JPS6144622B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for instantaneously detecting the amount of machining per unit time (machining efficiency) in machining using an acoustic emission (hereinafter referred to as AE) detection device. This can be used for adaptive control in machine tools.

By the way, the conventional adaptive city system detects the driving torque using the following method.

Detects motor load current (load power).

Detection is performed by installing a torque detector on the drive shaft or tool mounting shaft.

However, in order to perform adaptive control using these methods,
There are drawbacks such as the need to modify the machine tool and increased costs.

The present invention has been made in view of the above points,
It is sufficient to simply attach the AE detector to the machine tool, jig, tool, or workpiece, and almost no modification of the machine tool is required.

The present invention will be explained below based on embodiments shown in the drawings.

In FIG. 1, D is a workpiece, E is a fixed cutting tool (a rotary type is also possible), and F is a tool holder. 1 is fixed to the tool holder F
This is an AE detector, which detects the AE waves generated when cutting the workpiece and converts the AE signal into an electrical signal as shown in FIG. 3a. 2 is a preamplifier connected to the output side of AE detector 1;
The weak electrical signal is amplified as shown in Figure 3b. 3
is a discriminator connected to the output side of preamplifier 2, and this is the discriminator connected to the output side of preamplifier 2, as shown in Figure 3c.
Envelope detection is performed on the output signal. It has been confirmed through experiments that the change in the AE output voltage (Fig. 3c), which serves as the control signal for the machine tool, is approximately proportional to the amount of cutting per unit time of the tool E, as shown in Fig. 4. .

FIG. 5 shows the AE detector, where G is a piezoelectric element made of lead titanate, H is an epoxy resin base, and J is an output connector.

Acoustic emission AE refers to a phenomenon in which acoustic pulses are emitted when an object undergoes plastic deformation or destruction, and has conventionally been used for non-wave damage inspection, defect detection, destruction prediction, etc.

As is clear from the above explanation, the present invention utilizes the proportional relationship between the amount of machining per unit time and the output voltage of an AE detector attached to a tool, etc. in machining. This is a method that instantly detects the amount of processing per unit time, and according to the present invention,
Simply attaching the AE detector to the machine tool, jig, or workpiece is an excellent feature that requires almost no modification of the machine tool.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is a block diagram, Fig. 2 is a block diagram, Fig. 3 is an output waveform diagram, and Fig. 4 is a diagram of AE output voltage and processing amount per unit time. A diagram showing the relationship, and FIG. 5 is a sectional view showing the structure of the AE detector. D: Workpiece, E: Cutting tool, F: Tool holder, 1: AE detector, 2: Preamplifier, 3: Discriminator.

Claims (1)

[Claims] 1 In machining, the amount of machining per unit time can be instantly calculated by using the proportional relationship between the amount of machining per unit time and the output voltage of an acoustic emission detector attached to a tool, etc. Instant detection method for machining amount.