JPS6246620Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cab suspension with a height adjustment mechanism. Conventionally, in cab suspensions in which the cab is supported by the chassis frame via an elastic member, the amount of deformation of the elastic member varies depending on the number of occupants in the cab or the presence or absence of luggage on the roof rack, etc. The height may also change.

Therefore, it is conceivable to adjust the height of the cab by interposing a telescoping mechanism between the elastic member and the cab or chassis frame, and by expanding and contracting the telescoping mechanism using a power cylinder. In this case, since the distance between the cab and the chassis frame is narrow in the vertical direction, it is important that the telescoping mechanism and the power cylinder can be sufficiently arranged in a vertically narrow space, and that it is also difficult to adjust the amount of expansion and contraction of the telescoping mechanism by the power cylinder. It is required that it be easy.

The present invention was devised in view of the above, and includes a cab supported by a chassis frame via an elastic member, and a telescoping mechanism interposed between the elastic member and the cab or the chassis frame. A power cylinder that expands and contracts, a displacement sensor that detects the amount of displacement between the cab and the chassis frame,
and a pressure control device that controls the pressure within the power cylinder to adjust the height of the cab relative to the chassis frame according to the output of the displacement sensor, and the expansion and contraction mechanisms are rotatable in series with each other. It is composed of a vertically extendable pantograph mechanism in which two sets of link rows each consisting of two connected links are arranged in parallel, and the power cylinder is interposed between the two sets of link rows and extends almost horizontally. This is a cab suspension with a height adjustment mechanism that is characterized by being extended.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the figure, 2 is the chassis frame, 4 is the cab 6
Cab frames, 8 and 10, which form the lower skeleton of
are brackets fixed to the chassis frame 2, 12 and 14 are brackets fixed to the cab frame 4, respectively, and 16 has one end attached to the bracket 8.
This is a suspension arm whose other end is pivoted to a bracket 12. 18 is a pantograph mechanism whose lower end is attached to the suspension arm 16 and whose upper end is attached to the spring receiving member 20; 22 is a spring compressed between the bracket 12 and the spring receiving member 20;
4 is a shock absorber interposed between the bracket 12 and the spring bearing member 20, and 26 is a power cylinder that extends and contracts the pantograph mechanism. 28
The lower end is attached to the bracket 10 and the upper end is attached to the spring receiving member 30.
32 is a spring compressed between the bracket 14 and the spring bearing member 30; 34 is the spring installed between the bracket 14 and the spring bearing member 3;
Shock absorber interposed between 0 and 36
is a power cylinder that expands and contracts the pandagraph mechanism 28. In addition, pantograph mechanisms 18, 28
In this case, two sets of link rows each consisting of two links connected in series and rotatably to each other are arranged in parallel. Reference numerals 38 and 40 are variable resistance displacement sensors that are provided between the front end and the rear end of the cab frame 4 and the chassis frame 2, respectively, and continuously detect the displacement position between the cab frame 4 and the chassis frame 2. be.

42 is an oil pump that supplies oil sucked from the oil reservoir 44 to the power cylinders 26 and 36, and 46 is a motor that drives the oil pump 42. 48 is a solenoid 50, which is interposed between the oil pump 42 and the power cylinders 26, 36;
52 and is a switching valve operated by pump 4
The oil pumped from 2 is sent to the power cylinder 26,
36, a second position B where the oil pumped from the pump 42 is returned to the oil reservoir 44 as it is, and a third position C where the oil in the power cylinders 26, 36 is returned to the oil reservoir 44. I can do it. 54 are displacement sensors 38 and 40
The chassis frame 2 of cab 6 responds to the signal from
56 is a power source, 58 is a height adjustment switch used when adjusting the height, and 60 is a control circuit that energizes the solenoids 50 and 52 appropriately so that the displacement amount becomes the set value. It is a pilot lamp that lights up at times.

Then, by closing the switch 58,
When the cab 6 is lower than the set value with respect to the chassis frame 2, the switching valve 48 is switched to the first position A based on signals from the sensors 38 and 40, and the motor 46 is driven to supply oil from the pump 42 to the power cylinder. 26, 36, and when the amount of displacement of the cab 6 becomes zero, the switching valve 48 is switched to the second position B and the motor 46 is stopped. Further, when the cab 6 is higher than the set value with respect to the chassis frame 2, the switching valve 48 is switched to the third position C by signals from the sensors 38, 40, and the oil in the power cylinders 26, 36 is transferred to the oil reservoir 44. When the displacement amount of the cab 6 becomes zero, the switching valve 48
is switched to the second position B.

According to the above configuration, for example, the occupant on the cab 6,
By closing the switch 58 regardless of the weight of the luggage, the height of the cab 6 relative to the chassis frame can be maintained at the set value. This has the effect of greatly reducing the visual discomfort caused by the change in color.

Further, since the ratio of the vertical displacement amount of the pantograph mechanisms 18, 28 to the stroke amount of the power cylinders 26, 36 becomes small, not only can the power required for the power cylinders 26, 36 be reduced, but also the power required for the power cylinders 26, 36 can be reduced. , 36, the error in the height adjustment amount of the cab 6 can be reduced even if the accuracy of the expansion/contraction adjustment amount of the cab 6 is somewhat poor. Furthermore, as mentioned above, the power of the power cylinders 26, 36 is small, and the power cylinders 26, 36 are arranged to extend horizontally between both link rows of the pantograph mechanisms 18, 28, so the length in the vertical direction can be reduced. This has the effect that the elastic members 22 and 32 can be sufficiently disposed within a narrow space between the cab 6 and the chassis frame 2.

Furthermore, if the switch 58 in the above embodiment is provided with a function of automatically opening after the engine has started, even if the switch 58 is forgotten to open, the displacement of the cab 6 due to vibrations during driving will not be detected. Can be configured.

Furthermore, it is also possible to mechanically fix the power cylinders 26, 36 when the switch 58 is closed so that no load is applied to the power cylinders 26, 36.

[Brief explanation of the drawing]

Figure 1 is a side view showing one embodiment of the present invention;
The figure is an explanatory diagram showing a hydraulic circuit and an electric circuit including the power cylinders 26, 36 and displacement sensors 38, 40 of FIG. 1. 2... Palm frame, 6... Cab, 16...
...Suspension arm, 18,28...Pantograph mechanism, 22,32...Spring, 26,
36...Power cylinder, 38, 40...Displacement sensor, 42...Pump, 48...Switching valve, 54...
...control circuit.

Claims (1)

[Scope of utility model registration request] In the cab supported by the chassis frame via an elastic member, a power cylinder for expanding and contracting a telescoping mechanism interposed between the elastic member and the cab or the chassis frame; and a pressure control device that controls the pressure within the power cylinder to adjust the height of the cab relative to the chassis frame in accordance with the output of the displacement sensor, The telescopic mechanism is composed of a vertically telescopic pantograph mechanism in which two sets of link rows each consisting of two links rotatably connected in series are arranged in parallel. A cab suspension with a height adjustment mechanism that is interposed between rows and extends substantially horizontally.