JP2684347B2 - Turning method to reduce air cut time - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turning method for shortening an air cut time used for processing a work in the field of various machine tools. 2. Description of the Related Art Conventionally, as a grinding method using a grinder, for example, a method disclosed in Japanese Patent Publication No. 56-7824 is known. The method disclosed in this publication measures the size of the supplied work piece by piece by the end of the machining of the work piece at the latest, at the latest, depending on whether the maximum size of the work piece is smaller or larger than the reference size. Depending on the amount of time or a large amount, the standby position of the grindstone for the next machining cycle is set to be before or after the standby position for the previous machining cycle so that the rapid advance stroke of the grindstone to the point just before machining becomes constant. Is to prevent troubles such as hitting the workpiece during rapid forward movement and to reduce waste of air cutting time. In the conventional method, when a work is machined, the maximum size of the work must be measured during or before the work of the preceding stage and compared with a reference size. Therefore, the machining of the work cannot be performed independently of the machining of other works. Also, with this method, changing the standby position makes the rapid advance stroke until just before machining of the grindstone constant, but the stroke in the rough-grinding feed section is as long as the maximum measured dimension of the workpiece differs from the reference dimension. It increases or decreases to cause changes in rough grinding conditions. Moreover, since the end point of rapid advance is the maximum outer diameter position of the work, this method moves the blade rapidly from the surface of the work to the set position, and then reduces the moving speed to efficiently turn the work. It is not applicable when doing. The present invention has been made to solve the above-mentioned problems, and after the blade tip is brought close to the surface of the work, the moving speed of the blade is reduced. A turning method for processing each work, wherein the ultrasonic sensor is fixed to a fixing member such that the distance to the tip of the blade at the standby position becomes a predetermined value a in the moving direction of the blade, The position at which the moving speed should be switched is specified in advance as the closest distance d between each work surface and the tip of the blade, and the distance c between the ultrasonic sensor and each work surface is calculated before processing each work. Based on the measurement value c, the predetermined value a, and the closest distance d, the distance to move the blade from the standby position is defined as c-a-d. Calculate and total While measuring the moving distance x of the cutting tool by the measuring means, the calculated value c with the tip of the cutting tool facing the work surface.
The blades are moved close to each other by -a to d, and then the moving speed of the blade is reduced. Here, the closest distance d is a relative distance between each work surface and the tip of the blade at a position where the moving distance of the blade is switched to a slow value, and the closest distance d is specified, for example, artificially. . FIG. 1 shows an embodiment in which the present invention is applied to a drilling machine. FIG. 1 shows a blade 4 held by a spindle cylinder 2 via a chuck 3, a motor 5 for controlling the vertical movement speed of the spindle cylinder 2, a table 6 on which a work 7 is placed, and the like. Has been done. Ultrasonic sensor 1
Is a fixing member 1 that is separate from the main barrel 2 that moves vertically.
It is attached to 2. Also, the descending distance x of the spindle cylinder 2
In order to measure, the measuring means 13 such as a linear scale is provided along the length direction of the spindle cylinder 2. The ultrasonic sensor 1 accurately measures the distance b to the table 6 by transmitting an ultrasonic wave having good directivity to the table 6 before the work 7 is placed and receiving the reflected wave. When ultrasonic waves are transmitted to the surface of the work 7 placed on the table 6, the distance c between the ultrasonic sensor 1 and the surface of the work 7 is accurately measured in the same manner, and the thickness t of the work 7 is determined by the table 6 Measured value b up to the measured value c from the surface of the workpiece 7
It is calculated by subtracting. In the memory circuit 8 connected to the ultrasonic sensor 1, the distance c between the ultrasonic sensor 1 measured by the ultrasonic sensor 1 and the surface of the work 7 is c.
And the distance a from the ultrasonic sensor 1 to the tip of the blade 4 at the standby position are stored. The ultrasonic sensor 1
To the tip of the blade at the standby position depends on the mounting position of the ultrasonic sensor 1. The arithmetic circuit 9 connected to the memory circuit 8 is adapted to perform the arithmetic operation (c−a−d) when the set distance d for switching the descending speed of the spindle cylinder 2 is set. When the descending distance x of the spindle cylinder 2 from the standby position is input from the measuring means 13, the comparing circuit 10 connected to the arithmetic circuit 9 and the measuring means 13 calculates the value of this x and the arithmetic circuit 9 ( C-a-d). Then, only when the value of x becomes equal to the value of (c-a-d), a command is issued to the control circuit 11 to cause the motor 5
It is configured to reduce the rotation speed of No. 2 and switch the descending speed of the spindle cylinder 2 to a set value. In the case of the above construction, the distance (c-a) between the tip of the blade 4 at the standby position and the surface of the work 7 can be accurately determined by the ultrasonic sensor 1, and the spindle cylinder from the standby position can be obtained. Since the descending distance x of 2 can be accurately measured by the measuring means 13 such as a linear scale, an excellent effect can be obtained. That is, the ultrasonic sensor 1 is operated, and the set distance d of the moving speed of the spindle cylinder 2 is set.
When the drilling machine is driven with the set value, the spindle cylinder 2 is quickly lowered by the motor 5 while the descending distance x measured by the measuring means 13 is smaller than the value (c−a−d). After that, when the descending distance x becomes equal to (c−a−d), the control circuit 11 slows down the rotation speed of the motor 5 according to a command issued from the comparison circuit 10 and sets the descending speed of the spindle cylinder 2. Switch to a lower value. Therefore, it is possible to shorten the air cut time until the blade 4 approaches the work 7 and improve the efficiency of turning. Further, the measurement of the distance to the surface of the work 7 is different from the case where the optical sensor is used, even when cutting materials having various surface roughness, water, oil, etc. adhere to the ultrasonic sensor 1 and the work 7. Since the measurement can be performed by the ultrasonic sensor 1 without being affected by the above, it is possible to reliably prevent the blade 4 from causing a trouble with the work 7 when the spindle cylinder 2 is descending at a high moving speed. Moreover, the spindle cylinder 2 is switched so that the descending speed becomes slower when the tip of the cutting tool 4 moves to the position of the set distance d which is close to the surface of the work 7, so that the machining and finishing accuracy of the work 7 is excellent. Can be kept in a state. The application of the present invention is not limited to the case of the drilling machine, but can be applied to a lathe and other various machine tools. FIG. 2 shows an embodiment related to the present invention, in which an ultrasonic sensor 1 is attached to the surface of a spindle cylinder 2 of a drilling machine and is held by the spindle cylinder 2 via a chuck 3. It moves up and down together with the cutting tool 4 that is present. Reference numeral 5 is a motor that controls the vertical movement speed of the spindle cylinder 2. The ultrasonic sensor 1 is attached so that the distance a from the tip of the blade 4 becomes a preset constant value,
The set value a is stored in the storage circuit 8. The ultrasonic sensor 1 accurately measures the distance b to the table 6 by transmitting an ultrasonic wave having good directivity to the table 6 before the work 7 is placed and receiving the reflected wave. When ultrasonic waves are transmitted to the surface of the work 7 placed on the table 6, the distance c between the ultrasonic sensor 1 and the surface of the work 7 is accurately measured in the same manner, and the thickness t of the work 7 is determined by the table 6 Measured value b up to the measured value c from the surface of the workpiece 7
It is calculated by subtracting. Reference numeral 9 is an arithmetic circuit connected to the memory circuit 8. When a set distance d from the surface of the work 7 that switches the moving speed of the blade 4 is set in the arithmetic circuit 9, the arithmetic circuit 9 causes the work 7 in this state to move. The distance from the surface of the ultrasonic sensor to the ultrasonic sensor 1 (a +
The calculation of b) is performed. When the spindle cylinder 2 descends, the distance x to the surface of the work 7 measured by the ultrasonic sensor 1
Are continuously input to the comparison circuit 10. Comparison circuit 10
When the measurement distance x is input from the ultrasonic sensor 1, the x compares the calculated value (a + b) input from the calculation circuit 9 with x. While the value of x is larger than (a + b), the comparison circuit 1
No command is issued from 0 to the control circuit 11, and the descending speed of the spindle cylinder 2 by the motor 5 is maintained in a high state.
However, when the value of x becomes equal to (a + b), the comparison circuit 10 causes the control circuit 11 to reduce the rotation speed of the motor 5 to decrease the descending speed of the spindle cylinder 2 to the set value. The command is issued.
In the apparatus having the above configuration, when the ultrasonic sensor 1 is operated, the set distance d of the moving speed of the spindle cylinder 2 is set, and the drilling machine is operated, the distance x measured by the ultrasonic sensor 1
Is larger than the value of (a + b), the spindle cylinder 2 keeps the motor 5
Is quickly lowered by. However, the measured distance x
Becomes equal to (a + b), the control circuit 11 slows down the rotation speed of the motor 5 according to a command issued from the comparison circuit 10 and switches the descending speed of the spindle cylinder 2 to the set low value. According to the present invention, the distance between the tip of the cutting tool at the standby position and the work surface is accurately determined by an ultrasonic sensor having a wide measuring range and a sharp directivity, and the work surface is moved from the standby position. Since the tool is moved quickly to the set position close to the tool, and then the moving speed of the tool is slowed, the air cutting time until the tool comes close to the workpiece is shortened The efficiency of can be improved. Further, the distance measurement by the ultrasonic sensor has high measurement accuracy, and even when cutting materials having various surface roughnesses, oil, etc. are attached to the ultrasonic sensor or the work, they are hardly affected by them, Even when the blade is descending at a high moving speed, it is possible to prevent the blade from coming into contact with the work and causing trouble. In addition, even if the air cut time is shortened, the blade can be switched so that the descending speed becomes slow at the position close to the surface of the work, so that the work finishing accuracy of the work can be kept in a good state.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram showing an example of an apparatus for carrying out the present invention. FIG. 2 is a configuration diagram showing an example of an apparatus related to the present invention. [Explanation of reference numerals] 1 ultrasonic sensor 2 movable member (spindle cylinder) 4 blade 7 workpiece 12 fixing member 13 measuring means

Claims (1)

(57) [Claims] After quickly bringing the tip of the tool close to the surface of the work,
A lathe turning method for slowing down the moving speed of the cutting tool to process each work, wherein the ultrasonic sensor is fixed so that the distance to the tip of the cutting tool at the standby position becomes a predetermined value a in the cutting tool moving direction. The position where the moving speed of the cutting tool should be switched is specified in advance as the closest distance d between the surface of each work and the tip of the cutting tool, and the ultrasonic sensor and The distance c to each work surface is measured based on the output of the ultrasonic sensor, and the blade is moved from the standby position based on the measured value c, the predetermined value a, and the closest distance d. The power distance is calculated as c-a-d, and while the moving distance x of the cutting tool is measured by the measuring means, the tip of the cutting tool is quickly brought closer to the work surface by the calculated value c-a-d, and then the cutting tool. Moving Speed Turning method for reducing the air cut time, characterized by slow.