JP2003276661A - Crawler traveling device and traveling method of crawler traveling device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a crawler type traveling device having good turning performance. A crawler-type traveling device in which a sprocket 12, a crawler belt 15 wound around an idler 13a, 13b, and rolling wheels 14a to 14d circulates in a circumferential direction by rotationally driving a sprocket 12. In the device, the contact length of the crawler belt 15 when traveling on a pavement road surface is such that the rolling wheels 14a to 14c when traveling on a soft ground.
The length d is configured to be shorter than the contact length of the crawler belt 15 that contacts the ground.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crawler type traveling device.

[0002]

2. Description of the Related Art Conventionally, for example, a crawler unit (semi crawler) is used instead of a rear wheel tire of a four-wheel drive tractor.
There is a semi-crawler track tractor that is installed independently on the left and right. The crawler unit includes an upper sprocket, a track frame arranged below the sprocket, an idler provided in front of and behind the track frame, and a plurality of rolling wheels provided between the front and rear idlers of the track frame. , An endless crawler belt wound around the sprocket, the idler, and the rolling wheels.

[0003]

In the crawler type traveling device, the crawler belt has a large ground contact area and a low ground contact pressure as compared with tire wheels, and is suitable for running on rough terrain, but has a turning performance. There is a problem of being bad. The present invention has been made in view of the above problems, and an object thereof is to provide a crawler type traveling device with improved turning performance.

[0004]

The technical means taken by the present invention to solve the technical problem is that the sprocket is wound around the sprocket, the idler and the plurality of rolling wheels by rotationally driving the sprocket. In a crawler type traveling device in which the crawler belt circulates in the circumferential direction, the ground contact length of the crawler belt when traveling on a paved road surface is shorter than the ground contact length of the crawler belt that is grounded by the rolling wheels when traveling on flexible ground. It is characterized in that it is configured as follows.

Further, another technical means is a crawler type in which a sprocket, an idler, and a crawler belt wound around a plurality of rolling wheels are circulated and circulated in a circumferential direction by rotationally driving a sprocket. In the traveling device, the crawler belt is driven by a smaller number of rollers than the number of rollers provided when traveling on a paved road so that the contact length of the crawler belt when traveling on a paved road is shorter than that when traveling on a soft ground. It is characterized by being grounded. Another technical means is a crawler type traveling device in which a sprocket, an idler, and a crawler belt wound around a plurality of rolling wheels are circulated and circulated in a circumferential direction by rotationally driving a sprocket. Among the rolling wheels, at least the rolling wheels located at the front and rear ends are supported at a position higher than the other rolling wheels so that the ground contact length of the crawler belt when traveling on a paved road is shorter than when traveling on a soft ground. It is characterized by

Another technical means is to dispose a track frame below a sprocket, support an idler at the front and rear of the track frame, and support a plurality of rolling wheels between the front and rear idlers of the track frame. However, in the crawler type traveling device in which the crawler belt wound around the sprocket, the idler and the rolling wheels is circulated in the circumferential direction by rotationally driving the sprockets, in the front and rear end of the rolling wheels. It is characterized in that the rolling wheels and the front and rear idlers located at a certain portion are supported so that their lower ends are higher than the lower ends of the other rolling wheels.

[0007] Another technical means is a crawler type in which a sprocket is rotatably driven to circulate and circulate a crawler belt wound around a sprocket, an idler and a plurality of rolling wheels in a circumferential direction. A feature of the traveling device is that a mechanism for changing the ground contact length of the crawler belt is provided. Further, in the above configuration,
The ground contact length of the crawler belt can be made variable so that the ground contact length of the crawler belt becomes shorter than that when traveling straight ahead during turning. Another technical means is to arrange a track frame, which is swingably supported around a horizontal axis, below the sprocket, support an idler in front of and behind the track frame, and A crawler type traveling device in which a plurality of rollers are supported between idlers and a sprocket is rotationally driven so that a crawler belt wound around the sprocket, the idler and the wheels is circulated around in the circumferential direction. In this case, the idler is supported so that the height of the lower end of the idler is higher than the height of the lower end of the wheel adjacent to the idler, and the track frame is forcibly swung about the swing axis. The grounding length of the crawler belt can be achieved by grounding the crawler belt with the idler and the rolling wheels near the idler. Characterized by being configured to be shorter.

[0008] Another technical means is a crawler type in which a sprocket, an idler, and a crawler belt wound around a plurality of rolling wheels are circulated and circulated in a circumferential direction by rotationally driving a sprocket. In the traveling device, the contact length of the crawler belt is made variable by supporting the rolling wheels so that the vertical position can be adjusted. Another technical means is a crawler type traveling device in which a sprocket, an idler, and a crawler belt wound around a plurality of rolling wheels are circulated and circulated in a circumferential direction by rotationally driving a sprocket. The contact length of the crawler belt is variable so that the contact length of the crawler belt becomes shorter when the vehicle speed becomes faster than when traveling in the field.

Another technical means is a crawler type traveling device in which a crawler belt wound around a sprocket, an idler and a rolling wheel is circulated and circulated in a circumferential direction by rotationally driving a sprocket. The traveling method is characterized by shortening the ground contact length of the crawler belt and turning.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 9 show a first embodiment of a crawler type traveling device according to the present invention. In FIG. 3, reference numeral 1 is a semi-crawler tractor (vehicle) in which a crawler unit 2 (semi-crawler) is independently provided in place of a rear wheel of a four-wheel drive tractor, and a front wheel 7 is a steering wheel.

The tractor 1 is exemplified by a tractor with a cabin in which a cabin 4 is mounted on a rear portion of a vehicle body 3. A driver's seat 5 is provided in the rear portion of the cabin 4 and a driver's seat 5 is provided in front of the driver's seat 5. A steering handle 6 is provided.
The vehicle body 3 is configured by attaching a power transmission case 9 to a rear portion of the engine 8 via a flywheel housing, and the power transmission case 9 is configured by a clutch housing, a transmission case, and the like. The front wheels 7 are provided on both left and right sides of a front axle case supported by the front axle frame 10, and the front axle case is mounted and fixed to the engine 8 so as to project forward from the engine 8.
At 0, it is swingably supported around the front-rear axis.

As shown in FIG. 2, the crawler unit 2 has an outer end in the left-right direction of a rear axle case 19 (axle case) which is provided on the rear end side of the power transmission case 9 (mission case) so as to project in the left-right direction. It is attached to the side. In addition, in FIG. 2, one of the left and right crawler units 2 is
Illustration is omitted. As shown in FIGS. 1 and 2, the crawler unit 2 includes one sprocket 12, a pair of front and rear idlers 13a and 13b, a plurality of (four in the present embodiment) rolling wheels 14a to 14d, and these sprockets. 1
2, the idler 13a, 13b, the crawler belt 15 wound around the rolling wheels 14a to 14d, the track frame 16, and the transmission case 17 (gear case) are provided, and the sprocket 12 is rotated about the axial center in the left-right direction. The crawler belt 15 is circulated and circulated in the circumferential direction by being rotationally driven, and is thereby configured to travel.

First, the structure of the crawler unit 2 will be roughly described. The track frame 16 is composed of a rectangular tubular body and is arranged along the front-rear direction. Wheels 14a-d are supported. Idlers 13a, 13
b is arranged in front of and behind the track frame 16, and the wheels 14a to 14d are arranged below the track frame 16 in the front-rear direction. The sprocket 12 is arranged above the track frame 16 and above the middle portion between the front and rear idlers 13 a and 13 b, and is supported by the transmission case 17.

The transmission case 17 is attached and fixed to the outer side of the rear axle case 19 at the rear of the vehicle body 3 in the left-right direction.
A support portion 21 is provided below the transmission case 17, and a swing shaft 22 is supported by the support portion 21 so as to be rotatable about an axis in the left-right direction. The track frame 16 is attached to the idler 13a, 13b and the wheel 14
Together with a to d, they are swingably supported around the axis of the swing shaft 22.

The crawler unit 2 is integrally and detachably attached to the rear axle case 19 as a unit. Therefore, the load from the vehicle body 3 side of the tractor 1 acts on the track frame 16 via the transmission case 17, the support portion 21, and the swing shaft 22. The crawler belt 15 has a main body formed of rubber in an endless belt shape,
On the inner peripheral side, rubber drive protrusions 23 are provided at appropriate intervals in the circumferential direction and over the circumferential direction.

The drive projection 23 has a function of engaging the sprocket 12 in the circumferential direction and receiving a driving force from the sprocket 12, and engaging the rolling wheels 14a to 14d, the sprocket 12 and the idlers 13a, 13b in the left-right direction. It has a function of preventing wheel removal (preventing the crawler belt 15 from coming off). A support base 24 that supports the rear portion of the cabin 4 is attached to the rear axle case 19. Next, the configuration of the crawler unit 2 will be described in detail.

As shown in FIG. 4, a rear axle 25 (axle) in the left-right direction is provided in the lower portion of the transmission case 17, and a drive shaft parallel to the rear axle 25 is provided in the upper portion of the transmission case 17. 26 is provided, and an intermediate shaft 27 is provided between the rear axle 25 and the drive shaft 26 in parallel with them. The rear axle 25 and the intermediate shaft 27 are rotated about the axis in the left-right direction through bearings between the outer side wall of the transmission case 17 in the left-right direction and the wall portion of the rear axle case 19 on the outer end side in the left-right direction. It is supported freely.

The drive shaft 26 is rotatably supported around a shaft center in the left-right direction via bearings between the outer side wall and the inner side wall of the transmission case 17, and is left and right from the transmission case 17. The flange portion 28 is provided on the protruding end portion, and the sprocket 12 is attached and fixed to the flange portion 28. The rear axle 25 is provided with a first gear 29, and the drive shaft 26 is provided with
The second gear 30 is provided, and the intermediate shaft 27 is provided with an idler gear 31 that meshes with the first and second gears 29, 30, and the first gear 29, the second gear 30,
Power is transmitted from the rear axle 25 to the drive shaft 26 by the gear transmission mechanism (power transmission mechanism) including the idler gear 31, and the sprocket 12 is rotationally driven about the axis of the drive shaft 26.

In the structure described above, the sprocket 12 is arranged so that the rotation axis X of the sprocket 12 is located above the axis Y of the rear axle 25 that transmits power to the sprocket 12. As a result, the contact angle (contact range) of the crawler belt 15 with respect to the sprocket 12 can be increased, which increases the meshing ratio between the sprocket 12 and the drive projection 23 of the crawler belt 15 and increases the meshing teeth. It is possible to increase the number (refers to the number of meshing members 40 (meshing portions) that engage with the drive projections 23 of the sprocket 12 in the portion where the crawler belt 15 is wound around the sprocket 12). The load on the drive projection 23 from 40 is reduced, and the crawler belt 1
It is possible to provide the crawler unit 2 which has a longer life and is compatible with higher speed.

In the present embodiment, the meshing member 40
Are provided, four of which are drive protrusions 2.
It is designed to mesh with 3. The rear axle 25 is protruded inward in the left-right direction from the transmission case 17, and is interlocked with the transmission shaft 32 in the rear axle case 19 via a coupling 33. On the other hand, the power from the engine 8 is transmitted to the rear wheel differential device 34 after passing through the speed change mechanism in the power transmission case 9 via the clutch, and the power is branched from here to the transmission shaft 32 in the left and right rear axle cases 19. Power is transmitted from the left and right transmission shafts 32 to the rear axle 25.

A brake device 35 for braking the transmission shaft 32 (sprocket 12) is provided on the left and right inner ends of the rear axle case 19. The drive shaft 26 is
The swing shaft 22 is located vertically above the rear axle 25 and vertically below the rear axle 25. As shown in FIGS. 5 and 6, the sprocket 12 includes a ring-shaped mounting wheel 38 that is mounted and fixed to the flange portion 28 of the drive shaft 26, and ring-shaped side wheels located on both left and right sides of the mounting wheel 38. 39 and a meshing member 40 that meshes with the drive protrusion 23 of the crawler belt 15, and is divided into two in the circumferential direction (thus, the mounting wheel 38 and the left and right side wheels 39 are divided into two in the circumferential direction. Exist).

The sprocket 12 may be divided into three or four in the circumferential direction, or may not be divided. Further, when replacing the crawler belt 15, the sprocket 12 is replaced with the one sprocket structure 12
With A positioned at the top and the other sprocket structure 12B positioned at the bottom, the lower sprocket structure 1
By removing 2B and rotating the sprocket assembly 12A located on the upper side to the lower side, the tension of the crawler belt 15 is relaxed, and the crawler belt 15 can be replaced.

The mounting wheel 38 has a cylindrical portion 41 which is concentric with the rotation axis X of the sprocket 12, and a mounting flange 42 which projects radially inward from the inner peripheral surface of the cylindrical portion 41. On the other hand, a mounting seat 43 is formed on the outer peripheral side of the outer surface in the left-right direction of the flange portion 28 of the drive shaft 26, and the mounting flange 42 of the mounting wheel 38 is superposed on the mounting seat 43,
A mounting wheel 38 is detachably mounted on the drive shaft 26 by a stud bolt 44 penetrating the mounting flange 42 and screwed into a screw hole formed in the flange portion 28, and a nut 45 screwed into the stud bolt 44. It is fixed.

The inner peripheral portion 46 of the side wheel 39 is in contact with the side surface of the cylindrical portion 41 of the mounting wheel 38, and the right and left sides are mounted by the mounting bolt 47 which penetrates the inner peripheral portion 46 and is screwed into the cylindrical portion 41. The side wheel 39 is detachably attached to the attachment wheel 38. Outer peripheral portions 48 of the left and right side wheels 39 are projected outward in the radial direction with respect to the mounting wheels 38, and a cylindrical support hole having a bottomed cylindrical shape is provided on the facing surface of the outer peripheral portions 48 of the left and right side wheels 39. 49 are formed at intervals in the circumferential direction. Further, on the outer peripheral portion 48 of the left and right side wheels 39, there is formed a flange portion 50 that projects outward in the left-right direction (opposite side) and contacts the inner peripheral surface of the crawler belt 15.

The meshing member 40 is constituted by a pin, and has a cylindrical large-diameter engagement portion 51 at the center in the axial direction and a small-diameter shaft portion 52 protruding outward in the left-right direction from both left and right sides of the engagement portion 51. And the left and right shafts 52 are the side wheels 3
9 is inserted into and removed from the shaft support hole 49, and the meshing member 40 is attached and held by being sandwiched between the left and right side wheels 39. Therefore, by removing the outer side wheel 39 from the mounting wheel 38, the engagement member 40 can be removed from between the side wheels 39, and the engagement member 40 can be replaced.

Further, since the sprocket 12 is divided in the circumferential direction, when the engagement member 40 is replaced, the side on which the crawler belt 15 is not wound (lower side).
By removing the structure of the side wheel 39, the side wheel 39 can be easily removed (therefore, the structure of the side wheel 39 on which the crawler belt 15 is wound is removed. If
Rotate the sprocket 12 and position it on the side where the crawler belt 15 is not wound). Further, since the plurality of meshing members can be replaced by removing the side wheel 39, the meshing member 40 can be easily replaced as compared with the case where one meshing member is attached one by one.

A bush is externally fitted to the shaft portion 52, and a shim is provided in the inner portion of the shaft support hole 49, so that the meshing member 40 is rotatably supported around the axial center in the left-right direction. As a result, wear due to contact with the drive projection 23 is reduced and uneven wear is prevented. That is, when the sprocket 12 is rotationally driven, the drive projection 23 of the crawler belt 15 is relatively inserted between the meshing members 40 on the outer peripheral portion of the sprocket 12, and the meshing member 40 abuts the drive projection 23 to mesh with each other. Torque is transmitted from the sprocket 12 to the drive protrusion 23. At this time, since the meshing member 40 is rotatable, wear due to contact with the drive protrusion 23 is small and uneven wear is prevented. is there.

Although the inner side wheel 39 may be integrally formed with the mounting wheel 38, the inner side wheel 39 and the outer side wheel 39 can be manufactured at a low cost by using a common shape. Further, the meshing member 40 may be composed of a shaft provided between the outer peripheral portions 48 of the left and right side wheels 39, and a collar fitted to the shaft so as to be rotatable around the shaft center. In this case, the collar serves as an engaging portion that abuts the drive protrusion 23. Further, even in the sprocket 12 in which the flange portion 50 protruding outward in the left-right direction is provided on the outer peripheral side of the side wheel 39, the meshing member 40 should be sandwiched between the left and right side wheels 39 to be attached and fixed. By this, the meshing member 40 can be provided as close to the outer periphery of the sprocket 12 as possible, whereby the meshing member 12 is driven.
Can be engaged with the base side of the.

As shown in FIGS. 4, 7 and 8, the support portion 21 for supporting the swing shaft 22 has a tubular portion 54 having a horizontal axis, and the tubular portion 54 is integrated with the transmission case 17. And a connecting rib 55 that physically connects them. The swing shaft 22 is inserted into the cylindrical portion 54 from the outer side in the left-right direction and is supported rotatably around the axis in the left-right direction. Note that grease is injected between the swing shaft 22 and the inner surface of the tubular portion 54. Tube 5
A cover plate 57 is abutted on the end surface side of the inner side of 4 in the left-right direction via a collar 56, and a bolt 58 is screwed into a screw hole formed through the cover plate 57 in the swing shaft 22. As a result, the cover plate 57 is fixed to the swing shaft 22, and thus the swing shaft 22 is prevented from coming off.

The swing shaft 22 projects outward in the left-right direction from the outer end in the left-right direction of the tubular portion 54, and the outer end in the left-right direction of the swing shaft 2 is above the track frame 16 and on the sprocket 12. It is located below. This swing shaft 22
The left and right outer ends of the pair of flanges 5 are
The inner flange 59 is in contact with the outer end surface of the tubular portion 54 of the support portion 21 in the left-right direction through the collar 65 and is fixed to the upper surface of the track frame 16 by welding or the like. The outer flange 60 is fixed to the fixed plate 61 by welding or the like, and the outer flange 60 is fixed to the swing shaft 22 by a connecting member 62 fixed to the outer flange 60 and the swing shaft 22 by welding or the like.

Further, the inner and outer flanges 59, 60 are joined to each other by bolts 63 which penetrate the outer flange 60 and are screwed into the screw holes formed in the inner flange 59, whereby the track frame. 16 is supported by a supporting portion 21 via a swing shaft 22 so as to be swingable around a horizontal axis. In addition, the fixed plate 61
Is projected inward in the left-right direction from the track frame 16, and a reinforcing member 64 is provided across the protruding portion and the wall portion on the inner side in the left-right direction of the track frame 16.

Further, abutting portions 36 projecting outward in the radial direction are provided in front of and behind the tubular portion 54, and these abutting portions 36 are
A pair of front and rear stoppers 3 provided on the inner flange 59
By abutting on any one of 7, the swinging of the swinging shaft 22 of the track frame 16 or the like is restricted. A mounting plate 66 for mounting the rollers 14a to 14d is fixed to the lower surface side of the track frame 16 by welding or the like, and a screw hole 67 is formed in the mounting plate 66 from the lower side.

On the other hand, the rolling wheels 14a to 14d are a cylindrical portion 70 having a horizontal axis, and a support which is inserted into the cylindrical portion 70 and is rotatably supported around the horizontal axis via bearings. The shaft 71 and the support shaft 7 are arranged on both left and right sides of the tubular portion 70.
It is configured by a ring body 72 which is fitted on the outer periphery of the first body and is prevented from coming off. The tubular portion 70 is located above the drive projection 23, and the left and right wheels 72 are located on both the left and right sides of the drive projection 23, and rolls on the inner peripheral surface of the crawler belt 15. In addition, a mounting bracket 73 that abuts the lower surface of the mounting plate 66 is integrally extended to the cylindrical portion 70, and the mounting bracket 73 penetrates the portion of the mounting bracket 73 that abuts the mounting plate 66 to provide a mounting plate. The rolling wheels 14a to 14d are detachably attached to the track frame 16 by bolts 74 that are screwed into the screw holes 67 of 66.

Further, since the sprocket 12 is arranged so that its rotation axis X is located above the axis Y of the rear axle 25, a large space below the sprocket 12 can be provided. As a result, the lower space of the track frame 16 can be sufficiently large so that the wheel unit including the wheels 14a to 14d and the mounting bracket 73 can be attached to the lower surface side of the track frame 16 from below (track). The height of the frame 16 is sufficiently large) and the wheel assembly is detachably attached to the lower surface of the track frame 16 to ensure the attachment strength of the wheel 14a to 14d.

The front idler 13a is rotatably supported by a bracket 76 provided on a tension adjusting device 75 for adjusting the tension of the crawler belt 15, and the tension adjusting device 75 is mounted on the track frame 16. It is fixed to the front. The tension adjusting device 75 includes an outer cylinder portion 83 fixed to the track frame 16 by welding or the like, and an inner cylinder portion 8 inserted into the outer cylinder portion 83 from the front side so as to be retractable.
4 and a tension mechanism 85 housed in the outer tubular portion 83 and the inner tubular portion 84. On the front end side of the inner tubular portion 84,
A bracket 76 that supports the idler 13a on the front side is attached and fixed.

The tension mechanism 85 is interposed between the pressing member 86, the compression coil spring 87 interposed between the pressing member 86 and the bracket 76, and the pressing member 86 and the rear wall 83a of the outer cylindrical portion 83. The coil cylinder 87 biases the crawler belt 15 via the idler 13a, thereby tensioning the crawler belt 15 and at the same time the grease cylinder 88 is provided. The tension of the crawler belt 15 can be adjusted by advancing and retracting the piston rod.

The rear idler 13b is supported by a bracket 77 fixed to the rear end side of the track frame 16 so as to be rotatable about its axis in the left-right direction. Also,
The front and rear idlers 13a and 13b are, as shown in FIG.
A tubular portion 79 having a horizontal axis, a support shaft 80 inserted into the tubular portion 79 and rotatably supported around a horizontal axis via a bearing, and arranged on both left and right sides of the tubular portion 79. Body 81 that is attached to the support shaft 80 and prevented from coming off
And the left and right wheels 81 are the drive projections 23.
Are located on the left and right sides of the crawler belt 15 and roll on the inner peripheral surface of the crawler belt 15.

Further, as shown in FIG. 8, the front wheel 1
The mounting plate 66 to which the 4a is attached is the other rolling wheel 14b.
-14d is formed thinner than the mounting plate 66 in the vertical direction, and the height from the ground contact surface of the lower end of the front end rolling wheel 14a is higher than the lower ends of the other rolling wheels 14b to 14d by L. As described above, the front wheel 14 a is attached to the track frame 16. Further, the heights of the lower ends of the front and rear idlers 13a and 13b from the ground contact surface are also higher by M1 and M2 than the lower ends of the rollers 14b to 14d other than the rollers 14a on the front end side.

Therefore, in the crawler unit 2, the ground contact length E of the crawler belt 15 during traveling on the paved road surface (the range in which the crawler belt 15 is grounded in the front-rear direction, the ground contact length of the crawler belt 15 in the circumferential direction).
However, it is configured to be shorter than the ground contact length F of the crawler belt 15 grounded by the rolling wheels 14a to 14d when traveling on a flexible ground. When traveling on a soft ground (soft ground) such as a field, the crawler belt 15 may be, for example, substantially directly below the support shaft 80 of the front idler 13a (in the vicinity of immediately below) to the support shaft 80 of the rear idler 13b. Although it contacts the ground G in a range G up to immediately below (in the vicinity of immediately below), on the paved road surface, the crawler belt 15 has the support shaft 71 of the wheel 14d on the trailing end side substantially directly below the support shaft 71 of the second wheel 14b from the front. It will be grounded in a range E just below.

That is, as for the ground contact length of the crawler belt 15, the ground contact length of the crawler belt 15 becomes shorter on the paved road surface between the soft ground and the paved road surface (the ground contact area of the crawler belt 15 or the load from the vehicle body 3). The operating range becomes narrower), so that the traveling and turning can be performed relatively easily when traveling on the pavement surface, and the crawler belt 15 can be used when traveling in the field.
It has a wide ground contact area, low ground pressure, and is suitable for running on rough terrain. In the embodiment having the above-described configuration, the front wheel 14a is supported by the track frame 16 so as to be vertically movable, and the roller 14a is moved up and down by an actuator such as a hydraulic cylinder. May be supported on the track frame 16 so that the vertical position can be adjusted, and the rolling wheels 14a may be slightly lifted when traveling on the pavement.

Further, the second rolling wheel 14b from the front may be arranged at a high position similarly to the rolling wheel 14a on the front end side. When the number of rolling wheels 14a to 14d is larger, three or more rolling wheels are provided. The height of the wheels may be increased (the positions of the plurality of rollers may be higher than those of the other wheels). In the present embodiment, since the swing shaft 22 is closer to the rear side of the crawler unit 2 in the front-rear direction, the rolling wheel 14a on the front end side is raised. In the case of being closer to the front side in the front-rear direction or located in the central portion in the front-rear direction, the contact length of the crawler belt 15 can be shortened during traveling on a paved road surface by increasing the position of the rear wheel 14d. You may comprise so that it may become.

Further, the swing shaft 22 is used for the crawler unit 2
In the case of being located at the central portion in the front-rear direction, the front end side and rear end side rolling wheels 14a, 14d are made higher than the other rolling wheels 14b, 14c, so that the ground contact length of the crawler belt 15 can be shortened. Good. During traveling on the pavement road surface, the number of the rolling wheels 14b to 14d is smaller than the number of the rolling wheels 14a to 14d provided.
By configuring so that the load from the vehicle body 3 can be supported by d, the crawler belt 15 during traveling on the paved road surface
It is sufficient if the contact length of is short.

10 to 12 show a crawler unit 2 according to a second embodiment. In this embodiment, a mechanism for changing the ground length of the crawler belt 15 is provided. Specifically, by forcibly swinging the track frame 16 about the axis of the swing shaft 22, the idler 13b on the rear side and the wheels 14c and 14d near the idler 13b are illustrated. By grounding the crawler belt 15 with
The grounding length of No. 5 is shown to be short.

10 and 11, the track frame 16 includes a pair of front and rear swing brackets 90F, 90.
R is swingably supported around a shaft center in the left-right direction via a support shaft 91. The swing brackets 90F and 90R are provided with arm portions 92 extending obliquely downward. Rolling wheels 14a to 14d are rotatably attached to the lower portion via a support shaft 71 in the left-right direction. Also,
A hydraulic cylinder 93 for forcibly swinging the track frame 16 is interposed between the rear axle case 19 side and the track frame 16 side.

The hydraulic cylinder 93 is a cylinder body 9
The base side of the hydraulic cylinder 93 is rotatably supported by a mounting base 97 fixed to the rear axle case 19 and the transmission case 17 via a support shaft 98 in the left-right direction around the support shaft 98. The tip end side of the piston rod 95 is attached to the mounting base 99 fixed to the track frame 16 in the left-right direction.
It is rotatably pivoted about the axis of the support shaft 100 via 0. Also, this hydraulic cylinder 93 is
By supplying pressure oil to the oil chamber 102 on the top side of 01, the piston rod 95 is configured by a single-acting hydraulic cylinder protruding, and the piston 101 and the piston rod 95 are separated.

Since the other structure is substantially the same as that of the first embodiment, the illustration and description thereof are omitted. In this embodiment, during normal traveling, the top oil chamber 102 is in communication with the drain circuit, the piston rod 95 is freely retractable, and the idlers 13a, 13b and the rolling elements are rotated. The track frame 16 is allowed to swing around the swing shaft 22 so that the wheels 14a to 14d follow the unevenness of the ground.

When the ground contact length of the crawler belt 15 is shortened, pressure oil is supplied to the top oil chamber 102 to extend the piston rod 95. Then, as shown in FIG. 12, the track frame 16 is moved to the swing shaft 22.
The crawler belt 1 is swung around in the direction of the arrow A, and is driven by the idler 13b on the rear side and the rollers 14c, 14d on the rear side.
5, the grounding length of the crawler belt 15 can be shortened. In the crawler unit 2 of the variable ground length type in which the ground length of the crawler belt 15 can be changed as in this embodiment, the ground length of the crawler belt 15 is shortened when traveling on a paved road surface. The crawler belt 1 may be used when turning (whether traveling on a paved road or traveling on a field).
The ground contact length of 5 may be shortened so that the crawler belt 15 can be rotated.

Also in this embodiment, when traveling on the paved road surface, the track frame 16 is forcibly oscillated so that the rear idler 13b and the rear wheel 14c,
By grounding the crawler belt 15 by 14d, the ground contact length E of the crawler belt 15 when traveling on a paved road surface is grounded by the ground contact length G of the crawler belt 15 when traveling on a soft ground and the rolling wheels 14a to 14d when traveling on a soft ground. It is configured to be shorter than the ground contact length F of the crawler belt 15. A grease cylinder or another actuator may be used instead of the hydraulic cylinder 93 to forcibly swing the track frame 16. Also in this case, during normal traveling, the truck frame 1
6 is configured to be allowed to swing around the swing shaft 22.

In the case where the swing shaft 22 is provided closer to the front side than the central portion of the crawler unit 2 in the front-rear direction, the idler 13a on the front side and the rolling wheels 14 in the vicinity thereof.
The crawler belt 15 may be grounded by a and 14b. In addition, the tractor 1 is used during traveling such as when working on a field and when traveling on a paved road surface.
Since the vehicle travels at different traveling speeds, the ground contact length of the crawler belt 15 may be automatically switched depending on the difference in traveling speed. That is, it travels slowly (for example, 10 km / hour or less) when traveling in the field (for example, during work) and fast (for example, 35 km / hour) when traveling on a paved road surface. Whether the vehicle is traveling on a paved road surface is determined by a speed sensor or the like, and the hydraulic cylinder 9 is used so that the ground contact length of the crawler belt 15 changes.
3 is controlled.

Further, in the case where the crawler belt 15 is shortened to have a ground contact length at the time of turning so as to turn,
For example, when turning, the ground contact length of the crawler belt 15 is manually switched, or it is determined whether the vehicle is going straight or turning by detecting the turning angle of the handlebar 6,
The ground contact length of the crawler belt 15 may be switched depending on the cutting angle of the handle 6. 13 and 1
Reference numeral 4 denotes the third embodiment, in which the wheel 14c is supported by the track frame 16 so as to be able to move up and down via the hydraulic cylinder 104 (or another actuator).

Cylinder body 1 of the hydraulic cylinder 104
04A is fixed to the track frame 16 and is located at the tip end side of the piston rod 104B and is the second rolling wheel 14c from the rear.
A support shaft 71 that supports the shaft is rotatably supported around a horizontal axis. Other configurations are substantially the same as those in the first embodiment, and therefore, illustration and description thereof will be omitted. In this embodiment, by extending the piston rod 104B of the hydraulic cylinder 104, the track frame 16 swings around the swing shaft 22 in the direction of arrow B in FIG. As shown, the crawler belt 15 is grounded by the rear idler 13b and the rear wheels 14c and 14d, which makes it possible to shorten the ground length of the crawler belt 15.

FIG. 15 shows a fourth embodiment,
A plurality of rolling wheels 14b to 14d (in the illustrated example, the second and third from the front
The third and third rear wheels are supported so as to be vertically movable with respect to the track frame 16 and can be vertically driven by an actuator such as a hydraulic cylinder. Other configurations are substantially the same as those in the first embodiment, and therefore, illustration and description thereof will be omitted. In this embodiment, the plurality of rollers 14b to 14d are moved downward with respect to the track frame 16 as shown by imaginary lines, so that the ground length of the crawler belt can be shortened. There is.

Incidentally, in the case of this embodiment,
When the plurality of rolling wheels 14b to 14d are moved downward,
The crawler belt 1 is provided by the rollers 14b to 14d so that tension is imparted to the crawler belt 15 via b to d.
5 is pressed, but the crawler belt 15 is configured to be tensioned by the coil spring 87 of the tension adjusting device 75 as described above. Since the crawler belt 15 is pressed by the rolling wheels 14b to 14d, the tension adjusting device 75 can absorb (automatically adjust) the tension because it is not so large as the left side.

16 and 17 show another embodiment, in which the sprocket 12 is arranged on one side of the front and rear, the idler 13 is arranged on the other side of the front and rear, and a plurality of rolling wheels are provided between the sprocket 12 and the idler 13. A full crawler type crawler unit 2 in which 14 are arranged is adopted, and the height of the rolling wheel 14 on the front and rear direction end side is set to the crawler unit 2 of the other crawler unit 2 as in the first embodiment. It is arranged at a position higher than the height. The present invention is not limited to the above-described embodiment, and various types of design changes are possible.
The type of the crawler unit 2 may be a crawler unit that does not swing, and the type of the crawler-type traveling device is not limited to the type in which the crawler units are independently provided on the left and right, and the left and right sides of the track frame. The side frame provided on each side may be provided with a sprocket, an idler, a plurality of wheels, and a crawler belt.

Further, the vehicle adopting the present invention may be one having a crawler unit attached instead of the front wheels, one having four crawler units independently attached instead of the front and rear four wheels, and the like. Good.

[0056]

According to the present invention, it is possible to provide a crawler type traveling device having good turning performance.

[Brief description of drawings]

FIG. 1 is a side view of a crawler unit according to a first embodiment.

FIG. 2 is a rear cross-sectional view of the rear portion of the tractor.

FIG. 3 is a side view of the tractor.

FIG. 4 is a rear cross-sectional view of the upper portion of the crawler unit.

FIG. 5 is a side view of the sprocket.

FIG. 6 is a front sectional view of the sprocket.

FIG. 7 is a rear cross-sectional view of the lower portion of the crawler unit.

FIG. 8 is a side view of the lower portion of the crawler unit.

FIG. 9 is a cross-sectional view of the idler.

FIG. 10 is a side view of the crawler unit according to the second embodiment.

FIG. 11 is a rear view of the crawler unit.

FIG. 12 is a side view showing a state where the ground contact length of the crawler unit is shortened.

FIG. 13 is a side view of a crawler unit according to a third embodiment.

FIG. 14 is a side view showing a state where the ground contact length of the crawler unit is shortened.

FIG. 15 is a side view of a crawler unit according to a fourth embodiment.

FIG. 16 is a side view of a crawler unit according to another embodiment.

FIG. 17 is a side view of a crawler unit according to another embodiment.

[Explanation of symbols]

12 sprockets 13a idler 13b idler 14a-d rolling wheels 15 crawler belt 16 truck frame

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takashi Kobayashi             64 Ishizukitamachi, Sakai City, Osaka Prefecture Kubo Co., Ltd.             Ta Sakai Factory

Claims (10)

[Claims] 1. A crawler type traveling device in which a sprocket, an idler, and a crawler belt wound around a plurality of rolling wheels are circularly circulated in a circumferential direction by rotationally driving a sprocket. A crawler type traveling device characterized in that the ground contact length of the crawler belt at the time of traveling is shorter than the ground contact length of the crawler belt at the time of traveling on flexible ground by the rolling wheels. 2. A crawler-type traveling device in which a sprocket, an idler, and a crawler belt wound around a plurality of rolling wheels are circulated and circulated in a circumferential direction by rotationally driving a sprocket. The crawler belt is characterized in that the crawler belt is grounded by a smaller number of rolling wheels than the number of provided rolling wheels when traveling on a paved road so that the grounding length of the crawler belt when traveling on a paved road surface becomes shorter with time. Crawler type traveling device. 3. A crawler type traveling device in which a sprocket, an idler, and a crawler belt wound around a plurality of rolling wheels are circulated around in a circumferential direction by rotationally driving the sprocket. Among them, at least the wheel located at the front and rear direction end,
A crawler-type traveling device characterized in that it is supported at a position higher than other rolling wheels so that the ground contact length of the crawler belt when traveling on a pavement road is shorter than when traveling on a flexible ground. 4. A track frame is disposed below the sprocket, and an idler is supported in front of and behind the track frame, and a plurality of wheels are supported between the front and rear idlers of the track frame to drive the sprocket to rotate. As a result, in the crawler type traveling device in which the crawler belt wound around the sprocket, the idler, and the rolling wheels is circulated and circulated in the circumferential direction, the rolling wheels located at the front and rear ends of the rolling wheels are A crawler-type traveling device characterized in that front and rear idlers are supported so that their lower ends are positioned higher than the lower ends of other rolling wheels. 5. A crawler type traveling device in which a crawler belt wound around a sprocket, an idler and a plurality of rolling wheels is circulated around in a circumferential direction by rotationally driving a sprocket. A crawler type traveling device characterized in that a mechanism for changing the ground contact length is provided. 6. The crawler type traveling device according to claim 5, wherein the ground contact length of the crawler belt is variable during turning so that the ground contact length of the crawler belt is shorter than that during straight running. 7. A track frame is provided below the sprocket, the track frame being swingably supported around a horizontal axis, and the idler is supported in front of and behind the track frame, and between the front and rear idlers of the track frame. By supporting multiple rolling wheels and rotating the sprocket,
In a crawler-type traveling device in which a crawler belt wound around a sprocket, an idler, and a rolling wheel is circulated and circulated in a circumferential direction, the height of the lower end of the idler is the lower end of the rolling wheel adjacent to the idler. The idler is supported so as to be higher than the height, and by forcibly swinging the track frame around the swing axis, the crawler belt is grounded by the idler and the rolling wheels near the idler. Thus, the crawler belt traveling device is configured such that the ground contact length of the crawler belt is shortened. 8. A crawler type traveling device in which a sprocket, an idler, and a crawler belt wound around a plurality of rolling wheels are circulated and circulated in a circumferential direction by rotationally driving the sprocket. A crawler type traveling device characterized in that the ground contact length of the crawler belt is made variable by supporting the vertical position adjustment. 9. A crawler type traveling device in which a crawler belt wound around a sprocket, an idler, and a plurality of rolling wheels is circulated and circulated in a circumferential direction by rotationally driving a sprocket. The crawler belt traveling device is characterized in that the grounding length of the crawler belt is variable so that the grounding length of the crawler belt becomes shorter when the vehicle speed becomes faster than that. 10. A traveling method of a crawler type traveling device, wherein a crawler belt wound around a sprocket, an idler and a rolling wheel is circularly circulated in a circumferential direction by rotationally driving a sprocket. A traveling method of a crawler type traveling device, characterized in that the contact length of the crawler belt is shortened to make a turn.