ITTV20110088A1 - METHOD TO COMBINE COMPONENTS FOR THE MANUFACTURE OF A SPORTS TOOL - Google Patents

Description

METHOD FOR COMBINING COMPONENTS FOR THE MANUFACTURING OF A TOOL

SPORTY

DESCRIPTION

The present invention relates to a method for joining components for the manufacture of a sports tool.

It is known that the industrial production of a sports equipment often involves joining together components made at different stages of the manufacturing process.

Numerous methods are known in the state of the art for joining components for the manufacture of a sports tool.

Some methods involve the use of fastening means such as, for example, screws, rivets or the like.

A drawback of these methods lies in the need to prepare seats to accommodate the aforementioned fastening means, with the possibility of significantly compromising the structural integrity of the components themselves.

The use of fastening means is also unacceptable for the manufacture of many types of sports equipment, due to obvious aesthetic limitations.

Other methods involve gluing the components together, at mutually coupled gluing surfaces.

Although these methods are widely used in the manufacture of sports equipment, they are generally relatively complex, time-consuming and expensive to complete.

Other processes provide for welding, with the addition of material, the components at mutually coupled welding surfaces.

These methods are obviously usable only with components made of metallic material.

Furthermore, the presence of visible welding lines can significantly compromise the external appearance of the finished product and is unacceptable for many types of sports equipment.

Other methods involve using ultrasonic welding processes.

These methodologies are relatively complex to use if relatively small components are to be joined, as is often the case in the manufacture of sports equipment.

Methods are known which provide for the use of laser welding processes.

Laser welding is relatively expensive and complex to use, especially if it is necessary to make the laser beam reach welding surfaces that are not directly accessible from the outside.

Finally, other methods involve the use of vibration welding processes.

These processes are generally used to join together components in thermoplastic material, capable of melting at the temperatures developed during the welding process (typically below 250 ° C).

Processes of this type, currently available, cannot in practice be used if at least one of the components to be joined is made of non-thermoplastic material, for example thermosetting, or is made of material with relatively high melting temperatures, as in the case of steel. .

The main task of the present invention is to provide a method for joining components for the manufacture of a sports tool that allows to solve the drawbacks of the known art.

As part of this task, an object of the present invention is to provide a method that can be easily used to join components made with materials having non-homogeneous physical characteristics, in particular with regard to thermal behavior.

Another purpose of the present invention is to provide a method that does not compromise the structural integrity of the components themselves and / or of the finished product.

A further object of the present invention is to provide a method that does not compromise the external appearance of the finished product and allows to obtain aesthetically pleasing finishes.

A further object of the present invention is to provide a method which can be easily implemented at an industrial level, at competitive costs.

This aim and these objects, as well as other objects which will become evident from the following description and the attached drawings, are achieved, according to the invention, by a method for joining a first component and a second component for the manufacture of a sports tool, according to the claim 1, proposed below.

In its general definition, the method, according to the invention, is characterized by the fact that it includes:

a step of providing the first component, said first component comprising a first sealing surface covered by at least a first film of thermoplastic material; And

a step of providing the second component, said second component comprising a second welding surface; And

a step of positioning the first and second component in a welding mold, so that said first and second sealing surfaces face each other and the first plastic film is interposed between said sealing surfaces; And

a step of welding the first and second components at said first and second welding surfaces by means of a vibration welding process.

The aforementioned first component can be made of a thermosetting material, in particular a thermosetting material with a stiffness / density ratio higher than 30 (GPa * dm <3>) / Kg.

In such a case, the step of providing the first component preferably comprises the following steps:

positioning the first thermoplastic film within a first forming mold; And

positioning, within said first forming mold, a first pre-impregnated with thermosetting material, said first film in thermoplastic material being in contact with said first pre-impregnated at least in correspondence with the first sealing surface;

heating the first forming mold until obtaining a crosslinking reaction of the thermosetting material and adhesion of the first film of thermoplastic material to the aforesaid first sealing surface.

The first component can also be made of a metallic material or a non-thermoplastic material, for example a thermosetting material or wood.

In this case, the step of providing the first component preferably comprises the step of providing a semi-finished product of said first component and the step of gluing the first film of thermoplastic material to said semi-finished product, at least in correspondence with the first sealing surface.

A preferred embodiment of the method, according to the invention, provides that the step of providing the first component also comprises the step of performing a pre-forming of the first film in thermoplastic material, before its insertion into the first forming mold or before the its bonding to the first welding surface.

The second component is preferably made of a thermoplastic material.

In this case, the step of providing the second component includes the steps of:

forming a second semi-finished product of said second component; And

machining said second semi-finished product so that the second welding surface is at least partially knurled and / or has one or more protuberances.

The second component can be made of a non-thermoplastic material, for example a thermosetting material or wood, or of a metallic material.

In these cases, the second component is preferably covered, at least in correspondence with the second sealing surface, by a second film of thermoplastic material.

Further characteristics and advantages of the method, according to the invention, can be better perceived by referring to the description given below and to the attached figures, provided for purely illustrative and non-limiting purposes, in which figures 1-3 schematically illustrate some steps of the method , according to the invention.

With reference to the aforementioned figures, the present invention refers to a method 1 for joining a first component 2 and a second component 3 for manufacturing a sports tool.

In the context of the present invention, the term "sports equipment" identifies a tool provided for by the regulations and / or necessary for the practice of a sporting activity, for example a sports racket, such as a tennis racket, a badminton racket or a racket racquetball, or a golf club, baseball bat, hockey stick, lacrosse stick, sports bow, ski, ski pole, Nordic walking stick, and so on.

Method 1 provides a step 100 of providing the first component 2 which comprises at least a first welding surface 21.

According to the invention, the sealing surface 21 is covered by at least a first film 4 in thermoplastic material.

As is known, the main characteristic of a thermoplastic material is that of varying its viscosity as the temperature increases, until it reversibly reaches the fluid state.

Preferably, as illustrated in Figure 1, the sealing surface 21 is covered with a single film 4. Alternatively, it is also possible to use several superimposed layers of thermoplastic material.

The film 4 can be made, for example, of materials based on PE (Polyethylene), PC (Polycarbonate), PVC (Polyvinyl Chloride), or other polymers with a thermoplastic matrix.

Method 1 provides for a step 200 of providing the second component 3 which advantageously comprises at least a second welding surface 31.

According to the invention, the method 1 comprises a step 300 of positioning the components 2 and 3 in a welding mold 5 (in correspondence with two coupling half-shells 5A and 5B) so that the welding surfaces 21, 31 face each other. and film 4 is interposed between them.

The method finally comprises a step 400 of welding the components 2 and 3 at the welding surfaces 21 and 31, by means of a vibration welding process.

During this welding process, the half-shells of the welding mold 5 are operated in such a way as to move the welding surfaces 21 and 31 relatively to each other, while at the same time exerting a compressive force therebetween.

The heat generated by the rubbing of the two components, in correspondence with the sealing surfaces 21 and 31, determines the at least partial fusion of the film 4. The subsequent cooling and hardening of the molten film 4 ensures, as will be better illustrated below, effective adhesion. between the welding surfaces 21 and 31, even if the first component is made of a non-thermoplastic material.

Preferably, once the welding process is completed, method 1 involves a step 500 of extracting the assembly consisting of components 2 and 3 from the mold 5.

The first component 2 can be advantageously made of a material that is unable to change phase with increasing temperature, for example a non-thermoplastic material or wood.

Preferably, the first component 2 is made of a thermosetting material, for example a carbon fiber composite material.

Alternatively, the first component 2 can be made of a metal material with a relatively high melting temperature, for example steel.

If the component 2 is made of a thermosetting material, the method 1 preferably provides for covering the sealing surface 21 with the film 4 during the forming process of the component 2.

Preferably, the step 100 of providing the component 2 provides for a step 100 A of positioning the film 4 within a first forming mold 6.

A step 100B is therefore provided for positioning a first pre-impregnated 2A of thermosetting material within the forming mold 6 so that the film 4 is in contact with the pre-impregnated 2A at least in correspondence with the sealing surface 21.

After closing the mold, for example by means of a half-shell 6A, step 100C is then provided for heating the forming mold 6 until a crosslinking reaction of the thermosetting material 2A and the simultaneous adhesion of the film 4 to the sealing surface 21 is obtained.

Advantageously, step 100 provides for step 100D to extract the component 2 from the forming mold 6.

Alternatively, especially if the component 2 is made of metal or wood, the method 1 can advantageously provide for the step (not shown) of forming a first semi-finished product of the first component 2, for example by means of a thermoforming process, and to glue the film 4 to said first semi-finished product, at least in correspondence with the sealing surface 21.

Preferably, the step 100 of providing the first component 2 also comprises the step (not shown) of performing a preforming of the film 4, for example by means of a molding process with thermoforming.

This solution allows to obtain a better adhesion of the film 4 to the sealing surface 21.

The second component 3 is preferably made of a thermoplastic material, for example materials based on PA (Polyamide), ABS (Acrylonitrile Butadiene Styrene), PE (Polyethylene), TPU (Thermoplastic Polyurethane), PPS (Polyphenylene Sulfide), PBT (Polybutylene Terephthalate) ), PEEK (Polyetheretherketone), etc ..

In this case, the second component 2 can be advantageously inserted into the welding mold 5, with the sealing surface 31 directly in contact with the film 4, without the need to cover the latter with a further film of thermoplastic material (figure 1 ). During the vibration welding process, a portion of the film 4, in contact with the component 3, and a portion of the component 3, in contact with the film 4, melt.

At the end of the welding process, having completed the cooling, the welding surface 31 is welded to the film 4, which in turn adheres to the sealing surface 21 of the component 2. This creates a connection between the components 2 and 3 in correspondence with the respective welding surfaces 21 and 31.

Preferably, the step 200 of providing the second component 3 comprises a step (not shown) of providing a second semi-finished product of the second component 3, for example by means of an injection molding process.

Preferably, moreover, step 200 of method 1 also comprises the step (not shown) of machining said second semi-finished product so that the second welding surface 31 is at least partially knurled and / or has one or more protuberances.

If the second component 3 is made of thermoplastic material, the first welding surface 21 can advantageously have one or more cavities or undercuts (not shown) suitable for receiving part of the melted thermoplastic material during the vibration welding process.

The solutions illustrated above allow to improve the mechanical strength of the weld between components 2 and 3.

The second component 3 can also be made of a non-thermoplastic material, for example a thermosetting material or wood, or of a metal material with a relatively high melting temperature, for example steel.

In this case, method 1 advantageously provides that the second sealing surface 31 of the second component 3 is covered with at least a second film 7 made of thermoplastic material.

Preferably, as illustrated in Figure 3, the sealing surface 31 is covered with a single film 7. Alternatively, however, it is also possible to use several superimposed layers of thermoplastic material.

The film 7 can be made, for example, in materials based on PE (Polyethylene), PC (Polycarbonate), PVC (Polyvinyl Chloride), etc.

Advantageously, in step 300 of method 1, the second component 3 is advantageously positioned in the welding mold 5 (in correspondence with two coupled half-shells 5A and 5B) so that the sealing surfaces 21 and 31 face each other and the films 4 and 7 , placed between the upper surfaces 21 and 31, are in contact with each other (figure 3).

During this welding process, the half-shells of the welding mold 5 are operated so as to move the welding surfaces 21 and 31 relatively to each other, while at the same time exerting a compressive force therebetween.

The heat generated by the rubbing of the two components, in correspondence with the sealing surfaces 21 and 31, determines the at least partial fusion of the films 4 and 7.

The portions of the films 4 and 7 in contact melt, remaining sealed after cooling. Since the films 4 and 7 adhere in turn respectively to the sealing surfaces 21 and 31, the union between the components 2 and 3 is thus achieved in correspondence with the aforementioned sealing surfaces.

If component 3 is made of thermosetting material, method 1 advantageously provides for covering the sealing surface 31 with film 7 during the forming process of component 3.

Preferably, the step 200 of providing the component 3 involves the following steps (not illustrated):

positioning the film 7 within a second forming mold;

positioning a second prepreg of thermosetting material within the second forming mold so that the film 7 is in contact with the second prepreg, at least at the position of the sealing surface 31;

closing the second forming mold;

heating the second forming mold until obtaining a crosslinking reaction of the thermosetting material and the simultaneous adhesion of the film 7 to the sealing surface 31;

remove component 3 from the second forming mold.

If component 3 is made of non-thermoplastic or metallic material, method 1 advantageously provides for the step (not shown) of providing a semi-finished product of component 3, for example by means of a molding process, and gluing the film 7 to the welding surface 31.

Preferably, the step 200 of providing the second component 3 comprises the step (not shown) of performing a preforming of the film 7, for example by means of a thermoforming molding process.

The method, according to the invention, has significant advantages over the known art.

It allows you to easily join components that have non-homogeneous physical properties, in particular components with a different thermal behavior, for example made of thermosetting material and thermoplastic material.

The method, according to the invention, is also particularly suitable for joining components made of materials with a high stiffness / density ratio, such as composite materials or light alloys.

It allows to obtain high quality and reliable welds as regards resistance to mechanical stress.

The method, according to the invention, also allows to obtain a finished product with excellent finishes from an aesthetic point of view.

In particular, the method, according to the invention, is particularly suitable for joining together components that have welding surfaces covered with decorative films, obtainable by in-molding procedures ("in-molding decoration").

The method, according to the invention, is therefore particularly suitable for manufacturing processes of sports rackets.

The method, according to the invention, does not involve the use of adhesive materials or filler materials. For its execution, industrial equipment of known type, relatively simple to use, can be used.

The steps of the method, according to the invention, can be easily repeated several times to form and join together semi-finished products, until the finished product is obtained.

The method, according to the invention, is easily achievable at an industrial level, with significant advantages in terms of reducing production times and costs

Claims (11)

CLAIMS 1. Method (1) for joining a first component (2) and a second component (3) for the manufacture of a sports equipment characterized in that it comprises the following steps: providing (100) said first component (2), said first component comprising a first sealing surface (21) covered with at least one first film (4) of thermoplastic material; And providing (200) said second component (3), said second component comprising a second welding surface (31); And position (300) said first component and said second component in a welding mold (5), so that said first and second sealing surfaces (21, 31) are facing each other and that said first film (4) is interposed between said first and second welding surface; And welding (400) said first and second components at said first and second welding surfaces, by means of a vibration welding process. 2. Method according to claim 1, characterized in that said first component (2) is made of metallic material. 3. Method according to claim 1, characterized in that said first component (2) is made of non-thermoplastic material. 4. Method according to claim 3, characterized in that said first component is made of thermosetting material. Method, according to claim 4, characterized in that said step (100) of providing said first component comprises the following steps: positioning (100 A) said first film (4) within a first forming mold (6); and positioning (100B) a first pre-impregnated (2A) in thermosetting material within said first forming mold, said first film (4) being in contact with said first pre-impregnated at least in correspondence with said first sealing surface (21) ; And heating (100D) said first mold (6) until a crosslinking reaction of said thermosetting material and adhesion of said first film (4) to said first sealing surface (21) is obtained. Method, according to one or more of claims 1 to 4, characterized in that said step (100) of providing said first component comprises the following steps: providing a first semi-finished product of said first component (2); And gluing said first film (4) to said first semi-finished product, at least in correspondence with said first sealing surface (21). Method, according to one or more of the preceding claims, characterized in that said step (100) of providing said first component comprises the following step: performing a preforming of said first film (4). 8. Method according to one or more of the preceding claims, characterized in that said second component (3) is made of a thermoplastic material. Method, according to claim 8, characterized in that said step of providing said second component comprises the following steps: providing a second semi-finished product of said second component (3); and working said second semi-finished product so that said second welding surface (31) is at least partially knurled and / or has one or more protuberances. Method, according to one or more of claims 1 to 7, characterized in that said second component (3) is made of a non-thermoplastic material, said second sealing surface (31) being covered by at least a second film (7 ) in thermoplastic material. 11. Method according to one or more of the preceding claims, characterized in that said sports tool is a sports racket.