JPH04238504A - Synchronous control system - Google Patents

Abstract

PURPOSE:To synchronous-control the synchronous axes of an NC gear machine tool like a gear hobbing machine, etc., in which synchronous control among plural servo axes is necessitated as selecting freely the synchronous axes of the NC gear machine tool, and in addition, setting optionally a synchronizing coefficient. CONSTITUTION:Two servo axes necessitated to be synchronized are combined, and a parameter is set in the parameter area of a storage means 18 as a master axis and a slave axis. The master axis and the slave axes are selected fro among plural combinations of the servo axes by the selecting means 19 of the servo spindle. Synchronization between the optional axes can be designated by the optional coefficient by a synchronization command including the combination of the axes and the synchronizing coefficient.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a synchronous control method for synchronously controlling NC gear machine tools such as hobbing machines, and in particular a synchronous control method for controlling the axes of numerically controlled machine tools that require a variety of synchronous axis settings. Regarding.

0002

2. Description of the Related Art Hobbing machines that process gears can cut gears of various specifications using replacement gears. In addition, numerical control (NC) eliminates changing gears and makes setup changes easier.
Hobbing machines have also come into use.

[0003] In an NC hobbing machine, it is necessary to synchronize the spindle shaft and the rotating shaft of the gear to be cut. For this,
Feedback pulses from a position coder coupled to the hob shaft are distributed to the hob shaft and the C-axis at a constant ratio to perform synchronous control.

0004

[Problems to be Solved by the Invention] However, with conventional NC devices that control synchronization in hobbing machine functions, synchronization is achieved only between a limited number of axes, such as the main spindle and the C-axis, or the Z-axis and the C-axis. I couldn't. In addition, the synchronization coefficient between the synchronization shafts is determined by the commanded number of teeth, number of hob threads, gear helix angle,
Since it was automatically calculated on the NC device side from the module, etc., it was not possible to change the synchronization coefficient to achieve synchronization control.

The present invention has been made in view of the above points, and an object thereof is to provide a synchronous control method that allows synchronous control to be performed by freely selecting a synchronous axis. Another object of the present invention is to provide a synchronization control method in which a synchronization coefficient can be arbitrarily set.

[0006]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a synchronous control system for NC gear machine tools such as hobbing machines that requires synchronous control between multiple servo axes. The invention is characterized by comprising a storage means in which parameters are set for combinations of a plurality of servo axes to be used, and a selection means for specifying the parameters of the storage means to select any servo axis as a master axis or a slave axis. A synchronous control scheme is provided.

[0007]

[Operation] Parameters are set for two servo axes that require synchronization as a master axis and a slave axis. By setting parameters for multiple sets of servo axes and giving a command including the parameters, synchronization between arbitrary axes can be specified using an arbitrary coefficient.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram for explaining the synchronous control method of the present invention for a hobbing machine. Work 1 is a gear to be hobbed. This work 1 is a servo motor 1
1 through gears 12a and 12b about a C-axis 14 with a Z-axis 13 as the rotation axis. A hob 2 that moves relative to the workpiece 1 has a large number of cutting teeth, and is attached to a spindle shaft (hereinafter referred to as the main shaft 3). The main shaft 3 is rotated at a predetermined speed by a spindle motor 5 in response to a command from a spindle amplifier 4, and the hob 2 hobs the workpiece 1. spindle motor 5
Further, a position coder 7 is connected via gears 6a and 6b, and outputs a feedback pulse proportional to the rotation of the spindle motor 5. This feedback pulse is sent to the synchronization control means 8.

The synchronous control means 8 instructs the spindle amplifier 4 to rotate a rotation command including the rotation speed of the spindle 3, and simultaneously controls the C-axis 14.
A rotation command including the rotation speed is given to the servo amplifier 10. The rotational speed of the main shaft 3 and the rotational speed of the C-axis 14 are set at a constant ratio, and as a result, based on the rotation command from the synchronization control means 8, the servo amplifier 10 drives the servo motor 11 in synchronization with the main shaft 3. to rotate the C-axis 14. Note that the synchronization control means 8 includes a position coder 7 that is being synchronized.
An internal counter 15 is provided to constantly count the number of feedback pulses from the servo amplifier 10 and the number of output pulses commanded to the servo amplifier 10.

[0010] Thereby, the workpiece 1 can be rotated in a certain relationship with the hob 2, and the gear can be machined. Workpiece 1 and hob 2 are further equipped with Z for cutting helical gears.
A drive means for moving the work in the direction of the shaft 13, a drive means for the Y-axis 16 for hob shift synchronization, a drive means for the V-axis 17 for rotating the grindstone for polishing the hob 2, etc. are provided. Although these driving means are omitted in the drawings, they are synchronized by a synchronization control means 8 in the same way as the main shaft 3 and the C-shaft 14.

[0011] The plurality of servo axes that require synchronization are selected as necessary. To this end, in the present invention, the synchronous control means 8 is provided with a storage means 18 in which combinations of servo axes are set as parameters, and the parameters of this storage means 18 are specified to select any servo axis as the master axis or slave axis. A selection means 19 is provided for selecting.

The synchronization command input to the synchronization control means 8 instructs preprocessing for synchronization control in the following format. GxxPnQk; Here, Gxx is a synchronization start command, Pn is a servo axis parameter designation, Qk is a synchronization coefficient designation, n is a parameter set number to be described later, and k is a synchronization coefficient.

[0013] In the preprocessing step for synchronous control,
The two axes that require synchronization are parameterized. That is,
The parameter storage means 18 stores a master axis and a slave axis as two axes that require synchronization, along with a parameter n. Here, the axis that can be set as the master axis is the main axis or any servo axis, and any servo axis can be set as the slave axis.

When the preprocessing is completed, the synchronization control means 8 outputs a drive command in the form of a distributed pulse to the designated master axis and slave axis. By issuing the synchronization start command Gxx multiple times, it is also possible to set multiple sets of synchronization axes and simultaneously control these servo axes in synchronization. In addition, the end of synchronization is performed using a synchronization end command Gy that includes parameter specification.
yPn; can be used to terminate each parameter set number n.

FIG. 2 is a flowchart illustrating each step of preprocessing. [S1] When the synchronization start command Gxx is determined, the process proceeds to step 2. [S2] Read n from the Pn command and determine the master axis (M) and slave axis (S) from the corresponding parameter numbers. [S3] Set the n-th synchronization flag Fn to 1. [S4] If the determined master axis is the main axis, proceed to step 5. [S5] Set 1 to the 1 rotation signal wait flag Fw. [S6] Read the synchronization coefficient k from the Qk command and set the synchronization relationship between the master axis and the slave axis. [S7] When the synchronization end command Gyy is determined, the process proceeds to step 8. [S8] Read n from the command of Pn, and set the n-th group's synchronization flag Fn to 0. Note that by appearing the synchronization start command Gxx multiple times, it becomes possible to control a plurality of nested sets of servo axes in synchronization.

FIG. 3 is a flowchart illustrating each step of the distribution process. [S11] Detect the n-th synchronizing flag Fn. This flag detection is performed for all selectable parameter sets from n=1. Note that if this flag Fn is not detected, the process ends. [S12] Based on the detected flag Fn, check the servo axis selected as the master axis. If the master axis is other than the main axis, the process proceeds to step 13, and if the master axis is determined to be the main axis, the process proceeds to step 14. [S13] Let A be the distributed pulse to the master axis. [S14] Detect the one-rotation signal wait flag Fw. If this flag Fw is detected, the process proceeds to step 15. [S15] A one-rotation signal wait process is performed. That is, when the master axis is the main axis, a one-rotation signal is detected, alignment becomes possible, and then synchronization processing is started. [S16] Set the 1-rotation signal wait flag Fw to 0. [S17] Read the feedback pulse from the spindle position coder and set it as A. [S18] The product of the number of pulses A given in step 13 or step 17 and the synchronization coefficient k is calculated and added to the distributed pulses of the slave axis.

FIG. 4 shows a plurality of combinations of master axes and slave axes stored in the parameter area. A combination of two servo axes that require synchronization is:
Main axis and C-axis required when cutting spur gears, Z-axis and C-axis required when cutting helical gears, Y-axis and C-axis required for hob shift synchronization, hob polishing during cutting. The main axis, V-axis, etc. that are required when doing so are assumed. The set number of the servo axis selection is stored as a parameter value in the parameter area of the storage means 18, and the synchronization command is valid in both the automatic operation mode and manual operation mode of the hobbing machine. I can do it.

FIG. 5 is a block diagram of the hardware of a numerical control device (CNC) for implementing the present invention. A processor 21 of the numerical control device (CNC) controls the entire numerical control device according to a system program stored in a ROM 22. ROM22 has EPROM or EE
PROM is used. An SRAM is used as the RAM 23, and various data are stored therein. The nonvolatile memory 24 stores machining programs 24a, parameters, etc., and uses battery-backed CMOS, etc.
The contents are retained even after the numerical control device is powered off.

A PMC (programmable machine controller) 25 receives commands for the M function, S function, T function, etc., decodes and processes the commands using a sequence program 25a, and outputs an output signal for controlling the machine tool. In addition, it receives limit switch signals from the machine side or switch signals from the machine operation panel, processes them in the sequence program 25a, and outputs output signals to control the machine side. Signals necessary for the numerical control device are sent via the bus 35 to the RAM 23 and read by the processor 21.

The graphic control circuit 26 converts the data stored in the RAM 23, such as the current position and amount of movement of each axis, into a display signal and sends it to the display device 26a, which displays it. As the display device 26a, a CRT, a liquid crystal display, or the like is used. The keyboard 27 is used to input various data.

The input/output circuit 32 exchanges input/output signals with the machine side. In other words, the limit switch signal on the machine side,
The PMC 25 receives the switch signal from the machine operation panel and reads it. It also receives an output signal from the PMC 25 for controlling a pneumatic actuator on the machine side, and outputs it to the machine side.

The manual pulse generator 33 outputs a pulse train for precisely moving each axis according to the rotation angle, and is used to precisely position the machine. The manual pulse generator 33 is usually mounted on a machine operation panel. The spindle amplifier 4 drives the spindle motor 5, the position coder 7 outputs position detection pulses, and the additional detector 31 counts synchronization pulses fed back from the main shaft 3. 34
is a shared RAM.

A processor 41 for controlling the added servo axes controls the entire added servo axes according to a system program stored in the ROM 42. R.O.
EPROM or EEPROM is used for M42. SRAM corresponds to the storage means 18 in FIG.
The RAM 18 is provided with parameter areas for setting feedback pulses from the main shaft 3 and command pulses for the C-axis and the like. The position control circuit 44 is connected to the processor 4
1 receives a position command and outputs a speed command signal for controlling the servo motor 11 to the servo amplifier 10. The servo amplifier 10 amplifies this speed command signal and drives the servo motor 11. A position detector 47 is coupled to the servo motor 11 . The position detector 47 feeds back the position detection pulse to the position control circuit 44.

In the above embodiment, the synchronization in the hobbing machine function is not limited to the main axis and the C axis, or the Z axis and the C axis, but also the Y axis.
It can also be set for the axis and C axis, the main axis and V axis, etc.
The range of compatibility with hobbing machines is expanded. In addition, the synchronization coefficient can be operated using a numerical value based on a calculation formula created by the user.

[0025] In the above explanation, the synchronization change on the hobbing machine was explained, but thread cutting, polycon processing, superimposition synchronization, etc.
It can also be applied to other synchronization functions in numerical control. Also,
An electronic gearbox or a software gearbox may be used as a method of synchronous control between a plurality of servo axes, but the present invention can also be widely applied to such NC gear machine tools to achieve similar effects.

[0026]

[Effects of the Invention] As explained above, in the present invention, synchronous control can be performed by freely selecting a synchronous axis.
It becomes possible to set the synchronization axis and command the synchronization coefficient more universally than ever before.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram for explaining the synchronous control method of the present invention for a hobbing machine.

FIG. 2 is a flowchart illustrating each step of preprocessing.

FIG. 3 is a flowchart illustrating each step of distribution processing.

FIG. 4 is a diagram showing a plurality of combinations of master axes and slave axes.

FIG. 5 is a block diagram of hardware of a numerical control device (CNC).

[Explanation of symbols]

1 Work 2 Hob 3 Main shaft 8. Synchronous control means 18 Parameter storage means 19 Servo axis selection means

Claims (4)

[Claims] 1. In a synchronous control method for an NC gear machine tool such as a hobbing machine that requires synchronous control between a plurality of servo axes, a storage means is provided in which a combination of a plurality of servo axes that require synchronization is set as a parameter. , a selection means for specifying parameters in the storage means and selecting an arbitrary servo axis as a master axis or a slave axis. 2. The synchronous control according to claim 1, wherein the selection means includes a preparation function command for starting synchronization, and simultaneously specifies a combination of servo axes for which synchronization is to be enabled and a synchronization coefficient therebetween. method. 3. The preparation function command for synchronization start, when the selected servo axis is the main axis of the machine tool,
3. The synchronous control method according to claim 2, wherein synchronization is started after detecting a one-rotation signal of the main shaft. 4. The synchronous control method according to claim 1, wherein the synchronous command to the machine tool is valid in either automatic operation mode or manual operation mode. method.