JP4124181B2 - Crawler type traveling device - Google Patents

Description

  The present invention relates to a crawler type traveling device equipped in a working machine such as a hydraulic excavator.

  As shown in FIGS. 4 to 7, the crawler type traveling device includes a car body 1, left and right crawler frames 2, 2, and crawlers (crawler belts) 3, 3 wound around the outer periphery of the crawler frames 2, 2. Composed.

  The car body 1 is provided with a pair of left and right axles 4 and 4 projecting outward in the vehicle width direction on both the front and rear sides, and a swivel base 5 is provided on the upper surface of the central portion. A revolving body is mounted so as to be able to revolve.

  The left and right crawler frames 2 and 2 are provided with hollow axle boxes 6 and 6 on both the front and rear sides, and the front and rear axles 4 and 4 are slidably fitted to the axle boxes 6 and 6 in the axial direction of the axle. Both the crawler frames 2 and 2 are connected to the car body 1 so as to be movable in the vehicle width direction as indicated by double-line arrows in FIG.

  In addition, the expansion / contraction cylinders 7 and 7 are provided in a horizontal posture between the car body 1 and both the crawler frames 2 and 2 at the center in the front-rear direction of the car body 1. The frames 2 and 2 move in the vehicle width direction, and the vehicle width is enlarged or reduced.

  4 and 5, reference numerals 8 and 8 denote drive wheels provided at the rear ends of the left and right crawler frames 2 and 2, and reference numerals 9 and 9 denote idle wheels provided at the front ends thereof, which drive the crawlers 3 and 3. The

  Further, the left and right crawler frames 2, 2 are provided with track springs 10 that impart a forward elastic force to the idler wheels 9 and exhibit a buffer function.

  The track spring 10 is installed horizontally between a bracket on the idler wheel 9 side and a spring receiver on the crawler frame 2 side (both not shown) while passing under the front axles 4 and 4.

  Therefore, the height positions of the lower surfaces of the axles 4 and 4 are determined on the basis that they do not interfere with the track spring 10.

  On the other hand, since the upper surface of the axle is determined based on the height limit of the entire traveling device, the thickness dimensions of the axles 4 and 4 are determined by these.

  Here, in the conventional traveling device, the upper and lower surfaces of the axles 4 and 4 are substantially the same as the upper and lower surfaces of the entire car body 1, and the entire car body 1 is formed with substantially the same thickness.

As a result, the expansion / contraction cylinders 7 and 7 are installed at a height position that substantially coincides with the center in the vertical direction of the axles 4 and 4 at the center of the car body 1 (see Patent Document 1).
Japanese Patent Laid-Open No. 10-17274

  However, according to this configuration, the cylinder centers of the expansion and contraction cylinders 7 and 7 are considerably higher than the height position G of the center of gravity of the crawler frames 2 and 2. In FIG. 6, “a” indicates a positional deviation amount (deviation) between the cylinder center and the crawler frame center-of-gravity height position G. When this deviation “a” increases, the cylinder thrust of the expansion / contraction cylinders 7, 7 is converted into the crawler frame 2, Loss in converting to a moving force (expansion / contraction force) of 2 was large.

  For this reason, there has been a problem that smooth operation cannot be performed particularly when the expansion / contraction operation is performed while receiving the road surface resistance while the crawler 3 is grounded.

  Therefore, the present invention provides a crawler type traveling device in which the expansion / contraction cylinder is installed at a position where the center of the cylinder is close to the height position of the center of gravity of the crawler frame, whereby the cylinder thrust can be efficiently transmitted to the crawler frame as expansion / contraction force. It is to provide.

  The invention according to claim 1 is a car body having a pair of left and right axles projecting outward in the vehicle width direction on both front and rear sides, and a pair of left and right crawler frames connected to the axle so as to be movable in the vehicle width direction. And a crawler laid over the outer circumferences of the two crawler frames, and an expansion / contraction cylinder provided between the car body and the two crawler frames at the center in the front-rear direction of the car body. In the crawler type traveling device configured to move both crawler frames in the vehicle width direction so that the vehicle width can be changed, the lower surface of the center part of the car body in the front-rear direction protrudes below the lower surfaces of the axles on both sides. The expansion / contraction cylinder is provided at the protruding portion in a state of being located below the axle center.

  According to a second aspect of the present invention, in the configuration of the first aspect, the lower surface of the center part in the front-rear direction of the car body protrudes downward and the maintenance opening is provided on the left and right inclined surfaces of the protruding portion.

  According to the present invention, the lower surface of the central portion of the car body in the front-rear direction protrudes downward from the lower surfaces of the two axles, and the expansion / contraction cylinder is provided at the protruding portion in a state of being positioned below the axle center. It can be installed lower than before, that is, close to the height position of the center of gravity of the crawler frame.

  Therefore, the cylinder thrust can be efficiently transmitted to the crawler frame as expansion / contraction moving force with little loss. For this reason, even when the resistance is large, such as when expanding or contracting while the crawler is in contact with the ground, it can be expanded and contracted smoothly without difficulty.

  In addition, since only the central part in the front-rear direction protrudes downward, both front and rear sides (other than the central part) of the protruding part are kept at a high position, and a space for installing equipment (mainly track springs) arranged below the crawler frame is secured. be able to.

  Here, the following two ways are conceivable as the form in which the lower surface of the central portion of the car body projects downward from the lower surface of the axle.

  (i) The thickness of the central part of the car body including the protruding part is made substantially the same as the thickness of the car body in the conventional device, and the lower surface of the protruding part is made the axle by making the thickness of the axle smaller than that of the conventional one. Form that protrudes below the lower surface.

  (ii) The thickness dimension of the axle is the same as the axle thickness dimension of the conventional device. By making the thickness dimension of the car body central portion including the protruding portion larger than the thickness dimension of the car body in the conventional device, A form in which the lower surface protrudes below the lower surface of the axle.

  In the present invention, either of the above (i) and (ii) may be taken, but usually takes the form of (i) because the thickness of the car body is limited by the overall height of the traveling device.

  Further, if the form (i) is adopted, the lower surface of the axle is higher than the conventional one, so that there is an advantage that an operator can easily get into the lower surface of the axle at the time of inspection from the lower surface side of the axle.

  According to the invention of claim 2, since the center part in the front-rear direction of the car body is protruded downward and the maintenance opening is provided on the left and right inclined surfaces of the protrusion part, the equipment installed in the car body center part When inspecting or repairing (for example, expansion / contraction cylinder), piping, wiring, etc., the maintenance opening is on the inclined surface instead of the horizontal surface, so that maintenance work from the lower side can be easily performed.

  An embodiment of the present invention will be described with reference to FIGS.

  The basic configuration of the crawler type traveling device according to this embodiment is the same as the conventional traveling device shown in FIGS.

  That is, the traveling device includes a car body 11, left and right crawler frames 12, and a crawler 13 that is wound around the outer periphery of the crawler frame 12.

  The shape and arrangement of members (crawler frame 12, crawler 13, next expansion / contraction cylinder 17, drive wheel 18, idler wheel 19, and track spring 20) provided on both the left and right sides are shown here with reference to FIG. In the figure, only one side is shown.

  The car body 11 is provided with a pair of left and right axles 14 and 14 projecting outward in the vehicle width direction on both front and rear sides, and a swivel base 15 on which an upper revolving body is pivotably mounted on the upper surface of the center portion. It has been.

  The left and right crawler frames 12 are provided with hollow axle boxes 16 and 16 on both front and rear sides, and the front and rear axles 14 and 14 are fitted to the axle boxes 16 and 16 so as to be slidable in the axial direction of the axle. The crawler frame 12 is connected to the car body 11 so as to be movable in the vehicle width direction.

  Further, an expansion / contraction cylinder 17 is provided in a horizontal posture between the car body 11 and both the crawler frames 12 at the center portion in the front-rear direction of the car body 11, and the expansion / contraction operation of the expansion / contraction cylinder 17 causes the left and right crawler frames 12 to move in the vehicle width direction. The vehicle width is enlarged or reduced by moving to.

  In FIG. 1, 18 is a drive wheel provided at the rear end of the left and right crawler frames 12, 19 is an idler wheel provided at the front end, and the crawler 13 is driven by these.

  In addition, the left and right crawler frames 12 are provided with a track spring 20 that exerts a forward elastic force on the idler wheel 19 to exert a buffer function, and passes through the lower side of the front axles 14, 14. And a spring receiver on the crawler frame 12 side (both not shown) are installed horizontally.

  In this traveling device, the lower surface of the center part of the car body 11 in the front-rear direction is projected below the lower surfaces of the two axles 12, 12, and the expansion / contraction cylinder 17 is in a state where the center is positioned below the axle center A. It arrange | positions in this protrusion part 21. FIG.

  Here, in this embodiment, the thickness dimension S1 of the center part of the car body including the protruding portion 21 is substantially the same as the thickness dimension S2 of the car body 1 in the conventional apparatus shown in FIG. The projecting portion 21 is formed by making S11 smaller than the conventional axle thickness dimension (substantially the same as the car body thickness dimension S2).

  Further, the projecting portion 21 is formed in a downwardly tapered shape (inverted trapezoidal shape), and the right and left inclined surfaces 22 and 22 are equipment such as an expansion / contraction cylinder 17 arranged in the center of the car body, piping, wiring, and the like. Maintenance openings 23 and 23 (shown in FIG. 3) are provided for performing maintenance.

  Thus, since the lower surface of the central portion of the car body 11 protrudes downward from the lower surface of the axle and the expansion / contraction cylinder 17 is provided in the protruding portion 21, the cylinder 17 is positioned below the axle center A, that is, the height of the center of gravity of the crawler frame. It can be installed close to the position G.

  B in FIG. 2 indicates the amount of deviation (deviation) between the cylinder center and the height position G of the crawler frame center of gravity, and this deviation b can be made smaller than the conventional deviation a shown in FIG. The cylinder thrust of the cylinder 17 can be efficiently transmitted to the crawler frame 12 as expansion / contraction moving force with little loss. For this reason, even when the resistance is large, such as when expanding or contracting while the crawler is in contact with the ground, it can be expanded and contracted smoothly without difficulty.

  In addition, since only the central portion of the car body 11 in the front-rear direction protrudes downward, both the front and rear sides (other than the central portion) of the projecting portion 21 are kept at a high position, and the device disposed below the crawler frame such as the track spring 17. Installation space can be secured.

  In addition, since the lower surface of the axle is higher than before, it is easy for an operator to get into the lower surface of the axle during an inspection from the lower surface side of the axle.

  Furthermore, since the projecting portion 21 is projected in an inverted trapezoidal shape and the left and right inclined surfaces 22 and 22 are provided with maintenance openings 23 and 23, the inside of the projecting portion 21 is raised during maintenance of the expansion / contraction cylinder 17, piping, wiring, and the like. Easy to look over from a wide range of viewpoints and easy to get into. For this reason, it becomes easy to perform maintenance work from the lower side.

  By the way, the protruding portion 21 may be protruded vertically downward with respect to the axles 14 and 14 instead of the tapered shape.

It is a side view of the traveling device concerning an embodiment of the present invention. It is a side view of the car body in the same device. It is the perspective view which looked at the car body from the lower side. It is a top view of the conventional traveling apparatus. It is the same side view. It is a side view of the car body in the same device. It is the perspective view which looked at the car body from the bottom.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Car body 12 Crawler frame 13 Crawler 14,14 Axle 17 Expansion / contraction cylinder 21 Protruding part 22,22 Inclined surface 23,23 Maintenance opening

Claims (2)

  A car body having a pair of left and right axles projecting outward in the vehicle width direction on both front and rear sides, a pair of left and right crawler frames connected to the axle so as to be movable in the vehicle width direction, A crawler spanned on the outer periphery, and an expansion / contraction cylinder provided between the car body and the two crawler frames at the center in the front-rear direction of the car body. In the crawler type traveling device configured to be able to change the vehicle width by moving the vehicle to the rear, the lower surface of the center part in the front-rear direction of the car body protrudes below the lower surfaces of the two axles, and the expansion / contraction cylinder is A crawler type traveling device provided at the projecting portion in a state of being located below the axle center.   The crawler type traveling device according to claim 1, wherein a lower surface of the center portion of the car body in the front-rear direction protrudes downward and a maintenance opening is provided on the left and right inclined surfaces of the protruding portion. Traveling device.

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