KR20000064061A - Bicycle Mounted with an Internal Combustion Engine - Google Patents

Abstract

SUMMARY OF THE INVENTION An object of the present invention is to provide a bicycle with an internal combustion engine capable of obtaining a length of an exhaust pipe sufficient to ensure good exhaust efficiency in a bicycle with an internal combustion engine provided with a muffler between the internal combustion engine and the rear wheel. do.

In a low-power bicycle equipped with a pedal to enable manpower driving and having an internal combustion engine installed at a lower portion of a vehicle frame having a substantially V-shape formed by a main frame and a seatpost, a muffler 50 is provided between the internal combustion engine and the rear wheel. The bicycle is provided with an internal combustion engine connected to the muffler 50 after the exhaust pipe 45 extending from the exhaust port of the internal combustion engine is bent in the front-rear direction from the lower side of the internal combustion engine.

Description

Bicycle with Internal Combustion Engine {Bicycle Mounted with an Internal Combustion Engine}

The present invention relates to a bicycle to which an internal combustion engine is attached, and more particularly, to the arrangement of a muffler.

In a bicycle with an internal combustion engine in which an internal combustion engine is disposed below the body frame, the body frame extends from the head pipe 01, as shown in the example described in Japanese Unexamined Patent Publication No. 8-108875. It is formed in the V-shape from the main frame 02 and the seat post 03 which came out, and the internal combustion engine 04 is provided in the lower part of the vehicle body frame.

The internal combustion tank 05 is mounted on the V-shaped bent portion of the main frame 02 and the seat post 03, and a carrier basket 07 having a long vertical length between the rear wheels 06 behind the seat post 03 is provided. It is arranged.

And a muffler 08 is installed between the internal combustion engine 04 and the rear wheel 06, and the exhaust pipe 09 extending from the exhaust port of the internal combustion engine 04 extends substantially horizontally to the rear below the internal combustion engine, so that It is connected to the muffler 08.

The bicycle with the internal combustion engine basically has the shape of a bicycle, and since the body width is narrow, each device is also required to be stored within the narrow body width to maintain the light appearance of the bicycle. ), But the muffler 08 approaches the internal combustion engine 04 so that the exhaust pipe 09 is shortened, and the exhaust pipe length is sufficient to ensure good exhaust efficiency. Can't get it.

The present invention has been made in view of the above, and an object thereof is to provide an internal combustion engine capable of obtaining a length of an exhaust pipe sufficient to ensure good exhaust efficiency in a bicycle with an internal combustion engine provided with a muffler between an internal combustion engine and a rear wheel. This is to provide an attached bike.

In order to achieve the above object, the present invention provides a bicycle in which the internal combustion engine is provided on the lower portion of the vehicle body frame which is provided with a pedal to enable manpower driving and has a substantially V-shape formed by the main frame and the seat post, wherein the internal combustion A muffler was installed between the engine and the rear wheel, and after the exhaust pipe extending from the exhaust port of the internal combustion engine was bent in the front-rear direction from the lower side of the internal combustion engine, the bicycle was attached to the internal combustion engine connected to the muffler.

Since the exhaust pipe is connected to the muffler provided between the internal combustion engine and the rear wheel after being bent in the front-rear direction from the lower side of the internal combustion engine, the length of the exhaust pipe sufficient to ensure good exhaust efficiency can be obtained.

The invention according to claim 2 is characterized in that, in the bicycle with the internal combustion engine according to claim 1, the bent portion of the exhaust pipe is within the left and right widths of the pedal width.

The exhaust pipe can be prevented from interfering with the pedal, and at the same time, it can be prevented from protruding in the vehicle body width direction and damaging the pleasant appearance of the vehicle body.

In the invention according to claim 3, in the low-battery to which the internal combustion engine according to claim 1 or 2 is attached, both halves of the muffler are formed by combining the partitions with a partition therebetween, and an exhaust pipe and a tail pipe are connected to either half. Characterized in that installed.

The exhaust pipe and tail pipe are installed only on one half body, and nothing is required to be mounted on the other half body, which facilitates assembly.

The invention according to claim 4 is characterized in that, in the bicycle with an internal combustion engine according to claim 3, the muffler is formed by incorporating an upper half and a lower half separated by the partition between the partitions.

The design of the exhaust pipe is facilitated because the degree of freedom to set the vehicle body width direction position at which the exhaust pipe is inserted into the muffler is large.

1 is an overall side view of a bicycle with an internal combustion engine according to a first embodiment of the present invention;

2 is a side view of the air cleaner and its vicinity;

3 is a cross-sectional view taken along the line III-III of FIG.

4 is a cross-sectional view taken along the line IV-IV in FIG. 2;

5 is a top view of a part of the exhaust pipe and the muffler in cross section;

6 is a cross-sectional view taken along the line VI-VI in FIG. 5,

7 is a side view of a bicycle to which a conventional internal combustion engine is attached.

<Description of the symbols for the main parts of the drawings>

1: Bicycle with internal combustion engine 25: Chain

2: body frame 26: pedal arm

3: head pipe 27: pedal

4: main pipe 30: air cleaner

5: seatpost 31: battery

6, 7: backstay 32: storage case

8: rear wheel bearing 33: lid member

9: rear wheel 34: screw

10: rear fender 35, 36: bolt nut

11: all fork 37: suction duct

12: front wheel 38: connecting tube

13: Fender all 40: carburetor

14: handle 45: exhaust pipe

15: internal combustion tank 50: muffler

16: sheet 51: upper case

17, 18: bracket 52: lower case

19: stand 53: separator

20: internal combustion engine 54: communication tube

21: shifting gear case 55: tail pipe

22: pedal crankshaft 56: mounting piece

23: drive sprocket 57: bolt nut

24: driven sprocket 58: support stay

EMBODIMENT OF THE INVENTION Hereinafter, 1st Embodiment which concerns on this invention is shown and described in FIGS.

The whole side view of the bicycle 1 with an internal combustion engine of this embodiment is shown in FIG.

The body frame 2 extends from the head pipe 3 to the rear side of the main pipe 4 with a slight downward inclination, and at the rear side, a seat post 5 is installed to incline upward and extend upward. It is approximately V-shaped when seen from.

The seat post 5 extends a little lower than the engaging portion with the main pipe 4, and from the lower end, a pair of left and right backstays 6 extend downwardly at the rear and bend horizontally on the way to the rear. And a pair of left and right backstays 7 which extends horizontally from the top of the seat post 5 to the rear inclined downwards, so that the rear ends of both backstays 6, 7 are rear wheel bearings 8 )

The rear wheel 9 is axially supported by the rear wheel bearing part 8, and the rear fender 10 covers the upper side of the rear wheel 9.

The stand 19 is freely mounted to the rear wheel bearing 8.

On the other hand, the front wheel 12 is axially supported by the lower end of all the forks 11 pivotally supported by the head pipe 3, and the handle 14 is attached to the upper end.

The panda 13 covers the upper side of the front wheel 12 altogether.

The internal combustion tank 15 extends from the engagement portion with the head pipe 3 of the main pipe 4 to the center portion, and the seat 16 is mounted on the upper end of the seat post 5.

The small internal combustion engine 20 of a 4-cycle 1 cylinder hangs below the V-shaped body frame 2.

It is fixed to the joint part of the main pipe 4 and the seat post 5, and the bracket 17 is installed by hanging down, and the lower side mounting bracket of the upper part of the crankcase 20a of the internal combustion engine 20 is supported by the lower end. The rear side mounting bracket of the internal combustion engine 20 is supported through the support shaft 18a to the bracket 18 which is supported through 17a and protrudes to the whole of the backstay 6.

As for the internal combustion engine 20, the cylinder 20b is erected in the inclined front side from the crankcase 20a, and the transmission gear case 21 is integrally provided in the back of the crankcase 20a.

The pedal crankshaft 22 and the drive sprocket 23 are installed on the output shaft 21a protruding left and right from the transmission gear case 21 via a one-way clutch, and the driven sprocket 24 provided in the rear wheel bearing part 8 is provided. The chain 25 spans between).

Pedal arms 26 are fitted to the pedal crankshaft 22 at left and right ends, respectively, and the pedals 27 are freely rotatably supported at their ends.

Therefore, by driving the internal combustion engine 20, the drive sprocket 23 can be rotated through the transmission gear, and the rear wheel 9 can be rotated and driven through the chain 25, and the pedal 27 is pressed by manpower. It is also possible to travel by rotating the rear wheel 9 through the chain 25.

The air cleaner 30 and the battery 31 are housed in a common case 32 in a space between the rear wheels 9 from the rear of the seat post 5.

The case 32 is divided up and down, the upper flat box constitutes the air cleaner case 32a, the lower flat box becomes the battery storage case 32b, and has a common rectangular opening on the right side, The lid member 33 closes the opening, and the lid member 33 is screwed onto the case 32 by two screws 34 and 34.

Referring to FIG. 2, the case 32 is formed in a substantially rectangular shape when viewed from the side, and is inserted into the rectangular space surrounded by the seat posts 5 and the rear wheel 9 and the top and bottom by the backstays 6 and 7. .

Mounting pieces 32c and 32d are projected on the front and lower surfaces of the case 32, and the bolt and nut 35 are attached to the bracket 5a on which the front mounting piece 32c is projected to the seat post 5, respectively. 3 is screwed together (see Fig. 3), and the lower mounting piece 32d is screwed by a bolt nut 36 to the bracket 6a protruding from the lower back stay 6 (Fig. 3). 4), the case 32 is mounted to the vehicle body frame 2.

As shown in FIGS. 3 and 4, the air cleaner 30 is formed by incorporating an air cleaner element 32a between the air cleaner case 32a and the lid member 33, and the inside of the air cleaner element ( 30a) is divided into the dirty side 30b on the right side and the clean side 30c on the left side.

The seat post 5 extends up and down the center of the front surface of the air cleaner 30, and the suction duct 37 on the right side and the connecting tube 38 on the left side extend from the front surface of the air cleaner 30. It extends forward with 5) in between.

The suction duct 37 on the right side of the seat post 5 penetrates through the lid member 33 and is inserted into the contamination side 30b, and the connecting tube 38 on the left side of the seat post 5 is air cleaner case 32a. It penetrates through and is inserted in the clean side 30c.

The connecting tube 38 extending forward from the front left side of the air cleaner case 32a is bent downwardly along the left side of the seat post 5, and then bent forwards again to form the left side of the bracket 17. Therefore, the junction part 38a of the front-end | tip is joined to the vaporizer | carburetor 40 arrange | positioned upward of the crankcase 20a.

And the connecting tube 38 is on the right rather than the left pedal arm 26 and is between the bracket 17.

And the intake pipe 39 extending upward from the cylinder 20b tilted forward obliquely is connected to the vaporizer 40 located upwardly inclined than the cylinder 20b.

Since the vaporizer | carburetor 40 is arrange | positioned toward the left rather than the center of a vehicle body, and the connecting tube 38 which connects with the air cleaner 30 follows the left side surface of the seat post 5, the connecting tube 38 is moved back and forth. It extends straight in the direction and reduces intake resistance.

And since the air cleaner 30 and the battery 31 are installed in the common case 32, and the lid member 33 blocks the common opening on the right side, the number of parts is small and the assembly efficiency is good, and the said lid By opening the member 33, maintenance such as replacement of the air cleaner element 30a and operations such as replacement of the battery 31 can be easily performed.

The battery 31 is inserted into the battery storage case 32b from the right side of the vehicle body and is covered by the lid member 33 so that it is not visible from the outside.

Since the heavy battery 31 is provided below the air cleaner 30, the center of gravity of the battery 31 can be made low.

And the muffler 50 is installed in the open space of the wide end in the lower side between the curved rear and the rear wheel (9) of the transmission gear case (21).

The mounting piece 56 which is mounted on the upper case 51 of the muffler 50 on the bracket 21b protruding from the curved rear face of the transmission gear case 21 is attached by screwing with a bolt nut, and the muffler 50 ) Is hanging.

The exhaust pipe 45 extending from the front exhaust port of the cylinder 20b extends downwardly inclined downward along the lower surface of the cylinder 20b which is inclined forward and is substantially horizontal from the bottom of the crankcase 20a. It is bent to extend to the rear, and is connected to the muffler 50 in a S-shape back and forth once between the muffler 50.

As shown in Fig. 5, the exhaust pipe 45 extends from the exhaust port slightly to the right of the body center line L-L 'and shifts to the left side at an inclined portion 45a extending downward at the rear, and approximately The curved portion 45b, which is horizontally curved, is parallel to the body center line L-L 'and extends backward to form a first straight portion 45c, and the curved portion curved in a U shape on the right side near the muffler 50. Extends forward through 45d to form a second straight portion 45e, and extends backward through the curved portion 45f curved in a U-shape on the right side at the same forward position as the bent portion 45b; Three straight portions 45g are formed, and the third straight portions 45g extend backward and are inserted into the muffler 50 as they are.

The first, second and third straight portions 45c, 45e, 45g of the exhaust pipe 45 are on the same horizontal plane along the lower surface of all the crankcase 20a and the transmission gear case 21, and the curved portions 45d, 45f) is narrowed in the left-right width of the muffler 50, and is accommodated between the left-right pedal arms 26 and 26.

5 and 6, the muffler 50 has a rectangular shape when viewed from the top, and the upper case 51 and the lower case 52 are welded and integrated at the same time with the separator 53 interposed therebetween. The upper space divided by the separator 53 is the first expansion chamber 51a, and the lower space is the second expansion chamber 52a.

The upper case 51 has a shape in which the front face follows the rear wheel 9 along the curved rear face of the transmission gear case 21 and is accommodated therebetween.

The exhaust pipe 45 is inserted into the second expansion chamber 52a in the lower case 52 of the muffler 50, and the extension pipe portion 45h is curved in a U-shape by extending the inside to the rear and supporting the stay ( 58, extended slightly forward, curved upward to penetrate the separator 53, and open the upper end from the separator 53 into the upper first expansion chamber 51a.

A communication pipe 54 is separately installed in the separator 53 to connect the first expansion chamber 51a and the second expansion chamber 52a to communicate with each other, and the tail pipe is installed through the rear wall of the lower case 52. 55 connects the 2nd expansion chamber 52a and the exterior, and is made to communicate.

Therefore, the exhaust gas of the internal combustion engine 20 enters the first expansion chamber 51a first through the exhaust pipe 45 having the required S shape in front and rear, and then communicates with the communication pipe 54 from the first expansion chamber 51a. Entering into the second expansion chamber (52a) through, and is discharged to the outside from the tail pipe (55).

Since the muffler 50 is provided with the exhaust case 45 and the tail pipe 55 in the lower case 52 without installing anything in the upper case 51, the assembly is simple and the number of jigs is very small and very adhesive. This is good.

In addition, since the upper case 51 and the lower case 52 are welded at the same time with the separator 53 interposed therebetween, the airtight holding is surely performed.

Moreover, since the muffler 50 is divided into upper and lower halves, and the 1st expansion chamber 51a and the 2nd expansion chamber 52a are provided up and down, the exhaust pipe 45 is inserted into the muffler 50, and the vehicle body left and right width directions The degree of freedom for setting the position is large, so that the exhaust pipe 45 can be easily designed in an S-shape in the front-rear direction.

Since the bicycle 1 with the internal combustion engine is basically in the shape of a bicycle, and the vehicle body width is narrow, it is required to store each device in a narrow body width to maintain the light appearance of the bicycle.

Thus, the muffler 50 is not disposed on the side of the rear wheel 9 and is disposed at the left and right center positions by using the space between the front transmission gear case 21 and the rear wheel 9, and thus the cylinder 20b. The distance between the exhaust port and the muffler 50 and the exhaust pipe are shortened and the exhaust pipe is shortened to form an S-shaped exhaust pipe back and forth under the crankcase 20a and the shift gear case 21, which is sufficient to ensure good exhaustion efficiency. The length of the exhaust pipe is secured.

In the exhaust pipe 45 having an S shape, since the curved portions 45d and 45f narrow the entire left and right width within the pedal width, the exhaust pipe 45 is accommodated between the left and right pedal arms 26 and 26, so that the exhaust pipe 45 is the body of the vehicle. It protrudes in the width direction to prevent damaging the bike's light appearance.

And the air cleaner 30 and the battery 31 are also installed in the center position of the left-right width direction using the dead space between the seat post 5 and the rear wheel 9. As shown in FIG.

Since the suction duct 37 and the connecting tube 38 extend from the left and right with the seat post 5 of the air cleaner 30 provided at the back of the seat post 5 interposed therebetween, The connecting tube 38 can be accommodated within the required left and right widths without interfering with the seat post 5.

Claims (4)

In a bicycle provided with a pedal capable of manpower driving, and the internal combustion engine is installed in the lower part of the vehicle body frame formed of a substantially V-shape by the main frame and the seat post, A muffler is installed between the internal combustion engine and the rear wheel, And an exhaust pipe extending from the exhaust port of the internal combustion engine is connected to the muffler after the exhaust pipe is bent in the front-rear direction from the lower side of the internal combustion engine. The bicycle with an internal combustion engine according to claim 1, wherein the bent portion of the exhaust pipe is within the left and right widths of the pedal width. The bicycle with an internal combustion engine according to claim 1 or 2, wherein the muffler is formed by merging two halves divided by half with a partition between them, and an exhaust pipe and a tail pipe are installed on one half of the muffler. The bicycle with an internal combustion engine according to claim 3, wherein the muffler is formed by merging an upper half and a lower half which are divided into upper and lower halves with a partition interposed therebetween.