JPH0630567U - Oil seal - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an oil seal that further improves the function of preventing sticking between seal bodies and suppresses the manufacturing cost of a molding die. In an oil seal (1) having an annular seal body (2) made of a rubber-like elastic body, projections (7, 8) having a substantially triangular cross section that axially protrude over the entire circumference of both end faces (5, 6) of the seal body (2). Was formed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an oil seal used for automobiles, household appliances, etc., and to an oil seal having a rubber-like elastic body.

[0002]

[Prior art]

 FIG. 4 is a cross-sectional view of a conventional oil seal 100 in a packaging form (rolling), and FIG. 5 is a plan view of the oil seal 100.

The oil seal 100 has an annular seal body 101 made of a rubber-like elastic body, and a seal lip 102 is integrally formed on the inner peripheral side of the seal body 101. The oil seal 100 is housed in the case 103 in a stacked state as shown in FIG.

A protrusion 105 having a substantially trapezoidal cross section is provided on one end surface (flat portion) 104 of the seal body 101. As shown in FIG. 5, the protrusions 105 are formed on the circumference of a circle in equal numbers. The oil seal 100 is vulcanized and molded by a mold. Therefore, the mold has holes that form the protrusions.

By contact between the protrusion 105 and the end surface 106 of the seal body 101 of the oil seal 100 located above, the adhesion due to the close contact between the end surfaces 104 and 106 is prevented, and the separability between the oil seals 100 is secured. is doing.

[0006]

[Problems to be solved by the device]

 However, the oil seal 100 has the following problems.

Since the tip of the protrusion 105 is flat, the protrusion 105 and the end face 106 are still in surface contact with each other. Therefore, the adhesion between the oil seals 100 cannot be completely eliminated.

Since the protrusions 105 are formed equally on the circumference of the seal body 101, the portion of the seal body 101 without the protrusions 105 is bent downward by its own weight, and the surface of the seal body 101 located below the surface of the seal body 101. Contact and stick.

The projections 105 are formed on the circumference of the seal body 101 in an equal arrangement. In order to form the protrusion 105, the die used must be cut by a milling machine or the like to form a plurality of holes. Therefore, the manufacturing cost of the mold increases.

The present invention is to solve the above problems, and an object of the present invention is to provide an oil seal that can further improve the function of preventing sticking between seal bodies and reduce the manufacturing cost of a molding die. .

[0011]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides an oil seal having an annular seal body made of a rubber-like elastic body, in which an axially protruding projection having a substantially triangular cross-section is formed over the entire circumference of the end surface. .

[0012]

[Action]

 The tips of the protrusions having a substantially triangular cross section are in line contact with the opposite end faces of the seal body over the entire circumference. The seal main body does not bend because the protrusions extend over the entire circumference. Since the hole of the die corresponding to the protrusion is annular, it can be cut at one time, reducing the number of machining steps.

[0013]

【Example】

 FIG. 1 is a sectional view of an oil seal 1 to which the present invention is applied in a packed state (rolled). The oil seal 1 has a cylindrical seal body 2 made of a rubber-like elastic body, and an annular seal lip 4 is integrally formed on the seal body 2 via an inward flange 3.

On both end surfaces (flat end surfaces) 5 and 6 of the seal body 2, projections 7 and 8 having a substantially triangular cross section, which project in the axial direction, that is, the vertical direction in the drawing, are integrally formed. FIG. 2 is a plan view of the oil seal 1. The protrusion 7 is formed over the entire circumference of the end face 5.

FIG. 3 is an enlarged sectional view of the protrusion 7. The height A from the tip of the protrusion 7 to the end face 5 is set to about 0.1 mm, and the radial width B of the protrusion 7 is set to about 0.2 mm. The tip angle θ of the protrusion 7 is set to about 90 degrees.

The protrusion 8 is also configured similarly to the protrusion 7. Further, in the illustrated embodiment, the projections 7 and 8 have the same circumference, that is, have the same diameter, but they may have different diameters.

A metal ring 9 having a substantially L-shaped cross section is embedded from the seal body 2 to the inside of the inward flange 3. A spring 11 is attached to the back surface of the seal lip 4.

In the above configuration, the oil seal 1 is stacked in the case 10 so that the seal lip 4 faces the same direction as shown in FIG. Then, the protrusion 8 of the upper oil seal 1 and the protrusion 7 of the lower oil seal 1 are in line contact with each other, and the end surfaces 6 and 5 of the upper and lower oil seals 1 are not in contact with each other.

Therefore, it is possible to prevent the oil seals 1 from sticking to each other and improve the separability. Further, since the protrusions 7 and 8 are in line contact with each other, adhesion can be almost completely prevented.

Further, since the projections 7 and 8 are formed over the entire circumference, the seal body 2 does not bend due to its own weight, and the sticking prevention function is further enhanced.

Further, since the projections 7 and 8 are formed in an annular shape over the entire circumference, the hole of the mold for forming the oil seal 1 is also an annular shape, and can be cut at once by a lathe or the like. Therefore, the number of processing steps can be reduced, and the die manufacturing cost can be suppressed.

Furthermore, in this embodiment, the height A of the protrusions 7 and 8 is set to 0.4 mm, so that the axial dimension of the product does not increase.

Furthermore, when the protrusions 7 and 8 are set to have different diameters, the protrusion 7 comes into contact with the end face 6 and the protrusion 8 comes into line contact with the end face 5, and the same effect as above can be obtained.

If two or more protrusions are provided on the same end face, a negative pressure may be generated between the protrusions due to contact with the mating end face, and a suction cup-like action may occur. Therefore, one protrusion is preferable.

If the projections 7 and 8 are provided on both end surfaces 5 and 6 as described above, it is also effective when the oil seal 1 is packed (unipack) with the seal lip 4 facing in the opposite direction. When the protrusions are provided only on one end face, the oil seals 1 are regularly arranged as shown in FIG.

When the oil seal of the present invention was compared with the conventional oil seal, the results shown in the following table were obtained.

[0027]

[Table 1]

[0028]

[Effect of device]

 Since the present invention is configured as described above, when the oil seals are overlapped with each other, the projections and the end faces are in line contact with each other, and the end faces of the oil seals are not in contact with each other. Therefore, it is possible to prevent the oil seals from sticking to each other and improve their separability. In addition, since the protrusion is a line contact, the sticking can be almost completely prevented.

Further, since the protrusion is formed over the entire circumference, the seal body does not bend due to its own weight, and the sticking prevention function is further enhanced.

Further, since the protrusion is formed in an annular shape over the entire circumference, it is sufficient to cut the mold for forming the oil seal once. Therefore, the number of processing steps is reduced, and the manufacturing cost of the mold can be suppressed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a stacked oil seal of the present invention.

FIG. 2 is a plan view of the oil seal of FIG.

FIG. 3 is an enlarged sectional view of a protrusion of the oil seal of FIG.

FIG. 4 is a cross-sectional view of a conventional oil seal in a stacked state.

5 is a plan view of the oil seal of FIG.

[Explanation of symbols]

 1 Oil seal 2 Seal body 3 Inward flange 4 Seal lip 5,6 End face 7,8 Protrusion 9 Metal ring 10 Case 11 Spring A Protrusion height B Protrusion width θ Projection tip angle

Claims (1)

[Scope of utility model registration request] 1. An oil seal having an annular seal body made of a rubber-like elastic body, characterized in that a projection having an approximately triangular cross-section that protrudes in the axial direction is formed over the entire circumference of the end surface of the seal body. Oil seal.