JPH0617940A - Retainer-equipped oil seal and manufacture thereof - Google Patents

Abstract

PURPOSE:To enhance the accuracy of a retainer-equipped oil seal and the ease with which the oil seal is assembled to a vehicle engine block, the oil seal being secured in place by fitting of two positining holes of the retainer with two positioning knock pins provided to the engine block. CONSTITUTION:A round hole 12 for a knock pin is formed in the ear piece 11b of a retainer 11 and an oblong hole 13 is formed in the ear piece 11c of the retainer 11, the oblong hole 13 being elongated in the direction of alignment of knock pins and having the same shape as the round hole 12 in the vertical direction. Such a retainer 11 is set in a metal mold having positioning protrusions of circular cross section, one of which can be fitted into the round hole 12 and the other into the oblong hole, and then the metal mold is closed and an oil seal 17 is formed integrally with the inner peripheral flange lie of the retainer 11. Since one of the positioning holes is oblong 13, assembling of the oil seal in the metal mold and to an engine block is facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil seal with a retainer used for sealing a crankshaft portion of an engine block for a vehicle and a method for manufacturing the oil seal.

[0002]

2. Description of the Related Art Conventionally, in order to maintain the sealing performance of the oil seal, it is necessary to assemble the oil seal with a retainer used in this type of device by minimizing the eccentricity between the shaft and the oil seal. For that purpose, it is required to assemble the retainer holding the oil seal to the engine block with high accuracy.
Knock pins for book positioning are used.

FIG. 3 shows an example of a conventional oil seal with a retainer of this type. The retainer 1 has a tubular main body 1a and three ears 1b, 1c, 1d extending radially outward from the bottom of the main body 1a. 18 ears 1b, 1c
The ear piece 1d extends in the direction of 0 degrees, and the ear piece 1d extends in the direction of 90 degrees. Knock pin holes 2 and 3 and mounting screw holes 4 and 5 for positioning are formed in the ears 1b and 1c, respectively, and mounting screws hole 6 is formed in the ear piece 1d. A flange 1e is formed on the inner peripheral surface of the upper portion of the main body 1a of the retainer 1, and an oil seal 7 is integrally formed of a rubber material at the inner end of the flange 1e.

Such an oil seal with a retainer is
It is used by inserting it into the crankshaft protruding from the hole of the engine block of the vehicle engine. That is, the oil seal 7 is inserted into the crankshaft, and the body 1a of the retainer 1 closes the hole through which the crankshaft protrudes.
Is fitted to the two knock pins projecting from the engine block, and then the mounting screws are inserted through the mounting screw holes 4, 5 and 6 to be fixed to the engine block.

FIG. 4 shows a method of manufacturing such an oil seal with a retainer. The lower mold 8 is formed with a protrusion 8a fitted to the inner peripheral surface of the main body 1a of the retainer 1 and a cavity 8b for molding the oil seal 7. The middle mold 9 is provided with a recess 9a for escaping the outer peripheral surface of the main body 1a of the retainer 1 and the ear pieces 1b, 1c, 1d. The upper mold 10 includes a flange 1e of the retainer 1.
A protrusion 10a for holding the oil seal 7 and a cavity 10b for molding the oil seal 7 together with the lower mold 8 are formed.

The retainer 1 is set in the lower mold 8 by fitting the inner peripheral surface of the main body 1a into the projection 8a of the lower mold 8.
Then, an unvulcanized rubber material is placed in the cavity 8b of the lower mold 8, the middle mold 9 and the upper mold 10 are closed and heated for a certain period of time to mold the oil seal 7 and the oil seal 7.
Are vulcanized and bonded to the retainer 1.

[0007]

However, in the conventional oil seal with a retainer shown in FIG. 3, in order to obtain a highly accurate oil seal with little eccentricity, a knock pin for positioning provided on the retainer 1 is used. Holes 2 and 3
The hole diameter D, the center distance A between the knock pin holes 2 and the retainer 1, the center distance B between the knock pin holes 2 and 3, and the offset distance C between the knock pin holes 2 and 3 with respect to the center line of the retainer 1. It is processed with high accuracy with the required tolerance,
Even if each dimension can be machined within the tolerance, depending on the combination of each dimension, the knock pin of the engine block cannot be installed smoothly, and press-fitting work such as hitting with a hammer is required, and the assembling workability is improved. There was a problem of lowering.

In the conventional method of manufacturing an oil seal with a retainer shown in FIG. 4, the retainer 1 is positioned with respect to the lower die 8 by fitting the inner peripheral surface of the main body 1a and the protrusion 8a of the lower die 8. Since this is done, the lip of the oil seal is formed with reference to the main body 1a. However, assembling the oil seal with retainer to the engine block is based on the knock pin hole.Therefore, when the oil seal with retainer is assembled to the engine block, the eccentricity of the lip increases due to variations in the machining position of the knock pin hole.
There is a problem of lowering the sealing performance.

Further, in order to solve the above problem, the retainer 1
Instead of fitting the main body 1a of the above with the projection 8a of the lower mold 8,
It is conceivable to provide the lower mold 8 with a projection that can be fitted into the knock pin holes 2 and 3. However, this projection and the knock pin hole 2,
After all, the fitting with 3 becomes the same as the fitting with the knock pin of the engine block and the knock pin holes 2 and 3, and the diameter and position of the protrusion must be processed with high precision, and the die cost is high. Not only that, but even if it can be processed with high accuracy, it becomes difficult to set the retainer in the lower mold depending on the combination of the dimensions, and the workability is significantly reduced.

Therefore, a first object of the present invention is to provide an oil seal with a retainer which is easy to assemble to an engine block and has high precision.

A second object of the present invention is to provide a method of manufacturing an oil seal with a retainer, which is easy to set in a mold and has high precision.

[0012]

According to the present invention, in order to achieve the first object, one of the two knock pin holes of the retainer is a round hole and the other is long in the arrangement direction of the two knock pins. It is a long hole.

In order to achieve the above-mentioned second object, the present invention provides a mold with a positioning projection having a circular cross section which can be fitted into a knock pin hole of a retainer, one of which has a round hole and the other of which has a long hole. The retainer is positioned in the mold by fitting the projection and the knock pin hole.

[0014]

Therefore, according to the oil seal with a retainer of the present invention, one of the two knock pin holes of the retainer is a round hole, and the other is a long hole long in the arrangement direction of the two knock pins. Positioning may be performed only by using a round hole as a reference in the direction in which the knock pins are arranged, and the elongated hole has a higher degree of freedom, so that the engine block can be easily assembled.

Further, according to the method of manufacturing an oil seal with a retainer of the present invention, the knock pin hole of the retainer, one of which has a round hole and the other of which has a long hole, is fitted to a positioning protrusion having a circular cross section provided on the mold. Since the retainer is positioned by doing so, the retainer can be easily assembled to the mold.

[0016]

【Example】

(First Embodiment) FIG. 1 shows an oil seal with a retainer according to a first embodiment of the present invention, (a) is a plan view and (b) is a sectional view. The retainer 11 has a tubular main body 11a and three ear pieces 11b, 11c, 11d extending radially outward from the bottom of the main body 11a. Ear piece 11
b and 11c extend in the direction of 180 degrees, and the ear piece 11d extends in the direction of 90 degrees with respect to them. A round hole 12 for a knock pin for positioning is formed in one ear piece 11b, and a long hole 13 for a knock pin for positioning is formed in the other ear piece 11c. Also, each ear piece 11b,
Mounting screw holes 14, 15 and 16 are formed in 11c and 11d. Further, a flange 11e is formed on the upper inner peripheral surface of the main body 11a of the retainer 11, and an oil seal 17 is integrally formed of a rubber material on the inner end of the flange 11a.

The diameter 12 of the round hole 12 for the knock pin is machined with the same dimensional tolerance ± b as in the conventional case.
The tolerance of the distance A from the center of 2 to the center of the retainer 11 and the offset distance C from the center of the round hole 12 and the long hole 13 to the center line of the retainer 11 is set to ± a.
In addition, the center-to-center distance B between the round hole 12 and the slot 13 and the slot 13
Since the dimension E in the longitudinal direction is not required to have high accuracy, general tolerances ± c and ± d are adopted. The dimension D of the elongated hole 13 in the lateral direction is the same as the diameter of the round hole 12 and processed with the same accuracy.

An oil seal with a retainer, in which each part of the retainer 11 is machined with such dimensions, is positioned by fitting the knock pin round hole 12 and the elongated hole 13 of the retainer 11 to the knock pin of the engine block.
At that time, in FIG. 1, in the vertical direction, a round hole 12 and an elongated hole 13 are provided.
Although the position is regulated by the short side direction, the lateral direction is regulated only by the round hole 12, and the degree of freedom in the longitudinal direction of the long hole 13 becomes large, so that the knock pin can be easily fitted. Moreover, since the dimensions A and C that affect the eccentricity are machined with a highly accurate tolerance ± a, the eccentricity of the oil seal 17 can be minimized. Furthermore, since the tolerance of the center distance between the knock pin round hole 12 and the elongated hole 13 can be made smaller than in the conventional case in which both are round holes, the retainer manufacturing cost can be reduced.

As described above, according to the first embodiment,
Retainer 11 has two knock pin holes, one of which is a round hole 1
2 and the other is long in the direction in which the knock pins are arranged, and the direction perpendicular to this is a long hole 13 having the same size as the diameter of the round holes 12, so it is sufficient to use the round holes 12 as a reference in the direction in which the knock pins are arranged. Since the elongated hole 13 has a greater degree of freedom, the positioning of the engine block with respect to the knock pin can be easily performed.

Further, the tolerance in machining the knock pin round hole 12 and the elongated hole 13 for positioning is determined by the distance A between the centers of the round hole 12 and the retainer 11 and the center of the round hole 12 and the elongated hole 13. Offset distance C to the center line of retainer 11
Since it is only necessary to set the two with high precision, the retainer 11
Can be easily processed, and the manufacturing cost can be reduced.

In this embodiment, the retainer oil seal is described as an example of the retainer-integrated oil seal in which the retainer 11 and the oil seal 17 are integrally molded. However, the retainer oil seal according to the present invention is made of metal. It also includes a type in which a separate oil seal having a reinforcing ring is incorporated in the retainer 11, and the shape of the retainer is not particularly limited to the above, such as those having different numbers of mounting screw holes and ear pieces. .

(Second Embodiment) Next, a method of manufacturing an oil seal with a retainer according to a second embodiment of the present invention will be described with reference to FIG. The lower die 18 has the first
Round hole 1 for knock pin of retainer 11 described in the embodiment
Positioning projections 18a and 18b having a circular cross section for positioning 2 and the slot 13 and a cavity 18c for molding the oil seal 17 are formed. The positioning protrusions 18a and 18b may be pins embedded in the lower mold 18. Positioning protrusions 18a, 18
The diameter of b, the distance between the centers, and the offset distance are determined in consideration of the materials of the retainer and the mold. The middle mold 19 includes the outer peripheral surface of the main body 11 a of the retainer 11 and the ear piece 11 a.
Recesses 19a are formed for escaping b, 11c, 11d and positioning protrusions 18a, 18b. The upper die 20 has a protrusion 20 that presses the flange 11e of the retainer 11.
a and a cavity 20b for molding the oil seal 17 together with the lower mold 18 are formed.

The retainer 11 has a round hole 1 for the knock pin.
2 and the elongated hole 13 to the positioning protrusions 18a, 1 of the lower mold 18.
8b is fitted and set in the lower mold 18. At that time, although the positions are regulated by fitting the positioning projections 18a and 18b with the round holes 12 and the elongated holes 13 in the direction perpendicular to the paper surface, the positioning projections 18a and the round hole 1 are positioned in the left-right direction of the paper surface.
Since the position is regulated only by fitting with the retainer 2, the retainer 1
It becomes easy to set the one on the lower mold 18. Moreover, similarly to the processing of the retainer 11, the center-to-center distance of the positioning protrusions 18a and 18b corresponding to B of FIG. 1 does not require so high accuracy, so that the manufacturing cost of the mold can be kept low.

In this way, the retainer 11 is attached to the lower mold 18
After setting, the unvulcanized rubber material is placed in the cavity 18c of the lower mold 18, the middle mold 19 and the upper mold 20 are closed and heated for a certain period of time to mold the oil seal 17 and the oil seal 17 to the retainer 11. Vulcanize and bond, open the mold and take out the product.

As described above, according to the second embodiment,
Since the lower mold 18 is provided with the positioning protrusions 18a and 18b having a circular cross section that can be fitted into the knock pin round hole 12 and the elongated hole 13 of the retainer 11, the retainer 11 can be easily set in the lower mold 18. In addition, the positioning protrusions 18a,
Since it is not necessary to process the center-to-center distance of 18b with very high accuracy, the manufacturing cost of the mold can be suppressed. Furthermore, since the lip of the oil seal is formed with the knock pin hole as a reference, in other words, the lip is formed in the state where the retainer oil seal is assembled to the engine block, so it is necessary to manufacture a highly accurate retainer oil seal with small eccentricity. You can

Although the oil seal 17 is molded by the compression molding method in this embodiment, the oil seal 17 may be molded by injection molding or transfer molding. . Further, the positioning protrusion may be provided on the middle size or the like.

[0027]

As described above, in the oil seal with a retainer according to the present invention, one of the two knock pin holes of the retainer is a round hole and the other is a long hole elongated in the arrangement direction of the two knock pins. , It is possible to realize a highly accurate oil seal with a retainer that can be easily assembled to the engine block.

Further, according to the method of manufacturing an oil seal with a retainer of the present invention, one of the retainer knock pin holes, one of which is a round hole and the other of which is a long hole, is fitted to a positioning protrusion having a circular cross section provided on the mold. Since the retainer is positioned by doing so, it is possible to realize a method of manufacturing the oil seal with a retainer, which is easy to assemble the retainer into the mold and has high accuracy.

[Brief description of drawings]

FIG. 1A is a plan view of an oil seal with a retainer according to a first embodiment of the present invention. (B) A sectional view of the oil seal.

FIG. 2 is a sectional view of a mold for manufacturing an oil seal with a retainer according to a second embodiment of the present invention.

FIG. 3A is a plan view of an oil seal with a retainer in a conventional example. (B) A sectional view of the oil seal.

FIG. 4 is a sectional view of a mold for manufacturing an oil seal with a retainer in a conventional example.

[Explanation of symbols]

 11 Retainer 12 Round Hole for Knock Pin 13 Oblong Hole for Knock Pin 14, 15, 16 Mounting Screw Hole 17 Oil Seal 18 Lower Mold 18a, 18b Positioning Protrusion 19 Medium Model 20 Upper Model

Claims (2)

[Claims] 1. An oil seal with a retainer fixed to the engine block by fitting two positioning holes of a retainer to two positioning knock pins provided in the engine block, and positioning the two retainers. An oil seal with a retainer, one of which is a round hole and the other is a long hole that is long in the direction in which the two knock pins are arranged. 2. A retainer having a positioning round hole and an elongated hole is set in a mold provided with positioning protrusions having circular cross sections which fit into the round hole and the elongated hole, and then the mold is closed. A method of manufacturing an oil seal with a retainer, wherein an oil seal is integrally formed on the inner peripheral portion of the retainer.