Power unit support device

Abstract

To alleviate a restriction in layout of a bridge frame in a vehicle body frame, and facilitate designing of the vehicle body frame or enhance freedom in designing the vehicle body frame.SOLUTION: A power unit support device 41 that supports a power unit 21 on a vehicle body frame 2 of a saddle riding vehicle includes a link member 42 that links the vehicle body frame 2 to the power unit 21, and a power unit swinging limitation mechanism 71 that limits swinging of the power unit 21 relative to the link member 42. The power unit swinging limitation mechanism 71 includes a projection 85 that is incorporated in the power unit 21 and projects forward from the power unit 21, an upper limitation part 73 that is incorporated in the link member 42, disposed above the projection 85, and limits upward movement of the projection 85 at a time when the power unit 21 swings, and a lower limitation part 74 that is incorporated in the link member 42, disposed below the projection 85, and limits downward movement of the projection 85 at a time when the power unit 21 swings.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a power unit support device that is provided in a saddle-ride type vehicle and supports a unit swing type power unit on a vehicle body frame. [Background technology]

[0002] Straddle-type vehicles such as scooters are often equipped with a unit swing-type power unit. The power unit includes an engine or an electric motor as a power source for propelling the saddle-type vehicle. A rear wheel is supported at the rear of the power unit. The power unit is swingably supported on the vehicle body frame via a power unit support device, and the entire power unit functions as a swing arm.

[0003] The power unit support device supports the power unit on the body frame so that it can swing, and has the function of suppressing transmission to the body frame of vibrations caused by the operation of the engine and other components provided in the power unit, as well as vibrations caused when the rear wheels pass over uneven ground. Conventional power unit support devices include a link that connects the body frame and the power unit, and a link swing restriction mechanism that restricts swing of the link relative to the body frame.

[0004] In many cases, the front end of the link is swingably connected to a portion of the body frame located below the center in the fore-and-aft direction of the saddle-ride type vehicle via a shaft extending in the vehicle width direction. The rear end of the link is swingably connected to the power unit case via another shaft extending in the vehicle width direction. Rubber bushings are provided at the connection between the body frame and the link and at the connection between the link and the power unit case.

[0005] The link swing restriction mechanism basically has a structure in which a concave (or convex) member is fixed to the body frame, a convex (or concave) member is fixed to the link, and these concave and convex members are meshed with each other with an elastic member such as rubber interposed between them. This structure limits the range of swing of the link relative to the body frame to the range in which one of the meshed concave and convex members can displace relative to the other.

[0006] Japanese Patent Application Laid-Open Publication No. 2012-158241 (Patent Document 1) describes a motorcycle (10) equipped with a link mechanism (24) and a link restricting portion (55). The reference numerals in parentheses indicate the reference numerals used in the publication. The link mechanism (24) and the link restricting portion (55) correspond to a conventional power unit support device. The link mechanism (24) supports a unit swing (30) on a pair of left and right lower frames (87L, 87R) that form part of the body frame (20). The link restricting portion (55) restricts the amount of rotation of the link mechanism (24) relative to the body frame (20).

[0007] As shown in FIG. 2 of the publication, in a motorcycle (10), a pair of left and right lower frames (87L, 87R) are provided with a link mechanism (24), and a unit swing (30) is journaled by the link mechanism (24). As shown in FIG. 6 of the publication, the link mechanism (24) has a pair of left and right link portions (118L, 118R). The front ends of each link portion (118L, 118R) are supported by the lower frames (87L, 87R) via an outer cylinder (114), an inner cylinder (115), a rubber bushing (116), a link pivot (23), and link brackets (105L, 105R), etc. The unit swing (30) is supported by the rear ends of each link portion (118L, 118R) via a rotating cylinder (121), a connecting shaft, etc.

[0008] As shown in Figures 6 to 8 of the publication, the link restricting portion (55) has box portions (111L, 111R), arm portions (117L, 117R), and a stopper rubber (120). The box portions (111L, 111R) are fixed to a cross frame (91) that spans between a pair of left and right lower frames (87L, 87R). The arm portions (117L, 117R) extend forward from the outer cylinder (114). The arm portions (117L, 117R) are inserted into the box portions (111L, 111R) via the stopper rubber (120). [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-158241 Summary of the Invention [Problem to be solved by the invention]

[0010] As described above, a conventional power unit support device includes a link swing restriction mechanism that restricts swing of the link relative to the body frame. The link swing restriction mechanism has a structure in which one of a concave member and a convex member that mesh with each other is fixed to the body frame, and the other is fixed to the link. In a motorcycle (10) described in JP 2012-158241 A, the box portions (111L, 111R) correspond to the concave member, and the arm portions (117L, 117R) correspond to the convex member. The box portions (111L, 111R) are fixed to a cross frame (91) that spans between left and right lower frames (87L, 87R), and the arm portions (117L, 117R) are fixed to an outer cylinder (114) of the link mechanism 24.

[0011] From the viewpoint of realizing a simple structure for restricting the swinging of the link relative to the body frame, it is considered that the optimal location for fixing the concave member (or convex member) of the link swing restriction mechanism in the body frame is a cross frame or bridge frame spanning a pair of left and right lower frames or side frames, etc.

[0012] However, if the concave member (or convex member) of the link swing restricting mechanism is fixed to the cross frame or the bridge frame, the placement of the cross frame or the bridge frame is limited in order to allow the concave member and the convex member of the link swing restricting mechanism to mesh with each other. Specifically, the cross frame or the bridge frame must be placed close to the links. Such limitations on the placement of the cross frame or the bridge frame can be an obstacle when setting the rigidity and other properties of the body frame, and may make the design of the body frame more difficult or reduce the degree of freedom in the design of the body frame.

[0013] For example, placing the cross frame close to the links can cause problems such as the rigidity of the body frame becoming lower or higher than desired. Also, because placing the cross frame close to the links reduces the rigidity of the body frame, it becomes necessary to add another cross frame to increase the rigidity of the body frame, which can result in problems such as the body frame becoming heavier or the manufacturing costs of the body frame increasing.

[0014] The present invention has been made in consideration of problems such as those described above, and an object of the present invention is to provide a power unit support device that can eliminate or reduce restrictions on the placement of cross frames or bridge frames in a body frame, thereby facilitating the design of the body frame or increasing the degree of freedom in the design of the body frame. [Means for solving the problem]

[0015] In order to solve the above problems, the present invention provides a power unit support device for supporting a unit swing type power unit, which has a power source for propelling a saddle-riding type vehicle, on a body frame of the saddle-riding type vehicle, the power unit support device comprising: a link on one side of which is swingably connected to the body frame via a first shaft extending in the left-right direction and on the other side of which the power unit is swingably connected via a second shaft extending in the left-right direction; and a power unit swing restriction mechanism that restricts swing of the power unit relative to the link, wherein the power unit swing restriction mechanism has: a protrusion that is provided on the power unit and protrudes forward from the power unit; an upper restriction portion that is provided on the link and positioned above the protrusion and that comes into contact with the protrusion when the protrusion moves upward due to swing of the power unit, thereby restricting upward movement of the protrusion; and a lower restriction portion that is provided on the link and positioned below the protrusion and that comes into contact with the protrusion when the protrusion moves downward due to swing of the power unit, thereby restricting downward movement of the protrusion. [Effects of the Invention]

[0016] According to the present invention, it is possible to eliminate or reduce restrictions on the placement of cross frames or bridge frames in a vehicle body frame, thereby facilitating the design of the vehicle body frame or increasing the degree of freedom in the design of the vehicle body frame. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is an explanatory diagram showing a saddle-ride type vehicle provided with a power unit support device according to an embodiment of the present invention, viewed from the left; [Figure 2] 2 is an explanatory diagram showing an enlarged view of a power unit, a power unit support device, etc. in the saddle-ride type vehicle in FIG. 1. [Figure 3] 1 is an explanatory diagram showing a front portion of a power unit and a power unit support device as viewed from below in a saddle-ride type vehicle provided with the power unit support device according to an embodiment of the present invention; [Figure 4] 4A and 4B are explanatory diagrams showing the link member and the sway restricting member in the power unit support device of an embodiment of the present invention, in which Figure 4(A) shows the link member as viewed from the rear left, Figure 4(B) shows the sway restricting member provided on the link member as viewed from the rear, and Figure 4(C) shows a cross section of the sway restricting member cut along the cutting line CC in Figure 4(B). [Figure 5] 1 is an explanatory diagram showing a state in which a link member and the like in a power unit support device according to an embodiment of the present invention are viewed from the left. FIG. [Figure 6] 3 is an explanatory view showing a cross section of a link member and a crankcase taken along the cutting line AA in FIG. 2, as viewed generally from below. FIG. [Figure 7] 1 is an explanatory diagram showing a state in which a front portion of a power unit is viewed from below with a link member removed in a saddle-ride type vehicle provided with a power unit support device according to an embodiment of the present invention; [Figure 8] 8A and 8B are explanatory diagrams showing the left case portion and protrusion of the crankcase in a saddle-type vehicle equipped with a power unit support device according to an embodiment of the present invention, where FIG. 8A shows the left case portion as viewed from the right, FIG. 8B shows a cross section of the arm portion and protrusion cut along cutting line DD in FIG. 8A as viewed from below, and FIG. 8C shows a cross section of the arm portion and protrusion cut along cutting line EE in FIG. 8A as viewed from the front. [Figure 9] 4 is an explanatory diagram showing a cross section of the swing restricting member, the protrusion, etc. taken along the cutting line BB in FIG. 3, as viewed from the right. FIG. [Figure 10] Figure 10(A) is an explanatory diagram showing a modified example of the protrusion of a power unit support device of an embodiment of the present invention, Figure 10(B) is an explanatory diagram showing another modified example of the protrusion of a power unit support device of an embodiment of the present invention, Figure 10(C) is an explanatory diagram showing the power unit support device of another embodiment of the present invention as viewed from below, and Figure 10(D) is an explanatory diagram showing the power unit support device cut along cutting line FF in Figure 10(C) as viewed from the right. DETAILED DESCRIPTION OF THE INVENTION

[0018] A power unit support device according to an embodiment of the present invention is a device for supporting a unit swing type power unit, which has a power source for propelling the saddle-riding type vehicle, on a body frame of the saddle-riding type vehicle. The power unit support device includes a link and a power unit swing restriction mechanism.

[0019] The link is a member that connects the body frame and the power unit. One side of the link is swingably connected to the body frame via a first shaft that extends in the left-right direction, and the other side of the link is swingably connected to the power unit via a second shaft that also extends in the left-right direction.

[0020] The power unit swing restriction mechanism is a mechanism that restricts swing of the power unit relative to the link. The power unit swing restriction mechanism has a protrusion, an upper restriction portion, and a lower restriction portion. The protrusion is provided on the power unit and protrudes forward from the power unit. The upper restriction portion is provided on the link and disposed above the protrusion, and restricts upward movement of the protrusion by coming into contact with the protrusion when the protrusion moves upward due to swing of the power unit. The lower restriction portion is provided on the link and disposed below the protrusion, and restricts downward movement of the protrusion by coming into contact with the protrusion when the protrusion moves downward due to swing of the power unit. The swing of the power unit is restricted by restricting up and down movement of the protrusion by the upper restriction portion and the lower restriction portion.

[0021] In the power unit support device of this embodiment, the protrusion is provided on the power unit, and the upper and lower restricting portions are provided on the link. Thus, in the power unit support device of this embodiment, components constituting the power unit sway restriction mechanism are not provided on the body frame. The conventional power unit support device described above includes a link sway restriction mechanism that restricts sway of the link relative to the body frame. However, the conventional power unit support device has a problem in that the placement of the cross frame or bridge frame is restricted by providing one of the concave and convex members of the link sway restriction mechanism on the cross frame or bridge frame of the body frame. The power unit support device of this embodiment solves this problem because the components constituting the power unit sway restriction mechanism are not provided on the body frame. The power unit support device of this embodiment eliminates or reduces restrictions on the placement of the cross frame or bridge frame due to the application of the power unit support device, thereby simplifying the design of the body frame or increasing the degree of freedom in the design of the body frame. For example, the bridge frame can be positioned appropriately to set the rigidity of the body frame to a desired level. Furthermore, by placing the bridge frame in an appropriate position, the desired rigidity of the body frame can be ensured while reducing the number of other bridge frames and reinforcing frames, thereby making the body frame lighter and less expensive. [Example]

[0022] An embodiment of the power unit support device of the present invention will be described. In the description of the embodiment, when describing the directions of front (Fd), rear (Bd), top (Ud), bottom (Dd), left (Ld), and right (Rd), please refer to the arrows drawn at the bottom right of each figure.

[0023] (saddle-type vehicle) Fig. 1 shows a saddle-riding type vehicle 1 provided with a power unit support device 41 according to an embodiment of the present invention, as viewed from the left. Fig. 2 shows an enlarged view of the power unit 21, power unit support device 41, etc., in the saddle-riding type vehicle 1 in Fig. 1. Fig. 3 shows the front of the power unit 21 and the power unit support device 41 as viewed from below.

[0024] As shown in Fig. 1, the saddle-riding type vehicle 1 of this embodiment is a scooter-type motorcycle. The saddle-riding type vehicle 1 has a body frame 2 that forms the skeleton of the vehicle. The body frame 2 is made of a metal material such as steel. The body frame 2 has a head pipe 3, a down frame 4, a pair of side frames 5, and a bridge frame 6.

[0025] The head pipe 3 is disposed at the upper front portion of the saddle-riding vehicle 1. The down frame 4 extends downward from the head pipe 3 while tilting rearward. A pair of side frames 5 spread out laterally from the lower end of the down frame 4, extending rearward through the lower left and lower right portions of the longitudinally intermediate portion of the saddle-riding vehicle 1, and then further extending upward and rearward. Each side frame 5 has a lower frame portion 5A and a seat rail portion 5B. The lower frame portion 5A is a portion of the side frame 5 that extends rearward from the lower end of the down frame 4 to the lower left or lower right portion of the longitudinally intermediate portion of the saddle-riding vehicle 1. In other words, the lower frame portion 5A is a portion of the side frame 5 that extends from the front end of the side frame 5 to a portion of the side frame 5 that is located below the front portion of the seat 18, as viewed from the side of the saddle-riding vehicle 1. The seat rail portion 5B is a portion of the side frame 5 that extends upward and rearward from the lower left or lower right portion of the longitudinally intermediate portion of the saddle-riding vehicle 1. That is, the seat rail portion 5B is a portion of the side frame 5 that extends from a portion of the side frame 5 that is located below the front portion of the seat 18 to the rear end of the side frame 5, as viewed from the side of the saddle-ride type vehicle 1. As shown in FIG. 3 , the bridge frame 6 extends in the left-right direction and is installed between the pair of side frames 5. Specifically, the bridge frame 6 is installed between the lower frame portion 5A of the left side frame 5 and the lower frame portion 5A of the right side frame 5, connecting these lower frame portions 5A to each other. The bridge frame 6 is also installed at a position separated from the link member 42 of the power unit support device 41. Although not shown, a reinforcing frame is installed between the rear end portions of the seat rail portions 5B of the pair of side frames 5.

[0026] Furthermore, in each side frame 5, a link member connecting portion 7 for connecting a link member 42 of the power unit support device 41 to the side frame 5 is provided at the rear of the lower frame portion 5A (at the boundary between the lower frame portion 5A and the seat rail portion 5B). As shown in FIG. 2, the link member connecting portion 7 protrudes downward and rearward from the rear of the lower frame portion 5A. Furthermore, the link member connecting portion 7 is fixed to the outer peripheral surface of the rear of the lower frame portion 5A by means of, for example, welding.

[0027] In the saddle-type vehicle 1, a steering shaft (not shown) is rotatably supported within the head pipe 3, and a front fork 11 is attached to the lower end of the steering shaft as shown in Fig. 1. A front wheel 12 is rotatably supported at the lower end of the front fork 11. A handlebar 13 is attached to the upper end of the steering shaft.

[0028] The saddle-ride type vehicle 1 also includes a unit swing type power unit 21. The power unit 21 is provided below the rear of the saddle-ride type vehicle 1, and is supported on the body frame 2, specifically, on the rear of the lower frame portions 5A of the pair of side frames 5, by a power unit support device 41, which will be described later.

[0029] As shown in FIG. 2 , the power unit 21 has an engine 22 as an internal combustion engine and a transmission 35. The engine 22 is, for example, a single-cylinder four-stroke gasoline engine. The engine 22 has a crankcase 23 that houses a crankshaft, a cylinder 31 that houses a piston, a cylinder head 32 that houses an intake valve, an exhaust valve, a camshaft, etc. and is equipped with a spark plug, and a cylinder head cover 33 that covers the top of the cylinder head 32. The cylinder 31 and the cylinder head 32 are covered by a cylinder cover 34. The engine 22 is disposed such that the cylinder 31 protrudes forward from the crankcase 23 while tilting slightly upward. Therefore, the cylinder 31 is located approximately in front of the crankcase 23, the cylinder head 32 is located approximately in front of the cylinder 31, and the cylinder head cover 33 is located approximately in front of the cylinder 31. The engine 22 is disposed approximately in the center of the saddle-ride type vehicle 1 in the left-right direction.

[0030] As shown in FIG. 3 , the crankcase 23 is formed by joining together a left case portion 24 that forms the left portion of the crankcase 23 and a right case portion 25 that forms the right portion of the crankcase 23. The left case portion 24 and the right case portion 25 are made of, for example, an aluminum alloy. The left case portion 24 and the right case portion 25 are manufactured by, for example, die-casting. The left case portion 24 and the right case portion 25 are joined together using fastening members 30 such as bolts. The crankcase 23 is a specific example of a "container case," the left case portion 24 is a specific example of a "first case portion," and the right case portion 25 is a specific example of a "second case portion." The crankshaft is a specific example of a "component that forms a power source."

[0031] Additionally, a pair of left and right arm portions 26 for connecting the power unit 21 to a link member 42 of the power unit support device 41 is provided below the front portion of the crankcase 23. The left arm portion 26 protrudes forward from the lower left front portion of the left case portion 24. The right arm portion 26 protrudes forward from the lower right front portion of the right case portion 25. The left arm portion 26 is integrally molded (cast in this embodiment) with the left case portion 24, and the right arm portion 26 is integrally molded with the right case portion 25.

[0032] The transmission 35 is, for example, a centrifugal continuously variable transmission. The transmission 35 has a drive pulley, a driven pulley, a drive belt, a clutch, etc., and further has a transmission case 36 that houses these components. The transmission case 36 is formed integrally with the left case portion 24 of the crankcase 23.

[0033] An exhaust port is provided in the lower part of the cylinder head 32 at a position to the right of the center K in the left-right direction of the saddle-riding type vehicle 1, and one end of the exhaust pipe 15 is connected to the exhaust port. As shown in Fig. 3, the exhaust pipe 15 extends from the exhaust port of the cylinder head 32, passing between the cylinder head 32 and the link member 42 of the power unit support device 41, to the right, and then extends rearward. The other end of the exhaust pipe 15 is connected to a silencer (not shown) provided on the lower right side of the rear of the saddle-riding type vehicle 1.

[0034] As shown in Fig. 1, a rear wheel 16 is rotatably supported at the rear of the power unit 21. The rear of the power unit 21 is supported at the rear of the seat rail portion 5B of the left side frame 5 via a rear cushion 17. A seat 18 for a driver or other person to sit on is provided at the upper portion of the saddle riding type vehicle 1, extending from the middle portion in the fore-and-aft direction to the rear portion. A vehicle body cover 19 (shown by a two-dot chain line in Fig. 1) is also provided on the saddle riding type vehicle 1. The saddle riding type vehicle 1 is also provided with a braking system, intake system components, a fuel tank, etc., but these are not shown or described here.

[0035] (Power unit support device) The saddle-ride type vehicle 1 is provided with a power unit support device 41 that supports the power unit 21 on the body frame 2, specifically, on the rear of the lower frame portions 5A of the pair of side frames 5. As shown in FIGS. 2 and 3 , the power unit support device 41 includes a link member 42, two front connecting shafts 47, a rear connecting shaft 59, and a power unit swing restriction mechanism 71. The link member 42 is a member that connects the side frames 5 and the power unit 21. The two front connecting shafts 47 are shafts that swingably connect the link member 42 to the left side frame 5 and the right side frame 5. The rear connecting shaft 59 is a shaft that swingably connects the power unit 21 to the link member 42. The power unit swing restriction mechanism 71 is a mechanism that restricts swing of the power unit 21 relative to the link members 42. The link member 42 is a specific example of a "link," the front connecting shaft 47 is a specific example of a "first shaft," and the rear connecting shaft 59 is a specific example of a "second shaft."

[0036] (Link member, front connecting shaft, rear connecting shaft) FIG. 4A shows the link member 42 as viewed from the rear left, FIG. 4B shows the rocking restricting member 72 provided on the link member 42 as viewed from the rear, and FIG. 4C shows a cross-section of the rocking restricting member 72 cut along section line CC in FIG. 4B. FIG. 5 shows the link member 42 as viewed from the left, connecting the link member connecting portions 7 fixed to the pair of side frames 5 and a pair of arm portions 26 provided on the crankcase 23 of the power unit 21. Note that in FIG. 5, a portion of the connecting portion between the link member connecting portion 7 and the link member 42 is cut away to show the interior of the connecting portion, and a portion of the connecting portion between the link member 42 and the arm portions 26 is cut away to show the interior of the connecting portion. FIG. 6 shows the cross-section of the link member 42 and the crankcase 23 cut along section line AA in FIG. 2, viewed generally from below.

[0037] As shown in Fig. 4(A), the link member 42 is formed by bending a pipe made of a metal material such as steel into a substantially U-shape. As shown in Fig. 3, the link member 42 is arranged so that both end portions extend upward and forward and the middle portion extends in the left-right direction. The left end of the link member 42 is located below the left side frame 5, the right end of the link member 42 is located below the right side frame 5, and the middle portion of the link member 42 is located below the cylinder head 32.

[0038] As shown in FIG. 4A, the left and right ends of the link member 42 are provided with front connecting shaft insertion portions 43 for inserting the front connecting shaft 47. Each front connecting shaft insertion portion 43 is cylindrical and made of a metal material such as steel, and is arranged so that its axis extends in the left-right direction. The two front connecting shaft insertion portions 43 are fixed to the link member 42 by joining their outer circumferential surfaces to the left and right ends of the link member 42, respectively, by means of, for example, welding. The front connecting shaft insertion portions 43 are arranged coaxially with each other. As shown in FIG. 5, an outer collar 44 is provided inside each front connecting shaft insertion portion 43, a rubber bushing 45 is provided inside the outer collar 44, and an inner collar 46 is provided inside the rubber bushing 45. For example, the outer collar 44 is press-fitted into the inside of the front connecting shaft insertion portion 43, the rubber bushing 45 is press-fitted into the inside of the outer collar 44, and the inner collar 46 is press-fitted into the inside of the rubber bushing 45. The rubber bushing 45 may also be fixed to the outer collar 44 and the inner collar 46 by baking. The inner collar 46 is fixed between the left and right side walls of the link member connecting portion 7 by the front connecting shaft 47 and a nut 48.

[0039] As shown in FIG. 3 , each front connecting shaft 47 extends in the left-right direction. The two front connecting shafts 47 are arranged coaxially. One front connecting shaft 47 is inserted into holes formed in the left and right side walls of the left link member connection portion 7 and into an inner collar 46 provided inside the left front connecting shaft insertion portion 43. The one front connecting shaft 47 is fixed to the left link member connection portion 7 by fastening a nut 48 onto a thread formed on the right end of the one front connecting shaft 47. The other front connecting shaft 47 is inserted into holes formed in the left and right side walls of the right link member connection portion 7 and into an inner collar 46 provided inside the right front connecting shaft insertion portion 43. The other front connecting shaft 47 is fixed to the right link member connection portion 7 by fastening a nut 48 onto a thread formed on the left end of the other front connecting shaft 47. As a result, the link member 42 is swingably connected to the left and right side frames 5.

[0040] Furthermore, arm connectors 49 are provided on the left and right sides of the portion of the link member 42 extending in the left-right direction, respectively, for connecting a pair of arm sections 26 provided on the crankcase 23 of the power unit 21 to the link member 42. As shown in FIG. 4(A), each arm connector 49 protrudes rearward from the link member 42. Each arm connector 49 is formed of a metal material such as steel. Each arm connector 49 has a bottom wall 50, an outer side wall 51, and an inner side wall 52, and is formed in a generally U-shape when viewed from the rear. The front portion of each arm connector 49 is joined and fixed to the outer peripheral surface of the link member 42 by means of, for example, welding. A hole 53 is formed in the outer side wall 51 of each arm connector 49, through which a rear connecting shaft 59 is inserted. A hole 54 is formed in the inner side wall 52 of each arm connector 49, through which a cylindrical member 55 is inserted.

[0041] A cylindrical member 55, through which the rear connecting shaft 59 is inserted, is provided between the left and right arm connectors 49. The cylindrical member 55 is formed in a cylindrical shape that is elongated in the left-right direction. As shown in FIG. 4(C), the cylindrical member 55 is disposed rearward of the link member 42. As shown in FIG. 4(A), the left end of the cylindrical member 55 is fixed in the hole 54 of the left arm connector 49 by means of, for example, welding, and the right end of the cylindrical member 55 is fixed in the hole 54 of the right arm connector 49 by means of, for example, welding. The cylindrical member 55 also passes through a bracket 83 (described later) in the left-right direction.

[0042] As shown in FIGS. 5 and 6 , rear connecting shaft insertion holes 27 for inserting rear connecting shafts 59 are formed in the front ends of the left and right arm portions 26 provided on the crankcase 23 of the power unit 21. The rear connecting shaft insertion holes 27 extend in the left-right direction and are arranged coaxially with one another. An outer collar 56 is provided inside each rear connecting shaft insertion hole 27, a rubber bushing 57 is provided inside the outer collar 56, and an inner collar 58 is provided inside the rubber bushing 57. For example, the outer collar 56 is press-fitted into the rear connecting shaft insertion hole 27, the rubber bushing 57 is press-fitted inside the outer collar 56, and the inner collar 58 is press-fitted inside the rubber bushing 57. The rubber bushings 57 may be fixed to the outer collar 56 and the inner collar 58 by baking. The inner collar 58 provided in the rear connecting shaft insertion hole 27 of the left arm section 26 is fixed between the right surface of the outer side wall 51 of the left arm linking section 49 and the left end surface of the cylindrical member 55 by a rear connecting shaft 59 and a nut 60. The inner collar 58 provided in the rear connecting shaft insertion hole 27 of the right arm section 26 is fixed between the left surface of the outer side wall 51 of the right arm linking section 49 and the right end surface of the cylindrical member 55 by a rear connecting shaft 59 and a nut 60.

[0043] As shown in FIG. 3 or 6 , the rear connecting shaft 59 extends in the left-right direction. The rear connecting shaft 59 is disposed rearward of the link member 42. The rear connecting shaft 59 is inserted through the hole 53 of the left arm connector 49, the inside of an inner collar 58 provided in the rear connecting shaft insertion hole 27 of the left arm 26, the cylindrical member 55, the inside of the inner collar 58 provided in the rear connecting shaft insertion hole 27 of the right arm 26, and the hole 53 of the right arm connector 49. The rear connecting shaft 59 is fixed to the left and right arm connectors 49 by fastening a nut 60 to a screw formed on the right end of the rear connecting shaft 59. In this way, the power unit 21 is swingably connected to the link member 42.

[0044] (Power unit oscillation control mechanism) 3, power unit swing restriction mechanism 71 has swing restriction member 72 provided on link member 42, and protrusion 85 provided on crankcase 23 of power unit 21. As will be described in detail later, when power unit 21 swings up and down relative to link member 42, protrusion 85 comes into contact with cushion members 75, 77 provided on swing restriction member 72, thereby restricting the swing range of power unit 21 relative to link member 42 (see FIG. 9).

[0045] As shown in FIG. 3 , the rocking restricting member 72 is disposed rearward of the rear connecting shaft 59 and forward of the front surface of the left-right center portion (the portion between the left and right arm portions 26) of the crankcase 23. The rocking restricting member 72 is disposed to the left of the left-right center K of the saddle-riding type vehicle 1, but is disposed in a position close to the left-right center K of the saddle-riding type vehicle 1. The rocking restricting member 72 is also located below the cylinder 31. When viewed from below the saddle-riding type vehicle 1, the rocking restricting member 72 is located to the right of the left outer surface of the cylinder 31 and to the left of the right outer surface of the cylinder 31. The rocking restricting member 72 is also disposed between the two arm connecting portions 49, as shown in FIG. 4(A) . The rocking restricting member 72 is formed, for example, by bending a metal plate made of steel or the like into a generally L-, C-, or U-shape.

[0046] The rocking restricting member 72 is fixed to a portion of the link member 42 that extends in the left-right direction via a bracket 83 made of a metal material such as steel. The bracket 83 protrudes rearward from the link member 42. The rocking restricting member 72 is fixed to the rear end of the bracket 83 so that the open portion of the L-shaped, C-shaped, or U-shaped member faces rearward. The link member 42 and the bracket 83 are joined by means of welding, for example, and the bracket 83 and the rocking restricting member 72 are also joined by means of welding, for example. Holes are formed in the side walls on both sides of the bracket 83, and the cylindrical member 55 passes through these holes to penetrate the bracket 83 in the left-right direction, as shown in FIG. 4(C).

[0047] The rocking restricting member 72 has an upper restricting portion 73 and a lower restricting portion 74. That is, the upper portion of the rocking restricting member 72 extends upward and rearward, and the lower portion of the rocking restricting member 72 extends downward and rearward. The upper portion of the rocking restricting member 72 that extends upward and rearward is the upper restricting portion 73, and the lower portion of the rocking restricting member 72 that extends downward and rearward is the lower restricting portion 74. The upper restricting portion 73 has a flat plate-like shape that extends in the left-right and front-rear directions and is inclined so that its rear end faces diagonally upward. The upper restricting portion 73 has the function of restricting upward movement of the protrusion 85, thereby restricting upward rocking of the power unit 21 relative to the link member 42. The lower restricting portion 74 has a flat plate-like shape that extends in the left-right and front-rear directions and is inclined so that its rear end faces diagonally downward. The lower restricting portion 74 restricts downward movement of the protruding portion 85, thereby restricting downward swing of the power unit 21 relative to the link member .

[0048] As shown in FIG. 4B , a cushion member 75 is provided on the surface of the upper regulating portion 73 facing downward and rearward. The cushion member 75 is formed in a generally plate-like shape from an elastic material such as rubber. The surface of the cushion member 75 facing downward and rearward is generally flat overall, although the central portion in the left-right direction is slightly raised downward and rearward. Protrusions 76 for fixing the cushion member 75 to the upper regulating portion 73 are integrally formed on the back surface of the cushion member 75 facing upward and frontward. As shown in FIG. 4C , the cushion member 75 is fixed to the upper regulating portion 73 by press-fitting the protrusions 76 into through-holes formed in the upper regulating portion 73. A cushion member 77 is provided on the surface of the lower regulating portion 74 facing upward and rearward. The cushion member 77 is identical to the cushion member 75. The cushion member 77 is fixed to the lower regulating portion 74 by press-fitting protrusions 78 into through-holes formed in the lower regulating portion 74.

[0049] Furthermore, the protrusion 76 of the cushion member 75 protrudes upward and forward from the surface of the upper restricting portion 73 that faces upward and forward. Furthermore, the protrusion 78 of the cushion member 77 protrudes downward and forward from the surface of the lower restricting portion 74 that faces downward and forward. Because the protrusions 76, 78 of the cushion members 75, 77 protrude outward from the rocking restricting member 72 in this manner, when attaching the cushion members 75, 77 to the rocking restricting member 72 during manufacture of the power unit support device 41, the cushion member 75 can be easily attached to the upper restricting portion 73 by inserting the tip of the protrusion 76 of the cushion member 75 into the through hole of the upper restricting portion 73 and then pulling the tip of the protrusion 76. Furthermore, the cushion member 77 can be easily attached to the lower restricting portion 74 by inserting the tip of the protrusion 78 of the cushion member 77 into the through hole of the lower restricting portion 74 and then pulling the tip of the protrusion 78.

[0050] Furthermore, the surface of cushion member 75 fixed to upper restricting portion 73 facing downward and rearward serves as upper receiving surface 81. When power unit 21 swings upward relative to link member 42 and protrusion 85 moves upward, upper surface 85A of protrusion 85 comes into contact with upper receiving surface 81. Furthermore, the surface of cushion member 77 fixed to lower restricting portion 74 facing upward and rearward serves as lower receiving surface 82. When power unit 21 swings downward relative to link member 42 and protrusion 85 moves downward, lower surface 85B of protrusion 85 comes into contact with lower receiving surface 82.

[0051] Fig. 7 shows the front part of the power unit 21 with the link member 42 removed, as viewed from below. Fig. 8(A) shows the left case portion 24 of the crankcase 23, as viewed from the right. Fig. 8(B) shows a cross section of the arm portion 26 and the protrusion 85 taken along section line DD in Fig. 8(A), as viewed from below. Fig. 8(C) shows a cross section of the arm portion 26 and the protrusion 85 taken along section line EE in Fig. 8(A), as viewed from the front.

[0052] As shown in FIG. 7 , the protrusion 85 is fixed to the power unit 21 and protrudes forward from the power unit 21. Specifically, the protrusion 85 is fixed to the front lower part of the crankcase 23 and protrudes forward from the front lower part of the crankcase 23. As shown in FIG. 3 , the protrusion 85 is disposed rearward of the rear connecting shaft 59. That is, the protrusion 85 protrudes forward from the crankcase 23, but its protruding end does not reach the rear connecting shaft 59. The protrusion 85 is disposed between the pair of left and right arm portions 26. The protrusion 85 is disposed in a region extending from the center K in the left-right direction of the saddle riding type vehicle 1 to the left portion. Specifically, the protrusion 85 is disposed in a region extending from the center K in the left-right direction of the saddle riding type vehicle 1 to the left arm portion 26.

[0053] 8(A), the protrusion 85 is integrally molded (cast in this embodiment) with the left case portion 24 of the crankcase 23. As described above, the left arm portion 26 is integrally molded with the left case portion 24. The protrusion 85 is integrally molded with this left arm portion 26. In other words, the left end portion of the protrusion 85 is integrated with the right rear portion of the left arm portion 26.

[0054] Furthermore, a plurality of bosses 28A to 28H for attaching fastening members 30 for joining the left case portion 24 and the right case portion 25 are integrally molded with the left case portion 24. A hole 29 is formed in each of the bosses 28A to 28H for inserting the fastening members 30 for fastening. The protrusion 85 is integrally molded with one boss 28G, which is disposed at the lower front portion of the left case portion 24, among the plurality of bosses 28A to 28H integrally molded with the left case portion 24. That is, the lower rear portion of the protrusion 85 is integrated with the boss 28G, as shown in FIG. 8(B).

[0055] When viewed from below, the protruding portion 85 extends in the left-right direction from the right end of the left case portion 24 to the left arm portion 26, as shown in Fig. 7. When viewed from the left, the protruding portion 85 is formed in a generally triangular shape, as shown in Fig. 8(A). The tip of the protruding portion 85 is arc-shaped. The protruding portion 85 has a flat upper surface 85A that slopes downward and extends forward, and a flat lower surface 85B that extends substantially horizontally.

[0056] Furthermore, a left hollow portion 86, a right hollow portion 87, and a rib 88 are formed inside the protruding portion 85. As shown in FIGS. 8(B) and 8(C), the left hollow portion 86 is formed inside the left part of the protruding portion 85 and opens to the left surface of the protruding portion 85. The right hollow portion 87 is formed inside the right part of the protruding portion 85 and opens to the right surface of the protruding portion 85. The rib 88 is located between the left hollow portion 86 and the right hollow portion 87 inside the protruding portion 85 and is formed so as to separate the left hollow portion 86 and the right hollow portion 87. The rib 88 is a partition wall that extends in the front-rear and up-down directions. The left hollow portion 86 is a specific example of a "first hollow portion," and the right hollow portion 87 is a specific example of a "second hollow portion."

[0057] FIG. 9 shows a cross section of the rocking restricting member 72, the protrusion 85, etc., taken along section line BB in FIG. 3, as viewed from the right (left in FIG. 3). As shown in FIG. 9, the rocking restricting member 72 and the protrusion 85 are arranged to face each other in the front-to-rear direction when viewed overall. The protrusion 85 is inserted into the space between the upper restricting portion 73 and the lower restricting portion 74 of the rocking restricting member 72. The upper restricting portion 73 is arranged above the protrusion 85, and the lower restricting portion 74 is arranged below the protrusion 85. As described above, the surface of the cushion member 75 fixed to the upper restricting portion 73 facing downward toward the rear constitutes the upper receiving surface 81. The upper receiving surface 81 faces the upper surface 85A of the protrusion 85. As described above, the surface of the cushion member 77 fixed to the lower restricting portion 74 facing upward toward the rear constitutes the lower receiving surface 82. The lower receiving surface 82 faces the lower surface 85B of the protrusion 85.

[0058] Additionally, the upper surface 85A of the protrusion 85 is inclined so as to approach the lower surface 85B of the protrusion 85 as it moves forward. Additionally, the upper receiving surface 81 is inclined so as to approach the lower receiving surface 82 as it moves forward. The inclination angle α of the upper receiving surface 81 relative to the lower receiving surface 82 is larger than the inclination angle β of the upper surface 85A of the protrusion 85 relative to the lower surface 85B of the protrusion 85.

[0059] Furthermore, the upper surface 85A of the protrusion 85, the lower surface 85B of the protrusion 85, the upper receiving surface 81, and the lower receiving surface 82 each extend in the radial direction of the rear connecting shaft 59. That is, the upper surface 85A of the protrusion 85 is formed so that a straight line L1 that passes over the upper surface 85A of the protrusion 85 and extends in the front-to-rear direction intersects with the axis X of the rear connecting shaft 59. Specifically, the arrangement and inclination of the upper surface 85A of the protrusion 85 are set so that the straight line L1 intersects with the axis X. Furthermore, the lower surface 85B of the protrusion 85 is formed so that a straight line L2 that passes over the lower surface 85B of the protrusion 85 and extends in the front-to-rear direction intersects with the axis X of the rear connecting shaft 59. Specifically, the arrangement and inclination of the lower surface 85B of the protrusion 85 are set so that the straight line L2 intersects with the axis X. Furthermore, the upper receiving surface 81 is formed so that a straight line L3 that passes over the upper receiving surface 81 and extends in the front-to-rear direction intersects with the axis X of the rear connecting shaft 59. Specifically, the arrangement and inclination of the upper receiving surface 81 are set so that the straight line L3 intersects with the axis X. Furthermore, the lower receiving surface 82 is formed so that a straight line L4 that passes over the lower receiving surface 82 and extends in the front-to-rear direction intersects with the axis X of the rear connecting shaft 59. Specifically, the arrangement and inclination of the lower receiving surface 82 are set so that the straight line L4 intersects with the axis X.

[0060] For example, when the rear wheel 16 passes over an uneven surface on the ground, the power unit 21 swings relative to the link member 42. Specifically, at this time, the power unit 21 rotates about the axis X of the rear connecting shaft 59. Accordingly, the protrusion 85 also rotates about the axis X of the rear connecting shaft 59. In FIG. 9 , when the power unit 21 rotates clockwise about the axis X, the protrusion 85 also rotates clockwise about the axis X and moves upward. When the amount of clockwise rotation of the power unit 21 becomes equal to or greater than a predetermined amount, the upper surface 85A of the protrusion 85 comes into contact with the upper receiving surface 81. This limits the clockwise rotation of the power unit 21. Furthermore, the impact generated when the upper surface 85A of the protrusion 85 hits the upper receiving surface 81 is reduced by the elastic deformation of the cushion member 75. 9, when the power unit 21 rotates counterclockwise about the axis X, the protrusion 85 rotates counterclockwise about the axis X accordingly, and the protrusion 85 moves downward. When the amount of counterclockwise rotation of the power unit 21 reaches or exceeds a predetermined amount, the lower surface 85B of the protrusion 85 comes into contact with the lower receiving surface 82. This limits the counterclockwise rotation of the power unit 21. Furthermore, the impact generated when the lower surface 85B of the protrusion 85 hits the lower receiving surface 82 is reduced by the elastic deformation of the cushion member 77.

[0061] In power unit support device 41 having the above configuration, transmission of vibrations generated by operation of engine 22 to body frame 2 is reduced mainly by rubber bushing 45 provided at the connection between link member connection portion 7 and link member 42, and rubber bushing 57 provided at the connection between arm connection portion 49 and arm portion 26. Furthermore, when power unit 21 wobbles, for example, because rear wheel 16 passes over uneven ground, vibrations caused by the swinging of power unit 21 are reduced mainly by rear cushion 17, but are also reduced by rubber bushings 45, 57 and cushion members 75, 77 provided on swing-restricting member 72.

[0062] As described above, power unit support device 41 of the embodiment of the present invention is provided with power unit swing restriction mechanism 71 that restricts swing of power unit 21 relative to link member 42, and power unit swing restriction mechanism 71 has protrusion 85, upper restriction portion 73, and lower restriction portion 74, with protrusion 85 being provided on power unit 21 and upper restriction portion 73 and lower restriction portion 74 being provided on link member 42. As described above, in power unit support device 41 of the embodiment, the components that make up power unit swing restriction mechanism 71 are not provided on body frame 2. The conventional power unit support device described above is provided with a link swing restriction mechanism that restricts swing of the link relative to the body frame, but the conventional power unit support device has a problem in that the placement of the cross frame or bridge frame is restricted by providing one of the concave and convex members of the link swing restriction mechanism on the cross frame or bridge frame of the body frame. According to the power unit support device 41 of the embodiment of the present invention, this problem can be solved because the components that make up the power unit sway restriction mechanism 71 are not provided on the body frame 2. According to the power unit support device 41 of the embodiment, the restrictions on the placement of the cross frame or bridge frame that are imposed by applying the power unit support device 41 can be eliminated or reduced, making it possible to simplify the design of the body frame 2 or increase the degree of freedom in the design of the body frame 2. For example, in order to set the rigidity of the body frame 2 to a desired level, the bridge frame 6 can be placed in an appropriate position. Furthermore, by placing the bridge frame 6 in an appropriate position, the number of other bridge frames and reinforcing frames can be reduced while ensuring the desired rigidity of the body frame 2, thereby enabling the weight and cost of the body frame 2 to be reduced.

[0063] Furthermore, in the power unit swing restricting mechanism 71 of the power unit support device 41 of this embodiment, the protrusion 85 is disposed rearward of the rear connecting shaft 59 and between the pair of arm portions 26, and the upper restricting portion 73 and the lower restricting portion 74 are disposed rearward of the rear connecting shaft 59 and between the pair of arm joint portions 49. This allows the power unit swing restricting mechanism 71 to be disposed between the pair of arm portions 26 of the crankcase 23. This allows a large space to be secured between the rear portion of the lower frame portion 5A of the left side frame 5 and the rear portion of the lower frame portion 5A of the right side frame 5. This increases the degree of freedom in the placement of the cylinder head 32 and the exhaust pipe 15 that are disposed between the rear portion of the lower frame portion 5A of the left side frame 5 and the rear portion of the lower frame portion 5A of the right side frame 5. For example, the position of the cylinder head 32 can be set lower to expand the luggage storage space below the seat 20, or the position of the cylinder head 32 can be moved forward to manufacture a compact scooter with a short wheelbase.

[0064] Furthermore, in the power unit swing restricting mechanism 71 of the power unit support device 41 of this embodiment, the protruding portion 85 is integrally molded with the crankcase 23. This makes it possible to reduce the number of parts in the power unit support device 41. Furthermore, by integrally molding the protruding portion 85 with the crankcase 23, which is formed by aluminum die-casting, it is possible to reduce the weight of the saddle-riding type vehicle 1.

[0065] Furthermore, in power unit swing restriction mechanism 71 of power unit support device 41 of the present embodiment, protrusion 85 is formed integrally with arm portion 26. This makes it possible to increase the rigidity of protrusion 85. Furthermore, in power unit swing restriction mechanism 71 of power unit support device 41 of the present embodiment, protrusion 85 is molded integrally with boss 28G for attaching fastening member 30 that joins left case portion 24 and right case portion 25 of crankcase 23. This also makes it possible to increase the rigidity of protrusion 85.

[0066] Furthermore, in the power unit swing restricting mechanism 71 of the power unit support device 41 of this embodiment, the protrusion 85 is integrally molded with the left case portion 24 of the crankcase 23. A left hollow portion 86 opening to the left surface of the protrusion 85 is formed inside the left portion of the protrusion 85, and a right hollow portion 87 opening to the right surface of the protrusion 85 is formed inside the right portion of the protrusion 85. A rib 88 separating the left hollow portion 86 and the right hollow portion 87 is formed between the left hollow portion 86 and the right hollow portion 87 inside the protrusion 85. In this way, by forming the hollow portions 86, 87 in the protrusion 85, the left case portion 24 with which the protrusion 85 is integrated can be made lighter, and by forming the rib 88 in the protrusion 85, the rigidity of the protrusion 85 can be increased. Furthermore, when the left case portion 24 with which the protrusion 85 is integrated is molded by casting, the structure of the mold can be simplified and blowholes can be reduced.

[0067] Furthermore, in the power unit swing restriction mechanism 71 of the power unit support device 41 of this embodiment, the upper restricting portion 73 and the lower restricting portion 74 are disposed in positions close to the left-right center K of the saddle-riding type vehicle 1. As a result, when the power unit 21 swings, the protrusion 85 comes into contact with the upper restricting portion 73 or the lower restricting portion 74, and the pressing force that pushes the upper restricting portion 73 or the lower restricting portion 74 is applied near the left-right center K of the link member 42. Therefore, it is possible to prevent the force applied to the link member 42 from being biased to the left or right when the power unit 21 swings. If the left-right bias of the force applied to the link member 42 is large, it is necessary to increase the strength of the link member 42, the link member connecting portion 7, etc. to withstand the input of such a large biased force. However, if such a biased force is small, the strength of the link member 42, the link member connecting portion 7, etc. can be reduced accordingly. As a result, it is possible to reduce the weight and size of the link member 42 or the link member connecting portion 7.

[0068] In the power unit swing restricting mechanism 71 of the power unit supporting device 41 of this embodiment, the inclination angle of the upper receiving surface 81 relative to the lower receiving surface 82 is equal to or greater than the inclination angle of the upper surface 85A of the protruding portion 85 relative to the lower surface 85B of the protruding portion 85. Furthermore, the protrusion 85, the upper regulating portion 73, and the lower regulating portion 74 are positioned rearward of the rear connecting shaft 59, and the upper surface 85A of the protrusion 85 is formed so that a straight line L1, which passes over the upper surface 85A of the protrusion 85 and extends in the front-to-rear direction, intersects with the axis X of the rear connecting shaft 59; the lower surface 85B of the protrusion 85 is formed so that a straight line L2, which passes over the lower surface 85B of the protrusion 85 and extends in the front-to-rear direction, intersects with the axis X of the rear connecting shaft 59; the upper receiving surface 81 is formed so that a straight line L3, which passes over the upper receiving surface 81 and extends in the front-to-rear direction, intersects with the axis X of the rear connecting shaft 59; and the lower receiving surface 82 is formed so that a straight line L4, which passes over the lower receiving surface 82 and extends in the front-to-rear direction, intersects with the axis X of the rear connecting shaft 59. As a result, when the upper surface 85A of the protrusion 85 hits the upper receiving surface 81 due to the swinging of the power unit 21, the direction of the force applied from the upper surface 85A of the protrusion 85 to the upper receiving surface 81 becomes perpendicular to the upper receiving surface 81. In other words, the direction of the force applied from the upper surface 85A of the protrusion 85 to the surface of the cushion member 75 becomes perpendicular to the surface of the cushion member 75. Therefore, uneven wear of the cushion member 75 and damage to the protrusions 76 can be suppressed. If the upper surface 85A of the protrusion 85 is not formed so that the straight line L1 intersects with the axis X, or if the upper receiving surface 81 is not formed so that the straight line L3 intersects with the axis X, when the upper surface 85A of the protrusion 85 hits the upper receiving surface 81 (the surface of the cushion member 75) due to the swinging of the power unit 21, the direction of the force applied from the upper surface 85A of the protrusion 85 to the surface of the cushion member 75 will not be perpendicular to the surface of the cushion member 75. In this case, a force is applied to the cushion member 75 that tends to slide the cushion member 75 in the front-rear direction relative to the upper restricting portion 73. As a result, the cushion member 75 may wear unevenly prematurely, or the protrusion 76 may be damaged, such as being torn off. The power unit swing restricting mechanism 71 of this embodiment can suppress uneven wear of the cushion member 75 and damage to the protrusion 76.Similarly, according to the power unit swing restriction mechanism 71 of this embodiment, when the lower surface 85B of the protrusion 85 hits the lower receiving surface 82 (surface of the cushion member 77) due to the swing of the power unit 21, the direction of the force applied from the lower surface 85B of the protrusion 85 to the surface of the cushion member 77 is perpendicular to the surface of the cushion member 77, thereby suppressing uneven wear of the cushion member 77 or damage to the protrusion 78, etc.

[0069] Furthermore, in the power unit support device 41 of the present embodiment, both ends of the generally U-shaped link member 42 are connected to the link member connecting portion 7 fixed to the left side frame 5 and the link member connecting portion 7 fixed to the right side frame 5 using two front connecting shafts 47. This makes it possible to ensure a larger space between the rear of the lower frame portion 5A of the left side frame 5 and the rear of the lower frame portion 5A of the right side frame 5, compared to when both ends of the link member 42 are connected to the link member connecting portions 7 fixed to the left and right side frames 5 using a single long shaft. This therefore increases the degree of freedom in arranging the cylinder head 32 and the exhaust pipe 15 that are disposed between the rear of the lower frame portion 5A of the left side frame 5 and the rear of the lower frame portion 5A of the right side frame 5.

[0070] In the above embodiment, the shape of protrusion 85 in a side view is generally triangular as shown in Fig. 8(A), but as shown in Fig. 10(A), the shape of protrusion 91 in a side view may be such that upper surface 91A and lower surface 91B are parallel and the front end is arc-shaped. Also, in the above embodiment, protrusion 85 is formed integrally with arm portion 26 of left case portion 24, but as shown in Fig. 10(B), protrusion 92 can also be formed by attaching a cylindrical member to arm portion 26 of left case portion 24 with fastening member 93 such as a bolt.

[0071] In the above embodiment, the swing restricting member 72 and the protrusion 85 are disposed rearward of the rear connecting shaft 59, but the present invention is not limited to this, and the swing restricting member and the protrusion may be disposed forward of the rear connecting shaft. An example of this is shown in Figures 10(C) and 10(D).

[0072] FIG. 10(C) shows a power unit support device 121 according to another embodiment of the present invention, in which the swing restricting member 128 and the protrusion 132 are disposed forward of the rear connecting shaft 125, as viewed from below. FIG. 10(D) shows a cross section of the power unit support device 121 taken along section line FF in FIG. 10(C), as viewed from the right (left in FIG. 10(C)). As shown in FIG. 10(C), the front ends of a pair of left and right link members 122 extending in the front-rear direction are swingably connected to the left and right side frames via a front connecting shaft 123 and a rubber bushing 124, as in the above-described embodiment. The rear ends of the pair of link members 122 are swingably connected to the front lower part of the crankcase 120 via a rear connecting shaft 125 and a rubber bushing 126. A power unit swing restricting mechanism 127 having a swing restricting member 128 and a protrusion 132 is provided between the pair of link members 122 and in front of the front lower part of the crankcase 120. That is, a mounting member 131 extending in the left-right direction is installed between the pair of link members 122, and a rocking restricting member 128 is attached to the mounting member 131. The rocking restricting member 128 is located forward of the rear connecting shaft 125. In addition, a protrusion 132 that protrudes forward is provided on the front lower part of the crankcase 120. The protrusion 132 protrudes forward from a portion of the front lower part of the crankcase 120 that is forward of the portion through which the rear connecting shaft 125 is inserted. Therefore, the protrusion 132 is located forward of the rear connecting shaft 125. In addition, as shown in FIG. 10(D), the front end of the protrusion 132 is inserted between the upper restricting portion 129 and the lower restricting portion 130 of the rocking restricting member 128.

[0073] In FIG. 10(D), for example, when the rear wheels pass over uneven ground, the power unit rotates about the axis J of the rear connecting shaft 125. Accordingly, the protrusion 132 also rotates about the axis J of the rear connecting shaft 125. When the power unit rotates clockwise about the axis J and moves upward, the protrusion 132 rotates clockwise about the axis J and moves downward accordingly. When the amount of clockwise rotation of the power unit exceeds a predetermined amount, the protrusion 132 comes into contact with the lower restricting portion 130. This restricts the clockwise rotation of the power unit. Furthermore, when the power unit rotates counterclockwise about the axis J and moves downward, the protrusion 132 rotates counterclockwise about the axis J and moves upward accordingly. When the amount of counterclockwise rotation of the power unit exceeds a predetermined amount, the protrusion 132 comes into contact with the upper restricting portion 129. This limits the clockwise rotation of the power unit.

[0074] Furthermore, in the above embodiment, the power unit rocking restriction mechanism 71 is disposed to the left of the center K in the left-right direction of the saddle riding type vehicle 1. This makes it possible to prevent the power unit rocking restriction mechanism 71 from interfering with the exhaust pipe 15, which is disposed to the right of the center K in the left-right direction of the saddle riding type vehicle 1. However, the present invention is not limited to this, and the power unit rocking restriction mechanism 71 may be disposed to the right of the center K in the left-right direction of the saddle riding type vehicle 1, or the power unit rocking restriction mechanism 71 may be disposed in the center of the saddle riding type vehicle 1 in the left-right direction.

[0075] Furthermore, the maximum value of the distance between the upper surface 85A of the protrusion 85 and the upper receiving surface 81 and the maximum value of the distance between the lower surface 85B of the protrusion 85 and the lower receiving surface 82 can be set appropriately from the viewpoint of vibration reduction, etc. Furthermore, the distance between the upper surface 85A of the protrusion 85 and the upper receiving surface 81 and the distance between the lower surface 85B of the protrusion 85 and the lower receiving surface 82 may each be set to zero. In other words, the upper surface 85A of the protrusion 85 may be in constant contact with the upper receiving surface 81, and the lower surface 85B of the protrusion 85 may be in constant contact with the lower receiving surface 82.

[0076] Furthermore, in the above embodiment, the engine 22 is used as an example of a power source for propelling the saddle-ride type vehicle 1, but an electric motor may also be used as a power source for propelling the saddle-ride type vehicle.

[0077] Furthermore, the present invention can be modified as appropriate within the scope that does not contradict the gist or concept of the invention that can be read from the claims and the entire specification, and power unit support devices that involve such modifications are also included in the technical concept of the present invention. [Explanation of symbols]

[0078] 1. Saddle-type vehicle 2 Body frame 5 Side frame 5A Lower frame 21 Power Unit 22 Engine (power source) 23, 120 Crankcase (storage case) 24 Left case part (first case part) 25 Right case part (second case part) 26 Arm section 28B Boss 30 Fastening members 41, 121 Power unit support device 42, 122 Link member (link) 47, 123 Front connecting shaft (first shaft) 59, 125 Rear connecting shaft (second shaft) 71, 127 Power unit oscillation control mechanism 73, 129 Upper restriction part 74, 130 Lower restriction part 81 Upper receiving surface 82 Lower support surface 85, 91, 92, 132 protrusion 85A, 91A top surface 85B, 91B bottom surface 86 Left cavity (first cavity) 87 Right Cavity (Second Cavity) 88 Ribs

Claims

1. 1. A power unit support device for supporting a unit swing type power unit having a power source for traveling of a saddle-riding type vehicle on a body frame of the saddle-riding type vehicle, comprising: a link whose one side is swingably connected to the body frame via a first shaft extending in the left-right direction, and whose other side is swingably connected to the power unit via a second shaft extending in the left-right direction; a power unit swing restriction mechanism that restricts swing of the power unit relative to the link, The power unit swing restriction mechanism includes: a protrusion provided on the power unit and protruding forward from the power unit; an upper restricting portion that is provided on the link, is disposed above the protruding portion, and restricts the upward movement of the protruding portion by coming into contact with the protruding portion when the protruding portion moves upward due to swinging of the power unit; a lower regulating portion provided on the link, positioned below the protrusion, and configured to restrict downward movement of the protrusion by coming into contact with the protrusion when the protrusion moves downward due to swinging of the power unit.

2. the power unit has a pair of left and right arm portions each protruding forward from the power unit, the link has a pair of left and right connecting portions to which the pair of arm portions are respectively connected via the second shaft, the protruding portion is disposed rearward of the second shaft and between the pair of arm portions, 2. The power unit support device according to claim 1, wherein the upper and lower restricting portions are disposed rearward of the second shaft and between the pair of connecting portions.

3. 3. The power unit support device according to claim 2, wherein the protrusion is integrally formed with at least one of the pair of arms.

4. the power unit has a housing case that houses components that form the power source, the storage case is formed by joining together a first case portion that forms one side portion of the storage case in the left-right direction and a second case portion that forms the other side portion of the storage case in the left-right direction, a boss for attaching a fastening member for connecting the first case portion and the second case portion is integrally formed with the first case portion; 4. The power unit supporting device according to claim 1, wherein the protrusion is integrally formed with the boss of the first case portion.

5. the power unit has a housing case that houses components that form the power source, the storage case is formed by joining together a first case portion that forms one side portion of the storage case in the left-right direction and a second case portion that forms the other side portion of the storage case in the left-right direction, the protrusion is integrally formed with the first case portion, The protrusion is a first cavity formed inside one side portion of the protrusion in the left-right direction and opening to the one side surface of the protrusion in the left-right direction; a second cavity formed inside the other side portion of the protrusion in the left-right direction and opening to the other side surface of the protrusion in the left-right direction; 4. The power unit support device according to claim 1, further comprising a rib located inside the protrusion between the first cavity and the second cavity, the rib being formed to separate the first cavity and the second cavity.

6. 6. The power unit support device according to claim 1, wherein the upper regulating portion and the lower regulating portion are arranged at a position corresponding to the center of the saddle-riding type vehicle in the left-right direction or at a position close to the center of the saddle-riding type vehicle in the left-right direction.

7. an upper surface of the protrusion inclined toward the lower surface of the protrusion as it extends forward; an upper receiving surface of the upper restricting portion that faces an upper surface of the protruding portion is inclined toward a lower receiving surface of the lower restricting portion that faces a lower surface of the protruding portion as it moves forward; 7. The power unit support device according to claim 1, wherein an inclination angle of the upper receiving surface relative to the lower receiving surface is equal to or greater than an inclination angle of the upper surface of the protrusion relative to the lower surface of the protrusion.

8. 8. The power unit support device according to claim 7, wherein the protrusion, the upper regulating portion, and the lower regulating portion are arranged rearward of the second shaft, the upper surface of the protrusion is formed so that a straight line passing over the upper surface of the protrusion and extending in the front-to-rear direction intersects with the axis of the second shaft, the lower surface of the protrusion is formed so that a straight line passing over the lower surface of the protrusion and extending in the front-to-rear direction intersects with the axis of the second shaft, the upper receiving surface is formed so that a straight line passing over the upper receiving surface and extending in the front-to-rear direction intersects with the axis of the second shaft, and the lower receiving surface is formed so that a straight line passing over the lower receiving surface and extending in the front-to-rear direction intersects with the axis of the second shaft.

Images