JPH0434149Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an air suspension device that elastically supports the cab of a tail-cab automobile using air pressure.

(Prior Art) Recently, an air suspension device has been proposed that elastically supports the cab of a tail-cab automobile using air pressure (see, for example, British Patent No. 1483967 and Japanese Patent Application Laid-open No. 158169/1983). This type of air suspension device consists of front and rear air bellows that are attached to the chassis frame and elastically support the cab, and front and rear leveling valves that are installed between the front and rear air bellows and the air tank. The front and rear leveling valves each have a leveling lever that responds to the upper surface of the front and rear air bellows. These front and rear air bellows are deflected by the weight of the cab, and the amount of deflection is optimally controlled by a leveling valve. However, when the cab tilts from this state, the load on the rear air bellows is removed, so the air bellows extends to its limit, and the leveling valve attempts to exhaust air until the air in the air bellows runs out. Furthermore, since the load on the front air bellows increases, the air bellows contracts to its limit and the air pressure rises to its maximum pressure. On the other hand, if the cab tilts down from this tilted state,
The front air bellows expand rapidly, and the rear air bellows contract rapidly, consuming a large amount of time and air to return to their original state.

(Purpose of the invention) The purpose of the invention is to provide an air suspension device for a tilted cab, which does not require air to be supplied or discharged from the air bellows when the cab is tilted, and therefore allows the air bellows to act immediately when the cab is released. Our goal is to provide the following.

(Structure of the invention) The air suspension device for the tailed cab according to the invention is provided between front and rear air bellows that are attached to the frame of the car seat and elastically support the cab, and between the front and rear air bellows and the air tank. It consists of a front and rear leveling valve, and each of the front and rear leveling valves has a leveling lever that responds to the upper surface of the front and rear air bellows, but each is provided between the front and rear air bellows and the corresponding front and rear leveling valves. The vehicle further includes a cut valve which is connected to the hydraulic circuit so as to be closed when the cab is tilted and open when the cab is tilted down.

With this configuration, when the cab is tilted down, the cut valve closes and air is prevented from being supplied to the front air bellows, and air is prevented from being discharged from the rear air bellows, so when the cab is tilted down, the air bellows is closed immediately. You can work and support Kyabu.

(Embodiment) An embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 schematically shows an air suspension device 10 for a tailed cab according to the present invention. A pair of front and rear air bellows 16, 18 are attached to the frame 12 and elastically support the cab 14; the front and rear air bellows 16, 18; and an air tank 20.
(See Figure 5) The front and rear leveling valves 22, 24 are provided with leveling levers 22a, 24a that respond to the upper surfaces of the front and rear air bellows 16, 18, respectively. have. As shown in FIG. 2, the air bellows 16 and 18 have a rubber bound stopper 2 therein which abuts against the lower seat 26.
8, the lower seat 26 and the bound stopper 28
The stroke interval between is set. The lower seat 26A and the bound stopper 28A may be installed outside the air bellows 16, 18, as shown in FIG. In either case, Figures 2B and 3
As shown in FIG. B, the bound stoppers 28, 28A on the front air bellows 16 side also serve as stoppers when the cab 14 is tilted.

As can be seen from FIGS. 1 and 5, the air suspension device 10 of the present invention includes front and rear air bellows 16, 18 and corresponding front and rear leveling valves 22, 24, respectively. It further includes cut valves 30 and 32. These front and rear cut valves 30, 32 are hydraulic valves connected to a hydraulic circuit 36 of a tilt cylinder 34 of the cab 14 so as to be closed when the cab 14 is tilted and open when the cab 14 is tilted down. cut valve 30,
An example of 32 is shown in Figures 4A and B, and
In the illustrated embodiment, these cut valves 30, 32
is the valve hole 40, 42 of one valve case 38
It consists of a piston-shaped valve body 44 that is slidably fitted across the valve bodies 44 and an oil hole 46 that sucks and discharges oil so as to displace these valve bodies 44. Each valve body 44 has a communication hole 44a. Valve hole 4
A spring 48 is provided which biases it into alignment at 0.42 so that it is normally open. Oil hole 46
is connected to a hydraulic circuit 36 as shown in FIG. Incidentally, in FIG. 4A, numerals 50 and 52 indicate an air intake port and an air discharge port, respectively.

Therefore, when the hydraulic circuit 36 is controlled to release the cab block and extend the cab cylinder 34 in order to tilt the cab 14, the hydraulic pressure is also supplied to the cut valves 30 and 32, so that the valve body 44 moves as indicated by the dotted line in FIG. As shown, the air bellows 1 rise before and after closing the cut valves 30 and 32.
6 and 18 are cut from the leveling valves 22 and 24, so that even if the cab 14 is tilted, air will not be supplied to the air bellows 16 or air will not be discharged from the air bellows 18.
The air within the air bellows 16, 18 is maintained as is. Therefore, when the hydraulic circuit 34 is controlled so that the cab cylinder contracts in order to tilt down the cab 14 again, the cut valve 30,
Hydraulic pressure is discharged from 32, and the cut valve 30,3
2 is opened, the cab 14 is immediately restored to its previous state, and the cab 14 is supported by the air bellows 16 and 18.

Incidentally, a timer may be provided to open the cut valve after the cab is completely tilted down. Further, the timer may be made unnecessary by adjusting the pressure for opening the cut valve. Furthermore, although the fluid pressure circuit is a hydraulic circuit in this embodiment, it may be a pneumatic circuit.

(Effect of the invention) According to the invention, as described above, when the cab is tilted, the cut valve closes and air is prevented from being supplied to the front air bellows and air is prevented from being discharged from the rear bare bellows. When the cab is tilted down, the air bellows can work immediately to support the cab.Therefore, since it does not take time for the air bellows to restore, the cab can be supported reliably, and no wasted air is consumed. Furthermore, since the cut valve only needs to be connected to the fluid pressure circuit of a member such as a cab cylinder, the structure is simple and can be provided at low cost.

[Brief explanation of the drawing]

Figure 1 is a schematic side view of the air suspension device for a tailed cab according to the present invention, Figures 2 A and B are enlarged cross-sectional views of the air bellows used in the present invention in different states, and Figures 3 A and B are respectively FIG. 2 is an enlarged sectional view of the modified example in different states, FIGS. 4A and 4B are an enlarged sectional view and side view of the cut valve, respectively, and FIG. 5 is a system diagram of the air circuit used in the present invention. 10... Tail cab air suspension device, 12... Seat frame, 14... Cab, 16, 18... Front and rear air bellows, 20,
22... Leveling valve, 20a, 22a...
Leveling lever, 26, 26A...lower seat, 2
8, 28A... Bound stopper, 30, 32...
...Cut valve, 34...Tailt cylinder, 3
6...Hydraulic circuit.

Claims (1)

[Claims for Utility Model Registration] (1) Front and rear air bellows attached to the chassis frame and elastically supporting the cab, and front and rear leveling valves provided between the front and rear air bellows and the air tank. The front and rear leveling valves are respectively provided between the front and rear air bellows and corresponding front and rear leveling valves in a tail cab air suspension device having a leveling lever that responds to the upper surface of the front and rear air bellows. An air suspension for a tailed cab, further comprising a cut valve connected to a hydraulic pressure circuit so as to be closed when the cab is tilted and opened when the cab is tilted down. Device. (2) The air suspension device for a tailed cab according to claim 1, wherein the fluid pressure circuit is for a tailed cylinder of the cab.