JPS6344563B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an electronic control device for controlling a variable damping force hydraulic shock absorber applied to a suspension system of an automobile, etc., and more specifically, it is capable of changing the damping force when a turn signal is activated, such as when the vehicle is turned. This invention relates to a control device. Conventionally, in order to improve the riding comfort or running stability of automobiles, etc., a motor installed inside or outside the piston rod is rotated by a predetermined angle depending on the driving conditions of the automobile, etc., and this rotational force is used to adjust the damping force. A variable damping force type hydraulic shock absorber that can perform desired damping force adjustment by rotationally controlling an adjuster, and a control device for controlling this hydraulic 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 a changeover switch for selecting one of the desired damping force setting positions (in this conventional example, each damping force setting position is divided into three categories: high, medium, and low), and 2 is this changeover switch. A selection reference signal generation circuit receives one selection signal selected by 1 and generates a selection reference signal according to the selection signal; 3 is a selection reference signal output from this selection reference signal generation circuit 2, which will be described later. A signal comparison circuit 5 compares the output signal corresponding to the rotation angle position of the motor 4 to determine whether the selection reference signal and the output signal match or match. This is a motor drive circuit that operates in response to various signals. 4 is a motor that is driven or stopped by the motor drive circuit 5; 6 is a motor that detects the rotational angular position of the drive shaft 4a of the motor 4, and the signal comparison circuit 3 corresponds to the rotational angular position of the motor 4; This is a rotation angle position detection circuit that inputs the output signal. In addition, when this rotational angle position detection circuit 6 is constituted by a predetermined encoder, a signal conversion circuit 7 is provided 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 between the rotation angle position detection circuit 6 and the signal comparison circuit 3. T is a hydraulic shock absorber having a configuration 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 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 11 is provided 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.
is provided. 15 is the piston rod 10 and piston 11;
The stud 15 has an overall cylindrical shape that connects the regulator accommodating section 1.
6 and an axial through hole 17 that communicates the interior of the adjuster accommodating portion 16 and the lower liquid chamber 13 are formed, respectively. Further, the cylindrical wall portion 15a of the stud 15 has a second
As shown in FIG. 3, which is a cross-sectional view taken along the - line in the figure, each of the plurality of liquid chambers, which are arranged at predetermined intervals in the circumferential direction, have mutually different opening areas and communicate with the upper liquid chamber 12. Orifices 18, 19, and 20 are bored. Inside the adjuster accommodating portion 16 of the stud 15,
An adjuster 8 rotatably driven by a motor 4 housed in the hollow portion of the piston rod 10 is rotatably housed, and the adjuster 8 has an axial passage that opens toward and communicates with the lower liquid chamber 13. Hole 2
2 and a communication hole 23 that can selectively communicate with any one of the orifices 18, 19, and 20 provided in the stud 15 is formed. The input end of the motor 4 is connected to a motor drive circuit 5 as shown in FIG. 1 via predetermined harnesses 24, 24, and the motor 4 is driven by this motor drive circuit 5. ing. 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 as shown in FIG. A corresponding selection reference 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 current information of the drive shaft 4a provided in the motor 4 from the rotation angle position detection circuit 6. Since the rotational position detection signal indicating the rotational angular position is input after being converted into a digital value by the signal conversion circuit 7, these two signals are compared in this signal comparison circuit. This signal comparison circuit 3 outputs a match signal when the two signals match, and a mismatch signal when they do not match. Therefore, the motor drive circuit 5 is operated by these signals. That is, when the coincidence 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, so that the output signals from the signal comparison circuit 3 match. The motor 4 continues to rotate until the signal is received. In this way, the orifice 19 provided in the stud 15 for setting the medium damping force selected by the changeover switch 1,
The communication hole 23 of the adjuster 8 is opened and communicated. Therefore, by bypassing a portion of the working 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 can be adjusted to ensure a desired damping force. As explained in detail above, the conventional control circuit S
According to the configuration of the hydraulic shock absorber T, one of the three damping force setting positions of high, medium, and low can be set by manually operating the changeover switch 1 according to the vehicle running condition. The desired damping force can be obtained by selecting the desired damping force. 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. It is desirable to increase the damping force obtained with pressure dampers. However, when selecting and switching the damping force by the manual operation, it is difficult to operate and it is not expected that the driver will immediately perform the switching operation when turning the vehicle. Therefore, in order to deal with this problem, when the vehicle enters a turning state, the damping force setting position is automatically set to "high".
It is desirable to add a control circuit to move the device to the position shown in FIG. This invention has been made in view of the above-mentioned points of view, and it improves the control circuit of a variable damping force type hydraulic shock absorber, and adjusts the damping force setting position to "high" by a signal obtained from a turn signal switch. '' position. The present invention will be described in detail below based on the drawings. That is, FIG. 4 is a block diagram showing the circuit configuration of a control device for a hydraulic shock absorber according to the present invention, and in the figure, the same components as those used in the conventional control device shown in FIG. A code is attached.
Reference numeral 1 in the figure is a changeover switch for selecting one of the desired damping force setting positions;
(Hard H), “Medium” (Normal N), Low (Soft S)
One of the three damping force setting positions can be selected. 2 is a selection reference signal generation circuit that receives one selection signal selected by the changeover switch 1 and generates a selection reference signal according to the selection signal; 30 is a signal obtained by the turn signal switch 31; a turn signal gate circuit that outputs a signal that corrects the setting position of the damping force to the "high" position regardless of the selection reference signal generated from the selection reference signal generation circuit 2 when the signal is inputted. , 3 is a signal comparison circuit that compares the selection signal outputted from the turn signal gate circuit 30 and the output signal corresponding to the rotational angular position of the motor 4, and determines whether these selection signals and output signals do not match or match. , 5 is a motor drive circuit that operates in response to the mismatch or match signals output from the signal comparison circuit 3. 4 is a motor driven or stopped by the motor drive circuit 5; 6 is the motor 4; more specifically, the motor 4;
This is a rotational angular position detection circuit that detects the rotational angular position of the drive shaft 4a and inputs an output signal corresponding to the rotational angular position to the signal comparison circuit 3. When this rotation angle position detection circuit 6 is constituted by a predetermined encoder, the signal conversion circuit 7 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 installed as described above. It is 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 the motor 4 rotates an adjuster for adjusting damping force. The circuit indicated by the overall symbol C is a turn signal correction circuit, which detects a switch signal obtained from a turn signal switch 31 with a turn signal detection control circuit 32, and when a switch signal is detected, a turn signal gate circuit. The turn signal detection control circuit 32 is configured to correct the damping force of the hydraulic shock absorber T by inputting a low level O signal to the turn signal switch 30 . Even after the damping force has stopped, a damping force correction signal is output for a short period of time. A specific example of the circuit will be explained with reference to FIG. Each soft damping force setting position H,
A low level is given to the selected input among the terminals 1a, 1b, and 1c inputs of N and S, and among these inputs, the inputs at the setting positions H and S are as follows.
They are output to line a and line b via anti-circumstance diodes D ₁ and D ₂ and a CR integration circuit for noise removal, respectively, and the input at the setting position N is output to a NOR gate via anti-circumference diode D ₃ and a CR integration circuit. It is considered to be the gate input on one side of _G1 . In addition, a diode D ₄ ,
D ₅ is provided, and a Noah gate is provided to prevent contact abnormalities of switch 1 that generally occur in open mode.
The output of NOR gate G ₁ is input to the failure detection circuit 33 so that it can be detected as a low level output of G ₁ . Line a is used as one side gate input of AND gate _G2 constituting the turn signal gate circuit 30, line b is used as one side gate input of NAND gate _G3 via inverter _I1 ,
A signal from the turn signal detection control circuit 32 is input to the other gates of the AND gate G ₂ and the NAND gate G ₃ . The turn signal detection control circuit 32 controls the left and right turn signal switches 31.
The contact signals of a and 31b are input to the gate of the AND gate G ₄ through the loop prevention diodes D ₆ and D ₇ , preferably further through a CR integration circuit for noise removal (not shown), _respectively . The output of the NOR gate G5 is input to one side of the NOR gate _G5 via the inverter _I2 , and is also input to the other side of the NOR gate _G5 via the off-delay timer circuit _Tm . The output of is used as the other side 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.
These OR gates G _{6 and} G ₇ receive the output of the failure detection circuit 33 that detects abnormality in the control circuit as the gate input on the other side. These OR gates constitute a damping force switching signal generation circuit that outputs a signal corresponding to the normal damping force setting position.
The outputs of G ₆ and G ₇ are input to the signal comparison circuit 3, respectively. Next, the operation in the above configuration will be explained. First, when the changeover switch 1 is set to the normal N position, the output of the Noah gate G ₁ is at a high level (hereinafter referred to as "1"), lines a and b are also "1", and the output of the Noah gate G ₁ is given. The fault detection circuit 33 outputs a low level (hereinafter referred to as "0"), and the turn signal detection control circuit 32 outputs "1" when the turn signal switch 31 is open. , the B terminal has “1,
1" is input. Next, when the changeover switch 1 is set to the hard (H) position, "0" is input to the NOR gate _G1 by the diode _D4 , so the output of the NOR gate _G1 is "1", and the line a is "0",
Since line b is "1", "0, 1" are input to the A and B terminals. Also, if selector switch 1 is set to the soft (S) position, the Noah gate
Since "0" is input to _G1 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, “1, 0” is input to the B terminal. These conditions are shown in Table 1.

[Table] The signal output shown in Table 1 above is from the signal comparison circuit 3.
and is compared with the signal from the rotation angle position detection circuit 6 which is input to the other side of the signal comparison circuit 3 and drives the motor 4 via the motor drive circuit 5 to obtain a desired damping force. can be obtained. Next, a case will be described in which either the left or right turn signal switch 31a, 31b is closed during the above operation and the vehicle enters a turning state. That is, when either the left or right turn signal switch 31a, 31b is closed, the gate input of one of the AND gates _G4 becomes "0", so the AND gate _G4 outputs "0", and this Since the output is given as a gate input of "1" to one side of the NOR gate _G5 and "0" to the other side via the inverter _I2 or the off-delay timer circuit Tm, this NOR gate _G5 inputs "0". Output. In addition, the output "0" of this NOR gate _G5 is caused by the turn signal switch 31 being opened from closed and the AND gate G5 being output "0".
When the output of G ₄ changes from "0" to "1",
Although the gate input on one side of this NOR gate _G5 is converted to "0" by the inverter _I2 , the gate input on the other side is generally CR by the operation of the off-delay timer circuit Tm.
Since "1" is given for a certain period of time determined by the discharge time constant of the circuit, it is held for that certain period of time.
Now, assuming that the damping force setting position is set to the soft S position and the turn signal switch 31 is closed in order to turn the vehicle, "1" on line a is given as the gate input on one side. , the AND gate _G2 outputs "1" to the A terminal of the comparator circuit 3, and the "0" on line b is converted by the inverter _I1 and given as one side gate input, and the B of the comparator circuit 3 outputs "1". Since "0" is given as the gate input on the other side of the NAND gate _G3 which outputs "0" to the terminal, the AND gate
G ₂ outputs “0” and NAND gate G ₃ outputs “1”
A, B of the comparator circuit 3
A "0, 1" signal will be input to the terminal. That is, according to Table 1, the signal "0, 1" corresponds to the damping force setting position of the hard (H) position, and after all, the damping force setting position is set when the turn signal switch 31 is operated. Regardless of the signal obtained by the selection signal generation circuit 2, it is possible to automatically shift to the hard (H) position, and,
By increasing the damping force obtained by the hydraulic shock absorber T, stable cornering of the vehicle is guaranteed. Next, when the turn is completed and the vehicle moves straight, and the turn signal switch 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 output, AND gate G ₂ and NAND gate G ₃ are respectively connected to lines a and
A "1, 0" signal corresponding to the signal b is output, and the input signals to the A and B terminals of the comparator circuit 3 are "1, 0".
The setting position of the damping force returns to the soft (S) position again. FIG. 6 is a specific circuit diagram showing another embodiment of the present invention. The difference from the embodiment shown in FIG. 5 is that control of the front wheels is important for stable cornering of the vehicle. From the point of view of meaning, the damping force was shifted to the hard (H) position only on the front wheel side. For this purpose, the comparison circuit 3 connected to the rear wheel side is connected to a line a', which is branched from the lines a and b in front of the turn signal gate circuit 30.
b' allows the signal from the selection reference signal generation circuit 2 to be directly inputted, and the output stage of the selection reference signal generation circuit 2 receives the signal from the failure detection circuit 33 to receive a damping force switching signal. A damping force switching signal generation circuit 34 is added to output the damping force switching signal generation circuit 34. With this configuration, only the damping force of the hydraulic shock absorber on the front wheel side can be shifted to the hard (H) position by the signal obtained from the turn signal switch 31. FIG. 7 is a specific circuit diagram showing still another embodiment of the present invention. According to this embodiment, lines a and b are lines a R and B respectively, which control a hydraulic shock absorber located on the right side of the vehicle _. , b _R and lines a _L , b _L that control the hydraulic shock absorber also located on the left side,
A turn signal gate circuit 30 is provided in each of these right-hand lines a _R , b _R and left-hand lines a _L , b _L . Further, a turn signal detection control circuit 32 is layered on each of the right turn signal switch 31a and the left turn signal switch 31b, and the gate input of the turn signal gate circuit 30 interposed in the left lines a _L and b _L is provided. as the output of the turn signal detection control circuit 32 connected to the right turn signal switch 31a, and as the gate input of the turn signal gate circuit 30 interposed in the right lines a _R and b _R.
The output of the turn signal detection control circuit 32 connected to the left turn signal switch 31b is provided. In addition, the right lines a _R and b _R and the left line on the output side of the turn signal gate circuit 30
Each of a _L and b _L is provided with a damping force switching signal generation circuit 34 that receives a signal from the failure detection circuit 33 and outputs a damping force switching signal. With this configuration, when the vehicle turns right, the damping force of the hydraulic shock absorber located on the left side is increased, and when the vehicle turns left, the damping force of the hydraulic shock absorber located on the right side is increased, which impairs ride comfort. You can make stable turns without any trouble. Note that the failure detection circuit 33 shown in FIGS. 5 to 7 detects when the time required from the start to the completion of the damping force adjustment control, which results in contact abnormality of the changeover switch 1 or mismatched output of the signal comparison circuit 3, is longer than the set time. The circuit determines that there is an abnormality in the control system when the above failure occurs, and the circuit is configured to force the selection reference signal output from the selection reference signal generation circuit to the normal position of the selection damping force when the above-mentioned failure occurs. motor drive circuit 5
to drive and control. As explained in detail above, in the present invention,
In addition to the conventional damping force adjustment based on manual switching operation, signals obtained from the turn signal switch can be used to adjust the damping force to a higher level even if the vehicle is adjusted to a lower damping force setting position and is driving. Since the force setting position is automatically corrected, it is possible to maintain good running stability when turning without any operational complexity.

[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. 7 and 7 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, 30...Turn signal gate circuit, 31...Turn signal switch, 32...Turn signal detection control circuit, C...
...Turn signal correction 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. a signal comparison circuit that compares the selection reference signal outputted from the generation circuit with an output signal corresponding to the rotational angular position of the motor and determines whether or not the selection reference signal and the output signal match; A motor drive circuit that operates in response to the output mismatch or match signals, a motor that is driven or stopped by this motor drive circuit, and a rotation angle position of the drive shaft of this motor that is detected and sent to the signal comparison circuit. It consists of a rotation angle position detection circuit that inputs an output signal corresponding to the rotation angle position,
A cylindrical piston rod that connects with each other a removable piston rod that extends through one end of a cylinder filled with hydraulic fluid under a liquid-tight seal, and a piston that separates the inside of the cylinder into upper and lower fluid chambers. By rotationally driving an adjuster rotatably housed inside the stud with the motor, hydraulic fluid is displaced and flows between the upper and lower fluid chambers via the damping force generating means provided on the piston. In a variable damping force hydraulic shock absorber configured to adjust the flow amount, a selection reference signal corresponding to a low damping force setting position from a selection reference signal generation circuit is generated by a signal obtained from a turn signal switch. A turn signal correction circuit is provided between the selection reference signal generation circuit and the signal comparison circuit, which corrects the signal to a signal corresponding to a higher damping force setting position and inputs the signal to the signal comparison circuit. An electronic control device for variable damping force hydraulic shock absorbers.