KR101497375B1 - Locking device of steering apparatus for vehicle - Google Patents

Abstract

The present invention relates to a locking device of a steering apparatus for a vehicle. The locking device selectively restricts a rotation of a rotational axis of the steering apparatus for a vehicle, and comprises: a fixed body; a moving body reciprocating to be distance from or close to the fixed body, wherein a locking plunger is fixated on an end thereof and reciprocates for a protrusion plate fixed in the rotational axis and rotated with the moving body together, and a projection to be interconnected; a solenoid arranged around the moving body to apply a force for the moving body to be transferred; a case covering the solenoid; and a spring interposed between the fixed body and the moving body, applying a force moving to the direction for the moving body distance from the fixed body by an elastic restoring force. The locking device of the steering apparatus for a vehicle is provided to enable a reliable operation for a long period of time while minimizing the amount of power consumption and heat generation, and to improve accuracy of a position control of the locking plunger to secure linearity for a reciprocating movement control of the locking plunger.

Description

TECHNICAL FIELD [0001] The present invention relates to a locking mechanism for a steering device for a vehicle,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a locking mechanism for a steering apparatus for an automobile, and more particularly to a steering apparatus for assisting a steering load required for a driver's operation of an automobile by using an electric power, And more particularly, to a locking mechanism of a steering apparatus for an automobile and a steering apparatus having the locking mechanism.

An automotive steering apparatus is an apparatus for adjusting the traveling direction of a vehicle, and is also referred to as a steering apparatus. The steering device adjusts the traveling direction of the vehicle by rotating the steering wheel installed in the driver's seat clockwise or counterclockwise.

However, in order to rotate the steering wheel, a part of the weight of the vehicle acts on the wheels and the like. In particular, it takes a large force (steering load) to operate only by the force of the driver while the vehicle is stationary. Accordingly, as shown in Figs. 1 and 2, a motor driving power steering (MDPS) for rotating the spindle 10 extending from the steering wheel is mounted. That is, the worm wheel 11 provided on the spindle 10 is installed to be engaged with the worm gear 21 of the drive shaft 22 that is driven to rotate by the steering motor 20, The steering motor 20 can be easily operated to rotate the steering wheel in the direction of rotating the steering wheel. If it is necessary to prevent the steering wheel from rotating easily due to the high speed of the vehicle, So that the steering wheel 20 can not be easily rotated by applying a rotational load to the steering wheel.

However, as shown in FIGS. 1 and 2, the steering motor 20 is disposed at an angle of 90 degrees with the spindle 10 extending from the steering wheel, so that the steering motor 20 is separated from the axis of the spindle 10 There is a problem that a separate casing must be provided in order to arrange it and occupy a lot of space in the engine room.

In addition, since the mechanical noise generated between the worm wheel 11 and the worm gear 21 causes the driver to feel uncomfortable, there is a great need for a method for enabling a more quiet steering operation . Further, when vibration is transmitted to the worm gear 21 by the operation of the steering motor 20, the meshing noise of the teeth due to the vibration becomes larger between the worm wheel 11 and the worm gear 21, There is a problem that an uncomfortable feeling is generated.

An object of the present invention is to surely block the electric power consumed for holding the locking plunger in a pulled-up state and the amount of heat generated while minimizing the amount of electric power required to interrupt the steering force.

It is another object of the present invention to improve the accuracy of the position control of the locking plunger by securing linearity in controlling the reciprocating movement of the locking plunger in order to block the steering load.

Another object of the present invention is to improve the accuracy of the position control of the locking plunger by uniformly maintaining the magnetic field formed by the solenoid during the movement control of the moving body of the locking mechanism using the solenoid.

SUMMARY OF THE INVENTION The present invention has been accomplished to solve the above problems, and it is an object of the present invention to provide a locking mechanism for selectively restricting rotation of a rotary shaft of an automotive steering device, A moving body made of a magnetic material and fixed to the end of the locking plunger, the locking plunger reciprocating to move away from the fixed body and reciprocating to be engaged with the protrusion of the locking plate fixed to the rotating shaft and rotating together; A solenoid disposed around the moving body to exert a force to move the moving body toward the fixed body by being magnetized in a direction pulling the moving body; A case surrounding the solenoid; A spring interposed between the fixed body and the movable body for applying a force to move the movable body in a direction away from the fixed body by an elastic restoring force; Wherein one of the movable body and the fixed body is formed with a recessed portion formed with an inclined slope and the other of the movable body and the fixed body is formed with a protrusion having an inclined slope, Wherein the protrusion is partially or more inserted into the concave portion in a state where the protruding portion is close to the fixed body.

This is because the solenoid operates only while the steering load is being assisted to release the interference between the latching protrusion of the latching plate and the locking plunger, and in the locking state in which the steering load is not assisted, the locking projection of the latching plate and the locking plunger To interfere. In this way, when the steering load is not assisted as the solenoid is operated to allow the rotation of the rotary shaft only while the steering load is assisted, the rotation of the steering wheel is mechanically blocked using the elastic restoring force of the spring, It is possible to reliably block the rotation of the steering wheel.

In particular, the present invention is characterized in that the movable body and the fixed body are formed with a recessed portion formed with an inclined slope, and the other of the movable body and the fixed body is formed with a protrusion having an inclined slope, And the protruding portion is partially or more inserted into the concave portion in a state where the moving body is close to the fixed body. As described above, by forming the concave portion and the protruding portion with the tapered slopes on the opposed surfaces of the movable body made of a magnetic body and the fixed body made of the magnet, the opposed area between them becomes larger corresponding to the inclined surface, It is possible to compensate the nonlinearity of the force due to the difference in distance between the fixed bodies, thereby securing the linearity of the force, and at the same time, exerting a higher force.

If the stroke (distance) is gradually increased according to the characteristics of the solenoid actuator, it is possible to move the movable body by applying a large current. However, if the distance between the movable body and the fixed body is shortened, Since the magnetic force pulling each other between the body and the fixed body as the magnet increases, the force generated by the solenoid becomes large even if a small current is applied. Therefore, according to the present invention, the current applied to the solenoid is applied as a first current, and after a predetermined time has elapsed, the current is applied with a second current lower than the first current, And the amount of heat generated in the solenoid can be minimized.

That is, when the distance between the movable body and the fixed body is far away, a high first current (for example, about 3A) is applied and when the movable body is close enough to the fixed body (for example, (For example, about 0.2 A), which is about 1/30 to 3/20 times lower than the current (for example, about 0.2 A) of the current, the retaining plunger is kept from retracting from the retaining plate while maintaining low power consumption and low calorific power . Therefore, even if the battery is used for a long time, the possibility of failure due to heat generation can be reduced.

Preferably, a control circuit for controlling the solenoid is accommodated in the case, and the control circuit is located on the opposite side of the fixed body with respect to the moving body. As described above, since the control circuit for controlling the solenoid is not located on the side surface of the solenoid but on the opposite side of the fixed body, the solenoid control circuit can be easily installed and the overall structure is compact, and the shape of the case surrounding the solenoid is cylindrical So that the path of the magnetic force formed around the solenoid is secured symmetrically and the solenoid can be accurately controlled by the uniform distribution of the magnetic force.

Since the locking plunger repeatedly contacts with the latching protrusion of the latching plate, it is necessary to ensure high durability and hardness. For this purpose, it is preferable that the locking plunger is made of a steel material (for example, SM45C) which is easily heat-treated. On the other hand, since the moving body is magnetized only in the ON state without being magnetized in the OFF state of the solenoid, it is preferable that the moving body is formed of a material close to pure iron or pure iron (material having a small carbon amount). At least, it is preferable that the carbon content is made smaller than the material of the locking plunger.

According to another aspect of the present invention, there is provided a steering apparatus comprising: a hollow rotary shaft rotatably disposed around an input shaft extending from a steering wheel of an automobile; A drive motor for rotationally driving the hollow rotary shaft; A deceleration unit that decelerates the rotational speed of the hollow rotary shaft and transmits a rotational driving force of the decelerated rotational speed to the output shaft; The locking plunger reciprocatingly moving toward the outer circumferential surface of the latching plate in which a plurality of latching projections protrude along the circumferential direction and selectively reciprocating the locking plunger so that a part of the locking plunger is positioned between the latching projections a locking mechanism; An auxiliary device for an automobile is provided.

According to the above configuration, when the steering angle of the steering wheel and the information of the vehicle through various sensors are inputted and the hollow shaft is rotationally driven by the driving motor with the control value calculated by the ECU, The harmonic decelerating portion decelerates the rotational speed of the output shaft and rotates and drives the output shaft. As a result, the input shaft and the output shaft are arranged coaxially, and the hollow rotary shaft, which is rotationally driven by the drive motor, is arranged coaxially, so that the structure can be compact and occupy a small volume.

In addition, since the rotational speed of the driving motor is transmitted to the output shaft by the quiet harmonic deceleration portion with a large reduction ratio, all the components are compactly configured with respect to one central axis, and the steering load is assisted It is also possible to achieve a more quiet operation.

Further, the harmonic decelerating portion is formed with a straightness guide extending along the axial direction of the hollow rotary shaft so as to secure a straightness with the hollow rotary shaft, and is bent radially inwardly, and an end of the linear- So that the center axis of the harmonic deceleration portion is firmly fixed to the center axis of the hollow rotary shaft from the coaxial axis and is not allowed to deviate from the center axis of the hollow rotary shaft even when vibration or the like generated during operation is generated and transmitted to the harmonic deceleration portion. Therefore, it is possible to obtain an advantageous effect that the noise of the gear teeth of the harmonic deceleration portion can be kept low.

The 'inner ring' described in this specification and claims refers to a portion which is in contact with the input side of the harmonic deceleration portion and rotates together, and the 'outer ring' refers to a portion which rotates together with the output side of the harmonic deceleration portion.

As described above, according to the present invention, in constructing the locking mechanism of the steering apparatus, the movable body which reciprocally moves integrally with the locking plunger is provided with the recessed portion formed with the inclined sloping surface, The protruding portion is formed so that the protruding portion is partially or more inserted into the concave portion in a state in which the movable body is in proximity to the fixed body so that the opposing area between the movable protruding portion and the movable body is large, In addition, it is possible to mitigate the tendency of the force acting nonlinearly on the basis of the difference of the movement distance, and it is possible to obtain an advantageous effect that the movement control of the locking plunger is facilitated and correct.

The present invention is characterized in that a current applied to the solenoid is applied as a first current and then a second current lower than the first current is applied after a predetermined time elapses, It is possible to reduce the amount of use and greatly reduce the amount of heat generated.

Further, according to the present invention, the control circuit for controlling the solenoid of the locking mechanism is installed in the case, and is positioned at the opposite side of the fixed body from the solenoid, so that the solenoid control circuit can be easily installed and a compact structure as a whole can be obtained. The path of the magnetic force formed by maintaining the cylindrical shape can be secured symmetrically and uniformly, and the advantage that the solenoid can be precisely controlled through the uniform distribution of the magnetic force can be obtained.

1 is a schematic view showing a configuration of a general automotive steering system
2 is a view showing a configuration of a load assisting device of the steering apparatus of Fig. 1
FIG. 3 is a perspective view showing an appearance of an automotive steering apparatus according to an embodiment of the present invention,
Fig. 4 is a plan view of Fig. 3,
Fig. 5 is a longitudinal sectional view taken along the cutting line XX of Fig. 4,
FIG. 6 is an enlarged view of a portion 'A' in FIG. 5,
7 is an enlarged view of a portion 'B' in FIG. 5,
8 is an enlarged view of a portion 'C' in FIG. 5,
Fig. 9 is a partially exploded perspective view of Fig. 3,
Fig. 10 is a perspective view showing an alignment structure of the output shaft and the second casing of Fig. 3,
11 is a longitudinal sectional view of the locking mechanism of Fig. 3,
FIG. 12 is an enlarged sectional view showing the configuration of the harmonic decelerating portion of FIG. 3,
13A is a voltage waveform graph applied to the solenoid of FIG. 3,
13B is a graph of the change of the suction force according to the stroke (distance).
11 is an enlarged sectional view showing the configuration of the harmonic decelerating portion of Fig. 3,

Hereinafter, a steering apparatus 100 equipped with a locking mechanism 160 according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the subject matter of the present invention.

Fig. 3 is a perspective view showing an external appearance of an automotive steering apparatus according to an embodiment of the present invention, Fig. 4 is a plan view of Fig. 3, Fig. 5 is a longitudinal sectional view along a cutting line XX of Fig. FIG. 7 is an enlarged view of the portion 'B' of FIG. 5, FIG. 8 is an enlarged view of the portion 'C' of FIG. 5, FIG. 9 is a partially exploded perspective view of FIG. 3 is a longitudinal sectional view of the locking mechanism of Fig. 3, Fig. 12 is an enlarged sectional view showing the configuration of the harmonic decelerating portion of Fig. 3, Fig. 13a is an enlarged sectional view of the solenoid of Fig. FIG. 13B is a graph of a change in suction force according to the stroke (distance). FIG.

As shown in the drawing, an automotive steering apparatus 100 according to an embodiment of the present invention includes an input shaft 110 'formed of a spindle extending from a steering wheel of an automobile, and an input shaft 110' A driving motor 130 for driving the hollow rotary shaft 120 to rotate the hollow rotary shaft 120 and a second rotary shaft 120 for rotating the hollow rotary shaft 120 at a first rotation speed between 1/30 times and 1/60 times a second rotation speed An output shaft 110 rotated together with the outer ring 145 of the harmonic deceleration unit 140 and rotated by a torque assisted by the driving force of the driving motor 130, And a plurality of locking protrusions 152 formed on an outer circumferential surface of the locking plate 150. The locking plate 150 is selectively linearly moved so that the locking plunger 165 is engaged with the locking protrusions 152 of the locking plate 150, So as to limit the rotation of the hollow rotary shaft 120 And a locking unit (160).

The input shaft 110 'extends from the steering wheel, and the steering angle and speed of the input shaft 110' are sensed by a sensor (not shown) and transmitted to the ECU of the vehicle. At this time, although not shown in the drawing, a sensor for sensing the steering angle and rotational speed of the input shaft 110 'may be installed in the housing 139 surrounding the drive motor 130. 8, the end of the input shaft 110 'is rotatably supported by a bearing installed in the housing 139. The input shaft 110' is spaced apart from the output shaft 110 by a length indicated by a reference numeral y, And the output shaft 110 are coaxial with each other.

6, the hollow rotary shaft 120 is rotatably supported by a bearing 138 provided on the housing 130 with a predetermined gap d between the hollow shaft 120 and the input shaft 110 '. Accordingly, the hollow rotary shaft 120 can be rotated at a different rotational speed with respect to the input shaft 110 '.

The driving motor 130 is disposed so as to surround the hollow rotary shaft 120 and directly drives the hollow rotary shaft 120 to rotate. To this end, a portion corresponding to the rotor is integrally formed around the hollow rotary shaft 120, and a portion corresponding to the stator is disposed with a gap between the rotor and the rotor.

A housing 139 is installed around the driving motor 130 and a stator of the driving motor 130 is accommodated in the housing 130. A first end of the first housing 159 is fitted with a first step and a component is fixed to the first housing 159 by sandwiching the first housing 159, The fixed components are accurately aligned with respect to the center line of the input shaft 110 '. 9, a second step 159a is formed at the end of the first casing 159 in which the second casing 149 is fitted, and an output shaft (not shown) is formed at the inner surface of the second step 159a. The first casing 159 and the second casing 149 and the output shaft 119 are fitted to the outer surface of the second step 159a while one end of the second casing 149 is fitted to the outer surface of the second step 149a. 110 are correctly aligned.

Therefore, the assembling process of the steering apparatus 100 according to the present invention is facilitated, and it is possible to greatly reduce the noise and vibration generated during operation due to the accurate alignment.

The harmonic deceleration unit 140 includes an inner wheel 140a rotated at a first rotation speed while being in contact with a hollow rotary shaft 120 driven to rotate at a first rotation speed, An outer ring 145 that rotates at a second rotation speed decelerated by 30 to 60 times the first rotation speed and an outer ring 145 that rotates at a second rotation speed in the axial direction of the input shaft 110 ' And a straight guide 142 which is bent radially inward.

The inner ring 140a rotates together with the hollow rotary shaft 120 rotating at a high speed by the drive motor 130 and the outer ring 145 is rotated by the harmonic reduction gear between the inner ring 140a and the inner ring 140a, The second rotation speed is reduced by about 1/50 times as compared with the first rotation speed of the second rotary shaft. The outer ring 145 rotates integrally with the connecting portion 115 of the output shaft 110 so that the output shaft 110 is rotationally driven at the second rotational speed. Accordingly, the output shaft 110 is extended through the through hole 149b of the second casing 149 and is rotated at a second rotation speed that is about 1/50 times slower than the first rotation speed of the hollow rotation shaft 120, And is rotationally driven by the rotational driving force transmitted from the deceleration section (140).

The end of the rectilinear motion guide 142 is kept in contact with the input shaft 110 'so that the inner ring 140a and the outer ring 145, even when the drive motor 130 is operated, The noise and vibration of the teeth engaged between the inner ring 140a and the outer ring 145 can be maintained at a low level because the teeth are always firmly held in the posture aligned with the axial direction of the hollow rotary shaft 120. [

Since the second rotation speed of the outer ring 145 is similar to the rotation speed of the input shaft 110 'at this time, the end of the rectilinear motion guide 142 may make a sliding contact with the outer circumferential surface of the input shaft 110' A ball may be installed to make a rolling contact with the outer peripheral surface of the input shaft 110 '.

The latching plate 150 is integrally coupled to the outer circumferential surface of the hollow rotary shaft 120 and rotates together with the hollow rotary shaft 120. As shown in FIG. 9, the latching plate 150 has the latching protrusion 152 protruded from the outer circumferential surface periodically.

9, the end of the locking plunger 165 is located inside the first casing 159, and the locking plunger 165 and the latching protrusion 165 are actuated by the solenoid 163, (152).

7 and 12, the locking mechanism 160 includes a cylindrical case 169 having a receiving space formed therein, a fixed body 161 positioned at one end of the case 169, A moving body 162 having a surface facing the fixed body 161 and reciprocatingly moving toward and away from the fixed body 161 and formed of a magnetic body and a magnetic body 162 for generating a magnetic force for moving the moving body 162 A spring 164 seated on the spring receiving portions 161z and 162z of the fixed body 161 and the moving body 162 and a spring 164 mounted on the spring receiving portions 161z and 162z of the moving body 162. [ A locking plunger 165 fixed to an end of the body 162 and moving together with the moving body 162 and a control circuit 168 located at an end of the case 169. [

The case 169 is formed in a cylindrical shape according to the shape of the solenoid 163, and is fixed with a bolt to the first casing 139 as shown in FIG.

The fixed body 161 and the moving body 162 are located within the case 169 and are formed of a magnetic material. A protruding portion 161a is formed in an inclined tapered shape on the fixed body 161 facing the moving body 162. The movable body 162 opposed to the fixed body 161 is formed with a tapered taper- (162a) is formed.

Since the protruding portion 161a is inserted into the space 160s formed by the recessed portion 162a in a state where the fixed body 161 and the moving body 162 are close to each other, Not only does the moving body 162 serve to guide the path of the reciprocating movement of the moving body 162 relative to the fixed body 161 but also to increase the opposing surface area so that the moving body 162 can be moved with greater force And the linearity of the force can be secured by compensating the nonlinearity of the force due to the difference in distance between the movable body and the fixed body.

Although the protrusion 161a is formed on the fixed body 161 and the concave portion 162a is formed on the moving body 162, the protrusion 161a may be formed on the fixed body 161, And a concave portion may be formed in the moving body 162. [

The spring 164 is installed on the stationary body 161 and the seating portions 161z and 162z of the moving body 162 so as to be elastically deformable to widen the gap between the fixed body 161 and the moving body 162 Restoring force works. At this time, since the spring seating portions 161z and 162z are formed in the projecting portion 161a of the fixed body 161 and the concave portion 162a of the moving body 162, the moving body 162 is reciprocated And the resilient restoring force 164F of the spring 164 act on the coaxial axis, so that the component of the force that the moving body 162 reciprocates while being twisted can be eliminated. As a result, the reciprocating motion of the moving body 162 can be reliably realized without a permanent failure.

The solenoid 163 is wound with a coil to apply a current to the solenoid 163 to apply a force 163F for retreating the locking plunger 165 while magnetizing the moving body 162 located at the center of the solenoid 163, Lt; / RTI >

13B, the greater the distance between the moving body 162 and the fixed body 161, the larger the current is applied, the more the critical suction force F necessary to move the moving body acts. On the other hand, if the distance between the moving body 162 and the fixed body 161 is small, a sufficient attractive force F can be applied to maintain the moving state of the moving body 162 even if a small current is applied. 13A, when the interference between the locking plunger 165 and the locking protrusion 152 is to be canceled, the initial current applied to the solenoid 163 becomes a relatively high first current A voltage V1 is applied to the solenoid 163 so that a second current lower than the first current is applied to the solenoid 163 after the predetermined time T1 has elapsed and the movable body 162 is sufficiently close to the fixed body 1161 V2). The current value applied to the solenoid 163 may be controlled by the current control method, but the current value applied by adjusting the voltage by the pulse width control (PWM) method may be controlled. By adjusting the current value differently according to the position of the moving body 162, the locking plunger 165 can be moved from the latching plate 150 The retracted state can be maintained continuously.

The control circuit 168 is disposed in the case 169 but is not located outside the radius of the solenoid 163 so as not to interfere with the magnetic field generated by the solenoid 163 and is spaced apart in the axial direction of the solenoid 163 . That is, a housing space 169x is provided at one side of the fixed body 161, and the control circuit is seated in the housing space 169x.

With this configuration, compared with the case where the control circuit 168 is separately provided, the assembly and installation are simplified, the structure becomes compact and the handling is facilitated. In particular, the case 169, which surrounds the solenoid 163, So that the peripheral structures in the space where the magnetic force is distributed can be symmetrically distributed. Accordingly, since the path of the magnetic force formed around the solenoid 163 is uniformly and symmetrically provided, the reciprocating movement control of the moving body 162 by the solenoid 163 can be more precisely controlled by the uniform distribution of the magnetic force .

Since the locking plunger 165 is in contact with the latching protrusion 152 of the latching plate 150 which is fixed to the hollow rotary shaft 120 repeatedly, the locking plunger 165 is formed of a steel material having a carbon content higher than SM40C. Accordingly, the locking plunger 165 can be assembled in a heat-treated state to ensure high hardness, durability, and impact resistance. Since the movable body 162 reciprocating with the locking plunger 165 alternates between the magnetized state and the non-magnetized state in accordance with ON / OFF of the solenoid 163, (For example, SM20C or less). The locking plunger 165 is manufactured separately from the moving body 162 and fixed in a press-fitting or fastening manner.

A solid lubricating bushing 165a is provided at the entrance of the case 169 through which the locking plunger 165 reciprocates, thereby reducing friction while the locking plunger 165 is constantly reciprocating without rocking.

The locking mechanism 160 according to the present invention configured as described above is configured such that the first voltage V1 is applied to the solenoid 163 to allow the first current to flow so that the locking plunger 165 is attracted to the fixed body 161 The interference between the locking plunger 165 and the latching protrusion 152 is released to allow the rotation of the hollow rotation shaft 120. As a result,

When the moving body 162 approaches the fixed body 161, the second voltage V2, which is as small as 5% to 12% of the first voltage V1, is applied to the solenoid 163, The movable body 162 and the fixed body 161 can be kept in a close state even if a second current lower than the first current flows in the movable body 162. [ The interference canceling state of the locking plunger 165 and the latching protrusion 152 is maintained even when a small second current of approximately 0.1 A to 0.3 A flows, so that the amount of power consumption can be reduced as the amount of heat generation is drastically reduced.

On the other hand, when the voltage applied to the solenoid 163 is cut off to prevent the steering load from being assisted, the current does not flow through the solenoid 163, so that the suction force pulling the movable body 162 is lost. The locking plunger 165 is moved in the direction away from the fixed body 161 by the resilient restoring force of the spring 164 located between the fixed body 161 and the moving body 162 and the end of the locking plunger 165 The interference between the engagement protrusions 162 becomes a state of interference.

The locking mechanism 160 of the steering apparatus for an automobile according to an embodiment of the present invention includes the moving body 162 and the fixed body 161 that reciprocate integrally with the locking plunger 165, The protruding portion 161a is partially or more inserted into the recessed portion 162a in the state where the concave portion 162a and the protruding portion 161a are formed and close to each other, So that the movement of the locking plunger 165 can be performed more easily and accurately, and the force acting in accordance with the movement distance difference of the moving body 162 can be guided more linearly, .

In the present invention, the current applied to the solenoid is initially applied with a high first current, but after a predetermined time (T1) of approximately 1 second to 5 seconds has elapsed, the second current is applied to the solenoid, The amount of electric power consumed and the amount of heat generated can be greatly reduced, so that an environmentally-friendly and reliable operation can be realized without a failure for a long time.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention.

100: Steering device for automobile
110 ': Input shaft 110: Output shaft
120: Hollow rotating shaft 130: Driving motor
140: Harmonic deceleration section 142: Straight ahead guide
150: latching plate 160: locking device
161: fixed body 162: movable body
162: Solenoid 164: Spring
165: locking plunger 168: control circuit
169: Case

Claims (10)

A locking mechanism for selectively restricting rotation of a rotation shaft of an automotive steering device,
A fixed body formed of a magnet;
A moving body made of a magnetic material and fixed to the end of the locking plunger, the locking plunger reciprocating to move away from the fixed body and reciprocating to be engaged with the protrusion of the locking plate fixed to the rotating shaft and rotating together;
A solenoid disposed around the moving body to apply a force to move the moving body toward the fixed body by being magnetized by a magnetic pole in a direction pulling the moving body;
A case surrounding the solenoid;
A spring interposed between the fixed body and the movable body for applying a force to move the movable body in a direction away from the fixed body by an elastic restoring force;
Wherein one of the movable body and the fixed body is formed with a tapered portion formed with a sloped tapered surface, and the other of the movable body and the fixed body has a tapered tapered shape Wherein the projecting portion is partially or more inserted into the concave portion in a state where the moving body is close to the fixed body.
The method according to claim 1,
Wherein the spring is located at a central portion of the concave portion and the protruding portion.
The method according to claim 1,
Wherein a current applied to the solenoid is applied as a first current and then a second current lower than the first current is applied after a predetermined time elapses.
The method of claim 3,
And the second current is 1/30 to 3/20 times the first current.
The method according to claim 1,
Wherein a control circuit for controlling the solenoid is accommodated in the case, and the control circuit is located on the opposite side of the fixed body with respect to the moving body.
The method according to claim 1,
Wherein the locking plunger is formed of a steel material, and the moving body is formed of a magnetic material having a carbon content lower than that of the locking plunger.
A hollow rotary shaft rotatably disposed around an input shaft extending from a steering wheel of the vehicle;
A drive motor for rotationally driving the hollow rotary shaft;
A deceleration unit that decelerates the rotational speed of the hollow rotary shaft and transmits a rotational driving force of the decelerated rotational speed to the output shaft;
A plurality of locking protrusions protruding along the circumferential direction, the locking plunger reciprocally moving toward the outer circumferential surface of the locking plate, and selectively moving the locking plunger so that a part of the locking plunger is positioned between the locking protrusions, A locking mechanism according to any one of claims 1 to 6;
And a steering angle sensor for detecting steering angle of the steering wheel.
8. The apparatus according to claim 7,
The outer ring being rotatably driven at a second rotation speed decelerated relative to the first rotation speed of the inner ring rotates together with the output shaft while the inner ring is in contact with the hollow rotary shaft so as to be rotated together with the hollow rotary shaft, Wherein the harmonic deceleration portion is a harmonic deceleration portion that transmits a rotational driving force at a predetermined speed.
9. The method of claim 8,
Wherein the harmonic decelerating portion includes a straight guide extending along an axial direction of the hollow rotary shaft so as to secure a straight line with the hollow rotary shaft and bent radially inwardly and the straight guide extends from the outer ring, Wherein an end of the guide is supported by either the rolling contact or the sliding contact on the input shaft.
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