valve.