JPH0130301Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an adjuster cylinder provided in a side frame as a tension adjustment and shock absorbing device for a crawler track in a tracked work machine such as a hydraulic excavator or a bulltower.

(Prior Art) The running belt of a crawler-equipped working machine is constructed as shown in FIG. That is, a driven wheel 2 is rotatably attached to one end of the side frame 4, which is a box-shaped structure, via a bearing 6 that can move back and forth, and a driven wheel 2 is attached to the other end by a hydraulic motor (not shown). Drive wheels 3 to be driven are rotatably mounted, and these drive wheels 3
An endless crawler belt 1 is wrapped around the driven wheel 2 and the driven wheel 2, and the crawler belt 1 is supported by a roller 5 attached to a side frame 4.

Between the vertical frame 4a of the side frame 4 and the yoke 7 of the bearing 6, there is a buffer hydraulic cylinder 9 connected to an accumulator 8, and the tension of the crawler track 1 is adjusted by adjusting the amount of grease or pressure oil injected. The cylinders 10 are connected in series to form an adjuster cylinder.

However, according to this conventional configuration, since the track tension adjustment cylinder 9 and the buffer cylinder 10 are connected in series, the entire length of the adjuster cylinder becomes long. There was a problem that it became difficult.

(Problems to be solved by the invention) The invention has a compact structure that can be easily installed even in large tracked work machines, and is also advantageous in terms of supplying and discharging fluid for adjusting track tension such as grease. It is an object of the present invention to provide an adjuster cylinder having the following configuration.

(Means for solving the problem) The present invention connects the head side chamber of an adjuster cylinder attached to a side frame to an accumulator, and connects the first piston slidably housed in the tube of the adjuster cylinder. coupling a first hollow piston rod, slidably housing a second piston within the hollow first piston rod, coupling a second piston rod to the second piston; The second piston and the second piston rod are provided with crawler belt tension adjusting fluid supply holes that communicate with each other in the axial direction;
A fluid supply port communicating with the fluid supply hole and equipped with a valve is provided on the side surface of the distal end of the second piston rod, and a fluid supply port communicating with the fluid supply hole through the valve is provided on the top and bottom surfaces of the distal end of the second piston rod. The piston rod has an opening that is blocked, the upper opening is closed by a stopper, and the end of the second piston rod is engaged with the bearing support yoke of the driven wheel via a rotation prevention mechanism. Since the adjuster cylinder has a double cylinder structure, it is compact, and the head side of the large diameter tube is connected to the accumulator, so the pressure receiving cross section is large and a large pressure can be generated. On the other hand, the opening for supplying track tension adjustment fluid such as grease should always be provided on the side, and the opening with plugs should be provided at the top and bottom. Therefore, the same type of adjuster cylinders can be used as the left and right adjuster cylinders.

(Embodiment) FIGS. 1 and 2 show an embodiment of an adjuster cylinder according to the present invention. The tube 13 is fitted into the ring-shaped support tube 12 provided at 4a.
The other end thereof is supported by a support frame 14 having a rotation prevention mechanism (not shown) fixed to the side frame 4. The adjuster cylinder 11
The hydraulic oil chamber A is filled with pressure oil, and the hydraulic oil chamber A is connected to the accumulator 8. A first piston 15 is slidably accommodated in the tube 13 of the adjuster cylinder 11, and
A hollow first piston rod 16 is connected to the piston 15 of the piston 15 . Inside the hollow first piston rod 16, a second piston rod is slidably inserted.
the second piston 17;
A second piston rod 18 is connected to the piston rod. The second piston 17 and the second piston rod 18 are provided with tension adjusting fluid supply holes 19a and 19b that communicate with the chamber B between the first and second pistons 15 and 17 and with each other in the axial direction. In addition, as shown in FIG.
A fluid supply port 19c is provided on the upper and lower surfaces of the distal end of the second piston rod 18, and when the valve 20 is loosened, the fluid supply port 19c communicates with the fluid supply hole 19a and has a valve 20 attached thereto. An opening 19d and a grease discharge port 19e are respectively provided, which are closed to the fluid supply hole 19a when the tip is tightened and the tip is pressed against the sealing surface 19f. The upper opening 19d is the stopper 21.
It is blocked by.

The end surface of the second piston rod 18 is brought into contact with the end surface of the yoke 7 for supporting the bearing of the driven wheel, and the second piston rod 18 and the yoke 7 are engaged with each other via a rotation prevention mechanism. That is, the second
Horizontal grooves 22a and 22b are provided on the upper and lower surfaces near the end of the piston rod 18, and the yoke 7 has a fitting portion 23 that fits into each groove 22a and 22b.
Connecting fittings 23A, 2 having a, 23b, respectively
3B is fixed with a bolt 24 to prevent it from rotating, and is configured to prevent the second piston rod 18 from coming off due to vibration.

In this configuration, the impact applied to the adjuster cylinder 11 from the crawler track via the driven wheel 2, bearing 6, and yoke 7 is alleviated by the movement of the pressure oil in the hydraulic oil chamber A connected to the accumulator 8, and a buffering effect is achieved. Ru. In this case, since the hydraulic oil chamber A has a large pressure receiving area, it is possible to generate a large receiving pressure even if the pressure is relatively low. In addition, if the tension in the track becomes loose due to the use of the work equipment,
Valve 20, fluid supply port 19c, supply hole 19a,
The chamber B between the pistons 15 and 17 via 19b
The track tension can be restored by supplying the track.

Moreover, the grooves 22a, 22b and the fitting parts 23a, 23
By fitting with the second piston rod 18, the valve 20 provided on the second piston rod 18 can always be directed to the side, making it easy to supply fluid for adjusting track tension such as grease. Since openings 19d and 19e are provided above and below,
The same type of adjuster cylinder 11 can be used to be attached to either the left or right side frame 4, and when replacing grease, etc., the upper opening 19d side of the piston rod 18 is connected to the plug 21 in both left and right adjuster cylinders. Therefore, by loosening the valve, the sealing surface 19f of the valve 20 opens, and deteriorated grease and the like can be easily discharged from the lower opening 19e.

(Effects of the invention) As described above, since the adjuster cylinder of the invention is composed of a double cylinder, the overall length is shortened, and it can be easily installed on a large working machine. Since the hydraulic oil chamber of the tube is connected to the accumulator, a large pressure-receiving area can be obtained, and an adjuster cylinder suitable for installation on a large working machine can be provided. In addition, a rotation prevention mechanism is provided between the second piston rod and the bearing yoke of the driven wheel, and a fluid supply port for adjusting the track tension such as grease is provided on the side of the second piston rod, and the supply port valve is provided at the top and bottom. Since it has an opening that is closed, grease, etc. can be easily supplied from the side, and the same type of adjuster cylinder can be used for mounting on either the left or right side frame. In any of the adjuster cylinders, when the grease, etc. deteriorates and needs to be discharged to the outside for replacement, the upper opening is closed with a plug, so by loosening the valve, the lower Grease, etc. can be easily discharged from the side opening.

[Brief explanation of drawings]

Fig. 1 is a side view showing an embodiment of the adjuster cylinder according to the present invention, Fig. 2 is an enlarged sectional view taken along the line EE in Fig. 1, and Fig. 3 is a side view of a traveling body illustrating a conventional adjuster cylinder. It is a diagram.

Claims (1)

[Scope of utility model registration request] In a crawler work machine in which a driven wheel is attached to one end of a side frame via a bearing that is movable in the longitudinal direction, and a crawler belt is wrapped around the driven wheel, the head side chamber of an adjuster cylinder attached to the side frame is used as an accumulator. a hollow first piston rod connected to the adjuster cylinder, and coupled to a first piston slidably housed in a tube of the adjuster cylinder; housing a second piston;
A second piston rod is coupled to the second piston, and the second piston and the second piston rod are provided with a crawler tension adjusting fluid supply hole that communicates with each other in the axial direction, and a side surface of the tip end of the second piston rod. is provided with a fluid supply port that communicates with the fluid supply hole and is equipped with a valve, and on the top and bottom surfaces of the tip of the second piston rod, openings that communicate with and are blocked by the valve from the fluid supply hole. A crawler-equipped working machine characterized in that the upper surface side opening is closed by a plug, and the end of the second piston rod is engaged with the bearing support yoke of the driven wheel via a rotation prevention mechanism. Adjuster cylinder.