JPH0363945B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for joining two plastic materials by overlapping them and joining them without using an adhesive or the like.

[Conventional technology]

Conventionally, when manufacturing plastic parts used in automobiles, electrical appliances, etc., the flat parts of plates and parts are often joined together by overlapping each other. They were joined by coating or by mechanical methods such as bolting or riveting.

[Problem that the invention seeks to solve]

However, such conventional bonding methods have problems in that the bonding strength is sometimes insufficient, and the processing steps are complicated and productivity is low.

The present invention has been made in view of the above points, and an object thereof is to provide a new method for joining plastic materials that is easy to process and has high joint strength.

[Means for solving problems]

In order to achieve such an objective, the present invention
A pair of gripping members grips two overlapping plastic materials with their joint surfaces facing each other, and a concentric rod-shaped tool is inserted into the tool hole of each gripping member with the axis tilted relative to the joint surface. While holding the plastic material, the rod-shaped tool and the gripping member are vibrated relative to each other in the axial direction of the rod-shaped tool to locally heat soften the plastic material, and then both rod-shaped tools are simultaneously moved in the axial direction to remove the plastic material. Now joins materials.

[Effect]

Due to the relative vibration between the rod-shaped tool and the gripping member, the vicinity of the part where the plastic material is clamped by the rod-shaped tool is locally thermally softened due to thermal conversion of deformation energy, so if the rod-shaped tool is moved in this state, the softened part will become heavy. It transforms into a half-cut shape and is firmly joined.

〔Example〕

1 and 2 are longitudinal sectional views of a joining device shown for explaining the method of joining plastic materials according to the present invention, and FIG. 1 is a longitudinal sectional view before joining;
FIG. 2 is a longitudinal sectional view after joining. In the figure, two plastic materials 1 and 2 formed into a flat plate shape
are stacked with their joint surfaces 1a and 2a facing each other, and these plastic materials 1 and 2 are held in an inclined state by a pair of upper and lower triangular dies 3 and 4 as gripping members. has been done. In each of the upper and lower dies 3 and 4, punch holes 3a and 4a as tool holes are formed concentrically and perpendicularly to each other. 5 and 6 are inserted with their slanted end surfaces facing the planes of the plastic materials 1 and 2. Each of the punches 5 and 6 is configured to be driven by a drive device (not shown) to move in the axial direction. The punches 5 and 6 may be cylindrical with an elliptical cross section, or may be polygonal or prismatic with an uneven cross section like a star.

After gripping the plastic materials 1 and 2 with the dies 3 and 4 in this way and inserting the punches 5 and 6,
For example, drive the punches 5 and 6 with the drive device to punch 0.3mm.
When the punches are vibrated so as to reciprocate in the axial direction with a moderate amplitude, the contact points of the tips of the punches 5 and 6 generate heat, become thermally soft, and become easily deformed. This vibration may have a frequency of, for example, 50 Hz and last for several seconds. Following the vibration, when the punches 5 and 6 are moved downward by a distance of approximately 1/2 of the thickness of one of the plastic materials 2, the thermally softened plastic materials 1 and 2 are moved by the distance of the punches 5 and 6. It is deformed and half-blanked as shown in FIG. After processing, punches 5 and 6 and die 3,
4 is moved up and down to separate it from the plastic materials 1 and 2, and when the plastic materials 1 and 2 are removed, the two are firmly joined. In this example, the plastic material 1 was made of polypropylene, and the plastic material 2 was made of polycarbonate.

Plastic material 1 joined in this way,
In No. 2, the half-opening part is inclined, so if the movement in the direction of arrow A in the figure is restricted by a stepped part or a bent part, there is no risk of the joint coming apart.
If it is movable in the direction of arrow A, there is a risk that the bond will peel off, so in this case the above process is repeated twice. That is, after removing the joined plastic materials 1 and 2 explained in FIG. 1 and FIG. , 4 to hold it. When the same vibration of the punches 5 and 6 as described above and the half punching process are repeated, as a result, as shown in FIG. Joining is performed by half-blanking. The plastic materials 1 and 2 thus joined will not be peeled off from each other even if force is applied in either direction.

4 and 5 are longitudinal cross-sectional views of a bonding apparatus shown to explain a bonding method as another embodiment of the present invention. FIG. 4 is a longitudinal cross-sectional view of a bonding surface, and FIG. FIG. In this embodiment, a filler 7 made of the same material as the plastic material 1 and having a thickness of approximately 1/2 is inserted between the punch 5 on the lowering side and the plastic material 1, and then the same joining process as described above is performed. As shown in FIG. 5, the result of the bonding is that the filler 7 is filled into the concave hole formed in the plastic material 1 by the bonding process, and the surface of the plastic material 1 is not irritated. can.

Furthermore, FIGS. 6a, b, and c are longitudinal cross-sectional views of a bonding apparatus shown in the order of steps for explaining a bonding method as another embodiment of the present invention.
In place of the filler 7 shown in FIG. 5, a thicker filler 8 is inserted. When the filler 8 is inserted and the punches 5 and 6 are lowered greatly as shown in FIG. 6a, the filler 8 is inserted as shown in FIG. 6b.
is filled into the punch hole of the plastic material 2, so if another filler 9 is filled into the hole of the plastic material 1 as shown in FIG. can do. The fillers 7 and 8 in the embodiments shown in FIGS. 4 to 6 do not need to be the same type of plastic material as the plastic material 1 or 2, but may be a different type of plastic material or metal.

In each of the above embodiments, the plastic material 1 is made of polypropylene, the plastic material 2 is made of polycarbonate, and different types of plastic materials are bonded to each other. It goes without saying that they can be joined, and the materials of the plastic materials 1 and 2 are not limited. However, it goes without saying that the present invention is effective in joining different types of plastic materials, which has been difficult with conventional joining methods. Furthermore, although the punches 5 and 6 are vibrated in each of the above embodiments, the punches 5 and 6 may be kept stationary and the dies 3 and 4 that clamp the plastic materials 1 and 2 may be vibrated.

〔Effect of the invention〕

As is clear from the above description, in the method for joining plastic materials according to the present invention, two plastic materials stacked one on top of the other with their joint surfaces facing each other are gripped by a pair of gripping members, and the two plastic materials are held axially relative to the joint surfaces. While the plastic material is held between concentric rod-shaped tools inserted into the tool holes of each gripping member with their cores inclined, the rod-shaped tool and the gripping member are vibrated relative to each other in the axial direction of the rod-shaped tool to locally remove the plastic material. After being thermally softened, both rod-like tools are moved axially at the same time to join the plastic materials, allowing for adhesive or mechanical methods such as bolting or riveting. without doing 2
It is possible to extremely firmly join individual plastic materials by combining the joining effect of melting and the mechanical joining effect, and the reliability of the product is significantly improved, the joining process is easy, and productivity is improved. Furthermore, by applying the joining method according to the present invention in two places and making the inclination directions of each joint point opposite to each other, the joint becomes even stronger, and it is possible to firmly join the plastic materials of the pipes, which has been difficult to join in the past. It is extremely effective because it does not peel off even if force is applied to both plastic materials in either direction.

[Brief explanation of drawings]

1 to 6 a, b, and c are diagrams shown to explain the method of joining plastic materials according to the present invention, in which FIG. 1 is a longitudinal cross-sectional view of the joining device before joining, and FIG. 3 is a longitudinal sectional view of the welding device after joining, FIG. 3 is a longitudinal sectional view of a product joined at two locations with opposite inclination directions, and FIG. 4 is a longitudinal sectional view of the welding device before joining shown to explain another example FIG. 5 is a vertical cross-sectional view of the bonding device after bonding, and FIGS. 6 a, b, and c are longitudinal cross-sectional views of the bonding device shown in the order of steps to explain other embodiments. It is a front view. 1, 2... Plastic material, 1a, 2a... Joint surface, 3, 4... Dice, 5, 6... Punch,
7, 8...Filling material.

Claims (1)

[Claims] 1. Two pieces of plastic material overlapped with their joining surfaces facing each other are gripped with a pair of gripping members each having a concentric tool hole whose axis is inclined with respect to the joining surface, and the tip end is held against the plastic material. The rod-shaped tool inserted into each tool hole while in contact with the rod-shaped tool and the gripping member were vibrated relatively in the axial direction of the rod-shaped tool, thereby locally thermally softening the plastic material near the rod-shaped tool contacting part. A method for joining plastic materials, which is characterized in that both rod-shaped tools are then simultaneously moved in the same axial direction to join both plastic materials.