JP7249939B2 - vehicle - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle having a swing arm extending forward or rearward from a vehicle body frame.

2. Description of the Related Art A configuration disclosed in Patent Document 1, for example, is known as a vehicle having a swing arm extending forward or rearward from a vehicle body frame. In this patent document 1, a rigid foamed synthetic resin material is used as a core material, and a reinforcing fiber woven fabric impregnated with a matrix resin is wound multiple times on the surface of the core material to form a laminated state, and the matrix resin is removed by applying pressure and heat. A swing arm is disclosed that is integrally formed by curing.

As described above, in the configuration of Patent Document 1, a rigid foamed synthetic resin material is used as a core material, and a hardened layer of a matrix resin containing a reinforcing fiber woven fabric is formed on the surface thereof. Therefore, the swing arm disclosed in Patent Document 1 has strength equal to or greater than that of a swing arm made of metal such as aluminum alloy, and the weight of the swing arm as a whole can be reduced.

In the structure of Patent Document 1, a cloth woven using carbon fiber, glass fiber, aramid fiber, etc. is used as the reinforcing fiber woven cloth, and epoxy resin, polyester resin, etc. are mainly used as the matrix resin. A thermosetting resin is used.

In the configuration of Patent Document 1, the swing arm has a pair of arms positioned on the left and right and extending in the front-rear direction, and a cross member connecting the pair of arms. The cross member is provided with a shock absorber support to which the shock absorber is connected.

JP-A-5-139361

By the way, the swing arm extending from the vehicle body frame toward the front or rear of the vehicle is elastically supported by a suspension (buffer) with respect to the vehicle body frame. Also, the swing arm rotatably supports the wheel. An upward force input to the wheels is input to the suspension via the swing arm. The suspension generates reaction force when force is input from the swing arm. This reaction force is input to the swing arm.

Depending on the type of vehicle, it may be necessary to increase the strength of the portion of the swing arm to which the reaction force is input from the suspension. In order to improve the strength of the swing arm in the configuration of Patent Document 1, it is conceivable to increase the thickness of the stiffening layer by increasing the number of times the reinforcing fiber woven fabric is wound around the core material.

However, increasing the thickness of the stiffening layer as described above increases the weight of the entire swing arm.

INDUSTRIAL APPLICABILITY According to the present invention, in a vehicle having a swing arm extending forward or rearward from a vehicle body frame, it is possible to improve the strength of a portion of the swing arm to which force is input from the suspension while suppressing an increase in weight. Intended to obtain configuration.

The inventors examined the strength required for the swing arm. Specifically, first, the inventors examined the force acting on the swing arm.

As described above, a reaction force is input from the suspension to the swing arm due to the force input to the wheel in the upward direction. This reaction force is input to the portion of the swing arm to which the suspension is connected, that is, the cross portion. The reaction force input to the cross portion is input to the side surfaces of the left and right arm portions of the swing arm. The reaction force input to the side surfaces of the left and right arm portions is transmitted to the wheels via the swing arm.

When the reaction force is input from the suspension to the cross portion, downward force acts on the connection portion between the cross portion and the left and right arm portions.

In the configuration disclosed in Patent Document 1, as described above, the swing arm is configured by laminating reinforcing fiber woven fabrics in the thickness direction. Therefore, the cross member (cross portion) of the swing arm is also constructed by laminating reinforcing fiber woven fabrics in the thickness direction.

When the reaction force is input to the swing arm from the suspension, the reaction force acts downward on the cross portion. That is, the reaction force acts in the lamination direction of the reinforcing fiber woven fabric at the cross portion.

Therefore, in order to improve the strength of the cross portion against the reaction force, it is necessary to increase the number of layers of the reinforcing fiber woven fabric in the cross portion. When the number of laminations of the reinforcing fiber woven fabric is increased in this way, the weight of the entire swing arm increases.

In order to suppress an increase in the weight of the swing arm and improve the strength of the portion of the swing arm to which the reaction force from the suspension is input, that is, the connection portion of the suspension in the swing arm, the present inventors have The characteristics of FRP (fiber reinforced resin) obtained by curing a sheet (reinforced fiber woven fabric) with resin were investigated.

As a result of intensive studies, the present inventors have found that the strength of the member can be improved by forming the member made of FRP into a shape having a closed cross section.

Furthermore, the present inventors have considered the characteristics of such FRP members and have found the following configuration of the swing arm, which enables weight reduction while ensuring strength.

Specifically, the present inventors provided a concave portion in one of the left and right arm portions of the swing arm or the cross member, and provided a convex portion in the other, as a configuration for receiving the reaction force from the suspension. I came up with a configuration to insert into the recess.

As a result, it is possible to increase the strength of the portion of the swing arm to which force is input from the suspension while suppressing an increase in the weight of the swing arm.

Based on the study results as described above, the present inventors came up with the following configuration.

A vehicle according to one embodiment of the present invention includes a vehicle body frame that is long in the longitudinal direction of the vehicle, a swing arm that extends from the vehicle body frame toward the front or rear of the vehicle, and a swing arm that is elastic with respect to the vehicle body frame. The vehicle includes a supporting suspension and a wheel supported by the swing arm so that the rotation axis is positioned in the lateral direction of the vehicle. The swing arm includes a right arm portion extending in the front-rear direction of the vehicle, a left arm portion extending in the front-rear direction of the vehicle, and a swing arm extending in the left-right direction of the vehicle to connect the right arm portion and the left arm portion. a rotating right support portion provided at one end of the right arm portion in the longitudinal direction of the vehicle and rotatably supporting the right arm portion to the vehicle body frame; a rotating left support portion provided at one end of the left arm portion for rotatably supporting the left arm portion to the vehicle body frame; It has a wheel support portion that is provided at the other end portion in the front-rear direction and supports the wheel, and a suspension connection portion that is provided at the cross portion and to which the suspension is connected.
The right arm portion and the cross portion satisfy either one of (A) or (B) below, and the left arm portion and the cross portion satisfy either one of (C) or (D) below. Fulfill.
(A) The right arm portion includes a fiber-reinforced resin resin reinforced with fibers, and has a right arm convex portion that protrudes leftward and has a closed cross section when viewed in cross section in the front-rear direction, and the cross portion includes: , the resin includes a fiber-reinforced resin reinforced with fibers, and has a cross right load-bearing surface in contact with the right arm protrusion.
(B) The cross portion includes a fiber-reinforced resin resin reinforced with fibers, and has a cross right convex portion that protrudes to the right and has a closed cross section when viewed in cross section in the front-rear direction, and the right arm portion , the resin includes a fiber-reinforced resin reinforced with fibers, and has a right arm load bearing surface in contact with the cross right protrusion.
(C) The left arm portion includes a fiber-reinforced resin resin reinforced with fibers, and has a left arm convex portion that protrudes to the right and has a closed cross-section when viewed in cross-section in the front-rear direction, and the cross portion includes: , the resin includes a fiber-reinforced resin reinforced with fibers, and has a cross left load bearing surface in contact with the left arm protrusion.
(D) The cross section includes a fiber-reinforced resin resin reinforced with fibers, and has a cross left projection projecting leftward and having a closed cross-section when viewed in cross section in the front-rear direction, and the left arm section , the resin includes a fiber-reinforced resin reinforced with fibers, and has a left arm load bearing surface in contact with the left convex portion of the cross.

In the above-described configuration, the projections provided on one of the right arm portion and cross portion and on one of the left arm portion and cross portion have a closed cross-sectional shape when viewed in cross section in the front-rear direction. The other of the right arm portion and the cross portion and the other of the left arm portion and the cross portion each have a load receiving surface that contacts the convex portion. Further, the right arm portion, the left arm portion, and the cross portion each contain a fiber-reinforced resin reinforced with fibers.

As a result, the strength of the connecting portion of the cross portion to the right arm portion and the left arm portion can be improved without increasing the number of laminated fibers. Therefore, it is possible to improve the strength of the portion of the swing arm to which force is input from the suspension while suppressing an increase in the weight of the swing arm.

From another aspect, the vehicle of the present invention preferably includes the following configuration.
In the above (A), the cross portion containing the fiber-reinforced resin is provided with a cross right concave portion, and a part of the cross right concave portion constitutes the cross right load bearing surface,
In (B) above, a right arm recess is provided in the right arm portion containing the fiber-reinforced resin, and a part of the right arm recess constitutes the right arm load bearing surface,
In the above (C), the cloth portion containing the fiber-reinforced resin is provided with a cross left concave portion, and a part of the cross left concave portion constitutes the cross left load bearing surface,
In (D) above, a left arm concave portion is provided in the left arm portion containing the fiber-reinforced resin, and a part of the left arm concave portion constitutes the left arm load bearing surface.

By inserting the convex portion into the concave portion and supporting the convex portion by the load receiving surface formed by a part of the concave portion, the cross portion can be more reliably connected to the right arm portion and the left arm portion. , the force (reaction force) acting downward on the cross portion can be received by the convex portion and the load receiving surface. Therefore, the strength of the cross portion can be improved.

From another aspect, the vehicle of the present invention preferably includes the following configuration.
In (A) above, the cross right concave portion includes a cross right concave lower surface portion extending in the front-rear direction of the vehicle when the cross portion is viewed from the right direction of the vehicle and positioned below the cross right concave portion; A cross right recessed front portion extending in the vertical direction of the vehicle and positioned in front of the cross right recessed portion, and a cross right recessed portion rearward facing the cross right recessed portion front portion and positioned in the rear portion of the cross right recessed portion. and a cross right concave upper surface portion disposed opposite to the cross right concave lower surface portion and positioned above the cross right concave portion and constituting the cross right load bearing surface,
In (B) above, the right arm recess extends in the front-rear direction of the vehicle when the right arm is viewed from the left direction of the vehicle, and is positioned below the right arm recess. a right arm recessed portion lower surface portion constituting a right arm recessed portion, a right arm recessed portion front portion extending in the vertical direction of the vehicle and positioned in front of the right arm recessed portion, and a right arm recessed portion disposed opposite to the right arm recessed portion front portion and the right a right arm recessed portion rear surface portion positioned at the rear portion of the arm recessed portion; and a right arm recessed portion upper surface portion disposed opposite the right arm recessed portion lower surface portion and positioned at the upper portion of the right arm recessed portion;
In (C) above, the cross left concave portion includes a cross left concave lower surface portion extending in the front-rear direction of the vehicle when the cross portion is viewed from the left direction of the vehicle and positioned below the cross left concave portion; A cross left recess front portion extending in the vertical direction of the vehicle and positioned in front of the cross left recess, and a cross left recess rear portion disposed opposite the cross left recess front portion and positioned at the rear of the cross left recess. and a cross left recess upper surface portion disposed opposite to the cross left recess lower surface portion and positioned above the cross left recess portion and forming the cross left load bearing surface,
In (D) above, the left arm recess extends in the front-rear direction of the vehicle when the left arm is viewed from the right side of the vehicle, and is positioned below the left arm recess. , a left arm recessed front surface portion extending in the vertical direction of the vehicle and positioned in front of the left arm recessed portion, and a left arm recessed portion located opposite the left arm recessed front surface portion and the left It has a left arm recessed portion rear surface portion located at the rear portion of the arm recessed portion, and a left arm recessed portion upper surface portion located above the left arm recessed portion and arranged to face the left arm recessed portion lower surface portion.

Since the recess is surrounded by four surfaces, the projection can be inserted into the recess more reliably. Moreover, when a force is applied to the cross portion in a direction other than the downward direction, the convex portion inserted into the concave portion can receive the force on any of the four surfaces of the concave portion.

From another aspect, the vehicle of the present invention preferably includes the following configuration.
In the above (A), the cross portion containing the fiber-reinforced resin includes a fiber-reinforced resin reinforced with fibers, and one is at the connection portion between the right concave front portion of the cross and the lower surface portion of the right cross concave portion. a cross right concave front lower surface portion connected to the cross portion, the other extending forward and downward from the connecting portion and connected to the outer surface of the cross portion;
In the above (B), the right arm portion containing the fiber-reinforced resin includes a fiber-reinforced resin reinforced with fibers, and one is a connection portion between the right arm concave front surface portion and the right arm concave upper surface portion. and the other extending forward and upward from the connecting portion and connected to the outer surface of the right arm portion is provided,
In the above (C), the cross portion containing the fiber reinforced resin includes a fiber reinforced resin reinforced with fibers, and one of the cross portions is a connection portion between the left recessed front portion of the cross and the lower left recessed portion of the cross. a left recessed cross front lower surface portion connected to the cross portion, the other extending forward and downward from the connecting portion and connected to the outer surface of the cross portion;
In the above (D), the left arm portion containing the fiber-reinforced resin includes a fiber-reinforced resin reinforced with fibers, and one is a connection portion between the left arm concave front surface portion and the left arm concave upper surface portion. and the other extending forward and upward from the connecting portion and connected to the outer surface of the left arm.

As a result, the strength of the concave portions provided in the right arm portion or cross portion and the left arm or cross portion can be improved.

From another aspect, the vehicle of the present invention preferably includes the following configuration.
In (A) above, the cross portion containing the fiber-reinforced resin is opposed by a pair of right cross load-receiving surface supporting portions containing a fiber-reinforced resin reinforced with fibers and supporting the right cross load-receiving surface from above. and
In the above (B), the right arm portion containing the fiber-reinforced resin includes a pair of right arm load-receiving surface support portions containing fiber-reinforced resin reinforced with fibers and supporting the right arm load-receiving surface from below. provided facing each other,
In the above (C), a pair of left cross load bearing surface supporting portions including a fiber reinforced resin reinforced with fibers and supporting the left cross load bearing surface from above face the cross portion including the fiber reinforced resin. and
In the above (D), the left arm portion containing the fiber-reinforced resin includes a pair of left arm load-receiving surface support portions containing fiber-reinforced resin reinforced with fibers and supporting the left arm load-receiving surface from below. They are provided facing each other.

Thereby, the load receiving surface can be supported by a pair of load receiving surface support portions provided facing each other. Therefore, the force that is input from the convex portion to the load receiving surface can be supported by the load receiving surface supporting portion. Therefore, it is possible to improve the strength of the connecting portions between the cross portion and the right arm portion and the left arm portion.

From another aspect, the vehicle of the present invention preferably includes the following configuration. The cloth portion containing the fiber-reinforced resin has the right cross convex portion at the right end of the vehicle and the left cross convex portion at the left end of the vehicle. The right arm portion containing the fiber-reinforced resin has the right arm load bearing surface that contacts the right cross convex portion. The left arm portion containing the fiber-reinforced resin has the left arm load receiving surface that contacts the cross left convex portion.

As a result, the cross portion can be made more compact than when the right arm portion and the left arm portion are each provided with a convex portion and the cross portion is provided with a load bearing surface. Therefore, a swing arm capable of improving strength while suppressing an increase in weight can be realized with a compact configuration.

From another aspect, the vehicle of the present invention preferably includes the following configuration. A pair of right arm load receiving surface supporting portions including a fiber reinforced resin reinforced with fibers and supporting the right arm load receiving surface from below are provided facing each other on the right arm portion including the fiber reinforced resin. there is A pair of left arm load receiving surface supporting portions including a fiber reinforced resin reinforced with fibers and supporting the left arm load receiving surface from below are provided facing each other on the left arm portion including the fiber reinforced resin. there is

As a result, the cross portion can be more reliably supported by the right arm load bearing surface of the right arm portion and the left arm load bearing surface of the left arm portion.

From another aspect, the vehicle of the present invention preferably includes the following configuration. A right arm concave portion is provided in the right arm portion containing the fiber reinforced resin, and a left arm concave portion is provided in the left arm portion containing the fiber reinforced resin,
The right arm recess extends in the front-rear direction of the vehicle when the right arm is viewed from the left direction of the vehicle, and is positioned below the right arm recess, forming the right arm load bearing surface. a lower surface portion, a right arm recessed front portion extending in the vertical direction of the vehicle and positioned in front of the right arm recessed portion, and a right arm recessed portion facing the front portion and positioned in the rear portion of the right arm recessed portion. and a right arm recessed upper surface portion arranged to face the right arm recessed lower surface portion and positioned above the right arm recessed portion,
The left arm recess extends in the front-rear direction of the vehicle when the left arm is viewed from the right side of the vehicle, and is positioned below the left arm recess, forming the left arm load bearing surface. a lower surface portion, a left arm concave front portion extending in the vertical direction of the vehicle and positioned in front of the left arm concave portion, and a left arm concave front portion facing the left arm concave portion and positioned in the rear portion of the left arm concave portion. and a left arm recessed upper surface portion disposed facing the left arm recessed lower surface portion and positioned above the left arm recessed portion,
One of the right arm portions is connected to a connecting portion between the right arm concave front surface portion and the right arm concave upper surface portion, and the other extends forward and upward from the connecting portion to the outer surface of the right arm portion. having a connected right arm front upper surface,
One of the left arm portions is connected to a connecting portion between the left arm concave front surface portion and the right arm concave upper surface portion, and the other is connected to the outer surface of the left arm portion extending forward and upward from the connecting portion. The left arm front upper surface portion is

Thereby, the strength of the right arm concave portion provided in the right arm portion and the strength of the left arm concave portion provided in the left arm portion can be improved. Therefore, it is possible to improve the connection strength between the right arm portion and the left arm portion and the cross portion. Therefore, the strength of the swing arm can be improved.

From another aspect, the vehicle of the present invention preferably includes the following configuration. The right arm portion has a right arm right side surface portion that is positioned on the right side of the right arm concave portion in the left-right direction of the vehicle and that constitutes a part of the outer surface of the right arm portion. It has a left arm left side surface portion positioned on the left side of the left arm concave portion in the lateral direction of the vehicle and forming a part of the outer surface of the left arm portion.

As a result, the strength of each of the right arm portion and the left arm portion can be improved, and when the right arm portion is viewed from the right side of the vehicle, and when the left arm portion is viewed from the left side of the vehicle, It is possible to prevent the appearance of the right arm portion and the left arm portion from being spoiled.

From another aspect, the vehicle of the present invention preferably includes the following configuration. The right arm portion is positioned on the right side of the vehicle with respect to the wheels, and the left arm portion is positioned on the left side of the vehicle with respect to the wheels.

Thus, in the configuration in which the right arm portion and the left arm portion are arranged on the right and left sides of the wheel, the reaction force generated in the suspension accompanying the upward movement of the wheel causes the right arm portion and the left arm portion to move. A larger force is input to the connecting portion of the cross portion to the arm portion. By applying the above-described first configuration to such a configuration, it is possible to more effectively improve the strength of the cross portion to which the suspension is connected while suppressing an increase in the weight of the swing arm.

From another aspect, the vehicle of the present invention preferably includes the following configuration. The right arm portion and the left arm portion each including the fiber-reinforced resin have an outer dimension in the vertical direction larger than an outer dimension in the left-right direction when viewed in a cross-section in the left-right direction of the vehicle.

As a result, the vertical rigidity of the swing arm can be improved. Therefore, the swing arm has a higher strength against the downward force input to the swing arm from the suspension.

The terminology used herein is for the purpose of defining particular embodiments only and is not intended to limit the invention by the terminology.

As used herein, "and/or" includes all combinations of one or more of the associated listed constructs.

As used herein, the use of "including," "comprising," or "having," and variations thereof, refers to the features, steps, elements, components, and/or , may include one or more of the steps, acts, elements, components and/or groups thereof, although specifying the presence of equivalents thereof.

As used herein, "attached," "connected," "coupled," and/or equivalents thereof are used broadly and include "direct and indirect" attachment, It includes both connection and coupling. Furthermore, "connected" and "coupled" are not limited to physical or mechanical connections or couplings, but can include direct or indirect connections or couplings.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms defined in commonly used dictionaries are to be construed to have a meaning consistent with their meaning in the context of the relevant art and this disclosure, unless explicitly defined herein. , is not to be interpreted in an idealized or overly formal sense.

In describing the present invention, it is understood that a number of techniques and processes are disclosed. Each of these has individual benefits and can also be used in conjunction with one or more, or possibly all, of the other disclosed techniques.

Therefore, for the sake of clarity, the description of the invention refrains from unnecessarily repeating all possible combinations of the individual steps. However, the specification and claims should be read with the understanding that all such combinations are within the scope of the present invention.

Embodiments of vehicles according to the present invention will be described herein.

In the following description, numerous specific examples are set forth to provide a thorough understanding of the invention. However, it will be obvious to one skilled in the art that the invention may be practiced without these specific examples.

Accordingly, the following disclosure should be considered illustrative of the invention and is not intended to limit the invention to the specific embodiments illustrated by the following drawings or description.

[Definition of parallel]
In this specification, "parallel" means a state in which members are arranged along each other at a predetermined interval. Therefore, "parallel" includes not only the case where the spacing between members is constant, but also the case where the members extend in the same direction even if the spacing between the members is not constant.

[Definition of opposite]
In this specification, facing means that the surfaces of two members face each other and only a space exists between those surfaces. That is, when the members face each other, gas such as air may exist between the members.

According to the vehicle according to the embodiment of the present invention, a configuration is obtained in which the strength of the portion of the swing arm to which the suspension is connected can be improved while suppressing an increase in weight.

FIG. 1 is a left side view of a vehicle according to Embodiment 1 of the present invention. FIG. 2 is a left side view showing the schematic configuration of the vehicle, and a top view showing the schematic configuration of the rear arm. FIG. 3 is a perspective view showing a schematic configuration of the main frame. FIG. 4 is a perspective view showing a schematic configuration of the rear arm. FIG. 5 is a top view of the rear arm. FIG. 6 is a sectional view taken along line VI-VI in FIG. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. FIG. 8 is a top view of a state in which the rear arm is disassembled into a left arm portion, a cross portion and a right arm portion, viewed from above. FIG. 9 is a perspective view showing an enlarged left arm concave portion in the left arm portion. FIG. 10 is a perspective view showing an enlarged right arm concave portion in the right arm portion. FIG. 11 is a perspective view showing a state in which the rear arm is disassembled into a left arm portion, a cross portion and a right arm portion. FIG. 12 is a left side view of the vehicle schematically showing a case where the rear wheels are displaced upward. FIG. 13 is a diagram schematically showing the force that the rear suspension receives from the rear suspension when the rear wheel is displaced upward. 14 is a view corresponding to FIG. 8 of the rear arm of the vehicle according to Embodiment 2. FIG. 15 is a cross-sectional view taken along the line XV-XV in FIG. 14. FIG. 16 is a cross-sectional view taken along line XVI-XVI in FIG. 14. FIG. FIG. 17 is a perspective view showing an enlarged cross left concave portion in the cross portion. FIG. 18 is a perspective view showing an enlarged cross right concave portion in the cross portion. FIG. 19 is a view corresponding to FIG. 8 of the rear arm of the vehicle according to the third embodiment. FIG. 20 is a view corresponding to FIG. 8 of the rear arm of the vehicle according to Embodiment 4. FIG.

Each embodiment will be described below with reference to the drawings. In each figure, the same parts are denoted by the same reference numerals, and the description of the same parts will not be repeated. Note that the dimensions of the constituent members in each drawing do not faithfully represent the actual dimensions of the constituent members, the dimensional ratios of the respective constituent members, and the like.

Hereinafter, an arrow F in the drawings indicates the forward direction of the vehicle. An arrow U in the figure indicates the upward direction of the vehicle. An arrow R in the figure indicates the right direction of the vehicle. An arrow L in the figure indicates the left direction of the vehicle. Further, the front, rear, left, and right directions respectively mean the front, rear, left, and right directions as seen from the driver of the vehicle.

(Embodiment 1)
<Overall composition>
FIG. 1 is a side view showing an outline of the overall configuration of a vehicle 1 according to Embodiment 1. FIG. 1, the main frame 12, the rear arm 14, and the rear suspension 9 of the vehicle 1 are indicated by solid lines, and the others are indicated by broken lines. FIG. 2 is a left side view showing a schematic configuration of the vehicle 1 and a top view of the rear arm 14 as seen from above. A schematic configuration of the vehicle 1 will be described with reference to FIGS. 1 and 2. FIG.

A vehicle 1 is, for example, a motorcycle, and includes a vehicle body 2, front wheels 3, and rear wheels 4 (wheels). The vehicle body 2 includes a steering wheel 6, a seat 7, a rear suspension 9 (suspension), a vehicle body frame 10, and a rear arm 14 (swing arm).

The vehicle body frame 10 supports components such as the steering wheel 6, the seat 7, the rear suspension 9, the rear arm 14, and a power unit (not shown). The rear arm 14 rotatably supports the rear wheel 4 at its rear end and is supported by the vehicle body frame 10 via the rear suspension 9 . A detailed configuration of the rear arm 14 will be described later.

The body frame 10 has a head pipe 11, a main frame 12, and a rear frame (not shown).

The head pipe 11 is positioned in the front portion of the vehicle 1 and rotatably supports a steering shaft (not shown) connected to the steering wheel 6 . The head pipe 11 is connected to the front end of the main frame 12 .

As shown in FIG. 3, the main frame 12 is connected to the head pipe 11 so as to extend from the head pipe 11 toward the rear of the vehicle. The mainframe 12 has a left mainframe 20 and a right mainframe 30 . The left main frame 20 and the right main frame 30 are each formed in a plate shape extending in the vehicle front-rear direction.

Specifically, in this embodiment, the left main frame 20 includes a left main frame front portion 21 extending rearward and downward from the head pipe 11 and a left main frame front portion 21 extending downward from the rear end portion of the left main frame front portion 21 . a mainframe rear portion 22; The right main frame 30 includes a right main frame front portion 31 extending rearward and downward from the head pipe 11 and a right main frame rear portion 32 extending downward from the rear end portion of the right main frame front portion 31 . have.

Front ends of the left main frame 20 and the right main frame 30 are connected to the head pipe 11 respectively. That is, the front end portion of the left main frame front portion 21 of the left main frame 20 and the front end portion of the right main frame front portion 31 of the right main frame 30 are connected. The main frame 12 has a front connecting portion 12a to which the front end portion of the left main frame front portion 21 and the front end portion of the right main frame front portion 31 are connected.

A rear end portion of the left main frame rear portion 22 of the left main frame 20 and a rear end portion of the right main frame rear portion 32 of the right main frame 30 are connected by a cross member 17 extending in the horizontal direction. The main frame 12 has a rear connecting portion 12b to which the rear end portion of the left main frame rear portion 22 and the rear end portion of the right main frame rear portion 32 are connected.

The main frame 12 has an intermediate portion 12c between the front connecting portion 12a and the rear connecting portion 12b in the front-rear direction. At the intermediate portion 12c, the left main frame 20 and the right main frame 30 are linearly and not integrally connected when viewed from the front-rear direction. That is, the left main frame 20 and the right main frame 30 are linearly and not integrally connected when viewed in the front-rear direction at portions other than the front connection portion 12a and the rear connection portion 12b.

Therefore, the main frame 12 has a housing space 12d between the left main frame 20 and the right main frame 30 and in the central portion in the front-rear direction. A tank, an air cleaner and the like (not shown) are arranged in the housing space 12d.

As described above, the left main frame 20 and the right main frame 30 are not linearly and integrally connected when viewed in the front-rear direction at portions other than the front connection portion 12a and the rear connection portion 12b. Placement of parts is less subject to restrictions. Therefore, the degree of freedom in designing the arrangement of parts with respect to the main frame 12 can be improved.

A rear arm 14 is rotatably supported at rear portions of the left main frame 20 and the right main frame 30 . That is, the left main frame rear portion 22 is positioned to the left of the front end of the rear arm 14 and rotatably supports the front end of the rear arm 14 . The right main frame rear portion 32 is positioned to the right of the front end of the rear arm 14 and supports the front end of the rear arm 14 rotatably.

The main frame 12 has a left suspension support portion 25 extending rearward and upward from the left main frame 20 and a right suspension support portion 35 extending rearward and upward from the right main frame 30 .

The left suspension support portion 25 has a front end fixed to the left main frame 20 . The left suspension support portion 25 extends rearward and upward from the connecting portion between the left main frame front portion 21 and the left main frame rear portion 22 . The right suspension support portion 35 has a front end fixed to the right main frame 30 . The right suspension support portion 35 extends rearward and upward from the connecting portion between the right main frame front portion 31 and the right main frame rear portion 32 . The left suspension support portion 25 and the right suspension support portion 35 extend rearward and upward so that their rear ends approach each other in the left-right direction. The rear end portion of the left suspension support portion 25 and the rear end portion of the right suspension support portion 35 are connected in the left-right direction.

The main frame 12 has a suspension attachment portion 16 projecting rearward at the rear end portion where the left suspension support portion 25 and the right suspension support portion 35 are connected. The suspension mounting portion 16 supports the front end portion of the rear suspension 9 . Specifically, the suspension mounting portion 16 has a pair of cylindrical portions 16a arranged side by side with a predetermined interval in the left-right direction. The pair of cylindrical portions 16a are arranged so that the cylinder axis direction extends in the left-right direction. A front end portion of the rear suspension 9 is rotatably connected to a pair of cylindrical portions 16a.

A rear end portion of the rear suspension 9 is supported by a rear arm 14 . That is, the rear suspension 9 is supported by the suspension mounting portion 16 of the main frame 12 and the rear arm 14 . As a result, when a vertical load is input to the rear arm 14 that supports the rear wheel 4 , the load is input to the suspension mounting portion 16 of the main frame 12 via the rear suspension 9 .

The main frame 12 also supports a power unit and a rear frame (not shown). The power unit is attached to the lower portions of the left main frame 20 and right main frame 30 of the main frame 12 . The rear frame is attached to the left main frame 20 and the right main frame 30 of the main frame 12 behind the left suspension support portion 25 and the right suspension support portion 35 .

In FIG. 3, reference numerals 20a and 30a denote rear frame mounting portions provided on the left main frame 20 and the right main frame 30, respectively. Reference numerals 20b and 30b denote mounting portions for the rear arm 14 provided on the left main frame 20 and the right main frame 30, respectively. Reference numerals 20c and 30c denote power unit mounting portions provided on the left main frame 20 and the right main frame 30, respectively.

Although not shown, the seat 7 is supported by a rear frame. As shown in FIG. 1 , the seat 7 is provided at the central portion of the vehicle 1 in the front-rear direction. Accordingly, the occupant grips the steering wheel 6 located in the front part of the vehicle 1 while straddling the seat 7 .

The left main frame 20, the right main frame 30, and the rear frame may be made of a metal material, or may be made of a fiber-reinforced resin that is reinforced with fibers such as carbon fiber. Also, the left main frame 20, the right main frame 30, and the rear frame may be made of any material as long as it can function as a body frame of the vehicle 1.

<Rear arm>
Next, the configuration of the rear arm 14 will be described with reference to FIGS. 4 to 7. FIG. FIG. 4 is a perspective view showing a schematic configuration of the rear arm 14. As shown in FIG. FIG. 5 is a top view showing a schematic configuration of the rear arm 14. As shown in FIG. FIG. 6 is a sectional view taken along line VI-VI in FIG. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG.

As already mentioned, the front end of the rear arm 14 is rotatably supported by the main frame 12 . A rear end portion of the rear arm 14 rotatably supports the rear wheel 4 . As a result, the rear arm 14 rotates vertically around the front end portion rotatably supported by the main frame 12 when the rear wheel 4 is vertically displaced. The rear arm 14 is also connected to the main frame 12 by the rear suspension 9 .

Specifically, as shown in FIG. 4 , the rear arm 14 has a frame connection portion 14 a located at the front end and rotatably connected to the main frame 12 and a rear end located at the rear wheel 4 to rotate the rear wheel 4 . It has a pair of rear wheel support portions 14b (wheel support portions) that can be supported, and a pair of suspension connection portions 14c to which the rear suspension 9 is connected. The frame connecting portion 14a has a pivot shaft 71, which will be described later. The pivot shaft 71 is rotatably supported by the mounting portions 20b and 30b of the main frame 12. As shown in FIG. The rear wheel support portions 14b are positioned on the left and right sides of the rear wheel 4 and support the rear wheel 4 rotatably.

The rear arm 14 has a shape in which the central portion in the front-rear direction protrudes upward. Thereby, the rigidity of the rear arm 14 in the vertical direction can be improved. Therefore, as will be described later, the rear wheel 4 can be supported by the rear arm 14 when a vertical displacement is input to the rear wheel 4 .

The rear portion of the rear arm 14 is divided into left and right. A rear wheel support portion 14b is provided at each of the rear end portions of the rear portion divided into the left and right portions as described above. That is, the rear portion of the rear arm 14 is positioned to the left and right of the rear wheel 4 .

In this embodiment, the rear arm 14 has three members arranged in the left-right direction. Specifically, the rear arm 14 has a left arm portion 40 , a cross portion 50 and a right arm portion 60 . The left arm portion 40 constitutes the left portion of the rear arm 14 . The right arm portion 60 constitutes the right portion of the rear arm 14 . Cross portion 50 is positioned between left arm portion 40 and right arm portion 60 in the left-right direction. The left arm portion 40, the cross portion 50, and the right arm portion 60 are arranged side by side in the left-right direction and connected by, for example, adhesive or resin. Thereby, the left arm portion 40, the cross portion 50 and the right arm portion 60 are integrated.

The left arm portion 40 is positioned to the left of the rear wheel 4 . The right arm portion 60 is positioned to the right of the rear wheel 4 . Thereby, the rear arm 14 is arranged with respect to the rear wheel 4 so that the rear wheel 4 is positioned between the left arm portion 40 and the right arm portion 60 .

The left arm portion 40, the cross portion 50, and the right arm portion 60 are each reinforced with a fiber sheet containing carbon fiber resin (for example, epoxy resin, vinyl ester, phenolic resin, polyamide, polypropylene, polyphenylene sulfide, etc.). It is made of carbon fiber reinforced resin. The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction and bonded together by resin.

In the left arm portion 40, the cross portion 50, and the right arm portion 60, the fiber sheets are laminated in the thickness direction of each surface constituting the left arm portion 40, the cross portion 50, and the right arm portion 60, respectively. As a result, the strength of each surface forming the left arm portion 40, the cross portion 50, and the right arm portion 60 in the direction along each surface is higher than the strength in the thickness direction of each surface.

The rear wheel support portion 14b, a pivot shaft 71 and a connection fitting 72, which will be described later, are made of, for example, a metal material or a resin.

The left arm portion 40 has an outer dimension in the vertical direction larger than an outer dimension in the left-right direction when viewed in a cross section in the left-right direction. In addition, the left arm portion 40 has a shape in which the central portion in the front-rear direction protrudes upward. Thereby, the rigidity of the rear arm 14 in the vertical direction can be improved. Therefore, as will be described later, the rear arm 14 has a higher strength against a downward force input from the rear suspension 9 to the rear arm 14 .

The left arm portion 40 has a left arm left side surface portion 42 forming a left surface and extending in the front-rear direction, and a left arm right side surface portion 43 forming a right surface and extending in the front-rear direction. The left arm left side surface portion 42 and the left arm right side surface portion 43 have a shape in which the center portions in the front-rear direction protrude upward when viewed in the left-right direction. The left arm left side surface portion 42 and the left arm right side surface portion 43 are connected at their upper end portions by a left arm upper surface portion 48 and at their lower end portions by a left arm lower surface portion 49 .

The left arm portion 40 extends from the frame connection portion 14a to the rear wheel support portion 14b in the front-rear direction. That is, the front end portion of the left arm portion 40 is connected to the pivot shaft 71, and the rear end portion of the left arm portion 40 supports the rear wheel support portion 14b. Specifically, the left arm portion 40 has a cylindrical portion 41 at its front end, into which the pivot shaft 71 can be inserted. The left arm portion 40 has, at its rear end portion, a support portion insertion recess 40a in which the rear wheel support portion 14b can be arranged. The left arm portion 40 has an opening 40b through which a chain (not shown) that transmits driving force from a power unit (not shown) to the rear wheel 4 passes.

As shown in FIG. 5 , the left arm portion 40 has a left arm concave portion 44 on the left arm right side surface portion 43 in front of the central portion of the rear arm 14 in the front-rear direction. The left arm recessed portion 44 is recessed from the left arm right side surface portion 43 toward the left arm left side surface portion 42 in the left arm portion 40 . In this embodiment, the left arm concave portion 44 has a trapezoidal shape when viewed from above. Further, as shown in FIG. 6, the left arm concave portion 44 has a rectangular shape when viewed from the left-right direction. In the rear arm 14 , a left cross convex portion 53 of the cross portion 50 , which will be described later, is positioned in the left arm concave portion 44 . A detailed configuration of the left arm concave portion 44 will be described later.

As shown in FIG. 4, the right arm portion 60 has an outer dimension in the vertical direction larger than an outer dimension in the left and right direction when viewed in cross section in the left-right direction. In addition, the right arm portion 60 has a shape in which the central portion protrudes upward in the front-rear direction. Thereby, the rigidity of the rear arm 14 in the vertical direction can be improved. Therefore, as will be described later, the rear arm 14 has a higher strength against a downward force input from the rear suspension 9 to the rear arm 14 .

The right arm portion 60 has a right arm left side surface portion 62 forming a left surface and extending in the front-rear direction, and a right arm right side surface portion 63 forming a right surface and extending in the front-rear direction. The right arm left side surface portion 62 and the right arm right side surface portion 63 have a shape in which the center portions in the front-rear direction protrude upward when viewed in the left-right direction. The right arm left side surface portion 62 and the right arm right side surface portion 63 are connected at their upper end portions by a right arm upper surface portion 68 and are connected at their lower end portions by a right arm lower surface portion 69 .

The right arm portion 60 extends from the frame connection portion 14a to the rear wheel support portion 14b in the front-rear direction. That is, the front end portion of the right arm portion 60 is connected to the pivot shaft 71, and the rear end portion of the right arm portion 60 supports the rear wheel support portion 14b. Specifically, the right arm portion 60 has a cylindrical portion 61 at its front end portion, into which the pivot shaft 71 can be inserted. The right arm portion 60 has, at its rear end portion, a support portion insertion recess 60a in which the rear wheel support portion 14b can be arranged.

As shown in FIG. 5 , the right arm portion 60 has a right arm concave portion 64 on the right arm left side surface portion 62 in front of the center portion of the rear arm 14 in the front-rear direction. The right arm recessed portion 64 is recessed from the right arm left side surface portion 62 toward the right arm right side surface portion 63 in the right arm portion 60 . In this embodiment, the right arm concave portion 64 has a trapezoidal shape when viewed from above. Further, as shown in FIG. 7, the right arm concave portion 64 has a rectangular shape when viewed from the left-right direction. In the rear arm 14 , a cross right convex portion 54 of the cross portion 50 , which will be described later, is positioned in the right arm concave portion 64 . A detailed configuration of the right arm concave portion 64 will be described later.

Note that the left arm portion 40 and the right arm portion 60 have the same outer shape when viewed in the left-right direction.

As shown in FIGS. 4 and 5, the cross portion 50 extends from the frame connection portion 14a to the central portion of the rear arm 14 in the front-rear direction. Specifically, the cross portion 50 has a flat portion 51 whose front end is connected to the frame connection portion 14a and extends to the central portion of the rear arm 14 in the front-rear direction, and a vertical wall portion 52 that extends upward from the rear end of the flat portion 51. have The flat portion 51 and the vertical wall portion 52 are integrally formed.

The planar portion 51 has two plate-like members arranged in parallel in the vertical direction, although not shown. The flat portion 51 has a front end connected to the frame connection portion 14 a and both ends in the left-right direction connected to the left arm portion 40 and the right arm portion 60 .

The vertical wall portion 52 is connected to the rear end portion of the flat portion 51 and has both left and right end portions connected to the left arm portion 40 and the right arm portion 60 . The vertical wall portion 52 extends from the flat portion 51 to the same height as the center portions of the left arm portion 40 and the right arm portion 60 in the front-rear direction.

The cross portion 50 has a pair of left and right suspension connection portions 14 c formed at the connection portion between the rear end portion of the flat portion 51 and the front lower portion of the vertical wall portion 52 . That is, the suspension connecting portion 14 c protrudes upward with respect to the flat portion 51 and forward with respect to the vertical wall portion 52 . The suspension connecting portion 14c has a cylindrical connecting fitting 72 to which the rear end portion of the rear suspension 9 is connected.

A pivot shaft 71 is connected to the front end of the cross portion 50 . The pivot shaft 71 is a metal cylindrical member. The pivot shaft 71 is connected to the front end portion of the cross portion 50 so that the axial direction is the left-right direction. The pivot shaft 71 constitutes a part of the frame connecting portion 14a. The frame connecting portion 14 a has a pivot shaft 71 , a cylindrical portion 41 of the left arm portion 40 and a cylindrical portion 61 of the right arm portion 60 . The cylindrical portions 41 and 61 are connected to the pivot shaft 71 by, for example, resin or adhesive. Note that the cylindrical portion 41 and the pivot shaft 71 constitute a left rotation support portion 14d. In addition, the cylindrical portion 61 and the pivot shaft 71 constitute a rotation right support portion 14e.

As shown in FIG. 5 , the cross portion 50 has a cross left convex portion 53 and a cross right convex portion 54 projecting in the left-right direction forward of the central portion of the rear arm 14 in the front-rear direction. Cross left convex portion 53 extends leftward from flat portion 51 . The cross right convex portion 54 extends rightward from the flat portion 51 . The cross left protrusion 53 and the cross right protrusion 54 are trapezoidal when viewed from above. Moreover, as shown in FIGS. 6 and 7, the cross left protrusion 53 and the cross right protrusion 54 are rectangular when viewed in the left-right direction. The cross left convex portion 53 is positioned within the left arm concave portion 44 of the left arm portion 40 in the rear arm 14 . The cross right protrusion 54 is positioned within the right arm recess 64 of the right arm portion 60 in the rear arm 14 . The detailed configuration of the cross left convex portion 53 and the cross right convex portion 54 will be described later.

The left arm portion 40, the cross portion 50, and the right arm portion 60 configured as described above are adhesively fixed to each other in a state of being aligned in the left-right direction, as will be described later. That is, the left cross projection 53 of the cross portion 50 is inserted into the left arm recess 44 of the left arm portion 40, and the right cross projection 54 of the cross portion 50 is inserted into the right arm recess 64 of the right arm portion 60. In this state, the left arm portion 40, the cross portion 50 and the right arm portion 60 are adhesively fixed. Both axial end portions of the pivot shaft 71 connected to the front end portion of the cross portion 50 are inserted into the cylindrical portions 41 and 61 of the left arm portion 40 and the right arm portion 60, respectively.

<Connection structure>
Next, the connecting structure of the left arm portion 40, the cross portion 50 and the right arm portion 60 will be described with reference to FIGS. 5 to 11. FIG. FIG. 8 is a top view showing a state in which the rear arm 14 is disassembled into the left arm portion 40, the cross portion 50 and the right arm portion 60. As shown in FIG. FIG. 11 is a perspective view showing a state in which the rear arm 14 is disassembled into the left arm portion 40, the cross portion 50 and the right arm portion 60. As shown in FIG.

(Left arm recess)
As shown in FIGS. 5 , 6 , 8 , 9 and 11 , the left arm portion 40 has a left arm concave portion 44 on the left arm right side surface portion 43 . The left arm recess 44 has a left arm recess front surface 44a, a left arm recess rear surface 44b, a left arm recess top surface 44c, a left arm recess left surface 44d, and a left arm recess bottom surface 44e. That is, the left arm recess 44 is surrounded by a left arm recess front surface portion 44a, a left arm recess rear surface portion 44b, a left arm recess top surface portion 44c, a left arm recess left surface portion 44d, and a left arm recess bottom surface portion 44e. space.

The left arm concave portion 44 is made of carbon fiber reinforced resin in which a resin (eg, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc.) is reinforced with a fiber sheet containing carbon fibers. That is, the left arm recess front surface portion 44a, the left arm recess rear surface portion 44b, the left arm recess top surface portion 44c, the left arm recess left surface portion 44d, and the left arm recess bottom surface portion 44e are each reinforced by a fiber sheet containing carbon fiber resin. It is made of carbon fiber reinforced resin.

The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction of each surface and bonded with a resin.

The left arm recessed front surface portion 44 a is a surface located in the front portion of the left arm recessed portion 44 . The left arm recessed front surface portion 44 a extends in the left-right direction from the left arm right side surface portion 43 to a left arm recessed left surface portion 44 d located inside the left arm portion 40 relative to the left arm left side surface portion 42 . The left arm recessed portion rear surface portion 44b is a surface positioned at the rear portion of the left arm recessed portion 44 . Similarly to the left arm recessed front surface portion 44a, the left arm recessed rear surface portion 44b is also positioned inward of the left arm portion 40 from the left arm right side surface portion 43 in the left-right direction relative to the left arm left side surface portion 42. It extends to 44d. The left arm recessed front surface portion 44a and the left arm recessed rear surface portion 44b are arranged in parallel in the front-rear direction. That is, the left arm recessed front surface portion 44a and the left arm recessed rear surface portion 44b are arranged to face each other in the front-rear direction. The left arm recessed rear surface portion 44b is longer in the left-right direction than the left arm recessed front surface portion 44a.

The left arm concave upper surface portion 44 c is a surface positioned above the left arm concave portion 44 . The left arm recessed upper surface portion 44 c also extends in the left-right direction from the left arm right side surface portion 43 to the left arm recessed left surface portion 44 d located inside the left arm portion 40 relative to the left arm left side surface portion 42 . The left arm concave upper surface portion 44c has a trapezoidal shape when viewed from above. The left arm recessed portion lower surface portion 44 e is a surface positioned below the left arm recessed portion 44 . The left arm recessed lower surface portion 44 e also extends in the left-right direction from the left arm right side surface portion 43 to the left arm recessed left surface portion 44 d located inside the left arm portion 40 relative to the left arm left side surface portion 42 . The left arm concave upper surface portion 44c and the left arm concave lower surface portion 44e are arranged in parallel in the vertical direction. That is, the left arm concave upper surface portion 44c and the left arm concave lower surface portion 44e are arranged to face each other in the vertical direction. Similarly to the left arm recessed portion upper surface portion 44c, the left arm recessed portion lower surface portion 44e also has a trapezoidal shape when viewed from above.

The left arm recessed portion left surface portion 44 d is a surface located on the left portion of the left arm recessed portion 44 . The left arm concave left surface portion 44 d is located inside the left arm portion 40 relative to the left arm left side surface portion 42 along the left arm left side surface portion 42 . The left arm concave left surface portion 44d has a rectangular shape when viewed in the left-right direction.

On the left side of the left arm recess 44, the left arm left side surface 42 forming the left arm recess left surface 44d is positioned. Thereby, the left arm concave portion 44 is not exposed to the left of the left arm portion 40 . Therefore, it is possible to prevent the appearance of the rear arm 14 from being spoiled when the rear arm 14 is viewed from the left side.

In a state in which the left arm portion 40 and the cross portion 50 are combined, the left arm recessed front surface portion 44a, the left arm recessed rear surface portion 44b, the left arm recessed upper surface portion 44c, the left arm recessed left surface portion 44d, and the left arm recessed portion 44d. The cross left convex portion 53 of the cross portion 50 is positioned in the left arm concave portion 44 formed by the arm concave lower surface portion 44e. That is, the downward load of the cross portion 50 is received by the left arm concave lower surface portion 44e. The left arm recessed lower surface portion 44e constitutes a left arm load receiving surface. Further, as will be described later, a reaction force that the rear arm 14 receives from the rear suspension 9 when the rear wheel 4 is displaced upward is input to the left arm concave lower surface portion 44e.

Since force is input to the left arm recessed portion lower surface portion 44e as described above, the left arm portion 40 has a plurality of surfaces that support the left arm recessed portion lower surface portion 44e. Specifically, as shown in FIGS. 6, 9 and 11, in the present embodiment, the left arm portion 40 includes a left arm recessed front lower surface portion 45a, a left arm recessed rear lower surface portion 45b, and a left arm recessed left lower surface portion. 45d, and a left arm concave lower right surface portion 45f. The left arm recess front lower surface portion 45a, the left arm recess rear lower surface portion 45b, the left arm recess left lower surface portion 45d, and the left arm recess right lower surface portion 45f are left arm load bearing surface support portions. In this embodiment, the left arm recessed left lower surface portion 45 d is part of the left arm left side surface portion 42 , and the left arm recessed right lower surface portion 45 f is part of the left arm right side surface portion 43 . The left arm concave left lower surface portion 45 d may be provided separately from the left arm left side surface portion 42 . The left arm concave right side surface portion 45 f may be provided separately from the left arm right side surface portion 43 .

The left arm recess front lower surface portion 45a, the left arm recess rear lower surface portion 45b, the left arm recess left lower surface portion 45d, and the left arm recess right lower surface portion 45f are each made of resin (for example, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene). , polyphenylene sulfide, etc.) is composed of a carbon fiber reinforced resin reinforced by a fiber sheet containing carbon fibers.

The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction of each surface and bonded with a resin.

The left arm recessed front lower surface portion 45 a is positioned below and forward of the left arm recessed portion 44 . The left arm recessed rear lower surface portion 45 b is positioned below and behind the left arm recessed portion 44 . The left arm recessed portion left lower surface portion 45 d is positioned below the left arm recessed portion 44 and on the left surface of the left arm portion 40 . The left arm recessed portion lower right surface portion 45 f is positioned below the left arm recessed portion 44 and on the right surface of the left arm portion 40 . The left arm concave front lower surface portion 45a and the left arm concave rear lower surface portion 45b are arranged to face each other in the front-rear direction. The left arm recessed portion left lower surface portion 45d and the left arm recessed portion right surface portion 45f are arranged to face each other in the left-right direction.

The left arm recess front bottom surface 45a, the left arm recess rear bottom surface 45b, the left arm recess left bottom surface 45d, and the left arm recess right bottom surface 45f are connected to the left arm recess bottom surface 44e. It is also connected to the left arm lower surface portion 49 . Specifically, the left arm recess front bottom surface 45a, the left arm recess rear bottom surface 45b, the left arm recess left bottom surface 45d, and the left arm recess bottom right surface 45f are connected to the periphery of the left arm recess bottom surface 44e. The left arm recess front lower surface portion 45a extends forward and downward from the connecting portion between the left arm recess lower surface portion 44e and the left arm recess front surface portion 44a when viewed in the left-right direction. The left arm recess rear lower surface portion 45b extends rearward and downward from the connection portion between the left arm recess lower surface portion 44e and the left arm recess rear surface portion 44b as viewed in the left-right direction.

In this manner, the left arm recessed portion lower surface portion 44e is supported from below by the four surfaces of the left arm recessed portion front lower surface portion 45a, the left arm recessed portion rearwardly surface portion 45b, the left arm recessed portion left lower surface portion 45d, and the left arm recessed portion right surface portion 45f. By doing so, the downward load can be more reliably received by the left arm recessed portion lower surface portion 44e.

In addition, in the present embodiment, one side of the left arm portion 40 is connected to the connecting portion between the left arm concave portion front portion 44a and the left arm concave portion upper surface portion 44c of the left arm concave portion 44, and the other side is forward and from the connecting portion. It has a left arm concave front upper surface portion 46a extending upward and connected to the left arm upper surface portion 48 of the left arm portion 40 (the outer surface of the left arm portion 40). As a result, the strength of the left arm concave front surface portion 44a and the left arm concave upper surface portion 44c can be improved.

The left arm concave front upper surface portion 46a is made of carbon fiber reinforced resin in which a resin (eg, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc.) is reinforced with a fiber sheet containing carbon fibers. there is

The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction of the left arm concave front upper surface portion 46a and bonded with resin.

(Cross left protrusion)
As shown in FIGS. 8 and 11 , the cross portion 50 has a cross left convex portion 53 that protrudes leftward from the flat portion 51 and has a trapezoidal shape when viewed from above. The cross left convex portion 53 has a rectangular tubular shape when viewed from the left-right direction. That is, the left cross convex portion 53 has a closed cross-sectional shape when viewed in cross section in the front-rear direction.

Specifically, the cross left projection 53 has a cross left projection front surface portion 53a, a cross left projection rear surface portion 53b, a cross left projection upper surface portion 53c, and a cross left projection lower surface portion 53d. The cross left convex front surface portion 53a, the cross left convex rear surface portion 53b, the cross left convex upper surface portion 53c, and the cross left convex lower surface portion 53d constitute respective side surfaces of the square tube.

The cross left projection 53 is made of carbon fiber reinforced resin in which a resin (eg, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc.) is reinforced with a fiber sheet containing carbon fibers. That is, each of the left cross projection front surface portion 53a, the left cross projection rear surface portion 53b, the left cross projection upper surface portion 53c, and the left cross projection lower surface portion 53d is a carbon resin reinforced with a fiber sheet containing carbon fiber. It is made of fiber reinforced resin.

The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction of each surface and bonded with a resin.

As shown in FIGS. 6 , 8 and 11 , the cross left projection front surface portion 53 a is positioned in front of the cross left projection portion 53 . The cross left protrusion rear surface portion 53 b is located at the rear portion of the cross left protrusion 53 . The cross left convex upper surface portion 53 c is positioned above the cross left convex portion 53 . The cross left protrusion lower surface portion 53 d is positioned below the cross left protrusion 53 .

The cross left projection front surface portion 53a and the cross left projection rear surface portion 53b are arranged in parallel in the front-rear direction. The cross left projection front surface portion 53a and the cross left projection rear surface portion 53b are rectangular when viewed from the front-rear direction. The cross left projection rear surface portion 53b protrudes leftward from the cross left projection front surface portion 53a.

The cross left convex upper surface portion 53c and the cross left convex lower surface portion 53d are arranged in parallel in the vertical direction. The cross left convex upper surface portion 53c and the cross left convex lower surface portion 53d are trapezoidal in top view and have the same size.

As a result, the cross left convex portion 53 has a trapezoidal prismatic shape when viewed from above. With the cross left protrusion 53 inserted into the left arm recess 44 , the cross left protrusion lower surface 53 d of the cross left protrusion 53 contacts the left arm recess lower surface 44 e of the left arm recess 44 . That is, the cross left protrusion 53 is supported by the left arm recess lower surface portion 44 e of the left arm recess 44 .

(Right arm recess)
As shown in FIGS. 5 , 7 , 8 , 10 and 11 , the right arm portion 60 has a right arm concave portion 64 on the right arm left side surface portion 62 . The right arm recess 64 has a right arm recess front surface 64a, a right arm recess rear surface 64b, a right arm recess top surface 64c, a right arm recess right surface 64d, and a right arm recess bottom surface 64e. That is, the right arm recess 64 is surrounded by a right arm recess front surface portion 64a, a right arm recess rear surface portion 64b, a right arm recess top surface portion 64c, a right arm recess right surface portion 64d, and a right arm recess bottom surface portion 64e. space.

The right arm concave portion 64 is made of carbon fiber reinforced resin in which a resin (eg, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc.) is reinforced with a fiber sheet containing carbon fibers. That is, the right arm recess front surface portion 64a, the right arm recess rear surface portion 64b, the right arm recess top surface portion 64c, the right arm recess right surface portion 64d, and the right arm recess bottom surface portion 64e are each reinforced by a fiber sheet containing carbon fiber resin. It is made of carbon fiber reinforced resin.

The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction of each surface and bonded with a resin.

As shown in FIGS. 8 and 11 , the right arm recessed front surface portion 64 a is a surface positioned in front of the right arm recessed portion 64 . The right arm recessed front surface portion 64 a extends in the left-right direction from the right arm left side surface portion 62 to the right arm recessed right surface portion 64 d located inside the right arm portion 60 relative to the right arm right side surface portion 63 . The right arm recessed portion rear surface portion 64 b is a surface located at the rear portion of the right arm recessed portion 64 . Similarly to the right arm recessed front surface portion 64a, the right arm recessed rear surface portion 64b is also positioned in the left-right direction from the right arm left side surface portion 62 to the inside of the right arm portion 60 relative to the right arm right side surface portion 63. Extends to 64d. The right arm recessed front surface portion 64a and the right arm recessed rear surface portion 64b are arranged in parallel in the front-rear direction. That is, the right arm recessed front surface portion 64a and the right arm recessed rear surface portion 64b are arranged to face each other in the front-rear direction. The right arm recessed rear surface portion 64b is longer in the left-right direction than the right arm recessed front surface portion 64a.

The right arm recessed portion upper surface portion 64 c is a surface positioned above the right arm recessed portion 64 . The right arm recessed upper surface portion 64 c also extends in the left-right direction from the right arm left side surface portion 62 to the right arm recessed right surface portion 64 d positioned inside the right arm portion 60 relative to the right arm right side surface portion 63 . The right arm concave upper surface portion 64c has a trapezoidal shape when viewed from above. The right arm recessed portion lower surface portion 64 e is a surface positioned below the right arm recessed portion 64 . The right arm recessed portion lower surface portion 64 e also extends in the left-right direction from the right arm left side surface portion 62 to the right arm recessed right surface portion 64 d positioned inside the right arm portion 60 relative to the right arm right side surface portion 63 . The right arm concave upper surface portion 64c and the right arm concave lower surface portion 64e are arranged in parallel in the vertical direction. That is, the right arm recessed upper surface portion 64c and the right arm recessed lower surface portion 64e are arranged to face each other in the vertical direction. Like the right arm recessed portion upper surface portion 64c, the right arm recessed portion lower surface portion 64e also has a trapezoidal shape when viewed from above.

The right arm recessed portion right surface portion 64 d is a surface located on the right portion of the right arm recessed portion 64 . The right arm recessed right side surface portion 64 d is located inside the right arm portion 60 relative to the right arm right side surface portion 63 along the right arm right side surface portion 63 . The right arm concave right surface portion 64d has a rectangular shape when viewed in the horizontal direction.

On the right side of the right arm recess 64, a right arm right side surface portion 63 forming a right arm recess right surface portion 64d is positioned. As a result, the right arm concave portion 64 is not exposed to the right of the right arm portion 60 . Therefore, it is possible to prevent the appearance of the rear arm 14 from being spoiled when the rear arm 14 is viewed from the right side.

In a state in which the right arm portion 60 and the cross portion 50 are combined, the right arm recessed front surface portion 64a, the right arm recessed rear surface portion 64b, the right arm recessed upper surface portion 64c, the right arm recessed right surface portion 64d, and the right arm recessed portion 64d. The cross right convex portion 54 of the cross portion 50 is positioned in the right arm concave portion 64 formed by the arm concave lower surface portion 64e. That is, the vertical load of the cross portion 50 is received by the right arm concave lower surface portion 64e. The right arm recessed lower surface portion 64e constitutes a right arm load bearing surface. As will be described later, the reaction force received by the rear suspension 9 from the rear suspension 9 when the rear wheel 4 is displaced is input to the right arm concave lower surface portion 64e.

Since force is input to the right arm recessed portion lower surface portion 64e as described above, the right arm portion 60 has a plurality of surfaces that support the right arm recessed portion lower surface portion 64e. Specifically, as shown in FIGS. 7, 10, and 11, in the present embodiment, the right arm portion 60 includes a right arm recess front lower surface portion 65a, a right arm recess rear lower surface portion 65b, and a right arm recess lower right surface portion. and a right arm concave left lower surface portion 65f. The right arm recess front lower surface portion 65a, the right arm recess rear lower surface portion 65b, the right arm recess lower right surface portion 65d, and the right arm recess left lower surface portion 65f are right arm load bearing surface support portions. In this embodiment, the right arm recessed portion right lower surface portion 65 d is part of the right arm right side surface portion 63 , and the right arm recessed left lower surface portion 65 f is part of the right arm left side surface portion 62 . The right arm concave right side surface portion 65d may be provided separately from the right arm right side surface portion 63 . The right arm recessed left lower surface portion 65 f may be provided separately from the right arm left side surface portion 62 .

The right arm concave front lower surface portion 65a, the right arm concave rear lower surface portion 65b, the right arm concave right lower surface portion 65d, and the right arm concave left lower surface portion 65f are each made of a resin (for example, epoxy resin, vinyl ester, phenolic resin, polyamide, polypropylene). , polyphenylene sulfide, etc.) is composed of a carbon fiber reinforced resin reinforced by a fiber sheet containing carbon fibers.

The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction of each surface and bonded with a resin.

The right arm recessed front lower surface portion 65 a is positioned below and forward of the right arm recessed portion 64 . The right arm recessed rear lower surface portion 65b is positioned below and behind the right arm recessed portion 64 . The right arm concave lower right surface portion 65 d is positioned below the right arm concave portion 64 and on the right surface of the right arm portion 60 . The right arm recessed portion left lower surface portion 65 f is located below the right arm recessed portion 64 and on the left surface of the right arm portion 60 . The right arm recessed front lower surface portion 65a and the right arm recessed rear lower surface portion 65b are arranged to face each other in the front-rear direction. The right arm recessed portion right bottom surface portion 65d and the right arm recessed portion left bottom surface portion 65f are arranged to face each other in the left-right direction.

The right arm recess front bottom surface 65a, the right arm recess rear bottom surface 65b, the right arm recess bottom right surface 65d, and the right arm recess left bottom surface 65f are connected to the right arm recess bottom surface 64e. It is also connected to the right arm lower surface portion 69 . The right arm recess front bottom surface 65a, right arm recess rear bottom surface 65b, right arm recess right bottom surface 65d, and right arm recess left bottom surface 65f are connected to the periphery of the right arm recess bottom surface 64e. The right arm recess front lower surface portion 65a extends forward and downward from the connecting portion between the right arm recess lower surface portion 64e and the right arm recess front surface portion 64a when viewed in the left-right direction. The right arm recessed rear lower surface portion 65b extends rearward and downward from the connecting portion between the right arm recessed lower surface portion 64e and the right arm recessed rear surface portion 64b as viewed in the left-right direction.

In this manner, the right arm recessed portion lower surface portion 64e is supported from below by the four surfaces of the right arm recessed portion front surface portion 65a, the right arm recessed portion rear surface portion 65b, the right arm recessed portion right surface portion 65d, and the right arm recessed portion left lower surface portion 65f. By doing so, the downward load can be more reliably received by the right arm recessed portion lower surface portion 64e.

In the present embodiment, the right arm portion 60 has one end connected to the connection portion between the right arm recess front portion 64a and the right arm recess top surface portion 64c of the right arm recess portion 64, and the other end extending forward and upward from the connection portion. It has a right arm concave front upper surface portion 66a extending toward and connected to a right arm upper surface portion 68 of the right arm portion 60 (the outer surface of the right arm portion 60). Thereby, the strength of the right arm recessed front surface portion 64a and the right arm recessed upper surface portion 64c can be improved.

The right arm concave front upper surface portion 66a is made of carbon fiber reinforced resin in which a resin (eg, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc.) is reinforced with a fiber sheet containing carbon fibers. there is

The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction of the right arm concave front upper surface portion 66a and bonded with resin.

(Cross right protrusion)
As shown in FIGS. 8 and 11 , the cross portion 50 has a cross right convex portion 54 projecting rightward from the flat portion 51 and having a trapezoidal shape when viewed from above. The right cross projection 54 has a rectangular tubular shape when viewed in the left-right direction. That is, the right cross projection 54 has a closed cross-sectional shape when viewed in cross section in the front-rear direction.

Specifically, the cross right projection 54 has a cross right projection front surface portion 54a, a cross right projection rear surface portion 54b, a cross right projection upper surface portion 54c, and a cross right projection lower surface portion 54d. The cross right convex front surface portion 54a, the cross right convex rear surface portion 54b, the cross right convex upper surface portion 54c, and the cross right convex lower surface portion 54d constitute the respective side surfaces of the rectangular tube.

The cross right protrusion 54 is made of carbon fiber reinforced resin in which a resin (eg, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc.) is reinforced with a fiber sheet containing carbon fibers. That is, the right cross convex front surface portion 54a, the right cross convex rear surface portion 54b, the right cross convex upper surface portion 54c, and the right cross convex lower surface portion 54d are each made of carbon resin reinforced by a fiber sheet containing carbon fiber. It is made of fiber reinforced resin.

The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction of each surface and bonded with a resin.

As shown in FIGS. 7, 8 and 11 , the cross right convex front surface portion 54 a is located in front of the cross right convex portion 54 . The cross right protrusion rear surface portion 54 b is located at the rear portion of the cross right protrusion 54 . The cross right convex upper surface portion 54 c is positioned above the cross right convex portion 54 . The cross right protrusion lower surface portion 54 d is positioned below the cross right protrusion 54 .

The cross right projection front surface portion 54a and the cross right projection rear surface portion 54b are arranged in parallel in the front-rear direction. The cross right projection front surface portion 54a and the cross right projection rear surface portion 54b are rectangular when viewed from the front-rear direction. The right cross projection rear surface portion 54b protrudes to the right from the cross right projection front surface portion 54a.

The cross right convex upper surface portion 54c and the cross right convex lower surface portion 54d are arranged in parallel in the vertical direction. The cross right convex upper surface portion 54c and the cross right convex lower surface portion 54d are trapezoidal in top view and have the same size.

As a result, the right cross convex portion 54 has a trapezoidal prismatic shape when viewed from above. With the cross right protrusion 54 inserted into the right arm recess 64 , the cross right protrusion lower surface 54 d of the cross right protrusion 54 contacts the right arm recess lower surface 64 e of the right arm recess 64 . That is, the cross right protrusion 54 is supported by the right arm recessed portion lower surface portion 64 e of the right arm recessed portion 64 .

<Suspension reaction force>
Next, the force (suspension reaction force) that the rear suspension 9 exerts on the rear arm 14 having the configuration described above will be described with reference to FIGS. 12 and 13. FIG.

FIG. 12 is a left side view of vehicle 1 schematically showing a case where rear wheel 4 is displaced upward. In FIG. 12 , the state before the rear wheel 4 is displaced is indicated by a dashed line, and the rear wheel 4 after displacement is indicated by a solid line. FIG. 13 is a diagram schematically showing the force that the rear suspension 9 receives from the rear arm 14 when the rear wheel 4 is displaced upward as shown in FIG.

As shown in FIG. 12, when the rear wheel 4 of the vehicle 1 runs over a step or the like and is displaced upward (white arrow in FIG. 12), the rear wheel 4 and the rear arm 14 move from the position indicated by the dashed line to the position indicated by the solid line. , move up. At this time, the rear arm 14 rotates upward about the pivot shaft 71 of the frame connecting portion 14a. The rear suspension 9 connected to the suspension connecting portion 14c of the rear arm 14 is axially compressed as the rear arm 14 rotates as described above. When the rear suspension 9 is compressed in the axial direction, a reaction force is input from the rear suspension 9 to the suspension connecting portion 14c of the rear arm 14 (solid line arrows in FIGS. 12 and 13).

When the suspension connecting portion 14c of the rear arm 14 receives a reaction force from the rear suspension 9, the rear arm 14 receives a downward force. Then, a downward force is also input to the cross portion 50 provided with the suspension connecting portion 14c. As a result, a downward force is also input to the connecting portions between the cross portion 50 and the left arm portion 40 and the right arm portion 60 (broken line arrows in FIG. 13).

In this embodiment, the cross left convex portion 53 of the cross portion 50 has a left arm recess front surface portion 44a, a left arm recess rear surface portion 44b, a left arm recess upper surface portion 44c, and a left arm recess lower surface portion 44e. Located within the arm recess 44 . The cross right convex portion 54 of the cross portion 50 is positioned within a right arm recess 64 having a right arm recess front surface portion 64a, a right arm recess rear surface portion 64b, a right arm recess top surface portion 64c, and a right arm recess bottom surface portion 64e. To position. As a result, the cross left protrusion 53 and the cross right protrusion 54 are inserted into the left arm recess 44 and the right arm recess 64 respectively surrounded by the four surfaces. Therefore, the left cross protrusion 53 and the right cross protrusion 54 can be inserted more reliably into the left arm recess 44 and the right arm recess 64 . Moreover, due to the above-described configuration, even when a force is applied to the cross portion 50 in either the up-down direction or the left-right direction, the surfaces of the left arm concave portion 44 and the right arm concave portion 64 cause the cross left convex portion 53 to move. and the force input to the cross right convex portion 54 can be received.

Further, the cross left convex portion 53 and the cross right convex portion 54 of the cross portion 50 are positioned in the left arm concave portion 44 of the left arm portion 40 and the right arm concave portion 64 of the right arm portion 60, respectively. It is supported by the right arm concave lower surface portion 64e. Therefore, the downward force input to the cross portion 50 as described above is received by the left arm concave lower surface portion 44e and the right arm concave lower surface portion 64e.

In this embodiment, the surfaces forming the left arm portion 40, the cross portion 50, and the right arm portion 60 are made of carbon fiber reinforced resin in which fiber sheets laminated in the thickness direction are bonded with resin. Therefore, the weight of the rear arm 14 can be reduced.

Moreover, the configuration of the present embodiment can secure the strength of the rear arm 14 without increasing the number of laminated fiber sheets in order to secure the strength of the rear arm. Therefore, it is possible to improve the support strength of the cross portion 50 of the rear arm 14 to which the rear suspension 9 is connected, while suppressing an increase in the weight of the rear arm 14 .

Further, in the present embodiment, the left arm recess bottom surface portion 44e is supported by the left arm recess front bottom surface portion 45a, the left arm recess rear bottom surface portion 45b, the left arm recess left bottom surface portion 45d, and the left arm recess right bottom surface portion 45f. . The right arm recess bottom surface 64e is supported by a right arm recess front bottom surface 65a, a right arm recess rear bottom surface 65b, a right arm recess bottom right surface 65d, and a right arm recess left bottom surface 65f. As a result, the force input from the rear suspension 9 can be received more reliably by the left arm recessed portion lower surface portion 44e and the right arm recessed portion lower surface portion 64e.

Each surface of the left arm portion 40, the cross portion 50, and the right arm portion 60 has higher strength in the direction along the surface than in the thickness direction. Therefore, as described above, by supporting the left arm recessed portion lower surface portion 44e and the right arm recessed portion lower surface portion 64e by a plurality of surfaces, the portions ( The strength of the connecting portion between the left arm portion 40 and the cross portion 50 and the connecting portion between the right arm portion 60 and the cross portion 50) can be further improved. Thereby, the strength of the rear arm 14 can be further improved.

In this embodiment, the left arm portion 40 is positioned to the left of the rear wheel 4 . The right arm portion 60 is positioned to the right of the rear wheel 4 . Therefore, the force input from the rear suspension 9 to the rear arm 14 is input to the connecting portion between the left arm portion 40 and the cross portion 50 and the connecting portion between the right arm portion 60 and the cross portion 50 .

On the other hand, the connecting portion between the left arm portion 40 and the cross portion 50 and the connecting portion between the right arm portion 60 and the cross portion 50 are configured as described above, so that the input from the rear suspension 9 is reduced. In contrast, the strength of the rear arm 14 can be ensured.

(Embodiment 2)
FIG. 14 is a top view showing a state in which the rear arm 114 of the vehicle according to the second embodiment is disassembled into the left arm portion 140, the cross portion 150 and the right arm portion 160. FIG. 15 is a cross-sectional view taken along the line XV-XV in FIG. 14. FIG. 16 is a cross-sectional view taken along line XVI-XVI in FIG. 14. FIG.

This embodiment differs from the configuration of the first embodiment in the connection structure of the left arm portion 140, the cross portion 150 and the right arm portion 160. FIG. In the following, configurations similar to those of the first embodiment are denoted by the same reference numerals, descriptions thereof are omitted, and only points different from the first embodiment are described.

As shown in FIG. 14 , the left arm portion 140 has a left arm convex portion 144 that protrudes rightward from the left arm right side surface portion 43 . The right arm portion 160 has a right arm convex portion 164 that protrudes leftward from the right arm left side surface portion 62 . The cross portion 150 has a left side portion 159 a positioned at the left end of the flat portion 151 and a right side portion 159 b positioned at the right end of the flat portion 151 . The cross portion 150 has a cross left concave portion 153 located on the left side surface portion 159a into which the left arm convex portion 144 can be inserted, and a cross right concave portion 154 located on the right side surface portion 159b into which the right arm convex portion 164 can be inserted. .

In addition, the left arm convex portion 144 is provided in front of the central portion in the front-rear direction of the left arm portion 140 . The right arm protrusion 164 is provided forward of the central portion of the right arm portion 160 in the front-rear direction. The cross left concave portion 153 and the cross right concave portion 154 are provided in the rear arm 114 in front of the central portion in the front-rear direction.

The left arm protrusion 144 has a rectangular tubular shape with a rectangular cross section when viewed from the left-right direction. The left arm protrusion 144 has a rectangular shape when viewed from above. The left arm convex portion 144 has a left arm convex front surface portion 144a, a left arm convex rear surface portion 144b, a left arm convex upper surface portion 144c, and a left arm convex lower surface portion 144d.

The left arm projection 144 is made of carbon fiber reinforced resin in which a resin (eg, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc.) is reinforced with a fiber sheet containing carbon fibers. That is, the left arm convex front surface portion 144a, the left arm convex rear surface portion 144b, the left arm convex upper surface portion 144c, and the left arm convex lower surface portion 144d are each made of carbon fiber reinforced by a fiber sheet containing carbon fiber. It is made of fiber reinforced resin.

The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction of each surface and bonded with a resin.

The left arm projection front surface portion 144 a is a surface positioned in front of the left arm projection portion 144 . The left arm projection rear surface portion 144 b is a surface located at the rear portion of the left arm projection portion 144 . The left arm convex upper surface portion 144 c is a surface positioned above the left arm convex portion 144 . The left arm projection lower surface portion 144 d is a surface positioned below the left arm projection portion 144 .

The right arm convex portion 164 has a rectangular tubular shape with a rectangular cross section when viewed from the left-right direction. The right arm protrusion 164 has a rectangular shape when viewed from above. The right arm convex portion 164 has a right arm convex front surface portion 164a, a right arm convex rear surface portion 164b, a right arm convex upper surface portion 164c, and a right arm convex lower surface portion 164d.

The right arm projection 164 is made of carbon fiber reinforced resin in which a resin (eg, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc.) is reinforced with a fiber sheet containing carbon fibers. That is, the right arm convex front surface portion 164a, the right arm convex rear surface portion 164b, the right arm convex upper surface portion 164c, and the right arm convex lower surface portion 164d are each made of carbon fiber reinforced by a fiber sheet containing carbon fiber. It is made of fiber reinforced resin.

The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction of each surface and bonded with a resin.

The right arm protrusion front surface portion 164 a is positioned in front of the right arm protrusion portion 164 . The right arm protrusion rear surface portion 164 b is positioned at the rear portion of the right arm protrusion 164 . The right arm convex upper surface portion 164 c is positioned above the right arm convex portion 164 . The right arm protrusion lower surface portion 164 d is positioned below the right arm protrusion 164 .

Cross left recess 153 is recessed inwardly of flat portion 151 from left side surface portion 159a. As shown in FIG. 14, the cross left concave portion 153 has a rectangular shape when viewed from above. As shown in FIG. 15, the cross left concave portion 153 has a rectangular shape when viewed from the left-right direction. The cross left recess 153 has a cross left recess front surface portion 153a, a cross left recess rear surface portion 153b, a cross left recess top surface portion 153c, a cross left recess right surface portion 153d, and a cross left recess bottom surface portion 153e.

The cross left concave portion 153 is made of carbon fiber reinforced resin in which a resin (for example, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc.) is reinforced with a fiber sheet containing carbon fibers. That is, the cross left recess front surface portion 153a, the cross left recess rear surface portion 153b, the cross left recess top surface portion 153c, the cross left recess right surface portion 153d, and the cross left recess bottom surface portion 153e are each reinforced by a fiber sheet containing carbon fiber resin. It is made of carbon fiber reinforced resin.

The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction of each surface and bonded with a resin.

The cross left concave front surface portion 153 a is a surface located in the front portion of the cross left concave portion 153 . The cross left recess rear surface portion 153 b is a surface positioned at the rear portion of the cross left recess portion 153 . The cross left concave front surface portion 153a and the cross left concave rear surface portion 153b are arranged in parallel in the front-rear direction. That is, the cross left concave front surface portion 153a and the cross left concave rear surface portion 153b are arranged facing each other in the front-rear direction. The cross left concave front surface portion 153a and the cross left concave rear surface portion 153b are rectangular when viewed from the front-rear direction.

The cross left concave upper surface portion 153 c is a surface positioned above the cross left concave portion 153 . The cross left concave portion lower surface portion 153 e is a surface positioned below the cross left concave portion 153 . The cross left recess upper surface portion 153c and the cross left recess lower surface portion 153e are arranged in parallel in the vertical direction. That is, the cross left concave upper surface portion 153c and the cross left concave lower surface portion 153e are arranged to face each other in the vertical direction. The cross left recess upper surface portion 153c and the cross left recess lower surface portion 153e are rectangular in top view.

The cross left concave right surface portion 153 d is a surface located on the right side of the cross left concave portion 153 . The cross left concave right surface portion 153d has a rectangular shape when viewed in the horizontal direction.

In a state in which the left arm portion 140 and the cross portion 150 are combined, the cross left recess front surface portion 153a, the cross left recess rear surface portion 153b, the cross left recess upper surface portion 153c, the cross left recess right surface portion 153d, and the cross Left arm protrusion 144 of left arm 140 is positioned in cross left recess 153 formed by left recess lower surface 153e. That is, the downward load of the cross portion 150 is received by the cross left concave upper surface portion 153c. The cross left recessed upper surface portion 153c constitutes a cross left load receiving surface. Further, the reaction force that the rear arm 14 receives from the rear suspension 9 when the rear wheel 4 is displaced upward is input to the cross left concave upper surface portion 153c.

As described above, force is input to the cross left concave upper surface portion 153c, so the cross portion 150 has a plurality of surfaces that support the cross left concave upper surface portion 153c. Specifically, as shown in FIGS. 15 and 17, in the present embodiment, the cross portion 150 has a cross left recess front upper surface portion 155a, a cross left recess rear upper surface portion 155b, and a cross left recess upper left surface portion 155d. . The cross left recess front upper surface portion 155a, the cross left recess rear upper surface portion 155b, and the cross left recess upper left surface portion 155d are cross left load bearing surface support portions. In this embodiment, the cross left concave left upper surface portion 155 d is a part of the left side surface portion 159 a of the cross portion 150 . The cross left concave left upper surface portion 155 d may be provided separately from the left side surface portion 159 a of the cross portion 150 .

The cross left recess front upper surface portion 155a, the cross left recess rear upper surface portion 155b, and the cross left recess upper left surface portion 155d are each made of carbon resin (for example, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc.). It is composed of a carbon fiber reinforced resin reinforced by a fiber sheet containing fibers.

The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction of each surface and bonded with a resin.

The cross left concave front upper surface portion 155 a is located above and in front of the cross left concave portion 153 . The cross left concave rear upper surface portion 155 b is positioned above and behind the cross left concave portion 153 . The cross left concave upper left surface portion 155 d is located above the cross left concave portion 153 and on the left side surface of the cross portion 150 . The cross left recessed front upper surface portion 155a and the cross left recessed rear upper surface portion 155b are arranged to face each other in the front-rear direction.

Note that the cross portion 150 may have a cross left concave upper right surface portion located above and to the right of the cross left concave portion 153 and arranged to face the cross left concave upper left surface portion 155d in the left-right direction. good.

The cross left recess front upper surface portion 155 a , the cross left recess rear upper surface portion 155 b , and the cross left recess upper left surface portion 155 d are connected to the cross left recess upper surface portion 153 c and also connected to the upper surface portion of the cross portion 150 . The cross left recess front upper surface portion 155a, the cross left recess rear upper surface portion 155b, and the cross left recess upper left surface portion 155d are connected to the peripheral edge portion of the cross left recess upper surface portion 153c. The cross left recess front upper surface portion 155a extends forward and upward from the connecting portion between the cross left recess front surface portion 153a and the cross left recess upper surface portion 153c when viewed in the left-right direction. The cross left recess rear upper surface portion 155b extends rearward and upward from the connection portion between the cross left recess rear surface portion 153b and the cross left recess upper surface portion 153c when viewed in the left-right direction.

In this manner, the cross left recess upper surface portion 153c is supported from above by the three surfaces of the cross left recess front surface portion 155a, the cross left recess rear upper surface portion 155b, and the cross left recess upper left surface portion 155d. The upward load can be received more reliably by the portion 153c.

In the present embodiment, one side of the cross portion 150 is connected to the connection portion between the cross left recess front surface portion 153a and the cross left recess bottom surface portion 153e of the cross left recess portion 153, and the other is forward and downward from the connection portion. It has a cross left concave front lower surface portion 157 a extending toward and connected to the outer surface of the cross portion 150 . As a result, the strength of the cross left concave front surface portion 153a and cross left concave lower surface portion 153e can be improved.

The cross left concave front lower surface portion 157a is made of a carbon fiber reinforced resin in which a resin (for example, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc.) is reinforced with a fiber sheet containing carbon fibers. there is

The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction of the cloth left concave front lower surface portion 157a and bonded together by resin.

The cross right recessed portion 154 is recessed inwardly of the flat portion 151 from the right side surface portion 159 b of the flat portion 151 . As shown in FIG. 14, the right cross recess 154 has a rectangular shape when viewed from above. As shown in FIG. 16, the right cross recess 154 has a rectangular shape when viewed from the left-right direction. The right cross recess 154 includes a right cross recess front surface portion 154a, a right cross recess rear surface portion 154b, a right cross recess upper surface portion 154c, a right cross recess left surface portion 154d (see FIG. 14), and a right cross recess lower surface portion 154e. have

The cross right concave portion 154 is made of carbon fiber reinforced resin in which a resin (eg, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc.) is reinforced with a fiber sheet containing carbon fibers. That is, the right cross recess front surface portion 154a, the right cross recess rear surface portion 154b, the right cross recess upper surface portion 154c, the right cross recess left surface portion 154d, and the right cross recess lower surface portion 154e are each reinforced by a fiber sheet containing carbon fiber resin. It is made of carbon fiber reinforced resin.

The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction of each surface and bonded with a resin.

The cross right recessed front surface portion 154 a is a surface located in the front portion of the cross right recessed portion 154 . The cross right concave rear surface portion 154 b is a surface positioned at the rear of the cross right concave portion 154 . The cross right concave front surface portion 154a and the cross right concave rear surface portion 154b are arranged in parallel in the front-rear direction. That is, the cross right concave front surface portion 154a and the cross right concave rear surface portion 154b are arranged to face each other in the front-rear direction. The cross right concave front surface portion 154a and the cross right concave rear surface portion 154b are rectangular when viewed from the front-rear direction.

The cross right concave upper surface portion 154 c is a surface positioned above the cross right concave portion 154 . The cross right concave lower surface portion 154 e is a surface positioned below the cross right concave portion 154 . The cross right concave upper surface portion 154c and the cross right concave lower surface portion 154e are arranged in parallel in the vertical direction. That is, the cross right concave upper surface portion 154c and the cross right concave lower surface portion 154e are arranged to face each other in the vertical direction. The cross right concave upper surface portion 154c and the cross right concave lower surface portion 154e are rectangular in top view.

The cross right concave left surface portion 154 d is a surface located on the left side of the cross right concave portion 154 . The cross right concave left surface portion 154d has a rectangular shape when viewed in the left-right direction.

In a state in which the right arm portion 160 and the cross portion 150 are combined, the cross right recess front surface portion 154a, the cross right recess rear surface portion 154b, the cross right recess upper surface portion 154c, the cross right recess left surface portion 154d, and the cross A right arm convex portion 164 of the right arm portion 160 is positioned in the cross right concave portion 154 formed by the right concave portion lower surface portion 154e. In other words, the downward load of the cross portion 150 is received by the cross right concave upper surface portion 154c. The cross right recessed upper surface portion 154c constitutes a cross right load receiving surface. Further, the reaction force that the rear arm 14 receives from the rear suspension 9 when the rear wheel 4 is displaced upward is input to the cross right concave upper surface portion 154c.

As described above, force is input to cross right concave upper surface portion 154c, so cross portion 150 has a plurality of surfaces that support cross right concave upper surface portion 154c. Specifically, as shown in FIGS. 16 and 18, in the present embodiment, the cross portion 150 has a cross right recess front upper surface portion 156a, a cross right recess rear upper surface portion 156b, and a cross right recess upper right surface portion 156d. . The cross right recess front upper surface portion 156a, the cross right recess rear upper surface portion 156b, and the cross right recess upper right surface portion 156d are cross right load receiving surface support portions. In the present embodiment, the cross right concave upper right surface portion 156 d is a part of the right side surface portion 159 b of the cross portion 150 . The cross right concave upper right surface portion 156 d may be provided separately from the right side surface portion 159 b of the cross portion 150 .

The cross right recess front upper surface portion 156a, the cross right recess rear upper surface portion 156b, and the cross right recess upper right surface portion 156d are each made of carbon resin (for example, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc.). It is composed of a carbon fiber reinforced resin reinforced by a fiber sheet containing fibers.

The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction of each surface and bonded with a resin.

The cross right concave front upper surface portion 156 a is located above and in front of the cross right concave portion 154 . The cross right recess rear upper surface portion 156 b is located above and behind the cross right recess 154 . The cross right concave upper right surface portion 156 d is located above the cross right concave portion 154 and on the right side surface of the cross portion 150 . The cross right concave front upper surface portion 156a and the cross right concave rear upper surface portion 156b are arranged to face each other in the front-rear direction.

Note that the cross portion 150 may have a cross right concave upper left surface portion that is positioned above and to the left of the cross right concave portion 154 and that is arranged to face the cross right concave upper right surface portion 156d in the left-right direction. good.

The cross right recess front top surface 156 a , the cross right recess rear top surface 156 b , and the cross right recess top right surface 156 d are connected to the cross right recess top surface 154 c and also to the top surface of the cross portion 150 . The cross right recess front upper surface portion 156a, the cross right recess rear upper surface portion 156b, and the cross right recess upper right surface portion 156d are connected to the peripheral edge portion of the cross right recess upper surface portion 154c. The cross right recess front upper surface portion 156a extends forward and upward from the connecting portion between the cross right recess front surface portion 154a and the cross right recess upper surface portion 154c when viewed in the left-right direction. The cross right recess rear upper surface portion 156b extends rearward and upward from the connecting portion between the cross right recess rear surface portion 154b and the cross right recess upper surface portion 154c when viewed in the left-right direction.

In this way, the cross right recess upper surface portion 154c is supported from above by the cross right recess front surface portion 156a, the cross right recess rear upper surface portion 156b, and the cross right recess upper right surface portion 156d. A directional load can be received more reliably.

In the present embodiment, one side of the cross portion 150 is connected to the connecting portion between the cross right recess front surface portion 154a and the cross right recess bottom surface portion 154e of the cross right recess portion 154, and the other is forward and downward from the connection portion. Extending toward and connected to the outer surface of the cross portion 150 is a cross right recess front lower surface portion 158a. As a result, the strength of the right cross concave front surface portion 154a and the right cross concave lower surface portion 154e can be improved.

The cross right concave front lower surface portion 158a is made of a carbon fiber reinforced resin in which a resin (for example, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc.) is reinforced with a fiber sheet containing carbon fibers. there is

The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction of the cross right concave front lower surface portion 158a and bonded together by resin.

With the above configuration, the left arm protrusion 144 is positioned in the cross left concave portion 153 and the right arm protrusion 164 is positioned in the cross right concave portion 154 in a state in which the left arm portion 140, the cross portion 150, and the right arm portion 160 are combined. is located. That is, the downward load of the cross portion 150 is received by the left arm convex upper surface portion 144c and the right arm convex upper surface portion 164c. Therefore, when the rear wheel 4 of the vehicle is displaced upward as described in the first embodiment, the downward force input from the rear suspension 9 to the rear arm 114 is applied to the left arm convex upper surface 144c and It is received by the right arm projection upper surface portion 164c.

As described above, in the configuration of the present embodiment, as in the configuration of the first embodiment, it is possible to suppress an increase in the weight of the rear arm 114 and improve the support strength of the cross portion 150 of the rear arm 114 to which the rear suspension 9 is connected. can.

(Embodiment 3)
19 is a top view showing a state in which the rear arm 214 of the vehicle according to Embodiment 3 is disassembled into the left arm portion 140, the cross portion 250 and the right arm portion 60. FIG. In this embodiment, the connection structure between the left arm portion 140 and the cross portion 250 is the same connection structure as in the second embodiment, and the connection structure between the cross portion 250 and the right arm portion 60 is the same connection structure as in the first embodiment. is. In the following, configurations similar to those of the first and second embodiments are denoted by the same reference numerals, descriptions thereof are omitted, and only points different from the first and second embodiments are described.

As shown in FIG. 19 , the cross portion 250 has a left side portion 259 a positioned at the left end of the plane portion 251 . The cross portion 250 has a cross left concave portion 153 located on the left side surface portion 259 a of the flat portion 251 and into which the left arm convex portion 144 can be inserted, and a cross right convex portion 54 projecting rightward from the flat portion 251 .

With the above-described configuration, the left arm protrusion 144 is positioned in the cross left concave portion 153 and the cross right convex portion 54 is positioned in the right arm concave portion 64 when the left arm portion 140, the cross portion 250, and the right arm portion 60 are combined. is located. That is, the downward load of the cross portion 250 is received by the cross left concave upper surface portion 153c and the right arm concave lower surface portion 64e. Therefore, when the rear wheel 4 of the vehicle is displaced upward as described in the first embodiment, the downward force input from the rear suspension 9 to the rear arm 214 is applied to the cross left concave upper surface portion 153c and the right It is received by the arm recess lower surface portion 64e.

In this embodiment, as in Embodiments 1 and 2, the left arm portion 140, the cross portion 250, and the right arm portion 60 are each made of resin (for example, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc.). .) is composed of a carbon fiber reinforced resin reinforced by a fiber sheet containing carbon fibers. The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction and bonded together by resin.

Further, in the present embodiment, as in the first embodiment, the fiber sheets constitute the left arm portion 140, the cross portion 250 and the right arm portion 60 in the left arm portion 140, the cross portion 250 and the right arm portion 60, respectively. It is laminated in the thickness direction of each surface. As a result, the strength in the directions along the surfaces forming the left arm portion 140, the cross portion 250, and the right arm portion 60 is higher than the strength in the thickness direction of the surfaces.

Furthermore, although not shown in particular, in the present embodiment, the cross portion 250 also includes, as in the second embodiment, the cross left recess front upper surface portion, the cross left recess rear upper surface portion, the cross left recess upper left surface portion, and the cross left recess portion. and a lower front surface. As in the first embodiment, the right arm portion 60 includes a right arm concave front lower surface portion, a right arm concave rear lower surface portion, a right arm concave right lower surface portion, a right arm concave left lower surface portion, and a right arm front upper surface portion. and

As described above, the support strength of the cross portion 250 to which the rear suspension 9 is connected in the rear arm 214 can be improved while suppressing an increase in the weight of the rear arm 214 .

(Embodiment 4)
FIG. 20 is a top view showing a state in which the rear arm 314 of the vehicle according to Embodiment 4 is disassembled into the left arm portion 40, the cross portion 350 and the right arm portion 160. FIG. In this embodiment, the connection structure between the left arm portion 40 and the cross portion 350 is the same connection structure as in the first embodiment, and the connection structure between the cross portion 350 and the right arm portion 160 is the same connection structure as in the second embodiment. is. In the following, configurations similar to those of the first and second embodiments are denoted by the same reference numerals, descriptions thereof are omitted, and only points different from the first and second embodiments are described.

As shown in FIG. 20 , the cross portion 350 has a right side portion 359b positioned at the right end of the plane portion 351. As shown in FIG. The cross portion 350 has a cross left convex portion 53 projecting leftward from the plane portion 351 and a cross right concave portion 154 positioned on the right side surface portion 359b of the plane portion 351 and into which the right arm convex portion 164 can be inserted.

With the above-described configuration, when the left arm portion 40, the cross portion 350, and the right arm portion 160 are combined, the cross left convex portion 53 is positioned within the left arm concave portion 44, and the right arm convex portion 164 is positioned within the cross right concave portion 154. is located. That is, the downward load of the cross portion 350 is received by the left arm recessed portion lower surface portion 44e and the cross right recessed portion upper surface portion 154c. Therefore, as described in the first embodiment, when the rear wheel 4 of the vehicle is displaced upward, the downward force applied from the rear suspension 9 to the rear arm 314 is applied to the left arm concave lower surface portion 44e and the cross. It is received by the right concave top surface portion 154c.

In this embodiment, as in Embodiments 1 and 2, the left arm portion 40, the cross portion 350, and the right arm portion 160 are each made of resin (for example, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc.). .) is composed of a carbon fiber reinforced resin reinforced by a fiber sheet containing carbon fibers. The fiber sheet is formed into a sheet shape by weaving fibers. A plurality of the fiber sheets are laminated in the thickness direction and bonded together by resin.

Further, in the present embodiment, as in the first embodiment, the fiber sheets constitute the left arm portion 40, the cross portion 350 and the right arm portion 160, respectively, in the left arm portion 40, the cross portion 350 and the right arm portion 160. It is laminated in the thickness direction of each surface. As a result, the strength in the directions along the surfaces constituting the left arm portion 40, the cross portion 350, and the right arm portion 160 is higher than the strength in the thickness direction of the surfaces.

Furthermore, although not shown, in the present embodiment, the left arm portion 40 also includes, as in the first embodiment, a left arm recessed front lower surface portion, a left arm recessed rear lower surface portion, a left arm recessed left lower surface portion, and a left arm portion. It has a recessed lower right surface portion and a left arm recessed front upper surface portion. Further, the cross portion 350 has a cross right recess front upper surface portion, a cross right recess rear upper surface portion, a cross right recess upper right surface portion, and a cross right recess front lower surface portion, as in the second embodiment.

As described above, the support strength of the cross portion 350 to which the rear suspension 9 is connected in the rear arm 314 can be improved while suppressing an increase in the weight of the rear arm 314 .

(Other embodiments)
Although the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, without being limited to the above-described embodiment, it is possible to modify the above-described embodiment as appropriate without departing from the spirit thereof.

In each of the above embodiments, the forces input from the cross portions 50, 150, 250, and 350 are absorbed by the left arm recessed portion lower surface portion 44e, the right arm recessed portion lower surface portion 64e, the cross left recessed portion upper surface portion 153c, and the cross right recessed portion upper surface portion 154c. A load bearing surface is configured to receive the load. However, other surfaces of the left arm recess, the right arm recess, the cross left recess and the cross right recess may constitute the load receiving surface. That is, the surfaces of the left arm concave portion, the right arm concave portion, the cross left concave portion, and the cross right concave portion, which are in contact with the cross portion and receive the force input from the cross portion, constitute the load receiving surfaces.

In each of the above-described embodiments, the cross left convex portion 53, the cross right convex portion 54, the left arm convex portion 144, and the right arm convex portion 164 are rectangular when viewed in the left-right direction. However, the cross left convex portion, the cross right convex portion, the left arm convex portion, and the right arm convex portion may have any shape as long as they have a closed cross section when viewed in cross section in the front-rear direction. Further, the left cross convex portion, the right cross convex portion, the left arm convex portion, and the right arm convex portion do not need to have a closed cross-section in the entire projecting direction, and may be partially provided with a notch or a hole. . Furthermore, the left cross convex portion, the right cross convex portion, the left arm convex portion, and the right arm convex portion may have shapes other than trapezoidal and rectangular when viewed from above.

Similarly, in each of the above-described embodiments, the shapes of the left arm recess 44, the right arm recess 64, the cross left recess 153, and the cross right recess 154 are rectangular when viewed in the left-right direction. However, the left arm recess, the right arm recess, the cross left recess, and the cross right recess are not limited to being rectangular when viewed in the left-right direction. The left arm concave portion, the right arm concave portion, the cross left concave portion, and the cross right concave portion may have shapes other than trapezoidal and rectangular when viewed from above. The left arm concave portion, right arm concave portion, cross left concave portion, and cross right concave portion may have any shape as long as the cross left convex portion, cross right convex portion, left arm convex portion, and right arm convex portion can be inserted. There may be.

Also, the cross left protrusion, cross right protrusion, left arm protrusion, and right arm protrusion can be inserted into the left arm recess, the right arm recess, the cross left recess, and the cross right recess at any position on the rear arm. position.

In each of the above-described embodiments, the recesses of the left arm recess 44, the right arm recess 64, the cross left recess 153, and the cross right recess 154 are respectively a front surface portion, a rear surface portion, a side surface portion (left surface portion or right surface portion), and a bottom surface portion. and a top surface. However, the left arm recess, right arm recess, cross left recess and cross right recess may each have only a front surface, a rear surface, a bottom surface and a top surface. The left arm recess and the right arm recess may have only a front surface portion, a rear surface portion and a bottom surface portion. Also, the left arm recess and the right arm recess may have only the lower surface portion. The cross left recess and the cross right recess may have only a front portion, a rear portion and a top portion. Alternatively, the cross left recess and the cross right recess may have only the upper surface portion.

In each of the above-described embodiments, the load receiving surface (in the case of Embodiment 1, the left arm recessed portion lower surface portion 44e and the right arm recessed portion lower surface portion 64e) is supported by four surfaces as the load receiving surface support portion (for example, The left arm recess bottom surface 44e is supported by a left arm recess front bottom surface 45a, a left arm recess rear bottom surface 45b, a left arm recess left bottom surface 45d, and a left arm recess right bottom surface 45f. However, the load bearing surface may be supported by at least one pair of opposing surfaces.

For example, in the case of the first embodiment, the left arm recessed portion lower surface may be supported by the left arm recessed front lower surface and the left arm recessed rear lower surface. It may be supported by the lower right side surface of the arm recess. Alternatively, the right arm recess bottom surface may be supported by the right arm recess front bottom surface and the right arm recess rear bottom surface, or the right arm recess bottom surface may be supported by the right arm recess bottom right surface and the right arm recess left bottom surface. may

Further, in the case of the second embodiment, the cross left recess upper surface portion may be supported by the cross left recess front upper surface portion and the cross left recess rear upper surface portion. Further, the cross right recess upper surface portion may be supported by the cross right recess front upper surface portion and the cross right recess rear upper surface portion.

The load receiving surface may be supported by another surface in addition to the pair of surfaces facing each other.

In each of the above-described embodiments, the left arm portion 40 is provided with the left arm concave front upper surface portion 46a, the right arm portion 60 is provided with the right arm concave front upper surface portion 66a, and the cross portion 150 is provided with the cross left concave front lower surface portion. A portion 157a and a cross right concave front lower surface portion 158a are provided. However, these surfaces may not be provided. Further, the left arm portion 40, the right arm portion 60, and the cross portion 150 may be provided with other surfaces that reinforce the respective surfaces of the left arm recess 44, the right arm recess 64, the cross left recess 153, and the cross right recess 154. .

In each of the above embodiments, the left arm portions 40, 140, the cross portions 50, 150, 250, 350 and the right arm portions 60, 160 are made of carbon fiber reinforced resin. However, the left arm portion, the cross portion and the right arm portion may contain other materials such as metal, resin, elastomer, etc., as long as the resin contains carbon fiber reinforced resin.

In each of the above embodiments, the left arm portions 40, 140, the cross portions 50, 150, 250, 350 and the right arm portions 60, 160 are made of carbon fiber reinforced resin. However, the left arm portion, the cross portion and the right arm portion may be made of fiber-reinforced resin in which the resin is reinforced with fibers other than carbon fiber (eg, aramid fiber, polyethylene fiber, glass fiber, etc.). In each of the above embodiments, epoxy resin, vinyl ester, phenol resin, polyamide, polypropylene, polyphenylene sulfide, etc. are used as the resin. However, the resin may be any other type of resin as long as it can be reinforced with fibers.

In each of the above embodiments, the left arm portions 40, 140, the cross portions 50, 150, 250, 350, and the right arm portions 60, 160 are made of carbon fiber reinforced resin reinforced with fiber sheets containing carbon fibers. . A plurality of the fiber sheets are laminated in the thickness direction and bonded together by resin. However, the carbon fiber reinforced resin may be composed of a composite material in which a carbon fiber reinforced resin layer reinforced with carbon fibers and a foamed resin layer containing a foamed synthetic resin are laminated in the thickness direction. This composite material has a pair of the carbon fiber reinforced resin layers, and is a material in which the foamed resin layer is arranged between the carbon fiber reinforced resin layers. By using the composite material, it is possible to reduce the weight of each member including the carbon fiber reinforced resin and to easily change the thickness of each member as compared with the case of using only the carbon fiber reinforced resin layer. A resin capable of absorbing vibration may be used as the foamed synthetic resin of the foamed resin layer.

In each of the above embodiments, the left arm portions 40, 140, the cross portions 50, 150, 250, 350, and the right arm portions 60, 160 are made of carbon fiber reinforced resin reinforced by fiber sheets containing carbon fibers. ing. However, the left arm portion, the cross portion, and the right arm portion may be formed of fiber-reinforced resin using fibers in an unwoven state instead of fiber sheets. Further, the fibers may be continuous fibers having a predetermined length (for example, 1 mm) or more, or may be discontinuous fibers.

In each of the embodiments described above, the rear wheel 4 is rotatably supported by the rear wheel support portions 14b provided on the left arm portions 40 and 140 and the right arm portions 60 and 160, respectively. However, the rear wheel may be rotatably supported by a rear wheel support provided on at least one of the left arm and the right arm. Also, the rear arm may be configured such that only one of the left arm portion and the right arm portion is positioned on the side of the rear wheel.

In each of the above embodiments, the case of the rear arms 14, 114, 214, 314 that support the rear wheel 4 has been described. However, the configuration of each of the above embodiments may be applied to the front arm that supports the front wheel.

In each of the above-described embodiments, a motorcycle was described as an example of the vehicle 1, but the vehicle is not limited to a two-wheeled vehicle as long as the wheels are connected to the frame via a swing arm. etc., any vehicle may be used.

1 vehicle 2 vehicle body 3 front wheel 4 rear wheel (wheel)
9 Rear suspension (suspension)
14, 114, 214, 314 rear arm (swing arm)
14a frame connection portion 14b rear wheel support portion (wheel support portion)
14c Suspension connecting portions 40, 140 Left arm portion 41 Cylindrical portion 42 Left arm left side surface 43 Left arm right side surface 44 Left arm recess 44a Left arm recess front surface 44b Left arm recess rear surface 44c Left arm recess upper surface 44d Left arm recess left Surface portion 44e Left arm concave lower surface portion (left arm load receiving surface)
45a left arm concave front lower surface (left arm load bearing surface support)
45b Left arm concave rear lower surface portion (left arm load bearing surface support portion)
45d left lower left arm concave portion (left arm load receiving surface support portion)
45f Left arm concave right lower surface (left arm load bearing surface support)
46a Left arm concave front upper surface portion 48 Left arm upper surface portion 49 Left arm lower surface portion 50, 150, 250, 350 Cross portions 51, 151, 251, 351 Flat portion 52 Vertical wall portion 53 Cross left convex portion 53a Cross left convex portion front surface Part 53b Cross left convex rear surface 53c Cross left convex upper surface 53d Cross left convex lower surface 54 Cross right convex 54a Cross right convex front 54b Cross right convex rear 54c Cross right convex upper surface 54d Cross Right protrusion lower surface 60, 160 Right arm 62 Right arm left side 63 Right arm right side 64 Right arm recess 64a Right arm recess front 64b Right arm recess rear 64c Right arm recess upper surface 64d Right arm recess right surface 64e Right arm concave lower surface (right arm load bearing surface)
65a right arm concave front lower surface (right arm load bearing surface support)
65b Right arm concave rear lower surface portion (right arm load bearing surface support portion)
65d right arm concave lower right surface portion (right arm load receiving surface support portion)
65f right arm concave left lower surface (right arm load bearing surface support)
66a Right arm concave front upper surface 68 Right arm upper surface 69 Right arm lower surface 71 Pivot shaft 144 Left arm convex 144a Left arm convex front 144b Left arm convex rear 144c Left arm convex upper surface 144d Left arm convex cross left recess 153a cross left recess front surface 153b cross left recess rear surface 153c cross left recess upper surface (cross left load bearing surface)
153d Cross left recess right surface portion 153e Cross left recess lower surface portion 154 Cross right recess portion 154a Cross right recess front surface portion 154b Cross right recess rear surface portion 154c Cross right recess upper surface portion (cross right load bearing surface)
154d Cross right recess right surface portion 154e Cross right recess bottom surface portion 155a Cross left recess front upper surface portion (cross left load receiving surface support portion)
155b Cross left concave rear upper surface portion (cross left load bearing surface support portion)
155d Cross left concave upper left surface (cross left load bearing surface supporting portion)
156a cross right concave front upper surface (cross right load bearing surface support)
156b Cross right concave rear upper surface (cross right load receiving surface support)
156d Cross right recess upper right surface (cross right load bearing surface support)
157a Cross left concave front lower surface 158a Cross right concave front lower surface 164 Right arm convex 164a Right arm convex front 164b Right arm convex rear 164c Right arm convex upper surface 164d Right arm convex lower surface

Claims (11)

a body frame that is long in the longitudinal direction of the vehicle;
a swing arm extending forward or rearward from the vehicle body frame;
a suspension that elastically supports the swing arm with respect to the vehicle body frame;
a wheel supported by the swing arm such that its axis of rotation is positioned in the lateral direction of the vehicle;
A vehicle comprising
The swing arm is
a right arm extending in the longitudinal direction of the vehicle;
a left arm portion extending in the longitudinal direction of the vehicle;
a cross portion extending in the lateral direction of the vehicle and connecting the right arm portion and the left arm portion;
a rotating right support portion provided at one end of the right arm portion in the longitudinal direction of the vehicle and rotatably supporting the right arm portion to the vehicle body frame;
a rotating left support portion provided at one end of the left arm portion in the longitudinal direction of the vehicle and rotatably supporting the left arm portion to the vehicle body frame;
a wheel support portion provided at the other end portion in the front-rear direction of the vehicle in at least one of the right arm portion and the left arm portion for supporting the wheel;
a suspension connection portion provided at the cross portion and to which the suspension is connected;
has
The right arm portion and the cross portion satisfy either one of the following (A) or (B),
The vehicle, wherein the left arm portion and the cross portion satisfy either one of (C) or (D) below.
(A) The right arm portion includes a fiber-reinforced resin resin reinforced with fibers, and has a right arm convex portion that protrudes leftward and has a closed cross section when viewed in cross section in the front-rear direction, and the cross portion includes: , the resin includes a fiber-reinforced resin reinforced with fibers, and has a cross right load bearing surface in contact with the right arm convex portion, the cross right load bearing surface is located on the right side when the vehicle is viewed in the vertical direction. It extends in the front-rear direction between the front end and the rear end of the right arm protrusion so as to overlap with the arm protrusion.
(B) The cross portion includes a fiber-reinforced resin resin reinforced with fibers, and has a cross right convex portion that protrudes to the right and has a closed cross section when viewed in cross section in the front-rear direction, and the right arm portion , the resin includes a fiber-reinforced resin reinforced with fibers, and has a right arm load bearing surface in contact with the cross right convex portion, the right arm load bearing surface is located on the cross when viewed in the vertical direction of the vehicle. It extends in the front-rear direction between the front end and the rear end of the cross right protrusion so as to overlap with the right protrusion.
(C) The left arm portion includes a fiber-reinforced resin resin reinforced with fibers, and has a left arm convex portion that protrudes to the right and has a closed cross-section when viewed in cross-section in the front-rear direction, and the cross portion includes: , the resin includes a fiber-reinforced resin reinforced with fibers, and has a cross left load bearing surface in contact with the left arm convex portion, the cross left load bearing surface is located on the left side when the vehicle is viewed in the vertical direction. It extends in the front-rear direction between the front end and the rear end of the left arm projection so as to overlap with the arm projection.
(D) The cross section includes a fiber-reinforced resin resin reinforced with fibers, and has a cross left projection projecting leftward and having a closed cross-section when viewed in cross section in the front-rear direction, and the left arm section , the resin includes a fiber-reinforced resin reinforced with fibers, and has a left arm load bearing surface in contact with the left convex portion of the cloth, the left arm load bearing surface is located on the cross when the vehicle is viewed in the vertical direction. It extends in the front-rear direction between the front end and the rear end of the cross left protrusion so as to overlap with the left protrusion. In the vehicle according to claim 1,
In (A) above,
A cloth right concave portion is provided in the cloth portion containing the fiber reinforced resin,
A portion of the right cross recess forms the right cross load bearing surface,
In (B) above,
A right arm concave portion is provided in the right arm portion containing the fiber reinforced resin,
a portion of the right arm recess forms the right arm load bearing surface,
In (C) above,
A cloth left concave portion is provided in the cloth portion containing the fiber reinforced resin,
a portion of the cross left recess forms the cross left load bearing surface,
In (D) above,
A left arm concave portion is provided in the left arm portion containing the fiber reinforced resin,
A vehicle, wherein a portion of the left arm recess forms the left arm load bearing surface. In the vehicle according to claim 2,
In (A) above, the cross right concave portion includes a cross right concave lower surface portion extending in the front-rear direction of the vehicle when the cross portion is viewed from the right direction of the vehicle and positioned below the cross right concave portion; A cross right recessed front portion extending in the vertical direction of the vehicle and positioned in front of the cross right recessed portion, and a cross right recessed portion rearward facing the cross right recessed portion front portion and positioned in the rear portion of the cross right recessed portion. and a cross right concave upper surface portion disposed opposite to the cross right concave lower surface portion and positioned above the cross right concave portion and constituting the cross right load bearing surface,
In (B) above, the right arm recess extends in the front-rear direction of the vehicle when the right arm is viewed from the left direction of the vehicle, and is positioned below the right arm recess. a right arm recessed portion lower surface portion constituting a right arm recessed portion, a right arm recessed portion front portion extending in the vertical direction of the vehicle and positioned in front of the right arm recessed portion, and a right arm recessed portion disposed opposite to the right arm recessed portion front portion and the right a right arm recessed portion rear surface portion positioned on the rear side of the arm recessed portion; and a right arm recessed portion upper surface portion disposed facing the right arm recessed portion lower surface portion and positioned above the right arm recessed portion;
In (C) above, the cross left concave portion includes a cross left concave lower surface portion extending in the front-rear direction of the vehicle when the cross portion is viewed from the left direction of the vehicle and positioned below the cross left concave portion; A cross left recess front portion extending in the vertical direction of the vehicle and positioned in front of the cross left recess, and a cross left recess rear portion disposed opposite the cross left recess front portion and positioned at the rear of the cross left recess. and a cross left recess upper surface portion disposed opposite to the cross left recess lower surface portion and positioned above the cross left recess portion and forming the cross left load bearing surface,
In (D) above, the left arm recess extends in the front-rear direction of the vehicle when the left arm is viewed from the right side of the vehicle, and is positioned below the left arm recess. , a left arm recessed front surface portion extending in the vertical direction of the vehicle and positioned in front of the left arm recessed portion, and a left arm recessed portion located opposite the left arm recessed front surface portion and the left A vehicle, comprising: a left arm recessed rear surface portion located at a rear portion of an arm recessed portion; and a left arm recessed portion upper surface portion located above the left arm recessed portion and arranged to face the left arm recessed portion lower surface portion. In the vehicle according to claim 3,
In the above (A), the cross portion containing the fiber-reinforced resin includes a fiber-reinforced resin reinforced with fibers, and one is at the connection portion between the right concave front portion of the cross and the lower surface portion of the right cross concave portion. a cross right concave front lower surface portion connected to the cross portion, the other extending forward and downward from the connecting portion and connected to the outer surface of the cross portion;
In the above (B), the right arm portion containing the fiber-reinforced resin includes a fiber-reinforced resin reinforced with fibers, and one is a connection portion between the right arm concave front surface portion and the right arm concave upper surface portion. and the other extending forward and upward from the connecting portion and connected to the outer surface of the right arm portion is provided,
In the above (C), the cross portion containing the fiber reinforced resin includes a fiber reinforced resin reinforced with fibers, and one of the cross portions is a connection portion between the left recessed front portion of the cross and the lower left recessed portion of the cross. a left recessed cross front lower surface portion connected to the cross portion, the other extending forward and downward from the connecting portion and connected to the outer surface of the cross portion;
In the above (D), the left arm portion containing the fiber-reinforced resin includes a fiber-reinforced resin reinforced with fibers, and one is a connection portion between the left arm concave front surface portion and the left arm concave upper surface portion. and the other extending forward and upward from the connecting portion and connected to the outer surface of the left arm. In the vehicle according to any one of claims 1 to 4,
In (A) above, the cross portion containing the fiber-reinforced resin is opposed by a pair of right cross load-receiving surface supporting portions containing a fiber-reinforced resin reinforced with fibers and supporting the right cross load-receiving surface from above. and
In the above (B), the right arm portion containing the fiber-reinforced resin includes a pair of right arm load-receiving surface support portions containing fiber-reinforced resin reinforced with fibers and supporting the right arm load-receiving surface from below. provided facing each other,
In the above (C), a pair of left cross load bearing surface supporting portions including a fiber reinforced resin reinforced with fibers and supporting the left cross load bearing surface from above face the cross portion including the fiber reinforced resin. and
In the above (D), the left arm portion containing the fiber-reinforced resin includes a pair of left arm load-receiving surface support portions containing fiber-reinforced resin reinforced with fibers and supporting the left arm load-receiving surface from below. Vehicles facing each other. In the vehicle according to any one of claims 1 to 5,
The cross portion containing the fiber-reinforced resin has the cross right convex portion at an end portion in the right direction of the vehicle, and has the cross left convex portion at an end portion in the left direction of the vehicle,
The right arm portion containing the fiber reinforced resin has the right arm load bearing surface that contacts the cross right convex portion,
A vehicle according to claim 1, wherein the left arm portion containing the fiber-reinforced resin has the left arm load bearing surface that contacts the cross left convex portion. In the vehicle according to claim 6,
A pair of right arm load bearing surface supporting portions including a fiber reinforced resin reinforced with fibers and supporting the right arm load bearing surface from below are provided to face the right arm portion including the fiber reinforced resin,
A pair of left arm load receiving surface supporting portions including a fiber reinforced resin reinforced with fibers and supporting the left arm load receiving surface from below are provided facing each other on the left arm portion including the fiber reinforced resin. There is a vehicle. In the vehicle according to claim 6 or 7,
A right arm concave portion is provided in the right arm portion containing the fiber reinforced resin,
A left arm concave portion is provided in the left arm portion containing the fiber reinforced resin,
The right arm recess extends in the front-rear direction of the vehicle when the right arm is viewed from the left direction of the vehicle, and is positioned below the right arm recess, forming the right arm load bearing surface. a lower surface portion, a right arm recessed front portion extending in the vertical direction of the vehicle and positioned in front of the right arm recessed portion, and a right arm recessed portion facing the front portion and positioned in the rear portion of the right arm recessed portion. and a right arm recessed upper surface portion arranged to face the right arm recessed lower surface portion and positioned above the right arm recessed portion,
The left arm recess extends in the front-rear direction of the vehicle when the left arm is viewed from the right side of the vehicle, and is positioned below the left arm recess, forming the left arm load bearing surface. a lower surface portion, a left arm concave front portion extending in the vertical direction of the vehicle and positioned in front of the left arm concave portion, and a left arm concave front portion facing the left arm concave portion and positioned in the rear portion of the left arm concave portion. and a left arm recessed upper surface portion disposed facing the left arm recessed lower surface portion and positioned above the left arm recessed portion,
One of the right arm portions is connected to a connecting portion between the right arm concave front surface portion and the right arm concave upper surface portion, and the other extends forward and upward from the connecting portion to the outer surface of the right arm portion. having a connected right arm front upper surface,
One of the left arm portions is connected to a connecting portion between the left arm concave front surface portion and the right arm concave upper surface portion, and the other is connected to the outer surface of the left arm portion extending forward and upward from the connecting portion. a vehicle having a curved left arm front upper surface. In the vehicle according to any one of claims 6 to 8,
A right arm concave portion is provided in the right arm portion containing the fiber reinforced resin,
a portion of the right arm recess forms the right arm load bearing surface,
A left arm concave portion is provided in the left arm portion containing the fiber reinforced resin,
a portion of the left arm recess forms the left arm load bearing surface,
the right arm portion has a right arm right side surface portion positioned on the right side of the right arm concave portion in the left-right direction of the vehicle and forming a part of the outer surface of the right arm portion;
The vehicle, wherein the left arm portion has a left arm left side surface portion that is located on the left side of the left arm concave portion in the left-right direction of the vehicle and that constitutes a part of the outer surface of the left arm portion. In the vehicle according to any one of claims 1 to 9,
The right arm portion is positioned on the right side of the vehicle with respect to the wheels,
The vehicle, wherein the left arm portion is positioned on the left side of the vehicle with respect to the wheel. In the vehicle according to any one of claims 1 to 10,
A vehicle according to claim 1, wherein said right arm portion and said left arm portion each including said fiber-reinforced resin have an outer dimension in the vertical direction larger than an outer dimension in the left-right direction when viewed in cross-section in the left-right direction of the vehicle.

Images