JPS6181811A - Vehicle height control device - Google Patents

Abstract

PURPOSE:To save power consumption in a vehicle height control device of a hydraulic control type, by discharging a hydraulic pressure from one of front and rear hydraulic cylinders in a vehicle when a hydraulic pressure is supplied to the other. CONSTITUTION:In increasing a vehicle height, a motor 17 is driven to forwardly rotate a bi-directional pump 18 and supply a hydraulic pressure through a front main oil passage 19 to a front cylinder 1 to expand the front cylinder 1. At this time, a high pressure in the main oil passage 19 is supplied through a passage 41 to a pilot check valve 23 in a rear main oil passage 20 to open the check valve 23. Accordingly, a hydraulic pressure 12 in the rear cylinder 2 is supplied through the bi-directional pump 18 to the front cylinder 1. As a result, the rear cylinder 2 is expanded by a reaction force of a suspension spring S, and therefore vehicle height at both the front and rear sides are increased. In decreasing the vehicle height, the operation reversed to the above is carried out. Thus, power consumption may be reduced.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a vehicle height adjustment device, and in particular to a vehicle height adjustment device that supplies pressure oil to and discharges pressure oil from hydraulic cylinders disposed at each of the four wheels of a vehicle. The present invention relates to a vehicle height adjustment device configured to adjust vehicle height.

[Conventional technology]

For example, the following proposals have been made as vehicle height adjustment devices configured to adjust the height of a vehicle by supplying and discharging pressure oil to and from hydraulic cylinders disposed at each of the four wheels of the vehicle. be.

In other words, each hydraulic cylinder installed on each of the four wheels of a vehicle is connected to a bidirectional pump that is connected to a reservoir tank and driven by an electric motor to suck and discharge hydraulic fluid. supplies pressure oil into each hydraulic cylinder, thereby raising and adjusting the vehicle height, and at the same time, the bidirectional pump is reversed to discharge the pressure oil in each hydraulic cylinder into the reservoir tank, thereby raising the vehicle height. It is designed to lower the vehicle height.

Therefore, it is possible to adjust the desired vehicle height by operating a switch on the electric motor that drives the bidirectional pump.

[Problem that the invention seeks to solve]

However, according to the above conventional proposal, pressure oil is supplied all at once to the hydraulic cylinders installed at each of the four wheels of the vehicle to raise and adjust the vehicle height.
There are disadvantages in that the bidirectional pump becomes larger, the drive motor becomes larger, and the power consumption increases accordingly.

In addition, in particular, if a small pump and a small drive motor are used to reduce power consumption, the time required to raise and adjust the vehicle height by supplying pressure oil to each hydraulic cylinder becomes longer, making it impractical. There is an inconvenience that it disappears.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a new and practical vehicle height adjustment device that can reduce power consumption.

[Means for solving problems]

In order to solve the above-mentioned problems, the structure of the present invention is installed in a hydraulic cylinder which is disposed in each of the four wheels of a vehicle, and whose upper end is connected to the vehicle body side and whose lower end is connected to the axle side of the vehicle. In a vehicle height adjustment device that is configured to enable vehicle height adjustment by supplying pressure oil to or discharging pressure oil in the hydraulic cylinder, the front side of the vehicle is equal to the rear side of the vehicle. The present invention is characterized in that when pressure oil is supplied into one of the hydraulic cylinders, the pressure oil is discharged from the other hydraulic cylinder.

〔Example〕

The present invention will be explained below based on the illustrated embodiments.

FIG. 1 shows an embodiment of the vehicle height adjustment device according to the present invention, in which a hydraulic cylinder 1 is disposed on the front side of the vehicle, and a hydraulic cylinder 2 is disposed on the rear side of the vehicle. and a hydraulic circuit 3 respectively connected to the hydraulic cylinders 1.2.

The above hydraulic cylinders 1 and 2 are each shown as a single unit in the figure, but for the sake of explanation, only one of each cylinder is shown as a pair of left and right cylinders are provided on the front and rear sides of the vehicle. This is also the case in the following figures 2 and 3.

The front side hydraulic cylinder 1 has its upper end connected to the vehicle body 4 side, and its lower end connected to the vehicle axle 5.
In this embodiment, the lower end is connected to the axle 5 and the upper end is attached to the hydraulic shock absorber 6 connected to the vehicle body 4, and is fixed to the hydraulic shock absorber 6. It consists of a cylinder part 7 which is an outer cylinder, and a piston part 9 which is a spring seat that is slidably inserted so as to form an appropriate oil chamber 8 in the cylinder part 7.
is connected to the axle 5 side via a hydraulic shock absorber 6, and the piston portion 9 is connected to the vehicle body 4 side via a spring 10 interposed in a spring seat serving as the piston portion 9,
That is, they are connected.

Pressure oil can be supplied into the oil chamber 8 from the outside, and therefore, when pressure oil is supplied into the oil chamber 8,
The piston part 9 moves up inside the cylinder part 7, raising the lower end support point of the spring 10, and therefore, the hydraulic cylinder 1 is extended by the supply of pressure oil, and the height of the vehicle is adjusted higher. .

The rear hydraulic cylinder 2 has an upper end connected to the vehicle body 4 side and a lower end connected to the axle 5 side of the vehicle. In this embodiment, the lower end is connected to the axle 5 side.
a cylinder 11 connected to a cylinder 11; a piston 13 disposed within the cylinder 11 and defining an upper oil chamber 12;
It consists of a rod 14 that is connected to the piston 13 and whose upper end protrudes from the upper end of the cylinder 11, and a bracket 15 that allows the rod 14 to pass through and restricts the rod 14 from descending by more than a predetermined amount. By connecting the hydraulic cylinder 2 to the side, the hydraulic cylinder 2 can be installed in a vehicle.

Pressure oil can be supplied from the outside into the upper oil chamber 12. Therefore, when pressure oil is supplied into the upper oil chamber 12, the piston 13 moves down inside the cylinder 11,
As the rod 14 is lowered, the upper end of which is fixed to the bracket 15, the rod 14 is lowered, and the hydraulic cylinder 2 is compressed by the supply of pressure oil. The upper end of the hydraulic shock absorber 16 disposed in the vehicle is pushed down, and the height of the vehicle is adjusted to be lower.

That is, the front hydraulic cylinder 1 expands when pressure oil is supplied to adjust the vehicle height higher, and the rear hydraulic cylinder 2 expands when pressure oil is discharged to adjust the vehicle height higher. At the same time, conversely, when pressure oil is discharged from the front hydraulic cylinder 1, it is compressed and the vehicle height is adjusted lower, and when pressure oil is supplied to the rear hydraulic cylinder, it is compressed and the vehicle height is lowered. It will be adjusted.

Therefore, when trying to adjust the vehicle height by extending the front hydraulic cylinder 1, the rear hydraulic cylinder 2
If you want to lower the vehicle height by compressing the front hydraulic cylinder 1, that is, by discharging the pressure oil, you need to drain the pressure oil from the rear hydraulic cylinder 2. It would be a good idea to supply it.

The hydraulic circuit 3 enables the supply and discharge of pressure oil as described above.

The hydraulic circuit 3 includes an electric motor 17 as a drive source, a bidirectional pump 18 that rotates forward and reverse depending on the selected drive of the electric motor 17, and the bidirectional pump 18 and the oil in the front side hydraulic cylinder 1. A front side main oil passage 19 that communicates with the pump 8 and the bidirectional pump 18
and a rear side main oil passage 20 that communicates with the upper oil chamber 12 in the rear hydraulic cylinder 2, and a rear side main oil passage 20 that replenishes insufficient hydraulic oil in the main oil passages 19 and 20, or
, 2Q, and a reservoir tank 21 for draining excess hydraulic oil.

Each of the main oil passages 19 and 20 has a pilot check valve 22.23 on the bidirectional pump 18 side, a throttle 24.25 on each hydraulic cylinder 1.2 side, and a check valve 26.27 parallel to this. In addition, check valves 30 and 31 are provided in the supply oil passages 28 and 29 that connect each of the main oil passages 19 and 20 and the reservoir tank 21, respectively.

Also, the main oil passage 19.20 and the reservoir tank 2 are located between the bidirectional pump 18 and the pilot check valve 22.23 of the main oil passage 19.20.
1 and the pilot check valve 22.23 above.
main oil passage 1 positioned between and the orifice 24.25
9.20 and the reservoir tank 21 are provided with unload oil passages 32, 33, and 34, respectively.

35 is arranged, and each of the uno-do oil passages 3
2.33.34.35 respectively have relief valves 36.
37, 38, and 39 are arranged.

Note that the pilot check valves 22 and 23 provided in each of the main oil passages 19 and 20 are connected to pilot oil passages 40 and 4), respectively. The base ends of the oil passages 19 and 20 are respectively connected to the main oil passages 19 and 20 on the other side.

To explain in detail the operation of the hydraulic circuit 3 configured as above, first, when adjusting the height of the vehicle to raise it, the electric motor 17 is operated to rotate the bidirectional pump 18 in the normal direction, and the front side Pressure oil is supplied into the main oil passage 19. As a result, the main oil path 1
9 becomes high pressure, and this high pressure flows into the main oil passage 20 on the rear side.
The pilot check valve 23 is guided through a pilot oil passage 4) to a pilot check valve 23 disposed therein, and the pilot check valve 23 allows pressure oil from the rear hydraulic cylinder 2 side to flow to the bidirectional pump 18 side. is allowed.

Therefore, the upper oil chamber 12 in the rear hydraulic cylinder 2
The pressure oil inside flows into the bidirectional pump 18 through the throttle 25 and the opened pilot check valve 23, and the bidirectional pump 18 receives the inflowed hydraulic oil into the oil chamber 8 in the hydraulic cylinder cylinder on the front side. It will be supplied as pressure oil to Then, the front hydraulic cylinder 1 is extended by the supply of the pressure oil, and the front vehicle height of the vehicle is adjusted higher, and the pressure oil in the upper oil chamber 12 is released from the rear hydraulic cylinder 2. When the suspension spring 8 is discharged, the hydraulic cylinder 2 is extended by the reaction force of the suspension spring 8. In other words, the parallel hydraulic shock absorbers 16 are extended, and the rear vehicle height is also adjusted higher.

Furthermore, when adjusting the vehicle height, which has been raised as described above, to lower it, the bidirectional pump 18 is reversely rotated by operating a switch on the electric motor 17. by this,
A high pressure state occurs in the rear side main oil passage 20, and the high pressure is passed through the pilot oil passage 40 to the pilot check valve 22 disposed in the front side main oil passage 19.
, the pilot check valve 22 becomes open, allowing the pressure oil in the oil chamber 8 of the front hydraulic cylinder 1 to flow out. Follow me.
Pressure oil discharged from the front hydraulic cylinder 1 is supplied into the upper oil chamber 12 of the rear hydraulic cylinder 2 by the bidirectional pump 18.

As a result, the front hydraulic cylinder 1 is compressed and the front vehicle height of the vehicle is adjusted low, and the rear hydraulic cylinder 2 is also compressed by the supply of pressure oil, so that the suspension spring 'S- is compressed, and the vehicle height on the rear side of the vehicle is also adjusted lower.

Figure 2 shows another embodiment of the present invention, and the configurations of the hydraulic cylinder 1 and hydraulic circuit 3 disposed on the front side of the vehicle are the same as those shown in Figure 1. However, there is a difference in the configuration of the hydraulic cylinder 2 disposed on the rear side of the vehicle.

Here, to briefly explain the configuration of the rear hydraulic cylinder 2, the hydraulic cylinder 2 has a damping force generating mechanism, and includes a cylinder body 42 and a cylinder housed within the cylinder body 42. The piston rod 44 is connected to the piston part 43 and has a lower end protruding from the lower end of the cylinder body 42, and the piston rod 44 is slidable into a piston-side oil chamber 45 defined by the piston part 43 housed in the cylinder body 42. The upper end of the cylinder body 42 is connected to the vehicle body side of the vehicle, and the lower end of the piston rod 44 is connected to the axle side of the vehicle.

The piston portion 43 is provided with a check valve 48 that allows hydraulic oil to pass from the piston-side oil chamber 45 into the rod-side oil chamber 47, and the free piston 46 is provided with a check valve 48 that allows hydraulic oil to pass from the piston-side oil chamber 45 into the rod-side oil chamber 47. A check valve 50 that allows hydraulic oil to pass into a reservoir chamber 49 formed inside the upper end of the cylinder body 42 and a throttle 51 that allows communication between the piston-side oil chamber 45 and the reservoir chamber 49 are provided. has been done.

The rear main oil passage 20 extending from the hydraulic circuit 3 communicates with a rod side oil chamber 47 in the cylinder body 42 on the one hand, and into a piston side oil chamber 45 in the cylinder body 42 on the other hand. It is branched out so that it is connected. A solenoid valve 53, a variable throttle 54, and a check valve 55 parallel to the variable throttle 54 are disposed in the oil passage 52 that is branched and communicates with the piston-side oil chamber 45.

Note that a dust cover 56 is disposed between the lower end of the cylinder body 42 and the lower end of the piston rod 44.

Therefore, when the rear hydraulic cylinder 2 is formed as described above, when adjusting the height of the vehicle to raise it,
From the illustrated state, the bidirectional pump 18 is rotated forward to supply pressure oil into the main oil passage 19 on the front side, and the pilot check valve 23 disposed in the main oil passage 20 on the rear side is opened. The hydraulic oil in the rod-side oil chamber 47 is caused to flow out and is supplied into the front-side hydraulic cylinder 1 to extend it.

In addition, when adjusting the vehicle height to lower the height of the vehicle, the solenoid valve 53 is turned off from the state shown in the figure, the bidirectional pump 18 is reversed, pressure oil is supplied into the rear main oil passage 20, and the rod side oil chamber is The pressure oil is caused to flow into 47.

As a result, the piston portion 43 moves up within the cylinder body 42, and the rear hydraulic cylinder 2 is compressed.

When the hydraulic cylinder 2 expands and contracts, the oil in the rod-side oil chamber 47 is throttled by the external variable throttle 54 and flows into the piston-side oil chamber 45. Then, in the piston side oil chamber 45, the hydraulic oil corresponding to the amount of the missing piston rod 44 is removed from the riser plug 49.
It flows from inside through the throttle 51 of the free piston 46.

Also, during compression, the oil in the piston-side oil chamber 45 flows into the rod-side oil chamber 47 via the check valve 48, and the hydraulic oil corresponding to the amount of piston rod 44 entering into the piston-side oil chamber 45 flows into the rod-side oil chamber 47. It flows into the reservoir chamber 49 via the throttle 51.

In the embodiment described above, the solenoid valve 53 may be operated manually, in which case a drive signal for the bidirectional pump 18 may be simultaneously applied and turned off after a predetermined set time.

Further, although the throttle 51 in the free piston and the external variable throttle 54 serve as valves for generating damping force, these damping valves may be omitted.

Furthermore, a baffle plate may be disposed between the air surface and the oil surface in the reservoir chamber 49 to prevent aeration due to fluctuations in the oil level.

Figure 3 shows still another embodiment of the present invention, in which a front hydraulic cylinder 1 and a hydraulic circuit 3 are shown.
Although the structure is the same as that shown in FIG. 1, there is a difference in the structure of the rear hydraulic cylinder 2.

That is, this rear hydraulic cylinder 2 includes a cylinder body 57 whose lower end is connected to the positive shaft side of the vehicle, and the cylinder body 5.
It is connected to a piston 60 that partitions an upper oil chamber 58 and a lower oil chamber 59 within the cylinder body 7, and has a lower end protruding from the lower end of the cylinder body 57, an upper end protruding from the upper end of the cylinder body 57, and the protruding upper end is A solenoid switching valve 63 is provided in an oil passage 62 that externally communicates the lower oil chamber 58 and the lower oil chamber 59. have.

The hydraulic cylinder 2 shown in Figure 3 does not have a damping force generating mechanism, unlike the hydraulic cylinder 2 shown in Figure 2, but it is formed so that it can expand and contract after adjusting the vehicle height. It is something that

That is, when the solenoid valve 63 is energized and the bidirectional pump 18 is rotated in the forward direction with the solenoid valve 63 switched to the communicating position, the hydraulic oil in the upper oil chamber 58 flows out to the front side hydraulic cylinder 1 side, and the oil pressure is When the cylinder 2 is extended to adjust the vehicle height higher and the bidirectional pump 18 is reversed, pressure oil is supplied into the upper oil chamber 58, compressing the hydraulic cylinder 2 and adjusting the vehicle height lower. Become.

Further, when the solenoid valve 63 is switched to the cutoff position, it expands and contracts according to changes in the load on the hydraulic cylinder 2, and at this time, an external oil passage is provided between the upper oil chamber 58 and the lower oil chamber 59. They will communicate with each other via 62.

〔Effect of the invention〕

As described above, according to the present invention, either the front side hydraulic cylinder or the rear side hydraulic cylinder, which is arranged at each of the four wheels of the vehicle and is formed to enable the height adjustment of the vehicle, Since the vehicle height can be adjusted by supplying pressure oil and expanding or contracting it, it is possible to downsize the electric motor itself, which is one of the driving sources, and reduce power consumption. In addition to the advantages, the bidirectional pump driven by the electric motor can be made smaller, and the cost of the entire device can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a vehicle height adjusting device according to one embodiment of the present invention, FIG. 2 is a diagram showing another embodiment, and FIG. 3 is a diagram showing still another embodiment. Engineering...Hydraulic cylinder, 3...Hydraulic circuit, 4...Vehicle body, 5...Axle, 7...Cylinder part, 8...Oil chamber, 9...Piston part, 11...・Cylinder, 12...
・Upper oil chamber, 13...piston, 14...rod,
17... Electric motor, 18... Bidirectional pump, 1
9.20... Main oil path, 21... Tank, 22.
23...Pilot check valve.

Claims (5)

[Claims] (1) Supplying pressure oil into hydraulic cylinders that are disposed on each of the four wheels of a vehicle and whose upper end is connected to the vehicle body side and whose lower end is connected to the axle side of the vehicle, or In a vehicle height adjustment device configured to enable vehicle height adjustment by discharging pressure oil, pressure oil is discharged into a hydraulic cylinder on either the front side or the rear side of the vehicle. A vehicle height adjustment device characterized in that the pressure oil is formed so that pressure oil is discharged from the inside of the other hydraulic cylinder during supply. (2) When adjusting the height of the vehicle, pressure oil is supplied to the hydraulic cylinder on the front side of the vehicle, and the pressure oil inside the hydraulic cylinder on the rear side of the vehicle is discharged, and when adjusting the vehicle height to lower the vehicle, the pressure oil is supplied to the hydraulic cylinder on the front side of the vehicle. 2. The vehicle height adjustment device according to claim 1, wherein the vehicle height adjustment device is configured to discharge pressure oil in a hydraulic cylinder and to supply pressure oil into a rear hydraulic cylinder of a vehicle. (3) The vehicle height adjustment device according to claim 1, wherein the hydraulic cylinder on the rear side of the vehicle has a built-in damping force generating mechanism. (4) The vehicle height adjustment device according to claim 1, wherein the vehicle height adjustment device is configured such that pressure oil discharged from the front hydraulic cylinder of the vehicle is supplied to the rear hydraulic cylinder of the vehicle. (5) The vehicle height adjustment device according to claim 1, wherein the vehicle height adjustment device is configured such that pressure oil discharged from a rear hydraulic cylinder of a vehicle is discharged into a reservoir tank.