JPH0796870A - Undercarriage of crawler type construction machine - Google Patents

Abstract

(57) [Summary] [Purpose] To make it possible to easily expand and contract the gauge of the track frame of a crawler type construction machine with a structure advantageous in terms of strength. [Structure] Cylindrical holes 11 at the front and rear ends of the center frame 10,
12, a cylindrical beam 21 fastened to the track frame 20 with bolts 22 is fitted into the cylindrical hole 11 so as to be slidable in the vehicle width direction, and the cylindrical hole 12 is attached to the track frame 20 via an elastic support device 30. The cylindrical beam 23 is slidably fitted. The central portion of the center frame 10 and the central portion of the track frame 20 are connected by a hydraulic cylinder 13. Since the elastic support device 30 absorbs errors such as the center-to-center distance between the cylindrical holes 11 and 12 and the cylindrical beams 21 and 23 and parallelism, the cylindrical holes 11 and 12 and the cylindrical beams 21 and 2 are absorbed.
It is possible to increase the precision of fitting with 3 and prevent backlash to improve the strength, and the expansion and contraction of the hydraulic cylinder 13 facilitates the expansion and contraction of the track frame gauge.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a crawler type construction machine,
In particular, the present invention relates to an undercarriage of a hydraulic excavator, a crawler crane, etc., in which a track gauge can be expanded and contracted.

[0002]

2. Description of the Related Art FIG. 1 is a side view of a hydraulic excavator, and FIG. 2 is a front view thereof. An upper revolving structure 2 having a work machine 3 is mounted on the lower traveling structure 1. Track frames 5 are attached to the left and right of the center frame 4 of the undercarriage 1,
A crawler belt 6 is mounted on the track frame 5. Conventionally, when the width W of the lower traveling structure 1 shown in FIG. 2 is larger than the width S of the upper revolving structure 2 and the width W exceeds the transport limit, the space between the left and right track frames (track gauge) is reduced. A method of keeping the width W within the transportation limit is adopted.

Several proposals have been made as methods for expanding and contracting the interval between the left and right track frames. The first method is the one proposed in the actual Kaihei 3-115157.
Is a perspective view showing the flange 10 of the center frame 100.
1 is fastened to the track frame 103 with bolts 102, and the track frame 1 is always shown as a solid line.
03 at the outermost position, and at the time of contraction, move the track frame 103 to the position shown by the chain double-dashed line so that the bolt 10
Tighten at 2. The pitch of the bolts 102 in the vehicle width direction is such that the bolt holes are aligned even when the track frame 103 is moved. The second method is Shoukai 60-
FIG. 9 is a plan view showing the configuration of the center frame 11 as proposed in 160282.
0 has two square or round holes 111, and square or round beams 113 fixed to the left and right track frames 112 are slidably inserted. The center frame 110 and the left and right track frames 112 are connected by hydraulic cylinders 114. When the hydraulic cylinder 114 is extended, the left and right track frames 112
The distance between the hydraulic cylinder 11 and the hydraulic cylinder 11 is increased as in (a).
When 4 is contracted, the beam 113 moves by sliding in the hole 111, and the distance between the track frames 112 is reduced as shown in (b). The third method is proposed in JP-A-3-148388, and FIG. 10 is a front view showing the configuration.
As shown in (a), the center frame 120 and the left and right track frames 121 are connected by links 122 and 123 to form a parallel four-bar link. The center frame 120 and the left and right track frames 121 are connected by a hydraulic cylinder 124. 125 is a track. When the hydraulic cylinder 124 is extended, the space between the left and right track frames 121 is expanded as shown in (a), and when the hydraulic cylinder 124 is contracted, the space between the track frames 12 is reduced as shown in (b).

[0004]

However, the above method has the following problems. (1) In the first method, a large number of bolts must be attached / detached every time the track frame interval is expanded / contracted, which requires a large number of steps. In addition, it takes man-hours to clean mud accumulated on the bolts. (2) In the second method, since the two beams fixed to the left and right track frames are inserted into the two rectangular or round holes provided in the center frame, the dimensional accuracy between the holes and the beams is high. Is difficult to secure, and it is necessary to provide a gap between the hole and the beam. Therefore, if the work is performed for a long time, this backlash may be enlarged, which may cause damage. (3) In the third method, since the parallel four-bar link mechanism is used, if the space between the truck frames is reduced during transportation, the height increases, which may hinder transportation. Also,
Since it is only the link mechanism, it is difficult to secure the strength against the load in the front-rear direction.

The present invention has been able to pay attention to the above-mentioned problems, and the number of man-hours for expanding and contracting the track frame intervals is small,
An object of the present invention is to provide an undercarriage of a crawler-type construction machine, which has less rattling between a connecting portion between a center frame and a track frame, is advantageous in strength, and does not hinder transportation.

[0006]

To achieve the above object, in the first invention of the undercarriage of the crawler type construction machine according to the present invention, the track frames provided on both sides of the center frame of the undercarriage are provided. In a lower traveling body of a crawler-type construction machine that is movable in the vehicle width direction, a cylindrical hole for a beam is provided in each of the front and rear ends of the center frame in the vehicle width direction, and a cylindrical beam fixed to the track frame is provided on one side. A cylindrical beam slidably fitted in the cylindrical hole and slidably fitted in the track frame through an elastic body is slidably fitted in the other cylindrical hole, so that the center frame and the track frame are hydraulic cylinders. In the second aspect of the invention, the track frames provided on both sides of the center frame of the lower traveling body are connected. In a lower traveling body of a crawler type construction machine that is movable in the vehicle width direction, a cylindrical hole for a beam is provided in one of the front and rear ends of the center frame in the vehicle width direction, and the other is rotatable via a ball joint. A cylindrical member having a cylindrical hole for a beam is attached to the cylindrical frame, and the cylindrical beam fixed to the track frame is slidably fitted into the one cylindrical hole and can be horizontally rotated on the upper surface of the track frame. The cylindrical beam mounted on the cylindrical member is slidably fitted into the cylindrical hole of the tubular member, and the center frame and the track frame are connected by a hydraulic cylinder.

[0007]

According to the above construction, cylindrical holes are provided in the vehicle width direction at the front and rear ends of the center frame of the lower traveling body of the crawler type construction machine, and the cylindrical beam fixed to the track frame is provided in one of the cylindrical holes and the other. A cylindrical beam mounted on the track frame via an elastic body was slidably fitted in the cylindrical hole, and the center frame and the track frame were connected by a hydraulic cylinder. Since the elastic body can absorb the dimensional error between the center frame and the track frame, the gap between the cylindrical hole and the cylindrical beam can be reduced. In addition, a cylindrical member provided with a cylindrical hole in one of the front and rear ends of the center frame in the vehicle width direction and a beam cylindrical hole in the other through a ball joint is rotatably mounted and fixed to the track frame. The beam is slidably fitted into one of the cylindrical holes, and the cylindrical beam mounted on the upper surface of the track frame so as to be rotatable in the horizontal direction is slidably fitted into the cylindrical hole of the tubular member, and the center frame and the track frame Since the and are connected by a hydraulic cylinder, the space between the left and right track frames can be expanded / contracted by expanding / contracting the hydraulic cylinder, and the dimensional error between the center frame and the track frame due to the rotation of the tubular member and the rotation of the cylindrical beam. Since it can be absorbed, the gap between the cylindrical hole and the cylindrical beam can be reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a lower traveling body of a crawler type construction machine according to the present invention will be described below with reference to the drawings. FIG. 3 is a plan view of the first embodiment of the undercarriage. Cylindrical holes 11 and 12 penetrating in the vehicle width direction are provided at the front and rear ends of the center frame 10 of the lower traveling body. Truck frame 2
Cylinder beam 21 is fastened to 0 with bolt 22 and
It is slidably fitted in. On the other hand, a cylindrical beam 23 is attached to the track frame 20 via an elastic support device 30,
It is slidably fitted in the cylindrical hole 12 of the center frame 10. The gap between the cylindrical holes 11 and 12 and the cylindrical beams 21 and 23 is set small so that there is no play. FIG. 4 is FIG.
11 is a sectional view of the elastic supporting device 30 taken along line AA of FIG. A shaft 31 is fixed to the upper surface of the track frame 20, the cylindrical beam 23 is mounted by a rubber mount 32, and is fixed to the shaft 31 by a bolt 34 via a cover 33. The center portion of the center frame 10 and the center portion of the track frame 20 are connected by a single hydraulic cylinder 13.

Next, the operation will be described. The elastic support device 30 absorbs dimensional errors such as center-to-center distances between the cylindrical holes 11 and 12 of the center frame 10 and the cylindrical beams 21 and 23 and parallelism. Therefore, the cylindrical holes 11, 1
It is possible to reduce the backlash between the 2 and the cylindrical beams 21 and 23 and improve the strength. Expansion and contraction of the track gauge can be easily performed by expanding and contracting the hydraulic cylinder 13.

FIG. 5 is a plan view showing a second embodiment of the undercarriage, and FIG. 6 is a side view showing the BB arrow of FIG. A cylindrical hole 11 penetrating in the vehicle width direction is provided in one of the front and rear ends of the center frame 10, and a ball joint 14 fixed to the other has a cylindrical member 1 provided with a cylindrical hole 15 for a beam.
6 is rotatably mounted by a cap 17 and a bolt 18. The cylindrical beam 21 fastened to the track frame 20 with bolts 22 is slidably fitted in the cylindrical hole 11. On the other hand, a cylindrical beam 25 is mounted on the upper surface of the track frame 20 via a bearing 24 so as to be horizontally rotatable as indicated by an arrow.
Reference numeral 5 is slidably fitted in a cylindrical hole 15 of a tubular member 16. The gap between the cylindrical holes 11 and 15 and the cylindrical beams 21 and 25 is set small so that there is no play. The central portion of the center frame 10 and the central portion of the track frame 20 are connected by a single hydraulic cylinder 13.

Next, the operation will be described. Errors and variations in the distance between the centers of the cylindrical hole 11 of the center frame 10, the cylindrical hole 15 of the tubular member 16 and the cylindrical beams 21 and 25, and variations are caused by the rotational movement of the tubular member 16 and the rotation of the cylindrical beam 25. It can be absorbed by exercise. Therefore, the gap between the cylindrical holes 11 and 15 and the cylindrical beams 21 and 25 can be reduced, and the strength can be improved. Further, the expansion and contraction of the track gauge can be easily performed by expanding and contracting the hydraulic cylinder 13.

FIG. 7 is a plan view showing a third embodiment of the undercarriage, and parts other than the hydraulic cylinder are the same as in the second embodiment. A hydraulic cylinder 26 is arranged on the upper surface of the fitting portion between the cylindrical hole 11 of the center frame 10 and the cylindrical beam 21 fixed to the track frame 20.
0 and the track frame 20 are connected. Since the operation is the same as that of the second embodiment, the description will be omitted.

[0013]

As described above, according to the present invention, in the crawler type construction machine in which the track frames provided on both sides of the center frame of the undercarriage are movable in the vehicle width direction, the vehicle width is provided at the front and rear ends of the center frame. The cylindrical beam fixed to the track frame is slidably inserted into one of the cylindrical holes provided in the direction, and the cylindrical beam attached to the track frame is slidably inserted into the other cylindrical hole through the elastic body. Since the center frame and the track frame are connected by the hydraulic cylinder, the space between the left and right track frames can be easily expanded / contracted by expanding / contracting the hydraulic cylinder, and the gap between the cylindrical hole and the cylindrical beam can be reduced to reduce play. be able to. In addition, a cylindrical hole is provided at one of the front and rear ends of the center frame so that a cylindrical beam fixed to the track frame can be slidably inserted therein, and a ball joint fixed to the other of the center frame is provided with a cylindrical hole for the beam. A member was rotatably mounted, a cylindrical beam mounted rotatably in the horizontal direction was slidably fitted on the upper surface of the track frame, and the center frame and the track frame were connected by a hydraulic cylinder. Therefore, the space between the left and right track frames can be easily expanded or contracted by expanding and contracting the hydraulic cylinder, and the gap between the cylindrical hole and the cylindrical beam is reduced to reduce backlash, which improves strength, prolongs life, and facilitates transportation. An undercarriage of a crawler-type construction machine can be obtained without any trouble.

[Brief description of drawings]

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

FIG. 2 is a front view of a hydraulic excavator.

FIG. 3 is a plan view of a first embodiment of the undercarriage of the present invention.

FIG. 4 is a cross-sectional view of the elastic support device according to the first embodiment of the present invention.

FIG. 5 is a plan view of a second embodiment of the undercarriage of the present invention.

FIG. 6 is a side view of a tubular member portion according to a second embodiment of the present invention.

FIG. 7 is a plan view of a third embodiment of the undercarriage of the present invention.

FIG. 8 is a perspective view of a first example of a conventional lower traveling body.

FIG. 9 is a plan view showing a configuration of a second example of a conventional lower traveling body.

FIG. 10 is a front view showing the configuration of a third example of the conventional lower traveling body.

[Explanation of symbols]

 10 Center Frame 11, 12, 15 Cylindrical Hole 13, 26 Hydraulic Cylinder 14 Ball Joint 16 Cylindrical Member 20 Track Frame 21, 23, 25 Cylindrical Beam 24 Bearing 30 Elastic Support Device 31 Shaft 32 Rubber Mount 33 Cover

Claims (2)

[Claims] 1. A lower traveling body of a crawler type construction machine in which track frames provided on both sides of a center frame of the lower traveling body are movable in a vehicle width direction. A cylindrical hole for a beam is provided, a cylindrical beam fixed to the track frame is slidably fitted in one of the cylindrical holes, and a cylindrical beam mounted on the track frame via an elastic body is used for the other cylinder. An undercarriage of a crawler-type construction machine, which is slidably fitted in a hole and connects the center frame and the track frame with a hydraulic cylinder. 2. A lower traveling body of a crawler-type construction machine in which track frames provided on both sides of a center frame of the lower traveling body are movable in the vehicle width direction. A cylindrical hole for the beam is provided on the other side, and a cylindrical member having a cylindrical hole for the beam is rotatably provided on the other side through a ball joint, and the cylindrical beam fixed to the track frame is attached to the one cylindrical hole. A cylindrical beam slidably fitted to the upper surface of the track frame so as to be rotatable in the horizontal direction, and slidably fitted into a cylindrical hole of the tubular member, so that the center frame and the track frame are joined together. An undercarriage of a crawler type construction machine characterized by being connected by a hydraulic cylinder.