JPH0288101A - Work transfer confirmation method for facing type two spindle lathe and control device therefor - Google Patents

Abstract

PURPOSE:To confirm whether or not a work is securely held with a facing shuck by drawing a spindle on one side near to the spindle on the other side and the pressing pressure caused in the approaching direction is detected and compared with a set value, and a work is exchanged between both spindles. CONSTITUTION:When one surface of a work is processed, the jaws of a chuck is opened causing both main and sub spindles to synchronously rotate, and a sub spindle feed motor 5 is made to rotate in a working speed to receive the work by the shaft transfer instruction of a NC device 1 through an operation circuit 2, a D/A converter 3, and an amplifier 4 after made to rotate at the speed of quick feed. The output of the motor 5 is monitored by a load torque detection circuit 7 and always compared with a set value by a comparison circuit 8, and made to cause alarming as the work allowance, etc., are abnormal when the set load torque could not be detected until the transfer is finished, and when the set load is detected, the sub spindle holds the work by the jaws of the chuck, and the comparison circuit 8 inputs to the NC device 1 through the operation circuit 2 as a skip signal, and the NC device 1 instructs the next block to execute the command.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for confirming work transfer and reception using an opposed two-axis spindle and a control device thereof. More specifically, in a lathe with a main spindle and a sub-spindle facing each other, when moving the sub-spindle to pick up a workpiece on the main spindle side, check whether the sub-spindle side has securely picked up the workpiece. The present invention relates to a work transfer confirmation method for an opposed two-spindle lathe and its control device.

[Prior Art] Among various conventionally known lathes, an opposed two-spindle type lathe in which a sub-spindle is provided opposite to a main spindle is known. Each spindle is provided with a workpiece chuck, and the sub-spindle is driven by NC (numerical control) to grip the workpiece toward the main spindle. This opposed two-spindle lathe machine processes one end of the workpiece using the main spindle, then
A known machining method is known in which the other end of the work is processed by chucking the work into a chuck on the opposing sub-spindle side.

Figures 3 (a), (b), and (c) show the main spindle 1.
2 shows the order in which the workpiece W is gripped by the chuck 11 of No. 0 with the chuck 12 of the sub-spindle 13. When the machining of one side of the workpiece W held by the chuck 11 of the main spindle 10 is completed, the turret tool rest 14 is retracted (Fig. 3 (a>). The sub spindle 13 is rapidly forwarded to the main spindle 10 side. spindle 10 and
A synchronous rotation command is issued so that the sub-spin and the dollar 13 rotate synchronously (FIG. 3(b)).

The sub-spindle 13 is gradually sent to the main spindle 10 side, and the workpiece W is gripped by the chuck 12. The chuck 11 of the main spindle 10 is released and the workpiece W is released. Thereafter, the other end surface is processed on the sub-spindle 12 side. This machining method has the characteristics that it is not necessary to reverse the workpiece W and that machining can be performed simultaneously by the main spindle and the sub-spindle 13, resulting in good machining efficiency. This support for the workpiece W is placed in the sub-spindle 13 in the axial direction (Z-axis direction).
The chuck 1 on the main spindle 10 side is
The receiver goes to pick up the workpiece W held by the handler 1. The receiving and transferring position of the workpiece W is controlled by an NC control device. At this time, if the workpiece W is pressed against the jaws of the chuck 12 in the Z-axis direction (workpiece axis), an overload may occur, causing an alarm or damaging the workpiece W.

[Problems to be Solved by the Invention] The workpieces W to be machined are different in finishing dimensions and parallelism with the main spindle 10. For this reason, although the method described above is controlled by an NC device, each workpiece W is held at a slightly different position by the chuck 12 on the sub-spindle 13 side. If the sub-spindle is used to process the parts while this position is different, it will appear as an error in the final finished dimensions. This invention solves these problems.

SUMMARY OF THE INVENTION An object of the present invention is to provide a work transfer confirmation method and a control device therefor for confirming whether a workpiece is reliably gripped by an opposing chuck in an opposed two-spindle lathe.

[Means for solving the above problems] This invention takes measures to solve the above problems.

A first means is a facing type two-spindle lathe in which two spindles are arranged opposite to each other and chucks are provided on both spindles, and an approach stroke in which one of the spindles approaches the other spindle, and a chuck in one of the spindles. a detection process in which the workpiece is gripped and the pressing force in the approaching direction of both spindles is detected; a comparison process in which the detected value is compared with a predetermined setting value; This is a method for confirming workpiece transfer in an opposed two-spindle lathe, which is characterized by comprising a workpiece exchange step in which workpiece exchange is started between chucks.

The second means is an opposed type two-spindle lathe having two spindles disposed opposite to each other and chucks provided on both spindles, and a drive motor for bringing one of the spindles close to the other spindle; a load torque detection circuit that detects the load torque of the motor; a comparison circuit that compares the detected value of the load torque detection circuit with a preset setting value; and a comparison circuit that stops the drive motor based on the output value of the comparison circuit. This is a workpiece transfer confirmation control device for an opposed two-spindle lathe, which consists of an arithmetic circuit that issues a workpiece exchange command and a numerical control device that collectively controls the rotation of these devices.

[Function] In an opposed type two-spindle lathe with two opposing spindles and chucks provided on both spindles, one spindle is brought close to the other spindle, and the pressing force in the approaching direction of both spindles is detected. This detected value is compared with a predetermined set value, and the work is exchanged between the chucks of both spindles based on the output of this comparison result.

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the drawings and operation flowcharts. FIG. 1 is a functional block diagram of a work transfer confirmation control device. The arithmetic circuit 2 is a circuit that controls the sub-spindle feed drive motor 5. The arithmetic circuit 2 is
When an axis movement command for feeding and driving the sub-spindle is issued from the NC device main body 1, operation is started and a rotation drive command is issued to the sub-spindle feeding drive motor 5. Since the output of the arithmetic circuit 2 is a digital signal, this signal is converted into an analog signal by the D/A converter 3.

The analog signal output is amplified by an amplifier 4 and drives a sub-spindle feed drive motor 5. The sub-spindle feed drive motor 5 is a normal servo motor, and rotates in response to the output of the amplifier 4. A feedback signal generator 6 is attached to the output shaft of the sub-spindle feed drive motor 5, and its output is fed back to the arithmetic circuit 2.

The arithmetic circuit 2 receives this signal, detects the rotation speed of the sub-spindle feed drive motor 5, and recognizes the current position of the sub-spindle.

The load torque of the sub-spindle feed drive motor 5 is detected by a load torque detection circuit 7. The load torque of the sub-spindle feed drive motor 5 is a detection means for determining whether or not the workpiece W is properly held in close contact with the chuck, as will be described later. Generally, in a servo motor, the current supplied to the motor in November is approximately proportional to the load torque, so this supplied current is detected to measure the load torque.

The output of the load torque detection circuit 7 is also input to the amplifier 4. This means that when a certain torque limit command is issued to the amplifier 4, the amplifier 4 limits its output so that a torque exceeding a certain level does not come out from the sub-spindle feed drive motor 5. The output of the load torque detection circuit 7 is input to the amplifier 4 for this purpose. This output 1 to torque limiting circuit is a known technology and will not be described in detail here. On the other hand, the output of the load torque detection circuit 7 is input to the arithmetic circuit 2 via the comparison circuit 8.

The comparator circuit 8 outputs a signal when the load torque exceeds a set value, and the signal is input to the NC device 1 via the arithmetic circuit 2 as a skip signal. The comparison circuit 8 is a circuit that can arbitrarily set a pressing force setting value for setting the pressure for pressing the work against the chuck. As soon as the NC device 1 receives the output signal from the comparison circuit 8 as a skip signal, it
The output to the A converter 3 is stopped, and the rotation of the sub-spindle feed servo motor 5 is stopped. Commands the next block of instructions to be executed. These commands are preprogrammed.

Figure 2 shows the work handing/receiving confirmation device, NC device 1, and
FIG. 3 is a diagram showing a general flow of operation of the opposed two-spindle lathe. The main spindle 10 rotates and completes machining of one side of a predetermined workpiece W (p+, Fig. 3(a)
)). The jaws of the chuck 12 of the sub-spindle 13 are opened.
(P2). The main spindle and the sub-spindle rotate synchronously (P3, Fig. 3(b)). An axis movement command is issued from the NC device 1 and input to the arithmetic circuit 2. The output of the arithmetic circuit 2 is transmitted through a D/A converter 3 and an amplifier 4 to cause the sub-spindle feed drive motor 5 to rotate rapidly (P
4).

The sub-spindle 13 is rapidly traversed and located at the approach position (P4). After this rapid traverse, the workpiece W receiver enters the operating speed for storage. These feed rates are programmed. Moving on to the sub-spindle axis movement command, the output of the sub-spindle feed drive motor 5 is monitored by the load torque detection circuit 7. Load torque detection circuit 7
The output of
s, P6).

If this set load torque cannot be detected by the end of the movement position, it will be determined that there is some kind of abnormality and an alarm will be issued (
P6, Pa). The movement end position is the limit position when the set load cannot be detected even if error factors such as machining dimensional errors of the workpiece are considered to the maximum. If it cannot be detected before the movement end position, it is assumed that the workpiece W has an abnormal machining error or the like, and an alarm is generated. If the sub-spindle is sent further than this, the claws of the chuck 11 and the chuck 12 may interfere with each other. If an alarm occurs, the worker will receive this alarm.

process manually.

When the set load is detected, it is determined whether the position where the set load is detected is an appropriate position (Pa). Even if the workpiece's allowable machining error, chucking error, etc. are taken into account, the workpiece W may not always be detected at an appropriate position. Therefore, it is determined whether the set load is detected within the allowable dimensional error. If the position is correct, the sub-spindle 13 drives the jaws of the chuck 12 to chuck the workpiece W (Pzo).
.

[Other Examples] In the above example, the close contact between the workpiece and the chuck was detected using the input current of the load torque of the feed drive motor of the sub-spindle. However, this detection may be performed using other methods. for example,
A strain gauge is provided on the chuck of the main spindle or sub-spindle, and the strain gauge detects the pressing force applied to the workpiece in the axial direction. Also,
Incorporate a spring into the feed shaft of the sub-spindle 13,
Another good method is to determine the set load when this spring operates. Further, in the embodiment described above, an alarm is set immediately if the movement end position is exceeded, but since a detection error may occur, the movement may be returned to the original position and the above-mentioned operation is repeated.

In the embodiment described above, the sub-spindle was moved, but the main spindle may be moved to transfer work to and from the sub-spindle.

[Effects of the Invention] As described in detail above, the present invention makes it possible to reliably confirm that the workpiece is in close contact with the chuck when transferring the workpiece in an opposed type two-spindle lathe, thereby reducing chuck errors and improving the results. As a result, product processing accuracy is improved and processing defects are reduced.

[Brief explanation of drawings]

Figure 1 is a functional block diagram of the work transfer confirmation control device, Figure 2 is an operation flow diagram of the opposed two-spindle lathe, and Figure 3 is a functional block diagram of the work transfer confirmation control device.
The figure shows the order of operations for transferring and receiving workpieces.

Claims (1)

[Claims] 1. In an opposed two-spindle lathe having two spindles arranged opposite to each other and chucks provided on both spindles, an approach stroke in which one of the spindles approaches the other spindle; a detection process in which the workpiece is gripped by the spindle chuck and the pressing force in the approach direction of both spindles is detected; a comparison process in which the detected value is compared with a predetermined setting value; A work transfer confirmation method for an opposed two-spindle lathe, comprising a work exchange step of starting the exchange of the work between both chucks of the spindle. 2. In an opposed two-spindle lathe having two spindles arranged opposite to each other and a chuck provided on both spindles, a drive motor for bringing one of the spindles close to the other spindle, and a load on the drive motor. a load torque detection circuit that detects torque; a comparison circuit that compares the detected value of the load torque detection circuit with a preset value; and a control circuit that stops the drive motor and commands a workpiece exchange based on the output value of the comparison circuit. This is a workpiece transfer confirmation control device for an opposed two-spindle lathe, which consists of an arithmetic circuit that emits a signal, and a numerical control device that collectively controls the rotation of these two spindle lathes.