WO2019078120A1

WO2019078120A1 - Suspension

Info

Publication number: WO2019078120A1
Application number: PCT/JP2018/038139
Authority: WO
Inventors: 大輔郡司; 浩保熊谷; 真史疋田; 松田　靖之
Original assignee: 日本精工株式会社
Priority date: 2017-10-19
Filing date: 2018-10-12
Publication date: 2019-04-25
Also published as: JPWO2019078120A1; JP6590115B2

Abstract

This suspension is provided with multiple links that link a vehicle body-side member and a hub carrier. At least one of the multiple links is an expansion link. The expansion link is provided with: a fixed shaft; a first universal joint which links the fixed shaft to the vehicle body-side member so as to enable rotation and swinging with respect to the vehicle body-side member; a movable shaft which can slide with respect to the fixed shaft; a second universal joint which links the movable shaft to the hub carrier so as to enable rotation and swinging with respect to the hub carrier; and an actuator which is fixed to the fixed shaft and moves the movable shaft.

Description

suspension

The present invention relates to a suspension.

In the vehicle, a suspension is disposed between the vehicle body and the wheel. The suspension is a device for making it difficult to transmit vibrations due to the unevenness of the road surface to the vehicle body, and is a device for positioning the wheel. A multilink type suspension is known as one of suspension types. For example, Patent Document 1 describes an example of a multilink suspension.

JP, 2015-155255, A

By the way, it may be required to be able to change the relative attitude of the wheel with respect to the vehicle body according to the motion performance required of the vehicle.

The present disclosure has been made in view of the above problems, and an object of the present disclosure is to provide a suspension that can easily change the relative attitude of the wheel with respect to the vehicle body.

In order to achieve the above object, a suspension according to an aspect of the present disclosure includes a plurality of links connecting a vehicle body side member and a hub carrier, and at least one of the plurality of links is a telescopic link; The link includes a fixed shaft, a first universal joint connecting the fixed shaft to the vehicle side member so as to be rotatable and swingable with respect to the vehicle body side member, a movable shaft slidable relative to the fixed shaft, A second universal joint coupling the movable shaft to the hub carrier so as to be rotatable and swingable with respect to the hub carrier, and an actuator fixed to the fixed shaft to move the movable shaft.

Thereby, the suspension can change the attitude of the wheel by moving the movable shaft. The suspension can facilitate changing the relative attitude of the wheel relative to the vehicle body.

As a desirable mode of the above-mentioned suspension, the suspension is provided with the five telescopic links.

Thereby, the suspension can change the toe angle, the camber angle, the caster angle, the tread width and the wheel base by moving the movable shaft. The suspension can make it easier to change the relative attitude of the wheel with respect to the vehicle body.

According to the present disclosure, it is possible to provide a suspension that can easily change the relative attitude of the wheel with respect to the vehicle body.

FIG. 1 is a perspective view of the suspension of the present embodiment. FIG. 2 is a perspective view of the expandable link of the present embodiment. FIG. 3 is an exploded perspective view of the telescopic link of the present embodiment. FIG. 4 is an exploded perspective view of the telescopic link of the present embodiment. FIG. 5 is a plan view of the expandable link of the present embodiment. 6 is a cross-sectional view taken along the line AA in FIG. FIG. 7 is a bottom view of the expandable link of the present embodiment. FIG. 8 is a cross-sectional view taken along the line BB in FIG. FIG. 9 is an exploded perspective view of the fixed shaft of the present embodiment. FIG. 10 is a plan view of the expandable link of the present embodiment. FIG. 11 is a cross-sectional view taken along the line CC in FIG. FIG. 12 is an exploded perspective view of the universal joint of the present embodiment. FIG. 13 is a cross-sectional view taken along the line DD in FIG. FIG. 14 is an exploded perspective view of the clutch of the present embodiment. FIG. 15 is a perspective view of the suspension of the first modification. FIG. 16 is a perspective view of the fixed link. FIG. 17 is a perspective view of the suspension of the second modification. FIG. 18 is a perspective view of a suspension according to a third modification.

Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited by the following embodiments (hereinafter referred to as embodiments). Further, constituent elements in the following embodiments include those which can be easily conceived by those skilled in the art, those substantially the same, and so-called equivalent ranges. Furthermore, the components disclosed in the following embodiments can be combined as appropriate.

FIG. 1 is a perspective view of the suspension of the present embodiment. The vehicle 10 of the present embodiment includes a wheel 102, a hub unit 101, a vehicle body side member 18, a hub carrier 19, a suspension 1, and a control device 9. For example, the vehicle 10 includes four wheels 102, each of which includes a hub unit 101. The hub unit 101 incorporates, for example, a hub bearing, two motors, a transmission, and the like. The hub unit 101 rotatably supports the wheel 102 and drives the wheel 102. The vehicle body side member 18 is a member fixed to the vehicle body. The hub carrier 19 is a member fixed to the hub unit 101. The hub carrier 19 is also called knuckle.

The suspension 1 is a device that connects the vehicle body (chassis) of the vehicle 10 and the hub unit 101. The suspension 1 is a multilink type. As shown in FIG. 1, the suspension 1 includes a shock absorber 11 and five telescopic links 2 for one wheel 102.

The shock absorber 11 is a device for reducing the impact transmitted from the road surface to the vehicle body while the vehicle is traveling. One end of the shock absorber 11 is fixed to the vehicle body. The other end of the shock absorber 11 is fixed to the hub carrier 19. The shock absorber 11 can expand and contract in the vertical direction.

FIG. 2 is a perspective view of the expandable link of the present embodiment. FIG. 3 is an exploded perspective view of the telescopic link of the present embodiment. FIG. 4 is an exploded perspective view of the telescopic link of the present embodiment. FIG. 5 is a plan view of the expandable link of the present embodiment. 6 is a cross-sectional view taken along the line AA in FIG.

The expansion link 2 is a member for connecting the vehicle body side member 18 and the hub carrier 19. As shown in FIG. 1, two telescopic links 2 are disposed above the rotation axis of the wheel 102. Three telescopic links 2 are disposed below the rotation axis of the wheel 102. As shown in FIG. 2, the expansion link 2 includes a fixed shaft 3, a movable shaft 4, a first universal joint 6 a, a second universal joint 6 b, and an actuator 5.

The fixed shaft 3 is connected to the vehicle body side member 18 (see FIG. 1) via the first universal joint 6a. The fixed shaft 3 is cylindrical. As shown in FIGS. 3 and 4, the fixed shaft 3 includes a first member 31 and a second member 32. The first member 31 and the second member 32 are connected by a fastening member 301. When assembling the first member 31 and the second member 32, two positioning pins 302 are used. The first universal joint 6 a is attached to the first member 31.

The movable shaft 4 is connected to the hub carrier 19 (see FIG. 1) via the second universal joint 6b. As shown in FIG. 6, the movable shaft 4 is a hollow member having an internal space 40. A part of the movable shaft 4 is located inside the fixed shaft 3. The movable shaft 4 can slide relative to the fixed shaft 3. The movable length of the movable shaft 4 is regulated by a stopper 45 (see FIG. 6) provided on the movable shaft 4. The stopper 45 is disposed in a groove 315 provided on the inner peripheral surface of the first member 31. When the stopper 45 reaches the end of the groove 315, the stopper 45 contacts the first member 31 and the movable shaft 4 stops. This prevents the movable shaft 4 from coming off the fixed shaft 3.

FIG. 7 is a bottom view of the expandable link of the present embodiment. FIG. 8 is a cross-sectional view taken along the line BB in FIG. FIG. 9 is an exploded perspective view of the fixed shaft of the present embodiment.

As shown in FIG. 8, the movable shaft 4 includes a first flat surface 41, a second flat surface 42, a third flat surface 43, and a fourth flat surface 44 as surfaces facing the fixed shaft 3. The first flat surface 41 and the second flat surface 42 face the first member 31. The second plane 42 is at an angle to the first plane 41. An angle α between the first plane 41 and the second plane 42 is an acute angle. The third plane 43 and the fourth plane 44 face the second member 32. The fourth plane 44 makes an angle with the third plane 43. The angle β formed by the third plane 43 and the fourth plane 44 is an acute angle. For example, the third plane 43 is parallel to the first plane 41, and the fourth plane 44 is parallel to the second plane 42. Therefore, the angle β is equal to the angle α. As shown in FIG. 8, the cross section obtained by cutting the movable shaft 4 in a plane orthogonal to the rotation axis Z is an octagon having four pairs of parallel sides.

The rotation axis Z is a rotation axis of a screw shaft 57 described later. That is, the rotation axis Z is a straight line passing through the center of gravity of each cross section when the screw shaft 57 is cut in a plane orthogonal to the direction in which the screw shaft 57 extends. In the following description, a direction parallel to the rotation axis Z is referred to as an axial direction. Further, the direction orthogonal to the rotation axis Z is described as a radial direction.

As shown in FIG. 8, the first member 31 includes a first opposing surface 311, a second opposing surface 312, a first bush 351, and a second bush 352. The first opposing surface 311 faces the first flat surface 41 of the movable shaft 4. The second opposing surface 312 faces the second flat surface 42 of the movable shaft 4. For example, the first opposing surface 311 is parallel to the first plane 41, and the second opposing surface 312 is parallel to the second plane 42. The first bush 351 is formed in a plate shape, and is fitted in the recess 311 d provided in the first opposing surface 311. The thickness of the first bush 351 is larger than the depth of the recess 311 d. The first bush 351 is in contact with the first plane 41. The second bush 352 is formed in a plate shape, and is fitted in a recess 312 d provided in the second opposing surface 312. The thickness of the second bush 352 is larger than the depth of the recess 312 d. The second bush 352 is in contact with the second plane 42.

As shown in FIG. 8, the second member 32 includes a third facing surface 323, a fourth facing surface 324, a third bush 353, a fourth bush 354, a first elastic member 363, and a second elastic member. 364 and. The third facing surface 323 faces the third flat surface 43 of the movable shaft 4. The fourth opposing surface 324 faces the fourth plane 44 of the movable shaft 4. For example, the third opposing surface 323 is parallel to the third plane 43, and the fourth opposing surface 324 is parallel to the fourth plane 44. The third bush 353 is formed in a plate shape, and is fitted in the recess 323 d provided in the third opposing surface 323. The third bush 353 is in contact with the third plane 43. The first elastic member 363 is, for example, a disc spring. The first elastic member 363 is disposed between the bottom surface of the recess 323 d and the third bush 353. The first elastic member 363 presses the third bush 353 against the third plane 43. The fourth bush 354 is formed in a plate shape, and is fitted in the recess 324 d provided in the fourth opposing surface 324. The fourth bush 354 is in contact with the fourth plane 44. The second elastic member 364 is, for example, a disc spring. The second elastic member 364 is disposed between the bottom surface of the recess 324 d and the fourth bush 354. The second elastic member 364 presses the fourth bush 354 against the fourth plane 44.

As shown in FIGS. 6 and 8, the connecting portion of the first universal joint 6 a with the vehicle body side member 18 and the connecting portion of the second universal joint 6 b with the hub carrier 19 are planes including the rotation axis Z of the screw shaft 57. And the opposite side to the third bush 353 and the fourth bush 354. A connection portion of the first universal joint 6 a with the vehicle body side member 18 and a connection portion of the second universal joint 6 b with the hub carrier 19 are fastening portions 611 described later. The plane including the rotation axis Z of the screw shaft 57 is, for example, a plane PZ shown in FIG.

As shown in FIG. 9, each of the first bush 351, the second bush 352, the third bush 353 and the fourth bush 354 has a plurality of lubricant grooves 35d. The lubricant groove 35d is filled with a lubricant. The lubricant is, for example, grease. In the first bush 351, the lubricant groove 35d is open on the first plane 41 side. In the second bush 352, the lubricant groove 35d is open on the second plane 42 side. In the third bush 353, the lubricant groove 35d is open on the side of the recess 323d. In the fourth bush 354, the lubricant groove 35 d is opened to the concave portion 324 d side.

Note that the angles α and β shown in FIG. 8 may not necessarily be acute angles. Also, the third plane 43 may not be parallel to the first plane 41. The fourth plane 44 may not be parallel to the second plane 42.

FIG. 10 is a plan view of the expandable link of the present embodiment. FIG. 11 is a cross-sectional view taken along the line CC in FIG. FIG. 12 is an exploded perspective view of the universal joint of the present embodiment.

As shown in FIG. 10, the first universal joint 6 a is attached to the first member 31 of the fixed shaft 3. The first universal joint 6a connects the fixed shaft 3 to the vehicle body side member 18 so as to be rotatable and swingable with respect to the vehicle body side member 18 (see FIG. 1). The second universal joint 6 b is attached to the movable shaft 4. The second universal joint 6b couples the movable shaft 4 to the hub carrier 19 so as to be rotatable and swingable with respect to the hub carrier 19 (see FIG. 1). In the description that it can rotate and swing, rotation means rotating around straight line L1 (see FIG. 11), and swing means moving so that the angle θ between straight line L1 and straight line L2 changes. Do. The straight line L1 is a straight line passing through the center of gravity of each cross section obtained by cutting an arm 61 described later in a plane orthogonal to the longitudinal direction. The straight line L2 is a straight line perpendicular to the circle described by the outer shape of the outer bush 63 described later and passing through the center of the circle. An intersection point M (see FIG. 11) of the straight line L1 and the straight line L2 is the center of a convex arm 617p which is a spherical shape described later. In the present embodiment, the first universal joint 6a and the second universal joint 6b have the same structure. For the following detailed description, the second universal joint 6b is taken as an example. The description of the second universal joint 6b can also be applied to the description of the first universal joint 6a.

As shown in FIGS. 11 and 12, the second universal joint 6 b includes a housing 60, an arm 61, an outer bush 63, an inner bush 65, an elastic member 67 and a support member 69. The housing 60 is integrally formed with the distal end portion of the movable shaft 4. The housing 60 is cylindrical. The housing 60 of the first universal joint 6 a is integrally formed with the first member 31.

The arm 61 is a member connected to the hub carrier 19 (see FIG. 1). The arm 61 is formed of metal. The metal used for the arm 61 is, for example, steel. As shown in FIG. 11, a portion of the arm 61 is located inside the housing 60. As shown in FIGS. 11 and 12, the arm 61 includes a fastening portion 611, a flange portion 613, an intermediate portion 615, and a sliding portion 617. The fastening portion 611 and the flange portion 613 are located outside the housing 60. The fastening portion 611 is a cylindrical member having a thread on the outer peripheral surface. The flange portion 613 is a substantially conical member which is located on the housing 60 side of the fastening portion 611 and whose diameter increases toward the housing 60. The middle portion 615 is a substantially cylindrical member extending from the flange portion 613 to the housing 60 side. The middle portion 615 has two parallel flat surfaces on the outer circumferential surface. The sliding portion 617 is a substantially hemispherical member located on the housing 60 side of the intermediate portion 615. The sliding portion 617 includes an arm convex surface 617p, an arm concave surface 617q, and an arm end surface 617e. The arm convex surface 617p is an outer surface of the sliding portion 617 and is spherical. The arm concave surface 617 q is an inner surface of the sliding portion 617 and is spherical. The center of the arm concave surface 617 q is the same as the center of the arm convex surface 617 p. The arm end surface 617 e is an end surface of the sliding portion 617 connecting the arm convex surface 617 p and the arm concave surface 617 q. A part of the arm end surface 617 e is formed in a conical surface shape.

As shown in FIG. 11, the outer bush 63 is an annular member located between the inner circumferential surface of the housing 60 and the arm 61. The outer bush 63 is formed of metal. The metal used for the outer bush 63 is, for example, brass. The outer bush 63 is pressed into the inside of the housing 60. The outer bush 63 is provided with a bush concave surface 63q as an inner circumferential surface. The bush concave surface 63q is spherical and contacts the arm convex surface 617p. The center and the radius of the bush concave surface 63q are the same as the center and the radius of the arm convex surface 617p.

As shown in FIG. 11, the inner bush 65 is located inside the sliding portion 617 of the arm 61. That is, the inner bush 65 is located on the opposite side of the sliding portion 617 to the outer bush 63. The inner bush 65 is formed of metal. The metal used for the inner bush 65 is, for example, brass. The inner bush 65 includes a head 651 and a body 653. The head 651 is substantially hemispherical and has a bush convex surface 651p. The bush convex surface 651p is a spherical surface and is in contact with the arm concave surface 617q. For this reason, the sliding portion 617 is sandwiched between the bush convex surface 651 p of the inner bush 65 and the bush concave surface 63 q of the outer bush 63. The center and the radius of the bush convex surface 651p are the same as the center and the radius of the arm concave surface 617q. The body 653 is a substantially cylindrical member extending from the head 651 to the opposite side to the bush convex surface 651p.

The support member 69 supports the inner bush 65. As shown in FIG. 11, it is attached to the inside of the housing 60. The support member 69 is formed of metal. The metal used for the support member 69 is, for example, steel. The support member 69 includes an external thread 691, a first recess 693, and a second recess 695. The male screw 691 engages with the female screw 601 provided in the housing 60. The first recess 693 is a frusto-conical recess that opens toward the inner bush 65. The bottom surface of the first recess 693 is a plane perpendicular to the direction in which the body 653 of the inner bush 65 extends. The second recess 695 is a cylindrical recess provided on the bottom of the first recess 693. The body 653 is fitted in the second recess 695 and is guided by the inner peripheral surface of the second recess 695.

As shown in FIG. 11, the elastic member 67 is located between the inner bush 65 and the support member 69 and pushes the inner bush 65 toward the arm 61. The elastic member 67 is, for example, a disc spring. Two elastic members 67 are disposed so as to overlap between the body 653 and the bottom of the second recess 695.

The inside of the housing 60 is filled with a lubricant. The lubricant is, for example, grease. The sliding portion 617 of the arm 61 can move along the outer bush 63 and the inner bush 65. Therefore, the arm 61 can rotate and swing relative to the outer bush 63 and the inner bush 65. Further, as shown in FIG. 11, the arm end surface 617 e is in contact with the bottom surface of the first recess 693. When the arm end face 617 e contacts the bottom surface of the first recess 693, a gap 60 c is generated between the arm 61 and the housing 60.

In addition, the material used for each member of the 1st universal joint 6a and the 2nd universal joint 6b is not limited to the material mentioned above. The number of elastic members 67 provided in the first universal joint 6a and the second universal joint 6b is not particularly limited, and may be one or three or more. The first universal joint 6a and the second universal joint 6b may not necessarily have the same structure.

The first universal joint 6 a and the second universal joint 6 b may not necessarily be used for the expansion and contraction link 2. The expansion link 2 is an example of an object to which the first universal joint 6 a and the second universal joint 6 b are applied. For example, the first universal joint 6a and the second universal joint 6b can be applied to parts other than the suspension 1 of the vehicle 10, and can be applied to devices other than the vehicle 10.

As shown in FIG. 3, the actuator 5 includes a motor 51, a screw shaft 57, a bearing unit 55, a nut 59, a retaining ring 58, and a clutch 7.

As shown in FIG. 6, the motor 51 is disposed at the end of the fixed shaft 3 opposite to the movable shaft 4. The motor 51 is fixed to the fixed shaft 3. The motor 51 is provided with an encoder for detecting the rotation angle of the rotor. A shaft 511 that rotates with the rotor of the motor 51 extends toward the inside of the fixed shaft 3.

The screw shaft 57 is coupled to the shaft 511 via the clutch 7. The screw shaft 57 rotates with the shaft 511 around the rotation axis Z. A part of the screw shaft 57 is inserted into the movable shaft 4. The tip of the screw shaft 57 is located in the internal space 40 of the movable shaft 4. The screw shaft 57 passes through the nut 59.

The bearing unit 55 supports the screw shaft 57 to be rotatable with respect to the fixed shaft 3. The bearing unit 55 is fixed to the fixed shaft 3 and incorporates a bearing 551. The bearing 551 is fitted on the outer peripheral surface of the screw shaft 57.

As shown in FIG. 6, the nut 59 is fixed to the movable shaft 4 by a retaining ring 58 and moves together with the movable shaft 4. The nut 59 includes two radially projecting protrusions 591. The protrusion 591 is fitted in a recess 49 provided on the end face of the movable shaft 4. Thereby, the rotation of the nut 59 is restricted. The retaining ring 58 is fitted in a substantially annular groove provided on the inner circumferential surface of the movable shaft 4 and positions the nut 59 in the axial direction.

FIG. 13 is a cross-sectional view taken along the line DD in FIG. FIG. 14 is an exploded perspective view of the clutch of the present embodiment.

As shown in FIGS. 13 and 14, the clutch 7 includes an input side member 71, a first brake shoe 73, a second brake shoe 75, a brake drum 77, an engaging element 79, and an elastic member 74. Prepare.

As shown in FIG. 14, the input side member 71 is a substantially cylindrical member, and is attached to the shaft 511. The input side member 71 includes a key groove 715, a main body 710, a first pin 711 and a second pin 712. The main body 710 is substantially cylindrical along the shaft 511 and has a key groove 715. The shaft 511 comprises a key 515 which is an axially extending projection. The key 515 fits into the key groove 715. Thereby, the input side member 71 rotates with the shaft 511. The first pin 711 and the second pin 712 protrude from the end face of the main body 710 toward the screw shaft 57. The second pin 712 is disposed on the opposite side to the first pin 711 with respect to the rotation axis Z. As shown in FIG. 13, in a cross section obtained by cutting the first pin 711 and the second pin 712 in a plane orthogonal to the rotation axis Z, the radially outer surface of the first pin 711 is an arc. The radially inner surface of the first pin 711 is a flat surface. The outer shape of the second pin 712 in the cross section of FIG. 13 is point-symmetrical to the outer shape of the first pin 711 about the rotation axis Z.

As shown in FIG. 13, the first brake shoe 73 is a substantially semi-cylindrical member. The first brake shoe 73 includes a first fitting portion 730, a first engagement groove 731 and two first elastic member grooves 733. The first fitting portion 730 is a hole penetrating in the axial direction. The first fitting portion 730 can also be referred to as a first hole. The first pin 711 is fitted in the first fitting portion 730. The first engagement groove 731 and the first elastic member groove 733 are grooves provided on the surface on the second brake shoe 75 side. A first engagement groove 731 is disposed between the two first elastic member grooves 733. The first engagement groove 731 extends over the entire length of the first brake shoe 73 in the axial direction. The first elastic member groove 733 is disposed at the axial center of the first brake shoe 73. The first fitting portion 730 may not necessarily be a hole, and may be, for example, a recess.

As shown in FIG. 13, the second brake shoe 75 is a substantially semi-cylindrical member. The second brake shoe 75 includes a second fitting portion 750, a second engagement groove 751, and two second elastic member grooves 753. The second fitting portion 750 is a hole penetrating in the axial direction. The second fitting portion 750 can also be referred to as a second hole. The second pin 712 is fitted in the second fitting portion 750. The second engagement groove 751 and the second elastic member groove 753 are grooves provided on the surface on the first brake shoe 73 side. The second engagement groove 751 is disposed between the two second elastic member grooves 753. The second engagement groove 751 extends over the entire axial length of the second brake shoe 75. The second elastic member groove 753 is disposed at the axial center of the second brake shoe 75. The second fitting portion 750 may not necessarily be a hole, and may be, for example, a recess.

As shown in FIG. 13, an oval-shaped gap is formed by the first engagement groove 731 and the second engagement groove 751 when viewed from the axial direction. Also, a cylindrical gap is formed by the first elastic member groove 733 and the second elastic member groove 753.

The brake drum 77 is a member for braking the first brake shoe 73 and the second brake shoe 75. As shown in FIG. 13, the brake drum 77 includes a base 771 and two arms 773. The base 771 is cylindrical with a hole 770. The first brake shoe 73 and the second brake shoe 75 are inserted into the hole 770. The inner circumferential surface of the base 771 faces the outer circumferential surface of the first brake shoe 73 and the outer circumferential surface of the second brake shoe 75. The arm 773 is a plate-like member protruding from the outer peripheral surface of the base 771. The two arms 773 extend in opposite directions. The arm 773 fits in a recess 327 provided in the second member 32 shown in FIG. The brake drum 77 is fixed to the fixed shaft 3 by the arm 773 being sandwiched between the first member 31 and the second member 32. Therefore, the brake drum 77 does not rotate.

The engaging element 79 is attached to the screw shaft 57 and rotates with the screw shaft 57. As shown in FIG. 13, the engaging element 79 viewed in the axial direction has an oval shape. The engagement element 79 fits in the gap formed by the first engagement groove 731 and the second engagement groove 751.

The elastic member 74 is, for example, a compression coil spring. The elastic member 74 is disposed in the gap formed by the first elastic member groove 733 and the second elastic member groove 753. The elastic member 74 applies a force in a direction away from each other to the first brake shoe 73 and the second brake shoe 75.

When the motor 51 is driven, the input side member 71 rotates with the shaft 511. The rotation of the first pin 711 and the second pin 712 of the input side member 71 applies a force to the first brake shoe 73 and the second brake shoe 75 in a direction approaching each other. Thus, the engagement element 79 is gripped by the first brake shoe 73 and the second brake shoe 75. The rotation of the shaft 511 is transmitted to the screw shaft 57 as the first brake shoe 73, the second brake shoe 75, and the engaging element 79 rotate integrally.

On the other hand, when the motor 51 is stopped, an external force may be applied to the movable shaft 4. When an external force in the axial direction is applied to the movable shaft 4, the screw shaft 57 rotates. When the engaging element 79 rotates with the screw shaft 57, forces are applied to the first brake shoe 73 and the second brake shoe 75 in a direction away from each other. Thereby, the first brake shoe 73 and the second brake shoe 75 are pressed against the brake drum 77. The frictional force regulates the rotation of the first brake shoe 73 and the second brake shoe 75. For this reason, the engaging element 79 and the screw shaft 57 can not rotate. Therefore, even when an external force is applied to the movable shaft 4 when the motor 51 is stopped, the movement of the movable shaft 4 is restricted. That is, it is not necessary to supply power to the motor 51 in order to generate a reaction force for holding the position of the movable shaft 4. For example, the external force applied to the movable shaft 4 when the motor 51 is stopped is an external force transmitted to the movable shaft 4 when the wheel 102 contacts a curb or the like when the vehicle 10 is parked. The external force received by the wheel 102 from a curb or the like is transmitted to the movable shaft 4, and the screw shaft 57 is rotated.

The clutch 7 may not necessarily include the elastic member 74. In this case, the first elastic member groove 733 and the second elastic member groove 753 may be omitted. Also, the shape of the engaging element 79 viewed in the axial direction may not necessarily be oval, and may not be at least circular. That is, the distance from the rotation axis Z to the outer peripheral surface of the engaging element 79 may not be constant.

The control device 9 illustrated in FIG. 1 is a computer, and includes, for example, a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), an input interface, and an output interface. The control device 9 is, for example, an ECU (Electronic Control Unit) mounted on the vehicle 10. The control device 9 is electrically connected to the motor 51 of each telescopic link 2. The control device 9 controls each motor 51 individually. Thereby, the length (the position of each movable shaft 4) of each expansion-contraction link 2 changes.

The suspension 1 of the present embodiment is provided with five telescopic links 2 for one wheel 102. The suspension 1 can change the toe angle, the camber angle, the caster angle, the tread width, and the wheel base by changing the length of each telescopic link 2. The toe angle is an angle formed by a straight line orthogonal to the rotation axis of the wheel 102 with respect to a straight line parallel to the longitudinal direction of the vehicle when the vehicle 10 is viewed from the vertical direction. The camber angle is an angle formed by a straight line perpendicular to the rotation axis of the wheel 102 with respect to the vertical line when the vehicle 10 is viewed from the front-rear direction. The caster angle is an angle formed by a straight line parallel to the longitudinal direction of the shock absorber 11 with respect to the vertical line when the vehicle 10 is viewed from the left and right direction. The tread width is the distance between the centers of the left and right wheels 102. The wheel base is the center-to-center distance of the front and rear wheels 102.

The suspension 1 may not necessarily be applied to a vehicle having a hub unit 101 incorporating a motor or the like. The suspension 1 may be connected to a hub carrier provided with a hub bearing supporting the wheel 102.

The suspension 1 may not necessarily include the five telescopic links 2. The suspension 1 may include a plurality of links, and at least one of the plurality of links may be the telescopic link 2.

As described above, the suspension 1 includes a plurality of links connecting the vehicle body side member 18 and the hub carrier 19. At least one of the plurality of links is a telescopic link 2. The expansion link 2 includes a fixed shaft 3, a first universal joint 6 a connecting the fixed shaft 3 to the vehicle side member 18 so as to be rotatable and swingable relative to the vehicle side member 18, and a slide relative to the fixed shaft 3 Movable shaft 4, a second universal joint 6 b connecting the movable shaft 4 to the hub carrier 19 so as to be rotatable and swingable with respect to the hub carrier 19, fixed to the fixed shaft 3 to move the movable shaft 4 And an actuator 5.

Thereby, the suspension 1 can change the attitude of the wheel 102 by moving the movable shaft 4. The suspension 1 can facilitate changing the relative attitude of the wheel 102 with respect to the vehicle body.

The suspension 1 also includes five telescopic links 2.

Thus, the suspension 1 can change the toe angle, the camber angle, the caster angle, the tread width and the wheel base by moving the movable shaft 4. The suspension 1 can make it easier to change the relative attitude of the wheel 102 with respect to the vehicle body.

The telescopic link 2 has a cylindrical fixed shaft 3 and a first universal joint 6a connecting the fixed shaft 3 to the vehicle side member 18 so as to be rotatable and swingable with respect to the vehicle side member 18; A movable shaft 4 located inside the shaft 3 and slidable with respect to the fixed shaft 3 and a second universal joint 6b connecting the movable shaft 4 to the hub carrier 19 so as to be rotatable and swingable with respect to the hub carrier 19 And the actuator 5. The actuator 5 has a motor 51 attached to the fixed shaft 3, a screw shaft 57 rotated by the motor 51, and a nut 59 engaged with the screw shaft 57 and fixed to the movable shaft 4. The movable shaft 4 has a first flat surface 41, a second flat surface 42 at an angle to the first flat surface 41, a third flat surface 43 opposite to the first flat surface 41, and an opposite side of the second flat surface 42. And a fourth flat surface 44 located on the The fixed shaft 3 includes a first bush 351 in contact with the first plane 41, a second bush 352 in contact with the second plane 42, a third bush 353 in contact with the third plane 43, and a fourth bush in contact with the fourth plane 44. A third elastic member 363 presses the third bush 353 against the third flat surface 43, and a second elastic member 364 presses the fourth bush 354 against the fourth flat surface 44.

As a result, the attitude of the wheel 102 can be changed by moving the movable shaft 4 connected to the hub carrier 19. The telescopic link 2 can facilitate changing the relative attitude of the wheel 102 with respect to the vehicle body.

Further, the first elastic member 363 and the second elastic member 364 keep the first bush 351, the second bush 352, the third bush 353 and the fourth bush 354 in contact with the movable shaft 4. For this reason, the rattling of the movable shaft 4 is suppressed without requiring high processing accuracy. The telescopic link 2 can smooth the movement of the movable shaft 4.

Further, in the expansion link 2, the connecting portion (fastening portion 611) of the first universal joint 6 a with the vehicle body side member 18 and the connecting portion (fastening portion 611) of the second universal joint 6 b with the hub carrier 19 have screw shafts 57. And the third bush 353 and the fourth bush 354 are on the same side with respect to a plane including the rotation axis Z (e.g., the plane PZ shown in FIG. 8).

According to the positional relationship between the fixed shaft 3, the first universal joint 6a, the movable shaft 4 and the second universal joint 6b, a force directed to the first bush 351 and the second bush 352 is applied to the movable shaft 4 as the movable shaft 4 moves. Works. Even in such a case, the gap between the third bush 353 and the third flat surface 43 and the gap between the fourth bush 354 and the fourth flat surface 44 by the first elastic member 363 and the second elastic member 364 It becomes difficult to form a gap. For this reason, even when a force in the radial direction is applied to the movable shaft 4, the expansion / contraction link 2 can suppress rattling of the movable shaft 4.

Further, in the expansion link 2, an angle α between the first plane 41 and the second plane 42 and an angle β between the third plane 43 and the fourth plane 44 are acute angles.

For example, the movable shaft 4 may be deformed by a wheel load or the like received by the wheel 102 while the vehicle 10 is traveling (in particular, turning). In particular, deformation of the movable shaft 4 may occur around an axis parallel to the plane PZ shown in FIG. 8 and orthogonal to the rotation axis Z (about an axis parallel to the vertical direction of the paper surface in FIG. 8). The section coefficient of the movable shaft 4 with respect to the axis when the angles α and β are acute is larger than the section coefficient of the movable shaft 4 with respect to the axis when the angles α and β are obtuse. Thereby, the rigidity of the movable shaft 4 with respect to the moment applied to the movable shaft 4 is increased. For this reason, since the deformation of the movable shaft 4 is suppressed, the movement of the movable shaft 4 becomes smoother.

In the expansion link 2, each of the first bush 351, the second bush 352, the third bush 353, and the fourth bush 354 includes a plurality of lubricant grooves 35d filled with a lubricant.

As a result, the lubricant around the movable shaft 4 is less likely to be exhausted, so the movement of the movable shaft 4 becomes smoother. Further, since the deformation of the movable shaft 4 is suppressed by the acute angles α and β, the lubricant around the movable shaft 4 is applied to the movable shaft 4.

Further, the suspension 1 including the above-described expansion / contraction link 2 can smooth the movement of the wheel 102 by the rattle-suppressed movable shaft 4.

The universal joint (the first universal joint 6 a or the second universal joint 6 b) is located between the housing 60, the arm 61 partially located inside the housing 60, and the inner peripheral surface of the housing 60 and the arm 61. An outer bush 63, an inner bush 65 positioned on the opposite side of the arm 61 with respect to the outer bush 63, and a support member 69 supporting the inner bush 65 are provided. The arm 61 includes an arm convex surface 617p which is a spherical convex surface and an arm concave surface 617q which is a spherical concave surface. The outer bush 63 includes a bush concave surface 63q which is a spherical concave surface in contact with the arm convex surface 617p. The inner bush 65 includes a bush convex surface 651p which is a spherical convex surface in contact with the arm concave surface 617q.

If a ball joint having a conventional ball and socket is used, it is necessary to increase the diameter of the ball in order to widen the range of motion and to increase the allowable load. On the other hand, in the universal joint (the first universal joint 6a or the second universal joint 6b) of this embodiment, the arm 61 is sandwiched between the bush concave surface 63q of the outer bush 63 and the bush convex face 651p of the inner bush 65. Is held by. As a result, the contact area of the arm 61 with the outer bush 63 and the contact area of the arm 61 with the inner bush 65 can be easily maintained constant, so that the allowable load of the universal joint is increased. For this reason, even when the range of motion is increased and the allowable load is increased, the universal joint is smaller than the ball joint. Therefore, the universal joint can widen the range of motion and facilitate miniaturization.

The universal joint (the first universal joint 6 a or the second universal joint 6 b) further includes an elastic member 67 that pushes the inner bush 65 toward the arm 61.

As a result, the gap between the arm 61 and the inner bush 65 and the gap between the arm 61 and the outer bush 63 are less likely to occur. For this reason, rattling in the universal joint (the first universal joint 6a or the second universal joint 6b) is suppressed. As a result, since the attitude of the wheel 102 is stabilized, the traveling stability of the vehicle 10 is improved.

Further, in the universal joint (the first universal joint 6a or the second universal joint 6b), the arm 61 includes an arm end surface 617e located between the arm convex surface 617p and the arm concave surface 617q. When the arm end face 617 e is in contact with the support member 69, there is a gap 60 c between the arm 61 and the housing 60.

This reduces the bending stress applied to the arm 61 when the arm 61 is maximally inclined with respect to the housing 60. For this reason, breakage of the arm 61 is suppressed.

In the universal joint (the first universal joint 6 a or the second universal joint 6 b), the housing 60 is provided with a female screw 601. The support member 69 includes an external thread 691 that engages with the internal thread 601. That is, the support member 69 is fixed to the housing 60 by the engagement of the male screw 691 and the female screw 601.

Thereby, the supporting member 69 is fixed to the housing 60 at low cost as compared with the case where the supporting member 69 is fixed to the housing 60 by caulking the housing 60 or when the supporting member 69 is fixed to the housing 60 by welding. it can. In addition, the size of the gap 60c between the arm 61 and the housing 60 can be adjusted. Thereby, the universal joint (the first universal joint 6 a or the second universal joint 6 b) can suppress the arm 61 from interfering with the housing 60.

In the expansion link 2, at least one of the first universal joint 6a and the second universal joint 6b is the universal joint described above.

Thereby, since the movable range of the first universal joint 6a or the second universal joint 6b is wide, the expansion link 2 can easily change the relative attitude of the wheel 102 with respect to the vehicle body.

Further, since the universal joint (the first universal joint 6a or the second universal joint 6b) is small, it is possible to arrange a plurality of universal joints in the suspension 1 in close proximity. For this reason, since the suspension 1 can be provided with a plurality of telescopic links 2, it is possible to easily change the relative attitude of the wheel 102 with respect to the vehicle body.

In the expansion link 2, the actuator 5 engages with a motor 51 attached to the fixed shaft 3, a screw shaft 57 rotated by the motor 51, a clutch 7 disposed between the motor 51 and the screw shaft 57, and a screw shaft 57 It has a nut 59 fixed to the movable shaft 4. The clutch 7 includes an input side member 71, a first brake shoe 73, a second brake shoe 75, a brake drum 77, and an engaging element 79. The input member 71 rotates with the shaft 511 of the motor 51 and has a first pin 711 and a second pin 712. The first brake shoe 73 has a first fitting portion 730 in which the first pin 711 is fitted. The second brake shoe 75 has a second fitting portion 750 in which the second pin 712 is fitted, and is located opposite to the first brake shoe 73 with respect to the rotation axis Z of the screw shaft 57. The brake drum 77 has an inner circumferential surface facing the outer circumferential surface of the first brake shoe 73 and the second brake shoe 75 and is fixed to the fixed shaft 3. It rotates together with the screw shaft 57 and fits in the gap between the first brake shoe 73 and the second brake shoe 75.

Thereby, the telescopic link 2 can change the attitude of the wheel 102 by moving the movable shaft 4. The telescopic link 2 can facilitate changing the relative attitude of the wheel 102 with respect to the vehicle body. Furthermore, when the screw shaft 57 is rotated by the external force applied to the movable shaft 4, forces in the direction of separating from each other are applied to the first brake shoe 73 and the second brake shoe 75 by the engaging element 79. As a result, the first brake shoe 73 and the second brake shoe 75 are pressed against the brake drum 77, so that the engaging element 79 and the screw shaft 57 can not rotate. Therefore, even when an external force is applied to the movable shaft 4 when the motor 51 is stopped, the movement of the movable shaft 4 is restricted. The expansion link 2 can facilitate maintenance of the relative attitude of the wheel 102 with respect to the vehicle body. When the position of the movable shaft 4 is held, power supply to the motor 51 is unnecessary. The expansion and contraction link 2 can suppress power consumption.

The telescopic link 2 also includes an elastic member 74 that applies a force in a direction away from each other to the first brake shoe 73 and the second brake shoe 75.

Thereby, even when the engaging element 79 does not push the first brake shoe 73 and the second brake shoe 75, the elastic member 74 presses the first brake shoe 73 and the second brake shoe 75 against the brake drum 77. For this reason, the telescopic link 2 has the first brake shoe 73 and the second brake due to the gap between the engaging element 79 and the first brake shoe 73 and the gap between the engaging element 79 and the second brake shoe 75. The rattling of the shoes 75 can be suppressed.

Further, the suspension 1 including the actuator 5 described above can suppress power consumption of the vehicle by the presence of the clutch 7.

(First modification)
FIG. 15 is a perspective view of the suspension of the first modification. FIG. 16 is a perspective view of the fixed link. In addition, the same code | symbol is attached | subjected to the same component as what was demonstrated in embodiment mentioned above, and the overlapping description is abbreviate | omitted. In FIG. 15, the shock absorber 11 is omitted.

As shown in FIG. 15, the suspension 1 </ b> A of the first modification includes three telescopic links 2 and two fixed links 20. Two telescopic links 2 are disposed above the rotation axis of the wheel 102. Two fixed links 20 are disposed below the rotation axis of the wheel 102, and one telescopic link 2 is disposed below the two fixed links 20.

As shown in FIG. 16, the fixed link 20 includes a bridge portion 201, a first universal joint 6a, and a second universal joint 6b. The bridge portion 201 is a member that does not expand and contract. A first universal joint 6 a is provided at one end of the bridge portion 201, and a second universal joint 6 b is provided at the other end of the bridge portion 201. The fixed link 20 can not expand and contract, but can rotate and swing relative to the vehicle body side member 18 and the hub carrier 19.

The suspension 1A of the first modification can change the toe angle and the camber angle by changing the lengths of the respective expansion and contraction links 2, but is not suitable for changing the caster angle, the tread width and the wheel base. On the other hand, the suspension 1A of the first modification can be easily manufactured and easily controlled as compared with the above-described suspension 1.

(2nd modification)
FIG. 17 is a perspective view of the suspension of the second modification. In addition, the same code | symbol is attached | subjected to the same component as what was demonstrated in embodiment mentioned above, and the overlapping description is abbreviate | omitted. In FIG. 17, the shock absorber 11 is omitted.

As shown in FIG. 17, the suspension 1 </ b> B of the second modification includes two telescopic links 2 and three fixed links 20. Two telescopic links 2 are disposed above the rotation axis of the wheel 102. Three fixed links 20 are disposed below the rotation axis of the wheel 102.

The suspension 1B can change the toe angle by changing the length of each telescopic link 2, but is not suitable for changing the camber angle, caster angle, tread width, and wheel base. On the other hand, the suspension 1B can be easily manufactured and easily controlled as compared with the suspension 1A of the first modification described above. The suspension 1B is suitable for steering the left and right wheels 102 independently.

(Third modification)
FIG. 18 is a perspective view of a suspension according to a third modification. In addition, the same code | symbol is attached | subjected to the same component as what was demonstrated in embodiment mentioned above, and the overlapping description is abbreviate | omitted. In FIG. 18, the shock absorber 11 is omitted.

As shown in FIG. 18, the suspension 1 </ b> C of the third modification includes two telescopic links 2 and three fixed links 20. Two fixed links 20 are disposed above the rotation axis of the wheel 102. Two telescopic links 2 are disposed below the rotation axis of the wheel 102, and one fixed link 20 is disposed below the two telescopic links 2.

The suspension 1C can change the toe angle by changing the lengths of the respective expansion and contraction links 2, but is not suitable for changing the camber angle, the caster angle, the tread width, and the wheel base. On the other hand, the suspension 1C can be easily manufactured and easily controlled as compared with the suspension 1A of the first modification. The suspension 1C is suitable for steering the left and right wheels 102 independently.

In the suspension 1C, the distance between the second universal joints 6b of the two telescopic links 2 is large as compared with the suspension 1B of the second modification. Therefore, when the force applied to the movable shaft 4 is the same, in the suspension 1C, the torque applied to the wheel 102 is increased when changing the toe angle. On the other hand, when the maximum movement distance of the movable shaft 4 is the same, the toe angle that can be realized by the suspension 1C is smaller than the toe angle that can be realized by the suspension 1B of the second modification.

1, 1A, 1B, 1C Suspension 10 Vehicle 101 Hub unit 102 Wheel 11 Shock absorber 18 Vehicle side member 19 Hub carrier 2 Telescopic link 20 Fixed link 201 Bridge part 3 Fixed shaft 31 1st member 311 1st opposing surface 311d Recess 312 2 facing surface 312 d recess 315 groove 32 second member 323 third facing surface 323 d recess 324 fourth facing surface 324 d recess 351 first bush 352 second bush 353 third bush 354 fourth bush 363 first elastic member 364 second elasticity Member 4 Movable shaft 40 Internal space 41 1st plane 42 2nd plane 43 3rd plane 44 4th plane 45 Stopper 5 Actuator 51 Motor 511 Shaft 515 Key 55 Bearing unit 57 Screw shaft 58 Retaining ring 59 Nut 6a 1st self Joint 6b Second universal joint 60 Housing 60c Gap 61 Arm 611 Fastening part 613 Flange part 615 Intermediate part 617 Sliding part 617e Arm end face 617p Arm convex surface 617q Arm concave surface 63 Outer bush 63 q Bush concave surface 65 Inner bush 651 Head 651 p Bush convex surface 653 Body 67 Elastic member 69 Support member 691 Male thread 693 1st concave portion 695 2nd concave portion 7 Clutch 71 Input side member 710 Main body 711 1st pin 712 2nd pin 715 Key groove 73 1st brake shoe 730 1st fitting portion 731 1 engaging groove 733 first elastic member groove 74 elastic member 75 second brake shoe 750 second fitting portion 751 second engaging groove 752 second elastic member groove 77 brake drum 79 engaging element 9 control device Z rotation shaft

Claims

A plurality of links connecting the vehicle body side member and the hub carrier;
At least one of the plurality of links is a telescopic link,
The telescopic link is
With a fixed shaft,
A first universal joint connecting the fixed shaft to the vehicle body side member so as to be rotatable and swingable with respect to the vehicle body side member;
A movable shaft that can slide relative to the fixed shaft;
A second universal joint coupling the movable shaft to the hub carrier for rotation and rocking relative to the hub carrier;
An actuator fixed to the fixed shaft to move the movable shaft;
A suspension characterized by comprising.
The suspension according to claim 1, comprising five of the telescopic links.