JP2002172700A - Method for welding fluororesin parts and welding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for welding fluororesin parts by which no preheating process is required and the fluororesin parts can be welded on the same conditions, regardless of their material used, i.e., a high melt-point fluororesin or different kinds of fluororesins as well as a welding device. SOLUTION: An ETFE tube 2 into which a twist-proof rod 3 is previously inserted is introduced into a PFA flange 1, then the tube 2 is retained by a chuck 7 of a fixed side hollow barrel part 6 of a welder and the flange 1 is retained with the help of a chuck 5 on the rotary shaft 4 side. Finally the flange 1 and the tube 2 are welded together by a frictional heat generated on the contact face between the flange 1 and the tube 2 by the rotation of the flange 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for welding fluororesin parts, and more particularly to a method and a method for welding fluororesin parts by utilizing frictional heat generated by sliding. It relates to improvement of the device.

[0002]

2. Description of the Related Art Fluororesins have excellent heat resistance, chemical resistance and electrical insulation, and are widely used in the chemical industry, the electric and electronic industries, and the like. In particular, in the semiconductor manufacturing industry, which has been remarkably developed in recent years, it is frequently used for components used in processes requiring chemical resistance such as contact with chemicals. The product shapes are diverse, and the joining of components has become indispensable in order to manufacture at a lower cost in terms of cost, and the dimensional accuracy has become more severe. Conventionally, as a method of joining fluororesin parts, a method is used in which the joining surfaces of the fluororesin parts are brought into contact, and the frictional heat generated by sliding the contact surfaces relative to each other is used to heat and weld the fluororesin above its melting point. Are known.

[0003] Further, as a welding apparatus for a fluororesin part, when both fluororesin members are fixed by chucks and moved downward while rotating the upper chuck, the upper member contacts the lower member while rotating. Further, when a downward force is further applied to the upper chuck, pressure is applied to both the upper and lower members, and the frictional heat generated at that time heats the fluororesin above its melting point to fuse it.

[0004]

However, fluorine resin is difficult to weld by the conventional method because of its high melting point, difficulty in heating due to a low coefficient of friction, and a large amount of wear due to friction.

For example, in Japanese Patent Publication No. 62-58898, as a method of welding a fluororesin flange to a fluororesin pipe, a pipe mounting hole (borebore) is formed on the inner peripheral surface of the flange, and the pipe hole of this flange is formed. Press the pipe and preheat the welding surface of one of the fluoroplastic parts to a point close to the softening point beforehand.
A method of welding both parts with heat generated by relative rotational sliding friction of the flange is disclosed.

In the welding method described in the above publication, only the diameter portion of the end face of the tube comes into contact with the flange, and since the contact surface is extremely small, the relative rotation speed is reduced, and the tube is heated to a desired temperature by friction. Therefore, it is necessary to preheat the welding surface of the component to be welded to a position near the softening point. Therefore, it takes a considerable time to complete the welding.

Furthermore, in the above method, since the end of the tube comes into contact, burrs are generated on the inner diameter side of the tube,
It is necessary to perform a burr treatment on the inner diameter side after the welding treatment, which may cause a problem in a method of using a welded part that requires inner surface smoothness.

Further, in the case of pressing only in the direction parallel to the rotation axis as in the above-mentioned method, the amount of heating is small in the case of a high melting point fluororesin. Since the peripheral speeds are different, uniform heating is difficult, and therefore, it is difficult to uniformly weld the sliding surface with a material having a high melting point.

Although the conventional rotary welding apparatus does not require preheating, the contact portion between the end faces of the tube and the like is welded and fixed by frictional heat due to rotation as in the above publication, so that the part moves downward while rotating. However, it is necessary to generate frictional heat while strongly pressing both parts. Therefore, in addition to a rotation mechanism for rotating components, a mechanism for moving members up and down and pressing both members is also required in the apparatus, and the apparatus is increased in size. In addition, when the shape of the tube or the like is not a perfect circular shape, when the chuck is rotated, the tube slightly shakes, so that considerable care is required at the time of welding. Also, such devices are partially curved (not straight) to rotate by grasping the end of the tube
In the case of a tube, the rotation axis is shifted and rotation welding cannot be performed. Furthermore, since the ends of the welding members are brought into contact with each other for rotational welding, it is difficult to attach a bush or sleeve-shaped member to the center of the tube or rod. In addition, as a result of the study by the present inventors, when the welded member is fitted around the welded member and one of them is rotated, if the welded member is not uniformly held on the welded member by the chuck, welding unevenness occurs. It has been confirmed that.

The present invention has been made in order to solve the above-mentioned problems, and does not require preheating, has a large contact area, can increase a relative rotational speed, and has an inner surface of a tube part. Without burr
It is an object of the present invention to provide a method and an apparatus for welding a fluororesin component which can be welded in a short time even with a fluororesin having a high melting point or a different kind of fluororesin.

[0011]

In order to achieve the above object, a method of welding a fluororesin component according to the present invention is a method of welding a member to be welded made of a fluorine resin and a member to be welded, wherein the method comprises the steps of: The gist is that the members to be welded are disposed on each other, and at least one of the members is rotated so that the members are welded to each other by frictional heat generated on a contact surface between the members.

According to the present invention, there is provided a resin component welding apparatus which allows a welding member or a member to be welded to penetrate therethrough, a hollow body having a chuck for holding the welding member, and a welding member and a member to be welded disposed therearound. A hollow body having a chuck that enables the member to be welded to be pressed from the outer periphery to the welding member, a motor that rotationally drives one of the two hollow bodies with the chuck, and a rotation control unit for the motor. The gist comprises a brake portion for stopping rotation of the motor and a moving mechanism for moving the other hollow body with a chuck to adjust the distance between the hollow body with the chuck.

[0013] The fluororesin used in the present invention is not particularly limited, but is a tetrafluoroethylene-fluoroalkylvinyl ether copolymer resin (hereinafter referred to as "PFA"), a tetrafluoroethylene-hexafluoropropylene copolymer resin. (Hereinafter referred to as "FEP"), ethylene tetrafluoride-ethylene copolymer resin (hereinafter referred to as "ETFE"), vinylidene fluoride resin (hereinafter referred to as "PVDF"), and ethylene trifluoride chloride resin (hereinafter referred to as "PCTFE"). Is particularly preferred.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a preferred embodiment of the present invention, as shown in FIGS.
Then, the tube 2 made of ETFE into which the torsion preventing rod 3 has been inserted in advance is inserted, and as shown in FIG. 5, the tube 2 is firmly held using the chuck 7 provided on the fixed-side hollow body 6 of the welding machine, and welded. The flange 1 is firmly held by using a chuck 5 provided on the rotating shaft 4 side of the machine, and the rotating shaft 4 is driven to rotate the flange 1 so that the flange 1 and the tube 2 are welded by frictional heat generated on the contact surface thereof. To obtain a welded product.

Here, when the flange 1 is uniformly and firmly held in the circumferential direction by the chuck 5, unevenness in the pressure between the flange and the tube is eliminated, so that the welding can be performed uniformly, and the welding strength is improved, which is more preferable. Examples of the chuck that uniformly presses in the circumferential direction include a collet chuck and a three-jaw chuck formed so as to substantially cover the circumferential direction. When the rod 3 is inserted into the inside of the tube 2, pressure is easily applied between the tube 1 and the rod 3 when the tube 2 is rotated, and strong welding can be performed in a short time, which is more preferable.

[0016]

EXAMPLE 1 This example, as shown in FIGS. 1 to 4, the inner diameter phi ₂ (10
mm), outer diameter φ ₁ (16 mm), thickness 40 mm PFA
The inner diameter φ ₄ (8 mm) and the outer diameter φ ₃ (1
0 mm) ETFE tube 2 is prepared. Here 0.0~0.1m the tube outer diameter phi ₃ from the flange inner diameter phi ₂
It is preferable that m is small because it can be easily inserted into an arbitrary position of the tube.

A rod 3 made of SUS and having an outer diameter φ ₅ (8 mm) is inserted into the tube 2 to prevent the tube 2 from being twisted. Even in this case, the outer diameter φ of the rod 3
When ₅ the smaller 0.1~0.5mm than the inner diameter phi ₄ of the tube 2, easily inserted into the tube. Next, the rod 3
Is inserted so that the end of the tube passes through the hole of the flange 1.

Then, as shown in FIG. 5, with the tube 2 inserted into the flange 1, the flange 1 is firmly held by using the chuck 5 on the rotating shaft 4 side of the welding machine, and the tube 2 is connected to the welding machine. It is firmly held using a chuck 7 provided on the fixed-side hollow body 6. In this case, there is no problem if the flange 1 is held by the chuck 7 of the fixed-side hollow body 6 and the tube 2 is held by the rotating-side chuck 5. Then, the peripheral speed of the contact sliding surface of the flange 1 held on the rotating side of the welding machine with the tube 2 is set to 1.5 to 2.5 so that the peripheral speed becomes 2000 mm / sec.
Rotate for seconds. Thus, the PFA flange 1 and the ETFE
A welded product obtained by welding the tube 2 made by frictional heat generated on the sliding surface was obtained. The initial peripheral speed for starting rotation from the state where the members are in contact with each other is 0 mm / sec, but the final peripheral speed of the contact sliding surface between the members is determined in consideration of the friction coefficient between the resins used. It is good to set to 500 to 10000 mm / sec. Preferably it is 1500-4000 mm / sec. The time until the final peripheral speed depends on the welding member, welding machine, and motor used, but is preferably 0 to 5 seconds, preferably 1 to 3 seconds.

Embodiment 2 In this embodiment, the flange 1 of Embodiment 1 is made of FEP, and a welded product in which the flange 1 of FEP and the tube 2 of ETFE are welded by performing the same method as in Embodiment 1. Obtained.

[0020] Example 3 This example, as shown in FIGS. 6 to 8, the inner diameter phi ₆ (10
mm), outer diameter φ ₇ (16 mm), length 40 mm FEP
ETFE with outer diameter φ ₈ (10mm) for sleeve 8
A rod 9 is prepared. Here, when the rod outer diameter phi ₈ smaller 0.0~0.01mm than the sleeve inner diameter phi _6,
It is preferable because it can be easily inserted into an arbitrary position of the rod. Next, the rod 9 is inserted so that the tip of the rod passes through the hole of the sleeve 8. Note that there is no problem even if the tip 9a of the rod 9 is slightly inside the tip 8a of the sleeve 8.

Therefore, as shown in FIG. 9, with the rod 9 inserted into the sleeve 8, the sleeve 8 is held by using the chuck 5 on the rotating shaft 4 side of the welding machine, and the rod 9 is fixed to the welding machine. It is held using the chuck 7 of the side hollow body 6. In this case, there is no problem even if the sleeve 8 is held by the chuck 7 on the fixed hollow body side and the rod is held by the chuck 5 on the rotating side. After that, the sleeve 8 is rotated for 1.5 to 2.5 seconds so that the peripheral speed of the sliding surface of the sleeve 8 held on the rotating side of the welding machine to the rod 9 becomes 2000 mm / second. FE
A welded product obtained by welding the sleeve 8 made of P and the rod 9 made of ETFE was obtained.

Example 4 In this example, the tube 2 of Example 1 was made of PFA, and by performing the same method as in Example 1, a welded product obtained by welding the flange 1 made of PFA and the tube 2 made of PFA was obtained. Obtained.

Embodiment 5 In this embodiment, the sleeve 8 and the rod 9 of the third embodiment are
FA, and by performing the same method as in Example 3,
A welded product obtained by welding the PFA sleeve 8 and the PFA rod 9 was obtained.

Next, the most preferred embodiment of the apparatus for welding fluororesin parts according to the present invention is shown in FIGS.
10 to 12, A is a welding machine, 10 is a table, 11 is a rail, 12 is a fixed-side hollow body slidably provided on the rail, 13 is a chuck attached thereto, and 14 is a table. A rotating side hollow body provided above,
Reference numeral 15 denotes a chuck mounted thereon, 16 denotes a motor with a brake mechanism installed in the lower chamber of the table, 17 denotes a belt for transmitting the rotation of the motor to the hollow body 14, 18 denotes a rotation time and a rotation speed which are arbitrarily set. This is a motor control mechanism for performing the operation.

FIG. 13 shows an example of the use of the welding device. A tube 21 made of PFA into which a torsion preventing rod 20 is inserted is firmly held by a chuck 13 on the fixed side. The rotation side chuck 15 firmly holds the tube 21 in a pressurized state on the tube 21, and the tube 21 penetrates through the hollow portion 23 of the fixed side hollow body 12 and the hollow portion 24 of the rotating hollow body 14. By rotating the sleeve 22 in this state, the two members can be welded by frictional heat generated on the contact surface between the tube 21 and the sleeve 22.

The welding device having the above-described structure has a small rotating movable part, a small inertia at the start and stop of rotation, and a small load on the motor. Therefore, an additional stopping mechanism is required only by the brake mechanism built in the motor. do not do. Therefore, the overall structure can be reduced in size, can rotate at high speed, and can be welded even with a high melting point fluororesin.
In addition, welding at the inner and outer peripheral surfaces of the welding member whose welding surface is not the same plane, for example, a bush and a sleeve-like inner peripheral surface can be welded to the outer peripheral surface of an arbitrary portion in the longitudinal direction of the rod or pipe shape. .

[0027]

As described in detail above, according to the method of welding a fluororesin part of the present invention, the following effects can be obtained. (A) It is not necessary to preheat the contact surface of the welding member or the member to be welded. (B) Since the contact area is large and the rotation speed can be increased, the contact surface can be welded uniformly and in a short time. (C) Even a fluororesin having a high melting point or a different kind of fluororesin can be welded under the same conditions. (D) When welding the welding member in the form of a tube and a pipe to the welding member in the form of a flange, a sleeve, or a bush, no burr is generated on the inner peripheral surface side of the welding member. According to the apparatus for welding a fluororesin component of the present invention, the following effects can be obtained. (A) A bush or sleeve can be welded to an arbitrary outer peripheral surface of a long rod or pipe. (B) Even a partially curved tube can be welded. (C) Since the welding device only needs to have a mechanism for rotating and a function for stopping the rotation, the device can be simplified and downsized.

[Brief description of the drawings]

FIG. 1 is an assembled sectional view of a welding member showing one embodiment of a method for welding a fluororesin part of the present invention.

FIG. 2 is a cross-sectional view of a welding member as a tube.

FIG. 3 is a sectional view of a welding member serving as a flange.

FIG. 4 is a side view of a torsion preventing rod of a tube.

FIG. 5 is a cross-sectional view of a welding machine on which the assembled welding member is mounted.

FIG. 6 is an assembled sectional view of a welding member according to another embodiment of the present invention.

FIG. 7 is a sectional view of a welding member serving as a sleeve.

FIG. 8 is a side view of a welding member formed as a rod.

FIG. 9 is a sectional view of a welding machine on which the assembled welding member is mounted.

FIG. 10 is a front view of the apparatus for welding a fluororesin component of the present invention.

FIG. 11 is a plan view of the device.

FIG. 12 is a side view of the device.

FIG. 13 is a cross-sectional view showing a welded state of a tube and a sleeve using the device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 PFA flange 2 ETFE tube 3 SUS rod for twist prevention 4 Rotation shaft 5 Chuck 6 Fixing part 7 Chuck 8 FEP sleeve 8a Sleeve tip 9 ETFE rod 9a Rod tip A Welding machine 10 Table 11 Rail 12 Fixed Side hollow body 13 Chuck 14 Rotationally compensated hollow body 15 Chuck 16 Motor with brake 17 Belt 18 Motor control mechanism 20 Torsion prevention rod 21 PFA tube 22 PFA tube 23 Hollow portion 24 Hollow portion

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F211 AA16 AD12 AG08 AG24 TA01 TC07 TC11 TH02 TH06 TJ14 TJ22 TJ30 TN20

Claims (6)

[Claims] 1. A method for welding a welding member made of a fluororesin and a member to be welded, wherein the welding member is arranged around the welding member, and at least one member is rotated to contact the members. And fusing the members with each other by frictional heat generated on the surfaces. 2. The method according to claim 1, wherein the periphery of the member to be welded is uniformly pressed by a holding chuck against the member to be welded. 3. The method for welding a fluororesin component according to claim 1, wherein a torsion preventing rod is inserted into the welding member. 4. The fluororesin of both members is PFA, FE
The method for welding a fluororesin part according to any one of claims 1 to 3, wherein the same kind or different kind is selected from P, ETFE, PVDF, and PCTFE. 5. The method according to claim 1, wherein the welding member is a tube, and the welding member is assembled so as to penetrate the member to be welded. 6. A hollow body portion having a chuck capable of penetrating a welding member or a member to be welded and holding a welding member,
A hollow body having a chuck that allows the welding member and a member to be welded disposed therearound to penetrate therethrough, and a chuck for holding the member to be welded pressurized from the outer periphery to the welding member, and one of the hollow body with the chucks. A motor for rotationally driving, a rotation control unit for the motor, a brake unit for stopping rotation of the motor, and a moving unit for moving the other hollow body with a chuck to adjust a distance between the hollow body with a chuck and the other. A welding device for a resin component, comprising: a moving mechanism.