JPH02248236A - Joining method for plastic and joining stud - Google Patents

Abstract

PURPOSE:To inhibit spreading of a molten part at a necessary minimum and to make joining execution work easy by performing joining by both melting due to frictional heat build-up of mutual plastic materials and agitation of the molten part due to rotation. CONSTITUTION:When the joining material 2 made of plastic is rotated relatively to an object base material (plastic panel) 1 by a rotary tool 4 and pushed on the object base material 1, rotary friction is caused in this pushing part. Both the joining material 2 and the object base material 1 start to be melted by both the relative rotating velocity and heat build-up due to friction correspondent to pushing force. Agitating effect of mutual molten plastics due to relative rotation is added thereto and the systems of the molten parts of both plastics are made an entangled state. Therein when the rotation of the joining material 2 is stopped, the molten parts are cooled and solidified. Both plastics 1, 2 are strongly welded and joined together.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a plastic joining method and a joining stud, and more specifically, to a plastic joining method and a joining stud, and more specifically, a method that utilizes heat generation due to relative rotational friction between a plastic joining material and a target base material. The present invention relates to a method of fusion bonding a bonding material and a target base material, and a bonding stud used therein.

[Prior art] Conventionally, plastic deck materials have been bonded by using adhesives for target base materials of the same or different plastics, by using high frequency or ultrasonic fusion, or by hot air fusion. Methods are known.

In the method using adhesives, it is necessary to select the type of adhesive depending on the materials of the two plastics to be joined, and it takes time for the solvent to evaporate and the polymerization reaction to complete, so it is necessary to use adhesives to obtain strong joint strength. Expert knowledge is essential for material selection and construction, and a long curing period after construction is also required.

In addition, methods that utilize high frequency or ultrasonic fusion require special jigs or pre-forming of the joint in order to concentrate energy at the fusion site, and the equipment configuration for energy irradiation is also required. It is large-scale and requires skill, and the shapes and parts of objects that can be joined are limited.

Furthermore, the method of fusing with hot air has the disadvantage that deformation tends to occur because the hot air hits areas other than the bonded area.

[Problem to be solved by the invention] This invention has been made in view of the above-mentioned state of the prior art, and its purpose is to solve any problem that can melt with the target base material due to frictional heat generation. Sufficiently high bonding structural strength can be obtained even with plastic bonding materials, the spread of the molten part is kept to a minimum, and the bonding work is easy and efficient, and it is a simple rotary hand tool. It is an object of the present invention to provide a plastic joining method that allows a joining material to be welded from one side of a target base material, and a joining stud used for warping.

[Means for Solving the Problems] That is, in the plastic joining method according to the invention according to claim 1, when joining a plastic joining material and a target base material, the joining material is moved relative to the target base material. While rotating on its own axis, the bonding material is pressed against the target base material, and the bonding material is fusion-bonded to the target base material by heat generation due to rotational friction.

In this case, the above-mentioned fusion bonding can be roughly divided into two modes: one is a method in which the tip end surface of the bonding material is fused by rotational friction, and the other is a method in which the peripheral surface of the bonding material is bonded by rotational friction. This is a fusion method. Of course, both may occur at the same time.

In the plastic bonding method according to the invention described in claim 4, the bonding material common to the target base material and the adjacent plastic member is rotated in the same way, so that both the target base material and the adjacent plastic member are the same. The target base material and the adjacent member are integrally joined by the joining material by friction welding with the joining material.

In the plastic bonding method according to the invention as set forth in claim 5, after melting occurs at any rotational friction site between the rotating joint portion and the target base material, the rotation of the bonding material is stopped, and
The melted area is solidified by creating a flow of cooling fluid on the surface of the area, for example by sucking air through a nozzle or blowing out air or water.

The joining stud for plastic joining according to the invention set forth in claim 6 is directly used for carrying out the method invention described above, and has a rotation transmission structure at the tail end for receiving the rotational driving force of the rotary tool. It has a roughly columnar body made of thermoplastic plastic that melts due to heat generated by relative rotational friction with the target base material.

In the joining stud according to the invention as set forth in claim 7, the substantially columnar main body has a circularly tapered shape, and in the joining stud according to the invention as set forth in claim 7, the object target by the rotation is formed on the distal end surface of the main body. A blade is provided for cutting into wood.

[Function] In the plastic joining method according to the invention according to claim 1, when the plastic joining material is rotated relative to the target base material and the joining material is pressed against the target base material, this Rotational friction occurs at the pressing part, and the bonding material and the target base material begin to melt due to the heat generated by the friction according to the relative rotational speed and pressing force, and the stirring effect of the molten plastics due to the relative rotation. In addition, the structures of the two fused parts become entangled. Then, when the rotation of the joining material is stopped, the molten part cools and solidifies, and the two are firmly fused and joined.

In this way, in the present invention, welding is performed by the synergistic effect of frictional melting and stirring by relative rotation, so as long as the melting point temperatures are not too far apart, high strength can be achieved in joining most types of thermoplastic plus decks. Bonding can be achieved. For example, the target base material is fiber reinforced plastic (FRP)
In this case, the reinforcing fibers become entangled with the melted part of the bonding material due to friction in the molten resin, and the bonding strength after cooling and solidification becomes sufficient.

In addition, the joining work in the present invention involves simply rotating the joining material, pressing it against the target base material, and stopping the rotation when melting occurs in the friction area, so it does not require any skill and can be easily performed using a rotating hand tool such as an electric drill. It can be carried out efficiently, and since the joining material can be welded from only one side of the target base material, the construction is not restricted by the structure of the opposite side.

The plastic joining method according to the invention according to claim 4 includes:
The case where the target base material includes an adjacent plastic member is dealt with. In this case, the bonding material is similarly rotated,
Both the target base material and the adjacent member are rubbed against the same bonding material. As a result, a common friction melting portion of the common bonding material is formed between the target base material and the adjacent member, and an integral and strong bond is achieved by stirring the molten resins of the three members. In this method, for example, when there are sheet-like adjacent members stacked on top of the target base material, the rotating joining material penetrates both members and creates a rivet-like structure by stirring and fusing each other on the peripheral surface of the joining materials. When joining together, or when base materials are butted or adjacent to each other in a fillet joint structure as in normal welding of metal materials, welding is performed by friction melting while pressing a rotating joining material against these joints. This includes things such as.

The plastic joining method according to the invention according to claim 5 includes:
This defines the process for the final stage of friction welding of the invention according to claim 1. Here, after melting occurs at the rotational friction site between the rotating bonding material and the target base material, the rotation of the bonding material is stopped and, for example, air is sucked through a nozzle or air or water is blown out at the site. A flow of cooling fluid is generated on the surface of the melted portion, and the molten portion is forced to cool and solidify at an early stage. Kneading can contribute to speeding up construction work in the repeated process of joining the same type of joining material to many locations.

The joining stud for plus deck joining according to the invention as set forth in claim 6 is a joining material that is directly used in carrying out the method invention described above. This joining stud has a nearly columnar body made of thermoplastic plastic that melts due to heat generated by relative rotational friction with the target base material, and a rotation transmission structure at the tail end.
For example, the non-circular end of the rotating shaft of the rotary tool is inserted into a non-circular hole such as a square hole coaxial with the rotating shaft.

Of course, the rotation transmission structure of the tail end may have a shaft end shape that is gripped by a chuck of a rotary tool. This joining stud receives the rotational driving force from the rotary tool at its tail end and rotates, and by pressing it against the target base material, relative rotational friction with the target base material is generated and heat is generated. melt.

Preferably, the rotation transmission structure is a simple non-circular socket or grip shaft that can be attached to and detached from the main shaft of the rotary tool in use with a single touch.

In the joining stud according to the invention as set forth in claim 7, the substantially columnar main body has a circularly tapered shape, and therefore, a leading hole is previously drilled in the target base material, and the leading hole is provided with a tapered shape. When a tapered stud is rotated and press-fitted so that the circumferential surface of the stud slightly expands the inner wall surface of the pilot hole, effective heat generation and agitation of the molten resin are achieved over the entire area of friction on the circumferential surface of the stud. This allows a strong recessed stud installation without misalignment to be achieved.

In addition, in the joining stud according to the invention as set forth in claim 7, since the tip surface of the main body is provided with a blade for biting into the target base material by the rotation, the blade on the stud tip surface is used to target the target base material. It is possible to install studs without misalignment while drilling in the spot.

Embodiments of the present invention will be described below with reference to the drawings.

[Example] FIG. 1 shows how a plastic stud 2 is joined to a plastic panel 1 according to the invention.

The stud 2 is made of a thermoplastic resin such as polypropylene, and has a substantially columnar shape with a square hole 3 coaxial with the axis at the tail end. This stud 2 is inserted from the tail end into the chuck 5 at the end of the rotating shaft of a tool 4, which is an electric rotating hand tool, with one touch, and the square head (not shown) at the tip of the tool's rotating shaft is connected to the square hole 3. The socket is connected to receive the rotational drive of the tool 4. In addition, 6 is an operation knob for turning on/off the rotation of the tool 4 and adjusting the rotation speed, and 7 is a wire through hole provided in the stud 2.

FIGS. 2(a), 2(b), and 2(c) schematically show an enlarged view of the joining portion of the joining stud 22 similar to that described above. In FIG. 2(a), at the tip of the tool rotation shaft 26, a square head 27 is provided at the center and a plurality of holding spring pieces 28 are provided around the periphery. The stud 22 is made of a cylindrical thermoplastic plastic having a square hole 23 at its tail end, and when inserted into the tip of the tool rotation shaft from its tail end, the square head 27 of the rotation shaft is received in the square hole 23. It constitutes a rotation transmission coupling portion, and is held by a retaining spring 28 to prevent it from falling off.

In this state, the tool rotating shaft 26 is rotated as shown by the arrow and pressed against the target location of the plastic panel 21, which is the target base material. In this case, in order to accurately press the stud 22 onto the target location, the tip end surface of the stud 22 may be formed into a conical convex shape as shown in the figure, or a recess 25 about the size of a punch hole may be formed in advance at the target location on the panel 21. You can leave it as is.

This pressing causes the tip of the stud 22 to touch the panel 21.
Rotational friction occurs with the surface of the
As shown in b), melting occurs at the frictional region, and the resins of the stud and panel are agitated by rotation, and a bead 29 of mixed resin of both is formed. In this state, stop the rotation of the rotation @ 26, and when the bead 29 cools down and hardens, lift the tool rotation shaft 26 upwards to join the stud 22 on the panel 21 as shown in Fig. 2(C). It becomes a state.

Although the stud 22 in this example has a square hole 23, it may also be a stud 22a having a square head 23a as shown in FIG. should be made into a corresponding female configuration. Also, the external shape of the stud is not limited to a cylindrical shape.
As shown in FIG. 2(e), a prismatic stud 22b may be used. In addition, in FIG. 2(C), 23b is a female screw hole bored in the end face of the stud, and a male screw may be provided protruding in place of this female screw hole 23b. In this case, the stud 22b is rotationally driven by gripping the outer peripheral surface of the main body of the stud 22b with a tool shaft having a structure similar to that shown in FIG. 2(a). Further, 24 is a wire rod passing hole (wire rod holding ring) provided in the stud 22b, and its cover position is naturally determined at a position that does not interfere with the rotational drive of the stud.

FIG. 3 shows another embodiment, in which the bonding material 32 used is a tapered plus deck cone with a metal drill bit 30 embedded in its tip. This conical joining material 32 has a square hole 33 at its tail end, and is used for construction using the same rotary tool as described above. That is, Fig. 3 (b
) As shown in FIG.
4, press the conical joining material 32 rotated with a rotary tool from above the plus deck plate 34, and press it further while rotating, and the joining material 32 will be made of plastic by drilling with the drill bit 30 at the tip. It penetrates the plate 34 and enters the base material panel 31, and generates rotational friction with the plastic plate 34 and the base material panel 31 on the circular Sii surface of the bonding material 32. Heat generated by this friction melts the frictional area and rotates at the same time. The molten resin is stirred by. Therefore, after the bonding material 32 has penetrated to a predetermined depth and the resin has been stirred by friction, the rotation of the bonding material 32 is stopped, and the unnecessary beads 39 on the surface of the plastic plate are scraped off after waiting for the molten resin to cool and solidify. As shown in FIG. 3(C), the bonding between the base material panel 31 and the covering plastic plate 34 using the bonding material 32 is completed. In this case, it is preferable to drill a conical or other leading hole at the location where the base material panel 31 and the plastic plate 34 are to be joined.
In some cases, bonding can be achieved even without.

FIG. 4 shows an embodiment in which a metal plate 44 is stacked on the surface of a plastic base material 41 and fixed with plastic rivets 42. In this case, the plastic rivet 142 as a bonding material has a large diameter head 45 as shown in FIG. 4(a).
This is a headed rivet having a square hole 43 on the top surface of the head 45. On the other hand, a through hole 46 with a larger diameter than the body of the rivet 42 is bored at the location where the metal plate 44 is to be fastened, as shown in FIG. A deep circular depression 47 is provided. A metal plate 44 is correctly stacked on a base material 41, and a rivet 42 with a body slightly longer than the depth dimension from the bottom of the depression 47 to the surface of the metal plate 44 is prepared. Insert this rivet 42 into the through hole 46, fit the square end of the tip of the tool rotation shaft into the square hole 43 from above the head 45, and press it from above while rotating the rivet 42 with the tool rotation shaft. Recess 4 in the part and plastic base material 41
Relative rotational friction with the bottom surface of 7 occurs. The kneading generates heat at the frictional part, and both resins are melted and stirred, filling the depression 47, as shown in FIG. 4(C). Rivet 42
When the lower surface of the head 45 comes into contact with the surface of the metal plate 44, the rotation of the rivet 42 is stopped and the pressing state is maintained for a short time.The molten resin 49 in the depression 47 cools and hardens, and the rivet The metal plate 44 is fixed by the metal plate 42.

FIG. 5 shows an embodiment in which a cup-shaped plastic part 52 is joined to a plastic panel 51. Figure 5 (
The cup-shaped plus deck part 52 as shown in a) is
As shown in FIG. 5(b), the tool is rotated on the panel by being pressed by a tool rotating shaft 56 having a suction cup 55 attached to its tip. As a result, as shown in FIG. 5(C), melt-stir welding is performed between the bottom surface of the cup-shaped component 52 and the surface of the panel 51 by rotational friction.

FIG. 6 shows an example of joining of fillets between plastic plates. In FIG. 6(a), the horizontal plate 61a and the vertical plate 61b
are both plastic materials, and bonding material 62 is immersed and fused at intervals in the joint length direction at the fillet joints between the two. As this bonding material 62, the conical bonding material 32 shown in FIG. 3 described above can be used. at the required intervals,
Alternatively, after the bonding material 62 is immersed and fused without any gaps, as shown in FIG.
It is advisable to cut the fillets as shown in b). FIG. 7 shows an embodiment in which a butt joint between plastic plates 71a and 71b is joined using a joining material 72. In FIG. 7, plastic plates 7Ia and 71h form a butt joint, and grooves are formed on the joint surface as necessary. The bonding material 72 is rotated and pressed from directly above the joint groove, and pushed to a required depth. As in the case described above, both plastic plates and the bonding material are fused together due to the friction between the three members at this time.

FIG. 8 shows an example of forced cooling of the fused portion.

A non-rotating wear ring (cover) 82 is attached to the tip of the rotary tool 80 via a spring 83 so as to surround the rotary shaft end 86 . Wear ring 82 is bearing 84
It can rotate relative to the rotation shaft 86 and slide in the axial direction, and as shown in the figure, it surrounds the stud 2 on the surface of the base material 1 during the welding operation. The wear ring 82 has multiple ventilation holes 87 at its tip, and a duplex 89 that communicates with an intake pump (not shown) is connected to the boat 88.
It communicates with the internal space of the wear ring via. When joining the stud 2 to the base material 1 using the rotary tool 80 equipped with such a wear ring 82, the rotation of the rotation @ 86 is stopped at a time when the melting occurs and sufficient stirring is achieved during the joining operation. When the suction pump is activated at the same time, the suction of air as shown by the arrow creates a flow of cooling air on the surface of the welded area, and the forced air cooling quickly solidifies the welded area, making it easy to install the stud 2. The time required can be shortened.

In each of the above embodiments, the case where a hand-held hand tool is used as the rotary tool is mainly illustrated, but the present invention is not limited to this, and the present invention is not limited to this, and the present invention is not limited to this. It also includes cases where the joining work is performed by an automatic machine.

[Effects of the Invention] As described above, according to the present invention, since joining is performed by melting plastic materials due to frictional heat generation and stirring of the molten part by rotation, there is no frictional heat generation between the target base materials and the bonding process. Sufficiently high bonding structural strength can be obtained by using any type of plastic bonding material as long as it melts together, and the bonding work can be done easily and efficiently from one side of the target base material using a simple rotating hand tool. It is something that can be done.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing one embodiment of the present invention, Figure 2 (a)
(b) (c) (d) (e) is a process explanatory diagram showing a specific example of the joining part, Fig. 3 (a) (b) (
c) is a process explanatory drawing showing another specific example of the joining part, FIGS. Figure 5 (a) (
b) (e) is a process explanatory diagram showing yet another specific example of the joining part, FIGS. 6(a) and (b) are perspective views showing an example of joining a fillet joint, and FIG. 8 is an explanatory view showing an embodiment for joining a butt joint, and FIG. 8 is an explanatory view showing the configuration of a main part of a forced air cooling type welding tool. (Explanation of symbols of main parts) 1. Niblast panel (target base material), 2: Joining stud (joining material), 3: Square hole, 4: Rotating tool.

Claims (1)

[Claims] 1. When joining a plastic bonding material and a target base material, the joining material is rotated relative to the target base material, and the joining material is pressed against the target base material. A plastic joining method characterized by fusion joining the joining material to the target base material by heat generation due to rotational friction. 2. The plastic bonding method according to claim 1, wherein the front end surface of the bonding material is fused by rotational friction. 3. Claim 1, in which the peripheral surface of the bonding material is fused by rotational friction.
Plastic joining method described in. 4. The target base material includes an adjacent member, and both the target base material and the adjacent member are friction-fused with the same bonding material, and the target base material and the adjacent member are integrally joined by the bonding material. The plastic joining method according to claim 1, characterized in that: 5. The plastic bonding method according to claim 1, wherein after melting occurs at a rotational friction site between the bonding material and the target base material, the rotation is stopped and a flow of cooling fluid is generated on the surface of the site to solidify it. 6. It has a rotation transmission structure at the tail end to receive the rotational driving force of the rotary tool, and is equipped with an almost columnar body made of thermoplastic plastic that melts due to heat generated by rotational friction relative to the target base material. A joining stud for plastic joining characterized by: 7. The mating stud of claim 6, wherein said generally columnar body has a circularly tapered shape. 8. The joining stud according to claim 6, wherein a blade for biting into the target base material by the rotation is provided on the tip end surface of the main body.