JPH028573B2 - - Google Patents

Abstract

PURPOSE:To easily perform butt welding with good efficiency all the time by providing a control circuit to operate all the processes smoothly at preset pressing forces and time. CONSTITUTION:The ends of paired thermoplastic resin tubes to be butt-welded are polished, a heater is inserted between both the tubes, and the end faces of both the tubes are pressingly contacted with the heating face of the heater through an operating lever. When the pressing force through a torque wrench reaches a given set pressure, the timer 87 of a controller 85 is started through a start switch 86. At the same time, a pressing and welding process display lamp 51 is lighted through a drive circuit 50, and at the same time solenoids 43 and 44 are demagnetized. Thereby, a moving bar is fixed by a brake plunger, and the pressing forces of both the tubes are held. Under the condition, the pressing and welding process is performed for a given period of time by the timer 87 and the following processes, a heating and holding process, a heater removal process, a welding process, and a cooling process, are continuously performed at set pressing force and time. Better butt welding can thus be performed with good efficiency by an easy operation all the time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a butt fusion machine for melting and butt welding the ends of thermoplastic synthetic resin pipes.

In a conventional butt fusion machine, the ends of a pair of thermoplastic synthetic resin tubes to be butt welded are supported on the same axis, and the end surfaces of both tubes are pressed against a heater by operating an operating handle to maintain a constant welding temperature. After heating and melting for a period of time, the ends of both tubes are pressed together and fused together. Factors that affect the performance of welding thermoplastic synthetic resin tubes using a butt fusion machine include the heating temperature and pressure applied by the heater, as well as various factors such as the heating process, heater removal process, crimping process, and cooling process. One example is the working time of the process. However, conventionally, the working time of each process is measured using a wristwatch or the like while setting the pressing force using a torque wrench or removing the heater. Therefore, the working time and pressure of each step may vary depending on the operator, or the welding procedure itself may be incorrect. Therefore, if the joint is not inspected after the welding operation is completed, there is a risk that the welded state may remain poor.

The purpose of the present invention is to solve the above-mentioned technical problems,
To provide a butt fusion machine which can always obtain a good fusion state regardless of the operator.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of one embodiment of the present invention.
The ends of a pair of thermoplastic synthetic resin pipes, for example, polyethylene pipes 1 and 2, to be butt welded are connected to a clamp member 4 fixed to one end of a base 3, and are welded on the base 3 toward the clamp member 4. They are each clamped with the same axis line by a clamp member 5 which is supported so as to be movable toward and away from each other. When butting both tubes 1 and 2, the end surfaces of both tubes 1 and 2 are ground with a grinder 7.
After grinding, the grinder 7 is removed. Next, a heater 6 (see FIG. 8, which will be described later) is interposed between both the clamp members 4 and 5, and a welding operation is performed according to the procedure described later.

The clamp member 4 is pivoted by a pin (not shown) parallel to the axis of the tube 1 and can be opened and closed upward.
On the side opposite to the pin with respect to the axis of the tube 1, the end of the locking piece 11 is pivotally supported by a pin 10 parallel to the pin. The pipe 1 is integrally clamped to the clamp member 4 by threading a bolt 12 threaded onto the end of the lock piece 11 opposite to the pin 10 toward the locking protrusion 13.

This clamp member 4 is fixedly provided at one end of the base 3. A pair of guide rods 15 parallel to the axial extension of the tube 1 are provided between one end and the other end of the base 3.
is provided, and the clamp member 5 is connected to a guide rod 15.
It is movable along the

The clamp member 5 is pivoted by a pin (not shown) parallel to the axis of the tube 2 and can be opened and closed upward. On the opposite side of the axis of the tube 2 from the pin, the end of the locking piece 17 is pivoted by a pin 16 parallel to the pin. A bolt 18 is threaded onto the end of the lock piece 17 opposite to the pin 16. By threading this bolt 18 toward the locking protrusion 19, the tube 2 is integrally attached to the clamp member 5.

The grinder 7 is provided near the clamp member 4 and can be opened upward. That is, the grinding machine 7 is equipped with a swinging piece 21 that is pivotally supported by a pin 20 parallel to the pins 10 and 16 described above, and a locking bolt 22 screwed on the swinging piece 21 is connected to a locking protrusion. 23, it is locked in the position shown in the first figure. In this state, the end faces of both tubes 1 and 2 are ground. When the lock is released, the grinding machine 7 can be opened upwards. The heater 6 can be placed in the area where the grinder 7 was located when the grinder 7 was opened.

Pressure means 24 is provided for displacing the clamp member 5 toward the clamp member 4 to press the end surfaces of both tubes 1 and 2 against heater 6 and for pressing the end surfaces of both tubes 1 and 2 against each other. This pressurizing means 24 is
A support shaft 25 rotatably penetrates the clamp member 5 in a direction perpendicular to the pipe 2 and projects outward from the clamp member 5.
a link 26 that extends downward with one end pivotally supported on the protruding end of the support shaft 25; and a link 26 that has one end pivotally supported on one end of the base 3 via a pin 27 parallel to the support shaft and the other. a link 29 whose end is connected to the other end of the link 26 via a pin 28 parallel to the pin 27;
and a drive rod 30 whose lower end is fixed at right angles to the support shaft 25 and extends upward.

In this pressurizing means 24, by rotating the drive rod 30 around the support shaft 25 in the counterclockwise direction in FIG. 1, the clamp member 5 moves toward the clamp member 4 along the guide rod 15. .

A torque wrench 31 is provided to measure the pressing force exerted by the pressing means 24. As shown in FIG. 2, this torque wrench 31 includes a pointer 34 fixed to the upper end of a drive rod 30, and an operating rod made of a flexible material that is fixed in the middle of the drive rod 30 and extends upward. 33, and a scale plate 32 fixed to the operating rod 33.
It consists of In this torque wrench 31, when the operating rod 33 is grasped and pressed in the direction of the arrow 35 (see FIG. 1), the operating rod 33 presses the drive rod 30 while being bent, thereby causing the clamp member 5 to It is approached towards 4. The pressing force at that time is indicated by a pointer 34 on the scale plate 32.

In relation to the torque wrench 31, the torque wrench 3
A pressing force holding means 36 is provided to keep the pressing force set by 1 constant. This pressing force holding means 36 includes a guide cylinder 38 which is pivotally supported at the other end of the base 3 by a pin 37 parallel to the support shaft 25 and extends upward, and a guide cylinder 38 which is movably inserted into the guide cylinder 38. It includes a rod 39 and a connecting member 41 that is pivotally supported at the upper end of the moving rod 39 by a pin 40 having an axis parallel to the pin 37 and is connected to the operating rod 33 so as to be movable along the axis. .

A lock mechanism 42 is provided in the pressing force holding means 36 for fixing the relative displacement position of the moving rod 39 with respect to the guide tube 38. This lock mechanism 42
By fixing the position of the movable rod 39, it becomes possible to maintain the angular displacement position of the drive rod 30 and therefore the pressure set by the torque wrench 31 constant.

FIG. 3 is a cross-sectional view of the locking mechanism 42.
This locking mechanism 42 includes first and second solenoids 4 provided at the upper part of the guide tube 38 at right angles to the axis.
3,44. First and second solenoid 4
3, 44 first and second plungers 45, 46
The moving rod 39 passes through the guide tube 38 at right angles to the axis.
can come into contact with the surface of Moreover, the first plunger 45 of the first solenoid 43 is connected to the first spring 47.
The spring force of the first spring 47 is biased toward the movable rod 39, and the spring force of the first spring 47 is selected to be relatively large. Therefore, when the first solenoid 43 is demagnetized, the first plunger 45 abuts against the moving rod 39 with a relatively large force. Further, the second plunger 46 of the second solenoid 44 is connected to the second plunger 46 of the second solenoid 44.
The second spring 48 is biased in a direction approaching the moving rod 39 by the spring force of the second spring 48, and the spring force of the second spring 48 is selected to be relatively small. Therefore, when the second solenoid 44 is demagnetized, the second plunger 4
6 abuts against the moving rod 39 with a relatively small force.

According to the present invention, a pressure melting step using a heater,
A control circuit as shown in FIG. 4 is provided to smoothly and continuously operate the heating and holding process, the heater removal process, the crimping process, and the cooling process at preset pressing forces and times. Control means 85
A start signal is given from the start switch 86, and the timer 87 starts operating in response. The control means 85, according to a predetermined procedure,
The first and second solenoids 43 and 44 are excited via the drive circuits 88 and 89, and the first, second, third and fourth indicator lights 51, 52, 53 and 54 are excited via the drive circuit 50. The first and second buzzers 5 are turned on via drive circuits 55 and 56.
7 and 58 are driven to blow.

The start switch 86 is provided in association with the torque wrench 31, for example. That is, referring to FIGS. 5 and 6, a contact 59 is fixedly provided at a predetermined scale position on the scale plate 32, and a contact 60 that can come into contact with the contact 59 is provided on the pointer 34. provided. Note that the scale plate 32 is
It is made of non-conductive material. Contact 59
The position where is fixed is selected, for example, at a position of 1.3Kg/cm ² . This value is the set pressure when pressing both tubes 1 and 2 against the heater and when pressing both tubes 1 and 2 against each other. Note that since the set pushing force differs depending on the size of the tubes 1 and 2, the contact point 59
may be fixed at a position corresponding to the target size, and when a plurality of sizes are to be targeted, the contacts 59 may be arranged at a plurality of positions.

The operation will be explained with reference to FIG. In addition, the seventh
In the figure, the first to fourth indicator lights 51 to 54, the first
The second buzzers 57 and 58 indicate a lighting and blowing state at a high level, and the first and second solenoids 43 and 44 indicate an excited state at a high level. When a power source (not shown) is turned on to perform the fusion work, the first and second solenoids 43 and 44 are excited. Therefore, the moving rod 39 is connected to the guide tube 38.
The operating rod 33 can be freely rotated.

In this state, first, as shown in Fig. 1, the grinding machine 7
After grinding the end faces of the tubes 1 and 2 by the grinder 7
Remove. Next, as shown in FIG.
A heater 6 is interposed between the two. This heater 6 has heating surfaces 6a and 6b perpendicular to the axes of both tubes 1 and 2. In this state, by gripping the operating rod 33 and rotating it in the direction shown by the arrow 35, the tube 2 is moved from the tube 1.
The end surfaces of both tubes 1 and 2 are pressed against heating surfaces 6a and 6b. When this pressing pressure reaches, for example, 1.3 kg/cm ² , a start signal is given from the start switch 86 to the control means 85, and the timer 47 starts operating. At the same time, a first indicator light 5 for indicating the pressure melting process
1 lights up. Furthermore, the first and second solenoids 43 and 44 are demagnetized, so that the first and second plungers 45 and 46 are pressed against the surface of the moving rod 39 by the spring forces of the first and second springs 47 and 48. It will be done. Even if you release your hand from the operating rod 33 in this state, the position of the moving rod 39 is fixed, so the pressing force of both tubes 1 and 2 against the heater 6 is 1.3
Kg/cm ² is maintained. This pressurized melting process is set to a first set time T1 of, for example, 5 to 10 seconds.

When the first set time T1 has elapsed, the first indicator light 5
1 is turned off, and the second indicator light 52 for indicating the heating and holding process is turned on. Furthermore, the first solenoid 43 is energized and the first plunger 45 is drawn into the first solenoid 43 . Therefore,
The position of the moving rod 39 is determined by the relatively small spring force of the second spring 48.
The operating rod 33 rotates in the direction opposite to the arrow 35 until the spring force of the second spring 48 and the reaction force from the heater 6 are balanced. . In this balanced position, the pressing force on the heater 6 is, for example, 0.1 to 0.3 kg/
cm ² and the spring force of the second spring 48 is selected accordingly. This heating holding step is set to a second set time T2 of, for example, 40 seconds.

The heater removal step follows the heating holding step, and the first buzzer 57 is sounded intermittently from a predetermined time T', for example, 5 seconds before the end of the heating holding step, until the end of the heating holding step. Ru.
The first buzzer 57 allows the user to know that the heater removal process is approaching, and allows preparations for the heater removal process.

When the heating holding process is completed, the second solenoid 4
4 is energized, the second plunger 46 is drawn into the second solenoid 44, and the locked state by the locking mechanism 42 is released. Therefore, the pressing force on the heater 6 becomes zero. Further, when the heating holding process is completed, the second buzzer 58 is driven to continuously sound to notify that the heater removal process is now in progress. This heater removal process is set to a third set time T3, for example, 5 seconds.

Remove the heater 6 during the third set time T3,
By gripping the operating rod 33 again and rotating it in the direction of the arrow 35, the end surfaces of both tubes 1 and 2 are pressed against each other, and the crimping process is started. When the pressing force exerted by the operating rod 33 reaches 1.3 kg/cm ² , the start switch 86 is activated, thereby turning on the third indicator light 5 to indicate that the crimping process is in progress.
3 lights up. Furthermore, the first solenoid 43 is demagnetized, thereby causing the moving rod 39 to move toward the first spring 45.
fixed by a relatively large spring force of 1.3
A pressing force of Kg/cm ² is maintained, and both tubes 1 and 2 are crimped together. The time for this crimping process is the fourth set time T4
For example, it is set to 40 seconds.

When the fourth set time T4 has elapsed, the fourth indicator light 5
4 lights up to indicate that it is a cooling process, and the first solenoid 43 is demagnetized. As a result, the first plunger 45 is drawn into the first solenoid 43 in the locking mechanism 4a, and the movable rod 39 becomes free to move. Therefore, both pipes 1,
The mutual pressing force between the two becomes zero. The fifth set time T5 of such a cooling step is selected to be 180 seconds, for example.

When this cooling step is completed, the second buzzer 58 is sounded for, for example, 5 seconds to notify that the series of fusion steps have been completed.

Note that when the time longer than the third set time is spent removing the heater 6, the first solenoid 43 is demagnetized as shown by the broken line in FIG. Therefore, the movable rod 39 is fixed by the pressing force applied to the movable rod 39 by the first plunger 45, making it difficult to rotate the operating rod 33. By doing so, it is possible to prevent the deterioration of the fusing performance due to the long time it takes to remove the heater.

FIG. 9 is a front view showing a start switch 86 according to another embodiment of the present invention, and FIG. 10 is a side sectional view of FIG. 9. In this embodiment, a long hole 66 is formed in the scale plate 32 along the scale, and a protrusion 67 that passes through the long hole 66 and projects to the back side of the scale plate 32 is provided on the pointer 34. Further, on the back side of the scale plate 32, a proximity switch 68 is fixed at a preset scale position. The proximity switch 68 detects the proximity of the protrusion 67 and provides a start signal to the control means 85.

Note that a reed relay may be provided in place of the proximity switch 68, and a magnet may be provided in the pointer 34.

FIG. 11 is a sectional view of another embodiment of the present invention. In this embodiment, a start switch 70 is provided in association with the operating rod 33 of the torque wrench 31. That is, a guide shaft 71 is fixed to the operating rod 33 at right angles within its rotation plane, and a cylindrical operating handle 72 is fitted into the guide shaft 71 so as to be freely displaceable. Between the operating rod 33 and the operating handle 72,
A coil spring 73 surrounding the guide shaft 71 is interposed.

The start switch 70 is a limit switch, and is provided at a position where it is pressed by the operating handle 72 when the coil spring 73 is compressed to reach a predetermined set pressure, for example, a pressing force of 1.3 kg/cm ² . This also serves as a start switch. Note that a proximity switch may be provided in place of the limit switch, and a plurality of limit switches or proximity switches may be provided corresponding to a plurality of set pressures.

FIG. 12 shows a locking mechanism 7 according to another embodiment of the present invention.
5. FIG. The locking mechanism 75 of this embodiment includes a first rotary solenoid 76 and a second rotary solenoid 76.
A rotary solenoid 77 is provided, each solenoid 7
A first screw member 78 and a second screw member 79, which are screwed forward and backward by screws 6 and 77, are screwed into the guide cylinder 38. Each screw member 78, 79 is connected to the moving rod 39.
It extends perpendicularly to the axis of the moving rod 39 and can come into contact with the surface of the moving rod 39. Moreover, the rotation angle of the first rotary solenoid 76 is large, and therefore the movable rod 39 is fixed with a relatively large force. Also the second
The rotation angle of the rotary solenoid 77 is small,
Therefore, the moving rod 39 is fixed with a relatively small force. Such a lock mechanism 75 can also perform the same function as the lock mechanism 42 described above.

As another embodiment of the present invention, a single screw member screwed into the guide tube 38 may be rotated by a single stepping motor at two rotation angles, large and small. The movable rod 39 can also be fixed with two types of pressure, large and small.

In still another embodiment of the present invention, the protrusion of the tubes 1 and 2 from the clamp members 4 and 5 is kept constant, and the link 29 in the pressure means 24 and the guide tube 38 in the pressing force holding means 36 are Therefore, a start switch may be activated.

As described above, according to the present invention, it is possible to prevent the occurrence of defective fusion due to variations in time intervals and pressure, and errors in the fusion procedure, and to obtain a fused portion of stable quality. Furthermore, the fusing operation can be performed by a single operator, and since there is no need to monitor the present fusing machine especially after the crimping process, it is possible to perform the fusing process concurrently with other work, improving work efficiency. Furthermore, the fusing work can be performed by unskilled workers.

[Brief explanation of drawings]

1 is a front view of an embodiment of the present invention, FIG. 2 is a sectional view showing the torque wrench 31, FIG. 3 is a sectional view showing the locking mechanism 42, FIG. 4 is a block diagram showing the control circuit, and FIG. 5 is a front view showing the mounting position of the start switch 86, FIG. 6 is a right side view of FIG. 5, FIG. 7 is a timing chart for explaining the operation, and FIG. 1st
FIG. 9 is a front view showing a start switch 65 of another embodiment of the present invention;
10 is a side sectional view of FIG. 9, FIG. 11 is a sectional view showing a start switch of another embodiment of the invention, and FIG. 12 is a locking mechanism 75 of another embodiment of the invention. FIG. 1, 2...Pipe, 4, 5...Clamp member, 6...
... Heater, 24 ... Pressure means, 36 ... Pressing force holding means, 42, 75 ... Lock mechanism, 85 ... Control means, 86, 65, 70 ... Start switch, 87 ... Timer.

Claims (1)

[Claims] 1. The ends of a pair of thermoplastic synthetic resin tubes to be butt welded are clamped by a pair of clamp members, and both clamp members are brought close to each other by a pressurizing means, and the first setting to the heater is performed. In a butt fusion machine that butt-welds both tubes through a pressurized melting process using pressure, a heating holding process using a second set pressure, a heater removal process, a mutual crimping process for both pipes using a first set pressure, and a cooling process. , a pressing force holding means for holding the pressing force by the pressing force; and a holding force in the pressing force holding means is set to a first
and a lock mechanism that changes the pressure to a second set pressure and locks it, a start switch that detects when the pressurizing force by the pressurizing means reaches the first set pressure, and a timer that operates in response to a start signal from the start switch. and controlling the lock mechanism so that the pressure held by the pressing force holding means is the first set pressure in response to the input of the start signal, and the first set time set corresponding to the pressure melting process has elapsed. When the holding pressure by the pressing force holding means reaches the second
The locking mechanism is controlled so that the set pressure is reached, the locking function of the locking mechanism is released when the second set time corresponding to the heating holding process has elapsed, and the locking function is released within the third set time corresponding to the heater removal process. In response to input of the start signal from the switch, the locking mechanism is controlled so that the holding pressure by the pressing force holding means becomes the first set pressure, and when the fourth set time corresponding to the crimping process has elapsed. 1. A butt fusion machine comprising: control means for releasing the locking function of the locking mechanism. 2. The control means has a function of controlling a lock mechanism so as to stop the pressurizing operation of the pressurizing means when the heater removal process has exceeded a third set time. The butt fusion machine according to scope 1.