JP2001205503A - Main spring moving device for main spindle movable type automatic lathe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a main spindle moving device for a main spindle movable type automatic lathe capable of correctly moving a main spindle by moving only a quill main spindle as a part of the main spindle without requiring a large space. SOLUTION: This main spindle moving device for a main spindle movable type automatic lathe to be used in the main spindle movable type automatic lathe comprising a guide main spindle 23 disposed to be axially immovable to a column 2, and the quill main spindle 8 inserted into the guide main spindle 23 in composed of a cylindrical stator 72 coaxially enclosing a spline shaft 29 that is provided to be axially immovable in relation to the guide main spindle 23 and is axially movable to the guide main spindle 23 of the quill main spindle 8, and a rotor 73 coaxially fixed with the spline shaft 29 in the cylindrical stator 72 so as to face a linear motor coil 75 of the cylindrical stator 72.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a spindle moving device for a spindle moving type automatic lathe, and more particularly to a spindle moving device for a spindle moving / indexing type automatic lathe.

[0002]

2. Description of the Related Art A conventional spindle moving type automatic lathe has a structure in which a headstock is fed in an axial direction of a spindle. In order to move the headstock, a ball screw-nut mechanism and an electric motor for rotating the ball screw are used. In this structure, since the headstock is heavy, a motor having a high output must be used, and the ball screw-nut mechanism must be large. For this reason, even when the ball screw-nut mechanism and the electric motor are installed parallel to the main shaft,
Even when these are installed coaxially with the main shaft at the rear part of the main shaft, not only the ball screw-nut mechanism and the electric motor require a large space but also increase the manufacturing cost of the automatic lathe. In addition, since the headstock must be moved, more space is required.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to move a quill main shaft which is a part of a main shaft without using a large space, and to precisely move the main shaft so that the main shaft can be moved accurately. It is to provide a device.

[0004]

SUMMARY OF THE INVENTION According to the present invention, there is provided a spindle moving device for a spindle moving type automatic lathe, comprising: a column; a guide spindle which is immovably provided in the column in the axial direction; and a spline which is spline-engaged with the guide spindle. In the spindle moving type automatic lathe including a quill spindle inserted movably in the axial direction to the guide spindle, and a moving device for moving the quill spindle in the axial direction of the guide spindle with respect to the guide spindle, The moving device includes a cylindrical rotor fixed coaxially to the spline shaft, a cylindrical stator that surrounds the spline shaft coaxially with the spline shaft, and is held immovably with respect to the guide main shaft; , And a cylindrical linear motor having a cylindrical rotor fixed coaxially to the spline shaft.

[0005] The stator includes a linear coil, and the rotor includes a plurality of annular magnets on the outer peripheral surface such that positive and negative electrodes are alternately arranged in the axial direction. Further, a guide member made of a non-magnetic material having a cylindrical peripheral surface on which the outer peripheral surface of the magnet slides on the inner peripheral surface of the stator can be formed.

[0006] The guide member may be formed of a cylindrical non-magnetic tube. Alternatively, the guide may be made of a ceramic body sprayed on the inner surface of the stator.

The spindle moving device for a spindle moving type automatic lathe is desirably used for a spindle moving / indexing type multi-axis automatic lathe.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an embodiment of a spindle moving device for a spindle moving / indexing type multi-axis automatic lathe (hereinafter, simply referred to as "automatic lathe") of the present invention will be described below. The form will be described.

FIG. 1 is a longitudinal section of a front half of a spindle to which the first and second embodiments are applied, and FIG. 2 is a spindle to which the linear motors of the first and second embodiments are attached. 3 is an enlarged longitudinal sectional view around a collet chuck, FIG. 4 is a longitudinal sectional view of a first embodiment of the linear motor of the present invention, and FIG. 5 is a longitudinal sectional view of the first embodiment of the present invention. FIG. 6 is a longitudinal sectional view of a main part of the first embodiment of the linear motor, and FIG. 6 is a longitudinal sectional view of a main part of the second embodiment of the linear motor of the present invention.

As shown in FIGS. 1 and 2, a spindle indexing drum 1 is rotatable in a column 2 of an automatic lathe via a front ball bearing 3 (FIG. 1) and a rear flat bearing 4 (FIG. 2). And is fixed in the axial direction. A drum indexing motor 7 (FIG. 2) is provided between the spindle indexing drum 1 and the column 2. The drum indexing motor 7 is of a build-in type in which the stator section 5 is fixed to the column 2 and the rotor section 6 is fixed to the spindle indexing drum 1. The spindle indexing drum 1 is rotated at a predetermined angle in a predetermined circumferential direction. Figure out.

A plurality (for example, four) of substantially cylindrical main shaft rotary motor housings 22 are inserted and fixed in the drum 1 at equal intervals in the circumferential direction thereof in parallel with the shaft.
The main shaft 21 is coaxially inserted into the main shaft rotating motor housing 22. Each spindle 21 includes a guide spindle 23 and a quill spindle 8 provided therein, as described later. A spindle motor 28 is installed in each spindle motor housing 22, and its stator 2
The rotor 6 and the rotor 27 are fixed to the main shaft rotating motor housing 22 and the guide main shaft 23, respectively. Therefore, the main shafts 21 are arranged in the drum 1 in parallel with the shaft and at equal intervals in the circumferential direction of the drum 1.

Next, the main shaft 21 will be described. The guide spindle 23 of the spindle 21 is substantially cylindrical and is inserted into the spindle rotary motor housing 22. The guide spindle 23 is supported at its front and rear ends by a ball bearing 24 (FIG. 1) and a ball bearing 25 (FIG. 2) so as to be rotatable on the main shaft rotary motor housing 22 and immovable in its axial direction. Have been.

As shown in FIG. 2, the quill main shaft 8 of the main shaft 21 includes a cylindrical spline shaft 29 and a draw tube 3.
5. Spiral disc spring 37, collet chuck sleeve 3
8, a collet chuck 40, a compression coil spring 43, and a nut 44. The spline shaft 29 is coaxially inserted into the guide main shaft 23. A plurality of male splines 31 are formed on the outer peripheral surface of the spline shaft 29. The male spline 31 extends from substantially the center of the spline shaft 29 by at least the length corresponding to the maximum movement length (stroke length) of the main shaft 21. Reference numeral 33 denotes a female spline member. A female spline 32 that engages with the male spline 31 is formed on the inner peripheral surface, and is connected to the rear end of the guide spindle 23. Therefore, the spline shaft 29 is connected to the guide spindle 2
3 can reciprocate in the axial direction, and the guide spindle 23
And can rotate about its axis.

As shown in FIG. 3, a cylindrical hole 34 is formed in the front end of the spline shaft 29. A draw tube 35 (also shown in FIGS. 1 and 2) is inserted into the spline shaft 29 so as to be coaxial and slidable in the axial direction. The front end of the draw tube 35 is an expanded portion 36 inserted into the cylindrical hole 34 of the spline shaft 29. A spiral disc spring (first biasing means) 37 is installed in the cylindrical hole 34 of the spline shaft 29 and presses the rear end of the enlarged diameter portion 36 and the inner end wall of the cylindrical hole 34. The bulged portion 36 is constantly elastically urged forward together with the draw tube 35 by the spiral disc spring (urging means) 37.

The collet chuck sleeve 38 has a cylindrical shape with a bottom and is disposed in the cylindrical hole 34 of the spline shaft 29 in front of the expanded portion 36 of the draw tube 35. The front end of the collet chuck sleeve 38 has a spline shaft 29.
And a frusto-conical inner peripheral surface 39 is formed at the front end of the front end portion so as to increase its diameter toward the front. A collet chuck 40 is provided in the collet chuck sleeve 38. The collet chuck 40 has a head portion 42 having a front end portion formed with an outer peripheral surface 41 having a truncated cone shape facing forward, which is complementary to the inner peripheral surface 39 of the collet chuck sleeve 38.
, And the rear portion is cylindrical.

The compression coil spring (other urging means) 43 provided between the collet chuck 40 and the inner end wall of the collet chuck sleeve 38 is formed to have a lower urging force than the spiral disc spring 37, and Chuck 40,
At all times, the collet chuck sleeve 38 is elastically biased forward. Conversely, the collet chuck 40 constantly elastically urges the collet chuck sleeve 38 rearward by the compression coil spring 43. The nut 44 is fixed to the front end of the spline shaft 29 and surrounds the nut engaging part 42 a of the head part 42 of the collet chuck 40.

Referring to FIG. 3, when the draw tube 35 is at an advanced position where it is not operated by a draw tube retraction device described later, the draw tube 35 is pushed forward by the urging force of the spiral disc spring 37, and the draw tube 35 is expanded. The diameter portion 36 pushes the collet chuck sleeve 38 forward against the urging force of the compression coil spring 43. Then, the frustoconical inner peripheral surface 39 at the front end of the collet chuck sleeve 38 is fitted to the frustoconical outer surface 41 of the head portion 42 of the collet chuck 40.
Is pressed to reduce the inner diameter of the head portion 42 and cause the head portion 42 to grip the rod 45 penetrating therethrough. This state is a state where the bar 45 is clamped by the collet chuck 40.

On the other hand, when the draw tube 35 is retracted by the draw tube retracting device, the draw tube 35
The enlarged diameter portion 36 of FIG. At the same time, the collet chuck sleeve 38 is retracted by the urging force of the compression coil spring 43 with the rear end of the collet chuck sleeve 38 pressed against the front end of the draw tube 35. For this reason, the inner peripheral surface 39 of the collet chuck sleeve 38 has a truncated cone shape.
0 away from the outer peripheral surface 41 of the truncated cone. Therefore, the inner peripheral surface of the head portion 42 of the collet chuck 40 is
Move away from In this state, the collet chuck 40 is the bar 4
5 is in an unclamped state.

As shown in FIG. 2, a linear motor housing 46 is coaxially fixed to the spindle indexing drum 1 from the rear end of the spindle motor housing 22. This linear motor housing 46 has a cylindrical linear motor 47 to be described later.
Is inserted and fixed.

As shown in FIG. 1, a guide bush housing receiver 51 is fixed to a front end face of the spindle indexing drum 1 at a flange portion thereof. This flange portion also serves as an inner ring bearing of the ball bearing 3. The guide bush housing 5 is coaxial with the main shaft 21 in the guide bush housing receiver 51.
2, and is fixed to the guide bush housing receiver 51 by a fixing bolt 53 at a flange portion thereof.

The guide bush sleeve 54 is installed coaxially with the main shaft 21 in front of the guide bush housing 52, and is fixed by a fixing bolt 55 at a flange 54 a of the guide bush sleeve 54.
It is fixed to. The inner peripheral surface 54b at the front end of the guide bush sleeve 54 has a truncated conical surface whose diameter increases toward the front.

The guide bush 56 is provided in the guide bush sleeve 54 so as to be able to reciprocate in the axial direction with respect thereto and to be coaxial with the main shaft 21. Guide bush 56
Frusto-conical outer peripheral surface 56 increasing in diameter at the front end of
a is formed. The outer peripheral surface 56a has a shape complementary to the inner peripheral surface 54b of the guide bush sleeve 54 in the shape of a truncated cone, and can be engaged with the inner peripheral surface 54b. An annular connecting portion 57 is connected to the rear end of the guide bush 56, and a flange portion 57 a at the rear end is fixed to the guide bush housing 52 by a fixing bolt 58. Fixing bolt 58 between bolt head 58a at the rear end of fixing bolt 58 and flange 57a of connecting portion 57
The compression coil spring 59 is wound around the portion
7, the guide bush 56 is constantly urged in a forward direction away from the guide bush sleeve 54.

A piezoelectric actuator 60 is provided between the flange 54a of the guide bush sleeve 54 and the flange 57a of the connecting portion 57 at a position opposite to the fixing bolt 58 with respect to the axis of the main shaft 21. This uses a piezo element whose length changes according to the applied voltage. As the length of the piezoelectric actuator 60 is increased by applying an appropriate voltage, the guide bush 56 is pulled backward through the connecting portion 57. For this reason, the outer peripheral surface 56 a of the guide bush 56 strongly presses the inner peripheral surface 54 b of the guide bush sleeve 54 to reduce the inner diameter of the guide bush 56. In this way, the distance between the inner peripheral surface 61 of the guide bush 56 and the outer peripheral surface 62 of the rod 45 inserted into the inner peripheral surface 61 is adjusted, or the inner peripheral surface of the guide bush 56 is Outer peripheral surface 6 of material 45
2, the rod 45 can be gripped by the guide bush 56. Processing such as cutting can be performed on the bar 45 by a tool 63 such as a cutting tool immediately before the guide bush 56.

Referring to FIGS. 4 and 5, a spindle moving device (spindle moving means) of the present invention for reciprocating the spindle 21 in the axial direction will be described. This spindle moving device comprises a cylindrical linear motor 47. As shown in FIG. 5, the cylindrical linear motor 47 includes a cylindrical stator 72 and a cylindrical rotor 73. The rotor 73 goes straight and does not rotate itself, but will be referred to as a "rotor" according to ordinary technical terms.

The cylindrical stator 72 has a comb-shaped yoke 74 having a cylindrical longitudinal section as a whole, and a space 74 between the comb teeth.
a, and is inserted and fixed in the linear motor housing 46.

A cylindrical piston cylinder 76 and a cylindrical piston 77 are fixed to the rear end of the spline shaft 29 and the rear spline shaft 29 via ball bearings 78 and 79, respectively. Linear motor coil 75
Is substantially fixed to the outer peripheral surface of the piston cylinder 76 and the piston 77 at the inner peripheral surface at the front end thereof.

The rotor 73 has an annular magnet 81 (FIG. 5) fixed in order on the outer peripheral surface of the front end of the rotor sleeve 80 such that the positive and negative poles face the linear motor coil 75 in order. . This rotor 73 is
The excitation of the linear motor coil 75 causes the spline shaft 2
The linear motor coil 75 moves in a predetermined direction at a predetermined speed together with the draw tube 9 and the draw tube 35 within a range of the length S.

A guide tube 82 made of non-magnetic material such as SUS and having wear resistance and corrosion resistance is inserted and fixed to the inner peripheral surface of the cylindrical stator 72. The inner diameter of the guide tube 82 is
3, that is, the outer surface of the magnet 81 has an inner diameter that allows sliding without resistance. Therefore, when the rotor 73 moves in the axial direction, the guide tube 82 slides and guides the rotor 73 to accurately guide the rotor 73. In addition, guide tube 8
2 protects the stator 72, especially the linear motor coil 75, from its deterioration.

FIG. 6 is a longitudinal sectional view of a main part of a second embodiment of the spindle moving device for a spindle moving type automatic lathe according to the present invention.
The difference from the first embodiment shown in FIG. 5 is that in the first embodiment, instead of using the guide tube 82, ceramic such as white alumina is sprayed on the inner peripheral surface of the stator 72 so that the inner peripheral surface becomes second. In one embodiment, the ceramic tube 83 is formed substantially equal to the outer diameter of the outer peripheral surface of the rotor sleeve 80, which is the same as the inner periphery of the guide tube 82. The ceramic material is not only welded to the inner peripheral surface of the stator 72 but also
Since the ceramic tube 83 enters the gap between the two comb teeth and is welded here, the entire two surfaces of the ceramic tube 83 are tightly fixed to the stator 72. The other configuration is the same as that of the first embodiment, and the main parts and elements are denoted by the same reference numerals as those of the first embodiment, and the description thereof is omitted. The guide tube 82 of the first embodiment and the ceramic tube 83 of the second embodiment
Are collectively referred to as guide members.

Next, in the above-described two embodiments, the rotor 73 is moved forward or backward at a desired speed by appropriately exciting the linear motor coil 75 of the linear motor 47 according to a command from a control device (not shown). . Thereby, the quill main shaft 8 is also moved forward or backward at the same speed. The forward and backward positions of the rotor 73 and the quill main shaft 8 are determined by a differential displacement sensor (not shown) using a differential transformer or the like.
And the detection signal is sent to the control device to control the linear motor 47 so that the quill main shaft 8 moves to a predetermined forward position (for example, a bar processing end position) and a predetermined retreat position (for example, a bar feed start position). Position). The quill spindle 8 moves forward and backward by being guided by the guide spindle 23, so that the spindle does not move together with the heavy headstock unlike a conventional spindle-moving automatic lathe, so that the spindle is moved with a light weight. There is an advantage that can be. Further, no space is required for moving the headstock.

It is conceivable to use a flat type linear motor as the spindle moving device. However, in this type of linear motor, the main shaft must first be provided with a rigid support portion in order to apply a force to pull the main shaft in a direction perpendicular to the main shaft. The coil requires a large stator to obtain a driving force in the axial direction on the main shaft required to be formed on the flat surface of the stator. In addition, there is a problem that cooling becomes complicated and dust and oil proof are not easy.

On the other hand, in a cylindrical linear motor,
Because the magnetic attraction force perpendicular to the main shaft is offset, the main shaft support for that purpose is not necessary, or even if it is provided, it is a cylindrical structure that does not require a very high rigidity. There is an advantage that a sufficient driving force can be obtained. Therefore, here, a cylindrical linear motor is employed.

The spindle moving device for an automatic lathe according to the present invention can be used as follows. First, at the bar feed start position, the bar 45 is gripped by the collet chuck 40 and the guide bush 56 is moved to the bar 45 with or without applying an appropriate voltage to the piezoelectric actuator 60.
Release from Thereafter, the main shaft rotating motor 28 is rotated. Next, the linear motor 47 is operated to operate the quill spindle 8.
Is advanced with the bar 45. The quill main shaft 8 is a bar 45
When the machining end position of the tool 63 is reached, the rotation of the spindle rotating electric motor 28 is stopped, an appropriate voltage is applied to the piezoelectric actuator 60 to expand it, and the guide bush 56 grips the rod 45, and FIG. Pressurized oil is introduced from a hydraulic supply / discharge pipe 85 into a hydraulic chamber 84 between the piston cylinder 76 and the piston 77 as shown, and the piston cylinder 76 is retracted to move the collet chuck 40 through the draw tube 35 to the rod 45. Release from After a while
By operating the linear motor 47, the rotor 73 together with the quill main shaft 8 is retracted to the machining start position. Next, the bar 45
When the machining feed is required, the hydraulic oil is discharged from the hydraulic chamber 84, the piston 77 is advanced, the collet chuck 40 grips the rod 45, and the above steps are repeated.

As described above, the spindle moving device of the present invention can
Although the description has been given of the example in which the present invention is applied to an indexing type multi-axis automatic lathe, the present invention can be applied to a spindle moving single-axis automatic lathe and a spindle moving / non-indexing multi-axis automatic lathe.

[0035]

The spindle moving device for an automatic lathe according to the present invention is constituted by a cylindrical linear motor, which moves the quill spindle in the axial direction to move the spindle. A cylindrical linear motor can be used, and there is an effect that the main shaft can be moved with small power. Further, since the cylindrical linear motor is installed coaxially with the quill main shaft, there is also an effect that the main shaft can be moved efficiently and accurately without applying a force to the quill main shaft almost in the lateral direction. Further, by using the cylindrical linear motor, the volume occupied by the cylindrical linear motor can be reduced, and there is also an effect that the main spindle moving type automatic lathe can be downsized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a first half of an example of a main spindle moving / indexing type automatic lathe including a first half of a main spindle used in first and second embodiments of a main spindle moving apparatus for a main spindle moving automatic lathe. FIG.

2 shows the second half of the spindle of FIG. 1 and the second half of the spindle moving / indexing type automatic lathe of FIG. 1 including the spindle moving device of the first embodiment of the spindle moving type automatic lathe of the present invention; It is a longitudinal cross-sectional view of a main part.

FIG. 3 is a longitudinal sectional view of a main part of a main shaft of FIGS. 1 and 2;

FIG. 4 is a longitudinal sectional view of a first embodiment of a spindle moving device for a spindle moving type automatic lathe according to the present invention.

FIG. 5 is an enlarged vertical sectional view of a main part of FIG.

FIG. 6 is a longitudinal sectional view of a main part of a second embodiment of a spindle moving type automatic spindle lathe according to the present invention.

[Explanation of symbols]

 2 Column 8 Quill main shaft 23 Guide main shaft 29 Spline shaft 47 Cylindrical linear motor 72 Cylindrical stator 73 Rotor 74a Spacing between comb teeth 75 Linear motor coil 81 Magnet 82 Guide tube 83 Ceramic tube

Continuing on the front page (72) Inventor Hiroshi Terai 1-1-1 Higashizao, Nagaoka-shi, Niigata Prefecture F-term (reference) at Tsugami Machinery Division, Nagaoka Factory 3C045 FA04 FD01 FD03 FD05 FD08 5H641 BB06 BB14 BB19 GG02 GG04 GG07 HH03 HH05 HH08 HH09 JA02 JA09 JA19

Claims (6)

[Claims] A column; a guide spindle which is provided on the column so as to be immovable in an axial direction;
A quill main shaft that includes the guide main shaft and a spline shaft that is spline-engaged, and is movably inserted in the guide main shaft in an axial direction; and a movement that moves the quill main shaft relative to the guide main shaft in the axial direction of the guide main shaft. A spindle moving type automatic lathe comprising: a cylindrical stator which is coaxially surrounded by the spline shaft and is held immovably with respect to the guide main shaft; A spindle moving device for a spindle moving type automatic lathe, comprising a cylindrical linear motor having a cylindrical rotor inserted into the stator and fixed coaxially to the spline shaft. 2. The apparatus according to claim 1, wherein the stator includes a linear coil, and the rotor includes a plurality of annular magnets on the outer peripheral surface such that positive and negative electrodes are alternately arranged in the axial direction. Spindle moving device for a spindle moving type automatic lathe. 3. The main shaft according to claim 2, wherein a guide member made of a nonmagnetic material having a cylindrical peripheral surface on which the outer peripheral surface of the magnet slides is formed on the inner peripheral surface of the stator. Spindle moving device for mobile automatic lathe. 4. A spindle moving device for a spindle moving type automatic lathe according to claim 3, wherein said guide member is a cylindrical guide tube made of a non-magnetic material. 5. The apparatus according to claim 3, wherein said guide member is a ceramic tube sprayed on an inner surface of said stator.
4. The spindle moving device for a spindle moving type automatic lathe according to 4. 6. A spindle moving type automatic lathe according to claim 1, wherein said spindle moving type automatic lathe is a spindle moving / indexing type multi-axis automatic lathe. apparatus.