JP4923860B2 - Transmission ratio variable device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission ratio variable apparatus capable of correctly specifying the motor rotational angle even at the re-start after the lock operation. <P>SOLUTION: When an IFSECU selects a "semi-emergency mode" for executing the lock operation after the phase-locked energization as the lock control mode (Step 103: YES), it is determined whether or not a ridge of a lock holder is located at a position corresponding to an engagement part of a lock lever (a sensor pattern [4]) at the time, i.e., at the lock control starting point (Step 104). When the ridge is located at the position corresponding to the engagement part (Step 104: YES), the phase-locked energization is executed so that a part in an engagement groove (the sensor pattern [3]) is stopped at the position corresponding to the engagement part (Step 105), and then a locking device is operated to lock (Step 106). <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a transmission ratio variable mechanism including a lock device capable of restricting relative rotation between an input shaft and an output shaft by restricting rotation of a motor that is a drive source.

  Conventionally, there is a transmission ratio variable device that uses a motor as a drive source and adds rotation based on motor driving to rotation of an input shaft based on steering operation and transmits the rotation to the output shaft. Usually, such a transmission ratio variable device includes: A lock device that restricts relative rotation between the input shaft and the output shaft is provided.

  For example, a transmission ratio variable device described in Patent Document 1 includes a housing that rotates integrally with an input shaft, a motor shaft that is rotatably supported in the housing, and a motor shaft and an output shaft that are fixed to the housing. Thus, a rotation mechanism for transmitting the rotation of the input shaft to the output shaft and a differential mechanism for decelerating the rotation of the motor shaft and transmitting the rotation to the output shaft is provided. In this variable transmission ratio device, the lock device is formed with a lock lever provided on the housing side, and a plurality of engagement grooves fixed to the motor shaft and engaged with the lock lever on the peripheral surface. And a lock holder. That is, by engaging the lock lever with the engagement groove of the lock holder, the motor shaft and the housing are connected so as not to rotate relative to each other, and thereby the relative rotation between the input shaft and the output shaft connected to the housing is prevented. It has a configuration to regulate.

In many cases, the lock control in the transmission ratio variable device including the lock device as described above is managed in the following three modes.
○ Normal mode: This mode is applied when there is no particular abnormality on the transmission ratio variable device side, for example, when the ignition is off. After adjusting the position of the engagement groove and the position of the lock lever by motor control, The lock lever is released (the engaging portion abuts against the lock holder), and then the motor is rotated again to confirm the engagement between the engagement groove and the lock lever.

  ○ Emergency mode: For example, when an abnormality occurs in the transmission ratio variable device, this mode is applied when urgently fail-safe is required. In this emergency mode, the motor control is stopped immediately, At the same time, the lock lever is released.

O Quasi-emergency mode: This mode is applied in a state where there is no mechanical problem in the variable transmission ratio device, such as when the power supply line is disconnected, but there is no room for control in the normal mode. In this quasi-emergency mode, power is supplied to the motor with the energized phase fixed, that is, phase-fixed energization is performed for a predetermined time prior to the release of the lock lever. Then, by releasing the lock lever in a state where the motor is electrically locked, the lock lever and the lock holder are prevented from being damaged due to the lock lever colliding with the rotating lock holder.
Japanese Patent Laid-Open No. 2003-320943

  By the way, a brushless motor that rotates by supplying three-phase (U, V, W) driving power is generally used as the motor of the transmission ratio variable device as described above. In many cases, the drive power is supplied by rectangular wave energization that switches the energization phase and energization direction, that is, the energization pattern, every 60 electrical angles of the motor (see FIG. 7). Although this is not required to be as quiet as an electric power steering device (EPS), a transmission ratio variable device with a strong demand for small size and high output can obtain a large torque compared to sine wave energization, and This is because high-precision angle detection is unnecessary, and rectangular wave energization that can use a rotation angle sensor with a simple configuration using a Hall element or the like is suitable.

  Here, in the rotation angle sensor using the Hall element, as shown in FIG. 8, each phase pulse signal Pu, Pv, Pw outputted from the three Hall elements corresponds to the electrical angle magnification set in the motor. The predetermined rotation angle is set as one pulse period (electrical angle 360 °), and the signal level is changed and the phases are shifted from each other by 120 °. In the example shown in FIG. 8, the electrical angle magnification is 4 times, and the predetermined rotation angle corresponding to this is a mechanical angle of 90 ° (the electrical angle in parentheses). The rotation angle is detected by counting the combinations of signal levels of the respective phase pulse signals Pu, Pv, Pw (sensor patterns, patterns “1” to “6”) and their transitions. By storing the count number at that time, it is possible to specify the initial rotation angle (absolute angle) after the restart.

  The signal level combinations (patterns “1” to “6”) of the phase pulse signals Pu, Pv, and Pw shown in FIG. 8 are “1” when the signal levels are “Hi”. Is represented by a 3-bit binary number and further converted into a decimal number. Therefore, for example, a binary notation of a combination in which the P-phase pulse signal Pu (bit2) is “Hi”, the V-phase pulse signal Pv (bit1) is “Lo”, and the W-phase pulse signal Pw (bit0) is “Hi”. [1] [0] [1] is a pattern “5” obtained by converting this to decimal notation.

  However, the exact initial rotation angle cannot be specified when the motor control is resumed after the lock operation is performed in the semi-emergency mode in which the lock lever is released after the motor is locked with the lock operation and after the electric lock by the phase-fixed energization. There is a case.

  That is, conventionally, the phase-fixed energization in the semi-emergency mode is performed with the energized phase at the start time being fixed. For this reason, there is a possibility that the phase fixing energization is performed so that the engaging portion of the lock lever is released to the peak portion between the engaging grooves. Cannot be predicted. Therefore, an accurate absolute angle cannot be specified from the count number stored at the end of phase-fixed energization. After the lock operation in the quasi-emergency mode, the variable transmission ratio device itself is not abnormal and can often be restored only by restoring the power supply system. Control may be resumed. As a result, the vehicle steering apparatus has a problem that a deviation occurs in the steering neutral position.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a transmission ratio variable device that can accurately specify a motor rotation angle even when restarting after a lock operation. It is in.

In order to solve the above problems, an invention according to claim 1 is directed to an input shaft and an output shaft , a motor as a drive source, a rotation angle sensor for detecting a rotation angle of the motor, and rotation of the input shaft. Is transmitted to the output shaft and the rotation mechanism of the rotation shaft of the motor is decelerated and transmitted to the output shaft, and the rotation of the rotation shaft is constrained so that the input shaft and the output shaft are relatively A lock device capable of restricting rotation; and a control means for controlling the operation of the lock device while controlling the operation of the motor through the supply of three-phase drive power, the lock device comprising a rotation shaft of the motor The control includes: a lock holder that is integrally provided and has a plurality of engagement grooves formed on a peripheral surface thereof; and a lock lever that can restrain rotation of the lock holder by engaging with the engagement grooves. means , On the basis of the output signal of the rotational angle sensor detects the rotation angle of the motor, at the time of the lock control, and the engagement portion of the ridges formed between the two engagement grooves of the lock holder and the lock lever In order to prevent the motor from stopping at a corresponding position, phase locking energization that supplies the drive power with the energized phase fixed is performed to stop the motor, and then the engaging portion of the lock lever is moved to the lock holder. The gist of the present invention is to control the contact with the peripheral surface of the motor and specify the initial rotation angle of the motor after resuming the motor control based on the output signal when the motor control is stopped .

  That is, by engaging the phase fixing energization so that the engaging portion of the lock lever is reliably released into one of the engaging grooves of the lock holder, the engaging portion is engaged when the motor control is stopped. The groove can be determined. Thus, even when the motor control is resumed thereafter, the accurate initial rotation angle can be specified from the count number stored when the motor control is stopped. In the vehicle steering apparatus, it is possible to prevent the shift of the steering neutral position due to erroneous recognition of the initial rotation angle.

According to a second aspect of the present invention, the control means counts a transition of a sensor pattern output from the rotation angle sensor with a predetermined rotation angle corresponding to an electrical angle magnification set in the motor as one cycle. by detecting the rotation angle of said motor, said and determines the conduction phase in accordance with each sensor pattern, wherein each peak portion, particular when the respective peak portions is in the position corresponding to the engagement portion The gist is that the sensor pattern is formed to be output.

  According to the above configuration, by performing phase-fixed energization so as to hold a sensor pattern other than the specific sensor pattern, a position corresponding to the engagement portion of the lock lever can be easily set anywhere in the engagement groove. Can be stopped.

According to a third aspect of the present invention, the control means counts a transition of a sensor pattern output from the rotation angle sensor with a predetermined rotation angle corresponding to an electrical angle magnification set in the motor as one cycle. detecting the rotation angle of the motor by the addition to determining the conduction phase in accordance with each sensor pattern, when locked control start, conduction phase corresponding to the sensor pattern in the rotating direction upstream side of the sensor pattern of the starting point Is the energized phase in the phase-fixed energization.

  That is, a large amount of electric power is consumed when the motor is electrically locked by phase-fixed energization. And the power consumption becomes so large that the rotation of a motor is decelerated rapidly. However, in many cases, phase-fixed energization is performed prior to the lock operation, such as when the power amount is not sufficient, such as when the power supply voltage is lowered. Therefore, it is desirable that the phase-fixed energization is performed efficiently so as to gently decelerate the rotation of the motor. In this regard, if the energized phase corresponding to the sensor pattern upstream of the sensor pattern at the start of the lock control is the energized phase in the phase-fixed energization, the motor is slowly decelerated without sudden braking. Can be made. As a result, the motor can be stopped efficiently and reliably even when there is no margin in the amount of power.

  According to the present invention, it is an object of the present invention to provide a transmission ratio variable device capable of accurately specifying a motor rotation angle even when restarting after a lock operation.

Hereinafter, an embodiment in which the present invention is embodied in a vehicle steering apparatus including a transmission ratio variable device will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a vehicle steering apparatus 1 according to the present embodiment. As shown in the figure, the steering shaft 3 to which the steering wheel 2 is fixed is connected to a rack 5 via a rack and pinion mechanism 4, and the rotation of the steering shaft 3 accompanying the steering operation is performed by the rack and pinion mechanism 4. Is converted into a reciprocating linear motion of the rack 5. Then, the steering angle of the steered wheels 6, that is, the steered angle is varied by the reciprocating linear motion of the rack 5, so that the vehicle traveling direction is changed. The vehicle steering apparatus 1 according to the present embodiment is a so-called rack assist type electric power steering apparatus (EPS), and generates an assist torque generated by a motor 7 as a drive source via a ball screw mechanism (not shown). By transmitting to the rack 5, an assist force is applied to the steering system.

  Further, the vehicle steering apparatus 1 of the present embodiment has a variable transmission ratio that varies the transmission ratio (gear ratio) between the steering angle (steering angle) of the steering 2 and the steering angle (steering angle) of the steered wheels 6. A device 8 and an IFSECU 9 as a control means for controlling the operation of the transmission ratio variable device 8 are provided.

  More specifically, the steering shaft 3 includes a first shaft 10 as an input shaft to which the steering 2 is connected and a second shaft 11 as an output shaft connected to the rack and pinion mechanism 4. Includes a differential mechanism 12 that couples the first shaft 10 and the second shaft 11, and a motor 13 that drives the differential mechanism 12. The transmission ratio variable device 8 adds the rotation driven by the motor to the rotation of the first shaft 10 accompanying the steering operation and transmits it to the second shaft 11, thereby inputting the steering shaft to the rack and pinion mechanism 4. 3 is increased (or decelerated), thereby changing the transmission ratio of the steered wheels 6 to the steering 2. The motor 13 of this embodiment is a brushless motor, and rotates when supplied with driving power of three phases (U, V, W) from the IFSECU 9. And IFSECU9 controls the operation | movement of the transmission ratio variable apparatus 8 by controlling rotation of the motor 13 through supply of this drive electric power (transmission ratio variable control).

  More specifically, as shown in FIG. 2, the transmission ratio variable device 8 of the present embodiment has a housing 14 formed in a substantially bottomed cylindrical shape, and the motor 13 is a motor that is a rotating shaft thereof. The shaft 13a and the housing 14 are fixed in the housing 14 so as to be coaxial. And the connection part 15 provided in the upper wall part 14a of the housing 14 is spline-fitted with the 1st shaft 10. As shown in FIG.

  In the present embodiment, the differential mechanism 12 rotates a pair of circular splines 21 and 22 coaxially arranged, a flexspline 23 meshed with each spline inside these splines, and a meshing portion thereof. A known wave gear mechanism comprising a wave generator 24 is employed.

  The circular spline 21 is fixed to the housing 14 so as to be coaxial with the housing 14, and the other circular spline 22 is connected coaxially to the second shaft 11 via a connecting member 25. Each of the circular splines 21 and 22 has a different number of teeth, and the flexspline 23 is arranged inside each of these gears in a state of being bent in an elliptical shape so that the external teeth are The inner teeth of each gear are partially meshed with each other. Then, the circular spline 21 rotates together with the housing 14, and the rotation of the circular spline 21 is transmitted to the circular spline 22 via the flex spline 23, whereby the rotation of the first shaft 10 accompanying the steering operation is transmitted to the second shaft 11. To be communicated to.

  The wave generator 24 is disposed inside the circular splines 21 and 22 and the flex spline 23. The wave generator 24 is connected to the motor shaft 13a, and rotates inside the flex spline 23 as the motor shaft 13a rotates, so that the flexed spline 23 has an elliptical shape, that is, a circular spline 21, The meshing part with 22 is rotated. Then, based on the difference in the number of teeth between the circular spline 21 and the circular spline 22, the circular spline 22 rotates, whereby the rotation of the motor shaft 13a is decelerated and transmitted to the second shaft 11. Yes.

  In this embodiment, the spiral cable device 27 is provided on the upper wall portion 14a of the housing 14, and the solenoid 13 of the motor 13 and the lock device 30 described later is rotated by a predetermined rotation range ( In the allowable rotation range), it is electrically connected to the IFSECU 9.

  Further, in the transmission ratio variable device 8 of the present embodiment, the relative rotation between the first shaft 10 and the second shaft 11 is regulated by regulating the rotation of the motor shaft 13a, that is, the transmission ratio is mechanically fixed. In addition, a lock device 30 that cannot be changed is provided.

  More specifically, as shown in FIG. 3, the lock device 30 is fixed to one end of the motor shaft 13a so as not to be relatively rotatable, and a lock holder 32 having a plurality of engagement grooves 31 formed on the peripheral surface 32a, A lock lever 33 capable of restraining the rotation of the lock holder 32 by engaging with the engagement groove 31 is provided.

  In the present embodiment, the lock holder 32 formed in an annular shape is fixed coaxially with the motor shaft 13a, and each engagement groove 31 is formed at four positions at equal intervals (90 ° intervals) on the peripheral surface 32a. Has been. In the present embodiment, each engaging groove 31 includes a shallow groove 31a extending in the circumferential direction and a deep groove 31b provided at one end of the shallow groove 31a. And between the two adjacent engaging grooves 31, the peak part 34 which protrudes to a radial direction outer side is formed.

  On the other hand, the lock lever 33 is formed in a long shape and is pivotally supported in the housing 14 so as to be rotatable outside the lock holder 32. Specifically, a rotation shaft 35 extending along the axial direction of the motor shaft 13a is provided at one end of the motor housing fixed to the housing 14 (see FIG. 2). By being pivotally supported by the moving shaft 35, it is rotatably supported at a position facing the lock holder 32 (on a plane substantially the same as the rotation plane of the lock holder 32). In the present embodiment, an engagement portion 33 a that protrudes toward the peripheral surface 32 a of the lock holder 32 is formed at one end of the lock lever 33. As the lock lever 33 rotates, the engaging portion 33a abuts on the peripheral surface 32a of the lock holder 32 and engages with the engaging groove 31 (finally the deep groove 31b) formed on the peripheral surface 32a. By combining, the rotation of the lock holder 32, that is, the rotation of the motor shaft 13a can be restricted.

  In the locking device 30 of the present embodiment, the lock lever 33 has the engaging portion 33a thereof by the elastic force of the spring member 36 (actually a coil spring is used, but only its function is shown in the drawing conceptually). It is urged to rotate toward the lock holder 32 side. The other end of the lock lever 33 is connected to a solenoid 37 that is a drive source of the lock device 30.

  That is, when the locking device 30 of the present embodiment is not locked, the solenoid 37 is energized and the plunger 37a is pulled in so that the engaging portion 33a of the lock lever 33 is held at a position separated from the lock holder 32. It is configured as follows. When the lock is activated, the lock lever 33 is released by stopping energization of the solenoid 37, that is, the lock lever 33 is rotated by the elastic force of the spring member 36 so that the engaging portion 33a contacts the lock holder 32. Thus, the engaging portion 33a of the lock lever 33 and the engaging groove 31 of the lock holder 32 are engaged.

Next, the electrical configuration and control mode of the vehicle steering apparatus of the present embodiment will be described.
As shown in FIG. 1, the steering angle θs detected by the steering angle sensor 38 and the vehicle speed V detected by the vehicle speed sensor 39 are input to the IFSECU 9. The IFSECU 9 controls the rotation of the motor 13 based on the steering angle θs and the vehicle speed V, thereby executing the operation of the transmission ratio variable device 8, that is, the transmission ratio variable control.

  More specifically, as shown in FIG. 4, the IFSECU 9 includes a microcomputer 40 that outputs a motor control signal and a drive circuit 41 that supplies drive power to the motor 13 based on the motor control signal.

  The microcomputer 40 includes a motor control unit 42 as a control signal output unit, and a gear ratio variable control calculation unit 43 and a differential steer control calculation unit 44 provided in the motor control unit 42 have a steering angle θs and a steering angle θs, respectively. The vehicle speed V, the vehicle speed V, and the steering speed ωs are input. The gear ratio variable control calculation unit 43 calculates a gear ratio variable command angle θgr *, which is a control target component for changing the gear ratio (transmission ratio) according to the vehicle speed V, and the differential steer control calculation unit 44 Then, the differential steering command angle θls *, which is a control target component for improving the responsiveness of the vehicle, is calculated according to the steering speed ωs.

  The gear ratio variable command angle θgr * and the differential steer command angle θls * calculated by the gear ratio variable control calculation unit 43 and the differential steer control calculation unit 44 are input to the adder 45. The adder 45 superimposes the gear ratio variable command angle θgr * and the differential steer command angle θls * to thereby obtain the ACT command angle θta *, which is the control target amount of the motor 13, that is, the transmission ratio variable device 8. Calculated.

  Further, the motor control unit 42 is provided with a motor rotation angle calculation unit 47 that calculates (detects) the motor rotation angle θm based on the output signal of the rotation angle sensor 46 provided in the motor 13. Based on the motor rotation angle θm calculated by the angle calculation unit 47, the actual control amount of the transmission ratio variable device 8, that is, the ACT angle θta is calculated. The ACT angle θta is input to the position control calculation unit 49 together with the ACT command angle θta * calculated by the adder 45. Then, the position control calculation unit 49 calculates the current command ε by feedback calculation so that the actual ACT angle θta follows the ACT command angle θta * that is the command value, and outputs the current command ε to the motor control signal output unit 50.

  Here, in the present embodiment, the rotation angle sensor 46 provided in the motor 13 includes three Hall elements 46a to 46c corresponding to the respective phases of the motor 13, and the microcomputer 40 receives the output signals as The phase pulse signals Pu, Pv, and Pw output from the Hall elements 46a to 46c are input according to the rotation of the motor 13 (see FIG. 8). The motor rotation angle calculation unit 47 calculates a motor rotation angle θm (absolute angle) by counting a combination of signal levels of each phase pulse signal Pu, Pv, Pw, that is, a sensor pattern and its transition. To do. Note that the motor 13 of this embodiment also has an electric angle magnification of 4 times as shown in FIG. Further, when the motor control is stopped, the motor rotation angle calculation unit 47 stores the count number at that time. Then, based on the stored count number, the initial rotation angle after resuming the motor control is specified.

  The drive circuit 41 employs a known PWM inverter that includes a plurality (2 × 3) of switching elements (FETs) corresponding to the phases of the motor 13. Specifically, the drive circuit 41 includes FET 51a and 51d, FETs 51b and 51e, and FETs 51c and 51f connected in series, and each connection point of FETs 51a and 51d, FETs 51b and 51e, and FETs 51c and 51f. 52u, 52v, and 52w are connected to each phase motor coil of the motor 13, respectively. The gate terminals of the FETs 51a to 51f are connected to the microcomputer 40, and the FETs 51a to 51f are turned on / off in response to a motor control signal input from the microcomputer 40 (motor control signal output unit 50). The DC power of the in-vehicle power supply 53 is converted into three-phase driving power and supplied to the motor 13.

  More specifically, in the present embodiment, the drive power is supplied to the motor 13 by rectangular wave energization that switches the energization phase and energization direction, that is, the energization pattern, every 60 electrical angles of the motor (see FIG. 7). ).

  Specifically, each phase pulse signal Pu, Pv, Pw output from the rotation angle sensor 46 is input to the motor control signal output unit 50, and the motor control signal output unit 50 The energization pattern is determined based on a combination of signal levels of the phase pulse signals Pu, Pv, and Pw, that is, a sensor pattern. And a motor control signal is output to each FET 51a-51f which comprises the drive circuit 41 in order to switch an electricity supply pattern according to the transition of the sensor pattern accompanying rotation of the motor 13. FIG.

  The motor control signal output unit 50 then sets the duty ratio of the motor control signal (specifically, in order to correspond the amount of current supplied to the motor 13 to the value indicated by the current command ε calculated by the position control calculation unit 49. The on-duty ratio of the FETs 51d to 51f on the lower side is controlled.

  In this embodiment, the IFSECU 9 includes a drive circuit 65 for controlling the lock, that is, for supplying drive power to the solenoid 37, in addition to the drive circuit 41 for driving the motor. The drive circuit 65 turns on / off the power supply to the solenoid 37 based on the lock control signal output from the microcomputer 40.

  More specifically, the microcomputer 40 includes a lock control unit 66. The lock control unit 66 includes an IG on / off signal S_ig, an abnormal signal S_tr indicating an abnormality of the transmission ratio variable device 8, a power supply voltage V_b, and the like. Is entered. Then, the lock control unit 66 determines whether or not the lock device 30 is to be locked based on these inputted various signals (lock determination), and outputs to the drive circuit 65 when it is determined that the lock device is to be locked. Change the control signal to indicate that. In the present embodiment, the drive circuit 65 is configured by a switching element (power MOSFET), and the lock control signal is output as a duty (on duty) of the switching element. The lock control unit 66 sets the lock control signal to “OFF (Duty = 0)” during the lock operation, thereby turning off the solenoid 37, that is, releasing the lock lever 33 to lock the lock device 30. It has become.

(Lock control)
Next, a mode of lock control in the transmission ratio variable device of the present embodiment will be described.
Also in the transmission ratio variable device 8 of the present embodiment, the lock control is managed by the above three modes ("normal", "emergency", and "quasi-emergency"). Specifically, in the present embodiment, the “normal mode” is selected mainly when the IG on / off signal S_ig input to the lock control unit 66 has a value indicating “IG off”. "Is selected when the abnormal signal S_tr is input. The “semi-emergency mode” is selected mainly when the detected power supply voltage V_b is lower than a predetermined threshold value. When “semi-emergency mode” is selected, phase-fixed energization is performed so as to maintain the motor rotation angle at that time.

  Specifically, as shown in FIG. 4, when the lock control unit 66 determines that the lock operation should be performed in the lock determination, the motor control signal is changed prior to the change of the lock control signal for the drive circuit 65. A lock activation signal indicating which lock control mode is selected is output to the output unit 50. The motor control signal output unit 50 executes phase-fixed energization when the lock activation signal indicates the “quasi-emergency mode”, and the lock control unit 66 performs after a predetermined time has elapsed from the output of the lock activation signal. Then, the lock control signal output to the drive circuit 65 is changed to a signal that causes the lock operation.

  As described above, in the semi-emergency mode, when phase fixing energization is performed such that the peak portion 34 of the lock holder 32 stops at a position corresponding to the engaging portion 33a of the lock lever 33, the subsequent motor control is performed. When resuming, the exact initial rotation angle may not be specified. As a result, there is a problem that the steering neutral position shifts.

  In consideration of this point, in the transmission ratio variable device 8 of the present embodiment, when the IFSECU 9 (the microcomputer 40) selects “semi-emergency mode” as the lock control mode, at that time, the peak portion 34 of the lock holder 32 is obtained. Is in a position corresponding to the engaging portion 33 a of the lock lever 33. And when the peak part 34 exists in the position corresponding to the engaging part 33a, the location in the engaging groove 31 of the lock holder 32 stops in the position corresponding to the engaging part 33a of the lock lever 33. Execute phase-fixed energization so that

  More specifically, as shown in FIG. 5, in the present embodiment, the lock holder 32 is configured such that the four crests 34 are located at positions corresponding to the engaging portions 33 a of the lock lever 33. The motor shaft 13a is assembled so that the sensor pattern to be output is “4”. That is, as a result, the sensor pattern when the deep groove 31b of the engaging groove 31 is at a position corresponding to the engaging portion 33a is “6”, and when the shallow groove 31a is at a position corresponding to the engaging portion 33a. Other sensor patterns are output.

  In the present embodiment, the motor control signal output unit 50 outputs a sensor output by the rotation angle sensor 46 at that time, that is, when lock control is started, when a lock activation signal indicating “semi-emergency mode” is input. It is determined whether or not the pattern is “4”. When the sensor pattern is “4”, the sensor pattern output from the rotation angle sensor 46 is other than “4”. Specifically, the center portion of the engagement groove 31 of the lock holder 32 is the engagement of the lock lever 33. Phase-fixed energization is executed so that the position corresponding to the joint portion 33a is held at “3”. When the sensor pattern at the time of starting the lock control is other than “4”, phase-fixed energization is executed so as to hold the sensor pattern. Then, the lock control unit 66 changes the lock control signal output to the drive circuit 65 to a lock operation after a predetermined time has elapsed from the output of the lock activation signal.

  That is, by performing phase fixing energization so that the engaging portion 33a of the lock lever 33 is reliably released into any of the engaging grooves 31 of the lock holder 32, the engaging portion 33a The engaging groove 31 to be engaged can be determined. Thus, even when the subsequent motor control is resumed, the accurate initial rotation angle can be specified from the count number stored when the motor control is stopped.

Next, a processing procedure for lock control in the transmission ratio variable device of this embodiment will be described.
As shown in the flowchart of FIG. 6, the IFSECU 9 first determines whether or not to lock the locking device 30 based on various input signals such as the IG on / off signal S_ig, the abnormal signal S_tr, and the power supply voltage V_b. Determination (lock determination, step 101). Next, IFSECU 9 determines whether or not “emergency mode” is selected as the lock control mode (step 102). If “emergency mode” is not selected (step 102: NO), then “semi-emergency” It is determined whether or not “mode” is selected (step 103).

  When “semi-emergency mode” is selected in step 103 (step 103: YES), the IFSECU 9 indicates that the sensor pattern at the time, that is, the lock control start time, is the peak 34 of the lock holder 32. Is “4” indicating that it is in a position corresponding to the engaging portion 33a of the lock lever 33 (step 104). When the sensor pattern is “4” (step 104: YES), the sensor pattern output from the rotation angle sensor 46 is such that the central portion of the engagement groove 31 of the lock holder 32 is the engagement portion of the lock lever 33. Phase-fixed energization is executed so as to be held at “3” which is a position corresponding to 33a (step 105). When the sensor pattern output from the rotation angle sensor 46 is other than “4” in step 104 (step 104: NO), phase-fixed energization is performed so as to hold the sensor pattern at the time of starting the lock control. Execute (step 106). Then, after a predetermined time has elapsed since the start of phase fixing energization in step 105 or step 106, the lock lever 33 is released, that is, the lock device 30 is locked (step 107).

  If the “emergency mode” is selected in step 102 (step 102: YES), the IFSECU 9 immediately stops the motor control (step 108) and executes the step 107 without delay, thereby locking the lock device. 30 is locked. If the “semi-emergency mode” is not selected in step 103, that is, if the “normal mode” is selected (step 103: NO), the lock confirmation control described above is executed (step 109), and then step 107 is performed. Then, the locking device 30 is locked.

As described above, according to the present embodiment, the following operations and effects can be obtained.
(1) When IFSECU 9 selects “semi-emergency mode” in which the lock operation is executed after phase-fixed energization as the lock control mode (step 103: YES), at that time, that is, at the lock control start time, It is determined whether or not the 32 peak portions 34 are at a position (sensor pattern “4”) corresponding to the engaging portion 33a of the lock lever 33 (step 104). And when the peak part 34 exists in the position corresponding to the engaging part 33a (step 104: YES), the location (sensor pattern "3") in the engaging groove 31 in the position corresponding to the engaging part 33a. After phase-phase energization is performed to stop the operation (step 105), the locking device 30 is locked (step 106).

  That is, as described above, the phase lock energization is performed so that the engaging portion 33a of the lock lever 33 is reliably released into any of the engaging grooves 31 of the lock holder 32, so that the engagement is achieved when the motor control is stopped. The engaging groove 31 with which the mating portion 33a is engaged can be determined. Thus, even when the motor control is resumed thereafter, the accurate initial rotation angle can be specified from the count number stored when the motor control is stopped. As a result, it is possible to prevent the steering neutral position from being shifted due to erroneous recognition of the initial rotation angle.

  (2) The lock holder 32 is applied to the motor shaft 13a so that a specific sensor pattern (pattern “4”) is output when each peak portion 34 is in a position corresponding to the engaging portion 33a of the lock lever 33. Assembled.

  According to the above configuration, by performing phase-fixed energization so as to hold a sensor pattern other than the specific sensor pattern, any location in the engagement groove 31 can be easily set to the engagement portion 33a of the lock lever 33. It can be stopped at the corresponding position.

The above embodiment may be modified as follows.
In the present embodiment, the lock holder 32 has a sensor pattern output by the rotation angle sensor 46 of “4” when the four crests 34 are at positions corresponding to the engaging portions 33 a of the lock lever 33. Thus, it decided to assemble | attach to the motor shaft 13a. However, the present invention is not limited to this, and if each peak portion 34 is located at a position corresponding to the engaging portion 33a of the lock lever 33, the sensor pattern may be any type as long as a specific sensor pattern is output. It may be a thing.

  In the present embodiment, when the sensor pattern at the time of starting the lock control is “4” where the peak portion 34 of the lock holder 32 is at the position corresponding to the engaging portion 33a of the lock lever 33, the sensor pattern is The phase fixing energization is executed so that the central portion of the engaging groove 31 is held at “3” which is a position corresponding to the engaging portion 33a. However, the present invention is not limited to this, so long as any part of the engagement groove 31 stops at a position corresponding to the engagement portion 33a, any combination of energized phases at the time of phase fixing energization is possible. Good.

  -Also, if the motor is rotating at the start of the lock control, the energized phase corresponding to the sensor pattern upstream of the sensor pattern at the start is the energized phase in the fixed phase energization. Good. More specifically, referring to FIG. 5, when the lock holder 32 is rotating in the clockwise direction at the time of starting the lock control, the sensor pattern output by the rotation angle sensor is “ If it is “3”, for example, “1” may be selected as the sensor pattern on the upstream side in the rotation direction.

  That is, a large amount of electric power is consumed when the motor is electrically locked by phase-fixed energization. And the power consumption becomes so large that the rotation of a motor is decelerated rapidly. However, the “quasi-emergency mode” in which the phase-fixed energization is performed prior to the lock operation is often selected when the power amount has no margin, such as when the power supply voltage V_b is lowered. Therefore, it is desirable that the phase-fixed energization is performed efficiently so as to gently decelerate the rotation of the motor. In this respect, as described above, if the energized phase corresponding to the sensor pattern upstream of the sensor pattern at the start of the lock control is the energized phase in the phase-fixed energization, the motor is suddenly braked. It can be slowed down gently. As a result, the motor can be stopped efficiently and reliably even when there is no margin in the amount of power.

  In the present embodiment, the present invention is embodied in the transmission ratio variable device 8 of the vehicle steering apparatus 1, but may be applied to a transmission ratio variable device used for other purposes.

The schematic block diagram of the steering apparatus for vehicles. The schematic block diagram of a transmission ratio variable apparatus. The schematic block diagram of a locking device. The control block diagram of the steering device for vehicles. The schematic diagram which shows the relationship between the peak part and engagement groove | channel in a lock holder, and a sensor pattern. The flowchart which shows the process sequence of lock control. The wave form diagram which shows the aspect of a rectangular wave drive. The principle explanatory drawing of the motor rotation angle calculation method.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle steering device, 8 ... Transmission ratio variable device, 9 ... IFSECU, 10 ... 1st shaft, 11 ... 2nd shaft, 12 ... Differential mechanism, 13 ... Motor, 30 ... Locking device, 31 ... Engagement groove 32 ... Lock holder, 32a ... Peripheral surface, 33 ... Lock lever, 33a ... Engagement part, 34 ... Mountain part, Pu ... U-phase pulse signal, Pv ... V-phase pulse signal, Pw ... W-phase pulse signal, θm ... Motor rotation angle.

Claims (3)

An input shaft and an output shaft;
A motor as a drive source ;
A rotation angle sensor for detecting a rotation angle of the motor;
A differential mechanism for transmitting rotation of the input shaft to the output shaft and decelerating rotation of the rotation shaft of the motor and transmitting the rotation to the output shaft;
A locking device capable of restricting relative rotation between the input shaft and the output shaft by restraining rotation of the rotating shaft;
Control means for controlling the operation of the motor and controlling the operation of the locking device through the supply of three-phase drive power;
The lock device is provided integrally with the rotation shaft of the motor, and a lock holder having a plurality of engagement grooves formed on a peripheral surface thereof, and the rotation of the lock holder can be restricted by engaging with the engagement grooves. A lock lever,
The control means includes
Detecting the rotation angle of the motor based on the output signal of the rotation angle sensor;
At the time of lock control, the drive phase is fixed and the drive phase is fixed so that the motor does not stop at a position where a peak formed between two engagement grooves of the lock holder and an engagement portion of the lock lever correspond to each other. After performing phase-fixed energization to supply power and stopping the motor, control is performed so that the engaging portion of the lock lever comes into contact with the peripheral surface of the lock holder,
A transmission ratio variable device characterized by identifying an initial rotation angle of the motor after resumption of motor control based on the output signal when the motor control is stopped . The transmission ratio variable device according to claim 1,
The control means detects the rotation angle of the motor by counting transitions of a sensor pattern output from the rotation angle sensor with a predetermined rotation angle corresponding to the electrical angle magnification set for the motor as one cycle. , and determines the conduction phase in response to each of the sensor patterns, each mountain portion, so that certain of the sensor pattern output when the respective peak portions is in the position corresponding to the engaging portion formed A transmission ratio variable device. The transmission ratio variable device according to claim 1,
The control means detects the rotation angle of the motor by counting transitions of a sensor pattern output from the rotation angle sensor with a predetermined rotation angle corresponding to the electrical angle magnification set for the motor as one cycle. the addition to determining the conduction phase in accordance with each sensor pattern, at lock control start, the energized phase corresponding to the sensor pattern in the rotating direction upstream side of the sensor pattern of the starting point, conduction phase in the phase fixed conductive A transmission ratio variable device characterized by that.

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