JPS6245090B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a suspension control device that changes suspension characteristics in accordance with the driving state of an automobile or in accordance with manual operation.

(Prior art) The spring constant of the springs and the damping rate of the damper that make up the suspension of an automobile, in other words, the suspension characteristics, significantly affect the ride comfort and body posture of the automobile. For example, if the suspension characteristics are hard, the If the tires are too soft, the vehicle body will pitch or roll when braking or turning, making the vehicle's posture extremely unstable.

For such problems, for example, Japanese Patent Application Laid-open No. 1983-
Publication No. 30818 discloses an invention related to a "vehicle anti-roll device." This operates the orifice control solenoid of the shock absorber according to the vehicle speed and steering angle to increase the damping rate of the shock absorber during turning. According to this, during normal driving, the suspension characteristics are set to be soft to provide good riding comfort, and during cornering, the suspension characteristics are set to be hard to prevent rolling of the vehicle body.

By the way, such variable control of suspension characteristics is
As shown in the above publication, the opening and closing of the orifice of the damper (shock absorber) is controlled by a solenoid or motor, or the communication between the air chamber forming the air spring and the accumulator is interrupted by a solenoid valve. However, in order to ensure durability or prevent power loss, it is desirable to control these electromagnetic means so that they are energized only when the suspension characteristics are switched.

However, according to such a control method, once the switching of the suspension characteristics is completed and the energization to the electromagnetic means is stopped, there is nothing to actively hold the electromagnetic means in the controlled position. The electromagnetic means gradually moves naturally under the influence of the fluid flowing therein or due to vibrations from the road surface as the vehicle travels, causing it to deviate from the desired control position. Therefore, especially when a state in which the suspension characteristics should be kept constant continues for a long time, problems occur such as the characteristics becoming different from the required characteristics, or the characteristics becoming uneven between the front, rear, left, and right suspensions. To deal with this, it is possible to constantly apply a control signal to the electromagnetic means or to provide a separate means for fixing it at the control position, but as mentioned above, the former causes a lot of power loss and the durability of the electromagnetic means is limited. lowers the
Moreover, the latter has a complicated structure and requires additional electric power to operate the fixing means.

(Object of the Invention) The present invention deals with the above-mentioned actual situation in suspension control devices, and allows the suspension characteristics of each suspension to be constantly adjusted according to the driving condition without complicating the structure or significantly increasing power loss. The purpose is to maintain the characteristics required according to the vehicle conditions and ensure good ride comfort and stability of the vehicle body posture.

(Structure of the Invention) A suspension control device according to the present invention is configured as follows to achieve the above object.

That is, a suspension device with variable suspension characteristics, an electromagnetic means for changing the suspension characteristics of the suspension device, and a device that adjusts the suspension characteristics of the suspension device so that the suspension characteristics correspond to a suspension characteristic designation signal issued from a controller. The drive means outputs a drive pulse signal to the electromagnetic means, and the trigger means outputs an initialization command signal to the drive means so as to issue a drive pulse signal corresponding to the suspension characteristic designation signal at predetermined intervals. . According to such a configuration, the electromagnetic means is actuated by the drive pulse signal output from the drive means,
The suspension characteristics of the suspension device are set to the characteristics specified by the controller according to the driving state of the vehicle or the characteristics instructed by manual operation, and this drive pulse signal is set only when the suspension characteristics are switched. Instead, the electromagnetic means is initialized to the control position at that point in time by intermittently outputting it during a period when a constant characteristic is to be maintained.

(Example) The present invention will be described below based on an example shown in the drawings.

As shown in Figure 1, front, rear, left and right wheels 1...1
Suspension device 2 for suspending the vehicle body...2
are a coil spring 3, a damper 4 whose damping rate is variable, and a motor 5 which changes the damping rate of the damper 4.
It is composed of. On the other hand, a control device 6 is provided which sends a drive signal A to the motors 5...5 of each suspension device 2...2. A signal B, a signal C indicating the running condition of the automobile from the running condition detection sensor 8, and a signal D indicating the ON state of the switch from the ignition switch 9 are inputted. Here, the mode selection switch 7 has a function of switching the damper 4 between an automatic control mode and a manual control mode, and a function of switching the damper damping rate in the manual control mode. For example, a vehicle speed sensor, a steering angle sensor, a brake sensor, etc. are provided.

Next, the specific structure of each of the above suspension devices 2 will be explained with reference to FIG. It has a piston case 15 to which a wheel is attached via a bracket 14, and into which the piston rod 13 is inserted vertically and slidably, and the piston rod 13 and the piston case 15 have spring bearing members 16 and 17, respectively. The coil spring 3 is fixedly installed between both spring receiving members.

The piston case 15 is composed of an outer cylinder 18 and an inner cylinder 19. A main valve 20 provided at the lower end of the piston rod 13 is fitted into the inner cylinder 19, and an upper part of the inside of the inner cylinder 19 is fitted. Room 21
and a lower chamber 22, and the inner cylinder 1
The space between 9 and the outer cylinder 18 is a reservoir chamber 23. This reservoir chamber 23 is located at the upper end of the inner cylinder 1.
It communicates with an upper chamber 21 within the chamber 9, and its lower end communicates with a lower chamber 22 via a bottom valve 24 having an orifice.

On the other hand, the main valve 20 has an extension side orifice 26 configured to allow the working fluid to pass only from the upper chamber 21 to the lower chamber 22 side by means of a check valve 25, as shown in an enlarged view in FIG. A contraction side orifice 2 configured to allow working fluid to pass only from the lower chamber 22 to the upper chamber 21 side by a check valve 27.
8 and is further provided with an orifice valve 31 comprising a sleeve 29 and a valve body 30 rotatable within the sleeve 29. This orifice valve 31 is rotated by a control rod 32 inserted into the piston rod 13 by the motor 5 shown in FIGS. A state in which the through hole 29a and the through hole 30a in the valve body 30 are blocked, and both the through holes 29a and 30 shown in FIG.
A can be switched to a state where it is communicated. As a result, the damper 4 configured by the upper chamber 21, the lower chamber 22, and the main valve 20
However, there is a state in which the upper chamber 21 and the lower chamber 22 are communicated only by the orifice 26 or 28 and the damping rate is large, that is, a hard state. Even when the damping rate is communicated, the damping rate is switched to a small state, that is, a soft state.

Next, the configuration of the control device 6 will be explained with reference to FIG. 5. The control device 6 includes a determination circuit 41, a drive circuit 42, first and second timer circuits 43, 44
and a clock circuit 45 for operating the determination circuit 41 and the first timer circuit 43. The determination circuit 41 receives the signals B and C from the mode selection switch 7 and the driving state detection sensor 8, determines the suspension characteristics corresponding to the instructed mode or driving state, and designates the determined suspension characteristics. Sending out the suspension characteristic designation signal E to the drive circuit 42,
A switching signal F is output when the determination of suspension characteristics changes and when an ignition ON signal D is input from the ignition switch 9. This switching signal F and the initialization command signal G, which is output from the first timer circuit 43 when the set time _t1 has expired, are input to the second timer circuit 44 via the OR circuit 46, and accordingly, the The second timer circuit 44 sends the actuation signal H to the drive circuit 42 only during the set time _t2 . As a result, while the actuation signal H is being input, the drive circuit 42 uses the drive signal A corresponding to the suspension characteristic designation signal E sent from the determination circuit 41 as a pulse signal to drive each suspension device 2...2. Motor 5 in...
Send to 5. Then, the second timer circuit 44
When the set time _t2 has timed up, the reset signal I is sent from the second timer circuit 44 to the first timer circuit 43, and the input of the reset signal I causes the first timer circuit 43 to reset the time of the set time _t1 . It's about to start.

Here, a specific circuit example of the drive circuit 42 will be explained with reference to FIG. A pair of interlocking switches 53, 54 provided on the , - sides, respectively.
and a changeover switch 55 which operates in response to the suspension characteristic designation signal E to change the direction of energization of the drive signal A from the power source 51 to the motor 5. Further, on the motor 5 side, there is a limit switch 56 that stops energization when the motor 5 rotates by a certain angle;
Diodes 57 and 58 are connected to the two contacts 62a and 62b of No. 6, respectively, and regulate the direction of current flow.

Furthermore, as shown in FIG. 2, the limit switch 56 has a fixed disk 62 fixed within a case 61 of the motor 5 and a movable disk 64 that rotates integrally with the rotor 63 of the motor 5.
As shown in FIG. 7, the movable disk 64 is provided with band-shaped contacts 64a and 64b disposed in the circumferential direction, and the fixed disk 62 is provided with band-shaped contacts 64a and 64b.
For example, a brush-like contactor 6 in contact with 4a, 64b
2a, 62b, and 62c are provided. Then, one strip-shaped contact 64b and a corresponding third
The contact 62c is arranged so as to be in constant contact, and the other strip contact 64a and the corresponding first and second contacts 62a and 62b are arranged at both stroke ends of the rotation range of the movable disk 64. In this case, one contact 62a or 62b is a strip contact 64a.
It is placed away from the The movable disk 64 rotates integrally with the rotor 63 of the motor 5, and the rotor 63 and the valve body 30 of the orifice valve 31 in the damper 4 are connected via the control rod 32. The movable disk 64 and the valve body 30 always correspond in position, and as shown in FIGS. 4 and 7, when the through holes 29a and 30a in the orifice valve 31 are blocked, the 2
The contactor 62b is separated from the strip contact 64a, and from this state, the valve body 30 and the movable disk 64 rotate by a certain angle in the direction a, and the orifice valve 3
When the first through holes 29a and 30a communicate with each other, the first contact 62a separates from the strip contact 64a.

Next, the operation of the above embodiment will be explained.

Now, for example, the mode selection switch 7 shown in FIG.
The running state of the vehicle detected by the running state detection sensor 8 when the vehicle is set to automatic control mode changes the suspension characteristics of each suspension device 2...2 from a state where the suspension characteristics should be made hard to a state where the suspension characteristics should be made soft. or when the mode selection switch 7 is set to manual control mode, if an operation is performed to change the suspension characteristics from hard to soft, the switch 7 and sensor 8
The determination circuit 41 of the control device 6 receives signals B and C from the drive circuit 42 and converts the suspension characteristic designation signal E to the drive circuit 42 into a hard signal as shown by the symbol A in FIG.
Switch from E ₁ to soft signal E ₂ . At this time, the judgment circuit 41 outputs a switching signal F (a signal shown in FIG. 8).
F ₁ ) to activate the second timer circuit 44, and at the same time, the second timer circuit 44 sends an activation signal H to the drive circuit 42 only for the set time t ₂ .
(signal H ₁ shown in FIG. 8) is output. On the other hand, in the drive circuit 42, the suspension characteristic designation signal E
By switching, the interlocking switches 53 and 54 of the changeover switch 55 shown in FIG. 6 are switched from a state where the hard side contacts 53a and 54a shown by solid lines are connected to a state where the soft side contacts 53b and 54b shown as dotted lines are connected. At the same time as the main relay 52 is activated, the activation signal H causes the main relay 52 to conduct. In that case, the orifice valve 31 in the damper 4 is initially
As shown in FIG. 7, the through holes 29a and 30a are in a blocked state, and correspondingly, as shown in FIG. 7a, the first contact 62a of the limit switch 56 is closed.
is in contact with the strip contact 64a, so the drive circuit 42 outputs a drive signal A that energizes the motor 5 in the direction a, as shown in FIG. As a result, the motor 5 rotates in a direction corresponding to the energization direction, and accordingly, the valve body 30 of the orifice valve 31 is rotated from the state shown in FIG. 4a to the state a shown in FIG. 4b. The through holes 29a and 30a in the orifice valve 31 are communicated with each other, and the characteristics of the damper 4 are switched to a soft state. As the motor 5 or the valve body 30 rotates, the movable disk 64 of the limit switch 56 rotates in the direction a from the state shown in FIG. 7a to the state shown in FIG.
When the switching of the characteristics is completed, the first contact 62a separates from the strip contact 64a, thereby stopping the power supply to the motor 5, and after that, the set time _t2 of the second timer circuit 44 expires and the motor is activated. Output of signal H is stopped and main relay 52 is cut off.

However, when the output of the operating signal H is stopped, in the control device 6, the reset signal I is output from the second timer circuit 44 to the first timer circuit 43, and upon receiving this signal I, the first timer circuit 43 resets the set time.
Start clocking t ₁ . Then, when the set time t ₁ times up, the first timer circuit 43 outputs an initialization command signal G (signal G ₁ shown in FIG. 8), and upon receiving this signal G, the second timer circuit 44 activates the set time t 1 . The actuation signal H (also signal H ₂ ) is output again only during t ₂ . Therefore, the drive circuit 4
At step 2, the main relay 52 shown in FIG. 6 is turned on again for the set time _t2 , and the drive signal A is output.

In this case, the changeover switch 55 of the drive circuit 42
As shown by the dotted line, the interlocking switch 53,
54 soft side contacts 53b and 54b are connected, and on the motor 5 side, as shown by the dotted line, the second contact 62b of the limit switch 56 is connected and the first contact 62a is cut off. , even if the main relay 52 is conductive, the current-carrying circuit for the motor 5 is connected to the diode 5.
8, the motor 5 does not operate.

However, due to the influence of the fluid passing through the orifice valve 31, vibrations, etc., the valve body 30 of the orifice valve 31 naturally rotates from the control position shown in FIG. When the main relay is being cut off, the movable disk 64 in the limit switch 56 also rotates as shown by the chain line in FIG. 52
When conductive, the soft side contact 53b of the changeover switch 55, the diode 57 and the limit switch 5
The motor 5 is energized in the direction a through the first contact 62a of the motor 6. As a result, the above-mentioned natural rotation of the valve body 30 in the orifice valve 31 is eliminated, and the valve body 30 is returned to the control position (soft position) shown in FIG. 4b.

The above action is performed in the same way when the suspension characteristic is switched from soft to hard, and in this way, after the suspension characteristic is switched, the initialization signal is output periodically (for example, every 5 minutes) from the first timer circuit 43. By outputting the drive signal A from the drive circuit 42 at predetermined intervals based on the command signal G, if the orifice valve 31 deviates from the control position, that deviation is eliminated, and each suspension device 2...
The characteristics of the dampers 4...4 in No. 2 are maintained at the required characteristics.

In this embodiment, as shown by reference numeral B in FIG.
A switching signal F (signal F ₂ shown in FIG. 8) is outputted from the switch 42, and in conjunction with this, an actuation signal H (also signal H ₃ ) is sent from the second timer circuit 44 to the drive circuit 42. Therefore, for example, if the characteristics of the dampers 4 . . . 4 of each suspension 2 . Furthermore, even after the activation signal H (H ₃ ) is output based on the turning on of the switch 9, the initialization signal G (G _{2 .} . . ) is intermittently output from the first timer circuit 43 at every set time t ₁ . Even before the first change of suspension characteristics is performed, the damper 4...4
properties will be kept to the required properties.

(Effects of the Invention) As described above, according to the present invention, in the suspension control device that variably controls the suspension characteristics of the suspension according to the driving state of the automobile or according to manual operation, the suspension characteristics of the suspension device can be controlled. A drive pulse signal is outputted to the electromagnetic means for changing not only when switching the suspension characteristic, but also periodically during a period when a constant suspension characteristic is to be maintained. As a result, the electromagnetic means can be operated without causing a significant increase in power loss or deterioration of the durability of the electromagnetic means due to constant output of a drive signal, and without requiring means for fixing the electromagnetic means at a control position. It becomes possible to maintain the control position at that point in time. As a result, the suspension characteristics of the suspension of each wheel are maintained at the characteristics required depending on the driving condition or by manual operation, and good riding comfort and stability of the vehicle body are ensured.

Note that the present invention is not limited to the one in which the damping rate of the damper is variably controlled as shown in the embodiments, but also the one in which the spring constant of the spring constituting the suspension is variably controlled, or the damping rate of the damper and the spring are variably controlled. The same applies to those in which the spring constant is variable controlled at the same time, and also to those in which such suspension characteristics are controlled only for the front wheel suspension or the rear wheel suspension. The same can be applied. Furthermore, the control device shown in the embodiment can also be configured by a microcomputer.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a control system diagram, FIG. 2 is a vertical cross-sectional view showing the specific structure of the suspension device, FIG. 3 is an enlarged vertical cross-sectional view of the main parts, and FIG. Figures 4a and 4b are enlarged cross-sectional views showing the operation of the orifice valve taken along the line in Figure 3, and Figure 5 is a block diagram showing the configuration of the control device.
FIG. 6 is a circuit diagram showing a specific configuration example of the drive circuit in the control device, and FIGS. 7a and 7b are FIGS.
FIG. 8 is an enlarged cross-sectional view showing the action of the limit switch cut along a line, and FIG. 8 is a time chart showing the action of the embodiment. 2... Suspension device, 5... Electromagnetic means (motor), 41... Controller (judgment circuit),
42... Drive means (drive circuit), 43... Trigger means (first timer circuit), A... Drive pulse signal (drive signal), E... Suspension characteristic designation signal, G... Initialization command signal.

Claims (1)

[Claims] 1. A suspension device with variable suspension characteristics, an electromagnetic means for changing the suspension characteristics of the suspension device, and an electromagnetic means for changing the suspension characteristics of the suspension device; An automobile suspension comprising a driving means for outputting a driving pulse signal to an electromagnetic means, and a trigger means for outputting an initialization command signal to the driving means so as to issue a driving pulse signal corresponding to the suspension characteristic designation signal at predetermined intervals. control device.