JPH0455907A - Numerical controller having superposed control functions - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a serious accident despite the abnormality produced in the servo system of a Z1 axis by always adding the position changed variable of the Z1 axis to the position command value of a Z2 axis. CONSTITUTION:The position detection value PS1 obtained by a Z1 axis position detector 23 is inputted to a position changed variable detecting part 28 as well as to a Z1 axis servo control part 15. The part 28 detects the position changed variable PV of the Z1 axis and inputs it to an addition part 29. At the part 29 the variable PV is added to the position command value PC of a Z2 axis given from a Z2/X2 axis arithmetic part 13. This addition result PD is inputted to a Z2 axis servo control part 17 as the position command value of the Z2 axis. Thus the position of the Z2 axis is controlled. Thus the position changed variable of the Z1 axis is always added to the position command value of the Z2 axis. As a result, the occurrence of a serious accident can be prevented despite the abnormality produced in the servo system of the Z1 axis.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a numerical control device having a superimposed control function for superimposing machining control on two axes of a numerically controlled machine tool.

(Prior Art) FIG. 2 shows a mechanical configuration diagram of a general four-axis numerically controlled lathe. The workpiece 1 is gripped by the main shaft 2 and rotates with the main shaft as the center of rotation, and the tool rest 3 is controlled to move in the xl-axis and Z1-axis directions, and the tool mounted on the tool rest 3 5, the workpiece 1 is processed. In addition, the tool rest 4
is controlled to move in the x2-axis and z2-axis directions, and the workpiece 1 is machined by a tool 6 mounted on the tool post 4.

In response to this, numerically controlled lathes with a mechanical configuration as shown in Figure 3 have recently appeared. This machine has a main shaft 7 which is different from the machine configuration shown in Fig. 2, and the main shaft 2 is controlled to move in the rotation center axis direction (H-axis direction), and the tool rest 3 is controlled to move only in the x1@ direction. It has a mechanical configuration that allows for In this case, by making the main spindle 2 itself movable, for example, the workpiece 1 held by the main spindle 2 can be transferred directly to another main spindle 7 provided oppositely. Such advantages emerge.

However, in the f1 machine configuration as shown in Fig. 3, when machining the workpiece with the tool rest 4 and the workpiece JL6, the main shaft 2 is
When moving in the l-axis direction, it is necessary to always consider the amount of movement in the Zl-axis direction when moving the tool rest 4 in the 22-axis direction. In other words, the z2 axis is the main one! It is necessary to superimpose and control the zl axis of 1I12.

Here, a conventional technique for performing superimposition control on 2@ will be explained using FIG.

The cannibal program read from the cannibal program storage section 10 is interpreted by the program interpreter 11, and data necessary for position control is sent to the ZI@/XI axis calculation section 12 and the z2 axis/X2 axis calculation section 13, respectively.

Calculations for position control are performed in each calculation section 12 and 13, and the position command values of the x1 axis, Zl axis, and x2 axis are calculated respectively. Part 1
The signal is sent to the 5- and ×2-axis surf control section 16. And Z
The position command value PS sent to the l-axis support control section 15 is also sent to the change ball calculation section 26, and the change amount A of the position command value PS is calculated by the change ball detection section 26, and then sent to the addition section 27. Sent. The adding section 27 adds this change jirVA to the z2-axis position command value pc from the Z2@/X2'M calculation section 13, and sends the added data AD to the 12@saho control cylinder section 17. Upon receiving these position command values, the servo control units 14 to 1
7 drives each servo motor I8-2I, and position detectors 22-2 coupled to each servo motor 18-21
The position control of each axis is performed in response to the detected value from 5.

(Problem to be Solved by the Invention) As described above, when performing superimposition control, conventionally, the amount of change VA in the movement command value PS in the Zl-axis direction of the main spindle 2 is changed to the command value P for the 72-axis.
It is added to C. However, with this control method, Z
Since the control of the l-axis and 22-axis servo systems is performed completely independently, for example, if an error occurs in the 21-axis servo control during superimposition control and the zl-axis does not move correctly, the z2@ Since there is no way to know about the abnormality, the machine would move abnormally with respect to the workpiece 1, which could lead to a major accident.

In other words, the main shaft moves in the Zl axis direction, and the first turret moves
In a control device for a numerically controlled lathe that has a mechanism that moves only in the l-axis direction and the second tool rest moves in the x2-axis and z2-axis directions, when machining with the second tool rest while the main axis is moving
Superimposition control that takes into account the movement of the zl axis in addition to the movement of the axes is required. However, in conventional superimposition control, the amount of change in the movement command value of the zl-axis is added to the command value of the 72-axis, and this is done at the command value level, so if an abnormality occurs in the servo system of the zl-axis, etc. The 72nd axis would make abnormal movements relative to the workpiece, potentially leading to an accident.

The present invention was made in view of the above-mentioned circumstances, and an object of the present invention is to provide a numerical control device having a superimposed control function that prevents major accidents even if an abnormality occurs in the Zl axis servo system. It is about providing.

(Means for Solving the Problems) The present invention includes a main shaft that grips at least a workpiece and is movable in the direction of the Zl axis, which is a central axis of rotation, and an X axis perpendicular to the Zl axis.
a first tool rest movable in the l@ direction; and the z1@ and x
The present invention relates to a numerical control device for controlling a numerically controlled lathe equipped with a second tool rest movable in the z2-axis direction and the x2-axis direction parallel to one axis, respectively. While moving in the Zl@ direction, the z2 axis and x2
By controlling the movement of the axis, when processing the workpiece with the tool mounted on the second tool rest, the amount of change in the detected value from the position detector of the zl axis is set as the position command value for the Z2!1iIll. This is achieved by controlling the position of the z2-axis by using the value added to the z2-axis as a position command value for the z2-axis.

(Function) According to the present invention, since the amount of change in position of the Zl axis is always added to the position command value of 22@, it is as if the drive mechanism of the X2@ and This is the same mechanical configuration as the turret, 22-axis, and x2-axis drive mechanism automatically move as the main axis moves in the Z1-axis direction.

(Example) An embodiment of the present invention will be described with reference to FIG.

Note that blocks that are the same as those in FIG. 4 are given the same numbers and their explanations will be omitted.

In the present invention, the calculation outputs of the 21-axis/XI @ calculation section 12 are manually input to the XI-axis servo control section 14 and 21@servo control section 15, respectively, and the calculation outputs of the z2-axis/X2-axis calculation section 13 are It is input to the ×2-axis servo control section 16 and the addition section 29. Then, the position detection value Psi of the H-axis position detector 23 is input to the position change amount detection unit 28, and the position change amount Pν detected by the position change amount detection unit 28 is added to the addition unit 2.
9, this positional displacement amount pv is added to the calculation output from the z2-axis/X2-axis calculation section 13, and the addition result PD is manually inputted to the z2-axis servo control section 17.

In this way, in the present invention, the position detection value PSI detected by the zJ-axis position detector 23 is manually inputted not only to the Zl-axis control unit 15 but also to the position change amount detection unit 28, The unit 28 detects a positional change of 3yrpv in the position of the 21st axis and inputs it to the adding unit 29 manually. This addition section 29 is
Z2@/X2-axis position command value P from the X2-axis calculation unit 13
Add the position change amount pv to C, and the addition result PD is z
The position command values for the two axes are manually applied to the z2-axis surf control section 17 to control the position of X2@.

(Effects of the Invention) As explained above, in the numerically controlled lid of the present invention, the amount of change in the position of the zl axis is always added to the position command value of the Z2 axis, so it is as if the tool post and its The drive mechanisms for the Z2-axis and It is the same as having a mechanical configuration. Therefore, even if an abnormality occurs in the Zl axis servo system, it will not lead to a major accident.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing an embodiment of the present invention, Figure 2 is a mechanical configuration diagram of a general 4-axis numerically controlled lathe, and Figure 3 is a mechanical configuration diagram of a numerically controlled lathe that requires Z-axis superimposed control. , FIG. 4 is a block diagram showing an example of a conventional device. l...workpiece, 2...main spindle, 3.4...turret,
5.6...Tools, lO...Kaniprogram storage section,
11...Program interpretation section, 12...zl axis/XI
Axis calculation unit, 13...z2-axis/×2-axis calculation unit, 28...
- Position change amount detection section, 29... addition section. Yu2dan t

Claims (1)

[Claims] 1. At least a main shaft that grips the workpiece and is movable in the direction of the Z1 axis which is the center axis of rotation, a first tool rest movable in the direction of the X1 axis perpendicular to the Z1 axis, and a main shaft that is movable in the direction of the In a numerical control device for controlling a numerically controlled lathe equipped with a second tool post movable in parallel Z2-axis direction and X2-axis direction, the main shaft moves in the Z1-axis direction while the Z2-axis and By controlling the movement, when processing the workpiece with the tool mounted on the second tool rest, the amount of change in the detected value from the Z1-axis position detector is added to the position command value for the Z2-axis. A numerical control device having a superimposition control function, characterized in that the numerical control device has a superposition control function that controls the superposition processing of the Z axis by controlling the position of the Z2 axis using a value as a position command value for the Z2 axis.