JPH09277363A - Blow molding method and blowing nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely mold a blow molded product having a projected part or the like on an inner diameter side at a low cost by a method wherein an inner peripheral shape part consisting of any one of a projected part, a recessed part, or a roughened surface is formed at an inner peripheral position of a mouth part of the blow molded product with an outer peripheral forming part formed on an outer periphery of a blowing nozzle. SOLUTION: A tip part 4a of a blowing nozzle 4 is driven into a mouth part 3 of a parison 2 held by pinching with a mold 1 constituted, in a freely openable manner. The parison 2 is blow molded into a blow molded product inside a mold 1 by air injected from its tip part 4a. An outer peripheral shape part 10 consisting of any one of a projected part or a recessed part, or a roughened surface, etc., is formed, on an outer periphery of the tip part 4a of a main body 4A of the blowing nozzle 4. Then, the inner peripheral shape part 11 consisting of any one of the projected part, or the recessed part, or the roughened surface, etc., is formed along the outer peripheral shape part 10 at an inner peripheral position of an inner diameter of the mouth part 3 of the blow molded product 5 with the outer peripheral shape part 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow molding method and a blow nozzle, and more particularly, to a convex or concave portion at the inner peripheral position of the mouth of a hollow molded product by an outer peripheral shape portion formed at the tip of the blow nozzle. To a new improvement for forming.

[0002]

2. Description of the Related Art As a conventional hollow molding method and blow nozzle of this kind, as shown in FIG. 3, generally, a mouth portion 3 of a parison 2 held by being sandwiched by a mold 1 is used. The tip 4a of the blowing nozzle 4 is driven in, and the tip 4a
The parison 2 is hollow-molded into the hollow-molded product 5 in the mold 1 by the air injected from a. In this case, the upper end of the mouth 3 of the hollow molded product 5 is cut by the cut ring 4b of the blow nozzle 4.

[0003]

Since the conventional blow molding method and blow nozzle are configured as described above, there are the following problems. That is, since the tip of the blow nozzle is driven into the parison, the shape of the inner diameter of the hollow molded product to be hollow-molded is restricted by the nozzle tip outer diameter D at the tip of the blow nozzle, and this tip is the shaft. Since the inner peripheral surface of the upper part of the hollow molded product is formed linearly in the axial direction because it has a linear outer peripheral surface in the direction, It was not possible to meet the needs to form the outer peripheral shape portion. Further, if there is a method of forming the mold with a split mold or the like when attempting to form this outer peripheral shape part, the mold becomes extremely expensive, and a hydraulic circuit must be added mechanically, Practical application was extremely difficult in terms of cost.

The present invention has been made to solve the above problems, and in particular, a convex portion or an inner peripheral position of the mouth of a hollow molded article is formed by an outer peripheral shape portion formed at the tip of the blow nozzle. An object of the present invention is to provide a blow molding method and a blow molding nozzle in which a recess is formed.

[0005]

In the blow molding method according to the present invention, a blow nozzle is driven into a parison held by a mold, and a blow molded nozzle is molded with air injected through the blow nozzle. In the hollow molding method, either a convex portion, a concave portion or a rough surface is formed at the inner peripheral position of the mouth of the hollow molded article by an outer peripheral shape portion formed of a convex portion or a concave portion or a rough surface formed on the outer periphery of the blow nozzle. This is a method of forming the inner peripheral shape portion made of

A blowing nozzle according to the present invention is a blowing nozzle in which a tip of a main body is driven into a parison held by a mold, and a convex portion, a concave portion or a rough surface formed on the outer periphery of the tip portion is provided. This is a configuration having an outer peripheral shape portion made of any one.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a blow molding method and a blowing nozzle according to the present invention will be described below with reference to the drawings. The same or equivalent parts as those in the conventional example will be described using the same reference numerals. In FIG. 1, a mouth part 3 of a parison 2 held by being sandwiched by a mold 1 configured to be freely opened and closed.
The tip portion 4a of the blow nozzle 4 is driven into the nozzle, and the parison 2 is moved in the mold 1 by the air injected from the tip portion 4a.
Is hollow molded into a hollow molded product 5. In this case, the upper end of the mouth 3 of the hollow molded product 5 is cut by the cut ring 4b of the blow nozzle 4.

The tip portion 4a of the body 4A of the blow nozzle 4
An outer peripheral shape portion 10 made of a convex portion, a concave portion, a rough surface (a concave portion in the present embodiment), or the like is formed on the outer periphery of the hollow shaped article 5. At the inner peripheral position of the inner diameter of the inner peripheral shape portion 11 is formed along the outer peripheral shape portion 10 by any one of a convex portion, a concave portion, a rough surface (a projecting ring made of a convex portion in the present embodiment) or the like. Has been formed.

Next, in the hollow molded product 5 hollow-molded by using the blow nozzle 4 constructed as described above, when the inner peripheral shape portions 11 are formed at both ends as shown in FIG.
When the hollow molded product 5 is coaxially arranged on the outer circumference of the shaft 20 and the grease 22 is contained inside the bellows portion 21, the inner peripheral shape portion 11 slides on the outer circumference of the shaft 20 and the grease 22 It is possible to allow sliding without leaking outside. The shape of the inner peripheral shape portion 11 is not limited to the above-mentioned shape, and may be any shape.

[0010]

Since the blow molding method and the blow nozzle according to the present invention are configured as described above, the following effects can be obtained. That is, it is possible to form an inner peripheral shape portion formed of a convex portion, a concave portion or a rough surface on the inner peripheral side of the mouth portion of the hollow molded product on the inner diameter side by the outer peripheral shape portion formed at the tip of the blow nozzle, It is possible to inexpensively and reliably form a hollow molded article having a convex portion or the like on the inner diameter side by using the same mold as the conventional one.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram showing a blow molding method and a blow nozzle according to the present invention.

FIG. 2 is a cross-sectional view showing a hollow molded product molded according to the present invention.

FIG. 3 is a cross-sectional view showing a conventional blow molding method and a blow nozzle.

[Explanation of Codes] 1 Mold 2 Parison 3 Port 4 Blow Nozzle 4A Body 4a Tip 5 Hollow Molded Product 10 Outer Perimeter 11 Inner Perimeter

Claims (2)

[Claims] 1. A blow molding nozzle (4) is driven into a parison (2) held by a mold (1), and a hollow molded product (5) is molded by air injected through this blow nozzle (4). In the hollow molding method as described above, the mouth (3) of the hollow molded product (5) is formed by the outer peripheral shape portion (10) formed of either a convex portion or a concave portion or a rough surface formed on the outer periphery of the blow nozzle (4). The hollow forming method is characterized in that the inner peripheral shape portion (11) formed of a convex portion, a concave portion or a rough surface is formed at the inner peripheral position of (1). 2. A blowing nozzle in which a tip portion (4a) of a main body (4A) is driven into a parison (2) held by a mold (1), and formed on the outer periphery of the tip portion (4a). The blowing nozzle is characterized in that it has an outer peripheral shape portion (10) consisting of a convex portion, a concave portion or a rough surface.