JPS5915752B2 - Friction welding machine caulking amount monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a crimp amount monitoring device for a friction welding machine, and particularly to improving accuracy.

FIG. 1 is a front view showing a conventional device of this type, in which the pressure inside the hydraulic cylinder 2 that drives the tailstock 1 is
Pressure switch 3 increases when la and llb are contacted.
Detected by.

The signal from this pressure switch 3 causes the tailstock 1 to
The drive rod 5, which operates together with the limit switches 4a and 4b, is stopped. Then, the dogs 7a and 7b installed on the drive rod 5 actuate the limit switches 4a and 4b that continue to operate together with the tailstock 1, and when the pressure welding is completed, the dogs 7a and 7b operate the limit switches 4a and 4b, and when the pressure welding is completed, the limit switches 4a and 4b are operated in an excessive manner. The amount of caulking is monitored by transmitting a signal indicating whether it is normal or too small. However, work Il
In the case where the contact of Ilb is detected by the pressure switch 3, the change in pressure in the hydraulic cylinder 2 due to the sliding resistance when the tailstock 1 moves forward and the change in pressure when the workpieces Ila and Ilb are in contact are detected. Misidentification may result in false positives.

In other words, Fig. 2 is a graph showing the relationship between the elapsed time and the pressure change in the hydraulic cylinder 2 when the tailstock 1 starts to be driven. If the 10 resistors were sometimes distorted, a workpiece contact signal would be emitted at this part A, making it impossible to detect the normal amount of caulking. In addition, the mechanism consisting of a series of drive rods, solenoids, etc. is prone to slipping, and due to variations in the operating points of limit switches, it is difficult to maintain high accuracy over a long period of time. Accuracy of 0.1 mm or more could not be obtained. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a crimp amount monitoring device for a 20 friction welding machine that can monitor the crimp amount accurately and with high precision.

An embodiment of the present invention will be described below with reference to FIGS. 3 to 5. FIG. 3 is a schematic diagram of the above embodiment, and as shown in the figure, the magnetic scale 8 that moves together with the tailstock 1 and the detection head 9 that detects the magnetism 25 are mounted on the bed 10 facing each other. There is.

As the tailstock 1 moves forward (to the left in FIG. 3) by the hydraulic cylinder 2, the magnetic scale 8 moves at a predetermined pitch. Then, as shown in FIG. 5, a pulse generator 20 generates a pulse of -Co, lm/m.

Next, when the workpieces Ila and llb come close, the limit switch slows down the moving speed of the tailstock 1, and at the same time, the workpiece 35 approach signal is input to the pulse. Then, control is started by the control system of the above embodiment shown in FIG. In C, when the speed of the tailstock 1 temporarily becomes zero when the works Ila and Ilb come into contact, the contact detection circuit 21 detects that the pulse is interrupted for a predetermined period of time. From then on,
The number of pulses until the pressure welding of the works 11a and 11b is completed is counted by the pulse count circuit of the two-stage preset counter 22, and when the number of pulses exceeds a predetermined value,
This is detected by the upper limit preset circuit, and the workpiece 11a is
, 11b is excessively caulked. If the number of count pulses is less than a predetermined value, it is detected only by the lower limit value preset circuit, and the amount of caulking between the works 11a and 11b is set to be too small. If not, the work 11a, 1
It can be confirmed that the caulking amount of 1b is normal. In this way, the relationship between the pulse train generated when the tailstock 1 moves forward and the passage of time will be as shown in FIG. 5.

That is, at the start time B, the tailstock 1 is accelerated to a relatively high speed, and the vehicle moves to high-speed running C. And work 11A, llb
When the workpiece 11a approaches the closest position, the workpiece 11a is moved at low speed D.
, 11b, it temporarily stops E. When the works 11a and 11b come into contact, they generate heat and become caulked, and the tailstock 1 moves forward F again, and at a predetermined time, the spindle 12 stops, the heat generation stops, and the workpieces are upset G and stopped. That is, if a pulse is generated every time the tailstock 1 moves a predetermined distance, the tailstock 1 will temporarily stop when the works 11a and 11b come into contact, and the pulse interval will become extremely wide. Therefore, when this pulse interval becomes wider than a predetermined interval, for example, as shown in FIG. By exceeding the contact detection level, contact with the workpieces 11a, 11bf) can be detected. After this, the pulses until the completion of pressure welding are counted by the two-stage preset counter 22, and when this count value exceeds the upper limit value, the amount of caulking is excessive, and when it is less than the lower limit value, the amount of caulking is too small. If it is less than or equal to the lower limit value and less than or equal to the upper limit value, it is determined to be normal. Therefore, contact between the works 11a and 11b can be reliably detected, and thereby the amount of caulking can be monitored accurately and with high precision.
In addition, as described above, the present invention takes advantage of the fact that the workpieces 11a and 11b come into contact with each other, resulting in a temporary stop state and the pulse width becomes wider during this time. By integrating the pulse, the pulse width is detected as an integral value, and when this integral value exceeds a predetermined contact detection level, contact is detected.

Therefore, when the sliding resistance when the tailstock 1 moves forward increases, the pulse width becomes wider, but the workpieces 11a, 1
Unlike the case of contact in 1b, it does not occur that the forward speed slows down to the point where it temporarily stops, so the above contact detection level should be set appropriately taking these factors into account. Therefore, even if the sliding resistance fluctuates, malfunctions can be prevented and the amount of caulking can be accurately monitored. As described in detail above, the present invention monitors the amount of caulking from the pulses generated by the movement of the tailstock, so it is possible to provide an accurate and highly accurate device for monitoring the amount of caulking for a friction pressure g machine.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing 1U of a conventional device, FIG. 2 is a graph showing pressure changes in the cylinder of the above device, FIG. 3 is a schematic configuration diagram showing an embodiment of the present invention, and FIG. FIG. 5 is a block diagram of the above embodiment, FIG. 5 is a diagram showing the pulse train and speed of the above embodiment, and FIG. 6 is a waveform diagram explaining the operation of the above embodiment. 1...Tailstock, 8...Magnetic scale,
9...detection head, 20...pulse generator, 21...contact detection circuit, 22...
・Two-stage preset counter.

Claims (1)

[Claims] 1. A pulse generating means that generates a pulse in accordance with the movement of the tailstock, a contact detection means that monitors the interval between the pulses and performs contact detection when the pulse is interrupted for a predetermined time, and after this contact detection, A crimp amount monitoring device for a friction welding machine, comprising means for counting the pulses to obtain a crimp amount until the welding is completed, and comparing the crimp amount with a set value to determine whether the crimp amount is appropriate.