JPS6127228B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a track tension imparting device for a crawler-equipped vehicle or the like.

Conventionally, as shown in the side view of FIG. 1, a crawler belt tension applying device 06 in a known crawler-equipped vehicle is interposed between the shaft of an idler 04 and a track frame 02, and has a sprocket 03 and a guide roller 0.
7. It is provided in order to adjust the initial tension of the crawler belt 05 that is wrapped around the idler 04 and to allow foreign matter to escape if it gets caught.

As shown in the vertical cross-sectional view of FIG. 2, its structure consists of a spring 011 which is elastically loaded between spring receivers 012 and 013, and one end of which is a fork end to pivot the shaft of the idler 04. The other end is spring receiver 01
2, and the piston 018 whose one end is fixed to the spring receiver 013 are slidably inserted, and the other end is attached to the track frame 02.
The initial load of the crawler track 05 is determined by pressurizing grease or hydraulic oil into the cylinder 020 through a grease supply hole 021 drilled in the hydraulic cylinder 019.
4, the tension of the crawler belt 05 is adjusted.

However, such a track adjustment and shock absorbing device does not have enough space because various devices and a large number of guide rollers are attached to the track frame. There is a demand in the industry for the development of a sealed and maintenance-free device that can be used easily.

The present invention has been proposed in view of the above circumstances, and an object of the present invention is to provide a crawler track tension applying device that is compact and has an initial tension adjustment function that can be used even in wet areas.

Therefore, the present invention provides a piston or hydraulic pressure having one end fixed to the track frame and the other end sliding integrally with the initial tension applying hydraulic cylinder that applies a pressing force to the idler support member. In a crawler track tension imparting device, in which a shock absorbing hydraulic cylinder consisting of a cylinder is coaxially inserted and a check valve and a relief valve are inserted in parallel into a grease supply conduit that supplies grease to the shock absorbing hydraulic cylinder by an accumulator. The present invention is characterized by comprising a check valve interposed between the hydraulic cinder for applying initial tension and the hydraulic cylinder for buffering to permit movement of grease from the latter to the former.

The third embodiment of the present invention will be described with reference to the drawings.
The figure is a system diagram showing the first embodiment, and Figure 4 is the system diagram showing the second embodiment.
It is a system diagram showing an example.

First, in FIG. 3, 2 is a track frame, 4 is an idler, and 101 has one end as a fork end to pivot the shaft of the idler 4, and the other end coaxially contacts the initial tension adjustment piston 102. The contacting idler support member 103 is a spherical surface formed at the abutting end of the initial tension adjustment piston 102 with respect to the idler support member 101, 104 is a dust seal, and 105 is the outer periphery of the initial tension adjustment piston 102 having a relatively small cross-sectional area A2. A seal 106 is fitted into a carved annular groove, and 106 is an initial tension adjustment hydraulic cylinder having an initial tension pressure chamber 107 with a relatively small cross-sectional area A2 into which the initial tension adjustment piston 102 is slidably inserted. , 111 has a relatively large cross-sectional area A
This is a buffer hydraulic cylinder having one buffer pressure chamber 110, in which the buffer hydraulic cylinder 111 is made integrally with the initial tension adjustment hydraulic cylinder 106, and there is a partition wall 1 between both hydraulic cylinder pressure chambers 107 and 110.
In 09, both pressure chambers 107 and 110 are connected to a check valve 11.
An oil hole communicating through 7 is bored. 10
8 is a shutoff valve inserted in an oil passage communicating with the initial tension pressure chamber 107; 112 is a buffer hydraulic cylinder 11;
A buffer piston 113 with a relatively large cross-sectional area A1 is slidably inserted into the pressure chamber 110 of No. 1; 114 is a stopper which is fitted to the right end of the hydraulic cylinder 111 with a plurality of bolts 115 and has a through hole in the center, and 116 is a stopper with a buffer piston 112 formed at the inner end. A piston rod whose outer end passes through the center hole of the stopper 114 and is fixed to the truck frame 2; 118 is a check valve; 11
A relief valve 9 is set to a relief pressure Pr, and a check valve 118 and a relief valve 119 are connected in parallel and inserted into an oil passage extending along the axis of the buffer piston rod 116. 120 is an accumulator with a pressure Pa that supplies grease to the pressure chamber 110 of the buffer hydraulic cylinder 111 and the pressure chamber 107 of the initial tension adjustment hydraulic cylinder 106;
Reference numerals 1 and 122 indicate shutoff valves inserted in pipes communicating with the accumulator 120, and the grease in the accumulator 120 is branched from the pipe between the shutoff valves 121 and 122, passes through the check valve 118, and is sent to the hydraulic cylinders 111 and 122. 106 pressure chambers 110 and 107
will be sent to F is the tension of the crawler belt stretched between the idler 4 and the sprocket, l is the stroke of the buffer hydraulic cylinder 111, and P1 and P2 are the pressures of the grease in the pressure chambers 110 and 107, respectively.

In such a device, (1) First, in the initial setting state, Pa=P1=P2 and A1>A2, so
The initial tension F of the crawler track is F=A2·P2, and the buffer piston 112 is located at the right end of the pressure chamber 110 and is pressed against the stopper 114.

(2) Next, the track tension increases and this becomes Pr・A1
When the temperature exceeds that level, the relief valve 119 operates (see arrow), and the idler 4 and idler support member 10
1. The hydraulic cylinders 106 and 111 move to the right as one unit, and the grease in the pressure chamber 110 is removed from the relief valve 11.
9 and the shutoff valve 121 to return to the accumulator 120. During this period, P1>Pa, and when the hydraulic cylinders 106 and 111 move by an amount equal to the stroke l, the partition wall 109 moves toward the piston 112.
When it hits, its movement stops. Meanwhile, in the hydraulic cylinder 106, P2>P1, and the grease in the pressure chamber 107 does not move due to the action of the check valve 117.

(3) Also, when the crawler belt tension decreases and becomes P1<Pa, the accumulator 120 passes through the check valve 118.
of grease enters the pressure chamber 110. If the initial tension decreases beyond the adjustment capacity of the accumulator 120, the shutoff valve 122 is opened and grease is replenished from there at a pressure of Pa or more, thereby increasing the pressure of the accumulator and restoring the predetermined initial tension. be able to.

(4) When removing the crawler track, close the shut-off valve 121 and open the shut-off valve 108 to discharge grease from the pressure chamber 107 and move the idler 4.

According to such a device, it is possible to obtain a crawler tension imparting device that is smaller in size than known crawler adjustment and buffering devices, is a sealed type that can be used in wetlands, and also exhibits an automatic initial tension adjustment function. .

In the second embodiment shown in FIG. 4, the relative relationship between the buffer hydraulic cylinder and the buffer piston is reversed, and when the piston 112' is fitted to the right end of the initial tension adjustment hydraulic cylinder 106, the piston rod 1
16 is replaced by a hydraulic cylinder 111' into which a piston 112' is inserted, and the pressure chamber 110 is
A check valve 117 is provided in the oil passage communicating between the pressure chamber 107 and the pressure chamber 107.
The structure is slightly different from the first embodiment shown in FIG. 3 in three points: the iris 123 is inserted in parallel with the check valve 118, and the iris 124 is inserted in parallel with the check valve 118.

However, in addition to performing substantially the same tension adjustment and buffering effects as in the first embodiment, the second embodiment also suffers from repeated loads and a situation where the pressures P1 and P2 gradually increase. However, the throttles 123 and 124 can always restore the set state so that P1=P2=Pa, and when an excessive load is applied, the throttle effect has the effect of minimizing the movement of grease. can also be played.

In short, according to the present invention, one end of the hydraulic cylinder for applying initial tension that applies pressing force to the idler support member is fixed to the truck frame, and the other end slides integrally with the hydraulic cylinder for applying initial tension. Track tension is achieved by coaxially fitting a buffering hydraulic cylinder consisting of a piston or a hydraulic cylinder, and inserting a check valve and a relief valve in parallel in a grease supply pipe that supplies grease to the buffering hydraulic cylinder by an accumulator. In the applying device, a check valve is inserted between the hydraulic cylinder for applying initial tension and the hydraulic cylinder for buffering, and allows movement of grease from the latter to the former;
The present invention is extremely useful industrially because it provides a compact crawler tensioning device that can be used even in wetlands.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a known crawler-equipped vehicle;
FIG. 2 is an enlarged vertical sectional view showing the crawler tension applying device 06 of FIG. 1, FIG. 3 is a system diagram showing a first embodiment of the crawler tension applying device 06 of the present invention, and FIG. It is a system diagram showing an example. 2...Truck frame, 4...Idler, 1
01... Idler support member, 102... Piston for initial tension adjustment, 103... Spherical surface, 104... Dust seal, 105... Seal, 106... Hydraulic cylinder for initial tension adjustment, 107... Initial tension pressure chamber, 108 ...Shutoff valve, 109 ...Bulkhead, 11
0...Buffer pressure chamber, 111...Buffer hydraulic cylinder, 112...Buffer piston, 113...Seal, 114...Stopper, 115...Bolt,
116... Piston rod, 117... Check valve,
118...Check valve, 119...Relief valve, 12
0... Accumulator, 121, 122... Shutoff valve, 123, 124... Throttle, F... Crawler tension, l... Stroke, Pa... Pressure of the accumulator, P1... Pressure of the buffer hydraulic cylinder 111, P2 ...Hydraulic cylinder 106 for initial tension adjustment
pressure, Pr...relief pressure.

Claims (1)

[Claims] 1. A hydraulic cylinder for applying initial tension that applies pressing force to the idler support member has one end fixed to the track frame and the other end consisting of a piston or a hydraulic cylinder that slides integrally with the hydraulic cylinder for applying initial tension. In the crawler track tension imparting device, in which a damping hydraulic cylinder is coaxially inserted and a check valve and a relief valve are inserted in parallel into a grease supply conduit that supplies grease to the damping hydraulic cylinder by an accumulator. A crawler track tension imparting device characterized in that a check valve is inserted between the hydraulic cylinder for use in the initial tension imparting and the hydraulic cylinder for imparting initial tension to allow movement of grease from the former to the latter.