JPH0285060A - Power steering device - Google Patents

Abstract

PURPOSE:To permit the power steering in which the assistance characteristic is not deteriorated even in the high revolution range of a motor by detecting the angular speed of the motor for assisting steering and controlling the electric current for driving the motor according to the angular speed and steering torque. CONSTITUTION:A power steering device transmits the power of a motor 8 for auxiliary steering to a rack shaft 1 through an electromagnetic clutch 16, planetary gear reduction gear 9, and bevel gears 31 and 32. At this time, the steering torque applied onto the steering wheel is detected by a torque sensor 6, and the revolution position of the motor 8 is detected by a revolution detector 17, and the output signals of the torque sensor 6 and the revolution detector 17 are inputted into a control part 7, together with the output signal of a car speed detector 18, and the driving signal for driving the motor 8 and the electromagnetic clutch 16 are outputted. In this case, the angular speed of the steering wheel is detected on the basis of the output signal of the revolution detector 17, and the calculation for subtracting the corrected electric current determined according to the angular speed and the steering torque from the electric current for driving the motor 8 is carried out, and the motor 8 is drive-controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electric power steering device (power steering) that assists the force required to operate a steering wheel with the rotational force of an electric motor.

[Prior art]

An electric type that drives a steering assist motor based on the detection result of the steering torque applied to the steering wheels, uses the rotational force of the motor to assist the force required to steer the vehicle, and provides a comfortable steering sensation to the driver. A power steering device has been developed.

This power steering device has a rack shaft that extends in the left-right direction of the vehicle body and has both ends connected to the left and right wheels via separate tie rods, and engages with the rack shaft at a midway point. The rack consists of a pinion that is interlocked with the steering wheel, and converts the rotation of the pinion accompanying rotation of the steering wheel into movement in the length direction of the rack shaft for steering.
Automobiles equipped with pinion-type steering mechanisms are roughly classified into the following two types depending on the location of the steering assist motor. That is, the shaft of the pinion is further extended from the meshing position with the rack shaft, and the motor is disposed so as to transmit rotational force to the extended portion via an appropriate reduction gear;
An auxiliary pinion is provided that meshes with the rack shaft at a position in the longitudinal direction of the shaft that is different from the meshing position of the pinion, and the motor is arranged so as to transmit rotational force to the auxiliary pinion via a suitable speed reduction device. The former is called a 1-pinion type and the latter is called a 2-pinion type, depending on the number of pinions that mesh with the rack shaft.

In this way, in any of the above-mentioned power steering devices, the rotational force of the steering assist motor is transmitted to the extension of the shaft of the pinion or the auxiliary pinion via the reduction gear, so that the steering wheel can be moved straight to the straight position after steering. There is a problem in that when returning to normal position, the inertial force of the motor and the frictional resistance of the speed reducer slow down the return process, resulting in an unnatural steering feel.

To solve this problem, there is an invention disclosed in Japanese Unexamined Patent Publication No. 61-215166. This controls the motor using an acceleration/deceleration function according to the rotational speed of the motor.
The motor applies a restoring force to the steering wheel according to a restoring force function depending on the magnitude of the steering angle.

[Problems to be Solved by the Invention] However, in the above invention, acceleration/deceleration control and restoration control of the motor are performed based on the rotational speed and steering angle of the motor, and in particular, the high rotational speed range of the motor and the reverse braking torque are large. Therefore, there is a problem in that the assist force, which is the original purpose of power steering, decreases when high rotation of the motor is required, such as when turning suddenly, and the assist characteristics are impaired.

This invention was made in view of the above circumstances, and by detecting the angular velocity of the motor and controlling the current that drives the motor according to the angular velocity and steering torque, it is possible to prevent the assist characteristics from being impaired even in the high rotation range of the motor. The purpose of the present invention is to provide a power steering device that does not cause problems.

[Means to solve the problem]

The power steering device according to the present invention includes a steering mechanism that converts the rotation of a steering wheel into a left-right movement for steering, a steering angle detection means that detects a rotation angle of the steering wheel, and a In the power steering device, the power steering device includes a torque sensor that detects a steering torque that is detected, and a steering assist motor that is driven by a current that corresponds to the detected steering torque, in which the angular velocity of the steered wheel is detected based on the rotation angle. The present invention is characterized by comprising: an angular velocity detecting means for detecting the angular velocity; and a subtracting means for subtracting a correction current determined according to the angular velocity and the steering torque from the current for driving the motor.

[Effect]

In this invention, a subtraction means is provided to subtract a correction current determined according to the angular velocity and steering torque of the steering wheel from the current that drives the motor, and when the angular velocity of the steering wheel is large, such as during steering due to rotation, the steering torque is also large. When the steering wheel is turned back, the correction current is set small (and when the angular velocity is large and the steering torque is small, such as when the steering wheel returns), by increasing the correction current, it is possible to improve the following of the rotation of the motor to the steering wheel when steering with a sharp turn. This prevents the steering wheel from returning too far when returning.

[Examples] The present invention will be described below in detail based on drawings showing examples thereof. FIG. 1 is a partially cutaway front view of a power steering device according to the present invention, FIG. 2 is an enlarged sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is a rotation detector according to the second invention. l in Figure 1 showing the structure
It is an enlarged sectional view taken along the line -111.

In the figure, 1 is a rack shaft, and a rack shaft case 2 is fixed to a part of the vehicle body and has a cylindrical shape, with the longitudinal direction being the left and right direction.
is interpolated concentrically with this. Reference numeral 3 denotes a pinion shaft, which is supported inside a pinion shaft case 4 connected to one end of the rack shaft case 2 with its axis obliquely intersecting the rack shaft 1 .

As shown in FIG. 2, the pinion shaft 3 consists of an upper shaft 3a and a lower shaft 3b coaxially connected via a torsion bar 5. The upper end thereof is operatively connected to the steering wheel via a universal joint (not shown). The lower shaft 3b is supported within the re-pinion shaft case 4 at a position near its upper end by a four-point contact ball bearing 41, with its lower portion protruding an appropriate length from the lower opening of the re-pinion shaft case 4. . The four-point contact ball bearing 41 is fitted onto the lower shaft 3b from the lower end side, and is fixed by being caulked to the outer peripheral surface of the stepped portion formed near the upper end of the lower shaft 3b. After being positioned on the outside of the lower shaft 3b in the axial length direction with both sides of the inner ring held between the inner ring 42 and the lower shaft 3b, it is fitted into the binion shaft case 4 from the lower opening along with the lower shaft 3b. an annular shoulder formed at the bottom of the case 4;
A lock nut 4 is screwed into the case 4 from the opening.
3, the outer ring is held between both sides and positioned inside the binion shaft case 4 in the axial length direction, and applies a radial load and a bidirectional thrust load acting on the lower shaft 3b.

A pinion tooth 30 having an appropriate length in the axial direction is formed in the middle part of the lower shaft 3b protruding from the pinion shaft case 4. When fixed to the upper side of the rank shaft case 2 with fixing bolts 44, a rack is formed within the rack shaft case 2 at a position near one end of the rack shaft 1 over an appropriate length in the axial direction. meshes with tooth 10,
The lower shaft 3b and the rack shaft 1 are engaged with each other with their axes obliquely crossing each other. The lower shaft 3b is the rack shaft 1
A large bevel gear 31 is fitted to the lower end of the large bevel gear 31, coaxially with the large bevel gear 31 with its tooth forming surface facing downward, and surrounding the large bevel gear 31. It is supported by a needle roller bearing 33 in a bevel gear housing 20 that is connected to the lower side of the rack shaft case 2 in this manner. Therefore, the lower shaft 3b is connected to the four-point contact ball bearing 41.
The lower shaft 3b is supported by the needle roller bearings 33 on both sides of the meshing position between the rack teeth 10 and the pinion teeth 30, and the amount of deflection that occurs in the lower shaft 3b at the meshing position is maintained within a predetermined tolerance range. .

Furthermore, at the meshing position between the rack teeth 10 and the pinion teeth 30,
A pusher 12 is provided that presses the rack shaft 1 by the biasing force of a push spring 11 toward the pinion shaft 3 so that these are meshed without any gaps. It is supported by the shaft 3b in a state where it is sandwiched from both sides in the radial direction, and is also supported by a bearing bushing 13 fitted inside the end of the rack shaft case 2 on the opposite side to the position where it is connected to the binion shaft case 4. It is movable in the axial direction inside the rack shaft case 2. Both left and right ends of the rack shaft 1 protruding from both sides of the rack shaft case 2 are connected to tie rods 1 which are connected to left and right wheels (not shown) through separate ball joints 14.
5.15, and the wheels are steered to the left or right by moving the rack shaft 1 in the axial direction.

Reference numeral 6 in FIG. 2 is a torque sensor that detects the steering torque applied to the steering wheel, and is fitted onto the upper shaft 3a and rotates together with it, and has a lower end face centered on the axis of the upper shaft 3a. a resistor holding member 60 formed of an annular resistor;
A potentiometer is constituted by a detector holding member 61 that is fitted onto the lower shaft 3b and rotates together with the lower shaft 3b, and has a detector on its upper end surface that slides into contact with one point in the radial direction on the resistor. That's what happens. Upper shaft 3a of pinion shaft 3
rotates about its axis in response to the rotation of the steering wheel, but road resistance acting on the wheels acts on the lower shaft 3b via the rack shaft 1, and a torsion bar interposed between the two wheels acts on the lower shaft 3b. -5, a twist occurs in accordance with the steering torque applied to the steering wheel. The torque sensor 6 outputs the relative displacement in the circumferential direction that occurs between the upper shaft 3a and the lower shaft 3b due to the torsion of the torsion bar 5 as a potential corresponding to the position of sliding contact between the detector and the resistor. The initial '#JI adjustment is made so that a predetermined reference potential is output when the torsion bar 5 is not twisted, in other words, when the steering wheel is not operated.

The output signal of the torque sensor 6 is input to a control unit 7, and the control unit 7 compares this signal with the reference potential to recognize the direction and magnitude of the steering torque, and is arranged as described below. A drive signal is issued to the motor 8 for steering assistance.

The steering assist motor 8 transmits its rotational force to the lower shaft 3b via an electromagnetic clutch 16, a planetary gear reduction device 9, and a small bevel gear 32 having a smaller diameter than the large bevel gear 31 and meshing with the large bevel gear 31. It is.

The electromagnetic clutch 16 has an annular shape, and is fitted onto one side of the rotating shaft 80 of the motor 8 coaxially with a coil portion 161 fixed to the intermediate case 81 of the motor 8, and rotates together with the rotating shaft 80. and a disc-shaped engagement/disengagement part 163 that faces the main drive part 162 and engages with the main drive part 162 by electromagnetic force caused by energizing the coil part 161. Engages and disengages rotational force.

The planetary gear reduction device 9 is fitted into the engaging/disengaging part 163, rotates, and has a sun gear, one end of which is supported by a bearing fitted into the main moving part, and the other end fitted into a planetary carrier 93, which will be described later. a sun shaft 90 supported on a bearing, and the motor 8
an annular outer ring 91 coaxially fixed to the casing end face 82 of the rotating shaft 80; A plurality of planetary gears 92,92... that rotate around the axis of the sun gear and revolve around the axis of the sun gear, and a planetary carrier 9 that pivotally supports each of these planetary gears 92,92...
The motor 8 and the electromagnetic clutch 1 are arranged on one side of the rotating shaft 80, and have a smaller outer diameter than the motor 8.
It is integrated with 6. Output shaft 9 of planetary gear reduction device 9
Numeral 4 is fitted and fixed at the axial center position of the planetary carrier 93 located coaxially with the rotating shaft 80 of the motor 8, and protrudes to the outside of the casing by an appropriate length. The small bevel gear 32 is fitted onto the tip end of the output shaft 94 with its tooth forming surface facing toward the tip side, and the small bevel gear 32, together with the output shaft 94, is fitted with the planetary rollers 92, 92, It is designed to rotate according to the revolution of...

The motor 8, the electromagnetic flange 16, and the planetary roller speed reducer 9 are installed inside the bevel gear housing 20 with the small bevel gear 32 inside, with their axes substantially parallel to the axis of the rank shaft 1. Inside the housing 20, the small bevel gear 32 is meshed with the large umbrella i mold 31 fitted on the lower end of the lower shaft 3b, and a placket provided on the outside of the rack shaft case 2. ) 2a. Backlash adjustment between the large bevel gear 31 and the small bevel gear 32 is performed at the butt portion between the casing of the planetary roller reduction device 9 and the bevel gear housing 20 when the planetary roller reduction device 9 is fitted into the bevel gear housing 20. This can be easily achieved by changing the thickness and/or number of shims interposed in the shims.

Further, a rotation detector I7 for detecting the rotational position of the motor 8 is provided on the other side of the rotation shaft 80 of the motor 8. A magnet plate 170 having a shape with two N poles and two S poles, and a predetermined mounting angle β (β=135 in this embodiment) around the magnetic plate 170.
) Two reed switches 171 installed without
, 171. FIG. 4 is a waveform diagram showing the output waveform of the rotation detector.

The two reed switches 171171 have a mounting angle β of 13
Since they are mounted diagonally at 5 degrees, the output waveforms are output with a 90 degree phase shift. Since four waveforms are output in one rotation, the rotation detector 17 has a resolution of 1716 per rotation by detecting the rise and fall of the waveforms.

This rotation detector 17 can detect the rotation speed from 0 and can detect the relative position of the rotor, compared to conventional rotation detectors such as tacho generators.

In addition, it is smaller than a photo ink ladle type rotary encoder, is resistant to high temperatures, and is less likely to change over time, making it cheaper. Furthermore, since the output waveform is a pulse output, the detection results can be easily input into a CPU such as a microcomputer.

In addition to the output signal of the torque sensor 6 described above, the control unit 7 is also manually supplied with an output signal of a rotation detector 17 and an output signal of a vehicle speed detector 18 for detecting vehicle speed. 8 and the electromagnetic clutch 16 are output.

Next, control by the control section 7 will be explained.

FIG. 5 is a block diagram showing the configuration and control operation of the control section.

The torque detection signal of the torque sensor 6 advances its phase,
A phase compensation circuit 71a for stabilizing the system, an angular acceleration detection circuit 71b for detecting the angular acceleration ω of the rotation of the steering wheel, a midpoint determination circuit 71c for determining the midpoint of the steering mechanism, and a locking of the motor 8. A lock detection circuit 71f detects the rotational angular velocity ω of the steering wheel, an angular velocity detection circuit 71g detects the angular velocity ω of the rotation of the steering wheel, and a torque function generator 71g generates a function corresponding to the absolute value 1.1 of the steering torque 'r.

Further, the vehicle speed detection signal of the vehicle speed detector 18 is transmitted to a lock detection circuit 71f, a midpoint determination circuit 71c, a vehicle speed function generating section 73f that generates a function according to the vehicle speed V, and an angular acceleration detection circuit 7.
The angular acceleration ω of the steering wheel output from 1b is given, and a correction current Ic corrects the inertial force during acceleration/deceleration of the motor 8 and the inertial force around the vehicle's suspension according to the angular acceleration ω and the vehicle speed V.
A steering angle θ output from a steering angle determining circuit 71d (to be described later) and a correction current function unit 73b that determines the steering angle θ is given, and a changing current 1a that changes the characteristics of the instruction current ■ is determined according to the steering angle θ and the vehicle speed. The variable current function section 73c is manually operated.

Further, the rotation detection signal of the rotation detector 17 includes a lock detection circuit 71f, a midpoint determination circuit 71c, and an angular acceleration detection circuit 7.
1b, an angular velocity detection circuit 71g, and a steering angle determining circuit 71d that determines the steering angle θ from the rotation detection signal and the midpoint position of the midpoint determining circuit 71c.

The lock detection circuit 71f detects the rotation of the motor 8 based on the input rotation detection signal, vehicle speed detection signal, and torque detection signal when the torque and vehicle speed are larger than respective predetermined values, thereby detecting the presence or absence of a lock. What is the output signal of the drive circuit? 2b to the electromagnetic clutch 16.

Further, the output ω of the angular velocity detection circuit is given to an angular velocity function section 73d that generates a function according to the angular velocity.

Note that the variable current 1a is applied to the function section 73d, and the offset it is applied by the variable current 1a. Also, a support current function section 73a that generates a support current I to the motor 8.
is supplied with the output signal of the phase compensation circuit 71a and the changing current 1a. Furthermore, the output signal of the vehicle speed function generating section 73f is given to the torque function generating section 73g, which outputs a torque function fd according to the vehicle speed. The output is the subtraction current function section 73e.
A subtraction current 1r is generated based on the input and the output of the angular velocity function generating section 73d.

The output signal of the instruction current function unit 73a is input to a subtracter 74c, where a subtraction current It, which is an output of a subtraction current function unit 73e, which will be described later, is subtracted, and the subtraction result is input to an adder 74a.
given to.

The output signal of the correction current function section 73b is added to the adder 74a, and the addition result is given to the subtracter 74b.

In the subtracter 74b, the feedback signal from the current detection circuit 71e that detects the current consumption of the motor 8 is subtracted from the addition result, and the subtraction result is converted into PWM (Pulse-
Width Modulation: Pulse width modulation) drive circuit? 2a to the motor 8.

Next, the operation will be explained.

FIG. 6 is a flowchart I showing control of lock detection. In step 10, it is determined whether or not the ignition switch (not shown) has turned on. If it has not turned on, in step 11, the vehicle speed detector 18 is turned on. Load the vehicle speed■. It is determined in step 12 whether the vehicle speed ■ is larger than the vehicle speed threshold VSI, and if it is larger, the next step 13 is performed.
The steering torque T from the torque sensor 6 is read. It is determined in step 14 whether or not the steering torque T is larger than the torque threshold value T,1. It is determined whether or not the motor 8 is rotating, and if it is rotating, the return is made, and if it is not rotating, it is determined that the motor 8 is locked, and the electromagnetic clutch is turned off in step 17, and the motor 8 and the sun are connected. The connection with the gear reduction device 9 is disconnected, and the steering mechanism is freed from the motor 8. Then, in step 18, a lock alarm (not shown) is turned on and the process returns.

On the other hand, when it is determined in step 10 that the rising has started, the electromagnetic clutch 16 is turned off in step 19, and in step 2
At 0, the motor 8 is turned on. When the motor 8 is turned on, it is determined in step 21 that a predetermined time has elapsed, and then the rotational position of the motor 8 from the rotation detector 17 is read in step 22, and based on that value, it is determined in step 23 whether or not the motor 8 is rotating. If it is determined and rotating, step 24
The motor 8 is turned off at step 25, and the electromagnetic clutch is turned on at step 25. If it is determined in step 23 that the motor 8 is not rotating, the lock alarm is turned on in step 26 and the process returns.

Next, angular acceleration detection and motor inertia control using it will be explained.

FIG. 7 is a flowchart showing calculation of angular acceleration and control of motor inertia using it.

First, in step 30, the torque T from the torque sensor 6 is read, and then in step 31, the angular acceleration detection circuit 71b
At step 32, the rotational speed ω1 of the motor 8 is read from the rotation detector 17, and at step 32, the angular acceleration of the steering wheel is determined by the following calculation.

T=K (θi-θ.) θ, -θ0; Next, the motor 8 is determined in advance by the correction current function section 73b using the angular acceleration ω given to the steering wheel and the vehicle speed ■ obtained in step 33. A correction current 1c for correcting the influence of the inertia force and the inertia force around the wheel suspension is determined. Next, the correction current 1c obtained in step 34 is added to the adder 74a.
The indicated current I obtained manually by the indicated current function section 73a
is added. As a result, when angular acceleration is detected at the start and end of steering assistance by the motor 8, a correction current 1c corresponding to the inertia force and the inertia force around the suspension is added to the instruction current I, so that the steering The ring will be improved.

Next, the calculation of the midpoint of the steering wheel and the return control of the steering wheel using the calculation will be explained.

Figure 8 shows the return control of the steering wheel, Figure 9 shows the calculation of the midpoint of the steering wheel,
FIG. 10 is a flowchart showing the procedure for determining the left and right positions of the steering wheel. Further, FIG. 11 is a graph showing the characteristics of the relationship between motor current and torque in the indicated current function section,
The vertical axis represents the indicated current (2), and the horizontal axis represents the torque 'r. Further, the broken line shows the characteristics when the vehicle speed is high, and the dashed-dotted line shows the characteristics when the vehicle speed is high.

In FIG. 8, the torque T is first read in step 40, and it is determined in step 41 whether or not the torque T is within the dead zone. If the torque T is within the dead zone, the midpoint calculation, which will be described later, is performed in step 42. Determine whether the routine has finished. If the midpoint calculation has been completed, step 43
At step 44, the rotational position of Maw/Sunset is read from the rotation detector 17, and then at step 44, the steering angle θ is determined by the steering angle determination circuit 71d based on the rotational position and the midpoint. When the steering angle θ is determined, in step 45, a correction current 1a is set based on the steering angle θ and the vehicle speed ■.
is determined by the correction current function section 73c, and the instruction current function section 73
The value and direction of the instruction current I are calculated at step a.

On the other hand, if it is determined in step 40 that there is no dead zone, the process returns, and if the midpoint calculation has not been completed in step 42, the rotational position of the motor 8 is read from the rotation detector in step 46, and in step 47, the left and right The correction current ■δ is calculated based on the minimum steering angle value determined in the determination routine, and the value and direction of the instruction current ■ are calculated.

In the midpoint calculation routine shown in FIG. 9, the vehicle speed ■ is read in step 50, and the vehicle speed ■ is set to the threshold ■3□ in step 51.
Determine whether it is larger than the above, and if it is larger, step 52
The torque setting value TS2 is determined according to the vehicle speed, and then the torque T is read in step 53, and the torque T is smaller than the torque setting value T, □ in step 54.

Determine whether it is the right time or not. If it is small, the number of times it is small is counted in step 55, and the rotational position of the motor 8 at that time is read in step 56. And step 5
In step 7, add the rotational position to the total rotational position up to the previous time and divide the addition result by the number of counts to find the midpoint of the steering angle.
Update the value of the steering angle midpoint. Further, in step 51, when the vehicle speed ■ is smaller than the threshold value ■1, or when the torque T is larger than the torque setting value TsZ, the process returns.

However, this midpoint calculation requires a large amount of calculation time, so until the calculation is completed, return control is performed using the left/right determination routine described below.

In the left/right determination routine shown in FIG. 10, the vehicle speed V is read in step 60, and it is determined in step 61 whether the vehicle speed V is greater than the threshold value Vsl. If it is, the torque T is read in step 62, and the torque T is set in step 63. Integrate,
It is determined whether the direction of the integral value is to the right. If it is to the right, the right value of the minimum steering angle value is updated in step 65, and if it is to the left, the left value of the minimum steering angle value is updated in step 64, and the process returns.

On the other hand, as shown in FIG. 11, in the return control, the correction current 1a is determined from the steering angle θ, and the command current I during the return control of the steered wheels when the torque is within the uncontrolled range is varied in accordance with it and the vehicle speed . For example, when the vehicle speed ■ is high, as shown by the broken line, when the torque T enters the dead zone, the increase rate of the instruction current I is increased, and the motor 8 is controlled to speed up the return to the midpoint. When the torque T enters the dead zone as shown by the one-dot chain line, the motor 8 is controlled so as to reduce the rate of increase in the instruction current I and slow the return to the midpoint.

Next, the angular velocity control of the steering wheel, which is the gist of the present invention, will be explained. FIG. 12 is a flowchart showing the angular velocity control of the steering wheel. First, in step 70, the rotational position of the motor 8 is read from the output of the rotation detector 17. Next step 71
Find the rudder angle from the rotation position, and calculate the offset i according to the rudder angle.
is given to the angular velocity function section 73d. Next, in step 72, the vehicle speed ■ is read, and in step 73, the torque T is read. Next, in step 74, the vehicle speed function generator 73f calculates the vehicle speed function ``V'' based on the vehicle speed ■, and the torque function generator 73g determines the speed control amount fd based on it and the torque T.Next, in step 75, the angular velocity ω is determined by the torque function generator 73g. The detected angular velocity function fω is determined by taking the offset amount into consideration.Next, the subtracted current 1r is calculated using the angular velocity function fω determined in step 76 and the speed control ifd.
is obtained by the subtraction current function unit 73e, and inputted to the subtracter 74c, thereby subtracting the current corresponding to the torque T and the angular velocity ω from the instruction current I.

[Effects of the Invention] As explained above, according to the present invention, a current corresponding to the steering torque and angular velocity is subtracted from the motor instruction current, and when both the steering torque and the angular velocity are large, the amount of subtraction is reduced ( When the steering torque is small and the angular velocity is large, the subtraction amount is increased, so a large assist force is applied when steering due to a sudden rotation of the steering wheel, and a large deceleration force is applied when the steering wheel returns due to a sudden rotation. It sufficiently follows the rotation and has an equivalent effect of preventing the steering wheel from being returned too far when it is returned.

[Brief explanation of the drawing]

Fig. 1 is a partially broken new front view showing one embodiment of the power steering device according to the present invention, Fig. 2 is an enlarged sectional view taken along the line ■-■ of Fig. 1, and Fig. 3 is a second embodiment of the power steering device according to the present invention. FIG. 4 is a waveform diagram showing the output waveform of the rotation detector, and FIG. 5 is a block diagram showing the configuration and operation of the control unit. Figures 6 to 10 are flowcharts explaining each control operation, Figure 11 is a graph showing the characteristics of the relationship between motor current and torque in the indicated current function section, and Figure 12 is a flowchart for angular velocity control. be. 6... Torque sensor 8... Motor ■7... Rotation detector 71g... Angular velocity detection circuit 73d...
Angular velocity function generation section 73e... Subtraction current function section 73
f...Vehicle speed function generating section 73g...Torque function generating section patent Applicant: Koyo Seiko Co., Ltd. Agent Patent attorney: Noboru Kawano Diagram No. 1 Kokuminori Perforation No. 1 Optical procedure amendment (spontaneous) 1 ．． Display of the case 1986 Patent Application No. 212064 2, Name of the invention Power steering device 3, Person making the amendment Relationship to the case Patent applicant location 3-5-8 Minamisenba, Chuo-ku, Osaka Name (
124) Koyo Seiko Co., Ltd. Representative Takahiko Tsuboi 4, Agent Address ■543 Kono Patent Office, 207 Nisshin Building, 1-14-22 Shitennoji, Tennoji-ku, Osaka (Telephone: 06-779-3088) Details of funeral map "Detailed Description of the Invention" in the "Detailed Description of the Invention" and "Drawing 6, Contents of Amendment 6-1" column (1) "Detailed Description of the Invention" in the Specification (1) Lines 11 to 12 on page 2 of the Specification. 6 was corrected to ``linked and linked.'' (2) In the first line of page 6 of the specification, the words "according to the second invention" are deleted. (3) In the 20th line of page 6 of the specification, ``Lower axis 3bJ'' is corrected to ``[Lower axis 3bJ.'' (4) In the 1st line of page 7 of the specification, ``Lower axis 3bJ'' is corrected ``Correct the lower axis 3bJ.'' (5) In the 4th line of page 7 of the specification, [lower axis 3bJ is corrected to read ``lower axis 3bJ.'' (6) In the 5th line of page 7 of the specification. [Lower axis 3bj is corrected as ``Lower axis 3bJ.'' (7) In line 10 of page 7 of the old specification, [Lower axis 3bJ is corrected as ``Lower axis 3bJ.'' (8) Specification No. On page 7, line 13, the phrase "lower axis" is corrected to "lower axis." (9) In the 20th line of page 7 of the specification, ``Lower axis 3bJ'' is corrected to ``[Lower axis 3bJ.'' In the 2nd line of page 8 of α's specification, ``Lower axis 3bJ'' is corrected as ``Lower axis 3bJ''. 0υ In the 8th line of page 8 of the specification, [lower axis 3bJ] is corrected as ``lower axis 3bJ. ``Correct ``Lower axis 3bJ'' to ``Lower axis 3bJ.'' α■ In the 18th line of page 8 of the specification, ``Lower axis 3bJ'' is corrected to ``Lower axis 3bJ. In line 18, “Lower axis 3b
"J" should be corrected as "lower shaft 3bJ." 0ω In the 6th line of page 12 of the specification, "planetary rollers 92,
2..." should be corrected to "Planetary gear 92.92...". αe In lines 8 to 9 on page 12 of the specification, "planetary roller speed reduction device 9" is corrected to "planetary gear speed reduction device 9." αη On page 12 of the specification, lines 12-13, “lower shaft 3b
J is corrected to ``lower shaft 3bJ.'' In lines 16 to 17 of the 12th statement of the specification, ``planetary roller reduction device 9'' is corrected to ``planetary gear reduction device 9.'' 0ω In line 18 of No. 12 of the specification, "planetary roller reduction device 9" is corrected to "planetary gear reduction device 9." (2O+ In the 12th line of page 14 of the specification, “phase compensation circuit 71a” is corrected to “phase compensation unit 71a”. (21) In the 13th to 14th lines of page 14 of the specification, “angular acceleration "Detection circuit 71b" is replaced by "Angular acceleration detection section 71b"
I am corrected. (22) In the 14th to 15th lines of the specification, "midpoint determining circuit 71c" is corrected to "midpoint determining unit 71C." 23) In lines 15 and 16 of the 14th statement of the specification, [lock detection circuit 71f J] is corrected to ``lock detection unit 71f''. (24) In the 17th line of page 14 of the specification, "angular velocity detection circuit 71g" is corrected to "angular velocity detection unit 71g". (25) In lines 18 to 19 on page 14 of the specification, the phrase "inputs are respectively input to the torque function generating section 71g" is corrected to "inputs are respectively input to the torque function generating section 73g." (26) In the first line of pages 20 to 15 of Specification No. 14, “lock detection circuit 71f, midpoint determination circuit 71C” is corrected to “lock detection unit 71f, midpoint determination unit 71C”. do. (27) In the second and third lines of page 15 of the specification, "angular acceleration detection circuit 71b" is corrected to "angular acceleration detection unit 71b." (28) On page 15 of the specification, line 7, [Rudder angle determination circuit 71
d" has been corrected to read "rudder angle determining section 71d." (29) In line 10 of page 15 of the specification, the phrase “changing current to be determined” is replaced with “changing current which is the gist of the present invention to be determined”.
I am corrected. (30) Lines 13 to 14 on page 15 of the specification state “Detection circuit 71f, midpoint determination circuit 71C1, angular acceleration detection circuit 71b
, angular velocity detection circuit 71g" is replaced with "detection section 71f,
The midpoint determination unit 71c, the angular acceleration detection unit 71b, and the angular velocity detection unit 71g” are corrected. (31) On page 15 of the specification, line 15, [midpoint determination circuit 7
1C" is corrected to read "midpoint determining circuit 71c J.
1d" has been corrected to read "rudder angle determining section 71d." (33) In the 17th line of page 15 of the specification, the text "lock detection circuit 71r" is corrected to "lock detection unit 71f." (34) “Angular velocity detection circuit” in the 3rd line of No. 16 of the specification
The text has been corrected to read "angular velocity detection unit 71g." (35) In lines 7 and 8 of page 16 of the specification, the phrase "support current function section 73a that generates support current I" is corrected to "indication current function section 73a that generates instruction current ■." (36) On page 16 of the specification, line 8, “Phase compensation circuit 71
a" is corrected to read "phase compensation section 71a." (37) In lines 12 and 13 of page 16 of the specification, "angular velocity function generating section 73d" is corrected to "angular velocity function section 73d." (38) Delete "described later" in line 16 on page 16 of the specification. (39) In the third line of page 17 of the specification, the word "reduced" is corrected to "reduced". (40) In lines 8 and 9 of page 17 of the specification, [ignition]'-1 is corrected to read "ignition." (41) In the 9th line of page 17 of the specification, the phrase ``Whether it rises or not'' is corrected to ``Whether it rises or not.'' (42) In the second line of page 18 of the specification, "solar gear reduction device 9" is corrected to "planetary gear reduction device 9." (43) In the 14th line of page 18 of the specification, the phrase "turn on the clutch" is corrected to "turn on the clutch 16." (44) In the 3rd and 4th lines of page 19 of the specification, "angular acceleration detection circuit 71b" is corrected to "angular acceleration detection unit 71b." (45) In line 6 of No. 19 of the specification, the phrase "angular acceleration" is corrected to "angular acceleration fuwo." (46) In the first line from the bottom on page 19 of the specification (47) In the seventh line of page 20 of the specification, the words "will be added." will be corrected to "will be added." (48) On page 21 of the specification, line 10, “Rudder angle determination circuit 7
1d" has been corrected to read "rudder angle determining section 71d." (49) In line 12 of page 21 of the old specification, it says “Correction current 1aJ
[Correct the statement as [change current 1aJ]. (50) In the 12th to 13th lines of page 21 of the specification, the words "correction current function section 73c" are corrected to "variable current function section 73C." (51) In the 15th line of page 21 of the specification, "at step 40" is corrected to "at step 41." (52) In the 21st true line of the specification, [correction current 1aJ
(53) In the 9th line of page 23 of the specification, the phrase ``The correction current 1a is determined'' is corrected to ``The variable current Ta is determined.'' 6-2 "Brief explanation of the drawings" column (1) of the specification: "Related to the second invention" in line 10 on page 25 of the specification is deleted. (2) r71g on page 25, line 19 of the specification...
"Angular velocity detection circuit" has been corrected to "71g...Angular velocity detection section." 6-3 Figure 1 of the drawing is corrected as shown in the attached sheet. Figure 5 is corrected as shown in the attached sheet. Figure 7 is corrected as shown in the attached sheet. Figure 9 is corrected as shown in the attached sheet. Figure 11 is corrected as shown in the attached sheet. Attached document catalog correction drawing 1'a Ukeida

Claims (1)

[Scope of Claims] 1. A steering mechanism that converts the rotation of a steering wheel into a left-right movement for steering, a steering angle detection means that detects the rotation angle of the steering wheel, and a steering wheel that is applied to the steering wheel. In a power steering device comprising a torque sensor that detects torque and a steering assist motor driven by a current according to the detected steering torque, the angular velocity detects the angular velocity of the steered wheel based on the rotation angle. A power steering device comprising: a detection means; and a subtraction means for subtracting a correction current determined according to the angular velocity and the steering torque from the current for driving the motor.