JPH0687635U - Engine soundproofing equipment - Google Patents

Abstract

(57) [Summary] [Object] To provide a technique of shielding noise generated from an engine in a portion where an engine flywheel is covered with a housing. [Structure] A flywheel is fixed to a crankshaft protruding from an engine body, and an outer periphery of the flywheel is covered with a housing integrally configured by an engine-side housing and a working machine-side housing, and an opening is formed in the working machine-side housing. In the drilled configuration, the first annular shield protrusion is provided on the inner periphery of the engine-side end of the engine-side housing to form a narrow gap δ1 between the end face of the flywheel and the outer periphery of the flywheel. A second annular shield protrusion is formed on the inner surface of the engine, and a narrow gap δ2 is formed between the second annular shield protrusion and the inner surface of the outer peripheral portion of the engine side housing.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a technique of shielding noise generated from an engine in a portion where a flywheel of the engine is covered with a housing.

[0002]

[Prior art]

 Conventionally, a technology for shielding engine noise by reducing a gap between a housing and a flywheel has been filed as a prior application by the same person. For example, it is as in Japanese Patent Application No. 4-13917.

[0003]

[Problems to be solved by the device]

 However, in the conventional technique, although it is sufficiently effective in shielding noise emitted from the space between the housing and the flywheel, there are difficulties in terms of manufacturing. Of. That is, if the gap between the housing and the flywheel is made sufficiently small, as shown in Fig. 3, the noise level is lowered and the shielding effect is improved, but in consideration of manufacturing, assembling, tolerance, etc. The gap cannot be made small enough. In addition, it is possible to make the gap between the housing and the flywheel sufficiently small from the viewpoint of machining, but the size of the shielding effect conflicts with the difficulty of the manufacturing surface, so a configuration that satisfies both is required. It became.

[0004]

[Means for Solving the Problems]

 The problem to be solved by the present invention is as described above. Next, the means for solving the problem will be described. That is, the flywheel is fixed to the crankshaft protruding from the engine body, and the outer circumference of the flywheel is covered with a housing integrally configured with the engine side housing and the working machine side housing, and the opening part is provided on the working machine housing. The first annular shield protrusion is provided on the inner circumference of the engine-side end of the engine-side housing to form a narrow gap δ1 between the end-face of the flywheel and the outer circumference of the flywheel. A second annular shield protrusion is formed in the portion, and a narrow gap δ2 is formed between the second annular shield protrusion and the inner surface of the outer peripheral portion of the engine side housing.

[0005]

[Action]

 Next, the operation will be described. As shown in FIG. 2, according to the present invention, a narrowing portion constituted by the first annular shielding protrusion 16 is provided between the space V1 and the space V2, and a first part of the flywheel 3 is provided between the space V2 and the space V3. The second throttle portion is constituted by the two annular projecting shield portions 3a, and the air passing through the second throttle portion is discharged from the space V3 to the opening 14. In this way, when the opening 14 is included, the three diaphragms are formed, and the three large-capacity spaces of the space V1, the space V2, and the space V3 are formed between them to prevent the movement of air, The sound insulation effect is improved.

[0006]

【Example】

 Next, examples will be described. FIG. 1 is a front sectional view of a housing and a flywheel part of the present invention, FIG. 2 is a diagram illustrating a soundproof effect, and FIG. 3 is a diagram comparing soundproof effects.

In FIG. 1, a front sectional view of a connecting portion between a pump 6 for a hydraulic working machine attached as a working machine and the engine body 1 is shown. A cast flywheel 3 is attached to a crankshaft 2 protruding from an engine body 1 formed of a cylinder block with bolts 5a. A rubber coupling 4 is attached to the flywheel 3 by a bolt 5b, and a block 8 spline-fitted to an input shaft 7 of a hydraulic working machine pump 6 is attached to the rubber coupling 4 by a bolt 9. Since the air in the housing expands and contracts as the engine E rotates, it is necessary to form an opening 14 in the working machine side housing 13 in order to allow the air to flow in and out. There is. However, since the opening 14 is bored, noise on the engine E side comes out from the opening 14. The present invention attenuates the noise emitted from the opening 14.

The flywheel 3 is covered by a cast engine-side housing 10. The engine-side housing 10 includes an outer peripheral portion 11 that covers the second annular protruding shield portion 3a of the flywheel 3, an end portion 12 that faces the engine body 1 and that covers one end surface 3b of the flywheel 3, and a flywheel. The work machine side housing 13 covers the other end surface 3 c of the wheel 3. The outer peripheral portion 11 and the engine side end portion 12 are integrally cast as an engine side housing 10. The working machine side housing 13 is separately cast and attached to the outer peripheral portion 11 of the engine side housing 10. By providing the opening 14 in the working machine side housing 13, the expansion / contraction air in and out of the housing integrated by the engine side housing 10 and the working machine side housing 13 and the rise of the internal temperature are prevented. There is.

A first annular shield protrusion 16 formed in an annular shape with a width L 1 is protruded inside the engine-side end portion 12 of the engine-side housing 10, and the first annular shield protrusion 16 is provided on the flywheel 3. It is projected toward the end surface 3b which is the side surface on the engine side. The narrow gap δ1 between the axial direction of the first annular shield protrusion 16 and the flywheel 3 is such that the opposite end faces 16a and 3b of the first annular shield protrusion 16 and the flywheel 3 are machined. It has a fixed size.

That is, the narrow gap δ1 prevents the air vibration in the space V1 between the one end 12 of the housing 10 and the outer peripheral surface 3a of the flywheel 3 from propagating to the annular outer space V2. ing. Further, in the present invention, the second annular protruding shield 3a is projected on the outer peripheral portion of the flywheel 3, and the second annular protruding shield 3a and the inner surface of the outer peripheral portion 11 of the engine side housing 10 are narrow. A gap δ2 is formed. The narrow gap δ2 forms a throttle portion between the space V2 and the space V3 formed between the flywheel 3 and the working machine side housing 13, and from the space V3 toward the small-diameter opening 14, It discharges air.

The width of the first annular shield protruding portion 16 protruding on the inner wall of the engine side end portion 12 is L1, and the width of the second annular protruding shield portion 3a provided on the outer peripheral portion of the flywheel 3 is L2. There is. Then, L2> L1 is configured. As a result, the effect of damping the noise shielded by the shielding projection 16 is increased, the effect of the noise shielded by the second annular protruding shield 3a is reduced, and the noise is sequentially attenuated. The soundproofing effect can be improved.

[0012] Thus, it is possible to prevent noise from being generated without being emitted from the opening portion 14 in a state where the air vibration is kept as it is. Further, if the end faces 16a and 3b of the first annular shield protrusion 16 and the flywheel 3 which face each other are machined, the narrow gap δ 1 and the narrow gap δ2 can be set to desired dimensions, so that the machining area is reduced. You can do it.

[0013]

[Effect of device]

 Since the present invention is configured as described above, it has the following effects. That is, between the space V1 and the space V2, there is provided a throttle portion constituted by the first annular shield protrusion portion 16, and between the space V2 and the space V3, the second annular protrusion shield portion 3a of the flywheel 3. The configured second throttle portion is configured, and the air that has passed through the second throttle portion is discharged from the space V 3 to the opening portion 14. In this way, when the opening 14 is included, the three diaphragms are formed, and the three large-capacity spaces of the space V1, the space V2, and the space V3 are formed between them, and the movement of air is blocked so that sound insulation is achieved. It was possible to improve the effect.

Secondly, noise due to air vibrations in the space between the end surface of the housing and the end surface of the flywheel is prevented without increasing the internal temperature of the housing and without increasing the machining cost of the housing. You can do it. Moreover, since the first annular shield protrusion 16 and the second annular protrusion shield 3a are integrally cast and projected on either the housing or the flywheel, the soundproof effect can be improved without increasing the number of parts. It was made.

[Brief description of drawings]

FIG. 1 is a front sectional view of a housing and a flywheel portion of the present invention.

FIG. 2 is a diagram illustrating a soundproofing effect.

FIG. 3 is a drawing showing a relationship between a narrow gap δ and a noise decibel.

[Explanation of symbols]

 2 crankshaft 3 flywheel 3a second annular protruding shield 10 engine side housing 13 working machine side housing 14 opening 16 first annular shield protruding V1, V2 space δ1, δ2 narrow gap

Claims (1)

[Scope of utility model registration request] 1. A flywheel is fixed to a crankshaft projecting from an engine body, and an outer periphery of the flywheel is covered with a housing integrally formed by an engine-side housing and a working machine-side housing, and an opening is formed in the working machine-side housing. In the configuration in which the portion is bored, the first annular shield protrusion is provided on the inner circumference of the engine-side end of the engine-side housing to form a narrow gap δ1 with the end face of the flywheel. A soundproof device for an engine, characterized in that a second annular shield protrusion is formed on the outer periphery, and a narrow gap δ2 is formed between the second annular shield protrusion and the inner surface of the outer periphery of the engine-side housing.