JP2014015063A - Vehicle suspension device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle suspension device capable of realizing a low-floor vehicle body structure.SOLUTION: This vehicle suspension device 10 includes: a torsion bar 56 which is extended in a vehicle width direction, connected to a front end of an upper side trailing link 42 at one end in the longitudinal direction, connected to a vehicle body 20 at the other end in the longitudinal direction, and twisted and deformed accompanying the rotation of the upper side trailing link 42; and a rotary damper 58 for which a movable part 120 connected to the upper side trailing link 42 is connected relatively rotatably to a fixed part 122 connected to the vehicle body 20, and which attenuates the relative rotation of the fixed part 122 and the movable part 120 accompanying the rotation of the upper side trailing link 42.

Description

  The present invention relates to a vehicle suspension device used on the rear wheel side of an automobile.

  In the three-wheel electric vehicle shown in Patent Document 1 below, the rear wheel is connected to the vehicle body frame via a swing arm type suspension including a swing arm and a rear wheel suspension. The rear wheel suspension extends from the front end side of the swing arm to the vehicle upper side, and has an upper end connected to the vehicle body frame.

JP 2008-68808 A

  The rear wheel suspension as described above is generally constituted by a coil spring and a shock absorber, but installation of these components requires a long space vertically. Further, in order to support the upper end portion of the shock absorber, a strong structure such as a vehicle body frame is required above the shock absorber. For this reason, it becomes difficult to realize a low-floor vehicle body structure.

  An object of the present invention is to obtain a vehicle suspension device that can realize a low-floor vehicle body structure in consideration of the above facts.

  A vehicle suspension device according to a first aspect of the present invention includes a rear wheel support member that rotatably supports a rear wheel of an automobile, and a front end connected to the vehicle body so as to be rotatable about an axis along the vehicle width direction. And a trailing link that is connected to the rear wheel support member so as to be rotatable about an axis along the vehicle width direction, and extends in the vehicle width direction. A torsion bar that is connected to the front end portion of the trailing link and the other end portion in the longitudinal direction is connected to the vehicle body and is torsionally deformed as the trailing link rotates, and a movable portion connected to the trailing link is a vehicle body. And a rotary damper that is connected to the fixed portion connected to each other so as to be relatively rotatable and attenuates relative rotation between the fixed portion and the movable portion that accompanies the rotation of the trailing link.

  In the vehicle suspension device according to claim 1, when the trailing link rotates about the axis along the vehicle width direction with respect to the vehicle body about the front end portion connected to the vehicle body as the rotation center, the trailing link is moved to the rear end portion of the trailing link. The rear wheel connected via the wheel support member moves up and down with respect to the vehicle body. At this time, the torsion bar is torsionally deformed along with the rotation of the trailing link to absorb the impact, and the rotary damper attenuates the relative rotation of the movable part with respect to the fixed part, thereby causing the rear wheel to move up and down (vibration). Is attenuated.

  Here, since the above-mentioned torsion bar is spanned along the vehicle width direction between the front end portion of the trailing link and the vehicle body, the space occupied in the vertical direction can be reduced. Further, since the rotary damper described above is such that the movable part rotates relative to the fixed part as the trailing link rotates about the axis along the vehicle width direction, the shock absorber of the swing arm suspension described above In comparison, the occupied space in the vertical direction can be reduced. As a result, a low-floor vehicle body structure can be realized.

  A vehicle suspension apparatus according to a second aspect of the present invention is the vehicle suspension apparatus according to the first aspect, wherein the rotary damper has a rotation center of the movable part with respect to the fixed part as a rotation center of the trailing link with respect to a vehicle body. The movable part is connected to the trailing link on the vehicle rear side of the center of rotation of the trailing link.

  In the vehicle suspension device according to the second aspect, the rotary damper is arranged such that the rotation center of the movable portion relative to the fixed portion is coaxial with the rotation center of the trailing link relative to the vehicle body. The movable portion is connected to the trailing link on the vehicle rear side of the trailing link rotation center, that is, on the side where the trailing link extends from the vehicle body. Thereby, since the movable part can be rotated integrally with the trailing link, the configuration for transmitting the rotation of the upper trailing link to the movable part can be made simple and small.

  A vehicle suspension device according to a third aspect of the present invention is the vehicle suspension device according to the first or second aspect, wherein the torsion bar passes coaxially through the movable portion and the fixed portion of the rotary damper. doing.

  In the vehicle suspension device according to the third aspect of the present invention, the occupied space of the torsion bar and the rotary damper is shared by the above configuration, so that the occupied space of both can be substantially reduced. Moreover, since the torsion bar and the rotary damper can be unitized (sub-assembled), manufacturing efficiency can be improved.

  A vehicle suspension apparatus according to a fourth aspect of the present invention is the vehicle suspension apparatus according to the first or second aspect, wherein the torsion bar is disposed in front of the rear wheel support member, and the rotary The damper is disposed on the opposite side of the torsion bar via a connecting portion between the torsion bar and the trailing link.

  In the vehicle suspension device according to the fourth aspect, the torsion bar is disposed in front of the rear wheel support member on the vehicle, that is, on the same side as the rear wheel with respect to the trailing link. It is possible not to overhang to one side in the vehicle width direction. Further, since the rotary damper is disposed on the opposite side of the torsion bar via the connecting portion between the torsion bar and the trailing link, the torsion bar and the rotary damper can be disposed in a well-balanced manner in the vehicle width direction. .

  A vehicle suspension apparatus according to a fifth aspect of the present invention is the vehicle suspension apparatus according to the fourth aspect, wherein the trailing link includes a pair of left and right arms extending to the front side of the vehicle, and the rotary damper is And between the front end portions of the pair of arm portions.

  In the vehicle suspension device according to the fifth aspect, the rotary damper is disposed between the front end portions of the pair of left and right arms provided in the trailing link. That is, since the space occupied by the trailing arm and the rotary damper is shared, the space occupied by the rotary damper can be substantially reduced.

  A vehicle suspension apparatus according to a sixth aspect of the present invention is the vehicle suspension apparatus according to any one of the first to fifth aspects, wherein the trailing link is an upper trailing link, A lower trailing link is provided below the ring link, and the lower trailing link is connected to the front end portion so as to be rotatable about an axis along the vehicle width direction with respect to the vehicle body. A rear end portion is connected to the rear wheel support member so as to be rotatable about an axis along the vehicle width direction.

  In the vehicle suspension device according to claim 6, the rear wheel support member that rotatably supports the rear wheel is connected to the vehicle body via the upper trailing link and the lower trailing link. A suspension is constructed. A torsion bar and a rotary damper are connected to the upper trailing link. Since these torsion bars and rotary damper can reduce the space occupied in the vertical direction as described above, a low-floor vehicle body structure can be realized even in a configuration connected to the upper trailing link.

  The vehicle suspension device according to a seventh aspect of the present invention is the vehicle suspension device according to any one of the first to sixth aspects, wherein the rotary damper is configured to rotate the movable portion relative to the fixed portion. The friction type generates a friction force between the two.

  In the vehicle suspension device according to the seventh aspect, since the rotary damper is a friction type, the rotary damper can have a simple configuration.

  As described above, in the vehicle suspension device according to the present invention, a low-floor vehicle body structure can be realized.

1 is a perspective view of a three-wheeled electric vehicle configured by applying a vehicle suspension device according to a first embodiment of the present invention. It is a perspective view which shows the structure of the peripheral member containing the vehicle suspension apparatus which concerns on 1st Embodiment of this invention. It is the perspective view which looked at the same structure as FIG. 2 from another angle. FIG. 3 is a side view of the same configuration as FIG. 2 viewed from the left side of the vehicle. FIG. 3 is a partial cross-sectional view of the same configuration as FIG. 2 viewed from the vehicle rear side. FIG. 3 is a partial cross-sectional view of the same configuration as that of FIG. 2 as viewed from the vehicle front side. It is sectional drawing which shows the structure of the periphery of the upper side rubber bush which is a structural member of the vehicle suspension apparatus. The rotary damper which is a structural member of the vehicle suspension apparatus is shown, (A) is a side view, and (B) is a plan view. It is a perspective view which shows the structure of the peripheral member containing the vehicle suspension apparatus which concerns on 2nd Embodiment of this invention. It is the perspective view which looked at the same structure as FIG. 9 from another angle. It is the fragmentary sectional view which looked at the same composition as Drawing 9 from the vehicles front side.

<First Embodiment>
Hereinafter, the vehicle suspension apparatus 10 according to the first embodiment of the present invention will be described with reference to FIGS. It should be noted that arrow FR, arrow UP, arrow LH, arrow RH, and arrow OUT, which are appropriately shown in each figure, respectively indicate the front of the vehicle (traveling direction), the upper side of the vehicle, the left side of the vehicle, the right side of the vehicle, and the outward side of the vehicle width. ing. Hereinafter, when simply using the front-rear, left-right, and up-down directions, the front-rear direction in the vehicle front-rear direction, the left-right direction in the vehicle left-right direction, and the up-down direction in the vehicle up-down direction are indicated unless otherwise specified.

(Constitution)
FIG. 1 is a perspective view of a three-wheeled electric vehicle 12 provided with a vehicle suspension device 10 according to the present embodiment. The three-wheeled electric vehicle 12 is a three-wheeled electric vehicle having two front wheels and one rear wheel, and is configured to drive the left and right front wheels 16 steered by the steering 14 by a driving force of a motor (not shown). On the vehicle rear side of the left and right front wheels 16, a main frame 18 formed in a flat frame box shape by a material such as metal is provided. The main frame 18 constitutes the skeleton of the vehicle body 20 of the three-wheel electric vehicle 12. A rear frame 22 that constitutes the skeleton of the vehicle body 20 together with the main frame 18 is integrally fixed to the rear end portion of the main frame 18. The rear frame 22 includes a pair of upper and lower horizontal frame portions 24 and 26, and vertical frame portions 28, 30, and 32 that connect the upper and lower horizontal frame portions 24 and 26 in the vertical direction.

  As shown in FIGS. 2 to 6, the upper and lower horizontal frame portions 24 and 26 are formed by square pipes and extend along the vehicle width direction. Further, the vertical frame portion 28 disposed on the left end side of the vehicle is constituted by a pair of left and right connecting plates 34 and 36 arranged in the vehicle width direction. The left and right connecting plates 34 and 36 are formed in a U-shape (substantially U-shaped) with the opposite sides opened when viewed from the vehicle front-rear direction, and the left end sides of the upper and lower horizontal frame portions 24 and 26 are formed. It is connected vertically. Further, the vertical frame portion 30 disposed on the right end side of the vehicle is formed in a substantially U-shape (substantially U-shape) with the outer side in the vehicle width direction opened, and the upper and lower horizontal frame portions 24, 26 are arranged. The right end is connected vertically. Further, the vertical frame portion 32 arranged on the center side in the vehicle width direction is formed in a sun-shape (substantially B-shape) when viewed from the front-rear direction of the vehicle, and the vehicle width of the upper and lower horizontal frame portions 24, 26. A portion on the left side of the central portion in the direction is connected in the vertical direction.

  The vehicle suspension device 10 according to the present embodiment is provided between the rear frame 22 and the rear wheel 38 described above. The vehicle suspension device 10 includes a rear axle bracket 40 as a rear wheel support member that rotatably supports a rear wheel 38, an upper trailing link 42, an upper rubber bush 46 as an upper elastic body, and a lower trailing link. 48, a lower rubber bush 50 as a lower elastic body, a pair of left and right front rubber bushes 52, 54 as a front elastic body, a control link 55, a torsion bar (torsion shaft) 56, and a rotary damper 58 It is constituted by. Hereinafter, each component will be described.

  The rear axle bracket 40 includes a bracket body 60 formed in a plate shape from a material such as metal. A rear wheel 64 of the rear wheel 38 is rotatably attached to the bracket body 60 via an axle shaft (not shown), a hub 62 shown in FIG. A pair of upper and lower connecting portions 66 and 68 for connecting the upper trailing arm 42 and the lower trailing arm 48 are integrally or integrally provided on the opposite side of the bracket body 60 from the hub 62.

  The upper connecting portion 66 (hereinafter referred to as the upper connecting portion 66) is located on the upper side and the vehicle front side with respect to the wheel center S (see FIG. 4) of the rear wheel 38, and the upper end portion of the bracket body 60. To the vehicle width direction one side (the side opposite to the hub 62), and the front end side extends to the vehicle front side by bending the intermediate portion. As shown in FIG. 4, the lower connecting portion 68 (hereinafter referred to as the lower connecting portion 68) is located on the lower side and the vehicle front side with respect to the wheel center S of the rear wheel 38. It extends integrally from the lower end of the main body 60 downward. The upper connecting portion 66 and the lower connecting portion 68 are arranged in the vertical direction in the vehicle side view shown in FIG. 4, and the lower connecting portion 68 from the upper connecting portion 66 in the vehicle rear view shown in FIG. Also, the rear wheel 38 is offset to the tire ground contact center C side.

  Further, a rear extension 70 is integrally extended from the rear end of the bracket body 60 toward the vehicle rear side. A connecting piece 70A is provided at the rear end portion of the rearward extending portion 70 so as to protrude toward one side in the vehicle width direction (the side opposite to the hub 62). The connecting piece 70A is disposed away from the wheel center S of the rear wheel 38 on the vehicle rear side, and corresponds to a control link 55 described later.

  The upper trailing link 42 is configured by an A arm made of a metal pipe or the like, and has a pair of left and right arm portions 72 and 74 branched toward the vehicle front side. One arm portion 72 extends in the vehicle front-rear direction, and a front end portion is inserted between the lateral frame portions 24 and 26 of the rear frame 22. A cylindrical tubular portion 72A (see FIG. 6) whose axial direction is along the vehicle width direction is integrally provided at the front end portion of the arm portion 72, and a bearing is formed inside the tubular portion 72A. 77 is inserted. A connecting shaft 78 is fitted inside the inner ring of the bearing 77. The connecting shaft 78 extends in the vehicle width direction in the axial direction, and is fixed so as not to rotate relative to the vertical frame portion 32. A flange portion (large diameter portion) is provided at an intermediate portion in the axial direction of the connecting shaft 78, and the inner ring of the bearing 77 is supported by the flange portion. In addition, a connecting member 114 is attached to one end in the axial direction of the cylindrical portion 72A (the end opposite to the vertical frame portion 32). The connecting member 114 is formed in a truncated cone shape having a diameter that decreases toward the opposite side (here, the right side of the vehicle body) from the cylindrical portion 72A, and is coaxially and integrally fixed to the cylindrical portion 72A. ing. Further, a part of the connecting member 114 is inserted inside the cylindrical portion 72A, and the outer ring of the bearing 77 is supported by the part. Accordingly, the front end portion of the arm portion 72 is connected to the vehicle body 20 via the bearing 77 so as to be rotatable around the connecting shaft 78.

  Further, as shown in FIG. 2, a damper mounting portion 80 is provided on the front end side of the arm portion 72 and slightly behind the tubular portion 72A in the vehicle width direction so as to project to one side in the vehicle width direction (here, the vehicle left side). It has been. The damper mounting portion 80 corresponds to a rotary damper 58 described later.

  A cylindrical bearing portion 72B having an axial line direction along the vehicle width direction is integrally provided at the rear end portion of the arm portion 72. The bearing portion 72B is located on the side of the upper connecting portion 66 of the rear axle bracket 40, and the upper rubber bush 46 is attached to the bearing portion 72B.

  The upper rubber bush 46 is made of a rubber material and includes a cylindrical main body 46A fitted inside the bearing 72B as shown in FIG. The main body portion 46A is divided into right and left at the central portion in the axial direction, and is configured to be fitted to the bearing portion 72B from both sides in the vehicle width direction. Flange portions 46B and 46B having substantially the same diameter as the bearing portion 72B are provided at both axial ends of the main body portion 46A, and the bearing portion 72B is sandwiched from both sides in the vehicle width direction by these flange portions 46B and 46B. Yes.

  A connecting shaft 84 is inserted inside the upper rubber bush 46. One end of the connecting shaft 84 in the axial direction passes through the upper connecting portion 66, and nuts are screwed into male screw portions formed at both ends in the axial direction of the connecting shaft 84. Thus, the rear end portion of the arm portion 42 is coupled to the upper coupling portion 66 via the upper rubber bush 46 and the coupling shaft 84, and the arm portion 72 rotates around the coupling shaft 84 with respect to the rear axle bracket 40 (in the vehicle width direction). Around the axis line).

  The above-described upper rubber bush 46 is set such that the rigidity with respect to the lateral force (load in the vehicle width direction) acting on the rear wheel 38 is lower than the rigidity with respect to the longitudinal force (load in the vehicle longitudinal direction) acting on the rear wheel 38. Thus, it is configured to be easily deformed with respect to the lateral force and difficult to deform with respect to the longitudinal force. This rigidity characteristic is set by, for example, the relationship between the thickness dimension (thickness) T1 of the main body portion 46A and the thickness dimension (thickness) T2 of the flange portion 46B.

  As shown in FIG. 2, the rear end portion of the other arm portion 74 of the upper trailing link 42 is integrally joined to the rear end portion of the one arm portion 72. The other arm portion 74 is inclined with respect to the vehicle front-rear direction so as to move away from the one arm portion 72 toward the front end side, and the front end portion is bent toward the front of the vehicle. A ball joint 86 is attached to the front end portion of the other arm portion 74. The ball joint 86 is inserted between the pair of connecting plates 34 and 36 of the vertical frame portion 28 and is connected to the vertical frame portion 28 by connecting pins 88 (see FIG. 6) along the vehicle width direction. . Thereby, the front end part of the arm part 74 is connected with respect to the vehicle body 20 so that it can rotate freely (rotatable up and down, right and left).

  On the other hand, the lower trailing link 48 is disposed below the upper trailing link 42. Similar to the upper trailing link 42, the lower trailing link 48 is configured by an A arm made of a metal pipe or the like, and has a pair of left and right arm portions 90 and 92 branched toward the front side of the vehicle. ing. One arm portion 90 extends in the vehicle front-rear direction below the arm portion 72 of the upper trailing link 42, and the rear end portion is disposed on the side of the lower connection portion 68 of the rear axle bracket 40. A cylindrical bearing 90B having an axial direction along the vehicle width direction is integrally provided at the rear end of the arm 90. The bearing portion 90B has the same configuration as the above-described bearing portion 72B, and the lower rubber bush 50 is attached to the bearing portion 90B. The lower rubber bush 50 is configured in the same manner as the upper rubber bush 46 described above, and is fastened and fixed to the lower connecting portion 68 via a connecting shaft 94 inserted on the inner side in the same manner as the upper rubber bush 46. ing. Thus, the rear end portion of the arm portion 90 is connected to the lower connection portion 68 via the lower rubber bush 50 and the connection shaft 94, and the arm portion 90 is connected to the rear axle bracket 40 around the connection shaft 94 (the vehicle). It is possible to rotate around the axis along the width direction.

  Further, the front end portion of the arm portion 90 is located below the lateral frame portion 26 of the rear frame 22. A cylindrical bearing portion 90A (see FIG. 6) whose axial direction is along the vehicle width direction is integrally provided at the front end portion of the arm portion 90. The bearing portion 90A is shown in FIG. Thus, the front rubber bush 52 is attached. The front rubber bushing 52 has the same configuration as the upper rubber bushing 46 described above, and is attached to the bearing portion 90 </ b> A by the same mounting method as the upper rubber bushing 46. A pair of left and right brackets 98 are provided on both sides in the vehicle width direction of the front rubber bush 90A. These brackets 98 are made of sheet metal or the like bent in an L shape, and are fastened and fixed to the lower surface of the horizontal frame portion 26. A connecting shaft 100 penetrating these brackets 98 in the vehicle width direction is inserted into the front rubber bush 52. Both ends of the connecting shaft 100 in the axial direction are provided with male screw portions protruding to the outside of the left and right brackets 98 (opposite to the front rubber bush 52), and nuts are screwed into these male screw portions. Thus, the connecting shaft 100 is fastened and fixed to the left and right brackets 98. The connecting shaft 100 has an axial direction extending in the vehicle width direction, and the front end portion of the arm 90 is connected to the vehicle body 20 so as to be rotatable around the connecting shaft 100 (around the axis along the vehicle width direction).

  As shown in FIG. 2, the other arm portion 92 of the lower trailing link 48 is positioned below the arm portion 74 of the upper trailing link 42, and the rear end portion is behind the one arm portion 90. It is joined to the end side. The other arm portion 92 is inclined with respect to the vehicle front-rear direction so as to be separated from the one arm portion 90 toward the front end side, and the front end portion is bent toward the front of the vehicle. A cylindrical bearing portion 92A having an axial direction along the vehicle width direction is integrally provided at the front end portion of the other arm portion 92. The bearing portion 92A is located below the lateral frame portion 26 of the rear frame 22, and a front rubber bush 54 is attached to the bearing portion 92A as shown in FIG. The front rubber bush 54 has the same configuration as that of the front rubber bush 52 described above, and the bearing portion 92A is connected to the horizontal frame 26 via the front rubber bush 54, the left and right brackets 102, and the connecting shaft 104. Yes. The bracket 102 and the connecting shaft 104 have the same configuration as the bracket 98 and the connecting shaft 100 described above, and the front end portion of the arm portion 92 is around the connecting shaft 104 (around the axis along the vehicle width direction). The vehicle body 20 is rotatably connected.

  As described above, in this embodiment, the rear axle bracket 40 that rotatably supports the rear wheel 38 is connected to the vehicle body 20 via the upper trailing link 42 and the lower trailing link 48, and the double trailing link is provided. A suspension is constructed.

  On the other hand, the control link 55 includes a link main body 106 formed in a long cylindrical shape, and a pair of ball joints 108 and 110 attached to both ends in the longitudinal direction of the link main body 106. One ball joint 108 is attached to the connecting piece 70 </ b> A of the rear axle bracket 40 described above. Accordingly, one end portion (rear end portion) in the longitudinal direction of the control link 55 is rotatably connected to the rear axle bracket 40. The other ball joint 110 is attached to a bracket 112 attached to the lateral frame portion 26. Accordingly, the other end portion (front end portion) in the longitudinal direction of the control link 55 is rotatably connected to the vehicle body 20.

  The bracket 112 described above extends from the longitudinal end portion (here, the left end portion of the vehicle) of the lateral frame portion 26 toward the vehicle rear side. The control link 55 spanned between the bracket 112 and the connecting piece 70A of the rear axle bracket 40 extends in the vehicle front-rear direction in the vehicle side view, and in the vehicle width direction as it goes toward the front end in the vehicle plan view. It inclines with respect to the vehicle front-back direction so that it may go to one side (here vehicle left side).

  The torsion bar 56 is formed in a long cylindrical shape by spring steel, and is disposed between the horizontal frame portion 24 and the horizontal frame portion 26 with the axial direction extending in the vehicle width direction. The torsion bar 56 is disposed between the vertical frame portion 30 and the vertical frame portion 32 in front of the rear wheel 38 and the rear axle bracket 40 in the vehicle. One end of the torsion bar 56 in the axial direction (one end in the longitudinal direction) is connected to one end of the connecting member 114 in the axial direction (end on the reduced diameter side) so as not to be relatively rotatable by serration coupling. . As a result, one end portion in the axial direction of the torsion bar 56 is connected to the cylindrical portion 72A (the front end portion of the arm portion 72) of the upper trailing link 42 through the connecting member 114 so as to be integral and non-rotatable.

  The other end portion in the axial direction (the other end portion in the longitudinal direction) of the torsion bar 56 is connected to the vertical frame portion 30 via the connecting member 116. The connecting member 116 is formed in a cylindrical shape, and is arranged in a state where the axial direction extends in the vehicle width direction. As shown in FIG. 6, one end side in the axial direction of the connecting member 116 is rotatably fitted in a circular hole formed in the vertical frame portion 30. Thereby, the connecting member 116 is rotatably attached to the vertical frame portion 30. Further, one end of the connecting member 116 in the axial direction is integrally coupled with the other end of the torsion bar 56 in the axial direction being fitted inside. As a result, the other axial end portion of the torsion bar 56 and the connecting member 116 are connected so as not to be relatively rotatable, and the other axial end portion of the torsion bar 56 is connected to the vehicle body 20 via the connecting member 116. .

  Further, as shown in FIG. 3, a claw portion 116 </ b> A that protrudes downward (radially outward) is provided on the outer peripheral portion on the other axial end side of the connecting member 116. 116 C of this nail | claw part is contact | abutting from the vehicle rear side with the front-end | tip part of the adjustment bolt 118 attached to the lower end part of the vertical frame part 30. FIG. The adjustment bolt 118 is disposed in a state where the axial direction extends in the vehicle front-rear direction, and is screwed into a female screw portion formed at the lower end portion of the vertical frame portion 30. The adjustment bolt 118 restricts the relative rotation of the connecting member 116, that is, the other end portion in the axial direction of the torsion bar 56, around the axial line with respect to the vertical frame portion 30 (in the direction of arrow A in FIG. 3).

  On the other hand, the rotary damper 58 has a vertical frame portion on the side opposite to the torsion bar 56 (one longitudinal end side of the torsion bar 56) via the front end portion (tubular portion 72A) of the arm portion 72 of the upper trailing link 42. 28 and the vertical frame portion 32. The rotary damper 58 has a movable portion 120 fixed to the upper trailing link 42 and a fixed portion 122 fixed to the vehicle body 20 (connected so as not to be displaced).

  As shown in FIGS. 8A and 8B, the movable portion 120 includes a movable side plate 124 formed in a long shape by a sheet metal. The movable side plate 124 is arranged in a state where the longitudinal direction is along the longitudinal direction of the upper trailing link 42 (substantially the vehicle longitudinal direction) and the plate thickness direction is along the vehicle width direction. The rear portion 124A of the movable side plate 124 is fastened and fixed to the tip end portion of the above-described damper mounting portion 80 (see FIG. 2) by a pair of front and rear bolts.

  The fixed portion 122 includes four fixed side plates 126, 128, 130, and 132 that are formed in a substantially disc shape (here, a teardrop shape) by sheet metal. These fixed side plates 126, 128, 130, 132 are arranged in a state where the plate thickness direction is along the vehicle width direction. Between the fixed side plate 126 and the fixed side plate 128, a pair of friction plates 134 and 136 formed in the front side of the movable side plate 124 and a disc shape are sandwiched, and fixed to the fixed side plate 130. A pair of friction plates 138 and 140 formed in a disc shape are sandwiched between the side plates 132. These friction plates 134, 136, 138, and 140 are fixed to the fixed side plates 126, 128, 130, and 132.

  Bolts 142 pass through substantially the center portions of the fixed side plates 126, 128, 130, 132, the front portion 124B of the movable plate 124, and the center portions of the friction plates 134, 136, 138, 140. The front end side of the bolt 142 is inserted into the washer 144 and is screwed into the pair of nuts 146 and 148. The bolt 142 is disposed in a state where the axial direction is along the vehicle width direction, and is positioned coaxially with the connecting shaft 78 that is the rotation center of the upper trailing link 42 with respect to the vehicle body 20 and the torsion bar 56.

  Also, between the head 142A of the bolt 142 and the fixed side plate 126, and between the washer 144 and the fixed side plate 132, disc spring-like springs 150 and 152 formed in a substantially star shape by a spring material are provided. Intervene. Accordingly, the front portion 124B of the movable plate 124 and the friction plates 134 and 136 are elastically sandwiched between the fixed plates 126 and 128, and the friction plates 138 and 140 are elastic between the fixed plates 130 and 132. The movable side plate 124 is integrally connected to the friction plates 134, 136, 138, and 140 so as to be relatively rotatable around the bolt 142 with respect to the fixed side plates 126, 128, 130, and 132.

  Further, the front end portions of the fixed side plates 126 and 128 are joined together, and the front end portions of the fixed side plates 130 and 132 are joined together. Each of these joint portions is formed with a circular through hole 154 (see FIG. 8A), and one end portion in the axial direction of a support pin 156 formed in a columnar shape is inserted into each through hole 154. Has been. The support pin 156 is disposed in a state where the axial direction is along the vehicle width direction, and the other end in the axial direction is fixed to a bracket 158 attached to the vertical frame portion 32. Thereby, the relative rotation of the fixed side plates 126, 128, 130, 132 around the bolt 142 with respect to the vehicle body 20 is restricted.

  In the rotary damper 58 having the above configuration, when the upper trailing link 42 rotates up and down (swings) with respect to the vehicle body 20 around the front end, the movable side plate 124 of the movable portion 120 connected to the upper trailing link 42. Rotates relative to the fixed side plates 126, 128, 130, 132 and the friction plates 134, 136, 138, 140 around the bolt 142. As a result, the friction plates 134, 136, 138, 140 and the movable plate 124 come into sliding contact with each other, and a frictional force (damping force) is generated. As a result, the relative rotation of the movable part 120 with respect to the fixed part 122, that is, the swing of the upper trailing link 42 with respect to the vehicle body 20 is attenuated. Further, the frictional force can be arbitrarily adjusted by changing the tightening torque (elastic deformation amount) of the springs 150 and 152 by the bolt 142 and the nuts 146 and 148.

(Function and effect)
Next, the operation and effect of this embodiment will be described.

  In the vehicle suspension apparatus 10 having the above-described configuration, the upper trailing link 42 and the lower trailing link 48 rotate around the axis line along the vehicle width direction with respect to the vehicle body 20 with the front end portion connected to the vehicle body 20 as the rotation center. Then, the rear wheel 38 connected to the rear ends of the upper trailing link 42 and the lower trailing link 48 via the rear axle bracket 40 moves up and down with respect to the vehicle body 20. At this time, the torsion bar 56 is torsionally deformed with the rotation of the upper trailing link 42 to absorb the impact, and the rotary damper 58 attenuates the relative rotation of the movable part 120 with respect to the fixed part 122 to thereby reduce the rear wheel. The vertical movement (vibration) of 38 is attenuated.

  Here, since the above-described torsion bar 56 is bridged along the vehicle width direction between the front end portion of the upper trailing link 42 and the vehicle body 20, the occupied space in the vertical direction is small. Further, in the rotary damper 58 described above, the movable part 120 rotates relative to the fixed part 122 as the upper trailing link 42 rotates, so that the shock absorber for the swing arm type suspension described in the background art section. Compared to the above, the occupied space in the vertical direction can be reduced. Accordingly, a flat vehicle body structure with a low floor portion can be realized, and a space-saving and lightweight suspension structure having excellent suspension and design can be provided.

  Further, in the present embodiment, the rotary damper 58 is arranged such that the bolt 142 that is the rotation center of the movable portion 120 with respect to the fixed portion 122 is coaxially connected to the connecting shaft 78 that is the rotation center of the upper trailing link 42 with respect to the vehicle body 20. ing. Further, the movable portion 120 is connected to the damper mounting portion 80 of the upper trailing link 42 on the vehicle rear side, that is, the side where the upper trailing link 42 extends from the vehicle body 20 with respect to the rotation center of the upper trailing link 42. Thereby, since the movable part 120 can be rotated integrally with the upper trailing link 42, the configuration (here, the damper mounting part 80) for transmitting the rotation of the upper trailing link 42 to the movable part 120 is simplified. It can be made small.

  In the present embodiment, the torsion bar 56 is disposed in front of the rear axle bracket 40 and the rear wheel 38, that is, on the same side as the rear wheel 38 with respect to the upper trailing link 42. It is possible to prevent the rear wheel 38 from overhanging to one side in the vehicle width direction. Further, since the rotary damper 58 is disposed on the opposite side of the torsion bar 56 via the front end portion of the arm portion 72 that is a connecting portion between the torsion bar 56 and the upper trailing link 42, The damper 58 can be arranged with good balance in the vehicle width direction.

  In the present embodiment, the rotary damper 58 is disposed between the front end portions of the pair of left and right arms 72 and 74 included in the upper trailing link 42. Thereby, since the occupation space of the upper trailing arm 42 and the rotary damper 58 is shared (partially overlaps), the occupation space of the rotary damper 58 can be substantially reduced.

  Furthermore, in this embodiment, the upper trailing link 42 and the lower trailing link 48 constitute a double trailing link type suspension, and the torsion bar 56 and the rotary damper 58 are connected to the upper trailing link 42. . Since the torsion bar 56 and the rotary damper 58 can reduce the space occupied in the vertical direction as described above, a low-floor vehicle body structure can be realized even in a configuration connected to the upper trailing link 42. .

  Moreover, in this embodiment, since the rotary damper 58 is made into a friction type, the rotary damper 58 can be made a simple structure.

  Further, in the present embodiment, the rear end portion of the upper trailing link 42 is connected to the upper connecting portion 66 provided on the rear axle bracket 40 via the upper rubber bush 46, and the rear trailing link 48 is rearward. The end portion is connected to a lower connecting portion 68 provided on the rear axle bracket 40 via a lower rubber bush 50. Further, the upper connecting portion 66 and the lower connecting portion 68 are provided on the vehicle front side with respect to the wheel center S of the rear wheel 38, and are lined up and down in the side view of the vehicle and connected to the lower side in the vehicle front and rear direction. The part 68 is offset from the upper connecting part 66 to the tire ground contact center C side.

  For this reason, when a longitudinal force during vehicle braking or a lateral force during vehicle turning acts on the rear wheel 38, the upper rubber bush 46 and the lower rubber bush 50 are elastically deformed (bent). The rear wheel 38 can be rotated (steered) by a small angle around a virtual kingpin axis passing through the upper rubber bush 46 and the lower rubber bush 50.

  In addition, in the present embodiment, the front end portion is rotatably connected to the vehicle body 20, and the rear end portion is rotatably connected to the rear axle bracket 40 on the vehicle rear side of the wheel center S of the rear wheel 38. A control link 55 is provided. Therefore, when the rear wheel 38 rotates about the virtual kingpin axis as described above, the rotation direction of the rear wheel 38 can be restricted to a predetermined direction by the control link 55. Thereby, it becomes possible to obtain an appropriate compliance steer characteristic with respect to the lateral force and the longitudinal force acting on the rear wheel 38.

  That is, in this embodiment, the steering angle of the rear wheel 38 is appropriately adjusted by adjusting the deflection direction and the deflection amount of the upper rubber bush 46 and the lower rubber bush 50 and the rotation restriction direction of the rear wheel 38 by the control link 55. Can be controlled. That is, the toe angle of the rear wheel 38 changes depending on the amount of movement of the virtual kingpin shaft composed of the upper rubber bush 46 and the lower rubber bush 50 and the control link 55 in the vehicle width direction. Also, the camber angle of the rear wheel 38 changes as the tilt angle of the virtual kingpin axis changes. Therefore, by adjusting the elasticity of the upper rubber bush 46 and the lower rubber bush 50, the toe angle and camber angle of the rear wheel 38 can be appropriately changed.

  As a result, when the vehicle is braked, the rear wheel 38 is steered by a small angle so as to improve the straight running stability, and when the vehicle is turning, the rear wheel 38 is steered by a small angle in the direction of improving the turning stability (direction of understeer). . Therefore, the running stability of the vehicle can be improved with an extremely simple configuration.

  Further, in the present embodiment, the upper rubber bush 46 and the lower rubber bush 50 that enable a small angle steer of the rear wheel 38 are laterally acting on the rear wheel 38 rather than the rigidity against the longitudinal force acting on the rear wheel 38. The rigidity against the force is set low. As a result, the rear wheel 38 can be steered satisfactorily with respect to the lateral force F2 and the turning performance of the vehicle can be improved, and the change in the angle of the rear wheel 38 with respect to the longitudinal force can be suppressed. Can be improved.

  Further, in the present embodiment, the front end portions of the left and right arm portions 90 and 92 included in the lower trailing link 48 are connected to the vehicle body 20 via the front rubber bushes 52 and 54. Thereby, since the input to the vehicle body 20 via the lower trailing link 48 can be absorbed by the front rubber bushes 52 and 54, the riding comfort of the three-wheeled electric vehicle 10 can be improved.

<Second Embodiment>
Next, a second embodiment of the present invention will be described. In addition, about the structure and effect | action similar to the said 1st Embodiment, the same code | symbol as the said 1st Embodiment is provided, and the description is abbreviate | omitted.

  As shown in FIGS. 9 to 11, in the vehicle suspension device 10 ′ according to the second embodiment, the rotary damper 58 ′ is arranged on the same side as the torsion bar 56 with respect to the arm portion 72 of the upper trailing link 42. This is different from the vehicle suspension device 10 according to the first embodiment. The rotary damper 58 ′ has basically the same configuration as the rotary damper 58 according to the first embodiment, but the bolt 142 ′ and the nuts 146′148 ′ are the bolt 142 according to the first embodiment. The nuts 146 and 148 are formed larger in diameter. A through hole 160 that penetrates the bolt 142 ′ in the axial direction (vehicle width direction) is formed in the axial center portion of the bolt 142 ′. The through hole 160 has an intermediate portion in the axial direction of the torsion bar 56. It is inserted. That is, the torsion bar 56 passes through the movable portion 120 and the fixed portion 122 of the rotary damper 58 ′ coaxially, and the torsion bar 56 and the rotary damper 58 ′ are disposed at positions where they overlap each other.

  In this embodiment, since the occupied space of the torsion bar 56 and the rotary damper 58 'is shared, the occupied space of both can be substantially reduced. Moreover, since the torsion bar 56 and the rotary damper 58 'can be unitized (sub-assembled), it is possible to improve manufacturing efficiency.

(Supplementary explanation of the embodiment)
In each of the above embodiments, the front end portions of the left and right arm portions 90 and 92 of the lower trailing link 48 are connected to the vehicle body 20 via the front rubber bushes 52 and 54 (both are front elastic bodies). However, the present invention is not limited to this, and the front end portion of the lower trailing link may be connected to the vehicle body without using the front elastic body.

  Further, in each of the above embodiments, the upper rubber bush 46 (upper elastic body) and the lower rubber bush 50 (lower elastic body) act on the rear wheel 38 rather than the rigidity against the longitudinal force acting on the rear wheel 38. Although the configuration is such that the rigidity against the force is set low, the present invention is not limited to this, and the rigidity of the upper elastic body and the lower elastic body can be changed as appropriate.

  In each of the above embodiments, the rotary damper 58 is configured as a friction type. However, the present invention is not limited to this, and the rotary damper may be configured as a hydraulic type.

  Further, in the first embodiment, the rotary damper 58 is arranged between the front ends of the arms 72 and 74 of the upper trailing link 42 (trailing link) which is the A arm. However, the configuration of the trailing link and the arrangement of the rotary damper can be changed as appropriate.

  In each of the above embodiments, the torsion bar 56 is arranged in front of the rear axle bracket 40, that is, on the same side as the rear wheel 38 with respect to the upper trailing link 42 (trailing link). However, the present invention is not limited thereto, and the torsion bar may be arranged on the side opposite to the rear wheel with respect to the trailing link.

  Further, in each of the above embodiments, the rotary damper 58 has a configuration in which the rotation center of the movable portion 120 with respect to the fixed portion 122 is arranged coaxially with the rotation center of the upper trailing link 42 with respect to the vehicle body 20. However, the present invention is not limited to this, and the rotation centers may be arranged on different axes. In this case, for example, the movable portion and the trailing link are connected using a link or the like.

  Furthermore, in each said embodiment, although the vehicle suspension apparatus 10 was set as the structure applied with respect to the three-wheeled electric vehicle 12 of a front two-wheel rear one wheel, it is not restricted to this, The vehicle suspension apparatus which concerns on this invention is a four-wheeled vehicle. It can also be applied to automobiles.

  In addition, the present invention can be implemented with various modifications without departing from the scope of the invention. It goes without saying that the scope of rights of the present invention is not limited to the above embodiment.

10, 10 'Vehicle suspension system 12 Three-wheeled electric vehicle (three-wheeled vehicle)
20 Car body 38 Rear wheel 40 Rear axle bracket (rear wheel support member)
42 Upper trailing link (trailing link)
48 Lower Trailing Link 56 Torsion Bar 58, 58 'Rotary Damper 72, 74 Arm 120 Moving Part 122 Fixed Part

Claims (7)

A rear wheel support member for rotatably supporting the rear wheel of the automobile;
The front end portion is connected to the vehicle body so as to be rotatable around an axis line along the vehicle width direction, and the rear end portion is connected to the rear wheel support member so as to be rotatable around an axis line along the vehicle width direction. A trailing link,
A torsion bar that extends in the vehicle width direction and has one longitudinal end connected to the front end of the trailing link and the other longitudinal end connected to the vehicle body and torsionally deforms as the trailing link rotates. When,
The movable part connected to the trailing link is connected to the fixed part connected to the vehicle body so as to be relatively rotatable, and the relative rotation between the fixed part and the movable part accompanying the rotation of the trailing link is attenuated. A rotary damper,
A vehicle suspension system comprising:   The rotary damper is arranged such that a rotation center of the movable part with respect to the fixed part is coaxial with a rotation center of the trailing link with respect to a vehicle body, and the movable part is behind the rotation center of the trailing link. The vehicle suspension device according to claim 1, wherein the vehicle suspension device is connected to the trailing link on a side.   The vehicle suspension device according to claim 1, wherein the torsion bar passes coaxially through the movable portion and the fixed portion of the rotary damper. The torsion bar is disposed in front of the rear wheel support member;
3. The vehicle suspension device according to claim 1, wherein the rotary damper is disposed on a side opposite to the torsion bar via a connecting portion between the torsion bar and the trailing link.   The vehicle suspension device according to claim 4, wherein the trailing link includes a pair of left and right arms extending to the front side of the vehicle, and the rotary damper is disposed between front ends of the pair of arms.   The trailing link is an upper trailing link, and a lower trailing link is provided below the upper trailing link. The lower trailing link has a front end portion that is connected to the vehicle body. Claims 1 to claim 1, wherein the rear end portion is connected to the rear wheel support member so as to be rotatable about an axis along the vehicle width direction. The vehicle suspension device according to any one of 5.   The vehicle suspension device according to any one of claims 1 to 6, wherein the rotary damper is a friction type that generates a frictional force between the movable portion and the fixed portion when the movable portion is relatively rotated.