KR20170087285A - Device of compensating thermal displacement for a machine tool - Google Patents

Device of compensating thermal displacement for a machine tool Download PDF

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Publication number
KR20170087285A
KR20170087285A KR1020160007073A KR20160007073A KR20170087285A KR 20170087285 A KR20170087285 A KR 20170087285A KR 1020160007073 A KR1020160007073 A KR 1020160007073A KR 20160007073 A KR20160007073 A KR 20160007073A KR 20170087285 A KR20170087285 A KR 20170087285A
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KR
South Korea
Prior art keywords
ball screw
screw shaft
machine tool
measuring
displacement
Prior art date
Application number
KR1020160007073A
Other languages
Korean (ko)
Inventor
이정헌
이종언
조기봉
강석규
윤석현
Original Assignee
현대위아 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by 현대위아 주식회사 filed Critical 현대위아 주식회사
Priority to KR1020160007073A priority Critical patent/KR20170087285A/en
Publication of KR20170087285A publication Critical patent/KR20170087285A/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q11/00—Accessories fitted to machine tools for keeping tools or parts of the machine in good working condition or for cooling work; Safety devices specially combined with or arranged in, or specially adapted for use in connection with, machine tools
    • B23Q11/0003—Arrangements for preventing undesired thermal effects on tools or parts of the machine
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q1/00—Members which are comprised in the general build-up of a form of machine, particularly relatively large fixed members
    • B23Q1/25—Movable or adjustable work or tool supports
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q17/00—Arrangements for observing, indicating or measuring on machine tools
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00—Programme-control systems
    • G05B19/02—Programme-control systems electric
    • G05B19/18—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form
    • G05B19/401—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by control arrangements for measuring, e.g. calibration and initialisation, measuring workpiece for machining purposes
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00—Programme-control systems
    • G05B19/02—Programme-control systems electric
    • G05B19/18—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form
    • G05B19/404—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by control arrangements for compensation, e.g. for backlash, overshoot, tool offset, tool wear, temperature, machine construction errors, load, inertia

Abstract

[0001] The present invention relates to a measuring apparatus for measuring a displacement of a conveying shaft of a machine tool, and more particularly, it relates to a measuring apparatus for measuring a displacement of a ball screw shaft caused by heat generation of a machine tool using a position sensor, The present invention relates to an apparatus for measuring a displacement of a conveying shaft of a machine tool.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for compensating thermal displacement of a machine tool,

[0001] The present invention relates to a measuring apparatus for measuring a displacement of a conveying shaft of a machine tool, and more particularly, it relates to a measuring apparatus for measuring a displacement of a ball screw shaft caused by heat generation of a machine tool using a position sensor, The present invention relates to an apparatus for measuring a displacement of a conveying shaft of a machine tool.

Generally, the machine tool unit is provided with a transfer system for transferring the workpiece.

FIG. 1 is a view showing a transfer system of a conventional machine tool apparatus. Referring to FIG. 1, a conventional screw system 10 is a ball screw assembly for converting rotational motion into linear motion.

The ball screw assembly receives rotation power generated from a servomotor mounted on the ball 11 and rotates the ball screw shaft 12. The ball screw nut 13 reciprocates on the ball screw shaft 12 , And the saddle (14).

At this time, as the servo motor rotates, heat is generated in the ball screw shaft 12, the bearing 15, and the respective members, and thermal displacement may be generated.

Particularly, since the thermal displacement generated in the ball screw shaft 12 changes the transfer distance of the saddle 14 moved along the ball screw shaft 12, there is a problem that the machining precision for the workpiece is lowered.

That is, when the origin position (a) of the ball screw shaft 12 is changed to the variable origin position (a 'or a' ') on the heat side, the processing accuracy is lowered.

In order to solve such a problem, a measuring device for measuring the temperature of the feed axis as shown in Fig. 2 has been developed and used.

However, since the conventional displacement sensor for measuring the position of the saddle 14 measures the position of the saddle 14, the thermal displacement of the ball screw shaft 12 can not be directly measured, .

In addition, since the position sensor 16 is provided on the bearing bracket 17 to which a high heat source is transmitted from the bearing 15, thermal displacement is generated in the measurement position itself and the thermal displacement measurement accuracy .

SUMMARY OF THE INVENTION The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a method and apparatus for measuring a displacement of a ball screw according to heat generation of a machine tool by using a position sensor, And to provide a device for measuring the displacement of a conveying shaft of a machine.

Another object of the present invention is to provide a device for measuring the displacement of a conveying shaft of a machine tool capable of improving the measurement accuracy of a thermal displacement amount by providing a position sensor at a position independent of a heat source.

The objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, A driving motor installed in the bed, for generating a rotational power by forward rotation and reverse rotation; A ball screw shaft having one end connected to a rotation axis of the driving motor and receiving a rotational power; A ball screw nut inserted into the ball screw shaft and reciprocating in the longitudinal direction of the ball screw shaft as the ball screw shaft rotates; A saddle connected to the ball screw nut and moved together with the ball screw nut; And a position sensor installed on the bed or the saddle and provided at a position corresponding to one end of the ball screw shaft to generate a voltage value according to a distance between the ball screw shaft and one end of the ball screw shaft, Wherein one end of the screw shaft is provided with a diameter of one end and a diameter of the other end of the screw shaft different from each other.

In a preferred embodiment, one end of the ball screw shaft is tapered.

In a preferred embodiment, the other end of the ball screw shaft is formed in a shape corresponding to one end of the ball screw shaft, the position sensor has a position corresponding to one end of the ball screw shaft and a position corresponding to the other end of the ball screw shaft Respectively, and are provided in a pair.

In a preferred embodiment, a first support bearing supporting a rotational axis load of the drive motor; And a second support bearing installed on the bed and connected to the other end of the ball screw shaft to support a load of the ball screw shaft.

In a preferred embodiment, the drive motor is a servo motor.

The present invention also provides a spindle for machining a workpiece; A measuring device for measuring the displacement of the conveying shaft of the machine tool; And a NC (Numerical Control) device for controlling the spindle and the driving motor, wherein the feed axis thermal sensor is electrically connected to the NC device, and the deviation of the sensed voltage from the position sensor is transmitted to the NC device Wherein the real-time feedback is provided to the machine tool device.

The present invention has the following excellent effects.

First, according to the apparatus for measuring a displacement of a conveying shaft of a machine tool of the present invention, it is possible to perform reliable correction by directly measuring the amount of displacement of a ball screw due to heat generation of a machine tool using a position sensor .

Further, according to the apparatus for measuring the thermal displacement of the conveying shaft of the machine tool of the present invention, it is possible to improve the measurement accuracy of the thermal displacement amount by providing the position sensor at a position independent of the heat source.

1 is a view showing a transfer system of a conventional machine tool.
2 is a view showing a conventional conveying-shaft thermal-variable measuring apparatus.
FIG. 3 is a view showing an apparatus for measuring a transport axis thermal displacement of a machine tool according to an embodiment of the present invention.
FIG. 4 is an enlarged view of a thermal displacement measuring unit of the feed axis thermal displacement measuring apparatus of the machine tool according to the embodiment of the present invention. FIG.
5 is a view showing an apparatus for measuring a feed axis thermal displacement of a machine tool according to another embodiment of the present invention.
FIG. 6 is a view showing the principle of measurement of thermal displacement using a measurement apparatus for measuring a displacement of a feed axis of a machine tool according to the present invention.

Although the terms used in the present invention have been selected as general terms that are widely used at present, there are some terms selected arbitrarily by the applicant in a specific case. In this case, the meaning described or used in the detailed description part of the invention The meaning must be grasped.

Hereinafter, the technical structure of the present invention will be described in detail with reference to preferred embodiments shown in the accompanying drawings.

However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Like reference numerals designate like elements throughout the specification.

FIG. 3 and FIG. 4 are views showing a device for measuring a displacement of a transport axis of a machine tool according to the present invention.

Referring to FIGS. 3 and 4, the device for measuring the displacement of the feed axis of a machine tool according to an embodiment of the present invention includes a device for directly measuring a displacement amount of the ball screw shaft 130 according to heat generation of the machine tool And includes a bed 110, a driving motor 120, a ball screw shaft 130, a ball screw nut 140, a saddle 150, and a position sensor 160.

The bed 110 is a support for supporting the respective members 110, 120, 130, 140, 150 and 160.

Such a bed 110 is easy to generate vibration and bending due to the rotating cutting force of the spindle, the weight of the spindle, and the like, and therefore, a material having sufficient strength is used.

The driving motor 120 is mounted on the bed 110 and is a motor that generates forward and reverse rotation by generating rotation power.

Also, the driving motor 120 may be used as a servo motor.

One end (131) of the ball screw shaft (130) is connected to the rotation axis of the driving motor (110) to receive rotational power.

4, one end 131 of the ball screw shaft 130 is different in diameter from one end 131a to the other end 131b.

For example, one end 131 of the ball screw shaft 130 may have a turbulent shape.

This is to allow one end 131 of the ball screw shaft 130 to function as a barometer for measuring the thermal displacement of the ball screw shaft 130. A more detailed description of the principle of the thermal displacement measurement will be given later .

The ball screw nut 140 is inserted into the ball screw shaft 130 and is reciprocated in the longitudinal direction of the ball screw shaft 130 as the ball screw shaft 130 is rotated.

The saddle 150 is connected to the ball screw nut 140 and reciprocally moved together with the ball screw nut 140.

That is, since the ball screw shaft 130 is rotated by the rotational power generated from the driving motor 120 and the ball screw nut 140 is reciprocated on the ball screw shaft 130, So that the work piece provided on the saddle 150 fixed to the nut 140 is transported.

The position sensor 160 is a sensor for measuring a displacement amount of the ball screw shaft 130 and is installed in the bed 110.

The position sensor 160 is installed at a position corresponding to one end 131 of the ball screw shaft 130.

Also, the position sensor 160 may be mounted through the bracket 161.

5, the position sensor 160 may be installed at one side of the saddle 150 corresponding to the one end 131 of the ball screw shaft 130. As shown in FIG.

That is, the position sensor 160 is installed in the independent bed 110 or the saddle 140 independent of the heat source generated by the rotation of the driving motor 120, thereby improving the measurement accuracy of the amount of thermal displacement, Thereby enabling a high correction to be performed.

In addition, the apparatus for measuring the displacement of the feed axis of the machine tool according to the present invention may further include a first support bearing 171 and a second support bearing 172.

Here, the first support bearing 171 is a bearing for supporting a rotational axis load of the drive motor 120.

The second support bearing 172 is mounted on the bed and is connected to the other end 132 of the ball screw shaft 130 to support the load of the ball screw shaft 130.

 Hereinafter, with reference to FIG. 6, the principle of measurement of the apparatus for measuring the temperature of the feed axis of a machine tool according to the present invention will be described in more detail.

When the ball screw shaft 130 is thermally displaced by the heat source, the ball screw shaft 130 to be fed to the axis feed origin L by the feed command is moved to the variable origin position L1 or L2.

At this time, the position sensor 160 can detect a voltage difference between the distance to the axis feed origin L and the difference (D1 or D2) between the distance from the variable origin position (L1 or L2) Thereby enabling reliable correction of the thermal displacement of the screw shaft 130 to be performed.

That is, when thermal displacement occurs in the ball screw shaft 130, the position sensor 160 senses a voltage value according to a distance change with respect to the one end 131 of the ball screw shaft 130, The amount of displacement (elongation amount or shrinkage amount) of the ball screw shaft 130 can be precisely measured.

The other end 132 of the ball screw shaft 130 has a shape corresponding to one end 131 of the ball screw shaft 130 and the position sensor 160 has a shape corresponding to that of the ball screw shaft 130. And may be further provided at a position corresponding to the other end 132.

 This is because the position sensor 160 is provided in pairs at positions corresponding to both ends 131 and 132 of the ball screw shaft 130 to thereby measure the displacement amount of the ball screw shaft 130 more accurately I will.

In addition, the apparatus for measuring the displacement of the factory axis according to the present invention may be provided as a single machine tool device together with a spindle for machining a workpiece and an NC (Numerical Control) device for controlling the drive motor 120 have.

Here, the position sensor 130 is electrically connected to the NC device, and real-time position correction of the ball screw shaft 130 is enabled by real-time feedback of the sensed voltage deviation to the NC device.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, Various changes and modifications will be possible.

110: bed 120: drive motor
130: Ball screw shaft 131: One end of the ball screw shaft
132: the other end of the ball screw shaft 140: the ball screw nut
150: Saddle 160: Position sensor
171: first support bearing 172: second support bearing
L: Axis feed origin position L1, L2: Variable origin position

Claims (6)

Bed;
A driving motor installed in the bed, for generating a rotational power by forward rotation and reverse rotation;
A ball screw shaft having one end connected to a rotation axis of the driving motor and receiving a rotational power;
A ball screw nut inserted into the ball screw shaft and reciprocating in the longitudinal direction of the ball screw shaft as the ball screw shaft rotates;
A saddle connected to the ball screw nut and moved together with the ball screw nut; And
And a position sensor mounted on the bed or the saddle and provided at a position corresponding to one end of the ball screw shaft to generate a voltage value according to a distance between the ball screw shaft and one end of the ball screw shaft,
Wherein one end of the ball screw shaft has a different diameter at one end and a different diameter at the other end.
The method according to claim 1,
Wherein one end of the ball screw shaft is tapered.
3. The method of claim 2,
Wherein the other end of the ball screw shaft is formed in a shape corresponding to one end of the ball screw shaft,
Wherein the position sensor is installed at a position corresponding to one end of the ball screw shaft and at a position corresponding to the other end of the ball screw shaft, and is provided as a pair.
The method of claim 3,
A first support bearing for supporting a rotational axis load of the drive motor; And
And a second support bearing installed on the bed and connected to the other end of the ball screw shaft to support a load of the ball screw shaft.
The method according to claim 1,
Wherein the drive motor is a servo motor.
A spindle for machining a workpiece;
An apparatus for measuring a displacement of a feed shaft of a machine tool according to any one of claims 1 to 5; And
And an NC (Numerical Control) device for controlling the spindle and the driving motor,
Wherein the feed axis thermal impedance measuring device is electrically connected to the NC device and real-time feeds back the deviation of the sensed voltage from the position sensor to the NC device.
KR1020160007073A 2016-01-20 2016-01-20 Device of compensating thermal displacement for a machine tool KR20170087285A (en)

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KR1020160007073A KR20170087285A (en) 2016-01-20 2016-01-20 Device of compensating thermal displacement for a machine tool

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Application Number Priority Date Filing Date Title
KR1020160007073A KR20170087285A (en) 2016-01-20 2016-01-20 Device of compensating thermal displacement for a machine tool

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111230570A (en) * 2018-11-29 2020-06-05 广州义同机械实业有限公司 Method for compensating heat temperature rise of numerical control machine tool

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111230570A (en) * 2018-11-29 2020-06-05 广州义同机械实业有限公司 Method for compensating heat temperature rise of numerical control machine tool

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