JPH0811755A - Gage adjusting device for crawler vehicle - Google Patents

Abstract

PURPOSE:To shorten transport time and improve work efficiency by facilitating the fitting/removal of bolts for fastening the center frame and crawler frame of a large hydraulic shovel. CONSTITUTION:A seat plate 12 fixed to the lower face of the leg part 11 of a center frame 10 is slidably mounted on the bearing surface, fixed to the upper face of crawler frames 4, 5, and fastened by bolts 13 through frictional resistance reducing means 20. The frictional resistance reducing means 20 has a fixing member coming in contact with a fastened member, and a rotating member coming in contact with the bearing surface of the head of the fastening bolt 13. The frictional resistance reducing means 20 is also provided with a connecting member for fitting the rotating member into the fixing member through a ball and holding the fixing member and rotating member axially in the mutually rotatable state. Frictional resistance between the bolt head bearing surface and the fastend member at the time of fastening the bolt 13 is thereby reduced, so that the fastening torque of the bolt 13 is reduced to facilitate the fitting/removal of the bolt 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a track-adjustable vehicle whose gauge can be adjusted, and more particularly to a gauge adjusting device for a large hydraulic excavator.

[0002]

2. Description of the Related Art FIG. 1 is a side view of a large hydraulic excavator, and FIG. 2 is a rear view thereof. A center frame 10 is attached to the crawler frames 4 and 5 which support the left and right crawlers 2 and 3, and constitute the lower traveling body 1. An upper swing body 8 is rotatably mounted on the center frame 10.

In the case of a large hydraulic excavator, the outer width of the left and right crawlers 2 and 3, that is, the width W1 of the vehicle generally exceeds the size regulated by transportation. Therefore, at the time of transportation, it is necessary to move the crawlers 2 and 3 in the vehicle width direction to the position shown by the dotted line in FIG. 2 to narrow the vehicle width to W2 and keep it within the transportation regulation dimension.

FIG. 3 is a plan view showing a joint between the left crawler frame 4 and the center frame 10, and FIG. 4 is a side view of the same. Seating surfaces 6 and 7 are fixed to the upper surface of the crawler frame 4. A seat plate 12 provided on the lower surface of the leg portion 11 of the center frame 10 is slidably installed on the upper surfaces of the seat surfaces 6 and 7, and is fastened by a plurality of bolts 13. A guide 14 for sliding the crawler frame 4 in the vehicle width direction with respect to the center frame 10.
Is detachably attached to the crawler frame 4.

When the left and right crawler frames 4 and 5 are moved during transportation, a plurality of bolts 13 are removed and the crawler frames 4 and 5 are slid in the vehicle width direction to a position indicated by a thin chain double-dashed line in FIG. Move and keep the vehicle width within the transportation regulations. When the transportation is completed and the work is started, the crawler frames 4 and 5 are slid outward again to return to the original positions, and are fastened to the leg portions 11 of the center frame 10 by the plurality of bolts 13.

[0006]

However, in the case of a large hydraulic excavator, a plurality of bolts 13 that fasten the center frame 10 and the crawler frames 4 and 5 together have a large diameter (for example, 36 mm). There is. As is well known, when tightening a bolt, the tightening torque of the bolt is mostly consumed by the frictional resistance between the seat surface of the bolt head and the object to be tightened. Therefore, the tightening torque for obtaining the required axial force has a very large value. However, the clearance S between the heads of the plurality of bolts 13 and the crawlers 2 and 3 shown in FIG. 4 is not large enough to accommodate a large booster wrench. In addition, a high power wrench that enters the gap S is generally not commercially available, is expensive, and is heavy, which is inconvenient to handle. Therefore, when tightening the plurality of bolts 13 at a place other than the factory, a handle of a general wrench is inserted into a poipo having a length of about 2 m, and two workers perform the tightening work, which is a heavy labor. The removal work is also the same, and the worker is forced to perform a difficult work each time the vehicle is transported and consumes a lot of time.

The present invention has been made in view of the above problems, and it is possible to easily attach and detach the bolts that fasten the center frame and the crawler frame, thereby shortening the transportation time and greatly improving the working efficiency. It is an object of the present invention to provide a gauge adjusting device for a tracked vehicle that can perform the above.

[0008]

In order to achieve the above object, a gauge adjusting device for a tracked vehicle according to the present invention is provided with an upper surface of left and right crawler frames provided on both sides of a lower portion of a vehicle body.
A seat plate for slidably installing the leg portion of the center frame equipped with the upper swing body is provided, and the seat plate provided on the lower surface of the leg portion of the center frame and the seat surface of the crawler frame are detachable with bolts. A lower traveling body of a track-type construction vehicle in which the left and right crawler frames are fastened and movable in the vehicle width direction between the bolt and a seat plate provided on the lower surface of the leg portion of the center frame. Is a structure in which frictional resistance reducing means is interposed.

Further, in the above structure, the frictional resistance reducing means has a fixing member that abuts against the member to be tightened and a rotating member that abuts against the seating surface of the head of the tightening bolt, and the fixing member has a ball. The rotary member is fitted in via the connection member, and the fixed member and the rotary member are composed of a connecting member that holds the rotary member so as to be rotatable relative to each other in the axial direction.

[0010]

According to the above-mentioned constitution of the invention, the frictional resistance between the bolt head and the member to be tightened is reduced, the torque required for tightening or removing the bolt is reduced, and a sufficient tightening torque is sufficient for the shaft. Since the force can be obtained, the transportation time can be shortened and the work efficiency can be greatly improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a gauge adjusting device for a track-mounted vehicle according to the present invention will be described below with reference to FIGS.

FIG. 5 is a side view showing a first embodiment of a portion of a bolt 13 for fastening the bearing surfaces 6 and 7 of the crawler frames 4 and 5 and the seat plate 12 of the center frame 10, and the bolt 13 and the seat. Friction resistance reducing means 20 is interposed between the plate 12 and the plate 12. The overall structure for fastening the crawler frame 4 and the center frame 10 together is the same as that described with reference to FIGS.

FIG. 6 is a sectional view of the frictional resistance reducing means 20. A bolt hole 22 is formed in the center of a fixing member 21 having a U-shaped cross section.
Is provided, and the lower surface is in contact with the seat plate 12 that is the member to be tightened. A rotary member 23 having a bolt hole 24 is rotatably fitted into the fixed member 21 via a ball 25, and the fixed member 21 and the rotary member 23 are rotatable with respect to each other, and are connected to each other in the axial direction (for example, a connecting member). Wire etc.) 26
Are connected by. The ball 25 may be a roller, for example.

The bearing surface 15 of the head of the bolt 13 is in contact with the rotating member 23. When the bolt 13 is tightened, the bolt 13 and the rotating member 23 rotate integrally, and the fixing member 21 is a ball. 25 makes rolling contact. The tightening force is applied from the seat surface 15 of the head of the bolt 13 through the rotating member 23, the ball 25, and the fixing member 21 to the seat plate 1.
2 is transmitted to generate an axial force. As described above, since the rotating member 23 and the fixed member 21 are in rolling contact with each other through the balls 25, the frictional resistance generated between the bolt and the member to be tightened when the bolt 13 is tightened is extremely small,
A large axial force can be generated with a much smaller tightening torque than in the past. Therefore, even a small wrench can be sufficiently tightened, and the impact wrench can be used in the gap S between the crawlers 2 and 3 and the bolt 13 shown in FIG. 4, and the work can be performed by one person.

Therefore, the center frame 10 during transportation
Of the bolts 13 for fastening the crawler frames 4 and 5 to each other, and when the work is completed after the transportation is completed, the bolts 13 are removed.
When the center frame 10 and the crawler frames 4 and 5 are fastened with each other, the bolt attaching / detaching work can be completed very easily in a short time, the fatigue of the worker is reduced, and the work efficiency of the entire vehicle is improved. can do.

FIG. 7 is a side sectional view showing a second embodiment of the bolt 13 portion for fastening the seat surfaces 6 and 7 of the crawler frames 4 and 5 and the seat plate 12 of the center frame 10. That is, the frictional resistance reducing means 20 and the bolt 1
A guard 16 is provided around 3 to protect the friction resistance reducing means 20 and the bolt 13 from the rocks and the earth and sand from the outside.

[0017]

As described above, according to the present invention,
The frictional resistance generated between the bolt head seating surface and the member to be tightened when tightening the bolt is extremely small, and when the vehicle is transported, the bolt is removed to narrow the gauge, keeping the vehicle width within the transportation limit, or ending the transportation. However, even when the gauge is returned to the original position when the work is started and the center frame and the crawler frame are fastened, the bolts can be attached and removed very easily and in a short time, which shortens the transportation time and reduces The fatigue of the vehicle can be reduced and the work efficiency of the entire vehicle can be improved.

[Brief description of drawings]

FIG. 1 is a side view of a large hydraulic excavator.

FIG. 2 is a rear view of the same.

FIG. 3 is a plan view showing a portion where a center frame and a track frame are fastened together with bolts.

FIG. 4 is a side view of the same.

FIG. 5 is a side view showing a first embodiment of the bolt tightening method of the invention.

FIG. 6 is a side sectional view of a frictional resistance reducing means used in the bolt tightening method of the present invention.

FIG. 7 is a side sectional view showing a second embodiment of the bolt tightening method of the invention.

[Explanation of symbols]

4 ... Crawler frame, 6 ... Seat surface, 10 ... Center frame, 12 ... Seat plate, 13 ... Bolt, 20 ... Friction resistance reducing means.

Claims (2)

[Claims] 1. A seat plate for slidably installing legs of a center frame on which upper revolving units are mounted is provided on upper surfaces of left and right crawler frames provided on both sides of a lower portion of a vehicle body, and lower faces of the legs of the center frame. In a lower traveling body of a tracked construction vehicle, the left and right crawler frames are movable in the vehicle width direction by detachably tightening a seat plate provided on the crawler frame and a seat surface of the crawler frame with bolts. A gauge adjusting device for a tracked vehicle, characterized in that a frictional resistance reducing means is interposed between the center plate and a seat plate provided on the lower surface of the leg of the center frame. 2. The frictional resistance reducing means includes a fixing member that comes into contact with a member to be tightened and a rotating member that comes into contact with a seating surface of a head of the fastening bolt, and the fixing member is provided with a ball through the ball. The gauge adjusting device for a track-tracked vehicle according to claim 1, further comprising a connecting member that fits the rotating member and that holds the fixed member and the rotating member in a mutually rotatable and axial direction.