JP2527325Y2 - Oil seal device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an oil seal device for an internal combustion engine that prevents oil leakage from a rear end of a crankshaft.

<Prior Art> An oil seal device is provided in a portion of a crankshaft that penetrates a cylinder block in order to prevent oil leakage from inside the engine (Japanese Utility Model Laid-Open No. 57-43341 and Japanese Utility Model Laid-Open No. -142560 publication etc.).

As a conventional oil seal device of this kind, for example,
There is one as shown in FIG.

In the figure, a flywheel 4 is fixed to a rear end of a crankshaft 2 supported by a cylinder block 1 by bolts 3. As shown in FIG. 6, a ring-shaped seal member 5 having a seal lip 5a, a dust lip 5b and a spring 5C is provided on the peripheral wall of the rear end of the crankshaft 2 between the flywheel 4 and the cylinder block 1.
The retainer 6 is fixed to the cylinder block 1 and the flange portion of the oil pan 8 by bolts 7.

<Problem to be solved by the invention> However, in the conventional oil seal device, the retainer 6
Since the seal member 5 is attached by driving, the seal member 5 is easily deformed during assembly, misalignment such as misalignment between the crankshaft 2 and the seal member 5 is likely to occur, and the sealing performance is impaired. Further, since the driving method is employed, the sealing member 5 is provided to impart rigidity to the sealing member 5 and prevent co-rotation with the crankshaft 2.
In FIG. 6, a mandrel 9 is provided as a mounting member as shown in FIG. 6 so that a sufficient crimping force against the retainer 6 can be obtained. Because of this mandrel 9, there is a limit to reducing the radial thickness of the seal member 5, while the outer diameter of the seal member 5 is limited in layout with the oil pan 8 and the like. There has been a problem that it is difficult to increase the output of the engine because the rear end diameter of the crankshaft 2 cannot be increased.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an oil seal device for an internal combustion engine capable of increasing a rear end diameter of a crankshaft without a seal failure due to misalignment.

<Means for Solving the Problems> Therefore, the present invention provides an oil seal device for an internal combustion engine that prevents oil leakage from a peripheral wall at a rear end of a crankshaft to which a flywheel is attached. Protrusions are provided on the inner periphery of the mounting retainer to project toward the peripheral wall of the crankshaft,
A part of an outer peripheral side of a substantially ring-shaped seal member in which an inner peripheral seal lip is slidably contacted with the peripheral wall of the crankshaft so as to cover the protrusion is integrated with the protrusion by vulcanization bonding. The seal lip on the inner peripheral side of the seal member was formed so as to be offset from the projection in the direction of the front end of the crankshaft.

<Operation> According to this configuration, the seal member is vulcanized and bonded so as to cover the protrusion provided on the inner periphery of the retainer so as to increase the joint area, so that the seal member is attached to the retainer as in the related art. The co-rotation with the crankshaft can be prevented without providing a mandrel as a mounting member for mounting. Therefore, the radial reduction of the thickness of the seal member limited by the mandrel is alleviated, and the inner diameter of the seal member can be increased. Further, the influence of misalignment is reduced as compared with the conventional driving method. Furthermore, since the seal lip on the inner peripheral side of the seal member is formed offset from the projection in the direction of the front end of the crankshaft, the rigidity between the vulcanized adhesive portion of the seal member and the seal lip is reduced, for example, The followability of the seal lip to the vibration of the crankshaft is improved.

In addition, the vulcanization bonding of the seal member to the projection provided on the inner periphery of the retainer is performed by disposing an oil seal molding die having the shape of the seal member on the inner peripheral side of the retainer, and sealing the oil seal molding inside the oil seal molding die. This is performed by press-fitting a rubber member for forming the member, forming the seal member, and performing vulcanization bonding to the protrusion, and then removing the oil seal forming die.

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings.
The same elements as those in the related art are denoted by the same reference numerals, and description thereof is omitted.

1 to 4, which show an embodiment of the present invention, a ring-shaped sealing member 11 in the oil seal device of the embodiment is provided on the peripheral wall of the rear end of the crankshaft 2. As shown in FIG. 2, the seal member 11 has a seal lip 11a located on the inner side and a dust lip 11b located on the outer side with an interval in the axial direction of the crankshaft 2 on the inner peripheral side thereof. The seal lip 11a is provided with a spring 11C for applying a tightening force as in the conventional case.

The retainer 12 has a shape as shown in FIG.
A protruding portion 12b that protrudes toward the peripheral wall of the through hole 12a of the crankshaft 2 is formed. Then, the sealing member 11 is vulcanized and bonded so as to cover the projecting portion 12b, and as a result, the joining area in which the circumferential groove 11d of the sealing member 11 is fitted to the projecting portion 12b becomes large. ing. A plurality of bolt through holes 12c are provided on the periphery of the through hole 12a.
Also, a plurality of screw holes 12d are provided on the flat bottom surface. Then, it is fixed to the cylinder lock 1 as a fixed body and the flange portion of the oil pan 8 by the bolt 7 through the bolt through hole 12c and the screw hole 12d. Further, the seal lip 11a is formed at a position offset toward the tip of the crankshaft 2 with respect to the protruding portion 12b.

According to such a configuration, the sealing member 11 is vulcanized and adhered so as to cover the protruding portion 12b provided on the inner periphery of the retainer 12, so that the core member as a mounting member for attaching the sealing member 11 to the retainer 12 is provided. , It is possible to prevent co-rotation with the crankshaft 2. Also, seal lip
Since the protrusion 11a is formed at a position offset toward the distal end of the crankshaft 2 with respect to the protruding portion 12b, the rigidity of the seal member 11 is reduced, for example, the followability of the seal lip 11a to vibration of the crankshaft 2 And the sealing performance can be further improved. Therefore, the thickness of the seal member 11 in the radial direction can be reduced while improving the sealing performance, and the through hole 12a of the retainer 12 can be reduced while the sealing performance is improved, so that the retainer 12 can be made compact. Conversely, if the diameter of the through hole 12a of the retainer 12 is the same, the inner diameter of the seal member 11 can be increased. Therefore, the rear end diameter of the crankshaft 2 can be increased without interfering with the flange portion of the oil pan 8, so that the output of the engine can be increased by using the same cylinder block as before without changing the design of the cylinder block and the like. It becomes possible.

Further, as compared with the conventional driving method, the influence of misalignment at the time of assembly is small, and the sealing performance of the sealing member 11 is not impaired.

The vulcanization bonding of the seal member 11 to the projecting portion 12b provided on the inner periphery of the retainer 12 is performed by a through-hole on the inner periphery side of the retainer 12.
On the 12a side, for example, a two-part oil seal molding die (not shown) having the shape of the seal member 11 is provided, and a rubber member for molding the seal member 11 is pressed into the oil seal molding die, After the molding of the seal member 11 and the vulcanization bonding between the projecting portion 12b and the peripheral groove 11d of the seal member 11, the oil seal molding die is detached toward the through hole 12a.

<Effects of the Invention> As described above, according to the present invention, a sealing member is vulcanized and bonded so as to cover a projection provided on an inner periphery of a retainer so as to increase a bonding area, and a seal is formed. A mandrel as an attachment member for attaching the member to the retainer is not required, the radial thickness of the seal member can be reduced, and the seal member and the retainer can be made compact.
Further, if the size is the same, the rear end diameter of the crankshaft can be increased, so that the output of the engine can be increased. Further, the effect of misalignment can be reduced, and the sealing effect is further enhanced by synergy with the reduction in rigidity of the sealing member due to the formation of the sealing lip on the inner peripheral side of the sealing member offset from the projection toward the front end of the crankshaft. Can be improved.

In addition, a projection protruding toward the peripheral wall of the crankshaft is provided on the inner periphery of the retainer, and the outer peripheral side of a substantially ring-shaped seal member with which the sealship on the inner peripheral side slides on the peripheral wall of the crankshaft is provided. Since the structure is formed by sulfur bonding, it is easy to remove the oil seal molding die after the vulcanization bonding, and it is possible to improve the workability when integrally forming the seal member on the inner periphery of the retainer, thereby improving production efficiency. There is also an effect that the improvement can be achieved.

[Brief description of the drawings]

1 is an assembled state diagram showing an embodiment of the present invention, FIG. 2 is an enlarged view of a main part of the embodiment, FIG. 3 is a front view of a retainer,
4 is a cross-sectional view taken along the line II of FIG. 3, FIG. 5 is an assembled state diagram of the conventional example, and FIG. 6 is an enlarged view of a main part of the conventional example. DESCRIPTION OF SYMBOLS 1 ... Cylinder block, 2 ... Crank shaft, 7 ... Bolt, 8 ... Oil pan, 11 ... Seal member, 11a ... Seal lip, 12 ... Retainer

Continuation of the front page (56) References JP-A-60-148471 (JP, A) JP-A-59-142560 (JP, U) JP-A-56-156910 (JP, U) JP-A-59-4962 (JP) , U) Special Publication No. 35-5407 (JP, B1) Kanae Komiyama's Four Machines, "Machine Elements Machine Design ▲ 1 ▼ Leakage Prevention Law", published June 30, 1965 by Seibundo Shinkosha Co., Ltd. , Page 300, second column from bottom

Claims (1)

(57) [Scope of request for utility model registration] An oil seal device for an internal combustion engine for preventing oil from leaking from a peripheral wall at a rear end of a crankshaft to which a flywheel is attached, wherein the crank is provided on an inner periphery of a seal member attaching retainer fixed to a fixing portion with bolts. An outer peripheral portion of a substantially ring-shaped seal member in which a projection protruding toward the shaft peripheral wall is provided, and the inner peripheral side seal lip slidably contacts the crankshaft peripheral wall so as to cover the projection. An oil seal device for an internal combustion engine, wherein a seal lip on the inner peripheral side of the seal member is offset from the projection toward the front end of the crankshaft.