JPH04201786A - Rubber crawler - Google Patents

Abstract

PURPOSE:To obtain a rubber crawler of impeding generation of a crack by forming an end groove part of U-shaped section in bottom part both ends of a groove part appearing in a running track, and improving a shape of the groove part provided between the running tracks of rolling rolls. CONSTITUTION:Core metals 2, transversely arranged at a right angle to the lengthwise direction, are buried in a rubber elastic unit 1 by which a rubber crawler is formed. Rubber-made lugs 3 are provided in a grounding surface side. Further, a pair of protrusions 6 are extended from the core metal 2 in a condition that an engaging hole is interposed. In a rolling wheel provided in a machine body, an upper surface 7 of the protrusion 6 serves as a running track 8. Here, concentrated stress, generated when the rolling wheel 20 passes on the running track 8, is generated in both ends especially appearing in the running track 8 in the bottom part of a groove part 10. In order to cope with the above, small U-shaped end groove parts 11, 12 are formed in both end parts.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application) The present invention relates to a rubber crawler, and more particularly to the structure of a rubber crawler for changing shoes used in civil engineering, Ii, etc.

(Prior art) Rubber crawlers have traditionally been widely used as running strips for 1M lagoons such as Funpine, and in recent years, they have been replaced by iron shoe crawlers as running strips for civil engineering, tsuki, etc.
Rubber crawlers have come to be used in conjunction with this.

Since such rubber crawlers have rubber lugs on the ground side, even when running on paved roads, they do not damage the road surface, and the rubber lugs act as a buffer against vibrations transmitted from the road surface. None, it offers a comfortable ride.

This rubber crawler differs from the links of iron shoe crawlers using connecting bins, in that core metals are arranged side by side at right angles to the crawler's longitudinal direction, and a steel cord surrounding this from the outside is embedded in a rubber elastic body. A rubber lug is simultaneously molded on the ground surface side, and a pair of protrusions are erected on the inner peripheral surface of the metal core and protrude from the rubber surface.

However, the wheels provided on the machine body may run on the upper surface of this protrusion, or may run on a running surface provided on the outside of this protrusion and integrated with the core metal. That is, the former has a running track on the upper surface of the protrusion, and the latter has a running track on the outside of the protrusion.

FIG. 1 is a plan view of a rubber crawler showing an example of the former;
FIG. 2 is a central sectional view in the longitudinal direction.

In the figure, the reference numeral l indicates a rubber elastic body formed of a rubber crawler, which is an endless body, and core metals 2 are arranged side by side at right angles to the longitudinal direction of the rubber elastic body 1.
Although not shown, a steel cord serving as a tensile member is similarly buried on the outside of the core metal 2, that is, on the ground surface side.

3 in the figure is a rubber lug provided on the ground surface side. 4 is an engagement hole with a sprocket tooth, and the core metal 2
The center part of the holder is the engaging part 5.

Furthermore, a pair of protrusions 6.6 extend from the core metal 2, sandwiching the engagement holes 4 with the sprocket teeth.

In this example, the protrusions 6, 6 on which the wheels 20 provided on the fuselage rest
This is an example in which the upper surface 7 is a running track 8, and in order to allow the transfer 20 to run as long as possible on this running track 8, the pair of protrusions 6.6, that is, the running track 8, are slightly shifted from each other in the longitudinal direction of the rubber crawler. This is what is being deployed.

Further, FIG. 3 is a plan view of a rubber crawler showing the latter example, in which a pair of protrusions 6.6 are arranged side by side from the core bar 2, and the running track 8 of the wheel is placed on the outside of the protrusions 6.6. It has a structure in which it extends from the core metal 2 and is exposed on the inner peripheral surface of the rubber crawler.

Now, the rubber crawler is endless and runs while being wrapped around the front and rear sprockets and idlers, but at this time, the rubber located on the inner peripheral side of the tensile body is subjected to large compressive strain.

Furthermore, the wheel 20 travels on this running track 8, and if the rolling wheel 20 is located approximately in the center of this running track 8 (section a in the figure), there is no problem; When reaching part b in the figure, the core bar 2 will tilt significantly to the right due to the weight of the machine transmitted from this transfer 20. On the other hand, if the wheel 20 is located at the left end (portion C in the figure), the core bar 2 will similarly tilt significantly to the left.

Since the rubber crawler is entirely made of the rubber elastic body 1, it suffers from compressive strain when it wraps around the sprocket and idler, as well as the left and right sides of the core bar 2 that occur when the wheels travel 2 degrees. The shaking strain is absorbed by the rubber elastic body 1, but especially in the rubber part 9 where the running tracks 8 of the adjacent core metals 2 face each other, the rubber part 9 is subject to repeated compression and tension. Cracks often occur in the rubber track, shortening the life of the rubber crawler.

(Problem) For this reason, in order to cope with this repeated compression and tension action, grooves extending in the width direction of the rubber crawler as shown by reference numeral 10 have been previously formed in the rubber portion 9. .

However, although there was an improvement effect by forming such a groove 10, there are still many troubles caused by cracks generated from this groove 10 in products that simply form a groove (and this may shorten the service life). There have been some cases where the length has been shortened.

(Objective) The present invention skillfully solves the problems caused by the prior art, and provides a rubber crawler that prevents the occurrence of cracks by improving the shape of the groove provided between the running tracks of the rolling wheels. is its purpose.

(Solution) The solution of the present invention is as follows. That is, the first aspect of the present invention is a rubber crawler having a core metal embedded in an endless rubber elastic body in a row perpendicular to the longitudinal direction of the rubber elastic body, and a rubber crawler having a core metal embedded on the inner circumferential side thereof extending from the core metal. Also, a running track of the rolling wheels is formed that extends beyond the width of the core metal, and a groove portion having a U-shaped cross section extending in the width direction of the rubber crawler is formed in the rubber portion of the butting portion of the running track between adjacent core metals. The rubber crawler is further characterized in that end grooves having a U-shaped cross section are formed at both ends of the bottom of the groove facing the running track, and a second aspect of the invention is a rubber elastic body having an endless shape. A rubber crawler having core metals buried side by side at right angles to the longitudinal direction of the rubber crawler, and a running track of rolling wheels extending from the core metal and projecting out from the width of the core metal on the inner circumferential side thereof. A groove with a U-shaped cross section extending in the width direction of the rubber crawler is formed in the rubber portion of the abutting portion of the running track between adjacent core metals, and a U-shaped cross section is formed at the center of the bottom of the groove.
This invention relates to a rubber crawler characterized by forming a letter-shaped central groove.

(Function) The present invention employs the above configuration, and in any of the inventions, the concentrated stress generated at both ends of the groove bottom facing the running track is reduced, and the compressive and tensile stress of the rubber is reduced. This prevents cracks from forming due to repeated action.

That is, in the first invention, by forming smaller end grooves in advance at both ends of the bottom of the groove where stress is concentrated, it is possible to disperse the concentrated stress occurring in the rubber in these parts. In this case, the concentrated stress generated in this part can be released by a small central groove provided at the center of the bottom of the groove, thereby reducing strain in each part.

(Concrete example) The present invention will be described in more detail based on the drawings.

FIG. 4 is an enlarged longitudinal sectional view of the protrusion 6 of the core metal 2, that is, the rubber crawler on the running track 8, showing an embodiment of the first invention, and FIG. 5 is a further enlarged sectional view of the groove 10. It is a diagram.

The plan view of this embodiment is the same as that of FIG. 1 described above, and the side view thereof is omitted because it is also the same except for the shape of the groove portion 10.

Now, in these figures, the concentrated stress that occurs when the wheels pass over the running track 8 occurs at the bottom of the groove 10, particularly at both ends facing the running track, and there are small U-shaped end grooves at both ends. 11.12.

In this example, the width w1 of the end groove portion 11.12 has a width of approximately 1/4·W with respect to the bottom width W1 of the groove portion 10,
On the other hand, the depth dl of the end groove portion 11.12 is approximately 1/4·Wl with respect to the bottom width W.

FIG. 6 is an enlarged sectional view of the groove portion 10 showing an embodiment of the second invention.

In this example, a smaller U-shaped central groove 13 is formed at the center of the bottom width W2 of the groove 10. The groove width W2 of the central groove portion 13 was 1/3·W with respect to the bottom width W2 of the groove portion 10, and the depth d was also 1/3·W2.

The above example is an example of a rubber crawler in which the upper surface 7 of the protrusion 6 extending from the metal core is used as the running track 8 for the wheels. It goes without saying that even in rubber crawlers of the type that run on tracks, it has become possible to similarly reduce the occurrence of cracks in the rubber parts.

(Experimental Results) In the embodiment of the first invention, the shape of the end groove portion 11.12 is such that its groove width W is 0, 15 W + < w , < 0 with respect to the groove width W of the groove portion 10 . 35
W.

This is particularly effective when the relationship is such that the crack occurrence rate can be reduced to 70% or less of the normal rate.

Of course, it is also related to the depth dl of this end groove portion 11.12.
In general, the larger this d, the more effective it is, but 51.
This also has its own limit due to its structure, and this groove width W of the groove portion 10
1-, a width of about -0,1WI <d, <0.35W+ is practical.

Further, in the embodiment of the second invention, the width W of the central groove portion 13 is
2&<, 0, . 3 W4
In the case of the relationship <wx < O,,,8Wz, the occurrence of cracks is reduced, and especially when W,2-/W is between 0.5 and 0.7, the incidence of cracks is less than half. This was confirmed.

In this invention, the depth d2 of the central groove portion 13 also greatly contributes to the effect, and the relationship of 0.2W2 < d, < 0.6Wz is often the case (in particular, d2 and W2 are approximately the same). It is usually taken as a thing.

(Effects) As described above, in the present invention, by specifying the shape of the groove formed in the rubber elastic body at the butt part of the running track of the rolling wheels, it is possible to alleviate the concentrated stress that occurs there. This product reduces the distortion, thereby reducing the occurrence of cracks that occur in the rubber elastic body, and improves the durability (life) of the rubber claw, and its industrial value is Extremely high.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a conventional rubber crawler, Fig. 2 is a central sectional view in the longitudinal direction of Fig. 1, Fig. 3 is a plan view showing another conventional example of a rubber crawler, and Fig. 4 is a plan view of a conventional rubber crawler. FIG. 5 is a further enlarged sectional view of the groove 10 of FIG. 4, and FIG. 6 is a groove 10 showing an embodiment of the second invention. FIG. 1...Rubber elastic body 2...Core metal 3...Lug 4...Engagement hole with sprocket tooth 5...Engagement part 6...Protrusion 7... ...Top surface of projection 8...Running track 9...Rubber portion 10 with which the running track is opposed...Groove portion 11.12...End groove portion 13...Central groove portion 20... - Rolling wheel Wr -Wm... Bottom width of the groove w1... Width of the end groove w2... Width d of the central groove,... Depth d2 of the end groove... Center groove Depth Patent Applicant Bridgestone Corporation

Claims (2)

[Claims] (1) A rubber crawler having core metals embedded in an endless rubber elastic body in rows and rows at right angles to the longitudinal direction of the rubber elastic body, the core metal extending from the core metal on the inner peripheral surface side of the rubber crawler. forming a running track for the rolling wheels that extends beyond the width of the track, and forming a groove portion having a U-shaped cross section extending in the width direction of the rubber crawler in the rubber portion of the abutting portion of the running track between adjacent core metals;
Furthermore, a cross section U is provided at both ends of the bottom of the groove facing the running track.
A rubber crawler characterized by having a letter-shaped end groove. (2) A rubber crawler having a core metal embedded in an endless rubber elastic body in a row perpendicular to the longitudinal direction of the rubber elastic body, the core metal extending from the core metal on the inner peripheral surface side of the rubber crawler. forming a running track for the rolling wheels that extends beyond the width of the track, and forming a groove portion having a U-shaped cross section extending in the width direction of the rubber crawler in the rubber portion of the abutting portion of the running track between adjacent core metals;
Furthermore, a rubber crawler characterized in that a central groove portion having a U-shaped cross section is formed at the center of the bottom of the groove portion.