JP4959222B2 - Precision roll lathe saddle guide cooling device - Google Patents

Description

  The present invention relates to a precision roll lathe for machining circumferential grooves and axial grooves on the outer periphery of a roll, and more particularly to a saddle guide cooling apparatus.

  A machine tool for processing a roll includes a roll grinder and a roll lathe. 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 advance of machine 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 for 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

  When processing these lens sheet molding dies with 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. 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 horizontal groove, the roll is indexed by the headstock and then processed while feeding the carriage in the longitudinal direction. However, in order to process at a sufficient cutting speed, the feed rate must be increased.

  However, if the feeding speed of the carriage is increased, the rolling guide for guiding the saddle on which the carriage is placed generates heat. For this reason, there is a problem that thermal deformation occurs in the bed and saddle and the processing accuracy is lowered, and an ultra-precision processing surface cannot be obtained.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the problems of the prior art, suppress heat generated in the saddle guide, and perform saddle guide for a precision roll lathe capable of performing groove processing in the longitudinal direction of the roll with high accuracy. It is to provide a cooling device.

In order to achieve the above-mentioned object, the present invention includes a spindle stock for rotating a roll-shaped workpiece and indexing in a circumferential direction on a bed, and a reciprocating platform saddle on which a tool post is placed. in guiding the cooling device of the saddle of precision roll lathe that is, wherein the upper surface of the beds de, provided a number of roller rolling guide are arranged in parallel to guide the saddle and the workpiece longitudinal direction (Z axis), the bed A cooling jacket for cooling liquid extending along the rolling guide is formed inside the saddle, and a cooling jacket extending along the roller rolling surface of the rolling guide is also formed inside the saddle. is there.

  According to the present invention, it is possible to suppress heat generation on the rolling guide surface of the saddle, thereby making it possible to prevent deterioration in processing accuracy due to thermal deformation of the bed and saddle while utilizing the motion performance by the rolling guide, and to make a roll-shaped workpiece. On the other hand, not only vertical grooves (circumferential grooves) can be cut, but also horizontal grooves (axial grooves) can be processed with high accuracy.

Hereinafter, an embodiment of a saddle guide cooling device for 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 to which the present invention is applied, 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 19 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 is controlled. A function as a C axis) is added. In addition to the hydrostatic bearing, the bearing of the headstock 12 may be an air bearing or a bearing 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 includes a main shaft 23 instead of a conventional general tailstock shaft, and a shaft of the workpiece W is rotatably supported by a chuck 25 attached to the main shaft 23. Such a tailstock 14 has the same basic configuration as the headstock 12 except that it does not have a servo motor.

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. The cutter swivel 30 according to the present embodiment includes a swivel base body 31 and a top plate 32. On the top plate 32, a tool post 33 to which a plurality of cutting tools are attached and a fly cutter spindle device 34 are attached.

  A built-in servo motor constituting a B-axis for indexing an arbitrary bite of the tool post 33 or a fly cutter of the fly cutter spindle device 34 is incorporated in the swivel base body 31. The shaft that supports the top plate 32 is driven by this servo motor, and the top plate 32 can be turned.

  A tool post 33 is attached to one side of the top plate 32, and a fly cutter spindle device 34 is disposed at a position close to the other side. In this case, the fly cutter spindle device 34 is supported by a bracket 45 fixed to the tool post 33. The tool post 33 is a substantially semi-cylindrical tool post, and diamond tools 36 are arranged at predetermined intervals in the circumferential direction. In this embodiment, three diamond tools 36 can be determined by turning the tool post 33 every 90 degrees together with the top plate 32. However, four diamond tools 36 are turned every 60 degrees. There are various forms such as indexing. A counterweight 37 for balancing the weight of the fly cutter spindle device 34 is installed on the upper surface of the tool post 33.

  Next, the fly cutter spindle device 34 will be described. The fly cutter spindle device 34 includes a main body 34a, a servo motor 35, and a cutter holder 38 to which a fly cutter 39 is attached. Inside the main body 34a, a cutter spindle (not shown) is supported by an air bearing, and this cutter spindle is directly driven by a servo motor 35 and rotates at a high speed. The cutter holder 38 attached to the tip of the cutter spindle is a disc-shaped cutter holder in order to increase the peripheral speed. One fly cutter 39 made of a diamond tool is held on the outer periphery of the cutter holder 38. In this case, the cutter spindle device 34 supports the cutter spindle in a posture perpendicular to both the X-axis direction and the Z-axis direction, and rotates the fly cutter 39 at high speed in the XZ plane. The cutting edge of the diamond tool 36 attached to the tool post 33 is in the same plane as the XZ plane on which the fly cutter 39 rotates.

  In FIG. 3, an X-axis guide rail 40 having an inverted V-shaped guide surface is extended on the upper surface of the saddle 26, and a large number of rollers held by a retainer are arranged on the X-axis guide rail 40. A finite type rolling guide 41 is provided. Similarly, a Z-axis guide rail 42 having a guide surface formed in an inverted V shape extends on the upper surface of the bed 10, and a finite rolling guide 43 is provided on the Z-axis guide rail 42.

  In the roll lathe of this embodiment, the saddle 26 is fed at a much higher speed than the table 28. For this reason, the finite rolling guide 43 on the Z-axis guide rail 42 that guides the saddle 26 may generate heat. Therefore, cooling jackets 44 and 46 as shown in FIG. 4 are formed on the bed 10 and the saddle 26.

  As shown in FIG. 4, a cooling jacket 44 extending along the X-axis guide rail 42 is formed inside the bed 10. On the other hand, the bottom surface of the saddle 26 is formed with a V-groove 49 that forms a roller rolling surface on which the finite rolling guide 43 rolls. A cooling jacket 46 extending along the roller rolling surface of the V groove 49 is formed inside the saddle 26. Cooling water is introduced into these cooling jackets 44 and 46 from a cooling supply pipe (not shown) and is derived from cooling water discharge. The bed 10 is a cast product made of gray cast iron.

Both the Z-axis feed driving device that sends 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. In FIG. 3, reference numeral 47 indicates a permanent magnet array constituting a linear motor of the X-axis feed mechanism, and 48 indicates a permanent magnet array extending in parallel with the Z-axis guide rail 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.

  By properly using the tool post 33 and the fly cutter spindle device 34 installed on the tool swivel base 30 as follows, a vertical groove (groove in the circumferential direction) can be cut with respect to the workpiece W as well as a horizontal groove (axis) High-precision processing can also be performed on the direction grooves).

  The processing of the longitudinal groove is the same as that of a normal roll lathe. That is, of the diamond tool 36 of the tool post 33, the tool to be used 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 36, and the longitudinal groove can be turned.

  On the other hand, when machining the lateral groove, the fly cutter spindle device 34 is indexed by the B axis. And the position of the circumferential direction which should process the horizontal groove of the workpiece | work W with the C axis | shaft of the head stock 12 is calculated | required.

  As shown in FIG. 5, the servo motor 35 of the fly cutter spindle device 34 is activated, the cutter holder 38 is rotated at a high speed, and the fly cutter 39 is cut in the X-axis direction. Then, the lateral groove 52 is cut while feeding the fly cutter 39 along the Z axis. Thereby, the fly cutter 37 cuts the workpiece W intermittently to create the lateral grooves 52. Since the cutter holder 38 of the fly cutter spindle device 34 rotates at a high speed, an ideal cutting speed (about 300 m / min) can be given to the fly cutter 37.

  In addition, the precision roll lathe according to the present embodiment can perform conventional planar processing without using the fly cutter spindle device 34. That is, it is possible to index the diamond cutting tool 36 of the tool post 33 and cut the lateral groove in the workpiece W while feeding the carriage 16 at high speed in the Z axis.

As can be seen from the above description, when the lateral groove is machined in the workpiece W, the saddle 26 of the carriage 16 moves frequently and at high speed, so heat is generated in the Z-axis guide rail 42 and the finite type rolling guide 43.
With respect to this heat generation, since the cooling water flows through the cooling jacket 44 inside the bed 10 and the cooling jacket 46 inside the saddle 26, thermal deformation can be effectively suppressed. That is, heat exchange is performed between the roller rolling surface of the Z-axis guide rail 42 and the roller of the rolling guide 43, and the heat is absorbed by the cooling water flowing through the cooling jacket 44. Similarly, in the saddle 26, heat exchange is performed between the roller rolling surface of the V groove 49 on the bottom surface and the roller of the rolling guide 43 and is absorbed by the cooling water flowing through the cooling jacket 46. Since both the Z-axis guide rail 42 and the V-groove 49 have a V-shaped roller rolling surface, the contact area per volume increases, while the cooling jackets 44 and 46 extend along the V-shaped guide surface. Therefore, the heat conduction range is not diffused and the heat exchange efficiency with the cooling water can be increased. Moreover, in the case of the finite type rolling guide 43 as in the present embodiment, the rolling guide 43 also moves together with the movement of the saddle 26. Therefore, the rolling guide 43 is always cooled by the cooling water of the upper and lower cooling jackets 44 and 46. Will be.

  In addition, according to the roll lathe of this embodiment, when machining a horizontal groove using the fly cutter spindle apparatus 34, the Z-axis feed of the carriage 16 can be completed at a relatively low speed. For this reason, compared with the conventional roll lathe in which the feeding speed of the saddle 26 is increased to the limit, heat generation at the Z-axis rolling guide surface is originally small, so that the heat generation of the rolling guide can be reliably suppressed. .

  As described above, according to the precision roll lathe of the present embodiment, not only high-precision processing of the horizontal groove, but also high-precision processing can be performed while effectively suppressing the heat generation of the rolling guide for the vertical groove. Roll processing such as processing vertical and horizontal grooves on the roll in the vertical and horizontal directions is also possible. 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.

The side view of the precision roll lathe by one Embodiment of this invention. The top view of the precision roll lathe. The perspective view of the same knife swivel. The partial cross section front view which shows the saddle of the same precision roll lathe, and the cooling jacket provided in the bed. 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 fly cutter spindle device 44 cooling jacket 46 cooling jacket

Claims (3)

In a guide cooling device for a saddle of a precision roll lathe in which a spindle head for rotating a roll-shaped workpiece and indexing in a circumferential direction on a bed, and a saddle for a carriage on which a tool rest is placed, are installed .
Wherein the top surface of the beds de, many rollers are rolling guide arranged provided in parallel to guide the saddle and the workpiece longitudinal direction (Z-axis), a coolant extending along the rolling guide inside the bed And a cooling jacket extending along the roller rolling surface of the rolling guide is also formed inside the saddle. A table is installed on the saddle so as to be movable in a direction (X axis) perpendicular to the longitudinal direction of the workpiece, and a cutter swivel having an indexing shaft (B axis) is provided on the table. The swivel has a tool rest on which a plurality of cutting tools for machining circumferential grooves are attached to the workpiece, and a cutter spindle for rotating a fly cutter for machining axial grooves on the workpiece. The saddle guide cooling device for a precision roll lathe according to claim 1 , further comprising an installed fly cutter spindle device.   2. The precision according to claim 1, wherein the Z-axis rolling guide includes a guide rail having a V-shaped guide surface and a V-shaped finite type rolling guide that rolls on the V-shaped guide surface. Saddle guide cooling device for roll lathe.

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