JPH0579534A - Mounting device of suspension - Google Patents

Abstract

PURPOSE:To increase elastic modulus of an electrode, and to suppress change in position due to a shock absorber by connecting a plurality of electrodes together, for which variable elastic members are provided in parallel to each other, in common and in every other line, through an electric connection means. CONSTITUTION:A solid variable elastic member 7, which can select a spring characteristic, namely an elastic modulus, according to a voltage value to be applied, is used. The variable elastic member 7 is composed of a plurality of electrodes 7c, 7d provided in parallel to one another at a fixed pitch, and of an electrically insulating high polymeric material, for which fine particles are dispersed, which is electrically polarized due to the action of an electric field, and by which each gap between the respective electrodes 7c and 7d is covered. Electric connection means 7a, 7b, for which a solid layer 7e, the elastic modulus of which is changed according to the electric field intensity, and the plurality of electrodes 7c, 7d are connected together in common, in every other line, are provided, and the means are put between first members 5, 6 and second members 8, 9. Excessive contraction or stretching of an elastic body for absorbing vibration, and for connecting a rod 10 of a shock absorber 1 and car bodies 8, 9, are thus inhibited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting device for connecting a suspension to a vehicle body, and more particularly to an insulation structure for suppressing propagation of wheel vibration to the vehicle body.

[0002]

2. Description of the Related Art Generally, a suspension includes a shock absorber and a spring for supporting a vehicle body against wheels,
There is an elastic member for isolating the vibration that connects the end portions of the vehicle body supporting side to the vehicle body.

When a comfortable ride is obtained, the damping force of the shock absorber is set to be large (the spring characteristic is soft) to absorb the vibration of the wheel at a relatively low frequency. Further, in order to suppress the disturbance of the vehicle body posture (nose-up, nose-down, lateral inclination, etc.) during acceleration, deceleration, and steering of the vehicle, the vehicle is not driven in a running state or a driving state in which the posture is disturbed. The damping force is set small (hard spring characteristics).
Various kinds of damping force control have been proposed and are publicly known. For example, Japanese Patent Application Laid-Open No. 2-171310 discloses one damping force control device. The vibration-blocking elastic member that connects the vehicle-body-support-side end of the shock absorber to the vehicle body absorbs wheel vibrations, particularly vibrations of relatively high frequency and relatively small amplitude.

When the damping force of the shock absorber is increased so as to suppress the disturbance of the vehicle body posture during acceleration, deceleration, steering, etc. of the vehicle, the spring characteristics of the shock absorber become hard and the vehicle body sinks. Alternatively, the elastic member for vibration isolation, which suppresses the floating but connects the end portion of the shock absorber on the vehicle body supporting side to the vehicle body, has a constant elastic modulus and therefore is compressed and contracted or stretched to extend. This contraction or extension causes a change in the posture of the vehicle body that the shock absorber attempts to suppress, and the contraction or extension of the elastic member has a low effect of suppressing the change in posture due to the shock absorber.

Japanese Utility Model Publication No. 62-8162 discloses a mount structure including an elastic body such as rubber and an oil damper. An elastic body such as rubber has an effect of suppressing relatively high-frequency and relatively small-amplitude vibrations, and an oil damper has an effect of suppressing relatively low-frequency and relatively large-amplitude vibrations. In either case, when the shock absorber acts as a large damping force to suppress the sinking or floating of the vehicle body, the shock absorber contracts or extends, and the effect of suppressing the posture change by the shock absorber is weakened.

Japanese Patent Laid-Open No. 62-113935 discloses a liquid damper filled with a liquid having an electrorheological effect between metal plates having a rubber ring interposed therebetween. The viscosity of the liquid between the metal plates changes according to the voltage applied between the metal plates.
This liquid enters and leaves the space outside the rubber ring through the gap between the rubber ring and the metal plate, but when the electric field is changed, the viscosity changes, which changes the liquid resistance through the gap,
Spring characteristics change. However, if the shock absorber acts as a large damping force to suppress the sinking or floating of the vehicle body for a long time, that is, when the sinking force or the pulling force acts on the liquid damper for a relatively long time, the rubber ring end surface and the metal are There is less liquid flow through the gaps between the plates and the rubber ring is compressed to contract or stretch to stretch. This contraction or extension causes a change in the posture of the vehicle body that the shock absorber attempts to suppress, and the contraction or extension of the rubber ring has a low effect of suppressing the change in posture due to the shock absorber. That is, when the shock absorber becomes a large damping force to suppress the sinking or floating of the vehicle body, if the period is short, the damping force of the liquid damper is largely changed like the shock absorber. The contraction or expansion of the liquid damper may be suppressed, which may be effective in suppressing the posture change, but if the damping force of the shock absorber is maintained to be large for a relatively long time, the rubber ring gradually contracts or expands. And causes the vehicle body to sink or float.

[0007]

As described above, when the elastic member such as rubber, the oil damper, the liquid damper, etc. is used to suppress the sinking or floating of the vehicle body by the shock absorber becoming a large damping force. It contracts or stretches and weakens the effect of suppressing the posture change due to the shock absorber. In addition, since the oil damper and the liquid damper described above are filled with a liquid and therefore a relatively large load is applied, it is necessary to have a liquid-tight structure with a high load resistance, and the orifice and the gap are set accurately. This has to be done, which complicates construction and manufacturing.

The present invention aims to remedy this type of problem.

[0009]

SUMMARY OF THE INVENTION A suspension mount device of the present invention comprises a first member which is rotatably attached to an upper portion of a member (10) connected to a wheel and is vertically united.
(5,6); Second member (8,9) connected to the vehicle body and supporting the vehicle body;
In addition, multiple electrodes (7c, 7
d), made of an electrically insulating polymer material in which fine particles that are electrically polarized by the action of an electric field are dispersed, filling the space between these electrodes,
Solid layer (7e) whose elastic modulus changes according to the electric field strength, and
The first member (5, 6) and the second member (8) are provided with electric connection means (7a, 7b) in which the plurality of electrodes (7c, 7d) arranged in parallel are connected in common one by one. , 9) variable elastic member inserted between
(7); The symbols in parentheses indicate the corresponding elements of the embodiment shown in FIG.

[0010]

Operation: Since the variable elastic member (7) is one in which a plurality of electrodes (7c, 7d) arranged in parallel are commonly connected to each other by the electric connecting means (7a, 7b), the electric connecting means is connected. When a voltage between the adjacent electrodes (7c, 7d) is applied via (7a, 7b), an electric field proportional to the voltage is applied to the solid layer (7e) between the adjacent electrodes (7c, 7d). Then, the solid layer (7e) is made of an electrically insulating polymer material in which fine particles that are electrically polarized by the action of an electric field are dispersed, and the elastic modulus changes according to the electric field strength, so the electrical connection means (7a, The elastic modulus of the solid layer (7e) is determined by the voltage value between the adjacent electrodes (7c, 7d) applied via 7b), and the elastic modulus changes by changing the voltage value (FIG. 4). That is, the elastic modulus of the variable elastic member (7) can be controlled by the voltage value applied between the adjacent electrodes (7c, 7d) via the electrical connecting means (7a, 7b).

When the damping force of the shock absorber is increased so as to suppress the disturbance of the vehicle body posture during acceleration, deceleration, steering, etc. of the vehicle, the electrical connection means (7
By changing the voltage value applied between the adjacent electrodes (7c, 7d) via a, 7b) to a higher value, the amount of deflection of the variable elastic member (7) with respect to the load is reduced (Fig. 4), and the shock absorber
The spring characteristic of the bar is hardened to prevent the vehicle body from sinking or floating, and the amount of compression or extension of the variable elastic member (7) against the compressive force or the tensile force is reduced to suppress the posture change due to the shock absorber. Is greatly demonstrated.

Further, since the variable elastic member (7) has a laminated structure of the electrodes (7c, 7d) and the solid layer (7e), a liquid-tight structure having a high load resistance required for an oil damper or a liquid damper is provided. It is unnecessary, and the laminated structure can be easily and highly accurately formed by the synthetic resin laminating technique, which simplifies the structure and manufacturing.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the mounting apparatus of the present invention. In FIG. 1, the inner ring of the bearing 2 and the spring bearing 4 are fixed to the upper end of the piston rod 10 of the shock absorber 1, and the upper end of the spring 3 is fitted in the spring bearing 4. Absorber mounting brackets 5 and 6 are fixed to the outer ring of the bearing 2. An inner peripheral surface of a lower end of a generally donut-shaped variable elastic body 7 is joined to the mounting brackets 5 and 6. A vehicle body fitting 8 is joined to the outer peripheral surface of the variable elastic body 7. The vehicle body mounting member 8 is fixed to the vehicle body frame with a screw 9.

The variable elastic body 7 includes a conductive foil 7 between an outer rubber outer cover 7a having a conductive layer on its inner surface and an inner rubber outer cover 7b.
Electrically insulating polymer sheet 7 with c and 7d bonded to the back surface
The inner elastic body 7a and the inner rubber outer jacket 7b are joined together by interposing an inner elastic body in which e is laminated and integrated into a substantially donnut shape with a sufficient insulating distance between the conductive layers. It has been transformed. The electrically insulating polymer sheet 7e is disclosed in Japanese Patent Application Laid-Open No. 3-91541 filed by some of the inventors of the present application.
The sheet of electrically insulating rubber or polymer gel in which dielectric particles are dispersed is disclosed. The disk-shaped conductive foil 7d joined to the back surface of the odd-numbered sheet from the side of the vehicle body mounting bracket 8 in the internal elastic body formed of the laminated sheet 7e in FIG. Inner peripheral edge is inner rubber jacket 7
Since it extends to the inner peripheral edge of the disk-ring-shaped sheet 7e so as to substantially contact the conductive layer on the back surface (inner surface) of b, or projects slightly further inward (in the ring center direction),
In the state in which the inner elastic body made of a laminated body of the sheets 7e is filled between the outer rubber outer jacket 7a and the inner rubber outer jacket 7b as shown in FIG. See
The disk-ring-shaped conductive foil 7d bonded to the back surface of the outer cover is substantially electrically connected to the conductive layer on the back surface (inner surface) of the inner rubber outer cover 7b. However, the conductive foil 7d is attached to the outer rubber jacket 7
The outer peripheral edge of the disk-ring-shaped conductive foil 7d bonded to the back surface of the odd-numbered sheet is insulated from the conductive layer on the back surface (inner surface) of a by the disk-ring-shaped sheet 7e. It is inside the outer peripheral edge.

In FIG. 1, a disk-ring-shaped conductive foil 7c joined to the back surface of the even-numbered sheet from the side of the vehicle body mounting member 8 side.
Is the back surface (inner surface) of the outer rubber jacket 7a.
Disk-shaped shield so as to substantially contact the conductive layer of
Since it extends to the outer peripheral end of the sheet or slightly projects outward (in the direction outward from the center of the ring), the inner elastic body made of a laminated body of the sheets 7e has an outer rubber outer cover 7a as shown in FIG. In the state of being filled between the inner rubber outer cover 7b and the inner rubber outer cover 7b, the disk-shaped conductive foil 7c joined to the back surface of the even-numbered sheet from the side of the vehicle body mounting bracket 8 in FIG. It is substantially electrically connected to the conductive layer on the back surface (inner surface) of 7a. However, a disk-ring-shaped conductive foil 7 joined to the back surface of the even-numbered sheet so as to insulate the conductive foil 7c from the conductive layer on the back surface (inner surface) of the inner rubber outer cover 7b.
The inner peripheral edge of c is inside (in the direction from the center of the ring to the outer side) the inner peripheral edge of the disc-shaped sheet.

Here, the conductive foils 7d and 7c are the rubber outer cover 7
The substantial contact or substantially electrical connection with the conductive layers of b and 7a does not necessarily mean complete mechanical contact or connection, but the conductive layer of the inner rubber outer cover 7b and the outer rubber outer cover 7a. When a voltage (several hundreds to thousands of V) is applied between the conductive layers, the voltage hardly decreases and the odd-numbered sheet conductive foil 7d and the even-numbered sheet conductive foil 7c. Means an electrical connection that is sufficient to appear between.

Inner rubber jacket 7b and outer rubber jacket 7a
Each has an electrical lead connected to it.
Cores are electrically connected to the conductive layers. An electric lead connected to the inner rubber jacket 7b and an outer rubber jacket 7
When a voltage is applied between the electrical leads connected to a, this voltage is applied between the adjacent conductive foils 7c and 7d, and the electrically insulating rubber in which the dielectric particles are dispersed between the adjacent conductive foils 7c and 7d. Alternatively, an electrically insulating polymer sheet 7 made of polymer gel
This voltage is applied to e.

FIG. 4 shows the relationship between the deflection and the weight of the sheet 7e. In this embodiment, the higher the voltage applied to the sheet 7e (voltage between 7c / 7d), the higher the elastic modulus and the smaller the amount of deflection, and the greater the compression resistance and elongation resistance against compression force and tensile force. Become. On the contrary, if the voltage is lowered, the vibration absorption capacity is increased.

FIG. 2 shows the internal structure of the shock absorber 1 shown in FIG. 11, and a part of it is shown in enlarged form in FIG.
Upper end portions of an inner cylinder 12 and an outer cylinder 13 are concentrically fixed to an upper end base 11 through which the piston rod 10 penetrates. A piston 14 is fixed to the lower end of the piston rod 10. The lower end of the outer cylinder 13 is fixed to the lower end base 18, while the lower end of the inner cylinder 12 is fixed to the valve device 17 supported by the lower end base 18. The inner space of the inner cylinder 12 is
A piston 14 divides the space into an upper space 15 and a lower space 16. A space (lower end base space) 18a between the valve device 17 and the lower end base 18 is a space between the inner and outer cylinders 12 and 13, that is, an outer space 24, through the passage of the lower leg of the valve device 17. Is in communication with. A liquid is sealed inside the inner cylinder 12. Liquid and gas are enclosed in the outer space 24.

The valve device 17 has two sets of flow passages 19 and 2 for connecting the lower space 16 and the lower end space 18a.
2 are formed, and the first set of flow paths 19 is formed in the lower space 1
The opening on the 6 side is closed by a disc-shaped check valve member 20 pressed by a compression coil spring 21. Second
The pair of flow passages 22 are closed at the opening on the side of the lower end space 18a by a check valve member 23 pushed up by a leaf spring 23a.

When the wheel is pushed up due to the unevenness of the road surface, a force in the direction in which the piston 14 moves downward relative to the cylinder 12 acts between the cylinder 12 and the piston 14, and the piston 14 Tend to move relatively downward, and the pressure in the lower space 16 increases. When this pressure becomes equal to or higher than a predetermined value, the check valve member 23 is driven downward by the pressure against the pushing force of the leaf spring 23a, and the pressure in the inner space 16 is changed to the second passage 22 and the lower end valve. Passing through the space 18a to the outer space 24. This allows
The piston 14 can move downward, and the piston 14 moves downward. As a result, the thrust of the piston rod 10 (vehicle body) due to the thrust of the wheels is buffered.

When the wheel descends due to the unevenness of the road surface, a force in the direction in which the piston 14 moves relatively upward with respect to the cylinder 12 acts between the cylinder 12 and the piston 14, so that the piston 14 moves. The pressure in the lower space 16 decreases as it attempts to move relatively upward. When this pressure becomes equal to or lower than a predetermined value, the check valve member 20 is driven upward by the pressure against the pressing force of the compression coil spring 21, and the pressure of the outer space 24 is lowered to the lower end base space 18a and the first set. Through the flow passage 19 to the lower space 16. This allows the piston 14 to move upward, and the piston 14 moves upward. Thereby, the descent of the piston rod 10 (vehicle body) due to the descent of the wheels is buffered.

The damping force when the wheel device is pushed up and the damping force when the wheel is lowered by the valve device 17 as described above are
It is fixed because the flow passage cross-sectional areas of 2 and 19 are fixed. Next, the variable damping force mechanism of the shock absorber 1 will be described. Since the rod 10 is hollow and the lower end thereof penetrates the piston rod 10 in the vertical direction, the internal lower space (27, 28) of the piston rod 10 is described. ) Communicates with the lower space 16 through the flow port 10 a of the rod 10. A cup-shaped bottomed cylindrical body 25 having an airtight flange 26 in a substantially central portion is inserted into the inner lower space (27, 28) of the piston rod 10, and an upper opening edge portion thereof is on an inner wall of the rod 10. It is fixed. Flange 26 of this cylinder 25
The inner lower space (27, 28) of the piston rod 10 and the rod inner lower space 28 communicating with the lower space 16 and the side wall of the rod 10 in the circumferential direction. Upper space 2 in the rod that communicates with the upper space 16 through the flow ports 29, which are six holes formed at even intervals in the
It is divided into 7 and. On the side wall of the bottomed tubular body 26, six holes 30 are formed above the flange 26 and six holes 31 are formed below the flange 26 at equal intervals in the circumferential direction.
The lower surface of the end plate 25a, which is a ring-shaped magnetic material, is in contact with the upper opening end surface of the bottomed tubular body 25, and the end plate 25a pushes the bottomed tubular body 25 downward. , Is fixed to the rod 10 by press fitting. A bobbin 38a around which the electric coil 38 is wound is arranged on the end plate 25a. The lower large-diameter portion of the magnetic material plunger 32 enters the bottomed tubular body 25, and the upper small-diameter portion of the plunger 32 vertically penetrates the end plate 25a.

A ring-shaped groove 35 is formed in the lower large-diameter portion of the plunger 32, and two flanges 33, 34 are formed by the groove 35, and these flanges 33, 3 are formed.
4 is in contact with the inner surface of the bottomed tubular body 25. The groove (up-down direction) of the ring-shaped groove 35 is formed in the upper and lower holes 30 of the bottomed tubular body 25.
And 31 extend from the upper end to the lower end. Plunger 3
The upper end surface of the upper large-diameter portion 2 is a tapered taper surface, and a round hole for accommodating the compression coil spring 36 is formed in the center thereof. A nail-shaped magnetic core 37 is inserted into the coil bobbin 38a, and its lower leg end portion has a pyramid shape complementary to the taper surface of the plunger 32, and a compression coil spring is provided at the center thereof. A round hole is formed to receive the upper end of 36.

When the electric coil 38 is not energized (OFF), the repulsive force of the compression coil spring 36 causes the plunger 3 to move.
2 is pushed down so that the groove 35 becomes the hole 3 as shown in FIG.
1 is in complete communication with the whole, but the flange 33 has holes 30
Is almost closed, leaving a slight gap, so that the upper space 15-the hole 29-the rod upper space 27-the hole 30-the groove 35-
Hole 31-lower space 28 in rod-flow port 10a-lower space 1
6, the flow passage cross-sectional area of the communication passage between the upper and lower spaces (15-16) is the smallest, and the piston 14 is hard to move. That is, the damping force (adjustable damping force) determined by the plunger 32 is the lowest value of the damping force that can be set by the plunger 32.

The electric coil 38 is energized and the plunger 32 is energized.
Is sucked by the core 37 and is driven to the uppermost portion (the plunger 32 comes into contact with the core 37), the holes 30 and 31 are completely passed through the groove 35 as a whole, and the upper and lower spaces (1
The cross-sectional area of the flow passage between 5-16) becomes maximum, and the piston 14 is easy to move. That is, the damping force (adjustable damping force) determined by the plunger 32 is the maximum value of the damping force that can be set by the plunger 32.

The magnetic core 37 (the lower end shape thereof), the plunger 32 (the upper end shape thereof), the compression coil spring 36 (the spring constant thereof) and the electric coil 38 (the number of turns, the winding length and the winding thickness) are electrically The distance between the plunger 32 and the magnetic core 37 is designed to be substantially proportional to the value of the current flowing through the coil 38.
The distance of the plunger 32 with respect to the magnetic core 37, that is, the adjustable damping force is determined by the energization current value of.

FIG. 5 shows a damping force control device for the sun pension shown in FIG. Each of the suspensions 71 to 74 is composed of the variable elastic body 7 and the coil spring 3 shown in FIG. 1, and the shock absorber 1 shown in FIG. Each of these suspensions 71 to 74 is connected to the suspension controllers 51 to 54. The variable elastic bodies 7 of the suspensions 71 to 74 and the electric coil 38 are respectively connected to the controllers 51 to 5.
4 applies a voltage and also a current. Controller 51 ~
54 has substantially the same configuration, and has substantially the same logic and the voltage value applied to the variable elastic body 7 and the electric coil 3
The value of the energizing current of No. 8 is controlled.

To the piston rod 10 of the shock absorber 1 of the suspensions 71 to 74, a vibration sensor 41 for generating an analog voltage representing the amplitude of vertical vibration, that is, a vibration detection voltage, is coupled, and the vibration sensor 4 is connected.
The vibration detection voltage generated by 1 is the controller 51.
~ 54. Each of the controllers 51 to 54 includes a low-pass filter that receives a vibration detection voltage, and the low-pass filter.
A differential circuit that first-order differentiates the vibration detection voltage that suppresses high-frequency noise with a pass filter to obtain an analog voltage that indicates the vibration speed, and then second-derivates this to generate an analog voltage that indicates the vibration acceleration, and the absolute value of the vibration acceleration. An absolute value circuit that generates a voltage representing a value, that is, a vibration acceleration absolute value signal, and a computer system mainly including a microprocessor (hereinafter referred to as CPU) and an input / output interface.
Face (including a coil driver for energizing the coil 38 and a variable high voltage circuit for applying a voltage to the variable elastic body 7)
And an analog voltage representing the absolute value of the acceleration of vertical vibration (so-called vertical G of each sunpension part of the vehicle body), that is, a vertical vibration acceleration signal Vg is generated.
Read digitally with PU.

Each of the Sunpension controllers 51 to 54 has a damping force controller 7 including a CPU-based computer system and input / output interfaces.
0 is the damping force instruction data Ro1 addressed to each suspension
~ Give Ro4. The damping force controller 70 includes various sensors 5 for grasping a running state and a driving state of the vehicle.
5 to 62 and, though not shown, a switch or potentiometer for designating a damping force target value, a switch for designating a damping force control mode corresponding to the vehicle running state, and a mode control on / off instruction. Switches etc. are connected.

The damping force controller 70 responds to the designation by the input means such as the above switches and the running state and the driving state grasped by the various sensors, and a node for accelerating the vehicle.
Damping, nose down during deceleration, lateral leaning during steer, car body bouncing up and down due to road surface irregularities, etc. to prevent disturbance of the vehicle posture, and damping force of each suspension to ensure a comfortable ride. To calculate the
Assign Ro1 to Ro4 to each suspension.

Each of the computer systems of the suspension controllers 51 to 54 has a program and a shock absorber, which will be described later, for calculating a damping force for suppressing the vibration of the piston rod 10 even when the wheel vertically vibrates. The damping force of the bar 1 is set to the calculated required damping force, and the spring characteristic of the variable elastic body 7 is set to a value that does not cause excessive contraction or extension of the variable elastic body 7 in accordance with the required damping force. Program, a group of data referred to for calculating a damping force for suppressing vertical vibration of the rod 10, a group of data referred to for calculating a voltage applied to the variable elastic body 7 corresponding to the damping force, and others Various data of are stored. Each of the CPUs of the suspension controllers 51 to 54 has a vertical vibration acceleration absolute value signal obtained based on the detection value of the vibration sensor 41 and a damping force instruction data Roi (i = 1, 2,
(3, 4) is read into the memory at a predetermined cycle and the damping force ATdi (i = 1, 2, 3, 3) to be set in the shock absorber is read.
4) is calculated, converted into a voltage value to be applied to the variable elastic body 7, and a current value to be applied to the electric coil 38 (in this embodiment, the energizing current value is determined by energizing duty control). Since it is determined, specifically, it is converted into an energization duty), and the output of the voltage value is instructed to the variable high-voltage circuit that applies the voltage to the variable elastic body 7, and the current value corresponding to the current value to be energized is specified. The coil driver that energizes the electric coil 38 is instructed to turn on (energize) or turn off (deenergize) the duty. The coil driver connects between the electric coil 38 and the output end of the constant voltage power supply circuit when instructed to turn on, and cuts off this connection when instructed to turn off. The electric current value of the electric coil 38 is
The average value of the time series is If × (Ts−Td) / Ts. It should be noted that Ts is the length (time) of one cycle of the duty control, Td is the length (time) of non-energization (off) in the one cycle, and (Ts-Td) is one cycle. Is a length (time) of energization (ON), and If is an energization current value when energized continuously for one cycle Ts.

FIG. 6 shows a suspension controller 51.
The control operation of the CPU is shown. When the CPU is powered on, both the variable elastic body 7 and the electric coil 38 are turned off (no voltage is applied, no current is applied), and the internal register,
Set the timer, counter, etc. to the contents that should be set during standby, and set the prohibition of internal interrupt 1 and internal interrupt 2 described later (Step 2: In the following parentheses, the word step or subroutine is omitted, and Only the numbers attached are noted). Next, the CPU of the controller 51 writes the data Ts indicating one cycle Ts of the duty control to the off period register TD used for the energization duty control of the electric coil 38 (3), and the TD time limit. (TD is register T
The timer TD which takes (content of D) is started (4) and the internal interrupt 1 is enabled (5).

Incidentally, the energization duty control of the electric coil 38, as shown in (b) of FIG.
As a result, the electric coil 38 is de-energized during Td (≦ Ts), and the electric coil 38 is energized during the next (Ts−Td).
This is repeated every Ts cycle, and the content of the register TD specifies this Td. Internal interrupt 1
The contents of the above are shown in FIG. This internal interrupt 1 is
When the timer TD is started by the time-over of the timer TD and the process goes to the internal interrupt 1, when the TD (= Td) is less than Ts (periodic energization required: ENF = 1), the coil 38 is turned on (16, 30). , Timer Ts for determining energization time
-Start TD (21) and enable internal interrupt 2 (22). The contents of the internal interrupt 2 are shown in FIG.
The internal interrupt 2 turns off the electric coil 38 when the energization time Ts-Td in one cycle elapses.
It is started by the time over of the timer Ts-TD. When proceeding to the internal interrupt 2, the coil 38 is turned off (43),
A timer TD for determining the non-energization time is started (44). Due to internal interrupts 1 and 2, when TD (= Td) is less than Ts (periodic energization required: ENF = 1),
As shown in FIG. 9B, the electric coil 38 is repeatedly turned on and off, and the electric coil 38 is energized with a duty of (Ts-TD) / Ts × 100%.

TD (= Td) is Ts or more (continuous off required:
When ENF = 0), the coil 38
Is turned off (16, 17) and internal interrupt 2 is disabled (1
8). Since the coil 38 is not turned on by the internal interrupt 1, the electric coil 38 is continuously turned off.

When step 5 of FIG. 6 is completed, the CPU of the controller 51 causes the CPU of the controller 51 to sample the cycle of the absolute acceleration Vg of the vertical vibration of the front right wheel portion (= update cycle of the energization duty of the electric coil 38) dt. (6) by starting the dt timer dt for determining the above, converting the absolute acceleration value Vg of the vertical vibration of the front right wheel portion into digital data, writing it in the register VG, and controlling the damping force. Write the damping force instruction data Ro1 given by the controller 70 in the register ROUT (7). Next, the damping force Avdf for suppressing the vertical vibration of the front right wheel portion of the vehicle body is calculated based on the absolute acceleration value Vg of the vertical vibration of the front right wheel portion (8). In the calculation of Avdf (8), the acceleration absolute value V of the vertical vibration is stored in the memory area (adjustment data table) having the memory (ROM).
Since the standard value data (Avg) for the damping force adjustment corresponding to g is written, the CPU calculates the absolute value Vg of the vertical acceleration acceleration.
In (contents of register VG), the adjusted standard value data Avg associated therewith is specified, and this is read from the adjustment data table of the memory. Then, the damping force adjustment amount Avdf for suppressing the vehicle body vibration of the front right wheel portion that causes Vg is calculated as follows. Avdf = Kv1 · [Kv2 · Avg + Kv3 (Avg
-Avgp)] Kv1: Contribution ratio (distribution ratio) to the target damping force (Ro1), Kv2: Coefficient of proportional term of PI (proportional / derivative) control, Kv3: Coefficient of differential term of PI (proportional / derivative) control , Avgp: Standard value data Avg (= register for damping force adjustment amount read from the adjustment data table corresponding to Vg before dt)
Contents of AVGP), (Avg-Avgp): Amount of change in damping force adjustment standard value Avg during differential term (dt) Then, the damping force adjustment standard value Avg read this time is written to the register AVGP. The data written in the register AVGP is "Avdf calculation" next time (after dt).
In the calculation of Avdf when proceeding to (8), it is used as Avgp in the calculation of the change amount (Avg-Avgp) of the damping force adjustment standard value Avg.

CPU of the suspension controller 51
Next, the damping force AT to be set in the shock absorber 1
d1 is calculated as follows (9). ATd1 = Ro1 + Avdf Ro1 is a damping force instruction value given by the damping force controller 70.

CPU of the suspension controller 51
Is the damping force ATd to be set next in the shock absorber 1.
The voltage V7 to be applied to the variable elastic body 7 corresponding to 1 is calculated (10A). In a memory area (voltage value conversion table) having a memory (ROM), a voltage value data corresponding to the damping force setting value of the shock absorber 1 and having a spring characteristic of the variable elastic body 7 matching the damping force is provided. -Data V7 is stored. FIG. 8 shows the correlation characteristic of the voltage value data V7 with respect to the damping force setting value of the shock absorber 1. This voltage value data V7 is a spring characteristic (load characteristic) in which the variable elastic body 7 does not excessively contract or extend when the shock absorber 1 is hard (a large damping force) so as to suppress the disturbance of the vehicle body posture. Deflection amount for: variable elastic body 7 in FIG.
To determine. "Reading the voltage corresponding to ATd1"
At (10A), the voltage data V7 corresponding to ATd1 is read from the voltage value conversion table. And this data V
The voltage V7 designated by 7 is applied to the variable elastic body 7 via the variable high voltage circuit in the controller 51 (10B).
As a result, the conductive foil 7 of the variable elastic body 7 which is an odd number from the top
A voltage V7 is applied between d and the even-numbered conductive foil 7c,
The variable elastic body 7 is determined by the spring characteristic represented by the load-deflection amount curve (plurality) as shown in FIG. 4 corresponding to the voltage V7.

CPU of suspension controller 51
Next, the energization duty (off time Td that defines the duty) that produces the damping force ATd1 calculated in step 9 is calculated (10c). In this case, since duty data (off-period data) Td that causes each damping force is written in a memory area (duty conversion table) having a memory (ROM), the CPU Is the calculated damping force ATd1
Then, the off period data Td associated therewith is designated, and this data Td is read from the duty conversion table. Next, the CPU writes the read data Td in the register TD (11), and whether the data Td (= content TD of the register TD) is equal to or longer than one cycle Ts of energization duty control (continuous off is required). It is checked whether or not (on / off is required) (12). If it is Ts or more, 0 is written in the register ENF to specify continuous OFF (14), and if it is less than Ts, ON / OFF is specified to register ON.
Write 1 to F (13). The CPU next checks whether or not the timer dt has time-over (15), and if the timer has time-over, or if the timer has not time-over, waits for the time-over and returns to step 6 to set the timer dt. Star
To Hereinafter, steps 6 to 15 are performed in this order, and substantially d
Repeatedly in t cycles.

The suspension controller described above
By the control operation of the rotor 51, the damping force of the shock absorber 1 of the suspension 71 on the front right wheel portion is set to the damping force instruction value Ro1 designated by the damping force controller 70 in order to maintain the vehicle body posture properly. The damping force ATd1 corrected by the damping force Avdf for absorbing the vertical vibration of the vehicle body of the front right wheel due to the vehicle vibration of the right wheel is set to the damping force ATd1, and the spring characteristic of the variable elastic body 7 of the suspension 71 (load-deflection amount). )
However, the variable elastic body 7 is set so as not to excessively contract or extend at the damping force ATd1. The control operation of the suspension controllers 52 to 54 is similar to that of 51, and the suspension controllers 52, 53 and 54 are respectively suspensions 72, 73 for the front left wheel portion, the rear right wheel portion and the rear left wheel portion. Similarly, the damping force and the spring characteristics of the shock absorber and the variable elastic body of 74 and 74 are controlled. As a result, the damping force controller 70 is mainly used.
Control (calculation and instruction of Ro1 to Ro4), the damping force of the shock absorber of each wheel portion for maintaining the vehicle body posture properly is set, and mainly by the control of the suspension controllers 51 to 54. The damping force of the shock absorber of each wheel portion is corrected so as to absorb the vibration of each wheel portion, and their spring characteristics are set so that the variable elastic body of each wheel portion does not excessively contract or extend. It Therefore, the posture of the vehicle body is properly maintained, and the vertical vibration of each wheel is mainly due to the shock absorber, and the low frequency component is
The high frequency component is mainly absorbed by the variable elastic body, and its propagation to the vehicle body is suppressed.

[0042]

As described above, the suspension mounting device of the present invention uses the solid variable elastic member (7) whose spring characteristic, that is, elastic modulus, can be selected according to the applied voltage value, which is the electrode (7c, 7d). ) And the solid layer (7e) are laminated structure, the high load-bearing liquid-tight structure required for oil dampers and liquid dampers is not necessary, and the laminated structure is easy and highly accurate with synthetic resin lamination technology. , Which simplifies construction and manufacture.

When the damping force of the shock absorber is increased so as to suppress the disturbance of the vehicle body posture during acceleration, deceleration, steering, etc. of the vehicle, the electrical connection means (7
By changing the voltage value applied between the adjacent electrodes (7c, 7d) via a, 7b) to a higher value, the elastic modulus of the variable elastic member (7) increases and the amount of deflection with respect to the load decreases (Fig. 4). ), The spring characteristics of the shock absorber are hardened to prevent the vehicle body from sinking or floating, and the amount of compression or extension of the variable elastic member (7) with respect to the compressive force or the tensile force is reduced, and the shock absorber is reduced. Suppression of posture changes due to is greatly demonstrated.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the present invention.

FIG. 2 is a vertical sectional view of the shock absorber 1 shown in FIG.

FIG. 3 is a vertical cross-sectional view showing a part of FIG. 2 in an enlarged manner.

FIG. 4 is a graph showing the relationship between the amount of deflection and the load of the variable elastic body 7 shown in FIG.

5 is a block diagram showing a damping force control system for controlling a voltage applied to the variable elastic body 7 shown in FIG. 1 and a value of a current flowing through the electric coil 38 shown in FIG.

FIG. 6 is a suspension controller 51 shown in FIG.
2 is a flowchart showing the control operation of the CPU of FIG.

FIG. 7 is a suspension controller 51 shown in FIG.
7 is a flowchart showing the interrupt processing operation of the CPU.

FIG. 8 is a suspension controller 51 shown in FIG.
3 is a graph showing the correlation between the value specified by the voltage value data written in the memory and the value of the damping force ATd1 determined by the shock absorber.

9A is a graph showing a correlation between an off time Td written in a memory of the suspension controller 51 shown in FIG. 5 and a shock absorber damping force ATd1 caused by the off time Td. 2B is a time chart showing ON / OFF of the electric coil 38 shown in FIG.

[Explanation of symbols]

1: Shock absorber 2: Bearing 3: Coil spring 4: Spring bearing 5: Absorber mounting bracket 6: Absorber mounting bracket 7: Variable elastic body 7a: Outer rubber outer cover 7b: Inner rubber outer cover 7c: Conductive foil 7d: Conductive foil 7e: Electrically insulating polymer sheet 8: Car body mounting bracket 9: Screw 10: Piston rod 14: Piston 32: Plunger 37: Magnetic core 38: Electric coil

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoki Mohri 2-chome, Asahi-cho, Kariya city, Aichi Aisin Seiki Co., Ltd. (72) Inventor Takashi Nakai 2-chome, Asahi-cho, Kariya city, Aichi prefecture Address: Aisin Seiki Co., Ltd. (72) Inventor: Mitsuji Hirose, Aichi Prefecture, Nagakute-cho, Aichi-gun, Nagakute-cho, 41, Yokoshiro Yokouchi Central Research Institute Co., Ltd. (72) Inventor: Shiga Toru, Aichi-gun, Nagakute No. 41, Yokomichi, Chozaji, Kyoto City, Toyota Central Research Institute

Claims (1)

[Claims] 1. A first member that is rotatably coupled to an upper portion of a member that is coupled to a wheel and is integrally coupled in the vertical direction; a second member that is coupled to a vehicle body and supports the vehicle body; A plurality of electrodes arranged side by side, a solid layer made of an electrically insulating polymer material in which fine particles that are electrically polarized by the action of an electric field are dispersed, filling the space between these electrodes, and the elastic modulus of which changes according to the electric field strength; A mounting device for a suspension, comprising: a variable elastic member interposed between the first member and the second member; ..