JPH11115060A - Electric welding device with abnormality sensing function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sense the slip-off of a controller connector with a cable connector, the insufficient connection of the cable connector with the controller connector the defective contact and cable disconnection, and predict the cable disconnection so as to avoid the heat development by the increase of resistance value generated in an early disconnection state of the cable. SOLUTION: In a device in which connectors 9 and 11 are connected, power is supplied from a controller 10 to a heating coil with built-in joint through a cable 7 and a tube and a joint are welded together by the heat of the heating coil, the connector 11 is provided with terminals 115 and 116 , and the cable 7 is provided with a short circuit section 14 connected with the terminals 115 and 116 by the connector 9 and generating short circuit between the terminals 115 and 116 , and abnormality is sensed by the controller 10 based on whether the short circuit state of the terminals 115 and 116 is or not.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abnormality detecting method for supplying electric power to a heat generating coil incorporated in a joint such as a pipe joint or a saddle joint to fuse a pipe such as a valve to a joint by the heat generated by the heat generating coil. The present invention relates to an electrofusion device with a function.

[0002]

2. Description of the Related Art Conventionally, in an electrofusion apparatus, one end of a cable is connected to a terminal of a heating coil built in a joint, and a connector provided at the other end of the cable is connected to a connector provided at a controller. When the start switch is pressed, the controller causes a current to flow through the heating coil, the controller measures the current flowing through the heating coil, recognizes the resistance value of the heating coil, and further, the controller determines the diameter of the joint from the resistance value of the heating coil. Is determined, and the electric power required for fusion between the joint and the pipe is supplied to the heating coil for a time determined according to the diameter of the determined joint, whereby the joint and the pipe are fused.

In Japanese Patent Publication No. 7-43067, a heating wire is used to connect a plastic tube, a heating wire is buried in a contact surface with the tube, and a predetermined amount of electric power is applied to the heating wire by fusion with the tube. In the electrofusion joint, which is performed by heating and melting the contact surface, a display means for recording data on the resistance value is provided on the joint, and a plug, a jack or a connector is provided with a sensor for reading the display means, and the plug, When inserting a jack or connector, the resistance value read from the display means by the sensor is compared with the resistance value including the contact resistance of the plug, jack or connector measured from the heating wire, and the difference between the two exceeds the allowable range. A method for displaying a defect of an electrofusion joint characterized by displaying an abnormality is described.

Japanese Patent Publication No. 8-5135 discloses that a heating element is provided on the surface of a joint member that comes into contact with a pipe member when joining a pipe member made of a thermoplastic resin and a joint member made of the same thermoplastic resin. An electric fusion device that fuses the pipe member and the joint member by supplying a current to the heating element, wherein the current measurement unit measures a supply current to the heating element; The first measurement value is temporarily stored, and when the current value measured by the current measurement means after a predetermined time is smaller than the previous measurement value temporarily stored, the stored content is updated to thereby obtain the current measurement value. A current value indicating the minimum value stored in the storage means and a current value measured after a predetermined time, and comparing the current value When the current value measured after a short time is greater than the current value indicating the minimum value stored in the storage means, the counting means for counting plus one, and when counting up one or more times by the counting means, the pipe There is described an electric fusion apparatus characterized in that it is determined that a fusion between the member and the joint member is abnormal.

[0005]

In the above-mentioned electric fusion apparatus, if the connector is disconnected, the connector is insufficiently connected, the connection is poor, or the cable is disconnected, an appropriate current does not flow from the controller to the heating coil, and the joint is not connected. Normal fusion between the tube and the tube is not performed.

In the method of indicating a defect of an electrofusion joint described in Japanese Patent Publication No. 7-43067, an abnormality is determined from a resistance value including a contact resistance of a plug, a jack or a connector measured from a heating wire. Judgment and display indicate that insufficient connection or poor connection of the connector may be mistaken for a difference in the resistance value of the heating wire due to the difference in the diameter of the joint. Can not be detected.

Further, in the electric fusion apparatus described in Japanese Patent Publication No. 8-5135, a current supplied to a heating element is measured, and a fusion abnormality between the pipe member and the joint member is determined from the current. Therefore, there is a risk that insufficient connection and poor contact of the connector may be mistaken for a difference in the resistance value of the heating wire due to the difference in the diameter of the joint, and it is possible to accurately detect insufficient connection and poor contact of the connector. Can not.

The present invention can detect disconnection of the connector of the controller from the connector of the cable, insufficient connection between the connector of the cable and the connector of the controller, poor contact, disconnection of the cable, and detection of disconnection of the cable. An object of the present invention is to provide an electrofusion device with an abnormality detection function, which can be predicted and can avoid heat generation due to an increase in resistance value generated in an initial state of disconnection of a cable.

[0009]

According to a first aspect of the present invention, a first connector provided on a controller is connected to a second connector provided on a cable. An electric fusion device for supplying electric power to a heating coil incorporated in a joint via the cable and fusing a pipe to be joined to the joint and the joint by heat generated by the heating coil. Has an electric fusion terminal connected to the heating coil via the cable, and two conduction detection terminals, and the cable is connected to the two conduction detection terminals by the second connector. A short-circuit portion for short-circuiting between the two conduction detection terminals, and the controller detects an abnormality based on whether or not the two conduction detection terminals are short-circuited. It can detect the disconnection of the controller connector from the cable connector, the insufficient connection between the cable connector and the controller connector, the poor contact, the disconnection of the cable, and perform the normal fusion of the joint and the pipe. It becomes possible.

According to a second aspect of the present invention, in the electrofusion device according to the first aspect, the short-circuit portion is provided in the second connector, so that the configuration can be simplified.

According to a third aspect of the present invention, in the electrofusion device according to the first aspect, the short-circuit portion is provided in the middle of the cable or on the side of the heating coil. As a result, it is possible to avoid heat generation due to an increase in resistance value which occurs in an initial state of disconnection of the cable.

[0012]

FIG. 2 shows a first embodiment of the present invention. In the first embodiment, the joint 1 made of a thermoplastic resin and the tubes 2 and 3 made of a thermoplastic resin as well as heat generated by a nichrome wire (or a heating wire such as a nickel wire or a copper wire) built in the joint 1 are used. This is an electric fusion device having an abnormality detection function for performing fusion by the heat generated by the coil 4. The joint 1 is fitted to the outer peripheral surface of the end portion of the tube 2 and 3 and fused to form the tube 2 or 3.
Inherit. One heat generating coil 4 is coaxially embedded on the inner peripheral surface side of the joint 1, and both ends of the heat generating coil 4 are electrically connected to terminals 5 and 6 provided integrally on the outer peripheral side of the joint 1. . The heating coil 4 is folded one by one on the inner peripheral surface side of both ends of the joint 1 and is buried coaxially. One end of the joint 1 and the pipe 2 are fused by heat generated by one of the heating coils. Fitting 1
May be fused by the heat generated by the other heating coil.

FIG. 1 shows a circuit configuration of the present embodiment. Terminals 5 and 6 of the joint 1 is connected to an electric-fusion terminals 8 _1, 8 ₂ of the joint plug 8 provided at one end of the cable 7, the electric-fusion terminals 8 _1, 8 ₂ in the cable 7 Electric wires 7 ₁ , 7 ₂
Is connected to the electric welding terminals 9 ₁ and 9 ₂ of the connector 9 provided at the other end of the cable 7. This connector 9
Is connected to the connector 11 of the controller 10 so as to be able to come and go.

The sensor mold section 12 of the cable 7
Detecting the outside air temperature is provided a temperature sensor 13 as temperature detection means is mounted, the two terminals are wire 7 ₃ in the cable 7, 7 ₄ temperature sensor terminals 9 ₃ of the connector 9 via the temperature sensor 13 , it is connected to 9 _4. Two energization detecting terminal 9 _5, 9 ₆ in the connector 9 is connected to each one end of the disconnection check wire 7 _5, 7 ₆ in the cable 7, the electric wire 7
_5, 7 ₆ is wired up within joint plug 8. Electric wire 7 ₅ ,
7 by the other end of the ₆ are short-circuited are connected to each other to form a short-circuit section 14 for short-circuiting between the power detection terminal 9 _5, 9 _6.

The connector 11 has electric fusion terminals 11 ₁ , 11 ₂ corresponding to the electric fusion terminals 9 ₁ , 9 ₂ , temperature sensor terminals 9 ₃ , 9 ₄ , and conduction detection terminals 9 ₅ , 9 _{6 of the} connector 9. Temperature sensor terminals 11 ₃ and 11 ₄ , conduction detection terminals 11 ₅ and 11 ₆
The terminals 9 ₁ and 9 _{2 of} the connector 9, the terminals 9 ₃ and 9 ₄ for the temperature sensor, the terminals 9 ₅ and 9 _{6 for} detecting the electric current are connected to the terminals 11 ₁ and 11 _{2 of} the connector 11. sensor terminals 11 _3, 11 ₄ are connected energization detecting terminal 11 _5, 11 _6, respectively.

The controller 10 includes a DC power supply 15, an output control circuit 16 using a switch element composed of a field effect transistor as output control means, an emergency cutoff circuit 17 as emergency cutoff means, a CPU 18 as control means,
External memory 19 composed of EPROM, analog / digital (A / D) conversion circuit 20, detection circuit 21, connector 1
1 and 22, and a DC power supply 15 is connected to a commercial power supply via connectors 22, 23 and a plug 24.

As shown in FIG. 3, the controller 10 starts the fusion of the joint 1 with the pipes 2 and 3 by a start switch 25 as a fusion start instruction means. A switch panel having a stop switch 26 for stopping and a power switch 27 for turning on / off the DC power supply 15; and a display panel 29 as a display unit
It has. Detection circuit 21 includes a detection resistor 21a as shown in FIG. 4, the electric-fusion terminals 9 ₂ of connectors 9 and one end of the detection resistor 21a via the electric-fusion terminal 11 ₂ of the connector 11, of the cable 7 of the wire 7 _2, the other end of the detection resistor 21a is grounded is connected to the terminal 6 of the joint 1 through the electric-fusion terminals ₈₂ of the fitting plug 8.

The terminal 5 of the joint 1 includes an electric fusion terminal 8 ₁ of the joint plug 8, an electric wire 7 _{1 of the} cable 7, an electric fusion terminal 9 _{1 of} the connector 9, and an electric fusion terminal _{1 of} the connector 11.
1 _1, the emergency shutdown circuit 17, via the output control circuit 16 D
Connected to the output terminal of C power supply 15. Output control circuit 16
Is controlled by the CPU 18 to turn on / off the power supplied from the DC power supply 15 to the heating coil 4 to perform pulse width modulation (PWM), thereby outputting PWM pulse power to the heating coil 4.

Although the CPU 15 is separate from the analog / digital conversion circuit 20, the detection voltage of the detection resistor 21a and the temperature detection signal of the temperature sensor 13 are transmitted using a CPU having a built-in analog / digital conversion circuit. Analog / digital conversion by built-in analog / digital conversion circuit and C
You may make it input to PU. In addition, the detection resistor 21
a used a resistance of 0.05Ω, but the detection resistor 21a
It is sufficient that the resistance is Ω or less. As a detecting means for detecting the current flowing through the heat generating coil 4, a current transformer (pulse type DC current detecting sensor) 21b may be used as shown in FIG. 5 instead of the detecting resistor 21a.

The emergency shut-off circuit 17 is activated by a control signal from the CPU 18 when an abnormality is detected or when the operator
When is pressed, the circuit for supplying power from the DC power supply 15 to the heating coil 4 via the emergency cutoff circuit 17 is turned off (cut off) using a relay, and the circuit is normally kept on. The external memory 19 stores the fittings 1 for each fitting size (diameter).
The joint data relating to this is stored.

The DC power supply 15 serves as both a control power supply and an output power supply. The DC power supply 15 is connected to an external commercial power supply through connectors 22 and 23 and a plug 24, and is connected to an external commercial power supply.
The CPU 1 converts an AC voltage of 0 V into a predetermined DC voltage,
8, applied to the external memory 19 and the like. DC power supply 1
Reference numeral 5 denotes an output control circuit 16, an emergency cutoff circuit 17, an electric fusion terminal 11 _{1 of} the connector 11, an electric fusion terminal 9 _{1 of} the connector 9, and a cable, which converts a 100 V AC voltage from a commercial power supply into a predetermined DC voltage. 7 wire 7 ₁ , joint plug 8
Electrical fusing terminals 8 _1, via a terminal 5 of the joint 1 is supplied to the heating coil 4, the heating coil 4, the terminal 6 of the joint 1, the wire 7 _2, electrical fusing terminal 9 _second connector 9 of the cable 7, current flowing through the electric-fusion terminal 11 ₂ of the connector 11 to the ground is detected is converted into a voltage by the detection resistor 21a. The detection voltage of the detection resistor 21 a is converted from analog to digital by the analog / digital conversion circuit 20 and input to the CPU 18.

The power of the controller 10 is the power switch 2
7, the controller 10 sets the output power of the DC power supply 15 to the heating coil 4 to a weak low power such that the heating coil 4 does not generate heat (does not melt the joint 1 and the pipes 2 and 3). By repeatedly turning on the output control circuit 16 at predetermined intervals at predetermined intervals (for example, by setting the output voltage to 0.5 V), the DC power supply 15
Output power is pulse width modulated, and a weak low power pulse that does not heat the heating coil 4, for example, a duty ratio of 50
% Low-power pulses (PWM pulses) are supplied to the heating coil 4.

The current flowing through the heating coil 4 is detected by the detection resistor 21.
a is detected as a voltage, and the detection voltage of the detection resistor 21 a is converted from analog to digital by the analog / digital conversion circuit 20 and input to the CPU 18. The temperature sensor 13 detects the outside air temperature, and the detected temperature value of the temperature sensor 13 is converted from analog to digital by an analog / digital conversion circuit 20 and input to the CPU 18.

The CPU 15 reads the detection voltage of the detection resistor 21a and the temperature detection value of the temperature sensor 13 via an analog / digital conversion circuit 20, and reads the joint 1
Is accurately determined according to the outside air temperature.
The size (diameter) of the joint 1 is nominal 16 mm, nominal 2
0 mm, nominal 25 mm, nominal 30 mm, nominal 40 mm,
There is a nominal 50 mm.

As shown in FIG. 6, when a low power pulse is applied to the heating coil 4, the CPU 15 outputs the analog / digital conversion circuit 20 and the conduction detection terminal 11 of the connector 11.
_5, 11 read the voltage between the _sixth, the current detection terminal 11
_5, 11 by the voltage between the ₆ to determine whether the measurement value within the normal range (near 0V), the energization detecting terminal 11
_5, 11 ₆ to determine whether a short circuit condition cable 7
Connector 11 of controller 10 to connector 9 of
Disconnection, insufficient connection between the connector 9 of the cable 7 and the connector 11 of the controller 10, poor contact,
It is determined whether or not an abnormality such as disconnection has occurred, and when this abnormality has occurred, the emergency cutoff circuit 17 turns off the relay circuit to cut off the power supply from the DC power supply 15 to the heating coil 4. An abnormality is displayed on the display panel 29.

Here, if it is normal, the conduction detection terminal 1
1 _5, 11 ₆ While it is shorted state, the connector 1 of the connector 9 and the controller 10 of the dropout or cable 7 of the connector 11 of the controller 10 relative to the connector 9 of the cable 7
Inadequate connection with 1, contact failure, if abnormality arises disconnection of the cable 7 energization detecting terminal 11 _5, 11 ₆ is no longer short-circuited state.

Further, the cable 7 is in FIGS. 7 (a) wire 7 _1, 7 thickness of ₂ 0.75 mm ² (b), the wire 7 _3, 7 ₄ Thickness 0.3 mm ² is there. Thickness of the wire 7 _5, 7 _6, the wire 7 _5, 7 ₆ is set narrower than the wire 7 _{1-7 4} to break previously in use as compared to the electric wire 7 _{1-7 4,} for example, 0. 008 mm ² is set. Therefore, cable 7
The disconnection of the wire 7 ₅ 7 ₆ will occur before the disconnection of the wire 7 _{1-7 4.}

For this reason, the CPU 15 sets the power supply detection terminal 1
By 1 _5, 11 ₆ voltage between it is judged whether or not a measure of the normal range (near 0V), the cable 7 is disconnected (electric wire 7 _{1-7 4} is disconnected) whether would be predicted, by turning off the relay circuit of the emergency shutdown circuit 17 when the predicted disconnection of cable 7 (wire 7 _{1-7 4} (disconnected), the power supplied from the DC power supply 15 to the heating coil 4 The abnormality is displayed on the display panel 29 by shutting off.

As described above, abnormalities such as disconnection of the connector 11 of the controller 10 from the connector 9 of the cable 7, insufficient connection between the connector 9 of the cable 7 and the connector 11 of the controller 10, poor contact, and disconnection of the cable 7 occur. and when, because when the predicted disconnection of cable 7 (breaking of the wire 7 _{1-7 4)} displays the abnormality on the display panel 29 by interrupting the electric power supplied to the heating coil 4, the controller relative to the connector 9 of the cable 7 10 connectors 1
1 and connector 9 of cable 7 and controller 10
Inadequate connection between the connector 11, contact failure, or when an abnormality occurs that disconnection of the cable 7, the joint 1 and the pipe 2 when predicting the disconnection of the cable 7 (breaking of the wire 7 _{1-7 4),}
3, the joint 1 and the pipes 2, 3 can be reliably fused properly, and heat generation due to an increase in resistance value that occurs in an initial state of disconnection of the cable 7 can be avoided. be able to.

When the start switch 25 is pressed, the CPU 15 uses the joint data stored in the external memory 19 to turn on the DC power supply 15 when the start switch 25 is turned on based on an input signal from the start switch 25. The output power to the heating coil 4 is set to the required power (required heat) corresponding to the size of the joint 1 determined above and the temperature detected by the temperature sensor 13, and the output control circuit 16 determines the size of the determined joint 1 and the temperature sensor 13. The pulse power having a duty ratio corresponding to the size of the joint 1 is supplied to the heat generating coil 4 by turning on / off such that the pulse power having the duty ratio corresponding to the detected temperature is supplied to the heat generating coil 4. Therefore, the heat generating coil 4 generates heat and the joint 1 and the pipes 2 and 3 are fused.

When the set time of the fusion time stored as data in the external memory 19 corresponding to the determined size of the joint 1 has elapsed since the start switch 25 was turned on, the CPU 15 sets the heating coil 4 of the DC power supply 15 to ON. By stopping the power output to and turning off the output control circuit 16, the power supply to the heating coil 4 is stopped, and the display panel 29 displays that fusion of the joint 1 and the pipes 2 and 3 has been completed.

The CPU 15 reads the detection voltage of the detection resistor 21a and the temperature detection value of the temperature sensor 13 via the analog / digital conversion circuit 20 and monitors the abnormal values based on these values. By turning off the relay circuit, the power supply from the DC power supply 15 to the heating coil 4 is cut off, and an abnormality is displayed on the display panel 29.

FIG. 8 shows a part of the second embodiment of the present invention. In this second embodiment, the in the first embodiment, the electric wire 7 _5, 7 ₆ is omitted short-circuit part 14 of the cable 7
Are provided in the connector 9. Temperature sensor terminal 9 ₄ also serves as the current detection terminal 9 _6, the energization detecting terminal 9 ₅ and the temperature sensor terminals 9 ₄ are short-circuited by the short-circuit portion 14. In the cable 7, the thickness of the electric wires 7 ₁ and 7 ₂ is 0.75 mm ² , and the thickness of the electric wires 7 ₃ and 7 ₄ is 0.08 mm ² .

In the second embodiment, similarly to the first embodiment, the CPU 15 sends a low-power pulse to the heating coil 4.
When applied to reads the voltage between the energization detecting terminal 11 _5, 11 ₆ of the connector 11 via the analog / digital converter circuit 20, a voltage between the energization detecting terminal 11 _5, 11 ₆ in the normal range ( by determining whether the measured value of 0V vicinity), omission of the connector 11 of the controller 10 relative to the connector 9 of the cable 7 energization detecting terminal 11 _5, 11 ₆ to determine whether a short-circuit state It is determined whether or not an abnormality such as insufficient connection between the connector 9 of the cable 7 and the connector 11 of the controller 10, poor contact, or disconnection of the cable 7 has occurred. By turning off the relay circuit, the power supply from the DC power supply 15 to the heating coil 4 is cut off, and an abnormality is displayed on the display panel 29.

Further, when the wire 7 _3, 7 ₄ begins to break, CPU 15 the resistance value of the wire 7 _3, 7 ₄ begins to rise will determine that a detected temperature rise of the temperature sensor 13. Therefore, the internal temperature sensor provided in the controller 10, CPU 15 may detect the temperature and internal temperature of the temperature sensor terminals 11 _3, 11 ₄ from read temperature sensor 13 of the connector 11 via the analog / digital converter circuit 20 the electric wire 7 _3, 7 ₄ cable 7 is determined to have started to break disconnection of the wire 7 _3, 7 ₄ of the cable 7 when the difference is out of the range of normal by comparing the temperature detected by the sensor By predicting and turning off the relay circuit in the emergency cutoff circuit 17, D
The power supply from the C power supply 15 to the heating coil 4 is cut off to display an abnormality on the display panel 29.

The first and second embodiments are embodiments of the present invention according to claim 1, and include a controller 1
0 is connected to a second connector 9 provided on the cable 7, and power is supplied from the controller 10 to the heating coil 4 built in the joint 1 via the cable 7. Then, in the electrofusion apparatus for fusing the pipes 2 and 3 to be joined to the joint 1 and the joint 1 by the heat generated by the heat generating coil 4, the first connector 11 is connected via the cable 7. wherein the electric-fusion terminals 11 _1, 11 ₂ connected to the heating coil 4, and two current detecting terminal 11 _5, 11 ₆ or energization detecting terminal 11 ₅ and the temperature sensor terminal 11 _4, the cable 7 Are the two energization detection terminals 1 by the second connector 9.
1 _5, 11 ₆ or energization detecting terminal 11 ₅ and the temperature sensor terminals 11 are connected to ₄ wherein two energization detecting terminal 11 _5, 1
1 ₆ or energization detecting terminal 11 ₅ and the temperature sensor terminals 11 ₄
And a short-circuit portion 14 for short-circuiting between the controller 1
Since 0 when detecting an abnormality by the presence or absence of a short circuit state of the two current detecting terminal 11 _5, 11 ₆ or energization detecting terminal 11 ₅ and the temperature sensor terminal 11 _4, the controller connector relative to the connector of the cable pulls and cable Insufficient connection between the connector and the connector of the controller, poor contact, and disconnection of the cable can be detected, and normal fusion between the joint and the pipe can be performed.

The second embodiment is an embodiment of the second aspect of the present invention. In the electrofusion apparatus according to the first aspect, the short-circuit portion 14 is connected to the second connector 11.
Since there is provided the electric wire 7 _5, 7 ₆ can be a structure easily become unnecessary.

Further, the first embodiment is an embodiment of the invention according to claim 3, wherein in the electrofusion apparatus according to claim 1, the short-circuit portion 14 is connected to the heating coil 4 side of the cable 7. Therefore, it is possible to predict the disconnection of the cable, and to avoid heat generation due to an increase in the resistance value generated in the initial state of the disconnection of the cable.

In the first embodiment, the short-circuit portion 14 may be provided in the middle of the cable 7, for example, as shown in FIG. FIG. 10 shows a part of the third embodiment of the present invention. In the third embodiment, in the first embodiment, the temperature sensor terminals 11 ₄ of the connector 11, 9 ₄ of the connector 9, the energization detecting terminal 1 of the wire 7 ₄ Connectors 11
1 _6, the energization detecting terminal 11 ₆ of the connector 9, which has the electric wire 7 ₆ double as each wire 7 _1, 7 thickness of ₂ 0.75 mm ^2, the thickness of the wire 7 _3, 7 ₄ 0.3mm ² ,
Thickness of the wire 7 ₅ is 0.08 mm ^2. In addition, short-circuit part 1
4 may be constituted by a connector connected to the joint plug 8.

[0040]

As described above, according to the first aspect of the present invention, the first connector provided on the controller is connected to the second connector provided on the cable, and the controller is connected to the second connector via the cable. An electric fusion device that supplies electric power to a heating coil incorporated in a joint, and heats a tube to be joined to the joint and the joint by heat generated by the heating coil. An electric fusion terminal connected to the heat generating coil via a cable; and two conduction detection terminals, wherein the cable is connected to the two conduction detection terminals by the second connector to connect the two conduction detection terminals. The controller has a short-circuit portion for short-circuiting between the detection terminals, and the controller detects an abnormality based on the presence or absence of a short-circuit between the two conduction detection terminals. Inadequate connection with the controller connector dropout or cable connector and the controller connector contact failure, it is possible to perform normal fusion of the joint and the pipe to be able to detect the disconnection of the cable.

According to the second aspect of the invention, in the electrofusion device according to the first aspect, since the short-circuit portion is provided in the second connector, the configuration can be simplified.

According to the third aspect of the present invention, in the electrofusion apparatus according to the first aspect, since the short-circuit portion is provided in the middle of the cable or on the side of the heating coil, the disconnection of the cable can be predicted. As a result, it is possible to avoid heat generation due to an increase in resistance value which occurs in an initial state of disconnection of the cable.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a circuit configuration according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the first embodiment.

FIG. 3 is a front view showing the controller of the first embodiment.

FIG. 4 is a block diagram showing a part of the controller.

FIG. 5 is a block diagram showing a part of another embodiment of the present invention.

FIG. 6 is a flowchart showing a part of the operation flow of the controller.

FIG. 7 is a sectional view showing the cable of the first embodiment and a diagram showing the thickness of the electric wire of the cable.

FIG. 8 is a diagram showing a part of a second embodiment of the present invention.

FIG. 9 is a diagram showing a part of another embodiment of the present invention.

FIG. 10 is a diagram showing a part of a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Joint 2, 3 tube 4 Heating coil 7 Cable 9, 11 Connector 10 Controller 11 ₁ , 11 ₂ Electric fusion terminal 11 ₅ , 11 ₆ Conduction detection terminal 13 Short circuit part

Claims (3)

[Claims] A first connector provided on a controller is connected to a second connector provided on a cable, and supplies electric power from the controller to a heating coil incorporated in a joint via the cable. In the electrofusion device for fusing the pipe to be joined to the joint and the joint by the heat generated by the heat generating coil, the first connector is connected to the heat generating coil via the cable. A terminal, and two energization detection terminals, wherein the cable is connected to the two energization detection terminals by the second connector, and has a short-circuit portion that short-circuits the two energization detection terminals; An electrofusion device with an abnormality detection function, wherein a controller detects an abnormality based on the presence or absence of a short circuit between the two energization detection terminals. 2. The electrofusion device with an abnormality detection function according to claim 1, wherein the short-circuit portion is provided in the second connector. 3. The electrofusion device with an abnormality detection function according to claim 1, wherein the short-circuit portion is provided in the middle of the cable or on the side of the heating coil.