JP2010105066A - Headstock of cam grooving machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple, compact, and highly rigid headstock of a cam grooving machine capable of performing highly accurate machining without scratch lines. <P>SOLUTION: This headstock 10 of a cam grooving machine 20 used for machining by rotating a work W and using a rotary tool attached to a tool post 18 includes a tubular body 1 which is fixed to a bed 11 and disposed laterally toward the bed 11, a spindle 2 rotatably inserted into a body 1, tapered parts 2a, 2b having the tapered surfaces which are formed at both ends of the spindle 2 and increased in diameter from both ends toward the center, and bearing parts 3, 4 which are fixed to the body 1, have the tapered surfaces adaptable to the tapered parts 2a, 2b, and support the spindle 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a headstock for a cam groove machine.

Rolling bearings (bearings) have been used for the spindles of the headstock of conventional NC lathes. Rolling bearings have been developed in response to the need for high-speed rotation by developing various lubrication methods such as grease lubrication and oil-air lubrication. In addition, the rolling bearing has no problem in the processing accuracy of a general workpiece for turning, and has been frequently used because of needs such as cost and maintenance. However, at the level that requires ultra-high precision machining in the nano-region where the surface roughness is within 0.1μ, in rolling bearings, contact is made via rolling elements (mainly balls), so the bearing geometric error ( There was a problem that the influence of the swell) appeared on the cut surface as a catch and lowered the appearance. Furthermore, there is a problem that the performance of the product may be lowered.
Therefore, in particular, a non-contact bearing is adopted for the spindle of an ultra-precise NC lathe that requires machining accuracy by ultra-high precision rotational motion. There is a hydrostatic bearing as a non-contact bearing, and it is known that this geometric error (swell) is averaged to intervene air or oil fluid, and the influence is reduced (for example, see Patent Document 1). ).

  However, the hydrostatic bearing has a problem that the rigidity (thrust, radial) of the bearing is low. Furthermore, with hydrostatic bearings, high rigidity (thrust, radial) of the bearing can be secured. However, when oil is supplied, much cost and management are required for oil management by an oil cooling device or an oil supply device. There was a problem.

Japanese Patent Laid-Open No. 2001-219302 (FIG. 1)

  Therefore, the present invention has been made in view of these problems, and is simple, compact, and high without using dedicated equipment for managing oil such as oil cooling and oil supply devices required for hydrostatic bearings. It is an object of the present invention to provide a headstock for a cam groove processing machine that is rigid and can realize high-precision machining without any stitches.

  The invention according to claim 1 is a headstock (10) of a cam groove processing machine (20) that rotates a work (W) and performs processing with a rotary tool provided on a tool post (18), A cylindrical body (1) fixed to (11) and arranged in the left-right direction toward the bed (11), a main shaft (2) rotatably inserted in the body (1), and the main shaft ( 2), taper portions (2a, 2b) having taper surfaces that are formed in diameters from the end portions toward the center, and fixed to the body (1), and the taper portions (2a, 2b). And a bearing portion (3, 4) for supporting the main shaft (2).

  The invention according to claim 2 is the headstock (10) of the cam groove processing machine (20) according to claim 1, wherein molybdenum is thermally sprayed on the tapered surface of the bearing portion (3, 4), and The lubricating oil supply holes (3b, 4b) are arranged in the bearing portions (3, 4).

  According to the first aspect of the present invention, a cylindrical body fixed to the bed and arranged in the left-right direction, a main shaft rotatably inserted in the body, and formed at both end portions of the main shaft, from the end portion Hydrostatic bearing specifications with a tapered part with a taper surface expanded toward the center and a bearing part that is fixed to the body and has a tapered surface that fits the tapered part and supports the spindle Without using special equipment, it is possible to provide a headstock for a cam groove processing machine that is simple, compact, highly rigid, and capable of realizing high-accuracy machining without striking.

  According to the invention according to claim 2, by spraying molybdenum on the taper surface of the bearing portion and arranging the lubrication hole in the bearing portion, it is simple without using dedicated equipment for hydrostatic bearing specifications, It is possible to provide a headstock for a cam groove processing machine that is compact and has high rigidity and can realize high-accuracy machining without any difficulty.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view of the head stock of the present invention, and FIG. 2 is a right side view of FIG. FIG. 3A is a front view showing a cam groove processing machine equipped with a headstock, and FIG. 3B is a right side view.
The coordinate system of the machine tool is defined in JIS B6310. Regarding the horizontal lathe, the axis (left and right) direction of the main shaft of the headstock is defined as the Z axis, the front and rear direction perpendicular to the Z axis is defined as the X axis, and the vertical direction perpendicular to the Z axis and the X axis is defined as the Y axis. The rotation around the Z axis is defined as the C axis.

The overall arrangement of the cam groove processing machine 20 will be described.
As shown in FIG. 3A, on the upper surface of the bed 11, the headstock 10 is disposed on the left side, and an upright standing cross slide 17 is disposed on the right side. The vertical cross slide 17 has a three-axis configuration that can move in three directions, that is, a left-right (Z-axis) direction, a front-rear (X-axis) direction, and a vertical (Y-axis) direction with respect to the main shaft 2 of the headstock 10. Yes. A rotary tool 18 for machining the outer cam groove and a rotary tool 19 for machining the inner cam groove are arranged in front of the vertical cross slide 17.
Specifically, the bed 11 is formed in a rectangular shape, a base 11a is fixed to the upper left portion of the bed 11, and the headstock 10 is placed on the base 11a.
As shown in FIG. 3B, a Z-axis slide guide 11b for guiding the saddle 13 in the left-right (Z-axis) direction is provided on the upper portion of the bed 11, and a ball screw (not shown) and a ball screw A Z-axis moving mechanism 12 comprising a nut screwed in and a servo motor that rotationally drives the ball screw is disposed.
A saddle 13 is slidably mounted on the upper surface of the Z-axis slide guide 11b, and an X for guiding an L-shaped slide base (not shown) in the front-rear (X-axis) direction on the upper surface of the saddle 13. A sliding guide for the shaft is provided. Further, an X-axis moving mechanism 14 including a ball screw, a nut, and a servo motor 14c is disposed on the upper surface of the saddle 13. An L-shaped slide base (not shown) is slidably mounted on the upper surface of the X-axis slide guide.

  A Y-axis slide guide that guides the vertical cross slide 17 in the vertical direction is provided on the upright front surface of the L-shaped slide base. A Y-axis moving mechanism (not shown) including a ball screw, a nut, and a servo motor is disposed on the front surface of the L-shaped slide base via a pulley and a toothed belt. A vertical cross slide 17 is slidably brought into contact with the front surface of the Y-axis slide guide.

  The head stock 10 of the present invention will be described in detail. As shown in FIG. 1, the head stock 10 includes a rotatable main shaft 2, and the main shaft 2 is supported at both ends by a bearing portion 3, 4 on a body 1 which is a main body of the head stock 10, and the bearing portions 3, 4. In between, a built-in servo motor 5 is mounted. That is, the headstock 10 includes a body 1 that is a main body of the headstock 10, a main shaft 2 that is inserted and supported through a hole in the body 1, taper portions 2a and 2b formed at both ends of the main shaft 2, It is mainly composed of bearing portions 3 and 4 that rotatably support the tapered portions 2a and 2b, and a built-in servo motor 5 that rotationally drives the main shaft 2.

<Body>
As shown in FIG. 2, the body 1 is a main body of the headstock 10. The body 1 has a symmetrical structure. In the body 1, a flange portion 1 f (see FIG. 2) extending from the lower surface of the body 1 is fixed to a base 11 a placed on a bed 11 (see FIG. 3) by bolts 10 b, 10 b. A pin 10p is attached to one end of the lower surface of the body 1. The pin 10p serves as a fulcrum for rotation in the centering adjustment in the axis (Z-axis) direction.
As shown in FIG. 1, the body 1 is formed in a cylindrical shape, and in the left and right axial directions, a hole 1c is formed in the right end surface 1a, and a large hole 1d is formed in the left end surface 1b. In addition, screw holes 1e and 1e communicating with an oil passage for circulating cooling oil are provided in the upper portion, and piping joints for supply and discharge are mounted.

<Spindle>
The main shaft 2 is a shaft that is rotated by a rotational drive of a built-in servo motor 5 described later. As shown in FIG. 1, the main shaft 2 is inserted into the body 1, and tapered portions 2 a and 2 b having tapered surfaces whose diameters are increased from the end portions toward the center are formed at both ends of the main shaft 2. . That is, the right taper portion 2a and the left taper portion 2b are formed at both ends of the main shaft 2. The taper angle θ of the right taper portion 2a and the left taper portion 2b is 60 degrees which is the same here.
The taper angle θ may be 90 degrees or any other angle.
Further, a through hole 2d is formed in the main shaft 2, and coolant water is supplied to the cutting edge of the tool being cut by a coolant water supply device (not shown) to cool and discharge chips in the chuck member 10c. A chuck member 10 c that holds the workpiece W is attached to the right end portion of the main shaft 2.

<Bearing part>
The bearing portions 3 and 4 are bearings that are fixed to the body 1, have tapered surfaces that match the tapered portions 2 a and 2 b of the main shaft 2, and rotatably support the main shaft 2.
As shown in FIG. 1, the right bearing portion 3 is fixed to the right end surface 1a of the body 1 via a spacer 3c, and is fitted into the hole 1c. The right taper portion 2a of the main shaft 2 has the same taper angle θ. Tapered surfaces are matched. The right bearing portion 3 rotatably supports the right taper portion 2a.
Molybdenum is sprayed on the tapered surface of the right bearing portion 3, and the lubricating oil supply hole 3 b is disposed in the right bearing portion 3. The clearance between the tapered surfaces is preferably 1 to 3 μm.

The left bearing portion 4 is fixed to a position of the hole 8a of the end cover 8 that closes the large hole 1d of the left end surface 1b of the body 1 through the spacer 4c. The left bearing portion 4 is fitted to the left taper portion 2b of the main shaft 2 with the same taper degree θ, and rotatably supports the left taper portion 2b.
Molybdenum is sprayed on the tapered surface of the left bearing portion 4 in the same manner as described above, and the lubricating oil hole 4b is disposed in the left bearing portion 4. The clearance between the tapered surfaces is preferably 1 to 3 μm.

<Built-in servo motor>
Unlike the spindle motor, the built-in servo motor 5 is a servo motor. The rotor 5a of the built-in servo motor 5 is attached to the central portion of the outer periphery of the main shaft 2, and is fixed to the flange portion 2c with bolts. Further, stators 5b and 5b are disposed on the inner peripheral surface of the body 1 in accordance with the position of the rotor 5a.
Further, on the left side of the support 9 and the ring 6, an encoder for detecting a rotation angle and a rotation speed including a sensor head 7a for detecting the rotation position of the main shaft 2a and a detection ring 7b is arranged.
A ring 6 is fixed to the left end of the main shaft 2, and a detection ring 7 b is fixed to the ring 6 with a plurality of bolts. A sensor head 7a is disposed at a position close to the detection ring 7b. The sensor head 7 a is fixed to the end surface of the support 9 fixed to the end surface of the end cover 8.

  The head stock 10 is provided with a C-axis built-in servo motor 5 and an encoder for detecting C-axis rotation on the main shaft 2, thereby enabling high-precision composite processing required for cam groove processing. That is, since the headstock 10 can perform more accurate rotation and synchronous rotation, it is possible to perform complex machining with a rotary tool by a coordinated movement of three axes. In addition, the present invention can provide the headstock 10 of the cam groove processing machine 20 that is simple, compact, highly rigid, and capable of realizing high-precision machining.

Here, the operation of the head stock 10 will be described. Once a rotation command is issued to the headstock 10, as shown in FIG. 1, the built-in servo motor 5 drives the rotor 5a to rotate, and drives the main shaft 2 integrated with the rotor 5a to rotate. At that time, the lubricating oil is supplied from the lubricating oil supply holes 3a and 4a to the right tapered portion 2a and the left tapered portion 2b of the main shaft 2 by a lubricating device (not shown), so the right tapered portion 2a and the left tapered portion 2b of the main shaft 2 are provided. The taper surfaces of the right bearing portion 3 and the left bearing portion 4 of the bearing are completely separated by an oil film, resulting in fluid lubrication and no wear. Molybdenum having a low friction coefficient is adopted for the tapered surfaces of the right bearing portion 3 and the left bearing portion 4 of the slide bearing.
A radial load that is a force perpendicular to the axis of the main shaft 2 is received by the tapered surface of the right bearing portion 3 and the tapered surface of the left bearing portion 4. Further, the thrust force pressing from the right to the left in the axial direction is received by the tapered surface of the left bearing portion 4. Further, since the thrust force that is pulled from the left to the right in the axial direction is received by the tapered surface of the right bearing portion 3, there is rigidity against the force from all directions.
In the case of cam groove machining, the main shaft 2 is about 60 revolutions per minute and is rotated at a low speed, so there is no thermal expansion of the main shaft 2. Therefore, a sufficient gap of 1 to 3 μ can be secured.

  The present invention can be modified and changed in various ways within the scope of the technical idea. In the present invention, the head stock of the cam groove processing machine is used. However, for example, a head stock of a lathe or a head stock of a grinding machine may be used.

It is a front view which shows the cam groove processing machine which concerns on this invention. It is a right view of the cam groove processing machine which concerns on this invention. (A) is a front view which shows the cam groove processing machine carrying a headstock, (b) is a right view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Body 1a Right end surface 1b Left end surface 1c Hole 1d Large hole 1e Screw hole 1f Flange part 2 Main shaft 2a Right taper part 2b Left taper part 2c Flange part 2d Through-hole 3 Right bearing part 3a Taper part 3b, 4b Lubricating oil supply hole 3c Spacer 4 Left bearing portion 4a Taper portion 4c Spacer 5 Built-in servo motor 5a Rotor 5b Stator 6 Ring 7 Encoder 7a Head sensor 7b Detection ring 8 End cover 8a Hole 9 Support 10 Main shaft base 10b Bolt 10c Chuck member 10p Pin 11 Bed 11a Base 11b Z Sliding guide 12 Z-axis moving mechanism 13 Saddle 14 X-axis moving mechanism 15 L-shaped slide base 15a Y-axis sliding guide 16 Y-axis moving mechanism 17 Vertical cross slide 18 X-axis rotating tool for outer groove machining 19 X for inner groove machining Axis rotation Tool 20 cam groove machine

Claims (2)

A spindle stock (10) of an optical cam processing machine (20) that rotates a workpiece (W) and performs processing with a rotary tool provided on a tool rest (18),
A cylindrical body (1) fixed to the bed (11) and arranged in the left-right direction toward the bed (11);
A main shaft (2) rotatably inserted in the body (1);
Tapered portions (2a, 2b) having tapered surfaces formed at both ends of the main shaft (2) and having a diameter increased from the both ends toward the center;
Bearing parts (3, 4) fixed to the body (1) and having tapered surfaces adapted to the tapered parts (2a, 2b) and supporting the main shaft (2);
A headstock (10) of a cam groove processing machine (20), comprising: 2. The taper surface of the bearing part (3, 4) is thermally sprayed with molybdenum, and the lubricating oil hole (3b, 4b) is disposed in the bearing part (3, 4). The headstock (10) of the described cam groove processing machine (20).

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