JP2006182188A - Transmission ratio variable steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission ratio variable steering device hardly generating noise at driving of a lock lever. <P>SOLUTION: The transmission ratio variable steering device 1 is provided with a lock mechanism 3 for locking an upper steering shaft 71 and a motor shaft 13. The lock mechanism 3 has a lock holder 24 integrally rotatably provided on the motor shaft 13; a lock pin 23 integrally provided on housings 6-8; a lock lever 25 pivotably supported around the lock pin 23 by inserting the lock pin 23 to a shaft hole 25 and having an engagement claw part 25b engageable with a lock groove 24a at one end; first and second torsion coil springs 30, 31 having one ends 30a, 31a fixed to the housing 6-8 or the lock pin 23 and the other ends 30b, 31b fixed to the lock lever 25 and urging the engagement claw part 25b to the lock holder 24 side; and a solenoid 32 for driving the engagement claw part 25b. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transmission ratio variable steering apparatus.

  Conventionally, Patent Document 1 discloses a transmission ratio variable steering apparatus. This variable transmission ratio steering device is used in a steering device as shown in FIG. In this steering apparatus, a steering handle 70 of a vehicle is connected to an upper end of an upper steering shaft 71 as an input shaft. Further, the lower end of the upper steering shaft 71 and the upper end of the lower steering shaft 72 as an output shaft are connected via the transmission ratio variable steering device 1.

  Further, a pinion (not shown) is provided at the lower end of the lower steering shaft 72 via a constant velocity joint (not shown), and the pinion is meshed with a rack 74 in the steering gear box 73. One end of each tie rod 75 is connected to each end of the rack 74, and a steered wheel 77 is connected to the other end of each tie rod 75 via a knuckle arm 76.

  Further, the upper steering shaft 71 is provided with a steering angle sensor 78 that detects the steering angle of the steering handle 70, and the lower steering shaft 72 is provided with a steering angle sensor 79 that detects the steering angle of the steered wheels 77. Yes. The steering angle of the steering handle 70 and the turning angle of the turning wheel 77 detected by the steering angle sensor 78 and the turning angle sensor 79 are input to the ECU 80. The ECU 80 also receives a vehicle speed output from a vehicle speed sensor 81 that detects the vehicle speed. The ECU 80 outputs a control signal for controlling the transmission ratio variable steering apparatus 1 to the transmission ratio variable steering apparatus 1.

  As shown in FIG. 7, the transmission ratio variable steering device 1 is provided with a lock mechanism 3, a motor 4, and a wave gear mechanism 5 as a gear mechanism in housings 6 to 8 that are integrally coupled. Is provided with a spiral cable device 2. A lower end 71 a of the upper steering shaft 71 and an upper end 72 a of the lower steering shaft 72 are connected to the transmission ratio variable steering apparatus 1.

  A cylindrical fitting portion 6 a is formed on the upper steering shaft 71 side of the housing 6. A lower end 71a of the upper steering shaft 71 is fitted to the fitting portion 6a via a leaf spring 6b, so that the housing 6 and the upper steering shaft 71 rotate as a unit.

  The motor 4 has a motor housing 10 fixed in the housing 7. The motor housing 10 includes a motor housing body 10a and a motor end plate 10b. The motor housing body 10 a has a cup shape with a shaft hole 10 c at the center, and is fixed to the housing 7. A motor end plate 10b is fixed to the upper steering shaft 71 side of the motor housing body 10a so as to close the opening of the motor housing body 10a. A stator 12 is fixed to the inner peripheral surface of the motor housing body 10 a, and a rotor 14 that is rotationally driven by the stator 12 is provided in the stator 12. A motor shaft 13 is fixed to the rotor 14, and the motor shaft 13 protrudes in the axial direction at both ends of the rotor 14. One end 13a of the motor shaft 13 is supported by a ball bearing 15 provided between the motor end plate 10b and the other end 13b of the motor shaft 13 is provided between the shaft hole 10c of the motor housing body 10a. It is supported by a ball bearing 16. Thereby, the motor shaft 13 can rotate coaxially with respect to the motor housing main body 10a and the housings 6-8. One end 13 a of the motor shaft 13 on the spiral cable device 2 side can be fixed to the housings 6 to 8 by the lock mechanism 3. On the other hand, the other end 13 b of the motor shaft 13 is connected to the wave gear mechanism 5.

  The wave gear mechanism 5 has a wave generator 17 in which the other end 13 b of the motor shaft 13 is fitted and can rotate integrally with the motor shaft 13. The wave generator 17 includes a cam 17a having an elliptical cross section perpendicular to the axis, and a ball bearing 17b provided on the outer periphery of the cam 17a. The inner ring of the ball bearing 17b is fixed to the outer periphery of the cam 17a, and the outer ring of the ball bearing 17b can be elastically deformed via the ball. An annular flexspline 19 that can be elastically deformed integrally with the outer ring of the ball bearing 17 b is provided on the outer periphery of the wave generator 17. External teeth 19 a are formed on the outer periphery of the flex spline 19. An annular stay circular spline 20 is formed on the motor 4 side in the housing 7. Inner teeth 20 a having a greater number of teeth than outer teeth 19 a of flex spline 19 are formed on the inner periphery of stay circular spline 20, whereby stay circular spline 20 meshes with flex spline 19. Further, an annular drive circular spline 21 adjacent to the stay circular spline 20 is rotatably supported on the side of the lower steering shaft 72 in the housing 7 via a bearing metal 7a. The same number of inner teeth 21 a as the outer teeth 19 a of the flex spline 19 are formed on the inner circumference of the drive circular spline 21, whereby the drive circular spline 21 is also meshed with the flex spline 19. A protection plate 9 is provided between the motor housing body 10 a and the wave gear mechanism 5. An upper end 72 a of the lower steering shaft 72 is fixed to the drive circular spline 21.

  As shown in FIGS. 8 and 9, the lock mechanism 3 includes a lock holder 24 fixed to the outer periphery of one end 13 a of the motor shaft 13 on the spiral cable device 2 side and having a plurality of lock grooves 24 a recessed in the outer periphery. Have. The motor end plate 10b is integrally provided with a lock pin 23 parallel to the axis via a lock base 38 (in FIG. 8, the lock base 38 is omitted). A lock lever 25 that can swing around the lock pin 23 is pivotally supported via a bush 29 press-fitted into its own shaft hole 25a. At one end of the lock lever 25, an engagement claw portion 25b that can be engaged with the lock groove 24a is formed. A first torsion coil spring 30 having one end 30 a fixed to the tip of the lock pin 23 and the other end 30 b fixed to the lock lever 25 is provided around the bush 29 on the surface side of the lock lever 25. A second torsion coil spring 31 is provided around the bush 29 on the back side of the lock lever 25, with one end 31 a fixed to the lock base 38 and the other end 31 b fixed to the lock lever 25. These first and second torsion coil springs 30 and 31 urge the engaging claw portion 25b of the lock lever 25 toward the lock holder 24 by their urging force. The lock base 38 is fixed with a solenoid 32 that drives the engaging claw portion 25b to the opposite side of the lock holder 24 when energized.

  As shown in FIG. 10, the solenoid 32 has a resin bobbin 34 housed in a cup-shaped solenoid housing 33 a having an open end, and a coil 35 is wound around the bobbin 34. An iron core 36 is provided at the rear end of the bobbin 34, and a plunger 37 having a tip 37a protruding from the solenoid housing 33a is slidably provided in the bobbin 34. The tip of the solenoid housing 33a is closed by a cover member 33b so as to allow the plunger 37 to slide. A pin 37c extending in parallel with the lock pin 23 is fixed to the distal end portion 37a of the plunger 37 via a flange-shaped stopper 37b. As shown in FIG. 8, the pin 37c is opposite to the engaging claw portion 25b. The other end of the lock lever 25 is engaged.

  The spiral cable device 2 shown in FIG. 7 is provided with a cylindrical casing 26 held by a vehicle body (not shown), and provided inside the casing 26 so as to be relatively rotatable with respect to the casing 26. And an inner cylinder 27 fixed to the housing 6. In addition, a flexible flat cable 28 is provided between the housing 26 and the inner cylinder 27 by insulatingly coating a plurality of lead wires. One end of the flexible flat cable 28 is connected to the inner cylinder 27. It is wound around the inner cylinder 27 and the other end is connected to the casing 26. The lead wire connected to the flexible flat cable 28 and extending from the inner cylinder 27 is connected to the stator 12 of the motor 4 and the lead wire connected to the flexible flat cable 28 and extended from the housing 26 is not shown in the figure of the vehicle body. The battery and the ECU 80 are connected by a connector.

  In this variable transmission ratio steering apparatus 1, as shown in FIG. 10, if the solenoid 32 of the lock mechanism 3 is energized, the iron core 36 is excited by the coil 35, and the first and the second shown in FIGS. The plunger 37 shown in FIG. 10 is magnetically attached to the iron core 36 against the urging force of the two torsion coil springs 30 and 31. As a result, the lock lever 25 shown in FIGS. 8 and 9 swings around the lock pin 23 counterclockwise in the figure, and the engaging claw portion 25b is not engaged with the lock groove 24a of the lock holder 24. . In this state, when the driver steers the steering wheel, the steering angle is transmitted to the housings 6 to 8 through the input shaft 71 as shown in FIG. At this time, the motor 4 rotationally drives the rotor 14 according to the steering angle. The rotation of the rotor 14 is transmitted to the gear mechanism 5 via the motor shaft 13 and the output shaft 72 is rotationally driven.

  On the other hand, as shown in FIG. 10, when the energization to the solenoid 32 of the lock mechanism 3 is stopped, the iron core 36 is demagnetized. Accordingly, the plunger 37 shown in FIG. 10 is separated from the iron core 36 by the urging force of the first and second torsion coil springs 30 and 31 shown in FIGS. 8 and 9, and the lock lever 25 shown in FIGS. 8 and 9 is locked. The pin 23 swings to the right in the drawing, and the engaging claw portion 25b engages with the lock groove 24a of the lock holder 24. In this state, since the housing 6 and the motor shaft 13 are connected and fixed, when the driver steers the steering wheel, the steering angle is transmitted to the housings 6 to 8 via the input shaft 71 as shown in FIG. In addition, the steering angle is transmitted to the motor shaft 13. The rotation of the motor shaft 13 is transmitted to the gear mechanism 5 and the output shaft 72 is driven to rotate.

  As described above, the locked state in which the engaging claw portion 25b of the lock lever 25 is engaged with the lock groove 24a of the lock holder 24 is applied when the transmission ratio variable control is disabled due to a failure of the motor 4 or the like. . In this locked state, the steering handle 70 side and the steered wheel 77 side are directly connected, so that even when the motor 4 fails, steering with a fixed transmission ratio is possible. The reason why the locked state is achieved by stopping energization of the solenoid 32 is for fail-safe (the locked state can be set even when a failure such as disconnection occurs in the solenoid 32). The reason why the two first and second torsion coil springs 30 and 31 are used to engage the engagement claw portion 25b of the lock lever 25 with the lock groove 24a of the lock holder 24 is also for failsafe. It is.

  Thus, in this variable transmission ratio steering apparatus 1, the first and second torsion coil springs 30 and 31 of the lock mechanism 3 drive the lock lever 25 to lock the input shaft 71 and the motor shaft 13 (13a) in an emergency or the like. The turning angle is transmitted to the turning system in a state where the transmission ratio between the steering angle and the turning angle is varied while being in a possible state.

Japanese Patent Laid-Open No. 2003-320943

  However, it has been clarified that the conventional transmission ratio variable steering device generates an abnormal noise when the lock lever is driven.

  The present invention has been made in view of the above-described conventional situation, and an object to be solved is to provide a transmission ratio variable steering device that is unlikely to generate abnormal noise when the lock lever is driven.

  In order to solve the above-mentioned problems, the present inventors investigated the cause of abnormal noise. And the following knowledge was acquired.

  That is, as shown in FIG. 9, in this lock mechanism 3, a bush 29 having excellent slidability is press-fitted into the shaft hole 25 a of the lock lever 25, and the bush 29 is made to swing around the lock pin 23. Has a minute gap C (exaggerated in the figure) between the lock pin 23 and the lock pin 23. Further, the first and second torsion coil springs 30 and 31 are wound around the outer peripheral surface of the bush 29 extending to the front surface side and the back surface side of the lock lever 25. The first torsion coil spring 30 on the surface side of the lock lever 25 has one end 30 a fixed to the tip of the lock pin 23, the other end 30 b fixed to the lock lever 25, and the engagement claw portion 25 b of the lock lever 25. It is biased toward the lock holder 24 side. The second torsion coil spring 31 on the back side of the lock lever 25 also has one end 31a fixed to the lock base 38 and the other end 31b fixed to the lock lever 25, which also locks the engagement claw portion 25b of the lock lever 25. It is biased toward the holder 24 side.

  Therefore, in a state where the engaging claw portion 25b of the lock lever 25 is in contact with the lock holder 24, as shown in FIG. 11, a force F30x in a direction approaching the lock holder 24 is applied to the lock lever 25. A force F30y that balances the force F30x is applied to the lock pin 23. For this reason, a force F30 in a direction away from the lock holder 24 acts on the bush 29 as a reaction force thereof. Similarly, the second torsion coil spring 31 on the back surface side of the lock lever 25 similarly applies a force F31x in a direction approaching the lock holder 24 to the lock lever 25 and a force F31y that balances the force F31x against the lock pin 23. give. For this reason, the force F31 in the direction away from the lock holder 24 acts on the bush 29 as these reaction forces. For this reason, the bush 29 is pushed away from the lock holder 24 by the resultant force F of the force F30 and the force F31. For this reason, as shown in FIGS. 9 and 12, the bush 29 and the lock lever 25 position the gap C on the opposite side to the lock holder 24.

  When the solenoid 32 is energized from this state and the engagement claw portion 25b of the lock lever 25 is separated from the lock holder 24 (in FIG. 12, the lock lever 25 is swung counterclockwise), FIG. As shown, since the lock lever 25 is pulled together with the bush 29 by the force Fs when the plunger 37 is magnetically attached to the iron core 36, the bush 29 and the lock lever 25 move toward the lock holder 24 at that moment, The lock pin 23 collides (the gap C moves to the lock holder 24 side). An abnormal noise is generated at the time of this collision. This abnormal noise is remarkable when the bush 29 is made of metal. The present invention has been completed based on the above findings.

  The applicants proposed that the bush 29 made of an elastic body is provided between the lock pin 23 and the lock lever 25 based on the same knowledge (Japanese Patent Application No. 2003-289236). In this way, even when the resin bush 29 is used, abnormal noise is generated. Further, making the material of the bush 29 more elastically deformable is also limited from the viewpoint of durability, and it is necessary to suppress the generation of abnormal noise while maintaining high durability.

In other words, the transmission ratio variable steering apparatus of the first invention is provided so as to be rotatable integrally with the housing, the input shaft for transmitting the steering angle of the steering handle, and fixed in the housing, so that the motor shaft can be rotated. A motor, an output shaft that is rotatably supported by the housing and transmits a turning angle to a steering system, and is provided between the motor shaft and the output shaft in the housing. A gear mechanism for increasing and decreasing the angle and outputting to the output shaft, and a lock mechanism provided between the input shaft and the motor shaft in the housing and locking the input shaft and the motor shaft;
The lock mechanism is provided so as to be rotatable integrally with the motor shaft, a lock holder having a plurality of lock grooves recessed on the outer periphery, a lock pin provided integrally with the housing, parallel to the shaft center, and a shaft hole The lock pin is inserted into the lock pin and is pivotally supported so as to be swingable around the lock pin. The lock lever has an engaging claw portion engageable with the lock groove at one end, and one end of the lock pin on the housing or the lock pin. A torsion coil spring that is fixed and has the other end fixed to the lock lever and biases the engaging claw portion toward the lock holder, and a solenoid that drives the engaging claw portion, and the steering angle In the transmission ratio variable steering device that varies the transmission ratio with the turning angle,
A bush is provided between the lock pin and the shaft hole, and the bush is a bearing bush positioned in the shaft hole, and a spring around which the torsion coil spring is wound outside the shaft hole. It is characterized by comprising a receiving bush.

  In the variable transmission ratio steering apparatus according to the first aspect of the invention, the bush provided between the lock pin and the shaft hole of the lock lever is composed of the bearing bush and the spring receiving bush, and the bearing bush is located in the shaft hole and the lock lever is moved. The spring is preferably pivoted around the lock pin, and the spring receiving bush is positioned outside the shaft hole and receives the winding of the torsion coil spring.

  For this reason, in a state where the engaging claw portion of the lock lever is in contact with the lock holder, a force in a direction away from the lock holder acts on the spring receiving bush, but the force does not act on the bearing bush. Rather, since the other end of the torsion coil spring is fixed to the lock lever, only the force in the direction approaching the lock holder acts on the bearing bush. For this reason, although the spring bearing bush is pushed away from the lock holder, the bearing bush is pushed away from the lock holder. For this reason, the spring bearing bush is positioned on the opposite side of the lock holder and the gap is positioned on the opposite side of the lock holder. However, the bearing bush and the lock lever are positioned on the lock holder side, and the gap is provided. It will be located on the lock holder side.

  When the solenoid is energized from this state and the engagement claw part of the lock lever is separated from the lock holder, the solenoid is positioned on the lock holder side before the bearing bush and the lock lever are pulled, The bearing bush and the lock lever do not move toward the lock holder, and the bearing bush and the lock pin do not collide.

  Therefore, the variable transmission ratio steering apparatus of the first invention is unlikely to generate abnormal noise when the lock lever is driven.

  The torsion coil spring can be composed of a first torsion coil spring located on the front side of the lock lever and a second torsion coil spring located on the back side of the lock lever. In this case, even if one of the torsion coil springs is broken, the other torsion coil spring can engage the engaging claw portion of the lock lever with the lock groove of the lock holder, thereby realizing fail safe. it can.

  Thus, when the first and second torsion coil springs are employed, the spring receiving bush includes a first spring receiving bush around which the first torsion coil spring is wound and a second spring receiver around which the second torsion coil spring is wound. It can consist of a bush. Thereby, since the 1st and 2nd spring receiving bush receives the force by the 1st and 2nd torsion coil spring, respectively, the above-mentioned effect can be produced reliably.

A transmission ratio variable steering apparatus according to a second aspect of the invention is provided with a housing, an input shaft that transmits the steering angle of the steering handle, and a motor that is fixed in the housing and that can rotate the motor shaft. And an output shaft that is rotatably supported by the housing and transmits a turning angle to a turning system, and is provided between the motor shaft and the output shaft in the housing, and the rotation angle of the motor shaft is A gear mechanism that increases and decreases and outputs to the output shaft, and a lock mechanism that is provided between the input shaft and the motor shaft in the housing and locks the input shaft and the motor shaft,
The lock mechanism is provided so as to be rotatable integrally with the motor shaft, a lock holder having a plurality of lock grooves recessed on the outer periphery, a lock pin provided integrally with the housing, parallel to the shaft center, and a shaft hole The lock pin is inserted into the lock pin and is pivotally supported so as to be swingable around the lock pin. The lock lever has an engaging claw portion engageable with the lock groove at one end, and one end of the lock pin on the housing or the lock pin. A torsion coil spring that is fixed and has the other end fixed to the lock lever and biases the engaging claw portion toward the lock holder, and a solenoid that drives the engaging claw portion, and the steering angle In the transmission ratio variable steering device that varies the transmission ratio with the turning angle,
A bush having an uneven surface on the outer peripheral surface is provided between the lock pin and the shaft hole.

  In the transmission ratio variable steering device of the second invention, since the bush provided between the lock pin and the shaft hole of the lock lever has irregularities on the outer peripheral surface, even if the bush and the lock pin collide, the force at that time is reduced. It can be absorbed by the deformation of the irregularities.

  Therefore, the variable transmission ratio steering apparatus of the second invention is also less likely to generate abnormal noise when the lock lever is driven.

  In the transmission ratio variable steering apparatus of the first and second inventions, the bush is preferably made of resin. The bush made of resin is excellent in buffering properties and makes the effects of the first and second inventions more reliable.

  It is also possible to embody the first and second inventions simultaneously. In this case, the effects of the first and second inventions are made more reliable.

  Embodiments 1 and 2 embodying the present invention will be described below with reference to the drawings.

  The transmission ratio variable steering apparatus 1 according to the first embodiment employs a bush 40 shown in FIG. 1 as the lock mechanism 3. The bush 40 includes a bearing bush 42 positioned in the shaft hole 25a of the lock lever 25, a first spring receiving bush 41 on which the first torsion coil spring 30 is wound and positioned above the shaft hole 25a, A second spring receiving bush 43 is provided below the shaft hole 25a and around which the second torsion coil spring 31 is wound. The bearing bush 42 and the first and second spring receiving bushes 41 and 43 are elastic bodies, and specifically, are made of resin such as PTFE. Other configurations are the same as those of the conventional transmission ratio variable steering apparatus. Note that a soft metal can also be used as the elastic body.

  In the lock mechanism 3 of the variable transmission ratio steering device 1, as shown in FIG. 2, the first and second spring bearing bushes 41 in a state where the engaging claw portion 25 b of the lock lever 25 is in contact with the lock holder 24. 43, force F30, F31 in the direction away from the lock holder 24 acts, but the force F30, F31 does not act on the bearing bush 42. Rather, since the other ends 30b and 31b of the first and second torsion coil springs 30 and 31 are fixed to the lock lever 25, a force in a direction approaching the lock holder 24 is applied to the bearing bush 42 as shown in FIG. Only F30x and F30x act. For this reason, the first and second spring bearing bushes 41 and 43 are pushed away from the lock holder 24, but the bearing bush 42 is pushed away from the lock holder 24. For this reason, the bearing bush 42 and the lock lever 25 position the gap C on the lock holder 24 side.

  When the solenoid 32 is energized from this state and the engaging claw portion 25b of the lock lever 25 is separated from the lock holder 24, the solenoid 32 pulls on the bearing bush 42 and the lock lever 25 before they are pulled to the lock holder 24. The position is closest (the gap C is located on the lock holder 24 side). For this reason, even if it is pulled by the solenoid 32, it can be swung while the gap C is maintained on the lock holder 24 side, and the bearing bush 42 and the lock pin 23 do not collide.

  Therefore, the transmission ratio variable steering device 1 is unlikely to generate abnormal noise when the lock lever 25 is driven. In particular, since the bearing bush 42 is made of a resin such as PTFE, the bearing bush 42 is excellent in buffering properties, and this effect is surely produced.

  Further, in the transmission ratio variable steering device 1, even if one of the first and second torsion coil springs 30 and 31 is broken, the engagement claw portion 25b of the lock lever 25 is locked by the other to the lock groove 24a of the lock holder 24. Can be engaged, and fail-safe can be realized. Other operations are the same as those of the conventional transmission ratio variable steering apparatus 1.

  The transmission ratio variable steering apparatus 1 according to the second embodiment employs a bush 44 shown in FIGS. 4 and 5 as the lock mechanism 3. On the outer peripheral surface of the bush 44, serrations 44a are formed as irregularities. The shape of the serration 44a is not limited, but a convex having a small volume is preferable because of its high deformability. This bush 44 is also made of PTFE. Other configurations are the same as those of the conventional transmission ratio variable steering apparatus.

  In this variable transmission ratio steering apparatus 1, since the bush 44 provided between the lock pin 23 and the shaft hole 25a of the lock lever 25 has serrations 44a on the outer peripheral surface, the bush 44 and the lock pin 23 collide. However, the force at that time can be absorbed by the deformation of the unevenness.

  Therefore, the variable transmission ratio steering apparatus 1 is also less likely to generate abnormal noise when the lock lever 25 is driven. Other functions and effects are the same as those of the first embodiment.

  Note that the bush 44 can be divided into three parts and configured in the same manner as in the first embodiment. Moreover, the bush 40 of Example 1 and the bush 44 of Example 2 can also be comprised with a copper-type metal.

  The present invention is applicable to a transmission ratio variable steering apparatus that includes a lock mechanism that locks an input shaft and a motor shaft and varies a transmission ratio between a steering angle and a turning angle.

FIG. 3 is a cross-sectional view of a principal part showing a lock mechanism in the variable transmission ratio steering apparatus of the first embodiment. FIG. 3 is a plan view showing a lock mechanism according to the variable transmission ratio steering apparatus of the first embodiment. FIG. 3 is a plan view showing a lock mechanism according to the variable transmission ratio steering apparatus of the first embodiment. FIG. 6 is a cross-sectional view of a principal part showing a lock mechanism in a variable transmission ratio steering apparatus according to a second embodiment. FIG. 4A is a longitudinal sectional view of the bush, and FIG. 4B is a transverse sectional view of the bush. It is a block diagram of the steering apparatus which concerns on Example 1, 2 and the conventional transmission ratio variable steering apparatus. It is the longitudinal cross-sectional view of Example 1, 2 and the conventional variable transmission ratio steering apparatus. FIG. 8 is a cross-sectional view taken along arrows IIX-IIX in FIG. 7 according to Examples 1 and 2 and a conventional transmission ratio variable steering device. It is principal part sectional drawing which concerns on the conventional transmission ratio variable steering apparatus, and shows a lock mechanism. It is sectional drawing of a solenoid in connection with the conventional variable transmission ratio steering apparatus. It is a perspective view which shows the lock mechanism in connection with the conventional variable transmission ratio steering apparatus. It is a top view which shows the lock mechanism in connection with the conventional variable transmission ratio steering apparatus. It is a top view which shows the lock mechanism in connection with the conventional variable transmission ratio steering apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transmission ratio variable steering apparatus 6, 7, 8 ... Housing 70 ... Steering handle 71 ... Input shaft (upper steering shaft)
72 ... Output shaft (lower steering shaft)
13 ... motor shaft 4 ... motor 5 ... gear mechanism (wave gear mechanism)
DESCRIPTION OF SYMBOLS 3 ... Lock mechanism 24 ... Lock holder 24a ... Lock groove 23 ... Lock pin 25 ... Lock lever 25a ... Engagement claw part 30 ... 1st torsion coil spring 31 ... 1st torsion coil spring 32 ... Solenoid 40, 44 ... Bush (41 ... first spring bearing bush, 42 ... bearing bush, 43 ... second spring bearing bush)
44a ... Unevenness (serration)

Claims (4)

A housing, an input shaft that is integrally rotatable with the housing, transmits a steering angle of a steering handle, a motor that is fixed in the housing and that can rotate the motor shaft, and is rotatably supported by the housing; An output shaft that transmits a turning angle to the turning system, and a gear mechanism that is provided between the motor shaft and the output shaft in the housing, and that increases and decreases the rotation angle of the motor shaft and outputs it to the output shaft And a lock mechanism provided between the input shaft and the motor shaft in the housing and locking the input shaft and the motor shaft,
The lock mechanism is provided so as to be rotatable integrally with the motor shaft, a lock holder having a plurality of lock grooves recessed on the outer periphery, a lock pin provided integrally with the housing, parallel to the shaft center, and a shaft hole The lock pin is inserted into the lock pin and is pivotally supported so as to be swingable around the lock pin. The lock lever has an engaging claw portion engageable with the lock groove at one end, and one end of the lock pin on the housing or the lock pin. A torsion coil spring that is fixed and has the other end fixed to the lock lever and biases the engaging claw portion toward the lock holder, and a solenoid that drives the engaging claw portion, and the steering angle In the transmission ratio variable steering device that varies the transmission ratio with the turning angle,
A bush is provided between the lock pin and the shaft hole, and the bush is a bearing bush positioned in the shaft hole, and a spring around which the torsion coil spring is wound outside the shaft hole. A transmission ratio variable steering device comprising a receiving bush. The torsion coil spring comprises a first torsion coil spring located on the front side of the lock lever and a second torsion coil spring located on the back side of the lock lever;
The spring receiving bush comprises a first spring receiving bush around which the first torsion coil spring is wound, and a second spring receiving bush around which the second torsion coil spring is wound. 1. A transmission ratio variable steering apparatus according to 1. A housing, an input shaft that is integrally rotatable with the housing, transmits a steering angle of a steering handle, a motor that is fixed in the housing and that can rotate the motor shaft, and is rotatably supported by the housing; An output shaft that transmits a turning angle to the turning system, and a gear mechanism that is provided between the motor shaft and the output shaft in the housing, and that increases and decreases the rotation angle of the motor shaft and outputs it to the output shaft And a lock mechanism provided between the input shaft and the motor shaft in the housing and locking the input shaft and the motor shaft,
The lock mechanism is provided so as to be rotatable integrally with the motor shaft, a lock holder having a plurality of lock grooves recessed on the outer periphery, a lock pin provided integrally with the housing, parallel to the shaft center, and a shaft hole The lock pin is inserted into the lock pin and is pivotally supported so as to be swingable around the lock pin. The lock lever has an engaging claw portion engageable with the lock groove at one end, and one end of the lock pin on the housing or the lock pin. A torsion coil spring that is fixed and has the other end fixed to the lock lever and biases the engaging claw portion toward the lock holder, and a solenoid that drives the engaging claw portion, and the steering angle In the transmission ratio variable steering device that varies the transmission ratio with the turning angle,
A transmission ratio variable steering apparatus, wherein a bush having an uneven surface is provided between the lock pin and the shaft hole.   The transmission ratio variable steering apparatus according to any one of claims 1 to 3, wherein the bush is made of resin.

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