JPH0155093B2 - - Google Patents

Abstract

PURPOSE:To raise the quality and yeild of products as well as to prevent maloperations by a method in which a lock mechanism to automatically control heating and bonding operations is mechanically built in, and before or after the lapse of a given time period, the succeeding operations are locked. CONSTITUTION:A pipe clamp 10 or a socket clamp 50 is slid toward the counterpart one by means of a handle 23 or 63, and a heater block 100 is contacted with and fitted into a pipe P and a saddle S. After the periphery of the pipe end and the inner surface of the socket are heated for a given period of time t1 by the heater, both the clamps are separated from the heater block and the heater block 100 is quickly removed out. The inner surface end of the socket S is contacted with inserted with the peripheral end of the pipe P and bonded. After the bonding for a given period of time t3, the pressing force is released, the joint faces are cooled, and the socket S is completely hot-bonded with the pipe P. In short, unless a given period of time is passed or after a given period of time is passed, the succeeding operations are stopped to prevent the occurrence of maloperations.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a socket fusion machine for welding a pipe joint called a socket made of resin (eg, polyethylene) to resin (eg, polyethylene pipe or plastic pipe).

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 welding through a resin pipe joint such as a socket (of various shapes such as straight or elbow). That is, when a socket is fused 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. A socket fusion machine is generally used for such connection work. A socket fusion machine basically has a tube clamp device that clamps a pipe and a socket clamp device that clamps a socket, and these two clamp devices are connected to each other so that they can approach and separate from each other by a pair of parallel guide rods. be done.

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 The inner circumference of the socket is melted, so the pipe is inserted into one end of the heater and the socket is fitted onto the outer circumference of the other end of the heater) until the joining surfaces of the pipe and socket (the outer circumference of the pipe and the inner circumference of the socket) are melted. After heating for a predetermined time, the pipe and socket are separated from the heater, 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 time. All of these operations are done manually. Therefore, it is completely 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 object of the present 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. By not allowing subsequent work to be performed until later or after a predetermined period of time has elapsed, work errors due to worker skill or carelessness are prevented from occurring, thereby increasing product quality and yield. It turns out.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a socket fusing machine equipped with a locking mechanism according to the present invention will be described in detail 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. Both of these 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 10
is a pair of fixed clamp halves 13 and movable clamp halves 15 that can be divided into two around the pivot 11.
The 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 the present 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 body 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. Therefore, a heater (block) has an inner diameter end into which the outer circumference of the pipe P is inserted and an outer diameter end which fits into the inner circumference of the socket S.
100 is hung so as to bridge the heater receiver (protrusion) 21 of the pipe clamp part 10 and the heater receiver (protrusion) 56 of the socket clamp part 50 (the heater block 100 has a long groove in which the protrusions 21 and 56 fit). ). Holding the U-shaped handle 23 or the handle 63, the pipe clamp part 1
0 or the socket clamp portions 50 are slid toward each other to bring the heater block 100 into contact with the pipe P and the 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 providing a locking 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 clamping device 50 (or the pipe clamping device 10) along the guide rod 3 is always involved in the heating and melting work, the heater removal work, and the socket crimping work as described above. This sliding movement is forcibly locked at a predetermined time so that subsequent work cannot be started until or after a predetermined time has elapsed.

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

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 a tip shaft portion 81 of an eccentric shaft 81 rotatably supported on the machine base 1.
It is fixed to A. The eccentric shaft 81 has an eccentric shaft portion 81B that extends parallel to the guide rod 3 and has engagement irregularities such as grooves, notches, or threads formed on the outer periphery.
On the other hand, the slider 59 is fixedly provided with a bushing 83 having a concave and convex portion 84 on its inner circumference that engages with the engagement concave and convex portions. As shown, a clearance 89 is formed. Solenoid 7 as described below
1 is energized and turned ON, the solenoid plunger 73 protrudes to the 73' position as shown in FIG.
As a result, the lever 75 rotates to the 75' position, causing the eccentric shaft 81 to rotate clockwise by the same angle.
As a result, the uneven portion of the eccentric shaft portion 81B of the eccentric shaft 81 engages with the corresponding uneven portion 84 of the bush 83, and the slider 59 can no longer move in the axial direction of the guide rod 3. In this way, the eccentric shaft 81 and the bush 83 are engaged only when the solenoid 71 is activated, and the movement of the slider 59 and therefore the socket clamp portion 50 are controlled.
constitutes a clutch that prevents the movement of the When the solenoid 71 is inactive, the bush 83 and the eccentric shaft 81 have a clearance 89 between them and do not interfere with each other at all, so the slider 59 can freely move along the guide rod 3.

A control signal S for turning on and off the solenoid switch 71 is given by a micro switch 91 provided on the slider 59, for example. A rod 95 is fixed to the machine base 1 and extends parallel to the guide rod 3, and on this rod 95, for example, there is a rod 95 extending from the position of the socket clamp device 50 during heating and melting to the position of the socket clamp device when crimping the socket. An extending dog 97 having a width W is preferably fixed in an adjustable position by an adjusting screw 99. Therefore, when moving the socket clamp part 50 toward the pipe clamp part 10 during heating and melting and socket crimping, the detector (roller) of the micro switch is used.
93 contacts the dog 97, and the micro switch 9
1 is turned on, and the ON signal S can be sent to the control box 150.

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 in a predetermined position, the socket clamp portion 50 is slid toward the pipe clamp portion 10 to bring the heater block 100 into fitting contact with the pipe P and socket S. At this time, the micro switch MSW91 is turned on by the dog 97, and as a result, the solenoid 71 is activated, and the eccentric shaft 81 and the bush 83 are engaged and locked. At the same time, timer _T1 is activated and the locked position is maintained until the set time _t1 is reached. Therefore, even if the operator mistakenly attempts to remove the socket clamp device 50 from the heater in order to stop the heating and melting before the elapse of time t ₁ seconds, the socket clamp device 50 cannot be returned to its original position due to the engagement between the bush 83 and the eccentric shaft 81. At the same time as the predetermined heating and melting time _t1 elapses, solenoid switch 7
1 is turned off and the locking mechanism is released. As a result, the operator can always use the socket clamping device 50.
can be returned to the initial position (Fig. 8A).

When the socket clamp device 50 is returned to the initial position, the micro switch 91 is removed from the dog 97 and is turned off, 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 contact with the pipe P.

At this time, the micro switch 91 is turned ON again by the dog 97, and the slider 59 of the socket clamp device is locked by the excitation of the solenoid switch 71. At the same time, timer _T3 starts and counts the crimping time _t3 . Therefore, the predetermined time t ₃
Since the lock is not released until the crimping time is completed, the socket clamp device 50 cannot be returned to the initial position due to operator carelessness before the crimping time is completed. 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, the timer
T ₄ starts and the cooling (cooling) time t ₄ is counted. Timer _T4 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 pipe device to the initial position after heating and melting is completed, and more than ₂ hours elapse before the socket is crimped to the heater melting surface, the signal will be sent to the solenoid switch. The lock mechanism is automatically activated. Therefore, the socket clamping device 50 cannot be moved and therefore the socket cannot be crimped onto the heater. thus
If more than ₂ hours have passed, 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.

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, the above-described lock mechanism 71, 73, 75,...8
1, 83 and heating work and crimping work detection mechanism 9
1, 93, 95, and 97 may be provided in exactly the same manner on the pipe clamp device side.

Furthermore, by incorporating a binary counter into the control box 150, the micro switch 91 is turned on when it makes contact with the dog 97 for the first time (outbound trip) and turned off when it makes contact with the dog 97 for the second time (return trip). dog 97
It is not necessary to have the width W as shown in FIG. 4, and it is also possible to place one small dog on the front side (on the right side in FIG. 4) of the position of the socket clamp device 50 during heating and melting. be.

[Brief explanation of drawings]

Figure 1 is a front view showing the overall structure of a pipe joint fusion splicer 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, and Fig. 5 is a view seen from the arrow direction of Fig. 4 (however, the lever is shown with imaginary lines for ease of understanding). ), Figure 6 is a sectional view taken along the - line in Figure 5, and Figure 7 is a cross-sectional view taken along the line -
This figure shows the display panel section of the control box shown in FIG. 5, and FIGS. 8A and 8B are flowcharts of the operation of the socket welding 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, 75 ... Lever, 81 ... Eccentric shaft, 83 ... Bush, 91 ... Micro switch, 97 ... Dog.

Claims (1)

[Claims] 1. A pipe clamp device for clamping a pipe and a socket clamp device for holding a socket to be fused to the pipe are arranged oppositely along a pair of parallel guide rods extending between them so that they can approach and separate from each other, After the fused surfaces of the pipe and socket are heated and melted by a heater for a predetermined time (t ₁ ), the heater is removed within a predetermined time (t ₂ ), and the fused surfaces of the pipe and socket are crimped together for a predetermined time (t ₃ ). A socket welding machine for welding a socket to a pipe by means of a detection means for detecting relative approach/separation movement between the two clamping devices, and a detection means for detecting relative approach/separation movement between the two clamping devices, and a detection means that operates in response to a signal from the detection means to fuse the two clamping devices at a predetermined time. and a locking mechanism for preventing relative movement of the socket.