JP4825331B2 - Active suspension device for vehicle - Google Patents

Description

  The present invention relates to a vehicle active suspension device that includes a suspension device that suspends wheels on a vehicle body and an actuator that outputs a power source by decelerating the rotation of a power source with a speed reducer and moves the suspension device up and down by the actuator.

The drive arm is provided on the output shaft of the actuator that decelerates the rotation of the motor with the planetary gear mechanism, and the suspension arm that connects the intermediate portion of the suspension arm that supports the knuckle to the vehicle body so as to be movable up and down is linked with the suspension arm. Japanese Patent Application Laid-Open No. 2004-151561 discloses that the vehicle is positively moved up and down to improve ride comfort performance and steering stability performance.
JP 2001-328414 A

  By the way, in the above-mentioned conventional one, if a shock load is input to the suspension arm when the wheel gets over the road surface unevenness, the speed reducer with a large reduction ratio functions as a speed increaser, so it is substantially locked. As a result, the suspension arm can only make a stroke in the vertical direction for the elastic deformation of the rubber bush joint. As a result, there is a problem that not only the problem of reducing the riding comfort due to the impact transmitted from the wheel to the vehicle body, but also the durability of the actuator speed reducer and motor is reduced.

  The present invention has been made in view of the above circumstances, and in an active suspension device for a vehicle, the suspension device is allowed to move up and down in response to an input from the road surface, thereby improving riding comfort and improving the durability of the actuator. For the purpose.

To achieve the above object, according to the first aspect of the present invention, the actuator includes: a suspension device for suspending a wheel on a vehicle body; and an actuator for decelerating and outputting the rotation of a power source with a reduction gear. In the vehicle active suspension device for vertically moving the suspension device, the speed reducer includes an input transmission member connected to the power source, a fixed transmission member fixed to a housing via a clutch mechanism, and the suspension device. An output transmission member connected to the housing, and the clutch mechanism is sandwiched between a wavy uneven portion formed on at least one of the fixed transmission member and the opposing surface of the housing, and the fixed transmission member and the housing. A plurality of balls in contact with the concavo-convex portion, and between the fixed transmission member and the housing. The Lumpur as pressed between, and a biasing means for biasing the opposite end of the ball-side end of the fixed transfer member, when the torque acting on the fixed transfer member is less than a predetermined value An active suspension device for a vehicle characterized in that the fixed transmission member is fixed to the housing, and when the torque acting on the fixed transmission member is a predetermined value or more, the fixed transmission member is slipped with respect to the housing. Proposed .

According to the invention described in claim 2 , in addition to the configuration of claim 1 , the speed reducer includes a planetary gear mechanism, and the input transmission member, the fixed transmission member, and the output transmission member are There is proposed an active suspension device for a vehicle that is a sun gear, a ring gear, and a planetary carrier of a planetary gear mechanism .

  The third housing 34 of the embodiment corresponds to the housing of the present invention, the sun gear 61 of the embodiment corresponds to the input transmission member of the present invention, and the planetary carrier 62 of the embodiment corresponds to the output transmission member of the present invention. The ring gear 64 of the embodiment corresponds to the fixed transmission member of the present invention, the disc spring 66 of the embodiment corresponds to the biasing means of the present invention, and the electric actuator A of the embodiment corresponds to the present invention. Corresponding to the actuator, the motor M of the embodiment corresponds to the power source of the present invention.

  According to the configuration of the first aspect, the clutch transmission mechanism is provided on the fixed transmission member of the reduction gear of the actuator that moves the suspension device up and down, and the fixed transmission member is fixed to the housing when the torque acting on the fixed transmission member is less than a predetermined value. When the torque acting on the fixed transmission member exceeds a predetermined value, the fixed transmission member is slipped with respect to the housing, so that the suspension device can be moved up and down when a large load is input from the road surface to enhance the riding comfort. In addition, the durability can be enhanced by preventing an excessive load from being applied to the actuator due to the load.

In addition, a ball is brought into contact with a wavy uneven portion formed on at least one of the fixed transmission member and the opposing surface of the housing, and the fixed transmission member is urged by the urging means toward the housing with the ball interposed therebetween to constitute a clutch mechanism. Therefore, when the torque is less than the predetermined value, the fixed transmission member can be securely fixed to the housing, and when the torque is greater than the predetermined value, the fixed transmission member can be reliably slipped with respect to the housing.

According to the second aspect of the present invention, the input transmission member, the fixed transmission member, and the output transmission member of the speed reducer are constituted by the sun gear, the ring gear, and the planetary carrier of the planetary gear mechanism. The reduction gear can be miniaturized by arranging the output transmission member coaxially .

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 8 show a first embodiment of the present invention. FIG. 1 is a perspective view of an active suspension device, FIG. 2 is an enlarged sectional view taken along line 2-2 in FIG. 1, and FIG. 3 is a harmonic drive mechanism. 4 is a sectional view taken along line 4-4 of FIG. 2, FIG. 5 is an enlarged sectional view taken along line 5-5 of FIG. 2, FIG. 6 is an explanatory diagram of the operation of the harmonic drive mechanism, and FIG. FIG. 8 is a graph showing the relationship of the axial force of the link with respect to the rotation angle of the drive arm.

  As shown in FIG. 1, a multi-link suspension device S that suspends a knuckle 11 that rotatably supports a wheel W on a vehicle body includes a lower arm 12 that extends in the vehicle width direction, an upper arm 13 that extends in the vehicle width direction, A trailing arm 14 extending obliquely rearward from the vehicle body, a leading arm 15 extending obliquely forward from the vehicle body, and a lateral arm 16 extending in the vehicle width direction are provided. The lower end of the damper 17 that buffers the vertical movement of the wheel W is connected to the knuckle 11. Then, the tip of the drive arm 21 that swings by the electric actuator A supported by the vehicle body via the bracket 20 is connected to the intermediate portion of the lower arm 12 via the link 22.

  As shown in FIG. 2, the electric actuator A is composed of a motor M and a speed reducer R, and the housing of the substantially cylindrical speed reducer R having the axis L is bolted to the first housing 31 and the second housing 32. .., And the second housing 32 and the third housing 34 are connected by bolts 35. The driving force of the rotating shaft 36 of the motor M coupled to the opening of the first housing 31 is reduced by a first-stage deceleration by a harmonic drive (registered trademark) mechanism 37 housed in the first and second housings 31 and 32. Then, after being decelerated at the second stage by the planetary gear mechanism 38 housed in the third housing 34, the drive fixed to the output shaft 40 supported by the opening of the third housing 34 via the ball bearing 39. It is output to the arm 21.

  As shown in FIGS. 2 to 4, the harmonic drive mechanism 37 includes a circular spline 41 formed in a ring shape, a flexible spline 42 formed in a thin cup shape with a metal elastic body, and an elliptical wave generator 43. Consists of. The circular spline 41 is fixed to the second housing 32 with bolts 44, and the inner teeth 41a. The flexible spline 42 includes a disk-shaped fixing portion 42a and a cylindrical flexible portion 42b, and external teeth 42c that mesh with the inner teeth 41a of the circular spline 41 on the outer peripheral surface of the flexible portion 42b. Is formed. The number of outer teeth 42c of the flexible spline 42 is set slightly smaller (for example, two) than the number of inner teeth 41a of the circular spline 41. A relay rotating member 46 is supported on the second housing 32 via a ball bearing 45, and the fixing portion 42 a of the flexible spline 42 and the bearing member 47 are fastened to the relay rotating member 46 with bolts 48.

  The other end of the input shaft 50 having one end coupled to the rotating shaft 36 of the motor M via a coupling 49 is supported by the bearing member 47 via a ball bearing 51. The wave generator 43 fixed to the input shaft 50 includes an elliptical rotor 52 and a flexible ring 54 supported on the outer periphery thereof via a ball bearing 53. The surface is press-fitted into the inner peripheral surface of the flexible portion 42b of the flexible spline 42. Therefore, as the wave generator 43 rotates, the shape of the flexible portion 42 b of the flexible spline 42 is periodically elastically deformed so as to wave from a free state circle to an ellipse that follows the shape of the rotor 52.

  As shown in FIG. 2, the planetary gear mechanism 38 includes a sun gear 61 coupled to the relay rotation member 46, a planetary carrier 62 coupled to the output shaft 40, and a planetary carrier 62 supported by the sun gear 61. And a ring gear 64 that is rotatably supported by an annular bearing 34 a provided in the third housing 34 and meshes with the pinions 63. On one side surface of the ring gear 64 in the axis L direction, a wavy uneven portion 64a is formed over 360 ° (see FIG. 5), and a plurality of ball support holes 34b formed in the third housing 34 and the uneven portion. A plurality of balls 65...

  An annular disc spring support groove 32a is formed in the second housing 32 opposite to the ball support hole 34b across the bearing 34a of the third housing 34, and a plurality of disc springs 66 are formed in the disc spring support groove 32a. Are stored in a stacked state. The relationship between the compression amount of the disc springs 66 and the generated load is shown in FIG. The elastic force of the disc springs 66 urges the ring gear 64 to the right in FIG. 2 via the thrust bearing 67 so that the balls 65 are compressed between the concave and convex portions 64a of the ring gear 64 and the ball support holes 34b. Act on. The uneven portion 64a, the balls 55, and the disc springs 66 constitute the clutch mechanism C of the present invention.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  When the motor M of the electric actuator A is driven, the rotation of the rotating shaft 36 of the motor M is output to the relay rotating member 46 in a state where the rotation is reduced through the harmonic drive mechanism 37.

  FIG. 6 is an explanatory view of the deceleration action of the harmonic drive mechanism 37. As shown in FIG. 6A, in the initial state, one internal tooth 41a (see ▼) of the circular spline 41 fixed to the second housing 32 and the flexible spline 42 deformed into an oval shape by the wave generator 43 It is assumed that one external tooth 42c (see Δ mark) of the flexible portion 42b is engaged.

  From this initial state, when the wave generator 43 is rotated 90 ° clockwise by the motor M to the state of FIG. 6B, the flexible spline 42 is in a state where the major axis extends in the vertical direction as the wave generator 43 rotates. To the state where the long axis extends in the left-right direction, the outer teeth 42c... And the inner teeth 41a. When the wave generator 43 rotates 180 ° clockwise from the initial state, the state shown in FIG. 6C is obtained, and when the wave generator 43 rotates 360 ° clockwise from the initial state, the state shown in FIG. 6D is obtained. The wave generator 43 is in the same position in the initial state of FIG. 6A and the state of FIG. 6D rotated 360 °, but the flexible spline 42 has the number of teeth of the inner teeth 41a of the circular spline 41. And the number of teeth of the external teeth 42c of the flexible spline 42 (two in the embodiment) are rotated counterclockwise. That is, every time the wave generator 43 rotates 360 ° in the clockwise direction, the flexible spline 42 rotates counterclockwise by two inner teeth 41a of the circular spline 41, and a large reduction ratio is obtained.

  When the rotation of the rotating shaft 36 of the motor M is decelerated by the harmonic drive mechanism 37 and transmitted to the relay rotating member 46 in this way, the sun gear 61 of the planetary gear mechanism 38 fixed to the relay rotating member 46 rotates. The pinions 63 meshed with the sun gear 61 and the ring gear 64 revolve the planetary carrier 62 while rotating. As a result, the output shaft 40 integral with the planetary carrier 62 rotates around the axis L together with the drive arm 21, and the lower arm 12 connected to the drive arm 21 via the link 22 moves up and down, thereby the knuckle 11 with respect to the vehicle body. The position of the wheel W, that is, the position of the wheel W can be positively changed in the vertical direction, thereby improving the riding comfort performance and the steering stability performance.

  As described above, when the drive arm 21 is swung by the driving force of the motor M of the electric actuator A, the torque acting on the ring gear 64 of the planetary gear mechanism 38 is less than a predetermined value. The third housing 34 is restrained so as not to rotate. That is, since the ring gear 64 urged in the direction of the axis L by the elastic force of the disc springs 66 is pressed against the balls 65, the balls 65 cannot get over the corrugated undulations 64a of the ring gear 64, and the ring gear 64 is substantially fixed to the third housing 34.

  However, when the wheel W gets over the unevenness of the road surface, a large torque is reversely transmitted from the lower arm 12 to the output shaft 40 of the reduction gear R, and the torque acting on the ring gear 64 of the planetary gear mechanism 38 exceeds a predetermined value. When the balls 65 get over the corrugated uneven portion 64 a of the ring gear 64, the clutch mechanism C slips, and the ring gear 64 rotates relative to the third housing 34.

  FIG. 8 is a graph showing the relationship of the axial force of the link 22 with respect to the rotation angle of the drive arm 21. The broken line is a characteristic corresponding to the conventional example not including the clutch mechanism C, and it can be seen that the driving arm 21 hardly rotates and the axial force of the link 22 rapidly increases and decreases. On the other hand, the solid line is a characteristic corresponding to the embodiment provided with the clutch mechanism C. When the clutch mechanism C slips due to an external force, the drive arm 21 rotates, and the change rate of the axial force of the link 22 becomes small. I understand that

  As a result, even if the motor M of the electric actuator A does not rotate, the lower arm 12 can move up and down, and the impact over the road surface unevenness is prevented from being directly transmitted to the vehicle body, thereby improving the riding comfort. Can do. Moreover, even if a large torque is reversely transmitted from the lower arm 12 to the output shaft 40 of the speed reducer R, the torque is released due to slippage of the ring gear 64 of the planetary gear mechanism 38, so that the planetary gear mechanism 38, harmonic drive mechanism 37 or It is possible to prevent the durability from being lowered due to excessive torque acting on the motor M. Further, when the balls 65 get over the corrugated irregularities 64a of the ring gear 64 against the elastic force of the disc springs 66, a shock absorbing function for absorbing the impact can be exhibited.

  Further, since the reduction gear R is configured by coaxially arranging the planetary gear mechanism 38 and the harmonic drive mechanism 37 having a rotationally symmetric structure on the axis L, it is possible to obtain a large reduction ratio while keeping the reduction gear R small in diameter. .

  Next, a second embodiment of the present invention will be described with reference to FIG.

  In the first embodiment, the concavo-convex portion 64a of the ring gear 64 is configured by an arc having the same radius as the radius of the ball 65, but the concavo-convex portion 64a of the second embodiment has a radius of the ball 65. The ring gear 64 has a shape extended in the circumferential direction with a larger radius.

  According to this embodiment, when a large torque is reversely transmitted from the lower arm 12 to the output shaft 40 of the reduction gear R when the wheel W gets over the unevenness of the road surface, the clutch mechanism C slips with a relatively small torque. Since the ring gear 64 rotates relative to the third housing 34, the impact from the road surface is more difficult to be transmitted directly to the vehicle body, and the riding comfort can be enhanced.

  Next, a third embodiment of the present invention will be described with reference to FIG.

  In the first embodiment, the concavo-convex portions 64a of the ring gear 64 are configured by arcs having the same radius as the radius of the balls 65, but the concavo-convex portions 64a of the third embodiment have a shape in which trapezoids are continuous. have.

  According to this embodiment, the magnitude of the torque that the clutch mechanism C slips can be changed only by changing the inclination angle of the trapezoidal slope and the distance between the pair of trapezoidal slopes (that is, the depth at which the balls 65 are fitted). Can be adjusted arbitrarily.

  Next, a fourth embodiment of the present invention will be described based on FIG. 11 and FIG.

  In the fourth embodiment, an annular cam member 68 fixed to the third housing 34 is provided, and a paper cushioning member 69 is sandwiched between the third housing 34 and the cam member 68. A plurality of ball support holes 34 c formed in the third housing 34, a plurality of ball support holes 68 a formed on the back surface of the cam member 68, and a plurality of ball fitting holes 69 a formed in the buffer member 69. A plurality of lock balls 70 are fitted to each other, and the cam member 68 is fixed to the third housing 34 so as not to rotate by these lock balls 70. And the trapezoidal 2nd uneven part 68b ... formed in the front of the cam member 68 and the trapezoid 1st uneven part 64b formed in the ring gear 64 are engaging without gap.

  According to this embodiment, when a large torque is reversely transmitted from the lower arm 12 to the output shaft 40 of the speed reducer R when the wheels W get over the unevenness of the road surface, the lock balls 70. When the first concavo-convex portions 64b of the ring gear 64 slip while compressing the disc springs 66 with respect to the second concavo-convex portions 68b of the cam member 68 fixed via the ring gear 64, the ring gear 64 moves relative to the third housing 34. Thus, it is possible to improve the ride comfort by preventing the relative rotation and the impact over the road surface unevenness from being directly transmitted to the vehicle body.

  In particular, the second concavo-convex portions 68b of the cam member 68 and the first concavo-convex portions 64b of the ring gear 64 are not in point contact via the ball, but are in surface contact with each other. Can increase the sex. Further, since the buffer member 69 is interposed between the third housing 34 and the cam member 68, the shock transmitted from the ring gear 64 to the cam member 68 is absorbed by the buffer member 69 and is not easily transmitted to the third housing 34. be able to.

  Next, a fifth embodiment of the present invention will be described with reference to FIG.

  In the fifth embodiment, the electric actuator A is connected to the lower arm 12 of the suspension device S. In the fifth embodiment, two electric actuators A are provided in the stabilizer 71 of the suspension device S. is there.

  That is, the stabilizer 71 is composed of left and right stabilizer halves 73 and 73 bent in an L shape, and the outer ends of both the stabilizer halves 73 and 73 are connected to a suspension arm and a knuckle of a suspension device (not shown). . The structure of each electric actuator A is the same as that of the first embodiment, and two mounting brackets 74, 74 fitted to the outer periphery of the first to third housings 31, 32, 34 are vehicle body frames 72. The output shaft 40 (see FIG. 2) is coaxially connected to the inner end of the stabilizer half 73 via a joint 76.

  Accordingly, if the left and right electric actuators A and A are driven in the same direction, the left and right wheels W and W can be moved up and down in the same phase, and if the left and right electric actuators A and A are driven in opposite directions to each other. The left and right wheels W, W can be moved up and down in opposite phases.

  Thus, also according to the fifth embodiment, when a large load is input to the wheels W, W from the road surface, the same operational effects as those of the first embodiment described above can be achieved.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, in the embodiment, the harmonic drive mechanism 37 and the planetary gear mechanism 38 are employed for the speed reducer R, but the structure of the speed reducer R is arbitrary.

  In the first to third embodiments and the fifth embodiment, the uneven portion 64a is formed on the ring gear 64 side of the planetary gear mechanism 38, but the uneven portion is formed on the third housing 34 side. Can do.

The perspective view of the active suspension apparatus which concerns on 1st Embodiment 2-2 line enlarged sectional view of FIG. Disassembled perspective view of harmonic drive mechanism Sectional view along line 4-4 in FIG. FIG. 5 is an enlarged sectional view taken along line 5-5. Action diagram of the harmonic drive mechanism Graph showing the relationship of load to the disc spring stroke Graph showing the relationship of the axial force of the link to the rotation angle of the drive arm The figure corresponding to the said FIG. 5 based on 2nd Embodiment. The figure corresponding to the said FIG. 5 based on 3rd Embodiment. The figure corresponding to the said FIG. 5 based on 4th Embodiment The disassembled perspective view of the clutch mechanism which concerns on 4th Embodiment The perspective view of the active suspension apparatus which concerns on 5th Embodiment

34 Third housing (housing)
38 planetary gear mechanism 61 sun gear (input transmission member)
62 Planetary carrier (output transmission member)
64 Ring gear (fixed transmission member)
64a Uneven portion 65 Ball 66 Disc spring (biasing means )
A Electric actuator (actuator)
C Clutch mechanism M Motor (power source)
R Reducer S Suspension device W Wheel

Claims (2)

A suspension device (S) for suspending the wheel (W) from the vehicle body, and an actuator (A) for decelerating and outputting the rotation of the power source (M) with a reduction gear (R). In the active suspension device for a vehicle that moves the suspension device (S) up and down,
The speed reducer (R) includes an input transmission member (61) connected to the power source (M), a fixed transmission member (64) fixed to the housing (34) via a clutch mechanism (C), An output transmission member (62) connected to the suspension device (S),
The clutch mechanism (C) includes a wavy uneven portion (64a) formed on at least one of the opposing surfaces of the fixed transmission member (64) and the housing (34), the fixed transmission member (64), and the housing. (34) The ball (65) is sandwiched between the plurality of balls (65) that are in contact with the concavo-convex portion (64a), and the fixed transmission member (64) and the housing (34). And a biasing means (66) for biasing the end of the fixed transmission member (64) opposite to the end of the ball (65 ), and acts on the fixed transmission member (64). When the torque is less than a predetermined value, the fixed transmission member (64) is fixed to the housing (34), and when the torque acting on the fixed transmission member (64) is a predetermined value or more, the fixed transmission member (64). The housing Vehicle active suspension system, characterized in that to slip relative to 34). Before Symbol reducer (R) includes a planetary gear mechanism (38), wherein the input transmission member (61), the fixed transmission member (64) and the output transmission member (62), each of said planetary gear mechanism (38) The active suspension device for a vehicle according to claim 1, wherein the sun gear, the ring gear, and the planetary carrier .

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