JPH05193004A - Butt welding apparatus for pipe made of synthetic resin - Google Patents

Abstract

PURPOSE:To prevent the deformation and heat deterioration due to oxidation of a heating melting section, and conduct butt welding properly and efficiently by keeping distances among each end face in a plurality of synthetic resin pipes constant by spacers and uniformly heating and melting each end face by heating plates disposed in a noncontact manner among the end faces. CONSTITUTION:Each end section of a pair of pipes 2, 3, which must be welded and is composed of a synthetic resin, is held by a pair of chucks 6, 7 in a butt welding apparatus 1. A spacer 11 is interposed between each chuck 6, 7, and the spacer is moved by a driving device 12, thus setting a distance between the end faces of each pipe 2, 3. A heating plate 13 is interposed between the end faces of each pipe 2, 3 while forming a clearance, and the heating plate 13 is moved by a driving device, thus heating each end face under a noncontact state. At least one of each chuck 6, 7 is shifted by the driving device 15, and each end face heated end melted is pressure-welded mutually. On the other hand, each operation of the heating plate driving device and the chuck drive 15 is controlled by controllers respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding apparatus for butt-welding pipes made of a heat-meltable synthetic resin such as polyarylene sulfide containing a polyphenylene sulfide resin (hereinafter referred to as PPS).

[0002]

2. Description of the Related Art A synthetic resin pipe made of PPS or the like has a very small amount of water-soluble components, and therefore is suitable for use as a pipe for ultrapure water for cleaning in the production of electronic devices such as VLSI. Furthermore, when piping a pipe made of PPS resin or the like,
For the reason that joining with an adhesive is difficult and elution from the adhesive becomes a problem, so-called butt welding in which pipe ends are melted and joined by heat is widely adopted. And, as such a conventional butt welding device, Japanese Patent Publication No.
As disclosed in Japanese Patent Laid-Open No. 3-28011, a heating plate is brought into contact with both end faces of a resin pipe, both end faces of the resin pipe are melted, and then the melted both end faces are pressure-bonded to each other. There is known such a device, and Japanese Patent Application Laid-Open No. 62-
As disclosed in JP-A-279925, without using a heating plate, both end surfaces of a resin pipe are blown with hot air to melt both end surfaces in a non-contact manner, and then the melted both end surfaces are pressure-bonded to each other. A method of joining is also known.

[0003]

By the way, Japanese Patent Publication No. 63-
According to the apparatus disclosed in Japanese Patent No. 28011, since the heating plate is brought into contact with both end faces of the resin pipe, it is not easy to remove the heating plate from both end faces after heating. Because, if the heating plate cannot be removed from both end surfaces of the molten resin pipe by maintaining its shape in a predetermined manner, a protrusion called a bead (also called a burr) may be formed on the inner surface of the joint, This is because the joint may bend. If there are such beads at the joint, the flow of the fluid in the pipe will be disturbed there, so
It becomes a cause for accumulation of fine particles, and bacteria and algae are generated, which makes it unsuitable as a pipe for ultrapure water. Further, in the above method of contacting both end surfaces of the tube with the heating plate, a slight amount of the molten resin adhering to the heating plate is gradually subjected to thermal metamorphism and mixed into the molten resin as an impurity in the next pressure welding operation. There is also.

According to the method disclosed in Japanese Patent Laid-Open No. 62-279925, it is necessary to rotate the resin pipe, which is difficult to apply to a long resin pipe. Both end faces that are melted by the wind pressure from the side have a tendency to be slightly bent toward the center, and if the both end faces are slightly bent toward the center in this way, there is a risk of promoting the generation of beads. It is even stronger if a tapered groove is provided on the. Further, if the rotation is not performed in a predetermined manner, both end faces thereof may be deteriorated by oxidative heat due to hot air, which is not satisfactory in any case.

The present invention has been made in view of the above points, and an object thereof is to enable non-contact heating of both end faces of a synthetic resin pipe by heating plates to melt them. It is an object of the present invention to provide a butt welding device for synthetic resin pipes that can minimize the generation of beads and prevent deterioration due to oxidative heat. Another object of the present invention is to provide a welding apparatus which automatically reduces the generation of beads to the butt welding of synthetic resin pipes.

[0006]

According to the present invention, the above object is used by arranging a pair of chucks for sandwiching respective ends of a pair of synthetic resin pipes to be welded, and between the chucks. , A movable spacer for setting the end face distance of the pair of pipes, and a movable heating plate which is arranged with a gap between the end faces of the pipe whose end face distance is set to a predetermined value and heats both end faces in a non-contact state, A heating plate moving device that moves the heating plate between both end faces and the outside thereof and at least one of a pair of chucks that moves the chucks to press the end faces melted and heated by the heating plate under a predetermined pressure. It is achieved by a butt welding device for a synthetic resin pipe, which is provided with a device and a control device for controlling the operations of the heating plate moving device and the chuck moving device.

In the present invention, preferably, a chuck driving device for switching the chuck between a pair of tubes between a clamped state and a clamped state, and a spacer moving device for moving the spacer between the pair of chucks and outside thereof. Further, the control device also controls the operations of the chuck driving device and the spacer moving device.

Also, in the present invention, the heating plate is rotatably provided, and the heating plate moving device rotates the heating plate to move the heating plate between the opposite end faces of the pair of pipes and outside thereof. It is equipped with a rotary actuator.

Further, in the present invention, the pair of chucks are provided with a sealing device for sealing the periphery of the end faces of the pair of tubes heated by the heating plate.

[0010]

In the butt welding apparatus for a synthetic resin pipe of the present invention, a pair of synthetic resin pipes to be butt-welded by a movable spacer disposed between a pair of chucks and abutting against the movable spacer. Each end of is arranged. The pair of tubes thus arranged are clamped and fixed by the chucks. After that, the spacer is moved to the outside of the pair of chucks, and then the heating plate is arranged with a gap between the pipe end faces whose distance is set to a predetermined value by the spacer, whereby both end faces are heated and melted in a non-contact state. When heated in this way, the heating plate is moved out of the space between the pair of chucks, then at least one of the pair of chucks is moved, and both end faces heated and melted by the heating plate are pressed at a predetermined pressure. To be done.

The present invention will now be described in more detail based on the preferred embodiments shown in the drawings. The present invention is not limited to these specific examples.

[0012]

SPECIFIC EXAMPLE As shown in FIGS. 1 to 5, a butt welding device 1 for a synthetic resin pipe of this example is made of a synthetic resin to be butt welded, and in this example, a pair of pipes 2 and 3 made of PPS, respectively. A pair of chucks 6 and 7 for clamping the ends 4 and 5 of the tube, and the tube 2
A chuck drive device 8 (not shown on the side of the chuck 7) for sandwiching and releasing the chucks 6 and 7 from the chucks 6 and 7, and an end surface 9 of the tubes 2 and 3 disposed between the chucks 6 and 7. A movable spacer 11 for setting the inter-plane distance D1 of 10 to a predetermined value, and a spacer moving device 12 for moving the spacer 11 between the chucks 6 and 7 and outside thereof.
And a movable heating plate which is arranged with gaps D2 and D3 between the tube end surfaces 9 and 10 whose distance D1 is set to a predetermined value by the spacer 11 to heat the opposed end surfaces 9 and 10 of the tubes 2 and 3 in a non-contact state. 13, a heating plate moving device 14 for moving the heating plate 13 to and between the opposite end faces 9 and 10 of the tubes 2 and 3, and at least one of the chucks 6 and 7, in this example, moving the chuck 7. , A chuck moving device 15 for pressing the end surfaces 9 and 10 of the tubes 2 and 3 heated and melted by the heating plate 13 into contact with each other with a predetermined pressure, a chuck driving device 8, a spacer moving device 12, and a heating plate moving device 1.
4 and a control device 16 for controlling the operation of the chuck moving device 15.

The chuck 6 comprises two lower chuck plates 21 and 22 fixed to the frame 20 of the apparatus and two upper chuck plates rotatably attached to the frame 20 by shafts 23 and 24 in the A direction. The ends 4 of the tube 2 are received substantially in the center of the upper surfaces 28 and 29 of the lower chuck plates 21 and 22, which are arranged in parallel with each other and are bridged by the rear plate 27. Semicircular recesses 30 and 31
Of the upper chuck plates 25 and 26, which are bridged by the rear plate 32 and are arranged in parallel with each other, approximately at the center of the lower surfaces 33 and 34 of the upper chuck plates 25 and 26, corresponding to the semi-circular recesses 30 and 31. Semi-circular recesses 35 and 36 are formed to receive the ends 4 of the. Positioning pins 37 and 38 are further planted on the lower surfaces 33 and 34.
Upper surface 2 of the lower chuck plates 21 and 22 so that
Holes 39 and 40 are formed in 8 and 29. On the other hand, the chuck 7 is formed in substantially the same manner as the chuck 6 except that it is provided on the moving table 45 of the chuck moving device 15. That is, two lower chuck plates 46 and 47 fixed to the moving table 45 and a rear plate 48 that holds the lower chuck plates 46 and 47 in parallel with each other and bridges them are provided with shafts 49 and 5.
It is provided with two upper chuck plates 51 and 52 which are rotatably attached in the direction A through 0. The upper and lower surfaces 53 and 54 of the lower chuck plates 46 and 47 are provided with the pipe 3
Semicircular recesses 55 and 56 are formed to receive the ends 5 of the upper chuck plates 51 and 52, which are bridged by the rear plate 57 and are arranged in parallel with each other, at approximately the center thereof. , Semicircular recesses 60 and 61 for receiving the end 5 of the tube 3 are formed corresponding to the semicircular recesses 55 and 56. Positioning pins 62 and 63 are further planted on the lower surfaces 58 and 59, and the upper surfaces 53 and 54 of the lower chuck plates 46 and 47 are inserted so that the pins 62 and 63 are fitted.
Holes 64 and 65 are formed in the hole.

The chuck driving device 8 is an air cylinder 70.
And one end 71 of the air cylinder 70 has a shaft 7
It is rotatably connected to the bracket 73 via 2, and the bracket 73 is fixed to the frame 20 with bolts or the like. Piston rod 7 of air cylinder 70
4 is rotatably connected to a bracket 76 via a shaft 75, and the bracket 76 is attached to the chuck 6 by a bolt or the like.
It is fixed to the rear plate 32. When the piston rod 74 is expanded and contracted in the B direction by the operation of the air cylinder 70,
The upper chuck plates 25 and 26 of the chuck 6 are the bracket 7
6 through the rear plate 32 and the shafts 23 and 24 as the center A
The chuck 6 is pinched and unpinched with respect to the tube 2 in this manner.

The chuck driving device on the chuck 7 side (not shown) is also equipped with an air cylinder, and one end of the chuck driving device on the chuck 7 side is rotatably connected to the moving base 45. Except that the chuck driving device 8 has the same structure as that of the chuck driving device 8. Therefore, when the air cylinder of the chuck driving device on the chuck 7 side is actuated, the upper chuck plates 51 and 52 of the chuck 7 center around the shafts 49 and 50. The chuck 7 is pivoted in the direction, and the chuck 7 is clamped and released from the tube 3 in synchronization with the chuck 6. Since the chuck driving device on the chuck 7 side operates in the same manner as the chuck driving device 8 in this manner, the description thereof will be omitted below. It is preferable that the air cylinder is used as a power source for the chucks 6 and 7 in this manner because the tubes 2 and 3 can be elastically clamped, but the present invention is not limited to this, and for example, a hydraulic cylinder or a pneumatic or hydraulic type. It may be constituted by a rotary actuator and further an electric motor.

The chuck driving device of the present invention is not necessarily required to be used, and the fasteners for the chucks 6 and 7 may be manually locked and unlocked. As a fastening tool in this case, for example, a push screw rotatably supported is arranged on the side surface of the lower chuck plate 21 opposite to the shaft 23 in FIG. An example is one in which a screw insertion groove is formed on the side surface corresponding to the opposite set screw. However, it is more preferable that the chucks 6 and 7 are clamped automatically by the chuck driving device. This is because, when the chuck driving device is used, when the end faces 9 and 10 of the pipes are opposed to each other and abutted against the spacer 11, the pipes to be joined to both hands are equally pressed, as will be described later. , And when the heating plate 13 is brought into the heating position, the gaps D2, D3 between the heating plate 13 and the end faces 9 and 10 of the tubes can be exactly equalized. On the other hand, in the case of manual operation, the chucks 6 or 7 are clamped separately, which is not only inferior in productivity but also difficult to abut with uniform pressure. Gap D2,
D3 may be pinched slightly differently.

The spacer 11 has a thickness D1 = 40 m in this example.
Although it is a square bar-shaped member having m, it is needless to say that it may be a plate-shaped member similar to the member having another shape, for example, the heating plate 13, and the thickness D1 is not limited to this. It goes without saying that it is determined from the set values of the gaps D2 and D3. The spacer moving device 12 is composed of a pneumatic rotary actuator 82 mounted in a recess 81 of the frame 20, and the output rotary shaft 8 of the actuator 82.
When one end of the spacer 11 is fixed to 3, and the actuator 82 is operated, the spacer 11 is rotated in the C direction, and is moved between the chucks 6 and 7 and outside thereof.
Of course, the rotary actuator 82 may be replaced by a hydraulic rotary actuator, an electric motor, or a direct-acting actuator.

The spacer moving device 12 may be configured such that the spacer 11 is inserted / removed in a linear motion, not in a rotary motion between the use position between the chucks 6 and 7 and the outside thereof. Further, the spacer moving device 12 of the present invention does not necessarily have to be used, and may be manually inserted and removed. In either case, it is preferable that the spacer 11 be inserted as perpendicularly as possible to the central axis in the length direction of the pipes to be joined.

In this example, the heating plate 13 is made up of a porous ceramic plate case containing nichrome wire.
Another heating plate capable of uniformly heating the end faces 9 and 10 of the rods 3 and 3, for example, an electrically insulating member such as a ceramic in which a rod-shaped heating wire is uniformly embedded over the entire surface may be used. Heating plate 13
The surface temperature of the can be appropriately determined by the melting temperature of the pipes 2 and 3 to be butt-welded, the gaps D2 and D3, the heating time, etc.
In the present example in which D2 = D3 = 0.5 mm, 450 ° C. to 45 °
A range of 9 ° C is preferably used. Heating plate drive device 14
Is equipped with a pneumatic rotary actuator 92 attached to the frame 20 via a bracket 91, and the arm 9 is attached to the output rotary shaft 93 of the actuator 92.
4, one end 95 is fixed, the heating plate 13 is attached to the other end of the arm 94, and when the actuator 92 is operated and the arm 94 is rotated in the E direction, the heating plate 1
3 is also rotated in the E direction to be moved between the opposite end faces 9 and 10 of the tubes 2 and 3 and out of it. Alternatively, the rotary actuator 92 may be configured with a hydraulic rotary actuator or an electric motor, or a direct drive actuator instead.

The chuck moving device 15 is arranged with the air cylinder 101 supported by the supporting member 100 at one end, the moving table 45 fixed to the tip of the piston rod 102 of the air cylinder 101, and the piston rod 102 in between. Further, two guide rods 103 and 104 and a valve circuit 106 for controlling the supply and discharge of the air pressure of the compressed air source 105 to and from the air cylinder 101 are provided.
Is composed of a precision pressure reducing valve 107 and a direction switching electromagnetic valve 108, and the air cylinder 101 is actuated by the air pressure supplied from the valve circuit 106 to move the piston rod 102 to the F
When it is expanded and contracted in the direction, the movable table 45 is guided by the guide rods 103 and 104 and is also moved in the F direction.
As a result, the chuck 7 is also moved in the F direction.
The chuck moving device 15 moves the chuck 7 toward the chuck 6, and at the same time, presses the end surfaces 9 and 10 of the tube heated and melted by the heating plate 13 at a predetermined pressure. At this time, the pressure contact pressure transmitted to the end surfaces 9 and 10 is determined by the product of the difference in air pressure applied to both surfaces of the piston 101a that reciprocates in the cylinder 101 and the cross-sectional area of the piston 101a, as described with reference to FIG. .. The pressures of the two compartments 101b and 101c in the cylinder 101 with the piston 101a interposed therebetween are switched by the solenoid valve 108 such that one is the decompression pressure of the precision decompression valve 107 and the other is the atmosphere opening pressure. .. Therefore, the pressure of the pressure contact is uniquely determined by the pressure reduction pressure of the precision pressure reducing valve 107 unless the pressure contact area of the end faces 9 and 10 is changed, and the pressure is always constant in the pressure contact process. There is no need to provide a special detection device. The crimping pressure for the end surfaces 9 and 10 of the tubes 2 and 3 can be determined by the presence or absence of a groove on the end surfaces 9 and 10 of the tubes 2 and 3, the heating time, the material of the tubes 2 and 3, and the like. When the tip angle is 30 degrees, the groove length is 1 mm, the heating time is 45 seconds, and D2 = D3 = 0.5 mm, the pressure is about 3 kg per square centimeter. In addition,
In this example, the air cylinder 101 is used as the power source of the chuck moving device 15 to obtain the air-elastic pressure bonding pressure, but instead of this, a hydraulic cylinder or an electric motor may be used as in the above devices. The movable table 45 has a recess 109.
When the chuck 7 is moved toward the chuck 6, the spacer 11 is housed in the recess 109 so that the moving table 45 does not collide with the spacer 11.

The control unit 16 includes a control electric circuit 110,
A foot switch 111 for instructing the operation start, a reset push button switch 112, and a dual type timer 113 for setting a heating time and a pressure bonding time and measuring the time.
And limit switches 114 to 119. The electric circuit 110 includes switches 111, 112, 114.
~ 119 and the spacer drive device 12, in order to perform the operation described later based on the electric signal from the timer 113,
Valve circuits 120, 121, 123 and 10 of the chuck driving device 8, the heating plate driving device 14 and the chuck moving device 15.
An actuation signal is sent to the solenoid valve 6. The electric circuit 110 including the timer 113 is composed of a microcomputer,
The operation of the matching device 1 may be performed by a program stored in advance. The switch 114 is in the clamping release position shown in FIG. 1 when the upper chuck plates 25, 26, 51 and 52 are rotated in the A direction, and the switch 115 is the same when the upper chuck plates 25, 26, 51 and 52 are rotated in the A direction. 6, the switch 116 indicates the upper rotation position shown in FIG. 1 when the spacer 11 rotates in the C direction, and the switch 117 also indicates the upper rotation position shown in FIG. 1 when the spacer 11 rotates in the C direction. The downward rotation position,
The switch 118 is in the left rotation position shown in FIG. 1 when the heating plate 13 is rotated in the E direction, and the switch 119 is also in the right rotation position shown by the alternate long and short dash line in FIG. 6 when the heating plate 13 is rotated in the E direction. The electric signal is detected and the electric signal of the electric circuit 110 is detected.
To send to. The heating time measured by the timer 113 is 45 seconds in this example, but this time is the surface temperature of the heating plate 13, the melting temperature of the end faces 9 and 10 determined by the material of the tubes 2 and 3, the gaps D2 and D3, and the opening. It can be appropriately set depending on the presence or absence of the former. The frame 20 and the support member 100 are attached to a base 131 having a roller 130, respectively.

Further, the control device 16 may be provided with a temperature indicating controller which controls the power supply to the heating plate 13, for example, which is used in combination with a voltage controller or a temperature sensor incorporated in the heating plate 13. ..

The butt welding apparatus 1 described above operates as follows. First, the upper chuck plates 25, 26, 51, 52,
The spacer 11 and the heating plate 13 are arranged at the non-sandwiched position, the upper rotation position and the left rotation position as shown in FIG. 1, respectively, and the moving table 45 moves the chuck 7 from the chuck 6 to the chuck 6 as shown in FIG. It is located in the farthest position. In this state, the end portions 9 and 10 of the tubes 2 and 3 are manually brought into contact with the opposite side surfaces of the spacer 11, respectively, so that the end portion 4 is arranged in the recesses 30 and 31, and the end portion 5 is arranged in the recesses 55 and 56. To be done. Next, the switch 111 is pushed by the foot and the valve circuit 12
1 solenoid valve is actuated, whereby the air cylinder 70
As a result, the upper chuck plates 25, 26, 51 and 52 are rotated in the A direction and brought to the holding position as shown in FIG. In the position shown in FIG. 6, the recesses 35, 36, 6
0 and 61 also have the ends 4 and 5 of the tubes 2 and 3, respectively, and the chucks 6 and 7 clamp the ends 4 and 5 of the tubes 2 and 3 by the aeroelastic force exerted by the air cylinder 70. Hold. Since the thickness of the spacer 11 is D1 here, the distance between the end faces 9 and 10 of the tubes 2 and 3 thus holding the ends 4 and 5 in this way is likewise set exactly at D1.

The upper chuck plates 25, 2 are placed at the positions shown in FIG.
When 6, 51 and 52 are introduced, a detection signal is issued from the switch 115 for detecting this, whereby the expansion / contraction operation of the air cylinder 70 in the B direction is stopped via the valve circuit 121 and the state is maintained. Together with the valve circuit 12
0 solenoid valve is operated and the rotary actuator 82 is operated. When the actuator 82 is operated, the spacer 11
Is rotated in the C direction and is arranged at the lower rotation position as shown by the dotted line in FIG. In the initial rotation in the C direction, since the spacer 11 is in contact with the end faces 9 and 10, the spacer 11 is rotated while sliding on the end faces 9 and 10. When the spacer 11 is rotated to the downward rotation position in this way, a detection signal is issued from the switch 117 that detects this, and thereby the rotation operation of the actuator 82 in the C direction with respect to the spacer 11 is stopped via the valve circuit 120. Then, the state is maintained and the solenoid valve of the valve circuit 123 is operated to operate the rotary actuator 92. In this example, the actuator 92 is operated by the switch 1
It is started by the generation of the detection signal of 17, but it may be started by the generation of the detection signal of the switch 115 instead, and more generally, it is the spacer 11 and the heating plate 1.
The operation start time of the actuator 92 may be set so as not to collide with each other and to shorten the working time.

The heating plate 13 is rotated in the E direction by the operation of the actuator 92, and is arranged in the right rotation position as shown by the alternate long and short dash line in FIG. Since the heating plate 13 is narrower than the thickness D1 of the spacer 11 by the gaps D2 and D3, the heating plate 1
3 is brought to the right pivot position without contacting the end faces 9 and 10 of the tubes 2 and 3 on both sides, and its two sides with the gaps D2 and D3 to the end faces 9 and 10, respectively. It is arranged between both chucks 6 and 7. When the heating plate 13 is arranged at the right rotation position, a detection signal is issued from the switch 119 for detecting the heating plate 13, and thereby the rotation operation of the actuator 92 in the E direction with respect to the heating plate 13 is stopped via the valve circuit 123. And its state is retained,
At the same time, the timer 113 starts the operation of measuring the heating time. When the heating plate 13 is thus arranged between the end faces 9 and 10, the end faces 9 and 10 are heated by the heating plate 13 for a predetermined time and melted. Since the melting start temperature of the tubes 2 and 3 of this example (the rising temperature of the endotherm accompanying the melting of the sample in the differential scanning calorimeter) is 275 ° C., the end faces 9 and 10 above this temperature and below the melting end temperature, More specifically, the regions from the end faces 9 and 10 to about 0.5 mm in the axial direction are heated and melted. When the set time of 45 seconds elapses from the heating and melting condition, the timer 113 outputs a time-completion signal, which causes the solenoid valve of the valve circuit 123 to operate again and the rotary actuator 92 to operate. Due to this operation of the actuator 92, the heating plate 13 starts to rotate in the opposite direction to the above, and the heating plate 13 is arranged between the chucks 6 and 7. Thereafter, the heating plate 13 is rotated by the actuator 92 and brought to the left rotation position shown in FIG.
When the detection signal is issued from 8, the rotation operation of the actuator 92 with respect to the heating plate 13 in the E direction is stopped via the valve circuit 123, and the state is maintained.

On the other hand, the detection signal from the switch 118 is
Separately, the solenoid valve 108 of the valve circuit 106 is operated, and at the same time, the operation of counting the pressure bonding time of the timer 113 is started. By the operation of the solenoid valve 108, the air cylinder 101 moves the moving table 45 in the F direction so that the chuck 7 approaches the chuck 6. As a result, the tube 3 sandwiched by the chuck 7 is brought close to the tube 2, and finally the end face 10 which is heated and melted is pressed against the end face 9 which is also heated and melted. Even if the vicinity of the heated and melted end faces 9 and 10 is crushed during the crimping, the crimping force is accurately kept constant by the pressure reducing valve 107 of the valve circuit 106. It should be noted that the time from the placement of the heating plate 13 between the chucks 6 and 7 to the pressure bonding operation is fairly high at the melting start temperature of the tubes 2 and 3 of 275 ° C., and there is a possibility that the tubes 2 and 3 may be cooled immediately. Therefore, it is required to be extremely short, which is about 0.5 seconds in this example, but it is preferable to shorten this as much as possible.

When the crimping time set in correspondence with the completion of the crimping and the complete cooling of the welded portion, 20 seconds in this example, the timer 113 again issues a time-completion signal, whereby the valve circuit 121. Solenoid valve of the valve circuit 106 is also activated with a slight delay, and as a result, the air cylinder 70 causes the upper chuck plates 25, 26, 5 to operate.
1 and 52 start to rotate in the A direction to release the clamped state with respect to the tubes 2 and 3, and the moving table 45 is moved in the F direction so as to separate the chuck 7 from the chuck 6 by the air cylinder 101, and the upper chuck plate 25, 26, 51 and 52 are shown in FIG.
When it is brought to the pinch release position shown in FIG. 1, the air cylinder 70 is stopped from operating via the valve circuit 121 by the detection signal from the switch 114 for detecting it, and the upper chuck plates 25, 26, 51 and 52 are moved. The movable table 45 is brought to the position shown in FIG. 2 and held at that position. Upper chuck plates 25, 26, 51 and 5
After the 2 is brought to the clamping release position shown in FIG. 1, the butt welded tubes 2 and 3 are manually recessed 30, 31, 55.
And 56. Finally, when the switch 112 is pressed, the actuator 82 is operated via the valve circuit 120 to rotate the spacer 11 in the C direction, and the spacer 11 is arranged at the upper rotation position shown by the solid line in FIG. The detection signal from 116 stops the operation of the actuator 82 via the valve circuit 120, and the spacer 11 is held at the upper rotation position. Thereafter, new pipes 1 and 2 to be butt-welded are placed on the chucks 6 and 7, and the above operation is repeated.

As described above, in the butt welding apparatus 1 of the present embodiment, the distance D1 between the end faces 9 and 10 to be heated and melted is always made constant by the spacer 11 in advance, and the distance D1 between the fixed end faces 9 and 10 is not fixed. Since both end faces 9 and 10 made of PPS are uniformly heated and melted by the heating plate 13 arranged in contact with each other, it is possible to eliminate the possibility of bending and deformation of the heating / melting portion which may occur when the heating plate 13 is removed. Moreover, it is possible to minimize the occurrence of beads, and in addition, there is very little risk of deterioration due to oxidation heat. Further, as a result of being able to automatically and continuously perform butt welding, the working time can be shortened.

By the way, in the above specific example, the vicinity of the end faces 9 and 10 of the tubes 2 and 3 is exposed to the outside during heating and crimping. There is a risk that the end faces 9 and 10 and the vicinity thereof will not be uniformly heated, or that the end faces 9 and 10 will be rapidly cooled after the heating plate 13 is removed. Therefore, as shown in FIG. 7, a sealing device 200 for sealing around the end surfaces 9 and 10 of the pair of tubes 2 and 3 heated by the heating plate 13 is provided on the pair of chucks 6 and 7 to provide the butt welding apparatus of the present invention. You may form. The sealing device 200 includes lower chuck plates 22 and 46.
Also, half-halved outer cylinders 205, 206, 207 and 20 having semi-annular ends 201, 202, 203 and 204 fixed to opposite side surfaces of the upper chuck plates 26 and 51, respectively.
8 and half outer cylinders 205, 206, 207 and 208
The inner half of the cylinder is provided with half inner cylinders 209, 210, 211 and 212 movably arranged in the axial direction, that is, the G direction, and coil springs 213, 214, 215 and 216. Bodies 209, 210, 211 and 21
2 is its engaging flanges 220, 221, 222 and 223.
Are engaged with the engaging collar portions 224, 225, 226 and 227 of the half outer cylinders 205, 206, 207 and 208, respectively, and are divided into half outer cylinders 205, 206, 207 and 20.
8 and holds upper and lower chuck plates 26 and 22.
Coil springs 215 and 213, which are arranged between the respective inner half cylinders 211 and 209, respectively.
1 is slidable on one side surface 232 of the heating plate 13, and the half-divided inner cylinders 211 and 2 are arranged so as to be pressed and contact airtightly.
09 is elastically urged to the chuck 7 side, and each of the upper and lower chuck plates 51 and 46 and the half inner cylindrical body 21.
A coil spring 2 arranged between each of 2 and 210
Reference numerals 16 and 214 denote the semi-annular end surfaces 234 and 235 of the half inner cylinders 212 and 210, and the other side surface 2 of the heating plate 13.
The half-split inner cylinders 212 and 210 are elastically biased toward the chuck 6 so as to be slidable and press-contact with 36. In addition, when the heating plate 13 is not arranged between the both end surfaces 9 and 10, the coil springs 215, 213,
The half-divided inner cylinders 209 and 211 and the half-divided inner cylinders 210 and 212 are urged by 216 and 214 to approach each other, and the semi-annular end faces 230 and 231 are hermetically sealed to the corresponding semi-annular end faces 234 and 235. Contact. Therefore, the heating plate 13
Is heated so that the contact surfaces of the semi-annular end faces 230 and 231 and the corresponding semi-annular end faces 234 and 235 are easily pushed open to be arranged between the end faces 9 and 10 of the tubes 2 and 3. The outer edge 237 of the plate 13 has a tapered guide surface 238.
A taper guide surface (not shown) similar to the taper guide surface 238 is formed on the semi-annular end faces 231, 235, 230 and 234 of the half inner cylinders 209, 210, 211 and 212. Further, a taper guide surface is formed for the spacer 11 for the same purpose.

If such a sealing device 200 is provided, the periphery of the end faces 9 and 10 is isolated and sealed from the outside, so that heating of the heating plate 13 in the vicinity of the end faces 9 and 10 is performed by heating or rising air flow. The end faces 9 and 10 and their vicinity can be uniformly heated without being disturbed by the air flow due to other causes, and the heating plate 13 is heated between the end faces 9 and 10 and melted, and the heating plate 13 is placed between the end faces 9 and 10. As a result of the airtight contact between the semi-annular end faces 230 and 231 and the semi-annular end faces 234 and 235, the surroundings of the end faces 9 and 10 are also isolated and sealed from the outside even in this state. It is possible to avoid an inconvenient situation in which the vicinity of the end faces 9 and 10 heated and melted after removing the heating plate 13 is cooled more rapidly than expected. Further, this sealing device 200 has the effect of suppressing or flattening the bead formed outside the joint between the pipes 2 and 3, and the bead inside the joint is cooled slowly, so that its height is high. Tend to be suppressed.

The sealing device 200 is constructed so that when the coil springs 213, 214, 215 and 216 are most elastically compressed (contracted) in the pressure contact step, stoppers work respectively to prevent the springs from returning. Is preferred. The heating process in this case is performed by rotating the heating plate 13 to the heating position and then releasing the stopper.

Also, in the above, the flat sides 232 and 236 are
Although the vicinity of the end faces 9 and 10 was heated by the heating plate 13 having the above, the inner faces 250 and 251 of the pipes 2 and 3 on the side of the end faces 9 and 10 are tapered faces, that is, the so-called groove angle H, as shown in FIG. Inner surface 2 forming points 252 and 253
In order to reduce the bead generated in 50 and 251 as much as possible, the annular protrusions 256 and 257 having the annular outer peripheral surfaces 254 and 255 that are inclined similarly to the groove angle H are formed.
May be provided on the side surfaces 232 and 236 respectively to form the heating plate 13. When the end faces 9 and 10 are heated with the heating plate 13 having the annular protrusions 256 and 257, the portions of the grooves 252 and 253 can be uniformly heated and melted, so that the groove angle H can be freely selected up to a large angle. Further, since the groove surfaces 252 and 253 are sufficiently melted and wet, the beads flow and the beads generated on the inner surfaces 250 and 251 can be minimized. The heating plate 13 having the annular projections 256 and 257 may be applied to the tubes 2 and 3 having no such grooves 252 and 253.

Further, as shown in FIG. 9, the halves of the attachments 271 and 27 are fitted into the recesses 35 and 30, respectively.
2 to the upper and lower chuck plates 25 and 21 (the same applies to other upper and lower chuck plates) and their flange portions 27.
3 and 274 may be detachably attached by using countersunk screws 275 and the like, and the ends of the pipes to be butt-welded may be sandwiched via the recesses 276 and 277 of the half attachments 271 and 272. Therefore, if a large number of half attachments 271 and 272 having recesses 276 and 277 corresponding to the outer diameters of various tubes to be butt-welded are prepared, the half attachments can be replaced without replacing the chucks 6 and 7. Butt welding for tubes of various outer diameters can be performed immediately by simply replacing 271 and 272.

[0034]

As described above, according to the present invention, the distance between the end faces of the pipe to be heated and melted is always made constant by the spacer in advance, and the heating which is arranged in a non-contact manner between the made constant end faces. Since both ends of the synthetic resin pipe are uniformly heated and melted by the plates, there is no risk of bending and deformation of the heating and melting part that may occur during removal of the heating plate, and furthermore, the occurrence of beads is minimized. In addition, the risk of deterioration due to oxidation heat is extremely small, and butt welding can be automatically and continuously performed. As a result, the working time can be shortened.

[Brief description of drawings]

FIG. 1 is a side view of a preferred embodiment of the present invention.

FIG. 2 is a front view of the specific example shown in FIG.

FIG. 3 is a partial plan view of the specific example shown in FIG.

FIG. 4 is a block diagram of a control system of the specific example shown in FIG.

5 is a partial detailed explanatory diagram of the valve circuit of the specific example shown in FIG. 1. FIG.

FIG. 6 is an operation explanatory diagram of the specific example shown in FIG. 1.

FIG. 7 is a partial front view of another preferred embodiment of the present invention.

FIG. 8 is a partial front view of still another preferred embodiment of the present invention.

FIG. 9 is a partial perspective view of still another preferred embodiment of the present invention.

[Explanation of symbols]

 1 Butt Welding Device 2, 3 Tubes 6, 7 Chuck 8 Chuck Driving Device 11 Spacer 12 Spacer Driving Device 13 Heating Plate 14 Heating Plate Driving Device 15 Chuck Moving Device

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[Procedure amendment]

[Submission date] August 3, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

In the present invention, the heating plate is rotatably supported.
To the heating plate moving device embodying comprises a rotary actuator that moves it rotates the pressurized hot plate freely this rotation in opposite between the end surfaces and the outer side of the pair of tubes
Preferably.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

Furthermore in the present invention, a pair of end faces a pair of chucks sealing equipment to seal the periphery of the tube that is heated by the heating plate
It is preferable to provide each of them.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction content]

The sealing device 200 has a coil spring 21.
3, 214, 215 and 216 are the most repressed (contracted)
Coil spring or
A stopper (not shown) is attached to each of the corresponding half-divided inner cylinders.
It may be configured so that ()) works. In this case, the heating process
Between the processes before the pressure welding process, the sealing device 200 is a spring.
Is compressed and the stopper is applied (semi-annular shape in Fig. 7)
Whether the end faces 230, 231, 234 and 235 are the heating plate 13
Away from the heating plate 13 and turn the heating plate 13 to the heating position.
Release the stopper immediately after moving or just before the compression process
The subsequent steps are executed.

Claims (4)

[Claims] 1. A pair of chucks for sandwiching the respective ends of a pair of synthetic resin tubes to be welded, and a movable spacer which is used by being arranged between the chucks and which sets the end face distance of the pair of tubes. And a movable heating plate which is arranged with a gap between the end faces of the pipe whose end face distance is set to a predetermined value to heat both end faces in a non-contact state, and the heating plate is moved between both end faces and outside thereof. And a chuck moving device that moves at least one of the pair of chucks and presses the end faces that are heated and melted by the heating plate with a predetermined pressure, and the operation of the heating plate moving device and the chuck moving device. Butt welding device for synthetic resin pipes equipped with a control device for controlling 2. A chuck drive device for switching a chuck between a pair of tubes between a clamped state and a clamped state.
The butt welding apparatus according to claim 1, further comprising a spacer moving device that moves the spacer between the pair of chucks and outside thereof, and the controller also controls the operations of the chuck driving device and the spacer moving device. 3. The heating plate moving device is provided with a rotary actuator for rotating the heating plate to move it between the end faces of the pair of pipes facing each other and outward thereof.
Or the butt welding apparatus as described in 2. 4. The butt welding apparatus according to claim 1, wherein the pair of chucks is provided with a sealing device that seals the periphery of the end faces of the pair of tubes heated by the heating plate.