JP2002036841A - Shock absorber with vehicle height adjustment function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly raise a temperature of a heating and cooling medium for performing a vehicle height adjustment and to perform this vehicle height adjustment with a simple vehicle height detection mechanism. SOLUTION: A proximity switch 18 is provided on either of a cylinder side 1 and a piston rod side 2 and detects a position of a magnetic body on either of facing matter thereof; the piston rod side 2 or the cylinder side 1. A pressure medium in a pressure chamber 17 formed with the cylinder 1, the piston rod 2, and a case 6 is heated and expanded by a heater 16 generating a heat by an operation of the proximity switch 18 when a vehicle height drops to raise the pressure of the medium in the pressure chamber 17. The cylinder 1 and the piston rod 2 thereby are relatively displaced to raise the vehicle height.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock absorber having a vehicle height adjusting function provided between a vehicle body and an unsprung member of an automobile.

[0002]

2. Description of the Related Art A shock absorber includes a cylinder and a piston rod having one end attached to a piston that slides in the cylinder and movably inserted into the cylinder, and one of the cylinder and the piston rod. Is connected to the unsprung member, and the other is connected to the vehicle body so that a damping force against vibration of the unsprung member can be obtained.

On the other hand, a cylinder for adjusting the vehicle height is interposed between the shock absorber and the vehicle body, and when the vehicle height decreases, a pressure fluid is supplied from a pressure source to this cylinder to increase the vehicle height. In such a manner, the vehicle height can be adjusted as described above. In this case, since a pump driven by the engine is used as the pressure source, the load on the engine is large and fuel efficiency is deteriorated.

[0004] On the other hand, conventionally, a vehicle height adjusting section in which a pressure medium that changes gas and liquid is sealed in a pressure chamber is provided, and the pressure medium is heated and cooled using cooling water of an engine as a heat medium. There has been proposed a shock absorber with a vehicle height adjustment function that can raise and lower the vehicle height.

[0005] By the way, to adjust the vehicle height, some vehicle height detection mechanism is required. Conventionally, a vehicle height sensor such as a potentiometer for outputting a signal according to the vehicle height change is separately provided.

[0006]

However, in a conventional shock absorber with a vehicle height adjustment function, when a potentiometer or the like is used for vehicle height detection, wiring of a vehicle height sensor and a harness for the vehicle height sensor is performed. , Sensor signal processing circuits, etc. are required, increasing the number of parts used, complicating assembly work, and increasing the size of the configuration.In addition, when installing the vehicle height sensor, adjusting work to improve detection accuracy There was a problem that it was troublesome.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a vehicle height detection mechanism having a proximity switch integrally provided in a shock absorber main body can perform vehicle height detection with high accuracy, and can perform positioning and positioning of the proximity switch. An object of the present invention is to provide a shock absorber with a vehicle height adjusting function that can easily perform an assembling operation.

[0008]

In order to achieve the above object,
A shock absorber with a vehicle height adjusting function according to the present invention includes a cylindrical case having one end airtightly connected to a piston rod and the other end slidably in contact with the outer periphery of a cylinder, a cylinder side and a piston rod side. Proximity switch provided on any one of these, and detecting the position of the magnetic body on the piston rod side or the cylinder side facing each of them, and formed between the cylinder and the piston rod and the case, the pressure medium An electric current is supplied by the operation of the proximity switch by the magnetic body when the vehicle height is lowered and the pressure chamber to be housed therein is supplied with electric current to generate heat. And a heater for relatively displacing the vehicle in the direction in which the vehicle height increases.

The shock absorber with a vehicle height adjusting function according to the present invention is characterized in that the magnetic body has a predetermined length in the vertical direction which enables the proximity switch to continue to be turned on while the vehicle height is lower than a set level. It is formed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a partially cutaway front view showing a shock absorber with a vehicle height adjusting function of the present invention. In FIG. 1, reference numeral 1 denotes a cylinder serving as a main body of a shock absorber. One end of a piston rod 2 is attached to a piston sliding in the cylinder 1.

An eye 1a provided at the upper end of the cylinder 1 can be attached to the vehicle body.
An eye 2a provided on a lower cap (not shown) integral with the lower end of the spring can be attached to the unsprung member.

A rod guide 3 is fitted into the lower part of the lower end of the piston rod 2, and a holder 4 is inserted through the lower end of the piston rod 2 so as to contact the lower end of the rod guide 3. The holder 4 is fixed to the piston rod 2 together with the rod guide 3 by a nut 5 screwed into the lower end.

The lower end of the piston rod 2 and the holder 4 are provided with mounting holes for fitting a heater plug, which will be described later, as a heater.

A lower end of a case 6 is hermetically fixed to an upper surface of an outer peripheral portion of the holder 4. A substantially upper half of the case 6 covers an outer periphery of a substantially lower half of the cylinder 1 at a predetermined gap G. ing.

A holder, a collar, and a sealing member (all not shown) are provided at the upper end of the case 6 so as to airtightly close the gap G. Therefore, the case 6 can be slid airtightly with respect to the cylinder 1.

A lower end of an outer shell 7 surrounding the outer periphery of the case 6 is attached to an outer peripheral portion of the holder 4, and an upper end of the outer shell 7 is fixed to the collar. Further, the lower cap having the eye 2a integrally attached thereto is attached to a lower end of the outer shell 7.

Further, a cylindrical resin cover 8 is attached to the outer periphery of the outer shell 7 by screws 9, and the upper end of the resin cover 8 is fixed to the collar (not shown). The screw 9 is inserted into a boss member 10 having one end fitted into a mounting hole below the resin cover 8, and the tip of the screw 9 is screwed into the outer shell 7.

A rectangular frame portion 8a as viewed from the side is projected below the resin cover 8, and one end of a circuit board 11 is horizontally held in the frame portion 8a as shown in FIG. Is fixed to the boss portion 14 by screws 13.

The mounting plate 12 is made of a metal material such as aluminum having good thermal conductivity, and has a heat radiating effect of a heater current control FET (field effect transistor) 15 mounted on the mounting plate 12. . This FET1
Reference numeral 5 is connected to the circuit pattern of the circuit board 11.

Reference numeral 16 denotes a heater plug as a heater for heating the pressure medium, which penetrates the resin cover 8 and the outer shell 7 in the frame portion 8a, and is inserted into the end of the piston rod 2 and the mounting hole of the holder 4. It is held horizontally.

The holder 4 has a notch 4a opening upward.
The end of the heating rod 16a of the heater plug 16 faces the notch 4a.

Further, the notch 4a communicates with a pressure chamber 17 in the case 6 below the cylinder 1, and the gap G also communicates with the pressure chamber 17. In the pressure chamber 17, gas-liquid changes, for example, R134a of alternative Freon gas,
A low-boiling pressure medium such as R152a is enclosed,
This is directly heated and expanded by the heating rod 16 a of the heater plug 16, and acts to increase the internal pressure of the pressure chamber 17.

The rise of the internal pressure causes the cylinder 1 to be pushed upward with respect to the piston rod 2. The heater plug 16, the pressure chamber 17, and the pressure medium together with a proximity switch, which will be described later, constitute a vehicle height adjusting means A.

A proximity switch 18 is provided on the side of the piston rod 2, that is, in the middle of the resin cover 8 connected to the piston rod 2 via the holder 4 and the outer shell 7.
Further, a lead wire 19 for transmitting an on / off signal by an on / off operation of the proximity switch 18 is provided.

The cylinder 1 side, that is, the cylinder cover 20 covering the outer peripheral surfaces of the cylinder 1 and the resin cover 8 is made of a magnetic material (ferromagnetic material) such as iron or nickel.
Is made as a material, and this is disposed so as to be able to move in the vertical direction with a certain gap with respect to the proximity switch 18.

A cord 23 for supplying a current from an external power supply to the heater plug 16 and the like is inserted into a part of the frame portion 8a through a rubber bush 22 penetrating inside and outside the frame portion 8a.

Although not shown, a thermistor for compensating the temperature of the circuit is provided in the frame portion 8a as required. In addition, a resin lid 24 is placed over the opening of the frame portion 8a, and is fixed by screws 25.

FIGS. 2 and 3 are a front view conceptually showing the positional relationship between the proximity switch 18 provided on the resin cover 8 and the cylinder cover 20 which is a magnetic material, and a partially cutaway side view. .

Here, the proximity switch 18 is arranged in a direction in which the lead axis is horizontal, and this proximity switch 18 is connected via a lead wire 19 to the electric circuit section 26 including the FET 15, thermistor, resistor and the like. ing.

Here, the entire cylinder cover 20 is formed of a magnetic material, that is, a magnetic material.

The proximity switch 18 is an iron plate operated proximity switch that opens and closes in response to the proximity of a magnetic substance such as iron or nickel. Operate to turn on or off.

In the present embodiment, the contact is turned on when the cylinder cover 20 approaches.

Further, the proximity switch 18 can detect the proximity of the magnetic body from all directions.
It is turned on by detecting proximity from one direction (upward).

Next, the operation will be described. First, when the load acting on the vehicle body is small, the distance between the vehicle body and the unsprung member is kept sufficiently large, and as shown in FIG. 2 protrudes from the inside of the cylinder 1 by a considerable amount in the extending direction.

Accordingly, the resin cover 8 on the side of the piston rod 2 is connected to the cylinder cover 20 attached to the cylinder 1.
It protrudes greatly from the inside in the extension direction.

Therefore, the cylinder cover 20 is largely separated from the proximity switch 18 in the vertical direction, that is, sufficiently away from the lower edge of the cylinder cover 20, and the proximity switch 18 does not detect the proximity of the magnetic substance. The state is maintained.

When the proximity switch 18 is turned off, the supply of current to the heater plug 16 is interrupted because the FET 15 is turned off in the circuit.
There is no heating control.

On the other hand, the load acting on the vehicle body increases,
When the vehicle body lowers beyond the set level, the piston rod 2 enters the cylinder 1, and accordingly, the resin cover 8 also enters the cylinder cover 20, and stops at a position as shown in FIG. 4, for example.

For this reason, the proximity switch 18 detects the proximity of the cylinder cover 20, which is a magnetic material, and turns on. As a result, the FET 15 is turned on, and current is supplied to the heater plug 16 from an external power supply.
The heating rod 16a of the heater plug 16 is heated under the control of.

The heating rod 16a is provided with the notch 4 of the holder 4.
a, the pressure medium in the pressure chamber 17 is directly heated, and the heating causes the pressure medium to expand quickly and increase the internal pressure of the pressure chamber 17.

The cylinder 1 moves upward with respect to the case 6 on the piston rod 2 side due to the increase in the internal pressure of the pressure chamber 17. Therefore, the vehicle body to which the eye 2b is attached rises with respect to the unsprung member to which the eye 2a is attached.

This rise is continued until the proximity switch 18 is turned off by a stroke at which the proximity switch 18 is not affected by the cylinder cover 20 made of a magnetic material, and then stopped at the set level rise position. Becomes In this way, the vehicle body is held at a predetermined level.

In this case, since the entire cylinder cover 20 is made of a magnetic material, the ON operation of the proximity switch 18 can be continued while the vehicle height is equal to or lower than the set level.

Further, since it is not necessary to attach a magnet or the like to the cylinder cover 20, the thickness of the cylinder cover 20 does not increase, so that the outer diameter of the cylinder cover 21 is required to be larger than the outer diameter of the resin cover 8. It is not necessary to increase the size as described above, and it is possible to avoid an increase in the size of the entire shock absorber.

Further, since it is not necessary to attach a magnet for position detection to the cylinder cover 20, the positioning of the proximity switch 18 for adjusting the vehicle height can be performed very easily, and the rotation of the cylinder cover 20 with respect to the proximity switch 18 can be performed. There is no concern that the positional displacement in the direction affects the vehicle height detection sensitivity.

The entire cylinder cover 20 is not made of a magnetic material, but is made of a magnetic material only for a predetermined width (height) within the stroke area of the piston rod 2 with respect to the cylinder 1, and the other is made of a non-magnetic material such as aluminum. Can also.

FIGS. 5 to 7 show, on the contrary, a magnetic cover 8A in place of the resin cover 8 and a non-magnetic cover 20A made of resin or aluminum instead of the cylinder cover 20. An example in which a proximity switch 18 is attached to the outer periphery of the non-magnetic cover 20A is shown.

Also in this case, when the load acting on the vehicle body is small, as shown in FIGS. 5 and 6, the proximity switch 18 does not detect the proximity of the magnetic body cover 8A, and the vehicle height rise control is not performed. I can't.

However, when the load on the vehicle body increases, the proximity switch 18 detects the proximity of the magnetic cover 8A, as shown in FIG. For this reason, the vehicle height rise control is performed. That is, the same vehicle height control as described above is performed.

Further, in the present invention, since the heating rod 16a is in direct contact with the pressure medium, the pressure medium can be directly heated as compared with the conventional case where the exhaust heat of the engine is used indirectly. Therefore, the pressure in the pressure chamber can be quickly increased due to the expansion of the pressure medium, and there is an advantage that the vehicle height can be smoothly adjusted immediately after the start of the engine without delay.

[0051]

As described above, according to the present invention, one end portion is airtightly connected to the piston rod, and the other end portion is slidably contacted with the outer periphery of the cylinder. Proximity switch for detecting the position of the magnetic body on the piston side or cylinder side facing each of them is provided on either one of the piston rod side and the piston rod side. The pressure medium is heated and expanded by a heater that is supplied with electric current by the operation of the proximity switch when the vehicle height decreases and generates heat, thereby increasing the pressure in the pressure chamber, and moving the cylinder and the piston rod relative to the direction in which the vehicle height increases. The pressure in the pressure chamber can be raised quickly by direct heating of the pressure medium, and the vehicle height can be adjusted accordingly. A very simple vehicle height detection mechanism integrated with the shock absorber body, that is, a configuration that eliminates the use of magnets and the like for operating the proximity switch and that does not increase the outside diameter, can be realized with high accuracy and low cost. The effect that the positioning of the proximity switch for determining the starting point of the vehicle height adjustment can be performed very easily can be obtained.

Further, according to the present invention, the magnetic body has a predetermined vertical length which allows the proximity switch to continue to be turned on while the vehicle height is lower than the set level. The advantage is obtained that the increase in the vehicle height can be reliably controlled to a position exceeding the set level.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a shock absorber with a vehicle height adjusting function according to an embodiment of the present invention.

FIG. 2 is a front view of a shock absorber with a vehicle height adjusting function conceptually showing a positional relationship between a cylinder cover and a proximity switch in FIG. 1;

3 is a side view of the shock absorber with a vehicle height adjusting function of FIG.

FIG. 4 is a side view partially broken away showing an operation state of the shock absorber with a vehicle height adjusting function of FIG. 3;

FIG. 5 is a front view of a shock absorber with a vehicle height adjusting function conceptually showing a positional relationship between a magnetic body cover and a proximity switch according to the present invention.

6 is a side view showing a part of the shock absorber with a vehicle height adjusting function of FIG.

7 is a side view, partially broken away, showing an operating state of the shock absorber with a vehicle height adjusting function of FIG. 6;

[Explanation of symbols]

 Reference Signs List 1 cylinder 2 piston rod 6 case 8A magnetic material cover (magnetic material) 16 heater plug (heater) 17 pressure chamber 18 proximity switch 20 cover (magnetic material) 21 magnet

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Satoru Satoru 2-4-1 Hamamatsucho, Minato-ku, Tokyo World Trade Center Building Inside Kayaba Industry Co., Ltd. (72) Inventor Yukio Hayakawa 1-4-4 Chuo, Wako-shi, Saitama No. 1 F-term in Honda R & D Co., Ltd. (Reference) 3D001 AA10 BA01 CA01 DA03 DA16 3J069 AA54 CC09 CC15 DD13 EE50 EE70

Claims (2)

[Claims] 1. A cylindrical case having one end airtightly connected to a piston rod and the other end slidably contacting the outer periphery of a cylinder, and being provided on one of a cylinder side and a piston rod side. A proximity switch for detecting the position of the magnetic body on the piston rod side or the cylinder side facing each of them; a pressure chamber formed between the cylinder and the piston rod and the case to accommodate a pressure medium; An electric current is supplied by the operation of the proximity switch by the magnetic material at the time of lowering and heat is generated, and the heat causes the pressure medium to expand by heating and expanding the pressure medium, thereby raising the cylinder and the piston rod in the direction of increasing the vehicle height. A shock absorber with a vehicle height adjusting function, comprising a heater for relative displacement. A cylindrical case having one end airtightly connected to the piston rod and the other end slidably contacting the outer periphery of the cylinder; and a cylinder case provided on one of the cylinder side and the piston rod side. A proximity switch for detecting the position of the magnetic body on the piston rod side or the cylinder side facing each of them; a pressure chamber formed between the cylinder and the piston rod and the case to accommodate a pressure medium; An electric current is supplied by the operation of the proximity switch by the magnetic material at the time of lowering and heat is generated, and the heat causes the pressure medium to expand by heating and expanding the pressure medium, thereby raising the cylinder and the piston rod in the direction of increasing the vehicle height. A heater for causing relative displacement, wherein the magnetic body is provided with a predetermined upper and lower position that enables the proximity switch to continue to be turned on while the vehicle height is lower than a set level. A shock absorber with a vehicle height adjustment function characterized by having a length in a direction.