JPH06312459A - Butt fusion method and fusion machine for thermoplastic resin tubes - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a fusing machine capable of butt-fusing thermoplastic resin pipes with a high fusing strength while suppressing a bead to a minimum. [Structure] Fixed clamp 1A and movable clamp 1B
And a heater 2, a movable clamp 1B is provided so as to be movable toward and away from the fixed clamp 1A, and the heater 2 has a tubular end held by the fixed clamp 1A and a tubular end held by the movable clamp 1B. Between a use position where the end can be heated and a standby position where there is no obstacle when the end face of the thermoplastic resin pipe held by the fixed clamp 1A and the end face of the thermoplastic resin pipe held by the moving clamp 1B are abutted against each other The movable clamp 1A and the movable clamp 1B are provided with a cooling mechanism 11 for cooling the clamps 1A and 1B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a fusion machine for abutting and fusing ends of a thermoplastic resin tube, and particularly, the thermoplastic resin tube is formed of a material having a high melting point. A method and device suitable for the case.

[0002]

2. Description of the Related Art A method in which an end of a thermoplastic resin tube is brought into contact with a heater to heat it until it is melted, and then the melted end faces are butted against each other at a predetermined pressure and fused is generally adopted ( For example, German Patent Application Publication No. 2
212055).

However, when the thermoplastic resin tube is made of a material having a high melting point and the heater has to be heated to 300 ° C. or higher, there is no coating material for the heater and the releasability deteriorates. Heater temperature is 4
It is customary to perform non-contact heating at a temperature of 00 degrees or more.

JP-A-1-11, an example of which is described
In the fusing method of Japanese Patent No. 0128, the end surface of the thermoplastic resin pipe is cut while being inclined to the inner surface side, so that at the time of fusing, the pressure is concentrated on the outer edge side of the end surface so that the molten resin is as much as possible. It is pushed out. In other words, this seeks to meet the demand for butt fusion of thermoplastic tubes so that the inner beads do not interfere with the flow of fluids and are a sanitary problem in clean applications. It is a thing.

[0005]

However, in the above-mentioned conventional butt fusion method, the temperature of the end surface of the thermoplastic resin tube rises from the outer edge near the heater and the melting progresses during heating. In addition, by the time the inner edge is in an appropriate molten state, the outer edge advances to a portion where melting is unnecessary. Therefore, in this way, if the end surface of the thermoplastic resin tube is entirely melted to obtain high fusion strength, as a result, beads will be generated inside during fusion. There was a problem.

In view of the above problems, the present invention provides a butt fusion method and a fusion machine capable of butt-fusing a thermoplastic resin tube with a high fusion strength while keeping the beads to a minimum. Is intended to provide.

[0007]

In order to achieve the above object, the butt fusion method for thermoplastic resin pipes of the present invention comprises the steps of heating and melting the end faces of the thermoplastic resin pipes with a heater,
In the butt fusion method, in which the end faces of the molten thermoplastic resin pipe are butted against each other at a predetermined pressure and fused, when the end face of the thermoplastic resin pipe is heated, the thermoplastic resin is slightly separated from the end face side. The end of the resin tube was cooled.

Further, a fusing machine capable of easily realizing this fusing method is provided with a first clamp and a second clamp which are formed so as to be able to grip an end portion of a thermoplastic resin pipe,
And a heater formed so that the end surface of the thermoplastic resin tube can be heated, the second clamp is provided so as to be movable in a direction approaching or separating from the first clamp, and the heater is A position where the end surface of the thermoplastic resin tube held by the first clamp and the end surface of the thermoplastic resin tube held by the second clamp can be heated, and the thermoplastic resin held by the first clamp The end face of the tube and the second
In the fusion machine provided so as to be movable between a standby position that does not hinder when the end face of the thermoplastic resin tube held by the clamp is abutted, the first clamp and the second clamp are A cooling mechanism for cooling each clamp was provided.

[0009]

When the thermoplastic resin pipes are butt-welded together by using the fusion machine according to claim 2, first, the first clamp is made to grasp one end of one thermoplastic resin pipe and Two
Let the clamp hold the other end of the thermoplastic resin tube. At this time, the end portion of the thermoplastic resin pipe is held by the first clamp and the second clamp at a portion slightly spaced from the end face side.

Next, while the cooling mechanism cools the first clamp and the second clamp, the end face of the thermoplastic resin pipe held by the first clamp and the thermoplastic resin pipe held by the second clamp are cooled. The end surface of is heated close to or in contact with a heater arranged at a use position until it is melted. At this time, the cooled first clamps and second clamps take heat from the end portions of the thermoplastic resin pipes and prevent melting from proceeding to unnecessary portions.

Then, the heater is moved from the use position to the standby position, the second clamp is moved to approach the first clamp, and the end faces of both thermoplastic resin tubes are melted in the first clamp. The end surface of the thermoplastic resin tube gripped by the second clamp and the end surface of the thermoplastic resin tube gripped by the second clamp are butt-welded together at a predetermined pressure. At this time, since the end faces of the thermoplastic resin tube are butt-fused with a minimum amount of melting margin, only a minimum amount of beads are generated.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the construction of a fusing machine according to an embodiment of the present invention will be described with reference to FIGS. The fusion machine of the present embodiment is
As shown in the side view of FIG. 1, the plan view of FIG. 2, and the front view of FIG. 3, a fixed clamp 1A, a moving clamp 1B, a heater 2, a spacer 3, and a cooling mechanism 11 are shown.
And are equipped with.

The fixed clamp 1A is fixed to a base 1a, and the base 1a is fixed on a base 6. Since the configuration of the fixed clamp 1A is the same as the configuration of the moving clamp 1B which will be described later, each constituent member shown in the drawings is given the same reference numeral as the constituent member of the moving clamp 1B, and the description thereof is omitted. To do.

As shown in FIG. 3, the movable clamp 1B is composed of a receiving member 1b and a stopper member 1d connected to the receiving member 1b by a hinge 1c so that the end of the thermoplastic resin pipe can be held. Between the receiving member 1b and the stopping member 1d, a pair of liner 1e having a ring-shaped half is attached. In addition, the liner 1e
The one having an inner diameter corresponding to the outer diameter of the end portion of the thermoplastic resin pipe to be gripped is appropriately selected and mounted between the receiving member 1b and the stopping member 1d. Reference numeral 1f in the figure denotes a liner fixing knob for fixing the upper liner 1e to each of the receiving member 1b and the stopping member 1d,
In the figure, 1g regulates the rotation of the stopper member 1d around the hinge 1c and moves the end portion of the thermoplastic resin pipe to move the clamp 1B.
It is a tube fixing knob for fixing to. Further, as shown in FIG. 4, a cooling hole 1h is formed in the movable clamp 1B so as to surround the liner 1e over substantially the entire circumference.

The moving clamp 1B is fixed to the pedestal 1a, and the pedestal 1a is moved along the guide rail 7 provided on the upper surface of the base 6 in a direction toward or away from the fixed clamp 1A. It is possible. The fixed clamp 1A and the movable clamp 1B are installed so that the thermoplastic resin pipes gripped by both of them are arranged coaxially. Therefore, the movable clamp 1B is fixed by the clamped thermoplastic resin pipes. Will move in the axial direction.

Reference numeral 8 in the drawing denotes a moving shaft for moving the mount 1a to which the moving clamp 1B is fixed.
It is slidably supported by the bearing 5. Further, the bearing 5 is provided with a fixing knob 9 that restricts the slide of the moving shaft 8 in a horizontal state and allows the slide in a vertical state.

The heater 2 is formed so that the end surface of a thermoplastic resin tube (for example, polyphenylene sulfide resin tube) can be heated. The heater 2 is disposed laterally of the fixed clamp 1A and the movable clamp 1B and is pivotally attached to a base 6, and the fixed clamp 1
A position where the end surface of the thermoplastic resin tube gripped by A and the end surface of the thermoplastic resin tube gripped by the movable clamp 1B can be heated (position indicated by a chain double-dashed line in FIG. 3), and the fixed clamp 1A Moves between the end surface of the thermoplastic resin tube held by 1A and the end position of the thermoplastic resin tube held by the moving clamp 1B between the standby position (the position indicated by the solid line in FIG. 3) that does not hinder the operation. It is possible. Reference numeral 4 in the drawing denotes a forward / reverse rotation type motor for moving the heater, which moves the heater 2 from the standby position to the use position during the forward rotation, and moves the heater 2 from the use position to the standby position during the reverse rotation. . In addition, this motor 4
Is preferably one that can be moved between the standby position and the use position within 0.5 seconds one way. Further, the heater 2 is preferably a cartridge type, but may be a cast type. Further, the temperature can be arbitrarily set up to a height of about 500 degrees, and it is preferable that the temperature distribution is uniform.

The spacer 3 has a thickness in the direction parallel to the axial direction of the thermoplastic resin tube held by the fixed clamp 1A and the movable clamp 1B, which is 2 mm larger than that of the heater 2.
It is formed to be thick. Further, the spacer 3 is axially attached to a base 6 arranged on the side of the fixed clamp 1A and the movable clamp 1B (on the side opposite to the heater 2), and is gripped by the fixed clamp 1A. A use position where the end face of the thermoplastic resin pipe thus made and the end face of the thermoplastic resin pipe held by the moving clamp 1B can be brought into contact with each other (Fig. 3).
3) and the end surface of the thermoplastic resin tube held by the fixed clamp 1A and the end surface of the thermoplastic resin tube held by the moving clamp 1B are not interfered with each other (FIG. 3). And the position indicated by the two-dot chain line). In addition, 10 in the figure
Is a spacer set knob for manually operating the spacer 3.

The heater 2 and the spacer 3 are
The centers in the thickness direction are positioned so as to be arranged on the same plane.

The cooling mechanism 11, as shown in FIG.
A pump 11a and a reciprocating transport pipe 11b having a forward path and a backward path such as a partition pipe are provided, and cooling water is passed by the pump 11a through the forward path of the reciprocating transport tube 11b. After pressure feeding to the cooling hole 1h of the clamp 1B, the reciprocating transport pipe 11
The structure is such that it is returned to the pump 11a through the return path of b, cooled, and again pressure-fed to the outward path of the reciprocating transport pipe 11b.
That is, cooling water is continuously passed through the cooling hole 1h of the fixed clamp 1A and the cooling hole 1h of the movable clamp 1B,
Thereby, the fixed clamp 1A and the movable clamp 1B can be cooled.

Therefore, when the thermoplastic resin pipes P and P are butt-welded together by using the fusion machine of this embodiment,
First, as shown in (a) of FIG. 4, a spacer 3 in which the end portion of one thermoplastic resin pipe P is gripped by the fixed clamp 1A and the end face of the thermoplastic resin pipe P is arranged at the use position. And the end portion of the other thermoplastic resin pipe P is gripped by the moving clamp 1B, and the end face of the thermoplastic resin pipe P is brought into contact with the spacer 3.
At this time, the end portion of the thermoplastic resin pipe P is gripped by the fixed clamp 1A and the moving clamp 1B at a portion having a distance of about 5 mm on the end face side. By this operation, the pair of thermoplastic resin pipes P to be fused are positioned so that the distance between the end faces is always constant.

Next, the spacer 3 is moved from the use position to the standby position by the spacer set knob 10, and the heater 2 is moved from the standby position to the use position.
At this time, as shown in FIG. 4B, a gap of 1 mm is formed between the heater 2 and the end surface of each thermoplastic resin pipe P due to the difference between the thickness of the heater 2 and the thickness of the spacer 3. It Then, the fixed clamp 1A is provided by the cooling mechanism 10.
Cooling water is passed through the cooling hole 1h of FIG. 1 and the cooling hole 1h of the movable clamp 1B to fix the fixed clamp 1A and the movable clamp 1B.
While cooling, the end surface of the thermoplastic resin tube P held by the fixed clamp 1A and the end surface of the thermoplastic resin tube P held by the moving clamp 1B are heated by a heater until they are melted. Then, the fixed clamp 1A and the movable clamp 1B take heat from the end portions of the thermoplastic resin pipes P and prevent the melting from proceeding to an unnecessary portion.

Then, the heater 2 is moved from the use position to the standby position, and the moving clamp 1B is moved to approach the fixed clamp 1A so that the end faces of both the thermoplastic resin pipes P are fixed to the fixed clamp 1A in a molten state. The end surface of the thermoplastic resin pipe P held and the end surface of the thermoplastic resin pipe P held by the moving clamp 1B are butt-welded together with a predetermined pressure. At this time, since the end faces of the thermoplastic resin pipe P are butt-fused with a minimum amount of melting margin, only a minimum amount of beads are generated. The time from the end of heating the end surface of the thermoplastic resin pipe P to the fusion of the end surfaces of the thermoplastic resin pipe P with a predetermined butting pressure is preferably within 5 seconds, and preferably within 1 second. At this time, cooling of the fixed clamp 1A and the movable clamp 1B may be stopped.

That is, in the fusing machine of this embodiment, when the end face of the thermoplastic resin pipe P is heated, the necessary portion can be melted while preventing the melting to proceed to the unnecessary portion. The beads can be suppressed to a minimum, and the end faces of the thermoplastic resin pipe P can be butt-welded together with high fusion strength.

The distance between the heater 2 and the end surface of the thermoplastic resin pipe P held by the fixed clamp 1A and the end surface of the thermoplastic resin pipe P held by the moving clamp 1B is always set to a constant distance. As a result, the melted state of the end face is stabilized, and thus the fused state can be stabilized.

FIG. 5 shows a preferable shape of the end surface of the thermoplastic resin pipe P to be butt-fused. That is, in the end surface of the thermoplastic resin pipe P, the portion P1 from the inner edge to the vicinity of the wall thickness center should be inclined inward, and the portion P2 outside the wall thickness center should be perpendicular to the pipe axis. Is preferred. Then, at the time of heating, first, the outer portion P2 begins to melt from the vicinity of the thickness center portion, and then the inner portion P1 gradually begins to melt from the vicinity of the thickness center portion toward the inside. Therefore, compared with the conventional method in which the entire end face is gradually melted from the outer edge to the inner edge, the time from the start of melting the outer edge to the completion of melting of the inner edge can be shortened, and therefore the outer edge is excessively heated. It can be prevented from disassembling. Further, at the time of fusion, since the outer portion P2 is fused from the vicinity of the thickness center portion, the inner portion P1 is gradually fused from the outside to the inside from the vicinity of the thickness center portion,
The fusion pressure can be concentratedly pushed to the outside of the thermoplastic resin pipe P by concentrating the fusion pressure from the vicinity of the thickness center portion to the outer portion P2.

By the way, a polyphenylene sulfide resin tube having a diameter of 25 mm was butt-fused under the conditions of a heater temperature of 450 ° C., a heating time of 60 seconds and a bonding load of 40 kgf, and as a result, the inner bead height was only 0.2 mm. I was able to suppress it.

Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific structure is not limited to this embodiment, and there are design changes and the like within the scope not departing from the gist of the present invention. Also included in the present invention.

For example, in the embodiment, the fusion machine having the fixed clamp and the movable clamp has been described, but both clamps may be movable. In that case, either clamp may be moved when the end surface of the thermoplastic resin tube is brought into contact with the spacer and when the end surfaces of the thermoplastic resin tube are brought close to each other.
The movement of the clamp is not limited to manual movement, but may be automatically performed by a driving device such as a motor. Similarly, the spacer may be moved automatically.

When heating the end surface of the thermoplastic resin tube, the end surface may be brought into contact with the heater without pressure. In that case, it is not necessary to position the thermoplastic resin tube by the spacer.

Further, in the method of the embodiment, the fusion machine in which the clamp is provided with the cooling mechanism is used. However, a component such as a belt is wound around the end of the thermoplastic resin tube, and the component is cooled. Good. In addition to the cooling water, liquid nitrogen or the like may be used as the refrigerant.

[0032]

As described above, in the butt fusion method and fusion machine for thermoplastic resin pipes of the present invention, when the end face of the thermoplastic resin pipe is heated, it is melted to an unnecessary portion. Since it is possible to melt the necessary portion while preventing the progress of the above, it is possible to obtain an effect that the beads can be suppressed to the minimum and the thermoplastic resin pipes can be butt-fused with high fusion strength.

[Brief description of drawings]

FIG. 1 is a side view showing a fusion machine according to an embodiment.

FIG. 2 is a plan view showing a fusion machine according to an embodiment.

FIG. 3 is a front view showing the fusion machine of the embodiment.

FIG. 4 is a diagram showing a butt fusion method for thermoplastic resin pipes using the fusion machine of the embodiment, (a) is for positioning the thermoplastic resin pipe, and (b) is for the thermoplastic resin pipe. When heating,
(C) shows the state when the thermoplastic resin tube is fused.

FIG. 5 is a cross-sectional view showing an example of an end portion of a thermoplastic resin tube.

[Explanation of symbols]

 1A Fixed clamp 1B Moving clamp 2 Heater 11 Cooling mechanism P Thermoplastic resin tube

Claims (2)

[Claims] 1. A butt fusion method in which an end surface of a thermoplastic resin tube is heated and melted by a heater, and then the end surfaces of the melted thermoplastic resin tube are butted against each other at a predetermined pressure and fused. A butt fusion method for thermoplastic resin pipes, characterized in that, when the end faces of the pipes are heated, the ends of the thermoplastic resin pipes, which are slightly spaced apart from the end faces, are cooled. 2. A first clamp and a second clamp formed so as to be able to hold the end of the thermoplastic resin pipe, and a heater formed so that the end face of the thermoplastic resin pipe can be heated. A second clamp is provided so as to be movable in a direction approaching or separating from the first clamp, and the heater is provided on the end surface of the thermoplastic resin tube held by the first clamp and the second clamp. A use position where the end surface of the gripped thermoplastic resin tube can be heated, an end surface of the thermoplastic resin tube gripped by the first clamp, and an end surface of the thermoplastic resin tube gripped by the second clamp In a fusion machine which is provided so as to be movable between a standby position that does not cause an obstacle when butting each other, a cooling mechanism for cooling each clamp is provided in the first clamp and the second clamp. To Characteristic fusion machine.