JP3021166B2 - Engine cover - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine cover for covering an engine body.

[0002]

2. Description of the Related Art An engine cover is provided to protect an engine body and to prevent noise generated by the engine body from radiating to the outside. Therefore, since the engine cover is required to have appropriate rigidity, it is usually made of metal or hard synthetic resin. In addition, a plurality of cover members are often connected to each other, and such an engine cover is mounted on the engine body as a whole.

[0003] Vibration is induced in the engine cover mounted on the engine body by engine vibration, and the vibration easily causes the engine cover itself to generate noise. In particular, this noise is caused by the relative vibration of the joint surfaces that come into contact with each other at the joint between the cover member and the cover member and the joint between the cover member and the engine body. It opens and the internal sound leaks out from here.

Therefore, it is necessary to fix the two adjacent members tightly and firmly at the joint, or to interpose an anti-vibration material between the joint surfaces, so that many parts are required.

Japanese Unexamined Utility Model Publication No. Sho 57-110599 discloses a sound insulating cover made of rubber or synthetic resin containing a wire mesh or a metal wire. This sound insulating cover is a simple plate-shaped one and has a sufficient thickness. Since it has no rigidity, this
An engine cover that covers and protects the outer periphery of the engine body cannot be formed.

Further, Japanese Utility Model Publication No. Sho 62-15476 discloses an engine cover formed of an elastic body such as rubber as a seamless integral body, and the engine cover includes a cooling fin for a cylinder. A fin damper that fits between the cooling fins of the cylinder head and the cooling fin of the cylinder head is integrally formed. Since the engine cover is also supported by the engine body by the fin damper, it can retain the shape of the engine cover.Without the fin damper, such an elastic body was provided with an appropriate rigidity. It is impossible to form an engine cover.

The present invention overcomes the above-mentioned conventional problems, has sufficient rigidity, soundproofing, and vibration-proofing effects, and requires a small number of parts for mounting and connecting the vibration-proofing material and the cover itself, and has a simple structure. It is intended to provide an engine cover.

[0008]

The engine cover of the present invention is made of rubber, elastic synthetic resin, or the like, straddling the contact portion between the cover member and the cover member or the contact portion between the cover member and the engine body. An elastic piece made of an elastic material is fixed to each of the abutting members at both ends thereof and attached in tension.

In this engine cover, the cover member and the cover member, or the cover member and the engine body, which are in contact with each other, are pressed together by the elastic piece in a tension state, and are brought into close contact along the contact portion. Therefore, it is not necessary to dispose a large number of connecting parts such as screws along the contact part, so that the number of parts is significantly reduced. Further, since the two members can be tightly joined only by fixing both ends of the elastic piece to the adjacent members, the joining can be performed extremely easily and quickly.

The elastic piece functions as a coupling member as described above, and is in close contact with the surface of the engine cover over a wide area, and itself functions as a soundproofing material or a vibrationproofing material. Therefore, the number of parts for attaching the soundproof material and the vibration damping material to the engine cover is reduced, and the structure of the engine cover is simplified.

[0011]

An embodiment in which the present invention is applied to a swing type engine unit such as a scooter will be described below.

FIG. 1 is a sectional view showing the entire swing type engine unit. This unit includes an engine 1 in the front and an axle 3 that supports the rear wheel 2 in the rear, and has a front portion pivotally supported by a vehicle body (not shown) so as to be vertically swingable. The axle 3 extends one side of the crankcase 4 of the engine 1 rearward, and is supported at its rear end.

5 is a cylinder of the engine 1 and 6 is a crankshaft. A cooling fan 7 is fixed to an end of the crankshaft 6 which penetrates through the crankcase 4 and protrudes rightward in the figure, and cools the engine 1 by cooling air generated by the fan 7 when the engine rotates. It is made to forcibly cool. The engine 1 is covered with a cover 8 from the outer periphery of the fan 7 to the outer periphery of the cylinder 5, and the cover 8 is provided with an air intake 9 at a position in front of the fan 7. The cover 8 guides the cooling air introduced from the air inlet 9 and generated by the fan 7 around the cylinder 5, prevents the noise of the engine 1 from directly radiating to the outside, and protects the engine 1 from the outside. .

On the side of the engine 1 opposite to the fan 7, a transmission case 10 which is open outward is formed by the crankcase 4 extending rearward as described above. At the front, the crankshaft 6 protrudes into the transmission case 10, and between the driven shaft 11 provided at the rear and the crankshaft 6, the variable pulleys 12a and 12b and the V belt Automatic transmission 14 consisting of 13
The engine power is transmitted from the crankshaft 6 to the axle 3 via the automatic transmission 14, the clutch 15, the driven shaft 11, and the gear device 16. The open portion of the transmission case 10 is covered by a cover 17 separate from the cover 8, thereby shielding noise inside the transmission case 10,
It is made to protect inside.

The covers 8 and 17 are both made of metal or hard synthetic resin and have a desired rigidity.

FIGS. 2 to 6 show an example in which the present invention is applied to the cover 8. FIG. FIG. 2 corresponds to a perspective view of the cover 8 of FIG.

The cover 8 includes a fan cover (cover member) 18 that covers the fan 7 side of the engine 1 from the outer peripheral portion to the upper cylinder 5 and a shroud (cover member) 19 that covers the opposite side of the cylinder 5. Made up of The lower portions of these cover members 18 and 19 are appropriately fastened to the engine body by bolts via mounting portions 20.

The upper portions of the fan cover 18 and the shroud 19
Each of the cylinders 5 of the engine 1 is opposed to each other so as to surround each half-peripheral portion thereof, and a contact portion 21 is formed at the center where opposing edges of each member contact each other. This abutment
For example, as shown in FIG. 3, the convex line 23 on the shroud 19 side may be fitted into a concave portion 22 formed on the edge of the fan cover 18.

When the fan cover 18 and the shroud 19 vibrate, the concave portion 22 and the convex line 23 repeat relative displacement, thereby generating noise, and the gap between the concave portion 22 and the convex line 23 is generated. When opened, the cooling air leaks to the outside and the internal sound leaks to the outside, so that it is desirable that the recess 22 and the convex wire 23 are always in close contact. Ie fan cover 18
It is desired that the shroud 19 and the shroud 19 are firmly connected along the contact portion 21.

However, in this cover 8, the contact portion
No connecting means such as screws for firmly connecting the fan cover 18 and the shroud 19 to the fan 21 are provided. The contact between the fan cover 18 and the shroud 19 at the contact portion 21
Are obtained by an elastic piece 24 fixed to the fan cover 18 and the shroud 19 at both ends. Since the elastic piece 24 is stretched between the fan cover 18 and the shroud 19 in a tensioned state, the fan cover 18 and the shroud
19 are attracted to each other and adhere along the contact portion 21.

The elastic piece 24 is formed by molding an elastic material, such as rubber or elastic synthetic resin, which elastically expands by applying an appropriate tensile force into a plate having a shape as shown in FIG. Have been. An engagement hole 25 is provided at an end of a portion along the surface of the shroud 19 of the main body portion 24a of the elastic piece 24, and an end of a portion along the surface of the fan cover 18 is provided at an end of the elastic portion 24. Engagement holes 26a and 26b are provided. A projecting portion 24b extending upward in a band shape is provided at a position of the main body portion 24a slightly offset toward the engaging hole 26, and a circular hole 27 is provided at the tip of the projecting portion.

On the other hand, an engagement projection 28 which is aligned with the engagement hole 25 is provided on the rear surface of the shroud 19 (FIG. 2), and a fan cover is provided.
On the back surface of 18, an engagement projection 29 which is aligned with the engagement holes 26a, 26b
a and 29b are protruded (FIGS. 5 and 6).

The elastic piece 24 is, for example, firstly provided with engagement holes 26a, 26b.
Are engaged with the engagement protrusions 29a and 29b on the fan cover 18 side,
The main body 24a is turned to the shroud 19 side across the contact part 21, and the engaging hole 25 is engaged with the engaging projection 28. At this time, if the main body 24a is not extended to some extent, the engaging hole 25 Are not matched with the engagement projections 28. Therefore, when the main body 24a is mounted between the engagement projections 29 and the engagement projections 28 in this manner, the main body 24a is tensioned in a direction connecting both side ends thereof, and the elastic force thereof causes the fan cover 18 and the shroud
19 are pressed against each other at the contact part 21, and the contact part 21 is in a tightly connected state.

The protruding portion 24b of the elastic piece 24 is turned around the head of the fan cover 18, and a circular hole is formed in the protrusion 30 protruding from the head.
Engage 27. The center of the lower edge of the main body 24a is along the positioning pieces 31 provided on the fan cover 18 and the shroud 19, respectively. In this manner, the main body portion 24a is suspended from above through the protruding portion 24b, received by the positioning pieces 31 from below, and positioned on the outer peripheral surfaces of the fan cover 18 and the shroud 19, and is positioned on the outer peripheral surface. Close to the entire surface without difficulty. Therefore, the elastic piece 24 functions as a connecting member for connecting the fan cover 18 and the shroud 19 as described above, and also functions as a soundproofing material or a vibrationproofing material spread over a large area on the surface of the cover 8. .

In this embodiment, since the peripheral portion of the air inlet 9 of the fan cover 18 is not covered with the elastic piece 24, in order to prevent noise from this portion, the outer surface of the portion is further coated with polyurethane. A soundproofing material 32 made of, for example, is provided. A protruding edge 33 is provided on the outer surface of the fan cover 18 so as to surround a portion extending from the periphery of the air intake 9 to the upper side thereof. From the cover plate 34. The cover plate 34 has its peripheral edge fitted to the protruding edge 33 and the rivet 35
To the fan cover 18.

The protruding edge 33 is notched in the vicinity of the engaging projections 29a, 29b, and the engaging protruding portions 29a, 29b are provided on an extension of the protruding edge 33 in the notched portion. Then, the end of the elastic piece 24 is inserted into the notch so that the engagement hole 26 can be engaged with the engagement protrusion 29.

As described above, if necessary, a part of the cover 8 may be further provided with a soundproofing material or a vibration-proofing material. However, since the elastic piece 24 itself functions as a soundproofing (vibrating) material as described above, The required number of such soundproofing (vibration) materials is small, and therefore the number of components required for soundproofing (vibration) is significantly reduced.

While the present invention has been described in detail with respect to an example in which the present invention is applied to the cover 8 including the fan cover 18 and the shroud 19 in the engine unit of FIG. 1, the present invention can be applied to the cover 17 of the engine unit. It is.

FIG. 7 shows an example in which the present invention is applied to attaching the cover 17 to the engine body, that is, the crankcase 4, and is a drawing corresponding to a cross section along line VII-VII in FIG. 1 at this time. Both ends of the cover 17 abut against the edges of the crankcase side walls 4a, 4b forming the transmission case 10, respectively, to form abutting portions 36a, 36b, and straddle these abutting portions 36a, 36b. An elastic part 37 similar to the elastic part 24 is fixed at its ends to engagement projections 38a and 38b provided on the side walls 4a and 4b, and is attached in tension. The contact portions 36a and 36b are urged by the tension of the elastic piece 37.
Will adhere.

In this embodiment, since both of the contact portions 36a and 36b are connected by a single elastic piece 37, the elastic piece 37
Are fixed to the engine body side, that is, to the side wall 4a and the side wall 4b. However, for example, when only the contact portion 36a is connected, both ends of the elastic portion piece 37 may be fixed to the side wall 4a and the cover 17, respectively. Good.

[0031]

According to the present invention, the two members can be tightly joined only by fixing both ends of the elastic member to the cover member and the cover member or the cover member and the engine body which are in contact with each other. There is no need to arrange a large number of connecting parts such as screws along the contact part, so that the connection can be made very simply and quickly, and the number of parts is significantly reduced.

Further, since the elastic portion itself functions as a soundproofing material or a vibration-proofing material, the number of parts for mounting the soundproofing material and the vibration-proofing material is reduced, and the structure of the engine cover is simplified.

[Brief description of the drawings]

FIG. 1 is an overall sectional view of a scooter engine unit.

FIG. 2 is a perspective view showing an example in which the present invention is applied to an engine cover including a fan cover and a shroud of the engine unit.

FIG. 3 is a sectional view showing an example of a contact portion of the engine cover.

FIG. 4 is a developed plan view of the elastic piece.

FIG. 5 is a side view of the engine cover as viewed from a fan cover side.

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

FIG. 7 is a schematic sectional view showing another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Rear wheel, 3 ... Axle, 4 ... Crankcase, 5 ... Cylinder, 6 ... Crankshaft, 7 ... Fan, 8 ...
Cover, 9: air intake, 10: transmission case, 11: driven shaft, 12: variable pulley, 13: V-belt, 14: automatic transmission,
15 clutch, 16 gear unit, 17 cover, 18 fan cover, 19 shroud, 20 mounting part, 21 contact part, 22
... recess, 23 ... convex line, 24 ... elastic piece, 25, 26 ... engaging hole, 27
… Circular holes, 28, 29… engagement projections, 30… projections, 31… positioning pieces, 32… soundproofing materials, 33… projections, 34… covering plates, 35… rivets, 36… contact parts, 37… elastic parts Piece, 38 ... engagement projection.

Claims (1)

(57) [Claims] An elastic piece made of an elastic material such as rubber or an elastic synthetic resin is provided across an abutting portion between a cover member and a cover member or an abutting portion between a cover member and an engine body. An engine cover fixed to each of the abutting members and attached in tension.