JPS6154625B2 - - Google Patents

Description

[Detailed description of the invention] (Field of technology) The present invention relates to a track belt for a tracked vehicle.

(Prior art) When one end roll of a pair of end rolls that supports and guides the endless track belt is rotated in a horizontal plane, one edge of the endless track belt expands and the other side edge stretches. Track strips that are shortened and curved to allow a tracked vehicle to turn are known in the art. The track strip has a central portion which extends parallel to the direction of travel of the tracked vehicle and can be bent with a curvature determined by its turning radius, and which is substantially inextensible in the longitudinal direction. FIG. 7 is an explanatory diagram showing the relationship between this type of endless track belt and a tracked vehicle (see Japanese Patent Publication No. 1983-6137). In the figure, reference numeral 3 denotes a steering frame rotatably attached to the chassis of the tracked vehicle with a pivot pin 5. In each steering frame 3,
A shaft 6 is attached to support an end roll 2 that supports and guides the endless track belt 10. 11 is an orbital element;
12 is a central portion of the endless track belt 10 that cannot be extended. When the steering frame 3 is rotated around the pivot pin 5, one side edge of the track band 10 is extended and the other side edge is shortened, causing the track band 10 to curve and the tracked vehicle to turn. do.

In the above-mentioned type of endless track belt, the side edges of the endless track belt are configured to be elastically expandable and retractable in order to uniformly and smoothly bend the endless track belt when the vehicle turns. For example, the track strip is accordion-folded on both sides of its central portion to provide elasticity in its plane.

Problems to be Solved by the Invention One of the disadvantages of the above-mentioned tracks is the tendency of the tracks to aggregate and bulge in parts, known as bagging. be. Needless to say, this movement of the track belt - this movement occurs especially when the vehicle turns -
This not only causes the problem that the vehicle deviates from the desired course, but also causes the problem that the track strip is prematurely damaged.

An object of the present invention is to provide an endless track belt that does not cause bagging like the previously known endless track belts.

More particularly, the object of the invention is to provide a track belt that automatically retracts on the inside of the turn and automatically extends on the outside of the turn, uniformly over the entire length of the track. be.

(Means for Solving the Problems) The present invention has a central part extending in the longitudinal direction of the track belt, which can be bent laterally to a curvature corresponding to the turning radius of the tracked vehicle, but not in the longitudinal direction. is configured so that it does not extend, and its both side edge portions are configured to be shorter than the length of the central portion and elastically expandable, thereby allowing the endless track belt to be installed between a pair of end rolls in a straight-travel position. When the tracked vehicle is turned, the both side edge portions are extended to generate a predetermined internal prestress in the both side edge portions, and when the track belt is bent for turning of the tracked vehicle, the side edge portions are expanded. is characterized in that the internal prestress decreases at the inner side edge portion of the turn, and increases at the outer side edge portion of the turn.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the figure, 10 indicates an endless track belt according to the present invention.
In the embodiment shown in FIGS. 1 and 2, the track belt 10 consists of a series of track elements 11 which are rotatably connected to one another in any manner known per se. The track strip 10 may also consist of a single piece, ie one track element.
Track element 11 includes halves 12, 13 and central part 1
It consists of 4. The series of central portions 14 of the track strip 10 join together to form the central portion of the track strip 10 and are substantially non-extensive. However, it can be smoothly bent to a curvature that matches the turning radius of the vehicle. The track elements 11 of the track band 10 are provided with holes 15 for the teeth of the support and/or traction gear (not shown) of the track band.

The track element halves 12, 13 are made of a suitable elastic material;
For example, it is made of plastic sheet materials such as polystyrene, polyvinyl chloride, polybutadiene, and polypropylene. The plastic sheet halves 12, 13 are pressed to compress them more strongly towards their edges, thereby creating a certain level of internal stress in these halves. half body 12 consisting of a plastic sheet;
13 is finally heat treated so that the internal stresses are completely relieved and half 1 of the track element 11 is
2 and 13 remain in the shape shown in FIG. A similar pressing and heat treatment is carried out in the case of a track strip consisting of a single track element, so that the track strip 10 is shorter at the edges compared to the center.

If a track strip 10 is assembled from the track elements 11 made as described above, and the track strip 10 is therefore straight and parallel to the running direction of the vehicle (FIG. 2), half of the track element 11 will be assembled. body 1
2 and 13, their tapered portions are elongated and a given internal prestress state is created at the edge portion of the track band 10. This condition tends to cause the track band to contract at the edge portion. A similar internal prestress condition occurs in a track belt consisting of a single track element treated in the manner described above. When a vehicle equipped with the endless track belt according to the present invention turns, the endless track belt 10 easily assumes a curved shape on the inside of the turn without bulging. The internal stress is, for example, selected such that at the minimum turning radius of the vehicle, the internal stress in the track strip 10 becomes approximately zero on the inside of the turn. Naturally, the internal stress state is chosen such that at the minimum turning radius of the vehicle there remains a small internal stress in the half body inside the turn of the track element of the track strip. The part of the track belt that is clearly outside the turn must be extended;
As a result, the internal stresses in the track outside the turn of the track 10 are higher than the initial prestress. This is exactly the same when the endless track belt 10 consists of one track element.

The halves 12, 13 of the track element 11 preferably consist of a number of elongate members 16 attached to each other. The elongate members 16 of the halves 12, 13 of the track element 11 preferably have a corrugated cross section 17 (FIGS. 3 and 4). This corrugated cross section has the effect that deformation can occur uniformly over the entire part. No abrupt local changes occur that could cause cracks in the track belt. In this state, the cross section is
It cannot be obtained in the case of a zigzag shape as described in the specification of Japanese Patent Publication No. 54-6137.

Both side edges of the track band 10 are surrounded by edge bands 18 made of a resilient material such as rubber.
The edge band 18 is preferably dimensioned so as to act at the same time as a limiting device for the lateral length of the track band 10.

Note that FIG. 4A is a cross-sectional view taken along the line '--' in FIG. 2, and FIG. 4B is a cross-sectional view showing a modification of FIG. 4A (the thickness is thicker than the edges). Fifth
The figure is a partial schematic diagram showing the connection structure of the track elements 11. Each track element 11 has toothed portions 26 provided at its end edges that engage with each other, and these toothed portions 26
They are connected by a connecting rod 28 that passes through them.

FIG. 6 is a partially cutaway developed plan view of the endless track belt 10 made of a single piece, that is, the entire synthetic resin sheet 20. The synthetic resin sheet 20 is shaped such that both side edges thereof are shorter than the central portion 22 thereof. In the figure, 24 is a hole provided in the center portion 22 in which the teeth of the traction gear engage, and 46
is a toothed portion that connects both end edges as shown in FIG.

(Effects of the Invention) According to the present invention, it is possible to completely prevent the occurrence of local bulges at the inner side edge portion of the turning when the vehicle turns, thereby improving the steering performance of the vehicle and extending the life of the track belt. can do.

In the above description, only one preferred embodiment has been described, but as will be apparent to those skilled in the art, various modifications may be made to the endless track belt of the present invention without departing from the scope of the claims of the present invention. Changes are possible.

[Brief explanation of the drawing]

Fig. 1 is a plan view schematically showing one track element of a track belt according to the present invention in a free state, and Fig. 2 shows a state in which it is mounted on the roll of a tracked vehicle and is substantially parallel to the running direction of the vehicle. FIG. 3 is an enlarged sectional view taken along the line - of FIG. 1, and FIG. 4 is an enlarged view taken along the line - of FIG. 2. Cross-sectional view, Figure 4A is the second
4B is a sectional view showing a modified example of FIG. FIG. 7 is an explanatory diagram showing the relationship between a conventionally known endless track belt and a tracked vehicle. 10: Track belt, 11: Track element, 12,1
3: half body, 14: central part, 16: elongated member, 1
8: Edge band.

Claims (1)

[Claims] 1. It is installed between a pair of end rolls, and when the end rolls are steered, one edge of the end roll is extended while the other side edge is shortened and moved to a curved position. a longitudinally extending central portion 14 which is configured to turn the tracked vehicle by turning the tracked vehicle, and which is capable of bending laterally to a curvature corresponding to the turning radius of the tracked vehicle but cannot extend in its longitudinal direction; ，
14,..., the both side edge portions are configured to be shorter than the length of the central portion and elastically expandable, so that the pair of ends where the endless track band is in the straight-travel position When installed between the rolls, both side edge portions are stretched to generate a predetermined internal prestress on both side edge portions, and the track belt 10 is curved for turning of the tracked vehicle. When the rotation occurs, the internal prestress decreases at the inner side edge portion of the turn,
An endless track belt, characterized in that the internal prestress is configured to increase at an outer side edge portion of the orbit. 2. The track strip consists of a number of track elements 11, the halves 12, 13 of each track element having a shape tapering towards their edges. The endless track belt described in Range 1. 3. The endless track belt according to claim 1, characterized in that the side edge portions consist of a single piece that is shorter than the central portion. 4. Claims 1 to 3, characterized in that when the track band curves to a curvature corresponding to the minimum radius of rotation of the tracked vehicle, the internal prestress on the inside of the turn almost disappears. An endless track belt as described in any of the above. 5. The endless track belt according to claim 2, characterized in that elastic edge bands 18 are attached to both side edges thereof. 6. According to claim 5, the elastic edge band 18 is dimensioned to such a length that it simultaneously acts as a side edge length limiting means of the track belt 10. endless track belt. 7 Each half 1 of the track element 11 of the track belt 10
2, 13 are a number of interconnected elongated members 1
6. The endless track belt according to any one of claims 2, 5, and 6, characterized in that it consists of 6. 8. Track belt according to claim 7, characterized in that the elongated member 16 has a corrugated cross-section.