WO2012008189A1

WO2012008189A1 - Track frame for track type vehicle

Info

Publication number: WO2012008189A1
Application number: PCT/JP2011/059007
Authority: WO
Inventors: 生井　喜雄; 慎一田邉
Original assignee: 日立建機株式会社
Priority date: 2010-07-15
Filing date: 2011-04-11
Publication date: 2012-01-19
Also published as: JP2012020677A; CN203127002U

Abstract

The inner upper plate (18B) of an inner plate (18) which forms an idler wheel bracket (17) is tilted obliquely downward from the idler wheel (6) side toward the rising plate (18A) of the inner plate (18). The outer upper plate (19B) of an outer plate (19) is tilted obliquely downward from the idler wheel (6) side toward the rising plate (19A) of the outer plate (19). As a result, the inner plate (18) and the outer plate (19) are symmetric about the idler wheel (6) in the left-right direction. The configuration causes the cross-sectional strength of the inner plate (18) secured to a connection flange (16) and the cross-sectional strength of the outer plate (19) to be equal, so that the durability of the idler wheel bracket (17) is increased.

Description

Track frame for tracked vehicles

The present invention relates to a track frame of a tracked vehicle including a crawler such as a hydraulic excavator or a hydraulic crane.

In general, a hydraulic excavator as a representative example of a tracked vehicle is a self-propelled lower traveling body equipped with a crawler belt, an upper revolving body that is turnably mounted on the lower traveling body, and the upper revolving body. It is roughly constituted by a working device provided so as to be able to move up and down. The hydraulic excavator can stably travel on rough terrain such as a work site, and performs excavation work of earth and sand using a work device.

In this case, the lower traveling body of the hydraulic excavator is usually provided on the left and right sides of the center frame with a track frame having side frames extending in the front and rear directions, and on the front and rear sides of the side frames. An idler wheel, a drive wheel provided on the other side of the front and rear sides of the side frame, and a crawler belt wound around the idler wheel and the drive wheel are provided.

Here, the side frame is provided with a side frame main body located at the front and rear center portions and a connection flange on one side of the front and rear directions of the side frame main body, to which the idler wheel is attached. The bracket includes a driving wheel bracket that is provided on the other side of the front and rear directions of the side frame body via another connection flange and to which a driving wheel is attached.

In this case, the side frame body has an inverted U-shaped cross-sectional shape with an open bottom end and extends in the front and rear directions. The side frame body includes an inner surface plate attached to a leg portion of the center frame, and the inner surface plate. And an outer plate facing each other in the left and right directions, and an upper plate connecting the inner plate and the upper end of the outer plate.

On the other hand, the idler wheel bracket is usually arranged on the center frame side with the idler wheel interposed therebetween, and an inner plate provided with an inner upper plate bent toward the idler wheel on the upper end side, and the center frame with the idler wheel interposed therebetween. And an outer side plate provided with an outer upper plate that is bent toward the idler wheel on the upper end side. On the other hand, between the inner plate and the outer plate of the idler wheel bracket, there is provided a yoke guide that supports an inverted U-shaped yoke that rotatably supports the idler wheel so as to be movable forward and backward.

Furthermore, a tension adjusting device for adjusting the tension of the crawler belt is usually provided between the yoke supporting the idler wheel and the side frame body. In the tension adjusting device, when the crawler belt is deformed due to road surface undulation or the like, the yoke is moved forward and backward along the yoke guide of the idler wheel bracket according to the expansion and contraction of the coil spring constituting the tension adjusting device. Thereby, the distance between the idler wheel supported by the yoke and the drive wheel is appropriately changed according to the deformation of the crawler belt, and the tension of the crawler belt can be adjusted (Patent Document 1).

JP 2003-48570 A

By the way, when a hydraulic excavator travels on rough terrain or muddy ground, mud or the like is jumped up by the crawler track, so it is necessary to prevent the mud or the like from adhering to and accumulating on the side frame main body or idler wheel bracket.

On the other hand, in the hydraulic excavator according to the prior art, the upper surface plate constituting the side frame main body is inclined obliquely downward from the inner surface plate toward the outer surface plate, so that the mud fallen on the upper surface plate along the inclination. What can discharge | emit to the outer surface board side is known.

On the other hand, with respect to the idler wheel bracket, for example, by making the height dimension of the outer plate smaller than the height dimension of the inner plate, the inner upper plate of the inner plate and the outer upper plate of the outer plate are respectively separated from the inner plate. It is inclined diagonally downward toward the board. Thereby, the mud etc. which fell to the idler wheel bracket can be discharged | emitted to the outer side board side along the inclination of an inner upper board and an outer upper board.

However, if the height of the outer plate constituting the idler wheel bracket is made smaller than the height of the inner plate in order to improve the mud scavenging property of the idler wheel bracket, means such as welding should be used on the connection flange. Compared to the strength (cross-sectional strength) of the inner plate to be joined using, the strength of the outer plate is lowered.

In this way, when the strength of the inner plate and the outer plate for supporting the yoke to which the idler wheel is attached becomes uneven, for example, the excavator turns in the left and right directions (curve travel). As a result, the outer plate having low strength is twisted, and as a result, the durability of the idler bracket is lowered.

The present invention has been made in view of the above-described problems of the prior art, and can improve the durability of the idler wheel bracket by making it possible to equalize the strength of the inner and outer plates while maintaining the mud sweeping property of the idler wheel bracket. It is an object of the present invention to provide a track frame for a tracked vehicle that can perform the above.

(1). In order to solve the above-described problems, the present invention comprises a center frame and a side frame attached to the center frame via left and right legs and extending in the front and rear directions. A side frame body located at the center in the rear direction, a front wheel frame bracket, a free wheel bracket provided on one side of the rear direction via a connection flange to which a free wheel is mounted, a front side of the side frame body, A driving wheel bracket provided on the other side in the rear direction via another connection flange, to which a driving wheel is attached, and the side frame main body includes an inner surface plate attached to the leg portion, the inner surface plate and the left, The floating plate comprises an outer surface plate facing rightward and an upper surface plate that connects the inner surface plate and the upper end portion of the outer surface plate and is inclined obliquely downward from the inner surface plate toward the outer surface plate. The bracket is disposed on the center frame side with the idler wheel interposed therebetween and has an inner plate provided with an inner upper plate on the upper end side, and is disposed on the opposite side of the center frame with the idler wheel disposed on the upper end side. The present invention is applied to a track frame of a tracked vehicle constituted by an outer plate provided with an upper plate.

The inner upper plate of the inner plate forms an inclined surface inclined obliquely downward from the idler toward the inner plate, and the outer upper plate of the outer plate is the idler wheel. In other words, an inclined surface inclined obliquely downward toward the outer plate is formed.

With this configuration, the inner upper plate provided on the inner plate of the idler wheel bracket is inclined obliquely downward from the idler wheel toward the inner plate, and the outer upper plate provided on the outer plate is changed to the idler wheel. It is possible to incline obliquely downward toward the outer side plate. Therefore, it is not necessary to make the height dimension of the outer plate smaller than that of the inner plate, and the height dimension of the inner plate and the outer plate can be set almost equal. As a result, the strength (cross-sectional strength) of the inner plate and the strength (cross-sectional strength) of the outer plate that are joined to the connection flange by means such as welding can be made uniform. As a result, it is possible to suppress the twisting of one of the inner plate and the outer plate constituting the idler wheel bracket when turning the tracked vehicle, and to increase the durability of the idler wheel bracket. Therefore, the reliability of the tracked vehicle can be improved.

Furthermore, the inner upper plate provided on the inner plate and the outer upper plate provided on the outer plate are inclined to the left and right sides with respect to the position of the idler wheel, so that mud or the like jumped up by the track Can be smoothly discharged along the inclined surfaces of the inner upper plate and the outer upper plate, and good mud scavenging property of the idler wheel bracket can be ensured.

(2). According to the present invention, between the corner portion where the outer surface plate and the upper surface plate of the side frame body intersect, and the corner portion where the outer plate and the outer upper plate of the idler wheel bracket intersect, the side frame body. And a step portion having a dimension larger than the plate thickness dimension of the connection flange connecting the idle wheel bracket and the idle wheel bracket.

With this configuration, the crawler belt wound around the idler wheel and the drive wheel is deformed due to road surface undulation, etc., so that loads opposite to each other from the side frame body and the idler wheel bracket to the connection flange. (Shear load) acts. In this case, the point of action of the load acting on the connection flange from the corner corner where the outer surface plate and the upper surface plate of the side frame body intersect, and the connection flange from the corner corner where the outer plate of the idler wheel bracket and the outer upper plate intersect. The distance from the acting point of the acting load can be increased. As a result, the shear stress acting on the connection flange can be reduced, and the durability of the connection flange can be increased.

(3). In the case of the item (2), according to the present invention, a corner corner portion where the outer surface plate and the upper surface plate of the side frame body intersect, and a corner corner portion where the outer plate and the outer upper plate of the idler wheel bracket intersect. The step portion formed between them is set to a dimension that is not less than 2 times and not more than 5 times the plate thickness dimension of the connection flange. With this configuration, the shear stress acting on the connection flange can be further reduced, and the durability of the connection flange can be further enhanced.

(4). According to the present invention, the inner plate and the outer plate of the idler wheel bracket are formed symmetrically in the left and right directions with the idler wheel interposed therebetween. With this configuration, the strength of the inner plate and the strength of the outer plate that are joined to the connection flange by means of welding or the like can be made uniform, and one of the inner plate and the outer plate constituting the idler wheel bracket can be made. It is possible to reliably prevent the side plate from being twisted.

(5). According to the present invention, the inner upper plate and the outer upper plate of the idler wheel bracket are connected by the upper connecting plate extending in the left and right directions at a position adjacent to the connecting flange, and the upper connecting plate is , It is configured to incline in a mountain shape so as to be symmetrical in the left and right directions from the central portion in the right direction toward the inner and outer plates of the idler bracket.

This configuration can increase the strength of the entire idler bracket. On the other hand, mud falling on the upper connecting plate is discharged to the inner plate side or the outer plate side along the angle of the mountain of the upper connecting plate, so that it is possible to improve the mud sweeping property of the idler wheel bracket.

(6). According to the present invention, the surface of the inner plate facing the idler wheel is provided with an inner guide that forms a closed space between the inner plate and the surface of the outer plate facing the idler wheel. Is provided with an outer guide that forms a closed space between the outer plate and the outer plate, and is formed between the closed space formed between the inner plate and the inner guide, the outer plate, and the outer guide. The closed space has a substantially equal cross-sectional area.

With this configuration, the cross-sectional strength of the inner plate fixed to the connecting flange and the cross-sectional strength of the outer plate can be made uniform, and the tracked vehicle performs left turn traveling and right turn traveling. In addition, it is possible to suppress the twisting of one of the inner plate and the outer plate. As a result, the durability of the idler wheel bracket can be enhanced, and the stability during traveling of the tracked vehicle can be enhanced.

It is a front view which shows the hydraulic shovel provided with the track frame by embodiment of this invention. It is a perspective view which shows a track frame alone. It is a perspective view which shows one side frame alone. FIG. 4 is an enlarged cross-sectional view of the side frame body and the like as viewed from the direction of arrows IV-IV in FIG. FIG. 5 is an enlarged cross-sectional view of the idler wheel bracket, idler wheel, connection flange, and side frame body as viewed from the direction of arrows VV in FIG. 1 with the crawler belt omitted. It is an expanded sectional view of the same position as Drawing 5 showing the idler wheel bracket which removed the idler wheel, a connection flange, and a side frame main part. FIG. 7 is a cross-sectional view of the idler wheel bracket, the connection flange, and the side frame body as seen from the direction of arrows VII-VII in FIG. 6. It is sectional drawing which shows the idler wheel bracket by a comparative example, a connection flange, and a side frame main body. It is sectional drawing seen from the arrow IX-IX direction in FIG. 8 which shows the idler wheel bracket, connection flange, and side frame main body by a comparative example. It is an expanded sectional view of the position similar to FIG. 6 which shows the idler wheel bracket by a modification.

Hereinafter, a case where a track frame of a tracked vehicle according to an embodiment of the present invention is applied to a hydraulic excavator will be described as an example and described in detail with reference to the accompanying drawings.

In the figure, reference numeral 1 denotes a hydraulic excavator as a typical example of a tracked vehicle. The hydraulic excavator 1 includes a tracked lower traveling body 2 capable of self-propelling and a swivel wheel 3 on the lower traveling body 2. An excavation work of earth and sand using the working device 5, which is roughly constituted by an upper swiveling body 4 that is mounted so as to be able to swivel, and a work device 5 that is provided on the front side of the upper swiveling body 4 so as to be able to move up and down. Etc.

Here, the track-type (crawler-type) lower traveling body 2 is for traveling on uneven surfaces such as construction sites and rough terrain, and includes one end of a track frame 11 described later and a side frame 14 described later. An idler wheel 6 provided rotatably on the side, a drive wheel 7 provided on the other end of the side frame 14, and a crawler belt 8 provided around the idler wheel 6 and the drive wheel 7. And is roughly composed.

Next, 11 denotes a track frame according to the present embodiment. The track frame 11 serves as a base of the lower traveling body 2 and forms a strong support structure. Here, as shown in FIG. 2, the track frame 11 is roughly constituted by a center frame 12 positioned in the center and side frames 14 described later disposed on both the left and right sides of the center frame 12. ing.

Reference numeral 12 denotes a center frame that constitutes the center portion of the track frame 11. The center frame 12 is formed in a substantially X shape when viewed from above, and is formed in an X shape that is substantially equal to the upper plate 12A. The lower plate 12B is disposed below the upper plate 12A with a gap, and a large number of (for example, eight) connecting plates 12C that connect the upper plate 12A and the lower plate 12B.

On the left and right sides of the center frame 12, four leg portions 12D formed of an upper plate 12A, a lower plate 12B, and connecting plates 12C are provided, two at a distance from each other in front and rear. The left and right side frames 14, which will be described later, are attached to the distal ends of the leg portions 12D. A large-diameter cylindrical support cylinder 13 is provided at the center of the upper plate 12 A, and the upper revolving body 4 is mounted on the support cylinder 13 via the revolving wheel 3.

Next, 14 shows the left and right side frames according to the present embodiment. These left and right side frames 14 are arranged on both the left and right sides of the center frame 12 and extend in the front and rear directions. As shown in FIG. 3, the side frame 14 is roughly configured by a side frame body 15, an idler wheel bracket 17, and a drive wheel bracket 26 described later.

Reference numeral 15 denotes a side frame main body positioned in the center of the front and rear directions (length direction) of the side frame 14, and the side frame main body 15 is formed with an inverted U-shaped cross-sectional shape having an open lower end side. It extends in the rear direction. Here, the side frame main body 15 is fixed to the tip of the left leg 12D of the center frame 12 by means of welding or the like, and rises substantially vertically, and the inner surface plate 15A and the left and right directions And an upper surface plate 15C connecting the upper end portion of the inner surface plate 15A and the upper end portion of the outer surface plate 15B.

A free wheel bracket 17 is attached to one end side in the front and rear directions of the side frame main body 15 via a connecting flange 16 described later, and the other end side in the front and rear directions of the side frame main body 15 is described later. A drive wheel bracket 26 is attached via the connection flange 25.

Here, as shown in FIGS. 4 and 6, in the side frame body 15, the height dimension H2 of the outer surface plate 15B is set smaller than the height dimension H1 of the inner surface plate 15A (H1> H2). . Accordingly, the corner portion (corner portion) 15D where the inner surface plate 15A and the upper surface plate 15C intersect is positioned higher than the corner corner portion 15E where the outer surface plate 15B and the upper surface plate 15C intersect, and the upper surface plate 15C is the inner surface plate. An inclined surface that is inclined obliquely downward from 15A toward the outer surface plate 15B is formed. In this case, as shown in FIGS. 2 and 5, there is almost no step between the upper surface plate 15 C constituting the side frame body 15 and the upper surface of the upper plate 12 A constituting the leg portion 12 D provided on the center frame 12. A continuous inclined surface is formed. Thereby, even when the mud or the like jumped up by the crawler belt 8 during the traveling of the excavator 1 falls on the side frame body 15, the mud or the like is discharged to the outer surface plate 15B side along the inclination of the upper surface plate 15C. It has a configuration that can.

Reference numeral 16 denotes a connection flange provided on one end side in the front and rear directions of the side frame main body 15. The connection flange 16 has a substantially J-shape on the idler wheel bracket 17 side, which will be described later, on the lower end side of a thick steel plate material. It is formed by bending. Here, the connection flange 16 has a shape substantially similar to the outer shape of the idler wheel bracket 17 as viewed from the front, and is formed as a plate that is slightly larger than the outer shape of the idler wheel bracket 17. On the other hand, the plate thickness dimension T of the connection flange 16 is set to, for example, about 19 mm to 25 mm. Further, the rear surface 16A of the connection flange 16 is fixed to an end edge portion on one end side of the side frame body 15 by means of welding or the like, and an idler bracket 17 described later is welded to the front surface 16B of the connection flange 16 or the like. It is fixed using the means.

In this case, the inner end edge 16C located on the leg 12D side of the center frame 12 in the connection flange 16 is closer to the leg 12D side (center frame 12 side) than the joint with the inner surface plate 15A of the side frame body 15. It protrudes. Further, a yoke insertion hole 16D through which a yoke (not shown) for supporting the idler wheel 6 so as to be movable in the front and rear directions is inserted in the center portion of the connection flange 16 is formed. Therefore, the connection flange 16 maintains the welding strength of each end edge of the side frame 14 as a whole even when the end edge shape of the side frame body 15 and the end edge shape of the idler wheel bracket 17 are different. It functions as a strength member.

Reference numeral 17 denotes an idler wheel bracket provided on one side of the front and rear directions of the side frame body 15 via the connection flange 16. The idler wheel bracket 17 is fixed to the front surface 16B of the connection flange 16 by means of welding or the like, and the idler wheel 6 is attached to be rotatable and movable in the front and rear directions. Here, as shown in FIGS. 5 to 7, the idler wheel bracket 17 is roughly constituted by an inner plate 18, an outer plate 19, an upper connecting plate 21, an inner guide 22, and an outer guide 23 which will be described later. ing.

Reference numeral 18 denotes an inner plate disposed on the center frame 12 side with the idler wheel 6 interposed therebetween. The inner plate 18 rises substantially vertically while facing the idler wheel 6, and the riser plate 18A The inner upper plate 18B is bent toward the idler wheel 6 from the upper end side. The inner plate 18 has a rear end edge portion fixed to the front surface 16B of the connection flange 16 by means of welding or the like, and extends forward and rearward from the connection flange 16. A later-described inner guide 22 is provided on a surface of the inner plate 18 that faces the idler wheel 6.

Here, regarding the shape of the inner upper plate 18B of the inner plate 18, the inner upper plate 18B has the idler wheel 6 side (position near the idler wheel 6) at the highest position, and from this position toward the rising plate 18A. An inclined surface that is inclined obliquely downward is formed. Thereby, the mud etc. which fell on the inner upper board 18B of the inner board 18 become a structure discharged | emitted to the inner board 18 side along the inclination of this inner upper board 18B.

Reference numeral 19 denotes an outer plate disposed on the opposite side of the center frame 12 with the idler wheel 6 interposed therebetween. The upper and lower plates 19B are bent toward the idler wheel 6 from the upper end side of the plate 19A. The outer plate 19 has a rear end edge portion fixed to the front surface 16B of the connection flange 16 by means of welding or the like, and extends forward and rearward from the connection flange 16. In addition, an outer guide 23 described later is provided on a surface of the outer plate 19 that faces the idler wheel 6.

Here, regarding the shape of the outer upper plate 19B of the outer side plate 19, the outer upper plate 19B has the idler wheel 6 side (position near the idler wheel 6) at the highest position, and from this position toward the rising plate 19A. An inclined surface that is inclined obliquely downward is formed. Thereby, the mud etc. which fell on the outer upper board 19B of the outer side board 19 become a structure discharged | emitted to the outer side board 19 side along the inclination of this outer upper board 19B.

In this way, the inner upper plate 18B of the inner plate 18 and the outer upper plate 19B of the outer plate 19 constituting the idler wheel bracket 17 are inclined diagonally downward on both left and right sides with respect to the position of the idler wheel 6. An inclined angled surface is formed. Therefore, the height dimension of the inner side plate 18 and the height dimension of the outer side plate 19 can be set substantially equal, and the inner side plate 18 and the outer side plate 19 are symmetrical in the left and right directions around the idler wheel 6. Is formed.

Therefore, as shown in FIGS. 6 and 7, the corner plate 19 C where the rising plate 19 A and the outer upper plate 19 B of the outer plate 19 constituting the idler wheel bracket 17 intersect is an outer plate constituting the side frame body 15. 15B and the upper surface board 15C are arrange | positioned in the position higher than the corner | angular corner part 15E where it crosses. Therefore, an upper and lower step 20 can be formed between the corner 19C of the outer plate 19 and the corner 15E of the side frame body 15.

In this case, as shown in FIG. 7, the dimension L of the stepped portion 20 is set to be larger than the plate thickness dimension T of the connection flange 16 to which the side frame body 15 and the idler wheel bracket 17 are fixed. The dimension is set to be not less than 2 times and not more than 5 times the plate thickness dimension T of the flange 16. For example, when the plate thickness dimension T of the connection flange 16 is 20 mm, the dimension L of the stepped portion 20 is set to 40 mm or more and 100 mm or less.

Thus, in the present embodiment, the thickness F of the connecting flange 16 is determined between the corner 19C of the outer plate 19 constituting the idler wheel bracket 17 and the corner 15E of the side frame body 15. The step portion 20 having a large dimension L is also formed. Here, as shown in FIG. 7, when the crawler belt 8 is wound around the idler wheel 6 and the drive wheel 7, an arrow is indicated from the corner portion 15 E of the side frame body 15 toward the connection flange 16 due to the tension of the crawler belt 8. A load in the F1 direction (shear load) is applied, and a load in the F2 direction (shear load) is applied from the corner 19C of the outer plate 19 constituting the idler wheel bracket 17 toward the connection flange 16. In this case, in this embodiment, the distance (step 20) between the point P1 of the load acting on the connection flange 16 from the corner corner 15E and the point of action P2 of the load acting on the connection flange 16 from the corner corner 19C. Can be maintained at a large value. As a result, the shear stress acting on the connection flange 16 can be reduced.

Reference numeral 21 denotes an upper connecting plate that connects the inner upper plate 18B of the inner plate 18 and the outer upper plate 19B of the outer plate 19, and the upper connecting plate 21 is substantially flat in plan view using a thick steel plate material or the like. It is formed in a U-shape and extends in the left and right directions at a position adjacent to the connection flange 16. The upper connecting plate 21 is fixed to the front surface 16B of the connection flange 16, the inner upper plate 18B of the inner plate 18, and the outer upper plate 19B of the outer plate 19 by means of welding or the like. The joining strength of the plate 19 is reinforced.

Here, the upper connecting plate 21 forms a mountain-shaped inclined surface so as to be symmetrical in the left and right directions from the central portion in the left and right directions toward the inner plate 18 and the outer plate 19 of the idler wheel bracket 17. ing. As a result, the mud or the like dropped on the upper connecting plate 21 is discharged along the inclined surface of the upper connecting plate 21 to the inner plate 18 side or the outer plate 19 side of the idler wheel bracket 17. .

Reference numeral 22 denotes an inner guide provided on a surface of the inner plate 18 facing the idler wheel 6, and the inner guide 22 has a substantially L-shaped cross-sectional shape and extends in the front and rear directions and a lower guide frame 22A. It consists of a frame 22B. The upper guide frame 22A is fixed to the rising plate 18A and the inner upper plate 18B of the inner plate 18 by means of welding or the like, and between the rising plate 18A, the inner upper plate 18B, and the upper guide frame 22A, A closed space 22C is formed. On the other hand, the lower guide frame 22B is fixed to the rising plate 18A of the inner plate 18 using means such as welding, and a closed space 22D is formed between the rising plate 18A and the lower guide frame 22B. Further, between the upper guide frame 22A and the lower guide frame 22B, there is formed a guide groove 22E that extends in the front and rear directions at a constant interval. The guide groove 22E guides a left bearing 24 described later.

Reference numeral 23 denotes an outer guide provided on a surface of the outer plate 19 that faces the idler wheel 6, and the outer guide 23 has a substantially L-shaped cross-sectional shape and extends in the front and rear directions, like the inner guide 22. It consists of an upper guide frame 23A and a lower guide frame 23B. The upper guide frame 23A is fixed to the rising plate 19A and the outer upper plate 19B of the outer plate 19 by means of welding or the like, and between the rising plate 19A, the outer upper plate 19B, and the upper guide frame 23A, A closed space 23C is formed. On the other hand, the lower guide frame 23B is fixed to the rising plate 19A of the outer plate 19 using means such as welding, and a closed space 23D is formed between the rising plate 19A and the lower guide frame 23B. In addition, a guide groove 23E extending in the front and rear directions with a constant interval is formed between the upper guide frame 23A and the lower guide frame 23B. The guide groove 23E guides a right bearing 24 described later.

In the guide groove 22E of the inner guide 22 and the guide groove 23E of the outer guide 23, left and right bearings 24 attached to the front end side of a yoke (not shown) are movable forward and backward, respectively. The both ends of the support shaft 6A provided on the idler wheel 6 are rotatably supported by the left and right bearings 24. As a result, the idler wheel 6 can move forward and backward while being guided by the inner guide 22 and the outer guide 23 of the idler wheel bracket 17 while being supported rotatably by the left and right bearings 24. ing.

Here, the inner plate 18 and the outer plate 19 constituting the idler wheel bracket 17 are formed symmetrically in the left and right directions around the idler wheel 6. For this reason, a closed space 22C formed between the inner plate 18 and the upper guide frame 22A of the inner guide 22, and a closed space 23C formed between the outer plate 19 and the upper guide frame 23A of the outer guide 23, Can be formed as a closed space having approximately equal cross-sectional areas. On the other hand, a closed space 22D formed between the inner plate 18 and the lower guide frame 22B of the inner guide 22 and a closed space 23D formed between the outer plate 19 and the lower guide frame 23B of the outer guide 23 are provided. Can be formed as a closed space having approximately the same cross-sectional area.

Thereby, the cross-sectional strength of the inner plate 18 fixed to the connection flange 16 and the cross-sectional strength of the outer plate 19 can be made uniform. One of them is configured to be able to suppress the occurrence of twisting.

Reference numeral 25 denotes another connection flange fixed to the other end side in the front and rear direction of the side frame

main body

15, and 26 denotes the other side of the front and rear direction of the side frame main body 15 through the other connection flange 25. The drive wheel bracket provided is shown. Here, the other connection flange 25 also maintains the welding strength between the side frame main body 15 and the drive wheel bracket 26.

The drive wheels 7 are attached to the drive wheel brackets 26, and the crawler belts 8 wound around the idle wheels 6 and the drive wheels 7 are driven by rotating the drive wheels 7 by a traveling hydraulic motor (not shown). It is configured to circulate. In this case, a tension adjusting device (not shown) is provided between the idler wheel 6 and the side frame main body 15, and even when the crawler belt 8 is deformed due to road surface undulation or the like when the hydraulic excavator 1 travels, the tension adjusting device. Thus, the tension of the crawler belt 8 can be adjusted appropriately by changing the distance between the idle wheel 6 and the drive wheel 7.

The hydraulic excavator 1 according to the present embodiment has the track frame 11 as described above, and the self-propelled to the work site by rotating the driving wheel 7 and rotating the crawler belt 8 between the idler wheel 6 and the excavator 1. Then, excavation work of earth and sand is performed using the working device 4.

During traveling of the hydraulic excavator 1, mud etc. are jumped up by the crawler belt 8, and this mud falls to the side frame main body 15 and the idler wheel bracket 17 constituting the side frame 14.

On the other hand, according to the side frame main body 15 according to the present embodiment, the upper surface plate 15C includes the upper end portion of the inner surface plate 15A disposed on the center frame 12 side and the outer surface plate disposed on the side opposite to the center frame 12. The upper end of 15B is connected. The upper surface plate 15C forms an inclined surface inclined obliquely downward from the inner surface plate 15A toward the outer surface plate 15B. Thereby, even when mud falls on the side frame main body 15, this mud etc. can be discharged | emitted to the outer surface board 15B side along the inclination of the upper surface board 15C.

On the other hand, in the idler wheel bracket 17 according to the present embodiment, the inner upper plate 18B of the inner plate 18 located on the center frame 12 side with the idler wheel 6 interposed therebetween is inclined obliquely downward from the idler wheel 6 side toward the inner plate 18. It forms as an inclined surface which inclines. Similarly, the outer upper plate 19B of the outer plate 19 located on the opposite side of the center frame 12 across the idler wheel 6 is formed as an inclined surface inclined obliquely downward from the idler wheel 6 side toward the outer plate 19. ing.

As a result, even when mud or the like falls on the idler wheel bracket 17, the mud or the like is discharged to the inner plate 18 side along the inclination of the inner upper plate 18B, and the outer plate along the inclination of the outer upper plate 19B. 19 side can be discharged. Thus, mud etc. are prevented from accumulating on the inner upper plate 18B of the inner plate 18 and the outer upper plate 19B of the outer plate 19 constituting the idler wheel bracket 17, and the mud sweeping property of the idler wheel bracket 17 is improved. By keeping it, the crawler belt 8 can smoothly move between the idler wheel 6 and the drive wheel 7.

Moreover, in the idler wheel bracket 17 according to the present embodiment, the inner upper plate 18B of the inner side plate 18 and the outer upper plate 19B of the outer side plate 19 are diagonally inclined on the left and right sides with respect to the position of the idler wheel 6. A mountain-shaped inclined surface inclined downward is formed. Therefore, the height dimension of the inner side plate 18 and the height dimension of the outer side plate 19 can be set substantially equal, and the inner side plate 18 and the outer side plate 19 are symmetrically about the idler wheel 6 in the left and right directions. Can be formed.

Thereby, a closed space 22C formed between the inner plate 18 and the upper guide frame 22A of the inner guide 22, and a closed space 23C formed between the outer plate 19 and the upper guide frame 23A of the outer guide 23, Can be formed as a closed space having approximately equal cross-sectional areas. Further, a closed space 22D formed between the inner plate 18 and the lower guide frame 22B of the inner guide 22 and a closed space 23D formed between the outer plate 19 and the lower guide frame 23B of the outer guide 23 are provided. Can be formed as a closed space having approximately the same cross-sectional area.

Thereby, the cross-sectional strength of the inner plate 18 fixed to the connection flange 16 and the cross-sectional strength of the outer plate 19 can be made uniform, and when the excavator 1 performs left turn traveling and right turn traveling, It is possible to suppress the twisting of one of the plate 18 and the outer plate 19. As a result, the durability of the idle wheel bracket 17 can be increased, and the stability of the excavator 1 during travel can be increased.

Further, the inner plate 18 and the outer plate 19 of the idler wheel bracket 17 are formed symmetrically in the left and right directions around the idler wheel 6. As a result, as shown in FIGS. 6 and 7, the thickness of the connection flange 16 is between the corner 19 C where the rising plate 19 A and the outer upper plate 19 B intersect with the corner 15 E of the side frame body 15. A stepped portion 20 having a dimension L larger than the dimension T can be formed.

Here, when the crawler belt 8 is wound around the idler wheel 6 and the drive wheel 7, as shown in FIG. 7, due to the tension of the crawler belt 8, the arrow from the corner portion 15 E of the side frame body 15 toward the connection flange 16. A load in the direction indicated by F 1 acts, and a load in the direction indicated by arrow F 2 acts from the corner portion 19 C of the outer plate 19 constituting the idler wheel bracket 17 toward the connection flange 16. At this time, in the present embodiment, the distance between the point P1 of the load acting on the connection flange 16 from the corner corner 15E and the point P2 of the load acting on the connection flange 16 from the corner corner 19C (step 20 Can be maintained at a large value.

As a result, an arrow F1 direction load acting on the connection flange 16 from the corner corner 15E of the side frame body 15 and an arrow acting on the connection flange 16 from the corner corner 19C of the outer plate 19 constituting the idler wheel bracket 17 are shown. The shear stress acting on the connection flange 16 due to the load in the direction F2 can be reduced, and the durability of the connection flange 16 can be increased.

Next, a comparison between the side frame 14 according to the present embodiment shown in FIGS. 6 and 7 and the side frame 114 according to the comparative example shown in FIGS. 8 and 9 will be described.

First, the side frame 114 according to the comparative example is attached to the side frame main body 15 similar to the side frame 14 according to the present embodiment and the front and rear sides of the side frame main body 15 via the connection flange 116. An idler wheel bracket 117 described later is provided.

Here, in the side frame body 15 constituting the side frame 114 according to the comparative example, the height dimension H2 of the outer surface plate 15B is smaller than the height dimension H1 of the inner surface plate 15A as in the case of the present embodiment. Is set. Thereby, the upper surface plate 15C that connects the upper end portions of the inner surface plate 15A and the outer surface plate 15B forms an inclined surface that is inclined obliquely downward from the inner surface plate 15A toward the outer surface plate 15B.

On the other hand, the idler wheel bracket 117 according to the comparative example includes an inner plate 118 composed of a rising plate 118A and an inner upper plate 118B, an outer plate 119 composed of a rising plate 119A and an outer upper plate 119B, and an inner upper plate 118B and an outer upper plate 118B. The upper connecting plate 120 is connected to the plate 119B, the inner guide 121 is provided on the inner surface side of the inner plate 118, and the outer guide 122 is provided on the inner surface side of the outer plate 119.

The inner guide 121 has an upper guide frame 121A and a lower guide frame 121B. A closed space 121C is formed between the inner plate 118 and the upper guide frame 121A, and the inner guide 121 and the lower guide frame 121B are provided between them. A closed space 121D is formed. Between the upper guide frame 121A and the lower guide frame 121B, a guide groove 121E extending in the front and rear directions is formed. On the other hand, the outer guide 122 includes an upper guide frame 122A and a lower guide frame 122B. A closed space 122C is formed between the outer plate 119 and the upper guide frame 122A, and the outer plate 119 and the lower guide frame 122B. A closed space 122D is formed between them. Between the upper guide frame 122A and the lower guide frame 122B, a guide groove 122E extending in the front and rear directions is formed.

In this case, the inner upper plate 118B of the inner plate 118 extends in the horizontal direction from the upper end side of the rising plate 118A toward the idler wheel. On the other hand, the outer upper plate 119B of the outer plate 119 forms an inclined surface inclined obliquely downward from the idler wheel toward the rising plate 119A. The inclination of the outer upper plate 119B is the same as that of the upper surface plate 15C of the side frame body 15. The inclination angle is set to be approximately equal.

Thus, in the idler wheel bracket 117 of the side frame 114 according to the comparative example, only the outer upper plate 119B of the outer plate 119 is inclined obliquely downward from the position of the idler wheel toward the rising plate 119A, and the inner plate 118 The height dimension of the outer side plate 119 is set smaller than the height dimension.

Therefore, in the side frame 114 according to the comparative example, the space between the outer plate 119 and the upper guide frame 122A is smaller than the closed space 121C formed between the inner plate 118 of the idler wheel bracket 117 and the upper guide frame 121A. The cross-sectional area of the closed space 122 C that is formed becomes smaller. As a result, the cross-sectional strength of the outer plate 119 is insufficient compared to the cross-sectional strength of the inner plate 118 fixed to the connection flange 116, and the outer plate 119 side is likely to be twisted when the excavator 1 turns. There arises a problem that the stability during running is lowered.

On the other hand, in the side frame 114 of the comparative example, the corner portion 119C where the rising plate 119A of the outer plate 119 and the outer upper plate 119B that constitute the idler wheel bracket 117 intersect with the corner portion 15E of the side frame main body 15. A step 123 in the upper and lower directions is formed between them. However, the dimension L ′ of the stepped portion 123 is smaller than the plate thickness dimension T ′ of the connection flange 116 to which the side frame body 15 and the idler wheel bracket 117 are fixed (L ′ <T ′).

Here, in the side frame 114 according to the comparative example, when a crawler belt (not shown) is wound around the idler wheel and the drive wheel, as shown in FIG. A load in the direction of arrow F1 acts from 15E toward the connection flange 116, and a load in the direction of arrow F2 acts from the corner portion 19C of the outer plate 119 constituting the idler wheel bracket 117 toward the connection flange 116. At this time, in the side frame 114 according to the comparative example, the distance (step difference) between the application point P1 of the load acting on the connection flange 116 from the corner 15E and the action point P2 of the load acting on the connection flange 116 from the corner 19C. The dimension L ′) of the portion 123 is small. As a result, the load in the arrow F1 direction acting on the connection flange 116 from the corner corner 15E of the side frame body 15 and the arrow acting on the connection flange 116 from the corner corner 119C of the outer plate 119 constituting the idler wheel bracket 117. The shear stress acting on the connection flange 116 due to the load in the direction indicated by F2 increases, and there arises a problem that the durability of the connection flange 116 decreases.

On the other hand, in the side frame 14 according to the present embodiment, the inner upper plate 18B of the inner plate 18 constituting the idler wheel bracket 17 is inclined obliquely downward from the idler wheel 6 toward the rising plate 18A of the inner plate 18. An inclined surface is formed, and the outer upper plate 19B of the outer plate 19 forms an inclined surface that is inclined obliquely downward from the idler wheel 6 toward the rising plate 19A of the outer plate 19. Thereby, the height dimension of the inner side board 18 and the height dimension of the outer side board 19 can be set substantially equal, and the inner side board 18 and the outer side board 19 are symmetrical about the idler wheel 6 in the left and right directions. Can be formed.

For this reason, a closed space 22C formed between the inner plate 18 and the upper guide frame 22A of the inner guide 22, and a closed space 23C formed between the outer plate 19 and the upper guide frame 23A of the outer guide 23, Can be formed as a closed space having approximately equal cross-sectional areas. Further, a closed space 22D formed between the inner plate 18 and the lower guide frame 22B of the inner guide 22 and a closed space 23D formed between the outer plate 19 and the lower guide frame 23B of the outer guide 23 are provided. , And can be formed as a closed space having approximately the same cross-sectional area.

As a result, the cross-sectional strength of the inner plate 18 fixed to the connecting flange 16 and the cross-sectional strength of the outer plate 19 can be made uniform, and when the excavator 1 performs left turn traveling and right turn traveling, It is possible to suppress the twisting of one of the plate 18 and the outer plate 19. Therefore, the durability of the idle wheel bracket 17 can be increased, and the stability of the excavator 1 during travel can be increased.

Further, the inner plate 18 and the outer plate 19 of the idler wheel bracket 17 are formed symmetrically in the left and right directions around the idler wheel 6. As a result, as shown in FIG. 6 and FIG. 7, the plate of the connection flange 16 is provided between the corner portion 19 C where the rising plate 19 A and the outer upper plate 19 B intersect with the corner portion 15 E of the side frame body 15. A stepped portion 20 having a dimension L larger than the thickness dimension T can be formed.

Therefore, as shown in FIG. 7, a load in the direction of arrow F 1 acts from the corner portion 15 E of the side frame body 15 toward the connection flange 16, and the corner portion of the outer plate 19 constituting the idler wheel bracket 17. When a load in the direction indicated by arrow F2 is applied from 19C to the connection flange 16, an application point P1 of a load acting on the connection flange 16 from the corner corner 15E and a load acting on the connection flange 16 from the corner corner 19C It is possible to keep the distance (the dimension L of the step portion 20) from the point of action P2 at a large value.

In the embodiment described above, the case where the upper connecting plate 21 connects the inner upper plate 18B of the inner plate 18 and the outer upper plate 19B of the outer plate 19 constituting the idler wheel bracket 17 is illustrated. . However, the present invention is not limited to this. For example, as in the modification shown in FIG. 10, the upper end of the inner upper plate 18B ′ extends toward the outer plate 19 and the upper end of the outer upper plate 19B ′ extends to the inner plate 18. The upper end portion of the inner upper plate 18B ′ and the upper end portion of the outer upper plate 19B ′ may be fixed to each other at the left and right center portions by means of welding or the like.

In the above-described embodiment, the hydraulic excavator 1 is described as an example of the tracked vehicle. However, the present invention is not limited to this, and can be widely applied to other tracked vehicles such as a hydraulic crane.

1 Hydraulic excavator (tracked vehicle)
6 idler wheel 7 drive wheel 11 track frame 12 center frame 14 side frame 15 side frame main body 15A inner surface plate 15B outer surface plate 15C

upper surface plate

15E, 19C corner corner 16 connection flange 17 idler wheel bracket 18

inner plate

18B, 18B 'inner upper Plate 19

Outer plate

19B, 19B 'Outer upper plate 20 Stepped portion 21 Upper connecting plate 22

Inner guide

22A, 23A

Upper guide frame

22B, 23B

Lower guide frame

22C, 22D, 23C, 23D Closed space 23 Outer guide 25 Other connection flange 26 Drive wheel bracket

Claims

A center frame (12) and a side frame (14) attached to the center frame (12) via left and right legs (12D) and extending in the front and rear directions;
The side frame (14) includes a side frame main body (15) positioned at the center in the front and rear directions, and a connection flange (16) on one side of the front and rear directions of the side frame main body (15). An idler wheel bracket (17) to which the idler wheel (6) is attached and a drive wheel (7) provided on the other side of the front and rear directions of the side frame body (15) via another connection flange (25). And a drive wheel bracket (26) to which
The side frame body (15) includes an inner surface plate (15A) attached to the leg portion (12D), an outer surface plate (15B) facing the inner surface plate (15A) in the left and right directions, and the inner surface plate ( 15A) and an upper surface plate (15C) that connects the upper end portions of the outer surface plate (15B) and is inclined obliquely downward from the inner surface plate (15A) toward the outer surface plate (15B),
The idler wheel bracket (17) is disposed on the center frame (12) side with the idler wheel (6) interposed therebetween, and an inner plate (18) provided with an inner upper plate (18B) on the upper end side, and the idler A track for a tracked vehicle comprising an outer plate (19) disposed on the opposite side of the center frame (12) with the wheel (6) in between and having an upper plate (19B) on the upper end side. In the frame,
The inner upper plate (18B) of the inner plate (18) forms an inclined surface inclined obliquely downward from the idler wheel (6) toward the inner plate (18),
The outer upper plate (19B) of the outer plate (19) is configured to form an inclined surface inclined obliquely downward from the idler wheel (6) toward the outer plate (19). Track frame for track-type vehicles.
The corner (15E) where the outer plate (15B) and the upper plate (15C) of the side frame body (15) intersect, the outer plate (19) and the outer upper plate (19B) of the idler bracket (17). Is larger than the plate thickness dimension (T) of the connection flange (16) connecting the side frame body (15) and the idler wheel bracket (17) between the corner (19C) where The track frame of a tracked vehicle according to claim 1, wherein a stepped portion (20) having (L) is formed.
The track frame of a tracked vehicle according to claim 2, wherein the stepped portion (20) is set to a dimension that is not less than 2 times and not more than 5 times the plate thickness dimension (T) of the connection flange (16).
The track according to claim 1, wherein the inner plate (18) and the outer plate (19) of the idler wheel bracket (17) are formed symmetrically in the left and right directions with the idler wheel (6) interposed therebetween. Type truck frame.
The inner upper plate (18B) and the outer upper plate (19B) of the idler wheel bracket (17) are connected by an upper connecting plate (21) extending in the left and right directions at a position adjacent to the connecting flange (16). With configuration,
The upper connecting plate (21) is angled so as to be symmetrical in the left and right directions from the center in the left and right directions toward the inner plate (18) and the outer plate (19) of the idler wheel bracket (17). The track frame of the tracked vehicle according to claim 1, wherein the track frame is configured to incline toward the vehicle.
An inner guide (22) for forming a closed space (22C, 22D) between the inner plate (18) and the inner plate (18) is provided on a surface of the inner plate (18) facing the idler wheel (6).
An outer guide (23) that forms a closed space (23C, 23D) between the outer plate (19) and the outer plate (19) is provided on a surface of the outer plate (19) facing the idler wheel (6).
The closed space (22C, 22D) formed between the inner plate (18) and the inner guide (22), the outer plate (19), and the outer guide (23). The track frame of a tracked vehicle according to claim 1, wherein the track frame has a cross-sectional area substantially equal to the closed space (23C, 23D).