JPH04189448A - Indexing controlling device for tool rest of nc lathe - Google Patents

Abstract

PURPOSE:To perform indexing for a tool rest correctly and stably by setting an output torque of a servo motor at zero when a tool rest clamp condition is checked for every execution of tool rest indexing, and setting its rotation angle for a holding means to be an instruction angle for next instruction for the same tool rest indexing. CONSTITUTION:A tool rest indexing angle instruction memory 5 reads an indexing angle instruction from a tool rest indexing surface recognized by a program interpreting part 2. A sequence control part 3 executes a tool rest unclamp action. In the meanwhile, a tool rest indexing control part 6 rotates a tool rest 12 to a designated angle. When rotation of the tool rest is completed, the sequence control part 3 puts a tool rest clamp instruction on. In addition, at completion of clamping, a torque zero instruction is generated from a torque instruction zero instruction part 8 to a servo motor control part 7. When a servo motor 9 stops generating a torque by the torque zero instruction, an indexing angle is fixed at the tool rest 12 according to a precision of indexing teeth. An actual tool rest indexing angle is written to a tool rest indexing angle instruction memory 5 for setting.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an indexing control device for a tool rest for an NC lathe, particularly an N
The present invention relates to an indexing control device for a tool rest for an NC lathe, which controls the drive of a cutter to a desired indexing position based on a C machining command.

[Prior art] In an NC lathe, not only the main spindle on which the workpiece is loaded is controlled by NC, but also the indexing of the tool post from which a plurality of tools or tools are arbitrarily selected. This makes it possible to perform various complex machining operations sequentially and unattended based on predetermined programs.

In such an NC lathe, the indexing control of the tool rest is
It is extremely important to select various desired multiple tools and combine them for complex machining, and the positioning accuracy directly affects machining accuracy, so the indexing rotation speed is high and rapid indexing is performed. There is a demand for an indexing control device that can also provide high positioning accuracy.

Conventionally, the indexing control of the tool post is divided into the turning operation of the tool post and the clamping/unclamping operation of the tool post. In addition, for clamp/unclamp operations, the indexing surface of the tool rest is detected by a position sensor and operated using a hydraulic valve, and a series of these rotations and clamp/unclamp operations are performed using NC commands. Sequence control is based on

Recently, the turret rotation control of NC lathes has been developed, for example, in patent application No.
As seen in No. 296579, it is possible to index the tool rest at high speed using a servo motor.

In the turret rotation control, the turret rotation command angle is fixed for each indexing surface according to the number of indexing surfaces of the turret, as shown in FIG.

FIG. 5(a) shows an example of a dodecagonal tool rest, and FIG. 5(b) shows an example of a halo angle tool rest.

FIG. 6 is a block diagram showing the configuration of a conventional indexing control device for a tool rest for an NC lathe. A program interpreter 2 is connected to the program memory 1 for reading and interpreting indexing commands.

The program interpreter 2 includes a sequence controller 3.
and a turret indexing control section 6 are connected in parallel, and the turret indexing control section 6 includes data for manually inputting the turret rotation command angle and a servo motor control section for controlling the servo motor 9. 7 is connected.

Furthermore, a position detector] 0 for detecting the rotational position of the servo motor 9 is connected to the rotation shaft 9b of the servo motor 9, and the position detector 10 is connected to a servo motor control unit that controls the servo motor 9. 7 is connected.

Further, a gear 13 is fixed to the motor shaft 9a of the servo motor 9, and a gear 14 connected to a rotatably supported turret shaft 12a meshes with the gear 13.

The tool rest 12 is fixed to the turret shaft 12a, and the tool rest 12 is rotated in the direction of the arrow to obtain a desired indexing surface.

Although not shown in detail in the figure, the reduction gear 14 of the reduction mechanism includes a clamp/unclamp mechanism driven by a clamp/unclamp solenoid controlled by the sequence control unit 3. In the unclamped state, the turret 12 is rotated by the servo motor 9, and when a predetermined indexing surface is obtained, a clamping operation is performed using a hydraulic cylinder.

Note that the reference numeral 11 in the figure is a limit switch that detects the clamp/unclamp state.

Next, the operation will be explained.

The program interpreter 2 reads the indexing command for the tool rest 12 stored in the program memory 1 and supplies the desired indexing command to the sequence controller 3 and the tool rest index controller 6.

= 5- Then, in the unclamped state, the servo motor control unit 7 causes the servo motor 9 to rotate the tool rest 12,
When a predetermined indexing surface is obtained, the sequence control section 3 turns on the solenoid to perform a clamping operation.

[Problems to be Solved by the Invention] The conventional indexing control device for a tool post for an NC lathe is configured as described above. There are errors and secular changes in indexing accuracy due to long-term use, and since the rotation command angle of each indexing surface is fixed for each indexing surface, it is not possible to deal with processing errors and secular changes, and the indexing position There were problems in that it took a lot of time to make adjustments, and when the turret was clamped, the tooth surfaces of the index teeth collided with each other, producing loud noise.

In addition, due to the weight of the tool holder and tools attached to the tool post, when determining the rotational position when indexing the tool post, the indexing teeth may skip over the position where they reliably engage, or accurate tool post indexing may not be possible. Ta.

-6= The present invention has been made in view of the above conventional problems,
The purpose is to provide an indexing control device for a tool rest for an NC lathe that can perform tool rest indexing accurately and stably and can cope with processing errors and aging of index teeth.

[Means for Solving the Problems] In order to achieve the above object, an indexing control device for a tool post for an NC lathe according to the present invention is provided. a rotation angle detection means for detecting the rotation angle of the table; a clamp state detection means for detecting the clamp state of the tool post; a holding means for holding the rotation command angle of the tool post; Output torque control means. Therefore, when the clamp state detection means confirms the clamp state of the tool post each time the tool post indexing is performed, the output torque of the servo motor is set to zero by the output torque control means, and the rotation angle detected by the rotation angle detection means is set to zero. The present invention is characterized in that the turning angle is configured to be set in the holding means as a command angle for the next command to index the same blade.

[Operations] With the above configuration, the indexing control device for a tool post for an NC lathe according to the present invention controls the turning of the tool post using a servo motor, and detects the turning angle of the tool post using a turning angle detection means. the clamp state of the tool post is detected by the clamp state detection means, the rotation command angle of the tool post is held by the holding means, and the clamp state of the tool post is checked by the clamp state detection means each time the tool post is indexed. At this time, the output torque of the servo motor is set to zero by the output torque control means, and the turning angle detected by the turning angle detecting means is set in the holding means as a command angle for the next command to index the same blade. There is no need to adjust the indexing angle.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing the configuration of an indexing control device for a tool rest for an NC lathe according to the present invention, and FIG. 2 is a diagram showing a drive transmission section from a servo motor to the tool rest in the present invention.

The indexing control device has a program memory 1 that stores indexing commands for the tool rest 12, etc., and a program interpreter 2 that reads and interprets the indexing commands is connected to the program memory 1. .

The program interpreter 2 includes a sequence controller 3.
and a tool post indexing angle command memory 5 serving as a holding means for holding the tool post indexing angle are connected in parallel.
The turret indexing angle command memory 5 is connected to a data input device 4 for inputting initial setting values and changed values of the turret rotation command angle and a turret indexing control section 6.

Further, a servo motor control unit 7 that controls the servo motor 9 is connected to the tool post indexing control unit 6, and the servo motor control unit 7 has output torque control that can make the output torque of the servo motor 9 zero. A torque command zero command section 8 is connected to the torque command zero command section 8, and a limit switch 11 is connected to the torque command zero command section 8 as a clamp state detection means for detecting the clamp=9- state of the tool post.

Furthermore, a position detector 10 as a turning angle detection means for detecting the rotational position of the servo motor 9 is connected to the rotation shaft of the servo motor 9. 7 and an AND circuit 15, the clamp confirmation signal from the limit switch 11 is input to the AND circuit 15, and the output of the AND circuit 15 is input to the turret indexing angle command memory 5. It looks like this.

In addition, FIG. 2 shows in detail the drive transmission part from the servo motor to the tool post, and the tool post base 16 has the tool post 1.
2 is rotatably supported by a turret shaft 12a.

Furthermore, a car pick-type index positioning tooth 17, which will be described later, is fixed to the tool post 12, and a tool post gear 18 is provided on the outer periphery of the car pick type index positioning tooth 17.

On the other hand, a servo motor 9 is fixed to the other surface of the tool rest base 16, a gear 13 is fixed to a motor shaft 9a of the servo motor 9, and a gear 14 rotatably supported on the gear 13. are meshing.

A reduction pinion 19 provided integrally with the gear 14
The tool post gear 18 is in mesh with the tool post, so that the rotational driving force of the servo motor 9 is reduced in speed and transmitted to the tool post 12.

Further, FIG. 2 shows a state in which the clamp/unclamp mechanism for the tool post 12 is incorporated into the tool post base 16, and the car pick type index positioning teeth 17 are directed toward the tool post 12 side as shown in the figure. It has index teeth 17a,
Similarly, a car pick type index positioning tooth 20 is formed on the side surface of the tool rest base 16 itself in parallel to the inner periphery of the car pick type index positioning tooth 17, and both positioning teeth 17
゜20 has the same number of index teeth carved on the same plane,
Both positioning teeth 17.20 have the same phase.

Further, the tool post base 16 is provided with a ramper 21 that is slidable in the axial direction of the turret shaft 12a, and the clamper 21 has the positioning teeth 17.
A car pick-type indexing fixed tooth 21a facing 20 is provided.

Therefore, as shown in FIG. 2, when the clamper 21 is moved to the right by the electromagnetic solenoid, the car pick-type indexing is fixed! 21a is the positioning 6117.2
0, and the tool rest 12 is indexed and positioned at this selected position.

The clamper 21 can be slid to the left in FIG. 2 by an electromagnetic solenoid, and as a result of this sliding, the indexing fixed tooth 2]a is separated from the positioning tooth 17.20, and in this state, the blade The table 12 is unclamped from the turret base 6, and can be rotated to any indexed position by the servo motor 9.

Fig. 3 shows an example of an NC command, in which the address "N001" and 1-NOIOJ are a sequence for commanding tool post indexing, and these tool post indexing are executed during the NC command for driving the NC lathe. Contains ejection instructions.

Then, rTololJ and rT in the indexing command
O202J is a specific indexing command in the embodiment, and the two-digit number following rTJ commands the indexing surface of the tool post, and the two following digits indicate a well-known tool offset.

Further, "X800" and rZ800J are position commands for the feed axis X and Z axis, respectively, when performing tool post indexing.

A preferred embodiment of the present invention has the above configuration, and its operation will be explained in detail below with reference to the flowchart of FIG. 4.

The program memory 1 stores Canadian programs such as those shown in FIG.
J) is read and interpreted to recognize the tool post indexing surface from the tool post indexing command (step Sl).

Then, the tool post indexing angle command memory 5 reads out the indexing angle command from the tool post indexing surface recognized by the program interpretation section 2 (see FIG. 5) (step S2).

Further, the signal indicating the turret indexing surface is also sent to the sequence control section 3, and the sequence control section 3 executes the turret unclamping operation by generating an unclamp signal (step S3).

On the other hand, the indexing command angle read from the turret indexing angle command memory 5 is sent to the turret indexing control section 6, and the turret indexing control section 6 controls the servo motor 9 by the servo motor control section 7. By doing so, the tool post 12 is rotated to the specified angle (step S4).

Then, when the turning of the tool post 12 to the specified angle is completed (step S5), the sequence control section 3 turns on the tool post clamp command (step S6).

Then, when the tool rest 12 performs a clamping operation under hydraulic control and the limit switch 11 is turned on, it is determined that the clamping is completed (step S7).

Furthermore, the ON signal from the limit switch 11 is sent to the torque command zero command section 8, and when the clamping is completed, the torque command zero command section 8 issues a torque zero command to the servo motor control section 7 (step S8).

Then, when the servo motor 9 stops generating torque due to the zero torque command, the indexing angle of the tool post 12 is fixed according to the accuracy of the indexing teeth 17a. The motor shaft 9a of the servo motor 9 is slightly rotated via the turret shaft 12a1 deceleration mechanism 13, 14, 18, ]9.

As a result, the position detector 10 coupled to the servo motor 9 will indicate the actual angle of the commanded tool post indexing plane.

Then, the AND circuit 15 which detects the tool post actual index angle signal indicated by the position detector 10 and the clamp ON signal detected by the limit switch 11 outputs the tool post actual index angle signal, and outputs the tool post actual index angle signal. The angle is written and set in the blade indexing angle command memory 5 (step S9).

Thereafter, similarly, the actual angles corresponding to other tool post indexing commands are automatically set in the tool indexing angle command memory 5 as the cutting program is executed. 'In addition, in the above embodiment, the actual indexing angle was set by the tool post indexing command from the machine program, but the actual indexing angle is not limited to this, and when indexing the tool in manual operation mode, the actual indexing angle can be set by the same operation as described above. It may also be possible to set it in the blade indexing angle command memory 5.

[Effects of the Invention] As described above, according to the present invention, when the clamp state of the tool post is confirmed by the clamp state detection means every time the tool post indexing is executed, the output) and the torque control means control the servo motor. The output torque is set to zero, and the rotation angle detected by the rotation angle detection means is set in the holding means as the command angle for the next command for indexing the same blade. It can withstand changes over time and eliminates the need to adjust the index position, resulting in accurate and safe tooth alignment and eliminates the possibility of the tooth surfaces of the index teeth colliding with each other when the turret is clamped, resulting in loud noise. This can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an indexing control device for a turret for an NC lathe according to the present invention, FIG. 2 is a diagram showing a drive transmission section from a servo motor to a tool rest in the present invention, and FIG. FIG. 4 is an explanatory diagram showing an example of NC commands stored in the program memory in FIG. 1, FIG. 4 is a flow chart diagram showing the operation of the present invention, and FIG. FIG. 6 is a block diagram showing the configuration of a conventional indexing control device for a tool rest for an NC lathe. 5... Turret indexing angle command memory 7...
Servo motor control section 8 ... Torque command zero command section 9 ... Servo motor 10 ... Position detector 11 ... Limit switch 12 ... Turret

Claims (1)

[Scope of Claims] A tool post control device that controls the turning of a tool post using a servo motor, comprising: turning angle detection means for detecting a turning angle of the tool post; clamp state detection means for detecting a clamp state of the tool post; A holding means for holding the rotation command angle of the tool post, and an output torque control means capable of reducing the output torque of the servo motor to zero, and the tool post clamp state is determined by the clamp state detection means every time the tool post indexing is executed. When this is confirmed, the output torque of the servo motor is set to zero by the output torque control means, and the turning angle detected by the turning angle detecting means is set in the holding means as a command angle for the next command to index the same blade. An NC characterized in that it is configured to
Indexing control device for lathe tool post.