JPH0658359A - Stepping motor controller for damping force variable type shock absorber - Google Patents

Abstract

PURPOSE:To provide complete initial setting of a stepping motor which drives the damping force control valve of a shock absorber. CONSTITUTION:This stepping motor controller is provided with the first initial setting device M1 which initial-sets a stepping motor MO with an ignition switch closed, a voltage detection device M2 which detects power voltage for supplying electric current to the stepping motor, and the second initial setting device M3 which initial-sets the stepping motor with the power voltage returned to a normal condition from a dropped condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable damping force type shock absorber, and more particularly to a step motor control device for a variable damping force type shock absorber.

[0002]

2. Description of the Related Art A damping force variable type shock absorber driven by a step motor having a damping force control valve built in a piston is well known in the prior art. In such a shock absorber, the rotational position of the step motor is detected. Since it is difficult in terms of space and cost to incorporate a rotary encoder or the like, the rotational position of the step motor is generally controlled by an open loop method. When the rotational position of the step motor is controlled in an open loop system, if the input load to the step motor becomes excessive, such as when the vehicle is traveling on a rough road, the command step to the step motor will match the actual step. So-called step out may occur.

As one of step motor control devices for dealing with such step-out, for example, as disclosed in Japanese Utility Model Laid-Open No. 62-15007, until the stopper of the rotor abuts the fixed stopper when the ignition switch is closed. 2. Description of the Related Art Conventionally, there has been known a control device configured to perform an initial setting (also referred to as a return-to-origin) to match a command step for a step motor and an actual step by rotating a rotor.

According to such a step motor controller,
Since the step motor is initialized before the vehicle actually starts traveling, the possibility of step-out is reduced and the damping force of the shock absorber is reduced compared to the case where the step motor is not initialized at all. It is possible to accurately control the desired damping force.

[0005]

However, in the step motor controller as described above, the voltage of the power supply for supplying the drive current to the step motor is temporarily changed by closing the ignition switch and driving the cell motor. However, if it is lowered, the rotor of the step motor cannot rotate by the angle necessary for the initial setting, and therefore the initial setting may not be surely performed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems in the conventional step motor control device, and an object of the present invention is to provide an improved step motor control device capable of reliably initializing the step motor. .

[0007]

According to the present invention, as shown in FIG. 1 (a), the above-mentioned objects are as follows: (1) A damping force control valve is driven by a step motor M0; A stepping motor control device for a variable shock absorber, which comprises first initializing means M1 for initializing the stepping motor in response to closing of an ignition switch, and a power supply for supplying current to the stepping motor. Stepping motor control device having voltage detecting means M2 for detecting a voltage and second initializing means M3 for initializing the stepping motor in response to a return from a state in which the power supply voltage has dropped to a normal state ,
Alternatively, as shown in FIG. 1 (b), (2) the damping force control valve is a stepping motor control device of a damping force variable shock absorber driven by a stepping motor M0,
This is accomplished by a step motor controller having initial setting means M4 for initializing the step motor in response to opening of the ignition switch.

[0008]

According to the above configuration (1), the stepping motor control device responds to the closing of the ignition switch by initializing means M1 for initializing the stepping motor, and the power supply voltage drops. And a second initial setting means M3 for initializing the step motor in response to a return from the above state to the normal state. Therefore, in response to the closing of the ignition switch, the step motor is first initialized by the first initializing means M1. During the initialization by the first initializing means M1, the starter motor is driven. Even when the power supply voltage drops, when the power supply voltage returns to the normal state, that is, the vehicle is still stopped or the vehicle speed is substantially 0, and the input load to the step motor is very small. In the step, the step motor is initialized by the second initial setting means M3, so that the step motor is surely initialized.

Further, according to the above configuration (2), the step motor control device has the initial setting means M4 for initializing the step motor in response to the opening of the ignition switch. Therefore, when the ignition switch is opened, that is, when the rotation of the engine is stopped and the power supply voltage does not drop due to driving of the starter motor, the stepping motor is initialized by the initializing means M4. Initial settings are surely performed.

[0010]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 2 is a longitudinal sectional view showing an example of a step motor built in the piston rod of the shock absorber and controlled by the control device of the present invention, and FIG. 3 is an enlarged plan view showing the stopper member shown in FIG. FIG. 4 is an enlarged bottom view showing the rotor core shown in FIG.

In FIG. 2, reference numeral 10 indicates a piston rod of the shock absorber. A rod end member 12 is fixed to the lower end of the piston rod 10 by screwing. The rod end member 12 is not shown in the figure.
A piston body having a damping force generation valve is fixed to the. The piston rod 10 has a step motor housing hole 16 extending along the axis 14 of the piston rod 10, and a step motor 18 is arranged in the housing hole. The step motor 18 includes a stator assembly 20 and a rotor 22 that fits on the stator assembly and rotates about the axis 14.

The stator assembly 20 includes an annular stopper member 24, a cylindrical body 26 fixed to the stopper member 24 at one end (lower end) and extending along the axis 14, and two pairs around the cylindrical body 26. A resin bobbin 36, which cooperates with the plurality of stator magnetic pole members 28 to 34 arranged to face each other, and the cylindrical body 26 to integrally hold each pair of the stator magnetic pole members 28 and 30, 32 and 34. 38, and a coil 4 formed by winding a conductive wire around these bobbins
0 and 42 and the lowermost stator pole member 34 in the drawing
And an annular spacer 44 interposed between the stopper member 24 and the flange portion 24 of the stopper member 24.

In the illustrated embodiment, the stopper member 24
Is fixed to the cylindrical portion at the upper end of the rod end member 12 by fitting, and one end of the cylindrical body 26 is fitted to the cylindrical portion at the upper end of the stopper member 24 and fixed to the stopper member by welding. Although not shown in detail in FIG. 1, each stator pole member includes a flange-shaped portion extending annularly around the axis perpendicular to the axis 14 and an axially extending portion extending from the flange-shaped portion with respect to each other. It comprises a plurality of circumferentially spaced stator pole teeth.

As shown in FIG. 2, the rotor 22 includes a rotor core 46, which is rotatably supported about the axis 14 by bearings 48 and 50 spaced from each other along the axis 14. . The bearing 48 is carried by the stopper 24, and the bearing 50 is fixed to the upper end of the cylindrical body 26 by welding.
It is carried by. On the outer peripheral surface of the rotor core 46, a plurality of permanent magnets 54 and 56, which are aligned with the stator magnetic pole members 28, 30, 32 and 34, are circumferentially spaced from each other and are arranged in two rows, are fixed. The radial outer peripheral surface of each permanent magnet is slightly spaced inward in the radial direction from the inner peripheral surface of the cylindrical body 26, so that when the rotor 22 is energized with current, the rotor 22 will be described later. Axis 1
4 is rotated about a predetermined angle and positioned.

As shown in FIGS. 2 and 3, the stopper member 24 has a plate-like fixed stopper 24a having a substantially flat cross-section that projects radially inward and extends along the axis 14. There is. Similarly, as shown in FIGS. 2 and 4,
The rotor core 46 has a plate-like stopper 46a which projects downward from the lower end and extends in the radial direction with respect to the axis 14 and which has a substantially fan-shaped cross section. These stoppers cooperate with each other to define an initial position of the rotor 22 about the axis 14 of the rotor 22 relative to the stator assembly 20 and to prevent the rotor 22 from rotating above a predetermined maximum rotation angle, as will be described in detail below. It is designed to prevent it.

As shown in FIG. 2, the rotor core 46
A ball screw device 58 is arranged inside. The ball screw device 58 has a ball screw shaft 62 extending along the axis 14 and having a spiral groove for receiving a plurality of balls 60 on the outer peripheral surface, and an outer peripheral surface fixed to the inner peripheral surface of the rotor core 46 and formed on the inner peripheral surface. And an outer race member 64 having a spiral groove for receiving the plurality of balls 60. Shaft 62
Has an integrally formed projection 62a having a rectangular cross section at its upper end, and the projection is reciprocally fitted along a shaft line 14 into a hole 66 having a rectangular cross section provided in the central projection 52a of the guide member 52, As a result, when the rotor core 46 rotates, the shaft 62 does not rotate in accordance with the rotation direction of the rotor core 46, and
It is designed to move upward or downward along the drawing.

The shaft 62 integrally has a small diameter portion 62b extending downward from the lower end along the axis 14 and is not shown in the drawing provided on the piston and the rod end member 12 at the small diameter portion. A valve element 68 of a damping force control valve for controlling the effective passage area of the bypass passage is connected.
Thus, when the rotor 22 rotates about the axis 14, its rotational movement is converted by the ball screw device 58 into a reciprocating movement of the shaft 62 along the axis 14, which drives the valve element 68 to increase or decrease the damping force. It has become.

The damping force generating valve and the damping force control valve provided on the piston do not form the subject of the present invention.
Although detailed description thereof will be omitted, if necessary, for example, Japanese Patent Application No. 3-24 filed by the same applicant as the applicant of the present application
Please refer to the description and drawings of Japanese Patent Application No. 8276 or Japanese Patent Application No. 3-253066.

As shown schematically in FIG. 5, the step of bringing the stopper 46a of the rotor core 46 into contact with one side surface of the stopper 24a of the stopper member 24 is step 0.
And a virtual step in which the stopper 46a contacts the other side surface of the fixed stopper 24a is step 17,
The step motor 18 of the illustrated embodiment stops at any of steps 0 to 17 when the coils 40 and 42 are not energized, and is positioned at any of steps 1 to 16 during normal operation of the shock absorber. The damping force gradually increases as the number of steps increases.

Although not shown in FIG. 2, the coils 40 and 42 of the step motor 18 are composed of coils A and A'and coils B and B ', respectively, and any one coil of the step motor is energized. Depending on whether the coil is positioned and stopped at the step shown in Table 1 below (stop position due to one-phase excitation) and which coil is energized, the step shown in Table 2 below. It is adapted to be rotated (positioned by two-phase excitation) and positioned. Note that steps 17.5 and 18 are virtual steps used only when initializing the step motor.

[0022]

[Table 1]

[Table 2] Steps A and B ′ of excited coil step motor 0.5 0.5 4.5 8.5 12.5 16.5 A and B 1.5 5.5 9.5 13.5 17.5 A 'And B 2.5 6.5 10.5 14.5 A'and B'3.5 7.5 11.5 15.5

The step motor constructed as described above is
In the illustrated embodiment, a vehicle speed sensor 7 for detecting the vehicle speed V.
0, the steering angle sensor 72 for detecting the steering angle θ, the acceleration sensor 74 for detecting the vertical acceleration G of the vehicle body, and the damping force serving as the base of the shock absorber to the low damping force (normal mode) or the medium damping force (sport mode). Based on the signals from the mode selection switch (SW) 76 to be set and the voltage detector 78 for detecting the voltage Ve of the power supply for supplying the current to the step motor, FIG. Each wheel is controlled simultaneously by the electronic control unit 82 shown, as will be described later.

The electronic control unit 82 has a microcomputer 84 as shown in FIG. The microcomputer 84 may be of a general configuration as shown in FIG. 6, and the central processing unit (CPU) 8
6, a read only memory (ROM) 88, a random access memory (RAM) 90, and an input port device 92
And an output port device 94, which are connected to each other by a bidirectional common bus 96.

The input port device 92 has a signal indicating the vehicle speed V detected by the vehicle speed sensor 70, a signal indicating the steering angle θ detected by the steering angle sensor 72, and an acceleration sensor 74.
The signal indicating the vertical acceleration G of the vehicle body detected by the signal, the signal indicating the mode M set by the mode selection switch 76, and the signal indicating the power supply voltage Ve detected by the voltage detector 78 are input. .

The input port device 92 appropriately processes the signal input thereto, and in accordance with the instruction of the CPU 86 based on the program stored in the ROM 88, the CPU and the RAM.
The processed signal is output to 90. R
The OM 88 stores the control programs shown in FIGS. 7 to 12 and maps corresponding to the graphs shown in FIGS. 13 to 15. The CPU 86 is adapted to perform various calculations and signal processing based on the control programs shown in FIGS. The output port device 94 is C
According to an instruction from the PU 86, although only one set is shown in FIG. 6, a control signal is output to the coil of the step motor 18 of each shock absorber through the drive circuit 98.

Next, the main routine of the step motor control in the illustrated embodiment will be described with reference to the flow chart shown in FIG. The routine shown in FIG. 7 is started by closing an ignition switch (not shown). Further, in the flowchart shown in FIG. 7, the flag Fv relates to whether or not the power supply voltage Ve detected by the voltage detector 78 is below a predetermined value, and 1 indicates that the power supply voltage Ve is below a predetermined value. The flag Fi indicates whether or not the step motor is being initialized, and the flag 1 indicates that the step motor is being initialized.

First, in step 100, the flag Fv is reset to 0, and in step 110, the current step Sn of the step motor is set to 18,
In step 120, the target step Sa is set to 0, in step 130 the flag Fi is set to 1, and in step 140 the routine jumps to the motor drive routine shown in FIG.

At step 150, the current step S
When it is determined whether or not n is 0, and when it is determined that Sn = 0 is not established, step 150 is repeatedly executed, and when it is determined that Sn = 0 is performed, step 160 is performed. If it is determined whether the flag Fv is 1 or not, and if it is determined that Fv = 1, then the process proceeds to step 180, and if it is determined that Fv = 0, then step 170 is performed. At that time, the count value T of the timer is reset to zero.

In step 180, it is judged whether or not the flag Fv is 0, and when it is judged that Fv = 1, step 180 is repeatedly executed and F
When it is determined that v = 0, step 10 is performed.
Return to 0.

In step 190, it is judged whether or not the flag Fi is 1, and when it is judged that Fi = 1, step 190 is repeatedly executed and F
If it is determined that i = 0, step 20
At 0, the maximum value Ssmax of the number of steps added for anti-roll and anti-bouncing is calculated, and at step 210, the instantaneous target step Sai of the step motor is the base step Sb and step 20 depending on the vehicle speed.
It is set to the sum of the maximum value Ssmax of the number of addition steps calculated at 0, and then the process returns to step 190.

In this case, the flag Fv is set to 1 when the power supply voltage Ve detected by the voltage detector 78 becomes equal to or lower than the first reference value Vel by executing the routine shown in FIG. 12 and the power supply voltage returns to the second reference value Veh or higher,
The routine shown in (b) is reset to 0 by being executed by an interrupt.

Number of addition steps Ss for anti-roll
r, the number of addition steps Ssb for anti-bouncing, and the base step Sb are calculated according to the routines shown in FIGS. Note that the routines shown in FIGS. 8 to 10 are executed by interrupts, for example, every 2 ms, 4 ms, and 8 ms.

As shown in FIG. 8, in the calculation routine of the anti-roll addition step number Ssr, step 3
At 00, the vehicle speed V and the steering angle θ are read, and at step 310, the addition step number Ssr for anti-roll is calculated from the map corresponding to the graph shown in FIG. 13 based on these values. To be done.

Similarly, in the calculation routine for the anti-bouncing addition step number Ssb shown in FIG. 9, the vehicle speed V and the vertical acceleration G of the vehicle body are read in step 400, and in step 410. Figure 1 based on these values
The addition step number Ssb for anti-bouncing is calculated from the map corresponding to the graph shown in FIG.

In the calculation routine of the vehicle speed sensitive base step Sb shown in FIG. 10, the vehicle speed V and the mode M set by the mode selection switch 76 are read in step 500, and in step 510. Based on these values, the vehicle speed sensitive base step Sb is calculated from the map corresponding to the graph shown in FIG.

In step 520, the vehicle speed V is, for example, 6
It is determined whether or not the vehicle speed is not more than the minimum value Vo that can be detected by the vehicle speed sensor such as km / h, that is, whether or not the vehicle is substantially stopped, and it is determined that V≤Vo is not satisfied. Is performed, the count value T of the timer is reset to 0 in step 530, and when it is determined that V≤Vo, the count value T of the timer is incremented by 1 in step 540.

In step 550, it is determined whether the count value T of the timer is equal to or greater than the reference value Te (a positive constant), that is, 30 seconds after the vehicle is substantially stopped. It is determined whether time has passed,
When it is determined that T ≧ Te, step 5
At step 60, the current step Sn is set to 18, at step 570 the target step Sa is set to 0, at step 580 the flag Fi is set to 1, and at step 610 shown in FIG. The process jumps to the executed motor driving routine, and then returns to step 500.

When it is determined in step 550 that T.gtoreq.Te is not satisfied, it is determined in step 590 whether the target step Sa is the same as the instantaneous target step Sai, and Sa = Sai. If it is determined that the target value Sa is not Sa = Sai, the target step Sa is set to the instantaneous target step Sai in step 600, and then the process proceeds to step 610. move on.

Next, the motor drive routine in the illustrated embodiment will be described with reference to the flow chart shown in FIG. The routine shown in FIG. 11 is, for example, 2.
It is executed by interruption every 5 ms.

First, in step 700, it is judged whether or not the current step Sn of the step motor is the same as the target step Sa, and if it is judged that Sn = Sa is not satisfied, step 710. At this time, it is judged whether or not the current step Sn is larger than the target step Sa. When it is determined in step 710 that Sn> Sa is not satisfied, it is determined in step 720 whether the current step Sn is an integer, and S
If it is determined that n is an integer, step 7
Go to 50.

At step 720, the current step Sn
If it is determined that is not an integer, step 7
In step 30, it is determined whether Sn is the target step Sa -0.5, and when it is determined that Sn = Sa -0.5 is not satisfied, the current step Sn is determined in step 740. Is set to Sn +1 and Sn = Sa -0.5
If it is determined that the current step Sn is set, the current step Sn is set to Sn +0.5 in step 750.

When it is judged in step 710 that Sn> Sa, it is judged in step 760 whether or not the current step Sn is an integer, and Sn.
When it is determined that is an integer, step 78
Go to 0. If it is determined in step 760 that the current step Sn is not an integer, step 77.
At 0, it is determined whether or not Sn is the target step Sa +0.5, and when it is determined that Sn = Sa +0.5 is not established, the current step Sn is Sn at step 790. -1 is set, and when it is determined that Sn = Sa +0.5, the current step Sn is set to Sn -0.5 in step 780.

In step 800, step 740,
Based on the current step Sn calculated in 750, 780 or 790, the coil 40 or 42 of the step motor is excited in the excitation pattern shown in Table 1 or Table 2 above. In step 810, it is judged whether or not the flag Fi is 1, and when it is judged that Fi = 1, it takes 20 ms to return to step 700 in step 850. It is set to Tinit every time, and then the process returns to step 700.

When it is determined in step 810 that Fi = 1 is not satisfied, it is determined in step 820 whether the current step Sn is the same as the target step Sa and Sn = Sa. If it is determined that it is not, the time until returning to step 700 in step 830 is set to Trun such as 6 ms, and Sn
When it is determined that = Sa, step 84
For example, the time required to return to step 700 at 0 is 15
Set to Thold such as ms.

When it is judged in step 700 that Sn = Sa, in step 860 the energization of each coil of the step motor is stopped, and step 87
At 0, the flag Fi is reset to 0, after which the process returns to step 700.

Thus, according to the first embodiment, when an ignition switch (not shown) is closed,
In step 100, the flag Fv is reset to 0,
In step 110, the current step Sn is set to 18, in step 120 the target step Sa is set to 0, in step 130 the flag Fi is set to 1, and then in step 140 By executing the motor drive routine shown in FIG. 11, the step motor is initialized when the ignition switch is closed.

That is, the current step Sn regardless of whether the actual current step of the step motor is 0-17.
Is regarded as 18 and the target step Sa is set to 0, and steps 710, 760 to 810, 850 are repeatedly executed until a positive determination is made in step 700 of FIG. 11, and the actual current step and the current step When the step Sn is set to 0, the step motor is initialized.

If the power supply voltage Ve does not drop below the first reference value Vel during the initial setting process when the ignition switch is closed as described above, step 1
In step 60, a determination of no is made, and in step 170, the count value T of the timer is reset to 0, and then the routine proceeds to normal damping motor control by step motor control in steps 190-210.

On the other hand, as shown in FIG. 16, in the initial setting process when the ignition switch is closed, for example, a starter switch (not shown) is closed, so that the power source voltage Ve becomes higher. When the value falls below the reference value Vel of 1, the flag F is set in step 800 of FIG.
After v is set to 1 and YES is determined in step 160, and it is determined in step 180 that the flag Fv has become 0, that is, the power supply voltage Ve is the second reference value. FIG. 12B in response to the fact that Veh is exceeded.
After the flag Fv is reset to 0 in step 850, the steps 100 and subsequent steps are executed again, whereby the step motor is initialized again.

FIG. 17 is a block diagram showing an electronic control unit as a second embodiment of the step motor control unit according to the present invention. 17, the members corresponding to the members shown in FIG. 6 are denoted by the same reference numerals as those assigned in FIG.

In this embodiment, one end of a sub-line 106 is connected to a portion between the ignition switch 104 and the battery 100 of the main line 102 for supplying a current from the battery 100 as a power source to another electronic control unit. ing. A relay switch 108 is provided in the middle of the sub line 106, and the other end of the sub line is a CPU.
86 and the drive circuit 98. The coil of the relay switch 108 is connected to the collector of the transistor 110, and the emitter of the transistor is grounded.

Also, in this embodiment, the voltage detector 78
Is also input to the positive terminal of the comparator 112, and the negative terminal of the comparator 112 is connected to the constant voltage power source of the voltage Veo as the third reference value of the power source voltage. Voltage detector 78
The high signal is output to the OR circuit 114 when the power supply voltage Ve detected by the above is higher than the third reference value Veo. The signal of the initialization flag Fi from the output port device 94 is input to the other input terminal of the OR circuit 114, and the output terminal of the OR circuit is connected to the base of the transistor 110.

Therefore, in this embodiment, when the ignition switch 104 is closed and the power supply voltage detected by the voltage detector 78 is equal to or higher than the third reference value Veo, or even when the ignition switch 104 is opened, the output is generated. When the flag Fi signal input from the port device 94 to the OR circuit 114 is 1, current is supplied to the microcomputer 84 and the drive circuit 98.

Further, in the electronic control unit 82 of this embodiment, the ROM 88 of the microcomputer 84 is shown in FIGS.
1, the control program shown in FIGS. 18 and 19 and FIG.
The electronic control unit has the same structure as the electronic control unit according to the first embodiment except that the maps corresponding to the graphs shown in FIGS.

Next, the control of the step motor in the second embodiment will be described with reference to the flow charts shown in FIGS. 18 and 19. In FIG. 18, steps corresponding to the steps shown in FIG. 7 are given the same step numbers as the step numbers given in FIG. 7.

As shown in FIG. 18, the main routine for controlling the step motor in this embodiment is executed from step 170, omitting steps 100 to 160 and 180 in the first embodiment. .

Further, as shown in FIG. 19, when it is detected that the power supply voltage Ve detected by the voltage detector 78 has dropped to the third reference value Veo or less due to the opening of the ignition switch 104, step 910. 11 the current step Sn of the step motor is set to 18, the target step Sa is set to 0 in step 920, the flag Fi is set to 1 in step 930, and in step 940 in FIG. Jump to the motor drive routine shown in.

Thus, according to the second embodiment, when the ignition switch 104 is opened and the power supply voltage Ve drops below the third reference value Veo, the current step Sn is set to 18 in step 910. Step 9
At step 20, the target step Sa is set to 0, and at step 930, the flag Fi is set to 1, so that the state in which the current is supplied to the microcomputer 84 and the drive circuit 98 is maintained, and then step 940. Then, the motor drive routine shown in FIG. 11 is executed to initialize the step motor after the ignition switch is opened. When the initial setting of the step motor is completed, a yes determination is made in step 700 of FIG. 11, and the flag Fi is reset to 0 in step 870, whereby the microcomputer 8
4 and the supply of current to the drive circuit 98 are stopped.

From the above description, it will be understood that according to the above-mentioned two embodiments, the initialization of the step motor is surely performed when the ignition switch is closed or after it is opened.

Further, according to the above-mentioned two embodiments, FIG.
In steps 830 to 850, the time interval at which the step motor is rotationally driven is variably set so as to be short when the damping force of the shock absorber is controlled, long when the step motor is initially set, and relatively long when the step motor is stopped. Therefore, the damping force of the shock absorber can be controlled with good responsiveness, and it is possible to improve the durability of the step motor by avoiding the rotor stopper hitting the fixed stopper hard at the time of initial setting of the step motor. Further, the step motor can be surely indexed to the target step and stopped.

Further, according to the above-mentioned two embodiments, when the state where the vehicle speed V is the predetermined value Vo or less like the signal waiting state of the vehicle continues for 30 seconds or more, for example, step 55 of FIG.
A determination of yes is made at 0, and steps 560 to 58 are performed.
By executing 0 and step 610, the step motor is initialized regardless of whether or not the parking brake is in the on state. Therefore, after the ignition switch is closed, the vehicle speed V is equal to or lower than the predetermined value Vo. And the initialization of the step motor can be performed more frequently than the case where the initialization is performed only when the parking brake is in the ON state. It is possible to reduce the risk that the damping force of the shock absorber is controlled incorrectly.

Although the present invention has been described in detail above with reference to specific embodiments, the present invention is not limited to these embodiments, and various other embodiments within the scope of the present invention. It will be apparent to those skilled in the art that

[0064]

As is apparent from the above description, according to the above configuration (1), when the ignition switch is closed, the step motor is first initialized by the first initial setting means M1 in response to the closing of the ignition switch. Even when the power supply voltage is lowered by the driving of the starter motor or the like during the initial setting by the first initial setting means M1, when the power supply voltage is returned to the normal state, that is, the vehicle is When the vehicle is still stopped or the vehicle speed is substantially zero and the input load on the step motor is very small, the step motor is initialized again by the second initialization means M3. Further, according to the above configuration (2), when the ignition switch is opened, that is, when the rotation of the engine is stopped and the power supply voltage does not decrease due to the driving of the cell motor, the step motor is initialized. Initialized by M4. Therefore, according to the present invention,
It is possible to reliably perform the initial setting of the step motor.

[Brief description of drawings]

1 (a) and 1 (b) respectively show the configuration of a step motor control device according to the present invention.
FIG. 6 is an explanatory diagram corresponding to the description of claim 2;

FIG. 2 is a vertical cross-sectional view showing an example of a step motor built in a piston rod of a shock absorber and controlled by a control device of the present invention.

FIG. 3 is an enlarged plan view showing a stopper member shown in FIG.

FIG. 4 is an enlarged bottom view showing the rotor core shown in FIG.

FIG. 5 is a solution diagram showing a relationship between a position of a stopper of a step motor and a step (rotational position).

FIG. 6 is a block diagram showing an electronic control device as a first embodiment of a step motor control device according to the present invention.

7 is a flowchart showing a main routine of step motor control achieved by the electronic control device shown in FIG.

FIG. 8 is a flowchart showing an addition step number calculation routine for anti-roll.

FIG. 9 is a flowchart showing an addition step number calculation routine for anti-bouncing.

FIG. 10 is a flowchart showing a base step number calculation routine according to a vehicle speed.

FIG. 11 is a flowchart showing a step motor drive routine.

FIG. 12 is a flowchart showing a routine for setting and resetting a flag Fv.

FIG. 13 is a graph showing the relationship between the vehicle speed V, the absolute value of the steering angle | θ |, and the number of addition steps for anti-roll.

FIG. 14 is a graph showing the relationship between the vehicle speed V, the absolute value of vertical acceleration | G |, and the number of addition steps for anti-bouncing.

FIG. 15 is a graph showing the relationship between vehicle speed V, base step, and setting mode.

FIG. 16 is a time chart showing an example of a case where the initialization is re-executed when the power supply voltage is lowered during the initialization of the step motor when the ignition switch is closed.

FIG. 17 is a block diagram showing an electronic control device as a second embodiment of the step motor control device according to the present invention.

FIG. 18 is a flowchart showing a main routine of step motor control achieved by the electronic control device shown in FIG. 17.

FIG. 19 is a flowchart showing a routine for initial setting of the step motor after the ignition switch is opened.

[Explanation of symbols]

 10 ... Piston rod 18 ... Step motor 20 ... Stator assembly 22 ... Rotor 24a ... Stopper 40, 42 ... Coil 46a ... Stopper 58 ... Ball screw device 68 ... Valve element 82 ... Electronic control device 84 ... Microcomputer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takayuki Tsuchiya 1 Toyota-cho, Toyota-cho, Aichi Prefecture Toyota Motor Corporation (72) Inventor Ichiji Okada 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Corporation (72) ) Inventor Kiyoshi Kono 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation

Claims (2)

[Claims] 1. A stepping motor control device for a damping force type shock absorber in which a damping force control valve is driven by a stepping motor, wherein the stepping motor is initialized in response to closing of an ignition switch. One initial setting means, a voltage detecting means for detecting the voltage of a power supply for supplying a current to the step motor, and an initializing step motor in response to a return from a state where the power source voltage has dropped to a normal state. A stepping motor control device having a second initial setting means for setting. 2. An initial setting for initializing the step motor in response to opening of an ignition switch when the damping force control valve is used as a step motor control device for a damping force variable shock absorber driven by a step motor. A stepper motor controller having means.