JPS6012267B2 - Track adjustment and shock absorber - Google Patents

Description

[Detailed Description of the Invention] In a tracked vehicle such as a bulldozer or hydraulic excavator,
In order to apply a constant tension to the track and buffer the impact load applied to the track, a track frame b is attached to the vehicle body a, as shown in FIG.
A sprocket c is pivotally supported at one end, an idler d is pivotally supported at the other end of the track frame b via a crawler adjustment and shock absorbing device f, and a crawler e is spanned between the sprocket c and the idler d. Ta.

Further, as shown in FIG. 2, the crawler track adjustment and shock absorbing device f consists of a grease cylinder g integrally fixed to the track frame b, and a piston h slidably mounted adjacent to the cylinder g. and a bolt i fixed integrally to the same piston h.
and a spring, a support i, a bracket k that pivotally supports an idler d, a spring support i integrally fixed to the bracket k, and the same bracket kl, which are fixed integrally and have an iron base movably attached to the bolt i. It consists of a sleeve m, a nut n screwed onto the tip of the bolt i, a spring o inserted into the spring receiver i, 1, and a protective tube p covering the spring o. , connect the discharge port of a hand grease pump (not shown) to the grease supply hole q of the cylinder g, and operate the hand grease pump to pressurize grease into the cylinder g to apply initial tension to the crawler track e. I was starting to give.

However, such a conventional crawler track adjustment and shock absorbing device (f) has become larger as the vehicle neck has become larger, and the pressure to press the grease into the cylinder (g) has become too high, making it difficult to operate the manual grease pump. It was difficult to accurately apply the initial tension.

Furthermore, the twill adjustment and shock absorbing device f has a complicated structure consisting of a large number of component parts, and the spring O, the bolt I, and the sleeve M are covered with a spring receiver IS and a protective tube P). Bolt i and spring receiver 1 while driving
Sediment, rainwater, etc. enter the protective tube p through the gap between the hole and the
Each of the above-mentioned components suffered from wear and was prone to breakage within a relatively short period of time.

The present invention relates to an improvement of a crawler adjustment and shock absorbing device that overcomes the above-mentioned difficulties. In a cylinder, an idler piston and a floating piston, which support an idler on which a crawler is spanned, are slidably arranged in series. A pressure reducing valve and a check valve for initial tension setting are interposed between the idler cylinder chamber sandwiched between the idler piston and the floating piston and the main system hydraulic power source, and the floating piston is connected to the idler cylinder chamber. A pressure reducing valve, a check valve, and an accumulator are interposed between the floating cylinder chamber separated by The object of the present invention is to provide a compact and highly durable crawler track adjustment and shock absorbing device that can provide the required tension.

As described above, the present invention provides a cylinder in which an idler piston and a floating piston are slidably mounted in series, and an idler piston and a floating piston are slidably mounted in series, and the idler piston and the floating piston support the idler. A pressure reducing valve for initial tension setting and a check valve are interposed between the cylinder chamber and the main system hydraulic pressure source, and the floating cylinder chamber partitioned by the floating piston from the idler cylinder chamber and the main system hydraulic pressure source are provided. A pressure reducing valve for setting at the start of buffer operation, a check valve, and an accumulator are interposed between the pressure reducing valve for setting the initial tension and the idler cylinder chamber to the pressure necessary to give the required initial tension. In this case, the check valve for setting the initial tension can maintain the set pressure, and therefore the pressure oil is automatically supplied to the idler cylinder chamber regardless of input. ``It is possible to give the required initial tension to the crawler track.

Further, in the present invention, the pressure in the floating cylinder chamber can be set to the pressure necessary to apply a required load for starting the buffer operation by the pressure reducing valve for setting the time to start the buffer operation, and the idler piston can be elastically moved. This can be used to buffer shocks and vibrations applied to the crawler track.

Furthermore, in the present invention, even if the crawler belt stretches due to the weight of the car bran or an impact load during driving, or oil leaks from the cylinder, pressure oil is automatically replenished into both cylinders to maintain a constant tension on the crawler track. can always be given.

Furthermore, the present invention provides two pairs of pressure reducing valves and check valves to provide two different constant pressure sources from one main system hydraulic source.

Furthermore, in the present invention, since an accumulator is provided in the pipeline on the side of the floating cylinder chamber, it is possible to absorb fluctuations in the flow of oil in and out of the floating cylinder chamber, and the reliability of the cushioning performance of the track support is significantly improved. It also has the effect of reducing oil stains, preventing damage to related hydraulic equipment, and being able to follow the rapid decline in the number of swallow cars.

The present invention will be described below with reference to an embodiment illustrated above the x tangent line in the cod diagram.

Even if one end of the pipe is connected to the main system oil source (not shown), the coaxial pipe is equipped with a pressure reducing valve for setting the load to start moving, and a check valve. When the idler movement start load setting cylinder mouse is connected to the pond, it is also connected to the accumulator mouse. Therefore, even if the floating piston 7 of the cylinder 81 for setting the idler movement start load has a cross-sectional area of As, and the floating piston 7 is coated with bran so as to be freely slidable, the inner cross-sectional area of the cylinder S on the Sekiguchi side is A.
A cylinder for setting the initial tension is installed at the foot of the idler piston that supports the toadler official residence, and an iron bag is placed at the foot of the idler piston to allow the cylinder to be fed freely.

In addition, a pressure reducing valve for initial tension setting and a check valve 18 are interposed in the pipe connecting the pipe Kame which is closer to the main system oil pressure source than the pressure reducing valve 3 and the cylinder 8 for setting initial tension.

Furthermore, a piping Kamegawa ko-shutoff valve Wataru 5 and an oil fill Yukame-kame connecting the initial tension setting cylinder Sagi and the main system are interposed. and idler movement start load setting cylinder 6
A shutoff valve fin is interposed in the piping 17 that connects the two.

Therefore, the pressure of the initial tension setting pressure reducing valve 12 is set to Po.
Then, the pressure in the initial tension setting cylinder 8 is set to the set pressure Po by the same pressure reducing valve 12, and the idler 10
An initial tension load Fo=AoPo is applied to the crawler track (not shown). Furthermore, if the set pressure of the pressure reducing valve 3 for setting the load for starting movement of the Hydra movement is set to Ps, the pressure in the cylinder 6 for setting the load for starting movement of the Hydra movement and the pressure in the accumulator 5 is set to the set pressure Ps by the pressure reducing valve 3, and the crawler Operation start load Fs = lees Ps on idler 10
When this is applied, the volume inside the accumulator 5 decreases, and the idler piston 9 is elastically shortened.

Furthermore, the operation start load Fs and the maximum stroke load F
m and the initial tension load Fo, Fo=o. 1~o. 2F
It is set so that the following relationship holds true: s Fm = 1.3 to 2.0 Fs.

Furthermore, although only one system is shown in the upper half of FIG. 3, there are actually two systems, one on each side of the wheel. Since the embodiment shown in the upper half of FIG. 3 is constructed as described above, the shutoff valve 15
, 18, the oil pressure of the main system oil pressure source (not shown) fluctuates over time as shown in FIG. The pressure inside the pressure reducing valve 3
, 12 cut off pressures exceeding the required set pressures Ps, Po, respectively, and the check valves 4, 13 maintain these set pressures Ps, Po.

In this case, since Ps>Po, the floating piston 7 collides with the step of the initial tension setting cylinder 8, and the initial tension load Fo=AoPo acts on the idler piston 9, which is applied to the crawler track. The required initial tension is applied to the twill and maintained constant.

In this state where the initial tension is applied to the track,
When a large tension is generated in the crawler track due to impact or vibration caused by wheel running, the idler piston 9 does not move until the load applied to the idler 10 reaches the operation start load Fs. Until Fs is exceeded and the maximum stroke load Fm is reached, the elastic bag in the accumulator 5 contracts and the floating piston 7 moves to the left, and in conjunction with this, the idler piston 9f moves toward the cylinder 8.
These shocks and vibrations are buffered.

If pressure oil leaks and the pressure in cylinders 6 and 8 decreases while the crawler track adjustment and shock absorbing device is in operation,
Predetermined set pressures Ps and P from the main system hydraulic power source, respectively.
Pressure oil whose pressure has been reduced to
Mow held at o.

Furthermore, when the shutoff valves 15, 18 are opened, the pressure oil in the cylinders 6, 8 is returned to the main system, and the idler piston 9 can be deeply advanced into the cylinders 6, 8 to remove the tracks. Further, if the pipe 1 is ruptured, the emergency shutoff valve 2 is automatically closed to prevent hydraulic fluid from flowing out from the main system hydraulic power source.

In this way, in the above-mentioned embodiment, the initial tension applied to the crawler track and the start-of-operation load can always be maintained at a constant value, and the hydraulic oil can be replenished automatically without any manual adjustment. can.

Further, in the above embodiment, FIGS. 1 to ! Since it does not require the spring o, spring receiver j, 1, bolt i, etc. of the conventional model shown in Figure 2, it is more compact, and there is no loss due to wear or rusting of these parts, and the durability is greatly improved. improve.

In the embodiment shown in the upper half of FIG. 3, as shown in the lower half of FIG. The pipe 14 closer to 16 and the inside of the cover 19 are connected to the pipe 20
In addition to having the same effect as the upper half embodiment, such an embodiment can also return leaked hydraulic fluid to the system.

In the embodiment shown in FIG. 3, the idler movement start load setting pressure reducing valve 3 is a pressure reducing valve with relief 3' as shown in FIG. It may be installed in the piping 1 closer to the 2nd.

As is clear from Fig. 5, the actuation start load Fs is 5 to 10 times the initial tension load Fo, and the cross-sectional areas As and Ao of the pistons 7 and 9 are not so different, so Po<Ps
As a result, when the pressure reducing valve 3 for setting the movement start load and the pressure reducing valve 12 for setting the initial tension are provided in parallel as in the embodiment shown in FIG. However, in the embodiment shown in FIG. When the initial tension setting pressure reducing valve 12 is arranged in series on the side, a relatively small fluctuating pressure of Ps - Po is applied to the initial tension setting pressure reducing valve j2, which has the effect of stabilizing the initial tension setting pressure Po. .

In each of the embodiments shown in the upper and lower halves of FIG. 3 and FIG.
It is sufficient to provide two systems. Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design modifications can be made without departing from the spirit of the present invention. .

[Brief explanation of drawings]

FIG. 1 is a side view of a wheel equipped with a conventional crawler adjustment and shock absorbing device, FIG. 2 is a longitudinal sectional plan view of the main part thereof, and FIG. An explanatory diagram illustrating the outline of each embodiment of the shock absorber; FIG. 4 is a characteristic diagram illustrating temporal changes in system oil pressure in the embodiments;
FIG. 5 is a characteristic diagram illustrating the buffer characteristics of the above embodiment, and FIG.
The upper half and lower half of the figure are explanatory diagrams schematically illustrating other embodiments, respectively. 1...Piping, 2...Emergency shutoff valve ~ 3...
Pressure reducing valve for setting at the start of buffer operation, 4...Check valve,
5... Accumulator, 6... Floating cylinder chamber 7... Floating piston, 8... Initial tension setting cylinder, 9... Idler piston, 10... Idler,
il...Piping 12...Reducing valve for initial tension setting, 13...Check valve, 14...Piping, 15...Shutoff valve, 16...Oil filter, 17... …·Piping,
18...・Shutoff valve "19...〇Cover" 20...Piping.Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. In a cylinder in which an idler piston and a floating piston that support an idler on which a crawler track is spanned are fitted in a slidable manner in series, between the idler cylinder chamber sandwiched between the idler piston and the floating piston and the main system hydraulic pressure source. A pressure reducing valve and a check valve for setting the initial tension are interposed between the floating cylinder chamber, which is partitioned by the floating piston from the idler cylinder chamber, and the main system hydraulic power source, to set the pressure at the start of buffer operation. A crawler track adjustment and shock absorbing device characterized by being equipped with a pressure reducing valve, a check valve, and an accumulator.