JP3919669B2 - Crawler travel device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a crawler traveling device mainly used for a tractor.
[0002]
[Prior art]
Propulsion lugs are formed in various patterns on the ground contact surface of the rubber crawler belt used in the crawler traveling device, for example, a long lug that reaches the belt outer end and a short lug that does not reach the belt outer end. Are alternately arranged in the belt circumferential direction (see Patent Document 1), and the U-shaped lugs extending from the belt width center to the belt outer end are staggered (see Patent Document 2). In both cases, by increasing the lug interval in the vicinity of the outer end of the crawler belt more than the lug interval at the center of the belt width, the soil retaining function at the site where the lug interval is large is enhanced to ensure propulsion, Driving vibration is suppressed by reducing the gap between the lugs at the center of the belt width.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 6-40361 (FIGS. 1, 8, 9, and 10)
[0004]
[Patent Document 2]
JP-A-6-329059 (FIG. 4)
[0005]
[Problems to be solved by the invention]
The lug protruding from the ground contact surface of the rubber crawler belt is generally formed at the top of the lug, with the front, rear, left and right side surfaces each being formed into a tapered surface for reasons of molding and strength. The flat ground contact surface is formed in a shape that is slightly smaller than the planar shape of the entire lug.
[0006]
When running on pastures with a crawler traveling device with a crawler belt wound around such a rug pattern, the outer edge corners of the lug are placed on the grassland when the rug reaching the outer edge of the belt rolls up and rotates along the rear wheel. By rotating upward from the state of biting into a circular arc locus, a part of the grass was scraped up with the roots, and the running track was likely to be rough. In other words, the outer end of the crawler belt is easily bent by the ground reaction force, and for this reason, when the outer end corner of the bent lug comes out to the ground, it is elastically restored along with the release of the ground pressure. One of the pastures was flipped up by the displacement combined with the displacement.
[0007]
The present invention has been made paying attention to such points, and can travel with sufficient propulsive force on a soft pasture and can suppress the roughening of the traveling trace. An object of the present invention is to provide a crawler traveling device.
[0008]
[Means for Solving the Problems]
[0009]
The crawler traveling device of the invention according to claim 1 is arranged in the shape of a letter C narrowed in the belt forward rotation direction on the outer peripheral surface of the rubber crawler belt, and the lugs are arranged in a staggered manner,
To the outer end portion of the top grounding surface of the lug, the front edge side and the rear edge side in the belt forward rotation direction of the lug and toward the spreading direction opposite to the tapered shape of the C shape An inclined grounding surface portion formed by an inclined surface is provided.
[0010]
According to the above configuration, it is possible to run with less vibration by reducing the pitch between the long lugs and the short lugs alternately arranged in the belt circumferential direction, and in the vicinity of the belt outer end, the belt is moved back and forth near the belt outer end. The holding length of the soil between adjacent long lugs is increased, so that the cutting (shearing) of the soil at this portion is suppressed, and as a result, the propulsive force is improved and the slip is suppressed.
[0011]
In addition, when the crawler belt is rolled up along the rear wheel when traveling forward on a pasture, the outer edge of the long rug that has digged into the soil tends to dig up the root of the pasture. Since an inclined ground contact surface portion directed rearward and outward is formed at the outer end portion of the ground , the above-described digging of the root portion is suppressed.
[0012]
Therefore, according to the first aspect of the invention, it is possible to travel on the pasture with sufficient propulsive force, and it is possible to suppress the running trace from being rough.
[0013]
According to a second aspect of the present invention, there is provided the crawler traveling device according to the first aspect of the invention, wherein the lug on the outer peripheral surface of the belt is a long lug formed from the belt width intermediate portion to the belt outer end, and the belt width intermediate portion to the belt outer side. It is composed of short lugs that extend to the front of the end, and these long lugs and short lugs are arranged in a zigzag shape with a tapered shape that narrows in the belt forward rotation direction. is there.
[0014]
According to the above configuration, the ground contact state by the lug group is continuous in the belt circumferential direction, and the vibration when the ground rolling wheel rolls and moves on the belt inner peripheral surface is reduced.
[0015]
Therefore, according to the second aspect of the invention, the above-mentioned effect of the first aspect of the invention can be brought about, and a more comfortable running can be achieved.
[0016]
According to a third aspect of the present invention, the crawler traveling device according to the second aspect of the present invention is such that the outer end portion of the long lug arranged in a C-shape is bent so as to be substantially perpendicular to the belt circumferential direction. is there.
[0017]
According to the said structure, the holding | maintenance function of the soil between long lugs adjacent back and forth near the belt outer end becomes still higher.
[0018]
Therefore, according to the invention of claim 3, while bringing about the above-mentioned effect of the invention of claim 2, the propulsion ability in the soft pasture is further improved.
[0019]
According to a fourth aspect of the present invention, in the crawler traveling device according to the second or third aspect of the present invention, an inclined ground contact surface portion extending in the belt forward rotation direction is formed at a front end portion of the long lug and the short lug in the belt forward rotation direction. It is what is.
[0020]
According to the above configuration, when the crawler belt is rotated forward, the ground contact is started from the inclined ground contact surface portion at the front end of the lug, so that the grazing into the pasture is smoothly performed.
[0021]
Therefore, according to the invention of claim 4, the above-mentioned effect of the invention of claim 2 or 3 is brought about, and it is further effective in suppressing the roughness of the running trace.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a tractor equipped with a crawler traveling device according to the present invention. This tractor is mainly used for pasture harvesting work, etc., and has a structure in which crawler traveling devices 2 are mounted in place of the left and right rear wheels of the four-wheel drive type tractor main body 1, respectively. Although not shown, a working device such as a grass cutting device or a grass collecting device is connected to the tractor main unit 1.
[0023]
In the crawler traveling device 2, a rubber crawler belt 8 is wound around a drive wheel 3, a front end tension wheel 4, a rear wheel 5, a grounding wheel 6 group, and a guide wheel 7 in a triangular shape. The drive wheel 3 is connected to a drive shaft 10 mounted on the rear axle case 9 of the tractor main machine 1, and the tension wheel 4, the rear end wheel 5, the ground wheel 6 group, The guide wheel 7 is mounted and supported on a track frame 11 that is swingably connected to a rear axle case 9 about a horizontal fulcrum X.
[0024]
Driving protrusions 12 are projected at a constant pitch in the circumferential direction at an intermediate portion in the width direction of the inner peripheral surface of the crawler belt 8, and driving pins 13 are laterally arranged at a constant circumferential pitch at the outer peripheral portion of the driving wheel 3. The crawler belt 8 is rotated forward or backward by engaging a driving pin 13 with the driving projection 12 and driving the driving wheel 3 forward or backward.
[0025]
Further, on the outer peripheral surface of the crawler belt 8, a propulsion lug 15 is projected in a pattern shown in FIG. The propulsion lug 15 includes a long lug 15a extending from the center of the belt width to the belt outer end and a short lug 15b extending from the center of the belt width to the belt outer end alternately in the belt circumferential direction, They are arranged in a zigzag pattern in a C shape narrowing in the rotation direction F. Further, the vicinity of the outer end of the long lug 15a, that is, the long lug portion extended outward from the short lug 15b is bent so as to be substantially perpendicular to the belt circumferential direction.
[0026]
As described above, the long lugs 15a and the short lugs 15b are alternately arranged in the belt circumferential direction, so that the soil retention length between the long lugs 15a adjacent to each other in the vicinity of the belt outer end is increased. The cutting (shearing) of the soil at the leverage is suppressed, and as a result, the propulsive force is improved and the slip is suppressed. In particular, the long lug portion extended outward from the short lug 15b is bent so as to be substantially orthogonal to the belt circumferential direction, so that it is held between the long lugs 15a adjacent to each other near the belt outer end. The soil that has been removed becomes more difficult to collapse, and the soil retention function in the vicinity of the outer end of the long lug 15a is further enhanced. In addition, the long lugs 15a and the short lugs 15b are in the shape of a letter C that narrows in the belt forward rotation direction F, and the zigzag arrangement makes the lug group continuously ground and vibration Less travel is possible. Further, when the crawler belt 8 is wound up and rotated along the rear wheel 5 at the rear end of the traveling device during forward traveling, the lug group is opposite to the belt forward rotational direction even if dirt is adhered between the lugs. Since it spreads in the shape of a square, the attached soil is easily removed from between the rugs, and the carrying around of the soil can be reduced.
[0027]
Here, an inclined ground contact surface portion M2 toward the belt forward rotation direction F is formed at the inner end portions of the long lugs 15a and the short lugs 15b, and when traveling forward on the meadow, the long lugs 15a and the short lugs 15b When the end portion starts to touch the ground, the ground is smoothly grounded without going through the soil at the inner corner of the lug 15.
[0028]
In addition, an inclined grounding surface portion M1 extending in the C-shaped spreading direction is formed at the outer end portion of the top grounding surface S in the long lug 15a across the front edge side and the rear edge side in the belt forward rotation direction. When the crawler belt 8 is rolled up along the rear wheel 5 when traveling forward on the pasture, the root portion of the pasture may be dug up at the corner of the outer end portion of the long lug 15 that has digged into the soil. It is suppressed by the formation of the inclined ground contact surface portion M1.
[0029]
The tension wheel 4, the rear end roller 5, the grounded roller group 6, and the guide wheel 7 are configured as a so-called outer wheel type roller wheel in which a pair of left and right wheel bodies are arranged at regular intervals. The wheel is engaged with the drive protrusion 12 from the left and right, so that the lateral movement of the crawler belt 8 is restricted.
[0030]
Here, as shown in FIGS. 5 and 6, the left and right side surfaces of the driving projection 12 of the crawler belt 8 are divided into a lower half 12 a and an upper half 12 b, and the standing inclination angle α of the lower half 12 a is set. On the other hand, the standing inclination angle β of the upper half 12b is set small.
Further, an inclined guide surface c is formed near the outer periphery of the inwardly facing side surface of the grounding wheel 6 that faces the left and right side surfaces of the driving projection 12 in parallel with the side surface of the lower half portion 12a of the driving projection 12. . Then, in a state where the inner periphery of the crawler belt 8 is correctly in contact with the outer periphery of the grounding roller 6, the inclined guide surface c is opposed to the side surface of the lower half 12a in a range lower than the height of the lower half 12a. It is set. Further, the curvature curvature r1 of the standing inner corner of the driving protrusion 12 and the curvature curvature r2 of the outer peripheral end of the inclined guide surface c in the grounding roller 6 are set to be the same or substantially the same. Although not shown in the drawings, the other wheels (the tension wheel 4, the rear end wheel 5, and the guide wheel 7) other than the grounded wheel 6 also have the same inclined guide surface as the above specifications on the inward side surface. ing.
[0031]
When the driving protrusion 12 and the grounding wheel 6 are configured as described above, when the crawler belt 8 receives a thrust force and travels down on a side slide when traveling on a flat ground, as shown by a solid line in FIG. The inclined guide surface c of the ground roller 6 is in contact with the side surface of the lower half portion 12a of the driving projection 12 so that the outer peripheral end of the inclined guide surface c is in close contact with the standing inner corner portion of the twelve. Since the area is sufficiently smaller than the entire area of the side surface of the driving projection 12 and the thrust force generated when traveling on flat ground is not so large, the side surface of the lower half portion 12a of the driving projection 12 and the inclined guide of the grounding wheel 6 are provided. The frictional heat generated at the contact portion with the surface c is relatively small, and the strength of the driving projection 12 is not reduced by the frictional heat even when traveling at high speed.
[0032]
Further, in the case of turning the body, running on an inclined land, or plowing work that runs in a laterally inclined posture with one wheel dropped on a tilling trace, the grounding wheel 6 is shifted upward relative to the crawler belt 8. However, since the inclined guide surface c of the grounding roller 6 is lower than the lower half 12a of the driving projection 12, it is used for the relative vertical movement up to the height indicated by the phantom line in FIG. There is no change in the contact area between the lower half portion 12a of the protrusion 12 and the inclined guide surface c of the grounding wheel 6, and the thrust load is reliably supported by the lower half portion 12a having a large thickness and high rigidity in the lateral direction.
[0033]
If contour running (inclined running), sudden turning, etc. are performed, the crawler belt 8 may be deformed in the lateral direction, causing a deviation in the arrangement of the driving projections 12. When 6 is engaged, a phenomenon (galling) that the grounding wheel 6 gets on and bites into the upper end corner of the driving projection 12 that is displaced is likely to occur.
Further, when the crawler traveling device 2 enters and exits the plowing groove, the driving protrusion 12 is used when the grounding wheel 6 is lifted with respect to the crawler belt 8 and then engaged with the next driving protrusion 12. The galling is likely to occur due to the positional deviation. Further, even when one side end of the crawler belt 8 gets over a relatively small obstacle such as a stone, a part of the crawler belt 8 is pushed up and deformed, thereby causing the positional deviation of the driving projection 12. When the grounding wheel 6 is engaged with the driving protrusion 12, the galling may occur. However, as described above, since the upper half 12b of the driving protrusion 12 is particularly tapered, the driving protrusion 12 is easily slipped between the left and right wheel bodies of the grounding wheel 6, The grounding wheel 6 smoothly guides and engages with the misaligned driving projection 12 without generating “scratching”.
[0034]
In addition, the tapered shape with a small rising inclination angle β is formed only by the upper half 12b, and the lower half 12a has a large rising inclination angle α and a large thickness in the left-right direction. The strength of the projection 12 is high.
[0035]
[Other Embodiments] (1) The above embodiment exemplifies a case where the driving protrusion 3 provided on the inner peripheral surface of the crawler belt 8 is engaged by the driving wheel 3 to rotationally drive the crawler belt 8. A driving hole can be formed at a constant circumferential circumferential pitch in the intermediate portion in the width direction of the crawler belt, and the claw of the sprocket-like driving wheel can be engaged with the driving hole and driven to rotate.
[0036]
(2) The present invention is a rug pattern in which the long lugs 15a and the short lugs 15b are arranged in parallel in the left-right direction (see Patent Document 1), or the center of the belt width by arranging the U-shaped lugs in a staggered manner. It can also be applied to a rug pattern in which short lugs are arranged at a small pitch on the part and long lugs reaching the belt side end are arranged at a large pitch on the outer side of the belt width (see Patent Document 2). .
[Brief description of the drawings]
[Fig. 1] Overall side view of agricultural tractor [Fig. 2] Side view of crawler traveling device [Fig. 3] Vertical front view of crawler traveling device [Fig. 4] Vertical front view showing drive unit of crawler traveling device [Fig. 5] FIG. 6 is an enlarged front view showing a belt guide portion by a grounded roller when traveling on a flat ground. FIG. 7 is a grounded wheel in a state where the crawler belt is laterally moved. FIG. 8 is a plan view of the lug pattern. FIG. 9 is a cross-sectional view taken along line AA in FIG. 8. FIG. 10 is a perspective view showing a part of the crawler belt.
8 Crawler belt 15a Long lug 15b Short lug F Belt forward rotation direction M1 inclined ground surface M2 inclined ground surface S S Top ground surface

Claims (4)

On the outer peripheral surface of the rubber crawler belt, the lugs are arranged in a cross-shaped shape that narrows in the belt forward rotation direction, and in a staggered manner,
To the outer end portion of the top grounding surface of the lug, the front edge side and the rear edge side in the belt forward rotation direction of the lug and toward the spreading direction opposite to the tapered shape of the C shape A crawler traveling device provided with an inclined ground contact surface portion formed by an inclined surface .   The lug on the belt outer peripheral surface is composed of a long lug formed from the belt width intermediate portion to the belt outer end, and a short lug formed from the belt width intermediate portion to the front of the belt outer end. The crawler traveling device according to 1.   The crawler traveling device according to claim 2, wherein an outer end portion of the long lug arranged in a C shape is bent so as to be substantially orthogonal to the belt circumferential direction. The crawler traveling device according to claim 2 or 3, wherein an inclined ground contact surface portion extending in the belt forward rotation direction is formed at a front end portion of the long lug and the short lug in the belt forward rotation direction.

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