JPS6222026B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a metal ring for an oil seal, and more particularly, it provides a method for manufacturing a metal ring for an oil seal that reduces the weight of the product and saves the amount of materials used.

Conventionally, as illustrated in FIG. 1, a metal ring 1 made of a plate-like material and a rubber-like elastic material is used to provide a cylindrical portion 2 and a radial portion 3 extending inward from one end of the cylindrical portion 2. When manufacturing the metal ring 1 of the oil seal consisting of the sealing member 5 bonded to the inner end of the ring 1, the through hole of the radial part 3 is hollowed out and the edge of the cylindrical part 2 is controlled in advance. A metal ring forming mold is prepared to form a substantially serpentine-shaped annular plate material by performing outer punching to form the outer dimensions of As shown in FIG. 2, a plate material having a band shape and having the same wall thickness as the metal ring 1 is fed with an appropriate feed pitch, and then subjected to an outer punching process, a hollow punching process, and a bending and squeezing process. The steps are carried out almost simultaneously to form a metal ring 1 having a cylindrical portion 2 as shown in FIG. 3 and a radial portion 3 extending inward from one end of the cylindrical portion 2 and having a through hole removed. However, conventionally, the width dimension B and material feed pitch of the strip plate material are set to about B = _{D 0 +} (1.5 to 3.5 mm), p = D ₀ + 1.5 mm x 2 for the outer dimension D 0. was normal.

The inventors set the axial width b (see Fig. 1) of the cylindrical portion 2 of the metal ring 1 to protect the sealing member 5 made of a rubber-like elastic material during assembly, handling, etc.
Alternatively, in order to regulate the relative position of the seal member 5 with respect to the bearing, it is usually set to a value larger than the axial width dimension of the seal member 5, but the housing into which the cylindrical portion 2 is inserted ( From the viewpoint of maintaining the sealing property on the fitting circumferential surface with (not shown), it is noted that the above-mentioned width dimension is not necessarily necessary, and that approximately 1/2 of the width dimension b or less is sufficient. By setting the width dimension and material feeding pitch of the strip material to be smaller than the outer dimension of the metal ring mentioned above, it is possible to save materials for manufacturing the metal ring and reduce the weight of the product. We have invented a method for manufacturing a metal ring for an oil seal that can be formed to have the correct dimensions, appropriately regulate the relative position of the oil seal with respect to a bearing, etc., and protect the seal member made of a rubber-like elastic material during handling.

In the mold used for manufacturing the metal ring for oil seals according to the present invention, the profile of the punching die and punching punch forming the blank is circular with a diameter of the punching dimension D ₀ as shown in FIG. It is formed in a shape in which the chord parts located at positions facing each other are removed, and has a structure that allows hollowing and bending of the radial part to be performed at the same time. As shown, strip-shaped plates having a width dimension B′ smaller than the outer diameter dimension D ₀ are inserted facing each other in a direction connecting the removed chord parts, and the outer diameter dimension D _{0 is}
As shown in Fig. 5, the blank is fed with a smaller feed pitch than the above, and the chord part of the circle whose diameter is the outer diameter D ₀ is removed from the four parts on the circumference. As shown in FIG. 6, the cylindrical portion 2 is
An oil seal metal ring having substantially arc-shaped cutout portions 7 is formed at four locations on the circumference at the end opposite to the radial portion 3.

The cylindrical portion 2 is formed into an incomplete cylindrical shape by adding a cutout 7, as shown in FIG.
Since a portion having the normal width dimension b of the cylindrical portion 2 is formed between the adjacent cutout portions 7, 7, it is easy to set the axial position of the oil seal during assembly, or to adjust the seal member during handling. There is no need to worry about the protection of

As is clear from FIGS. 4 and 5, increasing the depth in the axial direction of the cutout 7 indicated by the symbol e in FIG. 5 improves the sealing function at the fitting portion with the housing. There is a risk of reducing the sealing function by shortening the part that is responsible for the sealing function, and also eliminating the part that is held by the cutout 7 and maintains the width dimension b in the axial direction. When setting p', care must be taken so that the axial depth e of the cutout 7 does not become excessive in either the longitudinal direction of the strip plate material or in the direction orthogonal to the longitudinal direction.

Since the method for manufacturing a metal ring for an oil seal according to the present invention has the above-described constituent requirements, the following effects are brought about. Width dimension of strip plate material
Both B' and material feed pitch p' are set smaller than the outer dimension _D0 that forms the edge of the cylindrical part 2 of the metal ring by bending, thereby reducing material loss. This results in cost savings and a lighter product due to the formation of the cutout 7 at the end of the cylindrical part 2, and the formation of the full width of the cylindrical part in the diagonal direction of the outer cutout allows the relative position of the oil seal to be adjusted. This is properly regulated, and by controlling the axial depth e of the cutout portion 7, the sealing function at the fitting portion is sufficiently ensured.

Although the drawings show an example in which the cylindrical portion of the metal ring is not coated with a rubber-like elastic material, the present invention is not limited to this, and the outer peripheral surface of the cylindrical portion may be coated with a rubber material. The present invention can also be applied to the production of a metal ring for an oil seal that has a covered structure. In this case, the missing part of the cylindrical part can be filled by shaving rubber material, or the rubber part can be filled with rubber material. It is necessary to specially design the mold used for molding so that a cutout corresponding to the cutout of the metal ring is formed in the rubber coating as well.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing the structure of an oil seal to which the present invention is applied, Fig. 2 is a plan view showing a method of manufacturing a metal ring for an oil seal according to the prior art, and Fig. 3 is manufactured by the method shown in Fig. 2. FIG. 4 is a plan view showing the profile of the outer punching part of the mold used for manufacturing the metal ring for oil seals according to the present invention, and FIG. 5 is a cross-sectional view showing the structure of the metal ring according to the present invention. A plan view showing a method of manufacturing a metal ring for an oil seal,
FIG. 6 is a sectional view showing the shape of a metal ring for an oil seal manufactured by the method shown in FIG. 5 using the mold whose profile of one part is shown in FIG. 4. 1...Metal ring, 2...Cylindrical part, 3...Radial part, 5...Seal member, 7...Cut out part, b...Axial width dimension, D ₀ ...External extraction dimension, B, B'...Width dimension of strip plate material, p, p'...Material feed pitch, e...
...Notch depth.

Claims (1)

[Claims] 1 A metal ring for an oil seal, which has a cylindrical portion 2 and a radial portion 3 extending in the radial direction from one end of the cylindrical portion 2, and a seal member 5 made of a rubber-like elastic material is coupled to the end of the radial portion 3. In the manufacturing method of 1, an outer punching process is performed to form a shape in which chord parts located at mutually opposing positions are removed from a circle whose diameter is an outer cutout dimension D ₀ that regulates the edge of the cylindrical part 2, and the seal. A mold for forming a metal ring that performs hollowing to form the inner circumferential side of the radial portion 3 to which the member 5 is coupled and bending and drawing to form the cylindrical portion 2 has a diameter smaller than the outer dimension D ₀ . a step of supplying a strip-shaped plate material having a smaller width dimension B' with a material feed pitch p' smaller than the outer extraction dimension D ₀ in a direction in which the cut out chord parts are connected; The cylindrical portion has a substantially arc-shaped cutout 7 formed at its axial end by applying a pressing force to a metal ring molding die and performing external punching, hollow punching, and bending and drawing. 2 and forming the radial portion 3.