JPH11138550A - Manufacture of fabril-filled rubber molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the manufacturing method of a fabric-filled rubber molded body, with which the working efficiency at the assembling to a hydraulic equipment is enhanced so as to allow to improve its productivity, to reduce its quality control and to prevent troubles from developing. SOLUTION: By preparing a mold 1 having a bottom mold 2 equipped with an inverted truncated cone-like cavity-forming recessed part 2a and a top mold with an inverted truncated cone-like cavity-forming recessed part so as to make a pair with the bottom mold, a green rubber preform 4 is produced by a mold 1. Then, in the state that the rubber preform 4 is left along the bottom mold equipped with the inverted truncated cone-like cavity-forming recessed part, the top mold is released so as to cover a basic cloth 5 on the rubber preform 4 formed on the bottom mold 2. Then, the bottom mold and the top mold are made into an integral body so as to constitute for executing thermal vulcanization in the state that the basic cloth 5 is buried in the rubber preform 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a diaphragm, B
The present invention relates to a method for manufacturing a cloth-containing rubber molded article used as a working membrane of a fluid device called an F diaphragm or the like.

[0002]

2. Description of the Related Art A rubber molded body is used for a working film portion of a fluid device such as a diaphragm. In recent years, a rubber molded body with a cloth in which a cloth called a base cloth is embedded inside a rubber molded body is mainly used. It has become. In other words, this type of cloth-containing rubber molded body has a structure in which the strength against the operating pressure of the fluid device is given by the base cloth embedded inside the rubber molded body, and the airtightness is given by the rubber material. I have.

FIG. 3 is an explanatory view showing a method of manufacturing a conventional rubber molded article containing cloth. In FIG. 3, a method of manufacturing a cloth-containing rubber molded body includes a molding die having a lower mold 31 having a convex portion 31 a for forming a cavity and an upper mold 32 having a concave portion 32 a for forming a cavity forming a pair with the lower mold 31. This is performed using the mold 30. That is, as shown in (a), a method for producing a cloth-containing rubber molded article firstly forms a semi-vulcanized rubber molded article 33 in a cavity of a molding die 30 by rubber preform molding. As shown in (b), on a semi-vulcanized rubber molded product 33 attached on the lower mold 31, a base cloth 34 (or a pre-formed base cloth 34) preformed substantially in the same shape as the lower mold 31. (A non-clothed cloth may be used). Thereafter, as shown in (c), pressing is performed with a vulcanizing mold 35 to obtain a semi-vulcanized rubber molded product. After performing a vulcanization step of vulcanizing the base cloth 34 while embedding the base cloth 34 therein, the vulcanization mold 35 is released to form the cloth-containing rubber molded body 36 as shown in (d). Is manufactured.

In this rubber molded article with cloth, the side covered with the base cloth is called the cloth side because the base cloth exists in the vicinity of the rubber surface, and the opposite side has a sufficient rubber layer. So it is called the rubber side. As shown in the schematic conceptual diagram of FIG. 4, for example, when the cloth-containing rubber molded body 36 is incorporated into the fluid device 40 as a cylinder device as the working film portion 41, the pressure chamber 42 side is operated. Pressure P1
Is set higher than the pressure P2 on the piston 43 side. Therefore, the working membrane portion 4 of such a fluid device 40
In the case where the cloth-containing rubber molded body 36 is incorporated as 1, the cloth-containing rubber molded body 36 is positioned such that the rubber side is located on the pressure chamber 42 side and the cloth side is located on the piston 43 side in order to maintain airtightness. Must be placed.

[0005]

SUMMARY OF THE INVENTION
In the case of incorporating the cloth-containing rubber molded body 36 into the cylinder 0, it is necessary to arrange the rubber side on the pressure chamber 42 side of the fluid device 40 and the cloth side on the piston 43 side. Therefore, before assembling the molded body 36 into the fluid device 40, the molded body 36 must be turned upside down once, and the molded body 3 turned upside down as shown in FIG.
6 had to be used in the fluid device 40. For this reason, there is a problem that work efficiency at the time of assembling into a fluid device is poor, and productivity cannot be improved. In addition, if the operator forgets to turn over the fluid device, the fluid device cannot exhibit the predetermined performance, so that there is a problem that quality control needs to be performed excessively.

The present invention has been made in view of such circumstances, and its object is to increase the work efficiency when assembling in pneumatic equipment, improve productivity, and improve quality control. An object of the present invention is to provide a method for producing a cloth-containing rubber molded article that can reduce the number of occurrences and prevent the occurrence of a claim.

[0007]

In order to achieve the above object, a method for producing a rubber molded article with cloth according to the present invention comprises: a lower mold having an inverted truncated cone-shaped cavity forming recess; And a molding die having an upper mold having an inverted truncated cone-shaped cavity-forming convex portion forming a pair, and forming a rubber preform made of unvulcanized rubber with the molding die, Is left along the lower mold having the inverted truncated cone-shaped cavity forming recess, and after the upper mold is separated, a base cloth is applied on the rubber preform formed in the lower mold. Thereafter, the lower mold and the upper mold are integrated, and heat vulcanization is performed while the base fabric is embedded in the rubber preform.

[0008] The base cloth is buried near the surface of the rubber preform to which the base cloth is attached.

Further, the cloth-containing rubber molded body is configured to be used as a working membrane of a fluid device.

According to the present invention, in a molding die for molding a rubber preform, the rubber preform is left along a lower mold having an inverted truncated cone-shaped cavity forming recess, and the upper mold is released. After that, a base cloth is adhered on the rubber preform formed on the lower mold, and thereafter, the lower mold and the upper mold are integrated, and heat is applied while embedding the base cloth in the rubber preform. Since it is configured to be vulcanized, the rubber molded article is molded so that the rubber portion is located on the convex side of the rubber molded article containing cloth and the base cloth is located on the concave side thereof, and is incorporated in a fluid device. Can be manufactured. Therefore, when the rubber molded body with the cloth is incorporated into the fluid device, the operator does not need to turn the inside out, so that the work efficiency when incorporating the fluid device into the fluid device is improved, productivity is improved, and quality control is performed. This will reduce the occurrence of complaints.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is an explanatory diagram showing a method for producing a cloth-containing rubber molded article of the present invention with time. As shown in FIG. 1, a molding die 1 including a lower die 2 and an upper die 3 is prepared when the method of manufacturing a rubber molded article with a cloth of the present invention is performed. The lower mold 2 has an inverted truncated conical cavity forming recess 2.
The upper die 3 paired with the lower die 2 is provided with an inverted truncated cone-shaped cavity forming projection 3a. When the lower die 2 and the upper die 3 are integrated, a hat-shaped (hat-shaped hat-shaped) cavity is formed therebetween with a predetermined gap therebetween.

The thickness of the rubber preform molding gap formed when the lower mold 2 and the upper mold 3 are engaged with each other is set, for example, in the range of about 0.1 to 1.5 mm. I have. Although not shown, the lower mold 2 and the upper mold 3 are appropriately formed with a concave portion for beads and a groove portion for releasing extra rubber in a ring shape.

A method for producing a rubber molded article with cloth of the present invention, which is performed using the molding die 1 thus formed, will be described. First, as shown in FIG. 1A, a rubber preform 4 made of unvulcanized rubber is molded in a molding die 1. The molding of the rubber preform 4 made of unvulcanized rubber is performed, for example, by mounting a sheet-like molded product of unvulcanized rubber on the cavity surface of the lower mold 2 or by molding the unvulcanized rubber on the cavity surface of the lower mold 2. The lower mold 2 and the upper mold 3 are engaged with each other in a state where a plurality of sheet-like molded products (small pieces) are placed, and the pressing is performed. At this time, it is necessary to set the temperature and pressure of the molding die 1 within a range where the vulcanization of the unvulcanized rubber does not proceed. The pressurization may be performed, for example, in a range of about 3 to 90 seconds after several times of bumping.

The rubber used in the production method of the present invention may be a conventionally known synthetic rubber or natural rubber, and is not particularly limited. Examples of the synthetic rubber that can be used in the present invention include acrylonitrile-butadiene rubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber, propylene-butadiene rubber, acrylonitrile-isoprene rubber, chloroprene rubber, butyl rubber, ethylene-propylene rubber, and acrylic. Rubber, fluorine rubber, ether-thioether rubber, polysulfide rubber, urethane rubber, silicone rubber and the like can be mentioned. If necessary, additives such as a vulcanizing agent and a vulcanization accelerator, which will be described later, are added to such a rubber material, and then the mixture is kneaded by a kneading machine, and the obtained rubber mixture is previously formed into a sheet by a roll. Then, the thickness is adjusted by a calender to produce a sheet-shaped molded product (small piece), and thereafter, using this sheet-shaped molded product, a rubber molded product can be produced by the production method of the present invention.

The vulcanizing agent to be used can be appropriately selected from sulfur, zinc oxide, magnesium oxide, aromatic nitro compounds, organic peroxides and the like according to the rubber used.

Thiazole compounds such as 2-mercaptobenzothiazole (MBT) as a vulcanization accelerator;
Sulfenamide compounds such as N-cyclohexyl-2-benzothiazolsulfenamide (CZ), thiazoline compounds such as 2-mercaptothiazoline, tetramethylthiuram monosulfide (TT), tetraethylthiuram disulfide (TET) and the like Thiuram compounds, dithiocarbamate compounds such as dimethyldithiocarbamic acid, aldehydeamine compounds such as hexamethylenetetramine, guanidine compounds such as diphenylguanidine, thiazole compounds such as N, N-diethylcarbamoyl-2-benzothiazyl sulfide Etc. can be used.

The rubber molded article may contain an antioxidant, an organic fatty acid such as stearic acid, and a filler such as carbon black, if necessary. Such an additive is preferably contained in the range of 1 to 150 parts by weight based on 100 parts by weight of the rubber. As shown in FIG. 1A, when the upper mold 3 is released after the completion of the rubber preform step, a rubber rubber preform 4 having a hat shape is formed on the lower mold 2. In the present embodiment, the thickness of the rubber preform 4 is, for example, 0.1 to 1.5.
mm. If burrs are present in the rubber preform 4 taken out of the molding die 1 while being engaged with the lower die 2, the burrs are removed. Further, when there is insufficient rubber thickness at the end face portion or the like of the molded rubber preform 4, a sheet-like molded product (small piece) of the above-described unvulcanized rubber may be added to a corresponding portion.

After the rubber preform 4 has been left along the lower mold 2 having the inverted truncated cone-shaped cavity forming recess 2a and the upper mold 3 has been separated,
As shown in (b), the base cloth 5 is adhered on the rubber preform 4 formed on the lower mold 2. This base cloth 5
A flat shape may be used, or a shape formed in advance according to the shape of the lower mold 2 having the inverted truncated cone-shaped cavity forming recess 2a may be used. Base cloth 5
Is attached, as shown in FIG. 1 (b),
It is preferable that the base cloth 5 is pressed against the surface of the rubber preform 4 so that wrinkles do not occur. After the attachment of the base cloth 5 is completed, the surplus base cloth 5 on the periphery can be cut and removed.

As the base cloth 5 used in the production method of the present invention, a cloth using a yarn such as polyamide (6 nylon, 66 nylon, etc.), aramid, polyester, cotton, or the like is used as a plain weave.
The weft may be adjusted and woven into a tricot, knitted fabric, calamifu, or the like, and the woven fabric may be used as it is, or may be immersed in an adhesive or the like and dried to form a base fabric or the like.

Thereafter, as shown in FIG. 1 (c), the lower mold 12 and the upper mold 13 are integrated and thermally vulcanized while embedding the base cloth 5 in the rubber preform 4. . The lower mold 12 and the upper mold 13 used in this vulcanization step are:
It is used in common with the lower mold 2 and the upper mold 3 constituting the mold 1 for molding a rubber preform. Lower mold 12 and upper mold 1
3 is configured such that a hat-shaped cavity for molding a cloth-containing rubber molded body is formed between the lower mold 12 and the upper mold 13 in the engaged state as illustrated. .
That is, the thickness of the rubber preform molding gap formed when the lower mold 12 and the upper mold 13 are engaged with each other is set, for example, in a range of about 0.1 to 1.5 mm. Although not shown, the lower mold 12 and the upper mold 1
In 3, a concave portion for a bead and a groove portion for releasing excess rubber are appropriately formed in a ring shape. In addition, the thickness of the gap may be the same or may be set to a different thickness.

The molding of the cloth-containing rubber molded body 10 using the final molding die 11 is performed as described above.
The lower mold 12 and the upper mold 13 having the rubber preform 4 on which the rubber preforms 4 are attached are engaged with each other, and pressurized and heated. Pressurization can be performed, for example, after several bumpings,
The temperature and time during vulcanization can be appropriately set according to the rubber material and the like to be used.

After the final molding using such a molding die 11, as shown in FIG. 1 (d), the cloth-containing rubber molded body 10 is taken out from the molding die 11, and burrs are present. In this case, the burrs are removed to complete the production of the cloth-containing rubber molded body 10.

In the method of manufacturing a cloth-containing rubber molded article of the present invention described above, the lower mold 2 and the upper mold 3 of the mold 1 used in the rubber preform molding step are formed under the mold 11 used in the vulcanization step. Although shared with the mold 12 and the upper mold 13, the present invention is not limited to this.

In the rubber molded article 10 containing a cloth manufactured by the manufacturing method of the present invention, the rubber preform 4 is provided with the inverted truncated cone-shaped cavity forming recess 2a in the mold 1 for molding the rubber preform 4. After leaving the upper mold 3 along with the lower mold 2, the base cloth 5 is adhered onto the rubber preform 4 formed on the lower mold 2. Since the mold 13 and the mold 13 are integrated and the base cloth 5 is thermally vulcanized while being buried in the rubber preform 4, the base cloth 5 is placed near the surface of the rubber preform 4 on the side where the base cloth 5 is attached. It is buried. That is, in the cloth-containing rubber molded body 10, the rubber portion is located on the convex side, and the base cloth 5 is located on the concave side.

The fabric-containing rubber molded body 10 manufactured as described above is used as a working film portion 22 of a fluid device 21 as shown in FIGS. 2 (a) and 2 (b). As shown in the drawing, the fluid device 21 is a BF diaphragm, and has features such as no need for lubrication, and no risk of breakage or leakage due to vibration fatigue. 2A is a cross-sectional view illustrating a state in which the piston rod of the BF diaphragm is retracted, and FIG. 2B is a cross-sectional view illustrating a state in which the piston rod of the BF diaphragm is advanced.

As shown in the figure, the main body of the BF diaphragm 21 is formed by a casing 24 which defines a cylinder chamber 23. A piston rod 26 that advances and retreats into the cylinder chamber 23 is inserted into a lower portion of the casing 24, and a coil spring 27 for advancing the piston rod 26 is mounted around the piston rod 26. On the other hand, a pressure supply port 28 is opened in an upper part of the casing 24.

The casing 24 is divided into an upper casing 24a and a lower casing 24b. The casing 24 is integrally screwed to ring-shaped projections 25a, 25b integrally formed with the casings 24a, 24b. And, on the side wall of the lower casing 24b,
The fluid inlet 29a and outlet 29b are open. The peripheral portion of the working film portion 22 is mounted so as to be sandwiched between the projecting portions 25a, 25b of the casings 24a, 24b, and the center portion thereof is mounted on the distal end portion of the piston rod 26. The working film portion 22 is mounted so as to maintain airtightness, and partitions the inside of the cylinder chamber 23 into a pressure chamber side 23a and a piston side 23b.

As the working film portion 22, the above-mentioned rubber molded article 10 with cloth according to the present invention is used. The cloth-containing rubber molded body 10 is provided on the pressure chamber side 23 a of the BF diaphragm 21.
And the base cloth 5 is positioned. That is, the cloth-containing rubber molded body 10 allows the rubber preform 4 to remain along the lower mold 2 having the inverted truncated cone-shaped cavity forming recess 2a in the mold 1 for molding the rubber preform. , After the upper mold 3 is released, the lower mold 2
The base cloth 5 is adhered on the rubber preform 4 formed in the above, and thereafter, the lower mold 12 and the upper mold 13 are integrated,
Since the base cloth 5 is formed by heat vulcanization while burying the base cloth 5 in the rubber preform 4, the concave side of the cloth-containing rubber molded body 10 is formed as the base cloth side, and is incorporated in the BF diaphragm 21 as it is. Can be. Therefore, there is no need to perform a so-called reverse operation after molding, which has been conventionally performed.

In the BF diaphragm 21, the pressure P1 on the pressure chamber side 23a of the cylinder chamber 23 is set to be higher than the pressure P2 on the piston side 23b. The convex side is the pressure chamber side 2
3a, and is mounted so that its concave side is located on the piston side 23b, so that the rubber portion located on the pressure chamber side 23a can reliably maintain airtightness.

According to such an embodiment of the present invention, B
When a rubber molded body with cloth is incorporated into a fluid device such as an F-diaphragm, it is not necessary for the operator to turn the inside out, and the efficiency of the assembling operation is increased, productivity can be improved, and quality control is reduced. , Can prevent the occurrence of complaints.

[0032]

As described above in detail, according to the present invention, in a molding die for forming a rubber preform, the rubber preform remains along the lower mold having an inverted truncated cone-shaped cavity forming recess. And, after detaching the upper mold, a base cloth is applied on the rubber preform formed in the lower mold, and thereafter, the lower mold and the upper mold are integrated,
Since the heat-vulcanization is performed while the base cloth is embedded in the rubber preform, the concave side of the cloth-containing rubber molded body is molded as the base cloth side, and the cloth-containing rubber molded body is manufactured in a state of being incorporated into the fluid device. be able to. Therefore, when the rubber molded body with the cloth is incorporated into the fluid device, the operator does not need to turn the inside out, so that the working efficiency when incorporating the fluid device into the fluid device is improved, the productivity can be improved, and the quality can be improved. Management is reduced, and the occurrence of complaints can be prevented.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view for explaining one embodiment of a method for producing a cloth-containing rubber molded article according to the present invention, in which (a) is a cross-sectional view showing a state in which a rubber preform is molded; It is a cross-sectional view showing the situation of mounting the base cloth on the foam,
(C) is a sectional view showing a vulcanizing step of a rubber preform having a base cloth applied thereto, and (d) is a sectional view showing a completed cloth-containing rubber molded article.

2A and 2B are diagrams illustrating a state in which a cloth-containing rubber molded article of the present invention is incorporated in a BF diaphragm, wherein FIG. 2A is a cross-sectional view illustrating a state in which a piston rod is retracted, and FIG. It is sectional drawing which shows the state which advanced.

3A and 3B are diagrams illustrating an embodiment of a conventional method for producing a cloth-containing rubber molded body, in which FIG. 3A is a cross-sectional view illustrating a state in which a rubber preform is molded, and FIG. FIG. 4 is a cross-sectional view showing a situation in which a base cloth is attached to (c).
FIG. 3 is a cross-sectional view showing a vulcanizing step of a rubber preform to which a base cloth is adhered, and FIG.

FIG. 4 is a cross-sectional view conceptually showing a state in which a conventional cloth-containing rubber molded body is incorporated in a cylinder device.

[Explanation of symbols]

 Reference numerals 1, 11: Molding die 2, 12: Lower die 2a: Cavity concave part 3, 13: Upper die 3a: Cavity convex part 4: Rubber preform 5: Base cloth 10: Rubber molded body with cloth

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁶ Identification code FI B29K 105: 24

Claims (3)

[Claims] 1. A molding die having a lower mold having an inverted truncated cone-shaped cavity forming concave portion and an upper mold having an inverted truncated cone shaped cavity forming convex portion forming a pair with the lower mold is prepared. Forming a rubber preform made of unvulcanized rubber with the molding die, leaving the rubber preform along the lower mold having the inverted truncated cone-shaped cavity forming recess, and removing the upper mold. After that, the base cloth is adhered on the rubber preform formed on the lower mold, and thereafter, the lower mold and the upper mold are integrated, and the base cloth is embedded in the rubber preform. A method for producing a cloth-containing rubber molded article, wherein the molded article is heat-cured. 2. The method according to claim 1, wherein the base cloth is buried in the vicinity of the surface of the rubber preform to which the base cloth is attached. 3. The method for producing a cloth-containing rubber molded article according to claim 1, wherein the cloth-containing rubber molded article is used as a working film of a fluid device.