JPH0625643Y2 - Engine sound insulation structure - Google Patents

Description

[Detailed Description of the Invention] [Industrial application] The present invention relates to a sound insulation structure for an engine, and more particularly to a sound insulation structure for an engine that has high rigidity and is lightweight.

[Prior Art] During engine operation, the main bearing cap supporting the crankshaft on the cylinder block side may vibrate due to an explosive load and generate noise. These vibrations and noises are transmitted from the main bearing cap to the skirt portion of the cylinder block, reach the oil pan connected to the skirt portion, and are further multiplied.
The generation of such vibrations and noises can be suppressed by the insufficient supporting rigidity of the main bearing cap itself, and by being fixedly coupled with an oil pan made of a steel plate having a relatively low rigidity skirt. This is due to the fact that rigidity is not reinforced so much. The vibrations and the accompanying noises not only give occupants an unpleasant feeling, but also cause various troubles. Therefore, a means for suppressing the occurrences is desired.

By the way, during engine operation, the counterweight of the crankshaft that rotates at high speed may disturb the oil in the oil pan, cause bubbles, and raise the oil level.
As the oil level rises, the agitation of the oil by the counterweight part becomes stronger and the oil level rises further, creating a vicious circle. When the oil is agitated, problems such as power loss of the engine and increased oil consumption occur. So, for example, the actual exploitation 59-15751
No. 4 publication describes an oil pan baffle plate intended to solve such a problem. This is because a plate-shaped body that spreads over the entire cross section of the oil pan of the engine is provided close to the rotation trajectory of the counterweight of the crankshaft, and the plate-shaped body is placed at positions corresponding to both sides of the engine in the width direction of the engine. A long hole extending in the longitudinal direction is formed. In other words, as long as the oil stirred by the counterweight is above the oil pan baffle plate, the oil in the oil pan below the oil pan baffle plate should be clearly distinguished from each other in order to prevent foaming. Is.

[Problems to be solved by the invention]

By the way, the oil pan baffle plate of the above-mentioned conventional example is a plate-like body that spreads over the entire cross section of the oil pan,
That is, it has a flat plate shape and its rigidity is low. Therefore, although it is sandwiched and fixed by the cylinder block and the oil pan, the rigidity of the skirt portion of the cylinder block and the oil pan cannot be sufficiently reinforced. Also,
There is no relation with the main bearing cap, and it is not possible to suppress the occurrence of vibration of the crankshaft itself.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a sound insulation structure for an engine that has high rigidity and is lightweight.

[Means for solving problems]

According to the means of the present invention, a plate member having an inner side recessed into the oil pan to form a flat plate is sandwiched and fixed between the cylinder block and the oil pan, and the lower part of the main bearing cap is provided on the upper surface of the plate member. A projecting portion having a U-shaped cross section that is fixedly supported is provided, and a bead connected in the longitudinal direction between the projecting portions is provided on the plate member, and the vibration noise of the engine is reduced by the plate member. .

[Action]

The bead is clamped and fixed by the cylinder block and the oil pan, and the bead is connected so as to be connected in the longitudinal direction between the protrusions of the U-shaped cross section provided on the upper surface of the plate member whose inside is depressed into the oil pan to form a flat plate By being provided, the rigidity of the protrusion and the rigidity of the plate member itself are improved. for that reason,
The support rigidity of the main bearing cap is strengthened, and the generation of vibration of the crankshaft due to an explosion load is suppressed. The plate member having high rigidity further strengthens the rigidity of the joint portion between the cylinder block and the oil pan, and the rigidity of the skirt portion of the cylinder block is improved.
Vibration and noise propagation is suppressed. Since the plate member has high rigidity without increasing the number of parts by forming the beads as described above, it is relatively lightweight and can suppress vibration noise of the engine.

[Effect of device]

The engine sound-insulating structure of the present invention is sandwiched and fixed between a cylinder block and an oil pan, and a plate member having a flat plate shape with the inside depressed into the oil pan is provided on the upper surface of the plate member.
Since a protrusion having a U-shaped cross-section for fixedly supporting the lower portion of the main bearing cap is provided and a bead that is connected to the plate member in the longitudinal direction between the protrusions is provided, vibration noise of the engine is reduced. Since the above-mentioned plate member serving as the sound insulating member is formed to have high rigidity by simple processing of the plate material, it is possible to reduce the weight.

〔Example〕

 Hereinafter, the present invention will be described in detail based on embodiments.

In the sound insulation structure of the engine shown in this example, a plate member having high rigidity is arranged and fixed between the cylinder block and the oil pan to reinforce the rigidity of the skirt portion, and the plate member is connected to the main bearing cap. It is fixed to improve the support rigidity and to reduce the vibration noise of the engine, and is configured as follows.

As shown in FIG. 1, a plate member 3 which is sandwiched and fixed between a cylinder block 1 and an oil pan 2 and whose inner portion is depressed into the oil pan 2 to form a flat plate shape. Is provided. On the upper surface of the plate member 3, as shown in FIG. 2 and FIG.
A plurality of protrusions 5 having a U-shaped cross section for fixedly supporting the lower part of the are arranged and fixed in a plurality of rows in the lateral direction. A bead 6 that is connected in the longitudinal direction between the protrusions 5 is provided so as to protrude below the plate member 3.

An oil pan flange 11 is superposed on a mounting flange 8 at the lower end of the skirt portion 7 of the cylinder block 1 via a mounting flange 9 of the plate member 3, and these are integrally coupled and fixed by a bolt 10. As described above, the plate member 3 is in the form of a flat plate in which the inner portion of the plate member 3 is inclined downward from the mounting flange 9 and is depressed in the oil pan 2, and the rotation of the counterweight of the crankshaft (not shown) is increased above it. It has become acceptable. The protrusion 5 provided corresponding to the main bearing cap 4 is laterally attached to the flat portion 12 of the plate member 3 by spot welding, and a slightly shallow lateral groove 13 is provided between the protrusions 5 in the same direction. Is formed in. The lateral groove 13 is provided with an oil return hole 14 for returning the oil after lubrication into the oil pan 2. A plurality of beads 6 are formed so as to extend across the lateral groove 13 from the back side and connect to the protruding portions 5 so as to project to the back side of the plate member 3.

The protrusion 5 is attached to the lower end of the main bearing cap 4 as follows. That is, the bolt 15 with the spacer 17 embedded in the main bearing cap 4
Through the bolt hole 16 of the protrusion 5, and the upper surface of the protrusion 5 is inserted through the spacer 17 into the main bearing cap 4
Of the copper washer 1 that is abutted on the lower end of the
8 and the nut 20 is screwed through the flat washer 19 to fix the protrusion 5 to the main bearing cap 4. At the mounting positions of the main bearing caps 4a and 4b at the front and rear ends of the plate member 3, the plate member 3 is bent upward to form projecting end portions 3a and 3b, respectively. Its protruding end 3a
And 3b in the same manner as main bearing cap 4a
And 4b but with protruding ends 3a and 3b
Since the lower surface of the is formed flat, the copper washer 18
Is unnecessary.

In such a sound insulation structure of the engine, the rigidity of the plate member 3 itself formed of a steel plate or the like is provided by the bead 6 provided so as to be connected to the projecting portion 5 projecting on the plate member 3 in the longitudinal direction. And the rigidity between the protrusions 5 is also improved. As a result, the supporting rigidity for the main bearing cap 4 is improved and the rigidity of the skirt portion 7 of the cylinder block 1 is reinforced. By increasing the support rigidity of the main bearing cap 4, the generation of vibration due to an explosion load is suppressed, while the skirt portion 7
Due to the improvement in the rigidity, the vibration and noise are suppressed from propagating to the oil pan 2. Further, since the plate member 3 has high rigidity by forming the beads 6 as described above,
It can be made relatively lightweight without increasing the number of parts, which can contribute to weight reduction around the engine.

By the way, the plate member 3 also functions as a baffle plate for suppressing the fluctuation of the oil level of the oil in the oil pan 2. That is, the oil stirred by the counterweight is limited to the oil above the plate member 3, and the oil in the oil pan 2 below the plate member 3 is not stirred. Moreover, since the oil return hole 14 is formed in the lateral groove 13, the oil is satisfactorily recirculated after lubrication, and the rise of the oil level due to the bubbling of the oil is prevented.
Therefore, it is needless to say that generation of power loss of the engine and increase of oil consumption due to stirring of oil are prevented.

The bead connecting the protrusions in the longitudinal direction in the present invention is connected to the protrusions independently of each other as in the present example, and is also connected in the longitudinal direction over substantially the entire length of the oil pan. Alternatively, it may be formed on the upper surface of the plate member.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an embodiment of the sound insulation structure for an engine of the present invention, FIG. 2 is a sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a plan view. 1 ... Cylinder block, 2 ... Oil pan, 3 ... Plate member, 4, 4a, 4b ... Main bearing cap,
5 ... projection, 6 ... bead.

Claims (1)

[Scope of utility model registration request] 1. A plate member having an inner side depressed into an oil pan to form a flat plate is sandwiched and fixed between a cylinder block and an oil pan, and a lower portion of a main bearing cap is provided on an upper surface of the plate member. A projecting portion having a U-shaped cross section for fixed support is provided, and a bead connected in the longitudinal direction between the projecting portions is provided on the plate member, and the plate member reduces vibration noise of the engine. A sound insulation structure for the engine.