JP6603604B2 - Connection member and steering device - Google Patents

Description

  The present invention relates to a connection member and a steering device.

  Some steering devices connect a motor and a transmission unit so as to transmit torque by interposing a connecting member between a motor that generates a steering force and a transmission unit that transmits the steering force.

  As described above, there are a wide variety of connection members interposed between the motor and the transmission unit, and are disclosed in, for example, Patent Documents 1 to 3.

JP 2004-148990 A JP 2009-108892 A JP 2011-207457 A

  By the way, if the connecting member is hard, a rattling sound (striking sound) may be generated. On the other hand, if the connecting member is soft, there may be a delay in transmission of the steering force according to the driver's steering operation.

  An object of this invention is to implement | achieve the connection apparatus which suppresses generation | occurrence | production of a rattling sound and the delay of transmission of a steering force, and a steering apparatus provided with such a connection member.

  For this purpose, the connection member according to the present invention is interposed between the first engagement member connected to the output shaft and the second engagement member connected to the input shaft, thereby the first engagement. A connecting member for connecting a member and the second engaging member so as to be able to transmit torque, a surface layer portion composed of a surface layer material containing a resin component and a rubber component, and an inner layer containing a resin component and a rubber component And an inner layer part that is harder than the surface layer part.

  In addition, a steering apparatus according to the present invention includes a steering member that is steered by a driver, and a steering unit that steers wheels according to the steering operation, and the steering unit generates a steering force. A motor, a transmission unit for transmitting a steering force, a first engagement member connected to an output shaft of the motor, a second engagement member connected to an input shaft of the transmission unit, and the first engagement member And a second engaging member that connect the first engaging member and the second engaging member so that torque can be transmitted, and includes a resin component and a rubber component. It comprises a connecting member having a surface layer portion made of a surface layer material and an inner layer portion made of an inner layer material containing a resin component and a rubber component and harder than the surface layer portion.

  According to the present invention, it is possible to suppress a delay in generation of rattling noise and transmission of steering force.

It is a mimetic diagram showing typically an example of the schematic structure of the steering device concerning the embodiment of the present invention. It is a perspective view which shows an example of a structure around the turning force generation part which concerns on embodiment of this invention. It is AA arrow sectional drawing in FIG. It is a disassembled perspective view which shows an example of a structure of the turning force generation | occurrence | production part periphery which concerns on embodiment of this invention. It is a front view of the connection member concerning the embodiment of the present invention.

  A steering apparatus according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic diagram schematically illustrating an example of a schematic configuration of a steering apparatus according to an embodiment of the present invention. As shown in FIG. 1, the steering device 1 includes a steering unit 10 that receives a steering operation by a driver, a steering unit 20 that steers a wheel 400 according to the steering operation that the steering unit 10 receives, and a control unit 500. I have.

  In the steering device 1 described below, (1) the torque transmission path between the steering unit 10 and the steered unit 20 can be mechanically connected or disconnected, and (2) the torque transmission path is A steer-by-wire system that electrically controls the turning angle of the wheel 400 in accordance with the steering operation received by the steering unit 10 in the blocked state is adopted.

(Steering part 10)
As shown in FIG. 1, the steering unit 10 includes a steering member 102, a steering shaft 104, a torque sensor 12, a first universal joint 106, and an intermediate shaft 108. The steering member 102, the steering shaft 104, and the intermediate shaft 108 are provided. The shafts 108 are connected so as to be able to transmit torque to each other. Here, “connected so that torque can be transmitted” means that the other member rotates so that one member rotates as one member rotates. For example, one member and the other member are integrated. When the other member is fixed directly or indirectly to one member, and one member and the other member are connected to each other via a joint member or the like. Including at least the case where

  In the present embodiment, the upper end of the steering shaft 104 is fixed to the steering member 102 and rotates integrally with the steering member 102. Further, the lower end of the steering shaft 104 and the upper end of the intermediate shaft 108 are connected to each other via the first universal joint 106.

  The “upper end” refers to the upstream end (that is, the input end) in the steering force transmission path corresponding to the driver's steering operation, and the “lower end” refers to the steering force. It refers to the downstream end (that is, the output end) in the transmission path (the same applies hereinafter).

  The steering shaft 104 includes an upper steering shaft located on the upstream side in the steering force transmission path and a lower steering shaft located on the downstream side in the steering force transmission path. The upper steering shaft and the lower steering shaft are elastically connected to transmit torque. Torsion generated between the upper steering shaft and the lower steering shaft is detected by the torque sensor 12.

  When the driver performs a steering operation via the steering member 102, a twist angle corresponding to the magnitude of the steering operation torque is generated between the upper steering shaft and the lower steering shaft. The torque sensor 12 detects the twist angle and supplies a torque sensor signal SL12 indicating the detection result to the control unit 500. The steering unit 10 may include a steering angle sensor for detecting the steering angle of the steering member 102 and supply a signal indicating the detected steering angle or steering angular velocity to the control unit 500.

  Further, as an example of the steering member 102, an annular steering wheel is given as an example as shown in FIG. 1, but this is not a limitation of the present embodiment, and a steering operation by a driver can be accepted. Any other shape or mechanism may be used.

(Steering part 20)
The steered portion 20 is configured to steer the wheels 400 in accordance with the driver's steering operation received by the steering portion 10.

  As shown in FIG. 1, the steered portion 20 includes a second universal joint 202, a pinion shaft 204, a pinion gear 206, a rack bar 208, a tie rod 210, a knuckle arm 212, and a steered force generating portion 220. The intermediate shaft 108, the pinion shaft 204, and the pinion gear 206 are connected to each other so as to be able to transmit torque.

  In the present embodiment, the pinion gear 206 is fixed to the lower end of the pinion shaft 204 and rotates integrally with the pinion shaft 204. The lower end of the intermediate shaft 108 and the upper end of the pinion shaft 204 are connected to each other via the second universal joint 202.

  The rack bar 208 is configured to steer the wheels 400 according to the rotation of the pinion gear 206, and rack teeth that mesh with the pinion gear 206 are formed on the rack bar 208.

  In the steering apparatus 1 configured as described above, when the driver performs a steering operation via the steering member 102, the pinion gear 206 rotates and the rack bar 208 is displaced along the axial direction of the rack bar 208. As a result, the wheel 400 is steered via the tie rods 210 provided at both ends of the rack bar 208 and the knuckle arms 212 connected to the tie rods 210.

  In the example shown in FIG. 1, a configuration using a rack assist type in which the steering force is transmitted between the pinion shaft 204 and the rack bar 208 by the pinion gear 206 and the rack teeth is taken as an example. The configuration is not limited, and other configurations may be used as long as the steering force between the pinion shaft 204 and the rack bar 208 can be transmitted.

  As another configuration, the rack bar 208 employs a DPA-EPS (dual pinion assist system) in which an assist rack that meshes with the assist pinion gear is formed at a position different from the rack teeth that mesh with the pinion gear 206. Also good. Moreover, the structure which employ | adopts the column assist type which assists a steering shaft with the drive force of a motor may be sufficient.

(Steering force generator)
2 is a perspective view showing an example of the configuration around the turning force generation unit according to the present embodiment, FIG. 3 is a cross-sectional view taken along line AA in FIG. 2, and FIG. 4 shows the turning force. It is a disassembled perspective view which shows an example of a structure around a generation | occurrence | production part.

  As shown in FIGS. 2 to 4, the turning force generation unit 220 includes a motor 300, a transmission unit 320, a first housing 401, a second housing 402, a third housing 403, a fourth housing 404, a connection A member 600, a first engagement member 601, a second engagement member 602, and the like are provided. As shown in FIG. 3, the transmission unit 320 includes a driving pulley 303, a driven pulley 304, a belt 305, a conversion mechanism 306, and the like, and transmits a steering force.

  The belt 305 is wound around a driving pulley 303 and a driven pulley 304, and torque can be transmitted from the driving pulley 303 to the driven pulley 304.

  The driven pulley 304 is fixed to the nut 501. Therefore, torque transmitted from the drive pulley 303 to the driven pulley 304 is transmitted to the nut 501.

  The conversion mechanism 306 is configured to convert the rotational motion of the driven pulley 304 into the linear motion of the rack bar 208 in the axial direction. In the conversion mechanism 306 illustrated in FIG. 3, a nut having an inner peripheral surface in which a spiral groove 308 is formed, which is formed on the outer peripheral surface of the rack bar 208 and a nut 501 that is rotationally driven by the torque generated by the motor 300. A so-called ball comprising a spiral groove 309 having the same pitch as that of the spiral groove 308 of the nut 501 and a plurality of rolling balls (not shown) sandwiched between the spiral groove of the nut 501 and the spiral groove of the rack bar 208. A screw mechanism is adopted.

  However, the specific configuration of the conversion mechanism 306 is not limited to the above example, and any other configuration may be used as long as it can convert the rotational motion of the driven pulley 304 into the linear motion of the rack bar 208 in the axial direction. Also good.

  The connection member 600 is interposed between the first engagement member 601 connected to the output shaft and the second engagement member 602 connected to the input shaft, whereby the first engagement member 601 and the second engagement member are connected. It is a member which connects the member 602 so that torque transmission is possible. The configuration of the connection member 600 will be described in detail later.

  In the present specification, the motor main body 301 includes a configuration for rotating the output shaft, a case 310 (see FIG. 2) for housing these configurations, and a control unit 500 described later.

(Control unit 500)
The control unit 500 has at least a configuration for controlling the torque generated by the motor 300 of the turning force generation unit 220 in accordance with the steering operation by the driver. In the example illustrated in FIG. 2, the control unit 500 is disposed on the output shaft side of the motor 300 and is included in the motor main body 301.

  The controller 500 refers to the torque sensor signal SL12 supplied from the torque sensor 12, generates a turning force control signal SL220 for controlling the turning force generated by the turning force generator 220, and turns the steering. This is supplied to the force generator 220. The controller 500 may be configured to generate the steering force control signal SL220 by further referring to a signal indicating the steering angle of the steering member 102, a vehicle speed signal from a vehicle speed sensor, and the like.

  The control unit 500 may include an ECU (Engine Control Unit) for controlling the engine, a resolver sensor for detecting the rotation angle of the output shaft, and the like.

  The control unit 500 may be arranged on the opposite side of the motor 300 from the output side.

(housing)
As shown in FIG. 3, the first housing 401 houses a part of the rack bar 208, a part of the conversion mechanism 306, and the driven pulley 304.

  As shown in FIG. 3, the second housing 402 is fixed to the first housing 401 and accommodates the drive pulley 303.

  The third housing 403 is fixed to the first housing 401 and accommodates another part of the rack bar 208. The fourth housing 404 is attached to the second housing 402 so as to cover the end of the drive pulley 303 on the side opposite to the motor main body 301.

  Note that at least a part of the first housing 401, the second housing 402, and the third housing 403 may be integrally formed.

(Connecting member)
Next, the connection member 600 according to the embodiment of the present invention will be described in detail.

  The motor 300 has a motor main body 301 and an output shaft (not shown), and a first engagement member 601 is connected to the output shaft so as to be able to rotate integrally with the output shaft. Further, the drive pulley 303 has an input shaft (input shaft of the transmission unit) (not shown) at an end facing the motor 300, and the input shaft is second engaged with the input shaft so as to be integrally rotatable. A member 602 is connected.

  In the connection member 600, the connection member 600 is interposed between the first engagement member 601 and the second engagement member 602, and the connection member 600 includes the first engagement member 601 and the second engagement member 602. And so that torque can be transmitted. As a result, the input shaft of the drive pulley 303 rotates integrally with the output shaft of the motor 300.

  As shown in FIG. 4, the connection member 600 includes a plurality of teeth (third teeth) provided repeatedly along the rotation direction. The first engagement member 601 includes a plurality of teeth that are repeatedly provided along the rotation direction, and includes a plurality of teeth (first teeth) that are assembled to the teeth included in the connection member 600. The teeth of the engaging member 601 are assembled to the teeth of the connecting member 600 from the surface on one side of the connecting member 600. The second engagement member 602 includes a plurality of teeth repeatedly provided along the rotation direction, and includes a plurality of teeth (second teeth) assembled to the teeth provided in the connection member 600. The teeth of the engaging member 602 are assembled to the teeth of the connecting member 600 from the other surface of the second engaging member 602. Each tooth of the first engagement member 601 and each tooth of the second engagement member 602 are alternately assembled to each tooth of the connection member 600.

  The connection member 600 is sandwiched between the first engagement member 601 and the second engagement member 602, reliably transmits the torque of the motor 300 to the drive pulley 303, and alleviates sudden torque fluctuations. Furthermore, the connection member 600 prevents the occurrence of rattling noise between the first engagement member 601, the second engagement member 602, and the connection member 600.

  In FIG. 5, the front view of the connection member which concerns on embodiment of this invention is shown. As shown in FIG. 5, the connection member 600 has a surface layer portion 603 and an inner layer portion 604.

  In the present embodiment, the inner layer portion 604 is harder than the surface layer portion 603. In other words, the inner layer portion 604 is more rigid than the surface layer portion 603, and the surface layer portion 603 is more elastic than the inner layer portion 604.

  The surface layer portion material constituting the surface layer portion 603 and the inner layer portion material constituting the inner layer portion 604 may contain the same resin component and the same rubber component.

  Examples of the resin component contained in each of the surface layer portion 603 and the inner layer portion 604 include a thermoplastic resin. Examples of the thermoplastic resin include olefin-based, styrene-based, acrylic-based, urethane-based, epoxy-based, silicon-based, amide-based, and carbonate-based thermoplastic resins. Among these, polyethylene, polystyrene, polypropylene, polyvinyl chloride and the like are preferable, and polypropylene is particularly preferable.

  Examples of the rubber component contained in each of the surface layer portion 603 and the inner layer portion 604 include non-diene rubber. Examples of non-diene rubbers include butyl rubber (B), ethylene / propylene rubber (EPM), ethylene / propylene / diene rubber (EPDM), and urethane rubber (U). Preferred non-diene rubbers include ethylene / propylene / diene rubber (EPDM).

  And it is good to make the hardness of the surface layer part 603 and the inner layer part 604 different by changing the compounding ratio of the resin component and the rubber component of the surface layer part material and the inner layer part material. For example, the compounding ratio of the rubber component to the resin component in the surface layer material can be made larger than the compounding ratio of the rubber component to the resin component in the inner layer material. When the surface layer portion material and the inner layer portion material contain the same component, the surface layer portion 603 is hardly peeled off from the inner layer portion 604. Furthermore, the surface layer material and the inner layer material may be a composite material (TPV) having a structure in which a crosslinked rubber component is dispersed in a resin component.

  The surface layer portion 603 and the inner layer portion 604 are preferably joined together by, for example, two-color molding. That is, the connection member 600 can be manufactured by first molding the inner layer portion 604 in the mold and then molding the surface layer portion 603 in the same mold.

  As described above, the connection member 600 according to the present embodiment has the surface layer portion 603 and the inner layer portion 604 having different hardnesses, so that the motor 300 and the transmission portion 320 are connected to be able to transmit torque. It has suitable hardness. Since the connecting member 600 has the relatively hard inner layer portion 604, there is no delay in the transmission of the steering force according to the driver's steering operation. In particular, when the steer-by-wire method is employed as in this embodiment, there is no difference between the rotational position of the motor 300 and the rack stroke. On the other hand, since the connection member 600 has the surface layer portion 603 that is not relatively hard, the minute amplitude of the rack bar 208 can be absorbed, and the steering device on which the rack bar is mounted does not vibrate. Further, rattling (striking sound) due to contact between the teeth of the first engagement member 601 or the teeth of the second engagement member 602 and the teeth of the connection member 600 is suppressed.

  In addition, although the steer-by-wire system is adopted in the steering apparatus according to the present embodiment, the steering apparatus according to the present invention may employ an electric power steering system in which an assist force is exhibited by a motor. Further, the connection member according to the present invention may be applied to a configuration that can transmit the output of the motor to the worm gear as long as the output of the motor can be transmitted to the transmission target mechanism. Those provided at such sites are also included.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Steering device 208 Rack bar 300 Motor 301 Motor main body 303 Drive pulley 304 Driven pulley 305 Belt 320 Transmission part 401 1st housing 402 2nd housing 600 Connection member 601 1st engagement member 602 2nd engagement member 603 Surface layer part 604 Inner layer

Claims (8)

By interposing between the first engagement member connected to the output shaft and the second engagement member connected to the input shaft, torque can be transmitted between the first engagement member and the second engagement member. A connecting member to be connected,
A surface layer composed of a surface layer material containing a resin component and a rubber component;
Consists of an inner layer material containing a resin component and a rubber component, an inner layer portion harder than the surface layer portion,
The connection member characterized by having.   The connection member according to claim 1, wherein the surface layer portion and the inner layer portion are integrally joined. The first engagement member has a plurality of first teeth provided repeatedly along the rotation direction,
The second engagement member has a plurality of second teeth provided repeatedly along the rotation direction,
The connection member according to claim 1, wherein the connection member has a plurality of third teeth that are assembled to both the plurality of first teeth and the plurality of second teeth. The surface layer material and the inner layer material contain the same resin component, and the same rubber component,
The connection member according to any one of claims 1 to 3, wherein a compounding ratio of the resin component and the rubber component is different between the surface layer material and the inner layer material. The resin component is a thermoplastic resin;
The connection member according to claim 4, wherein the rubber component is a non-diene rubber.   The connection member according to claim 4 or 5, wherein the surface layer material and the inner layer material are a composite material having a structure in which the crosslinked rubber component is dispersed in the resin component. A steering device,
A steering member that is steered by a driver, and a steering unit that steers wheels according to the steering operation;
The steered portion is
A motor that generates steering force,
A transmission unit for transmitting the steering force,
A first engagement member connected to the output shaft of the motor;
A second engagement member connected to the input shaft of the transmission unit; and
A connecting member that connects the first engaging member and the second engaging member so as to transmit torque by being interposed between the first engaging member and the second engaging member, the resin component And a surface layer portion composed of a surface layer portion material containing a rubber component, and an inner layer portion composed of an inner layer portion material containing a resin component and a rubber component and harder than the surface layer portion. A steering apparatus comprising: A steer-by-wire steering device,
A steering member that is steered by a driver, and a steering unit that steers wheels according to the steering operation;
The steered portion is
A motor that generates steering force,
A transmission unit for transmitting the steering force,
A first engagement member connected to the output shaft of the motor;
A second engagement member connected to the input shaft of the transmission unit; and
A connecting member that connects the first engaging member and the second engaging member so as to transmit torque by being interposed between the first engaging member and the second engaging member, the resin component And a surface layer portion composed of a surface layer portion material containing a rubber component, and an inner layer portion composed of an inner layer portion material containing a resin component and a rubber component and harder than the surface layer portion. A steering apparatus comprising:

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