JP2019206234A - Steering device - Google Patents

Abstract

To provide a steering device which can allow precession movement while reducing space consumption.SOLUTION: A steering device 100 includes: a piston rod 101 of a shock absorber 10 disposed in a tire house 7; a joint mechanism 9 which connects the piston rod 101 with the tire house 7 in the tire house 7; and a motor 11 (a driving source) which transmits power to an output shaft 13 (a rotary shaft) for turning to rotate the output shaft 13. The joint mechanism 9 includes: a first joint (a spherical bearing 30) which pivotally supports the piston rod 101 in a swingable manner; and a second joint (a constant velocity joint 40) which houses the first joint and is used to support the output shaft 13 in a swingable manner. The first joint and the second joint are concentrically arranged.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a steering apparatus.

  As a steering device, there is known a steering device in which a motor for driving a shaft serving as a rotating shaft of steering is installed on a vehicle body (see, for example, Patent Document 1). This steering device steers left and right steered wheels independently.

JP 2012-106524 A

  By the way, the shaft performs a precession, but the structure for allowing the precession is large, and the actual condition is that the space in the vehicle body is consumed.

  An object of the present invention is to provide a steering device that can allow precession while suppressing space consumption.

  In order to solve the above problems, a steering apparatus according to an aspect of the present invention includes a piston rod of a shock absorber disposed in a tire house of a vehicle, and a joint that connects the piston rod and the tire house in the tire house. And a drive source that transmits power to the rotating shaft for turning and rotates the rotating shaft, and the joint mechanism includes a first joint that pivotally supports the piston rod, A second joint for housing the joint and supporting the rotary shaft so as to be swingable; the first joint and the second joint are arranged concentrically;

  According to the present invention, it is possible to provide a steering device that can allow precession while suppressing space consumption.

It is a schematic diagram which shows the principal part structure of the steering device which concerns on embodiment. It is a conceptual diagram which shows the principal part structure of the steering device which concerns on embodiment. It is sectional drawing which shows schematic structure of the unit part which concerns on embodiment. It is sectional drawing which is a unit part which concerns on embodiment, and shows the state which is performing precession.

  Hereinafter, embodiments will be specifically described with reference to the drawings. It should be noted that each of the embodiments described below shows a comprehensive or specific example. The numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

  Further, the drawings are schematic diagrams in which emphasis, omission, and ratio adjustment are appropriately performed to show the present invention, and may differ from actual shapes, positional relationships, and ratios.

  Steering device 100 according to the present embodiment is a steering device used for a vehicle equipped with a strut suspension mechanism, for example. FIG. 1 is a schematic diagram illustrating a main configuration of a steering apparatus 100 according to an embodiment. FIG. 2 is a conceptual diagram illustrating a main configuration of the steering device 100 according to the embodiment. The tire house 7 side is defined as the upper side, and the ground side is defined as the lower side, based on the axial direction of the output shaft 13.

  As shown in FIGS. 1 and 2, the steering device 100 includes a knuckle 2 attached to the steered wheel 1, a lower arm 4 connected to the lower part of the knuckle 2 via a ball joint 3, and a clamp on the upper part of the knuckle 2. And struts 6 connected via 5. The strut 6 is disposed in the tire house 7 of the vehicle and is supported by the tire house 7. The tire house 7 is a part of the vehicle body that forms a wheel house. That is, it can be said that the strut 6 is disposed in the wheel house. The strut 6 includes a unit portion 8 and a joint mechanism 9 that connects the unit portion 8 to the tire house 7.

  FIG. 3 is a cross-sectional view illustrating a schematic configuration of the unit unit 8 according to the embodiment. In FIG. 3, the piston rod 101 of the shock absorber 10 is not hatched and is a plan view. As shown in FIG. 3, the unit portion 8 includes a shock absorber 10 (see FIG. 2), a motor 11, a speed reducer 12, and an output shaft 13, which are unitized. “Unitization” means that components are connected to form an assembly.

  The shock absorber 10 includes a piston rod 101 and a cylinder 102 (see FIG. 2) that holds the piston rod 101 so as to advance and retract. The upper end portion of the piston rod 101 is connected to the joint mechanism 9. A piston 103 (see FIG. 1) is attached to the lower end portion of the piston rod 101, and a damping force is generated when the piston 103 slides in the cylinder 102.

  The piston rod 101 protrudes upward from the upper end of the cylinder 102. The cylinder 102 accommodates the lower end portion of the piston rod 101 and the piston 103 so as to be slidable in the vertical direction. Further, the cylinder 102 holds the piston rod 101 and the piston 103 rotatably. A support portion 104 (see FIG. 2) extending outward is provided at an intermediate position of the cylinder 102, and a spring 14 is interposed between the support portion 104 and the output shaft 13. ing. The spring 14 is a coil spring, and the piston rod 101 and the cylinder 102 are disposed inside thereof.

  The cylinder 102 and the output shaft 13 are connected via a spline such as a ball spline. As a result, the axial position of the cylinder 102 relative to the output shaft 13 varies, and the cylinder 102 rotates following the rotation of the output shaft 13. Here, the upper end portion of the spring 14 is fixed to the output shaft 13, and the lower end portion of the spring 14 is fixed to the support portion 104. For this reason, the spring 14 rotates following the rotation of the output shaft 13 and the cylinder 102.

  The knuckle 2 is connected to the lower end portion of the cylinder 102 via the clamp 5. Thereby, the rotation of the output shaft 13 is transmitted to the steered wheels 1 via the cylinder 102 and the knuckle 2. That is, the output shaft 13 is an example of a rotating shaft for turning.

  The motor 11 is a drive source that rotates the output shaft 13. The motor 11 is unitized with the output shaft 13 so as to be arranged in series with the output shaft 13. The motor 11 includes a stator housing 15, a rotor housing 16, a coil 17, and a magnet 18.

  The stator housing 15 is connected to the joint mechanism 9. Specifically, an accommodation recess 151 in which the joint mechanism 9 is accommodated is provided at the center of the upper end portion of the stator housing 15. The stator housing 15 includes an inner peripheral wall portion 152 that forms an inner peripheral surface of the housing recess 151, and an outer peripheral wall portion 153 that is disposed outside the inner peripheral wall portion 152. The inner peripheral wall portion 152 and the outer peripheral wall portion 153 form a cylindrical space whose lower end is open. In this space, a coil 17, a magnet 18, and a rotor housing 16 are arranged. In this space, a plurality of cores 19 are arranged along the circumferential direction on the outer peripheral wall portion 153, and a coil 17 is wound around each of the plurality of cores 19. An output shaft 13 is accommodated in the lower end portion of the stator housing 15 so as to be rotatable with respect to the outer peripheral wall portion 153 via a bearing 23 such as a cross roller bearing.

  The joint mechanism 9 is connected to the inner peripheral wall portion 152. Accordingly, the stator housing 15 is swingable with respect to the tire house 7, but the rotation is restricted. A bottom portion of the housing recess 151 is provided at an intermediate position in the inner peripheral wall portion 152. Specifically, the bottom of the accommodation recess 151 extends from the inner peripheral wall 152 toward the inner side in the longitudinal direction. The piston rod 101 passes through the bottom of the housing recess 151 in a freely rotatable manner. The lower end portion of the inner peripheral wall portion 152 protrudes downward from the bottom portion of the housing recess 151, and is disposed with an interval with respect to the entire circumference of the piston rod 101.

  The rotor housing 16 is a substantially cylindrical housing and is rotatably held with respect to the stator housing 15. Specifically, the rotor housing 16 is formed in a substantially cylindrical shape, and includes a large diameter portion 161 and a small diameter portion 162.

  The large diameter portion 161 is a portion having an inner diameter and an outer diameter larger than those of the small diameter portion 162. An inner peripheral wall portion 152 of the stator housing 15 is accommodated inside the large diameter portion 161. On the outer peripheral surface of the large diameter portion 161, a plurality of magnets 18 are arranged in the circumferential direction at positions facing the coil 17 and the core 19.

  The small diameter portion 162 is a portion located below the large diameter portion 161, and the piston rod 101 passes therethrough. The piston rod 101 is supported rotatably with respect to the small diameter portion 162 via a pair of bearings 163 and 163. As a result, when a current is supplied to the coil 17 and a magnetic field is generated between the coil 17 and the magnet 18, the rotor housing 16 rotates with respect to the piston rod 101.

  A cylindrical protrusion 164 that protrudes upward is provided at the upper end of the small diameter part 162. The protruding portion 164 faces the lower end portion of the inner peripheral wall portion 152 of the stator housing 15 with a gap in the radial direction. In other words, the protruding portion 164 and the lower end portion of the inner peripheral wall portion 152 are double-annular. A resolver 20, which is an example of a rotation sensor, is provided in a gap formed by the protruding portion 164 and the lower end portion of the inner peripheral wall portion 152. Specifically, the stator 21 of the resolver 20 is attached to the inner peripheral surface of the inner peripheral wall portion 152, and the rotor 22 is attached to the outer peripheral surface of the protruding portion 164.

  The speed reducer 12 is a device that decelerates the rotation of the rotor housing 16 and transmits it to the output shaft 13. In other words, the motor 11 transmits power to the output shaft 13 on the steered wheel 1 side with respect to the joint mechanism 9 through the reduction gear 12. Examples of the speed reducer 12 include a wave speed reducer such as a harmonic drive (registered trademark), a cycloid speed reducer, and the like. A circular spline 121 of the speed reducer 12 is fixed to the output shaft 13. The wave generator 122 of the speed reducer 12 is fixed to the small diameter portion 162 of the rotor housing 16. The speed reducer 12 decelerates the rotation input from the small diameter portion 162 to the wave generator 122 by the flex spline 123 and outputs the result from the circular spline 121 to the output shaft 13.

  The output shaft 13 is a rotating shaft that outputs the rotation of the motor 11 decelerated by the speed reducer 12 to the spring 14 and the cylinder 102. Specifically, the output shaft 13 integrally includes a housing portion 131 that houses the small diameter portion 162 of the rotor housing 16 and a main body portion 132 that is connected to the cylinder 102 via a spline.

  The accommodating part 131 is formed in a cylindrical shape with an open upper part, and the small diameter part 162 of the rotor housing 16 and the speed reducer 12 are accommodated therein. A circular spline 121 of the speed reducer 12 is fixed to the inner peripheral surface of the housing portion 131. The accommodating portion 131 is accommodated in the lower end portion of the stator housing 15 so as to be rotatable with respect to the outer peripheral wall portion 153.

  The main body part 132 includes a base part 133 and a cylindrical part 134. The base portion 133 is formed in a disc shape, and the accommodation portion 131 is fixed to the upper surface thereof, and the cylindrical portion 134 is fixed to the lower surface. The piston rod 101 passes through the base portion 133. A concave portion 135 surrounding the piston rod 101 is formed on the upper surface of the base portion 133. A bearing 136 that rotatably supports the piston rod 101 is provided in the recess 135. By this bearing 136, the output shaft 13 is rotatable with respect to the piston rod 101. The upper end portion of the spring 14 is fixed to the lower surface of the base portion 133.

  The cylinder part 134 is formed in a cylindrical shape, and the cylinder 102 is accommodated therein. The cylinder part 134 and the cylinder 102 are connected via the spline as described above. As a result, the cylinder 102 changes its axial relative position with respect to the cylindrical portion 134 and rotates following the rotation of the cylindrical portion 134.

  The joint mechanism 9 is a joint that couples the piston rod 101 and the stator housing 15 to the tire house 7. Specifically, the joint mechanism 9 includes a first joint that supports the piston rod 101 in a swingable manner and a second joint that supports the output shaft 13 in a swingable manner via the stator housing 15. Examples of the first joint include a spherical bearing or a ball joint. An example of the second joint is a constant velocity joint. In the present embodiment, the first joint is described as a spherical bearing 30 and the second joint is described as a constant velocity joint 40. The spherical bearing 30 and the constant velocity joint 40 are arranged concentrically. The concentric arrangement is an arrangement in which the rotation center of the spherical bearing 30 and the rotation center of the constant velocity joint 40 are substantially coincident. “Substantially match” includes not only a perfect match but also a match with an error of several percent. In FIG. 3, the rotation center of the spherical bearing 30 and the rotation center of the constant velocity joint 40 are indicated by a point P.

  The spherical bearing 30 has a ball (not shown) incorporated in the bearing housing 31. The ball has a spherical bearing surface, and the bearing housing 31 has a complementary spherical housing bearing surface corresponding to the ball bearing surface. As the bearing surface and the housing bearing surface slide relative to each other, the bearing housing 31 moves freely with respect to the ball. A piston rod 101 is connected to the bearing housing 31, and a support shaft 50 is connected to the ball. The support shaft 50 is fixed to the tire house 7 via a vibration isolator 60.

  With this spherical bearing 30, the piston rod 101 can swing and rotate with respect to the support shaft 50. That is, the piston rod 101 can precess with respect to the support shaft 50. As described above, the precession motion (the squeezing motion) of the piston rod 101 with respect to the support shaft 50 is allowed by the spherical bearing 30. The spherical bearing 30 is a part that supports the piston rod 101 so as to freely precess. Here, the precession movement is a conical movement such as a saw that is seen on a core rod of a frame that is turning around.

  The constant velocity joint 40 includes an outer joint member 41, an inner joint member 42, and a plurality of balls 43.

  The outer joint member 41 is fixed in the housing recess 151 of the stator housing 15. The outer joint member 41 is formed in an annular shape, and an inner peripheral surface thereof has a concave spherical shape.

  The inner joint member 42 is integrally provided with a pedestal 44 and a shaft portion 45. The pedestal 44 is fixed to the tire house 7 together with the support shaft 50 via the vibration isolator 60. The support shaft 50 is fixed to the pedestal 44 so as to penetrate therethrough.

  The shaft portion 45 projects downward from the center portion of the base 44. A recess 46 for receiving the bearing housing 31 of the spherical bearing 30 is formed on the lower surface of the shaft portion 45. The outer peripheral surface at the lower end portion of the shaft portion 45 is formed in a convex spherical shape. The outer peripheral surface is a complementary spherical surface corresponding to the inner peripheral surface of the outer joint member 41. The outer joint member 41 freely moves with respect to the inner joint member 42 by sliding the outer peripheral surface at the lower end of the shaft portion 45 and the inner peripheral surface of the outer joint member 41.

  The plurality of balls 43 are disposed in each of a plurality of holding holes 49 formed at predetermined positions in the circumferential direction of the outer joint member 41. Thus, the plurality of balls 43 are rotatably held by the outer joint member 41. The plurality of balls 43 are attached to the outer joint member 41 so as not to hinder the relative movement between the outer joint member 41 and the inner joint member 42. The plurality of balls 43 are disposed in an inner circumferential groove 154 formed on the inner circumferential surface of the housing recess 151 of the stator housing 15. Thereby, the reaction force based on the rotation of the motor 11 does not act on the constant velocity joint 40.

  The constant velocity joint 40 allows the motor 11 and the stator housing 15 to swing with respect to the support shaft 50. That is, the motor 11 and the output shaft 13 can precess with respect to the support shaft 50. As described above, the precession motion (grinding motion) of the motor 11 and the output shaft 13 with respect to the support shaft 50 is allowed by the constant velocity joint 40. The constant velocity joint 40 is a part for supporting the output shaft 13 so that it can freely precess.

  FIG. 4 is a cross-sectional view showing a state where the unit portion 8 according to the embodiment is performing precession. In FIG. 4, the outer shape of the motor 11 and the output shaft 13 in a state where the precession is not performed is indicated by a broken line L1. Moreover, in FIG. 4, the axial center of the piston rod 101 in the state which is not performing precession is shown with the dashed-dotted line L2.

  As shown in FIG. 4, the motor 11 and the output shaft 13 precess by a constant velocity joint 40. Specifically, the motor 11 and the output shaft 13 rotate while being inclined with respect to the support shaft 50 around the point P. Similarly, the piston rod 101 precesses by the spherical bearing 30. Specifically, the piston rod 101 rotates with respect to the support shaft 50 around the point P. The motor 11, the output shaft 13 and the piston rod 101 simultaneously perform precession, but the rotation of the output shaft 13 caused by the motor 11 does not affect the precession.

  As described above, the steering device 100 according to the present embodiment connects the piston rod 101 and the tire house 7 within the tire house 7 and the piston rod 101 of the shock absorber 10 disposed in the tire house 7. The joint mechanism 9 includes a motor 11 (drive source) that transmits power to the steering output shaft 13 (rotary shaft) and rotates the output shaft 13. The joint mechanism 9 includes a piston rod 101. A spherical bearing 30 (first joint) that pivotably supports the shaft, and a constant velocity joint 40 (second joint) that accommodates the spherical bearing 30 and supports the output shaft 13 so as to swing freely. The bearing 30 and the constant velocity joint 40 are disposed concentrically.

  According to this, since the spherical bearing 30 that supports the piston rod 101 so as to swing freely and the constant velocity joint 40 that supports the output shaft 13 so as to swing freely are arranged concentrically, the piston rod 101 and the output In a state where the precession of the shaft 13 is allowed, the spherical bearing 30 and the output shaft 13 can be disposed close to each other in the vertical direction. That is, the joint mechanism 9 can be downsized, and as a result, the steering device 100 can be downsized. Therefore, it is possible to provide the steering device 100 that can allow precession while suppressing space consumption.

  In addition, backlash can be suppressed even when compared with the case where a cardan joint is used as the joint mechanism.

  The motor 11 is disposed on the same plane with respect to the spherical bearing 30 and the constant velocity joint 40.

  According to this, since the motor 11 is arranged on the same plane with respect to the spherical bearing 30 and the constant velocity joint 40, the motor 11, the spherical bearing 30 and the constant velocity joint 40 can be arranged close to each other in the vertical direction. it can. Therefore, the steering device 100 can be further downsized.

  Further, the output shaft 13, the joint mechanism 9, and the motor 11 are disposed in the tire house 7.

  According to this, since the joint mechanism is downsized, the output shaft 13, the joint mechanism 9, and the motor 11 can be disposed in the tire house 7. Thereby, the space in the tire house 7 can be used effectively.

  The steering device 100 is used in a vehicle equipped with a strut suspension mechanism.

  As described above, since the steering device 100 allows both the precession movement of the piston rod 101 and the precession movement of the output shaft 13, it is preferably used for a vehicle equipped with a strut suspension mechanism. be able to. In particular, the strut suspension mechanism is preferably supported so as to be able to swing according to the tilting of the steered wheels connected to the lower end side of the mechanism. It is conceivable to employ various joints for the support structure of the strut type suspension mechanism, but it must be accommodated in a limited space and may be difficult to install. However, if the joint mechanism 9 reduced in size as described above is employed in the support structure of the strut suspension mechanism, the support structure can be easily accommodated in a limited space.

  As mentioned above, although the steering device concerning the present invention was explained based on the above-mentioned embodiment, the present invention is not limited to the above-mentioned embodiment.

  For example, in the above embodiment, the steering device used for a vehicle equipped with a strut suspension mechanism is illustrated. However, the characteristic configuration of the present disclosure can also be applied to a steering device used in a vehicle equipped with a suspension mechanism of another type. Other methods include a double wishbone suspension mechanism.

  Moreover, in the said embodiment, the case where the motor 11 was arrange | positioned on the same plane with respect to the spherical bearing 30 and the constant velocity joint 40 was illustrated. However, the motor 11 may not be arranged on the same plane with respect to the spherical bearing 30 and the constant velocity joint 40.

  In addition, it is realized by arbitrarily combining the components and functions in the embodiments and modifications without departing from the spirit of the present invention, and forms obtained by subjecting the embodiments to various modifications conceived by those skilled in the art. This form is also included in the present invention.

  The present invention is applicable to a steering apparatus having a shock absorber.

1 steered wheel, 2 knuckle, 3 ball joint, 4 lower arm, 5 clamp, 6 strut, 7 tire house, 8 unit part, 9 joint mechanism, 10 shock absorber, 11 motor (drive source), 12 speed reducer, 13 output shaft (Rotary shaft), 14 spring, 15 stator housing, 16 rotor housing, 17 coil, 18 magnet, 19 core, 20 resolver, 21 stator, 22 rotor, 23 bearing, 30 spherical bearing (first joint), 31 bearing housing, 40 constant velocity joint (second joint), 41 outer joint member, 42 inner joint member, 43 ball, 44 base, 45 shaft portion, 46 recess, 49 holding hole, 50 support shaft, 60 vibration isolator, 100 steering device, 101 piston rod, 102 cylinder, 103 piston 104 support part, 121 circular spline, 122 wave generator, 123 flex spline, 131 accommodating part, 132 main body part, 133 base part, 134 cylinder part, 135 concave part, 136 bearing, 151 accommodating concave part, 152 inner peripheral wall part, 153 outer periphery Wall portion, 154 inner circumferential groove, 161 large diameter portion, 162 small diameter portion, 163 bearing, 164 protrusion

Claims (4)

A shock absorber piston rod arranged in the tire house of the vehicle;
In the tire house, a joint mechanism for connecting the piston rod and the tire house;
A power source for transmitting power to the rotating shaft for turning and rotating the rotating shaft,
The joint mechanism includes a first joint that pivotally supports the piston rod, and a second joint that accommodates the first joint and supports the rotary shaft so as to swing.
The first joint and the second joint are arranged concentrically. The steering device according to claim 1, wherein the drive source is arranged on the same plane with respect to the first joint and the second joint. The steering apparatus according to claim 1, wherein the rotation shaft, the joint mechanism, and the drive source are disposed in the tire house. The steering device according to any one of claims 1 to 3, wherein the steering device is used in the vehicle on which a strut suspension mechanism is mounted.

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