JPS6299203A - Suspension device for vehicle - Google Patents

Abstract

PURPOSE:To incorporate a vehicle height detector by arranging a damping force generating mechanism at the upper portion and a magnetic detector on the inner wall of an inner tube communicated with a sub-chamber and inserting a rod member associated with a permanent magnet from the bottom section of an outer tube communicated with the inner tube and an oil chamber into the inner tube. CONSTITUTION:Upon relative motion of an inner tube 7 against an outer tube 2, oil will move between oil chambers 3, 11 while it also move to an oil chamber 41 of a sub-chamber 40 and a damping force generating mechanism 31 will function. Here, a gas chamber 42 of the sub-chamber 40 will also operate and exhibit a gas spring function. Upon full extension of the inner tube 7, a rebound rubber 18 is compressed by the upper section 15a of a rod member 15, thereby the flow path of a penetration hole 13 is reduced by means of a tapered section 15b and the damping force is increased. The motion of said inner tube 7 is detected by a permanent magnet rod 20 and the magnetic detectors 21, 22 of the inner tube 7 and vehicle height signal is produced. With such arrangement, the damping force generating mechanism and the magnetic detector can be contained in the inner tube.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle suspension system used in a suspension mechanism of an automobile.

[Conventional technology]

Conventional vehicle suspension systems, which have a damping force generation mechanism, have a rod inserted into a cylinder filled with hydraulic oil and compressed gas so that it can move freely in the axial direction, and a piston that has an orifice at the tip or middle of the rod. has been established. In this conventional example, when the rod expands and contracts with respect to the cylinder, the hydraulic oil in the cylinder passes through the orifice, thereby exerting a damping force.

[Problem that the invention seeks to solve]

In the conventional dual suspension system, damping force is generated by the flow of hydraulic oil within the cylinder, so it is difficult to arrange the damping force generating mechanism at the top of the cylinder.

Therefore, the damping force generating mechanism has been placed at the lower end or middle portion of the rod.

In such a structure, even if an attempt is made to incorporate a detector to detect the relative axial position of the rod inside the cylinder, the damping force generation mechanism will get in the way, making it difficult to secure space for installation, making it difficult to install a vehicle height detector, etc. could not be incorporated.

[Means for solving problems]

The vehicle suspension system of the present invention includes an outer cylinder into which a first oil chamber is nailed, and an outer cylinder which is inserted into the outer cylinder so as to be relatively movable in the axial direction, and which communicates with the first oil chamber inside. an inner cylinder having a second oil chamber; a third oil chamber disposed outside the inner cylinder and communicating with the second oil chamber via an oil passage; and a compressor located next to the third oil chamber. It includes a sub-chamber including an air chamber filled with gas, and a rod-shaped body whose one end is fixed to the bottom wall of the outer cylinder and whose other end extends into the inside of the inner cylinder. And in addition to providing a permanent magnet on this rod-shaped body, ``1
A magnetic detector is provided on a member on the inner cylinder side facing the side surface of the rod-shaped body.

[Effect]

In the vehicle suspension system configured as described above, when the inner cylinder moves relative to the outer cylinder in the axial direction, the volume of the air chamber in the subchamber changes, and as the volume changes, the oil chamber (second Oil flows between the oil chamber (oil chamber) and the oil chamber (third oil chamber) of the sub-chamber. Therefore, according to this structure, it is possible to provide the damping force generation mechanism between the second oil chamber and the third oil chamber. That is, it is no longer necessary to provide the damping force generating mechanism at the tip of the rod or in the middle as in the conventional case, and the damping force generating mechanism can be housed in a corner of the internal space, such as in the upper part of the inner cylinder.

By detecting the permanent magnet provided on the rod-shaped body with a magnetic detector provided on the inner cylinder side, it is possible to determine the relative axial position of the outer cylinder and the inner cylinder, that is, the vehicle height.

[Embodiment 1] In the vehicle suspension system shown in FIG. 1, a suspension main body 1 includes an outer cylinder 2 and an inner cylinder 7. The outer cylinder 2 has a first oil chamber 3 filled with hydraulic oil. A connecting member 5 is fixed to the lower end of the outer cylinder 2. This connecting member 5 is connected to an axle side member (not shown).

The inner cylinder 7 is inserted into the outer cylinder 2. The inner cylinder 7 is movable relative to the outer cylinder 2 in the axial direction and rotatable around the axis. A bearing 8.9 is provided between the inner cylinder 7 and the outer cylinder 2.

Inside the inner cylinder 7, there is a second oil chamber 11 filled with hydraulic oil.
is provided. This second oil chamber 11 communicates with the first oil chamber 3 through a through hole 13 formed in the bottom wall 12 of the inner cylinder 7 .

A rod-shaped body 15 is provided inside the outer cylinder 2. This rod-shaped body 15 has its lower end fixed to the bottom wall 2a of the outer cylinder 2. The upper end of the rod-shaped body 15 passes through the bipedal through-hole 13 and extends into the inner cylinder 7. An annular oil passage 16 is formed between the outer peripheral surface of the rod-shaped body 15 and the inner peripheral surface of the through hole 13.

In the case of this embodiment, the upper end 15a of the rod-shaped body 15 has a flange shape, and the lower portion 15b of the upper end 15a has a tapered shape such that the cross-sectional area on the upper end 15a side gradually increases. ing.

Therefore, when the vertical position of the portion 15b relative to the through hole 13 changes, the cross-sectional area of the oil passage 16 changes. Further, a rebound rubber 18 is provided between the upper end portion 15a and the bottom wall 12.

A permanent magnet 20 is provided at the bottom of the rod-shaped body 15.

Further, a magnetic detector 21 using, for example, a reed switch is mounted on the inner wall of the through hole 13 facing the side surface of the rod-shaped body 15.
．． 22 are provided.

These detectors 21 and 22 detect the magnetism of the magnet 20, and can output detection signals to the outside via the lead wire 23.

An end plate 25 is attached to the upper end of the inner cylinder 7, and a connecting member 26 is provided on the end plate 25.

This connecting member 26 is connected to a member on the vehicle body side.

A bump rubber 28 is attached to the lower surface of the end plate 25, and a cylindrical cover 29 is supported at the lower end of the bump rubber 28. This cover 29 covers the sliding portion between the inner tube 7 and the outer tube 2.

Further, a damping force generating mechanism 31 is housed in the upper part of the inner cylinder 7. The damping force generation mechanism 31 includes a plate valve 32 and a variable orifice 33. Plate valve 32 may be similar to those known in the art. The variable orifice 33 includes a valve body 36 that is rotationally driven by a motor 35 with a reduction gear.
By changing the rotational position of the valve body 36, the cross-sectional area of the flow path can be changed. The motor 35 is externally controlled via a lead wire 38. Since the motor 35 is housed inside the inner cylinder 7 in this manner, it is possible to prevent problems caused by adhesion of mud, rainwater, etc., and to prevent noise when the motor is driven.

Further, a subchamber 40 is provided outside the inner cylinder 7. This sub-chamber 40 includes a third oil chamber 41 and an air chamber 42 provided next to this oil chamber 41 . This air chamber 4
2 is filled with compressed inert gas such as nitrogen gas. The air chamber 42 and the oil chamber 41 are partitioned by a membrane 43 made of an elastic polymer or the like. Gas can be supplied to the air chamber 42 through a gas inlet 44.

The third oil chamber 41 communicates with the second oil chamber 11 via an oil passage 46 formed in the end plate 25.

In the vehicle suspension system having the above configuration, when the inner cylinder 7 moves relative to the outer cylinder 2 in the axial direction, the first oil chamber 3 and the second oil chamber 1
Oil flows between the third oil chamber 41 and the third oil chamber 41 through the oil passage 46. In this way, oil flows through the damping force generation mechanism 31, and damping force is obtained. Further, the volume of the air chamber 42 fluctuates as oil flows in and out of the subchamber 40, and its repulsive force functions as a gas spring.

Since the damping force generation mechanism 31 includes the variable orifice 33, the damping force can be adjusted by one level by driving the valve body 36 with the motor 35 and setting the cross-sectional area of the flow path to a desired value.

When the inner cylinder 7 is fully extended with respect to the outer cylinder 2, the rebound rubber 18 is compressed by the upper end 15a of the rod-shaped body 15, and the tapered portion 15b of the rod-shaped body 15 is located in the through hole 13, and the elastic side Since the cross-sectional area of the oil passage 16 gradually decreases, the damping force increases. Therefore, smooth nonlinear characteristics can be obtained on the extension side, resulting in good ride comfort and handling stability.

Although not shown, an oil supply/discharge mechanism is connected to at least one location of the oil chambers 3, 11.
．． By adjusting the amount of oil fed into the cylinder 41, the amount of extension (relative position in the axial direction) of the inner cylinder 7 with respect to the outer cylinder 2 can be changed arbitrarily. In other words, the vehicle height can be adjusted.

The relative axial position of the inner tube 7 with respect to the outer tube 2 is determined by sensing the magnet 20 with magnetic detection S21,22.

As an example, as shown in Table 1 below, the magnetic detector 21.22
The vehicle height condition can be determined by the ON/OFF operation. (
In the same table, 1 represents ON and 0 represents OFF) Table 1 [Example 2] In the second example shown in FIG. 2, parts common to Example 1 are given the same reference numerals and explained. will be omitted, and the differences will be explained below.

In this embodiment, a detector mounting member 50 is provided inside the inner cylinder 7. This member 50 has a cylindrical shape, for example, and is provided between the bottom wall 12 of the inner cylinder and the damping force generating mechanism 31. A plurality of (for example, four) magnetic detectors 51, 52, 53, and 54 are arranged in the vertical direction on this member 50.

Further, a permanent magnet 20 is provided on the upper part of the rod-shaped body 15. This magnet 20 causes magnetic detectors 51, 52, 53.
By turning ON and OFF 54, it is possible to determine the vehicle height setting position in five stages or less using eight stages of detection signals as illustrated in Table 2 below. (In the same table, 1 represents ON and 0 represents OFF) Also, as shown in FIG. 3, by providing magnetic dead zones 20a and 20b at the top and bottom of the magnet 20, excessive changes in vehicle height can be prevented. I can do it.

Table 2 [Effects of the Invention] According to the present invention, the damping force generating mechanism can be housed in the upper part of the inner cylinder, and the magnetic detector etc. can also be housed in the inner space of the inner cylinder, and the built-in vehicle height detector can be easily housed. can be converted into

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of a vehicle suspension system 1t showing one embodiment of the present invention, FIG. 2 is a vertical sectional view of a vehicle suspension system 1t showing another embodiment of the present invention, and FIG. FIG. 3 is a side view of the magnet shown in the figure. DESCRIPTION OF SYMBOLS 1... Suspension system main body, 2... Outer cylinder, 2a... Bottom wall, 3... First oil chamber, 7... Inner cylinder, 11... Second
oil chamber, 13... through hole, 15... rod-shaped body, 20...
...Permanent magnet, 21.22...Magnetic detector, 31...
- Damping force generation mechanism, 40... Sub-chamber, 41... Third oil chamber, 42... Air chamber, 46... Oil passage, 51,5
2,53.54...Magnetic detector.

Claims (3)

[Claims] (1) An outer cylinder having a first oil chamber inside, and a second oil chamber inserted into the outer cylinder so as to be relatively movable in the axial direction and communicating with the first oil chamber inside. an inner cylinder, a third oil chamber disposed outside the inner cylinder and communicating with the second oil chamber via an oil passage, and an air chamber filled with compressed gas adjacent to the third oil chamber. a sub-chamber, a rod-shaped body whose one end is fixed to the bottom wall of the outer cylinder and whose other end extends into the inner cylinder, a permanent magnet provided on the rod-shaped body, and a side surface of the rod-shaped body. 1. A vehicle suspension system comprising: a magnetic detector attached to a member on the inner cylinder side facing the inner cylinder; (2) The vehicle suspension system according to claim 1, wherein a damping force generating mechanism is housed in the upper part of the inner cylinder. (3) By forming a through hole in the bottom wall of the inner cylinder through which the rod-shaped body is inserted, and by making the rod-shaped body into a tapered shape in which the cross-sectional area on the tip side gradually increases, the rod-shaped body and the through-hole can be connected to each other. 2. The vehicle suspension system according to claim 1, wherein an oil passage having a variable cross-sectional area is formed therebetween.