JP2020026182A - Crawler type travel device and work vehicle - Google Patents

Abstract

To provide a crawler type travel device and work vehicle, capable of preventing reduction in a contact area even if a load becomes larger.SOLUTION: The crawler type travel device includes: a front axle 21 rotatingly driven ; a drive shaft outer case 22 rotatably supporting the front axle 21; a drive wheel 23 installed on the front axle 21; a plurality of track rollers 24, 24 disposed under the drive shaft 23 and oscillatably constituted around a truck frame shaft 242 parallel to the drive shaft 21; a pair of idling rollers 25, 26 arranged on each of the front and rear of the track rollers 24, 24 and constituted oscillatably around the front axle 21; and a running crawler 27 tensed on the drive shaft 23, the track rollers 24, 24 and the idling rollers 25, 26.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a crawler traveling device and a work vehicle provided with the crawler traveling device.

  Patent Literature 1 below discloses a tractor having a crawler traveling device instead of a rear wheel, in which a swing shaft is provided below a drive shaft, and a tension wheel, an idle wheel, and a ground contact roller are provided on a track frame via the swing shaft. A configuration having a ring is disclosed. In this tractor, the tension wheel, the idle wheel, and the ground wheel are swingable around the swing shaft together with the track frame.

Japanese Patent No. 60000229

  However, in Patent Literature 1, since the entire track frame swings, when the load at the time of work increases, the front part of the crawler rises and only the rear part comes into contact with the ground, and the contact area decreases, and the running performance decreases. There was a problem.

  In view of the above, an object of the present invention is to provide a crawler-type traveling device and a work vehicle that can prevent a decrease in a ground contact area even when a load increases.

The crawler traveling device of the present invention is a drive shaft that is rotationally driven,
A drive shaft outer case rotatably supporting the drive shaft,
A drive wheel attached to the drive shaft,
A plurality of track rollers arranged below the drive wheel and configured to be swingable around a swing axis parallel to the drive shaft,
A pair of idler rollers respectively arranged before and after the track roller and configured to be swingable around the drive shaft,
And a traveling crawler stretched over the drive wheel, the track roller, and the idler roller.

  According to this configuration, the traveling crawler in the area below the track roller is grounded during normal traveling. On the other hand, when the load is large, the pair of idler rollers swings around the drive shaft, one idler roller rises, the other idler roller descends, and the area below the other idler roller moves downward. Since the traveling crawler also comes into contact with the ground, the contact area is increased, and the running performance is improved.

In the crawler-type traveling device of the present invention, a support member for swingably supporting the idler roller around the drive shaft,
A biasing means provided on the drive shaft outer case and biasing the support member in a swinging direction.

  According to this configuration, the swing of the idle roller can be set appropriately.

In the crawler-type traveling device of the present invention, a support member for swingably supporting the idler roller around the drive shaft,
A first regulating member provided on the drive shaft outer case to regulate the swing of the support member.

  According to this configuration, the swing range of the idle roller can be restricted.

In the crawler traveling device of the present invention, a track frame that rotatably supports the track roller,
A track frame shaft that swingably supports the track frame on the drive shaft outer case,
A second regulating member provided on the track frame shaft to regulate the swing of the track frame.

  According to this configuration, the swing range of the track frame can be restricted.

  A work vehicle according to the present invention includes any one of the above crawler-type traveling devices at a front portion and / or a rear portion of a body.

  According to this configuration, the traveling crawler in the area below the track roller is grounded during normal traveling. On the other hand, when the load is large, the pair of idler rollers swings around the drive shaft, one idler roller rises, the other idler roller descends, and the area below the other idler roller moves downward. Since the traveling crawler also comes into contact with the ground, the contact area is increased, and the running performance is improved.

It is a left side view showing the whole work vehicle composition concerning this embodiment. It is a front view showing an example of a crawler type traveling device. It is AA sectional drawing of the crawler type traveling device shown in FIG. It is BB sectional drawing of the crawler type traveling apparatus shown in FIG. It is a mimetic diagram for explaining an operation effect of a crawler type traveling device concerning this embodiment. It is a front view showing an example of a crawler type traveling device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view of a work vehicle 1 to which a crawler traveling device according to the embodiment is applied. Although the work vehicle 1 is a tractor in the present embodiment, the work vehicle 1 is not particularly limited as long as it is a work vehicle to which the crawler traveling device of the present invention can be applied. In addition to the tractor, a rice transplanter, a combine, a civil engineering / construction work device Alternatively, a riding work vehicle such as a snowplow may be used. In the following description, the left side in the forward direction of the work vehicle 1 is simply referred to as “left” or “left side”, and the right side in the forward direction is simply referred to as “right” or “right side”.

  The work vehicle 1 includes a body frame 10a whose longitudinal direction is the front-back direction. A front axle case 10b is supported at a front portion of the body frame 10a, and a pair of left and right crawler-type traveling devices 10c, 10c is supported by the front axle case 10b.

  A bonnet 10d is mounted above the front part of the body frame 10a, and an engine 10e is arranged in the bonnet 10d. As shown in FIG. 1, a cabin 10f is mounted behind the hood 10d and above a rear part of the vehicle body frame 10a. In the cabin 10f, a seat, a steering handle, and the like (not shown) are arranged.

  As shown in FIG. 1, a rear end of the vehicle body frame 10a is connected to a transmission case 10g below the cabin 10f. Rear axle cases 10h, 10h are fixed to both left and right sides of the transmission case 10g, and a pair of left and right crawler traveling devices 10i, 10i are supported by the rear axle cases 10h, 10h.

  After the power of the engine 10e is shifted by the transmission case 10g, the power is transmitted to the pair of left and right crawler traveling devices 10c, 10c via the front axle case 10b, and is also transmitted to the pair of left and right crawler traveling via the rear axle cases 10h, 10h. It is transmitted to the devices 10i, 10i. By transmitting the power of the engine 10e, the front and rear crawler traveling devices 10c and 10c and the crawler traveling devices 10i and 10i are driven, and the work vehicle 1 travels. Further, after the power of the engine 10e is shifted by the transmission case 10g, it is also transmitted to a working machine such as a tilling device (not shown) mounted on the vehicle body frame 10a. By transmitting the power of the engine 10e, the working machine is driven.

  Next, the configuration of the front crawler traveling devices 10c, 10c will be described. FIG. 2 is a front view of the left crawler traveling device 10c. FIG. 3 is a sectional view taken along line AA of the crawler traveling device 10c of FIG. 2, and FIG. 4 is a sectional view taken along line BB of the crawler traveling device 10c of FIG.

  The crawler-type traveling device 10c includes a front axle (corresponding to a drive shaft) 21 that is driven to rotate, a drive shaft outer case 22 that rotatably supports the front axle 21, and a drive wheel 23 attached to the front axle 21. , A plurality of track rollers 24 disposed below the drive wheel 23, a pair of idler rollers 25 and 26 respectively disposed before and after the track roller 24, and the drive wheel 23, the track roller 24 and the idler roller 25, 26 and a traveling crawler 27 that is stretched between them. In FIG. 2, the drive wheels 23 are indicated by two-dot chain lines.

  The front axle 21 is disposed so as to penetrate the drive shaft outer case 22 outward from the front axle case 10b, and a drive wheel 23 is fixed to a tip 21a thereof. A bevel gear 211 is connected to a base end 21 b of the front axle 21. The bevel gear 211 is meshed with a bevel gear (not shown) in the front axle case 10b.

  The drive shaft outer case 22 rotatably supports the front axle 21 together with the front axle case 10b. When viewed from the axial direction of the front axle 21, the drive shaft outer case 22 includes a circular portion 22a that covers the bevel gear 211, and a tapered portion 22b that extends downward from the circular portion 22a. The front axle 21 is rotatably supported by the circular portion 22a, and a track frame shaft 242 described later projects from the tapered portion 22b.

  The driving wheel 23 is driven to rotate by the driving force of the front axle 21. The rotational driving force of the driving wheel 23 is transmitted to the traveling crawler 27 to rotate the traveling crawler 27.

  The plurality of track rollers 24 are rotatably supported by the track frame 241. In the present embodiment, two track rollers 24 are supported on the front and rear portions of the track frame 241 respectively. The track frame 241 is disposed below the driving wheels 23. The track frame 241 is provided with a regulating shaft 241a extending in the left-right direction toward the drive shaft outer case 22 side.

  The track frame 241 is supported by a track frame shaft 242 (corresponding to a swing axis) so as to be swingable about an axial center along the left-right direction. Therefore, even in a field with irregularities, the traveling crawler 27 in the area below the track rollers 24 can freely contact the ground.

  The track frame shaft 242 is arranged to be parallel to the front axle 21. The base end 242 a of the track frame shaft 242 is fixed to the drive shaft outer case 22. The base end 242a of the track frame shaft 242 projects through the drive shaft outer case 22, and a regulating plate 243 (corresponding to a second regulating member) is fixed to the projecting portion 242b. I have. The regulating plate 243 is a plate-like member having a concave portion 243a formed at a lower portion as shown in FIG. The regulating shaft 241a of the track frame 241 is disposed in the concave portion 243a, so that when the track frame 241 swings more than a certain amount, the regulating shaft 241a is brought into contact with the concave portion 243a to swing the track frame 241. Restrict within a certain range.

  An auxiliary member 244 is connected to the tip 242c of the track frame shaft 242. The lower end portion 244a of the auxiliary member 244 fixedly supports the distal end portion 242c of the track frame shaft 242, and the upper end portion 244b of the auxiliary member 244 rotatably supports the distal end portion 21a of the front axle 21.

  The idle roller 25 is disposed in front of the track frame 241. The crawler traveling device 10c includes a first bracket 251 that rotatably supports the idler roller 25. The first bracket 251 has an arch shape with a cross section open at the lower side, and the idling roller 25 is supported by the arch shape portion.

  The idle roller 26 is arranged behind the track frame 241. The idle roller 26 is rotatably supported by the second bracket 261. The second bracket 261 has an arched cross section with an open lower side, and supports the idler roller 26 at the arched portion.

  The idle rollers 25 and 26 are swingably supported by the support member 28 around the front axle 21. The idle rollers 25 and 26 swing around the front axle 21 so that the traveling crawler 27 in a region below the idle rollers 25 and 26 comes into contact with the ground to support the load of the work vehicle 1 and the idle position. The posture can be changed to a non-supporting posture in which the traveling crawler 27 in the region below the rolling rollers 25 and 26 does not touch the ground. The support member 28 is fixed at intervals around a cylindrical portion 281 rotatably supported by the drive shaft outer case 22, a flange portion 282 protruding from the outer periphery of the cylindrical portion 281, and around the flange portion 282. The front arm 283 and the rear arm 284 are provided.

  The cylindrical portion 281 is rotatably fixed to the outer periphery of the drive shaft outer case 22 that supports the front axle 21 via a bush. As shown in FIG. 2, the flange portion 282 has a substantially inverted triangular shape when viewed from the axial direction of the front axle 21. However, a notch 282d is formed at the lower end of the flange 282.

  Two height adjusting bolts 285, 285 are protruded from an upper surface 282a of the flange portion 282. The height adjusting bolts 285, 285 are arranged before and after the cylindrical portion 281 respectively. By rotating the height adjusting bolts 285, 285, the height of the bolt head can be changed.

  The forearm portion 283 is fixed to a front surface 282b of the flange portion 282. The forearm portion 283 is configured by a plurality of plate members. The distal end of the forearm 283 supports the first bracket 251 movably in the direction in which the traveling crawler 27 is tensioned. A disc spring 252 for urging the idle roller 25 in the direction in which the traveling crawler 27 is tensioned is provided between the forearm portion 283 and the first bracket 251.

  The rear arm 284 is fixed to a rear surface 282c of the flange 282. The rear arm portion 284 is configured by a plurality of plate members. The tip of the rear arm 284 supports the second bracket 261.

  A leaf spring 29 (corresponding to urging means) for urging the support member 28 in the swing direction is provided above the circular portion 22a of the drive shaft outer case 22. The leaf spring 29 is arranged above the support member 28. The leaf spring 29 has an elongated shape in the front-rear direction, and a center part in the front-rear direction is fixed to the drive shaft outer case 22 via a mounting member 291. The mounting member 291 has an arc shape having a smaller diameter than the outer diameter of the circular portion 22a of the drive shaft outer case 22 and a larger diameter than the outer diameter of the cylindrical portion 281 of the support member 28. Is fixed to a leaf spring 29.

  The bolt heads of the height adjusting bolts 285 and 285 of the support member 28 abut against the lower surfaces of the front end and the rear end of the leaf spring 29. Thereby, the leaf spring 29 can urge the support member 28 in the swing direction. Further, the urging force can be adjusted by changing the height of the height adjustment bolts 285, 285. In the stationary state shown in FIG. 2, the support member 28 is urged by a leaf spring 29 such that the lower ends of the idle rollers 25 and 26 are located above the lower ends of the track rollers 24. That is, in the crawler-type traveling device 10c, in the stationary state, the traveling crawler 27 in the region below the idle rollers 25 and 26 does not contact the ground, and only the track roller 24 supports the load of the work vehicle 1.

  In addition, a regulation protrusion 221 (corresponding to a first regulation member) for regulating the swing of the support member 28 is provided below the circular portion 22 a of the drive shaft outer case 22. The restriction protrusion 221 protrudes outside the drive shaft outer case 22. The restricting protrusion 221 is disposed in the notch 282d of the support member 28, and thereby, when the support member 28 swings more than a certain amount, the notch 282d is brought into contact with the restricting protrusion 221 so that the support member 28 Limit swing within a certain range.

  FIG. 5 is a schematic diagram for explaining the operation and effect of the crawler traveling device 10c of the present embodiment. By configuring the front crawler traveling device 10c as described above, the following operation and effect can be obtained.

  In the stationary state or the state where the tractive force is small, as shown in FIG. 5A, only the traveling crawler 27 in the area below the track rollers 24, 24 contacts the ground. Therefore, the contact length of the traveling crawler 27 is short, and steering is possible.

  On the other hand, in a state where the forward pulling force is large, the idler rollers 25 and 26 swing forward as shown in FIG. 5B, so that the idler roller 25 on the front side rises and moves forward of the traveling crawler 27. And the rear idler roller 26 descends, and the traveling crawler 27 in the area below the rear idler roller 26 also comes into contact with the ground. As a result, the angle of attack in front of the traveling crawler 27 is increased, and the contact length is increased, so that the contact area is increased.

  Similarly, in a state where the traction force in the reverse direction is large, the idler rollers 25 and 26 swing backward as shown in FIG. Is increased, the front idler roller 25 descends, and the traveling crawler 27 in the area below the front idler roller 25 also comes into contact with the ground. As a result, the angle of attack behind the traveling crawler 27 is increased, and the contact length is increased, so that the contact area is increased.

  Next, the configuration of the rear crawler traveling devices 10i, 10i will be described. FIG. 6 is a front view of the left crawler traveling device 10i.

  The crawler traveling device 10i includes a rear axle (corresponding to a drive shaft) 31 that is driven to rotate, a drive shaft outer case 32 that rotatably supports the rear axle 31, and a drive wheel 33 attached to the rear axle 31. , A plurality of track rollers 34 disposed below the drive wheel 33, a pair of idler rollers 35 and 36 disposed before and after the track roller 34, respectively, the drive wheel 33, the track roller 34 and the idler roller 35, 36 and a traveling crawler 37 stretched over the vehicle.

  The configuration of the rear crawler traveling device 10i is substantially the same as the configuration of the front crawler traveling device 10c, and different configurations will be mainly described. The plurality of track rollers 34 are rotatably supported by the track frame 341. In the present embodiment, two track rollers 34 are supported on the front and rear portions of the track frame 341 respectively. The front and rear two track rollers 34, 34 are swingably supported at the front of the track frame 341 by a first swing shaft 3411. The rear two large and small track rollers 34, 34 are swingably supported at the rear of the track frame 341 by a second swing shaft 3412. Thus, the traveling crawler 27 in the area below the four track rollers 34 can freely contact the ground even in a field having irregularities.

[Other embodiments]
In the above-described embodiment, the crawler-type traveling device is provided at the front and rear portions of the body. However, the crawler-type traveling device may be provided only at the rear portion, and normal wheels may be provided at the front portion.

  In the above-described embodiment, two track rollers 24 and four track rollers 34 are provided. However, three or five or more track rollers may be provided.

  As described above, the embodiments of the present invention have been described with reference to the drawings. However, it should be considered that the specific configuration is not limited to these embodiments. The scope of the present invention is shown not only by the description of the embodiment but also by the claims, and further includes meanings equivalent to the claims and all modifications within the scope.

Reference Signs List 1 work vehicle 10b front axle case 10c crawler traveling device 10i crawler traveling device 21 front axle 22 drive shaft outer case 23 drive wheel 24 track roller 25 idle roller 26 idle roller 27 traveling crawler 28 support member 29 leaf spring 31 rear Axle 32 Drive shaft outer case 33 Drive wheel 34 Track roller 35 Idling roller 36 Idling roller 37 Traveling crawler 221 Restriction projection 241 Track frame 242 Track frame shaft 243 Restriction plate

Claims (5)

A drive shaft that is rotationally driven;
A drive shaft outer case rotatably supporting the drive shaft,
A drive wheel attached to the drive shaft,
A plurality of track rollers arranged below the drive wheel and configured to be swingable around a swing axis parallel to the drive shaft,
A pair of idler rollers respectively arranged before and after the track roller and configured to be swingable around the drive shaft,
A crawler-type traveling device, comprising: a traveling crawler stretched over the drive wheel, the track roller, and the idle roller. A support member that supports the idler roller so as to swing around the drive shaft,
The crawler-type traveling device according to claim 1, further comprising: a biasing unit provided on the outer case of the drive shaft and biasing the support member in a swinging direction. A support member that supports the idler roller so as to swing around the drive shaft,
3. The crawler-type traveling device according to claim 1, further comprising: a first regulating member provided on the drive shaft outer case and regulating swinging of the support member. 4. A track frame that rotatably supports the track roller,
A track frame shaft that swingably supports the track frame on the drive shaft outer case,
The crawler-type traveling device according to any one of claims 1 to 3, further comprising: a second regulating member provided on the track frame shaft, for regulating swing of the track frame. A work vehicle provided with the crawler-type traveling device according to any one of claims 1 to 4 at a front portion and / or a rear portion of a body.

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