JP4199617B2 - Tailstock drive for multi-tasking lathe - Google Patents

Description

  The present invention relates to a tailstock driving device in a combined machining lathe.

The multi-tasking lathe has a function of performing various types of processing on a workpiece gripped by a main shaft.
When processing a long workpiece, the end of the workpiece on the side opposite to the main shaft may be supported by a tailstock and processed.
This tailstock driving device is disclosed in, for example, the following patent documents.
Japanese Patent Laid-Open No. 7-24605 JP-A-2-83144 JP-A-6-55310

In the above-mentioned Patent Document 1, since the spring mechanism is provided inside the tailstock, the entire structure is complicated and the weight is large. In addition, the movement stroke of the tailstock is also limited, and cannot be used for long strokes.
In Patent Document 2, the entire tailstock is moved by a ball screw and moved by the ball screw by a piston inside the housing to apply a thrust for the tailstock, which increases the operation time.
The thing of patent document 3 needs to always give the thrust for a tailstock with a motor, and is a mechanism with much power consumption.

  As means for solving the conventional problems described above, a tailstock driving device for a composite machining lathe according to the present invention includes a tailstock that is slidably mounted on a frame of the composite machining lathe, and a tailstock. A ball screw that is screwed onto the ball nut, a servo motor mounted on the frame side of the combined machining lathe, and a joint that is disposed between the output shaft of the servo motor and the ball screw and supports the ball screw so that it can rotate and move in the axial direction. A member, a coil spring that is mounted on the joint member and biases the ball screw toward the servo motor, and a disc brake that stops rotation of the joint member. The joint member includes a key that transmits the rotation of the servo motor to the ball screw, and a casing member that accommodates the coil spring and moves in the axial direction.

The tailstock driving device of the present invention can perform the tailstocking of a workpiece by a single operation, requires a short operation time, and has a simple driving device.
Since the tailstock pushes the workpiece with the spring force of the coil spring, power can be saved by turning off the power supply to the servo motor.
Further, the thrust applied to the tailstock can be set freely by setting the current value applied to the servo motor.

FIG. 1 is an explanatory view showing an outline of a combined machining lathe provided with a tailstock driving device of the present invention.
A combined machining lathe generally indicated by reference numeral 1 includes a main shaft 10 and grips a workpiece 20 with a chuck 12 of the main shaft 10. A center hole 22 is provided in the workpiece 20 as necessary. The combined machining lathe 1 includes a tool post (not shown) and performs necessary machining on the workpiece 20.
The tailstock 30 is slidably mounted on the bed of the composite working lathe 1 and is screwed to the ball screw 200 by a ball nut 32.

The whole tailstock drive apparatus shown by reference numeral 100 includes a servo motor 110, the output shaft 130 of the servo motor 110 rotates the coupling 140 in the direction of arrow _{R 1.} The coupling member 140 drives the joint member 150 to rotate.

The joint member 150 rotationally drives the ball screw 200, and the tailstock 30 slides in the arrow AB direction according to the amount of rotation of the ball screw 200.
The tailstock 30 has a sleeve 34, and a tailstock shaft 36 is attached to the tip of the sleeve 34.
The joint member 150 supports the ball screw 200 so as to be movable in the axial direction, and has a so-called floating structure. A coil spring 210 is provided between the joint member 150 and the ball screw 200. A disc brake 220 that stops the rotation of the joint member 150 is also provided.

FIG. 2 is an explanatory diagram showing the operation of the present invention.
When the workpiece 20 is centered, a rotation command is given to the servo motor 110 using a function prepared in the machining program, the ball screw 200 is rotated, and the tailstock 30 is moved from the standby position in the direction of arrow A. Move.

When the tailstock 30 is moved and the tailstock 36 at the tip is pressed against the center hole 22 of the workpiece 20, the movement of the tailstock 30 in the arrow A direction stops. In this state, the servo motor 110 continues to rotate. When the joint member 150 continues to rotate, the ball screw 200 are attracted to direction of arrow _{F 1,} the coil spring 210 is compressed.
When the coil spring 210 is compressed by a predetermined amount, the servo motor 110 stops rotating. At the same time, the disc brake 220 is operated to fix the joint member 150.

By this operation, the tailstock 30 maintains a state in which the workpiece 20 is pressed by the spring force P ₁ generated when the coil spring 210 is compressed.
In this state, since the power supply to the servo motor 110 is off, no energy is consumed.

FIG. 3 is an explanatory view showing the detailed structure of the tailstock driving device 100 of the present invention.
The tailstock driving device 100 includes a servomotor 110, and a cord 112 for electrical equipment, a hose 114 for hydraulic pressure, and the like are attached to the servomotor 110.

A housing 120 is attached to the front surface of the servo motor 110. The output shaft 130 of the servo motor 110 protruding into the housing 120 rotates the coupling member 140 via the key 132. The coupling member 140, the joint member 150 is driven to rotate via the key 142, the joint member 150 drives the ball screw 200 via a key 154 in the arrow _{R 2} direction.

The joint member 150 is connected to the coupling member 140 via the key 142 so as to be slidable in the axial direction.
A coil spring casing member 160 is fitted on the outside of the joint member 150, and the coil spring 210 is mounted inside the casing 160. A pressing plate 162 is attached to the outer periphery of the joint member 150 via a lock nut 152, and a thrust bearing 170 is sandwiched between the pressing plate 162 and the casing member 160 of the coil spring.

With this configuration, the joint member 150 together with the ball screw 200 can move into the direction of arrow _{F 1.}
Coil spring 210 is in a free state, has a length dimension _{L 1.} Even if the tailstock comes into contact with the workpiece and stops, the servo motor 110 continues to rotate until a predetermined current value is reached. This rotation, ball screw 200 and the joint member 160 is moved in direction of arrow _{F 1,} to compress the coil spring 200.

When the servo motor 110 reaches a predetermined current value, the power supply to the servo motor 110 is turned off and the disc brake 220 is mechanically operated. Thereby, the rotation of the joint member 150 is fixed.
In this state, the coil spring 210 maintains compressed length dimension L _2, to press the tailstock relative to the workpiece by its spring force.

  Therefore, by changing the set value of the current applied to the servo motor 110, the compression amount of the coil spring 210 can be changed, and the tailstock can be pressed against the workpiece with an arbitrary pressing force.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a multi-tasking lathe to achieve centering of a workpiece with an arbitrary pressing force by a single operation.

Explanatory drawing which shows the outline | summary of the tailstock drive device of this invention. Explanatory drawing which shows the effect | action of the tailstock drive device of this invention. Explanatory drawing which shows the structure of the principal part of the tailstock drive device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Combined machining lathe 10 Main axis | shaft 12 Chuck 20 Workpiece 22 Center hole 30 Tailstock 32 Ball nut 36 Center shaft 100 Tailstock drive device 110 Servo motor 120 Housing 130 Output shaft 140 Coupling member 150 Joint member 152 Lock nut 160 Casing Member 170 Thrust bearing 200 Ball screw 210 Coil spring 220 Disc brake

Claims (1)

A tailstock which is equipped slidably on the frame of the combined machining lathe, and a servo motor mounted on the frame side of the double coupling machining lathe, and the coupling member which is rotatably driven by the output shaft of the servo motor, coupling A joint member that is driven to rotate and move in the axial direction by the member, a ball screw that is driven by the joint member and screwed into the ball nut of the tailstock, and a ball screw that is mounted on the joint member and biases the ball screw toward the servo motor A coil spring, a disc brake that stops rotation of the joint member, the joint member includes a key that transmits the rotation of the servo motor to the ball screw, and a casing member that accommodates the coil spring and moves in the axial direction. When the spring is compressed by a predetermined amount, the power supply to the servo motor is stopped and the disk Tailstock drive of combined machining lathe actuating the rake.

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