JPS6344567B2 - - 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. On the other hand, T is a hydraulic shock absorber having a structure in which a damping force adjustment adjuster is rotated by the motor 4, the details of which are shown in FIGS. 2 and 3. That is,
In FIG. 2, 9 is a cylinder filled with hydraulic fluid, and 10 is a piston rod that extends through the cylinder 9 with one end sealed and the other end sealed. A piston 11 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 1
1 is equipped with a damping force generating means 14 that creates a flow resistance in the hydraulic fluid displacing between the upper and lower fluid chambers 12 and 13. Reference numeral 15 denotes a generally cylindrical stud that connects the piston rod 10 and the piston 11. Inside this stud 15, an adjustment element 8 rotatably accommodated is rotatably driven by the motor 4. Child housing section 16 and the adjuster housing section 1
Through holes 17 in the axial direction are formed to communicate the inside of the liquid chamber 6 and the lower liquid chamber 13, respectively. Furthermore, as shown in FIG. 3, on the cylindrical wall portion 15a of the stud 15, there are provided openings communicating with the upper liquid chamber 12 and having mutually different opening areas and spaced at predetermined intervals in the circumferential direction. Each orifice 18, 19, 20 is bored. 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, to a motor drive circuit 5 as shown in FIG. 1, and the 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 and inputted to the signal comparison circuit 7, 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 motor 4 continues to rotate 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. Therefore, by bypassing a portion of the hydraulic fluid flowing between the upper and lower liquid chambers 12 and 13 through the orifice 19, the damping force obtained by the damping force generating means 14 is adjusted. ,
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, when a vehicle such as an automobile suddenly starts or accelerates, a so-called scout phenomenon occurs due to a change in the drive torque of the axle, and the vehicle body temporarily recedes. In order to prevent this situation and improve vehicle ride comfort and handling stability, when the vehicle starts suddenly, the damping force obtained by the hydraulic shock absorber is applied for a certain period of time (for example, 2 seconds). degree), it is desirable to switch to a higher level. The present invention has been made in view of these demands, and is intended to change the damping force obtained by the hydraulic shock absorber from a low damping force setting position to a higher damping force setting position when the vehicle suddenly starts or accelerates. It is an object of the present invention to provide a control device that can automatically switch and correct the damping force, maintain the high damping force setting position for a predetermined period of time, and then return to the original damping force setting position. 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. In the embodiment shown in FIG. 4, an engine rotation speed detection sensor 28 for detecting an engine rotation speed signal, a clutch signal detection circuit 27 for detecting a clutch signal, and an engine rotation speed detection circuit 27 for detecting a clutch signal are provided. An engine acceleration detection circuit 29 as an engine acceleration detection means for detecting engine acceleration based on a rotational speed signal, and a vehicle speed sensor 3
A reference acceleration detection circuit 32 as a reference acceleration detection means for detecting a reference acceleration based on a vehicle speed signal corresponding to the vehicle speed obtained from 1, and a reference acceleration level based on the vehicle speed signal and an engine acceleration based on an engine acceleration signal. a comparator 33 that outputs a predetermined anti-scout signal when the ratio of the engine acceleration level to the reference acceleration level becomes larger than the reference value;
a timer circuit 34 that sends out an anti-scout signal output from the timer circuit 3 for a predetermined period of time;
4, the selection reference signal corresponding to the low damping force setting position S from the selection reference signal generation circuit 2 is set to a higher damping force setting position (N) or (H). and a gate circuit 30 for correcting the signal to a signal corresponding to the signal and inputting the corrected signal to the signal comparison circuit 3. In this embodiment, the clutch signal detection circuit 27 is comprised of a limit switch, etc., which outputs a signal of "1" as a clutch signal when the clutch is engaged, and the engine rotation speed detection sensor 28 is configured to detect engine rotation speed. It consists of a tachometer, etc. that detects speed. The engine acceleration detection circuit 29 also includes an AND gate that outputs an engine rotational speed signal only when a clutch signal is output from the clutch signal detection circuit 27.
G ₄ , an F/V conversion circuit 35 that converts the engine rotation speed signal output as a frequency magnitude from the AND gate G ₄ into a voltage level, and a signal from the F/V converter 35 that corresponds to the engine rotation speed. The differential circuit 36 differentiates the voltage level and outputs an engine acceleration signal corresponding to the engine acceleration as a voltage level. The reference acceleration detection circuit 32 also includes an F/V conversion circuit 3 that converts the vehicle speed signal from the vehicle speed sensor 31 into a voltage level and outputs the voltage level.
7, and a reference voltage generation circuit 39 that outputs a reference acceleration as a reference for comparison with the engine acceleration at a voltage level based on the vehicle speed signal from the F/V conversion circuit 37. Note that the reference acceleration is outputted from the reference voltage generation circuit 39 so that the voltage level state changes linearly or stepwise from a low voltage level state to a high voltage level state as the vehicle moves from a low speed driving state to a high speed driving state. It is becoming more and more common. Further, the timer circuit 34 includes an off-delay timer circuit 40 that sends out an anti-scout signal for a predetermined period of time (approximately 2 seconds) even after the clutch signal has stopped, and an off-delay timer circuit 40 that sends out an anti-scout signal for a predetermined period of time (approximately 2 seconds) even after the clutch signal has stopped, and an off-delay timer circuit 40 that sends out an anti-scout signal from a comparator 33 after a predetermined period of time has elapsed. It is composed of a NOR gate _G5 which outputs a "0" signal outputted as an OUT signal as a "1" signal. On the other hand, a selection reference signal generation circuit 2 generates a selection reference signal corresponding to one selection signal selected by the changeover switch 1.
Low damping force (hereinafter referred to as "hard, normal, soft")
That's what it means. ), a low-level signal is given to the selected input among the terminals 1a, 1b, and 1c inputs at each damping force setting position (H), (N), and (S), and among these inputs, the hard, Software setting position (H), (S)
The inputs are output to line a and line b via anti-circuit diodes D ₁ and D ₂ and a CR circuit for noise removal, respectively, and are further output to line a and line b via lines a and b to AND gate G ₂ and NAND gate G. ₃ are output respectively. Also,
The input from the set position (N) is made into one side gate input of the NOR gate _G1 via the bypass prevention diode _D3 and the CR circuit. Furthermore, from the input terminal 1b at the normal setting position (N), the input terminal 1a at the hard and soft setting positions (H) and (S),
1c is provided with diodes D ₄ and D ₅ in the forward direction, so that a contact abnormality of the changeover switch 1 that generally occurs in the open mode can be detected as a low level output of the NOR gate G ₁ , and the NOR gate G ₁
The output of is input to the failure detection circuit 41. Note that the output of the failure detection circuit 41 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 gate circuit 30 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 the damping force switching signal. The output of OR gate _G6 forming the generating circuit 38 is input. The line a is used as one side gate input of the AND gate _G2 constituting the gate circuit 30, and the line b is used as the one side gate input of the NAND gate _G3 via the inverter _I1 . A signal from the timer circuit 34 is input to the other gate of the gate G ₂ and the NAND gate G ₃ . Further, the output from the comparator 33 is input to one side of the NOR gate G ₅ constituting the timer circuit 34, and is also connected to the other side gate input of the NOR gate G ₅ via the off-delay timer circuit 40. The output of this NOR gate _G5 is used as the other gate input of each 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 connected to externally provided OR gates G _{6 and 3} , respectively.
The output of the failure detection circuit 41 that detects an abnormality in the control circuit S is given to _{the OR gates G 6 and} G ₇ as the gate input on the other side. A damping force switching signal generation circuit 38 is configured to output a signal corresponding to the normal damping force setting position N when the control circuit S is abnormal. The outputs of these OR gates G ₆ and G ₇ are
Each signal is input to the signal comparison circuit 3. In the above configuration, the relationship between the damping force setting positions (N), (H), and (S) of the changeover switch 1 and the signals input to the A and B terminals of the signal comparison circuit 3 is as follows. Become. 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,
Since b also outputs "1", "1, 1" is input to the A and B terminals of the signal comparison circuit (3). In this case, the failure detection circuit 41 to which the NOR gate _G1 output is applied outputs a low level (hereinafter referred to as "0"). Next, set changeover switch 1 to hard position (H).
In this case, "0" is input to the NOR gate _G1 by the diode _D4 , so the NOR gate
Since the output of G1 is " ₁ ", line a is "0", and line b is "1", the above A and B terminals have
"0, 1" is input. In addition, selector switch 1
When set to soft position (S), Noah Gate G ₁
Since "0" is inputted to by the diode _D5 , the output of the NOR gate _G1 is "1", line a is "1", and line b is "0", so the above A, B “1, 0” is input to the terminal. These conditions are shown in "Table 1".

[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. As described above, the control device according to the present invention operates, but when the vehicle suddenly starts or accelerates, it is necessary to prevent the vehicle body from falling backward. Then, the anti-squat signal is input from the comparator 33 to the gate circuit 30 for a predetermined period of time, and the gate circuit 30 operates to switch the low damping force obtained by the hydraulic shock absorber T to a higher damping force. That is, first, a case will be described in which the clutch is engaged and the vehicle suddenly starts from a stopped state. In this case, when the clutch is connected, the clutch signal detection circuit 27 outputs "1" as the clutch signal.
Since _a signal of After that, it is input to the differentiation circuit 36. and,
This differentiation circuit 36 outputs an engine acceleration signal corresponding to the engine acceleration. On the other hand, since the vehicle is stopped, the vehicle speed sensor 31 outputs a signal of "0" as the vehicle speed signal, and the reference voltage generation circuit 39 outputs a signal corresponding to the vehicle speed of "zero" via the F/V conversion circuit 37. A vehicle speed signal is output. A comparator 33 compares the reference acceleration based on this vehicle speed signal and the engine acceleration based on the engine acceleration signal. As a result, if the ratio of the level of engine acceleration to the reference acceleration is equal to or greater than the set reference value, the comparator 33 outputs an anti-scout signal of "1". This "1" output is input as "1" as the gate input on one side of the NOR gate _G5 , and as the gate input on the other side,
By operating the off-delay timer circuit 40, "1" is input for a predetermined period of time (for example, 2 seconds).
As a result, the anti-scout signal of "0" is output from the NOR gate _G5 . Therefore, if we assume that the vehicle is suddenly started from a stopped state with the damping force setting position set to the soft position (S), the "zero ” and the engine acceleration based on the engine acceleration signal output from the engine acceleration detection circuit 29 are compared in the comparator 33, and as a result, the ratio of the level of the engine acceleration to the reference acceleration is equal to or higher than the set reference value. In this case, the NAND gate G 3 and AND gate G 2 forming the gate circuit 30 are switched from the NOR gate G ₅ forming the timer circuit 34 to the NAND gate G ₃ and the AND gate G ₂ forming the gate circuit 30 for a predetermined period of time while the off-delay timer circuit 40 is operating. On the other side, "0" is input as a gate input. Therefore, from the AND gate _G2 to which the "1" signal of line a is given as the gate input on one side, the "0"
A signal of "0" is output by the logical product of "1" and "0", and on the other hand, the signal of "0" on line b is
A signal of " ₁ " is output from the NAND gate _G3 , which is converted by I1 and given as the gate input on one side, and the A and B terminals of the signal comparison circuit 3 are supplied with "0, 1". ” signal will be input. This 2-bit signal of “0, 1” is
According to Table 1 above, this corresponds to the damping force setting signal for the hard position H. Therefore, when the vehicle suddenly starts, the signal output from the selection reference signal generation circuit 2 is set to the soft position (S ), the signal can be automatically shifted to the hard position (H) even though the signal is "1, 0". Therefore,
By increasing the damping force obtained by the hydraulic shock absorber T, it is possible to effectively prevent the vehicle from rolling. Next, after the vehicle suddenly starts, a predetermined period of time (approximately 2 seconds)
After the elapse of time, the timer circuit 34 outputs an anti-scout signal of "0" for a predetermined period of time, and then
Since it outputs a "1" signal, AND gate G ₂ and NAND gate G ₃ output "1, 0" signals corresponding to the signals on lines a and b, respectively, and send them to the A and B terminals of signal comparison circuit 3. The input signal becomes "1, 0" and the damping force setting position returns to the soft position S again. The above is a case where the vehicle suddenly starts from a stopped state, but if the vehicle suddenly accelerates while it is running, the vehicle body will sag, so the damping force should be temporarily increased in this case as well. There is a need. Therefore, even in such a case, an anti-scout signal of "0" is input from the timer circuit 34 to the gate circuit 30 for a predetermined period. and signal comparison circuit 3
A "0, 1" signal corresponding to the damping force setting signal for the hard position (H) is inputted to the buffer T to increase the damping force obtained by the buffer T. By the way, whether or not the sagging phenomenon that occurs in the vehicle body is noticeable is not simply a result of whether the engine acceleration is high or low, but is also affected by whether the vehicle speed is high or low. Therefore, in the present invention, the reference acceleration output from the reference acceleration detection circuit 32 and the engine acceleration output from the engine acceleration detection circuit 29 are compared by the comparator 33, and the level ratio of the latter to the former is the reference value. , an anti-scout signal of "0" is input to the gate circuit 30 for a predetermined period of time to increase the damping force obtained by the hydraulic shock absorber T.
That is, when the level ratio is smaller than the reference value, the signal selected by the changeover switch 1 is inputted to the gate circuit 2 to maintain the selected damping force. Next, FIG. 5 is a specific circuit diagram showing another embodiment of the present invention, which differs from the embodiment shown in FIG. From the viewpoint that wheel side control is important, the rear wheel side hydraulic shock absorbers TB, TB are selected from among 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 damping force of is transferred to the hard position (H). For this reason, in this embodiment, at a position forward of the gate circuit 30, lines a and b connected to the terminals 1a and 1c at the hard position (H) and the soft position (S) are connected to the line a' and b', and connect these lines a' and b' to signal comparison circuits 3, 3 connected to the front wheel side hydraulic shock absorbers TF, TF, respectively,
The selection reference signal output from the selection reference signal generation circuit 2 based on the hard position (H) and the soft position (S) is passed through an AND gate G ₂ and a NAND gate G ₃ connected to a timer circuit 34. Instead, it is input only to the signal comparison circuits 3, 3 connected to the hydraulic shock absorbers TF, TF on the front wheel side. In this embodiment, an OR gate is provided at the output stage of the selection reference signal generation circuit 2, which receives a signal from the failure detection circuit 41 and outputs a damping force switching signal.
A damping force switching signal generation circuit 39 consisting of G ₈ and G ₉ is provided. With this configuration, the anti-scout signal obtained from the timer circuit 34 changes the damping force of the hydraulic shock absorbers TB, TB on the rear wheel side from the soft position (S) to the normal position (N) or the hard position. position
(H). In addition, in each of the above embodiments, when a clutch signal is output from the clutch signal detection circuit, the comparator detects the engine rotation speed signal obtained from the engine rotation speed detection sensor so that it can be applied to a manual transmission vehicle. However, in the case of automatic transmission vehicles, the clutch signal detection circuit is replaced by a clutch signal detection circuit.
An inhibit signal detection circuit may be provided, and when the inhibit signal is output from the circuit, the engine rotational speed signal may be input to the comparator side. Next, FIG. 6 is a block diagram showing still another embodiment of the present invention, in which the embodiment shown in FIGS. 4 and 5 detects the engine acceleration and the reference acceleration in analog quantities. On the other hand, this embodiment differs in that these are detected in digital quantities. That is, in this embodiment, the counting circuit 42 is used as the engine acceleration detection means for detecting the engine acceleration, while the counting circuit 42 is also used as the reference acceleration detection means for detecting the reference acceleration based on the vehicle speed signal obtained from the vehicle speed sensor 31. A comparator 44 compares the engine acceleration amount digitally output from these counting circuits 42 and 43 with a reference acceleration amount, and determines that the level ratio of the engine acceleration amount to the reference acceleration amount is lower than the reference value. When the anti-scout signal becomes large, a predetermined anti-scout signal is output to the timer circuit 34.
Note that 45 indicates each counting circuit 42, 43 and comparator 4.
This is a control circuit that temporally controls the operation of 4. Even with this configuration, it is possible to digitally detect the engine acceleration amount and the reference acceleration amount, and therefore it is possible to correct the damping force obtained by the hydraulic shock absorber to be higher. As is clear from the above description, according to the present invention, when the vehicle suddenly starts or accelerates, the damping force obtained by the hydraulic shock absorber is changed from the low damping force setting position to the higher damping force setting position. Automatically corrects switching,
After holding that high damping force setting position for a predetermined time,
It is possible to return to the original damping force setting position.
Therefore, it is possible to prevent the sagging phenomenon that occurs when the vehicle suddenly starts, etc., and it is possible to improve the riding comfort and steering stability of the vehicle. Further, in the present invention, a comparator is provided to compare the reference acceleration from the reference acceleration detection circuit and the engine acceleration from the engine acceleration detection circuit, and from this comparator, the level ratio of the latter to the former is determined to be higher than the reference value. Since the structure is configured so that a predetermined anti-scout signal is input to the gate circuit only when the anti-scout signal becomes large, the anti-scout signal can be effectively suppressed only when it is necessary to prevent the phenomenon of the car body sagging. It can be prevented.

[Brief explanation of drawings]

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 an example of the electrical circuit configuration of a hydraulic shock absorber control device according to the present invention, and FIG. 5 shows another embodiment of the present invention.
FIG. 6 is a block diagram including an electric circuit configuration, showing still another embodiment 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, 27 ... Clutch signal detection circuit, 28 ... Engine rotation speed detection sensor, 29, 42 ... Engine acceleration detection means, 30 ... Gate circuit, 31
... Vehicle speed sensor, 32, 43 ... Reference acceleration detection means, 33, 44 ... Comparator, 34 ... Timer circuit.

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. A variable damping force type hydraulic shock absorber 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, An engine rotation speed detection sensor for detecting an engine rotation speed, a clutch signal detection circuit or an inhibit signal detection circuit for detecting a clutch signal or an inhibit signal, and an engine rotation speed detection sensor for detecting an engine rotation speed based on the engine rotation speed signal when the clutch signal or inhibit signal is output. a vehicle speed sensor that detects a vehicle speed signal corresponding to the vehicle speed; a reference acceleration detection means that detects a reference acceleration based on the vehicle speed signal; and a comparison between the engine acceleration and the reference acceleration; a comparator that outputs an anti-squat signal when a level ratio of engine acceleration to a reference acceleration becomes larger than the reference value; a timer circuit that sends out the anti-squat signal output from the comparator for a predetermined period of time; The selection reference signal corresponding to the low damping force setting position from the selection reference signal generation circuit is changed to the selection reference signal corresponding to the higher damping force setting position based on the anti-scout signal output from the timer circuit. A control device for a variable damping force type hydraulic shock absorber, comprising a gate circuit for correcting the signal and inputting the corrected signal to the signal comparator.