JPH0374901B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a bent hose. More specifically, the present invention relates to a method for manufacturing a bend hose for transporting powder or granular material, in which a small piece of ceramic is attached to the inner circumferential surface to improve wear resistance.

(Prior Art) Generally, this type of hose for transporting powder and granular materials uses a ceramic sheet made by pasting a large number of small ceramic pieces on an unwashed rubber sheet, and the sheet is wound around a linear mandrel to form the hose body. This hose body is then wrapped with wrapping tape, and then the unvulcanized rubber of the hose body is vulcanized in a vulcanizing can. Since the hose itself has a certain degree of flexibility, this was achieved by forcibly bending the hose.

(Problems to be Solved by the Invention) However, when the hose is forcibly bent as described above, the small ceramic pieces hit each other on the inner side of the curved part, and the small ceramic pieces may be deformed or damaged. As a result of this abutment, each ceramic piece floats up in a mountain shape, and the so-called inner circumferential surface of the hose is deformed into a wave shape, and the gap between each ceramic piece expands on the side that becomes the outer surface of the curved part. However, wear in the gap during transportation of powder and granules is severe, and the bend portion of the hose must be replaced in a very short period of time.

(Means for Solving the Problems) The present invention was invented to solve the above problems, and relates to a method for manufacturing a bent hose having an arbitrary radius of curvature. A hose element is formed by wrapping the sheet around a mandrel, and then wrapping this hose element with wrapping tape. A flexible inner bag is inserted into a mold that curves into an arc, and then pressurized water is filled in the inner bag, and the unvulcanized rubber of the hose body is vulcanized. It was a great accomplishment.

(Function) According to the present invention, by applying pressure to the hose body from the inside through the inner bag while the hose body is wrapped with a wrapping tape, the pressure applied to the unvulcanized rubber in the hose body is applied. is obtained, and the curved state of the hose body is reliably maintained by the formwork, thereby preventing deformation during the pressurization.

(Example) First, prior to explaining the method of the present invention, the equipment used in the present invention will be explained.

In the figure, 1 is a mandrel for forming a hose body as described later.

2 is a cylindrical inner bag with open ends, made of an expandable material, and usually has a smaller diameter than the inner diameter of the manufactured hose, so that it expands when filled with pressurized water and becomes larger than the inner diameter of the hose. It is configured. Further, flanges 21, 21 are formed at the openings at both ends of the inner bag 2. It is sufficient that this inner bag has at least flexibility.

Reference numeral 3 denotes a formwork having a U-shaped cross section with an arbitrary radius of curvature, and includes a bottom plate 31 curved in an arc shape, and side plates 32 in the shape of a circular arc erected on the bottom plate 31 at a predetermined interval to face each other. , 33, and a pedestal 34 having a T-shaped cross section is provided on the bottom plate 31 at a central position between the side plates 32 and 33. The distance between the side plates 32 and 33 is approximately equal to the outer diameter of the manufactured hose. Further, the formwork 3 may be formed by combining a plurality of units as shown in the figure.

Reference numeral 4 denotes a closing body for closing one end opening of the inner bag 2, which includes a closing face plate 41 having a plurality of tightening holes 43... and a mounting plate 42 having a plurality of mounting holes 44... a pressure water supply pipe 45 formed in this way and having a valve 46 on this face plate 42;
A discharge pipe 47 with a valve 48 is provided.

Reference numeral 5 denotes a closing body for closing the opening at the other end of the inner bag 2, and like the closing body 4, it is formed of a closing face plate 51 and a mounting plate 52.

According to the method for manufacturing a bent hose according to the present invention, first, a ceramic sheet 60 is formed by pasting a large number of rectangular ceramic pieces 62 on an unvulcanized rubber sheet 61, and the sheet 60 is cut into narrow strips. , the ceramic sheet 60 is wound spirally around the mandrel 1 so that the small ceramic piece 62 is on the inside, and the unvulcanized rubber sheet 61 on the outside of the ceramic sheet 60 is activated with a solvent (co-glue). The unvulcanized rubber sheet 64 is spirally wound around the unvulcanized rubber sheet 64 in a band shape so as to extend from the ceramic sheet 60 to a part of the end caps 63, 63. A cord 65 is spirally wound around a vulcanized rubber sheet 64, another belt-shaped unvulcanized rubber sheet 66 is wound around the cord 65, and a metal spring is wrapped around the unvulcanized rubber sheet 66. 67 and the cover rubber 68 are inserted to form the hose body 6.

Next, a wrapping tape 7 is spirally wound around the hose body 6 formed as described above to perform so-called wrapping.

Thereafter, the hose body 6 is pulled out from the mandrel 1, and fitted into the mold 3 with the inner bag 2 inserted into the hose body 6.

Next, the closing bodies 4 and 5 are placed at both ends of the formwork 3 and fixed with bolts and nuts 8 . , 63 between the both end flange portions 21, 21 of the inner bag 2.
and tighten with bolts and nuts 9.

In this state, there are 3 to 4 parts inside the inner bag 2.
The inner bag 2 is filled with pressure water of about Kg/ ^cm2 .
The hose element 6 is then expanded and pressurized, and then the hose element 6 is placed in a vulcanization can together with the mold 3, and the unvulcanized rubber in the hose element 6 is vulcanized.

When the vulcanization is completed, the water is drained from the inner bag 2, the inner bag 2 is shrunk and removed from the hose body 6, and the hose body 6 is removed from the hose body 6.
is removed from the formwork 3 and finished as a bent hose with a predetermined radius of curvature.

(Effects of the Invention) As explained above, according to the present invention, it has become possible to manufacture a bend hose for transporting powder or granular material, which has ceramic pieces attached to the inner peripheral surface to improve wear resistance. .

Furthermore, when using the manufacturing method of the present invention, the hose body is wrapped with a wrapping tape and the hose body is pressurized from the inside through the inner bag, so that the unvulcanized material in the hose body is compressed. Sufficient pressing force can be obtained against the rubber, thereby ensuring high interlaminar strength in the hose body and ensuring sufficient vulcanization.Moreover, there is no need for a special sealing structure when pressurized water is filled in, and the manufacturing method of the present invention The method can be carried out using equipment of extremely simple construction.

Furthermore, the curved state of the hose body is reliably maintained by the mold, and it does not deform when pressurized as described above, making it possible to manufacture a bent hose with an accurate radius of curvature.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a plan view thereof, FIG. 2 is an enlarged sectional view taken along the line of FIG. It is a front view with a part notched away. 1...Mandrel, 2...Inner bag, 3
...Formwork, 4...Closed body, 5...Closed body, 6...
Hose body, 60... Ceramic sheet, 61...
...Unvulcanized rubber sheet, 62... Ceramic small piece,
7...wrapping tape.

Claims (1)

[Claims] 1. A method for manufacturing a bent hose with an arbitrary radius of curvature using a ceramic sheet made by pasting a large number of small ceramic pieces on an unvulcanized rubber sheet, in which the ceramic sheet is first wound around a mandrel to form a hose body. After wrapping this hose body with wrapping tape, the hose body is pulled out from the mandrel, and with a flexible inner bag inserted into the hose body, a formwork is formed that curves into an arc shape. After filling the inner bag with pressure water,
A method for manufacturing a bend hose, characterized by vulcanizing unvulcanized rubber of the hose body.