JPH02109606A - Method for controlling synchronous rotation of numerically controlled lathe - Google Patents

Abstract

PURPOSE:To offer a synchronous rotation control method between a main spindle and a sub-spindle in a numerically controlled lathe which can deliver not only round materials but also square materials by conforming the phases of the main spindle and sub-spindle at the time of delivering a workpiece from the main spindle to the sub-spindle during rotation. CONSTITUTION:In order to conform the phase difference between a main spindle 1 and a sub-spindle 7, the position PP of the sub-spindle 7 is detected based on the position detecting signal PPS of a position detector 11 by a sub-spindle position detecting portion 126. Also, the position MP of the main spindle 1 is detected based on the position detecting signal MPS of a position detector 5 by a main spindle position detecting portion 127. The difference in positions between both is detected by a phase difference detecting portion 128 and theta/2 half of the detected phase difference theta is transferred to a sub-spindle decelerating portion 129P and a main spindle accelerating portion 129M. Based on the phase difference theta/2 at the point of time of inputting a rotating speed conformation signal CN from a rotating speed comparing portion 124, the sub-spindle decelerating portion 129P outputs the decelerating quantity PDWN of the sub-spindle 7 to a sub-spindle rotation control portion 125. The sub- spindle rotation control portion 125 transfers a rotation command PDS in which the amount of decelerating quantity PDWN is subtracted from a sub-spindle rotation command at the time of conforming to a main spindle rotating speed to a sub-spindle motor driving portion 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a synchronous rotation control system between a main spindle and a sub-spindle in a numerically controlled lathe having a sub-spindle facing the main spindle.

(Prior art) Two opposing spindles, the main spindle (hereinafter referred to as
(hereinafter referred to as the main spindle) and sub-spindle (hereinafter referred to as the sub-spindle)
In a lathe having a main shaft, the first process is carried out by the main spindle, and the second process (for example, back processing) is carried out by the sub-main spindle. When transitioning from the i-th process to the second process, the sub-spindle is moved closer to the main spindle so that the workpiece is not directly transferred. The end of the first process and the beginning of the second process are turning, and if the main spindle does not need to be stopped during machining, if the workpiece can be transferred while the main spindle is still rotating, the main spindle should be stopped and then turned. This saves time until it is rotated again.

In conventional technology, when transferring a workpiece while the main spindle is rotating, it is assumed that the synchronous rotation between the main spindle and the sub-spindle is complete when the rotation speed of the main spindle and the sub-spindle are matched, and the rotation speed of the sub-spindle is considered to be complete.
In this state, the work was delivered. In other words, in the conventional technology, only the rotational speed (speed) of the main shaft and sub-main shaft is synchronously controlled, and a phase difference remains. For this reason, if the workpiece is a round material, there is no problem because the sub-spindle can grip it in any position, but if the workpiece is a square material, there are only a limited number of positions where the sub-spindle can stably grip it, so the main and sub-spindles are If there is a phase difference between the two, it may not be possible to understand it well.

(Problems to be Solved by the Invention) As described above, when transferring a workpiece while the main shaft is rotating, if the workpiece is a square piece of material, a function is required to match the phases of the main shaft and sub-main shaft during rotation.

The present invention was made in view of the above-mentioned circumstances, and an object of the present invention is to align the phases of the main spindle and sub-spindle when transferring a workpiece from the main spindle to the sub-spindle during rotation, so that only round materials can be transferred. An object of the present invention is to provide a synchronous rotation control system between a main spindle and a sub-main spindle in a numerically controlled lathe, which enables the transfer of square pieces without any problems.

(Means for Solving the Problems) The above-mentioned object of the present invention is to provide position detection means on the main spindle and the sub-spindle, and to transfer a workpiece between the main spindle and the sub-spindle while the main spindle and the sub-spindle are rotating. Detects the difference (phase difference) between the position detection values of both during rotation, decelerates either the main shaft or the sub-main shaft, and simultaneously accelerates the other to calculate half of the phase difference from both the main shaft and the sub-main shaft. This is achieved by bringing the phases closer and matching the phases. That is, the present invention provides synchronous rotation control in a numerically controlled lathe, which has a sub-spindle facing the main spindle, the main spindle and the sub-spindle are provided with position detection means, respectively, and the positions of the main spindle and the sub-spindle are respectively controllable. The above object of the present invention is to not only match the rotational speeds of the main spindle and the sub-main spindle when transferring a workpiece between the main spindle and the sub-main spindle while the main spindle and the sub-main spindle are rotating; The position detecting means detects a phase difference between the main shaft and the sub-main shaft, and temporarily decelerates either the main shaft or the sub-main shaft and temporarily accelerates the other, thereby adjusting the position. This is achieved by eliminating the phase difference and also matching the phases of the main axis and sub-main axis.

(Function) The present invention relates to a synchronous rotation control method between a main spindle and a sub-spindle in a numerically controlled lathe, and detects the phase difference when the rotational speeds of both the main spindle and the sub-spindle are matched and the phase difference is constant. do. At that time, each rotation command value of the main spindle and sub-spindle is C
If it is ON, then the rotation command value of the main shaft is increased by a slight amount (ψ) and the rotation command value of the sub-main shaft is decreased by a small amount (ψ) to perform phase matching. In other words,
If the phase difference is θ, θ÷(ψ×2)=N...
(ψ, +ψP). Here, ψ2. ψ2 is a fraction after the main axis and sub-main axis are slightly increased or decreased by ψ, respectively. In other words, command the main shaft N times with a rotation command value of (CON◆ψ), command once with a command value (CON + ψ), and at the same time command the sub-spindle N times with a rotation command value of (C0N-ψ). The phases should match when the command value (CON-ψ2) is issued once. After the phases match, the rotation command values for both the main shaft and the sub-main shaft are returned to COH, and a constant state is maintained with the phase difference=0.

(Example) FIG. 1 is a structural diagram of a main shaft 1 and a sub-main shaft 7 facing each other,
The workpiece 6 is passed between these two axes. That is, the chuck 2 is attached to the main @1,
The chuck 2 grips a workpiece 6, and a chuck 8 is attached to the sub-main shaft 7. The present invention mainly consists of
The workpiece 6 held by the chuck 2 is gripped by the chuck 8 while the by-product l1llI7 is rotating.

Main control device! 2, the main shaft motor drive unit 4 and sub main shaft motor drive unit 10 drive the main shaft motor 3 and sub main shaft 9, respectively, so that the rotations of the main shaft motor 3 and the sub main shaft 9 are controlled by the main shaft type and the sub main shaft, respectively. 7, whereby the main shaft 1 and the sub-main shaft 7 are rotationally driven. Position detector 5
and 11 detect the rotational positions of the main shaft 1 and the sub-main shaft 7, respectively. The position detection signals MPS and PPS of the position detectors 5 and 11 are manually inputted to the main control device 12.
outputs a rotation command MDS as a command for the main shaft motor 3, and also outputs a rotation command PDS as a command for the sub-main shaft motor 9.

FIG. 4 shows the positional relationship when the by-product fIth7 reaches the same rotational speed as the main shaft 1, and at this time the chuck 8 of the sub-main shaft 7 is still open. The circle on the right in FIG. 4 is a rotational coordinate centering on point O.

Point M on chuck 2 is the reference point of main 1th1, chuck 8
The upper point P is the reference point of the sub-principal axis 7, the point PM is the rotational coordinate value of the reference point M, and the point PP is the rotational coordinate value of the reference point P. It is assumed that the clockwise rotation when FIG. 4 is viewed from the left to the right is the rotation axis increasing direction, and that the main shaft 1 and the sub-main shaft 7 are both rotating in the rotation axis increasing direction.

In the case of FIG. 4, point pp is advanced by θ with respect to point PM, so if this continues, the chuck 8 of the sub-main spindle 7 will grasp the workpiece 6 with a delay of θ.

Hereinafter, a method for phasing the main shaft 1 and the sub-main shaft 7 during rotation according to the present invention will be explained. Here, an example will be explained in which the sub-main shaft 7 is decelerated and the main shaft 1 is accelerated to match the phases.

FIG. 2 shows control system blocks for realizing the system of the present invention in correspondence with FIG. 1. When the command analysis unit 120 in the main controller 12 outputs the spindle rotation command MRI, the spindle rotation control unit 121 outputs a rotation command MDS to the spindle motor drive unit 4 based on the spindle rotation command MHI, and The rotation speed calculation unit 123 calculates the rotation speed MR of the main shaft 1 based on the position detection signal UPS from the position detector 5. When the command analysis unit 120 outputs a synchronous rotation command SYR for the sub-spindle 7 with respect to the main spindle 1 while the main spindle 1 is rotating, the sub-spindle rotation control unit 125 controls the sub-spindle motor drive unit 10 based on the main spindle rotation command at that time. Outputs the sub-spindle rotation command PDS to the sub-spindle rotation speed calculation unit! 22 calculates the rotation speed PR of the sub spindle 7 based on the position detection signal PPS from the position detector 11. The zero rotation speed comparison unit 124 compares the rotation speed PR of the sub-product @7 with the rotation speed MR of the main spindle 1. , when they match, the rotation speed matching signal CN is sent to the sub-spindle rotation control unit 12.
Transfer to 5. When the sub-spindle rotation control unit 125 receives the rotation speed match signal CN manually, it continues to output the rotation command of the sub-generated @7 when the rotation speeds match to the sub-spindle motor drive unit IO. In the prior art, as mentioned above, the main! Control was performed to match only the rotation speeds of the Thl 11 and the sub-main shaft 7.

In the present invention, the main axis l and the by-product! In order to match the phase difference of +117, the sub-spindle position detection section 126 detects the position PP of the sub-spindle 7 based on the position detection signal PPS from the position detector 11, and the main spindle position detection section 127 detects the position. The position MP of the spindle 1 is detected based on the position detection signal MPS from the device 5, and the difference (phase difference) between the two positions is detected by the phase difference detection unit 128, and half of the detected phase difference θ is θ/2.
is transferred to the sub-main shaft deceleration section 129P and the main shaft acceleration section 129M.

The sub-main shaft deceleration unit 129P sets the deceleration amount PDWN of the sub-generated @7 to the sub-main shaft rotation control unit 125 based on the phase difference θ/2 at the time when the rotation speed matching signal CN is manually input from the rotation speed comparison unit 124.
Output to. The sub-spindle rotation control section 125 transfers a rotation command PDS that is decelerated by the deceleration amount PDWN from the sub-spindle rotation command when the rotation speed matches the main shaft rotation speed to the sub-spindle motor drive section 10 . At the same time, the spindle accelerator 129M accelerates the spindle l by an acceleration amount MO.
P is sent to the spindle rotation control section 121, and the spindle rotation control section 12
! sends to the spindle motor drive unit 4 a rotation command MDS that is accelerated by the acceleration ffi MOP than the previous spindle rotation command.

The sub-spindle deceleration control and main-spindle acceleration control as described above are continued until the phase difference θ becomes O, and when the phase difference becomes 0, the deceleration amount PDWN and the acceleration amount MOP are also set to 0, and from then on, the main-spindle rotation command and the sub-spindle rotation command The rotation command is output when the rotation number matching signal CN is output.

The flowchart in FIG. 3 shows the phase matching process of the main i1 and the sub-main shaft 7, and FIG. 5 shows the flow of the process in FIG.
1 to 56) shows changes in the rotation command values of the main @ 111 and the sub-main shaft 7.

First, in steps S1 and S2, a rotation command for the sub-spindle 7 is given so that the sub-spindle rotation speed matches the main shaft rotation speed. When the sub-spindle rotation speed matches the main spindle rotation speed, the phase difference detection unit 128
And the main axis! and detect the phase difference θ between the sub-main shaft 7 (step S
3). In this case, the main axis of the phase difference θ is the phase of the by-product @7! The 0th order is detected by how far it is ahead of the phase of
The rotation command value of the sub-spindle 7 is temporarily slightly decreased, and the rotation command value of the main shaft 1 is temporarily slightly increased to match the phases of the two (Steps S4 and S5 >, the amount of slight down and the slight When the amount of up is ψ, the following formula holds true.

θ；2ψ×N0(ψfight◆ψP) (ψM, ψP 〈ψ)・・・・・・ (1) Here, ψ
2. ψP is a fraction.

In other words, the rotation command value decreased by ψ is applied to the sub-spindle 7 N times.
If you command the rotation command value that has decreased by ψ once, and at the same time command the rotation command value that has increased by ψ N times to spindle 1, and once the rotation command value that has increased by ψ, the phases should match. It is. The amount of deceleration indicated by the downwardly hatched area DS to the left in FIG. 5 corresponds to the phase difference θ/2, and the amount of acceleration indicated by the downwardly shaded area US to the right corresponds to the phase difference θ/2. When the phase of the sub spindle 1 and the phase of the main spindle 1 match, the sub spindle 7 and the main spindle 1
The rotation command value is returned to the value at step S3 (step S6). In this way, the rotation speed and phase of the sub-main shaft 7 can be matched with those of the main shaft 1.

In addition, in the above description, the case where the sub-main shaft 7 is decelerated and the main IllIb1 is accelerated to achieve phase alignment has been described, but the sub-main shaft 7
In the case of accelerating the main shaft l and decelerating the main shaft l for phase matching, it is sufficient to think in exactly the same way. In addition, in the above description, from the main shaft 1 to the sub-main shaft 7
Although the case where the workpiece is transferred has been described, the case where the workpiece is transferred from the sub-spindle 7 to the main spindle 1 can be considered in exactly the same way.

(Effects of the Invention) As described above, according to the present invention, in a numerically controlled lathe having a sub-spindle facing the main spindle, even when the workpiece is a square piece of material, the workpiece can be transferred to the sub-spindle while the main spindle remains rotating. When moving from machining on the main spindle side to machining on the sub-spindle side, there is no need to stop and rotate the main spindle again, so the machining time can be shortened accordingly.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the configuration of two opposing main shafts and sub-main shafts, FIG. 2 is a block diagram showing the control system, FIG. The figure shows the positional relationship when the main spindle and sub-spindle rotate at the same rotation speed, and Fig. 5 is a diagram showing the transition of the rotation command values of the main spindle and sub-spindle corresponding to the flowchart in Fig. 3. . 1... Main shaft, 3... Main shaft motor, 7... Sub-main shaft,
9...Sub spindle motor, 12...Main controller, 120
...Command analysis section, 121...Spindle rotation control section,
124... Rotation speed comparison section, 128... Phase difference detection section, 129M... Main shaft acceleration section, 129P... Sub main shaft deceleration section. Figure 13

Claims (1)

[Claims] 1. In a numerically controlled lathe, which has a sub-spindle facing the main spindle, the main spindle and the sub-spindle are respectively provided with position detection means, and the positions of the main spindle and the sub-spindle can be controlled, respectively. When transferring a workpiece while the main spindle and sub-spindle are rotating, not only do the rotation speeds of the main spindle and sub-spindle match, but also the position detection means detects the phase difference between the main spindle and the sub-spindle. The phase difference is eliminated by temporarily decelerating one of the main axis or the sub-main axis and temporarily accelerating the other, thereby making the phases of the main axis and the sub-main axis coincide. A synchronous rotation control method for numerically controlled lathes characterized by: