JPS6229355Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of the invention] This invention uses a highly rigid connection frame to connect an engine case with an output shaft and a support case that supports the rear axle in small vehicles such as motorcycles and tricycles. Therefore, it relates to a small vehicle in which the power unit case is integrally connected and a belt or other wrapped transmission member is wound between the output shaft of the engine and the axle drive shaft. The present invention relates to a device that connects a cover of a hanging transmission member with a cover without a gap.

[Prior art]

Conventionally, it is known to provide a cover to a wrap-around transmission member provided on the side of a power unit case.
However, due to manufacturing errors in the engine case, rear axle support case, connection frame, etc., and connection errors between them, the distance between the engine case and the rear axle support case tends to vary, and the distance between the engine case and the rear axle support case tends to vary. The dimensions between the shafts of the two through holes and the power unit case may not match, making assembly difficult. It has been difficult to connect the power unit case and the cover of the wrapped transmission member without any gaps. Therefore, in order to avoid the influence of the above-mentioned error, a gap is provided between the power unit case and the cover of the wrapped transmission member (for example, U.S. Pat. No. 4,169,512).
However, it lacks completeness when it comes to dust-proofing and mud-proofing wrapped transmission members.

[Summary of the idea]

The purpose of this invention is to eliminate the above-mentioned problems and to provide a connection means with a simple structure that can seal between the power unit case and the cover of the wrapped transmission member. The end portion of the transmission member is formed into a cylindrical shape, while the cover of the wrap-around transmission member is composed of an inner member and an outer member that are overlapped and bonded to each other, and the inner member is formed of a relatively soft material, and the Two through holes are provided through which the shaft and the axle drive shaft are inserted, and the through holes are pressed and fixed to the edges of the ends of each of the cylindrical support cases.

〔Example〕

Hereinafter, this invention will be explained with reference to the illustrated embodiment. Reference numeral 1 indicates a motorcycle, in which a front wheel 4 is supported at the front of a body frame 2 via a front fork 3 so as to be able to turn left and right, and at the rear lower part. A power unit 5 is supported by a pivot 6 and a spring 7 so as to be vertically swingable. The power unit 5 is formed by connecting an engine 8 located at the front and an axle support case 11 for a rear wheel 9 located at the rear by a highly rigid connection frame 12.

As shown in FIGS. 2 and 3, the engine 8 includes a cantilevered crank supported between a crank box 15, which is a substantially cylindrical engine case, and a cover 16 that closes one side of the crank box 15. A shaft 17 is provided. A cylinder 18 is provided to protrude upward from the crank box 15.
A piston 19 is slidably fitted therein.
20 is a connecting rod that connects the piston 19 and the crank pin 21. The other side of the crank box 15 is closed by a cover 22 made of synthetic resin (polypropylene), and the cover 22 is provided with a reed valve-type check valve 24 for opening and closing the intake passage 23 and a carburetor 25. Reference numeral 26 denotes a decorative cover attached to the outside of the cover 22. A cover material 27 made of a synthetic resin foam is provided on the inner surface, and the interior of the room on the upstream side thereof communicates with the atmosphere through a hole 28.

The crankshaft 17 is provided with an ignition generator rotor 29 on the inside with the cover 16 in between, and a centrifugal clutch 30 on the outside. A power generating coil 31 is supported. 32 is a gear for starting the engine. The centrifugal clutch 30 is a centrifugal clutch 3
3, and a driven plate 35 that engages with and follows the centrifugal weight 33, and the driven plate 35 is integrally plastic-processed with the pulley 37 of the V-belt 36 using a steel plate. 38 is a fan for blowing engine cooling air; 39 is a cover for guiding cooling air;
It has an air intake port 39a that opens to the side of the vehicle.

The axle support case 11 is formed into a substantially cylindrical container shape by die-casting an aluminum alloy, and is closed by a lid member 40 . A rear axle 13 and an axle drive shaft 41 for driving the rear axle 13 are supported inside. 42 is a driven pulley attached to the axle drive shaft 41, and 43 is a reduction gear train attached to both axles.

The crank box 15 of the engine 8 and the axle support case 11 have steel plate flanges 12 at both ends of the steel pipe.
They are connected to each other by a connecting frame 12 formed by welding parts a and 12b. 44 and 45 are flanges 12
These bolts connect the parts a and 12b to the support case 11 and the crank box 15.

The cover 16 and lid member 40 that cover each end of the crank box 15 and the axle support case 11 each have a cylindrical outer periphery, and a cover 46 of the V-belt 36 is fitted onto the outer periphery of the end. be. cover 46
is composed of an inner member 47 and an outer member 48, which are bonded together. Both members 47 and 48 are each made of synthetic resin (polypropylene),
The tongue piece 46 is engaged with the peripheral wall 47a and the peripheral groove 48a.
a and the stepped portion 46b to prevent mud and water from entering. The inner member 47 is injection molded from a relatively soft material, and has two through holes 49 and 50 in the front and rear parts thereof, through which the crankshaft 17 and the axle drive shaft 41 are inserted. Two through holes 49, 50
Arcuate surfaces 49a and 50a that open toward the outside are formed on the sides. The arcuate surfaces 49a and 50a are pressed against the outer periphery of each end face of the cylindrical crank box 15 and the axle support case 11, and the bolt B
It is fixed by 1 and B2.

51 is an exhaust muffler for the engine, and 52 is a starting motor, which meshes with the starting gear 32 of the engine via a starting clutch (not shown).

The operation of this power unit will now be explained.
When the engine 8 is started and the speed of the crankshaft 17 reaches a predetermined high speed or higher, the centrifugal clutch 30 is engaged and the engine output is taken out to the pulley 37. That is, the rotation of the crankshaft 17 is transmitted via the V-belt 36 to the axle drive shaft 41 that is integrated with the driven pulley 42, and is transmitted to the rear axle 1 via the reduction gear train 43.
3. Rotate the rear wheel 14. In addition, in this embodiment, the axle drive shaft 41 and the rear axle 13 are prepared separately, and a deceleration means is interposed between them.
The present invention is not limited to this, and it is also possible to omit the deceleration means by making both shafts 13 and 14 the same, and this does not change the content of this invention in any way.

Next, the cover 4 of the crank box 15, support case 11, and V belt 36 in this power unit 5 is
The work process for assembling 6 will be explained. First, after connecting the engine case 15 and the support case 11 with the connection frame 12, the two through holes 49, 50 of the inner member 47 are pressed against the sides of both cases 15, 11, and the bolts B1, Tighten with B2. At this time, the distance between the axes of both cases 15 and 11 and the through hole 4
Even if there is some discrepancy between the center distances of 9 and 50,
The through holes 49 and 50 are guided by conical open curved surfaces that open outward, and the sides that strongly contact the cases 15 and 11 are elastically deformed and fit into the outer edges of both cases 15 and 11, so that the cases 15 and 11 It is possible to assemble the outer peripheral edge of the through hole 49, 50 without any gap, and the productivity of the assembly process can be improved.

[Effect of idea]

As mentioned above, in this invention, the outer periphery of each end of the engine case 15 and the support case 11 of the rear axle 13, which are connected by the connecting frame 12, is made into a cylindrical shape,
Two through holes 49 and 50 formed in the cover 46 of the V-belt 36 are pressed firmly against the engine case 15 and the support case in which the through holes 49 and 50 are formed into the cylindrical shape. Since it follows the outer peripheral edge of engine case 1
5 and the support case 11 of the rear axle 13 and the distance between the axes of the through holes 49 and 50 are somewhat eccentric, it is possible to assemble without creating a large gap, and therefore the assembly work is facilitated. can be done. In addition, since there is no large gap between the engine case 15 or the support case 11 and the cover 46, mud and soil are prevented from entering the interior, and the durability of the V-belt 36 can be increased. There is.

As shown in the embodiment, if the inner member 47 is made of synthetic resin, cracks may occur when the through holes 49 and 50 are pressed against the engine case 15 and the support case 11 to deform their peripheries. Because of this, it does not rust. Further, if the two large-diameter through holes 49 and 50 are formed into substantially open curved surfaces that open toward the outside of the cover 46, the engine case 15
The outer peripheral edges of the support case 11 and the support case 11 allow for easier deformation and fitting.

[Brief explanation of the drawing]

The drawing shows one embodiment of this invention.
The figure is a side view of the motorcycle, Figure 2 is an enlarged side view of its main parts, Figure 3 is its cross-sectional view, Figure 4 is its enlarged view, Figure 5 is an enlarged view of the mounting part, and Figure 6 is a partially enlarged view of the inner member. 5...Power unit, 8...Engine, 9...
Rear wheel, 11... Axle support case, 12... Connection frame, 13... Rear axle, 15... Crank box, 30
...Centrifugal clutch, 36...V belt, 41...
Axle drive shaft, 46...Belt cover, 47...Inner member, 48...Outer member, 49, 50...Through hole.

Claims (1)

[Claims for Utility Model Registration] (1) The engine case 15 supported relatively forward of the vehicle body frame 2 and the support case 11 of the rear axle 13 supported at the rear are connected by a highly rigid connection frame 12, Engine output shaft 17 and axle drive shaft 41
A belt or other winding transmission member 36 is attached between the
In a small vehicle in which each end of the engine case 15 and the support case 11 of the rear axle 13 is formed into a cylindrical shape, the cover 46 of the wrapped transmission member 36 is formed into an inner side that is overlapped and bonded to each other. It is composed of a member 47 and an outer member 48, and at least the inner member 47 is made of a relatively soft material, and two large diameter through holes 4 are provided at the front and rear.
9 and 50, and the through holes 49 and 50 are pressed against the outer peripheral edges of the cylindrical engine case 15 and the support case 11 to be fixed. (2) The power unit for a small vehicle according to claim 1, wherein the inner member 47 is made of synthetic resin. (3) The inner member 47 is made of synthetic resin, and the two large-diameter through holes 49 and 50 formed therein form a substantially open curved surface that opens toward the outside of the cover 46.Request for Utility Model Registration A power unit for a small vehicle according to item 1. (4) The power unit for a small vehicle according to claim 1, wherein the vehicle drive shaft and the rear axle are the same shaft.