JPH02171309A - Shock absorber device - Google Patents

Abstract

PURPOSE:To make damping force control smoothly by positioning and controlling a spool valve means, specifying a flow opening between spaces in a cylinder, by a solenoid driving in the direction reverse to that of a compressive coiled means exciting in one direction, in a cylinder piston type shock absorber device. CONSTITUTION:A piston rod 10 is made hollow and a bottomed cylindrical body 25 is formed in a lower inner space of the piston. An electric coil 38, plunger (spool valve means) 32, and compressive coiled spring 36 exciting the plunger 32 are housed in the space. The spring 36 is used for the plunger 32 to excite in the direction to narrow the flow opening of it; the electric coil 38 is used for the plinger 32 to drive in the direction to widen the flow opening of it. In this constitution, the force of the electric coil 38 is set by controlling the amount of electric flow according to the operating conditions, and the force of the spring 36 is balanced with that of the electric coil to determine damping force. With this constitution, damping force control can be made smoothly according to the operating conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a shock absorber, and more particularly to a mechanism for determining the damping force of a shock absorber.

(Prior Art) Suspensions are equipped with shock absorbers in order to suppress propagation of axle vibrations (particularly shocks) to the vehicle body and provide a comfortable ride for vehicle occupants. When the damping force of the shock absorber is set low, the propagation of axle vibration to the vehicle body is reduced, so one occupant feels soft movement when the axle vibrates, providing a comfortable ride. However, due to sudden braking, sudden acceleration, or relatively fast turning maneuvers (rotation of the steering wheel) at relatively high speeds,
The car body is tilted forward (nose down), copper treated (nose up),
When a force that causes the vehicle to lean to the left or right is applied, the vehicle body tends to lean in this way, and the lower the damping force, the greater this tendency becomes, resulting in poor handling stability.

Therefore, the shock absorber is equipped with a rotary valve that changes the area of the fluid passage between the two chambers divided by the piston in the cylinder to be large or small.

It is designed to selectively switch to a plurality of positions such as standard (intermediate) and soft (large aperture) (for example, Japanese Patent Laid-Open No. 194609/1983). According to this.

For example, set it to soft when you want a comfortable ride, and set it to hard when you are likely to perform sudden braking, sudden acceleration, or relatively fast turning steering at relatively high speeds relatively frequently. , if neither can be determined definitively, it is possible to select an appropriate damping force according to the road condition and driving condition by setting the damping force to standard.

However, recently there has been a strong demand for automatic vehicle attitude control, and the damping force required to maintain the vehicle attitude suitable for driving is calculated in accordance with the vehicle speed, steering angle, etc. Techniques have been proposed to automatically set this damping force to the shock absorber (for example, JP-A-59-1
68039), that is, a detection means for detecting a force applied to the vehicle body that causes a change in the load applied from the vehicle body to the wheels, and a detection value of the detection means.

An automatic damping force control device is provided which includes a control means for calculating a target damping force to suppress a change in the height of the vehicle body relative to the wheels due to a change in the force applied to the vehicle body, and setting the target damping force to a shock absorber.

[Problem to be solved by the invention]

However, although the magnitude of the force that causes a change in the posture of the vehicle body that occurs during driving is linear (stepless), the damping force setting of the shock absorber is set in stages such as hard, standard, and soft as mentioned above. Since the damping force control # (i.e., vehicle body posture control) according to the driving condition lacks smoothness.

SUMMARY OF THE INVENTION An object of the present invention is to provide a shock absorber device that can more smoothly implement damping force control according to driving conditions to ensure steering stability.

[Structure of the invention]

(Means for Solving the Problems) The shock absorber device of the present invention includes a cylinder (12)
, a piston (1) that partitions the inner space of the cylinder (12).
4) is fixed to the piston (14) and the cylinder (12
) and a piston (14) extending to the outside of the rod (10).
a spool valve means (32) that defines the degree of communication opening between the spaces (15, 16) that produces a pressure difference due to the vertical movement of the spool valve means (32); , a valve drive means (36) that forces the valve drive means (36) in one direction (narrowing direction), and a spool valve means (32) that drives the spool valve means (32) in the opposite direction (widening direction) to the direction forced by the valve drive means (36). Solenoid (37, 38, 25a),
a shock absorber (1); and a damping force control means (4) that controls the current value of the solenoid (37, 38, 25a) to determine the position of the spool valve means (32).
0) : is provided. Note that the symbols in parentheses are attached to corresponding elements in the embodiment shown in one drawing and described later.

(Function) The valve drive means (36) forces the spool valve means (32) in one direction (the direction that narrows the flow opening), and the solenoid (37, 38, 25a) forces the spool valve means (32) in the opposite direction. The valve means (32) is driven in the opposite direction (direction to widen the flow opening). The spool valve means (32) therefore receives the force exerted by the valve drive means (36) and the solenoid (37,3
g.

25a] is the position where the forcing force is balanced.

The flow opening degree, that is, the damping force has a value corresponding to the position.

Solenoid (37.3g, 25a) 1! When the current value is increased, the spool valve means (32) moves in the opposite direction (
The damping force changes to a value (a smaller value) corresponding to the movement position. In this way, the damping force changes in response to changes in the current value flowing through the solenoids (37, 3g, 25a), and since this current value can be changed steplessly, the damping force can be changed steplessly. Therefore, the damping force control means (40) is controlled by the solenoid (37,3g, 25
The spool valve means (32) is controlled by controlling the current value of a).
), the damping force can be set steplessly by the damping force control means (40).

Therefore, according to the shock absorber device of the present invention,
In response to stepless changes in force that cause posture changes to the vehicle body that occur during driving, damping force can be set steplessly to suppress the posture changes, and the damping force can be adjusted steplessly to suppress the posture changes. By precisely and smoothly controlling the damping force, it is possible to more precisely and smoothly prevent changes in vehicle body posture due to driving conditions and provide a comfortable ride.

Other objects and features of the invention will become apparent from the following description of an embodiment with reference to one drawing.

(Example) f51 Fig. 1a shows an enlarged longitudinal cross-section of a shock absorber l of an embodiment constituting the shock absorber device of the present invention, and Fig. 1b shows a further enlarged longitudinal cross-section of a portion of the shock absorber l, which supports a vehicle body. The upper end base 11 through which the piston rod 10 passes has an inner cylinder 12 and an outer cylinder 1.
The upper ends of 3 are fixed concentrically. Piston rod 1
A piston 14 is fixed to the lower end of the 0. The lower end of the outer cylinder 13 is fixed to a lower end base 18, while the lower end of the inner cylinder 12 is fixed to a valve gear ff117 supported by the lower end base 18.

The inner space of the inner cylinder 12 is connected to the upper space 15 by the piston 14.
and upper space 16. A space (lower end base space) 18a between the valve device 17 and the lower end base 18 communicates with the space between the inner and outer cylinders 12 and 13, that is, the outer space 24, through the passageway in the lower leg of the valve device ai7. ing. A liquid is sealed inside the inner cylinder 12.

The outer space 24 is filled with liquid and gas.

The valve device 17 includes an upper space 16 and a lower end base space L8.
Two sets of flow passages 19° 22 are formed that communicate between the space a, and the first set of flow passages 19 is an opening on the upper space 16 side and is pressed down by a compression coil spring 21. It is closed by a disc-shaped check valve member 20. 2nd set of flow passages 2
2 is an opening on the side of the lower end base space Iga, which is closed by a check valve member 23 pushed up by a leaf spring 23a.

When the axle is pushed up due to unevenness on the road surface, a force acts between the cylinder 12 and the piston 14 in a direction that moves the piston 14 downward relative to the cylinder 12, causing the piston 14 to move downward relative to the cylinder 12. and try to move downwards to
The pressure in the upper space 16 increases. When this pressure exceeds a predetermined value, the check valve member 23 is driven downward against the push-up blade of the leaf spring 23a, and the pressure in the inner space 16 is reduced to the second set of flow passages 22 and the lower end. It exits to the outside space 24 through the base space 18a. This allows the piston 14 to move upward, and the piston 14 to move downward. As a result, the piston rod 10 due to the upward thrust of the wheel
(vehicle body) thrust is buffered.

When the wheels descend due to unevenness on the road surface, a force acts between the cylinder 12 and the piston 14 in a direction that moves the piston 14 upward relative to the cylinder 12, causing the piston 14 to move upward relative to the cylinder 12. It tries to move upward, and the pressure in the upper space 16 decreases. When this pressure becomes less than a predetermined value, the check valve member 20 is driven upward against the pressing blade of the compression coil spring 21, and the pressure in the outer space 24 is reduced to the lower end base space 18a and the first set. It exits to the upper space through the flow path 19. As a result, piston 1
4 becomes possible to move upward, and the piston 14 moves upward. As a result, the piston rod 1 due to the lowering of the wheel
The descent of 0 (vehicle body) is buffered.

As explained above. The damping force when the wheel is raised and the damping force when the wheel is lowered by the valve system [17] are
Since the cross-sectional area of the flow path is fixed.

It is fixed.

Next, to explain the mechanism for providing a variable damping force provided for carrying out the present invention, the rod lO made of a magnetic material is hollow, and its lower end passes through the piston rod 10 up and down. The internal lower space of the piston rod 10 (
27, 28) communicate with the upper space 16 through the passage port 10a of the rod. An airtight flange 2 is provided approximately in the center of the inner lower space (27°28) of the piston rod 10.
A cup-shaped bottomed cylindrical body 25 having a diameter of 6 is inserted, and its upper opening edge is fixed to the inner wall of the rod IO. The inner lower space (27, 28) of the piston rod 10 is connected to the rod inner lower air passage 28 which communicates with the upper space 16 by the flange 26 of the cylindrical body 25 (a sealing material such as a ring coupled to the flange 26). It is divided into an inner rod upper space 27 that communicates with the upper space 15 through communication ports 29, which are six holes equally spaced in the circumferential direction on the side wall of the lO.

In the side wall of the bottomed cylindrical body 25, 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 an end plate 25a, which is a ring-shaped magnetic material, is in contact with the upper opening end surface of the bottomed cylinder 25, and the end plate 25a presses the bottomed cylinder 25 downward. It is fixed to the rod 10 by. A bobbin 38a around which an electric coil 38 is wound is disposed on the end plate 25a. A lower large diameter portion of the magnetic plunger 32 enters the bottomed cylinder 25, and an upper assembled diameter portion of the plunger 32 vertically penetrates the end plate 25a.

A ring-shaped groove 35 is formed in the engineering diameter portion of the plunger 32, and this groove 35 forms two flanges 33.3.
4 are formed, and these flanges 33 and 34 are in contact with the inner surface of the bottomed cylinder 25. The width (vertical direction) of the ring-shaped groove 35 extends from the upper end to the lower end of the upper and lower holes 30 and 31 of the bottomed cylindrical body 25. The upper end surface of the upper line diameter portion of the plunger 32 is an inverted conical tapered surface, and the center portion thereof is an inverted conical tapered surface.

A round hole is formed to accommodate the compression coil spring 36. The coil bobbin 38a has a nail-shaped magnetic core 37.
is inserted, and its lower end has a conical shape complementary to the tapered surface of the plunger 32, and a round hole is bored in the center thereof to receive the upper end of the compression coil spring 36.

When the electric coil 38 is de-energized, the plunger 32 is pushed down by the repulsive force of the compression coil spring 36.
As shown in FIG. 1b, the groove 35 completely communicates with the entire hole 31, but since the flange 33 almost closes the hole 30 with a small gap, the upper space 15 - the hole 29 - the rod. The route is upper space 27 - hole 3 - groove 35 - hole 3 - rod white lower space 28 - communication port 10a - upper space 16.

The cross-sectional area of the vertical space (between 15 and 163) is the lowest, making it difficult for the piston 14 to move. It is the highest value of power.

The electric coil 38 is energized, and the plunger 32 is attracted to the core 37 and reaches the top (the plunger 32 contacts the core 37).
When the holes 30 and 31 are each completely communicated with the groove 35, the cross-sectional area of the communication passage between the upper and lower spaces (15-16) becomes the maximum, and the piston 14 is easy to move, i.e. , the damping force determined by the plunger 32 (
The adjustable damping force) is the lowest value of the damping force that can be set with the plunger 32.

The magnetic core 37 (lower end shape), plunger 32 (upper end shape), compression coil spring (spring constant), and electric coil 38 (number of turns per turn length and winding thickness) are as follows:
For the current value of the electric coil 38, the magnetic core 37
The distance between the plunger 32 and the magnetic core 37 is designed to be approximately proportional, and the distance between the plunger 32 and the magnetic core 37, that is, the adjustable damping force, is determined by the current value of the electric coil 38.

Note that the above-described damping crab SM mechanism including the plunger 32 and the like may be installed in the valve system 5!17. Also.

Valve device! A fixed damping force mechanism consisting of the flow passages 19, 22, etc. of 7 may be configured in the piston 14. Alternatively, it is also possible to equip the current valve device W117 with a damping force adjustment mechanism such as the plunger 32, and configure the piston 14 with a fixed damping force mechanism consisting of the flow passages 19, 22, etc. of the current valve device 17. good.

Figure 2 shows the sub-controller that controls the damping force of the shock absorber l! A shock absorber 1 is installed on the front right wheel suspension (not shown) of the vehicle.
A shock absorber 2 is installed on the front left axle suspension (not shown), and a rear right wheel suspension (not shown) is installed on the front left axle suspension (not shown).
The rear left wheel suspension (not shown) is equipped with a shock absorber 3, and the rear left wheel suspension (not shown) is equipped with a shock absorber 4. The damping force of these shock absorbers 1 to 4 is set by subcontrollers 51 to 54, respectively. be done. Note that the shock absorbers 2 to 4 have the same structure as the shock absorber 1, and the subcontroller 52
The configuration and control operations of ~54 are also controlled by the sub-controller 51.
The configuration and control operation are the same.

The electric coils 38 of the shock absorbers 1-4 are energized by sub-controllers 51-54, respectively. The sub-controllers 51 to 54 have substantially the same configuration and control the current flowing through the electric coil 38 using substantially the same logic.

The piston rods 10 of the shock absorbers 1 to 4 include
Vibration sensors 41 to 44 that generate analog voltages representing the amplitude of vertical vibration, that is, vibration detection voltages are coupled to each of them, and the vibration detection voltages generated by the vibration sensors 41 to 44 are connected to signal processing interfaces of subcontrollers 51 to 54, respectively. Given to 39. Note that the vibration sensors 41 to 44 may be coupled to other members coupled to the piston rod 10 or to the vehicle body.

The interface 39 includes a low-pass filter that receives a vibration detection voltage, and a vibration detection voltage that suppresses high-frequency noise with the low-pass filter, which is first differentiated to obtain an analog voltage that indicates vibration speed, and which is second-order differentiated to indicate vibration acceleration. It includes a differentiation circuit that generates an analog voltage, and an absolute value circuit that generates a voltage that represents the absolute value of vibration acceleration, that is, a vibration acceleration absolute value signal.
), that is, a vertical vibration acceleration signal Vg, is applied to an A/D conversion input port AD of a microprocessor (hereinafter referred to as CPU) 40.

A rotation angle sensor 55 for detecting the rotation angle of the steering wheel is connected to the steering shaft of a vehicle equipped with the embodiment shown in FIG. to the processing interface 65. The interface 65 includes a differentiation circuit that differentiates an analog voltage representing one rotation angle to generate an analog voltage representing the rotation speed of the steering shaft, that is, a rotation speed signal Rs.
s is applied to the A/D conversion input port ADI of the CPU 60.

Pulses generated by a rotary encoder 56 coupled to the vehicle speed meter cable and generating electrical pulses at a frequency proportional to the rotational speed of the transmission output shaft are provided to a signal processing interface 66 . The interface 66 includes an F/V conversion circuit, and transmits a voltage at a level proportional to the frequency of the electric pulse, that is, a vehicle speed signal Vs, to the CPU 60.
is applied to the A/D conversion input port AD2.

The vehicle body is equipped with an acceleration sensor 57 that detects lateral acceleration (so-called lateral G) of the vehicle body and generates an analog voltage indicative of the acceleration, and the analog voltage is applied to a signal processing interface 67 . interface 67
includes an absolute value circuit that generates a voltage indicating the absolute value of the analog voltage, that is, a lateral acceleration absolute value signal Rg, and supplies the lateral acceleration absolute value signal Rg to the A/D conversion input port ΔD3 of the CPU 60.

The vehicle body has acceleration in the longitudinal direction of the vehicle body (so-called longitudinal G).
An acceleration sensor 58 is mounted that detects and generates an analog voltage indicative of the detection, and the analog voltage is applied to a signal processing interface 68. The interface 68 includes an absolute value circuit that generates a voltage indicating the absolute value of the analog voltage, that is, a longitudinal acceleration absolute value signal Pg.
The longitudinal acceleration absolute value signal Pg is applied to the A/D conversion input port AD4 of the CPU 60.

The main controller 70 is connected to a dip meter 81 that instructs the amount of damping force adjustment.

A of CPtJ60 via level adjustment amplifier s82.
An analog voltage indicating the amount of adjustment, that is, an adjustment value signal Aa is applied to AD5.

Also to the main controller 70. A switch 83 for instructing on (execution)/off (stop) of automatic damping force adjustment is connected, and a signal indicating the instruction (H: execution of automatic damping force adjustment/L: stop) is connected to the input port Am of the CPU 60. )
give.

The ROM 62 of the main controller 70 contains a program that performs damping force control to suppress changes in vehicle body posture (front/rear inclination, lateral inclination, etc.) due to changes in vehicle driving conditions, as well as programs for calculating damping force, which will be described later. A data group and various data to be referenced for this purpose are stored. The CPU 60 reads various signals Rs, Vs, Rg, and Pg obtained based on the detection values of the various sensors 55 to 58 described above into the internal RAM or external RAM 61 at a predetermined period, and calculates the target damping force. This is set in the latches of data output circuits 71-74. Data output circuits 71 to 74 output latch data to subcontrollers 51 to 74 via buffer amplifiers.
54. Decoder 5 of main controller 70
9 converts the element designation data of the address data output by the CPU 60 into an element designation signal, and provides the designation signal to the designated element. The CPU 60 sends operation control signals for each element to the control line.

In the ROM 45 of the sub-controllers 51 to 54.

Even if there is vertical vibration in the axle as described later, the piston rod 10
A program to perform damping force reduction control to suppress the vibration of the shock absorbers 1 to 4, a program to set the damping force of the shock absorbers 1 to 4 to the calculated required damping force, and a calculation of the damping force reduction amount for suppressing the vertical vibration of the rod IO. A data group and various data to be referenced for this purpose are stored. C
The PU 40 outputs the vertical vibration acceleration absolute value signal Vg obtained based on the detection values of the vibration sensors 41 to 44 described above and the data output circuits 51 to 54 of the main controller 70.
The target damping force data (Rout) given by Rout is read into the internal RAM or external RAM 46 at a predetermined period, and the damping force to be set for the shock absorber, that is, the required damping force (A
'rdt), and use this as the current value to be applied to the electric coil 38 (in this embodiment, the applied current value is determined by one energization duty control).

Specifically, the duty is converted into an energization duty), and the ON (energization)/off (non-energization) of the duty corresponding to the current value to be energized is provided to the coil driver 49 via the output interface (buffer amplifier) 48. coil driver 4
9 connects the electric coil 38 and the output end of a constant voltage power supply circuit (not shown) when instructed to turn on, and cuts off this connection when instructed to turn off. The current value of the electric coil 38 is:

With the average value of the time series.

IfX(Ts-Td)/Ts, where Ts is the length of one cycle of duty control (
time), Td is the length (time) during which the current is not energized (off), and (Ts - Td) is the length (time M) during which the current is energized (on) within one cycle. If is the current value when the current is applied continuously for one cycle Ts. The decoder 47 of the sub-controllers 51 to 54 converts child designation data of the address data output by the CPU 40 into an element designation signal.

A signal indicating that the designation has been made is given to the designated element.

The CPU 40 sends operation control signals for each element to the control line.

FIG. 3a shows the control operation of the CPU 60 of the main controller 70. The CPU 60 is powered on (step 1). (2) Outputs the signal level or data that should be output during standby (stopping damping force control) to the output port, and sets internal registers, timers, counters, etc. to the contents that should be set during standby (only shown). And various sensors 55~
To determine the sampling period (and target damping force update calculation period) dT for reading the detected values of 58.

Start the timer dT, which takes a time limit of dT (3), and read the detected values, etc. (4), that is, the analog voltage pg of the A/D conversion input ports ADI to AD5 (the absolute value of the acceleration in the longitudinal direction of the vehicle body). ), Rg (absolute value of lateral acceleration of the vehicle body), Vs (vehicle speed), Rs (rotational speed of the steering wheel) and Aa (damping force adjustment amount) are converted into digital data and registered as Regis 9PG, RG, VS, R
S and AA, and write the signal level of input port Am (H: damping force control execution/L: stop) to register AM.

Next, the CPU 60 determines the damping force adjustment amount corresponding to Vs (vehicle speed) and Rs (steering wheel rotation speed),
That is, the change in lateral acceleration corresponding to the rate of change in the turning radius of the vehicle that is expected to occur due to Vs and Rs;
A damping force adjustment amount E rdf appropriate for suppressing the change in lateral inclination of the vehicle body that would occur due to the above is calculated (5).

The details of this calculation operation are shown in FIG. 3b. A memory area (Table 1) in the ROM 62 contains information at various rotational speeds (Rs) of the steering wheel. Vehicle speed (Vs
) corresponding damping force adjustment standard value data (E rg) are written in groups for each rotation speed (R, q), so the CPU 60 writes the damping force adjustment standard value data (E rg) according to the rotation speed Rs (contents of register R8). 3b), and specify the intra-group individual data Erg using the vehicle speed Vs (contents of the register vS).

This individual data Erg is read out from table l in the ROM 62 (51). Then, a coefficient value (weighting coefficient) Ki that determines the contribution ratio with other damping force adjustments described later is added to the 5 read data Erg, and the generated value is generated by Vs (vehicle speed) and Rs (steering wheel rotation speed). Then, the damping force E rdf for suppressing the change in lateral inclination caused by the estimated spear acceleration corresponding to the expected rate of change in the turning radius of the vehicle is obtained (52).

Referring again to FIG. 3a, next the CPU 60.

Damping force adjustment corresponding to the longitudinal acceleration absolute value Pg,
In other words, a damping force adjustment amount Apdf suitable for suppressing the longitudinal tilt of the vehicle body caused by Pg is calculated (6).
.

The contents of "rA pdf calculation" (6) are shown in Figure 3c.
This is because the damping force adjustment jlRS value data (Apg) corresponding to the longitudinal acceleration absolute value Pg is written.

The CPU 60 corresponds to the longitudinal acceleration absolute value Pg (content of register PC): l! Specify the 4-integrated standard value data Δpg and use this individual data AP
g is read from Table 2 of the ROM 62 (61), and the damping force adjustment amount A pdf is used to suppress the longitudinal inclination caused by Pg (absolute value of acceleration in the longitudinal direction).
is calculated as follows (62).

Apdf=Kp,・(KP2・Apg+Kpa (Ap
g-Apgp)) Kpl: Coefficient value that determines the contribution ratio (distribution ratio) with other damping force adjustments Kp2: Coefficient KP3 of the proportional term of PI (proportional/derivative) control
: Coefficient A of the differential term of PT (proportional/derivative) control, pg
p: d steps ago, damping force adjustment all standard value data APg (register AP) read from Table 2 corresponding to Pg.
Contents of GP) (Apg - Apgp): Differential term (attenuation crab A!i1min m quasi-value during dT, amount of change in Apg) Then, write the damping force adjustment valve standard value APg read this time to the register APGP. Enter (63). This register APGP
The data written in the Apdf calculation when proceeding to "rApdf calculation" (6) in the first time (after dT),
Amount of change in damping force adjustment valve standard value APg (A pg A
pgp) is used as A PgP.

Referring again to FIG. 3a, the CPU 60 then selects a damping force adjustment amount corresponding to the absolute lateral acceleration value Rg, that is, a damping force appropriate for suppressing the Wt tilt of the vehicle body caused by Rg. A-integrated Ardf is calculated (7).

The contents of "rArdf calculation" (7) are shown in FIG. 3d.

The memory area (Table 3) in ROM[32] stores all standard damping force adjustment value data (A
rg) has been written, the CPU 60 specifies the lateral acceleration absolute value R, (contents of register RG) and the adjustment standard value data Arg associated with it, and writes this individual data Δrg. is read from table 3 in the ROM 62 (71).

Then, the damping force adjustment amount Ardf for suppressing the lateral tilt caused by Rg (absolute value of lateral acceleration) is calculated as follows (72).

Ardf= Kr1 ・[Kr2 Arg+ Kr3
(Arg - Argp)) K'1: Other damping force FII
Coefficient value Kr2 that determines the contribution ratio (distribution ratio) with the four integrals: Coefficient Kr of the proportional term of PI (proportional/derivative) control
a: Coefficient A of the differential term of PI (proportional/derivative) control A rg
p: Before dT, damping force adjustment all standard value data Arc (register AR
Contents of GP) (Arg - Argp): Differential term (amount of change in damping force adjustment valve standard value Arg during dT) Then, write the damping force adjustment valve standard value Arg read this time to register ARGP (73) , this register ARGP
In calculating Ardf when proceeding to "rArdf calculation" (7) for the data that has been heated for 5 times (after 6th block),
Amount of change in damping force adjustment valve standard value Arg (A, g-Argp
) is used as A rgp in the calculation.

Referring again to FIG. 3a, CPU 60 then:

The damping force adjustment amount E rdf , A calculated as described above
Add pdf and Ardf and add 4M to the sum obtained.
Coefficient i1 (weighting coefficient) Kc that determines the contribution ratio between the damping force and the damping force adjustment for suppressing upward vibration of the wheel portion, which will be described later.
Calculate the primary target damping force ATdf by multiplying by (8
), A Tdf = Kc・(Erdf+Apdf
+ Ardf).

Next, the CPU 60 adds the manual (potentiometer 81) input adjustment value Aadf (damping force adjustment value corresponding to the content Aa of the register AA) given to the main controller 70 to the primary target damping force ATdf. Calculate the secondary target damping force ATdf (9), A Tdf
g=A Tdf+Aadf.

The CPU 60 then checks the signal level of the register AM (theory A).
With reference to , it is determined whether the switch 83 is open (L: stop of damping force control is specified) or closed (H: execution of damping force control is specified) (10).

When the switch 83 is closed (H), the secondary target damping force ATdfo is written to the output register Rout (11
), when the switch 83 is open (L), the secondary target damping force ATdfo is the S semi-high damping value (fixed value) ATsm
Check whether it is above (14), and if so, write the secondary target damping force ATdfo to the output register Rout (11), but if ATdfO is less than ATsta, write ATg to the output register Rout. Write - (
15), that is, when damping force control stop is instructed (Am=I-).

The secondary target damping force ATdf0 calculated as described above for damping force control and the standard high damping value (fixed value) ATss,
Write the larger one to the output register Rout.

If the content of this output register Rout is the tertiary target damping force, this is calculated by the main controller 70. The final target damping force data is set in the latches of data output circuits 71 to 74. Namely.

The CPU 60 gives the data in the output register Rout to the data output circuits 71 to 74 and instructs each of the circuits 71 to 74 to read (latch) the data (1).
2).

Next, the CPU 60 waits for the timer dT to time out (13), and when the time has expired, returns to step 3 and starts the timer clT for the first time.

Execute steps 3 and below to install sensors, etc. 55 to 5.
8. Read the output of 81.83 and calculate the target damping force,
The updated data is output to data output circuits 71 to 74. In this way, the CPU 60 returns the same period of dT, reads the output of the sensor, etc., updates the target damping force, and updates the target damping force data of the data output circuits 71 to 74.

FIG. 4a shows the control operation of the CPU 40 of the sub-controller 51. When the CPU 40 is powered on, it outputs a signal level (L: non-energized) to be output during standby to the output port to the output interface 48, and outputs a signal level (L: non-energized) to the output port to the output interface 48, and outputs the signal level (L: non-energized) to the output port to the output interface 48.

Set the counter etc. to the content that should be set during standby.

Inhibition of internal interrupt 1 and internal interrupt 2, which will be described later, is set (22).

Next, the CPU 40 stores data Ts indicating one cycle Ts of duty control in the off period register TD used for controlling the energization duty of the electric coil 38 of the shock absorber 1.
is written (23), a timer TD that takes a TD time limit (TD is the contents of register TD) is started (24), and internal interrupt l is enabled (25).

Note that the energization duty control for the electric coil 38 is performed by the fourth
As shown in figure a, Td(Td
fmTs), the electric coil 38 is de-energized, and the next (T
s-Td), and this is repeated for the same period Ts, and the contents of the register TD specify this Td.

Therefore, internal interrupt 1 (Figure 4c) is triggered by timer TD.
Roughly speaking, the electric coil 38 is switched from off (non-energized) to on (energized), and a timer (Ts - Td) with a time limit of (Ts - Td) is activated.
-TO) and enable internal interrupt 2. Internal interrupt 2 (Figure 4d).

This internal interrupt 2 is activated when the timer (Ts-TD) times out, and the electric coil 38
The timer TD is started by switching from on (energized) to off (de-energized).

By executing these internal interrupts l and 2, the electric coil 3
8 is energized with a duty of (Ts - T D)/TsX 100%. TD is the contents of register TD (=
Td: Non-current period Td) shown in FIG. 4a.

At initialization (22), the contents of flag register ENF become O(
(specifying continuous off of the electric coil 38), and step 2
In step 3, Ts is written to register TD, which specifies the energization duty as 0% ('14 continuous off).
When the timer TD is started (24) and the internal interrupt 1 is enabled (25), when the timer TD times out, the CPU II O interrupts the internal interrupt! shown in FIG. 4c.
(Ding NT I) and step 36-37-38-3
At 9, L is given to the coil driver 49 via the output interface 48 to specify that the electric coil 38 is turned off (
37), disables internal interrupt 2 38), restarts timer TD L (39), and when timer TD times out, similar interrupt processing is executed again, so coil driver 49 is continuously turned off (L). ) is indicated and the electric coil 49 is not energized. That is, the shock absorber 1 is set to the maximum damping force.

Now, after completing step 25, the CPU 40.

Sampling period of the acceleration absolute value vc of the vertical vibration of the front cloth axle portion (=update period of the energization duty of the electric coil 38)
Start the dt timer dt to determine dt (26), and calculate the absolute value vg of the acceleration of the vertical vibration of the M stone wheel part.
is converted into digital data and written to the register VG, and the data held by the data output circuit 71 (Rout) is read and written to the register ROUT (27).
When the U60 updates and latches the data in the output register Rouj to the data output circuit 71, the decoder 59 gives the data output circuit 71 a signal specifying data capture (latch), and this signal is used as a busy signal to be sent from the data output circuit 71 to the CPU 40. This busy a
In order to avoid reading error data, the CPU 40 suspends the reading of the data Roue, waits until the busy signal disappears (changes from the busy level to the ready level), and then reads the data RO 14t.

Next, the CPU 40 calculates a damping force A vdf that suppresses the vertical vibration of the front right wheel portion of the vehicle body, based on the acceleration absolute value Vg of the vertical vibration of the front right axle portion (28).

FIG. 1Ib shows the contents of [Avdf g output J (28). In the memory area of the ROM 45 (Table 4), damping force adjustment standard value data (AVg) corresponding to the absolute acceleration value Vg of vertical vibration is written, so the CPU 40
is the vertical vibration acceleration absolute value Vg (contents of register VC), specifies the adjustment 4M quasi-value data Aνg associated with it, and stores this individual data Aνg in the ROM 45.
(28+). And Vg
Damping force adjustment amount Avdf to suppress vehicle body vibration of the front right wheel portion generated by (absolute value of acceleration in the vertical direction)
is calculated as follows (282).

Avdf= Kvl ・(Kv2 ・Avg+ Kva
(Avg - Av (Hp)) Kvl: Target damping force (
Coefficient value (weighting coefficient value) that determines the contribution ratio (distribution ratio) with R u *, ) Kv2: Coefficient Kv3 of the proportional term of Pl (proportional/differential) control
:Coefficient AνEP of the differential term of PT (proportional/derivative) control
: dt, before, damping force adjustment all standard value data Aνg (register AV
Contents of GP) (Aug-Avgp): Differential term (change in the damping force adjustment value 4M44 value AVg during dt) Then, write the damping force adjustment value Avg read this time to the register AVGP (283 ). Second register AVG
The data written to P will be transferred to rAvd next time (dll&).
In calculating Avdf when proceeding to f calculation J (28), attenuation crab J8'! Amount of change in standard value Avg for ji minutes (
It is used as Avgp in the calculation of AVg-Avgp).

Referring again to Figure 4a. Next, the CPU 40 calculates the damping force ATd to be set in the shock absorber 1 as follows (29).

ATd! = Roul knee Avdf, Ro
ut is the content of the register ROUT (attenuation value received from the data output circuit 71 (output register Ro of the CPU 60)
uL contents).

Next, the CPU 40 converts the calculated damping force ATd1 into a current value (energization duty of the electric coil 38: more precisely, the off period Td between the duty control period Ts) (30). In this case, ROM4
Since the duty data (off period data) Td that provides the required damping force is written in a certain memory area (Table 5) of Table 5, the CPU 40 calculates the calculated damping force ATd.
1 specifies the off-period data Td associated with it, and reads this individual data Td from table 5 of the ROM 45.

Next, the CPU 40 stores the read data Td in the register T.
Write to D (31), the corresponding data Td (= register TD
It is checked whether the content TD) is greater than or equal to one period Ts of the energization duty control (32).

If it is greater than or equal to Ts, this means that the electric coil 38 is turned off continuously, so to indicate this, O is written in the flag register ENF (34; synonymous with clearing the register ENF). If the data Td is less than TS, the electric coil 38
This means turning on (energized) and off (de-energized), so to indicate this, 1 is written in the flag register ENF (33).

Next, the CPU 40 waits for the timer dt to time out (35), and when the timer dt times out.

Return to step 26 and start timer dt.

Next, execute the steps from step 27 described above to read Vg and RQ u t, calculate the damping force ATd to be set in the shock absorber 1, and calculate this damping force ATd, which is the off period of -period TsrIIXJ of the energization duty control. Data T
d, write this to register TD, and check whether the written value is greater than or equal to Ts.

If it is above, 1 is written to the flag register ENF.

If it is less than the flag register ENF is cleared.

The same applies below. In this way, the CPU 40 updates the damping force of the shock absorber l (the energization duty of the electric coil 38) at the same cycle as dt.

When the content of the flag register ENF is O, when the timer TD times out and the process proceeds to internal interrupt 1 shown in FIG. 4c, the CPU 4Q executes steps 36-37-
Run 38-39 to turn off the electric coil 38.
7), disables internal interrupt 2 38), and starts timer TD by 1 (39), so TD (in this case T' D
= Td = Ts), only the internal interrupt I is executed, and the electric coil 38 is not turned on (energized).

The content of flag register ENF is 1 (register TD
When the content TD=Tcl is less than Ts).

When the timer TO times out, the CPU 40
Proceeding to internal interrupt l shown in Figure c, steps 36-40
Execute steps 41-42 to turn on (energize) the C1 electric coil 38 (40) and start the timer (Ts-TD) and enable internal interrupt 2 (42).

When the timer (Ts-TD) exceeds tie 2, the process proceeds to internal interrupt 2 shown in FIG. 4d, where the electric coil 38 is turned off (de-energized) (43) and the timer TD is started (44). As a result, when the content of the flag register ENF is 1, the electric coil 38 is turned on (energized) during ('I''s-]゛D), that is, during Ts-Td. Coil 38 is off (de-energized)
The electric coil 38 is turned on during the next T s - T d (
As in, it is commonly used.

- A current is passed through the electric coil 38 with a duty of (Ts-Td)/TsX100% of the period Ts, and a damping force (ATdl) corresponding to this duty appears in the shore absorber 1 (by the plunger 32 of it).

In the above embodiment, the target damping force (ATdf) is calculated in common for all the shock absorbers 1 to 4, and this is sent to each individual subcontroller 51 to 54.

Eh, in each individual sub-controller 1-roller 51-54, the required adjustment amount Avd corresponding to the acceleration of the vertical vibration of the nearest wheel of each shock absorber 1-4.
Calculate J' and select shock absorber 1 for each wheel.
The sound reduction force (ATd+) that should be set to 4 is calculated, and the damping force of each shock absorber 1 to 4 is set to this damping force (ATdl). (turning or turning left) 1 resistance to acceleration in the longitudinal direction (acceleration or deceleration = leaning forward or leaning backwards),
According to the polarity of the lateral acceleration (turning to the right or turning to the left = tilting to the left or leaning to the right), etc., determine the load distribution and polarity (stretch load or compression load) of each of the four wings due to these factors. The target damping force of each shock absorber may be individually calculated according to the load distribution and polarity, and these may be latched in the data output circuits 71 to 74.

〔Effect of the invention〕

In any case, in the shock absorber device of the present invention,
Valve drive means (36) drives spool valve means (32).

Opposite this, the solenoid (37, 38, 25a) forces the spool valve means (32) in the opposite direction (direction to widen the flow opening). ). Therefore, the spool valve means (32) is connected to the force exerted by the valve drive means and the solenoid (37°38.
25a) becomes a position where the forces forced are balanced, and the flow opening degree, that is, the damping force takes a value corresponding to this position. When the energizing current value of the solenoid (37, 38, 25a) is increased, the spool valve means (32) moves in the opposite direction (to widen the flow opening degree), and the damping force increases to a value corresponding to the movement position. (smaller value).

In this way, the damping force changes in response to a change in the current value flowing through the solenoids (37, 38, 25a), and since this current value can be changed steplessly, the damping force can be changed steplessly.

Therefore, the damping force control means (40) is controlled by the solenoid (3).
Since the position of the spool valve means (32) is determined by controlling the energizing current values of 7, 3g, and 25a), the damping force can be set steplessly by the damping force control means (40).

Therefore, according to the shock absorber device of the present invention,
Occurs while driving. In response to stepless changes in force that cause attitude changes to the vehicle body, the damping force can be set steplessly to suppress the attitude changes, making it possible to precisely and precisely control damping force according to driving conditions. By doing so smoothly, it is possible to prevent the vehicle body posture from changing in the 'i1 inversion layer state and to realize a comfortable ride more precisely and smoothly.

[Brief explanation of the drawing]

FIG. 1a is an enlarged longitudinal sectional view of a shock absorber used in one embodiment of the present invention. FIG. 1b shows the shock absorber 1 shown in FIG. 1a,
It is an enlarged partial vertical cross-sectional view in which a part is further enlarged. FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention. Figures 3a, 3b, 3c and 3d show the second
3 is a flowchart showing the control operation of the microprocessor 60 shown in the figure. Figures 4a, 4b, 4c and 4d show the second
3 is a flowchart showing the control operation of the microprocessor 40 shown in the figure. 1-ll: Shock absorber (shock absorber)
10: Histone rod (rod) 1 and upper end base 1
2: Inner cylinder (cylinder) 13: Outer cylinder 14 Piston 15: Upper space 16: Upper space (15
, 16: Space where a pressure difference occurs due to the vertical movement of the piston)
17 two-valve device! &1: Lower end base space 20: Check valve member 22: Flow passage 23a: Leaf spring 25: Bottomed cylindrical body 26: Flange 28 Two-rod inner lower space 30: Hole 32 Nib ring gear (spool valve means) 33.34: Flange 35: Groove 36: Compression coil spring (valve drive means) 37: Magnetic core
38: Electric coil (37, 38, 25a: solenoid) 38a: Coil bobbin 40: Microprocessor (damping force control means) 41 to 44: Vibration sensor
45: ROM4G: RAM
47: Decoder 48: Output interface 49: Coil drivers 51 to 54; Sub-controller 55: Handle rotation angle sensor 56: Rotary encoder 57, 58: Acceleration sensor 5
9: Decoder 60: Microprocessor 18: Lower end base 19: Flow path 21: Compression coil spring 23: Check valve member 211: Outside space 25a: End plate 27: Upper space inside rod 29: Flow port 31: Hole 61:RAM62:RO? 1 65-68 2 Signal processing interface 70: Main controller! ~Rollers 71-74: Data output circuit 8N
Potentiometer 82: Puffer Ambu 83
: Switch 84: Buffer amplifier east 1b figure 0a electrical 3b figure 3C figure voice 3d figure

Claims (1)

[Claims] A cylinder, a piston that divides the inner space of the cylinder, a rod fixed to the piston and extending outside the cylinder,
A spool valve means that defines a degree of communication opening between spaces that generate a pressure difference due to the vertical movement of the piston, and a valve that forces the spool valve means in one of two directions: widening and narrowing the degree of communication. a shock absorber having a drive means, and a solenoid that drives the spool valve means in a direction opposite to the direction in which the valve drive means forces the spool valve means; and a shock absorber that controls the energizing current value of the solenoid to A shock absorber device comprising: damping force control means for determining the position of the shock absorber.