JPH05200650A - Motor output display unit of machine tool - Google Patents

Abstract

PURPOSE:To enable such a machining operation as making the best use of motor power to be performed by making the operating conditions of a motor properly settable without relying on experience and perception. CONSTITUTION:A relationship 4 between revolving speed N and permissible actual output Pm of each motor 1 is registered in a controller 3, while the revolving speed N of each motor 1 is inputted together with a load output L, and the permissible actual power Pm in the revolving speed is calculated from the relationship 4 the revolving speed and the permissible actual output registered in advance, and this value is multiplied to the load output L inputted, thus actual output is operated. Furthermore, using this actual output P and time measured by a clock built in the controller 3, average output Pv is operated, thus a rate (an average output rate) R to the allowable value is displayed on a display unit 5 of a control panel together with the load output L.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for displaying the output of a spindle motor of a machine tool or a feed motor of a tool or a work.

[0002]

2. Description of the Related Art The load applied to a spindle motor and a feed motor of a machine tool varies not only with cutting conditions but also with operating conditions such as rotation start of a spindle at the start of machining and high-speed approach of a tool. .. On the other hand, the motor
It is necessary to operate so that the load does not exceed the rated output.
Therefore, in the conventional machine tool, the percentage of the rated output of each of the spindle motor and the feed motor is displayed, and the operator displays the output at each time (hereinafter referred to as "load output"). Is said to be 1
Processing is performed by setting the operating conditions so that it does not exceed 00%.

Although the load that can be applied to the motor is limited by its rated output, it is possible to operate with a load exceeding the rated output for a short time. On the other hand, machine tools are strongly required to reduce the tact time when performing one-step machining. Since this takt time includes the time required to start the spindle rotation and move the blade to the machining position, in order to shorten these times as much as possible, the spindle rotation should be started at an output exceeding the rated output. The reality is that people are moving tools.

[0004]

Since the time required for starting the rotation of the spindle and for moving the tool to the machining position at high speed is much shorter than the actual machining time, these operations are not possible during normal machining. There is no problem even if the output exceeds the rated output. However, in machining in which the spindle rotation is frequently accelerated and decelerated, even if the operating conditions are set so that the load output during cutting does not exceed 100%, the average output during one cycle of machining is within the allowable value. May damage the motor.

Therefore, in such a case, the operator sets the operating conditions so that the load load during cutting is low, considering the frequency of acceleration and deceleration.
This setting requires experience and is usually set on the light load side in consideration of safety, so there is a problem that machining that makes full use of the motor capacity cannot be performed.

[0006]

Therefore, the present invention displays the load output L of the spindle motor and the feed motor 1 for the tool or the work on the display device provided on the operation panel of the machine tool, and shows the history of the load output. The above problem is solved by displaying the average output Pv.

The display of the load output L on the display device 5 is performed by extracting the load output L from the amplifier 2 of the servo device controlling the spindle motor and the feed motors 1 and displaying it. The load output L is a percentage of the actual output with respect to the allowable actual output Pm that varies depending on the rotation speed of the motor, and is not proportional to the actual output value. On the other hand, the average output Pv is regulated by the relationship between the actual output value and time. Therefore, in the device of the present invention, the relationship 4 between the rotational speed n of each motor 1 and the allowable actual output Pm is registered in the controller 3, and the rotational speed n of each motor 1 is input together with the load output L and registered in advance. The allowable actual output Pm at the rotational speed is calculated from the relationship 4 between the rotational speed and the allowable actual output, and the actual output P is calculated by multiplying this by the input load output L, and the actual output P and the controller 3 are calculated. Average output Pv using the time measured by the built-in clock
Is calculated, and the ratio (average output ratio) R to the allowable value is displayed on the display device 5 of the control panel together with the load output L.

[0008]

According to the above-mentioned device, the average output rate R of each motor 1 can be displayed without significantly changing the controller 3, and the acceleration / deceleration of the motor is frequently performed. Indicates that the average output rate R exceeds 100% even when the load output L does not exceed 100%.
The operator can set operating conditions so that both the displayed load output L and average output rate R do not exceed 100%, and both load output L and average output rate R are 1
Since the operating conditions can be set so that the maximum output of the motor 1 can be exhibited within the range of not exceeding 00%, even an inexperienced operator can perform machining making the best use of the performance of the motor 1.

[0009]

EXAMPLE An example shown in the drawings will be described below. FIG. 1 shows the device of the present invention for only one motor 1, and the configuration shown in FIG. 1 is provided in the same number as the number of spindle motors and tool or work feed motors mounted on a machine tool. The motor 1 has its rotation speed n and torque controlled by an amplifier 2 of the servo device.
The load output L and the rotation speed n are given to the controller 3. In the controller 3, the relation 4 between the rotation speed n and the allowable actual output Pm is registered in advance for each motor. Controller 3
Is calculated based on the input rotational speed n from the relationship 4 between the registered actual rotational speed and the allowable actual output Pm at that rotational speed, and is multiplied by the input load output L, The actual output P is calculated.

Then, the integrated value of the calculated squared time of the actual output is divided by the elapsed time DT, and the square root thereof is calculated to calculate the average output Pv. Then, the ratio (average output ratio) R of the average output Pv to the allowable value is displayed on the display device 5 together with the load output L of each motor. For example, in the display shown in FIG. 1, the load output L of the spindle motor 1 is less than 100%, but the average output rate R is 1
It shows that the average output rate R exceeds the permissible value even though the load output L is within the permissible range, and the average output rate is based on this display. The load during cutting is reduced to 100%. The calculation load is limited by inputting the upper limit of the elapsed time as a calculation condition with a parameter related to the rated time.

[0011]

The display device of the present invention described above includes:
Since the average output rate is displayed together with the load output, the accurate load state of each motor can be determined by looking at both of them, and the damage to the motor caused by the average output rate exceeding 100% can be avoided. Further, since the operating conditions for maximizing the output of each motor can be set, it is possible to perform heavy cutting by making the most of the motor output, thereby shortening the machining time for one cycle.

[Brief description of drawings]

FIG. 1 is an explanatory view schematically showing a main part of the present invention.

[Explanation of symbols]

 1 Feed motor 5 Display L Load output Pv Average output

Claims (1)

[Claims] 1. A display device provided on an operation panel of a machine tool.
Load output of spindle motor or feed motor (1) to (5)
A motor output display device of a machine tool, which displays an average output (Pv) indicating a history of load output together with (L).