JPS6051977B2 - Manual handle braking method and device for NC machine tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to manual operation of an NC machine tool, and more particularly to a method and apparatus for braking a handle device for manually controlling movable parts such as a tool table or a processing table in a machine tool.

NC machine tools, particularly NC lathes, are generally equipped with a handle device that allows manual control of the position of a tool table, a processing table, etc.

This manual handle device not only provides convenience when manual operation is more efficient than NC machining, such as single item machining or prototype machining, but also when manual feeding is required, such as when setting a tool. It has many advantages, such as allowing manual feed by visual inspection during trial cutting. This type of conventional manual handle device has a pulse generator that generates a pulse signal in response to the amount of rotation of the manual feed handle, and uses the output pulse of the generator as a command signal to drive the NC device and control the servo motor. The method was adopted.

However, in the above configuration, the manual handle has no mechanical relationship with the movable parts such as the tool table and simply rotates the pulse generator, so it is possible to reduce fluctuations in the load of the servo motor to the handle operation. As a result, there was a risk of making a mistake in operating the handle and causing damage to the mechanical system, as the steering wheel could not be operated in a mechanically driven manner.

SUMMARY OF THE INVENTION Accordingly, the present invention aims to improve the above-mentioned problems of the prior art, and its object is to provide a manual handle control method and apparatus for an NC machine tool that can provide a mechanically driven operating feeling. J In order to achieve the above object, in this invention, an output signal is obtained by rotating the manual feed handle, a drive command signal corresponding to the output signal is obtained, and a drive command signal corresponding to the drive command signal is obtained. A method for driving and controlling a servo system to apply a braking force of strength 7 proportional to the drive command signal to the manual feed handle, and a drive generated in response to an output signal applied in accordance with the amount of operation of the manual feed handle. NC that drives and controls the servo motor using command signals
In the manual handle braking device for a machine tool, the manual feed handle is provided with an electromagnetic brake whose braking force changes in proportion to the strength of a drive command signal corresponding to load fluctuations of the servo motor.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the manual handle device according to the present invention.
An operating handle 1 for manually feeding a movable part such as a tool table or a processing table in an NC machine tool, an electromagnetic brake 3 provided on the operating handle 1, and a pulse generator 5, which accepts output pulses from the pulse generator 5 as command signals. It has an NC device 7 and a DC servo motor 9 whose drive is controlled by the NC device 7. The electromagnetic brake 3 has a fixed part 3a and a rotating part 3b. The fixed part 3a is fixed to a handle device main body, which will be described later, and an excitation winding L is provided inside the fixed part 3a.

A variable resistor R is provided in parallel with the excitation winding L to adjust the value of the current flowing through the winding L, and this LI:. A parallel connection of R is inserted in series in the drive line coupling the NC device 7 and the servo motor 9 so that it is excited in accordance with the armature current of the servo motor 9. On the other hand, the rotating portion 3b of the electromagnetic brake 3 is fixed to the handle shaft 11 of the operating handle 1 so as to be rotated along with the rotating operation of the handle 1. The electromagnetic brake 3 applies a braking force to the handle 1 according to changes in the armature current of the servo motor 9, that is, changes in the load whose position is controlled by the motor. A so-called powder brake can be used in which powder is enclosed and a force is applied by the frictional force generated between the two in response to the excitation force. The pulse generator 5 outputs a pulse signal corresponding to the amount of handle operation by engagement of a gear 15 coupled to its input shaft 13 and a gear 17 coupled to the handle shaft 11.

The pulse generator 5 may be any device that converts the rotation of the input shaft 13 into pulses, and may be, for example, a resolver or a pulse encoder. The output shaft of the servo motor 9 is connected to a ball screw 21 through a gear 19, and is movable by rotation of the ball screw 21 through movable parts such as a tool table or a processing table (not shown).

According to the above configuration, a braking force corresponding to the load fluctuation of the servo motor 9 is applied to the steering wheel operation, and an appropriate operating feeling can be obtained.

That is, gears 17 and 15 are rotated according to the rotation operation of manual handle 1.
When the pulse generator 5 is driven and a pulse signal corresponding to the amount of handle rotation is given to the NC device 7, the NC
The device 7 receives this pulse signal as a command signal and applies a drive current to the armature winding of the servo motor 9 via the excitation winding L of the electromagnetic brake 3. Since this driving electromagnetic wave changes according to the load fluctuation of the servo motor 9, a current value is given to the excitation winding L according to the fluctuation of the load applied to the servo motor 9, and the larger the load, the larger the braking force. However, if it becomes small again, a small braking force will be returned to the handle 1. Note that the excitation current of the winding/wire L can be controlled by adjusting the variable resistor R inserted in parallel with the excitation winding L, and it becomes possible to apply a more appropriate control force to the handle 1. FIG. 2 shows a specific example of the manual handle device according to the present invention, which is applied to a manual handle for Z-axis feeding of an NC lathe.

Note that the same reference numbers as in FIG. 1 correspond to the same parts. Second
In the figure, a handle device main body 31 is mounted on a frame F of an NC lathe, and a pulse generator 5 is fixed to the main body 31.

The input shaft 13 of the pulse generator 5 has an integrally coupled gear 15 and a gear 1 fixed to one end of the handle shaft 11.
7. The handle shaft 11 is rotatably held by the handle device body 31 via a bearing, and is made to protrude outside from a support plate 33 fixed to the body 31, and has a boss 35 at the protruding end so that the handle 1 is integrally formed with the handle shaft 11. Fixed. The electromagnetic brake 3 is provided inside the handle device main body 31. The fixed part 3a of the brake 3 has a substantially ring shape surrounding the handle shaft 11 and is fixed to the device main body 31 with means such as bolts, and the rotating part 3b is connected to the fixed part 3a.
With the key 37, turn the handle shaft 11 so that it faces the braking surface S.
Fixed. Therefore, when the handle 1 is rotated, the pulse generator 5 is generated via the handle shaft 11 and the gears 17 and 15.
is driven, the servo motor is controlled as described in FIG. As a specific example, we will take an NC lathe as an example and its Z.
Although the manual handle for shaft feeding has been described as an example, the present invention is not limited to this, and the present invention can of course be applied to all NC machine tools that require manual feeding operation.

As described above, according to the present invention, when operating the manual feed handle, the load corresponding to the amount of operation can be sensed as rotational torque by the operator's hand, thereby eliminating the risk of damage caused by feeding the device too much, thereby increasing safety. can be improved. Furthermore, since the user can experience the feeling of directly moving the device, it is also preferable in terms of workability.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the manual handle device according to the present invention, and FIG. 2 shows a specific configuration example of the manual handle device according to the present invention. 1... Handle, 3... Electromagnetic brake, 5... Pulse generator, 7... NC device, 9
······Servomotor.

Claims (1)

[Claims] 1. A manual feed handle is rotated to obtain an output signal, and a drive command signal corresponding to the output signal is obtained;
A manual handle braking method for an NC machine tool, characterized in that a servo system is drive-controlled in response to the drive command signal, and a braking force proportional to the drive command signal is applied to the manual feed handle. 2. In a manual handle braking device for an NC machine tool that drives and controls a servo motor by a drive command signal generated in accordance with an output signal given in accordance with the amount of operation of a manual feed handle, the manual feed handle is provided with a load fluctuation of the servo motor. An NC characterized by being provided with an electromagnetic brake whose braking force changes in proportion to the strength of a drive command signal corresponding to the
Manual handle braking device for machine tools.