JPH03107634A - Suspension damper - Google Patents

Abstract

PURPOSE:To obtain an excellent response characteristic and to enable non-stage change in damping force by utilizing a super magnetostrictive alloy which is immediately extended by receiving a magnetic force as an actuator and by limiting an effective opening area of an orifice with movable valve bodies to one end of this super magnetostrictive alloy. CONSTITUTION:A piston rod 9 is made a hollow cylinder body, whose upper end is blocked by a blank cap 11, and a super magnetostrictive alloy 12 which extends almost all over the longitudinal direction of the piston rod 9 is arranged in the piston rod 9. The super magnetostrictive alloy 12 is provided on the axis of the piston rod 6, and a coil 13 is arranged around it and connected to a connector 14 fixed at the upper end part of a blank cap 10 of the coil 13. Above openings 8a on the upper part oil chamber side of an orifice 8, mov able valve bodies 15 are arranged facing each of the openings 8a. Each of the movable valve bodies 15 are made in the shape of a cone whose diameter is gradually reduced toward the openings 8a side, and the openings 8a on the upper part oil chamber side of the orifice 8 are correspondingly made in the shape of a bowl which is gradually expanded toward their opening end.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a suspension damper device, and more particularly to a damper with variable damping force.

(Prior Art) Some of the dampers incorporated in heavy-duty sunpensions include the
A device in which the 1ffi power is variable is known. This type of damper uses a rotary valve that opens and closes some orifices and a low reactor as a driving source to switch the RH force in stages.

By the way, recently, in the case of vehicle suspensions, the suspension characteristics have been changed to M! according to the driving conditions. ! Control in four ways. The so-called active suspension is being installed for the first time. When an automatic damping force adjustment function is incorporated into this active suspension, a response function of 'f&damping force switching is required.

(Problem to be Solved by the Invention) However, in conventional general dampers, the rotary valve opens and closes the office while slidingly contacting other members, so it takes several tenths of a second to switch the damping force. It took a long time. Furthermore, in an active suspension, it is desirable that fJi force can be changed steplessly in order to realize suspension characteristics that correspond to driving conditions that change from moment to moment.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a suspension damper device with excellent response and capable of steplessly changing the damping force.

(Means and effects for solving the problems) In order to achieve the above object, the present invention has the following features.

a piston that is fitted into a cylinder and defines two oil chambers in the cylinder; an orifice provided in the piston that communicates with the upper two oil chambers; one end fixed to the piston and the other end fixed to the piston; A suspension damper device that includes a piston rod that protrudes from the cylinder to the outside is provided as follows: 1) The piston rod described in 1) is hollow, and the piston rod is inserted into the piston rod from one end to the other. A giant magnetostrictive alloy extending over the end portion and a coil surrounding the giant magnetostrictive alloy are disposed, and the piston end portion of the super 6R strain adjustment is disposed so as to face the opening of the slotted fixture. The iiT valve operating element is fixed therein, and the diameter of the iiT valve element is gradually reduced toward the opening side of the orifice.

That is, a giant magnetostrictive alloy that immediately expands when magnetic force is applied is used as an actuator, and the effective opening area of the orifice is narrowed down by the movable valve body fixed to one end of the giant magnetostrictive alloy.

In the above configuration, since the movable valve body can change the effective opening area of the orifice without coming into contact with other members, it is possible to quickly change the damping force. Further, the above-mentioned giant magnetostrictive alloy allows the effective opening area of the orifice to be changed steplessly by changing the strength of the applied magnetic force.

(Example) Hereinafter, an example of the present invention will be described based on the accompanying drawings.

In Fig. 1, reference numeral 1 denotes a damper for a strut type suspension, and since this damper l is used for the front wheel, a knax spindle 3, which constitutes the front wheel axle, is attached to the lower end of the outer tube 2. ing. Further, this damper l is of a double-tube type, and an inner tube (cylinder) 4 is provided in an outer tube 2, a piston 5 is rotatably fitted into this inner tube 4, and the inside of the inner tube 4 is , up and down by the piston 5,
An upper oil chamber 6 and a lower oil chamber 7 are defined. and,
The upper oil chamber 6 and the lower oil chamber 7 communicate with each other through an orifice 8 formed in the piston 5, and the orifice 8 is provided in multiple stages around the circumference of the piston 5. They are arranged in concentric circles (see Figure 3).

The piston 5 is fixed to the lower end of the piston rod 9. The piston rod 9 extends vertically within the upper oil chamber 6, and the upper end of the piston rod 9 projects outward from the upper end of the inner tube 4, and the area around the protrusion 9a of the piston rod 9 is not shown. Coil springs are arranged almost coaxially. In FIG. 1, reference numeral 10 denotes a spring receiver that supports the F end of the coil spring, and the spring receiver 1o is fixed to the upper end of the outer tube 2.

]22 The piston rod 9 is a hollow cylindrical body, and the upper end of the piston rod 9 is closed with a blind plug 1), and inside the piston rod 9, there is a piston rod 9 that extends almost all the way in the longitudinal direction of the piston rod 9. A giant magnetostrictive alloy 12 is disposed, the giant magnetostrictive alloy 12 is provided on the axis of the piston rod 9, a coil 13 is disposed around the super &a strain alloy 12, and the coil 13 is connected to the upper end of the blind plug 10. It is connected to a connector 14 fixed to the section.

The lower end of the super-E1) alloy 12 is penetrated into the piston 5 once. That is, the piston 5 is provided with a recess 5a that opens toward the upper oil chamber 6, and the lower end of the giant magnetostrictive alloy 12 is loosely fitted into the recess 5a. On the other hand, the upper oil chamber 1 of the orifice 8! ! 1) Opening 8
A movable valve body 15 is disposed above the opening 8a so as to face each opening 8a, and each IJ valve body 15 has a circular jfa shape whose diameter gradually decreases toward the opening 8a. , Correspondingly, the oil chamber side port 8a of the orifice 8 is L between.
It is said to be a forest-like open area that gradually expands towards the edge. Further, the piston 5 is provided with a seal member I7 around its circumference, and this seal member 17 is movable relative to the piston 5 (seal member 17
can move up and down with respect to the piston 5). A connecting member 18 is disposed in the piston 5 so as to be movable up and down, and the inner end of the connecting member 18 is fixed to the super FrFi↑ alloy 12, and the outer end II is fixed to the sealing member 17. There is.

In FIG. 1, reference numeral 40 is a control unit for the active suspension, and signals from sensors 41 to 43 are input to the control unit 40. sensor 41
is a small height sensor installed for each port. The sensor 42 is a lateral acceleration (lateral G) sensor. The sensor 43 is a sensor that detects vehicle speed. The control unit 40 outputs a high 1) 1 wholesale signal to the current value adjusting means 44, and the current value adjusting means 44 controls the coil 13.
The value of the current supplied to the valve body is adjusted steplessly according to the running condition of the hill, and the displacement of the movable valve body 15, that is, the effective opening area of the orifice 8, is adjusted as the giant magnetostrictive alloy 12 expands and contracts. This adjustment of the end of the effective surface of the orifice 8 is a stepless change in the damping force of the damper 1.

Here, the ultra-M1 strained alloy 12 has a composition of dysprosium (Dy), telephram (Tb), and iron fFe), and has a maximum magnetostriction value of 1500 to 2000 ppm, and this magnetostriction value depends on the strength of the magnetic field. Take the corresponding value. Furthermore, the magnetostriction value refers to the amount of expansion and contraction (ΔL) with respect to the length dimension (L) of the giant magnetostrictive alloy.
), that is, ΔL/L. Further, the response speed of the magnetomotive alloy is about 50 μsec.

With the above configuration, the damping force of the damper 1 can be changed steplessly and with excellent responsiveness. Moreover, since the super 6F1 alloy 12 has a length that almost matches the length of the piston rod 9, the super m+H combination &1.
It is possible to increase the absolute value of the amount of expansion and contraction of 2, it is possible to increase the adjustment range of the effective opening area of the orifice 8, and it is possible to realize a large change range of the damping force.

The control unit 40 also has the following functions. That is, when the JJi9 force is not modified, a weak current is always turned ON-OFI' to the coil 13 in a predetermined cycle. As a result, the super 1ifi 10 alloy 12 repeatedly expands and contracts with a stroke of extremely fN, and the sealing member I7 integrated with the super magnetostrictive alloy 12 vibrates up and down.

With the above configuration, when the piston 5 is in the static 1F state, the element of friction is removed between the seal member 17 and the inner tube 4, and the piston 5 changes from the static state to the dynamic state. A smooth transition is made possible, and stick staining of the piston 5 due to the static friction TL element between the seal member 17 and the inner tube 4 is eliminated.Incidentally, suppose that the vertical vibration of the seal member 17 causes noise inside the vehicle. If this is the cause, change this vertical vibration cycle to 500 Hz (
Hz) or more or 30 hertz (Hz) or less. That is, it is known that if the frequency is 500 hertz or more or 30 hertz or less, it will have almost no effect on the occupants.

With the above configuration, it is possible to prevent road noise caused by the stick of the piston 5 from entering the vehicle interior.

The application of vibration to the seal member 17 using the super FrFi'2 alloy 12 as an actuator is also applicable to, for example, a fixed orifice type damper or a variable damping force type damper that changes the damping force in stages. ,
In this case, a small length dimension of the giant magnetostrictive alloy 12 is sufficient.

(Effects of the Invention) As is clear from the above description, according to the present invention, the damping force can be changed steplessly with excellent responsiveness.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a suspension damper according to an embodiment, FIG. 2 is an enlarged cross-sectional view showing essential parts, and FIG. 3 is a plan view of a piston. a 2 3; Damper of strut type suspension; Inner tube (cylinder); Piston; Upper oil chamber; Lower oil chamber; Orifice; Opening of orifice on upper oil chamber side; Super 5i1 strain alloy; Coil 5 7 0 4; Movable valve body ;Sealing member;Control unit;Current value adjustment means

Claims (1)

[Claims] (1) A piston that is fitted into a cylinder and defines two oil chambers in the cylinder; an orifice provided in the piston that communicates with the two oil chambers; one end fixed to the piston, the other A suspension damper device having a piston rod whose end projects outward from the cylinder, wherein the piston rod is hollow, and a giant magnetostrictive alloy is disposed within the piston rod and extends from one end of the piston rod to the other end. and a coil surrounding the giant magnetostrictive alloy, the coil being arranged at the piston side end of the giant magnetostrictive alloy so as to face the opening of the orifice, and facing toward the opening of the orifice. A suspension damper device characterized in that a movable valve body whose diameter is gradually reduced according to the following is fixed.