JPH04303160A - Engine structure - Google Patents

Abstract

PURPOSE:To improve property for providing sealing effect between a cover member and an engine main body block, so as to reduce exhaust noise of an engine, in a structure formed in such a way that a separate cover member is installed on an engine main body block, and a water jacket space is formed between both components. CONSTITUTION:A cover member 9 is formed as double wall structure by providing a hollow part 9c between an inner wall 9a and an outer wall 9b, and it is installed on engine main body blocks 1, 2, 3 while holding sealing members 6 in the necessary positions. The recessed part 4 of the cylinder block 1 sealed by the inner wall 9a is formed as a water jacket space.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] This invention relates to the engine structure of a water-cooled engine, and in particular to an improvement in the engine structure in which a cover of a connecting member is attached to a recess formed in the side wall of an engine body block, and the recess space is used as a water jacket. Regarding.

0002

2. Description of the Related Art In a typical engine structure, a hollow portion is formed in an integral cylinder block, and the hollow portion is used as a water jacket. On the other hand, some engines have a recess formed in the side wall of the engine body block (mainly the cylinder block), and the recess is sealed, as shown in Japanese Utility Model Application Publication No. 58-79039, for example. There is also a known structure in which a cover member is attached to the water jacket, thereby using the sealed space as a water jacket.

0003

SUMMARY OF THE INVENTION An engine structure in which a separate cover member is attached to an engine body block to form a water jacket space has the following technical problems. One is to improve the sealing performance of the joint surface between the main body block and the cover member, and the other is to reduce the radiation efficiency of engine sound. In the above-mentioned Japanese Utility Model Application Publication No. 58-79039, an elastic body is used as the cover member to reduce the sound radiated from the engine. However, if an elastic body is used as the cover member, sealing between the cover member and the engine body block becomes difficult, resulting in leakage of cooling water and engine oil. On the other hand, if a material with high rigidity is used as the cover member, the sealing performance can be improved, but the sound radiated from the engine will be greater than in the case of an elastic cover member.

This invention was made in view of the above-mentioned conventional problems, and its purpose is to provide sealing of the joint surface in an engine structure in which a water jacket space is formed by attaching another cover member to the engine body block. The aim is to improve performance and reduce engine radiated sound.

[0005]

[Means for Solving the Problems] Accordingly, in the present invention, a cover member is attached to the joint surface via a seal member so as to seal the recess formed in the side wall of the engine body block, and thereby the sealed space is closed. In addition to forming a water jacket, the cover member had a hollow double wall structure, and the hollow part of the double wall structure was used as an air flow passage.

[0006]

[Operation] A water jacket space is formed between the inner wall of the cover member and the engine body block, and the hollow space between the outer wall and the double wall has a sound insulation function that reduces engine radiated sound. Fulfill.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic configuration of an engine structure according to an embodiment of the present invention, and FIG. 2 shows a double wall cover member 9 in this embodiment. The engine of this embodiment is a reciprocating piston type four-cylinder engine, and the engine main block has outwardly opening recesses 4 formed on both sides of the cylinder block 1, and also on both sides of the crankcase 3. A recess 5 is formed.

In FIG. 1, an engine main block 1,
The recesses 4, 5 on the right side of 2, 3 are filled with cover panels 7 and 8, and the recesses 4, 5 on the left side are filled with a double-walled cover member 9 according to the invention.

The cover panel 7 is assembled to seal the recess 4 of the cylinder block 1 via the packing 6.
It is firmly attached with bolts. This cover panel 7
The recessed portion 4 that is closed becomes a water jacket space. The cover panel 8 is assembled so as to seal the recess 5 of the crankcase 3 via the seal member 6, and is firmly fixed with bolts. This sealed recess 5 and cover panel 8 have the effect of reducing engine radiation noise.

The double wall cover member 9 has an inner wall 9a and an outer wall 9b.
Air flow passage Here, it is an integral structure part with a hollow part 9c that becomes the intake passage (or exhaust passage) of the engine, and the hollow part 9c that becomes the intake passage is a manifold that branches to each cylinder of a four-cylinder engine. It has a structure. Further, as shown in FIG. 1, the inner wall 9a of the double wall cover member 9 has a shape that simultaneously seals both the recess 4 of the cylinder head 2 and the recess 5 of the crankcase 3 on the left side of the engine body. A seal member 6 is inserted into each mounting surface, and a cover member 9 is firmly attached to the engine body blocks 1, 2, and 3 with bolts.

The recess 4 of the cylinder block 1 sealed by the inner wall 9a of the double wall cover member 9 becomes a water jacket space. Further, the hollow part 9c of the double wall cover member 9 itself becomes an intake passage, and its upper end side is the cylinder head 2.
It matches the intake opening of.

0012

[Effects of the Invention] As explained in detail above, in the engine structure according to the present invention, the cover member to be combined with the engine body block to form a water jacket space has a double wall structure, and this and the engine body block are connected to each other. Sufficient sealing performance can be obtained by sandwiching the sealing member between the joint surfaces, and the effect of reducing engine radiated sound can be obtained by the outer wall and hollow portion of the double-walled cover member. In particular, by utilizing the hollow portion of the double wall cover member as, for example, an intake passage, the engine itself can be configured compactly.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an engine main body according to an embodiment of the present invention.

FIG. 2 is a front view of the double wall cover member in the embodiment.

[Explanation of symbols]

1 Cylinder block 2 Cylinder head 3 Crank case 4 Recessed part 6 Seal member 9 Double wall cover member 9c Hollow part

Claims (2)

[Claims] Claim 1: A cover member is attached to a joint surface via a seal member so as to seal a recess formed in a side wall of an engine main body block, and the sealed space is thereby used as a water jacket, and the cover member 1. An engine structure characterized by having a hollow double-walled structure, and the hollow part of the double-walled structure serving as an air flow passage. 2. An engine structure characterized in that the hollow portion of the double wall structure cover member according to claim 1 is used as an intake passage of the engine.