JP2747668B2 - Frame structure of a four-wheeled vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame structure of a riding type four-wheeled vehicle such as a four-wheeled vehicle.

[0002]

2. Description of the Related Art In general, a riding type four-wheeled vehicle mounts front wheels on the front left and right sides of a frame (body frame) via suspension devices (struts and the like) and swings around a pivot shaft provided at the center of the frame. The left and right rear wheels are mounted on a swing arm that is movably supported and suspended by a load-carrying cushion unit, and the steering shaft that is supported by the front of the frame and connected to the left and right front wheels is turned by the handle. The vehicle is steered by driving the vehicle, and the vehicle is driven by driving rear wheels with an engine mounted in the center of the frame.

A fuel tank, a seat, a carrier, and the like are mounted on an upper portion of the frame from the front, and a driver grips the handle across the seat and mounts a foot board (step) mounted on the left and right of the lower portion of the frame. )
Steering with your feet on. Documents disclosing this type of riding-type four-wheeled vehicle include, for example, JP-A-1-223088.

The frame of the riding type four-wheeled vehicle is usually formed by a welding assembly such as a pipe, and generally includes left and right main upper members, left and right main lower members, and left and right main upper members. A plurality of side members that connect the lower member at a plurality of positions at predetermined intervals in the front-rear direction, a plurality of cross members that connect the left and right main upper members at a plurality of positions in the front-rear direction, and left and right extending rearward from the left and right main upper members. The vehicle includes a seat rail and left and right rear members that extend diagonally from the middle of the rear side member toward the middle of the seat rail.

A large number of brackets for mounting an engine, an air cleaner, a fuel tank, a seat, a carrier, a radiator, various electric parts, and the like are fixed to the frame by welding or bolting. When the engine is mounted on the frame, the engine is inserted into the frame from the side of the frame through the gap between the side members, and the engine is positioned and mounted by an engine mount bracket or the like. ing.

[0006]

However, the conventional frame structure of a riding-type four-wheeled vehicle has a disadvantage in that it becomes difficult to insert and mount it in the frame when the engine becomes large. For example, even with an existing engine, an engine with a belt converter has a large overall outer dimension, and it is difficult to mount the unit on a frame in a unitized state with a belt converter attached, thereby reducing the number of assembly steps. There is a disadvantage that it is difficult.

Further, in a frame having no sub-frame member, a high stress is generated at a joint between the main upper member and the main lower member (or the side member), so that a large gusset (triangular shape) is formed at this portion. Since the reinforcement member) is additionally welded, adding an engine mounting bracket to this gusset increases the weight of the frame and significantly increases the number of welding steps.

[0008] The present invention has been made in view of such prior art, and an object of the present invention is to allow the engine to be easily mounted on and lowered from a frame even when the engine becomes large. An object of the present invention is to provide a frame structure of a riding-type four-wheeled vehicle that can be made lightweight and compact without increasing the size and complexity of the frame.

[0009]

According to a first aspect of the present invention, there are provided a left and right main upper member, a left and right main lower member, and a left and right main upper member and a main lower member at a plurality of positions at predetermined intervals in the front-rear direction. In the frame structure of a riding type four-wheeled vehicle having a plurality of side members connected by a plurality of side members and a plurality of cross members connecting the left and right main upper members at a plurality of positions in the front-rear direction, a frame is provided on each of a left side and a right side. A front side member and a rear side member are provided in a front and rear position having a space at which the engine can be mounted substantially in the front and rear direction of the engine, and the vicinity of the lower end of the rear side member and the rear side member of the main upper member are provided. Removable with a bracket for mounting the engine on the part that is a predetermined distance ahead of the upper end connection With the structure for connecting a subframe member, it is to achieve the above object.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, an engine front portion for connecting the left and right main lower members at predetermined intervals in the front-rear direction of the engine mounting area substantially in the front-rear direction of the frame. By providing a cross member and a cross member at the rear of the engine, and by fastening a bracket previously attached to the engine from the lower surface of these cross members, it is possible to further reduce the gap between the engine bottom surface and the cross member. Thus, the above object is achieved more efficiently.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a left side view of a riding type four-wheeled vehicle suitable for applying the present invention, and FIG. 2 is a plan view of the riding type four-wheeled vehicle of FIG. 1 and 2, an engine 11 is mounted on a central portion of a frame (body frame) 10 made of a pipe welded structure, and left and right front wheels 12, 12 as steering wheels are provided on both front sides of the frame 10. Left and right rear wheels 13, 13 driven by an engine 11 are suspended at the rear of the frame 10.

A steering shaft 14 extending substantially vertically is supported at the front of the frame 10, and a bar handle 15 is fixed to an upper end of the steering shaft 14. A tie rod (not shown) leading to the front wheels 12, 12 is connected. The left and right front wheels 12 are independently suspended on both sides of the front portion of the frame 10.

The left and right rear wheels 13, 13 are suspended by a swing arm 16 and a load carrying cushion unit 17, and are driven by the engine 11 via a transmission mechanism (not shown) such as a drive shaft or a drive chain. This transmission mechanism is connected to a differential gear (not shown) that drives the left and right rear wheels 13, 13.

A front carrier 18, a fuel tank 19, a seat 20, and a rear carrier 21 are attached to an upper portion of the frame 10 from the front, and footboards (steps) 22 are attached to both lower portions of the frame 10. Further, covers made of molded products such as plastics, such as a front fender 23, a tank cover 24, a rear fender 25, and a side cover 26, are detachably attached to the frame 10. The driver
Straddle the seat 20, put your feet on the foot board 22,
The driver operates while gripping the bar handle 15 (specifically, the grip portion thereof).

FIG. 3 is a perspective view showing an embodiment in which the present invention is applied to the frame 10 in FIG. 3, the frame 10 includes left and right main upper members 31 and 31 extending in the front-rear direction, left and right main lower members 32 and 32 extending in the front and rear direction, and a main upper member 31 and a main lower member 3 on the left and right sides, respectively.
2 and a plurality of cross members 36, 37, 38 connecting the left and right main upper members 31, 31 at a plurality of positions in the front-rear direction. 39, 40, 4
1 and a plurality of cross members 42, 4 connecting the left and right main lower members 32, 32 at a plurality of positions in the front-rear direction.
3, 44, and 45.

The frame 10 also serves as a cross member 46 for connecting the left and right front side members 33 and 33, a cross member 47 for connecting the left and right rear side members 35 and 35, and a cross member. The steering support member 48, the rear end member 49 connecting the rear ends of the left and right main upper members 31, 31 and the rear left and right side members 35,
Main upper members 31, 31 in the middle of 35 and left and right
Left and right rear members 50, 50 for connecting the rear extension portion (seat rail portion) of the vehicle.

In FIG. 3, detachable sub-frame members 75 are provided on the left and right of the approximate center of the frame 10.
75 are connected. This subframe member 7
Reference numerals 5 and 75 are provided for facilitating the mounting and dismounting of the engine 11 even when the engine 11 is large, and for reducing the weight of the frame 10 while ensuring the required strength. In the illustrated example, the sub-frame members 75, 7
Each of the five has an engine mounting bracket 76
6 are provided. In addition, each subframe member 7
5 is bolted at its upper end to a bracket 77 provided on the main upper member 31 and at its lower end to a bracket 78 provided below the rearmost side member 35.

In FIG. 3, the left and right main lower members 32, 32 are connected to an engine guard 51 disposed in a lower region of the engine 11 (FIG. 1) mounted on the frame 10. The left and right main lower members 32, 32 are fixed to each other so as to protrude outward from positions at predetermined intervals in the front-rear direction (a total of four).
The step member 52 is fixed. Furthermore, on the lower front side of the left and right side members 35, 35 at the rearmost,
The left and right pivot bearings 53 of the swing arm 16 (FIG. 1) are fixed via a bracket or the like.

FIG. 4 is a left side view showing a main part of a frame structure of an engine mounting portion of a riding type four-wheel vehicle to which the present invention is applied. In FIG. 4, a front side member 34 and a rear side member 35 are respectively provided on the left and right sides of the engine mounting portion of the frame 10 at the front and rear positions having an interval at which the engine can be mounted substantially at the center in the front and rear direction of the frame. The bracket 77 is provided, and is fixed to the main upper member 31 on the same side as the portion near the lower end of the rear side member 35 (the bracket 78 in the illustrated example).
Both ends of the sub-frame member 75 are detachably fastened with bolts or the like.

As shown in the figure, the position of the upper end connecting portion of the sub-frame member 75 (the connecting portion with the main upper member 31) is at the upper end connecting portion of the rear side member 35 (the connecting portion with the main upper member 31). ) Is selected a predetermined distance (for example, about 100 mm to about 400 mm) ahead of the position, and are connected so as to form a substantially triangular space therebetween.

In this embodiment, as shown in FIG. 4, the engine 11 is mounted at four points, an upper part A, a rear part B, a front lower part C and a rear lower part D. The mounting portion of the upper portion A is provided on the cross member 38 (FIG. 3), the mounting portion of the rear portion B is provided on the bracket 76 of the left and right subframe members 75, and the mounting portion of the front lower portion C is provided. It is provided on the cross member 44 (FIG. 3), and the mounting portion of the rear lower portion D is provided on the cross member 45 (FIG. 3).

FIG. 5 is a sectional view showing a mounting structure of the rear portion B of the engine. In FIG. 5, a mounting hole 81 penetrating in the left-right direction is formed in a rear portion B of the engine 11,
Grommets 82 made of rubber-like elastic material for vibration isolation and support are mounted in the mounting holes of the brackets 76 of the left and right sub-frame members 75, and distance collars 83 are inserted into the inner diameters of the respective grommets 82.
The mounting bolt (mounting shaft) 84 is made to pass through the inside diameter of the engine 3 and the mounting hole 81 of the engine 11, and is fastened with a nut 85 so that the rear portion B of the engine 11 is
Attached to. 86 is a washer (washer)
Is shown.

FIG. 6 is a left-right longitudinal sectional view of the mounting structure of the front lower portion C of the engine 11, and FIG. 7 is a line 7--7 in FIG.
FIG. 7 is a sectional view along 7. The lower front portion C and the lower rear portion D of the engine 11 are attached to the cross members 44 and 45 with substantially the same structure. Therefore, the structure of the attachment portion of the front lower portion C to the cross member 44 will be described below. The detailed description of the mounting structure of the rear lower part D will be omitted.

6 and 7, a mounting hole 87 penetrating in the left-right direction is formed in a lower front portion C of the engine 11, and a mounting bolt (mounting shaft) 88 and a nut 89 penetrating the mounting hole 87 are used.
Engine brackets 90 are mounted on the left and right of the front lower part C of the vehicle. In the illustrated example, each of the left and right engine brackets 90, 90 is connected to the bolt via a spacer (or distance collar) 91 with a flange and a hollow cylindrical body (rubber grommet) 92 of a rubber-like elastic body for vibration-proof support. Engine 1 with 88 and nut 89
1 are attached to the left and right of the front lower part C of the vehicle.

As shown, each engine bracket 90 has an annular portion 90A having an inner diameter to which the rubber grommet 92 is fitted and mounted, and a pedestal portion 90B integrated by welding or the like below the annular portion. And the pedestal portion 90B
Mounting holes 90C, 90C are formed at predetermined intervals (two locations for each bracket) on the bottom surface of the vehicle, and nuts 90 are formed on the upper surfaces of the mounting holes 90C, 90C.
D and 90D are fixed by welding or the like.

The engine 11 is mounted on the cross member 44 in a state where the engine bracket 90 is mounted on the left and right sides of the front lower part C of the engine 11 via the distance collar 91 and the rubber grommet 92 with the mounting bolt 88 and the nut 89. The cross member 44 is formed of a molded plate member as a whole, and corresponds to a pair of front and rear mounting holes of the engine bracket 90 and nuts 90C and 90D at left and right positions corresponding to the left and right positions of the engine 11, respectively. Engine mounting holes 93 on the frame 10 side are formed at a pitch.

When mounting the engine 11 on the frame 10, the engine 11 with the engine bracket 90 attached is arranged at a predetermined position on the frame 10, and as shown in FIGS. An engine mounting bolt 94 is inserted from each mounting hole 93 from the side and screwed and fastened to each nut 90D of the left and right engine brackets 90, whereby the engine front lower portion C is mounted on the frame 10. In the illustrated example, the engine front lower portion C is fastened to the frame 10 by a total of four engine mounting bolts 94 via left and right engine brackets 90,90. The lower rear D of the engine 11
Is attached to the cross member 45 by substantially the same structure as the attachment structure of the front lower portion C described with reference to FIGS. 6 and 7.

The frame structure of the four-wheeled four-wheeled vehicle according to the embodiment described above has a front side at a front and rear position having a space at which the engine can be mounted at a substantially central portion in the front and rear direction of the frame 10 on each of the left and right sides. A member 34 and a rear side member 35 are provided, and a rear side member 35 is provided.
The lower end vicinity 78 of the main upper member 31 is connected to a portion 77 located a predetermined distance ahead of the upper end connection portion of the rear side member 35 of the main upper member 31 by a detachable sub-frame member 75 having an engine mounting bracket 76.
The left and right main lower members 32 are positioned at predetermined intervals in the front and rear of the engine mounting area substantially in the front and rear direction of the frame 10.
Are provided with a cross member 44 at the front of the engine and a cross member 45 at the rear of the engine.
1, the bracket 90 is fastened from the lower surfaces of these cross members 44 and 45.

According to the embodiment described above, the vicinity 78 of the lower end of the rear side member 35 and the portion 77 of the main upper member 31 located a predetermined distance ahead of the upper end connection portion of the rear side member 35 are formed. The structure is such that the detachable sub-frame member 75 having the engine mounting bracket 76 is connected so that even if the engine 11 becomes large, the engine can be easily mounted on and lowered from the frame 10. A frame structure of a four-wheeled vehicle is obtained. Also, the sub-frame member 75
Has a large degree of freedom in position (because it is not necessary to consider the detachability of the engine so much), it is easy to secure the strength of the frame.

Further, a cross member 44 at the front of the engine and a cross member 45 at the rear of the engine for connecting the left and right main lower members 32 are provided at predetermined intervals in the front and rear of the engine mounting area substantially in the center of the frame 10 in the front and rear direction. Bracket 90 previously attached to engine 11
Are fastened from the lower surfaces of these cross members 44, 45, so that even if the engine 11 becomes large, the engine can be more easily mounted on and lowered from the frame 10, and the engine 11 A frame structure of a riding type four-wheeled vehicle in which mounting and dismounting operations can be performed more easily is obtained. In addition, it is not necessary to take extra space in the vertical direction between the engine and the frame for attaching and detaching the engine, so that it is easy to secure the ground clearance of the frame.

[0031]

As is apparent from the above description, according to the first aspect of the present invention, the left and right main upper members are
The left and right main lower members, the side members connecting the main upper member and the main lower member on the left and right sides at a plurality of positions at predetermined intervals in the front-rear direction, and the left and right main upper members are connected at a plurality of positions in the front-rear direction. In a frame structure of a riding-type four-wheeled vehicle having a plurality of cross members, a front side member and a rear side member are respectively provided at a front and rear position having a space at which an engine can be mounted at a substantially central portion in the front and rear direction of the frame on each of a left side and a right side. A detachable sub-frame member having a bracket for mounting an engine on the side member, the portion near the lower end of the rear side member and the portion of the main upper member located a predetermined distance ahead of the upper end connection portion of the rear side member. So that even if the engine becomes large, Down the can or down or easily mounted to the frame, also the frame structure of the straddle-type four-wheel vehicle can be reduced in weight is provided while ensuring the required strength.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, an engine front connecting the left and right main lower members at predetermined intervals in the front and rear of the engine mounting area substantially in the front and rear direction of the frame. The cross member at the rear of the engine and the cross member at the rear of the engine are provided, and the bracket previously attached to the engine is fastened from the lower surface of these cross members. A frame structure of a riding-type four-wheeled vehicle that can be easily performed and that can easily secure the ground height of the frame is provided.

[Brief description of the drawings]

FIG. 1 is a left side view of a riding type four-wheeled vehicle suitable for applying the present invention.

FIG. 2 is a plan view of the riding type four-wheeled vehicle of FIG. 1;

FIG. 3 is a perspective view showing one embodiment in which the present invention is applied to the frame in FIG. 1;

FIG. 4 is a left side view showing a main part of a frame structure of an engine mounting portion of a riding type four-wheel vehicle to which the present invention is applied.

FIG. 5 is a sectional view showing a mounting structure of a rear portion of the engine.

FIG. 6 is a left-right longitudinal sectional view of a mounting structure at a lower front part of the engine.

FIG. 7 is a sectional view taken along lines 7-7 in FIG. 6;

[Explanation of symbols]

 10 Frame 11 Engine 12 Front Wheel 13 Rear Wheel 15 Handle 16 Swing Arm 20 Seat 31 Main Upper Member 32 Main Lower Member 33 Side Member 34 Side Member 35 Side Member 44 Cross Member 45 Cross Member 51 Engine Guard 75 Sub Frame Member 76 Engine Mounting Bracket 77 Bracket 78 Bracket 82 Rubber Grommet 83 Distance Collar 84 Mounting Bolt 85 Nut 88 Mounting Bolt 89 Nut 90 Engine Bracket 90A Annular Part 90B Pedestal 90D Nut 91 Distance Color 92 Rubber Gusmet 93 Mounting Hole (Cross Member) 94 Engine Mounting Bolt

Claims (2)

(57) [Claims] 1. A left and right main upper member, a left and right main lower member, a plurality of side members connecting the main upper member and the main lower member at a plurality of positions at predetermined intervals in the front-rear direction on the left and right sides, respectively. In a frame structure of a riding type four-wheeled vehicle having a plurality of cross members connecting the main upper member at a plurality of positions in the front-rear direction, the engine can be mounted at a substantially central portion in the front-rear direction of the frame on each of the left and right sides. A front side member and a rear side member are provided at front and rear positions having an interval, and the vicinity of the lower end of the rear side member and the portion of the main upper member located a predetermined distance ahead of the upper end connection portion of the rear side member are connected. Connectable by a detachable sub-frame member with an engine mounting bracket And the frame structure of a riding type four-wheeled vehicle. 2. A cross member at the front of the engine and a cross member at the rear of the engine that connect the left and right main lower members at predetermined intervals in the front and rear of the engine mounting area substantially in the front and rear direction of the frame, and are attached to the engine in advance. The frame structure for a riding-type four-wheeled vehicle according to claim 1, wherein the brackets are fastened from the lower surfaces of these cross members.