JP3870980B2 - Vehicle height adjustment device - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a vehicle height adjustment device that also serves as a suspension for an automobile, and more particularly, to a vehicle height adjustment device that is suitable for use in improving running performance on rough roads and correcting vehicle height drop during loading.
[0002]
[Prior art]
As this type of vehicle height adjusting device, for example, one disclosed in Japanese Utility Model Publication No. 64-52912 has been developed.
[0003]
In this vehicle height adjusting device, a shock absorber and a compression spring as a suspension spring are disposed below the vehicle body, and a hydraulic cylinder is provided between a mount member attached to the vehicle body and an upper spring seat holding the compression spring, The vehicle height is raised when pressure oil is supplied into the cylinder, and the vehicle height is lowered when pressure oil is discharged.
[0004]
[Problems to be solved by the invention]
The above-described conventional vehicle height adjusting device has a structure in which the vehicle height is simply adjusted to high and low by extending and contracting the hydraulic cylinder by supplying and discharging pressure oil to and from the hydraulic cylinder. Since the force cannot be adjusted at the same time, there are the following problems.
[0005]
First, the position of the center of gravity of the vehicle body becomes high when the vehicle is high, and the roll moment during turning increases, so that the operability is deteriorated as compared to when the vehicle is low.
[0006]
Secondly, even if the vehicle height is raised in order to correct the sinking of the vehicle body when the vehicle is loaded, it is not possible to correct the insufficient damping in the shock absorber, so that the ride becomes fluffy and the operability deteriorates.
[0007]
Therefore, the object of the present invention is to adjust the vehicle height to the high and low two stages and at the same time to change the damping force of the shock absorber to the hard and soft two stages, thereby increasing the center of gravity of the vehicle body when the high vehicle height is selected. even if the roll moment increases can achieve stable cornering, it is to prevent further fluffy riding comfort and the steering stability deteriorated even when corrected for body sunk at the time of loading of the luggage in raising so that.
[0008]
[Means for Solving the Problems]
In order to achieve the above-described object, according to the configuration of the present invention, a shock absorber and a suspension spring are disposed below the vehicle body, a hydraulic cylinder is interposed between the suspension spring and the vehicle body, and pressure oil is supplied into the hydraulic cylinder. In the vehicle height adjustment device that adjusts the vehicle height in two steps, the shock absorber has a cylinder, a piston rod that is movably inserted into the cylinder via the piston, and a compartment in the cylinder via the piston. A rod-side oil chamber and an anti-rod-side oil chamber, an extension port and a pressure port formed in the piston to communicate the two oil chambers, an extension-side leaf valve provided at the outlet of the extension port so as to be openable and closable, A pressure-side leaf valve provided at the outlet of the port so as to be openable and closable; a bypass formed in the piston rod and bypassing the extension-side leaf valve and the pressure-side leaf valve to communicate the two oil chambers; A leaf valve for both expansion and pressure provided in the opening of the bypass with respect to the oil chamber on the side of the cylinder, a switching valve that is movably inserted into the bypass and opens and closes the bypass, and a hydraulic cylinder formed in the piston rod. and an oil passage for guiding the pressure to the switching valve, and a pair of upper and lower transverse channel in which the bypass is opened to the rod side oil chamber and the anti-rod side oil chamber, from an axial passage communicating each transverse channel The switching valve comprises a land that opens and closes the upper lateral passage, and a spool that is movably inserted into the axial passage through the land, and opens the bypass on both upper and lower sides of the spool. a pair of upper and lower return spring for holding the spool position is provided, the pressure oil when the high vehicle height by supplying pressurized oil into the hydraulic cylinder of the spool via the oil passage upward Guided, by moving the spool switched to the hard damping force by closing the bypass, by opening the bypass return the spool when the low vehicle height to drain pressure oil from the hydraulic cylinder to the neutral position It is characterized by switching the damping force to soft .
[0010]
In the above case, a cylinder body in which a hydraulic cylinder is coupled to the vehicle body, a rod body inserted into the cylinder body through the piston body so as to be vertically movable, and a lower end carried by a suspension spring, and a piston body in the cylinder body And a pressure chamber which is partitioned by a hydraulic pressure source and connected to an oil passage in the piston rod.
[0011]
Similarly, a disk is provided above the piston, a through hole is formed through the disk in the vertical direction and communicated with the upper lateral passage, and a leaf valve for both extension and pressure is provided at the upper end of the through hole. In addition, it is preferable that a pressure side sub leaf valve is provided at the lower end of the through hole so as to be opened and closed.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIG.
[0014]
In the vehicle height adjusting device of the present invention, a shock absorber 6 and a suspension spring 1 are disposed below a vehicle body 2, a hydraulic cylinder 4 is interposed between the suspension spring 1 and the vehicle body 2, and pressure oil is contained in the hydraulic cylinder 4. The vehicle height is adjusted to high and low two stages by supplying and discharging the vehicle .
Then, the expansion side leaf valve 16 and the compression side leaf valve 17 for generating the damping force, the bypass R bypassing the extension side leaf valve 16 and the compression side leaf valve 17, and the bypass R are movably inserted into the shock absorber. A switching valve V that opens and closes the bypass R is provided. When the hydraulic oil is supplied into the hydraulic cylinder 4 to raise the vehicle height, the pressure oil moves the switching valve V and closes the bypass R to thereby reduce the damping force. Is switched to hard, and when the hydraulic oil is discharged from the hydraulic cylinder 4 to lower the vehicle height, the switching valve V is returned to the neutral position and the bypass R is opened to softly switch the damping force.
This will be described in more detail below.
[0015]
1 and 2 show an embodiment of the present invention.
[0016]
In this vehicle height adjusting device, a shock absorber 6 and a suspension spring 1 are disposed below a vehicle body 2, a hydraulic cylinder 4 is interposed between the suspension spring 1 and the vehicle body 2, and pressure oil is supplied into the hydraulic cylinder 4. The vehicle height is adjusted to two stages, high and low. In this case, the hydraulic cylinder 4 moves up and down through a housing H fixed in the center of the vehicle body 2 side mount body 3, a cylinder body 5 fixed in the housing H, and a piston body 8a in the cylinder body 5. A hollow rod body 8b that is freely inserted, a pressure chamber 12a and an oil chamber 12b defined in the cylinder body 5 by a piston body 8a, and a pressure chamber 12a and an oil chamber 12b that are formed in the piston body 8a and communicate with each other. Port 12c, a seal 11 provided below the cylinder body 5 for guiding the rod body 8b, a port 13 for guiding the pressure chamber 12a to the hydraulic pressure source, and a stop for the piston body 8a provided below the inner periphery of the cylinder body 5. Ring 40.
[0017]
The upper end portion of the piston rod 7 in the shock absorber 6 passes through the center of the rod body 8b and is coupled to the center of the upper end of the cylinder body 5 via bolts and washers, and the vehicle body 2, the cylinder body 5 and the piston rod 7 are interlocked. And move up and down.
[0018]
The rod body 8 b moves up and down while being guided by the inner periphery of the cylinder body 5 and the upper outer periphery of the piston rod 7, and the lower end of the rod body 8 b passes through the seal 11 and is supported on the suspension spring 1 side.
[0019]
The suspension spring 1 is interposed between an upper spring seat 9 and a lower spring seat 10 coupled to the outer peripheral side of the shock absorber 6 and constantly urges the piston rod 7 in the extending direction. Is in contact with the lower end of the rod body 8b of the hydraulic cylinder 4, and the hydraulic cylinder 4 and the vehicle body 2 are urged upward through the rod body 8b. The pressure chamber 12 a in the hydraulic cylinder 4 communicates with oil passages 33 and 34 formed in the piston rod 7.
[0020]
The shock absorber 6 includes an outer tube 35, a damper cylinder 37 in the outer tube 35, and a reservoir 36 defined between the outer tube 35 and the damper cylinder 37. The damper cylinder 37 includes a cylinder 14, a piston rod 7 that is movably inserted into the cylinder 14 via the piston 15, and a rod-side oil chamber A and an anti-rod-side oil that are partitioned in the cylinder 14 via the piston 15. An expansion port 38 and a pressure port 39 formed in the piston B and communicating with the two oil chambers A and B; an expansion side leaf valve 16 provided at the outlet of the expansion port 38 so as to be openable and closable; A pressure-side leaf valve 17 provided at the outlet so as to be freely opened and closed, and formed in a lower inlay portion of the piston rod 7, bypassing the extension-side leaf valve 16 and the pressure-side leaf valve 17, and communicating the two oil chambers A and B. The bypass R, the leaf valve 19 for both expansion and pressure provided in the opening of the bypass R with respect to the rod side oil chamber A, and the bypass R A switching valve V consisting spool 23 for opening and closing the R, which is formed in the piston rod 7 by the pressure of hydraulic cylinder 4 and a oil passage 33 leading to the upper end of the switching valve V. As a result, when high pressure oil is introduced into the pressure chamber 12a in the hydraulic cylinder 4, the pressure in the hydraulic cylinder 4 acts on the switching valve V via the oil passages 33 and 34, thereby bypassing the switching valve V. Energize downward to close R.
[0021]
Further, a disk 18 is provided above the piston 15 , a through hole 21 penetrating the disk 18 in the vertical direction, and a port 21a for communicating the through hole 21 with the bypass R in the piston rod are provided. A leaf valve 19 for both extension and pressure is provided at the upper mouth end of 21, and a pressure side sub leaf valve 20 is provided at the lower mouth end of the through hole 21 so as to be freely opened and closed.
[0022]
The bypass R in the piston rod 7 includes a pair of upper and lower lateral passages 22 and 26 that are formed in the inlay portion 27 and the nut 28 and open to the rod-side oil chamber A and the anti-rod-side oil chamber B, and each lateral passage 22. , 26 and an axial passage 24 communicating therewith . The switching valve V includes a land 41 that opens and closes the upper lateral passage 22 and a spool 23 that is inserted through the land 41 and an intermediate guide 42 so as to be vertically movable in the axial passage. A pair of upper and lower return springs 31 and 32 for holding the spool 23 are provided on the upper and lower sides of the spool 23 at positions where the bypass R is opened, and the pressure from the hydraulic cylinder 4 is guided through the oil passages 33 and 34 above the spool 23. Yes.
[0023]
That is, in the piston rod 7, a push rod 29 having a seal 30 interposed above the spool 23 and an upper spring 31 are arranged in series to urge the spool 23 downward. On the other hand, a guide 25 having a U-shaped cross section and a lower spring 32 are inserted into a hollow piston nut 28 screwed into the lower inlay portion 27 of the piston rod 7, and the spring 32 extends below the spool 23 via the guide 25. And the spool 23 is always urged upward. The upper and lower springs 31 and 32 are balanced to set the spool 23 in a neutral position, that is, a position where the land 41 opens the lateral passage 22 which is a part of the bypass R.
[0024]
The guide 25 is formed with a port 44 connecting the lower oil chamber 43 and the bypass R, and the guide 25 is lowered against the spring 32 where the spool 23 is lowered, and the oil in the oil chamber 43 is moved to the bypass R side. It can be discharged.
[0025]
Next, the operation will be described.
[0026]
1 and 2, the hydraulic cylinder 4 is compressed, and the switching valve V is in a state in which the bypass R is opened. At this time, the vehicle body has a low vehicle height.
[0027]
When traveling in this state and vibration from the road surface is generated, the shock absorber 6 expands and contracts to generate a soft damping force.
[0028]
For example, in the extension side actuation piston 15 is extended is by bending the inner peripheral side of the rod side oil chamber of oil A is Shin compression common leaf valve 19 flows into the through hole 21, further the bypass R serving transverse channel 22-1 through the notch key transverse channel 26 in the longitudinal passage 24 over the guide 42 flows in the counter-rod-side oil chamber B, this time, soft damping force due to the flow resistance of the leaf valve 19 and the bypass R for Shin compression common Will occur. Similarly, in the compression operation, the oil in the anti-rod side oil chamber B flows in the transverse passage 26-longitudinal passage 24-transverse passage 22-through hole 21 which is the bypass R, and the leaf valve is used for both expansion and pressure. 19 and the pressure-side sub leaf valve 20 are bent to flow out into the rod-side oil chamber A, and a soft pressure-side damping force is generated by the leaf valve 19 and the pressure-side sub leaf valve 20 that share the flow resistance and expansion / pressure of the bypass R. .
[0029]
On the other hand, when raising the vehicle height or correcting the sinking of the vehicle body due to load loading, pressure oil is introduced into the hydraulic cylinder 4 from the hydraulic source through the port 13.
[0030]
At this time, the pressure oil is supplied to the pressure chamber 12a, and the cylinder body 5 is raised by the internal pressure at this time, and the vehicle body 2 and the piston rod 7 are raised accordingly, and the high vehicle according to the supply amount of the pressure oil. The vehicle height can be set to high. At this time, the pressure oil in the pressure chamber 12 a is also introduced into the oil passages 33 and 34, and the pressure in the pressure chamber 12 a is applied above the spool 23 serving as the switching valve V. That is, the pressure from the oil passage 33 acts on the upper end of the push rod 29, and the spool 23 is pushed down against the lower spring 32 via the push rod 29, whereby the land 41 bypasses the lateral passage R. 22 is closed.
[0031]
In this state, oil does not flow in the bypass R during expansion and contraction. Therefore, in the extension operation, the oil in the rod side oil chamber A pushes open the extension side leaf valve 16 through the extension port 38 from the upper end notch of the piston 15 and flows out to the anti-rod side oil chamber B. A hard extension side damping force is generated by the valve 16. On the other hand, during the compression operation, the oil in the non-rod side oil chamber B pushes the pressure side leaf valve 17 through the pressure side port 39 and flows out into the rod side oil chamber A, and a hard pressure side damping force is generated by the pressure side leaf valve.
[0032]
When returning the vehicle height to the low vehicle height position, the pressure oil in the hydraulic cylinder 4 is returned to the tank, whereby the cylinder body 5 is lowered by the weight of the vehicle body and compressed to the state shown in FIGS.
[0033]
In the above vehicle height adjustment device, the vehicle height can be adjusted to high and low by extending and contracting the hydraulic cylinder 4, and at the same time, a hard damping force is obtained by a shock absorber at high vehicle height, and soft at low vehicle height. Damping force can be obtained.
[0034]
FIG. 3 relates to another embodiment of the present invention, in which a lateral passage 26 constituting a part of the bypass R is formed below the guide 25. That is, the guide 25 and the spring 32 are provided in the piston nut 28, and the lower oil chamber 43 of the guide 25 is communicated with the anti-rod side oil chamber B through the lateral passage 26 formed below the piston nut 28. .
[0035]
Further, the land 29 and the push rod of the spool 23 constituting the switching valve V are integrally formed. In this case, the switching valve V is not affected by the accumulation of tolerances, and stable performance can be obtained.
[0036]
Other operations are the same as those shown in the embodiment of FIGS.
[0037]
The structure other than the above-described structure is the same as that of the embodiment shown in FIGS.
[0038]
【The invention's effect】
The present invention has the following effects.
[0039]
(1) According to the invention of each claim, a vehicle height adjustment hydraulic cylinder and a shock absorber for generating a damping force are provided, and the shock absorber is attenuated simultaneously with the vehicle height adjustment using the pressure in the hydraulic cylinder. Since the force can be adjusted, a hard damping force can be obtained at a high vehicle height, and a soft damping force can be obtained at a low vehicle height.
[0040]
(2) Similarly, according to the invention of each claim, the pressure in the hydraulic cylinder is applied to the switching valve in the shock absorber to open and close the valve of the damping force variable mechanism to generate the hard and soft damping force. Therefore, a hard damping force can be obtained when selecting a high vehicle height, and the roll speed and overshoot can be reduced with respect to the roll during turning, so that stable turning traveling can be realized.
[0041]
(3) Similarly, if a high vehicle height is selected to compensate for the sinking of the vehicle height when the load is loaded, the damping force increases as the weight increases.
[Brief description of the drawings]
FIG. 1 is a longitudinal front view of a vehicle height adjusting device according to an embodiment of the present invention.
FIG. 2 is a partially enlarged cross-sectional view of FIG.
FIG. 3 is a partially enlarged cross-sectional view of a vehicle height adjusting device according to another embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Suspension spring 2 Car body 4 Hydraulic cylinder 5 Cylinder body 6 Shock absorber 7 Piston rod 8a Piston body 8b Rod body 12a Pressure chamber 14 Cylinder 15 Piston 16 Extension side leaf valve 17 Pressure side leaf valve 19 Leaf valve 33, 34 used for both extension and pressure Oil passage 38 Extension port 39 Pressure port A Rod side oil chamber B Anti-rod side oil chamber R Bypass V Switching valve

Claims (3)

A shock absorber and suspension spring are arranged below the vehicle body, a hydraulic cylinder is interposed between the suspension spring and the vehicle body, and pressure oil is supplied to and discharged from the hydraulic cylinder to adjust the vehicle height to high and low. In the vehicle height adjusting device, the shock absorber includes a cylinder, a piston rod movably inserted into the cylinder via the piston, a rod side oil chamber and an anti-rod side oil chamber defined in the cylinder via the piston, An extension port and a pressure port formed in the piston and communicating with the two oil chambers; an extension-side leaf valve provided at the outlet of the extension port so as to be opened and closed; a pressure-side leaf valve provided at the outlet of the pressure port; A bypass formed in the piston rod and bypassing the extension side leaf valve and the pressure side leaf valve and communicating with the two oil chambers, and provided in an opening of the bypass with respect to the rod side oil chamber A pressure shared leaf valve, a switching valve that is movably inserted into the bypass to open and close the bypass, and an oil passage that is formed in the piston rod and guides the pressure of the hydraulic cylinder to the switching valve. and a pair of upper and lower transverse passageways bypass is opened to the rod side oil chamber and the anti-rod side oil chamber consists axial passage communicating each transverse channel, the switching valve opening and closing a lateral passage of the upper And a pair of upper and lower return springs that hold the spool at positions where the bypass is opened on both upper and lower sides of the spool. , the pressure oil when the high vehicle height by supplying pressurized oil into the hydraulic cylinder guided above the spool via the oil passage, the bypass to move the spool Switching the damping force to a hard by Jill, and characterized in that switching the damping force to the soft by opening the bypass return the spool when the low vehicle height to drain pressure oil from the hydraulic cylinder to the neutral position Car height adjustment device. A cylinder body in which a hydraulic cylinder is coupled to the vehicle body, a rod body which is inserted into the cylinder body through a piston body so as to be movable up and down, and a lower end which is supported by a suspension spring; The vehicle height adjusting device according to claim 1, further comprising a hydraulic pressure source and a pressure chamber connected to an oil passage in the piston rod. A disk is provided above the piston, a through hole is formed through the disk in the vertical direction and communicated with the upper lateral passage, and a leaf valve for both expansion and pressure is provided at the upper end of the through hole. The vehicle height adjusting device according to claim 1 or 2, wherein a pressure side sub leaf valve is provided at a lower end of the through hole so as to be freely opened and closed.

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