JP2002200999A - Motorcycle with pedals - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce vibration of a body frame that results from vibration of an engine, to secure a rigid feeling when pedals are pressed, and to miniaturize the engine in a motorcycle with the pedals that comprises a crankshaft with at least a pair of crank weights and a rotatable pedal shaft that are removably supported by an engine case of the engine. SOLUTION: An engine body 33 including the engine case 35 is rigidly fixed to the body frame. Balancers 54 each of which a balance weight 54a disposed between the crank weights 45a to overlap the crank weights 45a when viewed from a direction parallel to an axis of the crankshaft 45, and are each stored inside the engine case 35 so as to rotate on an axis parallel to the crankshaft 45 in synchronization with a rotation of the crankshaft 45.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle with a pedal, and more particularly to a pedal shaft capable of transmitting a pedaling force input from pedals provided at both ends to a rear wheel, and rotating about an axis parallel to the pedal shaft. An engine having a crankshaft capable of transmitting rotational power to the rear wheels, wherein the engine case of the engine supports the crankshaft having at least a pair of crank weights and the pedal shaft is rotatable. The present invention relates to improvement of a motorcycle with a pedal that is supported.

[0002]

2. Description of the Related Art Conventionally, such a motorcycle with a pedal has
For example, it is known from Japanese Patent Application Laid-Open No. 8-108875 and the like, and a crankshaft and a pedal shaft are commonly supported on an engine case provided in an engine.
The aim is to reduce the size and weight of motorcycles.

[0003]

By the way, in the conventional motorcycle with a pedal, the engine body is mounted on the body frame via a rubber mount.
In general, it is difficult for the vibration of the engine to be transmitted to the body frame.However, an elastic material is interposed between the engine case that supports the pedal shaft and the body frame, ensuring a sense of rigidity when the rider steps on the pedal. It becomes difficult.

The present invention has been made in view of the above circumstances, and aims to reduce the vibration of a vehicle body frame due to the vibration of the engine, and to make the engine compact while ensuring a rigid feeling when the pedal is depressed. It is an object of the present invention to provide a motorcycle with a pedal that can be operated.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the invention according to claim 1 provides a pedal shaft capable of transmitting a pedaling force input from pedals provided at both ends to a rear wheel, An engine having a crankshaft capable of transmitting rotational power to the rear wheel by rotating about a parallel axis, and an engine case of the engine,
In a motorcycle with a pedal, wherein the crankshaft having at least a pair of crank weights is supported and the pedal shaft is rotatably supported,
The engine body including the engine case is rigidly fixed to the vehicle body frame, and is disposed between the two crank weights so as to partially overlap the two crank weights when viewed from a direction parallel to the axis of the crank shaft. A balancer having a balance weight is housed in the engine case so as to be able to rotate around an axis parallel to the crankshaft in conjunction with rotation of the crankshaft.

According to such a configuration, since the vibration of the engine is suppressed by the balancer, the vibration caused by the engine vibration of the vehicle body frame can be reduced even if the engine body is rigidly fixed to the vehicle body frame. And the rigid attachment of the engine body to the body frame
The rigidity of the pedals at both ends of the pedal shaft supported by the engine case of the engine body can be secured when depressed, and the support structure of the engine body to the body frame is compact because the anti-vibration structure is unnecessary. Can be Moreover, since the balance weight of the balancer is disposed between the pair of crank weights so as to partially overlap the two crank weights when viewed from the direction parallel to the axis of the crankshaft, the balance weight is provided despite the balancer. It is possible to reduce the width of the engine case in a direction along the axis of the shaft, thereby preventing the engine from being enlarged.

[0007] The invention according to claim 2 provides the above-described claim 1.
In addition to the configuration of the invention described above, a pair of balancers having a rotation axis on one diameter line extension of the crankshaft are arranged on both sides of the crankshaft when viewed from the axial direction of a cylinder bore provided in the engine body. According to this configuration, the pair of balancers capable of suppressing the rotational moment around the crankshaft can be compactly arranged between the pair of crankweights.

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the pedal shaft is supported on the engine case via a bearing, and the crankshaft and the balancer are mounted on the engine case. According to this configuration, the crankshaft and the balancer are supported by the holder that is separate from the engine case, thereby achieving concentration of the balancer mass. At the same time, it is easy to increase the rigidity of the holder to enhance the vibration isolation effect of the balancer and further suppress the transmission of vibration to the engine case, so that the transmission of vibration to the body frame and pedal shaft can be further reduced. By securing rigidity with the holder, it is possible to reduce the weight of the engine case.

According to a fourth aspect of the present invention, in addition to the configuration of the second aspect, the crankshaft and the pedal shaft are arranged such that the axis of the cylinder bore is inclined with respect to a straight line connecting the axes of the shafts. According to this configuration, the crankshaft and the pedal shaft are disposed despite the pair of balancers being disposed on both sides of the crankshaft when viewed from the axial direction of the cylinder bore. Can be brought as close as possible, and the size of the engine case can be reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

1 to 10 show a first embodiment of the present invention. FIG. 1 is a longitudinal sectional side view of a motorcycle with a pedal, and FIG. 2 is a sectional view of the engine taken along line 2-2 in FIG. 3 is a sectional view taken along line 3-3 of FIG. 2, FIG. 4 is a sectional view taken along line 4-4 of FIG. 3, FIG. 5 is an enlarged sectional view taken along line 5-5 of FIG. 1, and FIG. FIG. 7 is an enlarged vertical sectional view, and FIG.
7, FIG. 8 is a sectional view taken along line 8-8 of FIG. 6, and FIG. 9 is a sectional view of FIG.
6 is a sectional view taken along line 9-9, and FIG. 10 is a sectional view taken along line 10-10 in FIG.

First, in FIG. 1, a body frame 21 of a motorcycle with a pedal has a main frame 23 provided with a head pipe 22 at a front end and inclined rearward and downward, and a seat extending upward from a rear portion of the main frame 23. It has a post 24 and a pair of left and right rear frames 25.

A front fork 26 is steerably supported on the head pipe 22, a front wheel WF is pivotally supported at a lower end of the front fork 26, and a bar-shaped steering handle 27 is provided at an upper end of the front fork 26. .

A support pipe 29 having, at its upper end, a saddle-shaped seat 28 for a driver to sit on is inserted into the seat post 24 from above. Fixed to

A rear wheel WR is pivotally supported between the lower portions of a pair of left and right rear frames 25. A rider on a seat 28 is provided with a pair of left and right crank pedals 30 on the rear wheel WR.
Can be transmitted, and the output of the engine 31 mounted on the body frame 21 can be transmitted. A storage box 32 disposed on the rear side of the seat post 24 is supported above the seat post 24. The pair of rear frames 25 are disposed so as to cover the storage box 32 from the rear side. You. Thus, the storage box 32 stores a battery, a control device for controlling the engine 31, and the like.

Referring also to FIGS. 2 to 4, the engine 3
Reference numeral 1 denotes a side-valve type four-cycle engine. The engine body 33 of the engine 31 is connected to a cylinder block 34, an engine case 35 connected to a lower portion of the cylinder block 34, and an upper portion of the cylinder block 34. And a cylinder head 36.

The cylinder block 34 has a cylinder bore 3
7 is provided integrally with the cylinder portion 34a,
The engine body 33 is rigidly attached to the vehicle body frame 21 so that the cylinder portion 34a disposed on the rear side of the seat post 24 is inclined rearwardly upward between the seat post 24 and the rear wheel WR so as to follow the seat post 24. Is fixed.

The engine case 35 includes a first and second case members 38 and 39 which are connected to each other by forming a crank chamber 42 therebetween, and a working chamber 43 disposed outside the crank chamber 42. First and second case members 38, 3
9, a third case member 40 connected to the second case member 39 and a fourth case member 41 connected to the third case member 40.
3 is opened toward the rear wheel WR side.

The dividing surfaces of the first and second case members 38 and 39 are set on a plane including the axis C of the cylinder bore 37, and the first and second case members 38 and 39 form a part of the cylinder portion 34a. It is fastened to the cylinder block 34 so as to be sandwiched between them.

Most of the crankshaft 45 having an axis extending along the width of the motorcycle is housed in the crank chamber 42, and a piston 46 slidably fitted to the cylinder bore 37 via a connecting rod 47. It is connected to the crankshaft 45. This crankshaft 45 is
It has a pair of crank weights 45a, 45a, and is constituted by a pair of holding plates 48, 49 sandwiching the two crank weights 45a, 45a therebetween.
The crankshaft 45 is rotatably supported by a holder 50 housed in the first case member 35 and fastened to the first and second case members 38 and 39 of the engine case 35.

A plurality of cylindrical spacers 51 are interposed between the holding plates 48 and 49, and the spacers 5 are provided.
The two holding plates 48, 49 are provided with rivets 52,
Are connected to form the holder 50. The holder 50 is fastened to the first and second case members 38 and 39 of the engine case 35, respectively, and is fastened to the cylinder portion 34a of the cylinder block 34.

The outer rings of a pair of bearings, ball bearings 53, 53, are coaxially press-fitted into both holding plates 48, 49 of the holder 50, and the crankshaft 45 passes through the ball bearings 53, 53. It is rotatably supported by the holder 50.

A pair of balancers 54, 54 having a rotation axis on one diameter line of the crankshaft 45 and housed in the crank chamber 42 are provided on both sides of the crankshaft 45 as viewed from a direction along the axis C of the cylinder bore 37. The balance weights 54a, 54a of the balancers 54, 54 respectively partially overlap the two crank weights 45a, 45a of the crankshaft 45 when viewed from a direction parallel to the axis of the crankshaft 45. Thus, it is arranged between both crank weights 45a, 45a.

The two balancers 54, 54 are rotatably supported by a holder 50 via two pairs of ball bearings 55, 55; 55, 55. The outer rings of the ball bearings 55,. Both holding plates 4 of holder 50
8, 49.

A drive gear 56 is fixed to the crankshaft 45 between the holding plate 48 of the holder 50 and one of the crank weights 45a of the crankshaft 45.
Driven gears 57, 57 meshing with a drive gear 56 are fixed to the balancers 54, 54, respectively. Accordingly, both balancers 54,
54 rotate in opposite directions about an axis parallel to the crankshaft 45.

Along the front side of the crankshaft 45 along the front-rear direction of the body frame 21,
A pedal shaft 58 having an axis on an extension line to the lower side of the seat post 24 provided in the engine case 35 is arranged so that its axis is parallel to the crankshaft 45. 4th
The case members 38 and 41 are rotatably supported via ball bearings 59 and 60 as bearings. Moreover, the crank pedals 30 are provided at both ends of the pedal shaft 58 outside the engine case 35, respectively.

In the working chamber 43, a rotor 61 rotatably supported by the pedal shaft 58 so as to be rotatable around the same axis as the pedal shaft 58,
The engine case 35 is covered with the rotor 61.
Stator 6 fixedly supported by the first case member 38 of FIG.
2 is housed.

The second case member 39 of the engine case 35
A drive pulley 64 is mounted on the crankshaft 45 protruding into the working chamber 43 so as to be rotatable relative to the drive pulley 65. The driven pulley 65 fixed to the rotor 61 of the generator 63 and the driven pulley 65 An endless belt 66 is wound around the endless belt 64. Therefore, the crankshaft 4
The rotor 61 of the generator 63 is driven to rotate in accordance with the rotation of the rotor 5.

Referring also to FIG. 5, the rotational power of crankshaft 45 is transmitted to rear wheel WR through power transmission means 69 including a belt type continuously variable transmission 70 and a planetary gear type reduction gear 71. The power transmission means 69 is
When the motorcycle faces the forward direction, the engine 31
Is disposed on the left side with respect to the vertical plane including the axis C of the cylinder bore 37 provided in the cylinder bore 37.

The belt-type continuously variable transmission 70 has a centrifugal weight 72 and a drive pulley 73 provided on the crankshaft 45 in the working chamber 43 so as to change the effective radius by the action of the centrifugal weight 72; A driven pulley 74 that changes the effective radius in accordance with a change in the effective radius of the driving pulley 73; a driven pulley 73 and a driven pulley 74;
And an endless belt 75 wound therearound.

A transmission case 77 containing a driven pulley 74, a starting clutch 76 composed of a centrifugal clutch, and the planetary gear type speed reducer 71 is provided on the left side of the rear wheel WR in the forward direction of the motorcycle. The third case member 40 in the engine case 35 of the engine 31
Is extended rearward from the engine 31 and is connected to the transmission case 77. The transmission case 77 is fixedly supported by one of the pair of left and right rear frames 25.

One end of the axle 78 of the rear wheel WR is rotatably supported by the transmission case 77, and is driven by a driven pulley 74.
Is mounted on the axle 78 so as to be relatively rotatable, and the driven pulley 74
The start clutch 76 and the planetary gear type speed reducer 71 are interposed between the axle 78 and the axle 78.

In such a belt-type continuously variable transmission 70,
The effective radius of the driving pulley 73 increases due to the action of the centrifugal weight 72 accompanying the increase in the rotational speed of the crankshaft 45, and the effective radius of the driven pulley 74 decreases accordingly. As a result, the driving force of the engine 31 shifted by the belt-type continuously variable transmission 70 is further reduced by the planetary gear type reduction gear 71 and transmitted to the axle 78.

A back plate 80 of a drum brake 79 is disposed on the right side of the rear wheel WR in a state where the motorcycle faces the forward direction so as to be fixedly supported by the other of the pair of left and right rear frames 25. The other side of the axle 78 is rotatably supported by the back plate 80.

A driven sprocket 81 is fixed to the axle 78 outside the back plate 80. On the right side of the engine case 35, a driving sprocket 82 corresponding to the driven sprocket 81 is fixed to the pedal shaft 58, and the driving sprocket 82 and the driven sprocket 81
Is wound around the endless chain 83. Therefore, when the pedal shaft 58 is rotationally operated by depressing the crank pedal 30, the rotational power corresponding to the pedaling force is transmitted to the axle 78 of the rear wheel WR.

With particular attention to FIGS. 2 and 3, between the cylinder block 34 and the cylinder head 36 of the engine 31 which is a four-stroke engine of a side valve type, a combustion chamber 85 that exposes a part of the top of the piston 46 is provided. Is formed such that the center is located at a position shifted to the right from the axis C of the cylinder bore 37 in a state where the motorcycle faces the forward direction of the motorcycle. An ignition plug 86 is attached to the cylinder head 36 so that the inner end faces the combustion chamber 85.

The cylinder part 34a of the cylinder block 34
An intake port 87 that can communicate with the combustion chamber 85 is provided facing the main frame 23, and an exhaust port 88 that can communicate with the combustion chamber 85 is provided facing the rear wheel WR. The exhaust port 88
When the motorcycle faces the forward direction, it is arranged on the right side of the vertical plane including the axis of the cylinder bore 37.

An intake valve 89 for switching communication between the intake port 87 and the combustion chamber 85 and an exhaust valve 90 for switching communication between the exhaust port 88 and the combustion chamber 85 are provided.
The cylinder block 34 is openably and closably supported so as to face the combustion chamber 85 on the side of the cylinder bore 37, and is spring-biased in the valve closing direction.

That is, a power transmission means 69 for transmitting the rotational power of the crankshaft 45 to the rear wheel WR, and an intake valve 89
The exhaust valve 90 and the exhaust valve 90 are arranged on the left and right sides of the vertical plane including the axis C of the cylinder bore 37.

The intake valve 89 and the exhaust valve 90 are driven to open and close by a valve operating mechanism 91. The valve operating mechanism 91 includes a timing driving gear 92 fixed to the crankshaft 45 and a holder 50 for holding the holder 50. A timing driven gear 94 rotatably supported by a support shaft 93 fixed to the plate 48 and meshing with the timing drive gear 92, a cam 95 formed integrally with the timing driven gear 94, and driven by the cam 95. So that the cylinder block 3
4, and is supported by the cylinder block 34 in such a manner as to swing in accordance with the cam 95 and is interlocked with the exhaust valve 90, while being interlocked with the exhaust valve 90. And an intake side rocker arm 97 connected thereto.

The timing drive gear 92 reduces the rotational power of the crankshaft 45 to １ ／ and transmits it to the timing driven gear 94 and the cam 95. That is, the cam 95 rotates at a speed reduced to の of the rotation speed of the crankshaft 45.

The downstream end of an intake pipe 98 extending in the front-rear direction of the body frame 21 is connected to the cylinder portion 34a of the cylinder block 34 so as to communicate with an intake port 87. The upstream end of the intake pipe 98 is It is connected to a downstream end of a carburetor 99 housed in a rear portion of the main frame 23 in the body frame 21.

6 to 10, the main frame 23 of the vehicle body frame 21 includes a first cylindrical frame-shaped frame member 101 having a substantially rectangular cross section and a substantially U-shaped cross section. The first frame member 101 is integrally formed with a second frame member 102 having a rear end fastened to a front end of the first frame member 101 and a head pipe 22 integrally formed at the front end, and a seat post 24. And the third frame member 103 fastened to the rear end, and is formed hollow. That is, the front portion of the main frame 23 is formed to open vertically, the middle portion of the main frame 23 is formed to open front and rear, and the rear portion of the main frame 23 is formed to open rearward and downward.

The front portion of the main frame 23, that is, the second frame member 102 having the head pipe 22 integrally, is a cover 1 formed by connecting a pair of cover halves.
The outer surface of the cover 104 is flush with the outer surface of the first frame member 101.

A plurality of, for example, four protruding portions 105,
105 are provided integrally, and their projections 10 are provided.
The rear end of the second frame member 102 is fastened to the front end of each of the projections 1, 105 via bolts 106, 106.
The front end of the third frame member 103 is fastened to the rear end of the third frame member 105 via bolts 107, 107.

A fuel tank 108 is accommodated in a front portion of the main frame 23. A fuel injection pipe 108 a provided in the fuel tank 108 passes through an opening 109 provided at an upper portion of the cover 104 and rises upward. Protruding,
A cap 110 is detachably attached to the upper end of the fuel injection pipe 108a.

The fuel tank 1 in the main frame 23
An air cleaner 111 having a cleaner case 113 housed in a cleaner case 112 is housed between 08 and the carburetor 99.

At the rear of the fuel tank 108, the vibration isolating rubber 11
4 is provided, and a cylindrical boss 116 for fitting the anti-vibration rubber 114 is provided at the front of the cleaner case 112. A plurality of, for example, two flange portions 112 are provided at the rear portion of the cleaner case 112.
a, 112a are provided so as to protrude outward, and their flanges 112a, 112a
It is fastened to the front of the third frame member 113 at 7,117.

A fuel conduit 118 is connected to the middle part in the vertical direction at the rear of the fuel tank 108, and a fuel conduit 119 is connected to the lowermost part.
18 and 119 extend toward the carburetor 99 through a gap formed between the air cleaner 111 and the main frame 23, and the other ends of the fuel conduits 118 and 119 are connected to cocks of the carburetor 98. Is done. Thus, the cock guides fuel from the fuel conduit 118 to the carburetor 99, guides fuel from the fuel conduit 119 to the carburetor 99, and vaporizes fuel from both the fuel outlet pipes 118 and 119. It is possible to switch between a state in which it is not guided to the container 99.

The cleaner element 113 is mounted on an opening 120 provided in the cleaner case 112 so as to face the fuel tank 108 side.
A perforated plate 121 that supports 13 from inside the cleaner case 112 is fixed to the cleaner case 112.

Air introduced into the main frame 23 from a gap or the like formed between the opening 109 of the cover 104 and the fuel injection pipe 108a of the fuel tank 108 passes through the cleaner element 113 and the cleaner case 112.
It is purified by being sucked inside. The upstream end of the connection pipe 122 is connected to the rear of the cleaner case 112,
The downstream end of the connection pipe 122 is connected to the upstream end of the vaporizer 99. Therefore, the air purified by the air cleaner 111 is introduced into the vaporizer 99.

Referring again to FIGS. 2, 3 and 5, the cylinder block 3 is arranged such that the upstream end of an exhaust pipe 125 for guiding exhaust gas from the engine 31 communicates with the exhaust port 88.
4 is connected. The exhaust pipe 125 extends downward along the rear wheel WR between the engine 31 and the rear wheel WR.
Muffler 12 supported on the rear and arranged on the right side of the rear wheel WR
6 is connected to the downstream end of the exhaust pipe 125.

Further, a chain 83 for transmitting the rotational power of the pedal shaft 58 to the axle 78 of the rear wheel WR and a belt 75 for transmitting the rotational power of the crankshaft 45 to the axle 78 of the rear wheel WR are exhausted. It will be arranged on the left and right of the tube 125.

Next, the operation of the first embodiment will be described. The cylinder portion 34a of the engine 31 supported by the body frame 21 so that the crankshaft 45 is disposed on the rear side of the pedal shaft 58, An exhaust pipe 125, which is disposed between the seat post 24 and the rear wheel WR and inclines rearward and guides exhaust gas from the engine 31, extends downward along the rear wheel WR between the engine 31 and the rear wheel WR. Since the exhaust pipe 125 is arranged to extend and is connected to the muffler 126, the exhaust pipe 125 is separated from the vehicle body frame 21 and is arranged at a position distant from the pedal shaft 58, and the length of the exhaust pipe is easily secured so that the performance of the engine 31 is improved. Can be increased.

Further, the belt 75 for transmitting the rotational power of the crankshaft 45 to the axle 78 of the rear wheel WR and the chain 83 for transmitting the rotational power of the pedal shaft 58 to the axle 78 of the rear wheel WR are exhausted. The exhaust pipe 125 is disposed on the left and right of the pipe 125,
1. The front wheel, the rear wheel, the belt 75, and the chain 83 surround the front, rear, left, and right sides, so that a dedicated protector or the like for covering the exhaust pipe 125 is unnecessary, and the number of parts can be reduced.

An engine case 35 provided in the engine 31 supports a crankshaft 45 having a pair of crank weights 45a, 45a and a pedal shaft 58 rotatably supported. The engine body 33 is rigidly fixed to the vehicle body frame 21 and includes a pair of balancers 5.
4 and 54 are accommodated in the engine case 35 so as to be able to rotate around an axis parallel to the crankshaft 45 in conjunction with the rotation of the crankshaft 45.

Therefore, the vibration of the engine 31 is suppressed by the balancers 54, 54, and the vibration of the body frame 21 due to the engine vibration is reduced even if the engine body 33 is rigidly fixed to the body frame 21. And the body frame 2 of the engine body 33
1 can secure a rigid feeling when depressing the crank pedals 30 at both ends of the pedal shaft 58 supported by the engine case 35 provided in the engine body 33, and does not require an anti-vibration structure. Accordingly, the structure for supporting the engine body 33 on the vehicle body frame 21 can be made compact.

Further, the balance weights 54, 54 are arranged between the two crank weights 45a, 45a so as to partially overlap the two crank weights 45a, 45a when viewed from a direction parallel to the axis of the crank shaft 45. Since each of these has the balancer 54a, the width of the engine case 35 in the direction along the axis of the crankshaft 45 can be set to be small in spite of having the balancers 54, 54, thereby preventing the engine 31 from being enlarged. can do.

The two balancers 54, 54 have rotation axes on both sides of the crankshaft 45 as viewed from the direction along the axis C of the cylinder bore 37 provided in the engine main body 33 and extend on one diameter line extension of the crankshaft 45. And a pair of balancers 5 that can suppress the rotational moment around the crankshaft 45.
4, 54 can be compactly arranged between the pair of crank weights 45a, 45a.

While the pedal shaft 58 is supported by the engine case 35 via ball bearings 59 and 60, the crankshaft 45 and the balancers 54 and
54 is a holder 50 attached to the engine case 35.
Are supported via ball bearings 53, 53; 55, 55, respectively. That is, by supporting the crankshaft 45 and the balancers 54, 54 with the holder 50 that is separate from the engine case 35, the balancer mass can be concentrated and the rigidity of the holder 50 can be easily increased, so that the balancers 54, 54 prevent the balancer mass. By increasing the vibration effect, the transmission of vibration to the engine case 35 can be further suppressed, and as a result, the transmission of vibration to the body frame 21 and the pedal shaft 58 can be further reduced,
Also, by securing rigidity with the holder 50, the weight of the engine case 35 can be reduced.

Further, the axis of the pedal shaft 58 is arranged on an imaginary extension line below the seat post 24 which is a part of the body frame 21, and the crankshaft 45 is arranged behind the pedal shaft 58. The cylinder portion 34a of the engine 31 supported by the vehicle body frame 21 is arranged along the seat post 24 behind the seat post 24, and the carburetor 99 housed in the main frame 23 The frame 21 is connected to an upper portion of the engine 31 via an intake pipe 98 extending in the front-rear direction.

Therefore, it is possible to arrange the intake system and the exhaust system of the engine 31 so as to avoid the space necessary for the rotation of the crank pedals 30 at both ends of the pedal shaft 58. The engine 31 can be compactly configured so as to form a part, and the entire motorcycle can be reduced in size.

Further, since the engine 31 is a side valve type four-cycle engine, the intake port 87 and the exhaust port 8
8, the intake pipe 98 and the exhaust pipe 125 can be connected to the cylinder portion 34a. Therefore, the overall height of the engine 31 can be kept low even though the engine is a four-cycle engine capable of purifying exhaust gas. The space above the engine 31 and the space above the engine 31 can be gained.

The engine 31 further includes an intake valve 89 and an exhaust valve 90, and a power transmission means 69 for transmitting power from the crankshaft 45 to the rear wheel WR.
The left and right sides of the vertical plane including the axis are supported by the body frame 21 so that the cooling and heat insulating space of the cylinder portion 34a is secured between the two crank pedals 30 and the engine 31 is downsized. This can further contribute to the downsizing of the entire motorcycle.

By the way, the main frame 23 of the body frame 21 is formed in a hollow shape and is inclined backward and downward.
A fuel tank 108 is accommodated in the main frame 23 and a carburetor 99 located on the rear side of the fuel tank 108 is accommodated in the engine 31 disposed behind the main frame 23. A carburetor 99 is connected via an intake pipe 98 extending in the direction.

Therefore, it is not necessary to provide a space for securing the heat insulating space for the engine 31 around the main frame 23, and the main frame 23 can be downsized, that is, the vehicle body can be downsized, so that getting on and off the seat 28 is easy. The fuel tank 108 and the carburetor 99 can be effectively stored in the main frame 23. In addition, since the main frame 23 is inclined backward and downward, the fuel conduits 118 and 119 for supplying fuel from the fuel tank 108 to the carburetor 99 can naturally be inclined backward and downward. Fuel supply can be facilitated.

The carburetor 9 is provided in the main frame 23.
The air cleaner 111 disposed in front of the engine 9 is accommodated, and the intake system of the engine 31 can be compactly accommodated in the main frame 23.

Further, below the rear end of the main frame 23, a pedal shaft 5 capable of transmitting the pedaling force input from the crank pedals 30 provided at both ends to the rear wheels WR.
8, the intake system of the engine 31 can be compactly arranged around the crank pedals 30, which require a relatively large rotating space.

11 to 15 show a second embodiment of the present invention. FIG. 11 is a side view of a motorcycle with a pedal, FIG. 12 is an enlarged longitudinal sectional side view of a main part of FIG. 11, and FIG. 12 is a sectional view taken along line 13-13, FIG. 14 is an enlarged view of a main part of FIG. 13, and FIG. 15 is a sectional view taken along line 15-15 of FIG.

A second embodiment of the present invention will be described with reference to FIGS. 11 to 15. However, parts corresponding to the first embodiment are given the same reference numerals and are only illustrated. Detailed description is omitted.

First, referring to FIG. 11, a motorcycle body 141 of a motorcycle with a pedal has a main frame 143 having a front end provided with a top pipe 142 and having a rearward slope.
And a seat post 144 extending upward from a rear portion of the main frame 143.

A front fork 145 is supported on the head pipe 142 so as to be steerable.
A front wheel WF is pivotally supported at the lower end of the front fork 1.
A bar-shaped steering handle 146 is provided at the upper end of the 45.

A support pipe 148 having an upper end with a saddle-shaped seat 147 for a driver to sit on is inserted into the seat post 144 from above.
Is fixed to the seat post 144 so that the vertical position can be adjusted.

To the rear wheel WR, it is possible to transmit the pedaling force generated by the rider on the seat 147 depressing the pair of left and right crank pedals 30..., And the output of the engine 151 mounted on the body frame 141. Can also be transmitted.

Referring to FIGS. 12 to 15 together, engine 151 is a four-stroke engine of a side valve type. Engine body 153 of engine 151 is connected to a cylinder block 154 and a lower portion of cylinder block 154. And a cylinder head 156 coupled to an upper portion of the cylinder block 154.

The cylinder block 154 integrally has a cylinder portion 154a in which the cylinder bore 37 is provided. The engine body 153 includes the cylinder portion 154a arranged on the rear side of the seat post 144 and the seat post 144 and the rear portion. The body frame 141 is tilted rearward and upward along the seat post 144 between the wheels WR.
Rigidly attached to the

The engine case 155 supports the crankshaft 45 and the pedal shaft 58 having an axis disposed forwardly of the crankshaft 45 and on the lower extension of the seat post 144 in common. It is formed long in the front-back direction of the frame 121. Moreover, the front end of the engine case 155 is
Linked to

Most of the crankshaft 45 is accommodated in a crank chamber 152 formed in the engine case 155, and a piston 149 slidably fitted to the cylinder bore 37 is connected to the crankshaft via a connecting rod 150. 45. This crankshaft 45
Has a pair of crank weights 45a, 45a, and a holder 5 fastened to the engine case 155.
0, the crankshaft 45 has the ball bearing 53,
It is rotatably supported via 53.

As viewed from the direction along the axis C of the cylinder bore 37, on both sides of the crankshaft 45, a pair of balancers 54, 54 having a rotation axis on one diameter line of the crankshaft 45 and housed in the crank chamber 152. Are arranged, and both balancers 54 and 54 are provided with ball bearings 5.
5, 55; are rotatably supported by the holder 50 via 55, 55.

The balance weights 54 a, 54 a of the balancers 54, 54 are respectively partially overlapped with the crank weights 45 a, 45 a of the crankshaft 45 when viewed from a direction parallel to the axis of the crankshaft 45. , Between the two crank weights 45a, 45a.

The pedal shaft 58 is connected to the seat post 14
By placing the axis on the extension line to the lower side of 4,
Engine case 1 via ball bearings 59 and 60
55 is rotatably supported by the crank pedal 30 at both ends of the pedal shaft 58 outside the engine case 155.
... are provided respectively.

Further, the crankshaft 45 and the pedal shaft 58 are arranged in parallel at a position where the axis C of the cylinder bore 37 obliquely intersects a straight line L connecting the axes of the shafts 45, 58.

A drive gear 56 is fixed to the crankshaft 45, and driven gears 57, 57 meshing with the drive gear 56 are fixed to both balancers 54, 54, respectively. Accordingly, both balancers 54, 54 rotate in opposite directions about an axis parallel to the crankshaft 45 in conjunction with the rotation of the crankshaft 45.

A rotor 61 'of a generator 63' is coaxially connected to the crankshaft 45 outside the crank chamber 152. On the other hand, the cooling fan 15
7 are supported so as to be able to rotate relative to each other.
A driven gear 158 fixed to 57 is engaged with a driving gear 159 provided on the outer periphery of the rotor 61 '. That is, the cooling fan 1 is linked to the rotation of the crankshaft 45.
57 rotates.

The cooling fan 157 is
The fan case 160 is formed in a spiral shape whose upper end is opened so that cooling air is sucked from above the engine case 155 in accordance with the rotation of the cooling fan 157. You.

The rotational power of the crankshaft 45 is
The power is transmitted to the rear wheel WR via a power transmission means 69 'including a belt-type continuously variable transmission 70 and a reduction gear train 175, and the power transmission means 69' faces the forward direction of the motorcycle. , The engine 151 is disposed on the left side with respect to the vertical plane including the axis C of the cylinder bore 37 provided in the engine 151.

Drive pulley 73 of belt type continuously variable transmission 70
Is the driven gear 1 linked to the rotation of the crankshaft 45
An endless belt 75 is wound around the driven pulley 74 and the driven pulley 73, which is connected to the driving pulley 73 so as to be relatively rotatable relative to the pedal shaft 58 and changes the effective radius in accordance with the change in the effective radius of the driving pulley 73. Can be

On the left side of the rear wheel WR, a transmission case 77 'containing the driven pulley 74, the starting clutch 76 and the reduction gear train 175 is arranged.
The rear end of the support member 161 having a front end rigidly connected to the engine case 155 and extending to the side of the rear wheel WR, and a left outer wall of the engine case 155 are formed. And a rear portion of a case member 162 extending to the side of the rear wheel WR so as to cover the rear wheel WR.
61 is rotatably supported at the rear.

A rear plate 80 'of a drum brake 79 is disposed on the right side of the rear wheel WR in a state where the motorcycle faces the forward direction. The back plate 80 'is formed integrally with a rear portion of a support member 163 having a front end rigidly connected to the engine case 155 and extending to the side of the rear wheel WR. The right end of 78 is rotatably supported by a back plate 80 'at the rear of the support member 163.

A driven sprocket 81 is fixed to the axle 78 outside the back plate 80 '.
An endless chain 83 is wound around the driving sprocket 82 fixed to the driven sprocket 81 and the driven sprocket 81.
A case member 164 that forms the right outer wall of the engine case 155 extends to the side of the rear wheel WR so as to cover the drive sprocket 82, the chain 83, and the driven sprocket 81. Are connected to the back plate 80 '.

Between the cylinder block 154 and the cylinder head 156 of the engine 151, which is a side-valve four-cycle engine, a combustion chamber 165 facing a part of the top of the piston 149 is displaced forward from the axis C of the cylinder bore 37. It is formed so that the center is arranged at the position where it is located. A spark plug 86 is attached to the cylinder head 156 so that the inner end faces the combustion chamber 165.

The cylinder block 154 is provided with an intake port (not shown) that can communicate with the combustion chamber 165 facing forward, and an exhaust port that can communicate with the combustion chamber 165 faces the forward direction of the motorcycle. It is provided so as to be located on the left side when it is in the position. An intake valve for switching between communication and shutoff between the intake port and the combustion chamber 165 and an exhaust valve 167 for switching between communication and shutoff between the exhaust port and the combustion chamber 165 can be opened and closed by the cylinder block 1.
It is supported by 54 and is spring-biased in the valve closing direction.

The intake valve and the exhaust valve 167 are driven to open and close by a valve mechanism 168. The valve mechanism 168 includes a timing drive gear 169 fixed to one of the balancers 54, 54; Timing drive gear 1
A timing driven gear 171 meshed with the motor 69 and rotatably supported by the holder 50; and intake and exhaust cams 172, 17 formed integrally with the timing driven gear 171.
3 and an intake-side rocker arm (not shown) which is supported by the holder 50 so as to swing in accordance with the intake-side cam 172 and is linked to and linked to the intake valve, and is driven by the exhaust-side cam 173. The holder 50
And an exhaust-side rocker arm 174 that is supported by the exhaust valve 167 and is operatively connected to the exhaust valve 167.

The downstream end of an intake pipe 178 is connected to the front of the cylinder portion 154a of the cylinder block 154 so as to communicate with the intake port. The upstream end of the intake pipe 178 is located above the engine 151. Connected to the downstream end of the vaporizer 99.

A storage case 179 supported by a seat post 144 of the vehicle body frame 141 is disposed behind the carburetor 99, and a fuel tank 180 is stored in the storage case 179. In addition, a lid 182 that can be opened and closed is provided above the storage case 179 at a portion corresponding to the fuel injection cap 181 that is detachably mounted on the fuel tank 180.

The storage case 179 is provided with the air cleaner 18.
The air cleaner 183 is housed in a storage case 179 below the fuel tank 180 and has one end closed and the other end connected to the upstream end of the carburetor 99. 184,
A cleaner element 185 wound around the outer periphery of the pipe 184 in the storage case 179, and a flow hole 186 is formed in the pipe 184 where the cleaner element 185 is wound. That is, an unpurified chamber 187 is formed inside the storage case 179 except for the fuel tank 180 and the pipe 184, and air flowing into the unpurified chamber 187 from outside the storage case 179 is removed by the cleaner element 18.
The air that has been purified by flowing through the pipe 184 through the pipe 5 and the flow hole 186 is purified, and the purified air is guided from the pipe 184 to the vaporizer 99.

[0097] The upstream end of an exhaust pipe 188 for guiding exhaust gas from the engine 151 is connected to the cylinder portion 154a of the cylinder block 154 so as to communicate with the exhaust port. The exhaust pipe 188 is connected to the engine 151 and the rear wheel W
The muffler 189 extends downward between the rear wheels WR along the rear wheel WR, and is supported by a support member 163 connected to the engine case 155 and disposed on the right side of the rear wheel WR.
Is connected to the downstream end of the exhaust pipe 188.

As described above, the exhaust pipe 188 is connected to the engine 151.
And a pair of support members 161, 1 connected to the engine case 155 and rotatably supporting the axle 78 of the rear wheel WR by arranging the rear wheel WR along the rear wheel WR.
63 are arranged on the left and right of the exhaust pipe 188.

According to the second embodiment, the engine 151 is supported by the body frame 141 such that the crankshaft 45 is disposed behind the pedal shaft 58.
Is disposed between the seat post 144 of the body frame 141 and the rear wheel WR so as to incline rearward and upward, and the exhaust pipe 1 that guides exhaust gas from the engine 151 is provided.
88 is provided between the engine 151 and the rear wheel WR.
The muffler 179 is arranged to extend downward along the
, The exhaust pipe 188 is connected to the body frame 141.
And the engine 151 can be easily secured and the performance of the engine 151 can be enhanced while being arranged at a position distant from the pedal shaft 58.

Further, a pair of support members 161 and 163 connected to the engine case 155 and rotatably supporting the axle 78 of the rear wheel WR are disposed on the left and right sides of the exhaust pipe 188. Front, rear and left with the rear wheel WR and the pair of support members 161, 163,
Since the right side is enclosed, the number of parts can be reduced by eliminating the need for a dedicated protector or the like.

The front end of the engine case 155, which supports the crankshaft 45 and the pedal shaft 58 in common and is elongated in the front-rear direction of the body frame 141, is connected to the body frame 141.
Since the front portion of the engine case 155 is connected to the rear portion of the engine case 155, the pedal case 58 is rotatably supported by the engine case 155 supporting the crankshaft 45, and the engine case 155 supports the rear wheel WR. Since it also functions as a part of the member, the number of parts can be further reduced.

Further, an engine body 153 including an engine case 155 is rigidly fixed to the body frame 141, and the pair of balancers 54, 54 are parallel to the crankshaft 45 in conjunction with the rotation of the crankshaft 45. Since it is rotatable around the axis and housed in the engine case 155, the balancers 54, 54
As a result, the vibration of the engine 151 is suppressed,
Even if the engine body 153 is rigidly fixed to the body frame 141, vibrations caused by engine vibration of the body frame 141 can be reduced.
The crank pedals 30 at both ends of the pedal shaft 58 supported on the engine case 155 of the engine body 153 by rigidly fixing the 53 to the body frame 141.
Can be secured when stepping on..., And the support structure of the engine body 153 to the vehicle body frame 141 can be made compact by eliminating the need for a vibration-proof structure.

The balance weights 54a, 54a of the balancers 54, 54 are
Both crank weights 45 as viewed from a direction parallel to the axis of
a, 45a, and are arranged between the two crank weights 45a, 45a so as to partially overlap with each other.
Despite having 54, the width of the engine case 155 in the direction along the axis of the crankshaft 45 can be set small, thereby preventing the engine 151 from being enlarged.

The two balancers 54, 54 have rotation axes on both sides of the crankshaft 45 as viewed from the direction along the axis C of the cylinder bore 37 provided in the engine body 153, and extend on one diameter line extension of the crankshaft 45. And a pair of balancers 54,
54 can be compactly arranged between the pair of crank weights 45a, 45a.

Further, since the crankshaft 45 and the pedal shaft 58 are arranged in parallel at a position where the axis C of the cylinder bore 37 obliquely intersects a straight line L connecting the axes of the shafts 45 and 58, the cylinder bore 37
Although the pair of balancers 54 and 54 are disposed on both sides of the crankshaft 45 when viewed from the axial direction of the crankshaft 45, the crankshaft 45 and the pedal shaft 58 can be brought as close as possible, and the size of the engine case 155 can be reduced. Can be planned.

Further, the crankshaft 45 and the balancer 54 are mounted on the holder 50 which is separate from the engine case 155.
Since the bearings 54 are supported, the balancer mass can be concentrated, the rigidity of the holder 50 can be easily increased, and the vibration damping effect of the balancers 54, 54 can be enhanced to further suppress the transmission of vibration to the engine case 155. As a result, transmission of vibration to the body frame 141 and the pedal shaft 58 can be further reduced, and the holder 5
By ensuring rigidity at zero, the weight of the engine case 155 can be reduced.

The axis of the pedal shaft 58 is arranged on an imaginary extension line below the seat post 144,
The crankshaft 4 is located behind the pedal shaft 58.
The cylinder portion 154 a of the engine 151 supported by the vehicle body frame 141 with the 5 is disposed is arranged along the seat post 144 on the rear side of the seat post 144. Therefore, it is possible to arrange the intake system and the exhaust system of the engine 151 so as to avoid the space required for rotation of the crank pedals 30 at both ends of the pedal shaft 58.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible.

[0109]

As described above, according to the first aspect of the present invention, it is possible to reduce the vibration caused by the engine vibration of the vehicle body frame, to secure a rigid feeling when the pedal is depressed, and to realize the vehicle body. The structure for supporting the engine body on the frame can be made compact. In addition, the width of the engine case in the direction along the axis of the crankshaft can be set small, so that the engine can be prevented from being enlarged.

According to the second aspect of the present invention, the pair of balancers capable of suppressing the rotational moment around the crankshaft can be compactly arranged between the pair of crank weights.

According to the third aspect of the invention, the vibration transmission effect of the balancer can be enhanced to further suppress the transmission of vibration to the engine case, and the transmission of vibration to the vehicle body frame and the pedal shaft can be further reduced. The weight of the engine case can be reduced by ensuring the rigidity of the holder.

Further, according to the fourth aspect of the present invention, the crankshaft and the pedal shaft can be brought as close as possible to each other, and the size of the engine case can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a motorcycle with a pedal according to a first embodiment.

FIG. 2 is a cross-sectional view of the engine taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is an enlarged sectional view taken along line 5-5 of FIG. 1;

FIG. 6 is an enlarged longitudinal sectional view showing a part of a vehicle body frame.

FIG. 7 is a sectional view taken along line 7-7 of FIG. 6;

FIG. 8 is a sectional view taken along line 8-8 in FIG. 6;

FIG. 9 is a sectional view taken along line 9-9 of FIG. 6;

FIG. 10 is a sectional view taken along line 10-10 of FIG. 6;

FIG. 11 is a side view of a motorcycle with a pedal according to a second embodiment of the present invention.

12 is an enlarged vertical sectional side view of a main part of FIG. 11;

FIG. 13 is a sectional view taken along line 13-13 of FIG. 12;

FIG. 14 is an enlarged view of a main part of FIG.

FIG. 15 is a sectional view taken along line 15-15 of FIG. 14;

[Explanation of symbols]

21, 141 ... body frame 30 ... pedal 31, 151 ... engine 33, 153 ... engine body 35, 155 ... engine case 37 ... cylinder bore 45 ... crankshaft 45a ...・ Crank weight 50 ・ ・ ・ Holder 54 ・ ・ ・ Balancer 54a ・ ・ ・ Balance weight 53,55,59,60 ・ ・ ・ Ball bearing 58 as a bearing 58 ・ ・ ・ Pedal shaft WR ・ ・ ・ Rear wheel

Claims (4)

[Claims] 1. A pedal shaft (58) capable of transmitting a pedaling force input from pedals (30) provided at both ends to a rear wheel (WR), and rotating about an axis parallel to the pedal shaft (58). An engine (3) having a crankshaft (45) capable of transmitting rotational power to the rear wheel (WR)
, 151), the crankcase (45) having at least a pair of crankweights (45a) is supported on an engine case (35, 155) of the engine (31, 151), and the pedal shaft ( 58) is a motorcycle with a pedal rotatably supported by an engine body (33, 153) including the engine case (35, 155).
141), and is disposed between the two crank weights (45a) so as to partially overlap the two crank weights (45a) when viewed from a direction parallel to the axis of the crank shaft (45). A balancer (54) having a balance weight (54a) that rotates about an axis parallel to the crankshaft (45) in conjunction with the rotation of the crankshaft (45), thereby enabling the engine case (35, 155) to rotate. (2) A motorcycle with a pedal, which is housed in a bracket. 2. A rotation axis extending on one side of the diameter of the crankshaft (45) on both sides of the crankshaft (45) when viewed from the axial direction of a cylinder bore (37) provided in the engine body (33, 153). The motorcycle with a pedal according to claim 1, wherein a pair of the balancers (54) having: 3. The system according to claim 1, wherein the pedal shaft (58) is a bearing (5).
9, 60) through the engine case (35, 15).
5), wherein the crankshaft (45) and the balancer (54) are mounted on the engine case (35, 155).
The motorcycle with a pedal according to claim 1 or 2, wherein the holder (50) is mounted on the holder (50) via bearings (53, 55). 4. The crankshaft (45) and the pedal shaft (58) have their shafts (45,5).
Motorcycle with pedal according to claim 2, characterized in that the cylinder (37) is arranged in parallel at a position where the axis of the cylinder bore (37) obliquely intersects a straight line (L) connecting the axis of (8).