JP2023050021A - ACG cover for internal combustion engine - Google Patents

Abstract

To provide an ACG cover for an internal combustion engine capable of enhancing rigidity around a crank angle sensor without increasing the size of the ACG cover and of reducing an impact on sensor accuracy due to positional shift of the crank angle sensor.SOLUTION: An ACG cover for an internal combustion engine is used for an internal combustion engine E in which a crank shaft 10 is pivotally supported by a crank case 2 and an AC generator 40 is provided in a shaft end part 10a1 of the crank shaft 10 and that has a crank angle sensor 45, and accommodates the AC generator 40. The ACG cover includes: a side wall 51 opposing to the AC generator 40; and a peripheral wall 52 provided around the side wall 51. The side wall 51 has at least two projections 55, 56. The projections 55, 56 are provided at positions sandwiching the crank angle sensor 45, and thus rigidity around the crank angle sensor is enhanced without increasing the size of the ACG cover to reduce an impact on sensor accuracy due to positional shift of the crank angle sensor.SELECTED DRAWING: Figure 7

Description

The present invention primarily relates to improvements in ACG covers for internal combustion engines.

Conventionally, a crankshaft is rotatably supported by a crankcase, and is used in an internal combustion engine in which an AC generator is provided at one end of the crankshaft projecting through the crankcase. There is an ACG cover attached with a crank angle sensor that measures the rotation angle of the engine (see Patent Document 1).

Japanese Patent No. 6781347

It is desired to increase the rigidity around the crank angle sensor without increasing the size of the ACG cover, and to reduce the influence of the displacement of the crank angle sensor on the accuracy of the sensor.

In order to solve the above-described problems, the present invention provides a crankshaft that is pivotally supported by a crankcase, an AC generator that is provided at one end of the crankshaft that protrudes through the crankcase, and the crankshaft that has an AC generator. Used in an internal combustion engine equipped with a crank angle sensor that measures the rotation angle of
In the ACG cover of the internal combustion engine housing the AC generator,
A side wall facing the AC generator and a peripheral wall provided around the side wall,
the side wall comprises at least two protrusions;
The ACG cover for an internal combustion engine is characterized in that the projections are provided at positions sandwiching the crank angle sensor.

According to the above configuration, by providing the convex portion at the position where the crank angle sensor is sandwiched between the side walls surrounded by the peripheral wall, the rigidity around the crank angle sensor is increased without increasing the size of the ACG cover. positional deviation can be reduced to improve sensor accuracy.

In the above configuration, at least one of the protrusions has a recess on a surface facing the crank angle sensor,
The crank angle sensor may be arranged in the recess.

According to the above configuration, by providing the convex portion with the concave portion on the surface facing the crank angle sensor, the convex portion can be brought closer to the crank angle sensor, and the overall size of the ACG cover can be reduced.

In the above configuration, the convex portion may be provided in the vicinity of the outer periphery of the AC generator.

According to the above configuration, by providing the convex portion near the outer periphery of the AC generator, it is possible to increase the rigidity of the AC cover in the vicinity of the actual detection by the crank angle sensor.

In the above configuration, the side wall has an ACG accommodating portion in which the AC generator is accommodated, an outer edge portion continuous with the peripheral wall, and a stepped portion between the outer edge portion and the ACG accommodating portion,
the ACG housing portion is formed to protrude outward from the outer edge portion so as to house the AC generator;
The convex portion can also be provided continuously with the stepped portion.

According to the above configuration, since the protrusion is arranged in the vicinity of the portion where the AC generator is accommodated, the rigidity of the ACG cover in the vicinity of the actual detection by the crank angle sensor can be increased.

The said structure WHEREIN: You may make it the said convex part have a hole for bolt fastening.

According to the above configuration, since the convex portion can be used as a hole for fastening bolts, the functions of the parts can be integrated, and the rigidity around the crank angle sensor 45 can be increased without increasing the size of the ACG cover 50 .

According to the present invention, there is provided an ACG cover for an internal combustion engine that can increase the rigidity around the crank angle sensor without increasing the size of the ACG cover, and can reduce the influence of the displacement of the crank angle sensor on the accuracy of the sensor. can do.

1 is a left side view of a motorcycle equipped with a power unit using an ACG cover according to an embodiment of the present invention; FIG. It is a left side view of a power unit. FIG. 2 is a cross-sectional view of a main part of the power unit; FIG. 4 is a left side view of the power unit with the side wall of the ACG cover cut away; FIG. 4 is an enlarged left side view of the main parts of the power unit with the ACG cover removed; It is the figure which looked at the ACG cover from the inside. FIG. 4 is an enlarged perspective view of a main part of the ACG cover; FIG. 4 is a cross-sectional view taken along a line connecting the center of the cover mounting boss and the center of the reduction shaft;

A power unit using an ACG cover for an internal combustion engine according to one embodiment of the present invention will be described below with reference to FIGS. 1 to 8. FIG. FIG. 1 is a left side view of a motorcycle 100 as an example of a saddle type vehicle equipped with a power unit 1 using the ACG cover of the present invention. The present invention can also be applied to other straddle-type vehicles. The front and rear in the description of the present invention shall correspond to the front and rear directions of the vehicle in which it is mounted.

As shown in FIG. 1, the power unit 1 includes a SOHC type single-cylinder four-stroke internal combustion engine E and a transmission M integrated together. It is mounted on the motorcycle 100 so that the cylinder axis L is slightly inclined forward. A transmission case 3 is integrally formed behind a crankcase 2 that rotatably supports a crankshaft 10 of the internal combustion engine E to constitute a power unit case.

Referring to FIG. 2, a cylinder block 4 and a cylinder head 5 are sequentially superimposed and fastened together obliquely above the crankcase 2. A cylinder head cover 6 is placed on the cylinder head 5, and the cylinder block 4, A cylinder head 5 and a cylinder head cover 6 protrude from the crankcase 2 .

The rotational driving force of the crankshaft 10 of the internal combustion engine E is transmitted to the main shaft (not shown) via a clutch (not shown) that can be connected and disconnected, and is transmitted to the counter via the transmission M arranged behind the crankshaft 10. It is transmitted to a shaft (not shown) to rotate the rear wheels. The transmission M is equipped with a constant mesh transmission gear mechanism in which multiple drive gears (not shown) provided on the main shaft and multiple driven gears (not shown) provided on the counter shaft are in constant mesh. .

Referring to FIG. 3, the crankcase 2 is split left and right, and is configured by integrating a left crankcase 20 and a right crankcase 30 . The left and right crankcases 20, 30 have a left bearing wall 21 and a right bearing wall 31 that rotatably support the crankshaft 10. The left bearing wall 21 and the right bearing wall 31 form a crank chamber 2S. there is
The crankshaft 10 has crank webs 10w, 10w located in the crank chamber 2S between the left bearing wall 21 and the right bearing wall 31, penetrating the left bearing wall 21 and the right bearing wall 31, extending to the left and right outer sides of the left crankshaft. 10a and the right crankshaft portion 10b protrude. The left outer side of the crankcase 2 is covered with the ACG cover 50, and the right outer side is covered with the right case cover 7. - 特許庁

A driving sprocket 12 of a valve driving system is fitted to the left crankshaft portion 10a near the main bearing 11, and an AC generator 40 is provided at the left end of the left crankshaft portion 10a. A driven gear 14 of the starting mechanism is fitted therebetween.

The AC generator 40 is composed of a bowl-shaped outer rotor 41 having a magnet 41m provided around its inner peripheral surface, and an inner stator 42 having a generating coil 42c provided outside.
The outer rotor 41 is fitted to the shaft end portion 10a1 of the left crankshaft portion 10a of the crankshaft 10 and fixed with a nut ₂₅ to rotate together with the crankshaft 10. As shown in FIG.

The inner stator 42 is fixed to the ACG cover 50 with bolts 26, and when the ACG cover 50 is fixed to the left crankcase 20, the inner stator 42 is arranged inside the outer rotor 41, and the magnet 41m of the outer rotor 41 and the power generation of the inner stator 42 are coupled to each other. The coils 42c face each other. The outer rotor 41 has a large number of detection projections 41t formed on its outer peripheral surface at equal intervals in the circumferential direction.

FIG. 4 shows a state in which the inside of the AC generator can be seen by cutting the left wall of the ACG cover 50, and FIG. 5 is a left side view of the essential parts of the power unit 1 with the ACG cover 50 removed. As shown in FIGS. 4 and 5, the left bearing wall 21 of the left crankcase 20 has a circular wall portion 21a facing the AC generator 40, and an extension wall extending obliquely rearward and upward from the circular wall portion 21a. A portion 21b is provided.

A starter motor 60 is arranged above the crankcase 2 in contact with the right wall surface of the extending wall portion 21b. As shown in FIG. 5, the starter motor 60 has a motor output shaft 61 oriented in the vehicle width direction parallel to the crankshaft 10, and the motor output shaft 61 projecting leftward penetrates the extension wall portion 21b. are doing.

Referring also to FIG. 8, the motor output shaft 61 is formed with a pinion gear 61p. A large-diameter gear 64 and a small-diameter gear 65 are integrally provided on a reduction shaft 63 pivotally supported substantially in the center of the extension wall portion 21b. A pinion gear 61p meshes with the large-diameter gear 64, and a reduction gear mechanism 62 is constructed by meshing a large-diameter driven gear 66 provided on the crankshaft 10 via a one-way clutch with the small-diameter gear 65. ing. The reduction gear mechanism 62 is arranged along the left side surface of the extension wall portion 21b. At startup, the rotation of the motor output shaft of the starter motor 60 forces the crankshaft 10 to rotate via the reduction gear mechanism 62 to start the internal combustion engine E.

Referring to FIG. 5, a left bearing wall 21 of the crankcase 2 is formed with a peripheral wall 22 projecting leftward so as to surround the AC generator 40 and the reduction gear mechanism 62 . The left end face of the peripheral wall 22 is a mating face 22f with the ACG cover 50, and the peripheral wall 22 is formed with a plurality of fastening bosses 22b having bolt holes.

As shown in FIGS. 6 and 7, the ACG cover 50 attached to the left crankcase 20 from the left has a side wall portion 51 covering the left crankcase 20 from the left side and a peripheral wall portion 52 around the side wall portion 51. It is formed to protrude to the right. The left end surface of the peripheral wall portion 52 is a mating surface 52f with the left crankcase 20, and the peripheral wall portion 52 is formed with a plurality of boss portions 52b through which the bolts 70 are inserted. The mating surface 22f of the peripheral wall 22 of the left crankcase 20 and the mating surface 52f of the ACG cover 50 are aligned, and the bolt 70 is inserted through the boss portion 52b and screwed into the fastening boss portion 22b. An ACG cover 50 is attached to the crankcase 20 .

As shown in FIG. 7, the side wall portion 51 of the ACG cover includes a substantially disk-shaped ACG housing portion 51a in which the AC generator 40 is housed, an outer edge portion 51b that continues to the peripheral wall portion 52, and an ACG housing portion 51a and the outer edge. and a stepped portion 51c formed between the portion 51b. A part of the outer edge portion 51b extends obliquely upward and rearward from the ACG accommodating portion 51a to form an extending portion _51b1 that accommodates the crank angle sensor 45 and the reduction gear mechanism 62 therein. The ACG accommodating portion 51a projects outward from the outer edge portion 51b so as to accommodate the AC generator 40, and a stepped portion 51c is formed between the ACG accommodating portion 51a and the outer edge portion 51b.

An inner stator attachment portion 53 to which the inner stator 42 of the AC generator 40 is attached is formed in a cylindrical shape substantially at the center of the ACG accommodation portion 51a. The inner stator attachment portion 53 is provided with a plurality of bolt boss portions 53b, and as shown in FIG. Thus, the inner stator 42 is fixed to the ACG cover 50. As shown in FIG.

A peripheral wall portion 52 erected around the extending portion _51b1 of the ACG cover 50 has a crank angle sensor insertion tube 57 provided with a substantially circular crank angle sensor insertion hole 57a through which the crank angle sensor 45 is inserted. It is formed toward the crankshaft 10 direction. With the ACG cover 50 attached to the left crankcase 20, the crank angle sensor 45 is inserted into the crank angle sensor insertion tube 57, and then, as shown in FIG. It is fixed to the part 52 and is covered with the connection cap 46 .

As shown in FIG. 4, the crank angle sensor inserting tube 57 is formed so that the detecting portion 45s at the tip of the mounted crank angle sensor 45 is positioned close to the outer peripheral surface of the outer rotor 41. As shown in FIG. A detecting portion 45s of the mounted crank angle sensor 45 faces the outer peripheral surface of a large number of detection target projections 41t (see FIG. 3) formed on the outer peripheral surface of the outer rotor 41 of the AC generator 40. FIG. The crank angle sensor 45 detects the rotation angle of the crankshaft 10 by detecting a change in magnetic flux caused by the proximity of the detection target projection 41t of the rotating outer rotor 41 by means of the detection section 45s.

As shown in FIGS. 7 and 8, the extension _51b1 of the ACG cover 50 has a reduction shaft boss 54 into which the reduction shaft 63 of the reduction gear mechanism 62 is inserted. is set. The extension wall portion 21b of the left crankcase 20 also has a reduction shaft boss portion 24 erected in the direction of the ACG cover 50. As shown in FIG. When the ACG cover 50 is attached to the left crankcase 20 , the reduction shaft 63 is rotatably supported by the reduction shaft boss portion 24 of the left crankcase 20 and the reduction shaft boss portion 54 of the ACG cover 50 .

As shown in FIG. 6, the three-phase transmission line 43 extends upward from the power generation coil 42c of the inner stator 42 of the AC generator 40, passes through the extending portion 51b1 of the ACG cover 50, and is fitted to the peripheral wall portion 52. It penetrates the grommet 44 and extends to the outside. The three-phase power transmission line 43 is covered with a cover 71 , and the cover 71 is fitted into a fitting protrusion 59 formed by protruding from the side wall 51 , and then the bolt 72 inserted through the cover protrudes from the side wall 51 . It is screwed into the provided cover mounting boss portion 58 and fixed to the ACG cover 50 (see FIG. 8).

As shown in FIGS. 6 and 7, a pair of protrusions 55 and 56 are provided at positions sandwiching the crank angle sensor 45 supported by the crank angle sensor insertion tube 57. As shown in FIGS. The pair of protrusions 55 and 56 are substantially columnar in shape and extend from the extending portion _51b1 of the side wall portion 51 toward the left crankcase 20 side. The pair of protrusions 55 and 56 are formed so as to continue from the stepped portion 51c of the side wall portion 51 to improve the strength of the ACG cover 50. As shown in FIG. Also, the pair of protrusions 55 and 56 are formed farther from the crankshaft center C1 than the outer circumference of the outer rotor 41 of the AC generator 40, so that the rotation of the outer rotor 41 is not hindered.

As shown in FIGS. 6 and 7, one convex portion 56 of the pair of convex portions 55 and 56 is erected from the extending portion _51b1 of the side wall portion 51 and is located on the peripheral wall below the crank angle sensor 45. It is positioned inside the side wall portion 51 so as to be continuous with the portion 52 . Since it is provided continuously inside the side wall portion 51, the strength of both the side wall portion 51 and the extending portion _51b1 is increased.

The other convex portion 55 is erected from the side wall portion 51 toward the crankcase 20 at a position adjacent to the reduction shaft boss portion 54 and is formed in a shape continuous with the reduction shaft boss portion 54 . The height of the convex portion 55 from the side wall portion 51 is formed lower than the height of the reduction shaft boss portion 54 . A concave portion 55c is formed on the surface of the convex portion 55 facing the crank angle sensor 45 so as to fit the shape of the crank angle sensor 45 so as to avoid the crank angle sensor 45. As shown in FIG.

The convex portions 55 and 56 are bolt boss portions 55a and 56a, and bolt holes 55b and 56b through which bolts can be inserted are formed at the centers of the convex portions 55 and 56, and are used as members for fixing the crank angle sensor 45, for example. etc. can be attached.

Since the ACG cover 50 of the internal combustion engine according to the embodiment of the present invention is constructed as described above, it has the following effects.

The ACG cover 50 of the present embodiment has the crankshaft 10 pivotally supported by the crankcase 2, and the left crankshaft portion 10a of the crankshaft 10 protruding through the left crankcase 20 is attached to the shaft end portion _10a1. Used in an internal combustion engine E provided with an AC generator 40 and equipped with a crank angle sensor 45 for measuring the rotation angle of the crankshaft 10, a side wall 51 facing the AC generator 40 and a peripheral wall 52 provided around the side wall 51 The side wall 51 is provided with two protrusions 55 and 56, and the two protrusions 55 and 56 are provided at positions sandwiching the crank angle sensor 45. By providing the protrusions 55 and 56 at positions sandwiching the crank angle sensor 45, the rigidity around the crank angle sensor 45 is increased without increasing the size of the ACG cover 50, and the positional deviation of the crank angle sensor 45 is reduced. Accuracy can be improved.

Further, the convex portion 55, which is one of the convex portions 55 and 56, has a concave portion 55c formed on the surface facing the crank angle sensor 45, and the crank angle sensor 45 is arranged so as to be close to the concave portion 55c. The portion 55 can be arranged close to the crank angle sensor 45, and the overall size of the ACG cover 50 can be reduced.

Further, by providing the convex portions 55 and 56 near the outer circumference of the AC generator 40, the rigidity of the ACG cover in the vicinity of the actual detection by the crank angle sensor 45 can be increased.

Further, the side wall portion 51 has an ACG accommodating portion 51a in which the AC generator 40 is accommodated, an outer edge portion 51b continuous with the peripheral wall portion 52, and a stepped portion 51c between the outer edge portion 51b and the ACG accommodating portion 51a. , the ACG accommodating portion 51a is formed to protrude outward from the outer edge portion 51b so as to accommodate the AC generator 40, and the convex portions 55 and 56 are provided continuously with the stepped portion 51c, so that the AC generator 40 can be accommodated. Since the convex portion is formed in the vicinity of the portion where the crank angle sensor 45 is actually detected, the rigidity of the ACG cover 50 in the vicinity can be increased.

In addition, since the projections 55 and 56 have holes 55b and 56b for fastening bolts, the projections 56 and 56 can also be used as bolt bosses 55a and 56a, so that the functions of the parts can be integrated. Rigidity around the crank angle sensor 45 can be increased without enlarging the cover 50 .

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes are possible without departing from the gist of the present invention. , vehicles, internal combustion engines, etc., of course, include those implemented in various modes.
For convenience of explanation, the left-right arrangement of the illustrated embodiment has been described, but the present invention includes a different left-right arrangement as long as it is within the scope of the invention.

1... Power unit, 2... Crankcase,
10... crankshaft, _10a1 ... shaft end,
40 ... AC generator, 45 ... crank angle sensor,
50...ACG cover, 51...Side wall part, 51a...ACG accommodating part, 51b...Outer edge part, 51c...Stepped part, 52...Surrounding wall part, 55...Convex part, 55b...Bolt hole, 55c...Recessed part, 56...Convex part, 56b...Bolt hole E...Internal combustion engine, C1...Crankshaft center.

Claims (5)

A crankshaft (10) is pivotally supported by crankcases (2, 20, 30), and one shaft end (10a1) of _the crankshaft (10) protrudes through the crankcases (2, 20, 30). ) is provided with an AC generator (40), and is used in an internal combustion engine (E) equipped with a crank angle sensor (45) for detecting the rotation angle of the crankshaft (10),
In the ACG cover of the internal combustion engine housing the AC generator (40),
A side wall (51) facing the AC generator (40) and a peripheral wall (52) provided around the side wall (51),
the side wall (51) has at least two projections (55, 56);
An ACG cover for an internal combustion engine, wherein the projections (55, 56) are provided at positions sandwiching the crank angle sensor (45). at least one of the protrusions (55, 56) has a recess (55c) on a surface facing the crank angle sensor (45);
2. An ACG cover for an internal combustion engine according to claim 1, wherein said crank angle sensor (45) is arranged in said recess (55c). 3. The ACG cover for an internal combustion engine according to claim 1, wherein said projections (55, 56) are provided in the vicinity of an outer circumference of said AC generator (40). The side wall (51) includes an ACG accommodation portion (51a) in which the AC generator (40) is accommodated, an outer edge portion (51b) continuous with the peripheral wall (52), the outer edge portion (51b) and the ACG accommodation portion (51b). has a stepped portion (51c) between the portion (51a),
The ACG accommodating portion (51a) is formed to protrude outward from the outer edge portion (51b) so as to accommodate the AC generator (40),
The ACG cover for an internal combustion engine according to any one of claims 1 to 3, wherein said projections (55, 56) are provided continuously with said stepped portion (51c). An ACG cover for an internal combustion engine according to any one of claims 1 to 4, wherein said projections (55, 56) have holes (55b, 56b) for fastening bolts.

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