JPS6226189Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a pipe fusion machine for welding resin pipes (eg, polyethylene pipes or plastic pipes) to resin-made pipe joints such as sockets and saddles.

In recent years, resin pipes such as polyethylene have been increasingly used as gas pipes in place of conventional metal pipes. The resin pipes are connected to each other by heat fusion through resin pipe joints such as sockets (of various shapes such as straight or elbow) or saddles. That is, when fusing, for example, a socket to a resin pipe, a method is used in which the joint surfaces of the pipe and socket are heated and melted with a heater, and the heated and melted surfaces are crimped together. The thus crimped tube and socket are allowed to cool for a certain period of time and are then completely integrated into one piece. Pipe fusion machines used for such connection work are generally referred to as socket fusion machines or saddle fusion machines, depending on the type of pipe fusion machine, but the following explanation will be made using the socket fusion machine as an example for convenience. A socket fusion machine basically has a pipe clamp device that clamps a pipe and a socket clamp device (generally a pipe joint clamp device) that clamps a socket. Both clamp devices are connected by a pair of parallel guide rods. They are connected so that they can approach and separate from each other.

However, in the conventional fusion work, it is very important to control the heating and melting time using a heater and the time for pressing the molten surfaces together. Optimum values for these heat-melting times and crimping times are predetermined according to the pipe diameter, socket diameter, etc., and especially in the case of heat-melting times, fusion may occur even if the heat-melting time is longer or shorter than the predetermined optimum time. The reliability of the parts will be impaired, increasing the possibility that the product will be defective. However, the work procedure for socket welding is to place a heater between the opposing end surfaces of the pipe and socket to be welded, bring the pipe and socket closer together in the axial direction, and press them against the heater (generally, the pipe is Since the inner circumference of the socket is melted, the pipe is inserted into one end of the heater face attached to the heater, and the socket is fitted onto the outer circumference of the other end of the heater face. After the pipe and socket are heated for a predetermined period of time until the surfaces (surfaces) are melted, the pipe and socket are separated from the heater, and then the heater is quickly removed and the pipe and socket are moved toward each other again to press the molten surfaces together for a predetermined period of time. Since all the work is done manually, it is impossible for a single worker to do it. Therefore, a worker who manages the heating melting time and crimping time has traditionally been required separately from the worker who installs and removes the heater or crimps the pipe and socket, and therefore a minimum of two workers are required. Ta. If the crimping time is shorter than the predetermined value, the connection between the pipe and the socket will be incomplete, and if the heating time is longer than the predetermined time, not only will the melting range expand more than necessary, but the amount of melt will become too large. Furthermore, if the time is shorter than the predetermined time, a sufficient amount of melting cannot be obtained and welding becomes impossible. In practice, the heating time and crimping time are managed by relying on the primitive method of calling with a stopwatch, so that sometimes the stopwatch operator becomes distracted and the heating time exceeds a predetermined value. Furthermore, the need for a separate worker dedicated to time management also poses an undesirable problem in terms of labor saving and automation.

The purpose of this invention is to incorporate a lock mechanism that automatically controls heating work and crimping work into a machine, and to automatically turn on and off the lock mechanism in conjunction with heating melting work and crimping work, and to control the lock mechanism automatically when a predetermined period of time has elapsed. To improve product quality and yield by preventing work errors due to worker skill or carelessness by preventing subsequent work from being performed until later or after a predetermined time has elapsed. It is in.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a pipe welding machine equipped with a locking mechanism according to the present invention will be described in detail by taking a socket welding machine as an example with reference to the accompanying drawings.

The illustrated socket fusion machine (FIGS. 1 to 4) basically includes a pipe clamp device 10 for clamping a pipe P and a socket clamp device 5 for clamping a socket S.
It consists of 0. These two clamp devices are connected by a pair of parallel guide rods 3 provided on the machine base 1 so that they can approach and separate from each other. Pipe clamp device 1
0 is a pair of fixed clamp halves 13 and movable clamp halves 1 that can be divided into two around a pivot 11.
5, and a fixed clamp half body 13 is slidably attached to the guide rod 3. Both clamp halves 13 and 15 are tightened and fixed by clamp bolts 17 at positions diametrically opposed to the pivot shaft 11. One end of the clamp bolt 17 is connected to the fixed clamp half body 13, and by rotating the clamp knob 19, the movable clamp half body is pressed by the clamp knob 19, and both clamp halves can be tightened. A heater receiver 21 is provided on the movable clamp half 15 to receive a heater 100, which will be described later. Note that 23 is a handle used when moving the tube clamp device 10 toward the socket clamp device 50.

The socket clamp device 50 is also the pipe clamp device 1.
0, it is composed of a pair of fixed clamp half parts 53 and a movable clamp half part 55 that can be divided into two parts around a pivot pin 51. The movable clamp half body 55 and the fixed clamp half body 53 are connected to the pivot pin 5.
Torque tightening device 70 on the diametrically opposite side of 1
are detachably connected. The socket clamp device 50 is entirely movable in vertical and horizontal directions in order to center the pipe P and the socket S. Therefore, the fixed clamp half body 53 is a slider (reciprocating carriage) that is slidably attached to the guide rod 3 of the machine base 1.
59 via a support 65 so that the position can be adjusted. That is, the slider 59 is moved by the bolt 64.
For example, a vertical dovetail groove 66 is formed in the support body 65 fixed to the support body 65, and the stationary clamp half body 53 is fitted into this dovetail groove.

The torque tightening device 70 is used to control the tightening force for clamping the socket S to a predetermined value (if the tightening force is not increased to a certain extent, the socket may slip or shift relative to the clamp when the socket is pressed against the pipe or heater). On the other hand, since the socket is made of resin, it may crack or collapse if clamped too tightly, so the clamping force cannot be increased unnecessarily), but this is not directly related to this invention. A detailed explanation of its internal structure will be omitted. Incidentally, basically, the torque tightening device 70 may be a simple tightening bolt. A locking lever 68 is provided to secure the stationary clamp half 53 to the support 65 at a predetermined height. The lock lever 68 is a lock screw 62
The locking lever 68 is rotated by passing the locking screw through a corresponding hole (not shown) formed in the fixed clamp half and a corresponding threaded hole (not shown) formed in the support 65. As a result, the support 65 is strongly pressed against the stationary clamp half 53, and as a result, the stationary clamp half and the support are integrally fixed.

The socket clamp device 50 is connected to the tube clamp device 1.
A handle 63 for movement towards zero is attached to the slider 59. The movable clamp half 55 is provided with a heater receiver 56 similar to the heater receiver 21 of the tube clamp device 10 .

The process of fusing the socket to the pipe is as follows.

After attaching the pipe P and the socket S to the pipe clamp part 10 and the socket clamp part 50, respectively (the explanation is omitted as the attachment work is not directly related to the present invention), the two are attached before welding the socket S to the pipe P. It is necessary to melt the fused surface. Then, the inner diameter end 101 and the socket S into which the outer circumference of the pipe P is inserted are connected.
A heater (block) 100 equipped with a heater face having an outer diameter end 103 that fits into the inner periphery of the heater face.
The heater receiver (protrusion) 2 of the pipe clamp part 10
1 and the heater receiver (protrusion) 56 of the socket clamp section 50 (the heater block 100 is formed with a long groove into which the protrusions 21 and 56 fit). Holding the U-shaped handle 23 or handle 63, slide the pipe clamp part 10 or socket clamp part 50 toward each other to fit the heater block 100 into contact with the pipe P and saddle S. In this manner, the outer periphery of the pipe end and the inner periphery of the socket are heated and melted by the heater for a predetermined period of time. When the heating for the predetermined time _t1 is completed, the socket clamp section and the pipe clamp section are separated from the heater block and the heater block 100 is quickly removed.

This heater removal work needs to be done quickly.
This is because the fused surfaces of the pipe and saddle, which have been heated and melted, cool down rapidly.

After removing the heater block 100, the socket holder section 50 is again brought close to the pipe clamp section 10 along the guide rods 3, 3, and the outer circumferential end of the pipe P is inserted into contact with the inner circumferential end of the socket S and crimped.

Assuming that _t2 is the time from when the heater is removed to when the socket begins to be crimped onto the pipe P, it is desirable that _t2 be within 3 to 5 seconds at the latest. The above-mentioned heating and melting time t ₁ varies depending on the nominal diameter of the pipe and the nominal diameter of the socket, but is generally t ₁ =20 to 25 seconds. After crimping for a predetermined time t ₃ (t ₃ is generally t ₃ >30 seconds), the pressing force is released. Note that the above pressing force is generally performed by holding the handles 23 and 63 and pulling them together by hand. Eventually, the socket S is completely fused to the pipe P as the joint surface cools down (is allowed to cool).

Conventionally, in the socket fusion machine as described above (the above structure itself has already been applied for by the applicant), for example, it was unavoidable to remove the heater, which took more than ₂ seconds, and _{the 2} seconds had elapsed. For example, the socket may be crimped onto the pipe due to an accident, or the heater may be removed before ₁ second has elapsed due to the operator's carelessness or inexperience, resulting in the socket being fused to the pipe without sufficient heating and melting. There was a problem. All of these degrade the quality of the product and essentially necessitate redoing the fusing operation.

In order to solve this problem, the present invention is characterized by the provision of a lock mechanism that prevents the next operation from being performed until or after a predetermined period of time has elapsed.

In short, the present invention focuses on the fact that the work of sliding the socket clamp device 50 (or the pipe clamp device 10) along the guide rod 3 is always involved in the heating melting work, the heater removal work, and the socket crimping work as described above. However, this sliding movement is forcibly locked at a predetermined time so that the subsequent work cannot be started until or after a predetermined time has elapsed.

This locking mechanism will be explained below (5th,
(See also figures 6 and 7).

The locking mechanism according to the invention has an actuator in the form of a solenoid switch 71 fixed to the machine base 1. A lever 75 having a long hole 74 is provided at the tip of the plunger 73 of the solenoid switch 71.
are rotatably linked via a pin 77 of the plunger 73. The other end of the lever 75 is fixed to the tip of a shaft 81 rotatably supported on the machine base 1 in the pipe axis direction. The shaft 81 extends parallel to the guide rod 3 and has a stopper 83 in the center. As will be described later, when the solenoid 71 is energized and turned ON, the solenoid plunger 73 projects outward, and as a result, the lever 75 rotates clockwise in FIG. 3, causing the shaft 81 to rotate in the same direction and by the same angle. As a result, the stopper 83 fixed to the shaft 81 rises to the 83' position as shown in FIG.
can no longer move in the axial direction of the guide rod 3. When the solenoid 71 is inactive, the stopper 83 lies below the movement path of the clamp devices 10 and 50 and does not interfere with the movement of both clamp devices at all, so the slider 59 can freely move along the guide rod 3. be able to. That is, in FIG. 6, the bottoms of the movable parts of both clamp devices are located at positions corresponding to line 85.

A control signal S for turning on and off the solenoid switch 71 is given, for example, by a micro switch 91 (FIG. 5) provided in the clamp device 50. The micro switch 91 is movable together with the slider 59. The detector 93 of the micro switch 91 is a sleeve 95 fixed to the slider 59.
It is turned on and off by an adjuster bolt 99 of a first contact pin 97 that is slidably mounted inside the pipe in the axial direction. The first contact pin 97 has a plate-shaped abutment 98 at its tip, and the first spring 9
0, it is always pushed to the left in FIG. On the other hand, a second contact pin 80 is provided on the fixed clamp half 13 of the pipe clamp device 10 so as to face the first contact pin 97 in a straight line. The second contact pin 80 is connected to the fixed clamp half body 13
It is slidably mounted in the pipe axial direction within a sleeve 88 fixed to the pipe. The second contact pin 80 is also
The spring 86 constantly presses the contact pin 97 toward the first contact pin 97 . The second spring 86 has a greater spring force than the first spring 90. The amount of protrusion of the first contact pin 97 and the second contact pin 80 can be adjusted by adjusting bolts 99 and 84, respectively.

In this way, when the socket clamp part 50 is moved toward the pipe clamp part 10 during heating and melting and when crimping the socket, and the pipe and the socket or the pipe and the socket and the heater face are crimped, the second contact pin 80 is moved as shown in the broken line in FIG. As shown at 80', the first contact pin 97 is first brought into contact with the abutment 98, and then the first contact pin 97 is moved to the first position according to the pressing force.
Push the micro switch 9 to the right against the spring 90.
Turn on 1. The on signal is sent to control box 150, thereby turning on solenoid 71. The abutment 98 is sized so that it can also come into contact with the heater block 100, as shown in FIG.
This is because when the pipe and socket are heated by the heater, it is not possible to approach the position where they come into direct contact (because of the heater), so in this case it is necessary to turn on the micro switch using the heater.

Next, the operation of the lock mechanism will be explained (see Figs. 7 and 8).

FIG. 7 shows an example of the control box 150. First, timers T ₁ , T ₂ , T ₃ , and T ₄ with digital displays are used to determine heating melting time t ₁ , heater removal time t ₂ , crimping time t ₃ , and cooling time. Set time _t4 . The cooling time _t4 may be, for example, 180 seconds or more. In the illustrated embodiment, two types of time settings (t ₁ = 20 or 25
seconds), but it is not necessary to do so. Note that 151 is a power switch.

After the heater block 100 is set at a predetermined position, the socket clamp part 50 is slid toward the pipe clamp part 10 so that the heater face of the heater block 100 is brought into fitting contact with the pipe P and the socket S. At this time, the micro switch MSW91
is turned on by the heater block 100, and as a result, the solenoid 71 is actuated, the shaft 81 rotates, the stopper 83 is raised, and the slider 59 cannot be returned to its original position. The axial position of the stopper 83 is such that it can be stopped, for example, on the rear side of the socket clamp section 50 during heating by the heater and during pressure bonding. At the same time, timer _T1 is activated and the locked position is maintained until the set time _t1 is reached. Therefore, an operator may accidentally turn on the socket clamp device 5 in order to stop the heating and melting before ₁ second elapses.
Even if an attempt is made to remove 0 from the heater, the stopper 83 prevents it from returning to its original state. Predetermined heating and melting time
At the same time as _t1 elapses, the solenoid switch 71 is turned off and the lock mechanism is released. As a result, the operator can return the socket clamp device 50 to its initial position at any time (FIG. 8A).

When the socket clamp device 50 is returned to the initial position, the micro switch 91 is turned off because the detector 93 of the micro switch 91 is removed from the first contact pin 97, and at the same time, the timer _T2 is activated.

After removing the heater block 100, the socket clamp section 50 is brought close to the pipe clamp section 10 along the guide rod 3 again, and the socket S is brought into pressure contact with the pipe P.

At this time, the micro switch 91 is turned ON again and the solenoid switch 71 is energized, thereby locking the slider 59 of the socket clamp device. At the same time, timer _T3 starts and counts the crimping time _t3 . Therefore, since the lock is not released until the predetermined time _t3 has elapsed, the socket clamp device 50 cannot be returned to the initial position before the crimping time is completed due to operator carelessness. At the same time as _t3 hours have elapsed, the lock is released, and the socket clamp device 50 can be returned to the initial position and the pressing force can be released.
At the same time as this lock release, timer _T4 starts and counts cooling (cooling) time _t4 . timer
T ₄ is merely to inform the operator whether a predetermined cooling time has elapsed (so that, for example, the socketed pipe can be moved elsewhere).

On the other hand, if it takes time to remove the heater block after returning the socket clamp device to the initial position after heating and melting is completed, and it takes more than ₂ hours to press the socket to the heater melting surface, the signal is sent to the solenoid switch and automatically activates the lock mechanism. Therefore, the socket clamping device 50 cannot be moved and therefore the socket cannot be crimped onto the heater. In this way, if _t2 hours or more have elapsed, the product can be rejected as a defective product or the product can be heated and melted again. In that case (if ₂ hours have passed), it is preferable to notify the operator by displaying a buzzer or lamp.

The reason why the second spring 86 is made stronger than the first spring 90 is as follows. That is, as mentioned above, when applying the present invention to sockets of two different diameters, it is necessary to take into account that the amount of protrusion of the front end surface of the socket from the socket clamp differs depending on the diameter of the socket. I have to put it in.
That is, as the diameter of the socket becomes smaller, the above-mentioned protrusion amount also generally becomes smaller, so that no pressing force is applied yet at the position where the second contact pin 80 contacts the abutment 98 of the first contact pin 97. That is, it is necessary to bring both clamp devices closer to each other as the amount of protrusion of the socket becomes shorter. At that time, the second spring 8
6 begins to compress for the first time, allowing further movement of both clamps.

Thus, according to the present invention, the control of the heating time and the crimping time can solve the above-mentioned problems caused by worker's carelessness or erroneous sensitivity by using a lock mechanism that is linked to the heating operation and the crimping operation, respectively.

Incidentally, the above explanation has been made regarding the case where the socket clamp device 50 is moved toward the pipe clamp device 10, but when the pipe clamp device 10 is moved toward the socket clamp device, all that is required is to change the mounting position of the stopper. It can be done in exactly the same way.

[Brief explanation of the drawing]

Figure 1 is a front view showing the overall structure of the pipe fusion machine according to the present invention, Figure 2 is a left side view of Figure 1, and Figure 3 is a left side view of Figure 1.
The figure is a right side view of FIG. 1, FIG. 4 is a plan view of FIG. 1, FIG. 7 is a diagram showing the display panel section of the control box shown in FIG. 5, and FIGS. 8A and 8B are flowcharts of the operation of the pipe fusion machine according to the present invention. 3...Guide rod, 10...Pipe clamp device, 50
...Socket clamp device, 53...Fixed clamp half, 55...Movable clamp half, 71...
...Solenoid, 80...Second contact pin, 81...
Shaft, 83... Stopper, 91... Micro switch, 97... First contact pin.

Claims (1)

[Scope of utility model registration request] A pipe clamp device for clamping a pipe and a joint clamp device for holding a joint to be fused to the pipe are arranged oppositely along a pair of parallel guide rods extending between them so as to be able to approach and separate from each other. A pipe fusion machine that fuses the fitting to the pipe by heating and melting the fused surfaces with the fitting with a heater at a predetermined pressure and then crimping these fused surfaces together with a predetermined pressure, the above-mentioned pipe clamp device and A pair of spring-biased contacts are provided on the joint clamp device so as to face each other on the same straight line and come into contact with each other when the two approaches to a predetermined position, and the spring forces of the two contacts are set to be different from each other. A lock means is provided which is actuated when the contact with the weaker spring force is pushed back by a predetermined amount by the other contact, and which is actuated by an actuator responsive to a signal from the switch. A pipe fusion machine characterized in that the pipe fusion machine is provided so as to be freely retractable in the relative movement path of both clamp devices.