KR100479510B1 - Apparatus for detecting mis-setting of projection nut and method of controlling the same - Google Patents

Abstract

By detecting the inversion, omission, eccentricity, etc. of the supplied projection nut before welding, to provide a defect setting detection device and a control method of the projection nut that can minimize the occurrence of defects and maximize the productivity of the automatic welding process;

The outer circumference of the upper electrode tip of the shank lower portion disposed in the longitudinal direction on the movable body so as to detect the flipping of the movable body which is moved up and down by the pressure cylinder disposed in the upper electrode portion of the main body and the nut supplied over the hole of the panel to be processed An upper electrode portion including a nut inversion detecting means disposed on the side and an upper detecting means disposed on a side of the movable body so as to detect a lifting height of the movable body to detect a defective setting of the nut;

A nut position setting means arranged at a lower fixing body on which the panel on which the hole is processed is set to set the position of the nut, and a lower end portion of the nut position setting means to detect a lifting operation distance of the nut position setting means. Provided is a failure setting detection apparatus for a projection nut including a lower electrode portion including a shift rod lift distance detecting means connected thereto.

Description

Defective setting device of projection nut and its control method {APPARATUS FOR DETECTING MIS-SETTING OF PROJECTION NUT AND METHOD OF CONTROLLING THE SAME}

The present invention is to detect a poor setting of the projection nut when welding the projection nut to a predetermined panel to prevent the bad welding in advance, so that it is possible to obtain a variety of effects accompanying the projection nut, and the apparatus It relates to a control method.

For example, a projection nut refers to a part previously welded to a panel for coupling with other parts, and the projection nuts are on average 200 or more of hardware parts applied to a vehicle body of one passenger car.

In welding the projection nut as described above, it is necessary to weld concentrically with the machined hole in the vehicle body panel to minimize the occurrence of assembly defects. Such a connection nut is welded by the operation of the automation line as shown in FIG. It is universal to be done.

More specifically, in the drawings, a case of using two robots RBT1 and RBT2 is illustrated, but for convenience of description, the first robot RBT1 is selected and described.

First, when one operator loads the body panel pressed in a separate press process into the first, second and third jigs JIG1, 2 and 3, the first robot RBT1 starts and the first jig JIG1. The projection nut welder PRT1 and the projection welder PRT2 are used to weld the projection nut, and after welding is completed, the robot RBT1 unloads the vehicle body panel to the first jig JIG1 again. It is made of a process that is automatically taken out.

Of course, when the panel loaded on the second and third jigs JIG2 and 3 is completed in the first jig JIG1, the welding work is sequentially performed through the same process as the above process.

The panel loaded on the fourth, fifth and six jigs JIG4, 5 and 6 is also sequentially supplied with the second robot RBT2 to the third and fourth projection welding machines PRJ3 and 4 as described above. The welding is made while the projection welder is determined according to the size of the nut.

Reference numerals C1 and C2 in FIG. 1 are controllers for controlling the robot, and NF1, 2, 3, and 4 refer to nut feeders for automatically supplying nuts to the projection welding machine.

However, in the welding process of the projection nut as described above, there is no device for checking whether the nut is set in the correct place when supplying the nut, and thus the welding is performed in a state of being flipped, missing, and eccentric. There is a problem that the occurrence of defects is very large.

Therefore, the present invention has been invented as a means for solving the above problems, the object of the present invention is to detect the inversion, omission, eccentricity, etc. of the projection nut supplied before welding, to minimize the occurrence of defects, the productivity of the automatic welding process The present invention provides a defect setting detection apparatus and a control method of the projection nut to maximize the.

In order to realize this, the present invention provides a projection welding machine for automatically welding a projection nut supplied over a hole when a panel having a hole is supplied,

The outer circumference of the upper electrode tip of the shank lower portion disposed in the longitudinal direction on the movable body so as to detect the flipping of the movable body which is moved up and down by the pressure cylinder disposed in the upper electrode portion of the main body and the nut supplied over the hole of the panel to be processed An upper electrode portion including a nut inversion detecting means disposed on the side and an upper detecting means disposed on a side of the movable body so as to detect a lifting height of the movable body to detect a defective setting of the nut;

A nut position setting means arranged at a lower fixing body on which the panel on which the hole is processed is set to set the position of the nut, and a lower end portion of the nut position setting means to detect a lifting operation distance of the nut position setting means. Provided is a failure setting detection apparatus for a projection nut including a lower electrode portion including a shift rod lift distance detecting means connected thereto.

In addition, when the operation is started and the panel to be welded is supplied, the positioning pin is lifted by the operation of the pin shift cylinder, the nut is supplied from the nut feeder disposed adjacent to the welder, and the pressure cylinder is operated. A first step of lowering the upper electrode portion;

A second step of determining whether the first proximity switch is in an on state in order to detect whether the upper electrode part is normally lowered when the first step is completed;

A third step of detecting a plurality of determination elements and determining whether the supplied nut is set correctly if the condition of the second step is satisfied;

A fourth step of returning to the first step of performing welding by applying a welding current when the third step is satisfied, and controlling the lift of the pressurizing cylinder and the lowering of the pin shift cylinder;

If the condition of the second step is not satisfied, the pressure cylinder and the pin shift cylinder are returned to the initial state, and after cleaning the nut with an air blower, the fifth step is returned to the process of raising the positioning pin of the first step. Steps;

If the condition of the third step is not satisfied, the third step is repeated three times, and if the judgment element of the third step does not change, an alarm is issued to restore the initial state. Provided is a failure setting detection control method for a projection nut comprising a sixth step returned to the step.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described in detail.

Fig. 1 shows the layout of an automatic line for showing an application state of the present invention, and the detailed description in this embodiment described above will be omitted.

2 and 3 show a front view and a side view of a projection welding machine to which the present invention is applied, wherein the projection welding machine includes a main body portion 2, an upper electrode portion 4, and a lower electrode portion 6. .

In the above, the main body portion 2 forms a basic frame of the welding machine, and the upper electrode portion 4 including the pressurizing cylinder 8 is disposed above the main body portion 2.

The upper electrode part 4 is a nut flipping detection part 14 including an electrode tip 12 at the lower front side as shown in FIGS. 4 to 6 to the movable body 10 which is moved up and down by the elastic action of the pressure cylinder 8. The shank 16 is disposed in the longitudinal direction, the upper side detection means 18 is disposed on one side.

The upper electrode tip 12 is fixed to the lower end of the shank 16, the cap 20 forming the nut overturning detection portion 14 is the upper electrode tip in the state in which the detection hole 22 is formed at the bottom It is arrange | positioned in the form surrounding the outer side of 12, and is electrically connected with a control unit.

And the inner diameter of the detection hole 22 formed in the cap 20 in the above is somewhat larger than the outer diameter (d) of the upper end of the welded nut 24, it is made smaller than the diagonal length (D) of the lower projection of the nut (24) When the nut 24 is normally set, the contact between the nut 24 and the electrode tip 12 is made, and when turned upside down, the contact is not made.

In the upper detection means 18, as shown in Figure 6, the first, second, third dogs 26, 28, 30 disposed on the moving body 10, and the first, second, third dogs 26 And first, second and third proximity switches 34 and 36 and 38 disposed on the fixed body 32 directly below (28) and (30).

In the above, the first, second, and third dogs 26, 28, 30 are springs 46, 48, 50 in each of the three housings 40, 42, 44 fixed to the movable body 10. It is supported by the ballistically and is always arranged in a state holding downward downward force, are arranged sequentially sequentially with a predetermined interval (L1) (L2) mutually.

Accordingly, the first, second, and third proximity switches 34, 36, 38 may be sequentially contacted from the first dog 26 according to the height at which the movable body 10 descends.

At this time, the distance L1 of the first dog 26 and the second dog 28 is set equal to the overall height of the nut 24, and the distance of the second dog 28 and the third dog 30 is set. The interval L2 is set at the same interval as the interval L1.

The lower electrode part 6 includes a nut positioning means and a shift rod lifting distance detecting means. As shown in FIGS. 7 and 8, the nut positioning means has an upper portion fixed to the lower fixture 33. The positioning pin 58 is fixed by the coupling 60 via the compression spring 56 at the upper end of the shift rod 54 of the pin shift cylinder 52, and the outside of the positioning pin 58. The upper end of the pin shift cylinder 52 of the lower tip 62 is made of a fixed form.

And the lower end of the shift rod 54, the lifting distance detecting means of the shift rod 54 is arranged, the upper end of the shift rod lifting distance detecting means is the first hinge portion (h1) The pin shift cylinder 52 is connected to the cam link 64 coupled by the cam link 64 by a second hinge portion h2 at a predetermined interval between the cam link 64 and the first hinge portion h1. The link 68 hinged to the lower end of the projecting portion 66 protruding downward and the free end of the cam link 64 in accordance with the movement of the shift rod 54, the fourth, 5, 6 includes a switch fixing plate 76 on which the proximity switches 70, 72, 74 are disposed.

The fourth dog 78 formed at the free end of the cam link 64 from the distance L3 between the first hinge portion h1 and the second hinge portion h2 and the second hinge portion h2. The distance (L4) of the ratio is approximately 1: 5 so that a movement of about 2 mm of the positioning pin 58 is enlarged by about 5 times so that the fifth proximity switch 72 can be detected. It is set to about 10 mm.

In the figure, reference numeral 78 denotes an air blower for cleaning the abnormally detected nut.

The projection nut failure setting detection device of the present invention thus made detects the failure setting of the nut in the operation flow as shown in FIG.

First, when the operation is started and the panel 80 to be welded is loaded on the lower electrode portion 6 by the robot (S100), the positioning pin 58 is operated by the operation of the pin shift cylinder 52. ) Is raised (S110), and the nut is supplied from the nut feeder which is arranged adjacent to the welder (S120).

After the step S120 is completed, when the pressure cylinder 8 is operated to lower the upper electrode portion 4 (S130), the first proximity switch (1) by the contact of the first dog 26 and the first proximity switch 34 ( It is determined whether 34 is in the on state (S140).

The determination of whether the first proximity switch 34 is on in step S140 is to determine whether the upper electrode part 4 is normally lowered.

If it is determined that the first proximity switch 34 is in the ON state in step S140, it is determined whether the currently supplied nut is set correctly (S150). In step S150, whether the potential from the cap 20 is zero, It is determined whether the second and fourth proximity switches 36 and 70 are on and the third and fifth proximity switches 38 and 72 are off.

In the above, it is determined that the potential from the cap 20 is zero, as shown in FIG. 11, when the nut is not inverted or eccentric as shown in FIG. 12, and normally supplied as in FIG. 10. This is because dislocation is not generated by contact between the nut and the nut 24.

And it is determined that the second proximity switch 36 is turned on, the nut is not supplied in duplicate as shown in FIG. 13, but is normally supplied as shown in FIG. 10, and it is determined that the upper electrode part 4 is normally lowered and welded. Determining whether the third proximity switch 38 is in an off state means that the nut is missing as shown in FIG. 14 when the third proximity switch 38 is in an off state. Because.

In addition, determining whether the fourth proximity switch 70 is in the on state and the fifth proximity switch 72 is in the off state means that the positioning pin 58 is eccentrically supplied as shown in FIG. 15. In this case, it does not rise normally, so it is to judge this.

When the determination condition of the step S150 is satisfied, the welding current is applied to allow the nut to be welded (S160). After the welding is completed, the pressure cylinder 8 is raised, and the sixth proximity switch 74 is turned on. After the pin shift cylinder 52 is lowered until the welding is completed, and the welding is completed, the robot is controlled to return to the step S100 after the next step is made (S170).

If the condition is not satisfied in step S140, the pin shift cylinder 52 is lowered, the pressure cylinder 8 is raised, and the air blower 78 is operated for a predetermined time to clean the nut ( S180) and repeats to return to step S110.

In addition, if the condition is not satisfied at step S150, if the step S150 is repeated three times in a row and the condition is not satisfied and the status is not maintained, the alarm lamp or the buzzer is operated to perform manual recovery (S200). After restarting (S210) and returning to step S100, if there is an element changed during the count in step S190, the process proceeds to step S180 to restart again from the beginning in the state that the nut is supplied.

As shown in FIG. 16, the above operation control is performed by the cap 20 of the flip detection means and the first, second, third, fourth, fifth and sixth proximity switches 34, 36, 38, and 70. When the electric signal generated from (72) and (74) is input to the control unit (ECU), each part of the projection welding machine (oil, pneumatic control valve control, etc. supplied to the pressure cylinder, the pin shift cylinder, etc.) And by controlling the nut feeder.

As described above, according to the present invention, in welding the projection nut to a panel to be applied to an automobile, the inversion, omission, eccentricity, etc. of the projection nut is detected before welding, thereby preventing the occurrence of defects in advance, and the automatic welding process. It is effective to maximize productivity.

1 is a layout of a nut welding automation line for explaining the application of the present invention.

2 is a front view of a welder to which the present invention is applied.

3 is a side view of FIG. 2;

4 and 5 are front cross-sectional views of the upper electrode holder to which the present invention is applied, and half cross-sectional view of a cap to be applied to the upper electrode holder.

6 is a front view of a detection unit applied to the present invention.

7 and 8 are front and side views of the lower electrode holder.

9 is an operation flowchart for explaining an operating state of the present invention.

10 to 15 are excerpts for explaining the setting state of the nut.

16 is a block diagram illustrating the operation of the operational flow of FIG. 9.

Claims (8)

In a projection welding machine that automatically welds the projection nut that is fed over its hole when the panel is machined with the hole, The outer circumference of the upper electrode tip of the shank lower portion disposed in the longitudinal direction on the movable body so as to detect the flipping of the movable body which is moved up and down by the pressure cylinder disposed in the upper electrode portion of the main body and the nut supplied over the hole of the panel to be processed. An upper electrode portion including a nut inversion detecting means disposed on the side and an upper detecting means disposed on a side of the movable body so as to detect a lifting height of the movable body to detect a defective setting of the nut; A nut position setting means arranged at a lower fixing body on which the panel on which the hole is processed is set to set the position of the nut, and a lower end portion of the nut position setting means to detect a lifting operation distance of the nut position setting means. And a lower electrode part including a shift rod lifting distance detecting means connected thereto. The projection nut of claim 1, wherein the nut overturning detection means comprises a cap disposed at an outer side of the upper electrode tip by forming a detection hole formed at a lower portion of the nut larger than the upper outer diameter of the nut and smaller than the lower diagonal length of the nut. Bad setting detection device. According to claim 1, The upper detection means is first, second, and dog dogs which are sequentially arranged at a predetermined interval from each other in the state held in the spring fixed to the housing fixed to the moving body and retaining downward punching force; And a first, second and third proximity switch disposed on a fixed body directly below the first, second and third dogs. 4. The apparatus of claim 3, wherein the distance between each of the first and second dogs, the second and third dogs, is set equal to the overall height of the nut. The pin shifting cylinder according to claim 1, further comprising: a pin shift cylinder in which an upper portion is fixed to a lower fixture; A positioning pin secured by a coupling via a compression spring at an upper end of the shift rod of the pin shift cylinder; And a lower tip disposed at an upper end of a pin shifting cylinder outside the positioning pin. The shift rod lifting distance detecting means includes: a cam link having an upper end coupled to a lower end of the shift rod by a first hinge portion; A link hinged to a lower end of a protrusion projecting downwardly from the pin shift cylinder while being connected to the cam link by a second hinge portion at a predetermined distance from the first hinge portion; Detecting failure setting of the projection nut, characterized in that it comprises a fourth, fifth, sixth proximity switch disposed on the switch fixing plate at regular intervals in accordance with the movement trajectory of the dog of the cam link free end as the shift rod moves up and down. Device. When the operation starts and the panel to be welded is supplied, the positioning pin is raised by the operation of the pin shift cylinder, the nut is supplied from the nut feeder which is disposed adjacent to the welder, and the pressure cylinder is operated to operate the upper electrode. A first step of adding and falling; A second step of determining whether the first proximity switch is in an on state in order to detect whether the upper electrode part is normally lowered when the first step is completed; A third step of detecting a plurality of determination elements and determining whether the supplied nut is set correctly if the condition of the second step is satisfied; A fourth step of returning to the first step of performing welding by applying a welding current when the third step is satisfied, and controlling the lift of the pressurizing cylinder and the lowering of the pin shift cylinder; If the condition of the second step is not satisfied, the pressure cylinder and the pin shift cylinder are returned to the initial state, and after cleaning the nut with an air blower, the fifth step is returned to the process of raising the positioning pin of the first step. Steps; If the condition of the third step is not satisfied, the third step is repeated three times, and if the judgment element of the third step does not change, an alarm is issued to restore the initial state. And a sixth step returned to the step. The method according to claim 7, wherein the judging factor in the third step comprises: an element for judging whether or not the potential from the cap is zero, whether the supplied nut is inverted or eccentric; An element for judging whether the second proximity switch is on or not, whether the nut is normally supplied instead of being supplied in duplicate; An element that determines whether the third proximity switch is in an OFF state because the nut is lowered and the upper electrode portion is lowered more than normal; And the fourth proximity switch is in an on state and the fifth proximity switch is in an off state to determine whether the panel is normally supplied.