JPS61111878A - Monitor device for form of cutting on metal cutting machining - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Scope of Application of the Invention) Chips that surround a tool for a long time without being cut during metal cutting, and are housed in a tool mounting device as a contact element by utilizing their conductivity. A device, especially for automatic lathes, for monitoring the chip shape with respect to the tool and the evaluation circuit which closes the current circuit through contact points in the tool and chip chamber.

(Characteristics of the Known Technical Solution) In lathe operations and in conjunction with the development of manufacturing workshops for production with few workers, the management and control of chips becomes a first-class problem. Undesirable chip shapes, such as irregular or banded chips, often caused damage to the workpiece surface and interference with automatic workpiece and tool exchange. Additionally, the risk of tool damage increased. Irregular and band-shaped chips also impede the transport of the chips and therefore require a large amount of space.

All these disadvantageous concomitants of undesirable chip shapes result in isogura downtime and sources of accidents during chip evacuation.

Various measures have been taken to prevent the occurrence of irregular and band-shaped chips of this type. Therefore, by a corresponding formation of the cutting edge of the tool or by an additional oscillating movement of the mold in order to drive the feed, one-wave breakage of the chips is caused. Another method consists in predetermining manufacturing-technical cutting parameters aimed at short chips.

The machine M6A is equipped with a large number of different tools (tool storage and automatic tool change) and is programmed to the optimum cutting value from an economical point of view. Cannot be excluded. The cause is the large number and dispersion of core characteristics that affect the chip shape of the machine tool-tool-workpiece system. It is currently not possible to determine the chip shape from the outside with sufficient reliability.

The path being taken today to avoid damage as a result of unfavorable chip shapes is therefore the development of devices for automatic chip shape recognition.

Known devices for chip shape recognition are based on measuring the thermal radiation or ultrasonic reflections of the ejected chips. Another known chip shape monitor operates using a proximity trigger or beam interruption alarm device. Dynamic feed force components are already being utilized for chip shape recognition.

In the case of lathe work, an attempt was made to understand the traveling direction of chips in the form of chips by measuring them. For this purpose, one contact piece is insulated and installed at each of three different locations on the cutting face and flank face of the turning tool, and through these contact pieces, the current flowing to the evaluation circuit is caused by the discharged chips. The circuit is closed.

None of these known solutions has hitherto been effective in practice. In all cases laboratory models and correspondingly complex sensors are not suitable for use under commercial production conditions. This is because these narrow the operating space of the machine and prevent automatic exchange of workpieces or tools. Many of these senna have their function adversely affected under the use of production auxiliary materials. In addition, the burden of signal acquisition and signal transmission is extremely large. In machine tools with automatic exchange of tools and contact sensors installed on the tools, additional problems of signal transmission arise in order to guarantee functionality with a tolerable technical burden. Moreover, the sensor is sensitive to the action of external forces to a greater or lesser degree and is additionally exposed to damage due to the movement of chips.

(Objective of the Invention) The aim of the present invention is to provide a chip shape monitoring device that is highly reliable, has few failures, and satisfies the requirements for use in actual production.

(Detailed Description of the Invention) The present invention has a function for metal chip machining, with regard to chips that surround the tool for a long time without cutting, regardless of rough machining or finishing machining, and also with the use of manufacturing auxiliary materials. The contact elements should be kept separate from the tool (and should not have an adverse effect on the functioning of the machine and on the exchange of workpieces and tools, creating a device for monitoring chip shape with contact elements). The issue is the basis.

The present invention solves this problem by providing a tool mounting device which, in the immediate environment of the tool mounting point, has an end face facing the workpiece as well as a directly connected side surface which is insulated with respect to the base body of the tool mounting device. This problem is solved by providing a conductive layer.

This layer is connected to a transmission conductor placed inside the tool attachment device, the latter leading outward via a connection point to an evaluation circuit □, which outputs a signal in the event of a persistent contact. ``Tangled chips'' are also solved by activating the signal output 1 ``Long chips'' in the event of intermittent contact.

The conductive layer is preferably a wear-resistant plate insulated and mounted on the surface of the tool mounting device.

These plates should preferably consist of non-magnetic material.

In the case of a tool attachment device as part of a turret, the connection point is designed as an inductive proximity device.

A wireless measuring signal transmitter is already present which is provided in the turret to receive the measuring signal from the exchangeable measuring scanning device and which transmits the measuring signal from the turret to the stationary tool carrier part. The receiving point of the measuring signal transmitter 1, which is provided in the tool carrier part of the tool carrier, is connected to the evaluation circuit via a gate circuit.

Preferably, the signal output 0 wrapped chips 1 is activated during a predetermined sustained contact time in the range 0.5 to 4 seconds, and the signal output ``long chips'' is activated between 2 and 50 H.
The range pressure of z is activated upon a certain predetermined contact frequency. The signal output of the evaluation circuit is connected to a setpoint value source which increases the feed drive in stages.

Example An embodiment of the invention is shown in the drawing.

Turning tool mounting device 1 (standardized chip shape monitoring device)
The description is based on Figures 1 and 2). A turning tool 2 provided with a tip 2a is accommodated in the turning tool mounting device 1. As shown in FIG. The turning tool mounting device 1 has a cylindrical holder 1a, which is fixed to the disc turret 3 (FIG. 3).

The turning tool mounting device IK has a fixed contact element 4 which wraps around the surface of the turning tool mounting device I close to the protrusion of the turning tool 2, i.e. is adapted to the surface shape of the device. Contact element 4 is made of a non-magnetic steel plate. Contact element 4
An insulating underlay 5 is provided which is adapted as insulation for the turning tool mounting device l. The contact element 4 is covered with an insulating underlay 5
It is also screwed to the turning tool mounting device 1. For this purpose, an insulating bushing 6.7.8 for the fixing screw 9.10 is inserted into the turning tool mounting device 1. Contact element 4
is connected at one fixing point via a fixing screw 10 to a cylindrical bushing 11 inserted insulated into the turning tool mounting device 1, to which an electric wire 12 is connected, which connects the turning tool. It is guided through the mounting device 1 and connected to a small induction coil 13 (Fig. 1'3). The other input end of the milling lead 13 is connected via a wire 14 to ground or to the turning tool attachment device 1 and thus also to the tip 2a.

The induction coil 13 is housed in a housing 15, the latter being inserted into a cylindrical recess in the end face of the cylindrical receiver 1a of the tool mounting device 10 and fixed with screws 19.

Directly opposite the induction coil 13 is a proximity activator 16 . A housing 17 containing the proximity actuator 16 is fastened to a stationary tool carrier part l8. The air gap between the induction coil 13 and the proximity starter 16 can be adjusted by adding a disc spacer.

The wiring diagram (figure 4) shows an induction coil 13 that can be opened for a short time by a chip, which is represented as a switching contact 21 between contact element 4 and tip 2a.

A coupled induction coil 22 belonging to the proximity starter 16 is in the oscillator circuit, the latter being represented by a capacitor O connected to the coupled induction coil O. Electric wire 24 (spear 3
The signals associated with FIG. 1 are routed to an evaluation circuit (not shown).

When the ejected chips come into contact with the contact piece, they emit a signal, which is graphically represented in FIG. 5 with time t on the horizontal axis. ? FIG. 5a shows an irregular signal course, in which contact events of different lengths produce both short pulse-like signals and longer signals. Figure 5b shows three characteristic signal profiles. At time TL, 8 only signals appear which disappear again within a predetermined contact duration. At period T3 of spear 2, a collection of pulse-like signals appears, in which case a limit pulse number of 9 pulses is reached. This is determined from predetermined contact frequency and timing. At the next period 'rIJ8, a sustained contact occurs with the ejected chips that exceeds a predetermined sustained contact time T.

If the limit pulse number is exceeded or the predetermined continuous contact time is exceeded, the evaluation circuit signals "long chips".
Or the "signal wrapped chips" is activated.

The operating method of the chip shape monitoring device is as follows: During machining, a chip is sent out over the tool tip 2a and the switching element 2
The chips acting as 1 generate a signal Y when contact occurs with the contact element 4.

When the circuit from the chips to the contact element 4 is not closed, the signal level remains at its original level L.

As a result, no H level occurs in all short chips. Only longer chips that hit contact element 4 lead to signal level H.

If these chips still break off on their own immediately after that, ie before the predetermined continuous contact time has been reached, there is no need to intervene in the progress of the machining process. Starting when this time limit is exceeded,
The contact occurrence of the ejected chips is recognized by the evaluation circuit as a sustained contact time and a signal "Wrapped Chips" ws
is emitted. In this case, the chips sent out are usually wrapped around the turning tool and fixed. When the ejected chips simply but repeatedly close the circuit for a short period of time, thus emitting a pulse-like signal, the limit number of pulses igrenz is not reached within the period T, that is, in this embodiment, the number of pulses per period T is As long as the number of chips does not exceed nine, the risk of dangerous long chips can be eliminated. Only in the case of a count value that exceeds the limit pulse number igrenz is the signal 1 long chip "LS" emitted from the evaluation circuit.

When it comes to chip generation, the appearance of these pulse frequencies indicates that long chips that come into contact with each other many times are considered to be dangerous long chips because they often wrap around and generate chips when there is an extremely slight change in cutting conditions. Should. Therefore, in the case of multiple chips, by recognizing dangerous long chips and changing the machining parameters as a result, it is possible to prevent the occurrence of wrapped chips, which should be absolutely avoided. Each occurrence of a contact causes an attenuation of the oscillator circuit of the proximity starter 16, from which the above-mentioned signal (2) is derived and sent to the evaluation circuit.

When the depletion is eliminated by opening the switching contact 21, the signal is returned to L. A possible strategy is, for example, to increase the feed rate of the Tonikko process to a predetermined limit value by a certain step-over when the signal ``long chip'' LS and/or the signal ``wound chip'' WS is issued. The idea is to improve the chip shape or break the chip by using a step-by-step increase in the target value source for the alarm signal. ``When WS is present, a signal should be issued that intervention is required to remove chips wrapped around the tool.Signal for manual intervention in the machining process "Long chips" This can also be done if L8 continues to exist.

[Brief explanation of drawings]

FIG. 1 is an outline view of the side of the tool mounting device for turning tools that faces the workpiece. Figure 2 is a top view of the tool mounting device shown in Figure 1. FIG. 3 is a sectional view taken along line A-B of the It diagram. Figure 4 is a wiring diagram for signal acquisition. FIG. 5'a shows the signal curve in the case of a broken chip. Fifth. FIG. b shows the signal curve in the case of unbroken to 1 chip and the signal output derived therefrom by the evaluation circuit ``1 long chip to 1 wrapped chip.'' 1-Turning tool mounting device 1a-Cylindrical receiver 2-Turning tool 2a-Chip 3-Disc turret 4-Contact element 5-Underlay 6.7.8, -Insulating bush 9.1〇-Fixing screw 11- Cylindrical bushing 12.14, electric wire 13 - induction coil 15.17 - housing 16 - proximity starter 18 - tool carrier part 19 - screwing - disc spacer 21 - four switching contacts - coupled induction coil n - capacitor L8 - Long chips We - Coiled chips 5 one time period m - Persistent contact time igrenz - Limit contact frequency
[1 hour H - Signal level high L - Signal level low 16-1

Claims (1)

[Claims] 1. Chips that surround the tool for a long time without cutting during metal cutting, and by utilizing their conductivity, they can be used as contact elements in the tool and chip chamber housed in the tool mounting device. In a device for monitoring the shape of chips with respect to an evaluation circuit by closing a current circuit through the contact point of the tool (2), especially in the device for automatic lathes, the tool mounting device is placed in the direct environment of the mounting point of the tool (2). On the end face facing the workpiece as well as on the side directly adjoining, a conductive layer is applied, which is insulated from the base of the tool attachment device, and which layer is laid through the interior of the tool attachment device. It is connected to a transmission line (12), which is led to the outside via a connection point to the evaluation circuit, so that in the event of a persistent contact, the signal output "wound chip" (WS) and the intermittent A device characterized in that a signal output "long chip" (LS) is activated when a physical contact occurs. 2. The device according to claim 1, characterized in that the conductive layer on the surface of the tool mounting device is an insulating wear-resistant steel plate (4). 3. The device according to claims 1 and 2, characterized in that the wear-resistant steel plate (4) is made of a non-magnetic material. 4. Device according to claims 1 to 3, characterized in that in the tool attachment device as part of the turret (3), the connection point is designed as an inductive proximity starter (16). 5 Measurement at a measuring signal transmitter between the turret (3) and the stationary tool carrier part (18), which is provided for receiving the measuring signals of the electrical measuring scanning device housed in the turret (3). 5. Device according to claim 1, characterized in that the receiving point of the signal transmitter is connected to the evaluation circuit via a gate circuit. 6 Signal output “wrapped chips” (WS) is 0.5 to 4
A predetermined sustained contact time (T_W) in the range of seconds
6. The device according to claim 1, wherein the device is activated in the case of _S). 7. Device according to claims 1 to 6, characterized in that the signal output "long chips" (LS) is activated for a predetermined contact frequency in the range from 2 to 50 Hz. . 8. Device according to claims 1 to 7, characterized in that the signal output of the evaluation circuit is connected to a setpoint value source for increasing the feed drive stepwise.