SU1414523A1 - Apparatus for checking overload and breakdown of stem tool - Google Patents

Abstract

The invention relates to a machine tool industry, allows detecting the overload mode of a rod tool (drill, tap) until it breaks and can be used when machining parts on drilling and tapping machines with automatic work cycles. The purpose of the invention is to expand the functionality by eliminating the influence of voltage fluctuations in the network. When the tool 8 is overloaded, the first threshold element 18 is triggered, which reacts to a certain amount of output r of the water system of the above-mentioned phase currents of the main-movement wire electric motor 1. If tool 8 breaks, a second threshold element 19 is triggered, the setpoint of which is chosen according to the condition of short-term decreases in the tool load after passing through areas of the part 9 with solid inclusions. To tune the device from false alarms during sharp fluctuations of the supply voltage of the electric motor 1, an additional tuning channel with a sensor in the form of a voltage transformer 22 is used. For this, the level of the derivative linear motor voltage is monitored: in differentiation unit 23, the secondary voltage of the transformer 22 is flush, smoothed, differentiated and supplied to the third threshold element 24. The signals from the outputs of the first and second threshold elements 18 and 19 are blocked On the first and second elements AND 20.21, remove the permitting signal from the transformer 22. 1 sludge. S 3 (L cd to

Description

The invention relates to a machine tool and can be used in the processing of drilling and thread-cutting machines with automatic work cycles to detect overload rod tools (drill bit, tap).

The purpose of the invention is to expand the functionality.

The drawing shows a diagram of the device in relation to the drilling machine.

The device comprises a main drive motor 1, a reverse mechanism 2, a spindle speed setting body 3, a feed setting body 4, a feed mechanism 5, a spindle 6, a tool clamping mechanism 7 8, a workpiece to be machined 9.2 o of the part and a tool change.

current transformers 10 in the phases of the motor 1, a three-phase rectifier 11, through a smoothing capacitor 12 connected to the transformer 13, the secondary winding of which is divided 25 into two half-windings 14 and 15, the output of which is connected to the first and second diodes 16 and 17, respectively, connected respectively to the first and second threshold elements 18 and 19. -JQ The output of the threshold element 18 is connected to the first input of the first element And 20, the output of the threshold element 19 to the first input of the third element And 21. The secondary winding of the voltage transformer 22 Connected to the differential of the lean unit 23, the output of which through the third threshold element 24 and the inverter 25 is connected to the second inputs of the elements 20 and 21.

The device works as follows.

In order to detect tool overloading, a first threshold element 18 is used, which triggers when the derivative of the system of rectified phase currents of the electric motor (current i in the primary winding of the transreactor) of a certain nopoi o is exceeded. 35

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During the processing of the part 9, abrupt changes in the phase currents i, ig, ic of the electric motor 1 connected with overload or positive tool 8 can occur. Such modes arise with sharp fluctuations of three-phase supply voltage of the electric motor 1. To tune the protection device of false In the device, an additional channel of construction with a sensor in the form of a voltage transformer 22 is used, the primary of which is connected to the linear voltage of the electric motor 1, the main function of the processing channel to block the signal from the outputs of the first and second elements 18 and 19 into the control system of the station under sharp voltage fluctuations. For this, the level of the derived linear voltage of the motor is monitored: in block 23, the secondary voltage of the transformer 22 is rectified, live, and differentiated under the third threshold element 24. As the third threshold element is selected below the settings of the first second 19 threshold elements:

pa 13 sharply reduced to idle i ;. The derivative is negative in this case, the voltages on the secondary half windings 14 and 15 of the transformer 13 are negative. Diode 17 emits a voltage pulse only to the second threshold element 19, the response threshold of which is selected based on the condition of detuning from short-term decreases in the tool load after the instrument passes parts of the region with solid inclusions. When a tool breaks, the voltage level at the secondary half winding 15 exceeds the response threshold of the second threshold element 19, the latter is triggered, which is a signal to stop processing.

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During the processing of the part 9, abrupt changes in the phase currents i, ig ,, ic of the electric motor 1, not associated with overload or breakdown of the tool 8, are possible. Such modes occur during sharp fluctuations of the three-phase supply voltage of the electric motor 1. To tune the spurious protection device In the device, an additional channel of detuning with a sensor in the form of a voltage transformer 22 is used, the primary winding of which is connected to the linear voltage of the electric motor 1. The main function of the processing channel is to block the passage denie with pervog output signal and of the second members 18 and 19 in the machine control system during rapid oscillation voltage x. For this, the level of the derived linear voltage of the motor is monitored: in differentiation unit 23, the secondary voltage of transformer 22 is rectified, smoothed, differentiated and supplied to the third threshold element 24. The setting of the third threshold element 24 is selected below the settings of the first 18 and second 19 threshold elements: when

new value. When tools are overloaded, Q fluctuations in the supply voltage of the electric

The phase currents, the IQ of the electric motor increase, the derivative di / dt O. The voltages on the semi-windings 14 and 15 are positive, but the diode 16 transmits a voltage pulse only to the first threshold element 18 When the tool breaks, on the contrary, the phase currents of the electric motor and current i. in the primary winding transformer5

Rogovigatel 1, the signal at the output of the third threshold element 24 must appear earlier than at the outputs of the first and second threshold of the new elements 18 and 19. Blocking signals from the outputs of the elements (there is a release of the reg1 regulation on the first and second elements, pp1; its signal from transformer 72 n, from these elements. If a signal appears at the output of differentiating unit 23 and the third threshold element 24 operates, which indicates sharp fluctuations in the supply voltage of motor 1, the resolving signal from the inverter 25 disappears , from the first and second elements AND 20 and 21 (the BAN function is implemented).

In case of overload or breakdown of the tool 8, when there are no sharp fluctuations in the power supply voltage of the electric motor, at the output of the differentiating unit 23 and the third threshold element 24 the signal is at the level of logic o, and at the output of inverter 25 at the level of logic 1, the tune-out channel does not block the action devices.

Invention Formula

Device for monitoring overload and breakage of a rod tool, containing current transformers installed in the phases of the motor of the main drive drive of the machine, the secondary windings of which are connected

A star and a three-phase superheater and a smoothing capacitor are connected to the transreactor and the first diode and the first threshold element connected in series, characterized in that, in order to expand the functionality, the secondary winding of the transreactor is divided into two half-windings by connecting the midpoint to the busbar zero potential of the device, the first threshold element is connected to the output of one winding through the first diode, and the serially connected to the output of the other winding connected The second diode and the second feather element were injected; in addition, series-connected were introduced into the device. voltage transformer connected to the mains power supply of the electric motor, a rectifier, a differentiating device, a third threshold element and an inverter, the output of which is connected in parallel with the first inputs of the first and second elements introduced into the device, the second inputs of which are connected to the outputs of the first and second threshold elements respectively .

Claims (1)

Claim A device for controlling overload and breakage of a core tool, 2E containing current transformers installed in the phases of the main drive motor of the machine, the secondary windings of which are connected by a star and connected through a three-phase rectifier and smoothing capacitor to the transreactor, and the first diode and the first threshold element connected in series, characterized in order to expand the functionality, the secondary winding of the transreactor is divided into two half-windings by connecting the midpoint and with the bus of the zero potential of the device, the first threshold element is connected to the output of one half-winding through the first diode, the second diode and the second threshold element inserted into the device are connected to the output of the other half-winding, in addition, voltage transformers are connected in series, connected to the power supply of the electric motor, a rectifier, a differentiating device, a third threshold element and an inverter, the output of which is connected in parallel with the first inputs of the input oystvo first and second members, the second inputs of which are connected to the outputs of the first and second threshold elements.