ES2379712A1 - Piece of plastic material and procedure for obtaining said piece. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Piece of plastic material, which is constituted by a part (1) shaped internally hollow and at least a second part (2) as a protuberance or the like projecting from the outer wall of said first part, wherein the first part (1) is obtained by a blowing process and the second part (2) is obtained by an injection process where both processes are carried out in the same mold, the unión between the two parts being determined by a plurality of intrusion sections between the contact surfaces of both said two parts (1, 2). (Machine-translation by Google Translate, not legally binding)

Description

Plastic material part and procedure obtaining said piece.

Object of the invention

The present invention patent application Its purpose is to register a piece of plastic material with union system that incorporates notable innovations and advantages.

More specifically, the invention proposes the development of a union system for multiple parts of the same piece of plastic material, as well as the procedure for obtaining of that piece.

Background of the invention

It is well known to manufacture parts of plastic material consisting of an internally hollow body and additional peripheral parts attached thereto, such as by for example, pipes of pipes, tanks or any other closed hollow element that is usually part of a vehicle engine.

To obtain the hollow body is used usually an extrusion-blowing process conventional while to obtain the rest of parts, such such as ears, pipettes, inclusion of sensors, is carried out in Additional stages through injection, cutting, etc.

To get the final product requires a physical union between the different components, that is, between the main function element and auxiliary function elements or satelite. This union is made after the process of unit manufacturing and through complementary processes, such as, welding, manual clipping, etc.

This type of parts mentioned above obtained by various manufacturing processes have a great uncertainty regarding the quality of the finished product, an undesirable number of rejections of the product due to the low robustness of the process, which is linked to manual tasks and imperfect processes (welding and gluing).

Such deficiencies in the final product, usually associated with deficiencies in the union of the parts additional, they are usually detected in the same plant of transformation, on the assembly line or even when acting and mounted on the vehicle, with the consequent negative consequences for both the parts manufacturer and the vehicle manufacturer

In addition, another inconvenience no less important it is the fact that the current manufacturing method involves some high derivative costs, on the one hand, due to the need to have of tools for the realization of all the processes of transformation (extrusion-blow mold, mold injection and tooling intended for the union of multiple parts) and, on the other hand, of the high cycle times due to each of the three manufacturing processes are completely independent of each other.

Description of the invention

The present invention has been developed with the in order to provide a piece of plastic material with a system of union that resolves the aforementioned drawbacks, providing, in addition, other additional advantages that will be evident to from the description that follows.

It is an object of the present invention to provide a system for joining a piece of plastic material, which is constituted by an internally shaped part hollow and at least a second part as a protuberance or the like that protrudes from the outer wall of said first part, in which the first part is obtained by a blowing process and the second part is obtained by an injection process where both processes are performed in the same mold, and is characterized by the fact that the union between the two parts it is determined by a plurality of intrusion sections between the contact surfaces of both said two parts. These intrusions increase the contact surface between the parts of the piece, reducing the tension between surfaces and the relative pressures, improving the bonding properties between both parts. The use of the plurality of intrusion sections between the contact surfaces makes it possible to obtain parts made of soft plastic materials, which would present deformations in the joint area if this type of geometry were not performed in the section of
Union.

Therefore, said piece of plastic material it comprises an internally hollow shaped part and at least one second part by way of protuberance or similar protruding from the outer wall of said first part, and is characterized by the fact that the union between both parties is determined by a plurality of intrusion sections between contact surfaces of both said two parts.

It is another additional object of the present invention provide a process for the manufacture of a piece of plastic material, which is constituted by a part internally shaped hollow and at least a second part by way protrusion or similar protruding from the outer wall of said first part, the union between both parties being determined by a plurality of intrusion sections between the surfaces of contact of both said two parts, and is characterized by the fact that comprises a stage of blowing the piece internally hollow in a cavity of a mold and an injection stage of at minus a second part in an additional cavity provided in the inside said mold, taking place the union between both parts inside the mold.

Thanks to the features above described, a reduction in manufacturing costs is obtained in obtaining plastic parts of the type described with previously, which can be of the order of between 25 and 35% due to the integration of the molding processes of the various parts that make up the piece, and an increase in product quality finish in regard to mechanical resistance in areas of joining the fixings to the piece that has been obtained by blown. The described procedure also allows obtaining pieces made of soft plastic materials without produce deformations in the areas of union of the parts that make up the final piece.

Other features and advantages of this invention will be apparent from the description of a preferred, but not exclusive, embodiment illustrated by way of non-limiting example in the accompanying drawings, in the which.

Brief description of the drawings

Figure 1.- It is a perspective view of a piece of plastic material obtained with the procedure according with the present invention; Y

Figure 2.- It is a detailed elevation view schematized corresponding to the junction zone between two parts of the piece represented in figure 1.

Description of a preferred embodiment

In the automotive sector, there are parts of plastic material, such as PP, PE, EPDM, which are constituted by a part (1) conformed internally hollow and at minus a second part (2) as a protuberance or similar that protrudes from the outer wall of said first part and may have a function of retaining element of the part within a set, such as conduits, manifolds, etc., for the passage of fluids or gases that are provided in the mechanical part.

The union of such two parts (1) and (2) is determined by a plurality of intrusion sections (3) between the contact surfaces of both said two parts (1) and (2), such as seen more clearly in figure 2.

These intrusion sections (3) of each of the two parts (1) and (2) consist of a toothed region, thereby that both toothed regions are nestable and adjustable fixed with each other, so that once the mold piece comes out both two Parts (1) and (2) cannot be separated.

In a particular manufacturing process of according to the present invention to obtain the described part, it The molding is carried out in the first stage of the process. blown hollow body (corresponding to part (1) previously described) from a parison of plastic material moldable inside a cavity of a mold. At that stage plastic material is applied in a liquid state and at a temperature default melting and then air is blown into the inside the cavity by blowing means of known type that does not will be described herein as they are not subject to the invention.

In this first stage, the mold enclosure.

Subsequently, in a second stage, and after a predetermined period of time, injection molding is performed at high pressure of the second part (such as a bump) of plastic material inside another cavity arranged in the same mold of the first stage, said second cavity being located adjacent to the previous cavity.

The entry of material in this second phase of the process is done by a mouthpiece, a camera or by itself Injection spindle of known type for material output plastic in a liquid state at a melting temperature default

In this way, the second part is around of the tubular shaped body (the first part).

Lastly, and after a while of cooling the semi-molds are opened and ejected the mold piece with the help of ejectors, starting again A manufacturing cycle for the next piece.

The details, the shapes, the dimensions and other accessory elements, as well as the materials used in the System manufacturing, plastic part and procedure invention may be conveniently substituted by others that are technically equivalent and do not depart from the essentiality of the invention or of the scope defined by the claims to be include below.

Claims (3)

1. Piece of plastic material comprising a hollow interior part (1) formed and at least a second part (2) by way of protuberance or the like protruding from the outer wall of said first part, in which the first part (1 ) is obtained by a blowing process and the second part (2) is obtained by an injection process where both processes are carried out in the same mold, characterized by the fact that the union between both parts (1, 2) is determined by a plurality of intrusion sections (3) between the contact surfaces of both said two parts. 2. A piece of plastic material according to claim 1, characterized in that the intrusion sections (3) of each of the two parts (1, 2) consist of a toothed region, such that both toothed regions are fixed and adjustable to each other. 3. Procedure for the manufacture of a piece of plastic material, which is constituted by an internally shaped part hollow and at least a second part by way of protuberance or the like that protrudes from the outer wall of said first part, the union between both parts determined by a plurality of intrusion sections between the contact surfaces of both said two parts, characterized in that it comprises a blowing stage of the internally hollow part in a cavity of a mold and an injection stage of at less a second part in an additional cavity provided inside said mold, the union between both parts taking place inside the mold.