JP2013189063A - Electric power steering device - Google Patents

Abstract

An electric power steering apparatus capable of improving security at low cost is provided.
A sensor housing (first housing) and a driven gear housing (second housing) are fitted in an axial direction X1 of a steering shaft. A fixing screw 20 (fixing member) having a head portion 34 (operation part) in the driven gear housing 14 is screwed into the cover 19 covering the opening of the locking device main body 18 of the steering lock device 6 in the locking device main body 18. Yes. Due to the contact between the second restricting portion 38 of the steering shaft 3 and the lock key 22 (lock member), the movement of the lock key 22 is restricted upward (in the steering member 2 side) in the axial direction X1 of the steering shaft 3. . As a result, detachment of the sensor housing 13 from the driven gear housing 14 is prevented.
[Selection] Figure 1

Description

  The present invention relates to an electric power steering apparatus.

  A steering lock device has been proposed in which a lock device main body for holding a lock pin (steering lock means) is formed integrally with a sensor housing (for example, Patent Document 1).

Japanese Patent Laying-Open No. 2003-205824 (FIG. 1)

In the steering lock device of FIG. 1 of Patent Document 1, a cover that covers the opening of the lock device body is required. When the fixing screw for fixing the cover is exposed to the outside, there is a security problem.
That is, if the fixing screw is operated from the outside, the cover is removed, and the steering lock device is disassembled, there is a risk of theft. Although it is conceivable to use an expensive special screw that cannot be operated from the outside as the fixing screw, in that case, the manufacturing cost increases.

  Accordingly, an object of the present invention is to provide an electric power steering device that can improve security at low cost.

  In order to achieve the object, the invention of claim 1 is characterized in that the steering shaft (3) provided with the first restricting portion (37) and the second restricting portion (38) on the outer periphery and the steering shaft are inserted through each other. A first housing (13) and a second housing (14) fitted in the axial direction (X1) of the steering shaft, and a steering lock device (6) for restraining the steering shaft to be non-rotatable, The steering lock device is integrally provided with a single material in the first housing, and includes a lock device main body (18) that houses a drive member (21), and a cover (19) that covers an opening (18a) of the lock device main body. And a fixing member (20) which has an operation portion (34) disposed in the second housing and is fixed to the first housing by being locked to the cover in the locking device main body. And And a lock member (22) that is supported by the drive device body and that is operated by the drive member, and the rotation of the steering shaft is restricted by contact between the lock member and the first restricting portion, The movement of the lock member in the axial direction of the steering shaft is restricted by contact with the second restricting portion, and as a result, the first housing is prevented from being detached from the second housing. Provided is an electric power steering device (1).

In addition, although the alphanumeric character in a parenthesis represents the corresponding component etc. in embodiment mentioned later, this does not mean that this invention should be limited to those embodiment as a matter of course. The same applies hereinafter.
According to a second aspect of the present invention, the first housing may house a torque sensor (9) for detecting a steering torque applied to the steering shaft.

According to a third aspect of the present invention, the fitting length (L1) between the first housing and the second housing is a distance (L2) between the lock member and the second restricting portion with respect to the axial direction of the steering shaft. ) May be longer.
According to a fourth aspect of the present invention, the first housing has an end wall (16) fitted to one end (141) of the second housing, and the fixing member extends in parallel with the steering shaft. The fixing screw (20) may be configured, and the fixing screw may be inserted into the cover from the second housing through the end wall.

  Further, as in claim 5, the lock hole is provided with a collar (36) fitted to the outer periphery of the steering shaft and formed with a lock hole (35), and facing the circumferential direction (Z1) of the steering shaft. The pair of inner walls constitutes the first restricting portion, and the second restricting portion is constituted by an axially upper inner wall of the pair of inner walls of the lock hole facing the axial direction of the steering shaft. May be.

  According to the first aspect of the present invention, the operation portion of the fixing member that is locked to the cover in the lock device main body is disposed in the second housing. In the state where the steering is locked, the lock member abuts against the second restricting portion to prevent the first housing from being detached from the second housing, so that the operation portion of the fixing member cannot be exposed to the outside. Accordingly, since the cover cannot be removed and the steering lock device cannot be disassembled, security is greatly improved. Moreover, this can be achieved with a simple structure in which the second restricting portion is provided on the steering shaft, at a light weight and at a low cost.

  According to the invention of claim 2, the first housing (corresponding to a so-called sensor housing) and the lock device main body are integrally formed of a single material, so that the structure can be simplified. According to a third aspect of the invention, the fitting length between the first housing and the second housing is made longer than the distance between the lock member and the second restricting portion in the axial direction of the steering shaft. It is substantially possible to reliably prevent the housing from being pulled out.

  According to the invention of claim 4, in order to disassemble the steering lock device, it is necessary to operate the fixing screw. The fixing screw has an operating portion arranged in the second housing, and It passes through the end wall of the housing and is screwed into the cover within the lock device main body. Therefore, unless the first housing is detached from the second housing, the fixing screw cannot be operated from the outside, so that the security is high.

  According to the invention of claim 5, since the first restricting portion for restricting rotation and the second restricting portion for restricting axial movement are formed in the collar which is a single member, the structure can be simplified. it can.

1 is a partially broken schematic side view of an electric power steering apparatus according to an embodiment of the present invention. It is a disassembled perspective view of the principal part of an electric power steering device. It is a perspective view of the cover turned over. It is a perspective view of the principal part of the steering shaft with which the color was fitted. It is sectional drawing of the steering shaft by which rotation was controlled by the locking member.

Preferred embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a schematic configuration of an electric power steering apparatus according to an embodiment of the present invention. Referring to FIG. 1, an electric power steering apparatus 1 includes a steering member 2, a steering shaft 3 having one end connected to the steering member 2, a steering column 4 that is rotatably inserted through the steering shaft 3, A steering assist unit 5 provided on the steering column 4 and a steering lock device 6 provided on the steering column 4 are provided.

  The steering shaft 3 includes an upper first steering shaft 3a having one end connected to the steering member 2, and a lower second steering shaft 3b having one end coaxially connected to the first steering shaft 3a and capable of transmitting torque. And. Although not shown, the second steering shaft 3b has one end connected to the first steering shaft 3a so as to be integrally rotatable, and is connected to the input shaft and a torsion bar so that torque can be transmitted coaxially. And an output shaft.

  The other end of the steering shaft 3 (the other end of the second steering shaft 3b) is connected to a pinion shaft via a universal joint, an intermediate shaft, and a universal joint (not shown). The pinion shaft is meshed with a rack bar extending in the left-right direction of the vehicle, and a rack and pinion mechanism as a steering mechanism is configured by the pinion shaft and the rack bar. When the steering member 2 is rotated, the steered wheels are steered via the rack and pinion mechanism, the tie rod, and the knuckle arm.

The steering assist unit 5 includes an electric motor 7 that generates a steering assist force, a speed reducer 8 that decelerates the output rotation of the electric motor 7 and transmits it to the second steering shaft 3b (output shaft thereof), and the second steering shaft 3b. And a torque sensor 9 for detecting a steering torque applied to the steering member 2 based on the relative rotation amount between the input shaft and the output shaft.
The speed reducer 8 includes a drive gear 10 (for example, a worm) that is rotationally driven by the rotation shaft of the electric motor 7 and a driven gear 11 (for example, a worm wheel) that is connected to the second steering shaft 3b (the output shaft thereof) so as to be integrally rotatable. ).

A control unit (not shown) (for example, an electronic control unit) drives the electric motor 7 based on the detection result of the torque sensor 9 and the detection result of the vehicle speed sensor, and generates a steering assist force.
The steering column 4 includes a column tube 12, a cylindrical sensor housing 13 as a first housing that houses a torque sensor 9, and a cylindrical driven gear housing as a second housing that houses a driven gear 11 of a speed reducer 8. 14. A cylindrical drive gear housing 15 that houses the drive gear 10 of the speed reducer 8 is integrally formed with the driven gear housing 14 from a single material.

The sensor housing 13 (first housing) extends from the end wall 16, and an annular end wall 16 that fits into one end 141 of the driven gear housing 14 (second housing) (for example, a seal fitting as shown in FIG. 1). And a cylindrical portion 17 surrounding the torque sensor 9. The cylindrical portion 17 is fitted and integrated with the column tube 12.
The steering lock device 6 includes a lock device main body 18, a cover 19, a fixing screw 20 as a fixing member, an electromagnetic actuator 21 as a driving member, and a lock key 22 as a locking member that is operated by the electromagnetic actuator 21. ing.

  As shown in FIG. 1 and FIG. 2 which is an exploded perspective view, the lock device main body 18 is integrally formed of a single material on the sensor housing 13 as the first housing, and has a box shape. Specifically, the lock device main body 18 connects a pair of side walls 23 and 24 extending in parallel to the axial direction X1 from the end wall 16 of the sensor housing 13 and one end of the pair of side walls 23 and 24. And a bottom wall 26 formed integrally with a part of the side portion of the cylindrical portion 17.

  As shown in FIG. 2, the lock device main body 18 forms a rectangular opening 18 a surrounded by the end wall 16, the pair of side walls 23 and 24, and the connecting wall 25. The bottom wall 26 is formed with a through hole 27 for moving the lock key 22 back and forth. Further, the bottom wall 26 is formed with a square cylindrical projection 28 surrounding the through hole 27. The protrusion 28 functions to support, for example, a solenoid as the electromagnetic actuator 21.

The cover 19 covers the opening 18 a of the lock device main body 18. Specifically, the cover 19 has a rectangular cover body 29 that fits into the rectangular opening 18 a and a side edge of the cover body 29 (corresponding to a side edge along the end wall 16) close to the cover body 29. And an attachment portion 30 formed to protrude from the back surface.
Stepped receiving portions 31 (only the receiving portions 31 formed on the side walls 23 are shown in FIG. 2) are formed on the inner wall surfaces of the pair of side walls 23 and 24 of the locking device body 18. These receiving portions 31 receive the cover main body 29 with the opening 18a closed.

  As shown in FIGS. 2 and 3, the attachment portion 30 is a rectangular parallelepiped block, and one or more (a plurality in this embodiment) screw holes 32 are formed in the attachment portion 30. One or more fixing screws 20 as a fixing member (a plurality in the present embodiment) are provided. As shown in FIG. 1, each fixing screw 20 is inserted through a corresponding screw insertion hole 33 provided in the end wall 16. Then, it is screwed into the corresponding screw hole 32 of the mounting portion 30. That is, the fixing screw 20 fixes the cover 19 to the sensor housing 13 by engaging with the cover 19 in the lock device main body 18.

The head portion 34 as an operation portion of the fixing screw 20 is exposed on the back surface of the end wall 16 (the surface opposite to the lock device main body 18). That is, the head portion 34 (operation portion) of the fixing screw 20 is disposed in the driven gear housing 14 in a state where the sensor housing 13 (first housing) and the driven gear housing 14 (second housing) are coupled. Yes.
At the time of assembly, the cover 19 is fixed to the sensor housing 13 by the fixing screw 20, and then the end wall 16 of the sensor housing 13 (first housing) is press-fitted to one end of the driven gear housing 14 (second housing). Both housings 13 and 14 are joined together. Therefore, after assembly, the head 34 (operation part) of the fixing screw 20 is disposed in the driven gear housing 14 and is not exposed to the outside.

  The electromagnetic actuator 21 includes a main body housed and fixed in the lock device main body 18, and a telescopic rod (not shown) supported by the main body so as to be able to advance and retreat from the main body and connected to the lock key 22 so as to move together. It is composed of a solenoid. In addition, the solenoid as the electromagnetic actuator 21 may be arranged in parallel with the steering shaft 3, and the telescopic rod may actuate the lock key 22 via a link mechanism. Further, as the electromagnetic actuator 21, an electric motor or the like can be used instead of the solenoid.

  The electromagnetic actuator 21 of the steering lock device 6 is driven and controlled by the control unit (electronic control unit) that controls steering assist control. That is, when the ignition switch is operated, the signal is input to the control unit, and the control unit that receives the signal drives the electromagnetic actuator 21 to operate the lock key 22. As the operation unit of the steering lock device 6, a known configuration such as a control device operated by an IC card, a remote control device, or the like may be used instead of the ignition switch.

As shown in FIG. 1 and FIG. 5 which is an enlarged perspective view, a collar 36 defining a lock hole 35 is fitted and fixed to the outer periphery of the first steering shaft 3 a of the steering shaft 3. The collar 36 is provided with a first restricting portion 37 and a second restricting portion 38.
The first restricting portion 37 is configured by a pair of inner walls that face the circumferential direction of the lock hole 35. As shown in FIG. 5, when the lock key 22 is inserted into the lock hole 35, the lock key 22 and the first restricting portion 37 come into contact with each other to restrict the rotation of the steering shaft 2. That is, the steering shaft 2 is restrained so as not to rotate.

  The second restricting portion 38 is configured by an axially upper inner wall of the pair of inner walls facing the axial direction X1 of the lock hole 35. When the lock key 22 is inserted into the lock hole 35, the lock key 22 and the second restricting portion 38 come into contact with each other, thereby restricting the movement of the lock key 22 in the axial direction X1 (the steering member 2 side). As a result, the sensor housing 13 (first housing) is prevented from being detached from the driven gear housing 14 (second housing).

  According to this embodiment, the head 34 (operation part) of the fixing screw 20 (fixing member) locked to the cover 19 in the lock device main body 18 is disposed in the driven gear housing 14 (second housing). Yes. In a state where the steering is locked, the lock key 22 (lock member) abuts against the second restricting portion 38 to prevent the sensor housing 13 (first housing) from being detached from the driven gear housing 14.

Therefore, the head 34 of the fixing screw 20 cannot be exposed to the outside, and the fixing screw 20 cannot be operated. As a result, since the cover 19 cannot be removed and the steering lock device 6 cannot be disassembled, the security is greatly improved. Moreover, this can be achieved with a simple structure in which the second restricting portion 38 is provided on the steering shaft 3 at a light weight and at a low cost.
Further, since the sensor housing 13 (first housing) and the lock device body 18 are integrally formed of a single material, the structure can be simplified.

Further, the fitting length L1 between the sensor housing 13 and the driven gear housing 14 is made longer than the distance L2 between the lock key 22 and the second restricting portion 38 in the axial direction X1 of the steering shaft 3 (L1>). L2) It is substantially possible to reliably prevent the housings 13 and 14 from being removed.
Further, in order to disassemble the steering lock device 6, the fixing screw 20 must be operated. The fixing screw 20 has an operation part 34 disposed in the driven gear housing 14, and The end wall 16 is inserted and screwed into the cover 19 in the lock device main body 18. Therefore, unless the sensor housing 13 is detached from the driven gear housing 14, the fixing screw 20 cannot be operated from the outside, so that security is high.

  Further, since the first restricting portion 37 for restricting the rotation of the steering shaft 3 and the second restricting portion 38 for restricting the axial movement are formed on the collar 36 which is a single member, the structure can be simplified. it can. The present invention is not limited to the above embodiment, and the housing of the sensor housing 13 and the driven gear housing 14 may be outside. In addition, various modifications can be made within the scope of the claims of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Electric power steering device, 2 ... Steering member, 3 ... Steering shaft, 4 ... Steering column, 5 ... Steering assist unit, 6 ... Steering lock device, 7 ... Electric motor, 8 ... Reducer, 9 ... Torque sensor, 10 DESCRIPTION OF SYMBOLS ... Drive gear, 11 ... Driven gear, 12 ... Column tube, 13 ... Sensor housing (1st housing), 14 ... Driven gear housing (2nd housing), 16 ... End wall, 17 ... Cylindrical part, 18 ... Locking device Main body, 18a ... opening, 20 ... fixing screw (fixing member), 21 ... electromagnetic actuator (driving member), 22 ... lock key (locking member), 29 ... cover main body, 30 ... mounting portion, 32 ... screw hole, 33 ... Screw insertion hole 34 ... head (operation part) 35 ... lock hole 36 ... collar 37 ... first restriction part 38 ... second restriction part X1 ... axial direction Z1 ... circumferential direction

Claims (5)

A steering shaft provided with a first restricting portion and a second restricting portion on the outer periphery;
A first housing and a second housing through which the steering shaft is inserted and fitted in the axial direction of the steering shaft;
A steering lock device that restrains the steering shaft to be non-rotatable, and
The steering lock device is integrally provided with a single material in the first housing, and is disposed in the second housing, a lock device main body that accommodates a driving member, a cover that covers an opening of the lock device main body, and the second housing. A locking member that is fixed to the first housing by being locked to the cover in the lock device main body, and a lock that is supported by the lock device main body and is operated by the drive member. And a member,
The rotation of the steering shaft is regulated by the contact between the lock member and the first regulating part,
The movement of the lock member in the axial direction of the steering shaft is restricted by the contact between the lock member and the second restricting portion, and as a result, the first housing is prevented from being detached from the second housing. An electric power steering device configured to be configured as described above.   2. The electric power steering apparatus according to claim 1, wherein the first housing accommodates a torque sensor that detects a steering torque applied to the steering shaft.   3. The electric motor according to claim 1, wherein a fitting length between the first housing and the second housing is longer than a distance between the lock member and the second restricting portion with respect to an axial direction of the steering shaft. Power steering device. 4. The first housing according to claim 1, wherein the first housing has an end wall fitted to one end of the second housing,
The fixing member is constituted by a fixing screw extending in parallel with the steering shaft,
The electric power steering device, wherein the fixing screw is inserted into the end wall from the second housing and screwed into the cover in the lock device main body. In any one of Claims 1-4, The collar which was fitted by the outer periphery of the said steering shaft, and formed the lock hole,
The first restricting portion is constituted by a pair of inner walls of the lock hole facing the circumferential direction of the steering shaft,
The electric power steering device in which the second restricting portion is configured by an axially upper inner wall of a pair of inner walls of the lock hole facing the steering shaft in the axial direction.

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