JP2003267242A - Steering device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steering device for a vehicle having drivingly connecting means with a simple structure which drivingly connect an input side member rotated according to the operation of a steering means to an output side member rotated interlockingly with the operation of a steering mechanism when various types of fails occur in a separate steering device or a transmission ratio variable steering device. <P>SOLUTION: This steering device for the vehicle comprises a housing 40 covering the opposed parts of an input shaft 41 as an input side member and an output shaft 42 as an output side member and liquid chambers 46 arranged in the housing 40 parallel with each other through a sealing body 45. The first liquid 47 of a two-liquid mixed type liquid agent is stored in the liquid chamber 46, the second liquid 48 is stored in the housing 40, and the sealing body 45 is broken and removed by the operation of an inflator 49 to mix the first liquid 47 with the second liquid 48. By a drivingly connecting force generated by the mixing of these two liquids, the input shaft 41 and the output shaft 42 are drivingly connected to each other based on a chemical change. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle steering system for steering a vehicle in response to an operation of a steering means such as a steering wheel performed by a driver.

[0002]

2. Description of the Related Art Steering of a vehicle is performed by operating a steering means (generally, a steering wheel rotating operation) performed by a driver inside a passenger compartment, and manipulating a steering wheel (generally a front wheel). This is done by telling the steering mechanism that is arranged outside the vehicle compartment for direction.

As such a vehicle steering system, in recent years,
The steering means inside the vehicle compartment is mechanically separated from the steering mechanism outside the vehicle compartment, and a steering actuator is attached to a part of the steering mechanism. A separate type, so-called steer-by-wire type steering device has been proposed which is operated based on the detection result of the operation amount, and applies steering force to the steering mechanism to perform steering according to the operation of the steering means. There is.

In this type of steering apparatus, the correspondence between the operation amount of the steering means and the operation amount of the steering mechanism due to the operation of the steering actuator can be freely changed without mechanical restriction, and the vehicle speed can be changed. Level, turning degree, presence / absence of acceleration / deceleration, etc.
It has an advantage that it can flexibly respond to the change control of the steering characteristic according to the traveling state. An electric motor is generally used as the steering actuator in consideration of easiness of control for changing steering characteristics.

On the other hand, in such a separate type steering device, various sensors for detecting the traveling state of the vehicle including the steering actuator, the operating direction and the operating amount of the steering means,
In addition, it is important to take fail-safe measures for the steering control unit that controls the steering actuator based on the detection results of these sensors. Conventionally, while the steering actuator, the sensor, and the steering control unit have a dual system, A drive connecting means such as an electromagnetic clutch is interposed between an input side member that rotates according to the operation of the means and an output side member that rotates according to the operation of the steering mechanism, and this drive connecting means is used when a failure occurs. The engaging operation is performed, and the operating force of the steering means can be mechanically transmitted to the steering mechanism so that the manual steering can be performed.

As in the case of the above-described separated type steering device, the steering device is a steering device which can change the correspondence between the operation amount of the steering means and the operation amount of the steering mechanism, and rotates according to the operation of the steering means. A transmission device capable of changing the rotation transmission ratio is interposed between the input side member and the output side member that rotates in association with the operation of the steering mechanism, and the rotation transmission ratio is variably controlled according to the traveling state. As a result, a variable transmission ratio type steering device configured to obtain steering characteristics adapted to the traveling state has also been put into practical use.

[0007]

However, the drive connecting means provided in the separation type steering device is a connecting operation for driving and connecting the steering means and the steering mechanism at a limited opportunity when the above-mentioned fail occurs. In contrast to the above, the electromagnetic clutch generally used as the drive connecting means can perform the connection releasing operation as well as the connecting operation, and the operation circuit and the control unit for these operations can be provided. There is a problem that the configuration including the above becomes so-called over-spec, which complicates the configuration of the steering device and increases the product cost.

In the variable transmission ratio type steering device, the transmission device interposed between the input side member and the output side member, control means for variably controlling the rotation transmission ratio of the transmission device, and If any of the various sensors used for this control is in a fail state, there is a risk that steering may be hindered by erroneous variable control performed under the failure.

In order to solve such a problem, a mechanical lock means is provided inside the transmission and the lock means is operated when a failure occurs to drively connect the input side member and the output side member. However, there is a problem that the structure of the transmission becomes complicated due to the incorporation of the locking means, and it has been earnestly desired to realize a drive connecting means that can obtain a drive connected state with a simple structure.

The present invention has been made in view of such circumstances, and in a separation type steering device or a variable transmission ratio type steering device, an input side that rotates according to the operation of the steering means when various failures occur. An object of the present invention is to provide a vehicle steering system including a drive connecting means having a simple structure for drivingly connecting a member and an output-side member that rotates in conjunction with the operation of the steering mechanism.

[0011]

A vehicle steering system according to a first aspect of the present invention includes an input side member that rotates in response to an operation of the steering means, and an output side member that rotates in conjunction with the operation of a steering mechanism. Between the two, a drive connection means for drivingly connecting both members based on a chemical change is provided.

In the present invention, the drive connecting means is provided between the input side member and the output side member to drive and connect both members by generating a binding force based on a chemical change.

Further, in a vehicle steering system according to a second aspect of the invention, the drive connecting means in the first aspect of the invention includes a housing for covering a portion where the input side member and the output side member face each other, and a sealing body interposed in the housing. Liquid chambers arranged side by side, a two-liquid mixing type liquid agent that generates a drive connecting force by mixing the first liquid contained in the liquid chamber and the second liquid contained in the housing, and the seal. And means for removing the stopper.

In the present invention, the first liquid and the second liquid of the two-liquid mixed type adhesive such as the epoxy resin adhesive are provided in the housing and the liquid chamber which are arranged side by side with the sealing body interposed therebetween. Respectively, and when drivingly connecting the input side member and the output side member facing each other in the housing, the sealing body between the liquid chamber is removed to mix the first and second liquids, The adhesive force generated by this mixing connects the input side member and the output side member based on a chemical change.

Further, in a vehicle steering system according to a third aspect of the invention, the drive connecting means in the first aspect of the invention is arranged between the input side member and the output side member and has at least one mechanical contact portion. The vehicle steering apparatus according to the fourth aspect of the present invention is characterized in that: the vehicle steering apparatus according to the fourth aspect is provided with a transmission means and a means for supplying powder to the contact portion in order to cause seizure or biting in the contact portion. In the invention, the transmission means is a gear transmission including gears that rotate in conjunction with the input-side member and the output-side member and mesh with each other.

In the present invention, the mechanical contact portion between both members existing inside the transmission device interposed between the input side member and the output side member, for example, the gear existing inside the gear transmission device. The powder is supplied to the meshing part of the device by means such as spraying, and the powder is caught in the contact part to cause the seizure phenomenon. The input side member and the output side member are drivingly connected.

Further, in a vehicle steering system according to a fifth aspect of the present invention, the drive connecting means according to any one of the first to fourth aspects is detachably interposed between the steering means and the steering mechanism. It is characterized by being.

In the present invention, the drive connecting means which has been brought into the drive connecting state by the binding force based on the chemical change can be detached from between the steering means and the steering mechanism, and the drive connecting means is replaced with a new drive connecting means. Achieve a return to the initial state.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the drawings showing the embodiments thereof. FIG. 1 is a schematic block diagram showing a first embodiment of a vehicle steering system according to the present invention.

The illustrated vehicle steering system includes a steering mechanism 1 for causing a pair of steering wheels 10, 10 arranged on the left and right sides of a vehicle body to perform a steering operation, and a steering mechanism 1 for driving the vehicle. And a steering wheel (steering means) 2 that is rotationally operated for steering, and is configured as a separate steering device. To realize steering according to the operation of the steering wheel 2. A steering control unit 3 is provided for controlling the steering motor M ₁ attached to the steering mechanism 1 and for controlling the reaction motor M ₂ to apply an appropriate steering reaction force to the steering wheel 2. Between the steering wheel 2 and the steering wheel 2, there is provided a drive connection means 4 which is interposed to obtain a drive connection state when various kinds of failures occur during the control operation.

The steering mechanism 1 is a well-known rack and pinion type steering mechanism, and has both ends of a rack shaft 11 extending in the left-right direction of the vehicle body and moving in the axial direction, for steering wheels. Ten,
The knuckle arms 12, 12 are connected to the knuckle arms 12, 12 via the respective tie rods 13, 13 and the knuckle arms 12, 12 are pushed and pulled through the tie rods 13, 13 by the movement of the rack shaft 11 in both directions. , 10 is steered left and right.

A steering motor M ₁ for performing this steering
Is attached to an outer position of one half of a tubular rack housing H ₁ that supports the rack shaft 11 movably in the axial direction. Inside the rack housing H ₁ , a ball screw mechanism or the like is installed. It is configured to be transmitted to the middle of the rack shaft 11 via a motion conversion mechanism.

The steering motor M ₁ is rotationally driven according to a control command given from the steering control section 3 to a drive circuit (not shown). The steering control unit 3 issues the control command to carry out steering according to the rotation operation of the steering wheel 2 and performs a steering control operation for driving the steering motor M ₁ .

The rotation of the steering motor M ₁ driven in this way is converted into the movement of the rack shaft 11 in the axial direction by the motion conversion mechanism to carry out the above-mentioned steering. The actual steering angle of the steering wheels 10 and 10 that changes due to this steering is the rack shaft.
It is detected by the actual steering angle sensor 17 configured to detect the displacement of the connecting portion between the tie rod 13 on the one side and the tie rod 13 on one side, and is given to the steering control section 3. Also, on the tie rod 13 on one side,
Tie rod axial force sensor that detects the axial force acting in the axial direction
Reference numeral 18 is additionally provided, and the detection result is given to the steering control unit 3 as a signal indicating the steering reaction force actually applied to the steering mechanism 1 in association with the steering.

A pinion housing H ₂ is connected to the other half of the rack housing H ₁ so as to intersect with the other half of the rack housing H _1. Inside the pinion housing H ₂ ,
A pinion shaft 14 is rotatably supported about its axis. A pinion (not shown) is integrally formed on the lower half portion of the pinion shaft 14 located inside the pinion housing H ₂ , and is formed at a corresponding portion of the rack shaft 11 at an intersection with the rack housing H _{1 (} not shown). It is engaged with the rack teeth.

A universal joint 15a, an intermediate shaft 15b and a universal joint 15c are provided at the upper end of the pinion shaft 14 projecting above the pinion housing H _2.
The transmission shaft 16 is connected via. The transmission shaft 16 is rotatably supported around the shaft and extends upward toward the position where the steering wheel 2 is disposed. With the above configuration, when the rack shaft 11 moves in the axial direction for steering, this movement is converted into rotation about the axis of the pinion shaft 14 at the meshing portion of the rack teeth and the pinion, and this rotation is It is transmitted to the transmission shaft 16 via the universal joint 15a, the intermediate shaft 15b and the universal joint 15c. That is, the transmission shaft 16 moves the rack shaft 11, that is,
The steering mechanism 1 rotates about its axis as the steering mechanism 1 operates.

On the contrary, when a rotational force is applied to the transmission shaft 16, the rotational force is applied to the pinion shaft 14 via the universal joint 15c, the intermediate shaft 15b and the universal joint 15a, and this rotational force is applied to the pinion. Also, the movement is converted at the meshing portion of the rack teeth, and a moving force in the axial direction is applied to the rack shaft 11.

The steering wheel 2 arranged separately from the steering mechanism 1 has a column housing H ₃ which rotatably supports a column shaft 20 which is its rotating shaft, and an appropriate portion of a vehicle body (not shown). Supported by. A reaction force motor M ₂ that is rotationally driven to apply a steering reaction force to the steering wheel ₂ is attached to a middle portion of the column housing H ₃ . The output shaft of the reaction motor M ₂ is
When the reaction force motor M ₂ is rotationally driven, the column motor is extended to the inside of the column housing H ₃ and is transmitted to a midway portion of the column shaft 20 via a reduction mechanism such as a worm gear mechanism.
This rotational force is applied to the column shaft 20 under deceleration by the reduction mechanism.
The steering reaction force is applied to the steering wheel 2 fixed to the upper end of the column shaft 20.

The reaction force motor M ₂ is driven according to a control command given from the steering control section 3 to a drive circuit (not shown). The steering control unit 3 issues the control command to apply a proper steering reaction force to the steering wheel 2 based on the steering reaction force actually applied to the steering mechanism 1, and the reaction force motor M ₂
A reaction force control operation for driving the is performed.

The operating angle of the steering wheel 2 rotated against the steering reaction force is determined by the column housing H ₃
It is detected by the steering angle sensor 21 attached to the middle part of the
It is provided to the steering control unit 3. Further, the steering control unit 3 is provided with a detection result of a traveling state such as a vehicle speed, a yaw rate, a lateral acceleration, and a longitudinal acceleration, which influences steering, from a traveling state sensor 22 installed in each part of the vehicle.

A column shaft 20 serving as a rotation shaft of the steering wheel 2 is projected below the column housing H ₃ and faces the upper end of the transmission shaft 16 extending from the steering mechanism 1. The drive connecting means 4 is interposed in the facing portion.

FIG. 2 is a side sectional view schematically showing the structure of the drive connecting means 4. The drive connecting means 4 shown in the figure includes a housing 40 having a cylindrical shape, an input shaft (input side member) 41 and an output shaft (output) which are rotatably supported coaxially and which penetrate both end walls of the housing 40. Side member) 42. Large-diameter rotating discs 43 and 44 are fixed to one ends of the input shaft 41 and the output shaft 42 extending inside the housing 40 so as to face each other with a predetermined gap. The other ends of the input shaft 41 and the output shaft 42 extending to the outside of the housing 40 are detachably coupled to the ends of the column shaft 20 and the transmission shaft 16, and the input shaft 41 is The output shaft 42 rotates together with the column shaft 20 according to the operation of the steering means 2.
Is adapted to rotate in conjunction with the operation of the steering mechanism 1 together with the transmission shaft 16.

A recess is formed around the housing 40 by recessing a part of the peripheral wall outward, and the inside of the recess is liquid-tightly sealed by a sealing body 45 to form a liquid chamber 46. ing. The liquid chamber 46
The first liquid (main component or curing agent) 47 of a two-component mixed type adhesive that is cured by mixing a main component and a curing agent, such as an epoxy resin adhesive, to generate adhesive force, is housed inside In addition, a housing 40 arranged side by side in the liquid chamber 46 via the sealing body 45.
The second liquid of the adhesive (hardening agent or main agent) is
Is housed.

The sealing body 45 is a thin plate made of a material that can be destroyed by the action of a relatively small force, such as a resin material, and one portion of the peripheral wall of the recess forming the liquid chamber 46 is An inflator 49 is attached so as to explode in response to the reception of an operation signal given from the outside and introduce a high pressure into the liquid chamber 46 to destroy and remove the sealing body 45.

When the sealing body 45 is destroyed and removed by the operation of the inflator 49 as described above, the first liquid 47 contained in the liquid chamber 46 flows into the housing 40, and the rotary disc is rotated.
By the rotation of 43 and 44, the second liquid 48 contained in the housing 40 is agitated and mixed with the second liquid 48 to be cured, and an adhesive force is generated, and an output including the input shaft 41 having the rotating disc 43 and the rotating disc 44 axis
42 and 42 are joined together to provide a drive connection based on chemical changes. An operation signal for causing the inflator 49 to perform an explosion operation is given from the steering control section 3 as shown in FIG.

FIG. 3 is a side sectional view showing the internal structure of the drive connecting means 4 in the drive connected state. As shown in the drawing, the first liquid 47 and the second liquid 48 which are agitated and mixed in the housing 40 are shown. Is the rotating disk 43 on the input shaft 41 side and the rotating disk on the output shaft 42 side.
The hardened body 4a is hardened together with 44, and the rotation of the input shaft 41 is transmitted to the rotary disk 44 through the rotary disc 43 and the hardened body 4a, and is output to the column shaft 20 connected to the input shaft 41. The transmission shaft 16 connected to the shaft 42 rotates integrally. In contrast,
In the state shown in FIG. 2, only the stirring resistance of the second liquid 48 inside the housing 40 is applied to the rotating discs 43 and 44, and the column shaft 20 and the transmission shaft 16 are independent of each other. Can rotate.

The first liquid 47 contained in the liquid chamber 46 and the second liquid 48 contained in the housing 40 are not limited to the two-liquid-mixing type adhesive that generates an adhesive force by mixing them. For example, a liquid agent that increases the viscosity by mixing is mixed by stirring by the input shaft 41 and the output shaft 42 that relatively rotate in the housing 40 by removing the sealing body 45, and thereby the input shaft 41 and the input shaft 41 by the mixed liquid whose viscosity is increased. It may be configured to generate a drive coupling force with the output shaft 42.

The steering control operation of the steering control section 3 for the steering motor M ₁ is performed by, for example, multiplying the operating angle of the steering wheel 2 detected by the steering angle sensor 21 by a predetermined control gain. This target steering angle and the left and right front wheels 1 detected by the actual steering angle sensor 17 are obtained.
Feedback control is performed based on the deviation from the actual steering angle of 0 and 10.

At this time, the traveling state detected by the traveling state sensor 22 is used for selecting the control gain. This control gain decreases, for example, as the vehicle speed increases,
Further, it is set as a value that decreases with an increase in the degree of turning of the vehicle that is determined by the yaw rate and lateral acceleration. As a result, the target steering angle becomes small during high-speed traveling, becomes large during low-speed traveling, and becomes smaller during steered traveling as the vehicle makes a sharp turn, and the steering motor M ₁ based on such target steering angle becomes smaller. By the control, steering characteristics according to the traveling state can be obtained.

In the reaction force control operation of the steering control unit 3 for the reaction force motor M ₂ , for example, the actual reaction force applied to the steering mechanism 1 is obtained based on the input from the tie rod axial force sensor 18, The target reaction force to be applied to the steering wheel 2 is calculated by multiplying the obtained actual reaction force by a predetermined control gain, and the drive current corresponding to this target reaction force is applied to the reaction force motor M ₂
It will be done by supplying power to.

At this time, the traveling state detected by the traveling state sensor 22 is used to correct the control gain. This correction is performed, for example, such that the control gain increases as the vehicle speed and the turning degree increase, and the control gain increases as the deceleration degree obtained by the longitudinal acceleration increases. Further, the operation angle of the steering wheel 2 detected by the steering angle sensor 21 can be used for the correction of the target reaction force, and the increase characteristic of the drive current of the reaction force motor M ₂ can be changed.

By the above reaction force control operation, the rotational force of the reaction force motor M ₂ applied to the column shaft 20 is applied to the steering wheel 2 as a steering reaction force. The steering reaction force is obtained by correcting the actual reaction force applied to the steering mechanism 1 according to the traveling state, and allows the driver who operates the steering wheel 2 to experience a good steering feeling.

Further, during the execution of such steering control and reaction force control operation, the steering control section 3 includes the sensors on the input side, the steering motor M ₁ and the reaction force motor M ₂ on the output side, and
An abnormality diagnosis is performed for the steering control unit 3 itself, and if it is determined that an abnormality has occurred in any of the results of this abnormality diagnosis, erroneous steering control and reaction force control under this abnormality are stopped. At the same time, a connection control operation for the drive connecting means 4 is performed.

This connection control operation is performed by the inflator 49.
An operating signal to cause the inflator 49 to explode and destroy and remove the sealing body 45.
The liquid 47 and the second liquid 48 inside the housing 40 are mixed, and due to the adhesive bonding force generated at this time, the input shaft 41 and the output shaft 43
This is done to drive and connect the and based on the chemical change.

When the drive connection state is obtained in this way,
Column shaft 20 according to the rotating operation of the steering wheel 2
Is transmitted to the transmission shaft 16 via the drive connecting means 4, and further the universal joint 15c, the intermediate shaft 15b,
Emergency transmitted when the steering control and the reaction force control are stopped due to the result of the abnormality diagnosis by transmitting to the rack shaft 11 via the universal joint 15a and the pinion shaft 14 and applying a moving force in the axial direction to the rack shaft 11. Can be steered by manual steering by mechanical transmission from the steering wheel 2 to the steering mechanism 1.

In the vehicle steering system shown in FIG. 1, the drive connecting means 4 rotatably supports the input shaft 41 and the output shaft 42 in the housing 40, and the rotating discs are provided at the opposing portions of the shafts 41 and 42. Four
3, 44 are fixedly installed, and an inflator 49 as a means for removing the sealing body 45 is attached to a liquid chamber 46 arranged in parallel with the housing 40 via a sealing body 45. The first liquid 47 of the adhesive is stored in the liquid chamber 46, and the second liquid 48 is stored in the housing 40. The drive connection of the drive connecting means 4 is performed by the housing 40 and the liquid. The sealing body 45 between the chamber 46 is removed, and the first and second liquids of the two-liquid mixing type adhesive are removed.
Since it is realized by mixing 47 and 48, it is possible to minimize the complexity of the overall configuration of the steering device and the increase in product cost.

As described above, the drive connecting means 4 which is brought into the drive connecting state by the connecting force based on the chemical change such as the curing of the two-liquid mixed type adhesive cannot restore the initial state, but the drive connecting means 4 cannot be returned to the initial state. The connecting means 4 is, as described above, the input shaft.
41 is attached to the column shaft 20 and the output shaft 42 is attached to the transmission shaft 16 by detachable coupling coupling. The drive coupling means 4 in the drive coupled state is released from the coupling coupling and the column is removed. It is possible to realize a return to the initial state by removing it from between the shaft 20 and the transmission shaft 16 and replacing it with a new drive connecting means 4.

The means for removing the sealing body 45 is not limited to the destruction and removal due to the explosion of the inflator 49 shown in the embodiment, and for example, the sealing body 45 is removed by pulling it out to the outside. An appropriate configuration can be adopted.
Further, in the above embodiment, the sealing body 45 is removed according to the operation command from the steering control unit 3 to obtain the drive connection state. However, for example, the driving is performed according to an appropriate operation by the driver. It goes without saying that the connected state may be obtained.

The rotating discs 43 and 44 attached to the ends of the input shaft 41 and the output shaft 42 are not an essential requirement of the present invention, but contact with the hardened body 4a in the drive connection state shown in FIG. It is necessary to increase the area and realize a strong connection. Further, it is also possible to provide a blade plate on the facing surface of the rotating discs 43 and 44 to enhance the stirring effect of the first and second liquids 47 and 48 after the sealing body 45 is removed.

Further, when the drive connecting means 4 is brought into the drive connected state, the steering feeling experienced by the driver who operates the steering wheel 2 is greatly changed.
Is operated in parallel with the output of the operation signal to the drive connecting means 4 to perform an alarm operation such as sounding of an alarm sound or generation of a voice message, informing the driver that the steering feeling is changed, and steering wheel. It is desirable to carry out the operation of 2 carefully while urging the vehicle to approach the road shoulder and stop the vehicle.

FIG. 4 is a schematic block diagram showing a second embodiment of the vehicle steering system according to the present invention. The vehicle steering system shown in this figure includes a steering mechanism 1 for causing the steering wheels 10, 10 to perform a steering operation, and a steering wheel 2 mechanically connected to the steering mechanism 1. And a transmission device 5 that is interposed between the steering wheel 2 and the steering mechanism 1 and is capable of changing the rotation transmission ratio, and the rotation transmission ratio of the transmission device 5 is variable according to the steering state and the traveling state. And a transmission ratio control unit 6 for controlling the transmission ratio, and is configured as a variable transmission ratio steering device configured to obtain steering characteristics adapted to a steering state and a traveling state.

The steering mechanism 1 is a well-known rack and pinion type steering mechanism, in which both ends of a rack shaft 11 extending in the left-right direction of the vehicle body and moving in the axial direction are provided with wheels for steering. Ten,
The knuckle arms 12, 12 are connected to the knuckle arms 12, 12 via separate tie rods 13, 13, and the knuckle arms 12, 12 are pushed and pulled through the tie rods 13, 13 by the movement of the rack shaft 11 in the axial direction. It is configured to steer 10 and 10 left and right.

A pinion housing H ₂ is continuously provided on one side of the rack housing H ₁ so as to intersect with the rack housing H _1. Inside the pinion housing H _2, a pinion is rotatable about an axis. The shaft 14 is supported. A pinion (not shown) is integrally formed on the lower half portion of the pinion shaft 14, and is engaged with a rack tooth (not shown) formed at a corresponding portion of the rack shaft 11 at an intersection with the rack housing H ₁ .

Steering wheel 2 as steering means
Is a column shaft 20 rotatably supported on a predetermined part of the vehicle body.
It is fixed at the top of. A steering angle sensor 21 for detecting the rotational operation angle of the steering wheel 2 for steering is provided in the middle of the column shaft 20, and the detection result of the steering angle sensor 21 is given to the transmission ratio controller 6. Has been. Further, the transmission ratio control unit 6 is provided with a detection result of a traveling state such as a vehicle speed, a yaw rate, a lateral acceleration, a longitudinal acceleration, etc., which influences steering, from a traveling state sensor 22 installed in each part of the vehicle.

A transmission shaft 16 is connected to the upper end of the pinion shaft 14 protruding above the pinion housing H ₂ via a universal joint 15a, an intermediate shaft 15b and a universal joint 15c. The transmission shaft 16
Is rotatably supported around an axis and extends upward,
It is opposed to the lower end of the column shaft 20, and the transmission device 5 is interposed between the opposed parts.

With the above configuration, when the steering wheel 2 is rotated for steering, the column shaft 20
Rotates about its axis, and this rotation is transmitted to the transmission shaft 16 at a rotation transmission ratio realized in the transmission device 5, and further transmitted to the universal joint 15c and the intermediate shaft.
The torque is transmitted to the pinion shaft 14 via the 15b and the universal joint 15a, the movement is converted at the meshing portion of the pinion and the rack teeth, and a moving force in the axial direction is applied to the rack shaft 11 for steering.

FIG. 5 is a side sectional view schematically showing the structure of the transmission device 5. As shown in the figure, the transmission device 5 includes a cylindrical housing 50, an input shaft (input side member) 51 and an output shaft (an input side member) 51 that are rotatably supported coaxially and that penetrate through both end walls of the housing 50. Output side member) 52.

Inside the housing 50, a small-diameter sun gear 53 having teeth on the outer periphery and an outer side of the sun gear 53 are surrounded.
The teeth of the sun gear 53 and the ring gear 54 are equally distributed in the annular space between the ring gear 54 and the large-diameter ring gear 54 having teeth on the inner and outer circumferences.
A planetary gear transmission mechanism including a plurality of planetary gears 55, 55 that mesh with the inner teeth is configured.

The planetary gears 55, 55 ... Are individually rotatably held on a predetermined circumference of a disc-shaped carrier 56, and an output shaft 52 extending from one side of the housing 50 to the inside thereof is provided. The end portion of is coaxially fitted to the carrier 56,
The sun gear 53 is integrally formed at the end of the input shaft 51 extending inward from the other side of the housing 50. Further, an input shaft 51 and an output shaft 52 extending outside the housing 50.
The other end of the column shaft is detachably coupled to the ends of the column shaft 20 and the transmission shaft 16, and the input shaft 51 rotates together with the column shaft 20 according to the operation of the steering means 2 to output the output. The shaft 52 is adapted to rotate together with the transmission shaft 16 in association with the operation of the steering mechanism 1.

On the other hand, the teeth on the outer periphery of the ring gear 54 are meshed with the pinion 57 at the output end of the transmission motor M ₃ fixed to the outer periphery of the housing 50, and the ring gear 54 is transmitted from the transmission motor M _3. It is designed to rotate around the axis.

Further, a powder blower having a blowout port inside the housing 50 is provided outside the housing 50.
58 is fixed. The powder blower 58 is a metal powder,
A powder such as a resin powder is built in, and the powder is blown into the housing 50 through the blow-out port according to the reception of an operation signal given from the outside.

In the transmission device 5 configured as described above, when the column shaft 20 rotates in response to the rotation operation of the steering wheel 2, the input shaft connected to the column shaft 20.
51 and a sun gear 53 integrally formed at the end of the input shaft 51
Rotate in response to this rotation, and the planetary gears 55, 55, ... meshing with the outside of the sun gear 53 rotate about their respective axes.
Since this rotation occurs while meshing with the outer ring gear 54, the carrier 56 that holds the planetary gears 55, 55, ... rotates around its axis in accordance with the revolution of the planetary gears 55, 55.
The output shaft 52 fitted to the 56 rotates, and the transmission shaft 16 connected to the output shaft 52 rotates.

Here, when the speed change motor M ₃ is stopped and the ring gear 54 meshing with the outside of the planetary gears 55, 55 ... Is fixed, the rotation transmission from the rotation of the sun gear 53 to the rotation of the carrier 56. Is performed under deceleration according to the ratio of the number of teeth on the outer circumference of the sun gear 53 to the number of teeth on the inner circumference of the ring gear 54, and the rotation of the column shaft 20 is decelerated and transmitted to the transmission shaft 16.

When the speed change motor M ₃ is rotationally driven and the ring gear 54 meshing with the pinion 57 at the output end is rotated in the same direction (or opposite direction) as the rotation direction of the carrier 56, The rotation speed of the carrier 56, that is,
The rotation speed of the transmission shaft 16 increases (or decreases), and the transmission device 5
The rotation transmission ratio inside, that is, the column shaft 20 to the transmission shaft 16
Rotational transmission ratio to is changed.

During operation of the transmission device 5 as described above, the powder blower 58 operates, and when powder such as metal powder or resin powder is blown out into the housing 50 as described above, these powder blowers 58 The powder is caught in the meshing parts of the sun gear 53 and the ring gear 54, and the planetary gears 55, 55 ... The input shaft 51 and the output shaft 52 are drivingly connected by the coupling force, and the transmission from the column shaft 20 connected to the input shaft 51 to the transmission shaft 16 connected to the output shaft 52 is performed as follows. The rotation transmission ratio is 1: 1. An operation command from the transmission ratio controller 6 is given to the powder blower 58, and the powder is blown to obtain the drive connection state described above according to the operation command.

The transmission motor M ₃ is driven according to an operation command given from the transmission ratio control section 6 to a drive circuit (not shown). The transmission ratio control unit 6 uses the operating angle of the steering wheel 2 detected by the steering angle sensor 21 and the traveling state detected by the traveling state sensor 22 to control the transmission device 5 based on a predetermined control rule. The control operation of determining the rotation transmission ratio and issuing an operation command to the variable speed motor M ₃ to obtain this rotation transmission ratio is performed.

The rotation transmission ratio is determined so as to become smaller as the operation angle increases and becomes larger and smaller as the vehicle speed slows down. By controlling the motor M ₃ , it becomes possible to perform large steering with a small force during low speed traveling or stop, and to perform steering during high speed traveling with good responsiveness. The characteristics are obtained.

The steering apparatus shown in FIG. 4 is a manual steering apparatus in which steering is performed only by the rotational operation force applied to the steering wheel 2, but the steering mechanism 1 is provided with an actuator for steering assistance. Also in a steering device configured as a power steering device that assists steering by operating the actuator according to the steering torque applied to the steering wheel 2, the transmission device 5 and the transmission ratio control unit 6 are provided, and the transmission is performed. It goes without saying that the rotation transmission ratio for the device 5 can be controlled.

During the control operation performed as described above, the transmission ratio control unit 6 targets the input side steering angle sensor 21 and the traveling state sensor 22, the output side transmission motor M _{3 and the} transmission ratio control unit 6 itself. We are conducting an abnormality diagnosis that
When it is diagnosed that an abnormality has occurred in any of them, the erroneous control under this abnormality is stopped and the connection control operation is performed so as to bring the transmission device 5 into the drive connection state.

This connection control operation is performed by the powder blower.
The operation command is given to 58, and as described above, powder is blown out into the housing 50 in order to cause seizure or biting in the meshing parts of the sun gear 53 and the ring gear 54 and the planetary gears 55, 55 .... By the seizure or biting, the input shaft 51 and the output shaft 52 are integrally connected to obtain a drive connection state, and the steering operation of the steering wheel 2 is carried out at a rotation transmission ratio of 1: 1. 1 is transmitted, and an emergency steering can be performed when the abnormality occurs.

In the vehicle steering system shown in FIG. 4, the drive connection means for obtaining the drive connection state is the transmission 5
Powder blower that blows out powder inside the housing 50 of
This can be realized by a simple configuration in which only the 58 is attached, and it is possible to minimize the complexity of the overall configuration of the steering device and the increase in product cost. The powder material may be selected according to the material of the target sun gear 53, ring gear 54, and planetary gears 55, 55.

Further, the transmission 5 has the input shaft 51 as described above.
Is attached to the column shaft 20 and the output shaft 52 to the transmission shaft 16 by detachable coupling coupling, and the transmission device 5 brought into a drive connection state by a coupling force based on seizure or biting is Column shaft 20
It is possible to restore the initial state by removing it from between the transmission shaft 16 and the transmission shaft 16 and replacing it with a new transmission device 5.

In the above embodiments, the case where the planetary gear type transmission device 5 is provided has been described.
It goes without saying that the present invention can be applied to the case where other gear type transmissions and transmissions of types other than gears are provided. Further, in the above embodiment,
A powder blower according to an operation command from the transmission ratio control unit 6
Although it is configured to operate the 58 and obtain the drive connection state,
For example, the drive connection state may be obtained according to an appropriate operation by the driver. Further, the above drive connection state is not limited to the case where the input side member and the output side member are drive-connected at a rotation transmission ratio of 1: 1, but the input side member and the output side member are driven in a relative rotation state. Including the case of connecting.

[0074]

As described above in detail, in the vehicle steering system according to the present invention, the input side member that rotates in response to the operation of the steering means and the output side member that rotates in conjunction with the operation of the steering mechanism are chemically operated. Since the drive connection is made by the coupling force based on the change,
The present invention has excellent effects such that the drive connection state required when various kinds of failures occur can be realized with a simple configuration, and emergency steering under failure can be surely performed.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing a first embodiment of a vehicle steering system according to the present invention.

FIG. 2 is a side sectional view schematically showing the configuration of drive connecting means used in the vehicle steering system shown in FIG.

FIG. 3 is a side sectional view showing the internal structure of the drive connecting means in the drive connected state.

FIG. 4 is a schematic block diagram showing a second embodiment of the vehicle steering system according to the present invention.

5 is a side sectional view schematically showing a configuration of a transmission device used in the vehicle steering system shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Steering mechanism 2 Steering wheel (steering means) 3 Steering control section 4 Drive connection means 5 Transmission device (transmission means) 6 Transmission ratio control section 40 Housing 41 Input shaft (input side member) 42 Output shaft (output side member) 45 Sealing body 46 Liquid chamber 47 First liquid 48 Second liquid 49 Inflator 51 Input shaft (input side member) 52 Output shaft (output side member) 53 Sun gear 54 Ring gear 55 Planetary gear 58 Powder blower M ₁ Steering motor M ₂ Force motor M ₃ variable speed motor

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenji Azuma             3-5-8 Minamisenba, Chuo-ku, Osaka-shi, Osaka               Koyo Seiko Co., Ltd. (72) Inventor Takeo Iino             3-5-8 Minamisenba, Chuo-ku, Osaka-shi, Osaka               Koyo Seiko Co., Ltd. (72) Inventor Naotake Kanda             3-5-8 Minamisenba, Chuo-ku, Osaka-shi, Osaka               Koyo Seiko Co., Ltd. (72) Inventor Shingo Maeda             3-5-8 Minamisenba, Chuo-ku, Osaka-shi, Osaka               Koyo Seiko Co., Ltd. (72) Inventor Masayuki Ueno             3-5-8 Minamisenba, Chuo-ku, Osaka-shi, Osaka               Koyo Seiko Co., Ltd.

Claims (5)

[Claims] 1. A drive connection for drivingly connecting both members based on a chemical change between an input side member that rotates in response to an operation of a steering means and an output side member that rotates in conjunction with the operation of a steering mechanism. A vehicle steering system comprising means. 2. The drive connecting means includes a housing that covers a facing portion of the input side member and the output side member, a liquid chamber that is arranged in parallel with the housing through a sealing body, and a liquid chamber inside the liquid chamber. First liquid contained and second liquid contained in the housing
The vehicle steering system according to claim 1, further comprising: a two-liquid mixed type liquid agent that generates a driving connection force by mixing with a liquid, and a means for removing the sealing body. 3. The drive connecting means is formed between the input side member and the output side member, and has a transmission means having at least one mechanical contact portion, and causes seizure in the contact portion. The vehicle steering apparatus according to claim 1, further comprising means for supplying powder to the contact portion. 4. The vehicle steering system according to claim 3, wherein the transmission means is a gear transmission that includes gears that rotate in conjunction with the input side member and the output side member and mesh with each other. 5. The vehicle steering system according to claim 1, wherein the drive connecting means is detachably interposed between the steering means and the steering mechanism.