JPH01301231A - Plastic pipe joint and electric welding type connection method thereof - Google Patents

Abstract

PURPOSE:To achieve connection having sufficient capacity by dispensing with the setting of a current supply time to a plastic pipe joint, by forming a blind hole for a thermocouple to the main body of a socket pipe joint in the vicinity of the connector pin thereof. CONSTITUTION:After a plastic pipe 2A is inserted in the piercing hole of a plastic socket pipe joint 1, welding plugs 3 are respectively engaged with the connector pins 13 at both ends of the pipe joint 1 to be mounted thereto. At this time, the connector 31 of each welding plug 3 is engaged with each of the connector pins 13 and the cylindrical projection 16 of the pipe joint 1 is engaged with the gap between the lower part of the connector 31 and a holder 33. Further, a thermocouple 231 is inserted in the blind hole 15 for the thermocouple. Next, a current is supplied to the electric heating wire 12 of the socket pipe joint 1 through the welding plug 3 to generate heat, and the inner peripheral surface part of the socket pipe joint 1 and the outer peripheral surface of the insert part of the plastic pipe 2A are melted. At this time, the temp. rise of the welding plug 3 due to the thermocouple 321 is measured and, when the temp. thereof reaches the preset max. temp., a current is stopped to connect the pipe joint under cooling.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a plastic pipe joint for connecting a plastic pipe and a plastic pipe joint by electrical fusion, and a method for connecting the same by electric fusion.

[Prior Art] - Fig. 8 is a longitudinal sectional view of an S-type plastic pipe joint and a plastic pipe connected thereto. Figure 8 shows a plastic pipe 2A and a plastic pipe fitting lOO.
The same <2B as the two plastic pipes were connected by electrically welding one end of the plastic pipe joint 100 and electrically welding the other end of the plastic pipe joint 100 with the plastic pipe 2B. Indicates the condition.

The plastic V/A hand 100 consists of a pipe joint body 101, a heating wire 12, and two connector pins 13. The pipe joint body 101 has a cylindrical shape, is made of plastic, and has an annular projection 14 formed on the inner circumferential surface of the through hole, at an axially intermediate portion. The heating wire 12 is embedded in the inner peripheral surface of the pipe joint body 101 in a coiled manner. The lower portions of each of the two connector pins 13 are embedded in both ends of the pipe joint body 101, and are connected to each end of the heating wire I2.

The upper part of the connector pin 13 protrudes from the outer peripheral surface of the pipe joint body 101. A cylindrical projection 16 is formed around the connector pin 13 on the outer peripheral surface of the pipe joint body 101.

Next, plastic tube 2A and plastic tube 2B
The connection order of the pipe joint 100 made of plastic and tsuku will be explained.

First, plastic pipe 2A and plastic pipe 2
A is inserted into the through hole of the plastic pipe joint 100 from each end until it hits the protrusion 14. Next, connectors (not shown) are inserted into the connector pins 13 at both ends of the plastic pipe joint 100, respectively. The heating wire 12 of the plastic pipe fitting 100 is passed through this connector.
pass current through. This energization causes the heating wire 12 to generate heat,
The inner peripheral surface of the plastic pipe joint 100 and the outer peripheral surface of the insertion portions of the plastic tubes 2A and 2B are melted. After this melting, the electricity is stopped, the materials are cooled, and then these are bonded. After this, the connector is removed from the plastic pipe joint 100 to complete these connections.

Conventionally, energization control for this connection has been performed as follows. That is, first, the temperature and the plastic pipe fitting 100
This is a control in which the initial temperature on the surface of the plastic pipe fitting 100 is measured, the time for energizing the plastic pipe joint 100 is set based on the measured temperature, and the energization is carried out during this set time. An example of the relationship between the energization time and the initial temperature is shown in Figure 9. The energizing time is 120 seconds from 0″C to 1o from 0″C.
When it reaches "C", the energizing time is 110 seconds, 1 o
'c ~ 20 'C: 10 (Lsec, 20
90sec when 'C~30'C, 30°C~40°C
When , it is 80 seconds.

[Problem that the invention seeks to solve]

As described above, the energization control for setting the energization time to the plastic pipe joint has a problem in that it is difficult to set the energization time.

The reason for this is that the energization time must be set not only based on the initial ambient temperature, but also on the size of the plastic pipe joint, the plastic material, and the temperature measurement position, and also due to errors in the electrical resistance of the heating wire. The optimum energization time may vary depending on errors in current and voltage values, accuracy of temperature measuring equipment, etc.

An object of the present invention is to provide an electric fusion type connection method between a plastic pipe joint and a plastic pipe that does not require difficult setting of energization time and has sufficient connection performance, and is suitable for this connection method. plastic pipe fittings,
and to provide fusion plugs and thermocouples.

[Means to solve the problem]

The present invention comprises a socket pipe joint body which is approximately cylindrical in shape and made of plastic, a heating wire wrapped around and embedded in the inner peripheral surface of the socket pipe joint body, and each end of the heating wire connected to the bottom part of the socket pipe joint body which is embedded in the socket pipe joint body. A plastic socket pipe joint comprising two connector pins whose upper portions protrude from the outer peripheral surface of the socket pipe joint body, characterized in that a blind hole for a thermoelectric body is formed near the connector pins of the socket pipe joint body. and a method for connecting the plastic socket pipe joint and a plastic pipe by electric fusion, the first step being to connect the plastic socket pipe joint to the plastic pipe joint. A plastic tube is inserted, and secondly, a fusion plug consisting of a connector that fits into the connector pin of the plastic socket joint, a thermocouple, and a holder that holds these together is attached to the plastic socket tube. Fits into the connector pin of the joint and the blind hole for the thermocouple.

thirdly, passing an electric current through the heating wire of the plastic socket pipe joint through the connector of the fusion plug to generate heat; and fourth, measuring the temperature rise with a thermocouple of the fusion plug in advance. This is an electric fusion splicing method for plastic socket pipe joints, characterized in that one current is stopped when a set maximum temperature due to heat generation is reached.

[Effect]

The electric fusion type connecting method of plastic pipe fittings according to the present invention uses a thermocouple to measure the temperature of the plastic pipe fittings, and controls the energization to the plastic pipe fittings based on this temperature. , there is no difficult setting of energization time,
This connection method also has sufficient connection performance. Furthermore, since the plastic pipe fitting has a blind hole for the thermocouple, the temperature measured by the thermocouple is close to the fused part of the plastic pipe fitting, so it is suitable for energization control. are being measured.

〔Example〕

A plastic socket pipe joint according to an embodiment of the present invention will be explained based on FIG. FIG. 1 is a longitudinal sectional view showing a state in which a fusion plug 3 is attached to one end of a plastic socket pipe fitting 1 in an attempt to connect a plastic pipe 2A to one end of a plastic socket pipe fitting 1. . The plastic pipe 2A is exactly the same as the plastic pipe 2A described in the conventional technology section, and the plastic socket pipe fitting 1 is almost the same as the plastic pipe joint 100 described in the conventional technology section, but there are some differences. The point is that the plastic socket pipe joint 1 of this embodiment has a blind hole 15 for a thermocouple near the cylindrical projection 16 formed around the connector pin 13 of the socket pipe joint body 11. Therefore, the plastic socket pipe joint 1 is also symmetrical with respect to the axial middle, and the connector pin 139 in FIG. 1 has a cylindrical projection 16. A blind hole 15 for a thermocouple is also provided at the other end of the plastic socket pipe joint 1, and a fusion plug 3 is attached to this other end. Further, the plastic socket I/pipe joint 1 also consists of a socket pipe joint body 11, a heating wire 12, and two connector pins 13.

Here, the blind hole 15 for the thermocouple of the plastic socket pipe joint 1 is a hole into which a thermocouple, which will be explained later, is inserted, and the thermocouple that is wrapped and embedded in the bottom surface and the inner circumference of the socket pipe joint body 11 is a hole for inserting a thermocouple, which will be explained later. The distance between the outer diameter surface of the heating wire 12 and the outer diameter surface of the heating wire 12 is set to be somewhat larger than the distance between the outer diameter surface of the heating wire 12 and the inner circumference surface of the socket pipe joint body 11. This is because if it is too large, the accuracy will be poor because it will measure something close to the outside air temperature as before. On the other hand, if it is too small, the temperature of the heating wire is mostly measured, and the average temperature of the part to be melted is not measured. Also, it is not preferable that the diameter is too small because the heating wire may move and come into contact with the thermocouple during melting.

In fact, a desirable dimension is that the distance between the bottom surface of the blind hole 15 and the outer diameter surface of the heating wire 12 wound and embedded in the inner circumference of the socket pipe joint body 11 is 0.6" and 1.2 mm.

It is preferable that the outer diameter of the heating wire 12 is 0.4 to 0.6 mm, and the distance from the outer diameter surface of the heating wire 12 to the inner peripheral surface of the socket pipe joint body 11 is about 0.5 to 0.6 mm. I can say that.

Next, the fusion plug 3 will be explained based on FIG. 1.

The fusion plug 3 fits into and attaches to the connector pin 13 of the plastic socket pipe joint 1 and the blank hole 15 for the thermocouple. , a holder 33 that integrally holds a connector 31 and a thermocouple 32, and a camp 34 of this holder 33. There are two fusion plugs 3, each connected to a wire 6. The connector 31 includes a connector bushing 311 having a hole into which the connector pin 13 fits, a bushing case 312 that covers the outer circumferential surface of the connector bushing 311, and a connecting bin that connects the connector bushing 311 and the bushing case 312. It consists of 313. The thermocouple 32 consists of a thermocouple body 321 and a thermocouple case 322 that covers the thermocouple body 321.

The holder 33 integrally holds the connector 311 and the thermocouple 32 in parallel, and the holder 33 and the connector 31 are detachable, and the holder 33 and the thermocouple 33 are
Both are removable. The holder 33 fits into the upper part of the connector 31, and also fits into the upper and middle parts of the thermocouple 33. The area around the lower part of the connector 31 in the holder 33 is not in contact with the connector 31, but there are gaps at equal intervals. The wire 5 is connected to the energizing cable 54 and the lead wire 52
and a protective tube 53 that covers the energizing cable 54 and the lead wire 52. The energizing cable 54 is connected to the upper part of the connector bushing 311 and the lead wire 52 is
is connected to the thermocouple body 321. The cap 34 is made of rubber, and has a lower part fitted onto the outer peripheral surface of the upper part of the holder 33, an upper part fitted onto the outer peripheral surface of the protective tube 53 of the wire 5, and a connecting portion between the energizing cable 54 and the connector bushing 311. Covering the lead wire 52 and the thermocouple body 321 at the same time.
It covers the connection part with.

Next, details of the thermocouple main body 321 will be explained. FIG. 2 shows a partial vertical cross-sectional view of the thermocouple 3210, and FIG. 3 is a cross-sectional view taken along the line AA in FIG. The thermocouple 321 is the protective tube 32
5, two thermocouple wires 324 and 324', and a connecting portion 323 between them, and the thermocouple wires 324 and 324' are not particularly different from conventional thermocouple wires in material and shape. .

The protection tube 325 is made of ceramics, pottery, or the like, that is, it is made of a material that is electrically insulating and has a lower thermal conductivity than steel such as stainless steel. This shape is cylindrical, and there are two through holes 327 spaced apart from each other in the same direction as the axis of the cylinder.

The thermocouple wires 324 and 32 are inserted into these two through holes 327.
4' is passing through. Two thermocouple wires 324 and 32
The connecting part 323 of 4' is located at the lowermost end of the protective tube 325, and is a groove 3 formed so as to connect the two through holes 327.
It is within 26. The same <324' as the thermocouple wire 324 is connected, and the wire is sintered with brazing around this connection to be fixed in the groove 56.

The lowermost surface of the connecting portion 323 that has been brazed only becomes the surface that is not brazed. That is, the outer surface of the brazed portion is the lowermost outer surface of the connecting portion 323 and forms the lowermost outer surface of the thermocouple 321.

Since the thermocouple 321 of the embodiment described above is inserted into the blind thermocouple hole 15 of the plastic socket pipe joint 1, it directly measures the temperature of the molten part of the plastic socket pipe joint 1 itself. In addition, since the storage 3W pipe 325 is made of ceramic or earthenware with low thermal conductivity, the amount of heat absorbed by the plastic socket pipe fitting 1 is small, and the temperature is not measured at a low temperature. Since the contact area is limited to the brazed surface, it is possible to measure temperature with a fast response speed even to sudden temperature changes.

In the thermocouple 321 of this embodiment, the protection tube 325 is made of ceramic or earthenware to reduce the absorption of heat by the plastic socket pipe fitting 1. Furthermore, in order to reduce this heat absorption, the thermocouple wires 324 and 325 are made of ceramic or earthenware. This effect is observed when the diameter of ′ is made thinner.

However, the diameter of this wire is approximately 0.1 mm to 0.2 mm.
If the wire is too thin, it will be more difficult to weld and connect, and the risk of wire breakage will also increase.

Furthermore, reducing the outer diameter of the protection tube 325 is also effective in reducing absorption of heat.

However, if it is too thin, there will be problems with its strength, especially if it is made of ceramic, and it will break easily. Therefore, as shown in FIG. 1, it is better to integrally provide a protective case 322 around the thermocouple 321. The material of this protective case 322 has a low thermal conductivity and has a high ductility to compensate for the brittleness of ceramic. Some plastics are suitable.

Next, the order of connecting the plastic pipe 2A and the plastic socket joint 1 will be explained.

Further, the plastic tube 2A is inserted into the through hole of the plastic socket pipe joint 1 until it hits a protrusion (not shown). Next, the fusion plug 3 is fitted into each of the connector pins 13 at both ends (only one end is shown) of the plastic socket pipe fitting l.

Installing. At this time, the connector 31 of the fusion plug 3 fits into the connector pin 13, and the cylindrical projection 16 of the plastic socket pipe joint 1 fits into the gap between the lower part of the connector 31 and the holder 33. Furthermore, thermocouple 3
21 is inserted into the blind hole 15 for the thermocouple of the plastic socket pipe joint 1, and the lower end of the thermocouple 321 lightly contacts the bottom surface of the blind hole 15 for the thermocouple. At this time, an elastic means such as a spring may be provided between the holder and the holder to allow light contact.

Next, an electric current is applied to the heating wire 12 of the plastic socket pipe joint 1 through the fusion plug 3 to generate heat, thereby melting the inner circumferential surface of the plastic socket pipe joint 1 and the outer circumferential surface of the insertion portion of the plastic tube 2A. After this melting,
Turn off the power, cool down, and connect these. Finally, the fusion plug 3 is removed from the plastic socket pipe joint 1 to complete the connection.

The energization control in the connection order described above and the display at that time will be explained using FIGS. 4 and 5. FIG. 4 is a front view showing the display surface of the control device main body 4, in which one end of the two-piece wire 5 is connected to each of the two fusion plugs 3, and the other end of the two-piece wire 5 is connected to the control device main body 4.

First, the energizing button on the control device main body 4 is pressed to apply current to the plastic pipe joint 1 and cause it to generate heat. At this time, at the same time as the energization button is turned on, the temperature rise state of the plastic socket pipe joint 1 is continuously measured by the thermocouple 32 of the fusion plug 3, and is continuously displayed on the control device main body 4.

Second, the maximum temperature generated by the plastic socket pipe fitting 10 is set in advance in the control device main body 4, and when the temperature of the plastic socket pipe fitting 1 rises due to energization and reaches this set temperature, the temperature is automatically set. energization is stopped. At the same time, turn off the power button and turn on the cooling lamp.

Furthermore, at this time, an audible signal such as a buzzer or voice may be issued to indicate when the power supply is stopped.

Here, the maximum temperature set for the plastic socket pipe fitting 1 is approximately 130' when the material of the plastic pipe fitting 1 and the plastic pipe 2A is medium density polyethylene.
C is appropriate.

Thirdly, after the power supply to the plastic socket pipe joint 1 is stopped, this temperature drop situation is continuously measured and displayed,
The temperature at which the fusion plug 3 can be removed from the plastic socket fitting 1, that is, the temperature at which the joint state of the fused portion between the plastic pipe 2A and the plastic socket fitting 1 is not affected even when external force is applied. and set
When the set temperature is reached, a display such as a temperature display or a sound signal such as a buzzer or voice is issued.

In the case of the pipe 2A made of medium density polyethylene and the socket pipe joint 1 made of medium density polyethylene, this temperature is suitably about 60°C. In the electric fusion connection method of the plastic socket pipe fitting 1 and the plastic pipe static described above, the initial outside air temperature is -7°C and 122°C, respectively.
FIG. 5 shows the temperature of the plastic socket pipe joint 1 changing over time at 38°C.

Next, the contents displayed on the display screen of the control device main body 4 will be explained in more detail using FIG. 4.

When the power switch of the control device body 4 is turned on, the lamp shown in the figure lights up when the fusion plug 3 is fitted into the plastic socket pipe joint 1. This fit.

When installation is complete, the connection lamp lights up. Here thermocouple 32. Heating wire 121 Current-carrying cable 54° Lead wire 5
2 etc. is disconnected or there is a poor connection.The disconnection lamp in the ascending chamber lights up, and the connection lamp does not light up.

After the wiring lamp lights up, press the energizing lamp switch, and this lamp switch lights up while the power is on. At this time, if the applied current is abnormally large or abnormally small, the abnormality lamp lights up.

When power is automatically stopped, the energizing lamp switch turns off and the cooling lamp turns on. Next, during cooling, when the temperature drops to a set temperature at which the fusion plug 3 can be removed, the cooling lamp lights up, and the lamp shown in the figure showing the fusion plug 3 being removed from the plastic socket pipe joint 1 lights up. Here, when the energizing lamp switch is lit or the cooling lamp is lit, if the lighting time is abnormally short or long, the abnormal time lamp is lit. If these abnormal lamps light up, press the emergency stop switch and turn off the control device main unit 4.
The power may be cut off.

Next, the temperature of the joint on the display surface of the control device main body 4, the energized rod-shaped lamp, and the rod-shaped lamps for cooling and removing sushi will be explained. In the joint temperature column, the temperature of the ventral surface of the blind hole 15 of the plastic socket pipe joint 1, which is measured by the thermocouple 32 of the fusion plug 3, is continuously displayed. For example, each rod-shaped lamp for energizing, cooling, and removing is 0.
, 10°20...80, 90, 100% are displayed in a bar graph.

For example, when the current is being applied, the temperature at the time of starting the current, that is, before the current is applied, is 20'C, and the set maximum temperature at which the current is stopped is 1.
When the temperature is 30°C and the temperature at a certain point during energization is 75°C, the bar-shaped lamp energized at this point is (75-20)/
(130-20)=50% is displayed.

Next, while cooling is in progress, the temperature at the start of cooling is 130'C, which is the set maximum temperature at which electricity is stopped, and the set temperature at which the fusion plug 3 can be removed is 60°C, and the temperature at a certain point during cooling is 130'C. When is 100°C, the cooling rod lamp at this point is (130-200)/(130-60) = 4
2.9% → 40% is displayed. A removable bar-shaped lamp has a removable set temperature of 60°C 1 and a maximum of 88 temperatures, that is, when the temperature at the start of measurement is 20°C and the temperature at the time of removal is 50°C, (60-50) / (60-
20) Display =25%→30%.

The rod-shaped lamps for the temperature of the joint, the energizing lamp, and the cooling and removal lamps described above indicate whether the lamp is energized, cooling, or detachable. That is, for example, if the display only indicates that the energization lamp is lit during energization, it is impossible to know how long it will take for energization to end after this point, but these displays have the effect of giving you a rough idea.

In the above-described electric fusion connection method for plastic socket pipe joints, a thermocouple is used to measure the temperature, but there are other temperature sensors that can output temperature as an electrical signal, such as a thermistor or resistance thermometer. That's fine.

The plastic socket pipe joint 1 described above is a pipe joint that connects the plastic pipe 2A and the same <2B in a straight line. Next, the plastic branch pipe joint 6 for branching and connecting the plastic pipes 2C will be described with reference to FIG. 6 and FIG. 7, which is a sectional view taken along line AA in FIG. 6. The plastic tube 2C has a through hole 21C on its outer peripheral surface that penetrates to its inner peripheral surface. The plastic branch pipe joint 6 consists of a plastic branch pipe joint main body 61, a heating wire 62, and two connector pins 63. The branch pipe joint main body 61 has a shape obtained by dividing a cylinder in half in the axial direction, that is, a saddle portion 61 having a lower surface along the outer peripheral surface of the cylinder.
1 and a through hole 6111 made in the center of this saddle part 611
It consists of a cylindrical main body part 612 extending radially upward from the outer peripheral surface of the saddle part 611, and these parts are integral. Here, the radially upper side of the saddle portion 611 is the upper side when the inner circumferential surface of the saddle portion 611, that is, the surface along the cylindrical outer circumferential surface is the lower surface.

The saddle portion 611 has a branch pipe joint body 6 at both ends in the radial direction.
1 is a protrusion 61 for temporarily fixing it to the plastic tube 2C.
12 are formed. The cylindrical main body part 612 has a joint part, for example, a female thread 6121 at its upper end, and the plug 7 is screwed into this female thread 6121 so that it can be closed. Further, the cylindrical main body part 612 may have a branch pipe 6122 in this cylindrical intermediate part, and the branch pipe 612
2 may be connected to another pipe (not shown) to make a branch connection.

The heating wire 62 is wrapped around and embedded in the lower surface of the branch pipe joint body 61, that is, the lower surface and inner peripheral surface of the saddle portion 611. The lower portions of the two connector pins 63 are connected to both ends of the heating wire 620, and are embedded in both axial ends of the saddle portion 611 of the branch pipe joint body 61. The upper portions of the two connector pins 63 protrude from the outer peripheral surface of the saddle portion 611. Here, the saddle part 6 of the connector pin 63
11 and the area around the connector pin 63 of the saddle portion 611 are the same as those of the plastic socket pipe joint 1 described previously. That is, the saddle portion 611
There is a cylindrical protrusion 6 around the connector pin 63 on the outer peripheral surface of the
113 and a blind hole 6114 for a thermoelectric body are formed.

Further, the fusion plug and thermocouple are also the same as in the case of the plastic socket pipe joint described above.

Next, the connection order and energization control between the Plus Deck branch pipe joint 6 and the plastic pipe 2C will be explained.

First, the lower surface of the plastic branch pipe joint 6 is placed on the outer peripheral surface of the plastic pipe 2C and temporarily fixed. At this time, the saddle portion 6 of the plastic branch pipe joint 6
It is necessary to align the through hole 6111 of No. 11 with the through hole 21C of the plastic tube 2C.

The following is the same method as the electric fusion type connection method between the plastic socket pipe fitting 1 and the plastic pipe 2A, that is, the second step is to connect the previously described fusion plug 3 to the connector pin 63 of the plastic branch pipe fitting 6. and the blind hole 6114 for the thermocouple, and then connect the plastic branch pipe fitting 6 through the connector 31 of the fusion plug 3.
A current is passed through the heating wire 62 to generate heat.

Fourth, the temperature rise is continuously measured using the thermocouple 32 of the fusion plug 3, and the current is stopped when the preset maximum temperature due to heat generated by energization is reached, and when this stops, a buzzer, voice, etc. Give the signal to appear.

Fifth, after the current in the plastic branch pipe fitting 6 was stopped, the temperature drop was continuously measured using the thermocouple 32, and the temperature at which the fusion plug 3 could be removed was set, and the temperature dropped to this set temperature. Sometimes, a sound signal such as a buzzer or voice is given.

Sixth and finally, the fusion plug 3 is removed from the plastic branch pipe joint 6.

With the above steps, the electric fusion type connection between the plastic branch pipe joint 6 and the plastic pipe 2C is completed.

[Effects of the Invention] The electric fusion connection method for plastic pipe joints according to the present invention has the advantage that there is no need to set a difficult energization time, and the connection performance is sufficient. Further, in the electric fusion connection method of the plastic pipe joint of this embodiment, there is an indication of when the fusion plug can be removed, so that the fusion plug will not be removed too early or too late. In addition, there are audible cues when the power is turned off and when the sushi is ready for pick-up, so the operator can hear the cues and have a rough idea of when the sushi is coming, even if he or she is not looking at the control device itself. In addition, since the connector and thermocouple are held together in the fusion plug, they can be mated and installed at the same time.Furthermore, a blind hole for the thermocouple is provided, so temperature rises can be detected quickly. There is an effect that can be done.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing an example of a plastic pipe inserted into a plastic pipe joint and a fusion plug fitted and installed, and Fig. 2 is a partial vertical cross-section showing an example of a thermocouple. Figure 3 is a sectional view taken along the line A-A in Figure 2, Figure 4 is a front view of the main body of the control device, Figure 5 is a diagram showing the temperature change after power is started to be applied to the Plasdec pipe joint, Fig. 6 is a vertical cross-sectional view showing a plastic pipe joint and a plastic pipe, Fig. 7 is a cross-sectional view taken along line A-A in Fig. 6, Fig. 8 is a clear cross-sectional view of a conventional plastic pipe joint and pipe, and Fig. 9 is a cross-sectional view of a conventional plastic pipe joint and pipe. The figure is a diagram showing conventional energization control. DESCRIPTION OF SYMBOLS 1... Plastic pipe joint, 2... Plastic pipe, 3... Fusion plug, 4... Control device main body, 5
... wire, 6... plastic branch pipe joint. Figure 2 Rm' Figure 5 +0 20 30 40 50 60
70-□Electrification time (excerpt) Fig. 6--A Fig. 7 Fig. 8 Fig. 9 □Initial, M degree (0C)

Claims (1)

[Scope of Claims] 1) A socket pipe fitting body having a substantially cylindrical shape and made of plastic, a heating wire wrapped and embedded in the inner circumference of the socket pipe joint body, and a lower part connected to each end of the heating wire and the socket pipe fitting body made of plastic; In a plastic socket pipe joint consisting of two connector pins that are embedded in a joint body and whose upper parts protrude from the outer peripheral surface of the socket pipe joint body, a blind hole for a thermocouple is provided near the connector pins of the socket pipe joint body. A plastic pipe joint characterized by a formed. 2) A substantially half-cylindrical saddle portion having a lower surface along the outer peripheral surface of the cylinder, and a cylinder extending upward in the radial direction of the saddle portion from the outer periphery of a through hole drilled in the center of the saddle portion and having a joint portion at the end. A plastic branch pipe joint body integrally formed with a shaped main body, a heating wire embedded in the lower part of the branch pipe joint body, and a lower part connected to each end of the heating wire, the lower part of the branch pipe joint body In a plastic branch pipe joint consisting of two connector pins that are embedded in a saddle part and whose upper parts protrude from the upper surface of the saddle part, a blind hole for a thermocouple is formed near the connector pins in the main body of the branch pipe joint. Plastic pipe fittings featuring: 3) A plastic pipe joint according to claim 1 or 2, characterized in that a blind hole for a thermocouple is formed in the vicinity of a heating wire portion that is tightly wound and embedded. 4) In claims 1 to 3, the distance between the bottom of the blind hole for the thermocouple and the outer diameter surface of the heating wire wrapped and embedded in the inner circumference of the plastic pipe joint body is A plastic pipe joint, characterized in that the distance between the outer diameter surface of the heating wire and the opposing outer diameter surface and the inner peripheral surface of the plastic pipe joint body is slightly larger. 5) In claim 4, the distance between the bottom of the blind hole for the thermocouple and the outer diameter surface of the heating wire wrapped and embedded in the inner circumference of the plastic pipe joint body is 0.6 to 0.6. 1.2m
A plastic pipe joint characterized by m. 6) Claims 1 or 2 consist of a holder that holds a thermocouple and a connector bush together, and a cap that holds a lead wire of the thermocouple and a current-carrying cable; The formed concave or convex portion and the convex or concave portion formed on the inner circumference of the cap corresponding to the concave or convex portion fit and connect, and between the thermocouple and the lead wire, the connector bush and the current-carrying cable. A plastic pipe joint characterized by using fusion plugs that are removably connected with connectors. 7) In claim 6, the thermocouple consists of two thermocouple wires and an electrically insulating protective tube with low thermal conductivity, and the two thermocouple wires are arranged inside the protective tube. A plastic pipe fitting, characterized in that the connections are located at the lowest end of the protective tube and form an outer surface. 8) In the method for connecting a plastic socket pipe joint and a plastic pipe by electric fusion as set forth in claim 1, firstly, the plastic pipe is connected to the plastic socket pipe joint. Second, a fusion plug consisting of a connector that fits into the connector pin of the plastic socket pipe joint, a thermocouple, and a holder that holds them together is connected to the connector pin of the plastic socket pipe joint. Thirdly, through the connector of the fusion plug, a current is passed through the heating wire of the plastic pipe joint to generate heat, and fourth, the fusion plug An electric fusion connection method for plastic socket pipe fittings, which measures the temperature rise with a thermocouple and stops the current when the preset maximum temperature due to heat generation is reached. 9) In the method of connecting a plastic branch pipe joint and a plastic pipe using an electric fusion method as set forth in claim 2, firstly, the plastic branch pipe joint is attached to the plastic pipe. secondly, the fusion plug described in claim 8 is fitted and attached to the connector pin of the plastic branch pipe joint and the blind hole for the thermocouple; First, a current is passed through the heating wire of the plastic branch pipe joint through the connector of the fusion plug to generate heat, and fourth, the temperature rise is measured by the thermocouple of the fusion plug to reach a preset maximum temperature due to heat generation. An electrofusion connection method for plastic branch pipe fittings, characterized by stopping the current when the temperature is reached. 10) In the method for electrically fusion connecting a plastic branch joint according to claim 8 or claim 9, fifthly, after the current to the plastic joint is stopped, the thermocouple is connected to the thermocouple. Electricity of a plastic pipe joint, characterized in that a temperature drop at which the fusion plug can be removed from the plastic pipe joint is set by measuring a temperature drop, and an indication is displayed when the temperature drops to the set temperature. Fusion splicing method. 11) In the electric fusion connection method for plastic pipe joints according to claim 8 or 9, the fusion plug can be removed when the current to the plastic pipe joint is stopped. 1. A method for electrical fusion splicing of plastic pipe joints, characterized in that an audible display is produced at least when the temperature drops to a set temperature. 12) In the method for electrically fusion connecting plastic pipe joints according to claim 8 or claim 9, a thermistor or a resistance temperature sensor is used in place of the thermocouple. Features an electric fusion connection method for plastic pipe joints.