KR101603138B1 - Lapping device of screw for ball screw - Google Patents

Abstract

A screw lapping apparatus for a screw of a ball screw according to the present invention comprises a control unit installed at one side of a lathe and controlling a chuck to rotate alternately in forward and reverse rotations; A lapping unit installed at one side of the lathe and lapping a spiral groove formed on an outer circumferential surface of a screw for a ball screw fixed to the chuck; And a transfer unit for forcing the two-dimensional movement of the wrapping unit.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a ball screw,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a lapping apparatus for a screw for a ball screw, which wraps a screw groove of a screw, which is a constitution of a ball screw for converting rotational / linear motion into linear / rotational motion.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a lapping apparatus for a screw for a ball screw, which provides a repulsive force to a lapping material when the lapping material and a spiral groove are brought into contact with each other to improve the lapping performance.

The present invention provides a unit for moving a lapping material precisely two-dimensionally, and further includes a unit movable body for applying a predetermined pressure when a lapping material and a spiral groove make contact with each other, To a lapping apparatus for a screw.

BACKGROUND ART A ball screw is a mechanical component in which a screw in which a spiral groove is formed on an outer peripheral surface and a nut in which a spiral groove is formed in an inner peripheral surface are operated by the rolling motion of a ball, And one of the nuts and the nuts is fixed, and the other one is configured to convert the rotational motion into a linear motion upon rotation.

Therefore, ball screws are widely applied to feeding mechanisms of numerical control machine tools, aircraft control devices or other precision machinery and equipment.

The ball screw has a semicircular cross section formed by the inner circumferential surface of the nut and the outer circumferential surface of the screw. The semicircular cross section forms a circular cross section when the shaft is inserted into the nut, thereby forming a helical path.

A ball is inserted into the spiral passage formed by the combination of the nut and the screw, and the ball rolls and circulates along the passage, so that the nut or screw can reduce friction during rotation .

In order to minimize frictional force when the ball between the nut and the screw is circulated, the spiral groove formed in the nut and the screw is mirror-finished by lapping.

Among them, conventionally, regarding the lapping process of the screw according to the present invention, the inner circumferential surface of the helical groove is surface-modified by electrolytic polishing so that the helical groove can have a mirror surface.

If the manufacturer does not have such an electrolytic polishing apparatus, the screw is rotated by a chuck of a lathe, and then the user directly applies a tensile force to the spiral groove of the screw around the wrapping material (e.g., sandpaper) Thereby processing the surface of the helical groove.

However, the spiral groove of the screw to be wrapped has the following problems.

That is, there is a problem that the surface of the screw is irregularly machined because it is manually wrapped by the user.

In addition, since there is a limit to the force that can be applied to the screw due to the force of a person, there is a problem that workability is deteriorated and productivity is lowered.

In addition, when the lapping material is dried on the screw due to the carelessness of the operator, safety accidents are caused, which is not preferable.

In order to solve this problem, Korean Patent No. 0775969 discloses a method for automatically lapping a screw by alternately controlling the rotation direction of the chuck by forward / reverse rotation while selectively applying a tensile force to the wrapping material surrounded by the spiral groove of the screw A screw apparatus for screwing a ball screw is disclosed.

However, the device exerts a tensile force on the lapping material by stretching the length of the tensioning cylinder, thereby causing a frictional force between the lapping groove and the lapping material. And the rotation power of the rotary motor and the interference between the spiral groove and the lapping material force the conveyance of the lapping unit.

That is, since the lapping unit moves along the spiral groove as it is attracted by the interference without moving independently during transportation, there is a limitation in processing the high-precision spiral groove.

In addition, since the pressure applied to the spiral groove is not kept constant due to uneven movement of the wrapping unit, the spiral groove is irregularly shaped and the defect rate is increased.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a lapping apparatus for a screw for a ball screw, which provides a repulsive force to the lapping material when the lapping material contacts the spiral groove, .

The present invention provides a unit for moving a lapping material precisely two-dimensionally, and further includes a unit movable body for applying a predetermined pressure when a lapping material and a spiral groove make contact with each other, And to provide a lapping apparatus for a screw.

A screw lapping apparatus for a screw of a ball screw according to the present invention comprises a control unit installed at one side of a lathe and controlling a chuck to rotate alternately in forward and reverse rotations; A lapping unit installed at one side of the lathe and lapping a spiral groove formed on an outer circumferential surface of a screw for a ball screw fixed to the chuck; And a transfer unit for forcing the two-dimensional movement of the wrapping unit.

The wrapping unit includes a unit body for supporting a plurality of parts, a feeder for feeding and supplying the wrapping material wound on one side of the unit body, a cooler for supplying a cooling fluid to one side of the wrapping material, A unit movable body that linearly reciprocates within a predetermined range with respect to the body to adjust a contact position between the lapping material and the screw, a repulsive force that increases the pressure between the lapping material and the screw by generating a repulsive force when the lapping material contacts the screw, And a group.

The rebounder may be freely rotatable at a predetermined position of the unit movable body.

The rebounder is partially formed of an elastic member, and a portion in contact with the lapping material has a curvature corresponding to the spiral groove.

Wherein the rebounder generates a repulsive force in a direction parallel to a direction in which the restoring force of the lapping material acts when the lapping unit and the ball screw contact each other.

And the unit movable body is configured to be adjustable in angle with respect to the unit body.

The conveying unit may include a first conveying unit for forcing a linear reciprocating motion of the unit body at one side of the shelf and a second conveying unit for forcing a linear reciprocating motion of the unit body at one side of the first conveying unit .

The first conveyor and the second conveyor convey the unit bodies in directions perpendicular to each other.

And the unit movable body is inclined with respect to the unit body.

And the unit movable body moves in a linear direction different from a linear reciprocating motion direction of the first conveyor and the second conveyor.

In the screw lapping apparatus for a ball screw according to the present invention, the lapping material and the spiral groove act to provide a repulsive force to the lapping material upon contact.

Therefore, it is possible to increase the frictional force between the lapping material and the spiral groove, thereby improving the lapping performance.

In addition, the present invention further includes a unit movable body having a transfer unit for transferring the lapping material precisely two-dimensionally, such that the lapping material and the spiral groove make a constant pressure when contacting.

Therefore, there is an advantage that the helical groove can be lapped more precisely.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a use state showing a state where a lapping apparatus for a screw for a ball screw according to the present invention is installed on a shelf;
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a screw for a ball screw,
3 is an enlarged right-side perspective view of a lapping apparatus for a screw for a ball screw according to the present invention.
4 is an enlarged top plan view showing a lapping apparatus for a screw for a ball screw according to the present invention;
5 is a cross-sectional view for explaining the operation of the unit movable body, which is a component of the lapping apparatus for a screw for a ball screw according to the present invention.
FIG. 6 is a side longitudinal sectional view showing an operation state of a screw lapping apparatus in a screw lapping apparatus for a ball screw according to the present invention. FIG.
7 is a cross-sectional view for explaining the action of the rebounder, which is a component in the lapping apparatus for a screw for a ball screw according to the present invention.

Hereinafter, the configuration of a screw lapping apparatus for a ball screw according to the present invention will be described with reference to FIG.

FIG. 1 is a state diagram showing a state where a lapping apparatus for a screw for a ball screw according to the present invention is installed on a shelf M;

Prior to this, terms and words used in the present specification and claims should not be construed in a conventional and dictionary sense, and the inventor may appropriately define the concept of the term in order to describe its invention in the best possible way It should be construed as meaning and concept consistent with the technical idea of the present invention.

Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely preferred embodiments of the present invention, and are not intended to represent all of the technical ideas of the present invention. Therefore, various equivalents It should be understood that water and variations may be present.

As shown in the figure, the lapping apparatus is provided on the shelf M for smoothly lapping the inner circumferential surface of the helical groove S 'formed on the outer circumferential surface of the screw S, The chuck C rotates alternately in the forward and reverse directions while the lapping device contacts the spiral groove S 'and the wrapping material L Wrap.

That is, the lapping apparatus includes a control unit (not shown) for controlling the chuck to rotate alternately in forward and reverse rotations, a screw (not shown) provided on the upper surface of the central portion of the lathe M, A wrapping unit 100 for lapping the spiral groove S 'of the wrapping unit 100 and a transfer unit 200 for forcing the two-dimensional movement of the wrapping unit 100.

The control unit simultaneously controls not only the rotational speed and direction of the chuck C but also the operation of the transfer unit 200 so that the wrapping unit 100 can move linearly at the same speed at the time of screw S rotation.

For example, when the pitch of the helical groove S 'is 1 cm, the wrapping unit 100 is also controlled to move linearly by 1 cm when the screw S makes one rotation. Of course, when the rotation direction of the screw S is reversed, the linear movement direction of the wrapping unit 100 is switched to the opposite direction.

The detailed configuration of the wrapping unit 100 and the transfer unit 200 will be described with reference to FIGS. 2 to 4 attached hereto.

FIG. 2 is a left side perspective view showing an enlarged view of a lapping apparatus for a screw for a ball screw according to the present invention, and FIG. 3 is a right side perspective view showing an enlarged view of a lapping apparatus for a screw for a ball screw according to the present invention And FIG. 4 is a top perspective view showing an enlarged view of a screw lapping apparatus for a ball screw according to the present invention.

First, the transfer unit 200 is positioned below the wrapping unit 100 to force the wrapping unit 100 to move two-dimensionally.

That is, the conveying unit 200 includes a first conveyor 220 that reciprocates linearly in the longitudinal direction of the lathe M on the upper surface of the lathe M, And a second conveyor 240 for linearly reciprocating the lapping unit 100 in a direction perpendicular to the first conveyor 220.

Therefore, the lapping unit 100 can be transported at any position on the two-dimensional plane by the interaction of the first conveyor 220 and the second conveyor 240. [

The first conveyor 220 and the second conveyor 240 are configured to include a timing belt, a sprocket, an LM guide, a rail, and the like so as to transfer the lapping unit 100 more precisely.

A wrapping unit 100 is provided on the upper side of the transfer unit 200. The lapping unit 100 is fixed on the upper side of the second conveyor 240 and is capable of linear reciprocating movement in the longitudinal direction of the screw S by the operation of the first conveyor 220, It is possible to approach the screw S by the operation of the machine 240. [

A detailed configuration of the lapping unit 100 will be described.

The wrapping unit 100 includes a unit body 110 coupled to the second conveyor 240 and supporting a plurality of parts and a feeder for feeding the wrapping material L wound on one side of the unit body 110 A cooler 130 for supplying a cooling fluid to one side of the lapping material L and a lapping material 130 for moving in a linear reciprocating motion within a predetermined range with respect to the unit body 110 in front of the unit body 110, A unit moving body 140 for adjusting the contact position between the lapping material L and the screw S when the lapping material L and the screw S contact each other, And a repulsor 150 for increasing the contact pressure of the first and second electrodes.

The unit body 110 serves as a frame of the wrapping unit 100 in a configuration for supporting the feeder 120, the cooler 130, the unit movable body 140 and the repulsive device 150 described above.

The first conveyor 220 and the second conveyor 240 are also substantially movable.

A feeder 120 is provided in front of the unit body 110 (as viewed in FIG. 2). The feeder 120 includes a storage roller 122 storing a wrapping material L and a plurality of guide rollers 124 guiding a feeding direction of the wrapping material L stored in the storage roller 122. [ And a winding roller 126 for winding a lapping material L that has been subjected to a lapping operation while passing through a guide roller 124. [

It is needless to say that the position of the winding roller 126 and the storage roller 122 may be changed as necessary to enable the recycling of the wrapping material L and the role of the wrapping material 126 in accordance with the feeding direction of the wrapping material L.

The lapping material L has a frictional force and a durable material to directly contact the helical groove S 'to lap the helical groove S', and has a band shape having a narrow width as shown in the figure.

Therefore, the contact area becomes uneven when the spiral groove S 'is inserted into the state as shown in the drawing. In order to solve this problem, the rebounder 150 is provided.

The rebounder 150 is fixed to the front surface of the unit moving body 140 (as viewed in FIG. 2) so as to be freely rotatable and the outer side is formed of an elastic member so as to generate repulsive force by an externally applied force .

The detailed configuration and operation of the rebounder 150 will be described in detail below.

A plurality of motors are provided inside the unit body 110 to force rotation of the take-up roller 126 and the storage roller 122 and to communicate with the cooler 130 to supply the cooling fluid.

A unit movable body 140 is provided on the right side of the unit body 110. The unit movable body 140 is coupled to the unit body 110 but can selectively adjust the angle with respect to the unit body 110 and the helical groove S ' The unit movable body 140 is also inclined with respect to the unit body 110. Therefore,

Therefore, the feeder 120 fixed to the unit body 110 maintains a tilted state at a certain angle as shown in FIG. 4, and can move within a predetermined range in the direction of the arrow.

This is for the purpose of correcting the case where the lapping material L and the spiral groove S 'are not correctly positioned when they are brought into contact with each other by the operation of the second conveyor 240.

The unit movable body 140 can move with a small force in the arrow direction of FIG. 4, and can move only in the forward / backward direction by the operation of the second conveyor 240.

Therefore, when the lapping material L and the helical groove S 'are in contact with each other, a uniform force is provided, so that the friction force hardly changes.

A rebounder 150 is provided between the plurality of guide rollers 124. The rebounder 150 facilitates the contact between the lapping material L and the helical groove S 'when the lapping material L is inserted into the helical groove S' to perform the lapping, So that evenly lapping of the helical groove S 'is possible.

Therefore, the rebounder 150 is disposed to be inclined at a predetermined angle with respect to the longitudinal direction of the screw S so as to have the same angle as the forming angle of the helical groove S ' And pushes the lapping material L in the direction of the helical groove S '.

The rebounder 150 is configured such that its outer surface corresponds to the curvature of the spiral groove S ', and its outer side is made of an elastic material. This is to allow the wrapping material L to evenly contact the entire surface of the spiral groove S '.

Hereinafter, a process of lapping the spiral groove S 'of the screw S using the lapping apparatus will be described with reference to FIGS. 1 to 7 attached hereto.

FIG. 5 is a cross-sectional view for explaining the operation of the unit moving body 140, which is an embodiment of the screw wrapping apparatus for a ball screw according to the present invention, and FIG. 6 is a cross- And FIG. 7 is a cross-sectional view for explaining the operation of the rebounder 150, which is a component of the lapping apparatus for a screw of a ball screw according to the present invention, Respectively.

1, a screw S is installed on a chuck C of a shelf M and a wrapping material L is installed on a feeder 120. As shown in FIG.

The rotation speed of the chuck C and the feed speed of the first conveyor 220 are set in consideration of the pitch of the screw S. [

Thereafter, the second conveyor 240 is operated and the state shown in FIG. 6 is obtained. That is, the wrapping material L wrapped around the outer surfaces of the pair of guide rollers 124 is seated and brought into contact with the spiral groove S 'of the screw S, The outer surface of the rebounder 150 pushes the left surface of the lapping material L to the right.

Therefore, the rebounder 150 and the helical groove S 'are spaced apart from each other by the thickness of the lapping material L to generate a repulsive force in a direction parallel to the direction of the restoring force of the lapping material L do.

5, if the position of the lapping material L and the spiral groove S 'is not correct when the second conveyor 240 moves forward, the unit movable body 140 moves in the direction of arrow And the lapping material L can be smoothly inserted as if it surrounds the spiral groove S 'by the movement of the unit movable body 140. [

When the second conveyor 240 is further moved forward, the rebounder 150 is accommodated in the spiral groove S 'as shown in FIG. 7, so that a pressure is applied to the spiral groove S' The lapping efficiency of the groove S 'can be maximized.

When the chuck C rotates in this state, the screw S rotates in conjunction with the rotation of the chuck C, and the first conveyor 220 operates in conjunction with the pitch of the helical groove S ' The linear motion can be forced.

At this time, the cooler 130 supplies the cooling fluid to the contact portion between the lapping material L where the large frictional heat is generated and the spiral groove S '. When the rotation direction of the chuck C is reversed, The operation direction of the first conveyor 220 is also reversed.

The scope of the present invention is not limited to the above-described embodiments, and many modifications may be made by those skilled in the art based on the present invention.

100. Wrapping unit 110. Unit body
120. Feeder 122. Storage Roller
124. Guide roller 126. Wound roller
130. Cooler 140. Unit operating body
150. Rebound unit 200. Transfer unit
220. First conveying unit 240. Second conveying unit
C. Chuck L. Lapping material
M. Shelf S. Screw
S '. Spiral groove

Claims (10)

delete delete A control unit installed at one side of the lathe and controlling the chuck to alternately rotate forward and backward; A lapping unit installed at one side of the lathe and lapping a spiral groove formed on an outer circumferential surface of a screw for a ball screw fixed to the chuck; And a conveying unit for forcing the two-dimensional movement of the lapping unit, the lapping apparatus comprising:
The wrapping unit may include:
A unit body for supporting a plurality of parts,
A feeder for feeding and supplying a strip-shaped wrapping material wound on one side of the unit body;
A cooler for supplying a cooling fluid to one side of the lapping material,
A unit movable body that linearly reciprocates within a predetermined range in a state where the unit body is tilted with respect to the unit body at one side of the unit body to adjust a contact position between the lapping material and the screw,
And a rebounder which is formed of an elastic member and freely rotates at a predetermined position of the unit movable body and generates a repulsive force when the lapping material and the screw contact each other to increase the contact pressure between the lapping material and the screw,
Wherein the feeder and the rebounder are adjustable at an angle corresponding to a forming angle of the spiral groove by rotating the unit movable body relative to the unit body.
[5] The apparatus of claim 3, wherein the rebounder is partially formed of an elastic member, and a portion in contact with the lapping material has a curvature corresponding to the spiral groove.
The apparatus of claim 4, wherein the rebounder generates a repulsive force in a direction parallel to a direction in which a restoring force of the lapping material acts when the lapping unit and the ball screw contact each other.
delete 6. The apparatus according to claim 5,
A first conveyor for forcing a linear reciprocating motion of the unit body at one side of the shelf,
And a second conveyor for urging the linear reciprocating motion of the unit body at one side of the first conveying unit.
The apparatus of claim 7, wherein the first conveyor and the second conveyor convey unit bodies in directions perpendicular to each other.
delete The apparatus according to claim 8, wherein the unit movable body moves in a linear direction different from a linear reciprocating motion direction of the first conveyor and the second conveyor.

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