JP5240892B2 - Cooling water stop device for electric resistance spot welding machine, and electric resistance spot welding machine provided with the same - Google Patents

Description

The present invention relates to a water stop device for a cooling water of an electric resistance spot welding machine capable of preventing leakage of the cooling water when replacing an electrode of the electric resistance spot welding machine , and an electric resistance spot welding provided with the same. Related to the machine .

  Conventionally, as shown in Non-Patent Document 1, an electric resistance spot welder is configured to press and energize a work with an upper electrode and a lower electrode sandwiched between the upper electrode and the lower electrode, and the work is caused by electric resistance heat flowing in the work (member to be welded). It is widely used when welding white bodies of automobiles and the like.

  In this electric resistance spot welding, since the workpiece is welded with electric resistance heat by the current flowing between the electrodes, the electrodes are always exposed to heat. In order to prevent the electrode from welding to the workpiece due to this heat, as shown in FIG. 8, a water cooling pipe 51 facing the inside of the electrode 52 is provided in the electrode holder 50 and supplied from the water cooling pipe 51. The cap chip type electrode 52 was cooled with the cooling water.

  On the other hand, the shape of the tip of an electrode used in an electric resistance spot welder is deformed due to applied pressure or wear. If the electrode is deformed, the workpiece may be scratched, causing welding failure or spattering. For this reason, it is necessary to make the surface shape smooth by cutting the electrode with a tip dresser or the like every predetermined number of times of welding (for example, 1500 to 5000 times). However, since the number of electrodes decreases every time cutting is performed, there is a limit to the number of times of cutting, and when cutting a predetermined number of times, it is necessary to replace the entire electrode.

  When the electrode 52 is replaced, the supply of the cooling water is stopped and then the electrode 52 is replaced. However, even if the supply of the cooling water is stopped, the path of the cooling water such as the electrode holder 50 and the water cooling pipe 51 In this case, since the cooling water remains, the remaining cooling water is discharged from the electrode holder 50 and the water cooling pipe 51 when the electrode 52 is removed. Spills on the floor. For this reason, when replacing the electrode 52, it is necessary for an operator to place a bucket or the like under the electrode holder 50 to receive the cooling water, which is troublesome.

Chuo Seisakusho Co., Ltd. Electric resistance spot welder catalog

Provided is a water stop device for a cooling water of an electric resistance spot welding machine capable of preventing leakage of the cooling water when replacing an electrode of the electric resistance spot welding machine , and an electric resistance spot welding machine having the same To do.

The present invention made to solve the above problems is used in an electric resistance spot welding machine having a cooling water supply pipe that supplies cooling water to an electrode and a cooling water discharge pipe that discharges cooling water that has cooled the electrode. A cooling water stop device,
A solenoid valve for a cooling water supply pipe that shuts off the cooling water flowing through the cooling water supply pipe;
A compressed air supply pipe for supplying compressed air to the cooling water supply pipe on the electrode side of the electromagnetic valve for the cooling water supply pipe;
A solenoid valve for a compressed air supply pipe that blocks the compressed air flowing through the compressed air supply pipe;
In a cooling water stop device provided with control means for controlling opening and closing of the electromagnetic valve for cooling water supply pipe and the electromagnetic valve for compressed air supply pipe,
The cooling water discharge pipe is provided with a solenoid valve for cooling water discharge pipe that blocks the flow of cooling water,
When this cooling water discharge pipe solenoid valve is closed, the remaining water discharge pipe for discharging the cooling water discharged from the electrode is branched and connected,
This residual water discharge pipe is provided with a residual water discharge pipe solenoid valve that shuts off the cooling water ,
Further, when stopping the cooling water, the control means closes the cooling water supply pipe solenoid valve to shut off the cooling water supply, closes the cooling water discharge solenoid valve, and closes the residual water discharge pipe solenoid valve. The cooling water discharged from the electrode is discharged through the residual water discharge pipe, the compressed air supply pipe solenoid valve is opened for a predetermined time and compressed air is supplied to the cooling water supply pipe for a predetermined time, and then the compressed air supply is performed. In order to control the solenoid valve for the pipe, the cooling water supply of the electric resistance spot welder is prevented from causing poor cooling of the electrode due to air entering the cooling water supply pipe. It is a water device.

  In addition, it is preferable to provide a gas-liquid separator that removes air from the cooling water discharged through the residual water discharge pipe.

  In addition, a pressure sensor for detecting the water pressure of at least one of the cooling water supply pipe and the cooling water discharge pipe is provided, and when the water is not stopped, the pressure sensor has a water pressure of at least one of the cooling water supply pipe and the cooling water discharge pipe. When detecting that it has fallen, it is preferable that a control means performs control which closes the solenoid valve for cooling water supply pipes.

  An example of an electric resistance spot welder that embodies the method of stopping the cooling water of the electric resistance spot welder of the present invention includes a cooling water supply pipe that supplies cooling water to the electrode, and discharges the cooling water that has cooled the electrode. In an electrical resistance spot welder having a cooling water discharge pipe, a cooling water supply pipe electromagnetic valve for cutting off the supply of cooling water is provided in the cooling water supply pipe, and the cooling water supply on the electrode side of the electromagnetic valve for the cooling water supply pipe is provided. A compressed air supply pipe for supplying compressed air is branched and connected to the pipe, and the compressed air supply pipe is provided with a solenoid valve for compressed air supply pipe for cutting off the supply of compressed air. The solenoid valve for cooling water supply pipe and the compressed air Control means for controlling opening and closing of the supply pipe solenoid valve is provided.

  A check valve is provided to prevent the cooling water discharged through the cooling water discharge pipe from flowing back to the electrode side, and when the cooling water is stopped, the control means closes the electromagnetic valve for the cooling water supply pipe. It is preferable to control to close the compressed air supply pipe electromagnetic valve after shutting off the supply of the cooling water, opening the compressed air supply pipe electromagnetic valve for a predetermined time to supply the compressed air into the cooling water supply pipe.

  Alternatively, the cooling water discharge pipe is provided with a solenoid valve for cooling water discharge pipe that shuts off the cooling water flowing through the cooling water discharge pipe, and the residual water is discharged into the cooling water discharge pipe closer to the electrode than the solenoid valve for cooling water discharge pipe. The residual water discharge pipe solenoid valve that shuts off the cooling water is provided in the residual water discharge pipe, and the control means closes the cooling water supply pipe electromagnetic valve and stops the cooling water when the cooling water is stopped. The cooling water discharge solenoid valve is closed, the residual water discharge pipe solenoid valve is opened, and the cooling water discharged from the electrode is discharged through the residual water discharge pipe, and the compressed air supply pipe electromagnetic It is preferable to perform control to close the solenoid valve for the compressed air supply pipe after opening the valve for a predetermined time and supplying compressed air to the cooling water supply pipe for a predetermined time.

  In addition, a gas-liquid separator that removes air from the cooling water discharged through the residual water discharge pipe is provided, and the cooling water from which air has been removed by the gas-liquid separator is supplied to the cooling water supply pipe and circulated again. It is preferable.

  In addition, a pressure sensor for detecting the water pressure of at least one of the cooling water supply pipe and the cooling water discharge pipe is provided, and when the water is not stopped, the pressure sensor has a water pressure of at least one of the cooling water supply pipe and the cooling water discharge pipe. When detecting that it has fallen, it is preferable that a control means performs control which closes the solenoid valve for cooling water supply pipes.

  The cooling water supplied from the cooling water supply pipe is shut off, compressed air is supplied into the cooling water supply pipe for a predetermined time, and the cooling water remaining in the cooling water supply pipe and the cooling water discharge pipe is allowed to accompany the compressed air. Since the cooling water is discharged, the cooling water is removed from the cooling water supply pipe, the cooling pipe, and the cooling water discharge pipe, so that it is possible to prevent leakage of the cooling water even if the electrode is removed.

  Note that if the cooling water accompanying the compressed air is discharged through the cooling water discharge pipe, the cooling water is removed from the cooling water supply pipe, cooling pipe, and cooling water discharge pipe. Can be prevented.

  Alternatively, if the cooling water accompanying the compressed air is discharged through the remaining water discharge pipe branched and connected to the cooling water discharge pipe, air is mixed into the cooling water supply pipe, resulting in poor cooling of the electrode. Can be prevented.

  In addition, when air is removed from the cooling water discharged through the residual water discharge pipe accompanying the compressed air and the cooling water from which the air has been removed is supplied to the cooling water supply pipe, air is mixed into the cooling water supply pipe. Therefore, it is possible to prevent the electrode from being poorly cooled, and the cooling water is returned to the cooling water supply pipe again without being discharged to the outside. There is no discharge.

  Solenoid valve for cooling water supply pipe that shuts off the cooling water flowing through the cooling water supply pipe, compressed air supply pipe that supplies compressed air to the cooling water supply pipe on the electrode side of the electromagnetic valve for cooling water supply pipe, and the compressed air Compressed air supply pipe solenoid valve for blocking compressed air flowing through the supply pipe, and control means for controlling opening and closing of the cooling water supply pipe solenoid valve and the compressed air supply pipe solenoid valve are provided, so that cooling is possible even when the electrode is removed. It has become possible to provide a water stop device for cooling water in which water does not leak. In addition, because the control means opens and closes the solenoid valve for the cooling water supply pipe and the solenoid valve for the compressed air supply pipe, the operator operates the manual shutoff valve to open and close the cooling water supply pipe and the compressed air supply pipe. Compared to the cooling water stop device, the work of stopping the water can be saved.

  In addition, a check valve is provided to prevent the cooling water discharged through the cooling water discharge pipe from flowing back to the electrode side, and when the cooling water is stopped, the control means closes the electromagnetic valve for the cooling water supply pipe for cooling. When the supply of water is shut off, the compressed air supply pipe solenoid valve is opened for a predetermined time and compressed air is supplied into the cooling water supply pipe for a predetermined time, and then the compressed air supply pipe solenoid valve is closed, the cooling water supply pipe or cooling Since the cooling water is removed from the inside of the pipe and the cooling water discharge pipe, it is possible to provide a cooling water stopping device in which the cooling water does not leak even if the electrode is removed.

  Alternatively, the cooling water discharge pipe is provided with a solenoid valve for cooling water discharge pipe that blocks the flow of cooling water, and the residual water discharge that discharges the cooling water discharged from the electrode when the solenoid valve for cooling water discharge pipe is closed. The residual water discharge pipe solenoid valve for shutting off the cooling water is provided in the residual water discharge pipe by branching the pipe, and when stopping the cooling water, the control means closes the cooling water supply pipe electromagnetic valve to close the cooling water Shut off the supply, close the solenoid valve for cooling water discharge, open the solenoid valve for residual water discharge pipe, discharge the cooling water discharged from the electrode to the residual water discharge pipe, and solenoid valve for compressed air supply pipe If the control is performed to close the solenoid valve for the compressed air supply pipe after the compressed air is supplied to the cooling water supply pipe for a predetermined time after being opened for a predetermined time, the cooling water supply pipe is mixed with air, resulting in poor cooling of the electrode. Cooling water stop that can prevent It is possible to provide a device.

  In addition, if a gas-liquid separator that removes air from the cooling water discharged through the residual water discharge pipe is provided, it is possible to prevent air from entering the cooling water supply pipe and causing poor cooling of the electrode. It is possible to provide a cooling water stop device. Further, since the cooling water is returned again to the cooling water supply pipe without discharging the cooling water to the outside, it is possible to prevent the cooling water from being discharged to the outside wastefully.

  In addition, a pressure sensor for detecting the water pressure of at least one of the cooling water supply pipe and the cooling water discharge pipe is provided, and when the water is not stopped, the pressure sensor has a water pressure of at least one of the cooling water supply pipe and the cooling water discharge pipe. When it is detected that the temperature has decreased, the control means controls the solenoid valve for the cooling water supply pipe to close, and the electrode is detached from the electrode holder due to welding or being caught by the work piece. However, the pressure sensor detects a drop in the water pressure in the cooling water supply pipe and the cooling water discharge pipe, closes the solenoid valve for the cooling water supply pipe, and shuts off the cooling water supply. It is possible to provide a cooling water stop device that can be prevented.

  In an electrical resistance spot welding machine having a cooling water supply pipe for supplying cooling water to an electrode and a cooling water discharge pipe for discharging cooling water that has cooled the electrode, cooling water for cutting off the supply of cooling water to the cooling water supply pipe A supply pipe solenoid valve is provided, and a compressed air supply pipe for supplying compressed air is branched and connected to the cooling water supply pipe on the electrode side of the solenoid valve for the cooling water supply pipe, and the compressed air is supplied to the compressed air supply pipe. Since the solenoid valve for the compressed air supply pipe to be shut off is provided and the control means for controlling the opening and closing of the solenoid valve for the cooling water supply pipe and the solenoid valve for the compressed air supply pipe is provided, the cooling water may leak even if the electrode is removed. It became possible to provide no electrical resistance spot welder. In addition, because the control means opens and closes the solenoid valve for the cooling water supply pipe and the solenoid valve for the compressed air supply pipe, the operator operates the manual shutoff valve to open and close the cooling water supply pipe and the compressed air supply pipe. Compared to the electric resistance spot welding machine, it is possible to eliminate the trouble of water stopping work.

  A check valve is provided to prevent the cooling water discharged through the cooling water discharge pipe from flowing back to the electrode side, and when the cooling water is stopped, the control means closes the electromagnetic valve for the cooling water supply pipe. When the supply of cooling water is shut off, the compressed air supply pipe solenoid valve is opened for a predetermined time and compressed air is supplied into the cooling water supply pipe, and then the compressed air supply pipe solenoid valve is closed, the cooling water supply pipe and the cooling pipe are controlled. Since the cooling water is removed from the cooling water discharge pipe, it is possible to provide an electric resistance spot welder in which the cooling water does not leak even if the electrode is removed.

  Alternatively, the cooling water discharge pipe is provided with a solenoid valve for cooling water discharge pipe that shuts off the cooling water flowing through the cooling water discharge pipe, and the residual water is discharged into the cooling water discharge pipe closer to the electrode than the solenoid valve for cooling water discharge pipe. The residual water discharge pipe solenoid valve that shuts off the cooling water is provided in the residual water discharge pipe, and the control means closes the cooling water supply pipe electromagnetic valve and stops the cooling water when the cooling water is stopped. The cooling water discharge solenoid valve is closed, the residual water discharge pipe solenoid valve is opened, and the cooling water discharged from the electrode is discharged through the residual water discharge pipe, and the compressed air supply pipe electromagnetic When the valve is opened for a predetermined time and compressed air is supplied to the cooling water supply pipe for a predetermined time, and then the solenoid valve for the compressed air supply pipe is controlled to be closed, air enters the cooling water supply pipe, Electricity that can prevent the occurrence of defects It is possible to provide a resistance spot welder.

  In addition, a gas-liquid separator that removes air from the cooling water discharged through the residual water discharge pipe is provided, and the cooling water from which air has been removed by the gas-liquid separator is supplied to the cooling water supply pipe and circulated again. In addition, it is possible to provide an electric resistance spot welder that can prevent air from being mixed into the cooling water supply pipe and causing poor cooling of the electrode. Further, since the cooling water is returned again to the cooling water supply pipe without discharging the cooling water to the outside, it is possible to prevent the cooling water from being discharged to the outside wastefully.

  In addition, a pressure sensor for detecting the water pressure of at least one of the cooling water supply pipe and the cooling water discharge pipe is provided, and when the water is not stopped, the pressure sensor has a water pressure of at least one of the cooling water supply pipe and the cooling water discharge pipe. When it is detected that the temperature has decreased, the control means controls the solenoid valve for the cooling water supply pipe to close, and the electrode is detached from the electrode holder due to welding or being caught by the work piece. However, the pressure sensor detects a drop in the water pressure in the cooling water supply pipe and the cooling water discharge pipe, closes the solenoid valve for the cooling water supply pipe, and shuts off the cooling water supply. It is possible to provide an electric resistance spot welder that can be prevented.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view showing a reference embodiment of the present invention. Reference numeral 1 denotes an electric resistance spot welder main body, and an electrode holder 2 is attached to the electric resistance spot welder main body 1 so as to face each other. A cap chip type electrode 3 is attached to the tip of the electrode holder 2. When the electrode holder 2 is separated, the opposed electrodes 3 are also separated from each other. The workpiece is sandwiched between the opposed electrodes 3 and pressurized and energized to flow to the workpiece. The work piece is melted and welded with electric resistance heat.

  FIG. 2 shows a detailed view of the electrode portion. As shown in FIG. 2, the electrode holder 2 is hollow, and a substantially cylindrical cooling pipe 4 is accommodated inside the electrode holder 2. The tip of the cooling pipe 4 is disposed so as to face the inside of the cap chip type electrode 3. Cooling water is supplied into the electrode 3 from the cooling pipe 4 to cool the electrode 3.

  In FIG. 1, reference numeral 10 denotes a cooling water supply pipe, which is connected to the cooling pipe 4. The cooling water is supplied from the cooling water supply pipe 10 to the electrode 3 through the cooling pipe 4.

  The cooling water that has cooled the electrode 3 flows through the inside of the electrode holder 2 outside the cooling water pipe 4 and is discharged, as shown in FIG. In FIG. 1, reference numeral 11 denotes a cooling discharge pipe, which is connected to the electrode holder 2, and the cooling water discharged through the inside of the electrode holder 2 outside the cooling water pipe 4 is discharged outside through the cooling water supply pipe 11. It has come to be. In addition, the pressure of the cooling water which distribute | circulates the inside of the cooling water supply pipe | tube 10 and the cooling water discharge pipe 11 is 0.15-MPa (gauge pressure). In the present embodiment, the cooling water supplied from the cooling water supply pipe 10 first cools the upper electrode and then cools the lower electrode.

  The cooling water supply pipe 10 is provided with a cooling water supply pipe electromagnetic valve 12. The cooling water supply pipe solenoid valve 12 is closed when energized to cut off the supply of cooling water.

  In the present embodiment, the cooling water discharged from the cooling water discharge pipe 11 is supplied again to the cooling water supply pipe 10 through the cooling water supply pipe electromagnetic valve 12 so that the cooling water circulates. The cooling water discharged through the cooling water discharge pipe 11 may be discharged to the outside without being circulated through the cooling water supply pipe 10. When circulating the cooling water discharged through the cooling water discharge pipe 11 to the cooling water supply pipe 10, the cooling water discharged through the cooling water discharge pipe 11 is stored in one water storage tank. It is preferable to supply to the cooling water supply pipe 10. In this case, there is an advantage that the cooling water is cooled in the water storage tank and the temperature of the cooling water supplied to the electrode 3 is stabilized.

  A compressed air supply pipe 13 that supplies compressed air to the cooling water supply pipe 12 is branched and connected to the cooling water supply pipe 10 on the electrode 3 side of the electromagnetic valve 12 for the cooling water supply pipe. The compressed air supply pipe 13 is provided with a compressed air supply pipe solenoid valve 14 for blocking the supply of compressed air. The compressed air supply pipe solenoid valve 14 is opened when energized to supply compressed air to the cooling water supply pipe 10.

  A pressure regulator 15 is provided upstream of the compressed air supply pipe solenoid valve 14, and the compressed air is adjusted to a pressure of 0.4 MPa to 0.7 MPa (gauge pressure) by the pressure regulator 15.

  The cooling water discharge pipe 11 is provided with a check valve 16. The check valve 16 prevents the cooling water discharged to the cooling water discharge pipe 11 from flowing backward to the electrode 3 side.

  A pressure sensor 17 measures the water pressure in the cooling water supply pipe 10 and the cooling water discharge pipe 11.

  Reference numeral 18 denotes control means for controlling the opening / closing of the cooling water supply pipe solenoid valve 12 and the compressed air supply pipe solenoid valve 14. A switch 19 is connected to the control means 18. Alternatively, an operation signal and a stop signal are input to the control means 18 from the outside.

  In FIG. 3, the time chart of 1st Embodiment is shown and operation | movement of the water stop method of invention of 1st Embodiment is demonstrated. When replacing the electrode 3, in order to prevent leakage of the cooling water, the cooling water supply is shut off, and the cooling water remaining in the cooling water supply pipe 10, the cooling pipe 4, and the cooling water discharge pipe 11 is removed. Must.

  When the operator operates the switch 19 to the ON side or when an operation signal is input to the control means 18, the control means 18 supplies current to the cooling water supply pipe electromagnetic valve 12, and the cooling water supply pipe electromagnetic The valve 12 is closed and the cooling water supply is shut off.

  Further, the control means 18 inputs a current a to the compressed air supply pipe electromagnetic valve 14 for a predetermined time a, opens the compressed air supply pipe electromagnetic valve 14 for a predetermined time a, and then supplies the compressed air for a predetermined time a in the cooling water supply pipe 10. Supply. At this time, the cooling water remaining in the cooling water supply pipe 10, the cooling pipe 4, and the cooling water discharge pipe 11 is discharged to the outside through the cooling water discharge pipe 11 along with the compressed air.

  Since the cooling water is removed from the cooling water supply pipe 10, the cooling pipe 4, and the cooling water discharge pipe 11, the cooling water does not leak even when the electrode 3 is removed. When the replacement operation of the electrode 3 is completed and the operator operates the switch 19 to turn it OFF or a stop signal is input to the control means 18, the control means 18 moves to the electromagnetic valve 12 for the cooling water supply pipe. Then, the cooling water supply pipe solenoid valve 12 is opened, and the cooling water is supplied from the cooling water supply pipe 10 to the electrode 3 through the cooling pipe 4.

  The predetermined time a during which the current is supplied to the compressed air supply pipe solenoid valve 14 depends on the amount of cooling water remaining in the cooling water supply pipe 10, the cooling pipe 4, and the cooling water discharge pipe 11, but these cooling water supply pipes 10, a sufficient time for discharging the cooling water remaining in the cooling pipe 4 and the cooling water discharge pipe 11. When the amount of cooling water remaining in the cooling water supply pipe 10, the cooling pipe 4, and the cooling water discharge pipe 11 is 200 cc, the predetermined time a for supplying current to the compressed air supply pipe electromagnetic valve 14 is: 0.5 to 1 second. As shown in FIG. 3, in this embodiment, the control means 18 opens the compressed air supply pipe electromagnetic valve 14 simultaneously with closing the cooling water supply pipe electromagnetic valve 12. After the supply pipe solenoid valve 12 is opened, the compressed air supply pipe solenoid valve 14 may be controlled to be opened.

  It should be noted that by using an electromagnetic valve instead of the check valve 16 and opening and closing the electromagnetic valve, the cooling water discharged through the cooling water discharge pipe 11 can be prevented from flowing back to the electrode 3 side. Absent.

  The electrode 3 may fall off from the electrode holder 2 by being welded to the work piece or being caught by the work piece. If the electrode 3 falls off from the electrode holder 2, the cooling water leaks. For this reason, when the electrode 3 falls off and the water pressure in the cooling water supply pipe 10 and the cooling water discharge pipe 11 decreases, the pressure sensor 17 detects the water pressure in the cooling water supply pipe 10 and the cooling water discharge pipe 11. The control unit 18 detects the decrease, and controls the solenoid valve 12 for cooling water supply pipe to close the cooling water supply pipe solenoid valve 12 to shut off the supply of cooling water. Prevents leakage. Note that when the pressure sensor 17 detects a decrease in the water pressure in the cooling water supply pipe 10 or the cooling water discharge pipe 11, the abnormality may be notified by a buzzer or the like, or the welding line may be stopped.

Next, a description diagram of a first embodiment in FIG. 4, the first embodiment is described. Electrical resistance spot welder main body 1, electrode holder 2, electrode 3, cooling pipe 4, cooling water supply pipe 10, cooling water discharge pipe 11, cooling water supply pipe solenoid valve 12, compressed air supply pipe of the first embodiment 13. The compressed air supply pipe solenoid valve 14, the pressure regulator 15, and the pressure sensor 17 are the same as those in the reference embodiment .

However, in the first embodiment, instead of the check valve 16, the cooling water discharge pipe 11 is provided with a cooling water discharge pipe electromagnetic valve 20 that blocks the cooling water. The cooling water discharge pipe solenoid valve 20 is closed when energized. Further, a residual water discharge pipe 21 is branched and connected to the cooling water discharge pipe 11 closer to the electrode 3 than the electromagnetic valve 20 for the cooling water discharge pipe.

  The residual water discharge pipe 21 is provided with a residual water discharge pipe solenoid valve 22 for blocking the cooling water. This residual water discharge pipe solenoid valve 22 is opened when energized.

  Reference numeral 23 denotes control means for controlling the opening and closing of the cooling water supply pipe solenoid valve 12 and the compressed air supply pipe solenoid valve 14, the cooling water discharge pipe solenoid valve 20, and the residual water discharge pipe solenoid valve 22. A switch 19 is connected to the control means 23. Alternatively, an operation signal and a stop signal are input to the control means 23 from the outside.

In FIG. 5, the time chart of 1st Embodiment is shown and operation | movement of the cooling water stop method of invention of 1st Embodiment is demonstrated. When the operator operates the switch 19 to the ON side or an operation signal is input to the control means 23, the control means 23 supplies current to the cooling water supply pipe solenoid valve 12, and the cooling water supply pipe electromagnetic The valve 12 is closed and the cooling water supply is shut off.

  Further, the control means 23 supplies current to the residual water discharge pipe electromagnetic valve 22 and opens the cooling water discharge pipe electromagnetic valve 22, and simultaneously supplies current to the cooling water discharge pipe electromagnetic valve 20, thereby cooling the cooling water discharge pipe electromagnetic valve. The valve 20 is closed so that the cooling water discharged from the electrode 3 is discharged through the residual water discharge pipe 21.

  In addition, the control means 23 supplies a current a to the compressed air supply pipe electromagnetic valve 14 for a predetermined time a, opens the compressed air supply pipe electromagnetic valve 14 for a predetermined time a, and enters the cooling water supply pipe 10 for a predetermined time a compressed air. Supply. The cooling water remaining in the cooling water supply pipe 10, the cooling pipe 4, and the cooling water discharge pipe 11 is discharged to the outside through the remaining water discharge pipe 21 along with the compressed air.

  After the predetermined time “a” has elapsed, the control means 23 cuts off the supply of current to the residual water discharge pipe solenoid valve 22 and closes the residual water discharge pipe solenoid valve 22.

  Since the cooling water is removed from the cooling water supply pipe 10, the cooling pipe 4, and the cooling water discharge pipe 11, the cooling water does not leak even if the electrode 3 is removed. When the replacement work of the electrode 3 is completed and the operator operates the switch 19 to turn it OFF or a stop signal is input to the control means 23, the control means 23 is connected to the solenoid valve 12 for the cooling water supply pipe and The current supply to the cooling water discharge pipe solenoid valve 20 is cut off, the cooling water supply pipe solenoid valve 12 and the cooling water discharge pipe solenoid valve 20 are opened, and the cooling water flows from the cooling water supply pipe 10 through the cooling pipe 4 to the electrode 3. To be supplied.

As described above, in the first embodiment, when the water is stopped, the cooling water discharged along with the compressed air is discharged through the residual water discharge pipe 22 instead of the cooling water discharge pipe 11. It is possible to prevent air from entering the supply pipe 10 and causing a cooling failure of the electrode 3.

Figure 6 shows a diagram of a second embodiment, the second embodiment is described. Electric resistance spot welder body 1, electrode holder 2, electrode 3, cooling pipe 4, cooling water supply pipe 10, cooling water discharge pipe 11, cooling water supply pipe electromagnetic valve 12, compressed air supply pipe of the second embodiment 13. Compressed air supply pipe solenoid valve 14, pressure regulator 15, pressure sensor 17, cooling water discharge pipe solenoid valve 20, residual water discharge pipe 21, and residual water discharge pipe solenoid valve 22 are the same as in the first embodiment. is there.

In the second embodiment, a gas-liquid separator 25 is connected to the outlet of the residual water discharge pipe 21. Reference numeral 25a denotes an air filter, which discharges air from the air filter 25a and prevents foreign matter from entering the gas-liquid separator 25.

  A gas-liquid separator outlet solenoid valve 26 is provided at the outlet of the gas-liquid separator 25. The gas-liquid separator outlet solenoid valve 26 is opened when energized.

  Reference numeral 27 denotes control means for opening and closing the cooling water supply pipe solenoid valve 12, the compressed air supply pipe solenoid valve 14, the cooling water discharge pipe solenoid valve 20, the residual water discharge pipe solenoid valve 22, and the gas-liquid separator outlet solenoid valve 26. Control. A switch 19 is connected to the control means 27. Alternatively, an operation signal and a stop signal are input to the control means 27 from the outside.

In FIG. 7, the time chart of 2nd Embodiment is shown and operation | movement of the cooling water stop method of invention of 2nd Embodiment is demonstrated. When the operator operates the switch 19 to turn it on or an operation signal is input to the control means 27, the control means 27 supplies current to the cooling water supply pipe solenoid valve 12, and the cooling water supply pipe electromagnetic The valve 12 is closed and the cooling water supply is shut off.

  Further, the control means 27 supplies current to the residual water discharge pipe solenoid valve 22, opens the residual water discharge pipe solenoid valve 22, and simultaneously supplies current to the cooling water discharge pipe solenoid valve 20, thereby cooling the cooling water discharge pipe solenoid. The valve 20 is closed so that the cooling water discharged from the electrode 3 is discharged through the residual water discharge pipe 21.

  Further, the control means 27 supplies a current a to the compressed air supply pipe electromagnetic valve 14 for a predetermined time a, opens the compressed air supply pipe electromagnetic valve 14 for a predetermined time a, and supplies the compressed air for a predetermined time a in the cooling water supply pipe 10. Supply. The cooling water remaining in the cooling water supply pipe 10, the cooling pipe 4, and the cooling water discharge pipe 11 is discharged to the gas-liquid separator 25 through the remaining water discharge pipe 21 along with the compressed air.

  The cooling water discharged to the gas-liquid separator 25 is retained in the gas-liquid separation tank 25b in the gas-liquid separator 25 for a predetermined time, and the air is separated.

  After the predetermined time “a” has elapsed, the control means 27 cuts off the supply of current to the residual water discharge pipe electromagnetic valve 22 and closes the residual water discharge pipe electromagnetic valve 22, and simultaneously closes the gas-liquid separator outlet electromagnetic valve 26 for a predetermined time. b current is supplied, the gas-liquid separator outlet solenoid valve 26 is opened for a predetermined time b, and the cooling water from which air has been removed is discharged through the gas-liquid separator 25. The discharged cooling water is supplied to the cooling water supply pipe 10 through the cooling water supply pipe side electromagnetic valve 12 and circulates again.

  After a predetermined time b has elapsed, the control means 27 cuts off the supply of current to the gas-liquid separator outlet solenoid valve 26 and closes the gas-liquid separator outlet solenoid valve 26.

  Since the cooling water is removed from the cooling water supply pipe 10, the cooling pipe 4, and the cooling water discharge pipe 11, the cooling water does not leak even if the electrode 3 is removed. When the replacement work of the electrode 3 is completed and the operator operates the switch 19 to turn it OFF or a stop signal is input to the control means 27, the control means 27 is connected to the electromagnetic valve 12 for the cooling water supply pipe and The current supply to the cooling water discharge pipe solenoid valve 20 is cut off, the cooling water supply pipe solenoid valve 12 and the cooling water discharge pipe solenoid valve 20 are opened, and the cooling water passes through the cooling pipe 4 from the cooling water supply pipe 10 to the electrode. 3 is supplied.

As described above, in the second embodiment, the cooling water discharged together with the compressed air is removed by the gas-liquid separator 25, so that air is mixed into the cooling water supply pipe 10, It is possible to prevent the electrode 3 from being poorly cooled, and the cooling water is returned to the cooling water supply pipe 10 again without being discharged to the outside. There is nothing to do.

  The present invention is not only incorporated in an electric resistance spot welder, but also as shown in FIGS. 1, 4, and 6, a cooling water supply pipe solenoid valve 12, a compressed air supply pipe solenoid valve 14, and a pressure sensor. 17, the control devices 18, 23, 27, etc. as one unit, and cooling water connected to the cooling water supply pipe 10 and the cooling water discharge pipe 11 of the existing electric resistance spot welder at the insertion port 30. It can be configured as a water stop device.

  Needless to say, the present invention can be applied not only to a stationary electric resistance spot welder but also to a movable electric resistance spot welder such as a welding gun. Also, after welding a predetermined number of times in conjunction with the welding line, water is stopped so that an operation signal is input to the control means 18, 23, 27, the welding gun is moved by the welding robot, and the electrode is moved by the tip dresser. 3 may be shaped or the electrode 3 may be replaced with a tip changer.

  Needless to say, the present invention can be applied not only to the cap chip type electrode 3 but also to a weld nut welding electrode for welding a weld nut and a weld bolt welding electrode for welding a weld bolt.

  Although the present invention has been described above in connection with the most practical and preferred embodiments at the present time, the present invention is not limited to the embodiments disclosed herein. However, it can be changed as appropriate without departing from the spirit or concept of the invention that can be read from the claims and the entire specification, and the water stopping method and the water stopping device for the cooling water of the electric resistance spot welder accompanied by such a change, Electrical resistance spot welders should also be understood as being within the scope of the art.

It is explanatory drawing which shows reference embodiment. It is detail drawing of an electrode part. It is a time chart of reference embodiment. It is explanatory drawing which shows 1st Embodiment. It is a time chart of a 1st embodiment. It is explanatory drawing which shows 2nd Embodiment. It is a time chart of a 2nd embodiment. It is detail drawing of an electrode part.

DESCRIPTION OF SYMBOLS 1 Electric resistance spot welder body 2 Electrode holder 3 Electrode 4 Cooling pipe 10 Cooling water supply pipe 11 Cooling water discharge pipe 12 Solenoid valve for cooling water supply pipe 13 Compressed air supply pipe 14 Solenoid valve for compressed air supply pipe 15 Pressure regulator 16 Reverse Stop valve 17 Pressure sensor 18 Control means (first embodiment)
19 Switch 20 Solenoid valve for cooling water discharge pipe 21 Residual water discharge pipe 22 Solenoid valve for residual water discharge pipe 23 Control means (second embodiment)
25 Gas-liquid separator 25a Air filter 25b Gas-liquid separator 26 Gas-liquid separator outlet solenoid valve 27 Control device (second embodiment)
30 Insert 50 Electrode holder 51 Water-cooled tube 52 Electrode a Predetermined time b Predetermined time

Claims (4)

A cooling water stop device used in an electric resistance spot welding machine having a cooling water supply pipe for supplying cooling water to an electrode and a cooling water discharge pipe for discharging cooling water that has cooled the electrode,
A solenoid valve for a cooling water supply pipe that shuts off the cooling water flowing through the cooling water supply pipe;
A compressed air supply pipe for supplying compressed air to the cooling water supply pipe on the electrode side of the electromagnetic valve for the cooling water supply pipe;
A solenoid valve for a compressed air supply pipe that blocks the compressed air flowing through the compressed air supply pipe;
In a cooling water stop device provided with control means for controlling opening and closing of the electromagnetic valve for cooling water supply pipe and the electromagnetic valve for compressed air supply pipe,
The cooling water discharge pipe is provided with a solenoid valve for cooling water discharge pipe that blocks the flow of cooling water,
When this cooling water discharge pipe solenoid valve is closed, the remaining water discharge pipe for discharging the cooling water discharged from the electrode is branched and connected,
This residual water discharge pipe is provided with a residual water discharge pipe solenoid valve that shuts off the cooling water ,
Further, when stopping the cooling water, the control means closes the cooling water supply pipe solenoid valve to shut off the cooling water supply, closes the cooling water discharge solenoid valve, and closes the residual water discharge pipe solenoid valve. The cooling water discharged from the electrode is discharged through the residual water discharge pipe, the compressed air supply pipe solenoid valve is opened for a predetermined time and compressed air is supplied to the cooling water supply pipe for a predetermined time, and then the compressed air supply is performed. In order to control the solenoid valve for the pipe, the cooling water supply of the electric resistance spot welder is prevented from causing poor cooling of the electrode due to air entering the cooling water supply pipe. Water equipment.   2. The water stop device for cooling water of an electric resistance spot welder according to claim 1, further comprising a gas-liquid separator for removing air from the cooling water discharged through the residual water discharge pipe. A pressure sensor for detecting the water pressure of at least one of the cooling water supply pipe and the cooling water discharge pipe is provided, and the water pressure of at least one of the cooling water supply pipe and the cooling water discharge pipe is reduced except when the water is stopped. 3. The water stop device for cooling water of the electric resistance spot welder according to claim 1, wherein the control means performs control to close the electromagnetic valve for the cooling water supply pipe when it is detected.   An electric resistance spot welder comprising the cooling water stop device for the electric resistance spot welder according to claim 1.

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