JP2017024071A - Projection Welding Equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide projection welding equipment capable of making a determination of a front or back side not only in the absence of a pilot in a welding member but also in the presence of the pilot therein.SOLUTION: A movable electrode is provided with an air chamber having an exhaust port formed on a welding member-side end surface. An air passage formed by connecting an air source to the air chamber is provided with an air sensor for detecting an air current. A device for making a determination of a front or back side of a welding member, which determines output of the air sensor by a determination part, is provided. A pilot of the welding member can be fitted with play into the air chamber of the movable electrode.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a projection welding apparatus that welds a welding member provided with a welding projection on the back surface of a nut, washer or the like having a hole in a central portion to a base material.

  A projection welding apparatus that welds a welding nut (hereinafter referred to as a welding nut) provided with a welding projection on the back surface to a base material has a base material disposed on the lower electrode, and a lower electrode guide pin protruding through the base material. The welding nut is fitted to the upper electrode, the upper electrode is lowered and pressed against the welding nut, the base electrode and the welding nut are sandwiched between the lower electrode and the upper electrode, the upper electrode, the welding nut, the base material, and the lower electrode. A current is passed through the electrode to weld the weld nut to the base material. In such a case, the weld nut is supplied upside down, and if it is fitted to the guide pin of the lower electrode and welded, welding failure will occur. Parts welded with nuts will be defective.

  Conventionally, in order to solve such a point, as shown in FIGS. 5 and 6, an air passage 54 having a discharge port 53 is provided on the end surface of the upper electrode 51 on the welding nut 52 side, and air from the air source 55 is provided. In addition to providing an air sensor 56 in the passage 54, a front / back confirmation device for notifying by a notification device 57 when the output of the air sensor 56 is input and the welding nut 52 is supplied in the reverse direction is provided as shown in FIG. When the welding nut 52 is normally supplied, the discharge port 53 of the upper electrode 51 is closed by the guide pin 58 and the welding nut 52, so even if compressed air is sent from the air source 55, There is almost no air flow, and when the welding nut 52 is supplied in the reverse direction as shown in FIG. 6, the end surface of the upper electrode 51 contacts the welding protrusion 59 of the welding nut 52. Then, a gap is formed between the end surface of the upper electrode 51 and the back surface of the welding nut 52, and when compressed air is sent from the air source 55, the compressed air is welded to the end surface of the upper electrode 51 from the discharge port 53 of the upper electrode 51. Since air is discharged to the outside through a gap between the back surface of the nut 52, air flows through the air passage 54. The front and back of the welding nut is determined based on the difference in the air flow in the air passage. (For example, see Patent Document 1)

  In such a case, there is no problem as long as it is a welding nut without a pilot, but for example, there is a hexagonal welding nut / pilot (hereinafter referred to as a 1A type welding nut) defined in JISB1196 as a hexagonal welding nut (1A type). When welding to the base material, as shown in FIG. 7, the 1A type welding nut 61 protrudes on the same side as the welding projection 62, and the pilot 63 higher than the welding projection 62 is formed on the entire circumference of the screw hole, so that the 1A type When the welding nut 61 is supplied in the reverse direction, the end surface of the upper electrode 51 abuts on the pilot 63 of the 1A-type welding nut 61, so that the gap between the end surface of the upper electrode 51 and the welding nut 61 is closed by the pilot 63. Therefore, even if compressed air is sent from the air source 55, the air flow in the air passage 54 is almost the same as when the welding nut is normally supplied. No.

JP 06-238460 A

  In the above case, it is possible to determine the front and back when the pilot of the welding nut is not provided, but when there is a pilot, since there is almost no air flow in the air passage on both the front and back, there is a problem that the front and back cannot be determined. there were.

  An object of the present invention is to solve the above-mentioned problems and to provide a projection welding apparatus capable of determining the front and back not only when there is no pilot in the welding member but also when there is a pilot.

  The projection welding apparatus of the present invention, which has been made to solve the above problems, has a base material disposed on a fixed electrode, a welding projection is formed on the back surface side, and a hole is formed in the center, and the entire circumference of the hole In addition, a welding member having a pilot projecting higher than the welding projection in the same direction as the welding projection is supplied to the welding portion of the substrate, the movable electrode is operated, and the welding member and the substrate are fixed between the fixed electrode and the movable electrode. In the projection welding apparatus that welds the movable electrode, the welding member, the base material, and the fixed electrode by passing an electric current, the movable electrode is provided with an air chamber in which a discharge port is formed on the end surface of the welding member. An air sensor that detects the air flow is provided in an air passage formed by connecting an air source, and a welding member front / back determination device for determining the output of the air sensor by a determination unit is provided, and the air chamber of the movable electrode is provided. Welding member pilot There is characterized in that the can be fitted with play.

  Preferably, the air sensor is a pressure sensor.

  The air sensor is preferably an air volume sensor that detects the flow of air, and this is the invention of claim 3.

  In the present invention, the movable electrode is provided with an air chamber in which a discharge port is formed on the end surface of the welding member, and an air sensor that detects the flow of air is provided in an air passage formed by connecting an air source to the air chamber, A welding member front / back determination device for determining the output of the air sensor at the determination unit is provided, so that the pilot of the welding member can be fitted with play in the air chamber of the movable electrode. The front and back of a welded member with a pilot can also be determined, welding of the welded member in the reverse direction can be prevented, and poor welding of the parts welded with the welded member can be prevented.

The side view which shows embodiment of this invention. The partially cutaway side view of the principal part which shows the state in which the hexagonal welding nut and pilot presence of this invention were supplied normally. The partially cutaway side view of the principal part which shows the state in which the hexagonal welding nut and pilot presence of this invention were supplied reversely. Part A enlarged view of FIG. Sectional drawing which shows the state in which the conventional welding nut and no pilot were supplied normally The principal part sectional drawing which shows the state by which the conventional welding nut and the thing without a pilot were supplied conversely. The principal part sectional drawing which shows the state in which the conventional hexagonal welding nut and pilot presence were supplied reversely.

Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS.
Reference numeral 1 denotes a projection welding apparatus. The projection welding apparatus 1 has a base material 3 disposed on a lower electrode 2 that is a fixed electrode, and guide pins 4 of the lower electrode 2 are fitted into through holes 5 of the base material 3. A 1A type welding nut 9 in which a pilot 8 higher than the welding projection 6 is projected in the same direction as the welding projection 6 on the entire circumference of the screw hole 7 in the center is provided with a parts feeder (not shown). And is fitted to the guide pin 4, the upper electrode 10 that is a movable electrode is lowered, the guide pin 4 is fitted into the air chamber 11 formed in the upper electrode 10, and the upper electrode is attached to the 1A type welding nut 9. The 1A type welding nut 9 and the base material 3 are sandwiched between the upper electrode 10 and the lower electrode 2 by abutting and pressing the end face 10.

  Reference numeral 12 denotes an air source. The air source 12 is connected to the air chamber 11 from the side surface of the upper electrode 10, and a discharge port 13 of the air chamber 11 is formed on the end surface of the upper electrode 10 on the 1A-type welding nut 9 side. An air passage 14 is formed from 12 through the air chamber 11 of the upper electrode 10 and discharged from the discharge port 13 of the air chamber 11.

  The air chamber 11 is formed so that the pilot 8 is inserted into the air chamber 11 with play when the 1A-type welding nut 9 is supplied upside down. That is, when compressed air is supplied to the air chamber 11, the end surface of the upper electrode 10 on the 1A-type welding nut 9 side and the 1A-type from between the wall of the air chamber 11 and the pilot 8 as shown by the arrows in FIG. Air is discharged to the outside through the space between the back surface of the welding nut 9.

  Reference numeral 15 denotes a pressure sensor that detects the air pressure in the air passage 14, and reference numeral 16 denotes a determination unit that receives the output of the pressure sensor 15 and determines the front and back of the welding nut.

  Next, referring to FIGS. 2 to 4, a front / back determination method in the case of welding the 1A-type welding nut 9 according to the present invention will be described.

  First, the flow of air will be described. As shown in FIG. 2, when the 1A-type welding nut 9 is normally supplied and the upper electrode 10 is lowered and pressed against the surface of the 1A-type welding nut 9, the upper electrode Since the discharge port 13 of the 10 air chambers 11 is closed by the 1A-type welding nut 9 and the guide pin 4, when compressed air is sent from the air source 12 in this state, almost no air is discharged.

  As shown in FIGS. 3 and 4, when the 1A-type welding nut 9 is supplied upside down, the upper electrode 10 is lowered, and the pilot 8 of the 1A-type welding nut 9 enters the air chamber 11 of the upper electrode 10. When it is inserted with play and the upper electrode 10 abuts and pressurizes the welding projection 6 and compressed air is sent from the air source 12 in this state, the air is the wall of the air chamber 11 as shown by the arrows in FIG. Between the upper electrode 10 and the pilot 8 and between the upper electrode 10 and the back surface of the 1A-type welding nut 9 and discharged outside, the air pressure is lower than when the 1A-type welding nut 9 is normally supplied. .

  Next, the front / back determination method will be described. Between the case where the 1A-type welding nut 9 is normally supplied and the case where it is supplied reversely, for example, an intermediate air pressure is set as a reference value and stored in the determination unit. Then, the projection welding apparatus is operated, and the upper electrode 10 is lowered. After abutting and pressurizing the 1A-type welding nut 9, when compressed air is sent from the air source and the value of the pressure sensor exceeds the reference value, the determination unit determines that it is normal and continues the welding operation. When the value of the pressure sensor is lower than the reference value, the determination unit determines that the front and back of the 1A-type welding nut 9 are reversed, stops the welding operation, and issues an alarm.

  Further, when the welding nut / no pilot is normally supplied, when compressed air is sent from the air source as in the case of the 1A-type welding nut 9, almost no air is discharged, and the reverse is reversed. When supplied, air is exhausted to the outside through the gap between the end face of the upper electrode 10 and the back surface without the weld nut / pilot from the exhaust port of the air chamber 11 of the upper electrode 10 as in the prior art. In the same manner as in the case of the 1A-type welding nut 9, the front / back determination can be performed.

  The present invention is not limited to the above-described embodiment. For example, the 1A-type welding nut 9 has a projection such as a screw hole at the center and a hole such as an insertion hole for a screw shaft of a bolt. And a welding member such as a nut or washer having a pilot formed on the entire circumference of the hole. Further, the pressure sensor may be an air sensor that detects a change in the state of the air, for example, by detecting the air volume from the air source after the supply of the 1A-type welding nut.

  As described above, according to the present invention, the air passage 11 formed by providing the movable electrode 2 with the air chamber 11 in which the discharge port 13 is formed on the end surface on the welding member 9 side, and connecting the air source 12 to the air chamber 11. 14 is provided with an air sensor 15 for detecting the flow of air, a welding member front / back determination device for determining the output of the air sensor 15 by the determination unit 16, and the welding member 9 in the air chamber 11 of the movable electrode 10 is provided. Because pilot 8 can be fitted with play, it is possible to determine not only the welded member without pilot but also the welded member with pilot, preventing welding of the welded member upside down, and welding the welded member It can prevent poor welding of parts.

DESCRIPTION OF SYMBOLS 1 Projection welding apparatus 2 Fixed electrode 3 Base material 4 Guide pin 5 Through-hole 6 Welding protrusion 7 Screw hole 8 Pilot 9 Welding member 10 Fixed electrode 11 Air chamber 12 Air source 13 Exhaust port 14 Air passage 15 Pressure sensor 16 Determination part

Claims (3)

    Place the base material on the fixed electrode, form a welding projection on the back side, and have a hole in the center, and project a pilot higher than the welding projection in the same direction as the welding projection all around the hole. The welded member is supplied to the welded portion of the base material, the movable electrode is operated, the welded member and the base material are sandwiched between the fixed electrode and the movable electrode, and current is supplied to the movable electrode, the welded member, the base material, and the fixed electrode. In a projection welding device that welds by flowing air, an air chamber is formed in the movable electrode with an exhaust port formed on the end surface on the welding member side, and the air flow is detected in an air passage formed by connecting an air source to the air chamber. A welding member front / back determination device for determining the output of the air sensor by a determination unit, and enabling the pilot of the welding member to fit in the air chamber of the movable electrode with play. Blow welding equipment .     The projection welding apparatus according to claim 1, wherein the air sensor is a pressure sensor.     The projection welding apparatus according to claim 1, wherein the air sensor is an air volume sensor that detects a flow of air.

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