JPS6344565B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an improvement in a control device for controlling a variable damping force type hydraulic shock absorber applied to a suspension system of an automobile or the like. Conventionally, in order to improve the riding comfort or running stability of automobiles, etc., damping force adjustment adjusters have been developed by rotating a motor provided inside or outside the piston rod by a predetermined angle depending on the driving conditions of the automobile, etc. A variable damping force type hydraulic shock absorber that can perform desired damping force adjustment by rotationally controlling the damping force, and a control device for controlling this hydraulic pressure shock absorber are known. FIG. 1 is a block diagram of a control circuit used in such a conventional control device, and FIG. 2 is a sectional view showing the configuration of a hydraulic shock absorber controlled by this control circuit. Therefore, an overview of a conventional control circuit and a hydraulic shock absorber will be explained based on FIGS. 1 and 2. In FIG. 1, 1 is one of the desired damping force setting positions (in this conventional example, the damping force setting positions (H), (N), and (S) are divided into three categories: high, medium, and low). 2 is a selection reference signal generation circuit that receives one selection signal selected by this changeover switch 1 and generates a selection reference signal according to the selection signal; 3 is this selection reference signal generation circuit. 2 and an output signal corresponding to the rotation angle position of the motor 4 for adjusting the damping force of the hydraulic shock absorber, which will be described later, to determine the mismatch between the selection reference signal and the output signal. A signal comparison circuit 5 is a motor drive circuit that operates upon receiving the mismatch or match signals outputted from the signal comparison circuit 3. 4 is a motor driven or stopped by the motor drive circuit 5;
Reference numeral 6 denotes a rotational angular position detection circuit that detects the rotational angular position of the motor 4, specifically, the rotational angular position of the drive shaft 4a of the motor 4, and inputs an output signal corresponding to the rotational angular position to the signal comparison circuit 3. In addition, when this rotational angle position detection circuit 6 is constituted by a predetermined encoder, a signal conversion circuit for converting the contact signal outputted from this detection circuit 6 into a digital signal and inputting it to the signal comparison circuit 3 is provided. 7 must be provided between the rotation angle position detection circuit 6 and the signal comparison circuit 3. T is a hydraulic shock absorber having a structure in which a damping force adjustment adjuster is rotated by the motor 4, and
The details are shown in FIGS. 2 and 3. That is, in FIG. 2, 9 is a cylinder filled with hydraulic fluid, and 10 is a cylinder filled with hydraulic fluid.
is a piston rod which is sealed at one end and extends through the cylinder 9 in a sealed manner at the other end. 1
A piston 1 is slidably inserted into the cylinder 9, and the piston 11 separates the inside of the cylinder 9 into two chambers, an upper liquid chamber 12 and a lower liquid chamber 13. This piston 11 has
A damping force generating means 14 is provided for generating flow resistance in the hydraulic fluid displacing between the upper and lower fluid chambers 12 and 13. 15 is the piston rod 10 and piston 11;
The stud 15 has an adjuster accommodating part 16 for rotatably accommodating the adjuster 8 rotatably driven by the motor 4, and an adjuster accommodating part 16 for rotatably accommodating the adjuster 8, which is rotatably driven by the motor 4. An axial through hole 1 for communicating the inside of 16 and the lower liquid chamber 13
7 are formed respectively. Furthermore, stud 1
As shown in FIG. 3, the cylindrical wall portion 15a of No.
Orifices 18, 19, and 20 are provided which communicate with the upper liquid chamber 12 and have mutually different opening areas and are arranged at predetermined intervals in the circumferential direction. The regulator 8 has an axial through hole 22 that opens and communicates with the lower liquid chamber 13, and each orifice 1 provided in the through hole 22 and the stud 15.
A communication hole 23 that can selectively communicate with any one of 8, 19, and 20 is formed, respectively. Note that the input end of the motor 4 is connected to a predetermined harness 2.
4 and 24, it is connected to a motor drive circuit 5 as shown in FIG. 1, and this motor 4 is driven by this motor drive circuit 5. According to the configuration of the control circuit S and the hydraulic shock absorber T as described above, the vertical movement of the piston rod 10 accompanied by the piston 11 causes the through oil passages 25, 25 that constitute the damping force generating means 14 provided in the piston 11 to be A valve plate 2 that closes one open end of each of these through oil passages 25, 25.
A desired damping force can be ensured by displacing and flowing the working fluid between the upper and lower liquid chambers 12 and 13 while receiving resistance from the spring forces 6 and 26. On the other hand, if you select an arbitrary damping force setting position, for example, the medium damping force setting position (N) as shown in FIG. A selection reference signal corresponding to the selection signal is output from the selection reference signal generation circuit 2. This selection reference signal is connected to a signal comparison circuit 3, and in addition to the selection reference signal, this comparison circuit 3 also receives the selection reference signal from a rotation angle position detection circuit 6 to detect the current state of the drive shaft 4a provided in the motor 4. Since the rotational position detection signal indicating the rotational angular position at is converted into a digital value by the signal conversion circuit 7 and input, these two signals are compared in the signal comparison circuit 3. In this signal comparison circuit 3, if the two signals match, a match signal is output, and if they do not match, a mismatch signal is output. Therefore, the motor drive circuit 5 is operated by these signals. That is, when the match signal is input to the motor drive circuit 5, the supply of drive current from the motor drive circuit 5 to the motor 4 is stopped, and therefore the rotation of the motor 4 is stopped. On the other hand, when a mismatch signal is input to the motor drive circuit 5, a drive current is supplied from the motor drive circuit 5 to the motor 4 in accordance with this mismatch signal, and therefore the output signal from the signal comparison circuit 3 is The circuit of the motor 4 continues until a match signal is obtained. In this way, the communication hole 23 of the adjuster 8 opens and communicates with the orifice 19 provided in the stud 15 for setting the medium damping force selected by the changeover switch 1. For this reason, a part of the working fluid flowing between the upper and lower liquid chambers 12 and 13 is bypassed through the orifice 19 to adjust the damping force obtained by the damping force generating means 14. A desired damping force can be ensured. As explained in detail above, the conventional control circuit S
According to the configuration of the hydraulic shock absorber T, each damping force setting position is divided into three categories, high, medium, and low, by manually operating the changeover switch 1 according to the driving condition of the vehicle.
The desired damping force can be obtained by selecting one of (H), (N), and (S). By the way, the body of a vehicle such as an automobile tends to tilt when turning due to steering or the like. This inclination is determined by the moment about the roll axis of the vehicle body due to centrifugal force during turning and the stiffness of the suspension system in response to this moment. Therefore, in order to prevent the vehicle body from tilting and maintain stable running of the vehicle, the damping force setting position should be selected to be in the "high" position instead of the "low" position when turning, etc. Therefore, it is desirable to increase the damping force obtained by the hydraulic shock absorber. However, when selecting and switching the damping force by manual operation, it is not expected that the driver will immediately perform the switching operation when turning the vehicle due to the cumbersome operation. Therefore, in order to deal with this problem, a control circuit is developed that automatically shifts the damping force setting position from "low" to "medium" or "high" when the vehicle enters a turning state. It is desirable to add. On the other hand, when considering the running stability of a vehicle, generally speaking, as the vehicle speed increases, the running stability generally decreases. In particular, even if the vehicle is on a good road such as an expressway, when the vehicle is traveling on a highly uneven general road while maintaining a high speed above a certain speed, the driving stability is significantly reduced due to the increase in vibration of the vehicle. In order to deal with such problems, when the vehicle speed exceeds a preset vehicle speed,
As with the above-mentioned case when turning, select the damping force setting position to be "medium" or "high" instead of "low" to increase the damping force obtained by the hydraulic shock absorber and drive. It is desirable to do so. However, when switching the damping force by manual operation, it is difficult to operate and it cannot be expected that the driver will immediately switch the damping force upon sensing an increase in vehicle speed. The problem is that it is not possible to select the optimum damping force, which tends to lead to a decrease in running stability. To deal with this difficulty, the damping force setting position is automatically changed from "low" to "medium" when the vehicle enters a high-speed driving state.
It is desirable to add a control circuit that allows the switch to move to the "low" position without returning to the "low" position. In view of these demands, the present invention has been developed to provide a turning mode when a vehicle transitions from a straight-ahead driving condition to a turning driving condition, or when a vehicle transitions from a low-speed driving condition to a high-speed driving condition exceeding a preset vehicle speed. The damping force of the hydraulic shock absorber is automatically switched and corrected from a low damping force setting position to a higher damping force setting position based on the switch signal obtained from the signal switch circuit or the vehicle speed signal obtained from the vehicle speed sensor. However, it is an object of the present invention to provide a control device that can maintain good running stability when the vehicle is turning or at high speeds without any operational complexity. Embodiments of the present invention will be described below based on the drawings. FIG. 4 is a block diagram showing the circuit configuration of a control device for a hydraulic shock absorber according to the present invention. A reference numeral is given and the duplicate explanation will be omitted. As shown in FIG. 4, there is a selection reference signal generation circuit 2 that generates a selection reference signal according to one selection signal selected by the changeover switch 1, and a selection reference signal outputted from this signal generation circuit 2 and a liquid. A turn signal switch circuit 3 is connected to a signal comparison circuit 3 that compares output signals corresponding to the rotation angle position of the motor 4 for adjusting the damping force of the pressure buffer T.
1, the selection reference signal from the selection reference signal generation circuit 2 corresponding to the low damping force setting position (S) is changed to a higher damping force setting position (N) or (H). When the vehicle speed detected by the turn signal correction circuit 28 and the vehicle speed sensor 34 corrects the signal to a corresponding signal and inputs it to the signal comparison circuit, the selection criterion is determined. The selection reference signal corresponding to the low damping force setting position (S) from the signal generation circuit 2 is corrected to a signal corresponding to a higher damping force setting position N or H, and the corrected signal is input to the signal comparison circuit 3. A vehicle speed correction circuit 29 is provided for this purpose. The former turn signal correction circuit 28 is the turn signal switch circuit 3 in this embodiment.
The switch signal obtained in step 1 is detected by the turn signal detection control circuit 32, and when this switch signal is detected, a low level signal is input to the turn signal gate circuit 30.
It is configured to correct the damping force of the hydraulic shock absorber T, and preferably, the turn signal detection control circuit 32 corrects the damping force for a short time even after the switch signal from the turn signal switch circuit 31 stops. It is designed to output a correction signal.
On the other hand, in this embodiment, the latter vehicle speed correction circuit 29 first converts the vehicle speed signal obtained by the vehicle speed sensor 34 into a voltage value proportional to the vehicle speed using the F/V converter 36. A comparator 37 compares the output voltage from the F/V converter 36 with a reference voltage V _s corresponding to a predetermined vehicle speed set in advance, and the output voltage from the F/V converter 36 is Reference voltage
When it becomes larger than V _s , the vehicle speed signal gate circuit 35
The damping force of the hydraulic shock absorber T is then corrected by issuing an output "1". Therefore, a specific circuit example of the present invention will be explained below based on FIG. 5. In the figure, 1 is a damping force changeover switch, and 2 is a selection reference signal generation circuit. ).
Each terminal 1a, 1 of each damping force setting position H, N, S
A low level signal is given to the selected input among the b and 1c inputs, and among these inputs, the inputs at the hard and software setting positions (H) and (S) are as follows.
It is output to line a and line b via the loop prevention diodes D ₁ and D ₂ and the noise removal CR circuit, respectively, and each line a and b
are output to AND gate G ₂ and NAND gate G ₃ via . In addition, the input at setting position N is the wraparound prevention diode _D3 and CR.
It is connected to one side of the gate input of NOR gate _G1 through the circuit. Furthermore, diodes D ₄ and D ₅ are provided in the forward direction from the input terminal 1b at the normal setting position (N) to the input terminals 1a and 1c at the hard and soft setting positions (H) and (S). The contact abnormality of the changeover switch 1, which generally occurs in the open mode, can be detected as a low level output of the NOR gate _G1 , and the output of the NOR gate _G1 is input to the failure detection circuit 33. Note that the output of the failure detection circuit 33 is inputted as a low level signal to the other side of the OR gates G ₆ and G ₇ during normal operation. Furthermore, the output of the vehicle speed signal gate circuit 35 connected to the software setting position S is an input to one side of the signal comparison circuit 3, and the other side of the signal comparison circuit 3 receives a damping force switching signal. The output of OR gate _G6 forming the generating circuit 38 is input. The line a is a turn signal gate circuit 3.
0, and line b is used as one side gate input of the NAND gate _G3 via the inverter _I1 , and the AND gate _G2 , _the NAND gate _G3
A signal from the turn signal detection control circuit 32 is input to the other side gate of the turn signal detection control circuit 32 . This turn signal detection control circuit 32 is configured such that the contact signals of the left and right turn signal switches 31a and 31b are outputted through bypass prevention diodes _D8 and _D9 , respectively, and preferably further through a noise removal CR circuit (not shown). The output of _the AND gate _G4 is input to one side of the NOR gate _G5 via the inverter _I2 .
Noah gate through off-delay timer circuit Tm
The output of this NOR gate _G5 is used as the other gate input of _the AND gate _G2 and the NAND gate _G3 . Further, the outputs of the AND gate G ₂ and the NAND gate G ₃ are input to one side of the OR gates _{G 6 and G 7 provided} externally, respectively. The output of a failure detection circuit 33 that detects an abnormality in the control circuit S is given as a gate input, and a damping force switching signal that outputs a signal corresponding to the normal damping force setting position N when the control circuit S is abnormal. A generating circuit 38 is configured. These or gates
The outputs of G ₆ and G ₇ are input to the signal comparison circuit 3, respectively. In the above configuration, each damping force setting position (N) (H) (S) of the changeover switch 1 and each damping force setting position of the signal comparison circuit 3 is
The relationship with the signal input to the AB terminal is as follows. That is, first, when the changeover switch 1 is set to the normal position (N), the output of the NOR gate _G1 is as follows.
At high level (hereinafter referred to as "1"), line a,
b is also "1", and the failure detection circuit 33 to which the NOR gate _G1 output is given is at a low level (hereinafter referred to as
Also, since the turn signal detection control circuit 32 outputs "1" when the turn signal switch circuit 31 is open, the A and B terminals of the signal comparison circuit 3 are 1" is input. Next, when the primary switch 1 is set to the hard position (H), "0" is input to the NOR gate G ₁ by the diode D ₄ , so the output of the NOR gate G ₁ is "1", and the line a is "0", line b is "1"
Therefore, "0, 1" are input to the A and B terminals. Also, when selector switch 1 is set to the soft position (S), a diode is connected to Noah gate _G1 .
Since "0" is input by _D5 , the output of the NOR gate _G1 is "1", line a is "1", and line b is "0", so the A and B terminals are "1, 0" is input. These conditions are shown in Table 1.
Shown below.

[Table] The 2-bit signal shown in "Table 1" and the signal from the rotation angle position detection circuit 6 are
The signals are input to the signal comparison circuit 3 through the B terminal, and compared therein. Then, the motor 4 is driven by the motor drive circuit 5 until the output signal from the signal comparison circuit 3 becomes a matching signal, and thus the desired damping force is obtained. Next, the operation of the control device according to the present invention having the above configuration will be explained. First, a case will be described in which one of the left and right turn signal switches 31a, 31b is closed while the vehicle is running, and the vehicle enters a turning state. That is, the left and right turn signal switches 31a,
When either one of 31b closes, the AND gate
Since one of the gate inputs of _G4 becomes "0", the AND gate _G4 outputs "0", and this output is sent to the NOR gate _G5 via the inverter _I2 or the off-delay timer circuit Tm. Since "1" is applied to one side of the gate and "0" is applied to the other side, this NOR gate _G5 outputs "0". Also, the output “0” of this Noah gate _G5 is
The turn signal switch circuit 31 changes from closed to open, and the output of AND gate _G4 changes from "0" to "1".
In this case, the gate input on one side of this NOR gate _G5 is converted by the inverter _I2 and "0" is input, but the gate input on the other side is input to the operation of the off-delay timer circuit Tm. Therefore, since "1" is generally given only for a certain period of time determined by the discharge time constant of the CR circuit, it is held for that certain period of time. Therefore, if we assume that the damping force setting position is set to the soft position (S) and the turn signal switch circuit 31 is closed in order to turn the vehicle, "1" on line a is the gate on one side. is given as an input, and as a result, the signal comparison circuit 3
AND gate outputting "1" to the A terminal of
G ₂ and "0" on line b are converted by inverter I ₁ and given as one side gate input, and as a result, NAND gate G ₃ outputs "0" to the B terminal of signal comparison circuit 3. On each other side of
Since "0" is given as a gate input from the NOR gate _G5 that constitutes the turn signal detection control circuit 32, the AND gate _G2 outputs "0" and the NAND gate _G3 outputs "1". , "0, 1" signals are input to the A and B terminals of the signal comparison circuit 3. That is,
According to Table 1, the "0, 1" signal corresponds to the damping force setting signal of the hard position (H), and after all, the damping force setting position is selected when the turn signal switch circuit 31 is activated. Regardless of the signal obtained by the reference signal generation circuit 2, it can be automatically shifted to the hard position (H), and the damping force obtained by the hydraulic shock absorber T is increased. This ensures stable turning of the vehicle. Next, when the turn is completed and the vehicle moves straight, and the turn signal switch circuit 31 is opened, the turn signal detection control circuit 32 outputs the "0" signal for a desired fixed period of time as described above, and then outputs the "1" signal. Since it outputs, AND gate G ₂ and NAND gate G ₃
are “1,” corresponding to the signals of lines a and b, respectively.
0" signal is output, the input signals to the A and B terminals of the signal comparison circuit 3 become "1, 0", and the damping force setting position returns to the soft (S) position again. Next, the operating state when the vehicle speed reaches a predetermined vehicle speed and further exceeds this predetermined vehicle speed will be described. First, the vehicle speed sensor 34 senses whether the vehicle speed has reached a predetermined vehicle speed and notifies the F/V converter 36 . Generally, the vehicle speed is normally detected by the vehicle speed sensor 34 as an electrical pulse, that is, a frequency magnitude, so once it is converted to a voltage level by the F/V converter 36, one side of the input of the comparator circuit 37 is entered at the end. Since the reference voltage V _s corresponding to the preset vehicle speed is input to the comparison circuit 37, when the vehicle speed sensed by the vehicle speed sensor 34 becomes higher than the predetermined vehicle speed, the comparison circuit 3
The output of 7 becomes "1". Therefore, assuming that the vehicle is driven with the damping force setting position set to the soft position (S), when the vehicle speed is low, the A and B terminals will have "1, 0" as described above. is input, but when the vehicle speed gradually increases to a predetermined vehicle speed or higher, the output of the comparator circuit 37 becomes "1", and therefore the output of the OR gate _G7 becomes "1", and eventually the A and B terminals A signal of "1, 1" will be input to. Then, this “1,
According to Table 1, the signal "1" corresponds to the signal at the normal damping force setting position N.
1" and the signal from the rotation angle position detection circuit 6, and as a result, the damping force setting position automatically changes from the "soft position (S)" to the "normal position (N) as the vehicle speed increases. )", that is, the damping force setting position is one step higher. This state is shown in the graph of Figure 6. When the vehicle speed reaches a preset predetermined vehicle speed _V0 , the damping force that was set at the soft position (S) is automatically changed to the normal position (N). , that is, to a damping force setting position one step higher, and continues in that state thereafter. Note that if the damping force is set in advance to the hard position H or, in some cases, to a higher damping force H', the damping force will not be affected by the vehicle speed. Next, when the vehicle speed becomes decelerated and becomes less than the predetermined vehicle speed _V1 , the comparison circuit 37
Since the output becomes "0", the input signals to the A and B terminals become "1, 0", and the setting position of the damping force returns to the soft position (S) again. In FIG. 6, ΔV is a switching speed width provided to prevent hunting. As described above, according to this embodiment, when the vehicle transitions from a straight-ahead driving state to a turning driving state, or when the vehicle transitions from a low-speed driving state to a high-speed driving state that is higher than a preset vehicle speed, the turn Based on the switch signal obtained from the signal switch circuit 31 or the vehicle speed signal obtained from the vehicle speed sensor 34, the damping force of the hydraulic shock absorber T is changed from a low damping force setting position (soft position) S to a higher damping force. The set position (in this example, it can be automatically switched and corrected to the normal position (N),
Therefore, good running stability can be ensured when the vehicle is turning or at high speeds without causing any complication in operability. Next, FIG. 7 is a specific circuit diagram showing another embodiment of the present invention, which differs from the embodiment shown in FIG. From the viewpoint that side control has an important meaning, damping of the front wheel side hydraulic shock absorbers TF, TF of the front wheel side hydraulic shock absorbers TF, TF and the rear wheel side hydraulic shock absorbers TB, TB. The point is that only the force is transferred to the hard position (H). For this reason, in this embodiment, at a position forward of the turn signal gate circuit 30, a line is connected to the lines a and b connected to the respective terminals 1a and 1c at the hard position (H) and soft position (S). Branch a' and b' and connect these lines a' and b' to the hydraulic shock absorber on the rear wheel side.
The selection reference signal generation circuit 2 is connected to the signal comparison circuits 3 and 3 connected to the TB and TB, respectively, and based on the hard position (H) and the soft position (S).
The selection reference signal output from the AND gate G ₂ connected to the turn signal correction circuit 32 and the vehicle speed signal gate circuit 3 connected to the vehicle speed sensor 29
Hydraulic shock absorber TB on the rear wheel side without going through 5.
The signal is input only to the signal comparison circuits 3, 3 connected to the TB. In this embodiment, the output stage of the selection reference signal generation circuit 2 includes a damping force switching signal generation circuit consisting of OR gates G ₈ and G ₉ which receives a signal from the failure detection circuit 33 and outputs a damping force switching signal. 39 are provided. With this configuration, the damping force of the front wheel side hydraulic shock absorbers TF, TF is adjusted to the soft position (S) by the switch signal obtained from the turn signal switch circuit 31 or the vehicle speed signal obtained from the vehicle speed sensor 34. ) to the normal position (N) or hard position (H). Next, FIG. 8 is a specific circuit diagram showing still another embodiment of the present invention. In order to obtain stable turning running of the vehicle, when the vehicle is turning to the right, a hydraulic buffer located on the left side is used. The idea was to increase the damping force of the hydraulic shock absorber located on the right side when turning left. To achieve this purpose, in this embodiment, a turn signal gate circuit 30 is used to connect the lines a and b connected to the hard position (H) and soft position (S) terminals 1a and 1c. , right side lines aR, bR connected to the signal comparison circuits 3, 3 connected to hydraulic shock absorbers TR, TR located on the right side of the vehicle, and hydraulic shock absorbers TL, TL also located on the left side of the vehicle. The left lines aL, aL connected to the signal comparison circuits 3, 3 are branched. In addition, the turn signal detection control circuit 32 is connected to the right turn signal switch 31a.
and the output of the turn signal detection control circuit 32 connected to the right turn signal switch 31a as the gate input of the turn signal gate circuit 30 attached to each of the left turn signal switch 31b and interposed in the left lines aL, bL. On the other hand, the output of a turn signal detection control circuit 32 connected to the left turn signal switch 31b is provided as the gate input of the turn signal gate circuit 30 interposed between the right lines aR and bR. Note that a failure detection circuit 3 is connected to each of the right lines aR, bR and the left lines aL, bL on the output side of the turn signal gate circuit 30.
A damping force switching signal generation circuit 38 is provided which receives the signal from the damping force switching signal 3 and outputs a damping force switching signal. With this configuration, when the vehicle turns right, the damping force of the hydraulic shock absorbers TL, located on the left side is increased, and when the vehicle turns left, the damping force of the hydraulic shock absorbers TL, located on the right side is increased.
By increasing the damping force of TR and TR, stable cornering is possible without compromising ride comfort. The failure detection circuit 33 shown in FIGS. 5, 7, and 8 sets the time required from the start to the completion of the damping force adjustment control that results in contact abnormality of the changeover switch 1 or mismatched output of the signal comparison circuit. A circuit that determines that there is an abnormality in the control system when the time exceeds the specified time,
When the above-mentioned failure occurs, the motor drive circuit 5 is driven and controlled so as to force the selection reference signal output from the selection reference signal generation circuit 2 to the normal position (N) of the selection damping force. As is clear from the above description, in the present invention, since the turn signal correction circuit and the vehicle speed correction circuit are provided between the selection reference signal generation circuit and the signal comparison circuit, When the vehicle shifts from a low-speed running state to a turning running state, or when the vehicle shifts from a low-speed running state to a high-speed running state exceeding a predetermined vehicle speed, the damping force of the hydraulic shock absorber is changed from the low damping force setting position to a lower damping force setting position. It is possible to automatically switch to a high damping force setting position and make corrections, and therefore, it is possible to maintain good driving stability when the vehicle turns and at high speeds without any operational complications. This effect can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an example of a control circuit of a conventional variable damping force type hydraulic shock absorber, Fig. 2 is a cross-sectional view of main parts showing the configuration of the hydraulic shock absorber, and Fig. 3 is a - line in Fig. 2. FIG. 4 is a block diagram showing the circuit configuration of a hydraulic shock absorber control device according to the present invention, FIG. 5 is a main part circuit diagram showing a more specific embodiment of the present invention, and FIG. The figure is an operational characteristic diagram when the device of the present invention is operated, and FIGS. 7 and 8 are circuit block diagrams showing various other embodiments of the present invention. DESCRIPTION OF SYMBOLS 1...Selector switch, 2...Selection reference signal generation circuit, 3...Signal comparison circuit, 4...Motor, 5...
... Motor drive circuit, 6 ... Rotation angle position detection circuit, 7 ... Signal conversion circuit, 28 ... Turn signal correction circuit, 29 ... Vehicle speed correction circuit, 31 ... Turn signal switch circuit, 34 ... Vehicle speed sensor.

Claims (1)

[Claims] 1. A changeover switch that selects a desired damping force, a selection reference signal generation circuit that receives one selection signal selected by the changeover switch and generates a selection reference signal according to the selection signal, and the selection reference signal. The selection reference signal outputted from the generation circuit is compared with the output signal corresponding to the rotational angular position of the motor for adjusting the damping force of the hydraulic shock absorber, and the mismatch or coincidence of the selection reference signal and the output signal is determined. A signal comparison circuit that performs discrimination, a motor drive circuit that operates in response to each mismatch or match signal output from this signal comparison circuit, a motor that is driven or stopped by this motor drive circuit, and a drive shaft of this motor. In the damping force variable hydraulic pressure damping control device comprising a rotational angular position detection circuit that detects a rotational angular position and inputs an output signal corresponding to the rotational angular position to the signal comparison circuit, the selection reference signal is generated. The selection reference signal corresponding to the low damping force setting position from the selection reference signal generation circuit is connected between the circuit and the signal comparison circuit by a switch signal obtained from the turn signal switch circuit. A turn signal correction circuit is provided to correct the signal corresponding to the position and input it to the signal comparison circuit, and when the vehicle speed detected by the vehicle speed sensor exceeds a predetermined vehicle speed set in advance, a vehicle speed correction circuit for correcting a selection reference signal corresponding to a low damping force setting position from the selection reference signal generation circuit to a signal corresponding to a higher damping force setting position and inputting the signal to the signal comparison circuit; A control device for a variable damping force type hydraulic shock absorber.