JPH078931Y2 - Oil seal structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an oil seal structure, and more particularly to an oil seal structure capable of improving the assemblability of an oil seal mechanism and reducing the cost.

[Prior Art] In an engine, among the rotary shafts, for example, forced lubrication is performed particularly on a bearing that supports the end of the rotary shaft, for example, the end of the rotary shaft whose end projects outward from the engine body. An oil seal mechanism is attached to a position adjacent to the bearing in order to prevent an excessive amount of lubricating oil from leaking to the outside of the engine along the surface of the crankshaft.

An example of such an oil seal mechanism is disclosed in Japanese Patent Laid-Open No.
No. 61-6463. In the one described in this publication, a valve body for adjusting the amount of lubricating oil splashed against the oil seal member is arranged between the bearing and the oil seal member, and the position of the valve body is adjusted according to temperature changes. It is controlled by changing the stroke of the deformable shape memory alloy temperature-sensitive member.

[Problems to be Solved by the Invention] However, the conventional oil seal mechanism has a case portion 120, an oil seal portion 122, and a packing portion 124 as shown in FIG. Then, the oil seal portion 122 was press-fitted into the case portion 120.

When assembling the case part 120 and the oil seal part 122 to the cylinder block 104, it is necessary to interpose a separate packing part 124 between the cylinder block 104 and the case part 120, which is troublesome during the assembling process. There is an inconvenience.

Further, when manufacturing the oil seal structure, since the press-fitting process of press-fitting the oil seal part 122 into the case part 120 formed by casting is performed, it takes time and effort to manufacture, the manufacturing cost increases, and it is economically disadvantageous. There is an inconvenience that

[Object of the Invention] Therefore, in order to eliminate the above-mentioned inconvenience, an object of the present invention is to configure a case portion by a plate-shaped metal member that is bent, and the case portion is joined to a cylinder block in a hat-shaped cross section. The joining flange portion and the rising portion that is continuously provided to the joining flange portion and the flat portion that is continuously provided to the rising portion and that is substantially parallel to the joining flange portion are formed. To form a bolt insertion hole that allows the oil to pass through, and to form an U-shaped cross section that is continuous with the joint flange to hold the oil seal that seals the end of the crankshaft, and vulcanizes the packing on the joint flange. By molding and forming the oil seal part by vulcanizing the oil seal part in the U-shaped section, the assemblability of the oil seal mechanism is improved and the sealability is improved. It is an object of the present invention to realize an oil seal structure which is improved, simplifies the manufacturing process, reduces the cost, is economically advantageous, and can achieve the weight reduction.

[Means for Solving the Problems] In order to achieve this object, the present invention relates to an oil seal structure in which a crankshaft lower portion around a cylinder block is sealed by a case portion, an oil seal portion and a packing portion. And a joining flange portion joined to the cylinder block in a hat-shaped cross section, a rising portion connected to the joining flange portion, and a rising portion of the joining flange portion. Continuously forming a flat portion substantially parallel to the joint flange portion, a bolt insertion hole for inserting a fixing bolt attached to the cylinder block is formed in the flat portion, and an end portion of the crankshaft. To form a U-shaped section in a continuous manner so as to hold the oil seal part for sealing The packing portion is vulcanized and molded, and the oil seal portion is vulcanized and molded on the U-shaped cross section to form an oil seal mechanism.

[Operation] According to the configuration of the present invention, when the oil seal mechanism is assembled around the lower portion of the cylinder block around the crankshaft, the oil seal portion and the packing portion are already integrally formed by vulcanization molding in the case portion. As a result, the assembly process of the oil seal mechanism becomes easy and the assemblability is improved.
Further, the sealing property can be improved, the cost can be reduced, and the weight can be reduced.

[Embodiment] An embodiment of the present invention will be described in detail and specifically with reference to the drawings.

1 to 3 show an embodiment of this invention. 1 to 3, 2 is an engine, 4 is a cylinder block, 6 is a crankshaft, 8 is an oil pan, and 10 is a crankcase. The crankcase 10 is formed by the lower portion of the cylinder block 4 and the upper portion of the oil pan 8. In this crankcase 10, the crankshaft 6
Is rotatably provided by a bearing 14.

The crankshaft 6 has a clutch part (not shown) connected to one end thereof, and a flywheel 16 for smoothing the rotation of the engine 2 fixed to the other end thereof.

An oil seal mechanism 18 is provided at the other end of the crankshaft 6 on the flywheel 16 side.

The oil seal mechanism 18 has a case portion 20, an oil seal portion 22, and a packing portion 24. This case part 20
Is composed of a bent plate-shaped metal member.

That is, as shown in FIG. 3, in the mounting portion A of the case portion 20, the case portion 20 has an annular joining flange portion 20a joined to the cylinder block 4 and the joining flange portion 20a. A continuous cylindrical rising portion 20b and a flat portion 20c which is continuous with the rising portion 20b and is substantially parallel to the joint flange portion 20a are formed. The flat portion 20c is formed with a bolt insertion hole 20d through which the bolt 28 for fixing the oil seal mechanism 18 attached to the oil screw hole 4d of the cylinder block 4 is inserted.

Further, in the crankshaft portion B of the case portion 20, the case portion 20 is continuously provided with the joint flange portion 20a so as to hold the oil seal portion 22 that seals the end portion of the crankshaft 6, and has a U-shaped section 20-. 1 is formed. The U-shaped section 20-1 is bent and formed on the inner side of the cylinder block 4 side.

Further, in the oil pan portion C of the case portion 20, an oil pan joint portion 20-2 is formed so as to protrude rightward in FIG.

The packing portion 24 is integrally vulcanized and molded on the joint flange portion 20a at the bottom surface portion of the two skirts which is the joint surface of the mounting portion A of the case portion 20 to the cylinder block 4. That is, the packing portion 24 is flat and annular,
The surface of the joint flange portion 4a on the cylinder block 4 side is vulcanized and molded.

An oil seal portion 22 that seals the crankshaft 6 with a lip portion 26 is integrally vulcanized and molded in the U-shaped section 20-1.

If scavenged, this vulcanization molding is performed by adding or not adding a vulcanizing agent such as sulfur to the rubber, and applying a suitable treatment such as heating to form a strong bond between the rubber molecules. ,
A change that reduces plastic flow over a wide temperature range, increases elasticity and tensile strength, and reduces swellability by a solvent.

As a result, the oil seal mechanism 18 operates in the cylinder block 4
The case portion 20, the oil seal portion 22, and the packing portion 24 are integrally configured before being attached to the.

Next, the operation of this embodiment will be described.

When assembling the oil seal mechanism 18 around the crankshaft 6 on the flywheel 16 side below the cylinder block 4, the oil seal mechanism 18 can be attached in one operation.

That is, in the oil seal mechanism 18, the case portion 20, the oil seal portion 22, and the packing portion 24 have already been assembled together, so that the bolt 28 of the case portion 20 can be tightened and fixed to the cylinder block 4. The work of abutting the lip portion 26 around the crankshaft 6 and the work of interposing the packing portion 24 can be performed at the same time.

As a result, when the oil seal mechanism 18 is assembled, the oil seal mechanism 18 is integrally assembled with the case portion 20, the oil seal portion 22, and the packing portion 24, so that packing is performed between the cylinder block 4 and the case portion 20. This saves the trouble of interposing the portion 24, improves the assemblability of the oil seal mechanism 18, and is practically advantageous.

Further, at the time of manufacturing the oil seal mechanism 18, it is possible to save the labor of casting and molding the case portion 20, and the labor of press-fitting the oil seal portion 22 into the case portion 20, simplifying the manufacturing process, The manufacturing cost can be reduced, which is economically advantageous.

Furthermore, since the case portion 20 of the oil seal mechanism 18 is formed of a bent plate-shaped metal member, the weight of the engine 2 portion can be reduced.

Furthermore, when the bolt 28 is attached to the cylinder block 4, the joint flange portion 20a is pressed toward the cylinder block 4 side via the flat portion 20c and the rising portion 20b, so that the effective range of the surface pressure on the cylinder block 4 is reduced. It spreads and effectively presses the packing part 24 to improve the sealing property, prevents warping due to tightening, etc., and also does not cause a problem such as a return when the bolt insertion hole 20d is drilled, so that processing etc. It will be easy.

Further, according to this oil seal mechanism 18, since the crankshaft 6 and the oil seal portion 22 are positioned, the unsealed force and deviation in the sealed state are eliminated, the tightened state is stabilized, and the seal It is possible to improve the property.

Further, since dust and the like do not enter between the joint flange portion 20a of the case portion 20 and the cylinder block 4, harmful dust does not enter the bearing 14 and the like when the oil seal mechanism 18 is removed.

Furthermore, since the outer surface of the oil seal portion 22 is held by the U-shaped cross section 20-1, the oil seal portion 22 is protected from invasion of dust and contact with other parts, and the strength of the case portion 20 is improved. It also improves the distortion of the oil seal part 22,
It is possible to prevent falling and the like, and also to improve the strength of the lip portion 26 to improve the sealing performance, and also to expand the lubricating oil holding space.

[Effect of the Invention] As is apparent from the above detailed description, according to the present invention,
The case part is composed of a bent plate-shaped metal member, and the case part has a hat-shaped cross section and is joined to the cylinder block by a joining flange part, and a rising part and a rising part connected to the joining flange part. To form a flat part that is substantially parallel to the joint flange part, and a bolt insertion hole for inserting a fixing bolt to be attached to the cylinder block is formed in the flat part, and an oil seal part that seals the end part of the crankshaft is formed. Cross section U connected to the joint flange to hold
By forming a character part, vulcanizing and molding the packing part on the joint flange part, and vulcanizing and molding the oil seal part on the U-shaped section, the oil seal mechanism is configured, and thus the assemblability of the oil seal mechanism is improved. It is improved and can be practically advantageous.

In addition, the manufacturing process of the oil seal mechanism can be simplified, the cost can be reduced, and it can be economically advantageous.

Further, since the case portion is made of the bent plate-shaped metal member, the weight of the engine portion can be reduced.

Furthermore, the tightening force of the fixing bolt can be effectively applied to the joint flange portion to widen the effective range of the surface pressure, and the packing portion can be strongly pressed to improve the sealing performance.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention, FIG. 1 is a partially cutaway configuration view of an end portion of an engine crankshaft, FIG. 2 is an enlarged sectional view of an arrow II portion of FIG. FIG. 3 is an enlarged cross-sectional view of the essential parts of the oil seal structure. FIG. 4 is an enlarged sectional view of a main part of a conventional oil seal structure. In the figure, 2 is an engine, 4 is a cylinder block, 6
Is a crankshaft, 8 is an oil pan, 10 is a crankcase, 18 is an oil seal mechanism, 20 is a case part, 22 is an oil seal part, and 24 is a packing part.

Claims (1)

[Scope of utility model registration request] 1. An oil seal structure for sealing a crankshaft lower part of a cylinder block by a case portion, an oil seal portion and a packing portion, wherein the case portion is formed by a bent plate-shaped metal member, The case portion has a joining flange portion joined to the cylinder block in a hat-shaped cross section, a rising portion continuously provided to the joining flange portion, and a flat portion continuously provided to the rising portion and substantially parallel to the joining flange portion. The flat portion is formed with a bolt insertion hole through which a fixing bolt attached to the cylinder block is inserted, and the joint flange portion is formed to hold the oil seal portion that seals the end portion of the crankshaft. A U-shaped section is formed by connecting them, and the packing section is vulcanized and molded on the joint flange section and the U-shaped section is formed. Oil seal structure characterized by being configured the oil seal mechanism by vulcanization molding the oil seal portion in.