JPH0868333A - Engine device for bicycle with electric motor - Google Patents

Abstract

PURPOSE: To prevent adhesion of mud on and insertion of rain water into an auxiliary device, etc., and heat rumulation therein respectively, and improve the whole beautiful appearance of an engine unit by arranging a special shaped engine cover, a through hole, and an eaves part for the engine unit. CONSTITUTION: An engine unit 60 is constituted by arranging a carburetor 65 and an air cleaner 66a in this order behind a running air cooling type engine 61a equipped with a recoil startor 61b. An engine cover 64 is interposed between a recoil startor case 63 and an air cleaner case 66, and its outer shape is formed in such a way that both cases 63, 66 are formed in a continuous shape for covering the circumference of the carburetor 65. Additionally, a through hole for allowing the flow of air inside and outside is drilled through the side wall of the engine cover 64. The eaves part 64b is projected in such a way that the top part of the air suction port of the air cleaner 66a is covered by the engine cover 64.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine device for a bicycle equipped with an electric motor, which is mounted on a bicycle equipped with a motor which can be driven by an engine.

[0002]

2. Description of the Related Art As shown in FIGS. 6 and 7, a bicycle which can be driven by an engine, that is, a bicycle with a prime mover, has a structure in which an engine device is combined with a bicycle whose rear wheels are driven by pedals. ing.

FIGS. 6 and 7 show an example in which an engine is arranged at one end of a rear wheel shaft and a reduction gear is arranged at the other end, and an integrally united engine unit is attached to the rear wheel shaft. here,
Explaining the motorized bicycle, the motorized bicycle 1 has a bifurcated front fork 3 that supports a front wheel 2.

A steering stem 4 having a steering handle 5 attached to the upper end thereof is connected to the upper end of the front fork 3. The steering stem 4 is rotatably supported by the head tube 6. Further, a main frame 7 extending downward and rearward is connected to a rear portion of the head tube 6, and a rear fork 8 extending horizontally and to the left and right respectively is connected to a rear end of the main frame 7. There is.

Left and right members 8a, 8b of the rear fork 8
The seat post frame has a bifurcated lower part at the rear.
Mu 9 is erected. This sheet post frame 9 is kept in a forwardly tilted state, and a sheet 10 is attached to the upper end thereof.

A crank pedal 11 is rotatably laterally supported on the rear portion of the main frame 7. A drive sprocket 12 is integrally provided on the right side of the crankshaft 11a of the crank pedal 11.

A chain 13 is stretched between the drive sprocket 12 and a driven sprocket (not shown) which is arranged facing the inside of the rear end of the right member 8b for driving the rear wheel 15. , A power transmission mechanism using a pedal is configured. The chain 13 is tensioned by the chain tensioner 18.

The driven sprocket has a member 8 on the right side.
It is integrated with the left end of the input shaft (not shown) of the transmission 20 that is coupled and supported at the rear part of b. Rear wheels 15 are supported by the right member 8b via a transmission 20. An engine 50 connected to the transmission 20 is supported on the left member 8a, and the rear wheel 15 can be driven by the driving force generated by the engine 50.

Fenders 16 and 17 are provided above the wheels 2 and 15, respectively, and a fuel tank 19 is mounted and supported on the rear side of the upper portion of the seat post frame 9. As the engine 50, a forced air-cooled two-cycle engine in which cylinders are horizontally arranged rearward is used.

In this forced air-cooled two-cycle engine, a cowling 51 for forced cooling that wraps around the engine is used, and the outside air is located in the center of the cowling 51 by a fan (not shown) directly connected to the crankshaft of the engine. It takes in from a circular cooling air intake port that is circular and flows around the rearward-directed cylinder to cool the cylinder.

[0011]

By the way, an engine unit employing such a forced air-cooling type two-cycle engine, in order to efficiently flow the cooling air around the cylinder,
It is necessary to integrally provide the cowling 51 that also serves as an engine cover, but unlike this, an engine unit employing a traveling air-cooled engine does not require a cowling for cooling.

That is, in a motor-powered bicycle, the engine is not equipped with a fan for forced air cooling, and the engine is cooled by a relative air flow around the engine caused by traveling of the bicycle, a so-called running air-cooled engine. There is an engine called.

Since this type of engine has a simple cooling structure, it tends to be frequently used in a motorbike. However, in an engine unit that employs such a traveling air-cooled engine, the carburetor that is an auxiliary machine is inadvertently exposed to the outside, so that the aesthetic appearance of the entire engine unit is not good.

Moreover, the exposed accessories have the disadvantage that sludge may splash or rainwater may fall when the bicycle travels. Therefore, it is possible to cover with a cover.However, if a structure that simply covers the cover is adopted, there is a problem that heat is accumulated inside the cover and the cooling performance of the engine is significantly deteriorated. There is a risk that water may enter the air intake port of the air cleaner through the connection with the air cleaner, and this cannot be easily handled.

The present invention has been made by paying attention to the above-mentioned actual circumstances, and its purpose is to prevent sludge from adhering to auxiliary machinery and infiltration of rainwater by using an engine cover which is considered to be difficult. It is an object of the present invention to provide an engine device for a bicycle with a prime mover capable of preventing the occurrence of heat and further improving the aesthetics of the entire engine unit adopting a running air-cooled engine without heat retention.

[0016]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention according to claim 1 arranges a traveling air-cooled engine equipped with a recoil starter horizontally and in the traveling direction, and behind it. Is provided with an engine unit composed of a carburetor and an air cleaner arranged in this order, and a recoil star with a U-shaped cross section and an external shape between the recoil star case and the air cleaner case.
An engine cover, which is formed in a shape that is continuous with the shape of the case and the air cleaner case and is configured to cover the periphery of the carburetor, is interposed, and an engine cover is provided on the side wall of the engine cover. -There is provided a vent hole for circulating air inside and outside, and an eave portion is provided so as to project from the engine cover so as to cover the upper portion of the air intake port of the air cleaner.

According to a second aspect of the present invention, in addition to the above-mentioned object, a muffler for a traveling air-cooled engine to a carburetor is provided.
In order to achieve the purpose of shutting off the heat influence on (auxiliaries), the engine cover according to claim 1 is provided in a cantilever-like inward direction from the side wall to a position below the carburetor. This is because a heat shield plate was provided to shield the radiant heat from the muffler overhanging.

[0018]

According to the first aspect of the present invention, the recoil star take-up is provided by the engine cover having a U-shaped cross section.
The area around the carburetor exposed between the air cleaner and the air cleaner case is covered to prevent splashing of sludge and rainwater on the carburetor.

The eaves provided on the engine cover
Water is prevented from entering the air intake port of the air cleaner from the connection with the air cleaner. Moreover, since the outer shape of the engine cover is continuous with the recoil star case and the air cleaner case, the engine unit employing the traveling air-cooled engine is a recoil star case. , The engine cover and the air cleaner case are integrated to create a beautiful appearance.

In addition, since the air inside and outside the engine cover flows from the vent holes provided in the engine cover, the temperature rise (heat accumulation) inside the engine cover can be prevented.
This makes it possible to obtain an overall preferable engine unit at the engine cover.

According to the second aspect of the present invention, the radiant heat from the muffler of the engine to the carburetor is blocked by the heat shield plate provided on the engine cover. This allows
Unnecessary temperature increase of the carburetor is suppressed, and the engine performance becomes stable accordingly.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in FIGS. FIG. 1 shows a perspective view around an engine device of a motorbike to which the present invention is applied, and FIG. 2 shows a front view seen from the direction of arrow A in FIG.

In the figure, 61a is a traveling air-cooled engine, for example, a traveling air-cooled two-cycle engine with a recoil starter, 61 is a cylinder constituting the traveling air-cooled two-cycle engine 61a, and 62 is the same engine 61.
A starter case 61b provided on the side of a is a recoil starter supported by the starter case 62 and arranged on the side of the engine, and 63 is a recoil starter 61b.
, 64 is an engine cover which is an essential part of the present invention, 65 is a carburetor (auxiliary equipment) which is connected to the traveling air-cooled two-cycle engine 61a and supplies an air-fuel mixture to the engine, 66a is the same carburetor-6
The air cleaner 66 connected to 5 is the same air cleaner 66.
Air cleaner case constituting a, 68 is a traveling air-cooled type 2
It is a muffler connected to the cycle engine 61a. Reference numeral 72 denotes a grip of the recoil starter 61b.

An engine unit 60 is composed of each of these devices. An air intake port 66b is provided at the uppermost step of the side surface of the air cleaner 66 facing the carburetor 65 side.

On the other hand, reference numeral 69 in the drawing denotes a bifurcated rear fork which constitutes the bicycle body, and 70 denotes a bifurcated rear station. The engine unit 60 is rotatably supported on a rear wheel shaft (not shown) fixed at a position where the rear fork 69 and the rear steering 70 intersect. The engine unit 60 has a transmission 67, and a rear wheel (not shown) rotatably supported by a rear wheel shaft by rotation of a decelerated two-cycle engine 61a output from the transmission 67. It has a structure that can be driven to rotate.

In the engine unit 60, the case portion on the front side of the vehicle body (bicycle) separated from the rear wheel shaft is provided with the support fitting 7
It is fixed to the rear fork 69 via 1 so that the entire engine unit is not rotated by the reaction force when the rear wheels (not shown) are driven by the engine.

With such a mounting structure, the traveling air-cooled two-cycle engine 61a is mounted on the bicycle body with the cylinder 61 oriented horizontally and in the traveling direction (front). Then, a carburetor is placed behind the engine 61a.
65 and an air cleaner 66a are arranged in series in this order, and a muffler 68 is arranged below the carburetor 65 and the air cleaner 66a toward the side (rear) opposite to the traveling direction. The air cleaner 66a is fixed to the carburetor 65 with screws 75.

FIG. 1 shows a state in which the engine unit 60 is mounted on the rear axle of a bicycle. The engine cover 64 includes a recoil star case 63 and an air cleaner case which constitute the engine unit 60.
It is interposed between the sleeve 66 and the sleeve 66.

The structure of the engine cover 64 is shown in FIGS. That is, FIG. 3 is a left side view of the engine cover 64 of FIG. 2 as seen from the direction B, and FIG. 4 is C of FIG.
2 is a sectional view of the engine cover 64 taken along the line C, and FIG.
The right side view of the engine cover 64 of FIG.

Explaining the structure of the engine cover 64, the engine cover 64 is made of a resin such as polypropylene and has a substantially U-shaped cross section as shown in FIGS. 3 and 5. -When it is interposed between the spaces 63 and 66, it covers the carburetor-65 on the upper, lower, lateral sides.

Further, the outer shape of the engine cover 64 is formed in a streamline shape which is continuously connected to the recoil star case 63 and the air cleaner case 66, and produces a high aesthetic appearance.

The engine cover 64 has a screw 7
At 3, 74, the transmission 67 and the recoil star case 63 are respectively screwed. The engine cover
A mortise hole 64d is provided inside the lower portion of the air cleaner side of 64, and the mortise hole 64d is removably fitted to a projection (not shown) provided on the air cleaner 66a side. The engine cover 64 is positioned.

On the side wall covering the carburetor 65 of the engine cover 64, as shown in FIG. 4, a plurality of ventilation holes 64a elongated in the front-rear direction are formed in a vertical direction, and air is vented to the ventilation holes 64a. The inside and outside of the cover can be distributed through.

Further, an eaves portion 64b is provided on the upper portion of the contour portion connected to the air cleaner 66a at the rear end of the engine cover 64. This eaves portion 64b is the same engine cover.
Of the upper part of 64, the air intake port 6 of the air cleaner 66
A portion corresponding to the width of 6a is formed so as to protrude from the other portions so as to cover the air cleaner case 66, and the eaves portion 64b forms the engine cover 64 and the air cleaner 66a. The gap between the connecting portions is blocked to prevent water from entering the air inlet 66b of the air cleaner 66a through the connecting portions.

Further, the carburetor of the engine cover 64
As shown in FIGS. 3 and 5, a heat shield plate 64c is provided at a position on the lower side of 65 so as to project inward from the inner surface of the side wall of the engine cover 64 in a cantilever shape.

The heat shield plate 64c is provided over the entire lower portion of the carburetor 65 and the muffler 68 so as to shield the carburetor 65 from the muffler 68. is there. In other words, the heat shield plate 64c blocks heat from the muffler 68 to the carburetor 64,
The carburetor 65 is protected from the heat generated by the muffler 68.

The arrow E in FIG. 2 indicates the air cleaner 6.
6 shows the flow of air in the air intake port 66b of No. 6. Thus, in the engine unit 60 mounted on the rear axle of the bicycle, the engine cover 64 connects the recoil star case 63 and the air cleaner case 66 to close the open portion. , Carburetor-65
The recoil star case 63 and air cleaner case 6
It's hidden from between 6 and.

Moreover, since the engine cover itself has an outer shape that continuously connects the coil star case 63 and the air cleaner case 66, the recoil star case 63, the engine cover 64, and the air cleaner. The case 66 appears to have an integrated appearance.

As a result, it is possible to improve the aesthetic appearance of the entire engine unit employing the traveling air-cooled engine. Moreover, since the engine cover 64 covers the carburetor 65, which is susceptible to external influences, on the three sides of the carburetor 65, the carburetor 65 can be prevented from splashing sludge and rainwater. It is possible to prevent secondary rusting at −65.

In addition, the air inside and outside the cover flows through the vent holes 64a in the engine cover 64,
It is possible to prevent the temperature rise inside the engine cover (inside the cover) and eliminate the heat buildup inside the cover.

In addition, the eaves portion 64b of the engine cover 64.
By the rear end of the engine cover 64 and the air cleaner 6
Since the portion corresponding to the air intake port 66b of the air cleaner 66a in the connection portion with the air cleaner 6a is shielded, the air cleaner passes through the gap between the rear end of the engine cover 64 and the air cleaner 66a. It is possible to prevent water from entering the air intake port 66b of the nozzle 66a. This allows
It is possible to prevent the intake resistance of the air cleaner 66 from inadvertently increasing, and it is possible to prevent the secondary rusting of the air cleaner 66a as in the case of the carburetor 65.

Further, from the muffler 68 to the carburetor 6
The heat shield plate 64c that blocks the radiant heat to the engine
By being provided in 64, the effect of heat from the muffler 68 on the carburetor 65 can be blocked, and unnecessary temperature rise of the carburetor 65 can be suppressed, and the engine performance can be stabilized.

In the embodiment, the traveling air-cooled two-cycle engine equipped with the recoil starter is used as the traveling air-cooled engine, but the invention is not limited to this, and another traveling air-cooled engine, for example, a traveling air-cooled four-cycle engine is used. An engine may be used.

[0044]

As described above, according to the first aspect of the invention, the recoil star is provided by the engine cover.
The carburetor features are not exposed between the take-up case and the air cleaner case, and the recoil star case, the engine cover, and the air cleaner case appear to be integrated.

As a result, the aesthetic appearance of the engine unit employing the air-cooled engine can be remarkably improved.
Product strength can be improved. Moreover, since the surroundings of the carburetor are covered with the engine cover, it is possible to prevent unnecessary sludge splashing on the carburetor and rainwater from falling on the carburetor. Rust can be prevented.

In addition, since the air inside and outside the cover flows through the ventilation holes, it is possible to prevent an unnecessary temperature rise inside the cover and eliminate the heat buildup inside the cover. Further, due to the blocking effect obtained by the eaves part, it is possible to prevent water from inadvertently entering the air intake port of the air cleaner from the connection part with the air cleaner, and prevent inadvertent increase of intake resistance. Bring about the effect.

As a result, an overall preferable engine unit can be obtained by the engine cover. According to the invention of claim 2, in addition to the above effects,
Carburettor from engine muffler by heat shield
The radiant heat to can be cut off. As a result of blocking the heat effect from the muffler to the carburetor, the carburetor
It is possible to suppress the unnecessary temperature rise of the engine and stabilize the engine performance.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outer appearance of an engine unit according to an engine device for a bicycle with a prime mover according to an embodiment of the present invention.

FIG. 2 is a front view of the engine unit seen from the direction A in FIG.

FIG. 3 is a side view of the engine cover viewed from the direction B in FIG.

FIG. 4 is a cross-sectional view taken along the line C-C in FIG.

5 is a side view of the engine cover viewed from the direction D in FIG.

FIG. 6 is a right side view showing a conventional bicycle with a motor.

FIG. 7 is a left side view of the same.

[Explanation of symbols]

60 ... Engine unit 61a ... 2-cycle running air-cooled engine 61b ... Recoil starter 61 ... Cylinder 63 ... Recoil star case 64 ... Engine cover
64a ... Vent 64b ... Eaves 64c ... Heat shield
65 ... Carburetor 66a ... Air cleaner 66b ... Air suction port 66 ... Air cleaner case 68 ... Muffler

Front Page Continuation (72) Inventor Mihide Nakatani No. 1 Takamichi, Iwazuka-cho, Nakamura-ku, Nagoya-shi, Aichi Mitsubishi Heavy Industries, Ltd. Nagoya Machinery Works

Claims (2)

[Claims] 1. An engine unit comprising a traveling air-cooled engine having a recoil starter arranged horizontally and in the traveling direction, and a carburetor and an air cleaner arranged in this order behind the engine unit. Recoil starter basket forming the recoil starter
Is interposed between the air cleaner and the air cleaner case constituting the air cleaner, and has a U-shaped cross section and an outer shape continuous with the shapes of the recoil starter case and the air cleaner case. An engine cover that is formed in a shape that forms a shape that covers the periphery of the carburetor, and a vent hole that is provided in a side wall of the engine cover and that allows air inside and outside the engine cover to flow. An engine device for a bicycle with a motor, comprising: an eave portion provided so as to project from the engine cover so as to cover an upper portion of an air intake port of the air cleaner. 2. The bicycle with a prime mover according to claim 1, wherein the engine cover projects inward from the side wall in a cantilever shape to a position below the carburetor,
An engine device for a bicycle with a motor, comprising a heat shield plate for shielding radiant heat from a muffler.