JP2007137325A - Variable steering angle steering device, automobile, method of contracting steering system, and planetary roller mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable steering angle steering device having a contracting stroke in a steering device, an automobile having the same, a method of contracting a steering system, and a planetary roller mechanism which can be used for the steering device. <P>SOLUTION: A sun roller 2 of a planetary reduction mechanism is rotatably connected with a steering input shaft 15. The sun roller 2 and the steering input shaft 15 are inserted in a hollow inner part of a steering output shaft 16 formed to be hollow structure when a predetermined load in an axial direction is input to the steering input shaft 15 by second collision in a vehicular frontal collision. Thereby, the contracting stroke of the steering system when the predetermined load is input is ensured. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a variable steering angle steering device capable of changing a ratio of a steering output to a steering input, an automobile equipped with the same, a steering system contraction method, and a planetary roller mechanism.

As a conventional variable rudder angle steering device, a target rudder angle is calculated based on a vehicle speed and a steering angle, and based on this target rudder angle, a reduction gear composed of a planetary gear mechanism is driven by a motor arranged in series on a steering shaft. It is known that the transmission ratio of the steering angle is made variable by using the relative rotation between the input shaft and the output shaft obtained thereby, and as a result, a steering angle corresponding to the target steering angle is given to the steered wheels. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 10-324263

By the way, in order to protect the occupant when an unusually large load is applied to the steering shaft due to a vehicle frontal collision or the like, the steering device generally requires a contraction function.
However, in the conventional variable steering angle steering device, the motor is arranged in series with the steering shaft, or each component is prevented from being displaced in the axial direction by an external input. In the machine part, it was difficult to ensure a contraction stroke with respect to the load. In this case, it is necessary to secure a contraction stroke at another part, which leads to a situation in which the degree of freedom in design is reduced.

On the other hand, the variable steering angle steering device tends to have a long steering system due to a reduction gear on the steering shaft. is there.
In particular, when the variable steering angle steering device is provided with a torque sensor, the torque sensor is provided near the driver (for example, an upper column) in order to avoid disturbance. Then, in the portion where the torque sensor is provided, it is not possible to perform the contraction due to the hollow structure as conventionally used, and the contraction stroke is performed in other parts under the situation where the device layout is limited as described above. Will be secured. As a result, the degree of freedom in design is further reduced.

As described above, in the conventional variable rudder angle steering device, it is difficult to secure a contraction stroke for occupant protection.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a variable steering angle steering device having a contracting stroke in a steering device, an automobile equipped with the same, a method for contracting a steering system, and a planetary roller mechanism that can be used in the steering device. It is said.

In order to solve the above problem, a variable steering angle steering apparatus according to the present invention is
A variable steering angle steering device that transmits a steering input to a steering input shaft to a steering output shaft via a sun roller supported by a planetary roller,
When a collision load is input to the steering input shaft or the steering output shaft, a contraction stroke for the collision load is generated by movement of the sun roller in the axial direction with respect to the planetary roller.

In addition, the automobile according to the present invention is
An automobile equipped with a variable steering angle steering device that transmits a steering input to a steering input shaft to a steering output shaft via a sun roller supported by a planetary roller,
When a collision load is input to the vehicle body and a load based on the collision load is transmitted to the steering input shaft or the steering output shaft, the sun roller contracts with respect to the planetary roller due to the axial movement of the sun roller. It is characterized by producing a stroke.

Further, the steering system contraction method according to the present invention includes:
A steering system contraction method including a variable steering angle steering device that transmits a steering input to a steering input shaft to a steering output shaft via a sun roller supported by a planetary roller,
When a collision load is input to the steering input shaft or the steering output shaft, a contraction stroke for the collision load is generated by movement of the sun roller in the axial direction with respect to the planetary roller.

The planetary roller mechanism according to the present invention is
A planetary roller mechanism in which a planetary roller is disposed in contact with a roller surface around a sun roller,
A support means for supporting the sun roller at an axial position surrounded by the planetary rollers;
The support means is configured to move the sun roller in the axial direction from the state supported by the planetary roller when a predetermined load in the axial direction is input to the sun roller.

According to the variable steering angle steering apparatus of the present invention, when a collision load is input to the steering shaft, the sun roller and the planetary roller relatively move in the axial direction, so that a contraction stroke with respect to the collision load is ensured. That is, a contraction stroke can be secured in the variable steering angle steering device.
Further, according to the vehicle of the present invention, when a load is input to the steering input shaft or the steering output shaft due to the collision load input to the vehicle body, the sun roller and the planetary roller relatively move in the axial direction. Thereby, the contraction stroke with respect to a collision load is ensured. Therefore, a contraction stroke can be secured in the variable steering angle steering device. As a result, the vehicle body can be flexibly deformed in the primary collision, and the impact on the occupant can be reduced in the secondary collision.

Furthermore, according to the steering system contraction method of the present invention, when a collision load is input to the steering shaft, the sun roller and the planetary roller are moved relative to each other in the axial direction. A contraction stroke is ensured. That is, a contraction stroke can be secured in the variable steering angle steering device.
Further, according to the planetary roller mechanism according to the present invention, the support means releases the sun roller from the support position in response to the input of the predetermined load in the axial direction to the sun roller located at the position surrounded by the planetary roller. Move in the axial direction. Accordingly, it is possible to realize a planetary roller mechanism that generates a stroke with respect to a load input in the axial direction.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
(Constitution)
FIG. 1 is a schematic configuration diagram of a vehicle to which a variable steering angle steering device according to an embodiment of the present invention is applied. Reference numeral 20 in the drawing is a variable steering angle mechanism. The variable steering angle mechanism 20 varies a steering ratio, which is a ratio of the steering angle of the steered wheels 22 to the steering angle of the steering wheel 21, and the steering input shaft 15 connected to the steering wheel 21, and the steering It is provided in a path (torque transmission path) between the steering output shaft 16 connected to the wheel 22. The steering input shaft 15 and the steering output shaft 16 constitute a steering shaft.

  In this torque transmission path, a torque sensor 23 for detecting steering torque is provided on the steering wheel 21 side of the variable steering angle mechanism 20, and the steering wheel 22 side of the variable steering angle mechanism 20 is electrically driven. A steering force booster 24 composed of power steering is provided. In the figure, reference numeral 26 denotes a dash panel of the vehicle, 27 denotes an R & P type steering gear, and the steering output shaft 16 is connected to an intermediate shaft (intermediate shaft) 28 to drive the steering gear 27 to drive the steering wheel 22. Steer.

FIG. 2 is a schematic diagram illustrating the overall configuration of the variable steering angle mechanism 20 in the first embodiment, and FIG. 3 is a cross-sectional view of the variable steering angle mechanism 20. Here, FIG.3 (b) is CC 'arrow directional view in Fig.3 (a).
The variable steering angle mechanism 20 includes a motor 1, and controls the rotation speed and rotation direction of the motor 1 to shift the input from the steering wheel 21 to the steering input shaft 15 and output it to the steering output shaft 16. . The current supplied to the motor 1 is controlled by an electronic control device 30 described later.

The electronic control unit 30 calculates a target turning angle from detection signals of a steering angle sensor that detects the steering angle θ of the steering wheel 21 and a vehicle speed sensor that detects the vehicle speed V, and the actual turning angle is the target turning angle. The motor 1 is feedback-controlled so that
The variable rudder angle mechanism 20 is composed of a planetary speed reduction mechanism having a sun roller 2 with sun gear, a carrier 4 that supports the planet roller 3 with planet gear, and a ring roller 5 with ring gear. The planet roller 3 is a sun roller. 2 and the ring roller 5 in contact with each other. A support pin 3a supported by the carrier 4 is inserted into the planetary roller 3 with the planetary gear, whereby the carrier 4 supports the planetary roller 3 with the planetary gear. Here, the sun roller 2 with the sun gear, the planetary roller 3 with the planetary gear, and the ring roller 5 with the ring gear are geared rollers in which a roller and a gear are integrally formed on the same axis.

In the following description, when the sun gear-equipped sun roller 2, the planetary gear-equipped planetary roller 3, and the ring gear-equipped ring roller 5 are described together, they are simply abbreviated as the sun roller 2, the planetary roller 3, and the ring roller 5. .
A worm wheel 7 that meshes with a worm gear 6 provided on the output shaft of the motor 1 is provided on the outer periphery of the ring roller 5. Here, the worm wheel 6 is not rotated from the worm wheel 7, and the ring roller 5 is also stopped when the motor 1 is stopped.

In the present embodiment, the variable rudder angle mechanism 20 has a planetary speed reduction mechanism having the same shape facing each other in the direction of the steering shaft, the steering input shaft 15 side being the first planetary speed reduction mechanism 20a, and the steering output shaft 16 side being the second planetary gear. This is referred to as a speed reduction mechanism 20b.
The case (housing) 20c on which the first planetary speed reduction mechanism 20a and the second planetary speed reduction mechanism 20b are mounted is fixed so that the input side does not rotate with respect to the column outer tube 25, and the output side is the case 24a of the steering booster 24. It is fixed so that it does not rotate.

The steering input shaft 15 is connected to the same shaft without rotating relative to the carrier 4 of the first planetary speed reduction mechanism 20a, and the steering output shaft 16 is formed integrally and hollow with the carrier 4 of the second planetary speed reduction mechanism 20b. Yes. Further, the sun rollers 2 of the first planetary speed reduction mechanism 20a and the second planetary speed reduction mechanism 20b are connected (integrally formed).
Further, the steering input shaft 15 supports the one end (the steering input shaft 15 side) of the sun roller 2 of the first planetary reduction mechanism 20a by the bushing 14 so as to be displacement-constrained and rotatable. Further, a detaching piece 10 is inserted into the hollow interior of the steering output shaft 16, and this detaching piece 10 is connected to the other end of the sun roller 2 of the second planetary reduction mechanism 20b (on the steering output shaft 16 side) by a bush 14. ) Is supported in a displacement-constrained and rotatable manner.

  A connecting portion between the steering input shaft 15 and the carrier 4 of the first planetary speed reduction mechanism 20a and a connecting portion between the separation piece 10 and the steering output shaft 16 (the carrier 4 of the second planetary speed reduction mechanism 20b) are provided in the axial direction. A separation resin capsule 11 is provided as a movement restricting member designed to be broken by a shearing force when a predetermined load (load at the time of collision) is input.

That is, in the normal state, the movement of the sun roller 2 in the axial direction is restricted by the connection portions being fixed by the release resin capsule 11, but a predetermined load is applied in the axial direction from the steering input shaft 15 side. When the detachment resin capsule 11 is input and the rupture resin capsule 11 is broken, the steering input shaft 15, the sun roller 2 and the detachment piece 10 are relatively displaceable in the axial direction and inserted into the steering output shaft 16 having a hollow structure. It has come to be.
Here, the fitting portion between the steering input shaft 15 and the carrier 4 of the first planetary speed reduction mechanism 20a and the separation piece 10 and the steering output shaft 16 (the carrier 4 of the second planetary speed reduction mechanism 20b) are serrated. ing.

  With such a configuration, the input torque from the steering input shaft 15 is transmitted from the carrier 4 of the first planetary reduction mechanism 20a to the sun roller 2 of the first planetary reduction mechanism 20a. Subsequently, the sun roller 2 of the first planetary speed reduction mechanism 20a is transmitted to the sun roller 2 of the second planetary speed reduction mechanism 20b, and is transmitted from the sun roller 2 to the carrier 4 of the second planetary speed reduction mechanism 20b. Is transmitted to.

At this time, the torque transmission path at the time of low torque input (at the time of normal steering torque input during traveling) is a sun roller / planet roller, and the transmission path is formed only by the rollers. On the other hand, the torque transmission path at the time of high torque input is a sun gear / planetary gear, and the transmission path is formed only by gears.
As described above, the variable rudder angle mechanism 20 is a rolling transmission that transmits force by the frictional force of each geared roller, and includes a driving roller connected to the input side of the torque transmission system, and an output side of the torque transmission system. An oil film is formed between the roller and the driven roller connected thereto, and torque is transmitted by the shear stress generated in the oil film of the roller contact portion due to the surface speed difference of the roller.

  The torque sensor 23 is arranged by dividing the steering input shaft 15 into an input side and an output side, and has a torsion bar 23a that supports the steering input shaft 15 so that it can be twisted in the steering angle direction. Using the mechanical relative angle difference between the input side and the output side, a change in the strength of the magnetic force is detected as a current value flowing through the coil 23b. The coil 23b is stored in a torque sensor case 23c. In the figure, reference numeral 23d denotes a sensor base.

The torque sensor case 23c is fitted to the column outer tube 25, and the torque sensor case 23c is provided to minimize the impact on the occupant when an abnormal load is input to the steering column such as a front collision of the vehicle. 23c has a structure which shrink | contracts by sliding inside the column outer tube 25 inside.
Here, since the torque sensor case 23c is restrained in a state in which no relative movement occurs in the axial direction with respect to the steering input shaft 15, in this embodiment, the torque sensor case 23c slides inside the column outer tube 25. In order to proceed, a function is provided in which the steering input shaft 15 can be displaced in synchronization with the torque sensor case 23c. This function will be described in detail with reference to FIG.

FIG. 4 is a diagram for explaining a contraction function of the steering input shaft at the time of a vehicle collision, and shows a main part of the variable steering angle mechanism 20 as a sectional view in the axial direction.
As shown in FIG. 4, the above-described release resin capsule 11 includes a connection portion between the steering input shaft 15 and the carrier 4 of the first planetary speed reduction mechanism 20a, and a connection portion between the steering output shaft 16 and the removal piece 10. (See FIG. 4A), and is broken by a predetermined shearing force (shearing force corresponding to a collision load) (see FIG. 4B).
Each roller is mounted so as to generate a pressure contact force F according to the required transmission torque T, and the rolling transmission coefficient μ at this time is expressed by the following equation.
μ = (T / r) / F (1)

Further, assuming that the torque at which the sun roller slips is Ts and the sun roller diameter is Ds, the maximum transmission force Fs in the tangential direction when the relative slip occurs between the sun roller and the planetary roller is expressed by the following equation.
Fs = Ts / (Ds / 2) (2)
Therefore, if the sun roller has an axial force equal to or greater than the maximum transmission force Fs, relative slip occurs in the axial direction as in the case of torque transmission. Therefore, the maximum transmission force Fs is set smaller than the load generated when the steering system contracts, which is set as a requirement for impact energy absorption (hereinafter referred to as EA) at the time of a vehicle frontal collision. The site can function as a contraction mechanism.

By the way, in the present embodiment, the configuration in which the planetary speed reduction mechanism is arranged oppositely as the variable steering angle mechanism 20 is applied. Therefore, when the steering input shaft 15 slides toward the steering output shaft 16 at the time of a vehicle collision, the first planetary gear. The sun gear of the speed reduction mechanism 20a and the planetary gear of the second planetary speed reduction mechanism 20b may interfere with each other. In other words, the teeth of the sun gear of the first planetary speed reduction mechanism 20a and the teeth of the planetary gear of the second planetary speed reduction mechanism 20b may wrap and interfere with each other during sliding to prevent contraction.
Therefore, in the present embodiment, the end portions in the axial direction of the teeth of each gear are chamfered like a synchro mechanism of a transmission.

FIG. 5 is a diagram for explaining the state of the gears when the sun roller slides.
In FIG. 5, the sun gear 2a and the planetary gear 3a have gear end surfaces that may interfere with each other in the process of sliding the steering input shaft 15 toward the steering output shaft 16 in the event of a vehicle collision. It has a convex shape.
As a result, as shown in FIG. 5A, when the sun roller 2 slides in a state where the tooth phases of the sun gear 2a and the planetary gear 3a are wrapped, the state shown in FIG. As shown in c), the gears slide in a direction in which interference is eliminated, and smooth sliding is realized. That is, by providing an interference prevention mechanism in the gear P of FIG. 4B, the steering system can be contracted smoothly.

Further, during a secondary collision in a vehicle frontal collision, impact energy absorption (EA) is required to minimize the impact on the occupant. In order to enable this EA, a mechanism for generating a load (sliding resistance) simultaneously with contraction is necessary. In this embodiment, as shown in FIGS. 3 and 4, the inner diameter portion of the steering output shaft 16 is used. This is realized by providing the ring-shaped elastic body 12 on the surface. That is, when the sun roller 2 of the variable steering angle mechanism 20 that contracts integrally with the steering input shaft 15 slides into the steering output shaft 16, the annular elastic body 12 is deformed to generate a sliding resistance. To do.
Here, as the annular elastic body 12, a corrugated rigid plate press-fitting ring-shaped fastener using an elastic force, such as a tolerance ring, or the like is applied.

(Operation)
Next, the operation of the first embodiment of the present invention will be described.
Now, it is assumed that the front surface of the vehicle has come into contact with an obstacle or the like in front of the vehicle and a vehicle front collision has occurred. At this time, a collision of the driver with the steering wheel, a so-called secondary collision occurs, and a load due to the collision is input from the steering wheel side to the steering column.

FIG. 6 is a diagram illustrating the operation of the variable steering angle mechanism 20 when a secondary collision occurs.
When a secondary collision occurs and an axial force greater than the maximum transmission force Fs is input to the steering column, a force that causes relative slip in the axial direction acts on the sun roller 2, and this force is used as a shearing force to release resin. The capsule 11 is broken as shown by 11 'in FIG.
As a result of the breakage of the detachable resin capsule 11, the variable steering angle mechanism 20 becomes displaceable toward the steering output shaft 16 when the sun roller 2 is pushed out to the steering input shaft 15.

Then, from the normal state shown in FIG. 6 (a), as shown in FIG. 6 (b), the steering input shaft 15 pushes the sun roller 2 and accommodates it inside the steering output shaft 16, while the torque sensor case 23c and the steering input. The variable steering angle mechanism 20 is in a contracted state by integrally sliding with the shaft 15 into the column outer tube 25.
At this time, the sun gear of the first planetary reduction mechanism 20a and the planetary gear of the second planetary reduction mechanism 20b are sun gear 2a because the gear end is convex in the sliding direction on the roller surface as an interference prevention mechanism. When the sun roller 2 slides in a state where the tooth phases of the gear and the planetary gear 3a are overlapped, the gears slide in a direction in which the interference is eliminated (see FIGS. 5A and 5B).

As a result, the separation piece 10, the sun roller 2, and the steering input shaft 15 slide smoothly into the steering output shaft 16 without being hindered by interference between the sun gear 2a and the planetary gear 3a.
When the detaching piece 10 slides inside the steering output shaft 16, the annular elastic body 12 provided inside the hollow portion of the steering output shaft 16 is deformed to generate a sliding resistance.
As a result, a contraction stroke is secured in the variable rudder angle mechanism 20, and impact energy is effectively absorbed in the contraction operation in the contraction stroke.

  In the above embodiment, the first planetary speed reduction mechanism 20a constitutes a first stage planetary roller mechanism, the second planetary speed reduction mechanism 20b constitutes a second stage planetary roller mechanism, and the steering input shaft 15 is steered. An input shaft is constituted, and the steering output shaft 16 constitutes a steering output shaft. Further, the hollow of the steering output shaft 16 constitutes a housing portion, and the sun roller 2, the separation piece 10 and the separation resin capsule 11 constitute a contraction mechanism. Further, the detaching piece 10 and the detaching resin capsule 11 constitute a movement restricting member, and the annular elastic body 12 constitutes a sliding resistance generating means.

(Effects of the first embodiment)
(1) When a predetermined axial load is input to the steering shaft, the sun roller moves in the axial direction from a state where it is supported by the planetary roller, and is in a state where it is accommodated in the accommodating portion. Therefore, a contraction stroke can be secured in the variable steering angle steering device. That is, when a collision load is input to the steering shaft, the sun roller and the planetary roller relatively move in the axial direction, so that a contraction stroke with respect to the collision load is ensured. That is, a contraction stroke can be secured in the variable steering angle steering device. As a result, it is possible to increase the degree of design freedom.

(2) When a predetermined load is input to the steering shaft in the axial direction, the sun roller can be moved by releasing the movement restriction by the movement restricting member. It can function as a rudder angle mechanism, and can function as a contraction mechanism of the steering system at the time of a vehicle front collision.
(3) When a predetermined load is input in the axial direction to the steering shaft, the detachable resin capsule is broken so that the steering input shaft or the steering output shaft and the sun roller are movable, so that the steering is reliably performed. A system contraction mechanism can be realized.

(4) When a predetermined load is input to the steering shaft in the axial direction and the sun roller moves into the housing portion, a sliding resistance is generated along with this movement, so that the impact energy at the time of the front collision of the vehicle is surely absorbed. be able to.
(5) Since an annular elastic body is provided in the accommodating portion of the steering shaft and the sun roller moves into the accommodating portion, a sliding resistance is generated by the deformation of the annular elastic body. Can be absorbed.
(6) Since the end surface of the sun roller and the planetary roller gear, which may interfere with each other in the process of moving in the axial direction from the state where the sun roller is supported by the planetary roller, has a convex shape in the relative movement direction on the roller surface, When the steering system contracts, the gears passing each other deviate from each other, enabling smooth sliding.

(7) Since the accommodating portion is formed on the steering output shaft, and the sun roller disposed on the same axis as the steering output shaft is accommodated in the accommodating portion by a predetermined load input in the steering output shaft direction, the variable rudder A contraction mechanism can be secured in the corner mechanism.
Therefore, even if the hollow structure for contraction cannot be obtained because the torque sensor is mounted on the steering column, the contraction mechanism of the steering system can be realized by the predetermined load input. In addition, the steering system can be efficiently contracted against a secondary collision in a vehicle front collision.

  (8) When a load is input to the steering input shaft or the steering output shaft due to the collision load input to the vehicle body, the sun roller and the planetary roller move relative to each other in the axial direction. Is secured. Therefore, a contraction stroke can be secured in the variable steering angle steering device. As a result, it is possible to provide an automobile capable of flexibly deforming the vehicle body in the primary collision or reducing the impact on the occupant in the secondary collision.

(9) When a collision load is input to the steering shaft, the contraction method of the steering system is such that the sun roller and the planetary roller are moved relative to each other in the axial direction. That is, a contraction stroke can be secured in the variable steering angle steering device.
(10) Since the maximum transmission force of the release resin capsule is set to be smaller than the load generated when the steering system contracts, which is set as a shock energy absorption requirement at the time of a vehicle frontal collision, the steering input shaft and the sun roller are securely connected. It can be switched to a movable state. Further, since it is not necessary to provide a separate actuator or the like, this can be realized with a relatively simple configuration.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.
(Constitution)
In the second embodiment, the impact energy absorption when the steering system is contracted is realized by the deformation force of the fitting portion of the column outer tube instead of the annular elastic body in the first embodiment described above. Is.
FIG. 7 is a diagram illustrating a detailed configuration of the variable rudder angle mechanism 20 according to the second embodiment and its peripheral portions. As shown in FIG. 7, the variable steering angle steering apparatus according to the present embodiment does not have the torque sensor 23 and the annular elastic body 12 in the first embodiment shown in FIG. Since the column outer tube 25 has the same configuration as that of FIG. 3 except that the column outer tube 25 is configured by fitting the tube 25A and the tube 25B, the description will focus on different portions.

Unlike the first embodiment described above, the steering booster 24 in the present embodiment is used as a parking assist steering actuator that does not require the torque sensor 23 and a lane departure prevention steering actuator.
Thus, even when the torque sensor 23 is not provided on the steering wheel 21 side of the variable rudder angle mechanism 20, when an abnormal load is input from the steering input shaft 15 side due to a secondary collision in a vehicle frontal collision, As in the first embodiment described above, when the release resin capsule 11 is broken, the steering input shaft 15, the sun roller 2, and the release piece 10 are inserted into the steering output shaft 16, and the steering system is contracted. It becomes possible.

  The column outer tube 25 has a double cylinder structure in which a tube 25A disposed on the steering wheel 21 side is fitted to a tube 25B disposed on the steering output shaft 16 side. Here, the fitting portion between the tube 25A and the tube 25B has an elliptical shape as shown in the B-B 'arrow view, and the tube 25A is fitted in the tube 25B. Further, the non-fitting portion of the tube 25A has a circular shape as shown in the AA ′ arrow view, and the circular diameter in the non-fitting portion is smaller than the elliptical short diameter in the fitting portion. It has a large structure.

  With such a configuration, when the steering input shaft 15 contracts and the tube 25A moves into the tube 25B, the non-fitting portion of the tube 25A is deformed and enters the tube 25B. Thus, the impact energy is absorbed by the deformation load (sliding resistance) when the tube 25A enters the tube 25B. The configuration for generating a deformation load by the tube 25A and the tube 25B corresponds to the sliding resistance generating means.

(Operation)
Next, the operation of the second embodiment of the present invention will be described.
Now, it is assumed that the front surface of the vehicle has come into contact with an obstacle or the like in front of the vehicle and a vehicle frontal collision has occurred. At this time, a collision of the driver with the steering wheel, a so-called secondary collision occurs, and a load due to the collision is input from the steering wheel side to the steering column.
FIG. 8 is a diagram illustrating an operation of the variable steering angle mechanism 20 when a secondary collision occurs.
When a secondary collision occurs and an axial force greater than the maximum transmission force Fs is input to the sun roller 2 of the variable steering angle steering device 20, a force that causes relative slip in the axial direction acts, and this force is used as a shear force. As a result, the release resin capsule 11 is broken.

As a result of the breakage of the detachable resin capsule 11, the variable rudder angle mechanism 20 can be displaced toward the steering output shaft 16 when the sun roller 2 is pushed onto the steering input shaft 15, that is, the steering input shaft 15 is output to the steering. The shaft 16 is slidable inside.
Then, while the steering input shaft 15 pushes out the sun roller 2 and accommodates it inside the steering output shaft 16, the tube 25A enters the tube 25B, and the variable steering angle mechanism 20 is moved from the normal state shown in FIG. The contracted state shown in FIG.

At this time, when the tube 25A slides into the tube 25B, the tube 25A is deformed to generate a deformation load.
As a result, a contraction stroke is secured in the variable rudder angle mechanism 20, and impact energy is effectively absorbed in the contraction operation in the contraction stroke.
In the above embodiment, the column outer tube 25 of the steering input shaft 15 has a double cylindrical structure and constitutes a sliding resistance generating means.

(Effect of 2nd Embodiment)
(1) The steering input shaft (or the steering output shaft) has a double cylinder structure that fits with each other as the sun roller moves in the axial direction. Therefore, when a collision load is input to the steering shaft, a deformation load is generated by fitting the double cylinder deeper. Therefore, a contraction stroke can be secured in the variable steering angle steering device, and a sliding resistance can be generated when the steering system contracts, so that impact energy can be effectively absorbed. As a result, the degree of freedom in design can be further increased.
(2) Since the column outer tube is applied as a fitting member, it is possible to realize impact energy absorption when the steering system is contracted without requiring additional parts.

(Application examples)
In the second embodiment, the case where the cross-sectional shape of the non-fitting portion of the tube 25A is circular and the cross-sectional shape of the fitting portion of the tubes 25A and 25B is elliptical has been described. In addition to such a configuration, for example, the cross-sectional shape of the non-fitting portion of the tube 25A can be an elliptical shape, and the cross-sectional shape of the tube 25B can be a circular shape having a diameter smaller than the major axis of the elliptical shape of the tube 25A. Thus, about the tubes 25A and 25B, the shape accompanied by a deformation | transformation can be employ | adopted when the tube 25A moves to the tube 25B direction by the load of a secondary collision.
Moreover, in the said 2nd Embodiment, although the case where the column outer tube 25 was used as a fitting member was demonstrated, it fits with the sliding of the sun roller at the time of shrinkage | contraction of a steering system other than such a structure. A thing can be used as a fitting member.

(Third embodiment)
Next, a third embodiment of the present invention will be described.
(Constitution)
In the third embodiment, the first and second embodiments described above realize a steering contraction mechanism for a secondary collision at the time of a vehicle frontal collision, whereas a primary collision at the time of a vehicle frontal collision. The steering system contraction mechanism is realized.

FIG. 9 is a schematic view showing the overall configuration of the variable steering angle mechanism 20 of the third embodiment.
As shown in FIG. 9, in the variable rudder angle mechanism 20 in the present embodiment, the case 20c of the variable rudder angle mechanism 20 in the first or second embodiment described above is attached to the dash panel 26 of the vehicle.
The attaching direction is a direction in which the separation piece 10 is disposed on the steering wheel 21 side. In the first and second embodiments described above, the steering system contracts with respect to the load input from the steering wheel 21 side. In contrast to this, in the present embodiment, the steering system contracts in response to a load input from the steered wheel 22 side, that is, the R & P type steering gear 27 side.

Specifically, the steering input shaft 15 is formed integrally and hollow with the carrier 4 of the first planetary speed reduction mechanism 20a, and the steering output shaft 16 is concentric with the carrier 4 of the second planetary speed reduction mechanism 20b being not relatively rotated. It is connected. Further, the sun rollers 2 of the first planetary speed reduction mechanism 20a and the second planetary speed reduction mechanism 20b are connected (integrally formed).
Further, a detaching piece 10 is inserted into the hollow interior of the steering input shaft 15, and the detaching piece 10 displaces and restrains one end (the steering input shaft 15 side) of the sun roller 2 of the first planetary reduction mechanism 20 a. It is rotatably supported. Further, the steering output shaft 16 supports the other end (the steering output shaft 16 side) of the sun roller 2 of the second planetary reduction mechanism 20b so as to be able to displace and rotate.

  A connecting portion between the separation piece 10 and the steering input shaft 15 (the carrier 4 of the first planetary speed reduction mechanism 20a) and a connecting portion between the steering output shaft 16 and the carrier 4 of the second planetary speed reduction mechanism 20b include a shaft. A release resin capsule 11 designed to be broken by a shearing force when a predetermined load (load at the time of collision) is input in the direction is provided. That is, when a predetermined load is input in the axial direction from the steering output shaft 16 side and the release resin capsule 11 is broken, the steering output shaft 16, the sun roller 2, and the release piece 10 can be relatively displaced in the axial direction. Thus, it is inserted into the steering input shaft 15 having a hollow structure.

  Therefore, when the steering output shaft 16 has a hollow structure and the variable steering angle mechanism is disposed in the vicinity of the steering wheel as in the first and second embodiments described above, load input from the steering wheel 21 side, i.e., two When the steering input shaft 15 has a hollow structure and the variable steering angle mechanism is arranged in the vicinity of the steered wheel as in the present embodiment, the load input from the steered wheel 22 side, that is, Shrinkage against primary collision is possible.

(Operation)
Next, the operation of the third embodiment of the present invention will be described.
Now, it is assumed that the front surface of the vehicle has come into contact with an obstacle or the like in front of the vehicle and a vehicle frontal collision has occurred. At this time, a load due to a collision (so-called primary collision) is input from the front of the vehicle on the R & P type steering gear 27 side.
FIG. 10 is a diagram illustrating the operation of the variable steering angle mechanism 20 when a primary collision occurs.
When a collision occurs and an axial force that is greater than or equal to the maximum transmission force Fs is input to the sun roller 2 of the variable steering angle steering device 20, a force that causes relative slip in the axial direction acts on the sun roller 2, and this force is sheared. As a force, the release resin capsule 11 is broken.

As a result of the breakage of the detachable resin capsule 11, the variable steering angle mechanism 20 can be displaced toward the steering input shaft side by pushing the sun roller 2 to the steering output shaft 16.
Then, from the normal state shown in FIG. 10 (a), as shown in FIG. 10 (b), the steering output shaft 16 pushes the sun roller 2 into the steering input shaft 15 so that the variable steering angle mechanism 20 can be accommodated. It becomes a contracted state.
As a result, a contraction stroke for the primary collision is secured in the variable rudder angle mechanism 20.
In the above embodiment, the steering input shaft 15 constitutes the steering input shaft, and the hollow of the steering input shaft 15 constitutes the accommodating portion.

(Effect of the third embodiment)
(1) A structure in which the sun roller is housed in the housing portion of the steering input shaft and the steering system contracts with respect to a load input in the direction of the steering input shaft from the steering output shaft (load input from the steering wheel side). Therefore, a contraction mechanism for a primary collision in a vehicle front collision can be realized, and an impact on the occupant can be suppressed. This also increases the degree of freedom in design.

(Application examples)
In each of the above-described embodiments, the case where the variable steering angle mechanism is configured by arranging two planetary deceleration mechanisms facing each other has been described. However, the planetary deceleration mechanism can also be configured by one planetary deceleration mechanism.
For example, a support means (for example, the detaching piece 10 and the detaching resin capsule 11 in each of the above embodiments) for supporting the sun roller in an axial position surrounded by the planetary roller is provided, and the supporting means is provided on the sun roller in the axial direction. When a predetermined load is input, the sun roller is moved in the axial direction from the state supported by the planetary roller.

With such a configuration, the support means moves the sun roller in the axial direction in response to an input of a predetermined load and separates it from the state supported by the planetary roller, so that a contraction stroke can be secured in the planetary mechanism. it can.
As a specific example of the configuration as described above, if the steering input shaft and the sun roller are connected in a non-rotating state, and the steering output shaft and the carrier are configured integrally and hollow, a load input from the steering input shaft side is obtained. In contrast, the steering system can be contracted.

  In each of the above embodiments, either the first planetary speed reduction mechanism or the second planetary speed reduction mechanism is connected to the steering input shaft, the other carrier is connected to the steering output shaft, and the first planetary speed reduction mechanism is connected. Although the case where the sun rollers of the speed reduction mechanism and the second planetary speed reduction mechanism are connected to each other has been described, in addition to such a configuration, either the sun roller of the first planetary speed reduction mechanism or the second planetary speed reduction mechanism and the steering input shaft are connected. It is also possible to connect the other sun roller and the steering output shaft to connect the carriers of the first planetary speed reduction mechanism and the second planetary speed reduction mechanism. In this case, the sun rollers of the first planetary speed reduction mechanism and the second planetary speed reduction mechanism are rotatably connected to each other so that the sun rollers can slide in synchronization with the steering shaft when an axial load is input.

  Further, in each of the above embodiments, when the release resin capsule is provided and a predetermined load is input in the steering shaft direction, the release resin capsule breaks and the steering shaft and the sun roller are slidable. In addition to such a configuration, a connecting member that can switch the connection / release of the steering shaft and the sun roller by an actuator is provided in place of such a resin capsule, and the predetermined load is input. The steering shaft and the sun roller can be slidable by driving the actuator or the like to switch the connecting member to the released state.

1 is a schematic configuration diagram of a vehicle in an embodiment of the present invention. It is an outline figure showing the whole variable steering angle mechanism 20 composition in a 1st embodiment. It is sectional drawing of the variable steering angle mechanism 20 in 1st Embodiment. It is a figure explaining the contraction function of the steering input shaft at the time of a vehicle collision. It is a figure explaining the state of the gearwheel at the time of a sun roller sliding. It is a figure explaining operation | movement of 1st Embodiment. It is detail drawing of the variable steering angle mechanism in 2nd Embodiment. It is a figure explaining operation | movement of 2nd Embodiment. It is a general view of the variable rudder angle mechanism in 3rd Embodiment. It is a figure explaining the operation | movement in 3rd Embodiment.

Explanation of symbols

1 Motor 2 Sun Roller 3 Planetary Roller 4 Carrier 5 Ring Roller 6 Worm Gear 7 Worm Wheel 10 Detachment Top 11 Detachment Resin Capsule 12 Annular Elastic Body 15 Steering Input Shaft 16 Steering Output Shaft 20 Variable Steering Angle Mechanism 20a First Planetary Deceleration Mechanism 20b Second planetary reduction mechanism 21 Steering wheel 22 Steering wheel 23 Torque sensor 23a Torsion bar 23b Coil 23c Torque sensor case 24 Steering booster 25 Column outer tube 26 Dash panel 27 R & P type steering gear 28 Intermediate shaft (intermediate shaft)
30 Electronic control unit

Claims (13)

A first-stage planetary roller mechanism and a second-stage planetary roller mechanism integrally configured with a sun roller;
A steering input shaft that is connected to a support shaft of the planetary roller in the first stage planetary roller mechanism and is arranged coaxially with the sun roller;
A steering output shaft that is connected to a support shaft of the planetary roller in the second stage planetary roller mechanism and is arranged coaxially with the sun roller;
A rotating means for rotating either the ring roller in the first stage or second stage planetary roller mechanism;
An accommodating portion that is formed on the steering input shaft or steering output shaft side and can accommodate the sun roller;
When a predetermined load in the steering input / output axial direction is input to the sun roller, the contraction mechanism that moves in the axial direction from the state in which the sun roller is supported by the planetary roller and is accommodated in the accommodating portion;
A variable rudder angle steering device comprising:   The contraction mechanism has a movement restricting member that restricts the movement of the sun roller in a state where the sun roller is supported by the planetary roller, and when the predetermined load in the steering input / output axis direction is input to the sun roller, 2. The variable steering angle steering device according to claim 1, wherein the movement restricting member releases the restriction of movement of the sun roller and is in a state of being accommodated in the accommodating portion.   The variable steering angle steering device according to claim 2, wherein the movement restricting member is configured by a member that is broken or separated by a shearing force corresponding to the predetermined load.   The variable steering angle according to any one of claims 1 to 3, further comprising sliding resistance generating means for generating sliding resistance when the sun roller moves to the housing portion in the contraction mechanism. Steering device.   The sliding resistance generating means includes an annular elastic body installed along the inner peripheral surface of the housing portion, and the annular elastic body generates friction with the moving sun roller, thereby causing sliding resistance. The variable steering angle steering device according to claim 4, wherein At least one of the steering input shaft and the steering output shaft has a double-cylinder structure that fits with each other as the sun roller moves in the axial direction,
The variable rudder angle steering apparatus according to claim 4 or 5, wherein the sliding resistance generating means generates sliding resistance by a load accompanying the fitting.   The sun roller and the planetary roller are geared rollers in which a roller and a gear are integrally formed on the same axis, and the sun roller corresponds to the first planetary roller mechanism and the second planetary roller mechanism, respectively. When a gear portion is formed and a predetermined load in the steering input / output axial direction is input to the sun roller, the sun roller may interfere with each other in the process of moving in the axial direction from the state supported by the planetary roller. The variable steering angle steering device according to any one of claims 1 to 6, wherein end faces of gears of the sun roller and the planetary roller are convex in the relative movement direction on the roller surface.   The housing portion is formed on a steering input shaft, and the contraction mechanism is in a state in which the sun roller is housed in the housing portion when a predetermined load is input in a steering input shaft direction from a steering output shaft. The variable steering angle steering device according to any one of claims 1 to 7.   The accommodating portion is formed on a steering output shaft, and the contraction mechanism is in a state where the sun roller is accommodated in the accommodating portion when a predetermined load is input in a steering output shaft direction from a steering input shaft. The variable steering angle steering device according to any one of claims 1 to 8. A variable steering angle steering device that transmits a steering input to a steering input shaft to a steering output shaft via a sun roller supported by a planetary roller,
When a collision load is input to the steering input shaft or the steering output shaft, the sun roller and the planetary roller move relative to each other in the axial direction to generate a contraction stroke with respect to the collision load. Variable steering angle steering device. An automobile equipped with a variable steering angle steering device that transmits a steering input to a steering input shaft to a steering output shaft via a sun roller supported by a planetary roller,
When a collision load is input to the vehicle body and a load based on the collision load is transmitted to the steering input shaft or the steering output shaft, the sun roller contracts with respect to the planetary roller due to the axial movement of the sun roller. An automobile characterized by causing a stroke. A steering system contraction method including a variable steering angle steering device that transmits a steering input to a steering input shaft to a steering output shaft via a sun roller supported by a planetary roller,
When a collision load is input to the steering input shaft or the steering output shaft, a contraction stroke for the collision load is generated by movement of the sun roller in the axial direction with respect to the planetary roller. Shrinkage method. A planetary roller mechanism in which a planetary roller is disposed in contact with a roller surface around a sun roller,
A support means for supporting the sun roller at an axial position surrounded by the planetary rollers;
The planetary roller mechanism characterized in that the support means moves the sun roller in the axial direction from the state supported by the planetary roller when a predetermined load in the axial direction is input to the sun roller.

Images