JP3068779B2 - Rear wheel steering angle control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear wheel steering angle control device, and more particularly to an actuator for driving a steering mechanism connected to rear wheels of a vehicle, and a transmission mechanism for transmitting a driving force of the actuator to the steering mechanism. The present invention relates to a rear wheel steering angle control device.

[0002]

2. Description of the Related Art Conventionally, a steering angle control device for controlling a steering angle of a rear wheel of a vehicle is known, and various names such as a four-wheel steering device, a rear wheel steering device, and a rear wheel steering angle control device are known. Used. In this rear wheel steering angle control device, for example, the target steering angle of the rear wheels is set to a predetermined value according to the driving state of the vehicle,
The actual steering angle of the rear wheel is detected, and the actuator is driven in accordance with the steering angle deviation between the actual steering angle and the target steering angle, so that the steering angle of the rear wheel is controlled. For example, Japanese Patent Application Laid-Open No. 7-40894 discloses a vehicle steering control device, in which a three-phase electric motor is used as an actuator for driving a rear wheel steering mechanism.

[0003]

However, the conventional rear wheel steering angle control device including the actuator described in the above publication has a complicated structure and a large size, and it is difficult to assemble it at the time of manufacturing. In particular, when an electric motor is used, heat is generated at the time of driving, so that there is a limit to downsizing, and it is necessary to take measures against a failure caused by a rise in temperature.

For this reason, the applicant of the present application has disclosed in
No. 5226, it is an object to reduce the size of a rear wheel steering actuator, to simplify its structure and to prevent a decrease in reliability, and to provide a drive source, a reduction mechanism, a conversion mechanism, and an output shaft on the same shaft. A rear wheel steering actuator in which all are arranged is proposed. In this rear wheel steering actuator, a support member for integrally supporting the winding member to the housing member is formed by resin molding.
One bearing that supports the rotor member is fixed integrally with the support member, and further on a part of the inner peripheral wall of the support member,
The ring gear of the planetary gear mechanism is formed.
Incidentally, the rear wheel steering actuator in the same application means an actuator in a broad sense equivalent to the rear wheel steering angle control device, and an actuator when only the motor portion is represented in distinction from the transmission mechanism is referred to as an actuator in a narrow sense. it can.

In the above rear wheel steering actuator, both the winding part and the ring gear are formed inside the housing by integral molding of resin. At this time, since the thickness of the resin of the winding portion is larger than that of the ring gear, the ring gear portion is pulled toward the winding portion due to shrinkage of the resin after molding, and it is difficult to secure dimensional accuracy as a gear. Becomes For this reason, advanced resin manufacturing technology is required, and this is a new cost increase factor.

On the other hand, there is a demand for a further reduction in the size and weight of the rear wheel steering angle control device. However, the weight can be further reduced by using not only the ring gear but also the sun gear and the planetary gears made of resin. In this case, if an appropriate resin material is used, the width of the gear can be formed thin while maintaining the predetermined strength, and the length in the axial direction can be reduced, so that downsizing is also possible.

Accordingly, an object of the present invention is to provide a rear wheel steering angle control device provided with an actuator and a transmission mechanism, in which the entire apparatus is made small and lightweight while maintaining the dimensional accuracy of a ring gear used for the transmission mechanism. I do.

Further, the present invention provides a rear wheel steering angle control device provided with an actuator and a transmission mechanism, wherein various gears used for the transmission mechanism are each formed of an appropriate resin material, thereby maintaining a predetermined strength. Another challenge is to reduce the size and weight of the entire system.

[0009]

In order to solve the above-mentioned problems, the present invention has a steering mechanism connected to a rear wheel of a vehicle, a winding part and a rotor. An actuator for driving a steering mechanism; and a cylindrical housing for accommodating the actuator. A winding portion and a rotor of the actuator are provided in the housing, and the driving force of the actuator is connected to the rotor to control the driving force of the actuator. In a rear-wheel steering angle control device in which a transmission mechanism for transmitting to a mechanism is disposed adjacently, the transmission mechanism includes a ring gear fixed to an inner surface of the housing, and a shaft connected to the rotor and having the same axis as the axis of the ring gear. includes a sun gear which rotates together with the rotor centered, a plurality of planetary gears connecting with interposed between the ring gear and the sun gear, the ring gear and the front The sun gear, a predetermined amount of glass fibers
The planetary gear is formed of a resin material containing
The ring gear is formed of a resin material not containing lath fiber.
And the winding part is integrally formed inside the housing.
It is configured to be housed and fixed in the housing .

[0010]

[0011]

[0012]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a rear wheel steering angle control device according to one embodiment of the present invention, which includes a steering mechanism (not shown) such as a knuckle arm and a ball joint connected to a rear wheel (not shown) of a vehicle. The rear wheel is connected to both ends of the drive shaft 6 shown in FIG. 1 via a ball joint or the like, and the steering angle of the rear wheel is controlled in accordance with the axial movement of the drive shaft 6. It is configured to be. First, the housing 10 has, for example, a steel pipe main body 11 having a circular cross section, and bearing members 12 and 13 made of, for example, aluminum are joined to both ends thereof, and the drive shaft 6 is inserted through the center of the bearing members 12 and 13. Are slidably supported. A spline 6b is formed at one end of the drive shaft 6, and a groove 13b that meshes with the spline 6b is formed at an open end of the bearing portion 13.
Are configured not to rotate relative to the bearing portions 12 and 13. A bush 12b is interposed between the drive shaft 6 and the bearing 12.

A cylindrical molded portion 2 is integrally formed in a main body 11 of the housing 10 by molding a resin material containing a predetermined amount of glass fiber, and a transmission mechanism 7 is formed therein. I have. Furthermore, in the main body 11,
A three-phase winding part 3, a rotor 4, a magnet 5, and the like are housed adjacent to the molding part 2, and these constitute an actuator 1 of a three-phase motor. The rotor 4 is connected to the drive shaft 6 via a transmission mechanism 7 in the forming section 2. In the transmission mechanism 7, the rotation of the rotor 4 is controlled by first and second two sets of planetary gear mechanisms (represented by 70. , The rotational motion of the rotor 4 is converted into an axial reciprocating motion of the drive shaft 6 and transmitted by the conversion mechanism 80.

Formed part 2 formed inside body part 11
Has first and second planetary gear mechanisms 70, 70 on its inner surface.
The ring gear 72 is integrally formed, and a bearing 91 is integrally fixed to one end thereof. This bearing 9
For example, a ball bearing is used as 1 as shown in FIGS. In addition, the convex portion 11c formed inside the main body portion 11 forms the molded portion 2 for the main body portion 11.
Is configured to be prevented from moving. Therefore, the ring gear 72 is integrally fixed to the housing 10.

The winding part 3 is formed by molding a resin material into a cylindrical shape together with a resin holder 3d for holding a lead 3c for energizing the coil 3a. A cylindrical sub-assembly including the portion 3e is configured. The sub-assembly including the winding part 3 is housed in the main body part 11 and is fitted in close contact with the inner surface of the main body part 11, and the rotor 4 and the drive shaft 6 are housed in the hollow part of the winding part 3. It is configured as follows. Therefore, the heat generated in the winding part 3 is easily radiated through the main body 11.

On the other hand, the rotor 4 is made of a steel pipe having a circular cross section, and a step 4a having a concentric cross section is formed on one end side.
A recess 4b is formed at the other end. A magnet 5 composed of a pair of permanent magnets formed in a cylindrical shape shorter than the rotor 4 is fitted on the outer surface of the rotor 4, and is joined by an adhesive. Further, a cylindrical connecting member 71 is formed integrally with the rotor 4 by molding a resin material containing a predetermined amount of glass fiber.

The connecting member 71 has a cylindrical body 71b joined to the rotor 4, and has a tooth groove formed on the outer peripheral surface at one end thereof, and has a shape in which a sun gear 71a is integrally formed. An annular convex portion 71c is provided on the outer peripheral surface of the cylindrical body portion 71b.
The connecting member 71 is rotatably supported by the molded portion 2 at one end of the ring gear 72 via a bearing 91 in which the inner ring is locked to the convex portion 71c. Further, on the inner surface of the connecting member 71, a convex portion 71d is formed by the resin material penetrating into the concave portion 4b of the rotor 4. As a result, the connecting member 71 is integrated with the rotor 4, and rotates about the drive shaft 6 with respect to the forming section 2, and thus the main body 11. A ball bearing 92 is interposed between the step 4 a at the tip of the rotor 4 and the bearing 12, and the rotor 4 also rotates about the drive shaft 6 with respect to the bearing 12. Therefore, the rotor 4 is eventually rotatably supported by the housing 10.

The transmission mechanism 7 is configured as shown in FIG. 2 to FIG. 5 in an enlarged manner, and includes first and second planetary gear mechanisms 7.
0 and a conversion mechanism 80. First, the sun gear 71
The first planetary gear mechanism 70 is constituted by a, the ring gear 72, and three planetary gears 73a to 73c interposed therebetween. Planetary gears 73a to 73
3c are supported between the holding member 78 and the annular plate 75b of the connecting member 75, and a sun gear 75a integrally formed with the annular plate 75b is disposed around the drive shaft 6. Have been.

Further, planetary gears 76a to 76c are interposed between the sun gear 75a and the ring gear 72 to form a second planetary gear mechanism 70, and the rotation shafts 77a to 77c.
7c is supported between the holding member 79 and the nut 81 of the conversion mechanism 80. The holding member 78 and the annular plate 7
5b, and between the holding member 79 and the nut 81, three pins (represented by 78p and 79p, respectively).
Are supported, and the respective gaps are maintained. The nut 81 is made of, for example, brass and is formed in a cylindrical shape, and is rotatably supported on the inner surface of the main body 11 via a ball bearing 93. A screw groove (female screw) is formed in the hollow portion of the nut 81, and the trapezoidal screw (male screw) 6 a of the drive shaft 6 is arranged to mesh with the screw groove.

In this embodiment, the molded portion 2 including the ring gear 72 and the connecting members 71 and 75 including the sun gears 71a and 75a are all formed of a resin material containing a predetermined amount of glass fiber. As described above, since the resin material contains glass fiber, the strength is increased, the axial length of each gear can be shortened, and the size can be reduced. On the other hand, planetary gears 73a to 73c and 76
a to 76c are formed of a resin material containing no glass fiber. Therefore, when these planetary gears are engaged with the ring gear 72 and the sun gears 71a and 75a, the resin material containing glass fiber and the resin material not containing glass fiber are always engaged with each other, and the glass fiber is contained. The state of mesh between the resin materials is avoided, and wear between the gears can be reduced.

When the rotor 4 rotates, the sun gear 71a integral with the rotor 4 rotates. However, since the ring gear 72 is fixed to the main body 11 of the housing 10, the planetary gears 73a to 73c center around the sun gear 71a. Revolve. Thus, the planetary gears 73a to 73a
c rotates, and the sun gear 7 rotates.
5a rotates. Therefore, the planetary gears 76a to 76c revolve around the sun gear 75a, and the nut 81 that supports them is driven to rotate. Since the nut 81 is supported by the housing 10 via the bearing 93, the nut 81 rotates around the drive shaft 6, but does not move in the axial direction of the drive shaft 6. The trapezoidal screw 6a meshing with the nut 81 is formed integrally with the drive shaft 6, and the drive shaft 6 is held by the spline 6b and the groove 13b so as not to rotate with respect to the bearing 13. Therefore, the trapezoidal screw 6a moves in the axial direction, and eventually the drive shaft 6 moves in the axial direction. That is, in the transmission mechanism 7, the rotational motion of the rotor 4 is reduced by the first and second planetary gear mechanisms 70, and further converted by the conversion mechanism 80 into linear motion of the drive shaft 6 and transmitted.

On the other hand, as shown in FIG. 1, a magnetic pole sensor 40 as a relative steering angle detecting sensor is provided in the main body 11 of the bearing 12.
The rear wheel steering angle sensor 60 as an absolute steering angle detection sensor is provided outside the main body 11. The magnetic pole sensor 40 detects the position of the magnetic pole of a permanent magnet (not shown) that rotates together with the rotor 4 as a rotor.
A permanent magnet is buried in the rotating plate 44 fitted in the bearing, and a Hall element (not shown) is provided in the bearing portion 12 so as to face the permanent magnet. The detection signal of the magnetic pole sensor 40 is input to, for example, an input port of a microcomputer (not shown), and based on the detection signal, the position of the magnetic pole is detected by the microcomputer. Output from an output port (not shown). Further, the rear wheel steering angle sensor 60 is constituted by, for example, a potentiometer, and the detection signal is supplied to the microcomputer. Thus, the steering angle initial value (absolute steering angle) initially set based on the detection signal of the rear wheel steering angle sensor 60, and the steering angle change amount (relative steering angle) determined based on the output signal of the magnetic pole sensor 40. Corner), rear wheel (not shown)
Is required. The specific contents of the steering angle control including the energization control for the coil 3a are well known in the related art. For example, the target rear wheel steering angle obtained based on the vehicle speed, the front wheel steering angle, and the yaw rate is added to the actual rear wheel steering angle. Control is performed so that the steering angles match.

A method of manufacturing the rear wheel steering angle control device having the above-described configuration will be described. First, a convex portion 11c is formed by stamping a steel pipe from the outside of the main body 11, and an inner surface on one end side of the main body 11 is formed. The molded part 2 is molded from a resin material containing glass fiber. At this time, the ring gear 72 is formed at the same time, and the outer ring of the ball bearing constituting the bearing 91 is integrally molded. Also,
Since the concave portion corresponding to the convex portion 11c is formed in the molded portion 2, it does not move with respect to the main body portion 11. Next, the subassembly of the winding part 3 configured as described above is pushed from the other end of the main body 11 until the step portion of the main body 11 and the end of the winding part 3 come into contact with each other.

On the other hand, after the magnet 5 is fitted to the rotor 4, a cylindrical connecting member 71 is integrally formed by molding a resin material containing glass fiber.
The connecting member 71 is formed with the sun gear 71a, the cylindrical body 71b, and the projection 71c as described above. Then, the rotating plate 44 is fitted to the rotor 4, and the bearing 9 is attached to the step 4a.
After the fitting 2 is fitted, it is inserted into the hollow part of the winding part 3, and is pushed in until the projection 71 c of the connecting member 71 contacts the inner ring of the bearing 91.

Next, regarding the right portion of FIG.
After the inner ring of the bearing 93 is fitted on the outer peripheral surface of the shaft and one end of each of the rotating shafts 77a to 77c is supported on the nut 81, the planetary gears 76a to 76c formed of a resin material containing no glass fiber are mounted respectively. Is done. Further, a holding member 79 is mounted, and the other end of each of the rotating shafts 77a to 77c is supported by the holding member 79. At this time, for example, the pin 79p
Are pressed into the nut 81, and the holding member 79 is fixed to the nut 81. Subsequently, the sun gear 75a of the connecting member 75 formed of a resin material containing glass fiber,
It is mounted so as to mesh with the planetary gears 76a to 76c, and the rotating shafts 74a to 74c are supported on the opposite side to the annular plate 75b. These rotating shafts 74a
After mounting planetary gears 73a to 73c made of a resin material that does not contain glass fibers, mounting members 78 are mounted, and for example, all three pins 78p are caulked and fixed. Then, the drive shaft 6 is inserted into the housing 10, and the trapezoidal screw 6 a of the drive shaft 6 is screwed to the nut 81.

Thus, these subassemblies are housed in the ring gear 72 from the right side in FIG. 1, and include planetary gears 73a to 73c and planetary gears 76a to 76c.
c meshes with the ring gear 72, and the outer ring of the bearing 93 is fitted to the inner surface of the main body 11 adjacent to the ring gear 72. Finally, the bearings 12 and 13 are inserted into the drive shaft 6 and fitted to the main body 11, and then locked by the lock nut 14 at the main body 11. After being assembled as described above, ball joints 100 are screwed to both ends of the drive shaft 6, respectively. Thus, the housing 10 is configured as shown in FIG. 1, and the magnetic pole sensor 40, the actuator 1, and the components constituting the transmission mechanism 7 are accommodated therein.

[0027]

Since the present invention is configured as described above, the following effects can be obtained. That is, the rear wheel steering angle control device according to the present invention includes a ring gear and a sun gear of the transmission mechanism.
Made of a resin material containing a certain amount of glass fiber,
Tally gear made of resin material that does not contain glass fiber
And the ring gear is integrally molded inside the housing,
Part is configured to be housed and fixed in the housing
To minimize wear between gears while maintaining the required strength.
To ensure durability and shorten the axial length.
Therefore, the entire device can be formed small and lightweight without impairing the dimensional accuracy of the ring gear.

[0028]

[0029]

[Brief description of the drawings]

FIG. 1 is a sectional view of a rear wheel steering angle control device according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a part of a rear wheel steering angle control device according to an embodiment of the present invention.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a view showing a state where a holding member 78 is removed in FIG. 2;
It is a B sectional view.

FIG. 5 is a sectional view taken along line CC of FIG. 2;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Actuator 2 Molding part 3 Winding part, 3a coil, 3b Laminated core 4 Rotor 5 Magnet 6 Drive shaft, 6a Trapezoidal screw, 6b Spline 7 Transmission mechanism 10 Housing 11 Main body part, 11c Convex part 12, 13 Bearing part 40 Magnetic pole sensor Reference Signs List 60 rear wheel steering angle sensor 70 planetary gear mechanism 71 connecting member, 71a sun gear, 71b
Cylindrical part 72 Ring gear 73a-73c Planetary gear 74a-74c Rotating shaft 75 Connecting member, 75a Sun gear, 75b
Annular plates 76a-76c Planetary gears 77a-77c Rotating shafts 78, 79 Holding members 80 Conversion mechanisms 81 Nuts 91, 92, 93 Bearings

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsukasa Watanabe 2-1-1 Asahi-machi, Kariya-shi, Aichi Aisin Seiki Co., Ltd. (72) Inventor Kaoru Ohashi 1-Toyota-cho, Toyota-shi, Aichi Toyota Motor Corporation (72) Inventor Hisashi Somada 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Co., Ltd. (56) References JP-A-7-215226 (JP, A) JP-A-60-1554955 (JP, A) JP-A-7-285447 (JP, A) JP-A-61-196860 (JP, A) JP-A-9-118246 (JP, A) JP-A-61-134487 (JP, U) JP-A-2-86878 (JP, A) JP, U) Japanese Utility Model Hei 6-73504 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B62D 7/14 B62D 5/04 F16H 1/28

Claims (1)

(57) [Claims] 1. A steering mechanism connected to a rear wheel of a vehicle, an actuator having a winding portion and a rotor for driving the steering mechanism, and a cylindrical housing for accommodating the actuator. A rear wheel steering angle control device in which a winding portion and a rotor of the actuator and a transmission mechanism connected to the rotor and transmitting the driving force of the actuator to the steering mechanism are arranged adjacent to each other; A ring gear fixed to the inner surface of the housing, a sun gear connected to the rotor and rotating together with the rotor about the same axis as the ring gear, and interposed between the sun gear and the ring gear; A plurality of planetary gears, the ring gear and the
Is formed of a resin material containing a certain amount of glass fiber.
And the planetary gear is made of a tree containing no glass fiber.
The ring gear is formed of a grease material,
Side, and the winding part is housed in the housing
Wheel steering angle control system being characterized in that configured to and fixed.