JP2668135B2 - Seal manufacturing method - Google Patents

Description

The present invention relates to a method for producing a seal.

[Problems to be solved by conventional technology and invention]

Generally, a ring seal such as an O-ring has been formed by vulcanization by inserting a raw rubber cord into a mold or by injection molding.

Therefore, the method of inserting the string-like body has a poor work efficiency and is extremely troublesome for the worker. In addition, in either of the above-mentioned methods, a large amount of vulcanization cannot be performed at a time with this mold, and furthermore, the manufactured seal is made of the same material as a whole. That is,
If the seal is made of the same material, the fixing part for fixing and holding this seal is also soft, with good sealing properties, like the sealing part. There was a risk of coming off.

Therefore, according to the present invention, a seal manufacturing method for manufacturing a ring seal that can be easily manufactured and mass-produced, and that can be made different in hardness between inside and outside and does not come off during use. I will provide a.

[Means for solving the problem]

In order to achieve the above object, a seal manufacturing method according to the present invention is directed to a cylindrical member made of a rubber material that covers a core member by radially laminating a plurality of rubber layers having different hardnesses on the core member. And then, while covering the core member,
The cylindrical material is cut and cut into a ring shape to form a plurality of ring seals.

[Action]

A plurality of ring seals are formed by sequentially cutting the cylindrical material into a ring-shape. If the cutting pitch is changed, ring seals having various thicknesses can be manufactured. Further, when manufacturing a cylindrical material, it is sufficient to put a cylindrical body into a vulcanizing mold, so that it can be manufactured in a larger amount than a conventional mold in which cavities are arranged in a plane. Further, in the cylindrical material, by changing the shape of the outer peripheral surface (or the inner peripheral surface) of the cylindrical material (the shape of the cavity of the mold may be changed), the sealing portions of various shapes can be formed. Can be formed. Moreover, one core member can be used in common from the formation of the cylindrical material to the cutting and separation of the cylindrical material, and there is no need to pull out the core member from the cylindrical material during the manufacturing process. At the time of cutting, the core member holds the cylindrical material in a cylindrical shape.

〔Example〕

 Hereinafter, embodiments will be described with reference to the drawings.

FIG. 1 shows an embodiment of a method for producing a seal according to the present invention, by which a ring seal 3 composed of an inner layer 1 and an outer layer 2 is produced as shown in FIG. That is, the ring seal 3 is a so-called inner diameter seal, in which the outer layer 2 is a seal portion that presses against the inner peripheral surface 5 of the cylindrical body 4, and the inner layer 1 is a fixed portion that is fitted to the shaft portion 6.

 Next, a method for manufacturing the ring seal 3 will be described.

First, as shown in FIG. 1 (1), the core member 7 is coated with an unvulcanized coating layer 8a made of unvulcanized raw rubber, and then, as shown in FIG. It is put into a vulcanization mold 11 made of 10 and heated and pressed to vulcanize the coating layer 8a to form a vulcanized coating layer 8b. Next, the core member 7 to which the vulcanized coating layer 8b is attached is taken out of the mold 11, and as shown in FIG. 1 (III), after coating the coating layer 8b with the unvulcanized coating layer 12a,
As shown in FIG. 1 (IV), the mold is heated in a vulcanization mold 15 composed of upper and lower molds 13 and 14 different from the above-mentioned mold 11.
By applying pressure, the coating layer 12a is vulcanized to form a vulcanized coating layer 12b. After that, the core member 7 to which the vulcanized coating layers 8b and 12b are attached is taken out from the mold 15 to form the cylindrical material 16 made of a rubber material. In this case, the cylindrical material 16 is composed of two rubber layers, an inner layer 33 and an outer layer 34, as shown in FIG.

Next, a plurality of ring seals 3 are formed by cutting and separating the cylindrical material 16 into a ring shape as shown by a virtual line. In this case, the outer peripheral surface 16a is formed along the longitudinal direction. Are formed at predetermined pitches, and the spaces between the projections 19 are cut off.

However, when cutting, in order to cut reliably,
At least the tip of the blade portion 20a of the cutter 20 must surely reach the surface 7a of the core member 7, and therefore, before cutting,
The core member 7 may be replaced with a core member 21 as shown in FIG. (Of course, the core member 7 can be cut and separated without change.) That is, the core member 7 is pulled out from the cylindrical material 16 from the state of FIG. 1 (V), and thereafter, the core member 21 shown in FIG. Is inserted into the cylindrical material 16. Here, the core member 21 includes a core member main body 22 made of a metal such as steel, and a coating layer 23 made of urethane rubber, plastic, or the like that covers the outer peripheral surface of the core member main body 22.

Therefore, at the time of cutting, as shown in FIG.
Even when the tip of the blade portion 20a of the cutter 20 is slightly protruded into the coating layer 23, the tip of the blade portion 20a is not damaged, so that the material 16 is reliably cut and separated.

Further, as shown in FIG. 2 (II), it is also preferable to use a core member 25 in which peripheral grooves 24 are formed at a predetermined pitch along the longitudinal direction. That is, even when the tip of the blade portion 20a of the cutter 20 slightly protrudes from the inner layer 23, the recessed groove 24 forms an escape of the tip of the blade portion 20a, which damages the tip portion of the blade portion 20a, or the core member 2
The material 16 is reliably cut and separated without leaving any uncut portions without damaging the 5.

The core members 21 and 25 shown in FIGS. 2 (I) and 2 (II) have outer flange portions 26 and 27 formed at one end thereof. Is determined. Further, since it is not put into the vulcanizing molds 11 and 15, the core member at the time of this cutting may be formed of a plastic rod.

When cut and separated, the core members 7, 21, 25 are pulled out, and a plurality of ring seals 3 are formed.

Then, the inner layer 1 is nitrile rubber, chloroprene rubber, fluororubber or the like, and the outer layer 2 is also nitrile rubber, chloroprene rubber or the like. However, in the embodiment, the outer layer 1 constitutes a seal portion. The inner layer 2 is made harder than the outer layer 1. The outer layer 1 preferably has abrasion resistance.

Further, since the core member 7 is extracted from the state shown in FIG. 1, it is preferable to apply a release agent or the like to the outer peripheral surface 7a in advance. Furthermore, the inner and outer layers 33, 34 must be integrated. For example, if nitrile rubber is used for both the inner layer 33 and the outer layer 34, the inner and outer layers 33, 34 will be integrated during vulcanization. In the case of combining different types of rubber, the two may be integrated with an adhesive.

Thus, the ring seal 3 manufactured as described above is
As shown in FIG. 3, it is fitted into the concave circumferential groove 6a of the shaft portion 6,
Since the inner layer 1 is hard, even if the thickness T of the ring seal 3 is small, the fitting portion can be securely fixed, and during use, from the concave peripheral groove 6a of the ring seal 3 Can be prevented from jumping out. According to this method, the outer diameter D of the core member 7 (that is, the inner diameter of the seal 3) can be set to about 2 mm, and the thickness T can be set to about 0.5 mm.

Also, by changing the vulcanization mold 15, as shown in FIG. 4, it is possible to manufacture cylindrical blanks 16 having various shapes of outer peripheral surfaces 16a, thereby obtaining various shapes of ring seals. 3 can be manufactured.

Next, in FIG. 5, the inner layer 27 is a sealing portion and the outer layer 28 is a fixing portion. That is, the inner layer 27 is made of soft rubber having good sealing properties, and the outer layer 28 is harder than the inner layer.

The ring seal 3 shown in FIG. 6 is composed of three rubber layers of a fixed layer 29, an intermediate layer 30, and a seal layer 31 so that the seal layer 31 always presses the contact surface 32 with a constant pressure. You have set. That is, the seal layer 31 is formed from shrinkable rubber,
The mid layer 30 is formed from expandable rubber. Here, shrinkable rubber refers to a material that shrinks when abrasion resistance is added,
For example, it is a nitrile rubber having an acrylonitrile component of 40% or more, and the expansible rubber is a material which expands with oil or the like, for example, a nitrile rubber having an acrylnitrile component of 20% or less.

Therefore, even if the seal layer 31 contracts, the intermediate layer 30 expands to cover the contraction of the seal layer 31 and keep the pressing force constant at all times.

It should be noted that the present invention is not limited to the above-described embodiment, and can be freely changed in design without departing from the gist of the present invention.
The number of rubber layers formed on the cylindrical material 16 may be four or more, and the inner and outer diameters and lengths of the formed material 16 may be freely selected. The dimensions are free. Of course, the cutting pitch can be freely changed.

〔The invention's effect〕

Since the present invention is configured as described above, the following effects can be obtained.

Since the layer laminated on the core member 7 is a rubber material, the cylindrical material 16 having a plurality of layers can be easily formed, and the inner and outer layers can be cut at once without changing the cutter. The work of cutting the cylindrical material 16 is easy.

In the ring seal, the hardness is different between the inner peripheral surface side and the outer peripheral surface side, which is suitable for a part to be used. It can be a sealing material. That is, in the ring seal 3 to be manufactured, the sealing portion is made of a hard and abrasion-resistant material having good sealing properties, and the fixing portion can be made harder than the sealing portion, and is firmly fixed. Even if the ring seal 3 has an extremely small wall thickness dimension T, the ring seal 3 does not jump out from the fitting portion during use and has excellent durability.

One core member 7 can be used in common from the formation of the cylindrical material 16 to the cutting and separation of the cylindrical material 16, and it is necessary to pull out the core member 7 from the cylindrical material 16 during the manufacturing process. Therefore, the entire process can be simplified, and the production of the ring seal 3 is easy.

When the cylindrical material 16 is cut, the core member 7 is inserted through the cylindrical material 16, so that the cylindrical material 16 can be held in a cylindrical shape and the cylindrical material 16 is deformed. A large number of products can be formed accurately at a time, which can be cut stably without any trouble. Also,
There is no so-called "burr" on the sealing surface of the manufactured ring seal 3, and high quality is achieved.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing an embodiment of a seal manufacturing method according to the present invention, FIG. 2 is an enlarged sectional view showing a method of cutting and separating a cylindrical material, and FIG. 3 is a use state of a manufactured ring seal. FIG. 4 is an enlarged sectional view of a main part showing a modification of the cylindrical material, and FIGS. 5 and 6 are simplified sectional views of a ring seal in another embodiment in use. 3 ... Ring seal, 16 ... Cylindrical material.

 ───────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Tajima 663 Minoshima, Arita-shi, Wakayama Mitsubishi Cable Industry Co., Ltd. Mishima Works (72) Yoshio Aso, Inventor 6-19-1 Inari, Soka, Saitama SMC Corporation Inside the grass processing plant (56) References JP-A-61-90834 (JP, A)

Claims (1)

(57) [Claims] 1. A core material is formed by laminating a plurality of rubber layers having different hardnesses in a radial direction on a core member to form a cylindrical material made of a rubber material covering the core member, and thereafter covering the core member. A method for producing a seal, wherein the cylindrical material is cut and cut into a ring shape as it is to form a plurality of ring seals.