JPS61271190A - Snowmobile - 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] [Technical Field of the Invention] The present invention relates to a snowmobile with an excellent sense of speed, and in particular to a small and lightweight snowmobile that allows the user to enjoy a sense of speed even in a relatively small space such as a backyard. be.

[Prior art]

In general, conventional snowmobiles are designed to enjoy the sportiness of traveling at high speeds in wide open fields. The mechanism of the snowmobile for this purpose is located at the bottom of the long monolithic frame from front to back.
A pair of steerable skis and a drive unit are arranged in the front and rear, and an engine that drives the drive unit is mounted on the front side of the upper part of the frame, and a seat is mounted in the rear part located above the drive unit. It is configured to provide. In order to be able to run such a snowmobile in a relatively narrow place such as a backyard, it would be possible to downsize it, but even if it were made smaller with the above structure, it would still be difficult to drive in a narrow place.
Since it is not possible to achieve the same speed as when traveling in a vast wilderness, the speed perception is reduced accordingly, and the snowmobile lacks the sportiness that is inherent to it.

Incidentally, it has been found that even if the traveling speed of the vehicle is reduced to a certain extent, the lower the passenger's eyes are positioned, the higher the sense of speed can be. From this perspective, a snowmobile has been proposed in which the engine, which obstructs visibility at the front of the frame, is moved to the rear of the frame, the drive unit is also placed behind the seat, and the seat is lowered (U.S. (See Japanese Patent No. 3,828.872 and Japanese Utility Model Publication No. 53-13135). However, even if the engine is simply moved to the rear of the frame, there is a drive unit at the bottom of the frame, which limits the lower limit of the boarding height, and still provides sufficient speed. It is not possible.

Furthermore, in order to minimize the lower limit of the riding height imposed by the drive unit as mentioned above, if the vertical stroke of the suspension system is suppressed to a small value, the riding comfort will deteriorate, but in any case, it is not satisfactory. It's not a thing.

[Purpose of the invention]

An object of the present invention is to provide a snowmobile that can lower the position of the rider's eyes as much as possible, thereby increasing the sense of speed.

Another object of the present invention is to provide a snowmobile that can increase the vertical stroke of the suspension system without keeping the vehicle height low, thereby improving riding comfort.

Still another object of the present invention is to provide a snowmobile that can reduce the weight of the vehicle while maintaining sufficient rigidity of the frame.

[Structure of the invention]

To achieve the above object, a snowmobile according to the present invention has a frame divided into a front frame and a rear frame, and then the frame is swingably connected to the front frame via a traction arm, and the front frame is divided into a front frame and a rear frame. A pair of left and right steerable skis and a seat are provided on the frame side, and an engine and a drive unit are provided on the rear frame side. The rear frame is further elastically supported by the rear part of the front frame via a suspension device.

〔Example〕

The present invention will be explained below with reference to embodiments shown in the drawings.

In the snowmobile shown in FIG. 1.2, the vehicle body frame is composed of a front frame 1 and a rear frame 2, which are independent from each other. The rear part of the front frame 1 and the front part of the rear frame 2 are
The left and right pair of traction arms 3, 3 are connected by pivoting their front and rear ends, respectively, and this connection allows the rear frame 2 to swing relative to the front frame 1.

The front frame 1 is provided with a seat 4 at the rear portion of the upper surface side, and a footrest portion 5 which is inclined diagonally in the front end thereof. In addition, a fuel tank 5a is provided in front of the seat 4.
is provided, and a backrest 4a is provided at the rear. Furthermore, a pair of left and right skis 6.6 are attached to the front portion of the lower surface of the front frame 1. This pair of left and right skis 6.6
is linked to a handle 7 provided on the top surface side via a steering shaft 8 and a steering mechanism 9, and can be steered left and right by operating the handle 7.

The rear frame 2 is further provided with a third
As shown in detail in Figure 4, at least the top surface, front surface, and both left and right sides are each formed into a box surrounded by walls.

The top surface of this box-shaped rear frame 2 has a T
Buffer rubber 11, 11.1 with three shaped support stands 10
1, and an engine 12 is fixed to the upper surface of the support stand 10. 12a is a carburetor provided on the intake side of the engine 12, and 12a is an air cleaner.

On the other hand, a drive unit 13 is provided inside the box on the lower side of the rear frame 2. This drive unit 13 has a pair of left and right drive wheels 14, 14 at the forefront that rotate by receiving power from the engine 12, and three pairs of idle wheels 15.15, 16.16, 17.17
A track 18 is wound around these drive wheels 14 and idler wheels 15, 16, and 17. 18
A is a pair of left and right slide rails that come into contact with the inner surface of the track 18.

A split V-pulley 2 is attached to the output shaft 19 of the engine 12.
1.22, and a known variable type belt transmission 20 consisting of a belt 23 wound around the pulleys 21 and 22. This ■belt transmission 20 automatically changes gears according to the rotational speed of the engine 12, and the drive wheels 14 of the drive unit 13 are
The power is transmitted to the rotating shaft 14a of the rotary shaft 14a.

Reference numeral 25a denotes a cenocase, the upper part of which rotatably supports the rotary shaft 24, and the lower part of which is fixed to the side surface of the rear frame 2. The rear ends of the aforementioned traction arms 3.3 are respectively pivotally supported at both wheel ends of the rotating shaft 14a. The chino 25 is disposed outside the one of the traction arms 3, and inputs the power of the engine 12 to the rotating shaft 14a. By being disposed outside the traction arm 3 in this manner, maintenance of the chino 25 is facilitated. The above-mentioned chino 25, which is this power transmission means, may be replaced with other means such as a toothed belt or a belt. Reference numeral 37 denotes a cover that covers the engine 12 and the like on the upper part of the rear frame 2, and its lower ends on both sides are fixed to the outer ends of a side skid plate 26, which will be described later.

On both sides of the drive unit 13, there are side skid plates 26 and 26 extending laterally from the lower ends of both side walls of the rear frame 2.
are provided along the longitudinal direction, and this side skid plate 26
．． 26 prevents the drive unit 13 from sinking into the snow surface. That is, the drive unit 1 of the present invention
The trunk 18 of No. 3 is small in length and width, and therefore has a small snow contact area, so it tends to sink into the snow surface, but this side skid plate 26 prevents it from sinking excessively. In order to make such a function effective, the lower surface of the side skid plate 26 is fixed to the rear frame 2 so as to be located slightly above the lower surface of the trunk of the drive unit 13. A resin plate 26a with low frictional resistance is fixed to the lower surface of the side skid plate 26.

In a conventional snowmobile, the drive wheels in the drive unit are provided at a slightly higher position than the idler wheels, and the front portion of the track wound around these wheels is configured to be inclined diagonally forward and upward.

By providing such an inclined portion, it is not only possible to easily get over protrusions on the snow surface, but also to make it easier to bank the snow surface, which is effective in improving running performance.

However, the driving wheel 14 in this invention is the idler wheel 15.
16 and 17 in a side view, thereby lowering the overall height of the drive unit 1-13 and lowering the center of gravity. For this reason, the front inclined part of the trunk as in the conventional case is eliminated, but in this invention, as an alternative, the drive unit 13
A front skid plate 27 is provided that covers the entire width of the lower surface of the traction arms 3, 3 located on the front side.

This front skid plate 27 is inclined diagonally downward along the longitudinal direction from the front end of the traction arm 3, and the outer end at the rear end is in contact with the outer end of the side skid plate 26 in the traveling direction of the vehicle. They are arranged almost on the same line. Also, due to this shape, the front skid plate 27
The outer end of the rear end is in a positional relationship that projects laterally than the outer end of the track 18 of the drive unit 13. This front skid plate 27 can be expected to have the same effect as the conventional front inclined part.

The rear frame 2 provided with the engine 12 and the drive unit 13 as described above has a traction arm 3.
3, and the suspension device 28
is elastically supported by This suspension device 28 is composed of a suspension arm 29, a main shock absorber 30, and a coil spring 31 which is a sub shock absorber. Furthermore, an annular band 35 is provided between the intermediate portion of the traction arm 3 and the front frame 1 to restrict the extension.

The suspension arm 29 has a guide member 32 whose front end is pivoted to the front frame 1 and whose rear end is pivoted to the upper surface of the rear frame 2.
It is slidably fitted.

The main shock absorber 30 is the same as a known one that combines a hydraulic cylinder part and a coil spring, and its lower end is pivoted to the intermediate part of the suspension arm 29, and its upper end is pivoted to the front frame 1. There is. Sub-buffer coil spring 3
1 is interposed between a spring receiver 29a provided on the suspension arm 29 and a guide member 32, and applies an elastic force to rotate the rear frame 2 downward via the guide member 32. Also, 1 of suspension arm 29! At the e end, a stopper 3 made of cushioning rubber is provided on both sides, sandwiching the guide member 32.
3.34 is fixed to restrict the sliding length of the suspension arm 29 in the front-rear direction.

As mentioned above, the rear frame 2 is integrally suspended from the front frame 1 with the engine 12 and the drive unit 13 so as to be able to swing up and down, so there is nothing that interferes with the upper part during its vertical stroke. . Therefore, it is possible to take a large vertical stroke and improve riding comfort.

At this time, the main shock absorber 30 applies a shock absorbing force to all strokes performed by the front and rear parts of the rear frame 2. On the other hand, the coil spring 31 of the auxiliary shock absorber applies an elastic force that rotates the rear frame 2 downward, so when only the front part of the rear frame 2 strokes upward, no buffer force is applied. However, when the rear part strokes upward or when the whole body moves in parallel, a buffering force is applied. This is particularly effective when only the rear part of the rear frame 2 strokes upward, and as shown in FIG. 5, the coil spring 31 becomes compressed and exerts a buffering force.

The reason why the two main and sub buffers 30 and 31 are combined in this way is as follows.

In other words, the rear frame 2 makes extremely complex movements, such as only the front stroke, only the rear stroke, or the whole stroke in parallel, and accordingly, the reaction force of the shock absorber may be small or large. Reaction force is required,
A wide range of reaction force characteristics is required. However, it is extremely difficult to meet this requirement with the main buffer 30 alone.

By combining the two main and sub shock absorbers 30 and 31, when the reaction force is insufficient with the main shock absorber 30 alone (in this case, when only the rear stroke occurs), the sub shock absorber 31 can compensate for this. If so, this requirement can be met relatively easily.

FIG. 6.7 shows another embodiment of the present invention, in which side skid plates 26 in the above-mentioned embodiments are fixed, but movable side skid plates 46 are provided on the upper and lower sides. It is.

Similar to the fixed side skid plate 26, this movable side skid plate 46 also has a resin 'rJi 46a with low frictional resistance fixed to its lower surface.

This side skid plate 46 has lower ends of equal length links 47 and 48 pivoted at its front and rear sides, respectively.
The upper ends of 48 are respectively pivotally supported on the rear frame 2 to form parallel links of equal length, and are supported so as to be vertically movable in parallel. However, in this state, the side skid plate 46 is urged downward via the urging device 49 stretched between it and the rear frame 2. The biasing device 49 is constructed by interposing a coil spring 49a between a support rod 49b and a support tube 49C that are slidably fitted into each other. Further, as a lower limit position regulating member, an annular band 5o is provided between the rear frame 2 and the side skid plate 4G. This annular band 50 regulates the lower limit position of the side skid plate 46 so that its lower surface is always located slightly above the lower surface of the track 18. As shown in FIG. 8, this lower limit position regulating member has a link 47 and/or
Alternatively, an integral stopper 51 may be provided at the lower end of 48, and this stopper 51 may be engaged with the upper surface of side skid 46 to regulate the lower limit position.

If the side skid plate is of a fixed type as in 26 of the former embodiment, when the track 18 of the drive unit 13 spins on a soft snow surface where the amount of vehicle sinking is large, the side skid plate Since the truck 26 mainly receives the vehicle load, the load applied to the truck 18 decreases, making it impossible to exert sufficient traction force. On the other hand, in the case of the latter vertically movable side skid plate 46, the track 18
When the lateral skid plate 46 spins and the load on the side skid plate 46 increases, the side skid plate 46 strokes upward while balancing with the energizer 49, so the truck 18 increases the load on the side skid plate 46. It is possible to grasp the snow surface with almost the same contact pressure. Therefore, even on soft snow, it can exert a large traction force.

〔Effect of the invention〕

As described above, the snowmobile according to the present invention has a body frame divided into a front frame and a rear frame, and the front frame is provided with a pair of steerable left and right skis and a seat, while the rear frame is provided with an engine and a drive unit. The front part of such a rear frame is swingably connected to the rear part of the front frame via a traction arm, so there is an engine in the front part of the front frame that obstructs the view. At the same time, there is no drive unit in the lower part that regulates the lower limit height. Therefore, the height of the seat can be made as low as possible, thereby lowering the passenger's eye position and creating a greater sense of speed.

Additionally, if the rear frame on which the engine is mounted is elastically supported with respect to the front frame by a suspension system, it is possible to increase the vertical stroke while keeping the overall height of the front frame low, resulting in a comfortable ride. can be improved.

In addition, since the frame is divided into front and rear parts, and each frame is shorter, the bending and torsion moments applied to the frame are reduced, making it possible to maintain a certain level of rigidity even when the wall thickness is reduced. can. Therefore, the overall weight of the frame can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a side view of a snowmobile according to an embodiment of the present invention, and FIG.
The figure is a plan view showing the snowmobile with some of the parts on the upper side omitted, FIG. 3 is a side view showing an enlarged portion of the rear frame side of the snowmobile, and FIG. 4 is the same as the snowmobile. A plan view showing the rear frame side part with some of the upper parts omitted. Figure 5 shows the situation when the rear frame side part of the snowmobile moves up and down due to the unevenness of the snow surface. FIG. 6 is a side view showing the rear frame side part of a snowmobile according to another embodiment of the present invention, and FIG.
(2) A view in the direction of arrows, and FIG. 8 is a partially cutaway side view of another embodiment of the lower limit position regulating member of the side skid plate. 1.-Front frame, 2-Rear frame, 3--Traction arm, 4--Seat, 5--Footrest, 6-Ski, 12--Engine, 13--Drive unit, 14--・・Drive wheel, 15-Drive wheel, 1
5, 16. 17- Idle wheel, 18-) Rack.

Claims (10)

[Claims] (1) A front frame with a pair of steerable left and right skis at the bottom, a seat at the top and a footrest placed in front of the seat, an engine mounted at the top, and driven by the engine at the bottom. a rear frame having a drive unit configured by winding a track around a drive wheel and an idler wheel;
A traction arm is provided at the rear part of the front frame and the front part of the rear frame, the front end and the rear end of which are pivotally supported, respectively, to swingably connect the rear frame to the front frame. Features a snowmobile. (2) The rear frame is a box whose top, front, left and right sides are surrounded by walls, the drive unit is provided inside the rear frame, the engine is fixed to the top, and a suspension system is attached to the box. The snowmobile according to claim 1, wherein the snowmobile is suspended on the rear part of the front frame via the front frame. (3) The suspension device includes a suspension arm having a front end pivoted to the front frame and a rear end slidably engaged with a guide member pivoted to the rear frame, and an upper end pivoted to the front frame. a main shock absorber whose lower end is pivoted to an intermediate portion of the suspension arm; and an engagement portion where the suspension arm engages with the guide member, and which biases the rear frame downward with an elastic force. A snowmobile according to claim 2, comprising a sub-shock absorber. (4) Claim 2, wherein the towing arm has a rear end pivotally supported on the side of the box, and a power transmission means extending from the engine to the drive unit is disposed on the outside of the towing arm. The mentioned snowmobile. (5) While the drive wheels and idler wheels of the drive unit are arranged substantially linearly in a side view, a front skid plate is provided on the traction arm located on the front side thereof, and the front skid plate The traction arm extends diagonally downward from the upper end along the longitudinal direction of the towing arm, and the outer end of the rear end extends outward from the outer end of the track of the drive unit. Snowmobile. (6) Side skid plates are provided on both sides of the drive unit, and the lower surfaces of the side skid plates are positioned slightly above the lower surface of the track of the drive unit. snowmobile. (7) The outer end of the rear end of the front skid plate and the outer end of the side skid plate are located substantially on the same straight line in the vehicle traveling direction. Snowmobile. (8) The snowmobile according to claim 6, wherein the side skid plate is fixed to the rear frame. (9) Claims in which the side skid plate is attached to the rear frame via an energizer so as to be movable up and down, and whose downward movement is regulated to a fixed position via a lower limit position regulating member. The snowmobile described in paragraph 6. (10) Claim 9, wherein the side skid plate is vertically movable in parallel to the rear frame via equal-length parallel links, and the biasing device is formed of a coil spring. snowmobile.