JP2007301647A - Precision roll lathe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To highly precisely machine not only a vertical groove in the peripheral direction on the outer peripheral surface of a roll but also a lateral groove in the longitudinal direction. <P>SOLUTION: A precision roll lathe is equipped with a bed 10, a headstock 12 which is installed on the bed 10, rotates a workpiece while holding one end of a roll shaped workpiece with a chuck, and has an indexing axis (C axis) for indexing the workpiece in the circumferential direction, a tailstock 14 which is disposed on the bed 10 opposed to the spindle base 12 and rotatably supports the one end of the workpiece, a saddle 26 which is installed on the bed so as to move the longitudinal direction (Z axis) of the workpiece, a table 28 which is installed on the saddle 26 so as to move to the direction (X axis) perpendicular to the longitudinal direction of the workpiece, and a tool swivel slide 30 which is installed on the table and has a tool rest 33 having a plurality of tools 41 to be mounted. The tool swivel slide 30 is equipped with a spindle 34 for rotating the tool rest 33 itself with high speed, and an indexing axis (B axis) for indexing the tool of the tool rest 33. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a precision lathe for grooving a roll, and in particular, a precision roll lathe capable of machining a groove in the axial direction with high precision as well as machining a circumferential groove on the outer periphery of the roll. About.

  Machine tools that process rolls include roll grinders and roll lathes. The roll grinding machine includes a spindle stock, a tailstock, and a carriage, and a grinding wheel is provided on the carriage.

  Conventionally, in a roll grinding machine, a groove is machined on the outer circumferential surface in addition to grinding the outer circumferential surface of the roll with a grindstone. Patent Document 1 describes a roll grinding machine in which a groove processing device having a cutting saw blade for cutting a groove is provided on a carriage.

  A roll lathe is a lathe in which a tool post with a diamond tool is installed on a carriage. The basic usage is to process the circumferential groove while rotating the roll on the headstock and feeding the carriage back and forth (X axis). When machining the groove in the axial direction, the groove can be created in the axial direction by moving the carriage in the left-right direction (Z-axis) at high speed while indexing the roll on the headstock (C-axis).

  In recent years, with the advancement of control technology, ultra-precision machining with a lathe has been realized. As a result, a mold for molding an optical lens can be processed even on a lathe. For example, the present applicant has proposed a vertical lathe capable of processing a mold for forming a Fresnel lens (Patent Document 2). This vertical lathe can process the V-shaped lens groove of the Fresnel lens molding die with high accuracy.

  By the way, with the widespread use of liquid crystal display devices, the demand for lens sheets used for backlights of liquid crystal panels is increasing. In addition to the Fresnel lens described above, this type of lens sheet includes a lenticular lens sheet, a cross lenticular lens sheet, and a prism sheet.

Recently, it has been studied to form a lenticular lens sheet, a cross lenticular lens sheet, and a prism sheet using a roll-shaped mold with an extruder.
JP 2003-94239 A JP 2004-358624 A

  However, when these lens sheet molding dies are processed by a roll lathe, it is necessary to precisely process circumferential grooves (vertical grooves) and longitudinal grooves (lateral grooves) on the outer peripheral surface of the roll. However, there are the following problems.

  In the longitudinal groove processing, as described above, while turning the roll at high speed on the headstock, the diamond bite is sent in the radial direction to turn the groove, so it is good under the necessary and sufficient cutting speed by the high-speed rotation of the roll. A smooth surface can be obtained.

  However, when processing a lateral groove, there is a problem that a sufficient cutting speed cannot be obtained because the spindle is fed in the longitudinal direction after the roll is indexed by the spindle. In other words, the ideal cutting speed is about 300 m / min for a roll made of copper or nickel plating, whereas the moving speed is about 10 m / min even for a high-speed carriage. . Even if the carriage is moved as fast as possible, the cutting speed is not sufficient to obtain a high-precision machining surface, and an ultra-precision machining surface required for a mold for molding a lens sheet can be obtained. could not.

  Accordingly, an object of the present invention is to solve the problems of the prior art, and not only to process circumferential longitudinal grooves on the outer peripheral surface of the roll with high precision, but also to process longitudinal grooves with high precision. It is to provide a precision roll lathe that can be used.

  In order to achieve the above-mentioned object, the present invention provides a bed and a roll-shaped workpiece which is placed on the bed and holds the end of the workpiece while holding the chuck, while rotating the workpiece in the circumferential direction. A headstock having an indexing shaft (C-axis) for performing indexing; a tailstock arranged on the bed so as to face the headstock and rotatably supporting one end of the work; and a longitudinal direction of the work A saddle installed on the bed so as to be movable (Z axis), a table installed on the saddle so as to be movable in a direction (X axis) perpendicular to the longitudinal direction of the workpiece, and installed on the table A tool swivel having a tool rest to which a plurality of cutting tools are attached, the tool swivel comprising a spindle for rotating the tool rest itself at a high speed, and an indexing shaft for indexing the tool of the tool rest (B Axis) And it is characterized in Rukoto.

  According to the present invention, the tool swivel includes the spindle and the B-axis for indexing the tool, so that the tool can be used in its original way or as a substitute for the fly cutter spindle mechanism. Thereby, not only the vertical groove (circumferential groove) can be cut on the roll-shaped workpiece, but also the horizontal groove (axial groove) can be processed with high accuracy.

  In addition, when machining a lateral groove with a machine that uses a rolling guide to guide the carriage, the Z-axis feed of the carriage can be completed at a relatively low speed, so heat generation at the Z-axis rolling guide surface can be suppressed, As a result, it is possible to prevent a reduction in processing accuracy due to thermal deformation of the bed or saddle while utilizing the motion performance by the rolling guide.

Hereinafter, an embodiment of a precision roll lathe according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a side view of a precision roll lathe according to the present invention, and FIG. 2 is a plan view of the precision roll lathe.
1 and 2, reference numeral 10 indicates a bed. On the bed 10, a spindle stock 12, a tailstock 14, and a carriage 16 are arranged. The workpiece is a roll-shaped workpiece W and is rotatably supported by the headstock 12 and the tailstock 14.

  The headstock 12 is disposed at one end of the bed 10 in the longitudinal direction. The headstock 12 includes a main body portion 17, a main shaft 18, a chuck 19 attached to the tip of the main shaft 18, and a servo motor 20 that drives the main shaft 18. The main shaft 18 is supported by a hydrostatic bearing (not shown) built in the main body portion 17. The chuck 19 grips the axis of the workpiece W and transmits the rotation of the main shaft 18 to the workpiece. In the headstock 12, the servo motor 20 drives the main shaft 18 in order to rotate the workpiece W at a high speed. In addition, the encoder 22 detects the amount of rotation of the servo motor 20 and controls the amount of rotation of the servo motor 20, whereby an indexing shaft for indexing the workpiece W in the circumferential direction ( A function as a C axis) is added. The bearing of the headstock 12 may be an air bearing or a bearing bearing in addition to the hydrostatic bearing.

  Next, the tailstock 14 is disposed on the bed 10 so as to face the headstock 12. A guide surface (not shown) is provided on the upper surface of the bed 10, and the tailstock 14 is movably installed. The tailstock 14 rotatably supports the axis of the workpiece W at the center 25. In the tailstock 14, the tailstock to which the center 25 is attached is supported by a bearing. In this embodiment, the work W is supported by the headstock 12 and the tailstock 14, but instead of the tailstock 14, a support mechanism including a bearing and a chuck without a motor may be used. Good.

Next, the carriage 16 will be described.
The carriage 16 includes a saddle 26 installed on the bed 10 so as to be movable in the axial direction of the workpiece W. A table 28 is installed on the saddle 26 so as to be movable in a direction perpendicular to the axial direction of the workpiece W. In the precision roll lathe according to this embodiment, the axis for feeding the saddle 26 is the Z axis, and the axis for feeding the table 28 on the saddle 26 is the X axis. In this precision roll lathe, in addition to the X-axis and Z-axis, the spindle table 12 is provided with the C-axis, and the cutter swivel table 30 provided on the table 28 is provided with the B-axis. It is a machine.

  FIG. 3 shows the cutter swivel 30. FIG. 4 is a view showing the blade swivel 30 with the covers removed from the bed 10 and the saddle 26. The blade swivel 30 according to the present embodiment includes a swivel base body 31.

  A main shaft 34 is provided inside the swivel base body 31. The main shaft 34 is rotatably supported by a thrust bush 35 and a radial bush 36. In this embodiment, the thrust bush 35 and the radial bush 36 constitute an aerostatic bearing that supports the thrust load and radial load of the main shaft 34 by air pressure, respectively. An oil hydrostatic bearing may be used instead of the air hydrostatic bearing. A top plate 32 is connected to the main shaft 34, and a tool post 33 to which a plurality of cutting tools are attached is attached on the top plate 32.

A drive shaft 37 is coaxially attached to the top plate 32. A rotor 38 a of a servo motor 38 is fixed to the drive shaft 37, whereby a built-in type servo motor 38 is incorporated in the swivel base body 31 together with the stator 38 b. When the drive shaft 37 is rotationally driven by the servo motor 38, the tool post 33 is rotated together with the top plate 32. In this embodiment, a B-axis for indexing an arbitrary tool attached to the tool rest 33 is configured by position control performed by feeding back the rotation amount of the servo motor 38 by the encoder 39. In addition to configuring the B-axis that is an indexing shaft under the control of the servomotor 38, the servomotor 38 can also rotate the main shaft 34 at high speed.
A tool holder 40 is arranged on the outer peripheral portion of the tool post 33 at a predetermined interval in the circumferential direction, and a diamond tool 41 is detachably attached to the tool holder 40. In this embodiment, a maximum of four diamond cutting tools 41 can be determined by turning the tool post 33 together with the top plate 32 every 90 degrees. However, the present invention is not limited to this.

Since the tool post 33 is directly driven by the servo motor 38 together with the main shaft 34 and rotates at a high speed, the tool post 33 is equivalent to the fly cutter spindle mechanism by attaching only one diamond cutting tool 41 to the tool post 33. Can be used. In this case, the diamond turning tool 41 turns at high speed in the XZ plane. As shown in FIG. 4, the blade turning table 30 configured as described above has a V-shaped protrusion on the upper surface of the saddle 26. The X-axis guide 40 extends, and a rolling guide surface in which a large number of rollers 41 held by a retainer are arranged is formed on the X-axis guide surface 40. Similarly, the saddle 26 of the carriage 16 is guided by the Z-axis guide 42 on the upper surface of the bed 10. This Z-axis guide 42 is also a rolling guide surface on which rollers 43 are arranged.

Both the Z-axis feed driving device that feeds the saddle 26 and the X-axis feed driving device that sends the table 28 on which the blade swivel 30 is mounted are composed of linear motors. Reference numeral 44 indicates a permanent magnet array constituting the linear motor of the X-axis feed mechanism, and 45 indicates a permanent magnet array extending in parallel with the Z-axis guide surface 42.
The precision roll lathe according to the present embodiment is configured as described above. Next, its operation and effect will be described.
First, the function of the cutter swivel 30 mounted on the carriage 16 of the precision roll lathe of this embodiment will be described.

  In the tool swivel 30, since the main shaft 34 has both the original function of the main shaft and the B-axis indexing shaft, the original use of the tool post 33 and the use as a fly cutter spindle mechanism are properly used and combined. Can be processed.

  Therefore, by using properly as described below, not only the vertical grooves (circumferential grooves) can be cut with respect to the workpiece W, but also the horizontal grooves (axial grooves) can be processed with high accuracy.

First, the process which cuts a vertical groove in the workpiece | work W is demonstrated.
The processing of the longitudinal groove is the same as that of a normal roll lathe. That is, the cutting tool to be used among the diamond cutting tools 41 of the tool post 33 is indexed by the B axis. Further, the workpiece W is rotated by the servo motor 20 of the head stock 12. Then, the table 28 can be fed in the X-axis direction, cut into the workpiece W with the diamond cutting tool 41, and the longitudinal groove can be turned.

  As shown in FIG. 5, for example, when processing a roll used for a mold for forming a lenticular lens, each time one vertical groove 50 is cut, the cutting tool 41 is moved in the Z-axis direction by the groove width. Cut the longitudinal groove while feeding.

  On the other hand, when machining the lateral groove, only one diamond cutting tool 41 used as a fly cutter is attached to the tool post 33 of the tool turning table 30. On the other hand, the circumferential position at which the lateral groove of the workpiece W is to be machined is determined on the C axis of the headstock 12.

  As shown in FIG. 6, the servo motor 38 inside the tool swivel base 30 is activated, the tool rest 33 is rotated at a high speed, and the cutting edge of the diamond tool 41 is cut in the X-axis direction. Then, the lateral groove 52 is cut while the cutter swivel 30 is fed along the Z axis. As a result, the diamond cutting tool 41 of the tool post 33 intermittently cuts the workpiece W and creates a lateral groove 52.

  Since the tool post 33 rotates at high speed, an ideal cutting speed (about 300 m / min) can be easily given to the diamond tool 41. As described above, since the lateral groove can be machined at a necessary cutting speed regardless of the Z-axis feed speed which is limited by the capability of the carriage 16, the feed speed of the carriage 16 is limited and necessary as in the prior art. The problem that a precise machining surface of the lateral groove cannot be obtained is overcome because a high cutting speed cannot be obtained.

  Also, contrary to the conventional roll lathe where the feed rate is increased to near the limit, the Z-axis feed of the carriage 16 can be completed at a relatively low speed, so that heat generation on the Z-axis rolling guide surface is suppressed. The Thereby, the fall of the processing precision by the thermal deformation | transformation of the bed 10 or a saddle can be prevented, utilizing the exercise | movement performance by rolling guidance.

  As described above, according to the precision roll lathe of the present embodiment, both the horizontal groove and the vertical groove can be processed with high accuracy, so that it is possible to perform roll processing such as processing the vertical groove and the horizontal groove vertically and horizontally on the same roll. Become. For example, various lens sheet forming mold processing such as a mold for forming a cross lenticular lens sheet and a mold for forming a prism sheet can be realized.

  In the precision roll lathe according to the present embodiment, besides the above description, a lateral groove is formed in the workpiece W while feeding the carriage 16 to the Z axis using the indexed diamond tool 41 without rotating the tool post 33. It is also possible to perform planar processing for cutting.

The side view of the precision roll lathe by one Embodiment of this invention. The top view of the precision roll lathe. Sectional drawing of the cutter swivel provided in the carriage of the precision roll lathe. The perspective view of the same knife swivel. Explanatory drawing of the longitudinal groove process to the roll by the precision roll lathe of this invention. Explanatory drawing of the lateral groove process to the roll by the precision roll lathe of this invention.

Explanation of symbols

10 bed 12 spindle stock 14 tailstock 16 reciprocating carriage 19 chuck 20 servo motor 26 saddle 28 table 30 tool turntable 33 tool rest 34 spindle 41 diamond tool

Claims (4)

Bed and
A headstock having an indexing shaft (C-axis) that is installed on the bed and rotates the work while holding one end of the roll-shaped work with a chuck, and performs indexing in the circumferential direction of the work;
A tailstock arranged on the bed facing the headstock and rotatably supporting one end of the workpiece;
A saddle installed on the bed so as to be movable in the longitudinal direction (Z-axis) of the workpiece;
A table installed on the saddle so as to be movable in a direction (X axis) perpendicular to the longitudinal direction of the workpiece;
A tool swivel having a tool rest mounted on the table and having a plurality of cutting tools attached thereto,
The tool swivel comprises a main roll for rotating the tool rest itself at high speed and an indexing shaft (B axis) for indexing the tool of the tool rest.   The precision roll lathe according to claim 1, wherein the tool post and the main shaft constitute a fly-cut spindle mechanism.   2. The precision roll according to claim 1, wherein the cutter swivel includes a built-in servo motor that directly drives the main shaft and an index control encoder, and the main shaft also serves as an index shaft. lathe.   2. The precision roll lathe according to claim 1, wherein the Z-axis guide surface that guides the feed of the carriage includes a rolling guide in which a number of rollers are arranged on the upper surface of the bed in parallel with the Z-axis.

Images