JPH0349795B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a vehicle having a steering front wheel and a pair of driving rear wheels, and a power unit disposed between the driving rear wheels. This relates to the position of the power unit and the arrangement of the intake and exhaust systems.

[Prior art]

A starter-type automatic tricycle which has a front wheel for steering and a pair of rear wheels for driving, a power unit disposed between the rear wheels for driving, and a cover member covering the upper part of the power unit is disclosed in Japanese Patent Application Laid-Open No. 1989- As shown in Publication No. 136669,
It is publicly known.

[Problem to be solved]

In this type of tricycle, a cylinder, which is a high-temperature heating element, is housed in the cover member,
Due to the positional relationship between the exhaust silencer and intake auxiliary equipment such as the carburetor and air cleaner, the intake air temperature may rise, negatively affecting charging efficiency, and the cylinder and exhaust silencer may receive sufficient running air. In addition, hot air may get trapped inside the cover member that covers the upper part of the power unit, and the intake auxiliary equipment and the cover member are likely to be affected by heat.

[Means and actions for solving the problem]

The present invention relates to an improvement of a power unit for a vehicle that overcomes these difficulties, and includes a front wheel for steering and two rear wheels for driving, a power unit disposed between the two rear wheels for driving, and a power unit for driving the vehicle. In a rear two-wheeled vehicle and a vehicle provided with a cover member that covers the upper surface of the power unit, the cylinder of the engine is disposed on the rear side of the vehicle body with respect to the crankcase, and is oriented toward the rear of the vehicle body, and the cover member Intake auxiliary equipment is arranged in the front of a space partitioned by the intake auxiliary equipment and the power unit and located above the power unit, and an exhaust silencer is arranged at the rear of the space with a partition wall for the intake auxiliary equipment It is characterized by the fact that it is equipped with.

As described above, in the space defined by the cover member and the power unit, the cylinder serving as the heat source and the exhaust silencer are located at the rear of the space, and the cylinder is located below the exhaust silencer. However, since the space is partitioned into front and rear parts by a partition wall and the intake auxiliary equipment is arranged in the front section, the air heated by the heat source remains in the rear part of the space. , cannot flow forward, and is directly discharged from the space from behind the cover member opening due to the guiding effect of the running wind flowing from the front to the rear in the vicinity of the cover member opening. The intake auxiliary equipment located in the section can draw in low-temperature outside air.

〔Example〕

An embodiment of the present invention illustrated in FIGS. 1 to 9 will be described below.

The starter-type automatic tricycle 1 is composed of a front body 2 and a rear body 20. The front body 2 has a front wheel FW for steering, and the rear body 20 has a pair of left and right rear wheels RW for driving. are arranged respectively.

In the front body 2, a rear body cover 6 including a leg shield 4, a step 5, and an upright wall portion 6a located behind the step 5 is attached to the main frame 3, as in the starter type tricycle. A sheet 7 is arranged on the upper part of the body cover 6.

Further, the rear vehicle body 20 is connected to the main frame 3 via a connecting mechanism 10. Furthermore, this coupling mechanism 10 includes a joint shaft 11 that is pivotally supported on the main frame 3 so as to be able to swing vertically.
12, a joint case 13 that rotatably supports the joint shaft 12, and a bracket 13a that connects the joint case 13 to a crankcase (described later) (see FIGS. 1 to 3). ). A rear action 15 is disposed between the main frame 3 and the joint shaft 12.

In the rear vehicle body 20, rear wheels RW are arranged to sandwich a unit swing type power unit 21 from the left and right, and a resin cover member 50 covers the upper part of the power unit 21 and the pair of rear wheels RW. (See Figures 3 and 4).

Furthermore, the crankcase 22 of the power unit 21 is located on the front side of the vehicle body with respect to the cylinder 23, and is rigidly connected to the bracket 13a of the joint case 13 by three screws 14 at a stay 22a protruding from the front part. is combined with The cylinder 23 is located on the rear side of the vehicle body with respect to the crankcase 22, and is arranged in an inclined attitude toward the rear of the vehicle body. This inclined posture means that the angle θ between the central axis C of the cylinder 23 and the horizontal line H is relatively small. And crank case 22
The cylinder 23, except for a part of the stay 22a, is sized and shaped to fit within the outline of the rear wheel RW when viewed from the side of the vehicle body (see FIG. 3).

Furthermore, the general shape of the power unit 21 is shown in FIG.
A carburetor 37 is attached to the upper surface, and a fan cover 24 is attached to the side surface of the crankcase 22 to cover a cooling fan pivotally attached to the crankshaft.
6 is screwed and fixed to the crankcase 22.
A duct 25 is attached to the opening 24a of the fan cover 24 (see FIGS. 4, 5, and 7).
The cooling air introduced into the fan cover 24 through the fan cover 24 is supplied into the shroud 26, and is discharged toward the ground from the lower opening 26a of the shroud 26 while cooling the cylinder 23 (the third
(See Figure 8).

Further, the space above the power unit 21 covered with the cover member 50 is formed by a steel plate partition wall 60.
It is divided into the front and rear, and the intake auxiliary equipment 3 is located in the front space.
0 is disposed, and an exhaust muffler 40 is disposed in the rear space.

Further, the intake auxiliary machinery 30 refers to an air cleaner 31 and a carburetor 37. A duct 25 is located on the left side of the intake auxiliary machinery 30 and functions as a side wall, and on the right side of the carburetor 37,
A side wall 61 integrally attached to the right side of the partition wall 60 is located (see FIGS. 3 to 5 and 7).
Further, a partition plate 33 is formed integrally with the air cleaner case 32, and this partition plate 33 includes a cover member 50, a partition wall 60, a side wall 61 and a duct 25.
Together, they define an intake chamber A, within which a carburetor 37 is located. The intake duct 32a of the air cleaner 31 is integrally attached to the air cleaner case 32 and opens into the intake chamber A. When the engine is running, the air in the intake chamber A flows through the intake duct 32a. After being sucked into the cleaner 31 and cleaned by the element E, it is sucked into the crankcase 22 of the two-cycle engine together with gasoline through the connecting pipe 36 and the carburetor 37. (See Figures 3 to 5).

The bulkhead plate 33 is bent toward the front side of the vehicle body at the lower side to form a stay 34. At the stay 34, the air cleaner 31 is connected to the stay 2 of the crankcase 22 via a bracket 35.
It is fixed at 2a. The bracket 35 has a pair of stays 35a straddling the stay 22a,
It is fixed to the stay 22a with the screw 14, and the stay 3 is fixed to the opening 35b with the screw 34A.
4 is fixed. (See Figures 3 and 7).

Furthermore, a small chamber 34a oriented in the longitudinal direction of the vehicle body is formed on the lower surface of the stay 34, and an ignition coil 70 is housed inside the chamber 34a (see FIGS. 3 and 5).

Moreover, the bracket 35 not only supports the air cleaner 31 but also supports the cover member 50. That is, a stay 54A is provided protrudingly from the front end of the cover member 50.
The locking pin 54a attached to the bracket 35 is inserted into the opening 35c of the bracket 35 through the grommet 55, and is screwed into the corresponding opening of the bracket 35 with the screw 56 through the grommet 57 at the screwing opening 54b. (See Figure 7).

By the way, as mentioned above, the side wall 61 is attached to the right side of the partition wall 60, but this side wall 61 also extends to the exhaust muffler 40 side and is located on the right side of the exhaust muffler 40. Furthermore, a side wall 62 is attached to the left side of the partition wall 60 in correspondence with the rearwardly extending portion of the side wall 61. And the partition wall 60, left and right side walls 6
A heat shield plate 63 made of a steel plate is screwed onto the upper side of the exhaust silencer 40, and the exhaust silencer 40 is housed in a room partitioned by the partition wall 60, both side walls 61, 62, and the heat shield plate 63. (Figure 3, Figure 4, Figure 6, Figure 7
(see figure).

A bent portion 61a is formed at the lower side of the side wall 61 extending forward, and is screwed onto the bracket 64 at the bent portion 61a. This bracket 64 is fixed to a pair of threaded portions 22b so as to straddle the front and rear of the crankcase 22. Further, a stay 60a is attached to the lower side of the partition wall 60, biased toward the side wall 62, and the stay 60a is
It is screwed onto the crankcase 22. In summary, the partition wall 60 and both side walls 61, 6 integral therewith
2 is fixed to the crankcase side by a bent portion 61a and a stay 60a (see FIGS. 3 and 7).

Furthermore, the heat shield plate 63 has a pair of left and right openings 63.
In correspondence with this opening 63a, an opening 53 is also formed in the cover member 50, and a rubber duct 64 is fitted in both openings 53, 63a. This duct 64 is provided to release heat released from the exhaust muffler 40 and the cylinder 23 below it to the upper side of the cover member 50 (Figs. 3, 4, and 6).
(See Figure 7).

Note that although the heat shield plate 63 is inevitably heated, the radiant heat emitted from the heat shield plate 63 is absorbed by the cover member 5.
The heat is released upward from the cover member 50 through a heat dissipation window 52 formed at the rear of the heat sink.

On the other hand, the exhaust port 23a of the cylinder 23 is
The exhaust pipe 41 is located on the ground side and is fixed to the exhaust port 23a through an opening 26a of the shroud 26 formed corresponding to the exhaust port 23a. The exhaust muffler 40, which communicates with the exhaust pipe 41, is fixed to the crankcase 22 with screws 40b by a pair of left and right stays 40a protruding from the lower front part of the muffler 40 (see Fig. 7). , see Figure 9).

In addition, a stay 27 is screwed onto the top surface of the shroud 26, and a left side projecting from the rear end of the cover member 50 is provided.
The right pair of stays 54B is screwed into the screw opening 27a of the stay 27 (see FIG. 8). Therefore, the cover member 50 is fixed to the bracket 35 at the front and to the stay 27 at the rear. A protective plate 58 covers the rear end of the cover member 50 from the outside and is screwed into the screw opening 27b of the stay 27 with a screw 58a. Cover the top part from the rear. The open end of the exhaust pipe 42 extending from the exhaust silencer 40 is located at the lower end of the protection plate 58 (see FIGS. 3, 4, 7, and 8). In addition to the heat radiation window 52 and opening 53, an outside air introduction window 51 and a carburetor adjustment opening 50a are formed, and a cap 59 is removably fitted into the opening 50a (see FIG. 7).

This embodiment is configured as described above,
When the engine is running, outside air is introduced into the intake chamber A through the outside air introduction window 51, around the bulkhead plate 33, around the duct 25, etc., and is drawn into the intake chamber A through the intake duct 32a of the air cleaner 31. During this time, dust generated during driving or water droplets in rainy weather are removed from the partition plate 33, partition wall 60, side wall 61, and duct 2.
Since the air is removed by inertial collision with the air cleaner 31, the burden on the air cleaner 31 is reduced.

Further, the cylinder 23 is forcibly cooled by air introduced into the shroud 26 through the duct 25, and the hot air is discharged downward from the opening 26a. A part of the hot air emitted from the cylinder 23 rises and passes through the duct 64 to the cover member 5 along with the hot air emitted from the exhaust muffler 40.
0 is ejected outward.

In this way, the cylinder 23, the exhaust silencer 40
The hot air released from the air intake chamber A is extremely effective because it is released downward and above the cover member 50 without affecting the intake auxiliary equipment 30 in the intake chamber A or the resin cover member 50. Furthermore, the radiant heat generated from the exhaust muffler 40 is transferred to the cylinder 23.
In addition, since the temperature is lower than that in the air, and the partition wall 60 and the heat shield plate 63 are provided, there is almost no thermal influence on the intake auxiliary machinery 30 or the cover member 50.

Note that the heat of the heated heat shield plate 63 is taken into the cover member 50 through the outside air introduction window 51, and together with the running wind flowing between the duct 25, the side walls 61 and 62, and both rear wheels RW, the heat from the heat radiation window 52 to the outside of the cover member 50.

Furthermore, the intake auxiliary equipment 30 is arranged at the front side of the vehicle body, separated from the cylinder 23, and
3, or the hot air generated from the exhaust silencer 40,
The influence of heat on the air intake auxiliary machinery 30 is minimal, since the air is blown toward the rear of the vehicle body by the running wind.

In addition, the duct 25 and both side walls 61 and 62 are located between the intake auxiliary equipment 30 and the exhaust silencer 40 and both rear wheels RW, and are arranged to remove dust accompanying the rotation of the rear wheels RW.
Alternatively, it has the effect of blocking water droplets and the like.

Furthermore, by arranging the cylinder 23 at the rear of the crankcase 22 (on the rear side of the vehicle body) in an inclined position so as to point toward the rear of the vehicle body, the center of gravity of the power unit 21 is reduced as much as possible, and the center of gravity of the power unit 21 is reduced as much as possible. There is also the advantage that the overall height of the vehicle body 20 is reduced.

Note that the tilted posture of the cylinder 23 is parallel to the horizontal line H.
It is also possible to make the inclination angle θ (see FIG. 3) with respect to substantially zero.

〔Effect of the invention〕

In the present invention, the air heated by the heat generating source remains in the rear part of the space and cannot flow forward, and also flows from the front to the rear in the vicinity of the cover member opening. Due to the inducing effect of the running wind, the air is directly discharged from the space behind the opening of the cover member, and the intake auxiliary equipment located at the front of the space can take in low-temperature outside air, thereby reducing engine filling. Decrease in root ratio is avoided, resulting in high output and efficiency.

Further, in the present invention, the cylinder of the engine is disposed on the rear side of the vehicle body with respect to the crankcase so as to face toward the rear of the vehicle body, and the exhaust silencer is disposed above the cylinder, so that the center of gravity of the vehicle can be lowered.

Furthermore, in the present invention, the space defined by the cover member and the power unit is partitioned into front and rear parts by a partition wall, and intake auxiliary equipment is arranged in the space in front of the space, and an exhaust silencer is arranged in the space behind the space. Because of this arrangement, they can be compactly organized.

[Brief explanation of drawings]

FIG. 1 is a left side view of a tricycle equipped with a power unit according to an embodiment of the present invention, FIG. 2 is a rear view thereof, and FIG. 3 is a longitudinal sectional side view of the main part of the vehicle body.
FIG. 4 is a cross-sectional plan view of the main part, FIG. 5 is a sectional view taken along the - line in FIG. 3, FIG. 6 is a sectional view taken along the - line in FIG. 3, and FIG. FIG. 8 is a perspective view showing the attachment relationship between the cover member and the shroud in the rear vehicle body, and FIG. 9 is a perspective view of the exhaust silencer in the rear vehicle body. DESCRIPTION OF SYMBOLS 1... Auto tricycle, 2... Front body, 3... Main frame, 4... Leg shield, 5... Step, 6... Rear body cover, 6a... Standing wall, 7... Seat, 10... Connection mechanism, 11,1
2... Joint shaft, 13... Joint case, 13a... Bracket, 14... Screw, 15... Reaction, 20... Rear body,
21... Power unit, 22... Crank case, 22a... Stay, 22b... Screwed part, 23
...Cylinder, 23a...Exhaust boat, 24...
...Fan cover, 25...Duct, 26...Shroud, 27...Stay, 30...Intake auxiliary equipment, 31...Air cleaner, 32...Air cleaner case, 32a...Intake duct, 33...
...Partition plate, 34... Stay, 34a... Small room, 3
4A...screw, 35...bracket, 36...connecting pipe, 37...carburetor, 40...exhaust silencer, 40a...stay, 40b...screw, 41,
42...Exhaust pipe, 50...Cover member, 51...
Outside air introduction window, 52... Heat dissipation window, 53... Opening, 5
4A, 54B...stay, 54a...locking pin,
54b...Screw opening, 55...Grommet, 5
6... Screw, 57... Grommet, 58... Protective plate, 59... Cap, 60... Partition wall, 60a...
...stay, 61...side wall, 61a...bend portion, 6
2... Side wall, 63... Heat shield plate, 63a... Opening,
64...Duct, 70...Ignition coil, A...Intake chamber.

Claims (1)

[Claims] 1 It has a front wheel for steering and two rear wheels for driving, and a power unit is disposed between the two rear wheels for driving,
In a vehicle provided with a cover member that covers the upper surface of the rear two-wheel drive vehicle and the power unit, the engine cylinder is disposed on the rear side of the vehicle body with respect to the crankcase, and is oriented toward the rear of the vehicle body, Intake auxiliary equipment is disposed in the front of a space defined by the cover member and the power unit and located above the power unit, and a partition is provided for the intake auxiliary equipment at the rear of the space, A vehicle power unit characterized by being equipped with an exhaust silencer.