JPS62125966A - Car body frame of saddling type four-wheel car - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a vehicle body used in a straddle-type four-wheeled vehicle in which a straddle-type driver's seat is provided above an engine mounted near the center of the vehicle body frame. It's about frames.

(Background of the Invention) There have conventionally been straddle-type four-wheeled vehicles for driving on rough terrain that are equipped with wide, ultra-low-pressure tires. In this type of vehicle, a saddle-type driver's seat is installed above the engine mounted near the center of the vehicle body.
You ride by straddling this driver's seat.

In addition, many of these types of vehicles have a fuel tank and an intake air purifier located in front of the driver's seat and above the engine. The conventional vehicle body frame has one or two main pipes extending diagonally downward and rearward from the upper support part of the steering shaft, passing above the engine. For this reason, it was necessary to form recesses on the bottom surface or both left and right sides of the fuel tank and intake air cleaner to prevent the main pipe from interfering with the bottom surface of the fuel tank and intake air cleaner. As a result, it has been difficult to increase the capacity of the fuel tank and intake air purifier. Another problem was that the center of gravity of the car body tended to be high because the main pipe was located at a high position.

(Objective of the Invention) The present invention was made in view of the above circumstances, and it is possible to increase the capacity of equipment such as the fuel tank and intake air purifier installed in front of the driver's seat, and to lower the center of gravity of the vehicle body. To provide a body frame for a straddle-type four-wheeled vehicle that is suitable for riding.

(Structure of the Invention) According to the present invention, this object is to provide a straddle-type four-wheel vehicle that includes an engine mounted near the center of the vehicle body frame and a straddle-type driver seat disposed above the engine. The vehicle body frame includes a pair of left and right lower tubes that extend under the engine in the front-rear direction, and a pair of left and right upper tubes that extend downward from below the driver's seat through near the top surface of the crankcase of the engine. This is achieved by a body frame for a straddle-type four-wheeled vehicle, which is characterized by comprising a suitable vertical tube or the like that connects the lower tube and the upper tube.

(Embodiment) Fig. 1 is a partially sectional side view of an embodiment of the present invention, and Fig.
3 is a side view of the vehicle body frame, FIG. 4 is a plan view, and FIG. 5 is a front view.

In these figures, the reference numeral 10 denotes a vehicle body frame, and as shown in FIGS. 3 to 5, this frame 10 has a pair of left and right large-diameter lower tubes 12 whose rear portions are bent diagonally upward and rearward.
(12a, 12b), a pair of left and right upper tubes 14 (14a, 14b) whose front ends are bent substantially vertically downward and inclined diagonally upward from near the center toward the rear, and a front tube 16 (16a, 16b) and rear tube 18
(18a, 18b). 2 tube under the tree 1
2 are connected by appropriate cross tubes 20, 22, 24, 26. The front end of the upper tube 14 is the rain lower tube 1
It is fixed to a cross tube 20 that connects the front ends of the two. Further, the rear end of the lower tube 12 is fixed to the upper tube 14, and the lower tube 12 and the upper tube 14 are connected by a front tube 16 and a rear tube 18. Note that there are bearing brackets 28 (28a, 28b) at the connection between the rear tube 18 and the lower tube 12.
is fixed.

The front parts of the rain tubes 14 are connected by a cross tube 30, and a pair of left and right shock absorber towers 32 (32a, 32b) stand upward from the left and right ends of this cross tube 30, and the upper ends of both shock absorber towers 32 are Also cross tube 34
are connected. As a result, the tower 32 and the cross tubes 30, 34 form a closed loop having an inverted trapezoidal shape when viewed from the front (see FIG. 5). The center portion of the cross tube 34 is connected by a substantially horizontal tube 38 to the upper end of a bridge-shaped cross tube 36 which is hung over the rain tube 14 at the rear thereof.

The left upper tube 14a can be attached and detached near the center of the vehicle body, that is, between the front and rear tubes 16a and 18a. In FIG. 3.4, 14A is this attachment/detachment part, and both ends thereof can be bolted to the front part 14B and rear part 14C of the upper tube 14a, respectively. Note that 40 is a bridge-shaped cross tube that connects this attachment/detachment portion 14A and the upper tube 14b on the right side. The right end of this cross tube 40 is fixed to the upper tube 14b, while the left end thereof is fixed to a bracket 42 that spans the detachable portion 14A from above, and this bracket 42 is bolted to the detachable portion 14A.

As a result, the front and rear ends of the detachable portion 14A and the bracket 42
The attachment/detachment part 14A can be removed by loosening the bolts of each bolt connection part.

44 (44&, 44b) are a pair of left and right front wheels with wide ultra-low pressure tires, which are supported by a modified double wishbone type suspension system. That is, the upper part of the knuckle bracket (not shown) of the front wheel 44 is connected to the upper tube 14 by the upper arm 48 which is approximately A-shaped in plan view, and the lower part is connected to the front drive shaft 50 (only one shown) and the tension rod 52 (52a, 52b). ) are connected.

The inner end of the front drive shaft 50 is connected via a cross joint to a front differential 54 fixed to the lower tube 12, and the outer end is connected via a cross joint to a spindle 56 rotatably held by a knuckle bracket. are connected. Further, a cylindrical shock absorber 58 (58a, 58b) is interposed between the upper arm 48 and the upper end of the shock absorber tower 32.

60 (60a, 60b) are rear wheels with wide ultra-low pressure tires. The rear wheel 60 is fixed to a rear axle 64 that protrudes from a rear differential 62, and the rear differential 62 is integrated with a swing arm 66. This swing arm 66
The front end thereof is attached to the bearing bracket 28 (28a, 28b) located at the lower end of the rear tube 18 so as to be able to swing vertically, and is resiliently supported by a shock absorber 67.

68 is an engine mounted near the center of the vehicle body frame 10. The rain tube 12 passes below the engine 68 in the front-rear direction, and the rain tube 14 passes forward and downward near the upper surface of the crankcase 68a of the engine 68. The rotation of the output shaft 70 of the engine 68 is transmitted to the rear differential 62 via the universal joint 72 and the rear drive shaft 74. Note that the rear drive shaft 74 is inserted through the cylinder on the left side of the swing arm 66.

A distributor 76 is fixed to the engine 68 and extends downward across the output shaft 70 . This distributor 76 houses a gear group 80 that transmits the rotation of the engine output shaft 70 to the distributor output shaft 78.

This rotation of the distributor output shaft 78 is transmitted to the front differential device 54 via the universal joint 82, the front drive shaft 84, and the universal joint 86.

In FIG. 1.2, 88 is a front fender, 90 is a rear fender, and 92 is a straddle-type driver's seat fixed to the upper surface of the rear fender 90 and long in the front-rear direction. This driver's seat 92 is located above and behind the engine 68. Also 9
4 is a vaporizer located below the cross tube 40;
96 is an intake air purifier located below the driver's seat 92;
8 is an exhaust muffler. A fuel tank 100 is provided in front of the driver's seat 92, above the engine 68, and between the two cross tubes 36 and 40.

According to this embodiment, the output of engine 68 is distributed to a76
The power is distributed between the front wheel drive force and the rear wheel drive force. The front wheel driving force is transmitted to the gear group 80 of the distribution a76, the front drive shaft 84, and the front differential 54, and further transmitted from the front differential 54 to the left and right front wheels 44 via the left and right front drive shafts 50. . The rear wheel driving force is transmitted to the left and right rear wheels 60 via the rear drive shaft 74, the rear differential 62, and the rear axle 64, and the rear wheels 60 rotate at the same speed as the front wheels 44.

When removing the engine 68 from the vehicle body frame 10,
The detachable portion 14A of the left upper tube 14a' may be removed, and the engine 68 may be pulled up to the left through the gap in the detachable portion 14A.

Furthermore, since the fuel tank 100 is disposed between the cross tubes 36 and 40, there are no tubes that constitute the vehicle body frame 10 below it, and recesses are formed on the lower surface and both sides of the fuel tank 100 to form the vehicle body frame. There is no need to avoid interference with 10. Therefore, a large capacity of the fuel tank 100 can be ensured.

In the above embodiment, the fuel tank 10 is located in front of the driver's seat 92.
0 in an attempt to increase the capacity of the fuel tank 100, but the present invention is not limited to this, and it is also possible to increase the capacity by disposing an intake air purifier or other equipment at this position. good.

In addition, each of the left and right upper tubes may not only be formed of a single tube long in the front-rear direction, but may also be formed by, for example, fixing the rear half of the seat rail portion and the other front half, and substantially It is sufficient if it is integrated in the front-rear direction.

Further, in this embodiment, the rear end of the lower tube 12 is bent diagonally upward and rearward, and the rear end is fixed to the upper tube 18, but the present invention also includes a structure in which the rear end of the lower tube is connected with another vertical tube.

(Effects of the Invention) As described above, the present invention has a pair of left and right upper tubes that are formed to descend forward from below the driver's seat through the vicinity of the top surface of the engine crankcase, thereby increasing the overall height of the vehicle body frame. The center of gravity of the vehicle can be lowered, and the main tube is not located at a high position like in conventional models, resulting in a lower center of gravity. Furthermore, since there is no main tube in front of the driver's seat, it is possible to increase the capacity of devices such as a fuel tank and intake air purifier if they are installed here.

[Brief explanation of drawings]

FIG. 1 is a partially sectional side view of one embodiment of the present invention, and FIG.
3 is a side view of the vehicle body frame, FIG. 4 is a plan view, and FIG. 5 is a front view. 10... Vehicle body frame. 12...Lower tube, 14A...Detachable part, 14...Upper tube, 16...Front tube, 18...Rear tube, 68...Engine, 68a...Crank case 92 ...Saddle-type driving seat, 100...Fuel tank.

Claims (2)

[Claims] (1) An engine mounted near the center of the vehicle body frame,
In this straddle-type four-wheel vehicle equipped with a straddle-type driver's seat disposed above the engine, the body frame includes a pair of left and right lower tubes passing below the engine in the front-rear direction, and a straddle-type driver's seat arranged above the engine. A saddle characterized by comprising a pair of left and right upper tubes that descend forward from below the seat through the vicinity of the upper surface of the crankcase of the engine, and a suitable vertical tube or the like that connects these lower tubes and the upper tube. The body frame of a four-wheeled vehicle. (2) A body frame for a straddle-type four-wheeled vehicle according to claim 1, wherein at least one upper tube is partially bolted detachably near the center of the vehicle body.