JPH06297581A - Welding machine - Google Patents

Abstract

PURPOSE:To provide a welding machine enhancing the reliability of the connection strength in the butt welding of piping materials and usable on the execution spot such as a semi-clean room. CONSTITUTION:As the actuator 21 of a mechanism 20 imarting movement to the clamp 2 arranged with respect to a fixed clamp 1 so as to be freely approach and separate from the clamp 1, machinery setting the quantity of electricity to control quantity, for example, a torque motor 2 is used. The driving of the actuator 21 of the clamp moving mechanism 20 is controlled to always keep the abutting pressure in a weld bonding process constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fusion machine for joining pipe materials such as pipes and joints formed of a thermoplastic resin by butt fusion, and more specifically, for use in a semi-clean room or the like. The present invention relates to a fusion machine suitable for connecting piping materials (PPS molded products, etc.).

[0002]

2. Description of the Related Art As a fusion bonding machine for a piping material of a thermoplastic resin product, a piping material is gripped by a pair of clamps, and a connecting end portion of each piping material is melted by heating with a heater, followed by a handle operation. There is a structure in which one clamp is moved toward the other clamp to abut and fuse the respective melted portions at a predetermined pressure (for example, Japanese Utility Model Laid-Open No. 56-26217).

As another fusing machine, there is also a system device in which a clamp is automatically moved by a mechanism using an air cylinder.

[0004]

By the way, according to the former of the above-mentioned fusion machines, since the butting operation at the time of fusion bonding is performed manually (handle operation), the butting pressure Since there is a large variation, it is not possible to always obtain stable bonding strength.

On the other hand, according to the latter device, the variation in the abutting force at the time of fusion bonding is eliminated to some extent by automation, but the air cylinder used for the automation is
Sufficient results have not been obtained because the pressure control accuracy and responsiveness are not good, and the problem of reliability of joint strength still remains. In addition, according to this fusion machine, compressed air is required, but it is difficult to secure the air source at the piping construction site, and the compressed air is a factor causing pollution such as dust scattering. It is not suitable for plumbing on-site such as a clean room.

The present invention has been made in view of such circumstances, and an object of the present invention is to perform butt fusion of piping materials under stable conditions at all times, so that reliability of connection strength is high and moreover, It is to provide a fusion splicer that can be used at a construction site such as a semi-clean room.

[0007]

In order to achieve the above object, the fusion machine of the present invention is capable of moving toward and away from the fixed side clamp 1 as shown in FIGS. 1 to 3 corresponding to the embodiment. The clamp moving mechanism 20 for moving the moving side clamp 2 disposed in the electric actuator is an electric actuator (for example, a torque motor).
21 and its electric actuator 21
Is characterized by being configured to be controlled to keep the butt pressure constant during the fusion bonding process.

[0008]

By using, as the actuator of the clamp moving mechanism 20, a device such as a torque motor 21 that uses electricity as a controlled variable, the moving side clamp 2 is pressed against the fixed side clamp 1 in the fusion bonding process, that is, the fusion. The butting pressure at the time of joining and joining can be controlled with high accuracy.
Further, it is not necessary to separately prepare a drive source other than the power source at the piping construction site.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a front view showing the structure of an embodiment of the present invention, and FIG. 2 is a plan view thereof. 3 is a cross-sectional view taken along the line AA of FIG. Note that the specific configuration of the heater 3 is omitted in FIG.

First, the fixed side clamp 1 and the movable side clamp 2 are for holding the pipe materials (PPS molded products) P and J to be joined, and are arranged on the bed 5.
The clamps 1 and 2 are fixed to the ends of the mounts 1a and 2a slidably arranged on the guides 6a and 6b, and face each other.

Each of the clamps 1 and 2 has a structure in which it is vertically divided into two parts, and an upper half part thereof is structured to open upward with a hinge 2b (fixed side not shown) as a center. Tightening mechanisms 1c and 2c for fastening the upper and lower members are provided on the opposite sides of the respective hinges.
Further, the grip centers of the pair of clamps 1 and 2 coincide with each other.

The pedestal 1a of the fixed-side clamp is fixed to the bed 5 via the position-regulating presser bar 12 and its lock mechanism 10. The lock mechanism 10 is a mechanism that locks the movement of the presser bar 12 by operating the lever 11, and the lock of the presser bar 12 is released by moving the lever 11 from the horizontal position in the locked state to the upright position. it can. Further, by rotating the handle 13 in the unlocked state, the movement of the presser bar 12, that is, the position of the fixed side clamp 1 with respect to the bed 5 can be adjusted.

A clamp moving mechanism 20 is connected to the mount 2a of the moving clamp. The moving mechanism 20 includes a torque motor 21 and a mechanism for converting its rotational motion into a linear motion, for example, a cam mechanism including a groove cam 22 spirally cut on the outer peripheral surface of a cylindrical body 24 and a cam follower 23 thereof. When the rotation of the torque motor 21 is forward (clockwise), the pedestal 2a, that is, the moving side clamp 2 moves toward the fixed side clamp 1, and when the motor reverses, it moves in the opposite direction.

Here, the torque motor used in this embodiment is of a type with a power controller (voltage regulator) that is generally commercially available, and its volume (resistance value) is used.
The rotational force (torque) can be arbitrarily adjusted by appropriately setting. Therefore, in this embodiment, the pressure at the time of butt fusion welding can be set to a desired value by adjusting the volume of the torque motor 21.

On the other hand, on the bed 5 of the fusion machine, as shown in FIGS. 2 and 3, a heater 3 and a spacer 4 are arranged at positions facing each other with a pair of clamps 1 and 2 interposed therebetween. ing.

The heater 3 is for heating and melting the connecting ends of the pipe members P and J, and is supported by the rotating mechanism 30. The heater 3 is of a cartridge type, for example, and the heating temperature up to about 500 ° C. can be arbitrarily set.

The rotating mechanism 30 is a mechanism using a geared motor 31 with a brake as a drive source, and by the motor drive,
It is selectively arranged at a standby position (upright position shown in FIG. 3) and a use position, that is, an intermediate position between the two clamps 1 and 2 and a position corresponding to a gripping center of each of the clamps 1 and 2. . The heater is moved from the standby position to the use position by the normal rotation of the motor 31, and is returned to the standby position by the motor reverse rotation.

The spacer 4 is used for positioning when fixing the piping materials P and J to the clamps 1 and 2, and the whole thereof is supported by the manual rotation mechanism 40. The spacer 4 is thicker than the heater 3 by 2 mm, and the positioning surfaces 4a and 4b of the spacer 4 are located at the use position (the intermediate position between the two clamps 1 and 2). With respect to the positions of the heating surfaces 3a, 3b, the positions are set to be closer to the fixed side clamp 1 and the movable side clamp 2 by 1 mm. The spacer 4 is moved from the standby position (the upright state shown in FIG. 3) to the use position and returned to the standby position by the manual operation of the lever 41.

Although the structure of the mechanical system of the fusion machine has been described above, the limit switch LS1 for controlling the position of the heater 3 when it is moved to the use position and when it is returned to the standby position is also used as a control system. And LS2, and limit switch that regulates the position of moving side clamp 2 when retracted
LS3 is located. The position detected by the clamp limit switch LS3 is a predetermined distance from the positioning surface 4b of the spacer 4 on the moving side clamp 2 side (corresponding to the ejection of the pipe material J gripped by the moving side clamp 2). It is set at a position retracted by (distance).

Further, a load sensor S is installed between the pedestal 1a of the fixed side clamp and the pressing rod 12. The sensor S is a pressure sensor that detects a force (load) in the butting direction that acts on the fixed-side clamp 1.

The load sensor S and the above three limit switches LS1 to LS3 are connected to the control unit 7 as shown in the block diagram of FIG. Control device 7
ON / OFF operation of those limit switches LS1 to LS3 and output of sensor S, and ON / O of start switch SW1 and reset switch SW2 which are manual operation switches.
Based on the FF operation, it is configured to control driving / stopping and forward / reverse rotation of the torque motor 21 for moving the clamp and the motor 31 for moving the heater by an operation described later. Further, the control unit 7 starts the timer 8
The two motors 2 that have been reset and have their measured values also mentioned above
It is configured to be used as control information for drive control of 1 and 31. Further, the control device 7 is connected with a confirmation lamp 9 for informing the operator that fusion-bonding has been completed.

Next, the operation of the embodiment of the present invention will be described together with the operation of the control device 7. FIG. 6 is a flowchart showing the operation of the control device 7. First, an operator sets the connection pipe members P and J on the fusion machine before performing the automatic fusion bonding operation. For the setting, the lock of the fixed side clamp 1 is released, and the clamp 1 is retracted by operating the handle 13 to a position where it does not interfere with the operation of the tightening mechanism 2c of the moving side clamp 2.

Next, the spacer 4 is manually moved to be placed at the use position, and in this state, the pipe material J is placed on the moving side clamp 2 and the connecting end face thereof is made into the spacer 4.
The pipe material J is fixed by closing and tightening the clamp 2 in a state of being in contact with the positioning surface 4b of, and then the pipe material P is arranged on the fixed-side clamp 1, and the connecting surface of the pipe material P is fixed by a predetermined amount ( When the clamp 1 is closed / tightened in a state in which it is protruded only) and then the fixed side clamp 1 is advanced by operating the handle, when the connection end face of the pipe material P contacts the positioning face 4a of the spacer 4. Then lock it in that position. After this, the spacer 4 is moved and placed at the standby position.

The heater 2 is preheated,
The temperature is kept at 400 ° C or higher, for example. Now, after the above setting is completed, when the operator turns on the start switch SW1, the automatic operation of the fusion splicing is started, and first, the controller 7 drives the motor 31 for moving the heater (normal rotation). By this operation, the heater 2 moves from the standby position to the use position, and when the limit switch LS1 is turned on when the use position is reached, the drive of the motor 31 is stopped and the time measured by the timer 8 is measured. To start.

During this timekeeping, the heater 2 is maintained in the use position, but between the heating surfaces 2a and 2b of the heater and the connecting end surfaces of the pipe members P and J, respectively. A gap of 1 mm is formed, and the connecting ends of the pipe members P and J are heated and melted with the heater 2 in a non-contact state.

Here, such non-contact heating is performed because it is necessary to set the heater temperature to 400 ° C. or higher in order to heat PPS, which is a piping material, to a molten state. In heating, there is no coating material on the heater surface, and in addition to this, there is an advantage that the inner surface bead at the time of bonding can be minimized by non-contact heating.

Then, when the measured time t reaches a fixed time T1, that is, a time required for melting each connection end, the timer 8 is reset and the motor 31 for moving the heater is driven (reverse rotation). By this operation, the heater 2 moves toward the standby position, and when the position is reached and the limit switch LS2 is turned on, the driving of the motor 31 is stopped.

Next, the torque motor 21 for moving the clamp.
Drive (normal rotation). As a result, the moving side clamp 2 moves toward the fixed side clamp 1, and as shown in FIG.
The connection surfaces of the fixed-side piping material P and the moving-side piping material J are in contact with each other, but even after this contact, the torque motor 21
Drive continues. Therefore, the movable clamp 2 is kept pressed against the fixed clamp 1,
The butt load, that is, the value F detected by the load sensor S
However, when the preset pressure F0 is reached, the time counting by the timer 8 is started, and the time zone of the actual butt fusion operation is during this timing.

Here, in this example, the butt pressure is always kept constant in the above butt fusion process. That is, even in the fusion process, the torque motor 21 is kept in the driving state (normal rotation), and thus the moving side clamp 2 is constantly pushed with a constant force. In addition, in such a fusion bonding process, the melted portion rises due to the butt pressure, and the moving side clamp 2 is fixed to the fixed side clamp 1.
Although it is displaced (moved) to the side, since the rotational force of the torque motor 21 is constantly applied to the moving side clamp 2, the butt pressure does not decrease even if such displacement occurs.

Then, when the timed value t by the timer 8 reaches a predetermined time T2, the timer 8 is reset, and the driving (normal rotation) of the torque motor 21 is stopped for the first time at this time, and then, The confirmation lamp 9 indicating that the joining is completed is turned on.

When the lamp is turned on, the operator determines that the fusion-bonding is completed. At this point, first, the lock mechanism 10 of the fixed side clamp 1 is released, and the fastening of the clamp 1 is loosened a little. , The fixed side clamp 1 is retracted by operating the handle 13 of the lock mechanism, then both the clamp 1 and the movable side clamp 2 are opened, and the pipe materials P and J which have been connected are removed, and these operations are performed. After finishing, turn on the reset switch SW2.

When this switch SW2 is turned on, the control device 7 turns off the confirmation lamp 9 and drives (reverses) the torque motor 21 for moving the clamp. This causes the moving side clamp 2 to retract and its position to be the reset switch.
When the position of LS3, that is, the initial set position is reached and the switch LS3 is turned on, the drive of the torque motor 21 is stopped, and one fusion-bonding step is completed. After that, when connecting the next new pipe material, the procedure described above is sequentially repeated.

In the above embodiment of the present invention, the torque motor 21 is used as the drive source of the clamp moving mechanism 20, but the present invention is not limited to this, and as an alternative means, for example, a normal motor as the drive source. When a butt fusion is performed using a (servo motor), the load detection value by the load sensor S is used as a feedback signal, and feedback control such as controlling the power supply to the motor is performed to match the detection value with the target value. The method used can also be adopted. In that case, a plurality of strain gauges are installed on the periphery of the pipe material gripping portion of the fixed-side clamp 1, the butting pressure is detected separately from the load sensor S, and the detected value is used as a feedback signal. If this is set, higher precision control can be expected.

Further, in the clamp moving mechanism 20, as a mechanism for converting the rotational movement of the torque motor 21 into a linear movement, instead of the groove cam mechanisms 22 and 23 shown in FIG. 1, for example, a feed screw mechanism or a rack and pinion is used. Other general mechanism such as a mechanism may be adopted.

Further, in the above embodiments, the example of connecting the PPS pipe material was explained, but the fusion machine of the present invention is not limited to such a thermoplastic resin molded article having a high melting point, and for example, vinyl chloride or the like. It can also be used to connect piping materials molded of low melting point resin. In that case, it is possible to heat the connection end surface of the piping material by contacting it with a heater, but if contact heating is adopted, it is difficult to automate the movement of the heater to the use position, and non-contact heating In view of the fact that the inner surface bead at the time of joining can be suppressed to a low value with respect to contact heating, it is preferable to employ non-contact heating.

[0036]

As described above, according to the fusion machine of the present invention, for example, a torque motor or the like is used as an actuator of a mechanism for moving a clamp arranged so as to move toward and away from a fixed side clamp. Since a device having a controlled amount of electricity is used, the condition at the time of fusion bonding, that is, the butt pressure can always be kept constant. As a result, the reliability of connection strength is improved. Moreover, since it is not necessary to separately prepare a drive source other than the power source at the piping construction site, and since there are few problems such as dust, it can be used for piping construction in a semi-clean room.

[Brief description of drawings]

FIG. 1 is a front view showing the structure of an embodiment of the present invention.

FIG. 2 is a plan view of the embodiment.

3 is a sectional view taken along the line AA of FIG.

FIG. 4 is an explanatory view of the operation of the embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a control system according to an embodiment of the present invention.

FIG. 6 is a flowchart showing the operation of the control device 7 according to the embodiment of the present invention.

[Explanation of symbols]

 1 ... Fixed clamp 2 ... Moving clamp 20 ... Clamp moving mechanism 21 ... Torque motor 3 ... Heater 30 ... Rotating mechanism 31 ... Brake Geared motor 4 ・ ・ ・ ・ Spacer 7 ・ ・ ・ ・ ・ ・ Control device S ・ ・ ・ ・ Load sensor LS1 to LS3 ・ ・ ・ ・ ・ ・ Limit switch P, J ・ ・ ・ ・ Piping material

Claims (1)

[Claims] 1. A device for connecting pipe materials such as pipes and joints formed of a thermoplastic resin by butt fusion welding, and a fixed side clamp for gripping one of the pipe materials to be connected, A moving side clamp that is arranged so as to be able to move toward and away from the clamp and that holds the other piping material to be connected, a clamp moving mechanism that gives that movement, and each connection end of the piping material that is gripped by these two clamps. In the fusion machine configured to have a heater for heating the parts, the fusion end is melted by the heater heating, and then the melted parts are butted against each other by the movement of the moving side clamp. Driven by an actuator, and the electric actuator is configured to be controlled so as to keep the butt pressure constant during the fusion bonding process. Fusion machine characterized by.