SU58309A1 - Device for automatic control of the machine - Google Patents

Description

The proposed device is an attempt to further develop the automation of lathe and grinding machine types, namely, automation of machines for accurate and precise machining of parts having the form of rotation bodies. When automating these machines, significant difficulties arise that cannot be resolved with the help of the previously proposed principles.

So, for example, in the Wichman machine used for machining parts having the shape of rotation bodies, besides the accuracy of the contour setting and the inertia of moving parts, the cutter bluntness, bed shaking, elastic deformations of the subport, and other factors that make processing impossible up to micron.

In order to realize the possibility of automatic processing of parts with precisely this accuracy, the author proposes a device based on the new principle, which consists in continuous, accurate and not dependent on oscillations of any parameters, measuring the diameter of the workpiece during its processing.

ki on the machine and simultaneously comparing this size with the corresponding size of the reference part.

In the proposed device, devices already known and used in other machines with automatic control are used, such as photocells used to measure the dimensions of the workpiece, measuring knives loaded with springs, etc.

On the constructive side, the essence of the proposed device lies in the fact that the measuring knives are made in the form of screens for the photocell, mechanically connected to the moving parts of the sensors of the tracking system, controlling the flow on the machine, and mounted on the moving cores of the electromagnets controlled by said photo cells; while the blades are automatically supported on the contour line of the product, measure the appropriate size without touching the product.

If during machining of a particular part, the measured size does not coincide with the corresponding size of the reference part, then the feed

tool is automatically continued. If the difference in size decreases to a micron (or even below the required accuracy limit), then the transverse feed stops and the longitudinal feed brings the tool to the next place. In this case, of course, two passes are quite admissible - the first, rougher, and the second final. The reference part (as well as the automatic measuring device) is not exhausted, since there is no mechanical resistance. Jitter or beating of the part or bed, fluctuations in the voltage in the network, changes in the characteristics of the circuit elements, dulling or actuation of the tool do not affect the accuracy of processing. In addition, the need for constantly changing calibers is no longer necessary, and the productivity of the machine increases by increasing the feed rate and eliminating the additional measurement time with a manual caliber.

The device described in this author's certificate is intended to measure the dimensions of parts that are not processed using coolant.

The drawing shows a diagram of the device.

As can be seen from the diagram, two luminous fluxes of the light source S, modulated by means of a disk D with holes, driven by a motor M, pass through the corresponding optical system and are focused approximately at the end of the tips Aj and N of the double measuring knife. The holes on the disk D for the upper and lower light fluxes are open at different frequencies.

If the points an with the knife and the point b of the measured part are on the same straight line, then the light does not reach the photocell P. If the knife is slightly raised (for a full opening a micron fraction is enough), then light will be incident on the photocell F. The variable component of the photocurrent, after amplification in C / i and rectifying, feeds the coil of the electromagnet connected

with an NI or L / 2 knife. Under the action of a spring, the knife can move away from the a-b-c line to the outside, but an electromagnet forces it to approach this line. If the point b of the part rises, then the current in the electromagnet will disappear, and the knife will move away from the previous abc line, but then the current will again flow in the electromagnet, and the knife will be installed along some new line. Since the entire device of the head connected to the knife does not bear any load, it can be made quite light and small in size.

The distance between the two edges of the knife is chosen to be approximately 10-20 mm. In the transverse direction, the width of the knife is about one millimeter. When machining parts with large tapers, the width should be on the order of 50 ..

Thus, shakes accurately copy the distance between the extreme points of the part diameter. At the same time, an exact adjustment of the optical system is not necessary, since when it is shaken, it is all the same that the position of the knife on the line a-y-passes the absence of light regardless of the change in the position of the optics.

The beating of the part also does not noticeably affect the accuracy of measurements. Indeed, the beating in any direction can be decomposed into a beating in the vertical and horizontal directions. The beating in the horizontal direction, as is easy to see right away, has no effect, since the a-b-c line does not shift. A beating in the vertical direction causes only movement of both knives TVj and L, but the distance between them remains unchanged.

The drawing also shows schematically the cutter Q and the two brushes, the purpose of the latter, to prevent dust from entering point b.

Structurally, the measuring device should be designed on a massive frame with lower and upper measuring heads. The position of the knives is measured using a capacitance meter in the form of con L (d 4-d. Yr. I g.,.: I. J. With I 2 fixes the sum of the gaps. Required diameter l: the product is determined

.t / - / J - () 1-1-,

where / is the distance on the frame from the top fixed plate to the bottom and / 1 is the distance from the bottom plate to the point of the knife. The total capacitance C (Form. 1) is continuously compressed with the compensating capacitance C on the bridge, powered by a lamp generator of increased frequency. Capacitor C is made with shaped plates to achieve scale linearity. The scale on its axis marks

Lh (i.e. increase or,

on the contrary, the reduction in diameter compared with some given. The scale can correspond to, for example, zirSOu., ZtSOf.,. The scale of the scale can be adjusted by switching capacitors of constant capacitance, parallel connected to C and C.

Automatic comparing takes place as follows. If the output of the bridge is not zero, then depending on the voltage phase after amplifier G, one or another of TI or T thyratrons will ignite, as a result of which device E will start to rotate capacitor C in one direction or another until equilibrium occurs. On the axis of the device E there is a selsyn, which serves to influence the feeder.

The setting of the reference part in the proposed device can also be carried out by the method of the drawn contour, in the same way as in the Wichmann machine mentioned at the beginning of the description (or, for example, a contour cut from a sheet of cardboard); however, the author believes that the use of reference de (1)

Hoists are nevertheless more expedient, since the latter does not break down over time, since there is no mechanical contact with it.

The author notes that, despite the complexity of the circuit, the electrical device should be compact, since it is dominated by compact electronic and ionic apparatus.

The subject matter of the invention.

Claims (5)

1. A device for automatic control of a turning, grinding or the like machine using photocells to measure the dimensions of the workpiece with measuring legs or the like loaded with springs, characterized in that the measuring knives made in the form of screens for photocells and mechanically connected to the moving parts of the sensors of the tracking system, the feed control, are fixed to the moving cores of the electromagnets, which are controlled by the indicated photocells so that the blades automatically ski supported article on the contour line corresponding size was measured without touching the product. 2. In the device according to claim 1, the use of sensors of capacitive or induction types. 3. In the device of PP, 1 and 2, the use of a tracking system with thyratrons at the receiving end, the control device E, which serves to rearrange the compensation device C comparing the sensor. by this value: 4. In the device according to claim 3, the use of the selsyn located on the axis of apparatus E and which serves to influence the feed mechanism. 5. In the device on PP. 1-4 use of light modulators to modulate light rays incident on photocells.