JP2570527B2 - Electric fusion control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic pipe in which a heating wire is buried near the axial end faces of first and second plastic pipes, and a desired electric power is supplied to the heating wire. The present invention relates to an electric fusion control device (hereinafter, also referred to as a fusion control device for an electric fusion joint) for fusing between joints and connecting both plastics.

[0002]

2. Description of the Related Art As a fusion control method when two plastic tubes are fused by an electric fusion joint, there is a method described below.

A first technique (temperature detection method) is to insert a plastic pipe into a plastic joint and measure the temperature rise of the plastic pipe and the plastic joint when the heating wire is energized, and these temperatures reach a set temperature. Sometimes, energization is stopped (JP-A-63-111394).

In a second method (time detection method), the size of a plastic tube is identified from a resistance value before fusion, an appropriate fusion time is determined in consideration of an environmental temperature, and this is set in an energization stop timer. This is a method of operating this timer.

A third method (pressure detection method) is to provide a pressure detection hole in a plastic joint, insert a pressure sensor into the hole, detect a swelling at the bottom of the hole with the pressure sensor, and thereby use the melting point. Method for detecting arrival
-111393).

The fourth method (pressure detection time detection method) is as follows.
The entire time that the heating wire is energized is divided into the first half and the second half, and the power is dropped in the second half, and the timing of this drop is detected by the pressure sensor when the pressure rise due to thermal expansion of the molten resin that has been heated and melted The method is performed when the pressure reaches a preset pressure (Japanese Patent Laid-Open No. 2-231).
127 gazette). Further, the energizing time and the power switching time are set for each type of joint, and the joint is provided with identification means for displaying the type of the joint, and the joint is determined based on information read by the sensor from the identification means. (Japanese Unexamined Patent Application Publication No. Hei 2-231127).
No.).

Although the above-described methods are the basic operations of the fusion control method, it is most important to confirm that the plastic pipe and the plastic joint are completely fused together. In each of the methods, the swelling of the resin is detected by the pressure sensor, and the completion of the fusion is recognized by this.

[0008]

The above-mentioned methods have the following problems.

In the first method, a swell is detected by a pressure sensor. However, the swell depends on the temperature and the pressure, and it is difficult to control the swell in an appropriate range only by the temperature. In other words, it is difficult to ensure that the pipes are raised when the power supply is stopped because of lack of legality against pressure fluctuation due to the difference in clearance between the left and right plastic pipes.

In the second method, there is no guarantee that both the pressure detectors are raised when the power supply is stopped, as compared with the first method, and an error may occur due to humidity or the like when reading the resistance value.

Further, in both the first and second methods, it is necessary to design the swelling of the resin at the same time as stopping the energization within the appropriate range of the performance of the fused portion while considering the fusion conditions. Requires a lot of development time.

In the third method, when a swell is detected by one of the pressure sensors (during operation), energization of the heating wire is stopped, and the swell may not be generated by the other pressure sensor. This is because, as a preparation for fusion, if the joint on one side is improperly inserted, the resin does not rise, the energizing state of the heating wire continues forever, and there is a risk that it may lead to a fire due to smoking etc. If any of the sensors operates, it is necessary to stop energizing the heating wire. For this reason, even if there is no hindrance in the fusing performance, one side with no swelling must be judged to be a fusing defect. This problem arises when the left and right plastic sock tubes are inserted (clearance, etc.).

In the fourth method, although the rise of the resin is detected in order to recognize the completion of the fusion, the rise of the resin at the time of stopping the supply of electricity, that is, the plastic pipe is not used as the condition for stopping the supply of the heating wire. It is not known whether or not the fusion has been performed reliably.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fusion control apparatus for an electric fusion joint which can reliably control fusion between plastic pipes and easily manage the stoppage of energization of an operator.

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

According to the present invention, in order to achieve the above object, an invention according to claim 1 is provided in which the first and second plastic pipes to be connected come into contact with the outer peripheral surfaces near the end faces in the axial direction. A plastic joint in which a heating wire is buried, supplying desired electric power to the heating wire and fusing the outer peripheral surface of each plastic pipe to the inner peripheral surface of the joint. A first signal for outputting a detection signal when a rise in pressure due to thermal expansion of plastic melted and heated during application of a heating wire is detected. And the second pressure detecting means, and outputs from the first and second pressure detecting means, and when a detection signal is generated from one of the pressure detecting means, within a predetermined time from that point in time. Other pressure detection A determination means for determining whether or not a detection signal is generated from the step, and outputting a signal when a detection signal is generated from the other pressure detection means within a predetermined time; Power supply stopping means for stopping the supplied power. Next, claim 2
The invention corresponding to (1) is such that the first and second plastic tubes to be connected come into contact with the outer peripheral surfaces near the axial end surfaces thereof,
A plastic joint having a heating wire embedded therein is provided, and a desired power is supplied to the heating wire to fuse the plastic pipe outer peripheral surface and the joint inner peripheral surface. When an increase in pressure due to thermal expansion of the plastic that has been heated and melted during energization of the heating wire is detected, and is disposed in each of the insertion holes formed in the attachment portion surface,
First and second pressure detecting means for outputting a detection signal;
When the output from the first and second pressure detecting means is input and a detection signal is generated from one of the pressure detecting means, and a state in which no detection signal is generated from the other pressure detecting means, A determination unit is provided for determining whether to continue, and outputting a signal when the state is continued, and a power supply stopping unit for stopping power supplied to the heating wire when receiving a signal from the determination unit. Further, the invention according to claim 3 is the invention according to claim 1, wherein when the power supply stop means starts operating, a subtraction operation is started from a preset completion time of fusion-hardening of the plastic pipe, and Removing time notifying means for notifying the result of the subtraction as the removing time of the connected plastic pipe.

[0026]

[0027]

[0028]

According to the present invention, the following effects can be obtained. That is, according to the invention corresponding to claim 1, when the detection signals are generated from both the pressure detecting means, the electric power supplied to the heating wire is stopped, so that the fusion of the plastic pipe is reliably performed. Can be confirmed. This is because, when the fusion is performed normally, the resin surely rises in the sensor insertion hole of the plastic joint, and the detection signals from both pressure sensors are generated within a predetermined time. According to the second aspect of the present invention, when a detection signal is generated from one of the two pressure detection means and a detection signal is not generated from the other for a predetermined time, the power supplied to the heating wire is stopped. As a result, a function of preventing overheating of the heating wire is obtained, and troubles such as smoking can be prevented. Further, according to the third aspect of the present invention, the time until the plastic tube is completely fused and hardened after completion of energization of the heating wire, that is, the removal time of the plastic tube, is reported, so that the power of the fusion worker can be supplied. Management after stoppage becomes easier.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. Examples of the schematic configuration of the present invention are shown in FIGS. FIG. 1 is a block diagram showing a schematic configuration example of the present invention. As shown in FIG.
And a plastic joint 1 having a heating wire embedded in the outer peripheral surface thereof near the contact surface of the axial end surface of the second plastic pipe.
A power supply detecting means 60 for detecting that power has been supplied to the heating wire, in an electric fusion joint for supplying desired power to the heating wire and fusing the contact surface; First and second sensor insertion holes formed on both sides of the joint 1 with the contact surface interposed therebetween,

A first signal is provided in each of the sensor insertion holes, and outputs a detection signal when a rise in pressure due to thermal expansion of the plastic which has been heated and melted during the energization of the heating wire is detected.
And second pressure detecting means 40, 50;

The outputs from the pressure detecting means 40 and 50 and the output from the energization detecting means 60 are input, and the state in which the detection signals from both the pressure detecting means 40 and 50 are generated is determined.
Determining means 70 for outputting a determination signal;
And a power supply stopping means 80 for stopping the power supplied to the heating wire when a signal is generated.

FIG. 2 is a block diagram showing another schematic configuration example of the present invention. As shown in the figure, a plastic joint 1 having a heating wire buried in an outer peripheral surface thereof is disposed near a contact surface of an end face in an axial direction of a first and a second plastic pipe to be fused to each other. A power supply detecting means 60 for detecting that power is supplied to the heating wire, and sandwiching the contact surface between the plastic joints 1 in an electric fusion joint for supplying a desired power to the contact surface and fusing the contact surface. First and second sensor insertion holes respectively formed on both sides with

The first and second sensors are provided in the first and second sensor insertion holes, and output a detection signal when a rise in pressure due to thermal expansion of the resin melted by heating while the heating wire is energized is detected. 2, pressure detection means 40, 50;

The outputs from the pressure detecting means 40 and 50 and the power supply detecting means 60 are inputted, and
0, 50, when a detection signal is generated, and it is determined whether or not a state in which no detection signal is generated from another pressure detection means continues. 90,

When an output is generated from the determination means 90,
Start counting, count up after a predetermined time has elapsed,
Timer means 100 for detecting the output continuation time from the judgment means 90;

When a signal is generated from the timer means 100, a power supply stopping means 80 for stopping the power supplied to the heating wire, and a fusion failure detection means 8 for detecting a fusion failure.
5 is provided.

FIG. 3 is a block diagram showing a further schematic configuration example of the present invention. As shown in the figure, a plastic joint 1 having a heating wire buried in an outer peripheral surface thereof is disposed near a contact surface of an end face in an axial direction of a first and a second plastic pipe to be fused to each other. Power supply detecting means 60 for detecting that power is supplied to the heating wire in an electric fusion joint for supplying desired power to the contact surface and fusing the contact surface.
First and second sensor insertion holes respectively formed on both sides of the plastic joint 1 with the contact surface interposed therebetween;

A first signal is provided in each of the sensor insertion holes, and outputs a detection signal when a rise in pressure due to thermal expansion of the plastic that has been heated and melted during the energization of the heating wire is detected.
And second pressure detecting means 40, 50;

The outputs from the pressure detecting means 40 and 50 and the power supply detecting means 60 are input, and the state in which the detection signals from both the pressure detecting means 40 and 50 are generated is determined.
Determining means 70 for outputting a determination signal;
Power supply stopping means 80 for stopping the power supplied to the heating wire when a signal from

When the power supply stopping means 80 starts operating, the plastic pipe starts subtraction operation from the fusion hardening completion time set in advance, and the removal time notifying means 110 for notifying the removal time of the plastic joint 1 is provided. It is provided with. Although it is described here that the plastic joint 1 is removed, strictly speaking, it means removing the entire plastic pipe including both plastic pipes to be connected to the plastic joint, and the same applies to the following.

FIG. 4 is a sectional view showing the structure of the plastic joint 1 according to the embodiment of the present invention described above, and FIG. 5 is a diagram showing the schematic structure of the control device 2 for the plastic joint 1 in FIG. In the plastic joint 1, a heating wire 15 for heat generation is embedded in the inner peripheral surface of the joint body 10, and both ends of the heating wire 15 are electrically connected to the connector pins 11 and 12, respectively. It is exposed outside the main body 10 and can be electrically connected to an external power supply. Sensor insertion holes 13 and 14 are formed near the connector pins 11 and 12 of the joint body 10, respectively. Note that 16
a and 16b are plastic pipes, and 17 is a pipe stopper.

The control device 2 allows the connector 21 electrically connected to the cable 31 to be inserted and connected to the connector pins 11 and 12, respectively, and to be inserted into the pressure sensor insertion holes 13 and 14, respectively. Pressure sensor 22
a and 22b are fixed. In the control box 20, FIG.
, A power switch 23 for turning the power supply 23 on and off, a current monitor 26 for detecting that the input switch 24 is turned on, a timer switch 25 for counting the time after the start of energization, and a pressure sensor 22a, 2
2b, a current or voltage monitor 27 for detecting whether or not any of the pressure sensors 22b has been operated;
a and 22b detect that both have operated, the power supply 2
When it is detected by the monitor 27 that both the stop switch 28 for stopping the power supply from the power supply 3 and the pressure sensors 22a and 22b have been operated, the subtraction operation is started, and the plastic tubes 16a and 16b set in advance are melted. A removal explicit timer switch 29 that subtracts from the time of completion of the hardening and displays the joint removal time, a timer switch having a clock function when a signal is input from the current monitor 26 and the monitor 27 and a signal is input from the current monitor 26 2
5 and remove explicit timer switch 2
9 is set, and when a signal from the monitor 27 determines that only one of the pressure sensors 22a and 22b is operating, a microcomputer (CPU) 30 that gives a cut-off command to the input switch 24. It is configured.

The fusing control method in such a configuration will be described with reference to the flowchart of FIG. Here, a plastic pipe 1 to be fused to each other in advance is used.
The plastic joint 1 is provided on the outer peripheral surfaces of 6a and 16b in FIG.
The connector pin 1 is set as shown in FIG.
1 and 12, connectors 21 are respectively inserted and connected, and pressure sensors 22a and 22 are inserted into sensor insertion holes 13 and 14, respectively.
It is assumed that b has been inserted. In this standby state (S8), when the input switch 24 is closed,
The current flowing through the heating wire 15 is detected by the current monitor 26, and the detection signal is used in the CPU 30 to determine whether power is supplied to the heating wire 15 (S1). here,
When it is determined that power is supplied to the heating wire 15, the CPU 3
The power supply duration time is counted by the clock function within 0, and the timer switch 25 and the removal explicit timer switch 29 start operating respectively (S2). When a predetermined time has elapsed, the bottoms of the sensor insertion holes 13 and 14 of the plastic joint 10 rise, and a signal is generated from the monitor 27. This signal is input to the CPU 30, where it is determined whether the pressure sensors 22a and 22b have operated together. Is determined (S
3). If it is determined in S3 that both the pressure sensors 22a and 22b have operated, an open command is given to the stop switch 28 (S4), and the power supply to the heating wire 15 is stopped (S4).
5).

In this state, the plastic tubes 16a, 16
It is determined that b is fused. This is because when the plastic tubes 16a and 16b are not securely fused, no swelling occurs at the bottoms of the sensor insertion holes 13 and 14, so that the pressure sensors 22a and 22b do not rise.
From the detection signal.

In step S5, when the power supply is stopped, the removal explicit timer switch 29 is operated, and the preset removal remaining time is sequentially reduced and displayed (S6).
When the set time has elapsed, the plastic joint 1 is removed by the welding operator (S7). In this manner, the number of seconds after which the remaining removal time should be held is displayed by the removal explicit timer switch 29, so that the point that has conventionally caused the welding operator to be frustrated is eliminated.

Conventionally, there has been a configuration in which the melting state is displayed on a temperature monitor (JP-A-1-17884).
No. 37). In this case, since only the current temperature of the resin is displayed, it is not known from the displayed temperature how long the resin (plastic) will be cooled.

Immediately after the power supply is stopped in step S5, the fusion interface is in a molten state. Applying a force in this state has a great effect on the fusion performance. For this reason, conventionally, the determination of the predetermined time is left to the judgment of the welding operator himself / herself.

In S3, the pressure sensor 22
a and 22b do not operate, for example, the pressure sensor 22a
If only a predetermined time has elapsed (S9), a power supply stop command is given to the input switch 24 as an overheat prevention function (S10). In S3, it is determined whether one of the pressure sensors 22a and 22b has operated based on a change in the current or voltage of the monitor 27 by the CPU.
30 determines.

Here, the timer switch 25 for stopping power supply,
The removal explicit timer switch 29 will be specifically described. 1) The set value of the timer switch 25 is set as follows. The current supply to the heating wire is started, and the pressure sensors 22a, 22b
Let t1 be the time during which either of them operates. 2) Activate the timer switch 25 for stopping power supply, and set to stop power supply at α × t1 from the time point t1 described above. Specific examples of α are 0.05 to 0.5.

3) The set value of the removal explicit timer switch 29 is set as follows. Β × t from the time t1
Displays a message indicating that removal is prohibited during 1 For example, it is possible to display the remaining seconds. β is, for example, 0.25
2.0 4) The energization is stopped when the other pressure sensor operates.
Perform in 2. 5) When the pressure sensor does not operate in 4), the energization is stopped by the timer set in the item 2) at the time of t1 × (1 + α) from the start of energization. 6) Removal explicit timer switch 2 set in 3)
9 indicates a removable signal.

As described above, the pressure sensors 22a and 22b
When the detection signal is generated together from the above, the electric power to be supplied to the heating wire 15 is stopped.
It can be confirmed that the fusion was reliably performed. This is because, when the fusion is performed normally, the plastic swells in the sensor insertion holes 13 and 14 of the plastic joint 1 without fail.

Further, of the two pressure sensors 22a and 22b,
When the detection signal is generated from one side and the detection signal is not generated from the other side for a predetermined time, the power supplied to the heating wire 15 is stopped. As a result, the function of preventing overheating of the heating wire is obtained, and the generation of smoke or the like is obtained. Trouble can be prevented.

Further, the time until the plastic pipes 16a and 16b are completely fused and hardened after the heating wire 15 has been energized, that is, the removal time of the plastic joint 1, is notified by the removal explicit timer switch 29. It becomes easy for the worker to control the power supply after the power supply is stopped.

[0054]

According to the present invention, it is possible to provide a fusion splicing control device for an electric fusion joint which can reliably control fusion of plastic pipes to each other and can easily manage the stopping of energization of an operator.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration example of the present invention.

FIG. 2 is a block diagram showing another schematic configuration example of the present invention.

FIG. 3 is a block diagram showing still another schematic configuration example of the present invention.

FIG. 4 is a sectional view showing an example of the plastic tube of the present invention.

FIG. 5 is a diagram showing a schematic configuration of a plastic pipe and a control device of the present invention.

FIG. 6 is a block diagram showing one embodiment of the present invention.

FIG. 7 is a flowchart for explaining the operation of FIG. 6;

[Explanation of symbols]

1: plastic joint, 13, 14: sensor insertion hole, 4
0, 50 ... pressure detecting means, 60 ... energization detecting means, 70 ...
State determination means, 80: power supply stop means, 90: state determination means, 100: timer means, 110: removal time notification means.

Claims (3)

(57) [Claims] 1. A plastic joint in which a heating wire is embedded so as to contact an outer peripheral surface near an axial end face of a first and a second plastic pipe to be connected, and a desired electric power is supplied to the heating wire. An electric fusion control device for supplying the plastic pipe outer peripheral surface and the joint inner peripheral surface by supplying the plastic pipe outer peripheral surface and the joint inner peripheral surface; First and second outputting a detection signal when detecting an increase in pressure due to thermal expansion of plastic heated and melted during energization of the heating wire.
And the output from the first and second pressure detecting means is input, and when a detection signal is generated from one of the pressure detecting means, the other pressure is detected within a predetermined time from that time. A determination unit that determines whether a detection signal is generated from the detection unit, and outputs a signal when a detection signal is generated from the other pressure detection unit within the predetermined time; and when a signal from the determination unit is received. An electric fusion control device comprising: a power supply stopping unit configured to stop power supplied to the heating wire. 2. A plastic joint in which a heating wire is embedded so as to contact an outer peripheral surface near an axial end face of the first and second plastic pipes to be connected, and a desired electric power is supplied to the heating wire. An electric fusion control device for supplying the plastic pipe outer peripheral surface and the joint inner peripheral surface by supplying the plastic pipe outer peripheral surface and the joint inner peripheral surface; First and second outputting a detection signal when detecting an increase in pressure due to thermal expansion of plastic heated and melted during energization of the heating wire.
The output from the first and second pressure detecting means is input, and when a detection signal is generated from one of the pressure detecting means, the pressure is detected from the other pressure detecting means. A determination unit that determines whether a state in which no signal occurs continues and outputs a signal when the state continues; and a power supply stop that stops power supplied to the heating wire when a signal from the determination unit is received. Means for electrofusion control comprising: 3. The electrofusion control device according to claim 1, wherein when the power supply stopping means starts operating, a subtraction operation is started from a preset fusion hardening completion time of the plastic pipe, and An electrofusion control device provided with a removal time notifying means for notifying a result of the subtraction as a removal time of the connected plastic pipe.