JP2001310201A - Confirmation method and device of bar delivery quantity on automatic lathe and shank of projective cutting bite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent production of a defective product due to shortage of bar delivery quantity by providing a confirmation method and a confirmation device of the bar delivery quantity on an automatic lathe and a shank of a projective cutting bite for it easy to detect that there is made a clearance between a bar and a stopper, low at cost and easy to handle. SOLUTION: A weak electric current is electrified between the bar and the stopper to support the bar when a main spindle closes a chuck to grip the bar by relatively retreating, existence of a clearance between the bar and the stopper is detected in accordance with existence of electrification of this weak electric current, when the weak electric current is electrified, it is judged that there is no clearance between the bar and the stopper and delivery quantity of the bar is normal and when it is not electrified, it is judged that there is a clearance between the bar and the stopper and the delivery quantity of the bar is not normal in a bar delivery process to deliver the bar as a material of a work to work next after finishing working a former work on an automatic lathe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bar which is held by a spindle and a tool which is fixed to a tool rest, are relatively moved to process a work into a predetermined shape, and after the work is finished, the bar is processed. The present invention relates to a control method and a control device for an automatic lathe which automatically feeds out a material and continuously processes the next work, and a parting-off tool suitably used in adopting the control method and the control device for the automatic lathe. About shank.

[0002]

2. Description of the Related Art A long bar is inserted into and gripped by a main shaft, and the main shaft rotates, and the bar gripped by the main shaft and a tool fixed to a tool rest move relatively. 2. Description of the Related Art An automatic lathe for processing a work into a predetermined shape, automatically feeding a bar as a material of a work to be processed next after finishing the work, and continuously processing a large number of works is well known.

In such an automatic lathe, as a step of sending out a bar as a material of a work to be processed next after finishing the work, a collet chuck for gripping the bar is opened after a parting-off operation, and the bar is opened. The bar is relatively retracted by a predetermined distance, that is, the length of the workpiece to be machined next, with the collet chuck closed, and the collet chuck is closed to grip the bar again. There is a delivery process.

In this bar feeding step, the bar is used as a stopper (usually, the side surface of a parting tool for separating the work from the bar is used as a stopper as long as a bar having a normal size is used. However, for large-diameter rods that require a large pressing force, a special stopper with high rigidity may be used.) Adjusting the pressing force for pressing the rod can be used without any particular problem. However, if the diameter of the bar is very small and the length is very long, the bar is bent by the pressing force that presses the bar against the stopper. Vibration and noise may be generated while rotating, and the pressing force of the bar must be reduced.

If a bar having a smaller diameter is used, the pressing force of the bar is very small when the main shaft is relatively retracted by the length of the workpiece to be processed next in the bar feeding process. Therefore, even though the collet chuck is open, the friction between the inner surface of the open collet chuck and the outer periphery of the bar also causes the bar to retreat together with the main shaft, so that a gap is created between the bar and the stopper. .

As described above, if a gap is formed between the bar and the stopper, the bar is not fed out by a predetermined amount. As a result, the length of the workpiece to be processed next becomes insufficient. As a result, the work to be processed is a defective product having a shape lacking in the leading end. And, for such a work in which defective products are mixed, it is necessary to carry out a 100% inspection to remove the defective products, so that it takes a lot of trouble and time.

[0007] In the prior art, a tip gripping device for gripping the tip of the bar when the main shaft retreats to prevent the bar from retreating with the main shaft has been used in some cases. It is a complicated structure for gripping, and its size is very large compared to the work to be machined. To attach it, at least one bite holder (usually 2 to 2)
It is very difficult to use because it requires space for three tool holders), which limits the number of tools used for cutting, and also requires alignment when installing, making adjustment difficult. Met.

[0008] Therefore, a practical solution is to remove all defective workpieces by processing all the processed workpieces while processing the defective workpieces in a mixed state. Above was not considered.

[0009]

SUMMARY OF THE INVENTION The present invention eliminates these drawbacks, and is a simple and inexpensive and easy-to-handle automatic lathe for confirming the feed amount of a bar in an automatic lathe and a shank of a parting tool for the same. It is intended to provide.

[0010]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and the rod held by the main shaft and the tool fixed to the tool rest move relative to each other to a predetermined position. In the automatic lathe for processing the workpiece to the shape of the above, and automatically sending out the bar material after the completion of the processing of the workpiece and continuously processing the next workpiece, as the material of the workpiece to be processed next after the completion of the workpiece processing In the bar feeding step of feeding the bar, when the main shaft relatively retracts and closes the collet chuck that grips the bar, a weak force is applied between the bar and a stopper that supports the bar. A current is supplied, and the presence or absence of a gap between the bar and the stopper is detected by the presence or absence of the supply of the weak current.When the weak current is supplied, the gap between the bar and the stopper is provided. No gap It is determined that the feed amount of the bar is normal, and when the power is not supplied, there is a gap between the stopper and the feed amount of the bar is determined to be abnormal. It provides a method.

Here, the stopper is a parting tool for separating the work from the bar at the end of machining of the workpiece, and the weak current is supplied between the bar and the parting tool. It is desirable that the method be a method of checking the bar feed amount in an automatic lathe. Then, when it is determined that the feed amount of the bar is not normal, in a parting-off operation in the next processing step, a method of checking the feed amount of the bar in an automatic lathe that does not operate a separator that separates a chip from a workpiece. Preferably, furthermore, when the step determined that the feed amount of the bar is abnormal is continued for a predetermined number of times, or repeatedly occurs at a frequency higher than a predetermined level, the automatic lathe is stopped. It is desirable to use a method of confirming the bar feed amount in an automatic lathe that displays an alarm.

Further, according to the present invention, a bar gripped by a spindle and a tool fixed to a tool rest move relatively to process a workpiece into a predetermined shape, and after the workpiece has been processed, the bar is removed. In an automatic lathe that automatically feeds and continuously processes the next work, a stopper fixed to the tool post, and a bar that feeds out the bar as a material of a work to be processed next after finishing the work. In the feeding step, when the main shaft relatively retracts to close the collet chuck that grips the bar, a weak current is applied between the bar and a stopper that supports the bar, and this weak current is applied. A rod feed amount detecting means for detecting whether or not a current is supplied to the rod and determining whether or not the feed amount of the bar is normal; and indirectly connecting the rod and the bar feed amount detecting means. A first conductor to be connected; A bar feed amount in an automatic lathe, comprising: a second conductor that directly connects a topper and the bar feed amount detecting means; and an insulator that electrically insulates the stopper and the tool post. Is provided.

Preferably, the stopper is a device for confirming a bar feed amount in an automatic lathe which is a parting tool for separating the work from the bar at the end of machining of the work. A device for confirming the bar feed amount in an automatic lathe in which the tool holder of the tool rest is formed of an insulator as an insulator for electrically insulating the tool holder in an automatic lathe in which the tool holder of the tool rest is formed of ceramic. It is desirable that the device be a device for checking the feed amount of the bar.

Further, as an insulator for electrically insulating the cutting tool and the tool rest, a bar feeder in an automatic lathe in which an insulator is interposed between a tool holder of the tool rest and a shank of the parting tool. It is preferable that the device is a device for confirming the feed amount of the bar in an automatic lathe in which the insulator interposed between the tool holder of the tool post and the shank of the parting tool is a hard plastic or ceramic plate. Or a device for confirming a bar feed amount in an automatic lathe in which an insulator interposed between a tool holder of the tool rest and a shank of the parting tool is ceramic coated on a surface of a shank of the tool. Is desirable.

Further, according to the present invention, the bar held by the spindle and the tool fixed to the tool rest move relatively to process the work into a predetermined shape, and after the work is completed, the bar is processed. In the bar feeding step of an automatic lathe that automatically feeds out and continuously processes the next work, and after finishing the work, sends out the bar as a material of the work to be processed next, the spindle is relatively moved. When closing the collet chuck that retreats and grips the bar, a weak current is applied between the bar and a stopper that supports the bar, and the bar is determined by the presence or absence of the weak current. In an automatic lathe for detecting the presence or absence of a gap between the shaft and the stopper, a surface of the shank is coated with an insulator to be electrically insulated, and a connection terminal for a conductor connected to the bar feed amount detecting means. There is provided a parting Ri byte shank, characterized in that it comprises. Preferably, the insulator coated on the surface of the shank is ceramic.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments. FIG. 1 is a partially sectional front view showing an example of an automatic lathe to which a device for checking a bar feed amount in an automatic lathe of the present invention is applied, and FIG. FIG. 3 is a perspective view showing an example of a parting-off tool used for the checking device, and FIG. 3 is a flowchart showing an example of a method of checking a bar feed amount in an automatic lathe according to the present invention.

First, a general automatic lathe will be outlined. As shown in FIG. 1, the automatic lathe includes a headstock 1 and a tool post 2, and a spindle 4 rotatably supported by a bearing 3 is arranged on the headstock 1 in a horizontal direction. .
Here, FIG. 1 shows only the front bearing as the bearing 3, but naturally also has a rear bearing, and the main bearing can be rotated at a desired rotation speed by the front bearing and the rear bearing. I support it. At the tip of the main shaft 4, a bar material 5 as a raw material is provided.
A collet chuck 6 for gripping is provided, and the collet chuck 6 is configured to be opened and closed by a well-known chuck opening and closing mechanism (not shown). Further, the headstock 1 is slidable along the axial direction of the spindle 4 on the bed 7 under the control of a well-known headstock sliding mechanism (not shown).

Further forward of the tip of the main shaft 4 is a bed 7.
A column 8 fixed to the column 8 is arranged.
A guide bush 9 rotatably supporting the bar 5 gripped by the main shaft 4 is provided on the center line of the main shaft 4 in. In the drawing, a rotary guide bush is shown as the guide bush 9. The guide bush 9 includes a rotary guide bush and a fixed guide bush, which are arbitrarily selected and used as required. However, as in the automatic lathe according to the present invention, the diameter of the bar 5 is extremely small. In order to reduce the torsion of the bar 5 due to the rotation of the main shaft 4, a rotary guide bush having a small resistance in the rotation direction is often used when cutting the shaft.

The column 8 is provided with a tool rest 2 in which a tool holder 11 for holding a plurality of cutting tools such as a parting tool 10 is arranged radially toward the center line of the main shaft 4. Although only one tool holder 11 is shown in the figure, in practice, a plurality of tool holders 11 are radially arranged on the tool holder mounting base 12 toward the center line of the main shaft 4. The plurality of cutting tool holders 11 are selected by a well-known tool rest driving mechanism (not shown) and can be independently advanced and retracted. Further, although not shown, a drilling shaft having a drilling tool such as a drill is arranged further in front of the column 8 on the center line of the main shaft 4, and the bar 5 is often drilled from the axial direction. .

Since the automatic lathe is constructed as described above, in the cutting process, the bar 5 is gripped by the collet chuck 6 of the spindle 4 and rotated at a predetermined number of revolutions. The tool 10 fixed to the plurality of tool holders 11 provided on the tool rest 2 arranged on the column 8 advances and retreats toward the center line of the spindle 4 so that the spindle 4 The bar 5 gripped by the tool and the tool fixed to the tool holder 11 (such as the parting tool 10 in the drawing) relatively move, and by combining these movements, the bar 5 is formed into a workpiece having a predetermined shape. In this case, it is possible to carry out the outer shape cutting so as to make the number 13 or to make a hole with a drilling tool (not shown) such as a drill arranged on the center line of the main shaft 4.

Then, the work 1 processed into a predetermined shape
3 is finally cut off from the bar 5 by a parting-off tool 10 to form a product. At this time, in the cutting process, the separator 14 which has been retracted to a predetermined position is operated and disposed below the work 13, so that the work 13 is separated from the cutting chips in the cutting and stored in the product receiver 15. be able to. In particular, in an automatic lathe that cuts a work 13 having a very small diameter of the bar 5 like the automatic lathe according to the present invention, the outer diameter of the work 13 is very small. Is mixed once, the work 13 is buried in the chip and the work 1
Since it is very difficult to separate and take out only 3, the use of the separator 14 is indispensable.

After the work 13 processed into a predetermined shape is cut off, a bar 5
From the spindle 4 by a predetermined length. In this bar feeding step, the main shaft 4 is pressed while pressing the bar 5 forward.
When the collet chuck 6 is opened, the tip of the bar 5 is pressed and supported by a stopper (usually, since the cutting tool 10 is often used, the cutting tool 10 is used in the following description). In this state, the headstock 1 is retracted by a predetermined distance, that is, a distance corresponding to a projection amount of the bar 5 as a material of the work 13 to be processed next, and the collet chuck 6 is closed to grip the bar 5. Done.

The pressing force in the bar feeding process, that is,
The pressing force for pressing the bar 5 against the cutting tool 10 is usually
Since the bar 5 is applied to the rear end, as described above, when the bar 5 having a very small outer diameter and a very long length is used, the bar 5 is bent by this pressing force, and the spindle 5 is bent. In order to cause whirling in the inside 4, the pressing force must be reduced. If the pressing force is reduced, the collet chuck 6 is opened when the headstock 1 moves backward in the bar feeding process. Nevertheless, the bar 5 is pushed back or bent by the friction between the inner peripheral surface of the collet chuck 6 and the outer peripheral surface of the bar 5, and the bar 5 also retreats together with the headstock 1 and projects from the bar 5. A gap may be formed between the cutting tool 10 and the cutting tool 10.

When a gap is formed between the bar 5 and the cutting tool 10, the bar 5 is not fed out by a predetermined amount. As a result, the length of the work 13 to be processed next is reduced. Is insufficient, and the workpiece 1 to be machined
No. 3 is a defective product having a shape with a chipped end. As described above, it is extremely time-consuming and time-consuming because all of the works in which such defective products are mixed must be inspected to remove defective products.

A headstock 1 is fixed to the automatic lathe, and the tool rest 2 is moved in the axial direction of the main spindle 4 so as to be fixed to the bar 5 gripped by the spindle 4 and the tool rest 2. In some cases, the cutting tool moves relatively to perform cutting. Since the relative movement between the headstock 1 and the tool post 2 is completely the same in such an automatic lathe, only the most general type in which the headstock 1 slides will be described here.

As described above, the present invention detects that a gap is formed between the bar 5 and the cut-off tool 10 (or the stopper) when the headstock 1 retreats in the bar feeding step. In order to prevent the mixing of defective products, the automatic lathe to which the device for checking the bar feed amount in the automatic lathe of the present invention is applied, the device for checking the bar feed amount in the aforementioned normal automatic lathe is used. It is added. As shown in FIG. 1, the apparatus for confirming the feed amount of the bar is indirectly connected to the bar feed amount detecting means 20, the bar feed amount detecting means 20 and the headstock 1 through the bearing 3. The first conductor 21 electrically connects the bar 5 to the bar feed amount detecting means 20 and the second conductor 22 directly connects the bar feed amount detecting means 20 to the cutoff bite 10. are doing.

The bar feed amount detecting means 20 sets a low voltage of about several volts to 0.1 V by a chuck closing signal of the automatic lathe.
The first conductor 21 and the second conductor 21 are connected for a short time of about 2 to 0.5 seconds.
Voltage applying means 23 for applying a weak current by applying between current conductors 22 and current detecting means 24 for detecting the presence or absence of an actual current flowing through the first conductor 21 or the second conductor 22 by this voltage. (Provided on the second conductor 22 in the figure). Here, the first conductor 21 and the second conductor 21
In consideration of the reliability of detection and the electric corrosion of the cut-off tool 10 (stopper), the bearing 3 and the like, the current applied to the conductor 22 is a voltage applied so that a current of about 0.1 mA flows. It is desirable to adjust.

Further, when the current detecting means 24 detects the energization, there is no gap between the bar 5 and the cut-off tool 10 so that the feed amount of the bar 5 can be reduced. If it is determined that the current is normal and no current is detected, there is a gap between the bar 5 and the cut-off tool 10, and the bar 5
Has a determining means 25 for determining that the feed amount is not normal.

Further, if a current flows through the bed 7 of the automatic lathe when the voltage is applied by the voltage applying means 23, it is determined whether or not there is a gap between the bar 5 and the cutting tool 10. Can not do. For this purpose, in the present invention, an electrically insulating insulator is provided between the parting tool 10 (stopper) and the tool holder 11 of the tool rest 2. This insulator can be achieved by forming the tool holder 11 of the tool rest 2 from an insulator having sufficient mechanical strength, for example, a ceramic. By forming the tool holder 11 from ceramic, it has sufficient mechanical strength to perform cutting, has sufficient durability, and has sufficient properties as an electrical insulator, but is expensive. It also has the disadvantage that

As an insulator between the cutting tool 10 (stopper) and the tool holder 11 of the tool post 2,
This can be achieved by interposing an insulator, for example, a hard plastic or ceramic plate, between the tool holder 11 and the shank of the parting tool 10. This hard plastic or ceramic plate is
It surrounds at least three sides of the first tool mounting position, and requires sufficient rigidity to perform cutting. In this respect, the rigid plastic plate has a problem in rigidity, and the ceramic plate has a disadvantage that it is easily broken.

In order to eliminate these drawbacks, it is conceivable to apply an insulating coating having sufficient mechanical strength to the surface of the shank of the parting tool 10. FIG. 2 shows an example of a parting-off tool 10 employing ceramic as the coating material. As shown in the drawing, the shank 10a of the parting-off tool 10 of the present invention has the same shape as a normal parting-off tool, and has a similar cutting blade having a shape as required.

The shank 10 of the parting tool 10
The outer periphery of “a” is entirely coated with an insulating coating 10c. This coating 10c is desirably coated with a ceramic having a sufficient thickness and strength so that electrical insulation is not destroyed even if some scratches or scratches occur during handling. However, the coating only needs to have sufficient strength and rigidity, and may be a plastic having high mechanical strength. Further, at the rear end of the shank 10a, as a connection terminal for connecting the second conductor 22, for example, a screw hole 10d
Is provided.

Next, a method of confirming the bar feed amount in the automatic lathe of the present invention will be described with reference to the flowchart of FIG. When the automatic lathe is started by the start 30, a normal cutting process 31 is performed. This cutting process 31
The required cutting 32 is sequentially performed on the work 13 in accordance with a predetermined processing procedure, and when the cutting 32 is completed and only the cutting is performed, the separator 14 advances below the processing position of the automatic lathe (separator advance 33). . Next, the parting-off tool 10 moves forward to perform a parting-off operation and separates the work 13 (parting-off tool advance (parting-off operation))
34). The work 13 separated from the bar 5 is guided by the separator 14 and falls into the product receiver 15 to be stored.

Next, the process proceeds to a bar feeding step 35. In the bar feeding process 35, the parting tool 10 from which the workpiece 13 has been separated stops while advancing and functions as a stopper for the bar 5 (stopping the cutting tool (end of parting operation) 36) and is pressed forward. The rod 5 is moved forward and locked for positioning. Of course, when a dedicated stopper is provided, the parting tool 10 is retracted, and the stopper moves forward to the leading end position of the bar 5, and the stopper 5
Lock the forward movement and position.

Next, the collet chuck 6 of the spindle 4 is opened (the spindle chuck is opened 37), and the headstock 1 is retracted (the headstock retreat 38). At this time, as described above, since the bar 5 is pressed forward from the rear end, the bar 5
Is pressed against and locked by the parting-off tool 10 (or a stopper), only the headstock 1 retreats, and the bar 5 projects from the main shaft 4. The headstock 1 is moved to a predetermined distance (the work 13 to be processed next).
The collet chuck 6 is closed (spindle chuck closed (electricity check) 39), and the bar 5 is gripped by the spindle 4.

At the same time as the collet chuck 6 is closed, the voltage applying means 2 of the bar feed amount detecting means 20 of the present invention is used.
By 3, a voltage is applied between the bar 5 and the cut-off tool 10 (or stopper), and a weak current flows for a short time. The voltage is applied by the voltage applying means 23 at a timing of closing the spindle chuck in an automatic lathe in which the opening and closing of the collet chuck 6 is electrically controlled, and in an automatic lathe in which the collet chuck 6 is controlled mechanically, the operation of the chuck opening and closing mechanism. It is given by the detected signal.

The voltage is applied between the bar 5 and the cut-off tool 10 (or the stopper) by the voltage applying means 23, and at the same time, the presence or absence of a weak current which is actually flowing is detected by the current detecting means 24 (power supply). Yes 40), when this weak current is applied, the determining means 25 determines that there is no gap between the bar 5 and the cut-off tool 10 (or the stopper) and the feed amount of the bar is normal, When the power is not supplied, there is a gap between the bar 5 and the cut-off tool 10 (or a stopper), so that it is determined that the feed amount of the bar is not normal, and a signal indicating that the feed amount of the bar is defective is provided. Is output.

When this defect signal is output, it is estimated that the work 13 to be machined in the next cutting process 31 will be a defective product having a short overall length. After the parting tool 10 is retracted (parting tool retraction 41), the cutting program is skipped and the process proceeds to the parting tool advancement (parting operation) 34, where the unprocessed work 13 is cut off as it is. Discard it and repeat the bar delivery step 35 again. Alternatively, a special shortcut program is employed to prevent the bar 5 from being wasted by repeating the bar feeding step 35 again without retreating the parting-off tool 10 as shown by a dotted line in the figure. Is also possible.

However, when the automatic lathe is controlled by a mechanical control device such as a cam, it is difficult to perform such a shortcut, and as shown by a dashed line in FIG. It will return to 31. Then, when this failure signal is output, the operation of the separator 14 is locked in the next step of the parting-off tool advancement (parting-off work) 34, so that the separator 14 is not cut off from the bar (or the entire length thereof). This prevents the work 13 (of insufficient defective products) from being received by the separator 14 and stored in the product receiver 15.

If no defect signal is output, a normal processed product, that is, a non-defective product is to be processed. Therefore, after the cut-off tool is retracted (cut-off tool retreat 42), the work 13 is processed by a predetermined processing quantity. (Scheduled number processed 4
If 3) is determined and processing is still to be continued, the process returns to the cutting step 31 and normal cutting is performed. If the predetermined number of workpieces have been processed, the process is terminated 44 as it is.

When the case of outputting the defect signal occurs continuously a plurality of times, for example, three times in a row, some kind of abnormality, for example, that chips are caught between the rod material 5 and the collet chuck 6 or the like. After this, no matter how many times the bar feeding process 35 is repeated, a gap may be formed between the bar 5 and the cut-off tool 10 (or stopper), and the feed amount of the bar may not be normal. Will be higher. Similarly, when it occurs repeatedly at a frequency higher than the predetermined level, for example, when it occurs three or more times out of thirty consecutive times, it is similarly estimated that some abnormality has occurred. In such a case, it is desirable to stop the operation of the automatic lathe and notify an operator of the occurrence of an abnormality by an alarm signal, for example, a rotating red light.

[0042]

According to the present invention, the method and apparatus for confirming the feed amount of the bar in the automatic lathe according to the present invention and the shank of the parting tool for the same are constructed as described above, and are generated between the bar and the stopper. The gap, that is, the shortage of the bar feeding amount in the bar feeding step can be extremely easily detected, and the shortage of the work material length due to the shortage of the bar feeding amount can be easily and reliably detected. it can.

Accordingly, it is possible to prevent the occurrence of defective products due to the shortage of the work material length. Even if a defective product occurs, the defective product is separated and discarded together with the cutting chips. However, there is no need to perform such a 100% inspection to remove defective products.

In addition, even when compared with the conventional tip gripping device, it has a complicated structure for gripping the tip of the bar, and its size is very large as compared with the work to be processed.
In addition, the method and the apparatus for confirming the bar feed amount of the present invention are different from those of the conventional tip gripping apparatus in which the space for at least one tool holder is required for mounting, so that the number of tools used for cutting is limited. It is compact, very easy to install, requires no special adjustment, and when not in use, it is only necessary to remove the conductors or cut the circuit, so that handling becomes very easy.

Further, if the shank of the parting tool for the method and apparatus for confirming the bar feed amount in the automatic lathe of the present invention can be used, the tool post of the conventional automatic lathe can be used as it is. Becomes easier.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional front view showing an automatic lathe to which a device for checking a bar feed amount in an automatic lathe according to the present invention is applied.

FIG. 2 is a perspective view showing one example of a parting-off tool used for a device for checking a bar feed amount in an automatic lathe according to the present invention.

FIG. 3 is a flowchart of a method of checking a bar feed amount in an automatic lathe according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spindle stand 2 Turret 3 Bearing 4 Spindle 5 Bar material 6 Collet chuck 7 Bed 8 Column 9 Guide bush 10 Parting bite 10a Shank 10b Cutting edge 10c Coating 10d Screw hole 11 Bit holder 12 Bit holder mounting table 13 Work 14 Separator 15 Product receiver 20 Bar feed amount detection means 21 First conductor 22 Second conductor 23 Voltage application means 24 Current detection means 25 Judgment means

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B23B 27/04 B23B 27/04 31/00 31/00 D (72) Inventor Eiji Tajima 6-1, Honcho, Tanashi-shi, Tokyo No. 12 Citizen Watch Co., Ltd. Tanashi Factory F term (reference) 3C032 GG34 3C045 BA04 CA05 DA02 EA01 FC01 HA05 3C046 BB01

Claims (13)

[Claims] 1. A bar gripped by a spindle and a tool fixed to a tool rest move relatively to process a work into a predetermined shape, and automatically feed the bar after the work is completed. In an automatic lathe that continuously processes the next workpiece, after the completion of the processing of the workpiece, in a bar feeding step of feeding the bar as a material of a workpiece to be processed next, the main shaft relatively retracts and When closing the collet chuck that grips the bar, a weak current is applied between the bar and the stopper that supports the bar, and the bar and the stopper are determined by whether or not the weak current is applied. The presence or absence of a gap between them is detected, and when the weak current is applied, it is determined that there is no gap between the bar and the stopper and the feed amount of the bar is normal, and the power is not applied. Sometimes Bar feed amount of the confirmation method in the automatic lathe, characterized in that the feed quantity of the bar there is a gap is determined not to be normal between the stopper. 2. The method according to claim 1, wherein the stopper is a parting tool for separating the workpiece from the bar at the end of processing of the workpiece, and the weak current is supplied between the bar and the parting tool. The method for confirming a bar feed amount in an automatic lathe according to claim 1, characterized in that: 3. The method according to claim 1, wherein when it is determined that the feed amount of the bar is not normal, a separator for separating chips and a work is not operated in a parting-off operation in a next processing step. 2. The method of confirming the bar feed amount in the automatic lathe according to 2. 4. When the step in which the feed amount of the bar is determined to be abnormal is continuously performed a predetermined number of times, or repeatedly generated at a frequency higher than a predetermined level,
4. The method according to claim 1, wherein the automatic lathe is stopped and an alarm is displayed. 5. A bar gripped by a spindle and a tool fixed to a tool post move relatively to process a workpiece into a predetermined shape, and automatically feed the bar after the workpiece has been processed. In an automatic lathe that continuously processes the next workpiece, a stopper fixed to the tool post, and in a bar feeding step of feeding the bar as a material of a workpiece to be processed next after finishing the workpiece, When the main shaft relatively retracts and closes the collet chuck that grips the bar, a weak current is applied between the bar and a stopper that supports the bar, and the weak current is applied. A bar feed amount detecting means for detecting the presence / absence of the bar and determining whether or not the feed amount of the bar is normal; and a first indirectly connecting the bar and the bar feed amount detecting means. A conductor, and the stopper A second conductor for directly connecting the bar feed amount detecting means; and an insulator for electrically insulating the stopper and the tool rest, for confirming the bar feed amount in the automatic lathe. apparatus. 6. The apparatus according to claim 5, wherein the stopper is a parting tool for separating the work from the bar at the end of processing of the work. 7. A bar in an automatic lathe according to claim 5, wherein a tool holder of the tool rest is formed of an insulator as an insulator for electrically insulating the stopper and the tool rest. Confirmation device for material feed amount. 8. The apparatus according to claim 7, wherein the tool holder of the tool rest is formed of ceramic. 9. An insulator for electrically insulating the stopper from the tool post, wherein an insulator is interposed between a tool holder of the tool post and a shank of the parting tool. Item 7. A device for checking the feed amount of a bar in an automatic lathe according to item 5 or 6. 10. The bar according to claim 9, wherein the insulator interposed between the tool holder of the tool rest and the shank of the parting tool is a hard plastic or ceramic plate. Check device for feed amount. 11. The automatic machine according to claim 9, wherein the insulator interposed between the tool holder of the tool post and the shank of the parting tool is ceramic coated on the surface of the shank of the tool. A device for checking the bar feed amount on a lathe. 12. A bar gripped by a spindle and a tool fixed to a tool rest move relatively to process a work into a predetermined shape, and automatically feed the bar after the work is completed. The next workpiece is continuously processed, and after the processing of the workpiece is completed, in a bar feeding step of an automatic lathe that feeds the bar as a material of a workpiece to be processed next, the main shaft relatively retreats, and When closing the collet chuck that grips the bar, a weak current is applied between the bar and the stopper that supports the bar, and the bar and the stopper are determined by whether or not the weak current is applied. An automatic lathe for detecting the presence or absence of a gap between the shank, having a shank surface coated with an insulator to electrically insulate and having a connection terminal for a conductor connected to the bar feed amount detecting means Parting Ri bytes of the shank, characterized. 13. The method according to claim 1, wherein the insulator coated on the surface of the shank is ceramic.
The shank of the parting-off tool described in 2.