JP2603223Y2 - Engine cylinder block side cover - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a side cover of an engine cylinder block which reduces noise generated when the engine rotates.

[0002] A crankcase with a built-in crank receives rotational vibrations of the crank when the engine rotates, and produces a rotating sound,
Generates vibration.

Conventionally, as a noise reduction device for such an engine, as shown in FIG. 2, a rubber-made vibration damping material 2B also serving as a sealing material is joined to the surface of a thin steel plate 2A, and further covered with glass wool aluminum. The side cover 2 to which the soundproof material 2C is bonded is used.

[0004] By attaching such a side cover 2 to the engine crankcase 1, rotational noise, vibration noise, and the like generated by rotational vibration of the crank are absorbed and attenuated by the vibration-proof material 2 B and the sound-proof material 2 C, thereby being reduced. Thus, it is intended to reduce noise generated in the entire engine.

[0005]

[Problems to be Solved by the Invention] However, in such a conventional side cover 2, a rubber-molded vibration-proof material 2B must be bonded, which requires time and cost for the bonding process.

[0006] In order to obtain a sufficient vibration-proof and sound-proof effect, a vibration-proof material
It is necessary to take enough rubber thickness of 2B, but if the thickness of the anti-vibration rubber is increased, the material cost will increase, the weight will increase, and the thickness of the anti-vibration rubber will be increased because extra space is required There is a limit to this, so that sufficient noise and vibration damping effects cannot be obtained.

For the soundproofing material 2C, it is necessary to stick an aluminum film around the glass wool molding without any gaps due to the problem of water resistance. However, since this operation is performed manually, the cost increases, and at the same time, the cost increases. The effect on the human body cannot be ignored.

Although it is possible to reduce noise and vibration by increasing the thickness of the soundproofing material 2C, there is a restriction for the same reason as that of the vibration insulating rubber.

Further, as shown in FIG.
In order to secure weight reduction and strength, the side part 3 has ribs 4 and protrusions 5 of a complicated structure, and when the above-mentioned side cover 2 is attached thereon, the soundproof material 2C and the crank are provided. A space 6 is formed between the case 1 and the space 6, and noise and vibration resonate and increase due to the space 6.

In order to fill this space, it is impossible to mold the glass wool provided on the surface of the soundproof material 2C so as to completely adhere to the shape of the crankcase 1.

In addition, it is difficult to mold the rubber of the vibration isolator 2B so as to completely adhere to the shape of the crankcase 1 in place of the sound isolator 2C, and the molding cost increases. That is,
Neither the vibration-proof material 2B nor the sound-proof material 2C can completely fill the mating surface of the crankcase 1.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, in the present invention, an engine cylinder provided with a foamed silicone sheet having a surface for fitting to a side surface of an engine cylinder block is provided on a surface of a reinforcing plate. It proposes a block side cover.

In the side cover according to the present invention, a liquid foamed silicone resin is injected between a side portion of an engine cylinder block such as a crankcase provided at a predetermined interval and a reinforcing plate, and the resin is foamed and cured at a predetermined temperature. Manufactured by forming a foamed silicone sheet.

As such a liquid foamed silicone resin, for example, foamed silicone resin Three Bond 5277C
(Trade name) is preferred, and since this foamed silicone resin is almost harmless to the human body, it is excellent in workability and safety, and has a low viscosity of 100 poise or less at the time of injection. It has excellent close-packing properties to the side parts of the engine cylinder block such as the case, and it is possible to completely fill the gap between the side parts and the reinforcing plate.

[0015]

According to the present invention, a foamed silicone sheet having fine air bubbles therein can be formed at an appropriate thickness between the side portion of the engine cylinder block and the reinforcing plate, so that the rotational noise generated by the rotational vibration of the crank can be obtained. , Vibration noise and the like can be effectively absorbed and attenuated.

Further, since the gap between the side portion of the engine cylinder block having a complicated rib structure and the reinforcing plate is completely filled with the foamed silicone sheet, the rotational noise and vibration noise generated by the rotational vibration of the crank resonate. There is no space that increases.

Further, since the foamed silicone sheet is embedded in the side portion of the engine cylinder block or the surface of the reinforcing plate having a complicated rib structure and does not separate therefrom, there is no need to attach it to the side portion, thereby reducing the cost. Can be.

Further, in this invention, since the foamed silicone sheet having excellent water resistance and engine oil resistance is embedded without gaps in the side portions of the engine cylinder block or the surface of the reinforcing plate, it can be compared with the above-mentioned glass wool. Excellent water and oil resistance.

Furthermore, since the side cover according to the present invention brings the foamed silicone sheet having excellent heat resistance into contact with the side portion of the engine cylinder block, it can withstand use at high temperatures.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiment. A reinforcing plate 7 is provided at predetermined intervals on the side portion 3 of the crankcase 1 as shown in FIG. 3, and a liquid foamed silicone resin (trade name: Three Bond 5277C) is injected between the side portion 3 and the reinforcing plate 7. Then, it is foamed and cured.

As a result, a side cover 2 having a foamed silicone sheet 8 of a predetermined width fitted on the surface of the reinforcing plate 7 and the surface of the side portion 3 is obtained.

FIG. 4 shows the noise reduction effect using the side cover according to the present invention in comparison with the conventional example. The vertical axis represents the noise level (dB), and the horizontal axis represents the frequency of the generated noise (Hz). In the figure, curve A is the noise level when the side cover according to the present invention is attached to the side portion of the crankcase, curve B is the noise level when the side cover shown in FIG. 2 is attached, and curve C is the reinforcing plate. This shows the noise level when only the camera is mounted.

The noise measurement of these side covers during engine rotation is the result of measuring the microphone at a position about 1 m from the side cover.

As a result, the side cover according to the present invention has a higher frequency range (1 to 2 KHz) than the conventional side cover using a vibration-proof rubber / glass wool shown in FIG.
It has been found that a 1.5 dB average noise reduction effect can be achieved.

[0024]

[Effect of the Invention] In summary, according to this invention, the space between the side portion of the engine cylinder block and the reinforcing plate is completely filled with the foamed silicone sheet without any gap, so that the sound generated when the engine rotates can be effectively absorbed and reduced. Be transformed into

Further, the side cover according to the present invention can be easily attached to the side portion, has excellent water resistance and oil resistance with the side portion, and can withstand use at high temperatures.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing an embodiment of the present invention.

FIG. 2 is a longitudinal side view showing an example of use of a conventional side cover.

FIG. 3 is an exploded perspective view showing a side portion of an engine cylinder block.

FIG. 4 is a diagram showing a noise reduction effect using the side cover according to the present invention in comparison with a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine crankcase 2 Side cover 3 Side part 7 Reinforcement plate 8 Foamed silicone sheet

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-67392 (JP, A) JP-A-62-64531 (JP, A) 100040 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02F 7/00 F02B 77/13 F02B 77/11

Claims (1)

(57) [Scope of request for utility model registration] 1. An engine having a rib or projection having a complicated structure.
At predetermined intervals on the side of the cylinder block
A reinforcing plate is provided, and 100 points is provided between the side portion and the reinforcing plate.
Inject the liquid silicone resin below
And fitted to the surface of the side part on the surface of the reinforcing plate
A side cover for an engine cylinder block, wherein a foamed silicone sheet is formed .