JPH08319635A - Undercarriage device of hydraulic shovel - Google Patents

Abstract

PURPOSE: To easily change a track width of a crawler wherein a crawler frame has a connection section, which is provided with a bracket extended from an axle, a bracket fitted to the crawler frame and a connecting pin. CONSTITUTION: A hydraulic cylinder 12 is inserted between a bracket 16 for the hydraulic cylinder in an axle 11 and a bracket 24 for a pin in a crawler frame 20, and fixed by a pin 13 and connected with the axle 11 and the frame 20. When crawler track width is changed from a standard state to a narrow state, a working machine is directed to the side of the frame 20, connecting pins 14, 15 connecting the axle 11 and the frame 20 are extracted, a boom cylinder is moved in the lowering direction, and a car body is inclined. The stroke of a rod for the hydraulic cylinder 12 is conducted to the shrinkage side, the frame 20 is slid to the central side of the car body, a pinhole on the frame 20 side is displaced in parallel by the quantity of the change of track width to a pinhole on the axle 11 side, the pins 14, 15 are inserted when the pinholes mutually coincide, and the car body is lowered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension device for a hydraulic excavator, and more particularly to a suspension device for a hydraulic excavator for adjusting a gauge interval used in construction machines such as a hydraulic excavator.

[0002]

2. Description of the Related Art A conventional method for changing the track width of a crawler in a suspension system for a hydraulic excavator will be described with reference to FIGS. As shown in FIG. 9, the hydraulic excavator 100 includes a swing circle 10 on a lower traveling body 101.
The upper revolving superstructure 103 is disposed so as to be fully revolvable and rotatable via the two. In addition, the upper revolving structure 103 has a work machine 104.
The boom cylinder 105 rotates the boom 106 so that the boom 106 can move up and down, and the work machine 104 operates the bucket 107 up and down. As shown in FIG. 15, the undercarriage 101 comprises an axle 70 and left and right chrome frame 73, and the axle 70 is mounted on the upper surface of the left and right chrome frames 73 via a plate 72 of the axle 70 and a bolt 71.
Have been installed in. On the mounting surface of the plate 72 of the axle 70, two groups of bolt holes 71a are provided at two positions separated by a track width change amount (l) in the lateral direction of the vehicle body width. With a standard crawler gauge width (one side G), it is fastened on the outside as shown in FIG. When changing to a narrower track width (G-1), remove the bolts 71 that fasten the axle 70 and the cooler frame 73, align the inner bolt holes 71a, and fasten the bolts 71 again. It has become.

Further, as a prior art for changing the crawler rail width, for example, according to Japanese Utility Model Laid-Open No. 61-198354 shown in FIG. 16, a hole 81 of an axle 80 and a shaft 83 of a crawler frame 82 are provided. By fitting and coupling, the crawler frame 82 is slid by the expansion and contraction of the cylinder 84 to change the crawler track width.

Further, as a prior art for changing the track width of a crawler, for example, according to Japanese Patent Laid-Open No. 3-148388 shown in FIG. 17, an axle 90 and a crawler frame 91 are connected by parallel links 92, 93. By expanding and contracting the cylinder 94, the parallel links 92 and 93 are deformed to change the track width.

[0005]

However, in the bolt fastening method shown in FIG. 15, a large number of large size bolts are required to cope with a large external force, and a large amount of torque is required for this attachment / detachment, which makes difficult work difficult. It was accompanied. Also, the work such as aligning the tap hole of the chrome frame with the bolt hole of the axle is complicated and requires a long time.

The above-mentioned prior art, FIG.
In Japanese Patent Laid-Open No. 1983354, there is a problem that the size is increased because the fitting and expansion / contraction part bears the load at the time of work, and high-precision processing is required, resulting in high cost. Also, due to expansion and contraction of the cylinder, when the crawl frame slides on the axle, it cannot move in parallel with the smooth, and twisting occurs between the two, causing damage to this part and malfunction of the cylinder. There was a problem.

The above-mentioned prior art, FIG.
Japanese Patent No. 148388 has a problem that a link and a cylinder are required, the structure is complicated and the cost becomes high, and the vehicle height becomes high when the width of the crawler gauge is narrowed.

In the present invention, focusing on the above-mentioned conventional problems, the axle and the crawl frame are connected by a pin and a cylinder, and the working machine is used to lift the cradle frame to expand and contract the cylinder. To provide a low-cost and highly reliable undercarriage device for a hydraulic excavator in which the crawler frame can be moved in parallel to the smooth, and the crawler track width can be easily changed by simply replacing the pin. With the goal.

[0009]

In order to achieve the above object, a first invention of the underbody device for a hydraulic excavator according to the present invention is a lower surface of a tip end portion of a box-shaped axle and left and right cross wheels.
A suspension system for a hydraulic excavator, which is combined with the upper surface of a raframe so as to be overlapped with each other and which is moved in the left-right direction of the vehicle body to adjust the outer ends of the left and right crawler tracks. The raframe has at least two front and rear connecting portions spaced apart from each other in the front-rear direction, and the connecting portions extend from the box-shaped axle and are perpendicular to the front-rear direction, and the crora frame. The bracket is provided on the frame and is perpendicular to the front-rear direction, and both brackets are in contact with each other, and at least one coupling pin is provided above and below the overlapping surface.

A second aspect of the undercarriage device of the hydraulic excavator according to the present invention is to move the crawler belts on the left and right sides of the vehicle body by a cylinder disposed between the axle and the left and right crawler frames to outside the crawler belts. A suspension system for a hydraulic excavator for adjusting the ends, wherein a double-rod double-acting cylinder of equal cross-section connected by at least two series circuits is provided between an axle and left and right crawler frames. It is configured.

According to a third aspect of the undercarriage device of the hydraulic excavator according to the present invention, the lower surface of the tip end portion of the box-shaped axle and the upper surfaces of the left and right color crawlers are superposed on each other and combined. A suspension system for a hydraulic excavator that adjusts the outer ends of the crawler belt by moving the crawler belts on the left and right sides of the vehicle body by a cylinder disposed on the mating surface between the axle and the left and right crawler frames. -The raframe has at least two front and rear joints spaced apart in the front-rear direction, and these joints extend from the box-shaped axle and are perpendicular to the front-rear direction; -A bracket that is perpendicular to the front-rear direction and that is abutted on both brackets, and that has at least one connecting pin above and below the overlapping surface, and the axle and the left and right cross-shaped pins, respectively. Frame - is obtained by configuration and comprising at least two equal double rod type double acting cylinder cross-sectional area connecting a series circuit between the beam.

[0012]

According to the above construction, when the crawler rail width is changed from the standard state to the narrow state, the working machine is directed to the side of the crawler frame and the space between the axle and the crawler frame is changed. Remove the connecting pin connecting the and move the boom cylinder downward. When the bucket touches the ground, the reaction force tilts the vehicle body and lifts the crawler belt on one side. Here, when the rod of the hydraulic cylinder connecting the axle and the chrome frame is stroked to the shortening side,
The raframe slides toward the center of the vehicle. This allows
When the pinhole on the chrome frame is moved in parallel with the pinhole on the axle by the amount of track width change (l) and the pinholes match each other, insert the pin here and lower the vehicle body to complete the work. . To change from a narrow crawler track width to a standard condition, after the track on one side is lifted, the rod of the hydraulic cylinder that connects the axle and the crawler frame is stroked to the extension side. Then, the same work as described above may be performed.

Further, the connection between the axle and the chrome frame is a yoke type pin connection having a sliding surface, and the upward force transmitted from the chrome frame during excavator work is transmitted through the contact surface. In addition, since the pin receives the lateral force, the structure is simple and the connecting pin and the hydraulic cylinder are small and lightweight.

Further, according to the underbody device of the hydraulic excavator, in order to change the track width of the crawler, the axle and the crawler can be changed.
When the rods of the two hydraulic cylinders on the left and right, which are connected to the raframe, are stroked on the extension side and the contraction side, the two hydraulic cylinders are double rod double-acting cylinders with the same cross-sectional area. Moreover, since it is connected in a series circuit, the chrome frame always moves smoothly in parallel to the axle. Further, since the throttle valve is provided in the tank return circuit when the rod of the hydraulic cylinder is shortened, the crawler frame slowly moves in parallel without running away even when a lateral load is exerted by its own weight.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A concrete example of the underbody device for a hydraulic excavator according to the present invention will be described below with reference to the drawings. A first embodiment of a suspension device for a hydraulic excavator according to the present invention will be described with reference to FIGS. 1 to 8. FIG. 1 is a perspective view of the axle portion 10 and the left color frame 20. 2 is a side view of the axle portion 10, and FIG. 3 is a plan view. Figure 4 shows the left color
5 is a side view and FIG. 5 is a plan view. FIG. 6 is a side view showing a state in which the axle portion 1 and the left crawler frame 20 are connected to each other in the front direction, in a state where the crawler rail width is standard. FIG. 7 is a side view in a state where the track width is narrow. FIG.
FIG. 7 is a sectional view taken along line YY of FIG. 6.

The axle portion 10 includes a left crawl frame 2
0. Axle 11 composed of a box-shaped portion (M) supported by 0 and a cylindrical portion (N) fixed to the box-shaped portion (M) and holding an upper revolving structure, and a left crawl frame 20. A hydraulic cylinder 12 that moves, a hydraulic cylinder pin 13, and coupling pins 14 and 15. In FIG. 1, the right chrome frame has the same structure as the left chrome frame 20 and is therefore omitted.

The axle 11 has a plate 11a having a horizontal bottom surface on a leg portion, and is a U-shaped vertical plate having a groove which is vertical to the plate 11a and which is vertical to the front-rear direction and has an upper and lower opening. 11b (hereinafter referred to as U-shaped plate 11b) is fixed. The U-shaped plate 11b is provided with a pair of pin holes A1 and A2. The positional relationship between the pin holes A1 and A2 will be described later. In addition, U is on the axle 11.
A hydraulic cylinder bracket 16 that supports the bottom end of the hydraulic cylinder 12 is fixed to the rear of the character plate 11b.

The crawler frame 20 has a plate 21 having a horizontal upper surface on a leg receiving portion, and is perpendicular to the plate 21.
Vertical plates 22 are fixed in the front-rear direction. This vertical plate 22 has two sets of pin holes B1, B2 and C1,
C2 is provided. A shield plate 23 is fixedly installed on the upper side of the vertical plate 22.
Two pin brackets 24, which are inserted into the rod head of the hydraulic cylinder 12, are vertically fixed. The positional relationship between the two sets of pin holes B1, B2 and C1, C2 will be described later. As shown in FIG. 8, the outer width Wc of the shield plate 23 is larger than the inner width Wa of the U-shaped plate 11b. The hydraulic cylinder 12 is inserted between the hydraulic cylinder bracket 16 of the axle 11 and the pin bracket 24 of the chrome frame 20 and fixed by the pin 13 to connect the axle 11 and the chrome frame 20. Has been done. At this time, the vertical plate 22 has a U-shaped side surface.
It is a letter-shaped plate 11b, the upper side in the vertical direction is a shielding plate 23, and the lower side is a horizontal plate 21, which are concentrically enclosed.

The plate 11a of the axle 11 is mounted on the plate 21 of the chrome frame 20 and the vertical plate of the chrome frame 20 is placed between the U-shaped plates 11b of the axle 11. -To 22 is inserted. Axle 11
Pin holes A1 and A2 and the pin hole B of the chrome frame 20
By inserting the two connecting pins 14 and 15 at the positions where B1 and B2 are fitted together, as shown in FIG. 6, the two are connected with the standard track width (G). . In the above embodiment, the vertical plate 22 of the color frame 20 is inserted between the U-shaped plates 11b of the axle 11, and the plates are used as brackets to be connected by the connecting pins 14 and 15. However, one vertical plate is fixed to the axle 11, and
One vertical plate 22 of the frame 20 may be two plates, and a bracket may be connected between them.

The axle 11 and the color frame 20 are
As the hydraulic cylinder 12 expands and contracts, the axle 11
The overlapping surface P (hereinafter referred to as the contact surface P) of the plate 11a of FIG. 1 and the plate 21 of the chrome frame 20 is slidable and movable in the vehicle width direction. When the hydraulic cylinder 12 is operated to slide the chrome frame 20, the pin holes A1 and A2 of the axle 11 and the pin holes C1 and C2 of the chrome frame 20 are aligned with each other. By inserting the connecting pins 14 and 15 of the book, as shown in FIG. 7, the narrow track width (G-
In l), both are connected.

Next, the positional relationship of the pin holes will be described with reference to FIGS.
Described in. The relative positional relationship between the pin holes A1 and A2 of the axle 11 is exactly the same as the relative positional relationship between the pin holes B1 and B2 of the chrome frame 20 and C1 and C2.
Is in a position where B1 and B2 are translated in parallel by the lateral track width change amount (1). Pin hole A1 of axle 11
And the pin hole B1 of the chrome frame 20 is below the contact surface P, and the pin hole A2 of the axle 11 and the chrome frame.
The pin holes B2 of the frame 20 are opened above the contact surface P, respectively. Further, the distance between the center of the pin hole A2 of the axle 11 and the contact surface P of the color frame 20 is
The distance is the same as the distance between the center of the pin holes B2 and C2 of the chrome frame 20 and the contact surface P of the axle 11, and the value is shown in (h). Similarly, the contact surface P and the axle 11
And the distance between the contact surface P and the centers of the pin holes B1 and C1 of the chrome frame 20 are the same.

Next, a method of changing the crawler track width from the standard condition to the narrow condition will be described for the case of the left crawler frame 20. (1) FIG. 6 shows a state of having a standard track width.
First, the connecting pins 14 of the A1 and B1 parts and the A2 and B2 parts,
Remove 15. (2) As shown in FIG. 9, the upper-part turning body 103 is turned, and the working machine 104 is directed to the side of the chrome frame 20. When the boom cylinder 105 is operated and the boom 106 is moved in the lowering direction, the bucket 107 comes into contact with the ground, and the reaction force lifts the crawler belt on one side of the vehicle body upward. At this time, black
The shield plate 23 fixed to the vertical plate 22 of the frame 20 is a U-shaped plate 11 of the axle 11.
Since it is in contact with b, the chrome frame 20 will not come off from the axle 11. (3) In FIG. 6, pressure oil is supplied to the head side of the hydraulic cylinder 12, the rod is contracted, and the connecting pin 14 is inserted at the position where the pin hole C1 matches the pin hole A1. At the same time, the pin hole C2 also coincides with the pin hole A2, so the connecting pin 15 is inserted therein. (4) When the boom cylinder 105 is operated to move the boom 106 in the raising direction and the lifted vehicle body is lowered, the narrow troller rail width shown in FIG. 7 is obtained.

Although the method for reducing the chlorler track width has been described above, the procedure for expanding the chloror track width may be performed in the reverse order of the above. That is, in the state of having the narrow trolley width of FIG. 7, the connecting pins 14 and 15 of the A1, C1 part and A2, C2 part are pulled out, the vehicle body is lifted, and pressure oil is supplied to the bottom side of the hydraulic cylinder 12, The rod is extended, and the connecting pin 14 is inserted at the position where the pin hole B1 matches the pin hole A1. At the same time, when the connecting pin 15 is inserted into the pin holes B2 and A2 and the vehicle body is lowered, a state in which the standard track width is shown in FIG. 6 is obtained.

According to the first embodiment as described above, the axle 11 and the crow frame 20 are connected to each other by the connecting pins 14 and 15 and the hydraulic cylinder 12, and they are connected to change the track width of the crawler. Pull out the pins 14 and 15 to remove your own work machine 10.
4, the hydraulic cylinder 12 is stroked, the color cylinder frame 20 is slid, and the removed connecting pins 14 and 15 are inserted into another position. -It is possible to easily change the track width without the troublesome and complicated work such as using a special tool such as a rock block.

Since the yoke type pin connection having the slide surface P is adopted for the connection between the axle 11 and the crawler frame 20, the upward force transmitted from the crawler frame 20 at the time of excavator work. Since the connecting pins 14 and 15 receive the lateral force transmitted through the contact surface P between the chrome frame 20 and the axle 11, the connecting parts and hydraulic cylinder can be downsized, and the connecting pin can be reduced in weight. Next, the pins can be easily attached and detached. In addition, a coupling link and a slide mechanism that requires highly accurate processing are not required, and the structure is simple, and the cost is low in combination with the reduction in size and weight.

Next, a second embodiment of the underbody device of the hydraulic excavator will be described with reference to FIG. The chrome frame 20a
Other than the pin hole B3, the description is omitted. The pin hole B3 in FIG. 10 is the pin hole B2, C in FIG.
The two are connected to form one elongated hole. The center distance between the pins of the elongated holes is the track width change amount (l) in the lateral direction of the chrome frame 20a.

According to the second embodiment as described above, since it is not necessary to detach the connecting pin 15 when changing the track width, the track width changing operation can be performed more easily. The connecting pin 15 also serves as a guide when the chrome frame 20a and the axle 11 move relative to each other.

Next, a third embodiment of the underbody device of the hydraulic excavator will be described with reference to FIG. In addition, chrome frame 20b
Other than the pin holes B3 and B4, the description is omitted because it is the same as the first embodiment. The pin hole B3 in FIG. 11 is the pin hole B in FIG.
2, C2 are elongated holes as in FIG. 10, and pin holes B4
Indicates that the pin holes B1 and C1 of FIG. 4 are connected to each other to form one elongated hole. The center distance between the pins of the elongated holes is a rail width change amount (l) in the lateral direction of the chrome frame 20b.

According to the third embodiment described above, since it is not necessary to detach the connecting pins 14 and 15 when changing the track width of the crawler, the work of changing the track width can be performed very easily. The connecting pins 14 and 15 serve as guides when the chrome frame 20b and the axle 11 move relative to each other.

A fourth embodiment of the undercarriage device of a hydraulic excavator will be described with reference to FIGS. FIG. 12 is a plan view of the underbody device of the hydraulic excavator of the fourth embodiment, and FIG. 13 is a hydraulic circuit diagram. In FIG. 12, between the axle 11 and the left and right color crawl frames 20d and 30d, one is attached to a bracket 51 attached to the axle 11 by a pin 51a, and the other is attached to the left and right crora frame 20d. Alternatively, two double-rod double-acting hydraulic cylinders 53, 54 and 55, 56 each having the same cross-sectional area and attached to the bracket 52 by a pin 52a are provided at 30d. The body of each of these hydraulic cylinders has a pin 51
It is swingably attached by a and a pin 52a.
When the rods 53b to 56b of these hydraulic cylinders 53 to 56 are extended, the crawler frames 20d and 30d are moved outward, the track width of the crawlers is expanded, and the hydraulic cylinders 53 are extended.
When the rods 53b to 56b of Nos. 56 to 56 are contracted, the crawler frames 20d and 30d are moved inward, and the track width of the chlora is reduced.

The oil discharged from the pump 60 shown in FIG. 13 passes through the operation valve 61 for expansion / contraction selection and the operation valve 62 for left / right selection, and the two hydraulic cylinders 53, 54 on one side of the underbody device of the hydraulic excavator. Alternatively, the hydraulic cylinders 53, 54 are guided to the other two hydraulic cylinders 55, 56 on one side, and the hydraulic cylinders 53, 54 are connected to the hydraulic cylinders 55, 5 by the lines 63, 64, 65.
6 are connected in series by pipe lines 66, 67 and 68, respectively. Further, the pipe lines 65 and 68 are provided with a one-way throttle valve 69 for giving flow passage resistance to the pipe lines. In the hydraulic circuit diagram, auxiliary devices that are not directly related to the present invention are omitted.

Next, a method of changing the crawler track width from the standard condition to the narrow condition will be described with reference to FIG. 12 in the case of the left crawler frame 20d. First, the connecting pin 15a connecting the axle 11 and the left black frame 20d is pulled out, the working machine is projected, and the left black frame 20d is floated. Next, when the operation valve 62 is operated to the left side and then the operation valve 61 is operated to the contraction side, the discharge oil of the pump 60 enters the head side 53a of the hydraulic cylinder 53, the rod 53b is contracted, and the oil discharged from the bottom side 53c is removed. The head 54a of the hydraulic cylinder 54 is inserted, the rod 54b is contracted, and the chrome frame 20d moves in parallel. Therefore, when the removed coupling pin 15a is inserted in another position and the vehicle body is lowered, The width becomes narrow. At this time, the hydraulic cylinders 53, 54
Are connected in a series circuit, the rods 53b, 54
The shortening of b is done simultaneously. Further, the oil discharged from the bottom side 54c returns to the tank through the throttle valve 69 and the operation valves 62 and 61. In addition, when changing the crawler gauge width from the narrow state to the standard state, the same operation is performed except that the operation valve 61 is operated to the extension side.

According to this embodiment, since the hydraulic cylinders 53 and 54 are connected in a series circuit, the rod 5
3b and the rod 54b are displaced at the same time, and the displacement amounts are always the same. For this reason, when changing the crawler gauge width,
Since the chrome frame 20d always moves in parallel to the axle 11, the chrome frame 2d is moved to the axle 11.
Since it is not biased or twisted, the work of changing the track width can be efficiently performed, and the slide portion or the like is not damaged. Further, since the throttle valves 69 are provided in the pipes 65 and 68, the chrome frame 20d moves slowly without running away.

A fifth embodiment of the underbody device of the hydraulic excavator will be described with reference to FIG. FIG. 14 shows a plan view of the underbody device of the hydraulic excavator of the fifth embodiment. The first embodiment uses a single-rod double-acting hydraulic cylinder, whereas the fifth embodiment uses a double-rod double-acting hydraulic cylinder as in the fourth embodiment. The same parts as those in the first embodiment or the fourth embodiment are designated by the same reference numerals and the description thereof will be omitted. Regarding the operation, the same hydraulic circuit as in the fourth embodiment may be used, or an operating valve may be provided in the circuit to each double rod type double acting hydraulic cylinder to control them separately.

[0035]

As described above, according to the undercarriage device of the hydraulic excavator of the present invention, the axle and the left and right crawler frames are respectively connected to the front and rear at two positions by the pin and the hydraulic cylinder, and the crawlers are connected to each other. To change the rail width, pull out the pin, stroke the hydraulic cylinder, and
This can be done simply by sliding the pin and inserting the pin into another position, making it easy to change the track width without the hassle and complicated work of attaching and detaching bolts and using special tools such as chain blocks. You can do it. Axle and Crawler
Since a yoke type pin connection having a sliding surface is used for connecting the frame, the structure is simple and the connecting pin and hydraulic cylinder are small and lightweight, and the cost is low.

Also, by making the pin hole on the chrome frame side elongated, it is not necessary to attach or detach the pin, and the track width changing operation can be performed more easily.

Further, two double rod type double acting hydraulic cylinders are provided at each of the front and rear two positions of the left and right color frame, and since each two hydraulic cylinders are connected in a series circuit, The crawl frame always moves in parallel with the axle in a smooth manner, and the work of changing the track width can be performed efficiently without damaging the slide part or the like.

[Brief description of drawings]

FIG. 1 is a perspective view of an axle and a left crawl frame in a first embodiment of a suspension device for a hydraulic excavator according to the present invention.

FIG. 2 is a side view of the axle portion of the first embodiment.

FIG. 3 is a plan view of an axle portion of the first embodiment.

FIG. 4 is a side view of the left chrome frame of the first embodiment.

FIG. 5 is a plan view of the left chrome frame of the first embodiment.

FIG. 6 is an axle portion and left crawler frame of the first embodiment.
FIG. 3 is a side view showing a coupled state in front of the ram and in a state in which the crawler rail width is standard.

FIG. 7 is an axle portion and a left crawler frame of the first embodiment.
It is a side view in the state where the chlora rail width is narrow, showing the connected state in the front of the frame.

8 is a sectional view taken along line YY of FIG.

FIG. 9 is an explanatory diagram when changing the track width of the crawler.

FIG. 10 is a side view of the left crawl frame of the second embodiment of the underbody device of the hydraulic excavator of the present invention.

FIG. 11 is a side view of the left crawl frame of the third embodiment of the underbody device of the hydraulic excavator of the present invention.

FIG. 12 is a plan view of a underbody device for a hydraulic excavator according to a fourth embodiment of the present invention.

FIG. 13 is a hydraulic circuit diagram of the fourth embodiment.

FIG. 14 is a plan view of the underbody device for a hydraulic excavator according to a fifth embodiment of the present invention.

FIG. 15 is a perspective view of an axle and left and right color cradle frames of a suspension device for a first conventional hydraulic excavator.

FIG. 16 is a plan view of the axle and the left and right chrome frame of the underbody of the second conventional hydraulic excavator.
FIG. 16 (a) shows a state in which the crawler rail width is standard, and FIG.
(B) is a diagram showing a state in which the track width is narrow.

FIG. 17 is a plan view of an axle and left and right chrome frame of an underbody device of a third conventional hydraulic excavator, and FIG.
17 (a) shows the case where the chlora width is standard, and FIG.
(B) is a diagram showing a state in which the track width is narrow.

[Explanation of symbols]

10 ... Axle part, 11 ... Axle, 11b ... U-shaped vertical plate, 12 ... Single rod type hydraulic cylinder, 13 ... Hydraulic cylinder pin, 14, 15 ... Coupling pin, 20, 20
a, 20b, 20d ... left chrome frame, 22 ... vertical plate, 23 ... shield plate, 30d ... right chrome frame, 53, 54, 55, 56 ... double acting double rod type hydraulic cylinder, 60 ... Hydraulic pump, 61, 62 ... Operation valve, 6
9 ... Throttle valve, (M) ... Box-shaped portion of axle, (N) ...
Cylindrical part of the axle.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryuichi Huga 3-1-1 Ueno, Hirakata-shi, Osaka Komatsu Ltd. Osaka factory

Claims (3)

[Claims] 1. A lower surface of a tip portion of a box-shaped axle and an upper surface of left and right color crawlers are superposed and coupled, and the superposed surface is moved in the left-right direction of the vehicle body to allow the left and right crawler belts to move. In an undercarriage device of a hydraulic excavator for adjusting an outer end, at least two front and rear connecting portions are respectively spaced apart in the front-rear direction on left and right crawler frames, and the connecting portions are box-shaped. A bracket extending from the shaped axle and perpendicular to the front-rear direction, a bracket perpendicular to the front-rear direction provided on the crawler frame, and both brackets abutting each other, and at least one each above and below the overlapping surface. An undercarriage device for a hydraulic excavator, which comprises a connecting pin. 2. An undercarriage device of a hydraulic excavator for moving left and right crawler belts of a vehicle body to adjust the outer ends of the crawler belts by a cylinder arranged between the axle and the left and right crawler frames. An undercarriage device for a hydraulic excavator, characterized in that a double-action rod type double-acting cylinder having at least two cross-sections connected to each other by a series circuit is provided between the left and right color cradle frames. 3. The box-shaped axle has a lower surface at the tip end portion and an upper surface of the left and right chrome frame that are superposed and coupled with each other, and an overlapping surface between the axle and the left and right chrome frame. In an undercarriage device of a hydraulic excavator that moves left and right crawler belts of a vehicle body by a provided cylinder to adjust outer ends of the crawler belts, at least two front and rear portions are separated from each other by left and right crawler frames. And a bracket that extends from the box-shaped axle and is perpendicular to the front-rear direction, and a bracket that is provided on the chrome frame and that is perpendicular to the front-rear direction. At least one connecting pin above and below the overlapping surface, and at least two series circuits connected between the axle and the left and right chrome frame. Undercarriage device for hydraulic excavator, characterized in that it is composed of double rod type double acting cylinders having the same area.