JPH03210974A - Defective selecting device for electric resistance welding machine - Google Patents

Abstract

PURPOSE:To automate selection of nondefectives and defectives and to improve working efficiency by driving opening and closing drive parts based on quality discriminating means of the nondefectives and defectives and nondefective signals or defective signals from these discriminating means and opening and closing properly a nondefective outlet or a defective outlet. CONSTITUTION:Opening and closing members 8 and 11 to open and close the nondefective outlet 5 and the defective outlet 6 and the opening and closing drive parts 7 and 10 thereof are provided. The above-mentioned opening and closing drive parts 7 and 10 are driven based on the quality discriminating means 23, 24, 21, 22, 25, 26 and 27 and the nondefective signals or defective signals from these discriminating means 23, 24, 21, 22, 25, 26 and 27. At the time of nondefective signals, the defective outlet 6 is closed by the opening and closing member 11 and the nondefective outlet 5 is opened by the opening and closing member 8. In addition, a driving control part (CPU) 25 to control so as to close the nondefective outlet 5 by the opening and closing member 8 and open the defective outlet 6 by the opening and closing member 11 at the time of defective signals is provided. Further, products discharged from the defective outlet 6 proceed to a defective mounting part 12 and when these products are removed, the welding machine can be operated. By this method, defective generation recognition of an operator is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention [Industrial Field of Application] The present invention relates to a sorting device for sorting good products and defective products in spot welding machines among various electric resistance welding machines.

[Prior art] In spot welding, a workpiece set on a lower electrode is sandwiched and pressurized between upper and lower electrodes, and an electric current is applied to the workpiece to heat the workpiece by resistance heat generation at the contact part with the picture electrode. This is to fuse the pressure parts.

The causes of defective products in spot welding include when the specified objects to be welded are insufficient, when each object to be welded is not in the specified positional relationship, or when there is not the required number of dots on each object to be welded. , a case where the current value is not within a predetermined range, etc. can be considered.

Conventionally, when a defective product occurs due to such a cause, it is detected, and based on the detection signal, an indicator light lights up or a buzzer sounds to notify the worker of the defective product, and the welding machine is stopped. It looks like this. After the operator eliminates the cause of the failure, the welding machine becomes ready for operation when the operator operates the return key switch.

[Problem to be solved by the invention] However, defective products that occur due to the causes of defects mentioned above are put into the non-defective product storage box and mixed with non-defective products.
Moreover, it is sometimes difficult to distinguish between defective products and good products.
The task of sorting out defective products from good products was extremely troublesome.

Furthermore, just by operating the return key switch, the welding machine is ready for 11 operations, which reduces the worker's awareness that a defective product has occurred, and makes it easier for the worker to remove defective products from the non-defective product storage box. It was possible to forget.

The present invention aims to improve work efficiency by automatically sorting between good and defective products.

Structure of the Invention [Means for Solving the Problems] In view of this object, a defective product sorting device for an electric resistance welding machine according to the present invention has the following features as shown in the drawings of the embodiments described below.
A non-defective product outlet 5, a defective product outlet 6, an opening/closing member 8.11 for opening and closing both the mouths 5, 6, an opening/closing drive unit 7.10 thereof, and good/bad discrimination means 23.24, 21, 22, 25.26.
．． 27 and this discrimination hand ¥123, 24.21, 22.2
The opening/closing drive unit 7.10 is driven based on a good signal or a bad signal from 5, 26° 27, and when the signal is good, the defective product outlet 6 is closed by the opening/closing member 11, and the non-defective product outlet 5 is closed by the opening/closing member 8. When the defect signal is opened, the non-defective product outlet 5 is closed by the opening/closing member 8, and the defective product outlet 6 is closed.
Drive control unit 2 that controls the opening/closing member 11 to open the
5.

Furthermore, the present invention provides a defective product placement section 12 and a defective product detection means 13 corresponding to the defective product outlet 6, so that when a defective product is removed from the defective product placement section 12, the defective product detection means 13 A drive control section 25 is provided which controls the welding machine operation/stop selection means S to be in the operation selection state based on the detection signal.

After completion of welding, if the product is determined to be a good product, it will be discharged from the non-defective product outlet 5. If the product is determined to be a defective product, it will be discharged from the defective product outlet 06.

The product discharged from the defective product outlet 6 reaches the defective product placement section 12, and is detected by the defective product detection means 13. When this product is removed from the defective product placement section 12, the 'fj welding machine becomes operational.

[Example] An embodiment in which the present invention is embodied in a spot welding machine will be described below with reference to the drawings.

As shown in FIG. 1, a workpiece W to be welded is set on the lower electrode 1. An upper electrode 2 is provided above the lower electrode 1 so as to be movable up and down by an air cylinder 3b via a lifting mechanism 3a. This air cylinder 3b is driven or stopped by a start switch 3C.

A chute 4 for discharging products extends from the vicinity of the lower electrode 1, and a good product outlet 5 and a defective product outlet 6 are provided at the lower end of the chute 4. The 1% product outlet 5 is provided with an opening/closing member 8 that can be opened and closed by the piston rod 7a of the air cylinder 7, and the non-defective product outlet 5 is connected to a non-defective product storage box 9.

The piston rod 1 of the air cylinder 10 is connected to the defective product outlet 6.
An opening/closing member 11 that can be opened and closed by 0a is provided, and the defective product outlet 6 is connected to a defective product placement tray 12.

A defective product detection sensor 13 is attached to this defective product placement tray 12 .

Above the upper electrode 2, a support 17 having a component missing indicator light 14, an inappropriate current value indicator light 15, a dot dilation indicator light 16, and the like is erected. A control box 18 adjacent to this pillar 17 is provided with an abnormality buzzer 19, a return key switch 20, a hit number counter 21, and the like. Said shooter 4
A product detection photoelectric switch 22 consisting of a light projecting section 22a and a light receiving section 22b is provided in the middle. An eddy current type sensor 23 for detecting the position of the upper part tfI2 is provided in the lifting mechanism section 3a for raising and lowering the pole 2 in the upper part. Both the upper and lower electrodes 2, 1 are connected to a welding ammeter 24.

The starting switch 3cm defective product detection sensor 13, return key switch 20, dot count counter 21, product detection photoelectric switch 22, position detection eddy current sensor 23, and welding ammeter 24 are controlled as shown in FIG. 2, respectively. box 1
The CPU 25 is connected to the central processing unit 25 (hereinafter referred to as CPU) in the
Air cylinder 3b for lifting and lowering the th pole 2, air cylinder 7 for opening and closing the non-defective product outlet 5, air cylinder 10 for opening and closing the defective product outlet 6, component missing indicator light 14, inappropriate current value indicator 15, dot dilation indicator light 16, the abnormality buzzer 19 and the spot welding machine operation stop selection means S are each driven and controlled.

Now, first, the workpiece W to be welded is set on the lower electrode 1, and the workpiece e is set at the start of production or when replacing the upper electrode 2.
+W, the lowering position of the upper part ti2 is set to the optimum state, and the optimum lowering position of the upper electrode 2 is inputted to the CPU 25 by the position detection eddy current type sensor 23, and is stored in the program memory 26. Further, the optimum current value range corresponding to the workpiece W is input to the CPU 25 by the welding # ammeter 24, and the required number of dots for the workpiece W is input to the CPU 25 by the dot number counter 21, and the program memory 26
to be memorized. Both the opening/closing member 8 of the non-defective product outlet 5 and the opening/closing member 11 of the defective product outlet 6 are in a closed state.

Next, when the spot welding machine operation stop selection means S is set to the operation selection state and the start switch 3c is turned on, the CPU 25 drives the air cylinder 3b based on the input signal. By that drive, the upper electric #i! 2 is lowered via the lifting mechanism section 3a, and the workpiece W to be welded is pressurized by both the upper and lower 4S poles 21. Then, when the t current passes through both the upper and lower electrodes 2.1, welding occurs due to resistance heat generation at the contact portion with the picture electrode 2.1! The pressurized parts of the IJW are fused. After the a-contact is completed, the upper electrode 2 is raised by the air cylinder 3b via the lifting mechanism section 3a.

The product is dropped into the chute 4 and stopped, and the next workpiece W to be welded is set on the lower electrode 1.

During this series of welding processes, the lowering position of the upper pole 2 is detected by the eddy current sensor 23 for position 1 detection, and the detection signal is sent to the CP.
It is input to U25 and stored in the calculation memory 27. or,
The welding ammeter 24 detects the current value flowing through both the upper and lower electrodes 2.1, and the detection signal is input to the CPU 25 and stored in the calculation memory 27. Further, the counter 21 detects the number of dots on the 7fI# object W, and inputs the detected number of dots per product to the CPU 25 and stores it in the calculation memory 27.

As described above, when the product falls into the chute 4 after welding is completed, the product detection photoelectric switch 22 detects this.

Based on the detection signal, the hit point counter 21 is cleared, and the CPU 25 compares the position detected by the position detecting eddy current sensor 23 with a pre-stored optimum lowering position. When it is determined that these positions match each other, the CPU 25 then compares the current value detected by the current meter 24 during the welding with a pre-stored optimum current value range.

When it is determined that the detected current value is within the optimum current value range,
Next, the CPU 25 compares the detected number of dots per product with the required number of dots stored in advance. While maintaining the closed state of the opening/closing member 11, the opening/closing member 8 of the non-defective product outlet 5 is opened by the air cylinder 7, and the products on the chute 4 enter the non-defective product storage box 9 through the non-defective product outlet 5. Thereafter, the CPU 25 closes the opening/closing member 8 of the good product outlet 5 using the air cylinder 7 .

Then, when the starting switch 3c is turned on again, the same operation as in the case described above is performed, and the welding on the lower electrode 1 is performed!
The tIIW is welded into a product, and the product is placed in the good product storage box 9.

On the other hand, during the series of welding processes, if there is no workpiece W on the lower electrode 1 or the positional relationship of the workpiece 5IJIJW is bad, the lowering position of the upper electrode 2 will differ from the optimal lowering position. Therefore, the CPU 25 compares the position detected by the position detecting eddy current sensor 23 with a pre-stored optimal lowering position, and determines that these positions do not match each other.

Then, the CPU 25 turns on the oval component shortage indicator light 14, sounds the abnormality buzzer 19, and sets the spot welding machine operation stop selection means S to the stop selection state. Further, the CPU 25 uses the air cylinder 7 to maintain the opening/closing member 8 of the good product outlet 5, and uses the air cylinder 10 to maintain the closed state of the opening/closing member 8 of the defective product outlet 6.
Therefore, one product on the chute 4 does not enter the non-defective product storage box 9, but passes through the defective product outlet 6 and is placed on the defective product placement tray 12, and the defective product is transferred to the defective product detection sensor 13. is detected.

When the worker visually checks the defective product on the defective product placement tray 12 to confirm whether there is a defective product and removes the defective product from the defective product placement tray 12, the defective product detection sensor 13 detects this and outputs this detection signal. CP
Input to U25. Further, when the operator operates the return key switch 20, the detection signal is input to the CPU 25. Based on those detection signals, the CPU 25 configures the configuration 8.
The defect indicator lamp 14 is turned off, the abnormality buzzer 19 is turned off, and the spot welding machine operation stop selection means S is set to the operation selection state. Further, the CPU 25 maintains the closed state of the opening/closing member 8 of the non-defective product outlet 5 using the air cylinder 7, and closes the opening/closing member 11 of the defective product outlet 6 using the air cylinder 10.

Further, when the CPU 25 determines that the detected current value flowing through both the upper and lower electrodes 2.1 is not within the pre-stored optimum current value range, the current value inappropriate indicator lamp 15 lights up, the abnormality buzzer 19 sounds, and the spot welding machine The operation stop selection means S enters the stop selection state. The subsequent operations are similar to those described above.

Further, when the CPU 25 determines that the detected number of dots per product and the pre-stored required number of dots do not match each other, the dot enlargement indicator light 16 lights up and the abnormal buzzer 19 sounds, and the spot welding machine The operation stop selection means S enters the stop selection state. The subsequent operations are similar to those described above.

In this way, when any defective signal is generated, the defective product is always placed on the defective product placement tray 12, so the defective product will never be placed in the non-defective product storage box 9, and the operator can place the defective product on the tray 12. The simple task of removing defective products from the tray 12 is sufficient, and the sorting of defective products is automated, improving work efficiency.

Also, for the worker, it is a defective product fil! Since the work of removing defective products from the tray 12 is added, the worker's awareness of the occurrence of defective products is increased.

Effects of the Invention According to the present invention, sorting of defective products is automated and work efficiency is improved.

Furthermore, the worker is required to remove defective products from the defective part 12, which increases the worker's awareness of the occurrence of defective products.

[Brief explanation of drawings]

FIG. 1 is a schematic front view showing a spot welding machine according to this embodiment, and FIG. 2 is an electric bronch circuit diagram of a defective product sorting device according to this embodiment. 1...Lower electrode, 2...Upper electrode, 3b...Air cylinder, 3C...Start switch, 5...Good product outlet, 6...Defective product outlet, 7...Air cylinder ( opening/closing drive part), 8... opening/closing member, 9... non-defective storage box, 10
. . . Air cylinder (opening/closing drive unit), 11 . - Inappropriate current value indicator, 16... Dot dilation indicator, 19... Abnormal buzzer, 20... Key switch for recovery, 21... Dots counter, 22... Photoelectric type for product detection switch,
23...Eddy current type sensor for position detection, 24...Welding ammeter, 25...Central processing unit (CPU) as drive control means, S...Spot welding machine operation stop selection means, W.
...Object to be welded.

Claims (1)

[Claims] 1. A non-defective product outlet (5), a defective product outlet (6), an opening/closing member (8, 11) for opening and closing both the exits (5, 6), and an opening/closing drive unit (7, 10) thereof. ) and means for determining good or bad (23, 2
4, 21, 22, 25, 26, 27) and the opening/closing drive unit (7, 10) based on a good signal or a bad signal from the determining means (23, 24, 21, 22, 25, 26, 27).
), the defective product outlet (6) is closed by the opening/closing member (11) when a good signal is received, the non-defective product exit (5) is opened by the opening/closing member (8), and the non-defective product exit (5) is driven when a defective signal is received. ) is closed by an opening/closing member (8), and a drive control unit (25) for controlling a defective product outlet (6) to be opened by an opening/closing member (11). Good product sorting device. 2. In the first claim, a defective product placement section (12) and a defective product detection means (13) are provided corresponding to the defective product outlet (6), and the defective product is removed from the defective product placement section (12). The electric device is characterized by being provided with a drive control section (25) that controls the welding machine operation stop selection means (S) to be in the operation selection state based on a detection signal from the defective product detection means (13) when removed. Defective product sorting device for resistance welding machines.