JP2009162268A - Shift range switching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To absorb the rattling by a spline between an output shaft and a manual shaft while suppressing an increase in the axial physical size of a rotary actuator, and to prevent the mounting property deterioration of the rotary actuator due to the influences of a shift position sensor. <P>SOLUTION: A shift range switching device for eliminating the rattling by the spline comprises a first gear 81 provided on the output shaft 17, a second gear 82 engaging with the first gear 81 and supported by a second shaft 83 on the radial outside of the output shaft 17, and a torsion coil spring α for energizing the second gear 82 in one rotating direction. A rotary member 85 and a fixed member 86 form a non-contact rotating angle sensor which detects the set position of a shift range from the rotating angle of the rotary member 85. An output shaft rotation energizing means 80 which functions as the shift position sensor β is provided on the radial outside of the output shaft 17 for avoiding the mounting property deterioration of the rotary actuator 1 without increasing the axial physical size of the rotary actuator 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a shift range switching device including a rotary actuator that performs switching drive of a shift range switching mechanism.

An automatic transmission for a vehicle is equipped with a shift range switching mechanism (including a parking switching mechanism). In the past, the driver manually switched, but in recent years, the shift range switching mechanism has been Shift range switching devices (shift-by-wire: SBW) that are switched by a rotary actuator equipped with a motor are spreading in the market.
The shift range switching device switches the shift range in the shift range switching mechanism by rotationally driving a manual shaft that is rotatably supported by a rotary actuator. The shaft was connected by spline fitting (see, for example, Patent Document 1).

  As shown in FIG. 4, since the output shaft 17 of the rotary actuator 1 and the manual shaft 45 are coupled by spline fitting, looseness for assembly occurs in the rotational direction. For this reason, an error is generated between the output shaft 17 and the manual shaft 45 by an amount of play, which hinders high-precision control of the manual shaft 45 by the rotary actuator 1.

In order to solve the above problems, as shown in FIG. 5, a torsion coil spring α is arranged around the output shaft 17 and the output shaft 17 is biased in one direction of rotation so that the backlash of the spline fitting is reduced. It can be absorbed (not a well-known technique).
However, the means for arranging the torsion coil spring α around the output shaft 17 has a disadvantage that the physique in the axial direction of the rotary actuator 1 becomes large.

On the other hand, in order to detect the set position of the shift range of the automatic transmission, there is known one provided with a shift position sensor β for detecting the rotation angle of the manual shaft 45 as shown in FIG.
However, when the shift position sensor β is provided on the manual shaft 45, the space for mounting the rotary actuator 1 is reduced due to the influence of the shift position sensor β, and the mountability of the rotary actuator 1 is deteriorated.
JP 2005-265151 A

The present invention has been made in view of the above-mentioned problems, and a first object is to increase the physique in the axial direction of the rotary actuator by eliminating play caused by spline fitting between the output shaft of the rotary actuator and the manual shaft. The present invention is to provide a shift range switching device that suppresses the absorption and improves the controllability of the manual shaft by a rotary actuator.
The second object of the present invention is to provide the shift position sensor for detecting the set position of the shift range in order to achieve the first object and to determine the position of the shift range of the automatic transmission. An object of the present invention is to provide a shift range switching device capable of suppressing deterioration in mountability of a rotary actuator due to the influence of a shift position sensor.

[Means of claim 1]
In the shift range switching device employing the means of claim 1, the urging force applied to the second gear by the return spring is transmitted to the first gear and transmitted to the output shaft. That is, the output shaft is biased in one rotational direction by the biasing force of the return spring.
Thereby, the backlash of the spline fitting between the output shaft of the rotary actuator and the manual shaft is absorbed by the biasing force of the return spring, and the controllability of the manual shaft by the rotary actuator is improved.
Since the output shaft rotation urging means is provided on the outer side in the radial direction of the output shaft, compared to the case where a torsion coil spring is disposed around the output shaft (see FIG. 5), Does not lead to an increase in physique.
That is, by adopting the means of claim 1, the play due to the spline fitting between the output shaft of the rotary actuator and the manual shaft is absorbed while suppressing an increase in the size of the rotary actuator in the axial direction. The controllability of the manual shaft can be improved.

[Means of claim 2]
The output shaft rotation urging means in the shift range switching device employing the means of claim 2 is a relative rotation between a rotating member that rotates integrally with the second gear and a fixed member that is fixed to the housing of the rotary actuator. A shift position sensor is provided for detecting the angle and detecting the set position of the shift range of the automatic transmission.
The shift position sensor that detects the set position of the shift range from the relative rotation angle of the rotating member and the fixed member is provided on the radially outer side of the output shaft, so when the shift position sensor is mounted on the manual shaft ( Compared with FIG. 6), the deterioration of mountability of the rotary actuator due to the influence of the shift position sensor can be suppressed.
That is, by adopting the means of claim 2, in addition to the effect of claim 1, even if a shift position sensor is provided for determining the position of the shift range of the automatic transmission, it is influenced by the effect of the shift position sensor. Deterioration of mountability of the rotary actuator can be suppressed.

[Means of claim 3]
The shift position sensor in the shift range switching device employing the means of claim 3 is a non-contact rotation angle sensor that detects the rotation angle between the rotation member and the fixed member in a non-contact manner.

The shift range switching device of the best mode is to rotate the manual shaft that is rotatably supported, and to rotate the shift range in the automatic transmission and to rotate the manual shaft. And a rotary actuator for switching the shift range switching mechanism, and the output shaft of the rotary actuator is spline-fitted with the manual shaft.
The rotary actuator includes a first gear provided on the output shaft, a second gear meshing with the first gear, a second shaft rotatably supporting the second gear on the radially outer side of the output shaft, An output shaft rotation urging means including a return spring that urges the two gears in one rotation direction is provided.
Further, the output shaft rotation urging means detects the relative rotation angle between the rotating member that rotates integrally with the second gear and the fixed member that is fixed to the housing of the rotary actuator, and sets the shift range setting position. A shift position sensor for detecting

A shift range switching apparatus according to Embodiment 1 will be described with reference to the drawings.
(Description of shift range switching device)
The shift range switching device switches the shift range switching mechanism 3 and the parking switching mechanism 4 (see FIG. 3) mounted on the vehicle automatic transmission 2 (see FIG. 2) by the rotary actuator 1 (see FIG. 1). It is.

The rotary actuator 1 is a servo mechanism that drives the shift range switching mechanism 3, and as shown in FIG. 1, a synchronous electric motor 5 and a speed reducer 6 that decelerates and outputs the rotational output of the electric motor 5. With. The rotation of the electric motor 5 is controlled by the SBW / ECU 7 shown in FIG.
That is, the shift range switching device controls the rotation direction, the rotation number (the number of rotations), and the rotation angle of the electric motor 5 by the SBW • ECU 7, so that the shift range switching mechanism 3 driven via the speed reducer 6 and The parking switching mechanism 4 is controlled to be switched.

Next, a specific configuration example of the shift range switching device will be described. In the following, the rotary actuator 1 will be described with the right side of FIG. 1 as the front (or front) and the left side as the rear (or rear), but it does not relate to the actual mounting direction.
(Description of the electric motor 5)
The electric motor 5 of the first embodiment is a brushless SR motor (switched reluctance motor) that does not use a permanent magnet. The rotor 11 is rotatably supported, and is coaxial with the rotation center of the rotor 11. It is comprised with the stator 12 arrange | positioned.

The rotor 11 includes a rotor shaft 13 and a rotor core 14, and the rotor shaft 13 is rotatably supported by rolling bearings (a front rolling bearing 15 and a rear rolling bearing 16) disposed at the front end and the rear end. .
The front rolling bearing 15 is fitted and fixed to the inner periphery of the output shaft 17 of the speed reducer 6, and the output shaft 17 of the speed reducer 6 is freely rotatable by a metal bearing 19 disposed on the inner periphery of the front housing 18. It is supported by. That is, the front end of the rotor shaft 13 is rotatably supported via the metal bearing 19 provided on the front housing 18 → the output shaft 17 → the front rolling bearing 15.

The axial support section of the metal bearing 19 is provided so as to overlap the axial support section of the front rolling bearing 15. By providing in this way, it is possible to avoid the inclination of the rotor shaft 13 due to the reaction force of the speed reducer 6 (specifically, the reaction force of the load applied to the engagement between the sun gear 26 and the ring gear 27 described later).
The rear rolling bearing 16 is press-fitted and fixed to the outer periphery of the rear end of the rotor shaft 13 and is supported by the rear housing 20.

The stator 12 includes a stator core 21 fixed in a housing (front housing 18 + rear housing 20) and a plurality of excitation coils 22 that generate magnetic force when energized.
The stator core 21 is formed by laminating a large number of thin plates, and is fixed to the rear housing 20. Specifically, the stator core 21 is provided with stator teeth (inward salient poles) that project toward the inner rotor core 14 at predetermined angles (for example, every 30 degrees). Is provided with an exciting coil 22 for generating a magnetic force for each stator tooth. Each excitation coil 22 is energized and controlled by the SBW • ECU 7.

The rotor core 14 is formed by laminating a large number of thin plates, and is press-fitted and fixed to the rotor shaft 13. The rotor core 14 is provided with rotor teeth (outward salient poles) that project at predetermined angles (for example, every 45 degrees) toward the outer stator core 21.
The SBW / ECU 7 sequentially switches the energizing position and energizing direction of each exciting coil 22 to sequentially switch the stator teeth that magnetically attract the rotor teeth, thereby rotating the rotor 11 to one or the other.

(Description of reducer 6)
The speed reducer 6 shown in the first embodiment is an intermeshing planetary gear speed reducer (cycloid speed reducer) which is a kind of planetary gear speed reducer, and a rotor shaft via an eccentric portion 25 provided on the rotor shaft 13. 13, the sun gear 26 (inner gear: gear) attached in an eccentrically rotatable state, the ring gear 27 (outer gear: internal gear) with which the sun gear 26 meshes with the sun gear 26, and the rotation component of the sun gear 26 only. And transmission means 28 for transmitting to the output shaft 17.

The eccentric part 25 is an axis that rotates eccentrically with respect to the rotation center of the rotor shaft 13 and swings and rotates the sun gear 26, and the sun gear 26 is rotatable via a sun gear bearing 31 disposed on the outer periphery of the eccentric part 25. It is something to support.
As described above, the sun gear 26 is rotatably supported with respect to the eccentric portion 25 of the rotor shaft 13 via the sun gear bearing 31, and rotates while being pressed against the ring gear 27 by the rotation of the eccentric portion 25. Is configured to do.
The ring gear 27 is fixed to the front housing 18.

The transmission means 28 includes a plurality of inner pin holes formed on the same circumference of a flange that rotates integrally with the output shaft 17, and a plurality of inner pins that are formed in the sun gear 26 and are loosely fitted in the inner pin holes. Is done.
The plurality of inner pins are cylindrical bodies that protrude from the front surface of the sun gear 26.
The plurality of inner pin holes are round holes provided in the flange at the rear end of the output shaft 17, and are configured such that the rotation motion of the sun gear 26 is transmitted to the output shaft 17 by fitting the inner pin and the inner pin hole. Has been.
By being provided in this way, the rotor shaft 13 rotates and the sun gear 26 rotates eccentrically, whereby the sun gear 26 rotates at a reduced speed with respect to the rotor shaft 13, and the reduced rotation is transmitted to the output shaft 17.
Unlike the first embodiment, a plurality of inner pin holes may be formed in the sun gear 26, and a plurality of inner pins may be provided on the flange.

  The output shaft 17 is spline-coupled to a manual shaft 45 (described later) that drives and operates the shift range switching mechanism 3 and the parking switching mechanism 4, and the rotation of the output shaft 17 is transmitted to the manual shaft 45. Specifically, a shaft coupling hole into which the manual shaft 45 is inserted from the front is formed at the center of the output shaft 17, and a large number of spline grooves along the axial direction are formed on the inner peripheral surface of the shaft coupling hole. Yes. On the other hand, a large number of spline grooves that match the spline grooves of the shaft coupling hole are also formed on the outer peripheral surface of the rear end portion of the manual shaft 45. By inserting the shaft coupling hole into the rear end of the manual shaft 45, the rotary type The output shaft 17 of the actuator 1 and the manual shaft 45 are spline-fitted, and the manual shaft 45 is rotationally driven by the output shaft 17.

(Description of shift range switching mechanism 3 and parking switching mechanism 4)
The shift range switching mechanism 3 and the parking switching mechanism 4 are switched and driven by the output shaft of the rotary actuator 1 (specifically, the output shaft 17 of the speed reducer 6 described above).
The shift range switching mechanism 3 slides and displaces a manual spool valve 42 provided in the hydraulic valve body 41 to an appropriate position corresponding to the shift range, and switches a hydraulic pressure supply path to a hydraulic clutch (not shown) of the automatic transmission 2. The engagement state of the hydraulic clutch is controlled.

  The parking switching mechanism 4 meshes with a park pole 44 that is rotatably supported by a fixed member (such as a housing of the automatic transmission 2) on a parking gear 43 that rotates in conjunction with a drive shaft (such as a drive shaft) of the vehicle. And the engagement release is executed, and the switching (locking state) and unlocking (parking release state) of the parking gear 43 is executed. Specifically, the parking switching mechanism 4 is locked and unlocked by engaging and disengaging the concave portion 43a of the parking gear 43 and the convex portion 44a of the park pole 44, and by restricting the rotation of the parking gear 43, The drive wheels of the vehicle are locked via the drive shaft, the differential gear, etc., and the parking state of the vehicle is achieved.

On the other hand, a manual shaft 45 driven by the rotary actuator 1 is rotatably supported by the automatic transmission 2. A detent plate 46 having a substantially fan shape is attached to the manual shaft 45, and the manual shaft 45 and the detent plate 46 are provided to rotate integrally.
The detent plate 46 is provided with a plurality of recesses 46a at the radial tip (substantially fan-shaped arc portion), and the tip of the detent spring 47 fixed to the hydraulic valve body 41 (or inside the automatic transmission 2). When the engaging portion 47a is fitted into the recess 46a, the shifted shift range is maintained.
In this embodiment, a detent mechanism using a leaf spring is shown, but another detent mechanism using a coil spring or the like may be used.

A pin 48 for driving the manual spool valve 42 is attached to the detent plate 46.
The pin 48 meshes with a groove 49 provided at the end of the manual spool valve 42. When the detent plate 46 is rotated by the manual shaft 45, the pin 48 is driven in an arc and meshed with the pin 48. The manual spool valve 42 that performs linear motion in the hydraulic valve body 41.

When the manual shaft 45 is rotated clockwise as viewed in the direction of arrow A in FIG. 3, the pin 48 pushes the manual spool valve 42 into the hydraulic valve body 41 via the detent plate 46, The oil passage is switched in the order of D → N → R → P. That is, the shift range of the automatic transmission 2 is switched in the order of D → N → R → P.
When the manual shaft 45 is rotated in the reverse direction, the pin 48 pulls out the manual spool valve 42 from the hydraulic valve body 41, and the oil passage in the hydraulic valve body 41 is switched in the order of P → R → N → D. That is, the shift range of the automatic transmission 2 is switched in the order of P → R → N → D.

A park rod 51 for driving the park pole 44 is attached to the detent plate 46. A conical portion 52 is provided at the tip of the park rod 51.
The conical portion 52 is interposed between the projecting portion 53 of the housing of the automatic transmission 2 and the park pole 44. When the manual shaft 45 is rotated in the clockwise direction when viewed from the direction of arrow A in FIG. (Specifically, the R → P range), the park rod 51 is displaced in the direction of arrow B in FIG. 3 via the detent plate 46, and the conical portion 52 pushes up the park pole 44. Then, the park pole 44 rotates about the shaft 44b in the direction of arrow C in FIG. 3, the convex portion 44a of the park pole 44 meshes with the concave portion 43a of the parking gear 43, and is locked by the parking switching mechanism 4 (parking state). Is achieved.

  When the manual shaft 45 is rotated in the reverse direction (specifically, the P → R range), the park rod 51 is pulled back in the direction opposite to the arrow B direction in FIG. 3, and the force for pushing up the park pole 44 is lost. Since the park pole 44 is always urged in a direction opposite to the direction of arrow C in FIG. 3 by a torsion coil spring (not shown), the convex portion 44 a of the park pole 44 is disengaged from the concave portion 43 a of the parking gear 43. Becomes free, and the unlocking state (parking release state) of the parking switching mechanism 4 is achieved.

(Description of encoder 60)
As shown in FIG. 1, the rotary actuator 1 described above includes an encoder 60 that detects the rotation angle of the rotor 11 inside the housing (front housing 18 + rear housing 20). By detecting the rotation angle of the rotor 11 by the encoder 60, the electric motor 5 can be operated at high speed without stepping out.
The encoder 60 is an incremental type, and includes a magnet 61 that rotates integrally with the rotor 11, and a magnetic detection Hall IC 62 that is disposed opposite to the magnet 61 in the rear housing 20 and detects the passage of a magnetic flux generation part in the magnet 61 ( For example, a rotation angle detection Hall IC that detects the magnetic flux of multipolar magnetization of the magnet 61 and an index signal Hall IC that detects a magnetic flux generated each time the energization of each phase of the exciting coil 22 makes a round. Thus, the Hall IC 62 is supported by a substrate 63 fixed in the rear housing 20.

(Description of SBW / ECU 7)
The SBW • ECU 7 will be described with reference to FIG.
The SBW / ECU 7 that controls the energization of the electric motor 5 includes a CPU for performing control processing and arithmetic processing, storage means for storing various programs and data (ROM, RAM, SRAM, EEPROM, etc.), input circuit, output circuit, power supply circuit And a control signal is given to the coil drive circuit 71 that controls energization of each excitation coil 22 based on the calculation result.
Here, reference numeral 72 in FIG. 2 is an ignition switch (operation switch), reference numeral 73 is an in-vehicle battery, reference numeral 74 is a display device that displays the state of the shift range switching device (shift range switching state), etc. Reference numeral 75 denotes a vehicle speed sensor, and reference numeral 76 denotes other sensors for detecting the vehicle state, such as a shift range position detection sensor set by the occupant and a brake switch.

  The SBW • ECU 7 includes a “normal control unit” that controls the electric motor 5 so that a shift range operation unit (not shown) operated by the occupant and a shift range position recognized by the SBW / ECU 7 coincide with each other. Various control programs such as “rotor reading means” for grasping the rotation speed, rotation speed, and rotation angle of the rotor 11 from the output are installed.

[Background of Example 1]
As described above, since the output shaft 17 of the rotary actuator 1 and the manual shaft 45 are coupled by spline fitting, backlash for assembling occurs in the rotational direction. For this reason, as shown in FIG. 4, if no measures are taken against backlash, an error is generated between the output shaft 17 of the rotary actuator 1 and the manual shaft 45 by a backlash amount. This will hinder the control of the highly accurate manual shaft 45 by the actuator 1.

Therefore, as shown in FIG. 5, it is conceivable that a torsion coil spring α is arranged around the output shaft 17 and the output shaft 17 is biased in one rotational direction to absorb the play of the spline fitting. However, the means for arranging the torsion coil spring α around the output shaft 17 increases the size of the rotary actuator 1 in the axial direction.
On the other hand, as shown in FIG. 6, a shift position sensor β for detecting the rotation angle of the manual shaft 45 is known for determining the position of the shift range. However, when the shift position sensor β is provided on the manual shaft 45, the mounting space for the rotary actuator 1 is reduced due to the influence of the shift position sensor β, and the mounting property of the rotary actuator 1 is deteriorated.

[Features of Example 1]
A configuration employed by the shift range switching device of the first embodiment in order to solve the above problem will be described with reference to FIG.
The rotary actuator 1 supports a first gear 81 provided on the output shaft 17, a second gear 82 meshing with the first gear 81, and a second gear 82 rotatably on the radially outer side of the output shaft 17. Output shaft rotation urging means 80 including a second shaft 83 that rotates and a torsion coil spring α (an example of a return spring) that urges the second gear 82 in one rotational direction.

The output shaft rotation urging means 80 detects a relative rotation angle between a rotation member 85 that rotates integrally with the second gear 82 and a fixing member 86 that is fixed to the front housing 18 via a sensor cover 88 described later. And a shift position sensor β for detecting the set position of the shift range.
The shift position sensor β in this embodiment is a non-contact rotation angle sensor that detects the rotation angle between the rotation member 85 and the fixed member 86 in a non-contact manner.

The above will be specifically described.
The first gear 81 is a spur gear coupled to the outer peripheral surface of the output shaft 17 on the front side of the flange.
The second shaft 83 is a fixed shaft that protrudes forward of the front housing 18 and is supported by the front housing 18, and is provided in parallel with the output shaft 17.
The second gear 82 is a substantially fan-shaped gear provided integrally with a rotating member 85 that is rotatably supported around a second shaft 83 via a second bearing 87, The formed second gear 82 always meshes with the first gear 81.
With the above configuration, the rotation of the output shaft 17 is transmitted from the first gear 81 → the second gear 82 → the rotation member 85, and as a result, a rotation angle corresponding to the rotation angle of the output shaft 17 is given to the rotation member 85.

The torsion coil spring α is disposed on the outer periphery of the rotating member 85, and one end is locked to the front housing 18 and the other end is locked to the rotating member 85. The torsion coil spring α applies an urging force to the rotating member 85 in all shift ranges regardless of the set position of the shift range, and is in a state where tension is always applied so that the urging force is applied to the rotating member 85. It is assembled.
The torsion coil spring α generates a spring force (a force for packing backlash) that absorbs backlash due to the backlash of the first gear 81 and the second gear 82 and spline fitting between the output shaft 17 and the manual shaft 45. The torque applied to the output shaft 17 by the torsion coil spring α is smaller than the driving torque of the rotary actuator 1 and, of course, the recess 46 a of the detent plate 46 and the engagement portion 47 a at the tip of the detent spring 47. The torque is set smaller than the torque at which the manual shaft 45 starts to move against the fit.

The rotating member 85 supported by the second shaft 83 is disposed on the front surface of the front housing 18 and is covered with a sensor cover 88 that is attached and fixed to the front housing 18 from the front surface side of the front housing 18.
A shift position for detecting the set position of the shift range from the rotation angle of the rotation member 85 by the rotation member 85 driven to rotate by the first and second gears 81 and 82 and the fixing member 86 provided on the sensor cover 88. A sensor β is provided.

The shift position sensor β in this embodiment is a non-contact rotation angle sensor that detects the relative rotation angle of the rotation member 85 and the fixed member 86 in a non-contact manner, and a specific example thereof will be described.
In the non-contact rotation angle sensor according to the first embodiment, a permanent magnet 91 is attached to the rotation member 85 side, and a magnetic detection element (a Hall IC: not shown) is attached inside the fixed member 86. . When the rotation member 85 rotates and the permanent magnet 91 rotates, the magnetic flux density applied to the magnetic detection element changes, and the rotation angle between the rotation member 85 and the fixed member 86 is detected by the magnetic flux density applied to the magnetic detection element. To do. In addition, the code | symbol 92 in FIG. 1 is a connector for taking out the output of a magnetic detection element.

[Effect of Example 1]
In the shift range switching device of this embodiment, the urging force applied to the second gear 82 by the torsion coil spring α is transmitted to the first gear 81 and transmitted to the output shaft 17, and the output shaft 17 is transmitted by the urging force of the torsion coil spring α. It is biased in one direction of rotation.
As a result, the backlash of the spline fitting between the output shaft 17 of the rotary actuator 1 and the manual shaft 45 is absorbed (backlashed) by the biasing force of the torsion coil spring α, and the controllability of the manual shaft 45 by the rotary actuator 1 is improved. To do.
Since the output shaft rotation urging means 80 is provided on the outer side in the radial direction of the output shaft 17, compared with the case where the torsion coil spring α is arranged around the output shaft 17 (see FIG. 5), the rotary actuator No increase in the physique in the axial direction of 1.
That is, the play due to the spline fitting between the output shaft 17 of the rotary actuator 1 and the manual shaft 45 is absorbed while suppressing an increase in the size of the rotary actuator 1 in the axial direction, and the control of the manual shaft 45 by the rotary actuator 1 is absorbed. It is possible to improve the performance.

On the other hand, in the shift range switching device of this embodiment, when the output shaft 17 rotates by switching the shift range, the rotation of the output shaft 17 is transmitted from the first gear 81 to the second gear 82 to the rotating member 85 and to the fixed member 86. On the other hand, the rotation member 85 rotates relatively.
Since the shift position sensor β that detects the set position of the shift range from the relative rotation angle of the rotating member 85 and the fixed member 86 is provided on the radially outer side of the output shaft 17, the shift position sensor β is attached to the manual shaft 45. Compared with the case where β is mounted (see FIG. 6), deterioration of mountability of the rotary actuator 1 due to the influence of the shift position sensor β can be suppressed.
That is, even if the shift position sensor β is provided for detecting the set position of the shift range of the automatic transmission 2, it is possible to suppress deterioration in mountability of the rotary actuator 1 due to the influence of the shift position sensor β.

[Modification]
In the above embodiment, an example in which the torsion coil spring α is used as an example of the return spring has been described. However, other spring means that can apply a biasing force in the rotational direction to the second gear 82 may be used.
In the above embodiment, the permanent magnet 91 is disposed on the rotating member 85 side, and the magnetic detection element is disposed on the fixed member 86 side. Conversely, the magnetic detection element is disposed on the rotating member 85 side, and the permanent magnet is disposed on the fixed member 86 side. 91 may be arranged. In this embodiment, a non-contact rotation angle sensor is shown as an example, but a contact-type rotation angle sensor using a variable resistor may be used.

In the above embodiment, the shift position sensor β (rotation angle sensor) is provided by the rotation member 85 and the fixed member 86 that are rotationally driven by the second gear 82. However, the shift position sensor β (rotation angle sensor) is provided. It may be the one without the function.
In the above embodiment, an SR motor is used as an example of the electric motor 5, but other reluctance motors such as a synchronous reluctance motor, a surface magnet structure type synchronous motor (SPM), and an embedded magnet structure are used. Other motors such as a permanent magnet type synchronous motor such as a type synchronous motor (IPM) may be used.

(Example 1) which is sectional drawing of a rotary actuator. It is a system configuration figure of a shift range switching device. It is a perspective view of a parking switching mechanism and a shift range switching mechanism. It is sectional drawing of a rotary actuator (conventional example). It is sectional drawing of a rotary actuator (reference example 1). It is sectional drawing of a rotary actuator (reference example 2).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotary actuator 2 Automatic transmission 3 Shift range switching mechanism 17 Output shaft 18 Front housing (Rotary actuator housing)
45 Manual shaft 80 Output shaft rotation biasing means 81 First gear 82 Second gear 83 Second shaft 85 Rotating member 86 Fixed member α Torsion coil spring (return spring)
β Shift position sensor (Non-contact rotation angle sensor)

Claims (3)

A shift range switching mechanism that switches a shift range in an automatic transmission by rotating a manual shaft that is rotatably supported;
A rotary actuator that switches the shift range switching mechanism by rotationally driving the manual shaft, and
In the shift range switching device in which the output shaft of this rotary actuator is spline-fitted with the manual shaft,
The rotary actuator is
A first gear provided on the output shaft;
A second gear meshing with the first gear;
A second shaft that rotatably supports the second gear on the radially outer side of the output shaft;
A shift range switching device comprising: an output shaft rotation urging means including a return spring that urges the second gear in one rotation direction. In the shift range switching device according to claim 1,
The output shaft rotation urging means is
A relative rotation angle between a rotating member that rotates integrally with the second gear and a fixed member that is fixed to a housing of the rotary actuator is detected to detect a set position of a shift range of the automatic transmission. A shift range switching device comprising a shift position sensor. In the shift range switching device according to claim 2,
The shift position switching device, wherein the shift position sensor is a non-contact rotation angle sensor that detects a rotation angle between the rotation member and the fixed member in a non-contact manner.

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