JPS6246778A - Tilting device for cabin - Google Patents

Abstract

PURPOSE:To prevent the interference between a bumper and a cabin in tilt operation by extension-operating a shock absorbing hydraulic cylinder interlocked with the tilt operation of a cabin by a tilting hydraulic cylinder and advancing the bumper. CONSTITUTION:When, in a cab-over type tilt cabin type car, the cabin is tilted to the forward tilt attitude in order to maintain and inspect the equipment such as engine arranged number the cabin, the 'UP' button 34 of a tilt operating switch 33 is operated to start a motor 19, and a hydraulic pump 20 is driven. A hydraulic pressure is supplied into the oil chamber 14 of a shock absorbing hydraulic cylinder 12 through a solenoid valve 23, and a piston rod 17 is extended to advance a bumper 11. Then, the solenoid valve 23 is switched to the oil feeding position 37 of a tilting hydraulic cylinder 7, and an oil pressure is supplied into the hydraulic chamber 8 of the hydraulic cylinder 7, and a piston rod 9 is extended to tilt the cabin 6 forward.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cabin tilting device for a cab-over type tilt-cabin automobile.

<Prior art> Generally, in a cab-over type tilt-cabin type automobile,
The cabin is designed to be tilted forward in order to inspect and maintain equipment such as the engine and radiator located below the cabin.

Since large cabins require a large amount of force to tilt the cabin, it is known that the tilt operation is performed using a hydraulic cylinder (
Utility Model Application No. 1-9447.

This pivots the lower front end of the cabin to the frame, provides a tilt hydraulic cylinder between the frame behind this pivot and the center of the bottom of the cabin, and supplies hydraulic pressure to the tilt hydraulic cylinder from a hydraulic supply device. This allows the cabin to be tilted.

(Problems to be Solved by the Invention) In the cabin tilt device described above, when the cabin is tried to tilt forward significantly, the lower front end of the cabin interferes with the bumper, making it impossible to tilt the cabin significantly.
There was a problem in that the workability of inspecting and maintaining equipment such as engines deteriorated.

Therefore, it is conceivable to provide the bumper with a large protrusion in a position where it does not interfere with the cabin, but this would impair the appearance of the automobile when the cabin is not tilted.

(Means for Solving the Problems) The cabin tilting device of the present invention includes a tilting hydraulic cylinder that tilts the cabin of an automobile, and a bumper disposed at the lower front of the cabin that moves the vehicle body forward a predetermined distance. A shock absorbing hydraulic cylinder supported by a shock absorbing hydraulic cylinder, and a hydraulic pressure supply device supplying hydraulic pressure to the tilting hydraulic cylinder and the shock absorbing hydraulic cylinder are provided, and the hydraulic pressure supply device is linked to the tilting operation of the tilting hydraulic cylinder. The shock absorbing cylinder is driven to extend and the bumper is driven forward.

(Function) Since the cabin tilting device according to the present invention is configured as described above, when tilting the cabin, hydraulic pressure is supplied from the hydraulic pressure supply device to the shock absorbing hydraulic cylinder and the tilting hydraulic cylinder, and the shock absorbing hydraulic cylinder and the tilting hydraulic cylinder are supplied with hydraulic pressure. The jl Ta absorption hydraulic cylinder is extended by the hydraulic pressure supplied to the absorption hydraulic cylinder,
The bumper is driven forward.

Further, after or in parallel with the extension of the shock absorbing hydraulic cylinder, the tilting hydraulic cylinder is extended by the hydraulic pressure supplied to the tilting hydraulic cylinder, and the cabin is tilted into a forward tilting position.

Therefore, the bumper will have moved forward by a predetermined distance by the time the cabin tilt l- ends, so the cabin will not interfere with the bumper and will be in a tilted state in which it is largely tilted forward.

(Effects of the Invention) As explained above, the cabin tilting device according to the present invention includes a shock absorbing hydraulic cylinder that supports the bumper on the vehicle body so as to be able to advance a predetermined distance, and a tilting hydraulic cylinder that tilts the cabin. Hydraulic pressure is supplied from the hydraulic supply device to the tilting hydraulic cylinder, and the shock absorbing hydraulic cylinder is extended and driven in conjunction with the tilting operation of the tilting hydraulic pressure, thereby driving the bumper forward. By moving the bumper forward prior to operation, it is possible to reliably prevent interference between the cabin and bumper during cabin tilt, and
By tilting the cabin significantly without being obstructed by the bumper, it is possible to secure a large working space for maintenance and inspection of engines, etc.

Furthermore, since the hydraulic pressure supply device for the tilting hydraulic cylinder and the shock absorbing hydraulic cylinder is shared, the entire device can be made smaller and can be implemented at low cost.

Furthermore, when the cabin is not tilted, the bumper is retracted to the shock absorbing position, so it does not protrude significantly from the cabin and does not spoil the appearance of the vehicle.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a cab-over type tilt-cabin truck, and the wheels 2 of this truck 1 are shown in FIG.
A loading platform 4 is fixed behind the rear end of the front half of the frame 3 supported by the frame 3, an engine 5 is attached to the front of the frame 3, and a cabin 6 is provided above the engine 5. .

The front part of the cabin 6 is rotatably supported on the frame 3, and the cabin 6 is moved by a chill 1 hydraulic cylinder 7 provided between the rear part of the cabin 6 and the frame 3 as shown in solid lines. It is designed to be tilt operated.

The tilt hydraulic cylinder 7 is, as shown in FIG.
It is composed of a single-acting hydraulic cylinder in which the piston rod 9 is extended when hydraulic pressure is supplied to the extension oil chamber 8, and the piston rod 9 is contracted by a contraction spring 10 when the oil pressure in the extension oil chamber 8 is released. has been done.

Further, a bumper 1) is provided at the lower front of the cabin 6, and shock absorbing hydraulic cylinders 12 are fixed to the left and right frames, respectively, near the left and right ends of the bumper 1).
is connected to the tip of the piston rod.

As shown in FIG. 3, the shock-absorbing hydraulic cylinder 12 has compression springs 16 in the extension hydraulic chamber 14 and the contraction hydraulic chamber 15 on both sides of the piston 13. The piston 13 is configured to be located at the center of the cylinder barrel 12a during driving, and a bumper 1) is fixed to the front end of a piston rod 7 that projects forward from the cylinder barrel 12a.

The shock absorbing hydraulic cylinder 12 and the tilting hydraulic cylinder 7 are driven and controlled by a hydraulic pressure supply device 18 shown in FIG.

The hydraulic supply device 18 includes a hydraulic pump 20 that is driven by a motor 19 and pumps up and discharges hydraulic oil from a hydraulic oil tank 21.
and a three-position switching solenoid valve 22 that switches the oil path for supplying the hydraulic pressure discharged from the hydraulic pump 20, and selecting the hydraulic pressure from the three-position switching solenoid valve 22 to the shock absorbing cylinder 12 and the tilting cylinder 7. It is composed of a two-position switching type solenoid valve 23 that supplies the same, a control unit 24 that controls both the solenoid valves 22 and 23, and switches 29, 31, and 32.

The outlet side boat 25 and di of the two-position switching type solenoid valve 23
A check valve 27 and a throttle valve 28 are provided in parallel in an oil passage 26 that communicates with the extension hydraulic chamber 14 of the quick-hit absorption hydraulic cylinder 12, and are activated when the pressure in this oil passage 26 reaches a set pressure. A pressure switch 29 is provided.

Further, the contraction oil chamber 16 of the shock absorbing hydraulic cylinder 12 is connected to the three-position switching type solenoid valve 22 through an oil passage 31.

On the other hand, the control unit h 24 includes the above-mentioned pressure switch 29 and a bumper 1 in which the cabin 6 is tilted and the lower front end of the cabin 6 is moved forward by a predetermined stroke.
), a limit switch 32 that detects that the cabin 6 has returned to the non-chill l-position, and a tilt operation switch 33 are connected.

Next, the operation of the cabin tilt device will be explained.

When tilting the cabin 6 for maintenance/inspection of equipment such as the engine, first turn the tilt operation switch 33 "UP".
"When the button 34 is operated, the motor 19 is activated and the hydraulic pump 20 is driven. At the same time, the three-position solenoid valve 22 is switched to the hydraulic pressure supply position 35, and the hydraulic pump 20 is activated."
The hydraulic pressure is supplied to the extension hydraulic chamber 14 of the shock absorbing hydraulic cylinder 12 via the two-position switching solenoid valve 23, the piston rod is extended, and the bumper 1) moves forward by a predetermined stroke.

When the forward movement of the bumper 1) is completed, the hydraulic pressure in the extension hydraulic chamber 14 increases, the pressure switch 29 in the oil passage 26 closes, and the two-position solenoid valve 23 is activated via the control unit 24. The shock absorption hydraulic cylinder oil supply position 36 is switched to the tilt hydraulic cylinder oil supply position 37.

When the two-position solenoid valve 23 is switched in this way,
The extension hydraulic chamber 14 of the shock absorbing hydraulic cylinder 12 is locked with the piston rod 17 extended, and the piston rod 9 is extended by the hydraulic pressure supplied to the extension hydraulic chamber 8 of the tilt hydraulic cylinder 7. The cabin 6 is tilted forward.

At this time, the bumper 1) has already been moved forward and the front lower part of the cabin 6 does not interfere with the bumper 1), so the cabin 56 can be tilted significantly.

When the cabin 6 is tilted to its maximum extent, the proximity switch 31 provided at the front lower part of the cabin 6 closes when the bumper 1) approaches, and the three-position solenoid valve 22 moves to the block position 38 via the control unit 24. The shock absorbing hydraulic cylinder 12 and the tilting hydraulic cylinder 7 are fixed in the extended state.

Next, when the maintenance and inspection are completed and you want to return the bin 6 to the non-tilted state, turn the tilt operation switch 33 "DOW".
When the N" button 39 is operated, both cylinders 12 shown in "2"
・The three-position directional solenoid valve 22 is switched from the block position 38 where 7 is extended and fixed to the hydraulic return position 40,
The contraction spring 10 of the tilt hydraulic cylinder 7 returns the hydraulic pressure in the extension hydraulic chamber 8 to the hydraulic oil tank 21 via the two-position switching solenoid valve 23 and the three-position solenoid valve 22.
The tilt hydraulic cylinder 7 contracts, and the cabin 6 returns to the non-tilt state.

When the cabin 6 returns to the non-tilted state, the Mitsutwitch 32 closes, and the two-position solenoid valve 23 is switched to the oil supply position 36 via the control unit 24, and the hydraulic pressure for extending the shock absorbing hydraulic cylinder 12 is changed. The chamber 14 and the contraction hydraulic chamber 15 communicate with each other via a throttle valve 28 and also with the hydraulic oil tank 21 . As a result, the piston 13 of the shock absorbing hydraulic cylinder 12 is returned to the intermediate position where the compression springs 16 installed in the extension hydraulic chamber 14 and the contraction hydraulic chamber 15 are balanced, and the bumper 1
) is held in the shock absorbing position, and the tilt release operation of the cabin 6 is completed.

Here, if an impact is applied from the front to the bumper 1) at the impact absorption position, the impact will pressurize the oil in the extension hydraulic chamber 14 of the piston 13, while reducing the pressure in the contraction hydraulic chamber 15. Since the hydraulic pressure in the extension hydraulic chamber 14 flows through the oil passages 26 and 31 into the contraction hydraulic chamber 15 while being controlled in flow rate by the throttle valve 28, the shock applied to the bumper 1) is absorbed.

At this time, since the amount of oil discharged from the extension hydraulic chamber 14 due to the movement of the piston 13 is greater than the amount of oil sucked into the contraction hydraulic chamber 15 by the amount of the retraction movement of the piston rod 17,
This difference in oil will be returned to the hydraulic oil tank 21.

Note that the hydraulic pressure supply device may be partially modified as follows.

As shown in FIG. 4, a hydraulic cylinder 7 for tilting and a hydraulic cylinder 12 for shock absorption are connected in parallel to the hydraulic pump 20, and a two-position switching type solenoid valve 43 is connected to the hydraulic pressure supply path to the hydraulic cylinder 7 for tilting. A three-position switching type solenoid valve 44 is provided in the hydraulic pressure supply path to the shock absorbing cylinder 12.

During shock absorption, the hydraulic pressure from the extension hydraulic chamber 14 is controlled by the throttle valve 41.
The excess oil flows into the contraction hydraulic chamber 15 via the relief valve 42 and is returned to the hydraulic oil tank 21.

In such a device, hydraulic pressure can be supplied from the hydraulic pump 20 to the shock absorbing hydraulic cylinder 12 and the tilting hydraulic cylinder 7 at the same time, and the forward movement of the bumper 1) and the tilting movement of the cabin 6 can be performed simultaneously.

Note that a check valve that only allows flow from the hydraulic chamber to the hydraulic chamber 15 may be connected to the expansion hydraulic chamber 14 side of the throttle valve 41.

As shown in FIG. 5, the hydraulic pressure discharged from the hydraulic pump 20 is configured to be able to be supplied to the shock absorbing hydraulic cylinder 12 and the tilting hydraulic cylinder 7 via the three-position switching type solenoid valve 22. A check valve 46 and a throttle valve 47 are provided in parallel in the oil passage connecting the plane switching type solenoid valve 22 and the extension hydraulic chamber 14 of the shock absorbing hydraulic cylinder 12. When the solenoid valve 22 is switched to the hydraulic pressure supply position 35, the hydraulic pressure from the hydraulic pump 2o passes through the check valve 46 and the throttle valve 47 to the extension hydraulic chamber 14 of the shock absorbing hydraulic cylinder 12, and also to the tilt hydraulic cylinder 7. Since the throttle valve 49 is also supplied to the extension hydraulic chamber 8, the shock absorbing hydraulic cylinder 12 is rapidly extended in a short period of time, and the chill I hydraulic cylinder 7 is gradually extended.

On the contrary, when the three-position switching solenoid valve 22 is switched to the hydraulic return position 40, the oil in the extension hydraulic chamber 8 of the tilt hydraulic cylinder 7 is released from the check valve 48 and the throttle valve 49, causing an impact. Oil from the extension hydraulic chamber 14 of the absorption hydraulic cylinder 12 is supplied to the three-position directional solenoid valve 22 from the throttle valve 47.
Since the tilt release operation of the cabin 6 is quick, the bumper 1) is gradually moved back.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an overall perspective view of a cab-over type tilt cabin type trunk, and FIG. 2 is a configuration diagram of a hydraulic pressure supply device for a tilt hydraulic cylinder and a shock absorption hydraulic cylinder. , FIG. 3 is a longitudinal sectional view of the shock absorbing cylinder, and FIGS. 4 and 5 are views corresponding to FIG. 2 according to modified examples. 1. Tilt cabin type truck, 3. Frame,
6. Cabin, 7. Hydraulic cylinder for tilting,
1) Bumper, 12 Hydraulic cylinder for shock absorption,
18... Hydraulic supply device.

Claims (1)

[Claims] (1) A tilting hydraulic cylinder that tilts the cabin of an automobile; a shock-absorbing hydraulic cylinder that supports a bumper disposed at the lower front of the cabin on the vehicle body so as to be able to move forward a predetermined distance; and the above-mentioned tilting hydraulic cylinder. Equipped with a hydraulic cylinder for shock absorption and a hydraulic supply device that supplies hydraulic pressure to the hydraulic cylinder,
A tilting device for a cabin, wherein the hydraulic pressure supply device is configured to extend and drive a shock absorbing cylinder in conjunction with the tilting operation of a tilting hydraulic cylinder, thereby driving a bumper forward.