JPH07115280B2 - Unbalanced tool measuring device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an unbalanced tool measuring device, and in particular, it detects a vibration frequency and an amplitude based on an unbalanced tool and automatically sets a limit rotational speed. An unbalanced tool measuring device.

[Conventional technology]

Conventionally, a tool that is used by being attached to a rotating main spindle of a machine tool causes vibration due to a subtle imbalance in the tool itself as the number of rotations increases, which not only affects the product tolerance. Not, in some cases,
It may cause a dangerous situation such as tool damage.

[Problems to be solved by the invention]

In order to prevent the above situation, a vibration type was attached to the spindle to which the tool is attached, and the rotation speed of the tool was measured in the past, but it was only measured and the limit rotation speed was judged. However, it is up to the operator to control the operation of the machine, and there has been no device that automatically and accurately copes with the situation.

The present invention was devised in view of such problems, and even a skilled worker can easily set the limit rotational speed of the tool, and can automatically and accurately deal with the situation, It is an object of the present invention to provide an unbalanced tool measuring device that contributes to prevention of danger and improvement of machining accuracy without wasting time and effort.

[Means for solving problems]

In the present invention, means for solving the above problems will be described with reference to FIG. 1 showing a basic configuration example of the present invention. Attached to a spindle head of a machine tool 10 that performs machining based on an NC machining program. The vibrometer 12, the analyzer 14 for detecting the vibration frequency and the amplitude of the tool from the vibrometer 12, the rotation speed setting means 20 for stepwise increasing the spindle speed S of the machine tool 10, and the respective stages. Comparing means 30 for comparing the amplitude in the vibration frequency region corresponding to the rotation speed with a predetermined limit value,
Limit rotation speed setting means 40 for registering the rotation speed immediately before the amplitude exceeds the limit value as the limit rotation speed of the tool.
And a machining command means 50 for judging whether or not a machining command is issued by comparing the tool revolution speed instructed by the NC machining program with the limit revolution speed. In addition to this, the unbalanced tool measuring device further includes a storage means 60 for reading or writing data to each of the above-mentioned means, and a higher-level central processing unit (not shown-hereinafter, CPU) for controlling all of them. And referred to as).

[Action]

By increasing the rotational speed of the spindle in stages, it is possible to accurately grasp the rotational speed at the stage where the vibration frequency and amplitude exceed the limit values of the tool and the stage before the stage, and the stage before the stage. The rotation speed may be set as the limit rotation speed. Also, in actual machining, after comparing the tool rotation speed instructed by the NC machining program with the limit rotation speed and issuing a machining command, it is not always necessary to issue the machining command due to machine performance or tool rigidity. Since it is not always necessary to stop the work at the limit number of revolutions, the means for judging whether or not the official announcement is possible shall be provided.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the embodiments and the drawings.

FIG. 2 is a block diagram showing an example of an unbalanced tool measuring device embodying the present invention.

In FIG. 2, the unbalanced tool measuring device is a CPU 1 which also functions as a central processing unit of a host device, a display 2 with a keyboard and its input / output port 2a, and a spindle of an NC machine tool 10 with an ATC (automatic tool changer). Attached vibration meter 12
The vibration frequency X (H ₂ ) and the amplitude W (μ) of the tool are detected from the vibrometer 12, and the analyzer 14 in which the frequency range of measurement is set and the spindle speed S of the machine tool 10 are set in stages. Rotational speed setting means 20 for increasing the vibration frequency and the vibration frequency Xi or amplitude Wi at the rotational speed Si at each stage i at a predetermined limit value WMAX.
Comparison means 30 for comparing with the rotation speed setting means 40 for registering the rotation speed Si-1 of the stage i-1 immediately before the amplitude W exceeds the limit value of the tool as the limit rotation speed SS'n of the tool, NC
Machining command means 50 for judging whether or not a machining command is issued by comparing the tool revolution speed SSn designated by the machining program with the limit revolution speed SS′n, NC machining data memory 61, measurement program memory 62 and tool The storage means 60 is composed of a limit rotation speed memory 63.

3 and 4 are flowcharts showing the operation procedure of the above apparatus, FIG. 3 is a setting procedure of the limit rotation speed, and FIG. 4 is a command procedure of a machining command. Hereinafter, the above device will be described in detail according to the operation procedure.

In the second stage of the flow of FIG. 3, when the tool is specified and the n-th tool is attached by the automatic tool changer (ATC), the tool number and the tool number Tn to be measured are the rotation speed setting means. The signal is input to 20, and a signal is input from the AND gate 101 to the AND gate 102 and the AND gate 103 when both numbers match. Since the flag from the CPU 1 is directly input to the AND gate 102 and the signal inverted by the inverter 111 is input to the AND gate 103, the signal from the AND gate 101 is ANDed by the flag from the CPU 1. Either gate 102 or AND gate 103 will be passed. The former is used as a machining command activation command and the latter is used as a measurement program activation command. With the latter and a command to read the stored contents of the measurement program memory 62, the rotation number of the tool Tn is
Sn1 = 500 rpm, Sn2 = 1000 rpm, Sn3 = 1500 rpm ... Sni will be set in stages.

At the second stage of the flow, the vibration frequency X and the amplitude W are measured. The vibration frequency is fed back as a frequency region setting corresponding to the rotation speed at each stage, and the respective measured values of the amplitude Wi in the region are compared. Will be entered in 30. In the second stage of the flow, the amplitude Wi input via the AND gate 104 is compared with a predetermined limit value WMAX in the comparators 31 and 32. The predetermined limit value WMAX may be a constant value for the entire machine, may be set to be a constant value for each tool, or may be set for each of the above regions in correspondence with each rotation speed.

Now, as a result of the comparison, if the amplitude Wi does not exceed the predetermined limit value WMAX, a signal is output from the comparator 31, and if it exceeds the limit value WMAX, a signal is output from the comparator 32 and one of the following signals is output. It is input to the limit rotation speed setting means 40 of the stage. Comparator
The signal from 31 is input to the AND gate 105 to pass the rotation speed Sni at that stage to the first setting means 41, and the signal from another comparator 32 is input to the AND gate 106 to perform the same rotation. Pass the number Sni to the second setting means 42. As the stage of the flow, in the first setting means 41, the rotation speed Sni
Is used as the limit rotation speed SS′n, and the rotation speed increase designation means
At 43, the number of revolutions is increased step by step and the measurement is repeated. With the inverter 112, there is no signal and a rewrite command is not issued. The measurement is repeated until the predetermined limit speed SS 'is reached, but this limit speed is the limit speed SS' of the machine.
Alternatively, the limit rotation speed SS′n for each tool may be used. When the rotation speed Sni is input to the second setting means 42, it is replaced with the rotation speed Sni-1 one step before.

In the second stage of the flow, the rotational speed Sni above is changed to the limit rotational speed S
S'n is determined, and as the second stage of the flow, it is registered or rewritten in the tool limit rotational speed memory 63. As the stage of the flow, if it is confirmed that the setting is completed for all tools, the flow ends.

Although the flow of FIG. 3 is not completed for all tools, when the activation command of the machining command means is issued, the flow of command operation, an example of which is shown in FIG. 4, is started. After the tool Tn is specified, the step T of the flow is registered in the set rotational speed SSn corresponding to the tool Tn in the machining data memory 61 and the tool limit rotational speed memory 63. Limit speed S per tool
S'n is called by the machining command means 50, and as a second stage of the flow, both are compared by the comparator 51, and if the set rotational speed SSn of the machining data is equal to or less than the limit rotational speed SS'n,
Assuming that the machining work is not hindered, the machining command is output from the command processing means 52, the machining simulation is performed as the step of the flow, and if the result is satisfactory, the machining data memory 61 of the machining data Replace the set speed SSn with the limit speed SS'n.

When the set rotation speed SSn of the processing data is not equal to or lower than the limit rotation speed SS′n, an alarm is issued via the inverter 112, and the processing command is not issued unless the alarm processing is performed. However, depending on the rigidity of the tool, there may be no problem even if the rotation speed exceeds the limit rotation speed SS'n.
Alarm cancel signal register in processing command means 50
By preparing 53 and inputting a flag from the CPU 1, a processing signal can be issued by a signal passing through the AND gate 107.

If it is confirmed that the machining simulation has been completed for all the tools, the flow ends.

The command operation shown in FIG. 4 has been described by taking the machining simulation as an example. However, it is of course possible to directly execute the command operation by the same flow.

〔The invention's effect〕

As described above, according to the present invention, even a skilled operator can easily set the limit rotational speed of the tool, and can automatically and accurately deal with the situation, thus saving unnecessary labor and time. It is possible to provide an unbalanced tool measuring device that contributes to prevention of danger and improvement of machining accuracy without spending.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration example of the present invention, FIG. 2 is a block diagram of an example of an unbalanced tool measuring device embodying the present invention, and FIGS. 3 and 4 are operations of the above-described embodiment. It is a flowchart of a procedure. 1; CPU1 (central processing unit), 2; display with keyboard, 10; machine tool, 12; vibration meter, 14; analyzer, 20; rotation speed setting means, 30; comparison means, 40; limit rotation speed setting means, 50; processing command means, 60; storage means, SSn; set rotation speed (n = tool type), SS'n; limit rotation speed, Sni; rotation speed for each step (i = step).

Claims (1)

[Claims] 1. An unbalanced tool measuring device equipped with a vibrometer attached to a spindle to which a tool is attached, and an analyzer for detecting the vibration frequency and amplitude of the tool from the vibrometer, and performing machining based on an NC machining program. Therefore, the rotation speed setting means for increasing the rotation speed of the main shaft stepwise, the comparison means for comparing the amplitude in the desired vibration frequency region with a predetermined limit value, and the rotation speed immediately before the amplitude exceeds the limit value. Limit rotation speed setting means for registering the number as the limit rotation speed of the tool, and machining command means for comparing the tool rotation speed instructed by the NC machining program with the limit rotation speed and judging whether or not the machining command is issued. An unbalanced tool measuring device characterized by being provided.