CN110461700B - Suspension structure of saddle-ride type vehicle - Google Patents

Abstract

The suspension structure of the straddle-type vehicle includes: a frame (11); a power unit (10) that includes an engine (30) and is supported by the frame (11) so as to be able to swing; and a link member (60) having one end connected to the frame (11) side in a swingable manner and the other end connected to the power unit (10) side in a swingable manner, wherein a swing restricting portion (80) that restricts the swing of the power unit (10) is provided in a crankcase (34) of the engine (30).

Description

Suspension structure of saddle-ride type vehicle

Technical Field

The present invention relates to a suspension structure of a saddle-ride type vehicle.

The present application claims priority based on Japanese application No. 2017-061862 filed on 27/03/2017, the contents of which are incorporated herein by reference.

Background

Conventionally, a suspension structure of a saddle-ride type vehicle has been disclosed in which an engine in a power unit is supported by a rear frame in a vehicle body frame via a vibration-proof link (see, for example, patent document 1).

The vibration-proof link includes a pair of left and right engine-side brackets provided on the left and right sides of the engine, a pair of left and right links having one ends swingably connected to the respective engine-side brackets and the other ends swingably connected to the frame main portion of the rear frame, a cross member connecting the two links, and a pair of stopper rubbers provided on one of the links in contact with the reinforcing frame portion of the rear frame. A bolt (hereinafter, also referred to as an "engine-side bolt") that is coupled to one end of the two links and is horizontally disposed is supported by each engine-side bracket via a rubber bush (hereinafter, also referred to as an "engine-side rubber bush"). A bolt (hereinafter, also referred to as a "rear frame side bolt") that is coupled to the other ends of the two links and is horizontally disposed is supported by the frame main portion via a rubber bush (hereinafter, also referred to as a "rear frame side rubber bush"). An abutment surface against which the stopper rubber abuts is formed on the lower surface of the reinforcing frame portion.

In the above-described anti-vibration link, a load acting on the engine-side bolt from the engine of the power unit is absorbed by elastic deformation of the engine-side rubber bush, and is also absorbed by elastic deformation of the stopper rubber pressed against the abutment surface, and also by elastic deformation of the rear frame-side rubber bush.

Prior art documents

Patent document

Patent document 1: japanese laid-open patent publication No. 2000-313389

Disclosure of Invention

Problems to be solved by the invention

However, since the swing of the engine is restricted by the vehicle frame, it is necessary to improve the rigidity of the vehicle frame.

Accordingly, an object of the present invention is to restrict the swing of an engine without increasing the rigidity of a vehicle body frame in a suspension structure of a saddle-ride type vehicle.

Means for solving the problems

As a solution to the above problem, the present invention has the following configuration.

(1) A suspension structure for a saddle-ride type vehicle according to a first aspect of the present invention includes: a frame; a power unit including an engine and swingably supported by the frame; and a link member having one end connected to the frame side in a swingable manner and the other end connected to the power unit side in a swingable manner, wherein a swing restricting portion that restricts a swing of the power unit is provided in a crankcase of the engine, the swing restricting portion includes a restricting wall portion formed integrally with the crankcase, a downward extending portion that extends downward is provided in the other end of the link member, and a recess that opens upward and into which the downward extending portion fits is provided in an upper front portion of the power unit.

(2) In the suspension structure of the saddle-ride type vehicle according to the above (1), the link member may extend obliquely rearward and downward from the vehicle frame side and then extend obliquely forward and downward to be coupled to the power unit side in a side view.

(3) A suspension structure for a saddle-ride type vehicle according to a second aspect of the present invention includes: a frame; a power unit including an engine and swingably supported by the frame; and a link member having one end connected to the frame side in a swingable manner and the other end connected to the power unit side in a swingable manner, wherein a swing restricting portion that restricts a swing of the power unit is provided in a crankcase of the engine, the swing restricting portion includes a restricting wall portion formed integrally with the crankcase, and the link member extends obliquely rearward and downward from the frame side and then extends obliquely forward and downward and is connected to the power unit side in a side view. .

(4) In the suspension structure of the saddle-ride type vehicle according to the above (3), a downward extending portion that extends downward may be provided at the other end portion of the link member, and a recess that opens upward and into which the downward extending portion fits may be provided at a front upper portion of the power unit.

(5) In the suspension structure of the saddle-ride type vehicle according to the above (2) or (4), the swing restricting portion may be provided at an upper front portion of the power unit extending in a vehicle front-rear direction.

(6) In the suspension structure for a saddle-ride type vehicle according to the above (5), the downward extending portion may include an extending wall portion extending in a vehicle width direction intersecting a swing direction of the power unit, and an elastic member bulging in the swing direction with the extending wall portion interposed therebetween may be fitted into the recessed portion.

(7) In the suspension structure of a saddle-ride type vehicle according to (6), the downward extending portion may further include a pair of side wall portions that are connected to side ends of the extending wall portion and sandwich the elastic member from a side.

(8) In the suspension structure of the saddle-ride type vehicle according to the above (7), a throttle body may be disposed in front of the link member, and a connection pipe that connects the throttle body and an air cleaner may be disposed above the link member.

(9) In the suspension structure of the saddle-ride type vehicle according to any one of the above (1) to (8), a transmission may be disposed on one of left and right sides with respect to a left and right center line of a vehicle body, and a center of the other end portion of the link member may be offset to the side on which the transmission is disposed with respect to the left and right center line of the vehicle body.

(10) In the suspension structure of a saddle-ride type vehicle according to any one of the above (1) to (9), a connecting portion connected to the vehicle body may be provided in the crankcase, a center of the other end portion of the link member may be offset to one side in the vehicle width direction with respect to a vehicle body left-right center line, and a bracket that bridges a connecting pipe extending in the vehicle width direction and the connecting portion may be provided to the other side in the vehicle width direction with respect to the vehicle body left-right center line.

Effects of the invention

According to the suspension structure of the saddle-ride type vehicle described in the above (1) of the present invention, since the swing restricting portion that restricts the swing of the power unit is provided in the crankcase of the engine, the swing of the engine can be restricted without increasing the rigidity of the vehicle body frame as compared with the case where the swing restricting portion is provided in the vehicle body frame. In addition, in order to increase the rigidity of the vehicle frame, it is necessary to bend the vehicle frame or provide a reinforcing member. Therefore, the suspension structure is complicated or the number of components is increased, which may increase the size and weight of the suspension structure. In contrast, since the crankcase itself has high rigidity, the crankcase can be provided with the swing restricting portion with a simple structure, and the suspension structure can be prevented from being increased in size and weight.

According to the suspension structure of the saddle-ride type vehicle described in the above (2) of the present invention, since the swing restricting portion includes the restricting wall portion formed integrally with the crankcase, the number of components can be reduced, and the suspension structure can be simplified and reduced in weight, as compared with a case where the swing restricting portion and the crankcase are provided separately.

For example, the restricting wall portion and the crankcase can be formed integrally by casting, which is preferable.

According to the suspension structure of the saddle-ride type vehicle described in the above (3) of the present invention, the swing restricting portion is provided at the front upper portion of the power unit extending in the vehicle front-rear direction, and thus in a so-called upper link type power unit (hereinafter, also referred to as an "upper link unit swing engine") in which the other end of the link member is swingably connected to the front upper portion of the power unit, it is possible to suppress the swing of the engine without increasing the rigidity of the vehicle frame.

According to the suspension structure of the saddle-ride type vehicle described in the above (4) of the present invention, since the downward extending portion that extends downward is provided at the other end portion of the link member, and the recess that opens upward and into which the downward extending portion fits is provided at the front upper portion of the power unit, the number of components can be reduced, and the suspension structure can be simplified and reduced in weight, as compared to a case where a mechanism that restricts the swing of the engine (hereinafter, also referred to as a "stopper") is provided separately from the other end portion of the link member.

According to the suspension structure of the saddle-ride type vehicle described in the above (5) of the present invention, the downward extending portion includes the extending wall portion extending in the vehicle width direction intersecting the swing direction of the power unit, and the elastic member bulging in the swing direction with the extending wall portion interposed therebetween is fitted into the recessed portion, whereby the load generated when the power unit swings can be absorbed by the elastic deformation of the elastic member.

According to the suspension structure of the saddle-ride type vehicle described in the above (6) of the present invention, the downward extending portion further includes the pair of side wall portions that are connected to the side ends of the extending wall portion and sandwich the elastic member from the side, whereby the rigidity of the downward extending portion can be improved as compared with a case where the downward extending portion is provided with only the extending wall portion. In addition, the elastic member can be accommodated between the pair of side wall portions, and the elastic member can be downsized.

According to the suspension structure of the saddle-ride type vehicle described in the above (7) of the present invention, the link member extends obliquely rearward and downward from the vehicle frame side in a side view, and then extends obliquely forward and downward and is connected to the power unit side, whereby a space is formed in front of and above the link member, and therefore, the degree of freedom in arrangement of vehicle components can be improved.

According to the suspension structure of the saddle-ride type vehicle described in the above (8) of the present invention, the throttle body is disposed in front of the link member, and the connection pipe that connects the throttle body and the air cleaner is disposed above the link member, whereby the following effects are achieved. Since the throttle body and the connection pipe can be disposed as vehicle components in the front space and the upper space of the link member, respectively, peripheral components of the suspension structure can be concentrated. Therefore, it is preferable to miniaturize the entire vehicle.

According to the suspension structure of the saddle-ride type vehicle described in the above (9) of the present invention, the transmission is disposed on one of the left and right sides with respect to the left and right center lines of the vehicle body, and the center of the other end portion of the link member is offset to the side on which the transmission is disposed with respect to the left and right center lines of the vehicle body, whereby the power unit can be stably supported by the vehicle frame even when the weight of the power unit is offset to the side on which the transmission is disposed with respect to the left and right center lines of the vehicle.

According to the suspension structure of the saddle-ride type vehicle described in the above (10) of the present invention, the connecting portion connected to the vehicle body is provided in the crankcase, the center of the other end portion of the link member is offset to one side in the vehicle width direction with respect to the vehicle body left and right center line, and the bracket that bridges the connecting portion and the connecting pipe extending in the vehicle width direction is provided to the other side in the vehicle width direction with respect to the vehicle body left and right center line, whereby the stability of the vehicle rear portion can be improved even in the case where the center of the other end portion of the link member is offset to one side in the vehicle width direction with.

Drawings

Fig. 1 is a left side view of a motorcycle according to a first embodiment of the present invention.

Fig. 2 is a right side view of a main part of the motorcycle.

Fig. 3 is a plan view of the engine suspension structure of the motorcycle, including a section III-III in fig. 2.

Fig. 4 is a front view of the engine suspension structure and includes a section IV-IV of fig. 3.

Fig. 5 is a left side view of the above-described engine suspension structure and is a view including the V-V section of fig. 3.

Fig. 6 is a right side view of the inner case in the transmission case of the motorcycle.

Fig. 7 is a left side view of the link member of the above-described engine suspension structure.

Fig. 8 is a rear view of the link member.

Fig. 9 is a bottom view of the link member.

Fig. 10 is a front view of the elastic member of the above-described engine suspension structure.

Fig. 11 is a plan view of the elastic member of the engine suspension structure.

Fig. 12 is a left side view of the link member in the second embodiment.

Fig. 13 is a rear view of the link member in the second embodiment.

Fig. 14 is a rear view showing a clamped state of the elastic member in the second embodiment.

Fig. 15 is a left side view of the link member in the third embodiment.

Fig. 16 is a rear view of the link member in the third embodiment.

Fig. 17 is a bottom view of the link member in the third embodiment.

Fig. 18 is a rear view showing a clamped state of the elastic member in the third embodiment.

Fig. 19 is a bottom view showing a clamped state of the elastic member in the third embodiment.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. In the following description, the directions such as front, rear, left, and right are the same as those in the following vehicle unless otherwise specified. In the drawings used in the following description, arrow FR indicating the front of the vehicle, arrow LH indicating the left of the vehicle, and arrow UP indicating the upper side of the vehicle are shown at appropriate positions.

(first embodiment)

< vehicle entirety >

Fig. 1 shows a unit swing type motorcycle 1 as an example of a saddle type vehicle. Referring to fig. 1, a motorcycle 1 includes a front wheel 3 steered by a handlebar 2, and a rear wheel 4 driven by a power unit 10 including a power source. Hereinafter, the motorcycle may be simply referred to as a "vehicle". The motorcycle 1 of the embodiment is a scooter type vehicle having a bottom step 9 for placing feet of a passenger seated on a seat 8.

A steering system component including the handlebar 2 and the front wheel 3 is pivotally supported on a head pipe 12 at the front end of the frame 11 so as to be able to steer. The outer periphery of the frame 11 is covered with a body cover 5. In fig. 1, reference numeral 6 denotes a front fork.

The frame 11 is formed by integrally joining a plurality of steel materials by welding or the like. As shown in fig. 2, the body frame 11 includes a head pipe 12 positioned at a front end portion thereof, a down frame 13 extending obliquely rearward and downward from the head pipe 12, a pair of left and right under frames 14 extending substantially horizontally rearward from a lower end of the down frame 13, a pair of left and right seat frames 15 extending obliquely rearward and upward from rear ends of the left and right under frames 14, and a lower cross member 16 spanning between rear ends of the left and right under frames 14 in the vehicle width direction.

The left and right seat frames 15 include inclined portions 15a extending upward and rearward from the left and right lower frames 14, and horizontal portions 15b extending substantially horizontally from rear ends of the inclined portions 15a to rear ends of the vehicle frame 11.

The vehicle body frame 11 further includes a box support frame 17 between the left and right seat frames 15 across the lower portion of the inclined portion 15a in the vehicle width direction, a side extension member 18 extending outward in the vehicle width direction from the lower portion of the inclined portion 15a, a pivot plate 19 projecting rearward and downward from the inclined portion 15a, a front seat cross member 20 spanning between the front ends of the horizontal portions 15b in the vehicle width direction, and a rear seat cross member 21 spanning between the rear ends of the horizontal portions 15b in the vehicle width direction.

The power unit 10 is a unit swing type power unit in which an engine 30 as an internal combustion engine and an arm portion 31 supporting the rear wheel 4 are integrated.

The arm 31 has a transmission case 50 formed in a hollow case shape. A transmission 49 (see fig. 3) for transmitting the output of the engine 30 to the rear wheel 4 is housed in the transmission housing 50. For example, the transmission 49 includes a drive pulley, a driven pulley, and a V-belt. The transmission 49 is a belt type continuously variable transmission. As shown in fig. 1, a kick pedal 32 for starting the engine 30 is provided on the left side of the arm portion 31. In fig. 1, reference numeral 22 denotes a center bogie frame, and reference numeral 23 denotes a side bogie frame.

As shown in fig. 2, the power unit 10 is swingably supported on the frame 11 via a link member 60 disposed above the crankcase 34. One end of the link member 60 is swingably coupled to the frame 11 side, and the other end is coupled to the power unit 10 side. Hereinafter, among the components of the vehicle body frame 11, the component disposed on the left side may be denoted by "L" and the component disposed on the right side may be denoted by "R". In fig. 3, reference symbol CL denotes a vehicle body left-right center line.

As shown in fig. 3, the left and right pivot plates 19L, 19R include a pivot plate inner wall 19a located on the inside in the vehicle width direction and a pivot plate outer wall 19b located on the outside in the vehicle width direction. The pivot plate inner and outer walls 19a and 19b are formed with through holes 19h and 19i (hereinafter also referred to as "pivot plate inner wall hole 19 h" and "pivot plate outer wall hole 19 i") for a pivot shaft 19c extending between the pivot plate inner and outer walls 19a and 19b in the vehicle width direction. One ends (left and right pivot-side shaft support portions 61L, 61R) of the link members 60 are connected to the left and right pivot plates 19L, 19R via left and right pivot shafts 19 c. For convenience, in fig. 3, the pivot plate inner and outer wall holes 19h, 19i in the left pivot plate 19L are shown.

As shown in fig. 2, the power unit 10 swings about the pivot shaft 19 c. In fig. 2, an arrow V1 indicates the swing direction of the power unit 10 about the pivot shaft 19 c. A rear damper 7 that damps the swing of the power unit 10 is provided between the arm portion 31 and the seat frame 15.

The engine 30 includes a crankcase 34 accommodating a crankshaft 33 extending in the vehicle width direction, and a cylinder 35 rising upward and forward from a front end portion of the crankcase 34.

The cylinder 35 includes a cylinder block 35a, a cylinder head 35b, and a cylinder cover 35c in this order from the crankcase 34 side.

As shown in fig. 3, an intake pipe 25 is connected to an upper wall of the cylinder head 35 b. The intake pipe 25 extends rearward and is connected to a throttle body 26. The throttle body 26 is connected to an air cleaner box 28 through a connection pipe 27. In fig. 3, reference numeral 39 denotes a battery cell.

As shown in fig. 2, the air cleaner box 28 is supported on the upper portion of the arm portion 31 in the power unit 10. Thereby, the air cleaner box 28 (hereinafter, also simply referred to as "air cleaner 28") swings integrally with the power unit 10.

An exhaust pipe 36 is connected to a lower wall of the cylinder head 35 b. The exhaust pipe 36 is drawn out downward from the lower wall of the cylinder head 35b, bent, and extended rearward. The rear end of the exhaust pipe 36 is connected to a muffler 37 disposed on the right side of the rear wheel 4. The muffler 37 is fixed to the right rear portion of the crankcase 34 via a bracket 38.

The arm portion 31 extends rearward from the left rear portion of the crankcase 34 to the left side of the rear wheel 4. The rear wheel 4 is pivotally supported by a rear wheel axle 4a at the rear end of the arm 31. The rear wheel 4 is supported by the arm portion 31 in a cantilever-supported manner.

The transmission case 50 in the arm portion 31 extends in the front-rear direction on the left side in the vehicle width direction. As shown in fig. 6, a coupling portion 51 coupled to the vehicle body is provided at an upper front portion of the transmission case 50. The coupling portion 51 protrudes upward from the front upper portion of the transmission housing 50 (i.e., the upper portion of the crankcase 34).

As shown in fig. 4, the connection portions 51 are provided in a pair on the left and right of the upper portion of the crankcase 34. Hereinafter, the left connecting portion 51L is also referred to as a "left crankcase wall 51L", and the right connecting portion 51R is also referred to as a "right crankcase wall 51R". The crankcase left and right walls 51L and 51R are formed with through holes 51h and 51i (hereinafter, also referred to as "crankcase left wall hole 51 h" and "crankcase right wall hole 51 i") for a shaft 51c of a bolt spanning between the crankcase left and right walls 51L and 51R in the vehicle width direction.

As shown in fig. 6, an axle support portion 52 (rear wheel support portion) that supports the rear wheel axle 4a (see fig. 1) is provided at the rear portion of the transmission housing 50. The rear wheel axle 4a (see fig. 1) is rotatably supported by the axle support portion 52 and the like via a bearing (not shown).

The transmission housing 50 is provided with ribs 59 extending in the front-rear direction of the transmission housing 50. The rib 59 connects the vehicle width direction inner surface of the transmission housing 50 to the left crankcase 34L. The transmission housing 50 includes an inner housing 53 disposed on the inside in the vehicle width direction, and an outer housing (not shown) disposed on the outside in the vehicle width direction.

The inner case 53 has a box shape extending in the front-rear direction and opening the vehicle width direction outer side (left side). Specifically, the inner case 53 includes an inner case side wall 53a extending in the front-rear direction and having a thickness in the vehicle width direction, and an annular inner case peripheral wall 53b protruding outward (left side) in the vehicle width direction from an outer peripheral edge of the inner case side wall 53a and extending in the front-rear direction.

In the figure, reference numeral 53d denotes a rear absorber supporting portion that supports a lower portion of the rear absorber 7 (see fig. 2). In the figure, reference numeral 53c denotes a coupling projection for coupling the inner housing peripheral wall 53b and the outer housing peripheral wall (not shown).

The transmission housing 50 is provided with a crankcase wall portion 54 that constitutes a part of the left crankcase 34L (crankcase 34) and extends in the vehicle width direction. The crankcase wall portion 54 extends inward in the vehicle width direction from the inner case side wall 53 a.

The crankcase wall portion 54 includes a rear wall 54a that is bent and extended upward and downward, and a bottom wall 54b that is connected to a lower end of the rear wall 54a and is bent and extended forward and rearward so as to protrude downward. The rear wall 54a of the crankcase wall portion 54 is smoothly connected to the inner case side wall 53 a.

The crankcase 34 is provided with a partition wall 57 vertically partitioning the crank chamber 55 and the oil pan 56. The partition wall 57 extends inward in the vehicle width direction from the inner case side wall 53 a. In a side view of fig. 6, the partition wall 57 has an arc shape protruding downward.

A speed reduction mechanism housing chamber 58 is provided at the rear of the transmission housing 50. The speed reduction mechanism accommodating chamber 58 extends inward in the vehicle width direction from the inner case side wall 53 a. In the side view of fig. 6, the speed reduction mechanism housing chamber 58 has a ring shape that gently protrudes downward.

As shown in fig. 2, a storage box 40 capable of storing articles such as helmets is provided above engine 30 and between left and right seat frames 15 in the vehicle width direction. The upper opening of the storage box 40 is covered with a seat 8 (see fig. 1) so as to be openable and closable. The front lower portion of the storage box 40 is supported by the box support frame 17.

In fig. 2, reference numeral 41 denotes a cooling fan fixed to an axial end portion of the crankshaft 33, reference numeral 42 denotes a fan cover covering a right side of the crankcase 34, and reference numeral 43 denotes a cylinder cover covering the cylinder 35.

< Engine suspension Structure >

Next, a suspension structure 45 (hereinafter, also referred to as "engine suspension structure 45") of the power unit 10 of the motorcycle 1 will be described.

As shown in fig. 5, the engine suspension structure 45 includes a link member 60 having one end swingably connected to the frame 11 side and the other end swingably connected to the power unit 10 side, a downward extending portion 70 extending downward from the other end of the link member 60, and a swing restricting portion 80 restricting the swing of the power unit 10 in the crankcase 34 of the engine 30.

< Link Member >

The link member 60 is formed by integrally joining a plurality of steel materials by welding or the like. In the side view of fig. 5, the link member 60 has an outer shape extending obliquely rearward and downward from the frame 11 side and then extending obliquely forward and downward and being connected to the power unit 10 side. In other words, the link member 60 is formed into a V-shape projecting rearward in the side view of fig. 5.

As shown in fig. 3, the link member 60 includes: a pair of left and right pivot-side shaft support portions 61L, 61R that are cylindrical on the vehicle frame 11 side and extend in the vehicle width direction, and a pair of left and right first linking members 62L, 62R that are connected to the left and right pivot-side shaft support portions 61L, 61R at their front end portions and extend obliquely forward and backward so as to be positioned lower toward the rear side in the side view of FIG. 7, a connecting pipe 63 that projects gently downward rearward in the plan view of fig. 3 and extends in the vehicle width direction so as to straddle between the rear end portions of the left and right first connecting members 62L, 62R in the vehicle width direction, a cylindrical engine-side shaft support portion 64 that extends in the vehicle width direction on the crankcase 34 side of the engine 30 in the front view of fig. 4, and a second connecting member 65 that straddles between the upper and lower sides of the connecting pipe 63 and the engine-side shaft support portion 64 and extends obliquely so as to be located further downward toward the front side in the side view of fig. 5.

< pivot-side shaft support section >

As shown in fig. 3, the pair of left and right pivotal shaft- side support portions 61L, 61R are disposed coaxially with each other. The pivot-side shaft support portion 61 is, for example, a cylindrical sleeve. A cylindrical elastic member 61a is provided radially inward of the left and right pivot-side shaft support portions 61L, 61R. The elastic member 61a has an outer diameter substantially the same size as the inner diameter of the sleeve. The elastic member 61a is, for example, a cylindrical rubber bushing. Fastening members such as bolts are inserted radially inward of the elastic members 61 a. For convenience, in fig. 3, the elastic member 61a in the left pivot-side shaft support portion 61L is illustrated.

For example, the bolt penetrates the pivotal plate outer wall hole 19i, the radially inner side of the elastic member 61a, and the pivotal plate inner wall hole 19h in this order from the vehicle width direction outer side. The front end of the bolt projects inward in the vehicle width direction in the pivot plate inner wall 19 a. A nut is fastened and coupled to a front end (projecting end) of the bolt on the inside in the vehicle width direction of the pivot plate inner wall 19 a. Thus, the left and right pivot-side shaft support portions 61L, 61R are pivotally supported by the left and right pivot plates 19L, 19R so as to be rotatable about the axis of the bolt (pivot shaft 19 c).

< first connecting Structure >

The left and right first linking members 62L, 62R are U-shaped in the rear view of fig. 8. In the rear view of fig. 8, the left and right first linking members 62L, 62R include an inner linking wall 62a extending vertically and positioned on the inside in the vehicle width direction, an outer linking wall 62b extending vertically and positioned on the outside in the vehicle width direction relative to the inner linking wall 62a, and a lower linking wall 62c spanning between the lower end of the inner linking wall 62a and the lower end of the outer linking wall 62b in the vehicle width direction.

In the side view of fig. 7, the inner and outer coupling walls 62a, 62b (only the outer coupling wall 62b is shown in fig. 7) extend forward and backward so that the front end portions are coupled to the pivot shaft support portions 61 (only the pivot shaft support portion 61L is shown on the left in fig. 7) and the rear end portions are coupled to the coupling pipe 63. In the side view of fig. 7, the pivot shaft support portion 61 is connected to the front end portions of the inner and outer connecting walls 62a, 62b, and a concave portion 62g is formed so as to be recessed in an arc shape that protrudes rearward and downward so as to follow the outer shape of the pivot shaft support portion 61. In the side view of fig. 7, a connecting pipe insertion hole 62h that opens in a circular shape along the outer shape of the connecting pipe 63 and through which the connecting pipe 63 is inserted is formed at the rear end portion of the inner and outer connecting walls 62a, 62 b.

In the side view of fig. 7, the lower connecting wall 62c extends linearly and gently obliquely from the front lower ends of the inner and outer connecting walls 62a, 62b located forward and downward of the pivot-side shaft support portion 61 so as to be located downward toward the rear side, and then reaches the rear lower ends of the inner and outer connecting walls 62a, 62b located rearward and downward of the vehicle-widthwise outer end of the connecting pipe 63. The lower connecting wall 62c is provided with a plurality of through holes 62i and 62j that are vertically open. In the embodiment, the lower connecting wall 62c is provided with two through holes, a front through hole 62i located below the pivot-side shaft support portion 61 and a rear through hole 62j located below the vehicle-widthwise outer end portion of the connecting pipe 63.

< connecting pipe >

In the rear view of fig. 8, the connecting pipe 63 projects rearward and downward gently so as to extend in the vehicle width direction across the space between the rear end portions of the left and right first linking members 62L, 62R in the vehicle width direction. The connecting pipe 63 is formed by bending one pipe material. In the side view of fig. 7, the cross-sectional shape of the connecting pipe 63 (see fig. 5) is an annular shape having an outer diameter smaller than the pivot-side shaft support portion 61.

In the rear view of fig. 8, the connecting pipe 63 includes a pair of left and right first connecting member connecting portions 63aL and 63aR to which the left and right first connecting members 62L and 62R are connected, respectively, a second connecting member connecting portion 63b to which the second connecting member 65 is connected, and a pair of left and right intermediate connecting portions 63cL and 63cR to which the left and right first connecting member connecting portions 63aL and 63aR and the second connecting member connecting portion 63b are connected, respectively.

The left and right first linking member connecting portions 63aL, 63aR are located on the vehicle width direction outer end sides of the linking pipes 63 and are cylindrical in shape extending in the vehicle width direction. The left and right first connecting-member connecting portions 63aL, 63aR are arranged coaxially with each other.

The second connecting member connecting portion 63b is positioned between the left and right first connecting member connecting portions 63aL, 63aR in the vehicle width direction, and has a cylindrical shape extending in the vehicle width direction. The second coupling member connecting portion 63b is located rearward and downward from the first coupling member connecting portion 63a in the side view of fig. 7. In the side view of fig. 7, the outer peripheral edge of the second coupling member connecting portion 63b overlaps the outer peripheral edge of the first coupling member connecting portion 63 a.

As shown in fig. 8, the left and right intermediate connecting portions 63cL and 63cR have a cylindrical shape extending obliquely so as to be positioned further downward toward the second coupling member connecting portion 63 b. In the rear view of fig. 8, the length of the left intermediate connection portion 63cL in the vehicle width direction is shorter than the length of the right intermediate connection portion 63cR in the vehicle width direction.

< Engine-side shaft support part >

The engine-side shaft support portion 64 is a cylindrical tube. The engine-side shaft support portion 64 is disposed below the first connecting member connecting portion 63a in the side view of fig. 7. In the side view of fig. 7, the sectional shape of the engine-side shaft support portion 64 (see fig. 5) is an annular shape having an outer diameter smaller than that of the connecting pipe 63.

In the rear view of fig. 8, the vehicle width direction center 64p (extending direction center) of the engine-side shaft support portion 64 is offset to the left side from the vehicle width direction center 63p (extending direction center) of the connecting pipe 63. Here, the vehicle width direction center 64p of the engine-side shaft support portion 64 corresponds to the center of the other end portion of the link member 60.

In the rear view of fig. 8, the length of the engine-side shaft support portion 64 in the vehicle width direction is shorter than the length of the connecting pipe 63 in the vehicle width direction. In the rear view of fig. 8, the left end of the engine-side shaft support portion 64 is positioned below the left intermediate connection portion 63cL, and the right end of the engine-side shaft support portion 64 is positioned below the second coupling member connection portion 63 b.

As shown in fig. 4, the crankcase left and right walls 51L, 51R are arranged coaxially with each other. Cylindrical elastic members 51a (left and right elastic members 51aL, 51aR) are provided in the crankcase left and right wall holes 51h, 51 i. The left and right elastic members 51aL, 51aR have outer diameters substantially equal to the diameters of the crankcase left and right wall holes 51h, 51 i. For example, the left and right elastic members 51aL, 51aR are cylindrical rubber bushes. Fastening members such as bolts are inserted radially inside the left and right elastic members 51aL, 51 aR.

For example, a bolt is inserted from the right in the vehicle width direction through the radially inner side of the right elastic member 51aR in the right crankcase wall hole 51i, the engine-side shaft support portion 64, and the radially inner side of the left elastic member 51aL in the left crankcase wall hole 51h in this order. The front end of the bolt projects outward in the vehicle width direction from the crankcase left wall 51L. A nut is fastened and coupled to a front end (projecting end) of the bolt on the vehicle width direction outer side of the crankcase left wall 51L. Thus, the engine-side shaft support portion 64 is axially supported by the crankcase left and right walls 51L, 51R so as to be rotatable about the bolt shaft 51 c.

< second connecting Member >

In the side view of fig. 7, the connecting pipe 63 is connected to the upper end of the second connecting member 65. In the side view of fig. 7, the upper end portion of the second coupling member 65 is formed in an arc shape that projects forward and downward so as to follow the outer shape of the coupling pipe 63.

In the side view of fig. 7, an engine-side shaft support portion 64 is connected to a lower end portion of the second connecting member 65. In the side view of fig. 7, the lower end portion of the second coupling member 65 is formed in an arc shape that projects rearward and upward so as to follow the outer shape of the engine-side shaft support portion 64.

The second coupling member 65 includes a front coupling plate 66 extending between the front portion of the coupling pipe 63 and the front portion of the engine-side shaft support portion 64 in the vertical direction, and a rear coupling plate 67 extending between the rear portion of the coupling pipe 63 and the rear portion of the engine-side shaft support portion 64 in the vertical direction. In the side view of fig. 7, the front and rear connecting plates 66 and 67 extend obliquely between the upper and lower portions of the connecting pipe 63 and the engine-side shaft support portion 64 so as to be positioned further downward toward the front side. The front and rear webs 66, 67 are integrally joined to each other by welding or the like.

In the rear view of fig. 8, the front and rear linking plates 66, 67 include linking plate bodies 66a, 67a extending in the vehicle width direction, a pair of left and right extending walls 66b, 67b extending from the vehicle width direction outer ends of the linking plate bodies 66a, 67a into the space between the upper and lower portions of the linking pipe 63 and the engine-side shaft support portion 64, and extending pieces 66c, 67c extending rightward along the linking pipe 63 from the upper right portions of the linking plate bodies 66a, 67 a.

The front end edges of the left and right extending walls 67bL, 67bR of the rear linking plate 67 are located outside the rear end edges of the left and right extending walls 66bL, 66bR of the front linking plate 66 in the vehicle width direction. Rear end edges of the left and right extending walls 66bL, 66bR of the front linking plate 66 and front end edges of the left and right extending walls 67bL, 67bR of the rear linking plate 67 are integrally joined to each other by welding or the like.

The front and rear linking plates 66, 67 have a plurality of through holes 66h, 66i, 67h, 67i formed in the linking plate bodies 66a, 67a, respectively, so as to be separated in the vehicle width direction. In the embodiment, the linking plate main bodies 66a, 67a of the front and rear linking plates 66, 67 are provided with two through holes, i.e., left through holes 66h, 67h located on the left extending walls 66bL, 67bL side and right through holes 66i, 67i located on the right extending walls 66bR, 67bR side.

In fig. 8, reference numerals 66j and 67j denote cutouts provided in the lower center portions of the web main bodies 66a and 67a of the front and rear webs 66 and 67, respectively.

< lower extension >

A downward extending portion 70 extending downward is provided at the other end portion of the link member 60. In the rear view of fig. 8, the lower extending portion 70 has a trapezoidal shape (in other words, an inverted trapezoidal shape) whose lateral width decreases toward the lower side. In the rear view of fig. 8, the downward extending portion 70 is received within the left-right width of the web main bodies 66a, 67a below the second coupling member 65. In the side view of fig. 7, the downward extending portion 70 extends downward from the engine-side shaft support portion 64. The downward extending portion 70 includes a downward extending body 71 extending downward from the engine-side shaft support portion 64, and a pair of left and right side extending walls 72L, 72R extending rearward from the downward extending body 71.

In the bottom view of fig. 9, the downward extending body 71 is in a U shape (in other words, an inverted U shape that is horizontally long) that opens forward and extends in the vehicle width direction. In the bottom view of fig. 9, the downward extending body 71 includes an extending wall portion 73 extending in the vehicle width direction, and a pair of left and right front side wall portions 74L, 74R extending forward from the vehicle width direction outer ends of the extending wall portion 73.

In the bottom view of fig. 9, the extending wall portion 73 extends in the vehicle width direction that intersects the swing direction V1 (see fig. 2) of the power unit 10. In the embodiment, the extending wall portion 73 extends perpendicularly to the swing direction V1 (see fig. 2) of the power unit 10. As shown in fig. 8, the upper end edge of the extended wall portion 73 is linear along the extending direction of the engine-side shaft support portion 64. In the side view of fig. 7, the upper end edges of the left and right front side wall portions 74L, 74R (only the left front side wall portion 74L is shown in fig. 7) are formed in an arc shape that projects forward and downward so as to follow the outer shape of the engine-side shaft support portion 64. The upper end edge of the extended wall portion 73 and the upper end edges of the left and right front side wall portions 74L, 74R are integrally coupled to the engine-side shaft support portion 64 by welding or the like.

In the bottom view of fig. 9, the left and right lateral extension walls 72L, 72R are L-shaped. In the bottom view of fig. 9, the left and right laterally extending walls 72L, 72R include rear side wall portions 75 extending rearward from the vehicle width direction outer ends of the downwardly extending body 71, and rear connecting wall portions 76 extending outward in the vehicle width direction from rear ends of the rear side wall portions 75.

The left and right rear side wall portions 75L, 75R (only the left rear side wall portion 75L is shown in fig. 7) have a rectangular shape in a side view of fig. 7. The front end edges of the left and right rear side wall portions 75L, 75R and the rear end edges of the left and right front side wall portions 74L, 74R are integrally joined by welding or the like. In the bottom view of fig. 9, the length between the left and right rear side wall portions 75L, 75R in the vehicle width direction is longer than the length between the left and right front side wall portions 74L, 74R in the vehicle width direction.

In the rear view of fig. 8, the left and right rear connecting wall portions 76L, 76R are triangular in shape having oblique sides located further outward in the vehicle width direction as they go further upward. The upper end edges of the left and right rear connecting wall portions 76L, 76R are integrally joined to the lower end portion of the linking plate main body 67a of the rear linking plate 67 by welding or the like.

In the embodiment, the left and right front and rear side walls 74L, 74R, 75L, and 75R are connected to side ends of the extending wall 73, and sandwich the elastic member 90 from the side (see fig. 4). Hereinafter, the front and rear side walls 74L, 74R, 75L, 75R will also be simply referred to as "side wall 77".

In fig. 8, reference numeral 71j denotes a notch provided at the center of the lower portion of the lower extension body 71.

< swing restricting section >

As shown in fig. 5, the swing restricting portion 80 is provided at the front upper portion of the power unit 10. A recess 81h that opens upward and into which the downward extending portion 70 fits is provided in the front upper portion of the power unit 10. The swing restricting portion 80 includes a restricting wall portion 81 formed integrally with the crankcase 34 by the same member. That is, in the crankcase 34, the restricting wall 81 constitutes a part of a formation portion of the recess 81 h.

The restricting wall portion 81 includes a front restricting wall 82 rising upward on the front side of the recess 81h, and a rear restricting wall 83 rising upward on the rear side of the recess 81 h.

The front and rear restricting walls 82, 83 sandwich the elastic member 90 from the front and rear. The front and rear restricting walls 82, 83 extend in the vehicle width direction so as to be connected to the crankcase left and right walls 51L, 51R (see fig. 4). The vehicle-widthwise lengths of the front and rear limiting walls 82, 83 are longer than the vehicle-widthwise length of the downwardly extending portion 70. The lower extending portion 70 is accommodated between the left and right walls of the crankcase in the vehicle width direction.

< elastic Member >

As shown in fig. 5, an elastic member 90 bulging in the swing direction V1 (see fig. 2) across the extending wall portion 73 is fitted into the recess 81 h. As shown in fig. 4, the elastic member 90 has a rectangular parallelepiped shape extending in the vehicle width direction. As viewed from the front in fig. 10, the elastic member 90 includes: a front elastic portion 91 having a rectangular parallelepiped shape extending in the vehicle width direction; and a rear elastic portion 92 having a rectangular parallelepiped shape larger in the vehicle width direction and shorter in the vertical direction than the front elastic portion 91, and connected to the rear side of the front elastic portion 91.

As shown in fig. 5, the front elastic portion 91 is sandwiched from the front and the rear by the front restricting wall 82 in the swing restricting portion 80 and the extending wall portion 73 in the downward extending portion 70. The front elastic portion 91 is sandwiched by the left and right side wall portions 77 (see fig. 4) from the outside in the vehicle width direction. Specifically, the front elastic portion 91 is sandwiched by the left and right front side wall portions 74L, 74R (see fig. 9) of the downward extending portion 70 from the vehicle width direction outer side.

As shown in fig. 5, the rear elastic portion 92 is sandwiched from the front and the rear by the extending wall portion 73 in the downward extending portion 70 and the rear restricting wall 83 in the swing restricting portion 80. The rear elastic portion 92 is sandwiched by the left and right side wall portions 77 (see fig. 4) from the outside in the vehicle width direction. Specifically, the rear elastic portion 92 is sandwiched from the outside in the vehicle width direction by the left and right rear side wall portions 75L, 75R (see fig. 9) of the downward extending portion 70.

As shown in fig. 11, a groove 90m that opens upward and into which the extending wall portion 73 fits is formed between the front side elastic portion 91 and the rear side elastic portion 92 of the elastic member 90. A projection 93 that rises upward and fits into a notch 71j (see fig. 8) of the extending wall portion 73 is provided between the front elastic portion 91 and the rear elastic portion 92 in the groove 90 m. The projection 93 is located at the vehicle width direction center of the elastic member 90.

< peripheral Structure of Link Member >

As shown in fig. 5, the throttle body 26 is disposed in front of the link member 60. A connection pipe 27 for connecting the throttle body 26 and the air cleaner 28 (see fig. 3) is disposed above the link member 60. In the side view of fig. 5, the connection pipe 27 extends in a curved manner in the front-rear direction in the space above the connection pipe 63 in the link member 60.

As shown in fig. 3, a transmission 49 is disposed on the left side with respect to the vehicle body left-right center line CL. The center 64p of the other end portion of the link member 60 (in other words, the vehicle width direction center 64p of the engine-side shaft support portion 64) is offset leftward with respect to the vehicle body left-right center line CL. That is, the center 64p of the other end portion of the link member 60 is offset to the side where the transmission 49 is disposed with respect to the vehicle body left-right center line CL.

As described above, in the above embodiment, the engine suspension structure 45 includes the vehicle body frame 11, the power unit 10 including the engine 30 and swingably supported by the vehicle body frame 11, and the link member 60 having one end swingably connected to the vehicle body frame 11 side and the other end swingably connected to the power unit 10 side, and in the engine suspension structure 45, the crank case 34 of the engine 30 is provided with the swing restricting portion 80 that restricts the swing of the braking force unit 10.

According to this configuration, by providing the swing restricting portion 80 that restricts the swing of the braking force unit 10 in the crankcase 34 of the engine 30, the swing of the engine 30 can be restricted without increasing the rigidity of the vehicle body frame 11, as compared with the case where the swing restricting portion 80 is provided in the vehicle body frame 11. However, in order to increase the rigidity of the vehicle frame, it is necessary to bend the vehicle frame or provide a reinforcing member. Therefore, the suspension structure is complicated or the number of components is increased, which may increase the size and weight of the suspension structure. In contrast, according to this configuration, since the crankcase 34 itself has high rigidity, the swing restricting portion 80 can be provided in the crankcase 34 with a simple configuration, and the engine suspension structure 45 can be prevented from being increased in size and weight.

In the above embodiment, since the swing restricting portion 80 includes the restricting wall portion 81 formed integrally with the crankcase 34 by the same member, the number of components can be reduced, and the engine suspension structure 45 can be simplified and reduced in weight, as compared with a case where the swing restricting portion 80 is provided separately from the crankcase 34. For example, the restricting wall 81 and the crankcase 34 can be formed integrally by casting, which is preferable.

In the above embodiment, the swing restricting portion 80 is provided at the front upper portion of the power unit 10 extending in the vehicle front-rear direction, and thus a so-called upper link unit swing engine, in which the other end of the link member 60 is swingably connected to the front upper portion of the power unit 10, can suppress the swing of the engine 30 without increasing the rigidity of the frame 11.

In the above embodiment, since the downward extending portion 70 extending downward is provided at the other end portion of the link member 60 and the recess 81h opening upward and into which the downward extending portion 70 is fitted is provided at the front upper portion of the power unit 10, the number of components can be reduced as compared with the case where the stopper is provided separately from the other end portion of the link member 60, and simplification and weight reduction of the engine suspension structure 45 can be achieved.

In the above embodiment, the downward extending portion 70 includes the extending wall portion 73 extending in the vehicle width direction intersecting the swing direction V1 of the power unit 10, and the elastic member 90 bulging in the swing direction V1 across the extending wall portion 73 is fitted into the recessed portion 81h, whereby the load generated when the power unit 10 swings can be absorbed by elastic deformation of the elastic member 90.

In the above embodiment, the lower extending portion 70 further includes the pair of side wall portions 77 connected to the side ends of the extending wall portion 73 and sandwiching the elastic member 90 from the side, so that the rigidity of the lower extending portion 70 can be improved as compared with the case where the lower extending portion 70 includes only the extending wall portion 73. In addition, the elastic member 90 can be accommodated between the pair of side wall portions 77, and the elastic member 90 can be downsized.

In the above embodiment, the link member 60 extends obliquely rearward and downward from the vehicle body frame 11 side in a side view, and then extends obliquely forward and downward and is connected to the power unit 10 side, so that a space is formed in front of and above the link member 60, and thus the degree of freedom in disposing the vehicle components can be improved.

In the above embodiment, the throttle body 26 is disposed in front of the link member 60, and the connection pipe 27 for connecting the throttle body 26 and the air cleaner 28 is disposed above the link member 60, whereby the following effects are achieved. Since the throttle body 26 and the connection pipe 27 can be disposed as vehicle components in the front space and the upper space of the link member 60, the peripheral components of the engine suspension structure 45 can be collected. Therefore, it is preferable to miniaturize the entire vehicle.

In the above embodiment, the transmission 49 is disposed on the left and right sides with respect to the vehicle body left and right center line CL, and the center 64p of the other end portion of the link member 60 is offset to the side where the transmission 49 is disposed with respect to the vehicle body left and right center line CL, whereby the power unit 10 can be stably supported by the frame 11 even when the weight of the power unit 10 is offset to the side where the transmission 49 is disposed with respect to the vehicle body left and right center line CL.

In the above embodiment, the example in which the swing restricting portion 80 includes the restricting wall portion 81 formed integrally with the crankcase 34 by the same member has been described, but the present invention is not limited thereto. For example, the swing restricting portion 80 may be provided separately from the crankcase 34.

In the above-described embodiment, the example in which the swing restricting portion 80 is provided in the front upper portion of the power unit 10 extending in the vehicle front-rear direction has been described, but the present invention is not limited thereto. For example, the swing restricting portion 80 may be provided at a front lower portion of the power unit 10 extending in the vehicle front-rear direction.

In the above embodiment, the example in which the downward extending portion 70 further includes the pair of side wall portions 77 connected to the side ends of the extending wall portion 73 and sandwiching the elastic member 90 from the sides has been described, but the present invention is not limited to this. For example, the lower extension portion 70 may be provided with only the extension wall portion 73.

In the above embodiment, the link member 60 extends obliquely rearward and downward from the frame 11 side and then extends obliquely forward and downward to be connected to the power unit 10 side in a side view, but the present invention is not limited thereto. For example, the link member 60 may extend obliquely rearward and downward from the side of the frame 11 and be coupled to the side of the power unit 10 in a side view.

In the above embodiment, the transmission 49 is described as including the drive pulley, the driven pulley, and the V-belt, but the present invention is not limited thereto. For example, the transmission 49 may be provided with a member capable of performing other power transmission such as gear transmission and chain transmission.

(second embodiment)

As shown in fig. 12, the engine suspension structure of the second embodiment differs from the first embodiment in the structure of the link member and the downward extending portion. In the following description, the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

< Link Member >

As shown in fig. 12, the link member 160 includes a pair of left and right pivot shaft support portions 61L, 61R, a pair of left and right first connecting members 162L, 162R having upper portions connected to the left and right pivot shaft support portions 61L, 61R, respectively, and extending rearward and downward, a connecting pipe 163 projecting downward in the vehicle width direction in the rear view of fig. 13 so as to extend across between the lower portions of the left and right first connecting members 162L, 162R, an engine side shaft support portion 64, and a second connecting member 165 extending across between the connecting pipe 163 and the engine side shaft support portion 64 in the front-rear direction.

< first connecting Structure >

In the rear view of fig. 13, the left and right first coupling members 162L, 162R are U-shaped. In the rear view of fig. 13, the left and right first linking members 162L, 162R include an inner linking wall 162a extending vertically and positioned on the inside in the vehicle width direction, an outer linking wall 162b extending vertically and positioned on the outside in the vehicle width direction with respect to the inner linking wall 162a, and a front linking wall 162c spanning between the front end of the inner linking wall 162a and the front end of the outer linking wall 162b in the vehicle width direction.

In the side view of fig. 12, the inner and outer coupling walls 162a and 162b (only the outer coupling wall 162b is shown in fig. 12) are coupled at their upper portions to the pivot shaft support portion 61 (only the left pivot shaft support portion 61L is shown in fig. 12) and at their lower portions to the coupling pipe 163. In a side view of fig. 12, a pivot side recess 162g is formed in an upper portion of the inner and outer connecting walls 162a and 162b so as to be recessed in an arc shape along the outer shape of the pivot side shaft support portion 61. In the side view of fig. 12, a coupling pipe side recess 162h that is connected to the pivot side recess 162g and is recessed in an arc shape along the outer shape of the coupling pipe 163 is formed at the lower portion of the inner and outer coupling walls 162a and 162 b.

In the side view of fig. 12, the front connecting wall 162c extends from the front upper ends of the inner and outer connecting walls 162a, 162b located at the front upper portion of the pivot shaft support portion 61 so as to curve downward along the outer shape of the pivot shaft support portion 61, then extends linearly so as to be inclined downward toward the rear side, and reaches the rear lower ends of the inner and outer connecting walls 162a, 162b located below the vehicle width direction outer ends of the connecting pipes 163.

< connecting pipe >

In the rear view of fig. 13, the connecting pipe 163 includes a pair of left and right first connecting member connecting portions 163aL and 163aR to which the left and right first connecting members 162L and 162R are connected, respectively, a second connecting member connecting portion 163b to which the second connecting member 165 is connected, and a pair of left and right intermediate connecting portions 163cL and 163cR to which the left and right first connecting member connecting portions 163aL and 163aR and the second connecting member connecting portion 163b are connected, respectively.

The left and right first linking member connecting portions 163aL, 163aR are located on the vehicle width direction outer end sides of the linking pipes 163, and are formed in a cylindrical shape extending in the vehicle width direction. The left and right first connecting-member connecting portions 163aL, 163aR are arranged coaxially with each other.

The second connecting member connecting portion 163b is located between the left and right first connecting member connecting portions 163aL, 163aR in the vehicle width direction, and has a cylindrical shape extending in the vehicle width direction. The second coupling member connecting portion 163b is located rearward and downward of the first coupling member connecting portion 163a in the side view of fig. 12.

As shown in fig. 13, the left and right intermediate connecting portions 163cL and 163cR have a cylindrical shape extending obliquely so as to be positioned further downward toward the second coupling member connecting portion 163 b. In the rear view of fig. 13, the length of the left intermediate connection portion 163cL in the vehicle width direction is shorter than the length of the right intermediate connection portion 163cR in the vehicle width direction. In the rear view of fig. 13, the vertical length of the left and right intermediate connecting portions 163cL and 163cR is longer than the vertical length of the left and right intermediate connecting portions 63cL and 63cR (see fig. 8) in the first embodiment.

< Engine-side shaft support part >

In the side view of fig. 12, the engine-side shaft support portion 64 is disposed below the pivot-side shaft support portion 61. In the rear view of fig. 13, the vehicle width direction center 64p (extending direction center) of the engine-side shaft support portion 64 is offset to the left side from the vehicle width direction center 163p (extending direction center) of the connecting pipe 163.

In the rear view of fig. 13, the length of the engine-side shaft support portion 64 in the vehicle width direction is shorter than the length of the connecting pipe 163 in the vehicle width direction. In the rear view of fig. 13, the left end of the engine-side shaft support portion 64 is positioned forward of the lower portion of the left intermediate connection portion 163cL, and the right end of the engine-side shaft support portion 64 is positioned forward of the right portion of the second coupling member connection portion 163 b.

< second connecting Member >

In the side view of fig. 12, a connection pipe 163 is connected to a rear end portion of the second connection member 165. In the side view of fig. 12, the rear end portion of the second coupling member 165 is formed in an arc shape that projects forward so as to follow the outer shape of the coupling pipe 163.

In the side view of fig. 12, the engine-side shaft support portion 64 is coupled to the distal end portion of the second coupling member 165. In the side view of fig. 12, the front end portion of the second coupling member 165 has an arc shape that is convex rearward so as to follow the outer shape of the engine-side shaft support portion 64.

The second connecting member 165 includes an upper connecting plate 166 extending between the upper portion of the connecting pipe 163 and the upper portion of the engine-side shaft support portion 64 in the front-rear direction, and a lower connecting plate 167 extending between the lower portion of the connecting pipe 163 and the lower portion of the engine-side shaft support portion 64 in the front-rear direction. In the side view of fig. 12, the upper and lower connecting plates 166 and 167 extend obliquely gently so as to be positioned lower as they go further forward between the connecting pipe 163 and the engine-side shaft support portion 64. The upper and lower webs 166, 167 are integrally joined to each other by welding or the like.

The upper and lower linking plates 166 and 167 include linking plate bodies 166a and 167a extending in the vehicle width direction, a pair of left and right extending walls 166b and 167b extending from the vehicle width direction outer ends of the linking plate bodies 166a and 167a to the front and rear of the linking pipe 163 and the engine-side shaft support portion 64, and extending pieces 166c and 167c extending rightward along the linking pipe 163 from the right rear portions of the linking plate bodies 166a and 167a, as viewed from the rear of fig. 13.

The upper end edges of the left and right extending walls 167bL, 167bR of the lower linking plate 167 are positioned inward in the vehicle width direction of the lower end edges of the left and right extending walls 166bL, 166bR of the upper linking plate 166. The lower end edges of the left and right extending walls 166bL, 166bR of the upper linking plate 166 and the upper end edges of the left and right extending walls 167bL, 167bR of the lower linking plate 167 are integrally joined to each other by welding or the like. In fig. 13, through holes in the web bodies 166a and 167a of the upper and lower webs 166 and 167 are not shown.

< lower extension >

A downward extending portion 170 extending downward is provided at the other end of the link member 160. In the rear view of fig. 13, the downward extending portion 170 has an outer shape in which both ends in the vehicle width direction extend downward. In the rear view of fig. 13, the downward extending portion 170 is received within the left-right width of the web main bodies 166a, 167a in the front-lower direction of the second coupling member 165. In the side view of fig. 12, the downward extending portion 170 extends forward and downward from the engine-side shaft support portion 64. The downward extending portion 170 includes an extending wall portion 173 extending in the vehicle width direction, and a pair of left and right side wall portions 177L, 177R extending rearward and downward from outer ends of the extending wall portion 173 in the vehicle width direction.

The extending wall portion 173 is formed in a U shape that is open forward and upward and extends in the vehicle width direction when viewed from the extending direction of the downward extending portion 170. The extending wall portion 173 extends perpendicularly to the swing direction V1 (see fig. 2) of the power unit 10. The left and right side wall portions 177L, 177R are connected to the vehicle width direction outer ends of the extending wall portion 173 and extend rearward and downward. The upper end edge of the extended wall portion 173 and the upper end edges of the left and right side wall portions 177L and 177R are integrally coupled to the engine-side shaft support portion 64 by welding or the like. As shown in fig. 14, the left and right side wall portions 177L, 177R sandwich the elastic member 190 from the sides. In fig. 13, reference numeral 173j denotes a notch provided at the center of the lower portion of the extending wall 173.

According to the present embodiment, the lower extending portion 170 further includes the pair of side wall portions 177 connected to the side ends of the extending wall portions 173 and sandwiching the elastic member 190 from the sides, so that the rigidity of the lower extending portion 170 can be improved as compared with the case where the lower extending portion 170 includes only the extending wall portions 173. In addition, the elastic member 190 can be accommodated between the pair of side wall portions 177, and the elastic member 190 can be downsized.

(third embodiment)

As shown in fig. 15, the third embodiment is different from the first embodiment in that it further includes a bracket 278 bridging the connection pipe 63 and the connection portion 51 (see fig. 19), and in that the configuration of the link member and the downward extending portion in the engine suspension structure described above. In the following description, the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

< Link Member >

As shown in fig. 15, the link member 260 includes a pair of left and right pivot-side shaft support portions 61L, 61R, a pair of left and right first link members 62L, 62R, a connecting pipe 63, an engine-side shaft support portion 64, a second connecting member 265 that extends obliquely across the space between the upper and lower sides of the connecting pipe 63 and the engine-side shaft support portion 64 and that extends downward as it goes to the front side in the side view of fig. 15, and a bracket 278 that bridges the connecting pipe 63 and the connecting portion 51 (see fig. 19).

< second connecting Member >

In the side view of fig. 15, the connection pipe 63 is connected to the upper end of the second connection member 265.

In the side view of fig. 15, the engine-side shaft support portion 64 is connected to a lower end portion of the second connecting member 265. In the side view of fig. 15, the lower end portion of the second coupling member 265 has an arc shape that is convex rearward and upward so as to follow the outer shape of the engine-side shaft support portion 64.

The second coupling member 265 includes a front coupling plate 266 extending between the front portion of the coupling pipe 63 and the front portion of the engine-side shaft support portion 64 in the vertical direction, and a rear coupling plate 267 extending between the rear portion of the coupling pipe 63 and the rear portion of the engine-side shaft support portion 64 in the vertical direction. In the side view of fig. 15, the front and rear connecting plates 266, 267 extend obliquely between the upper and lower portions of the connecting pipe 63 and the engine-side shaft support portion 64 so as to be positioned further downward toward the front side. The front and rear webs 266, 267 are integrally joined to each other by welding or the like.

In the rear view of fig. 16, the front and rear linking plates 266, 267 include linking plate main bodies 266a, 267a extending in the vehicle width direction, a pair of left and right extending walls 266b, 267b extending from the vehicle width direction outer ends of the linking plate main bodies 266a, 267a into the vertical space between the linking pipe 63 and the engine-side shaft support portion 64, extending pieces 266c, 267c extending rightward along the linking pipe 63 from the upper right portions of the linking plate main bodies 266a, 267a, and projecting pieces 266d, 267d projecting leftward along the linking pipe 63 from the upper left portions of the linking plate main bodies 266a, 267 a.

The front end edges of the left and right extending walls 267bL, 267bR of the rear linking plate 267 are positioned outside the rear end edges of the left and right extending walls 266bL, 266bR of the front linking plate 266 in the vehicle width direction. Rear end edges of the left and right extending walls 266bL, 266bR of the front linking plate 266 and front end edges of the left and right extending walls 267bL, 267bR of the rear linking plate 267 are integrally joined to each other by welding or the like. In fig. 16, reference numerals 266h, 266i, 267h, 267i denote through holes formed in the web main bodies 266a, 267a of the front and rear webs 266, 267, and reference numerals 266j, 267j denote cutouts provided in the lower center portions of the web main bodies 266a, 267a of the front and rear webs 266, 267.

< lower extension >

A downward extending portion 270 extending downward is provided at the other end of the link member 260. In the side view of fig. 15, the downward extending portion 270 extends downward from the engine-side shaft support portion 64. The downward extending portion 270 includes a downward extending body 271 extending downward from the engine-side shaft support portion 64, and a pair of left and right side extending walls 272L and 272R extending laterally from the downward extending body 271 (see fig. 17).

In the bottom view of fig. 17, the lower extension body 271 has a crank shape extending in the vehicle width direction. In the bottom view of fig. 17, the lower extending body 271 includes an extending wall portion 273 extending in the vehicle width direction, a left side wall portion 277L extending rearward from a left end of the extending wall portion 273, and a right side wall portion 277R extending forward from a right end of the extending wall portion 273.

In the bottom view of fig. 17, the extending wall 273 extends perpendicular to the swing direction V1 (see fig. 2) of the power unit 10. In the bottom view of fig. 17, the left side wall 277L is connected to the left end of the extending wall 273 and extends rearward. In the bottom view of fig. 17, the right side wall portion 277R is connected to the right end of the extending wall portion 273 and extends forward. In the bottom view of fig. 17, the left extending wall 272L has an L shape extending leftward from the rear end of the left wall 277L and then extending to be bent forward. In the bottom view of fig. 17, the right extending wall 272R has an L shape extending rightward from the front end of the right wall 277R and then bent rearward. The upper end edge of the extending wall portion 273, the upper end edges of the left and right side wall portions 277L, 277R, the upper end edges of the left and right side extending walls 272L, 272R, and the engine-side shaft support portion 64 are integrally joined by welding or the like.

As shown in fig. 19, the left and right side wall portions 277L, 277R sandwich the elastic member 290 from the side. In the rear view of fig. 18, the lower portion of the elastic member 290 bulges downward than the downward extending portion 270. In the bottom view of fig. 19, a plurality of (seven in the embodiment) front convex portions 290a protruding forward are arranged in the vehicle width direction in the front portion of the elastic member 290. A plurality of (two in the embodiment) rear convex portions 290b projecting rearward are arranged in the vehicle width direction at the rear portion of the elastic member 290. In fig. 17, reference numerals 271j and 271k denote cutouts provided in the center of the lower portion of the lower extension body 271.

< Stent >

As shown in fig. 19, the bracket 278 bridges the right end portion of the second coupling member connecting portion 63b (see fig. 16) of the coupling pipe 63 and the right coupling portion 51R (crankcase right wall). The bracket 278 is disposed on the right side with respect to the vehicle body left-right center line CL. In the rear view of fig. 16, the holder 278 includes, on the right side of the engine-side shaft support portion 64, a holder main body 278a that is inclined so as to be positioned downward from the connecting pipe 63 side toward the left side and then extends so as to be bent downward, and a pair of front and rear extending pieces 278b that extend rightward and upward from the upper end portion of the holder main body 278a toward the connecting pipe 63. The upper end edges of the pair of front and rear extending pieces 278b are integrally joined to the right end portion of the second connecting member connecting portion 63b in the connecting pipe 63 by welding or the like.

The holder main body 278a is formed with a through hole (hereinafter, also referred to as a "holder through hole") that opens in the vehicle width direction, which is not shown. For example, the bolt is inserted from the right in the vehicle width direction through the bracket through hole, the radially inner side of the right elastic member 51aR in the right crankcase wall hole 51i (see fig. 4), the engine-side shaft support portion 64, and the radially inner side of the left elastic member 51aL in the left crankcase wall hole 51h (see fig. 4). A nut is fastened and coupled to a front end (projecting end) of the bolt on the vehicle width direction outer side of the crankcase left wall 51L. Thus, the engine-side shaft support portion 64 is axially supported by the crankcase left and right walls 51L, 51R so as to be rotatable about the bolt shaft 51 c.

According to the present embodiment, the crankcase 34 is provided with the crankcase right wall 51R coupled to the vehicle body, the center 64p of the other end portion of the link member 260 is offset to the left with respect to the vehicle body left-right center line CL, and the bracket 278 bridging the connecting pipe 63 extending in the vehicle width direction and the crankcase right wall 51R is provided on the right with respect to the vehicle body left-right center line CL, whereby the stability of the vehicle rear portion can be improved even when the center 64p of the other end portion of the link member 260 is offset to the left with respect to the vehicle body left-right center line CL.

According to the present embodiment, lower extending portion 270 further includes a pair of side wall portions 277 connected to side ends of extending wall portions 273 and sandwiching elastic member 290 from the sides, and thus the rigidity of lower extending portion 270 can be improved as compared with the case where lower extending portion 270 includes only extending wall portions 273. In addition, the elastic member 290 can be accommodated between the pair of side wall portions 277, and the elastic member 290 can be downsized.

In the present embodiment, the center 64p of the other end portion of the link member 260 is offset to the left with respect to the vehicle body left-right center line CL, and the bracket 278 is provided to the right with respect to the vehicle body left-right center line CL. For example, the center 64p of the other end portion of the link member 260 may be offset to the right with respect to the vehicle body left-right center line CL, and the bracket 278 may be provided to the left with respect to the vehicle body left-right center line CL. That is, the center 64p of the other end portion of the link member 260 may be offset to one side in the vehicle width direction with respect to the vehicle body left and right center line CL, and the bracket 278 may be provided to the other side in the vehicle width direction with respect to the vehicle body left and right center line CL.

The present invention is not limited to the above-described embodiments, and for example, the straddle-type vehicle includes all vehicles in which a driver rides over a vehicle body, and includes not only motorcycles (including bicycles with a prime mover and scooter-type vehicles) but also vehicles of three wheels (including front and rear wheels in addition to front and rear wheels). The present invention is applicable not only to motorcycles but also to four-wheeled vehicles such as automobiles.

The configuration in the above embodiment is an example of the present invention, and various modifications such as replacement of the components of the embodiment with known components can be made without departing from the scope of the present invention.

Description of reference numerals:

1 motorcycle (straddle-type vehicle); 10 a power unit; 11 a frame; 26 a throttle body; 27 connecting pipes; 28 an air cleaner; 30 an engine; 34 a crankcase; 45 engine suspension structure (suspension structure); 49 a transmission; 51a connecting part; 60. 160, 260 link members; 63. 163a connecting tube; a vehicle width direction center of the 64p engine-side shaft support portion (a center of the other end portion of the link member); 70. 170, 270; 73. 173, 273 extending wall portions; 77. 177, 277 side wall portions; 80 a swing restricting portion; 81 a restricting wall portion; a recess of 81 h; 90. 190, 290 an elastic member; 278 support bracket; CL vehicle body left and right center lines; v1 swing direction.

Claims (8)

1. A suspension structure of a saddle-ride type vehicle,

the suspension structure of the saddle-ride type vehicle includes:

a frame;

a power unit including an engine and swingably supported by the frame; and

a link member having one end swingably coupled to the frame side and the other end swingably coupled to the power unit side,

a swing restricting portion that restricts a swing of the power unit is provided in a crankcase of the engine,

the swing restricting portion includes a restricting wall portion formed integrally with the crankcase,

a downward extending portion extending downward is provided at the other end portion of the link member,

a recess which opens upward and into which the downward extending portion fits is provided in a front upper portion of the power unit,

the link member extends obliquely rearward and downward from the vehicle frame side in a side view, and then extends obliquely forward and downward and is coupled to the power unit side.

2. The suspension structure of the straddle-type vehicle according to claim 1,

the swing restricting portion is provided at a front upper portion of the power unit extending in a vehicle front-rear direction.

3. A suspension structure of a saddle-ride type vehicle,

the suspension structure of the saddle-ride type vehicle includes:

a frame;

a power unit including an engine and swingably supported by the frame; and

a link member having one end swingably coupled to the frame side and the other end swingably coupled to the power unit side,

a swing restricting portion that restricts a swing of the power unit is provided in a crankcase of the engine,

the swing restricting portion includes a restricting wall portion formed integrally with the crankcase,

the link member extends obliquely rearward and downward from the frame side in a side view, and then extends obliquely forward and downward and is coupled to the power unit side,

a downward extending portion extending downward is provided at the other end portion of the link member,

a recess which opens upward and into which the downward extending portion fits is provided in a front upper portion of the power unit,

the swing restricting portion is provided at a front upper portion of the power unit extending in a vehicle front-rear direction,

the downward extending portion includes an extending wall portion extending in a vehicle width direction intersecting a swing direction of the power unit,

an elastic member that bulges in the swing direction with the extension wall portion interposed therebetween is fitted into the recess.

4. The suspension structure of the straddle-type vehicle according to claim 3,

the downward extending portion further includes a pair of side wall portions connected to side ends of the extending wall portion and sandwiching the elastic member from a side.

5. The suspension structure of the straddle-type vehicle according to claim 4,

a throttle body is disposed in front of the link member,

a connection pipe connecting the throttle body and an air cleaner is disposed above the link member.

6. The suspension structure of the straddle-type vehicle according to any one of claims 1 to 5,

the transmission is arranged on the left and right sides with respect to the left and right center lines of the vehicle body,

the center of the other end of the link member is offset to the side where the transmission is disposed with respect to the vehicle body left-right center line.

7. The suspension structure of the straddle-type vehicle according to any one of claims 1 to 5,

the crankcase is provided with a connecting part connected with the vehicle body,

the center of the other end of the link member is offset to one side in the vehicle width direction with respect to the vehicle body left and right center line,

a bracket that bridges the connecting pipe extending in the vehicle width direction and the connecting portion is provided on the other side in the vehicle width direction with respect to the vehicle body left and right center lines.

8. The suspension structure of the straddle-type vehicle according to claim 6,

the crankcase is provided with a connecting part connected with the vehicle body,

the center of the other end of the link member is offset to one side in the vehicle width direction with respect to the vehicle body left and right center line,

a bracket that bridges the connecting pipe extending in the vehicle width direction and the connecting portion is provided on the other side in the vehicle width direction with respect to the vehicle body left and right center lines.

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