KR20090093480A - Apparatus for Driving Backup Clutch in Steer-By-Wire for Preventing Clutch-Slipping - Google Patents

Abstract

A backup clutch drive unit for a steer-by-wire is provided to maintain the high combining force between a first column axis and a second column axis by preventing the slip the backup clutch in order to reduce the abrasion. A backup clutch drive unit for a steer-by-wire comprises a first column axis(302), a sliding axle(320), a return spring(314), a second column axis(304), a sliding axle driving part and a ball spring housing(330). The first column axis comprises a cylindrical hollow part(316) at one end side. A first sliding structure is equipped at the inner circumference of the hollow part. The sliding axle comprises one or more columnar grooves(324) on the bottom side. The return spring is arranged at a stop part located between a tip-end part(312) of the first column axis and a spring supporting part(322). The second column axis comprises a second clutch(310) at the one end in order to unite with a first clutch(326). The sliding axle driving part reduces the driving force to make the first clutch join to the second clutch. A support bead(336) is settled in one among the columnar grooves, if the first clutch is combined in the second clutch.

Description

Apparatus for Driving Backup Clutch in Steer-By-Wire for Preventing Clutch-Slipping}

The present invention relates to a backup clutch drive for a steer-by-wire (SBW) for slip prevention. More particularly, the present invention relates to a backup clutch drive for a steering by wire for providing mechanical steering in the absence of a steering means due to a failure of an electrical device related to steering in a vehicle employing a steering by wire.

Steer-By-Wire (SBW) refers to a device that controls steering by hydraulic or electric assist force using only electric signals instead of a mechanical structure that connects steering wheel rotation to wheel rotation.

Steer-by-wire generally includes a steering angle sensor for detecting a steering angle on the steering input side, and a steering output sensor for detecting the rotation angle of the tire on the output side and a steering actuator for rotating the tire by generating an auxiliary force. It consists of.

When the driver turns the steering wheel, the steering wheel sensor detects the amount of rotation of the steering wheel and transmits it to the Electronic Control Unit (ECU), and the ECU controls the steering output to be generated by adjusting the steering actuator that can rotate the tire. .

However, in the steer-by-wire system, as long as the wire is in the path of the signal that senses steering and transmits it to the actuator, the electric signal is not supplied due to the break of the wire or the contact failure, so that the driver's steering intention is not properly transmitted to the tire. If not, the steering actuator or ECU may fail and cause a malfunction, such as a malfunction, which can cause fatal problems.

It is a backup clutch drive device for the steering by wire that does not cause the above problems.

1 is a view showing a conventional backup clutch drive device for the steering by wire.

As shown in FIG. 1, a conventional backup clutch drive device for a steering by wire includes a first column shaft 102, a second column shaft 104, an electromagnetic coil 106, an armature 108, an output side hub 110, Armature hub 112 and leaf spring 114. The armature hub 112 is fixed to the first column shaft 102 connected to the steering wheel (not shown), and the leaf spring is connected to the armature hub 112. The armature 108 is attached to the leaf spring 114. The output side hub 110 is fixed to the second column shaft 104 connected to the steering gear (not shown), and the electromagnetic coil 106 is wrapped around the output side hub 110.

When the steer-by-wire normally operates, the first column shaft 102 and the second column shaft 104 are in a mechanically separated state, and the steering of the driver transmitted to the first column shaft 102 is mechanically second. It is not transferred to the column axis 104. However, when an error occurs in the steer-by-wire, a current is applied to the electromagnetic coil 106. The magnetic field is generated by the current applied to the electromagnetic coil 106, and the armature 108 is attracted against the restoring force of the leaf spring 114 to come into contact with the output side hub 110.

When the armature 108 comes into contact with the output hub 110, the first column shaft 102 and the second column shaft 104 are mechanically connected, and the steering force of the driver is transmitted to the steering gear (not shown). It can solve the fatal problem resulting from the failure of the wire.

However, the vehicle may be shaken depending on the vibration of the vehicle and the road surface while driving. In this case, vibration is transmitted to the leaf spring 114 to cause the shaking of the armature 108 in contact with the output hub 110. May occur. In this case, the contact force between the armature 108 and the output hub 110 may be loosened. If the sliding force (slip) occurs due to the loosening of the contact force between the armature 108 and the output hub 110, the steering force of the driver may not be properly transmitted, and the armature 108 and the output side hub 110 may be damaged. There is a lot of friction, the wear is faster and the life is shortened.

In order to solve the above-mentioned problems, the present invention provides a backup clutch for a steer-by-wire for providing mechanical steering as a safety device against the absence of a steering means due to a failure of an electrical device related to steering in a vehicle employing a steer-by-wire. The purpose is to prevent the slip from occurring.

In order to achieve the above object, the present invention, in the backup clutch drive for the steering by wire for preventing slip, comprising a cylindrical hollow portion at one end, the first sliding structure is provided on the inner peripheral surface of the hollow portion Column axis; Cylindrical, the upper end portion, the stop portion and the lower end portion, wherein the upper end portion is inserted into the hollow portion is engaged with the first sliding structure and has a sliding force in the rotational direction is possible to slide in the longitudinal direction in the hollow portion A sliding shaft provided with a second sliding structure, the stopping portion having a spring support on a circumference, the lower end having one or more circumferential grooves, and a first clutch provided on a distal end of the lower end; A return spring disposed at the interruption portion between the front end portion of the one end of the first column shaft and the spring support portion; A second column shaft having a second clutch at one end thereof so as to engage with the first clutch when the spring support part is pushed out by the restoring force of the return spring which is in contact with the front end of the one end of the first column shaft; Surrounds an outer circumferential surface of the lower end of the sliding shaft, and forms a plurality of opening ends on the outer surface in the circumferential direction of the sliding shaft, and a receiving member is inserted from the opening end toward the sliding shaft, and is supported in the receiving member through the opening end. Inserting a bead so that the support bead is in contact with the sliding shaft, the ball member is accommodated in the receiving member to push the support bead from the outer surface toward the sliding axis, the ball spring through the opening end A ball spring housing having a fixing member on the outer surface so as not to be separated out; And generating a driving force for allowing the sliding shaft to be inserted into the hollow part greater than a restoring force of the return spring when the steer-by-wire is in normal operation so that the first clutch is disengaged with the second clutch. And a sliding shaft drive unit configured to reduce the driving force so that the first clutch is engaged with the second clutch by a restoring force of the return spring when the steering-by-wire is in error, wherein the first clutch includes the second clutch. When coupled to the support bead provides a backup clutch drive device for a steering by wire, characterized in that seated in one of the circumferential groove.

According to the present invention, the steering force of the driver is maintained by preventing the slip between the clutch of the first column shaft and the clutch of the second column shaft due to the shaking of the vehicle according to the vibration of the vehicle and the road surface while the vehicle is running. This makes it possible to deliver properly and to reduce the wear of the clutch of the first column shaft and the clutch of the second column shaft.

1 is a view showing a conventional backup clutch drive device for the steering by wire.

2 is a view illustrating a steer-by-wire system using a backup clutch driving apparatus 200 for a steer-by-wire for preventing slip according to an embodiment of the present invention.

3 is a diagram illustrating a backup clutch driving device for a steer-by-wire for preventing slip according to an embodiment of the present invention.

Figure 4 is a three-dimensional view of the backup clutch drive for the steering by wire according to an embodiment of the present invention.

5 is a cross-sectional view taken along the line X-X 'shown in the drawing of FIG.

6 is a view showing a shape using a plurality of support beads 336.

7 is a view showing the operation of the backup clutch drive device for the steering by wire according to an embodiment of the present invention.

8 illustrates the first groove boundary portion 702 in detail.

<Description of Symbols for Main Parts of Drawings>

102: first column axis 104: second column axis

106: electromagnetic coil 108: amateur

110: output side hub 112: amateur hub

200: backup clutch drive 202: ECU

204: steering angle sensor 206: steering actuator

208: steering gear 210: steering input shaft

212: steering output shaft 302: first column shaft

304: second column shaft 306: solenoid coil

310: second clutch 312: distal end of the first column shaft

314: return spring 316: hollow part

318: sliding groove 320: sliding shaft

322: spring support 324: circumferential groove

326: first clutch 327: bearing hole

328: bearing ball 330: ball spring housing

332: open end 334: cylindrical tube

336: support ball 338: ball spring

329: solenoid housing 340: C ring

602: support portion 702: first groove boundary portion

704: second home boundary

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function is obvious to those skilled in the art or may obscure the gist of the present invention, the detailed description thereof will be omitted.

2 is a view illustrating a steer-by-wire system using a backup clutch driving apparatus 200 for a steer-by-wire for preventing slip according to an embodiment of the present invention.

As shown in FIG. 2, when the steer-by-wire is normally operated, the steering amount of the driver generated by the steering angle sensor 204 is sensed and the ECU 202 recognizes and controls the steering actuator 206 to drive the steering actuator 206. In this case, the ECU 202 controls the backup clutch driving device 200 such that the steering input shaft 210 and the steering output shaft 212 are in a mechanically separated state so that the steering of the driver is not transmitted to the steering gear 208 mechanically. Do not.

When an error occurs in the steering by wire, the ECU 202 controls the backup clutch driving device 200 to control the steering input shaft 210 and the steering output shaft 212 to be in a mechanically connected state.

3 is a diagram illustrating a backup clutch driving device for a steer-by-wire for preventing slip according to an embodiment of the present invention.

In an embodiment of the present invention, it is assumed that a first column axis is a steering input axis and a second column axis is a steering output axis. Therefore, according to the exemplary embodiment, the first column shaft is the steering output shaft and the second column shaft is the steering input shaft.

As shown in FIG. 3, the backup clutch driving apparatus 200 for the steer-by-wire according to the exemplary embodiment of the present invention includes an input shaft 302, an output shaft 304, a sliding shaft driver, a return spring 314, and a sliding shaft ( 320 and the ball spring housing 330.

The input shaft 302 has a cylindrical hollow portion 316 at one end thereof, and a first sliding structure is provided on an inner circumferential surface of the hollow portion 316.

The sliding shaft 320 has a cylindrical shape, and includes an upper end, a stop part, and a lower end, wherein the upper end is inserted into the hollow part 316 to be engaged with the first sliding structure and has an engagement force in a rotational direction while having the hollow part 316. A second sliding structure is provided to enable sliding in the longitudinal direction, and the stop portion includes a spring support portion 322 on a circumference, and the bottom portion includes one or more circumferential grooves 324 and the bottom portion The front end of the first clutch 326 is provided.

The second sliding structure may include a plurality of bearing holes 327 formed in a row in the longitudinal direction and spaced apart on the upper end, and the bearing balls 328 may be inserted into the bearing holes 327. have. In this case, the first sliding structure is provided with a plurality of longitudinal sliding grooves 318 on the inner circumference of the hollow part 216 so as to face the bearing hole 327. As such, the first sliding structure may have a groove shape, and the second sliding structure may have a protruding shape, and the first sliding structure and the second sliding structure face each other to have engagement forces in the rotational direction. Sliding in the longitudinal direction is possible.

The return spring 314 is disposed at the stop of the sliding shaft 320 between the tip portion 312 of the one end of the input shaft 302 and the spring support 322 of the sliding shaft 320. Here, the front end portion 312 and the spring support portion 322 may have a surface facing each other to serve to contact and support the return spring 314, respectively.

The output shaft 304 can engage with the first clutch 326 when the spring support 322 is pushed out by the restoring force of the return spring 314 which is in contact with the tip 312 of the one end of the input shaft 302. The second clutch 310 is provided at one end.

The first clutch 326 and the second clutch 310 may use a friction clutch or may be an engagement clutch.

The ball spring housing 330 surrounds the outer circumferential surface of the lower end of the sliding shaft 320, and forms a plurality of opening ends 332 in the circumferential direction of the sliding shaft 320 on the outer surface, and from the opening end 332. The receiving member is inserted toward the sliding shaft 320, and the support beads 336 are inserted into the receiving member through the opening end 332 so that the supporting beads 336 are in contact with the sliding shaft 320. The ball spring 338 is accommodated to push the support ball 336 from the outer side toward the sliding shaft 320, and fixed to the outer surface so that the ball spring 338 does not escape out through the opening end 332 A member is provided.

As the receiving member, a cylindrical tube 334 may be used. The cylindrical tube 334 should not be separated from the ball spring housing 330 after being inserted into the opening end 332, and for this purpose, a flange-shaped support may be formed at one end of the cylindrical tube 334.

The fixing member may use the C ring 340, and a ring connecting groove (not shown) is additionally formed on the circumferential surface connecting the opening end 332 of the ball spring housing 330 to use the C ring 340. The C ring 340 may be mounted in the ring connection groove (not shown). Although the C ring 340 is used as the fixing member, it is not limited thereto.

The sliding shaft drive unit generates a driving force for allowing the sliding shaft 320 to be inserted into the hollow part 316 when the steer-by-wire is in normal operation, so that the first clutch 326 may be larger than the restoring force of the return spring 314. The driving force is reduced so that the first clutch 326 is engaged with the second clutch 310 by the restoring force of the return spring 314 when the steer-by-wire fails. Let's do it.

When the first clutch 326 is coupled to the second clutch 310, the support beads 336 are seated in one of the circumferential grooves 324.

In the present embodiment, the lower end of the sliding shaft 320 may be provided with two circumferential grooves 324, in which case the support bead when the first clutch 326 is released from the second clutch 310. 336 may be seated in the other of the circumferential grooves 324.

The sliding shaft drive unit may include a solenoid coil 306 arranged on the outer circumference of the sliding shaft 320 and a solenoid housing 329 accommodating the solenoid coil 306.

The solenoid housing 329 and the ball spring housing 330 may be integrally formed and connected to a column housing (not shown) or may be fixed using a separate support agent.

Figure 4 is a three-dimensional view of the backup clutch drive for the steering by wire according to an embodiment of the present invention.

Figure 4 is shown in three dimensions in order to facilitate the understanding of the backup clutch drive device for a steering by wire according to an embodiment of the present invention of Figure 3, some of the items shown in Figure 3 are not shown for convenience.

5 is a cross-sectional view taken along the line X-X 'shown in the drawing of FIG.

As shown in FIG. 5, a plurality of bearing grooves 327 are formed in a row spaced circumferentially on the upper end of the sliding shaft 320, and a bearing ball 328 is inserted into each bearing groove 327. . A plurality of longitudinal sliding grooves 318 are provided at the inner circumference of the hollow portion 216 of the input shaft 302.

6 is a view showing a shape using a plurality of support beads 336.

As illustrated in FIG. 6, a plurality of support beads 336 may be used, and the opening end 332, the ball spring 338, and the cylindrical tube 334 may be used in the ball spring housing 330 as many as the number of the support beads 336 used. ) And the like. The cylindrical tube 334 may be formed with a support 602 in the form of a flange.

7 is a view showing the operation of the backup clutch drive device for the steering by wire according to an embodiment of the present invention.

FIG. 7A shows the steer-by-wire during normal operation. FIG. In FIG. 7A, when the steer-by-wire is normally operated, the ECU 202 transmits a current to the solenoid coil 306 and a force in which the sliding shaft 320 moves due to the magnetic field generated at this time is generated. Sliding shaft 320 is produced by including a material of the material to enable movement by the magnetic field. The driving force generated by the solenoid current should be greater than the restoring force of the return spring 314. At this time, the first clutch 326 and the second clutch 310 are in a released state.

FIG. 7B is a diagram in which the sliding shaft 320 moves and is positioned in the middle when an error occurs in the steer-by-wire and the ECU 202 prevents current from flowing through the solenoid coil 306.

FIG. 7C illustrates that the sliding shaft 320 is moved when the steer-by-wire causes an error in the ECU 202 so that the current does not flow through the solenoid coil 306, and thus the first clutch 326 and the second clutch 310 are coupled to each other. It is a figure which shows the state.

In order to achieve the object of the present invention, each of the first groove boundary portion 702 and the second groove boundary portion 704 should have a predetermined magnitude of support force. If the magnitude of the bearing force of the first groove boundary portion 702 is too large, the ECU 202 flows current to the solenoid coil 306 so that the first clutch 326 and the second clutch 310 are disengaged. It becomes difficult to change. In addition, if the magnitude of the holding force of the first groove boundary portion 702 is too small, the first clutch 326 and the second clutch 310 may loosen due to tremors caused by vibration of the vehicle. Becomes difficult to achieve.

As shown in FIG. 7A, when the first clutch 326 is disengaged from the second clutch 310, when the support ball 336 is seated in the other of the circumferential grooves 324, the second groove boundary portion ( If the magnitude of the bearing force of 704 is too large, it is difficult to change the first clutch 326 and the second clutch 310 into the engaged state by the restoring force of the return spring 314. Therefore, while the magnitude of the supporting force of the second groove boundary portion 704 is not greater than the restoring force of the return spring 314, the appropriate supporting force may reduce the amount of current required to flow to the solenoid coil 306.

8 illustrates the first groove boundary portion 702 in detail.

The magnitude of the bearing force of the first groove boundary portion 702 is the first clutch 326 and the second clutch 310 due to the vibration caused by the vibration of the vehicle or the like when the ECU 202 stops supplying current to the solenoid coil 306. Must be large enough that the coupling does not loosen. In addition, the ECU 202 applies a current to the solenoid coil 306 so that the first clutch 326 and the second clutch 310 should be small so as not to be difficult to change to the released state. That is, the bearing force (coupling degree) of the first groove boundary portion 702 between the support ball 336 and the circumferential groove 324 is the initial movement of the sliding shaft 320 when a current is applied to the solenoid coil 306 It should not be so large that it is impossible.

Therefore, as shown in FIG. 8, the objective of the present invention can be achieved by experimentally tuning the magnitude of the inclination angle a of the first groove boundary portion 702 to adjust the bearing force of the first groove boundary portion 702.

Similarly, the inclination angle of the second groove boundary portion 704 is also experimentally tuned in size so that the magnitude of the bearing force of the second groove boundary portion 704 is not greater than the restoring force of the return spring 314, but the current is applied to the solenoid coil 306. When the application is stopped, the support force of the second groove boundary part 704 is adjusted to the extent that the first clutch 326 and the second clutch 310 can be changed into the engaged state by the restoring force of the return spring 314. As such, by adjusting the holding force of the second groove boundary portion 704, the size of the current required to apply the solenoid coil 306 to maintain the state in which the first clutch 326 and the second clutch 310 are disengaged can be kept small. have.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

According to the present invention, the steering force of the driver is maintained by preventing the slip between the clutch of the first column shaft and the clutch of the second column shaft due to the shaking of the vehicle according to the vibration of the vehicle and the road surface while the vehicle is running. This makes it possible to deliver properly and to reduce the wear of the clutch of the first column shaft and the clutch of the second column shaft.

In addition, when the clutch of the first column shaft and the second column shaft are maintained in the state of disengagement by providing one further columnar groove, the first clutch and the second clutch may be seated in the circumferential groove provided with additional support beads. By keeping the magnitude of the current required to apply the solenoid coil to maintain the uncoupled state, the power consumption can be reduced and the life of the solenoid coil can be extended.

Claims (7)

In the backup clutch drive for the steering by wire for preventing slip, A first column shaft having a cylindrical hollow portion at one end and having a first sliding structure at an inner circumferential surface of the hollow portion; Cylindrical, the upper end portion, the stop portion and the lower end portion, wherein the upper end portion is inserted into the hollow portion is engaged with the first sliding structure and has a sliding force in the rotational direction is possible to slide in the longitudinal direction in the hollow portion A sliding shaft provided with a second sliding structure, the stopping portion having a spring support on a circumference, the lower end having one or more circumferential grooves, and a first clutch provided on a distal end of the lower end; A return spring disposed at the interruption portion between the front end portion of the one end of the first column shaft and the spring support portion; A second column shaft having a second clutch at one end thereof so as to engage with the first clutch when the spring support part is pushed out by the restoring force of the return spring which is in contact with the front end of the one end of the first column shaft; Surrounds an outer circumferential surface of the lower end of the sliding shaft, and forms a plurality of opening ends on the outer surface in the circumferential direction of the sliding shaft, and a receiving member is inserted from the opening end toward the sliding shaft, and is supported in the receiving member through the opening end. Inserting a bead so that the support bead is in contact with the sliding shaft, the ball member is accommodated in the receiving member to push the support bead from the outer surface toward the sliding axis, the ball spring through the opening end A ball spring housing having a fixing member on the outer surface so as not to be separated out; And In the normal operation of the steer-by-wire, a driving force for allowing the sliding shaft to be inserted into the hollow part is greater than a restoring force of the return spring so that the first clutch is disengaged from the second clutch. Sliding shaft drive unit to reduce the driving force to engage the first clutch with the second clutch by the restoring force of the return spring in the case of the error of the steering-by-wire Including but not limited to: And said support bead is seated in one of said circumferential grooves when said first clutch is coupled to said second clutch. According to claim 1, The sliding shaft drive unit, A solenoid coil arranged on an outer circumference of the sliding shaft; And Solenoid housing for receiving the solenoid coil Steering-by-wire backup clutch driving apparatus comprising a. The method of claim 1, wherein the fixing member, Use a C ring, And a ring connecting groove is further formed on a circumferential surface connecting the opening end of the ball spring housing, and the C ring is mounted on the ring connecting groove. The method of claim 1, wherein the first clutch and the second clutch, A backup clutch drive for steering by wire, characterized in that the engagement clutch. The method of claim 1, The second sliding structure, The upper end portion has a plurality of bearing holes formed in a row spaced apart in the longitudinal direction and the circumference, The bearing hole is inserted into the bearing hole, The first sliding structure, And a plurality of longitudinal sliding grooves on the inner circumference of the hollow portion, which face the bearing hole. The method of claim 1, The lower end of the sliding shaft, Provided with two circumferential grooves, And said support bead is seated in the other one of said circumferential grooves when said first clutch is disengaged from said second clutch. The method of claim 1, The receiving member, A backup clutch drive for steering by wire, characterized in that the cylindrical tube.