JP5604436B2 - Rubber crawler - Google Patents

Description

  The present invention relates to a rubber crawler, and more particularly, to a rubber crawler having a driving protrusion engaging with sprocket teeth provided on an inner peripheral surface of a crawler main body and a core bar embedded in the crawler main body.

  2. Description of the Related Art Recently, rubber crawlers in which drive protrusions that engage with sprocket teeth attached to the drive shaft of a traveling machine body are formed on the inner peripheral surface of a crawler body and a cored bar is embedded in the crawler body are widely used. .

  FIG. 3 is a partial schematic side cross-sectional view of the crawler main body related to the rubber crawler disclosed in Patent Document 1. However, the state where the tooth portion of the sprocket is engaged with the drive protrusion of the crawler body is shown.

  A plurality of metal cores 12 are embedded in the crawler main body 10 at predetermined intervals in the circumferential direction of the crawler main body 10 in a posture in which the wing portions 12 a extend in the width direction of the crawler main body 10. A recess 20 is formed between the cored bar 12 and the cored bar 12 on the inner peripheral surface side of the crawler body 10. That is, the recesses 20 and the cored bar 12 are alternately arranged in the circumferential direction of the crawler body 12. A lug portion 26 is formed on the ground contact surface E side of the crawler body 10.

  A pair of projecting portions 12c and 12c projecting toward the inner peripheral surface of the crawler body 10 are formed at a substantially central portion of the core metal 12 in the width direction of the crawler body 10 (see also FIG. 4 described later). Is covered with the same rubber member as the crawler body 10 to form a pair of drive projections 14, 14. The drive projection 14 has a function of driving the crawler body 10 around in response to a rotational pressing force (drive force) from the tooth portion 32 of the sprocket 30 and a function of guiding a wheel (not shown). ing.

  The teeth 32 of the sprocket 30 are provided at equal intervals on the outer edge of the sprocket 30 and rotate in the direction indicated by the arrow A in FIG. Moreover, the depth of the recessed part 20 formed in the crawler main body 10 is slightly shallower than the depth in which the cored bar 12 is embedded, as shown in FIG. In other words, the height from the ground contact surface E to the bottom surface 20 a of the recess 20 is configured to be slightly higher than the height from the ground contact surface E to the bottom surface 22 of the core metal 12. Therefore, when the tooth portion 32 of the sprocket 30 applies a rotational pressing force to the drive protrusion 14, the tooth portion 32 also engages with the concave portion 20 as described above. A part is applied.

  FIG. 4 is a partial schematic development plan view of the crawler body. The recess 20 is formed in a substantially rectangular shape at a substantially central portion in the width direction of the crawler body 10. In FIG. 4, the region of the recess 20 is indicated by hatching. The length of the concave portion 20 in the width direction of the rubber crawler is a length straddling between the pair of drive protrusions 14 and 14. The tooth portion 32 of the sprocket 30 engages with the pair of drive protrusions 14 and 14 and the recess 20 also engages to apply a rotational pressing force (driving force), but the length of the tooth portion 32 in the rubber crawler width direction. Is substantially the same as the length of the recess 20 in the width direction of the rubber crawler or between the pair of drive protrusions 14, 14, and thus the tooth portion 32 is a pair of drive formed at the center in the width direction of the crawler body 10. The protrusions 14 and 14 are straddled.

  Further, between the pair of drive protrusions 14, 14, a flat part 18 between the protrusions and ridges 16, 16 are formed on both sides of the flat part 18 between the protrusions in the circumferential direction of the rubber crawler. With this raised portion 16, the contact area between the tooth portion 32 and the crawler body 10 can be increased, and the surface pressure applied by the tooth portion 32 can be reduced. In addition, although the groove part 36 is formed between a pair of drive projection parts 14 and 14, in these groove parts 36, mud, gravel, etc. are clogged between the recessed part 20 and a pair of drive projection parts 14 and 14. It is formed for so-called mud removal. Further, for the positioning of the cored bar 12 at the time of manufacturing the rubber crawler, or when the crawler main body 10 is wound around the sprocket 30 or idler (not shown) and the rubber member is deformed, the inner peripheral surface of the crawler main body 10 is deformed. It is also formed to prevent the strain from concentrating on the part. In addition, the groove part 36 and the protruding part 16 may be omitted depending on the usage environment of the rubber crawler, and are not necessarily required. FIG. 5 shows, as an example, a partial schematic development plan view of a crawler main body without a groove and a raised portion.

  FIG. 6 is a partial schematic front sectional view of the crawler body. However, the state where the tooth portion 32 of the sprocket 30 is engaged with the pair of driving projections 14 and 14 of the crawler main body 10 to apply a rotational pressing force (driving force) to the driving projection 14 is shown. A range in the width direction of the rubber crawler to which this driving force is applied is indicated by W. Since a large compressive force acts on the rubber member between the tooth portion 32 and the cored bar 12, the rubber member constituting the crawler body 10 is likely to be distorted. Thus, the tooth portion 32 and the cored bar 12 when the tooth portion 32 of the sprocket 30 is engaged with the drive projection portion 14 so that the inner peripheral surface of the crawler body 10 is not damaged and the durability is not easily deteriorated. The rubber thickness between the two is designed to be appropriate.

  A steel cord (not shown) is embedded in a reinforcing layer (not shown) that surrounds the cored bar 12 from the grounding surface side and exists endlessly in the circumferential direction of the crawler body 10. The crawler main body 10 is configured to smoothly circulate based on the driving force received from the sprocket 30 while restricting the circumferential extension of 10.

JP 2009-78796 A

  As described above, when the tooth portion 32 of the sprocket 30 is engaged with the pair of drive protrusions 14 and 14 of the crawler body 10 and a driving force is applied to the crawler body 10, the tooth portion 32 of the sprocket 30 and the core metal Since a large compressive force is applied to the rubber member interposed between the two members, the rubber thickness of that portion is designed to be optimum. However, as shown in FIG. 4, at the central part (core metal central part) 12b in the width direction of the crawler body of the core metal 12 and the base end part of the projection part 12c forming the drive projection part 14, the rubber member The thickness was different. That is, the thickness of the rubber member between the tooth portion 32 and the core metal 12 was different in the range where the tooth portion 32 of the sprocket 30 exerted the driving force. In FIG. 3, the difference in thickness is indicated by arrows t1 and t2. Therefore, the durability of the thin rubber portion corresponding to the base end portion of the protrusion 12c of the core metal 12 is inferior to the durability of the thick rubber portion corresponding to the core metal central portion 12b, and the thin portion is There was a concern about the end of life first.

  The present invention has been made in view of the above problems, and its object is to provide the sprocket teeth when the sprocket teeth engage with the drive protrusions of the rubber crawler and a driving force is applied to the rubber crawler. An object of the present invention is to provide a durable rubber crawler with a uniform rubber thickness of a rubber member interposed between a portion and a core metal.

In order to achieve the above object, a rubber crawler according to claim 1 has an endless belt-like crawler body, and a core metal embedded in the crawler body at a predetermined interval in the circumferential direction. The cored bar has a central portion, a pair of protrusions formed with the central portion interposed therebetween, and a wing portion extending a predetermined length on both sides of the base end portion of the pair of protrusions. In the state where the core metal is embedded in the rubber crawler body, the wing portion extends in the width direction of the crawler body, and the rubber member constituting the rubber crawler body is formed on the pair of protrusions. A pair of drive projections are formed so as to project on the inner peripheral surface side of the rubber crawler, and a pressing force is applied to the pair of drive projections by the rotation operation of the sprocket teeth to rotate the crawler body. In the rubber crawler, the core metal is the The width in the circumferential direction of the central portion existing between the pair of protrusions is made shorter than the width in the circumferential direction of the wing portion of the core metal, and at least to both outer sides of the base end portions of the pair of protrusions It is characterized in that the rubber thickness of the rubber member existing between the sprocket tooth portion and the cored bar is uniform during rotation of the sprocket tooth portion .

  With this configuration, the sprocket tooth portion exerts a driving force across the pair of drive protrusions. In this range, the rubber thickness of the rubber member existing between the sprocket tooth portion and the embedded core metal is uniform. Become. Therefore, when a rotational pressing force (driving force) is applied to the pair of driving projections by the sprocket teeth, the width of the core bar in the circumferential direction of the rubber crawler changes at the portion of the driving projection so far. However, the rubber member in the portion covering the protrusions is distorted and causes deterioration of the rubber member. However, the above configuration allows a uniform compressive force to be applied to the rubber member, resulting in an unfavorable rubber thickness. The deterioration of the rubber member due to the uniformity is prevented, and the durability of the rubber crawler is improved. Further, by reducing the central portion of the core bar, the core bar can be reduced in weight.

  The rubber crawler according to claim 2 is the rubber crawler according to claim 1, wherein a boundary portion between the central portion of the core metal and the wing portion is connected with a predetermined curvature. . Here, the predetermined curvature is preferably, for example, a curvature radius of 2 mm or more. By doing in this way, the lifetime of a metal core can be extended. When the curvature radius is set to 1 mm or less, stress concentrates on the boundary portion and rubber cracks are likely to occur inside the crawler body. Therefore, when the weight of the traveling machine body or the like is applied to the crawler body, it is possible to prevent stress concentration from occurring at the boundary portion between the central portion and the wing portion where the width of the core metal in the crawler circumferential direction is constant. Thus, it is possible to improve the durability of the rubber crawler.

  According to the rubber crawler of the present invention, the thickness of the rubber member interposed between the tooth portion and the cored bar is uniform when the tooth portion of the sprocket is engaged with the drive protrusion and a rotational pressing force is applied. In addition, since the compressive force is uniformly applied to the rubber member, the durability of the rubber crawler is improved, and the traveling machine body can be used for work and the like with confidence over a long period of time.

FIG. 4 is a partial schematic plan view of a crawler body according to an embodiment of the rubber crawler of the present invention. FIG. 4 is a partial schematic side sectional view of a crawler body according to an embodiment of a rubber crawler of the present invention. However, the state where the tooth portion of the sprocket is engaged with the drive protrusion of the crawler body is shown. It is a partial schematic side cross-sectional view of a crawler body according to a conventional rubber crawler. However, the state where the tooth portion of the sprocket is engaged with the drive protrusion of the crawler body is shown. FIG. 5 is a partial schematic plan view of a crawler body related to a conventional rubber crawler. FIG. 5 is a partial schematic plan view of a crawler body related to a conventional rubber crawler. However, it shows as an example about a thing without a groove part and a protruding part. It is a partial schematic front sectional view of a crawler body according to a conventional rubber crawler. However, the state where the tooth portion of the sprocket is engaged with the driving protrusion of the crawler body and the driving force is applied is shown.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the following embodiments.

  FIG. 1 is a partially developed plan view of a part of a crawler body according to the rubber crawler of the present invention. In particular, the portion where the cored bar is present is mainly shown. FIG. 2 is a partial schematic side view of the crawler body according to the rubber crawler of the present invention. However, the crawler body 10 shows an example in which the groove portion 36 and the raised portion 16 exist, and FIG. 2 shows that the tooth portion 32 of the sprocket 30 is engaged with the driving projection portion 14 and exerts a driving force. Show the state.

  The cored bar 12 is substantially the same except for a part shown in the background art. That is, the wing portion 12a is embedded in the circumferential direction of the crawler main body 10 at a predetermined interval in a manner that extends in the width direction of the crawler main body 10. On the inner peripheral surface side of the crawler body 10 and between the cored bar 12, a recess 20 is formed in which the tooth part 32 of the sprocket 30 is engaged. The recess 20 is formed in a substantially rectangular shape at the center in the rubber crawler width direction.

  The pair of protrusions 12c and 12c of the cored bar 12 are formed to protrude inward in the circumferential direction of the crawler body 10 and are covered with a rubber member to form a pair of drive protrusions 14 and 14. Between the pair of drive protrusions 14, 14, flat portions 18 between the protrusions and raised portions 16, 16 are formed on both sides of the flat portion 18 between the protrusions in the circumferential direction of the rubber crawler. As described above, the contact area between the tooth portion 32 and the crawler body 10 can be increased by the raised portion 16, and the surface pressure applied by the tooth portion 32 can be reduced. In addition, although the groove part 36 is formed between a pair of drive projection parts 14 and 14, in these groove parts 36, mud, gravel, etc. are clogged between the recessed part 20 and a pair of drive projection parts 14 and 14. It is formed for so-called mud removal. Further, the inner peripheral surface of the crawler main body 10 is positioned for positioning the cored bar 12 when manufacturing the rubber rubber crawler or when the crawler main body 10 is wound around the sprocket 30 or idler (not shown) and the rubber member is deformed. It is formed to prevent the strain from concentrating on the part.

  The core metal 12 of the present invention is different from the conventional core metal in the circumferential width of the rubber crawler. Conventionally, the central portion 12b of the metal core extends in the rubber crawler width direction with a constant width, and the width in the circumferential direction of the rubber crawler at the base end portion of the protrusion 12c of the metal core 12 constituting the drive protrusion 14 is small. When the tooth portion 32 applied a driving force to the crawler main body 10, the width in the circumferential direction of the rubber crawler changed within a range in which the driving force was exerted. Therefore, in the range where the driving force is applied, the thickness of the rubber member interposed between the tooth portion 32 and the cored bar 12 is different and not uniform. On the other hand, in the present invention, the metal core 12 has a width outside the range in which the proximal end portion of the projection 12c is in the rubber crawler width direction, that is, outside the range where the tooth portion 32 of the sprocket 30 outside the drive projection 14 exerts the driving force. In the range where the driving force is applied, the width in the circumferential direction of the rubber crawler is constant.

  With this configuration, the thickness of the rubber member of the core metal 12 and the tooth portion 32 is uniform within a range in which the tooth portion 32 of the sprocket 30 exerts a driving force. Here, when the tooth portion 32 of the sprocket 30 is engaged with the driving projection 14 and a driving force is applied, the rubber member covering the driving projection 14 and the pair of driving projections 14 and 14 exist. The rubber member constituting the wall portion of the recessed portion 20 is deformed by the pressing force, but the distance between the tooth portion 32 and the cored bar 12 is constant. In addition, the strength of the outer side of the base end portion of the protruding portion 12c of the core metal 12 is ensured, and the thickness of the rubber member interposed between the tooth portion 32 and the core metal 12 when a driving force is applied is constant. The range to be performed is preferably up to the outer side of the base end portion of the protruding portion 12c of the cored bar 12. However, if the problem of strength outside the base end of the projection 12c of the core metal 12 can be solved, the width of the core 12 is shortened beyond the base end outside of the projection 12c of the core 12 to the outside. Also good. In this case, the core metal 12 can be further reduced in weight.

  Therefore, when the tooth portion 32 of the sprocket 30 is engaged with the drive protrusion 14 and a driving force is applied, a large compressive force is applied to the rubber member existing between the tooth portion 32 and the cored bar 12. However, since the compression force is the above-mentioned distance, that is, the distance between the tooth portion 32 and the cored bar 12, and the thickness of the interposed rubber member is uniform, the uniform compression force is applied to the rubber member. Thus, deterioration of the rubber member due to uneven rubber thickness is prevented. In other words, conventionally, there has been a concern about the deterioration of the rubber member at the base end portion of the drive protrusion 14, but there is no concern in this embodiment. As a result, the durability of the rubber crawler 8 is improved as compared with the conventional one.

  Moreover, in FIG. 1, the length of the area | region extended in the width direction of the crawler main body 10 of the center part 12b of the metal core 12 is shown by Wp and W1. However, Wp relates to the metal core shown in the background art, and W1 relates to the metal core 12 according to the present invention. W1 is a range to both outer sides of the base end part of the projection part 12c. As can be seen from the figure, the cored bar 12 of the present invention has a longer length of the central part 12b than the conventional cored bar. Thereby, the durability of the rubber crawler is improved as described above, and the weight of the core metal is reduced.

  Further, the core metal 12 has a circumferential width of the crawler main body of the wing portion 12 a so that the rotation pressing force by the tooth portion 32 is applied through a rubber member constituting the rubber crawler main body 10. It is configured to be larger than the width in the direction. Therefore, the durability of the crawler body 10 can be improved without lowering the effect of the steel cord (not shown) embedded in the crawler body 10. That is, the adhesiveness between the steel cord and the cored bar 12 can be improved by making the width of the wing 12a in the circumferential direction of the rubber crawler larger than the central part 12a of the cored bar. The crawler body 10 can smoothly rotate based on the driving force received from the sprocket 30 while restricting the extension of the crawler.

  Moreover, the wing | blade part 12a of the metal core 12 and the metal core center part 12b are connected with a predetermined curvature. Here, the predetermined curvature is preferably, for example, a curvature radius of 2 mm or more. By doing in this way, the lifetime of a metal core can be extended. When the curvature radius is set to 1 mm or less, stress concentrates on the boundary portion and rubber cracks are likely to occur inside the crawler body. With this configuration, even when the weight of the traveling machine body is applied to the rubber crawler 8, it is possible to prevent the concentration of stress at the boundary portion. Accordingly, it is possible to improve the durability of the crawler body 10 while preventing the occurrence of stress concentration.

  According to the present embodiment, the circumferential width of the rubber crawler in the range where the tooth portion 32 of the sprocket 30 between the pair of drive protrusions 14 and 14 of the core metal 12 exerts the driving force is constant. When the tooth portion 32 engages with the pair of drive protrusions 14 and 14 formed on the inner peripheral surface of the crawler body 10 and a driving force is applied to the recess 20 and the drive protrusion 14, the tooth portion 32 and the core The distance from the gold 12 is constant. Therefore, since the thickness of the rubber member interposed between them is uniform, the compressive force applied to the rubber member between them is uniform, and the thin rubber member due to the mixture of the thin part and the thick part of the rubber member. The fear of deterioration is eliminated. Therefore, the rubber crawler 8 has a long life and can be used with peace of mind.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, although a configuration has been described in which flat portions between projections are formed between drive projections and ridges are provided on both sides of the crawler body in the circumferential direction, the present invention is not limited to this configuration.

8 Rubber Crawler 10 Crawler Main Body 12 Core Bar 12a Wing 12b Core Center 12c Projection 14 Drive Projection 16 Raised Part 18 Flat Between Projections 20 Recess 20a Recess Bottom 22 Core Bottom 26 Lug 30 Sprocket 32 Teeth 36 Groove A Rotation direction E Grounding surface t1, t2 Rubber thickness

Claims (2)

An endless belt-like crawler body, and a cored bar embedded in the crawler body at a predetermined interval in the circumferential direction,
The metal core has a central part, a pair of protrusions formed with the central part interposed therebetween, and a wing part extending a predetermined length on both sides of the base end part of the pair of protrusions. ,
In a state where the core metal is embedded in the rubber crawler main body, the wing portion extends in the width direction of the crawler main body, and the pair of protrusions are covered with a rubber member constituting the rubber crawler main body. A pair of drive projections projectingly formed on the inner peripheral surface side of the rubber crawler, and a pressing force is applied to the pair of drive projections by the rotational operation of the sprocket teeth to rotate the crawler body. In the crawler,
The core metal has a circumferential width between the pair of projections that is shorter than a circumferential width of the wings of the core metal, and at least the base ends of the pair of projections It is constant until both sides of the part ,
A rubber crawler characterized in that the rubber thickness of a rubber member existing between the sprocket tooth portion and the cored bar is uniform during rotation of the sprocket tooth portion .   The rubber crawler according to claim 1, wherein a boundary portion between a central portion of the cored bar and the wing portion is connected with a predetermined curvature.

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