JPS6359796B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a pressure welding process in a gas pressure welding machine for steel materials.

Generally speaking, gas pressure welding involves first heating and pressurizing two steel materials in a pre-work to bring the abutted end surfaces of the two steel materials into close contact without any gaps, and then uniformly heating the joined portion of the two steel materials in the main work. This method joins the two steel materials by applying pressure and forming a dumpling-shaped bulge at the joining portion of the two steel materials. In such gas pressure welding, it is necessary to uniformly heat and press the bonded portion to form a bulge of an appropriate size in the bonded portion so that sufficient strength can be obtained in the bulge.

However, since conventional gas pressure welding is mainly performed manually, the heating and pressurization of the joint parts is not constant. Therefore, the strength of the joint is greatly influenced by the skill of the worker.

Therefore, devices and control methods have been developed that perform gas pressure welding automatically rather than manually. However, since this gas pressure welding equipment or gas pressure welding control method controls the heating time of the steel material at a constant level during each stage of the process, it is difficult to control the heating time of the steel material at a constant level. As a result, the temperature of the heated part of the steel material changes, and therefore, even under the same set pressure, the amount of compression of the two steel materials differs due to the influence of the temperature change mentioned above, and the swelling part may be too small or too large. However, the problem of stabilizing and improving the strength of the joint remains unresolved.

The present invention aims to provide a control device for a gas pressure welding machine that solves the above-mentioned problems.

The present inventor believes that in order to stabilize and improve the strength of the joint between two press-welded steel materials, it is necessary to keep the compression amount (shrinkage margin) of the two steel materials constant and form a constant bulge. In light of this theory, we have conducted various studies to find a method that allows the bulge to remain constant even under external conditions.

In other words, in order to make the bulge constant, the amount of compression (shrinkage) of the steel material should be kept constant, and in order to make the amount of compression (shrinkage) of the steel constant, the pressure system that pressurizes the steel material (pressurization) should be kept constant. It is sufficient to keep the operating amount of the pressurizing system (pressurizing means) constant, and in order to keep the operating amount of this pressurizing system (pressurizing means) constant, it is necessary to monitor the pressurizing operation time, that is, the driving time of the pressurizing system (pressurizing means). It is better to keep it constant.

Therefore, in monitoring the pressurizing operation time of the pressurizing system (pressurizing means), the present inventor first determined that the pressurizing force of the pressurizing system (pressurizing means) is influenced by the external environment and The melting temperature changes, which causes it to rise and fall slightly,
Focusing on the fact that there are cases in which the pressurizing force is actually working (when the pressure increases) and cases in which the pressurizing force is not actually applied and is not working (when the pressure is decreasing), The inventors have invented that a bulge of a predetermined size can be formed by monitoring and integrating only the time during which pressure is applied. In other words, the pressurizing operation time of the pressurizing system (pressurizing means) is monitored and integrated, and if the pressurizing operating time becomes constant, the pressurizing system (pressurizing means)
The operating amount of is constant, and this pressurizing system (pressurizing means)
If the amount of operation becomes constant, the amount of compression (shrinkage) of the steel material
becomes constant, and if the amount of compression (shrinkage margin) of this steel material becomes constant, the bulge will become constant.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a control device for a gas pressure welding machine according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of an automatic gas pressure welding machine equipped with a control device of the present invention. In the figure, A is an automatic gas pressure welding machine (Japanese Patent Application No. 108631/1989) that the applicant previously applied for.
B and C are oxygen cylinders and acetylene cylinders, D is a power plug, and E is a reinforcing bar.

The automatic gas pressure welding machine A is provided with a drive motor 1 in the main body of the gas pressure welding machine, a reciprocating mechanism 3 linked to the drive motor 1, and a burner 6 connected to the reciprocating mechanism 3.
is attached via a holder 2, and a fixed reinforcing bar clamp holder 4 and a movable reinforcing bar clamp holder 5 are attached to the gas pressure welding machine main body.
The fixed reinforcing bar clamp holder 4 and the movable reinforcing bar clamp holder 5 are equipped with pressurizing means. This pressurizing means includes a hydraulic ram 8 attached to the fixed and moving reinforcing bar clamps 4 and 5, a hydraulic pump (not shown) connected to the hydraulic ram 8 via a high-pressure hose 9, etc., and the hydraulic pump. , a solenoid valve SOL1 that closes when a predetermined cumulative time of an integration timer T1 (described later) has been reached, a drive motor M operating switch TSW1, and a solenoid valve operating switch SW1. The burner 6 is connected to an oxygen cylinder B and an acetylene cylinder C via a rubber hose or the like 7.

Next, the operation of the above-mentioned gas pressure welding machine will be explained. First, the fixed reinforcing bar clamp holder 4 and the movable reinforcing bar clamp holder 5 are respectively clamped between the two reinforcing bars E and E, and the drive motor 1 is driven to reciprocate the burner 6 and move the reinforcing bars E and E. The two reinforcing bars E and E are heated by moving the center of reciprocation to follow the shrinkage. On the other hand, the solenoid valve
At the same time as SOL 1 is opened, the drive motor M is driven to operate the hydraulic pump, and pressure oil is supplied from this hydraulic pump to the hydraulic ram 8 via the high pressure hose 9, and the rod of the hydraulic ram 8 is extended to move the reinforcing bar E as shown in the arrow. The two reinforcing bars E and E are joined together by pressing in the direction shown in FIG.

Therefore, the control device for the gas pressure welding machine of the present invention in this embodiment is interposed between the drive motor M of the hydraulic pump and the hydraulic ram 8, and sets the upper limit pressure value and the lower pressure value to When the pressure of the hydraulic ram 8 reaches the lower limit pressure value, it turns ON and operates the drive motor M, and when the pressure of the hydraulic ram 8 reaches the upper limit pressure value, it turns OFF and stops the drive motor M. Pressure switch PS1 (for pre-work), pressure switch PS2 for low pressure (for main work), changeover switch P1 that switches the operation of this pressure switch PS1 for high pressure and pressure switch PS2 for low pressure, and this changeover switch P1 for high pressure Pressure switch PS1 to low pressure pressure switch PS
2, and monitors only the ON time during the ON-OFF operation of the low-pressure pressure switch PS2, that is, the operating time of the drive motor M of the pressurizing means, and integrates the operating time. It consists of an integration timer T1 as an integration means, and a buzzer BZ as a work stop notification means to notify the completion and stop of the main work when the integrated time of the integration timer T1 reaches a predetermined time. Next, its operation will be explained. First, in the preparatory work for gas pressure welding, the high pressure switch PS1 is turned on and off. Then, when the pressure of the hydraulic ram 8 reaches a predetermined upper limit pressure in the high pressure region, the drive motor M is stopped, and when the pressure of the hydraulic ram 8 reaches a predetermined lower limit pressure in the high pressure region, the drive motor M is activated. , the hydraulic ram 8 operates between a predetermined upper limit pressure and lower limit pressure in the high pressure region. In the previous work, the two steel materials E were heated and pressurized for the required time to bring the abutting end surfaces of the two steel materials E into close contact with each other without any gaps, and the abutting ends of the two steel materials E were made red hot. The operation of the pressure switch is changed from the high pressure switch PS1 to the low pressure switch PS2 to switch from the pre-work of gas pressure welding to the main work, and at the same time activate the integration timer T1. Then, due to the ON-OFF operation of the low pressure switch PS2, the hydraulic ram 8
When the pressure of the hydraulic ram 8 reaches a predetermined lower limit pressure in the low pressure region, the drive motor M is activated, while the hydraulic ram 8
When the pressure reaches a predetermined upper limit pressure in the low pressure region, the drive motor M is stopped, the hydraulic ram 8 operates between the predetermined upper limit pressure and lower limit pressure in the low pressure region, and the integration timer T1 is set to the low pressure pressure. Switch PS2 ON time (drive motor M
(operating time), that is, the pressurizing time of the hydraulic ram 8, and when this integrated time reaches a predetermined time, the solenoid valve SOL1 of the hydraulic means closes, the buzzer BZ is activated, and this work is completed. .

FIG. 2 is an electric circuit diagram of the pressurizing means and the control means of the control device in the gas pressure welding machine of the present invention in this embodiment.

In the figure, M is a drive motor for operating the hydraulic pump;
SOL1 is a solenoid valve that closes when the cumulative time of a cumulative timer T1, which will be described later, reaches a predetermined time;
TSW1 and SW1 are a drive motor operating switch and a solenoid valve operating switch. PS1 and PS2 are interposed between the drive motor M of the hydraulic pump and the hydraulic ram 8, set an upper limit pressure value and a lower limit pressure value, and are turned ON and driven when the pressure of the hydraulic ram 8 reaches the lower limit pressure value. A pressure switch for high pressure (for pre-work) and a pressure switch for low pressure (for main work), which operate motor M and turn OFF to stop drive motor M when the pressure of hydraulic ram 8 reaches the upper limit pressure value, P1 is a changeover switch that switches the operation of the high pressure switch PS1 and the low pressure switch PS2, and T1 is a changeover switch that switches the operation of the high pressure switch PS1 and the low pressure switch PS2, and T1 is
BZ is an integration timer that monitors only the ON time, that is, the operating time of the drive motor M of the pressurizing means and adds up the operating time, and BZ is an integration timer that stops the main work when the integration time of the integration timer T1 reaches a predetermined time. This is a buzzer to notify the end of this work. R1 and R2 are solenoid drive relays and relays for main work operation, R1a is a normally open contact of relay R1, R2a _-1 to a _-3 are normally open contacts of relay R2,
R2b _-1 to b _-2 are normally closed contacts of relay R2. Furthermore, the connecting dotted line portion indicates the operating side, and the connecting solid line portion indicates the driving side.

The integration timer T1 mentioned above is manufactured by OMRON STT-
I am using NR. This device is called a motor timer, and the motor and clutch are connected separately. In FIG. 2, timer TM is for the motor and timer TC is for the clutch. moreover,
It has two contacts T1b (normally closed) and T1a (normally open).
The operating characteristics are as follows. Timer TC integrates the ON time of timer TM. That is,
After power is applied to the timer TC via the normally closed contact R2b _-1 of the relay R2, even if the power is applied to the timer TM repeatedly on and off, when it is turned off, the integrated value at the time of the previous stage ON is retained. , the stored integrated value is used as the initial value (base) when the switch is turned on next time, and is integrated, and when it reaches the set value, a timeout occurs, and the contact T1b is turned off and the contact T1a is turned on. In the figure, power application to the timer TM is turned on and off by a switch PS2.

The control device for the gas pressure welding machine of the present invention has the above-mentioned configuration, and the method for controlling the gas pressure welding will be explained below with reference to the working process block diagrams of FIGS. 3 to 5.

First, the automatic gas pressure welding machine A is set on the two steel materials E via the fixed and moving reinforcing bar holders 4 and 5,
The burner 6 is held in the holder 2 of this automatic gas pressure welding machine A, and the fixing and moving reinforcing bar holders 4 and 5 are
Attach the hydraulic ram 8 to the.

Next, start the pre-work. That is, leave the control system changeover switch P1 OFF, set the high pressure switch PS1 to the operating side, turn on the pressurization system solenoid valve operating switch SW1 and drive motor operating switch TSW1,
Furthermore, the burner 6 of the heating system is ignited, and the drive motor operating switch MS of the burner drive system is left OFF. Then, the burner 6 heats the abutting ends of the two steel materials E while remaining in a stopped state (previously positioned at the abutting surfaces of the steel materials and stopped at that position).
On the other hand, the solenoid drive relay _R1 is activated, the normally open contact R1a is closed, and as a result, the solenoid valve _SOL1 of the pressurization system is opened, and the drive motor M is started and stopped by the ON/OFF operation of the high pressure switch PS1. As a result, the hydraulic ram 8 pressurizes the two steel materials E in the high pressure region between the predetermined upper and lower limit pressures, which are the set values of the high pressure switch PS1. That is, when the pressure of the hydraulic ram 8 reaches a predetermined upper limit pressure in the high pressure region, the drive motor M stops, and on the other hand, when the pressure of the hydraulic ram 8 reaches a predetermined lower limit pressure in the high pressure region, the drive motor M starts operating and the hydraulic pressure increases. As shown in FIG. 6, the ram 8 pressurizes the two steel materials E between a predetermined upper limit pressure and lower limit pressure in a high pressure region. Then, 2
The butted end surfaces of the steel material E of the book are completely in close contact with each other without any gaps.

Next, turn on the drive motor operating switch of the burner drive system.
Turn on MS and operate drive motor 1. Then, the burner 6 reciprocates in the axial direction of the steel material E via the reciprocating mechanism 3 of the burner drive system, and heats the abutting ends of the two steel materials E.

When the abutted ends of the two steel materials become red hot due to the heating and pressurization described above, the pre-work is completed, and then the main work is started. In other words, the high pressure switch PS1 is set by the control system changeover switch P1.
Switch from the operating side to the low-pressure pressure switch PS2 operating side, and activate the low-pressure pressure switch PS2 and integration timer T1. Then, the drive motor M repeats the stop and operation following the previous operation due to the ON-OFF operation of the low-pressure pressure switch PS2, and as a result, the hydraulic ram 8 moves to a predetermined value, which is the set value of the low-pressure pressure switch PS2, in the low-pressure region. Two steel materials E are pressurized between the upper limit pressure and the lower limit pressure. That is, when the pressure of the hydraulic ram 8 reaches a predetermined lower limit pressure in the low pressure region, the drive motor M is activated, and when the pressure of the hydraulic ram 8 reaches a predetermined upper limit pressure in the low pressure region, the drive motor M is stopped and the hydraulic ram is activated. As shown in FIG. 6, two steel materials E are pressurized between a predetermined upper limit pressure and lower limit pressure in a low pressure region. Turn on the low pressure switch PS2 mentioned above.
The operation of the OFF operation is as follows. Relay R2 for this work operation is activated by turning on changeover switch P1 and self-holding by turning on contact R2a _-1 .
Further, when the contact R2a _-2 is turned on, power is applied to the input side of the drive motor M via the low pressure switch PS2. The drive motor M operates when the timer contact T1b is normally closed. On the other hand, contact R2a _-3
When turned on, the timer TM is activated (this timer is provided to detect the end of work). Thereafter, when the low pressure switch PS2 is ON, the drive motor M operates, and when it is OFF, it stops, and this process is repeated. It should be noted that the ON/OFF repetition of this low pressure switch PS2 changes depending on the external environment such as the strength of the wind, as shown in FIGS. 6 and 7. On the other hand, the integration timer T1 integrates the operating time t of the drive motor M (the time during which the pressure of the hydraulic ram 8 in the graph of FIG. 6 reaches from the lower limit pressure to the upper limit pressure, that is, the operating time of the hydraulic ram 8). Furthermore, the burner 6 of the heating system heats the abutting ends of the two steel materials E while reciprocating following the previous operation.

Then, when the cumulative time t of the cumulative timer T1 reaches a predetermined time, the buzzer BZ is activated to notify the worker of the end of this work. This integration timer T1
Contact T1b changes from ON to OFF due to time-up.
, and relay R1 turns OFF. This turns contact R1a OFF and the solenoid valve
SOL1 is de-energized. On the other hand, the above buzzer BZ
continues to operate (sound the buzzer) while contact T1a of integration timer T1 is ON. The operation of this buzzer BZ is based on the integration timer T1.
will continue until it is reset. The integration timer T1 is reset by turning off the switch SW1.

As described above, since the working time of the drive motor M is constant regardless of the external environment, the pressurizing operation time of the hydraulic ram 8, that is, the amount of movement is constant, and the steel material E
The amount of compression becomes constant, and a bulge of a predetermined size is formed. That is, the upward and downward fluctuations in the pressure of the hydraulic ram 8 vary significantly depending on external environments such as changes in the flow rate of gas and changes in the strength of the wind. For example, if the wind is strong and the flame of burner 6 is blown away,
The melting temperature of the steel material E is low, the amount of shrinkage of the steel material E is correspondingly small, and therefore the pressure of the hydraulic ram 8 is as shown in Fig. 7a.
If the temperature rises suddenly as shown in , and the wind is weak and the flame of the burner 6 is not blown away, the melting temperature of the steel material E is high, and the amount of shrinkage of the steel material E is correspondingly large.
Therefore, the pressure of the hydraulic ram 8 rises gradually as shown in FIG. 7b, but the cumulative time of the pressure rise time of the hydraulic ram 8 (driving time of the drive motor M) t _a or t _b is constant. Since the speed of the hydraulic ram 8 is also constant, the amount of movement of the hydraulic ram 8 is constant.
Therefore, the amount of shrinkage of the steel material E remains constant regardless of the vertical fluctuations in the pressure of the hydraulic ram 8 caused by the external environment, and therefore a bulge of a predetermined size is formed. Note that the steel material E will shrink somewhat due to the residual pressure of the hydraulic ram 8, that is, the pressure while the pressure falls from the predetermined upper limit to the predetermined lower limit, but the amount of shrinkage is extremely small, so the amount of shrinkage when the hydraulic ram 8 is activated as described above can be ignored without adding to it.

As mentioned above, if the cumulative time t of the cumulative timer T1 reaches the predetermined time and the buzzer BZ is activated,
Pressure system solenoid valve operation switch SW1 and drive motor operation switch TSW1 are turned OFF, solenoid valve SOL1 is closed via relay R1, and drive motor M and hydraulic ram 8 are turned OFF.
On the other hand, extinguish burner 6 of the heating system, and turn off the drive motor operating switch MS of the burner drive system.
to stop the drive motor M, then stop the low pressure switch PS2 of the control system, and
By resetting the integration timer T1 via the switch SW1, a bulge of a predetermined size is formed at the abutting portion of the two steel materials E, and this work is completed.

In addition, in the block diagrams of Figures 3 to 5, ○A, ○B, ○C, and ○D in Figure 3 correspond to ○I, ○B, and ○D in Figure 4.
○Ro,
Following ○c and ○d, ○ho, ○he, ○to, and ○chi in Figure 4 follow ○ho, ○he, ○to, and ○chi in Figure 5, respectively.

Furthermore, in the above embodiment, the switching from the previous work to the main work is performed visually, but the above-mentioned integration timer T1 and a separate timer are used to automatically switch from the previous work to the main work. You can go.

As is clear from the above embodiments, the control device for the gas pressure welding machine of the present invention monitors the pressurizing operation time of the pressurizing means to maintain a constant pressure, so it is not affected by the external environment. However, it is possible to always form a bulge of a predetermined size, and therefore the strength of gas pressure welding can be stabilized and improved.

Note that, as a matter of course, the control device for the gas pressure welding machine of the present invention is not limited to the above-described embodiments. For example, the control circuit can be similarly realized using a logic circuit in addition to a relay circuit. Further, the control device of the present invention can be used with gas pressure welding machines other than the above-mentioned automatic gas pressure welding machines.

[Brief explanation of drawings]

The accompanying drawings show an embodiment of the control device for the gas pressure welding machine of the present invention, and FIG. 1 is a schematic diagram of an automatic gas pressure welding machine equipped with the control device of the present invention, and FIG. Electrical circuit diagram of control device, 3rd
5 to 5 are block diagrams of the work steps performed by the control device in the gas pressure welding machine of the present invention, and FIGS. 6 and 7 a and 7 are graphs showing the relationship between pressure fluctuations in the hydraulic ram and time. A... Automatic gas pressure welding machine, 1... Drive motor, 2
...Holder, 3...Reciprocating mechanism, 4...Fixing reinforcing bar clamp holder, 5...Moving reinforcing bar clamp holder, 6...Burner, 8...Hydraulic ram, E...Steel material, PS1...
Pressure switch for high pressure, PS2...pressure switch for low pressure, P1...changeover switch, T1...integration timer, BZ...buzzer, M...drive motor, SOL
1... Solenoid valve, TSW1... Drive motor operating switch, SW1... Solenoid valve operating switch.

Claims (1)

[Claims] 1. A fixed reinforcing bar clamping tool and a movable reinforcing bar clamping part that clamp two reinforcing bars, a pressurizing means attached to the fixed reinforcing bar clamping part and the moving reinforcing bar clamping part, and a reciprocating mechanism linked to a drive part. and a burner attached to the reciprocating mechanism, the fixed reinforcing bar clamping part and the movable reinforcing bar clamping part respectively clamp two reinforcing bars, and the driving part is driven to reciprocate the burner to reciprocate the two reinforcing bars. In a gas pressure welding machine that connects two reinforcing bars by operating the pressure means to pressurize two reinforcing bars while heating the reinforcing bars, the gas pressure welding machine connects to the pressure means and pressurizes the two reinforcing bars. Pressure switch means that stops the operation of the pressurizing means when the pressurizing force reaches a set upper limit pressure value, and starts the operation of the pressurizing means when the pressurizing force of the pressurizing means reaches a set lower limit pressure value. , a drive time integration means connected to the pressure means and for integrating the drive time of the pressure means; and a drive time integration means connected to the drive time integration means, when the cumulative time of the drive time integration means reaches a predetermined time. and work stop notification means for notifying the completion and stop of the work, and configured to operate the pressure control means and the drive time integration means at the stage of the main work after the completion of the previous work, and to integrate the drive time of the pressurizing means. A control device for a gas pressure welding machine characterized by the following.