JP3693186B2 - Energizing time control method and electrofusion apparatus for electrofusion joint - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an electric fusion joint (hereinafter simply referred to as a joint) in which a heating wire is embedded in a joint body made of a thermoplastic resin, and a pipe and a joint by energizing the heating wire of the joint. The present invention relates to an energization time control method for electrical fusion connection and an electrical fusion apparatus used at this time.
[0002]
[Prior art]
Conventionally, it is well known to connect a pipe made of a thermoplastic resin material such as polyethylene or polybutene and a joint by electric fusion.
In addition, as a method for controlling the energization time at this time, first, the electrical resistance of the current flowing through the heating wire embedded in the electric fusion joint is measured, and the type and diameter of the joint (the diameter is the nominal diameter of the connection port, the type is Of the so-called joint identification method, which selects the optimum energization time set for each joint type diameter in advance and automatically energizes only this time. There is an energization time control method (Japanese Patent Publication No. 3-27014).
[0003]
In addition, in this type of electric fusion joint, there are two-part joints having two fusion connection ports such as sockets and one-way joints having one fusion connection port like caps. Conventionally, the heating wires used for these have been continuously wound around the connection port with the same characteristics. Therefore, the electrical resistance value of the joint was twice as large at the socket joint at both ports than at the cap joint at one port.
[0004]
[Problems to be solved by the invention]
However, in the energization time control method described above, since there is usually a few percent of manufacturing variation in the electrical resistance of the heating wire itself, when there are many varieties, a part where the range of electrical resistance for each caliber overlaps is avoided in the design. In some cases, it was not possible to identify the important varieties of caliber.
In addition, as described above, in the conventional electric fusion joint, when trying to distinguish between the type and the diameter, even if the diameter is the same, the socket (both mouth joint) and the cap (single mouth joint) have an electric resistance value of 2 to 1. Therefore, there may occur a case where a small-diameter socket and a large-diameter cap have substantially the same electrical resistance value. If the identification is incorrect at this time, the socket may be overfused and the cap may be underfused. Therefore, there was a problem that the variety diameter could not be identified from this point.
In general, when an electrofusion apparatus is provided with an identification function, there is a problem that the structure and control are complicated and expensive.
[0005]
An object of the present invention is to provide an energization time control method and an electrofusion apparatus for an electrofusion joint capable of uniquely setting an appropriate energization time for each of various types of joints.
[0006]
[Means for Solving the Problems]
The present invention achieves the above object by setting the electrical resistance value and the energization time in a one-to-one relationship in order to uniquely set the electrical energy required for fusion.
That is, the present invention is an energization time control method by an electric fusion apparatus of an electric fusion joint in which a heating wire is embedded,
In the Rt diagram storage unit mounted on the electrofusion apparatus, the energization time t has a one-to-one correspondence with the electrical resistance value R of the heating wire provided in the electrofusion joint. Rt diagram is prepared in advance,
On the other hand, measuring the ambient temperature by the ambient temperature measuring unit,
Attaching the connector of the electrofusion apparatus to the connector pin provided at the end of the heating wire of the electrofusion joint;
By applying a small voltage to the heating wire, the resistance value setting unit, and a step asking you to electric resistance value R1 of the heating wire of the joint to be fused,
The energization time setting unit, wherein the energizing time according to the environmental temperature with the electric resistance value R1 wherein in comparison with the electric resistance value stored in the R-t diagram storing unit obtains the energization time t1 to the joint setting an energization time t2 in which t1 is corrected;
A step of the resistance value setting unit, Ru obtains a resistance value R2 of being energized after the start of energization,
The comparing unit, and a step of comparing the electric resistance R2 and the resistance value R1,
When a difference between the electric resistance value R1 and the electric resistance value R2 is within a predetermined range, a signal to stop energization is transmitted after the energization time t2 , or the electric resistance value a step difference between the the R1 resistance value R2 is when is outside a predetermined range for transmitting a signal for stopping the signal and power to outgoing alarms,
Tona is energizing time control method for an electro-fusion joint was so that.
In the above, it is possible to measure the ambient temperature and adjust any one or two of the energization time or current value or voltage value according to the ambient temperature to correct the electrical energy necessary for fusion each time. desirable.
In addition, as the Rt diagram, the electric resistance value R and the energization time t monotonously increase or monotonously decrease. A combination of two or more diagrams in which the electric resistance value R and the energization time T have a monotonically increasing relationship or a combination of two or more diagrams in which the monotonically decreasing relationship is desirable is desirable.
[0007]
Further, the present invention is an Rt diagram memory in which an Rt diagram having a relationship in which the energization time t has a one-to-one correspondence with the electric resistance value R of the heating wire provided in the electric fusion joint is stored. And
A resistance value measuring unit for obtaining the electric resistance value R1 of the heating wire of the joint to be fused;
An energization time setting unit that sets the energization time t1 by comparing the Rt diagram and the electrical resistance value R1;
An ambient temperature measurement unit for measuring the ambient temperature;
An energization time setting unit that corrects the energization time t1 in accordance with the ambient temperature and sets the energization time t2.
A comparison unit that measures the electrical resistance value R2 during energization and compares the electrical resistance value R1 and the electrical resistance value R2,
An alarm unit that issues an alarm when the electrical resistance values R1 and R2 are outside a predetermined range;
An energization start command section for instructing energization start; and
When the electrical resistance values R1 and R2 are within a predetermined range, energization is continued, and when the electrical resistance values R1 and R2 are outside the predetermined range, energization is stopped and an alarm signal is transmitted to the alarm unit. and a part,
This is an electrofusion apparatus in which each unit is placed in and controlled by a microcomputer CPU.
[0009]
[Action]
In the energization time control method of the present invention, the electrical resistance value R and the energization time t are set in advance on the Rt chart so that the electrical resistance value R and the energization time t correspond one-to-one for each type of caliber. By measuring R, the energization time t is obtained, and electric energy (hereinafter referred to as fusion energy) E necessary for fusion is uniquely given. Here, if the energization time is corrected in accordance with the ambient temperature, that is, the change in the resistance value due to the fusion site, season, or the like, a better fusion state can be obtained. In addition, the current value may be corrected and controlled in the current control method instead of the energization time, and the voltage value may be corrected and controlled in the voltage control method. This is appropriately selected according to the fusion apparatus and the situation.
In addition, when the resistance value R1 before the fusion work and the resistance value R2 during work, that is, during energization, are out of a predetermined range (for example, the difference between R1 and R2 is 5% or more) This means that it has occurred, and since this stops the energization, defects can be prevented in advance.
[0010]
The fusion energy is generally proportional to the area of the welded portion of the joint. However, if the fusion energy is determined only by the fusion area, pipes and joints with large diameters are too thick, resulting in insufficient fusion. In the case of a small diameter, the wall thickness is also small, resulting in overfusing. Therefore, the optimum fusion energy must be set in consideration of both the joint diameter and the fusion area. In the present invention, the fusion energy per one connection port is set to 1: 1 so that it does not overlap for each caliber type of joint, and the measured electrical resistance is irrespective of the type of one port or both ports. The energization time is uniquely determined based on the value, and as a result, the fusion energy corresponding to the diameter and thickness of the joint is supplied.
[0011]
In the Rt diagram, it is sufficient that the electric resistance value R and the energization time t have a one-to-one correspondence regardless of whether it is a straight line or a curve. In the case of the constant current control method, the fusion energy E and Rt Are proportional to each other, and therefore are easy to set on a monotonically increasing diagram as shown in FIGS. On the other hand, in the case of the constant voltage control method, since Rt is in an inversely proportional relationship, it is easy to set a monotonically decreasing diagram that decreases to the right. For single-ended joints and double-ended joints, it is easy to set the diagram as shown in FIG. 2 that combines the Rt diagram for single-ended joints and the Rt diagram for double-ended joints. Although the resistance value is 2 to 1, both have the same energization time, so the fusion energy per unit is equal. Further, since the change in the thickness and the fusion area is small when the aperture is small, it can be set even in a smooth diagram as shown in FIG.
[0013]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
First, the energization time control method according to the present invention will be described with reference to FIGS. The figure shows the relationship (Rt diagram) between the electrical resistance R and energization time t for each type of caliber size of the electric fusion joint. FIG. 1 shows a monotonic increase, and FIG. 2 shows two types of monotonically increasing lines. FIG. 3 is an example of combinations of monotonically increasing diagrams with different inclinations.
The solid line in FIG. 1 shows the relationship between the range of the electric resistance R of the socket nominal diameters of 10 mm (S10), 13 mm (S13) and 16 mm (S16) and the energization time t. The relationship between the range of the electrical resistance R of (RS13 × 10) and 16 × 13 mm (RS16 × 13) and the energization time t is shown.
[0014]
The range of electrical resistance R of each electric fusion joint is as follows: S10 is 1.50Ω ± 0.12Ω, S13 is 2.0Ω ± 0.16Ω, S16 is 2.50Ω ± 0.20Ω, RS13 × 10 is 1.75Ω ± 0.14Ω RS16 × 13 is 2.30Ω ± 0.18Ω. Note that the allowable range of the electric resistance R is derived from the allowable range in quality such as manufacturing error and fusion strength of the heating wire itself.
As can be seen from the figure, S13 and RS13 × 10 and S16 and RS16 × 13 have overlapping electric resistance ranges, and the conventional method cannot identify the type diameter of the joint.
On the other hand, in the energization time control method according to the present invention, there is no need to identify the type diameter, and the energization time t corresponding to the electrical resistance R of the electrofusion joint is given one-to-one. When the electrical resistance R is 1.84Ω which is the lower limit of tolerance, the energization time t is automatically given 26.8 seconds, and when the electrical resistance R of RS13 × 10 is 1.89Ω which is the upper limit of tolerance, the energization time is t is automatically given 27.8 seconds. As a result, the optimum fusion energy set for each type of caliber is given to each.
[0015]
Usually, the nominal diameters of the joints and pipes and the respective wall thicknesses are in a proportional relationship. That is, the thickness of the joint and the pipe increases as the diameter increases. Therefore, the heat capacity of the fusion part increases as the diameter increases, and a lot of fusion energy is required. FIG. 1 shows an embodiment according to a constant current control system. In order to increase the fusion energy as the nominal diameter increases, the electrical resistance increases as the diameter increases (from En = I2 Rt (I = constant)). It increases with R and energization time t. In this embodiment, the relationship between the electric resistance R and the energization time t is set on a diagram represented by t = 20R-10, but it is not necessary to limit to this mathematical formula, and t = This is done by selecting the optimum one from the monotonically increasing relationship represented by a1R + b1 or t = a2 R2 + b2. Here, a1, a2, b1 and b2 are constants.
[0016]
In the case of the constant voltage control method as another method, since the fusion energy increases as the nominal diameter increases (from En = V2 t / R (V = constant)), the electric resistance R is reduced. The energization time t is lengthened. Therefore, the optimum relationship between the electric resistance R and the energization time t is selected from the monotonically decreasing relationships represented by t = a3 / R + b3 or t = a4 R + b4. Here, a3, a4, b3 and b4 are constants. However, a4 <0. Therefore, as an embodiment of the constant voltage control system, although not shown, the electric resistance R and the energization time t are set on a diagram represented by a monotonically decreasing right downward as an inverse proportion.
[0017]
FIG. 2 shows a second embodiment of the Rt diagram. This example is a combination of a diagram t = 10R + 15 for a single-joint joint such as a cap (Ca) and a diagram t = 5R + 15 for a double-joint joint such as a socket (S). Here, the vertical axis represents the energization time t and the horizontal axis represents the electric resistance R, but it may be as shown in FIG.
As can be seen from the figure, the energization time t for the eight items Ca20, 25, 30, 40 and S20, 25, 30, 40 is set to 1: 1 for the electrical resistance R. Moreover, when Ca and S are viewed for each size, the electrical resistance R is set to 1 and the energization time t is set to be the same. For example, the electrical resistance R of Ca20 is about 1.6Ω, that of S20 is about 3.2Ω, and the energization time t is 31 seconds for both. Therefore, since the fusion energy per unit is the same amount for both Ca and S, both can perform good fusion under the same conditions.
[0018]
FIG. 3 shows a third embodiment of the Rt diagram. In this example, a diagram t = 1R + 26 for a small aperture and a diagram t = 5R + 15 for a relatively large aperture are continuously combined. For example, in the case of a small diameter of about Ca10 to S13, the fusion area and the wall thickness do not change so much, so even if the energization time t hardly changes, the electric resistance R can be set so as not to overlap or slightly overlap. Since the necessary fusion energy of the material does not substantially change, a suitable material can be provided. Such a diagram can also be set as an example.
Note that the Rt diagram of the present invention is not limited to the above-described example, and other modifications are possible. For example, when the diameter is 8 to 50 mm, there are about 40 types of fused portions. In this case, the electric resistance value R can be set within a range of about 0.5 to 9Ω. Further, it goes without saying that a monotonically decreasing Rt chart can be used as in the above-described monotonically increasing example.
[0019]
Next, the electric fusion joint will be described.
4 to 8 show an electric fusion joint that adjusts the electric resistance value of the entire joint by additionally winding a heating wire around a portion other than the fusion part, and FIG. 4 is a cross-sectional view of the socket of the double-ended joint. 5 to 7 are cross-sectional views of the cap of the single-ended joint, and FIG. 8 is a cross-sectional view of the adapter joint for connecting a water faucet and the like.
First, the socket joint of FIG. 4 is provided with fusion connection ports 11 and 12 for fusing and connecting the resin pipe 1 on the left and right sides of the socket body 10, and the heating wire 13 a is continuously provided near the inner surfaces of the fusion connection ports 11 and 12. And 13b are wound in a coil shape. Both ends of the heating wire 13 are coupled to connector pins 14 and 15 protruding from the socket body 10, and a power source of a controller is connected to the connector pins 14 and 15 so that the heating wire 13 is energized. The heating wire portion 13c for adjustment which is wound around other than the fusion portion is wound around the fusion connection ports 11 and 12 so that the joint body 10 is not melted or deformed by heat generated when the pipe 1 is fused. It is larger than the diameter, and is arranged at a substantially central part of the wall thickness of the joint body 10, and the winding pitch is larger than the pitch of the fusion splicing port portion. The length and the number of turns of the additional heating wire portion 13c can be adjusted and set on the Rt diagram for each type of diameter.
[0020]
In the cap joint of FIG. 5, there are a fusion splicing port 21 for fusing and connecting the resin pipe 1 to the inner surface of the cap body 20, and a closing wall 22 for closing the end. A heating wire 23 is wound around the fusion splicing port 21 and connector pins 24 and 25 are coupled to both ends thereof. The material and overall length of the heating wire 23 and the length of the heating wire 23a wound around the fusion splicing port 21 are substantially the same as those of the heating wire 13a per fusion splicing port of the socket joint in FIG. An additional heating wire 23c that adjusts the overall electric resistance value is wound around a portion 26 other than the fusion splice port that is separated to the extent that the fusion splicing port 21 on the blocking wall 22 side is hardly affected. The portion 26 other than the fusion splicing port around which the additional heating wire 23c is wound is formed so that the thickness of the joint body 20 is thicker than that of the fusion splicing port 21, and the heating wire 23c is substantially at the center of the thick wall. Winding is made larger than the winding diameter of the heating wire 23 a wound around the fusion splicing port 21. In this way, the cap body 20 is prevented from being deformed by the heat effect so that the heat effect of the heating wire 23c is not given to the fusion splicing port 21 portion.
[0021]
In the cap joint of FIG. 6, the cap body 30 is provided with the same material and length of heating wire as the socket joint of FIG. 4. The additional heating wire 33c for adjustment is wound around the inlet side of the fusion connection port 31 with a diameter larger than the winding diameter of the heating wire 33a of the fusion connection port 31, and a metal ring 36 is provided on the inner diameter side thereof. Therefore, the metal ring 36 absorbs the heat effect caused by heating of the extra heating wire portion, and does not affect the fusion splicing port 31 portion.
[0022]
The cap joint shown in FIG. 7 has the same heating wire specifications as the socket joint shown in FIG. 4, and the additional heating wire 43c for adjustment is covered with a heat insulating material 46 such as glass fiber, and is wound around the outer surface of the cap body 40 to be a connector pin. 45 is connected. The heat of the additional heating wire 43c is interrupted by the glass fiber heat insulating material 46 so as not to affect the fusion splicing port 41 and the cap body 40.
[0023]
FIG. 8 shows an adapter joint having a fusion splicing port 51 and a metal female screw connection port 52. A metal female screw insert 57 and a resin adapter fitting main body 50 are molded integrally therewith. Is. Also in this case, the heating wire uses the same heating wire as the socket joint of FIG. The additional heating wire 53c is embedded in the joint body on the side of the insert 57, and the heat generated by the additional heating wire 53c is absorbed by the insert 57 at the time of fusion with the resin pipe and affects the fusion connection port 51 with the resin pipe. Is not affected.
In addition, although the above-mentioned electric fusion joint was to adjust the resistance value at the additional heating wire part for adjustment using the same heating wire as the socket joint, it can be adjusted by changing the material and wire diameter. You may make it do. For example, the cap joint may be adjusted by using a heating wire made of a material having a large specific resistance value or by reducing the diameter of the heating wire.
[0024]
Next, the electrofusion apparatus, that is, the controller of the present invention will be described.
The controller of the embodiment described below adopts a constant current control method in which the input power supply AC100V is converted into a constant current power supply with a current of 5.5A (variable) inside the controller, and the energization time control is the electrical resistance value for each joint as described above. R is read, temperature correction is added to this, and energization time t is set.
FIG. 9 is a block diagram of the controller of the embodiment. Here, it is converted into a constant current power source of 5.5 A by the fusion power source 63 through the breaker 61 and the relay 62 in the controller 60. Thereafter, the connector 66 can be connected to the connector pin on the joint side via the relay 64.
[0025]
Next, a resistance value setting unit 66 for measuring and storing the electrical resistance of the heating wire between the connector pins is provided, and the initial resistance value R1 and the resistance value R2 during energization are measured here. The initial resistance value R1 is sent to the Rt diagram storage unit 67 that stores a predetermined Rt diagram in advance, and the energization time t1 corresponding to the resistance value R1 is set by the energization time setting unit 68. On the other hand, it has a temperature sensor 70 such as a thermistor for measuring the ambient environmental temperature, and a corrected energization time t2 setting unit 69 for correcting the energization time based on this environmental temperature. Here, since the energization time t2 may be obtained simultaneously without setting t1, these energization time setting units 66 and 69 may be combined. Further, it has a comparison unit 71 that compares the resistance value R1 measured in the initial stage with the resistance value R2 measured during energization, and a continuation stop command unit 72 that commands the energization to be stopped or continued according to the comparison result. The comparison unit may determine whether R1 and R2 are within a predetermined range or not. For example, when a heating wire whose resistance value does not depend on temperature is used, it is simply determined whether or not the difference is within an allowable amount. become. Then, each unit other as described above is adapted to be controlled placed in the microcomputer CPU 77. The energization start command unit 73 for instructing the start of energization is turned ON / OFF by a fusion start button attached to the upper surface of the main body, and an emergency stop button is provided on this surface.
[0026]
The external display (LCD) unit 75 displays energization time (countdown), size display, input voltage abnormality, output current abnormality, wire short (this is monitored during the energization period), connector dropout, overheating, environmental temperature abnormality ( Alarms such as -10 ° C or lower or 40 ° C or higher) are detected and displayed. Reference numeral 74 denotes a sound output in conjunction with the alarm display and energization stop command issued by the buzzer or when the fusion is completed. Further, the above-described alarm enables ON / OFF control of the fusion power source and the relay, and interlocks with the energization stop.
Reference numeral 76 denotes a control power source and an attached power source unit. The control power source is, for example, an analog power source a, a CPU power source b, a relay power source c, and an attached tool power source d.
[0027]
Next, the operation of the fusion control of the controller of the embodiment will be described based on the flowchart of FIG. Note that the numbers given in the drawings may not always match the control order.
1 Turn on the power to the controller. At the same time, the input voltage, frequency, leakage, etc. are checked.
2 Along with the above check, the ambient temperature is detected by a temperature sensor.
3 Next, connect the controller terminals to the connector pins of the joint.
4 Apply a minute voltage across the connector pin and measure the resistance value R1 of the heating wire.
5 The energization time t1 is set by comparing the resistance value R1 with a preset Rt diagram.
6 After the energization time t1 is set, or simultaneously with the setting, the energization time t2 is set by adding correction according to the environmental temperature. The energization time t2 is obtained by the following equation, for example. t2 = t1 × {1− (ambient temperature−23 ° C.) × temperature correction coefficient} The temperature correction coefficient is preferably about 0.006 to 0.01, and more preferably 0.008.
Actually, if t2 is simultaneously obtained by the above equation, the energization time t1 need not be set. If correction based on the environmental temperature is not applied, the energization may be stopped at time t1.
7 Turn on the fusion start button.
8 Take the voltage between the connector pins again at a relatively early time (within about 5 seconds) while energizing the fusion current (5.5 A), and measure the resistance value R2 at this time.
9 Compare the initial resistance value R1 and the resistance value R2 at the time of fusion.
10 When R1 ≠ R2 (with allowance of 5%), an alarm signal is issued as an abnormality and the buzzer sounds continuously.
11 When R1 = R2 (with allowance of 5%), continue energization.
12 When the energization time t2 has elapsed, the energization is stopped. And the buzzer of fusion completion is sounded intermittently.
As described above, the control of the energization time is simplified in terms of control because the time is set based on the resistance value of the heating wire without identifying the type diameter of the joint.
[0028]
【The invention's effect】
According to the present invention, the direct energization time is obtained from the electric resistance of the heating wire of each joint without distinction of the type diameter, and the optimum fusion energy is automatically given. Stable fusion splicing can be performed. In addition, the control becomes simple and a simple electrofusion apparatus is obtained.
In addition, by making the heating capacity per fusion splicing port the same for both the two joints and one joint, the electric fusion joint can be welded according to the fusion area and thickness of the joint and pipe. Energy can be imparted.
[Brief description of the drawings]
FIG. 1 is an Rt diagram illustrating a relationship between an electrical resistance R and an energization time t for explaining an embodiment of an energization time control method of the present invention.
FIG. 2 is an Rt diagram of the second embodiment.
FIG. 3 is an Rt diagram of the third embodiment.
FIG. 4 is a cross-sectional view of an electric fusion joint ( socket joint ) .
FIG. 5 is a cross-sectional view of an electric fusion joint ( cap joint ) .
FIG. 6 is a cross-sectional view of an electric fusion joint ( cap joint ) .
FIG. 7 is a cross-sectional view of an electric fusion joint ( cap joint ) .
FIG. 8 is a cross-sectional view of an electric fusion joint ( adapter joint ) .
FIG. 9 is a block diagram showing an embodiment of the electrofusion apparatus (controller) of the present invention.
FIG. 10 is a flowchart showing an example of fusion control.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Resin pipe 10 Socket joint main body 13, 23, 33, 43 Heating wire 13c, 23c, 33c, 43c, 63c Heating wire other than the fusion splicing port 20, 30, 40 Cap joint main body 22 Cap closing wall 36 Metal Ring 46 Heat insulating material 50 Adapter joint body 52 Female thread connection port 57 Insert with female thread 60 Electric fusion device (controller)
66, 69 Resistance value setting unit 67 Rt diagram storage unit 68 Energization time setting unit 70 Temperature sensor 71 Comparison unit 72 Energization stop command unit 73 Energization start unit 74 Alarm unit (buzzer)
75 External display

Claims (6)

In the energization time control method by the electric fusion apparatus of the electric fusion joint in which the heating wire is embedded,
In the Rt diagram storage unit mounted on the electrofusion apparatus, the energization time t has a one-to-one correspondence with the electrical resistance value R of the heating wire provided in the electrofusion joint. Rt diagram is prepared in advance,
On the other hand, measuring the ambient temperature by the ambient temperature measuring unit,
Attaching the connector of the electrofusion apparatus to the connector pin provided at the end of the heating wire of the electrofusion joint;
Applying a minute voltage to the heating wire and obtaining a resistance value R1 of the heating wire of the joint to be fused by the resistance value setting unit;
The energization time setting unit obtains the energization time t1 for the joint by comparing the electrical resistance value R1 with the electrical resistance value stored in the Rt diagram storage unit, and the energization time according to the ambient temperature. setting an energization time t2 in which t1 is corrected;
Obtaining a resistance value R2 during energization after starting energization by a resistance value setting unit;
A step of comparing the electric resistance value R1 and the electric resistance value R2 by a comparison unit;
When a difference between the electric resistance value R1 and the electric resistance value R2 is within a predetermined range, a signal to stop energization is transmitted after the energization time t2, or the electric resistance value Transmitting a signal for issuing an alarm and a signal for stopping energization when the difference between R1 and the electric resistance value R2 is outside a predetermined range;
An energization time control method for an electrofusion joint, comprising:   The said energization time setting part adjusts at least one of an energization time, an electric current value, and a voltage value according to the said ambient temperature, and correct | amends the electrical energy required for a fusion | melting. Energizing time control method for electric fusion joints.   3. The energization time control method for an electric fusion joint according to claim 1 or 2, wherein the Rt diagram shows a relationship in which the electric resistance value R and the energization time t monotonously increase or monotonously decrease. .   The Rt diagram is a combination of two or more diagrams having a monotonically increasing relationship between the electrical resistance value R and the energization time t, or two or more combinations of diagrams having a monotonically decreasing relationship. The energization time control method for an electrofusion joint according to claim 1 or 2, characterized in that:   3. The energization time control method for an electrofusion joint according to claim 1, wherein the Rt diagram is a combination of monotonically increasing or monotonically decreasing diagrams each having a different slope. An Rt diagram storage unit in which an Rt diagram having a relationship in which the energization time t has a one-to-one correspondence with the electric resistance value R of the heating wire provided in the electric fusion joint is stored;
A resistance value measurement unit for obtaining the electric resistance value R1 of the heating wire of the joint to be fused;
An energization time setting unit that sets the energization time t1 by comparing the Rt diagram and the electrical resistance value R1;
An ambient temperature measurement unit for measuring the ambient temperature;
An energization time setting unit that corrects the energization time t1 in accordance with the ambient temperature and sets the energization time t2.
A comparison unit that measures the electrical resistance value R2 during energization and compares the electrical resistance value R1 and the electrical resistance value R2,
An alarm unit that issues an alarm when the electrical resistance values R1 and R2 are outside a predetermined range;
An energization start command section for instructing energization start; and
When the electrical resistance values R1 and R2 are within a predetermined range, energization is continued, and when the electrical resistance values R1 and R2 are outside the predetermined range, energization is stopped and an alarm signal is transmitted to the alarm unit. And
An electrofusion apparatus, wherein each of the units is placed in and controlled by a microcomputer CPU.

Images