JP2003071603A - Vertical lathe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vertical lathe performing highly accurate turning with high motion accuracy of an X-axis moving of a saddle by avoiding generation of torsion deformation in a cross rail. SOLUTION: In this structure, the cross rail part 62 is provided with two linear guide parts 65 and 66 parallel each other to an upper surface part, a hollow is made between the two linear guide parts 65 and 66, both sides of the saddle 90 are supported by the two linear guide parts 65 and 66 by stretching over the hollow part 67, and a ram 120 is passed through the hollow part 67 and is suspended.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vertical lathe,
In particular, the present invention relates to a precision vertical lathe used for precision processing of a Fresnel lens molding die or the like.

[0002]

2. Description of the Related Art There is a vertical lathe as a machine tool for performing a turning process, and the vertical lathe is axially moved to a horizontally arranged rotary table and a cross rail extending in a radial direction of the rotary table (X
A saddle provided so as to be capable of axial movement), a ram provided on the saddle in a vertical direction (Z-axis direction), and a tool holder fixedly attached to a lower end portion of the ram to hold a bite tool. .

In the vertical lathe as described above, the work material is fixed on the rotary table, and under the rotation of the rotary table,
Make a cut by moving the saddle Z-axis to move the saddle X
The X-axis position of the bite tool can be changed by the axial movement to perform turning around the rotation center of the rotary table.

In the conventional vertical lathe, a linear guide portion is provided on the front surface (vertical one surface) of the cross rail, a saddle is engaged with the linear guide portion, and the saddle is guided by the linear guide portion to axially feed the saddle in the X-axis direction. To be done.

[0005]

In the vertical lathe described above, the weight of the saddle and the ram provided on the saddle acts as an eccentric load on the front side of the cross rail, causing torsional deformation of the cross rail. Torsional deformation on the cross rail causes deterioration of the movement accuracy of the saddle's X-axis movement,
This leads to a reduction in processing accuracy. Therefore, the conventional vertical lathe cannot perform super-precision turning that requires a high degree of processing accuracy, such as turning of the Fresnel lens molding die.

The present invention has been made in order to solve the above-mentioned problems, avoids the occurrence of torsional deformation in the cross rail, has high movement accuracy of the X-axis movement of the saddle, and has high turning performance. It is intended to provide a vertical lathe that can be accurately performed.

[0007]

In order to achieve the above object, a vertical lathe according to the present invention is capable of axial movement between a horizontally arranged rotary table and a cross rail portion extending in the radial direction of the rotary table. In a vertical lathe having a saddle provided, a ram vertically provided on the saddle, and a tool holder fixedly attached to a lower end portion of the ram, the cross rail portion includes two parallel top surface portions. A linear guide portion is provided, and a space between the two linear guide portions is hollow, the saddle is supported by the two linear guide portions on both sides across the hollow portion, and the ram is the hollow portion. Extends vertically through the.

According to the vertical lathe according to the present invention, the saddle is supported by the two linear guide portions on both sides across the hollow portion between the two linear guide portions, and the ram hangs down through the hollow portion. Therefore, the weights of the saddle and the ram act evenly on the two linear guide portions, and the weight of the dollar and the ram does not exert an unbalanced load on the cross rail, so that the cross rail is not twisted and deformed.

In the vertical lathe according to the present invention, the linear guide of the saddle can be constituted by a finite VV rolling guide. The finite V-V rolling guide means a plurality of needle rollers arranged at equal intervals by a roller holding cage having a V-shaped cross section having a predetermined length in the moving direction and engaging with each other (cross rail portion). It is sandwiched between linear guide rails with a V-shaped cross section (saddle and saddle), and has high rigidity and low friction, and high motion accuracy with less microwaviness is obtained compared to the rolling type rolling guide.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. (Overall Configuration) As shown in FIGS. 1 to 3, the vertical lathe includes a base 10, a rotary table 30 rotatably provided on the base 10 around a vertical axis, and a column portion 61. An upper structure 60 having a cantilevered cross rail portion 62 that extends horizontally in the radial direction of the rotary table 30 from the upper end of the column portion 61, and an extending direction of the cross rail portion 62 on the cross rail portion 62 ( The saddle 90 is provided so as to be movable in the X-axis direction, the ram 120 is provided so as to be movable in the vertical direction (Z-axis direction) on the saddle 90, and the lower end portion of the ram 120 is provided around the horizontal axis (B-axis). Swivel head 150 including a tool holder 151 that is rotatably provided and holds a tool
A cross rail support device 180 that is pivotable about a vertical axis and selectively holds the tip of the cross rail portion 62; and a linear table unit 210 that is detachably mounted on the rotary table 30. ing. A microscope 63 for detecting the position of the cutting edge of the cutting tool attached to the tool holder 151 is attached to the upper structure 60.

(Rotating Table) As shown in FIG. 4, the rotating table 30 is supported by the hydrostatic bearing 11 so as to be rotatable about the vertical axis from the base 10. The hydrostatic bearing 11 has a ring member 12 fixed to an upper portion of the base 10, and is provided between an inner peripheral surface of the ring member 12 and an outer peripheral surface of a ring member 31 fixed to a lower bottom portion of the rotary table 30. Defining a radial static pressure pocket 13.

Further, the hydrostatic bearing 11 is the ring member 1
The upper thrust static pressure pocket 14 is defined between the upper surface of the ring member 12 and the lower bottom surface of the rotary table 30, and the lower surface of the ring member 12 and the upper surface of the ring member 32 fixed to the lower bottom portion of the ring member 31. A lower thrust hydrostatic pocket 15 is defined therebetween.

The upper thrust static pressure pocket 14 and the lower thrust static pressure pocket 15 form opposed hydrostatic bearings, which supply hydraulic pressure to both static pressure pockets 14 and 15 when the table is rotated, and one side static pressure pocket when the table is clamped. 1
Hydraulic pressure is supplied only to 4 or 15, and the rotary table 30 is non-rotatably fixed (clamped) on the base 10 by the hydraulic pressure of the hydrostatic bearing portion. As a result, the hydrostatic bearing 11 is
It also functions as a rotary table clamp means for clamping the rotary table 30 at an arbitrary rotation angle position.

The base 10 rotatably supports a vertical table rotation drive shaft 33 by a rolling bearing member 16. A rotary drive disk 34 is fitted to the upper part of the table rotary drive shaft 33 by a key 35 in a torque transmitting relationship and is fixed by a fixture 36. The rotary drive disk 34 and the rotary table 30 are connected by a plurality (about four) of torque transmission pins 37 (only one is shown in the figure) fitted to both.

A timing pulley 39 is fitted to a lower end portion of the table rotation drive shaft 33 by a key 38 in a torque transmitting relationship and is fixed by a fixture 40. A motor base 41 is separately placed in the vicinity of the base 10 as a measure against heat, and a table drive motor 42 is mounted on the motor base 41. A timing pulley 44 on the drive side is fixed to the output shaft 43 of the table drive motor 42. An endless timing belt 45 is stretched between the timing pulleys 44 and 39.

With this transmission structure, the table drive motor 42 rotates the table rotary drive shaft 33 and the rotary drive disk 34 integral therewith, and the rotational force of the rotary table 30 causes the rotary table 30 to rotate on the table rotary drive shaft 33. Rotate around.

The rotary table 30 has a large number of vacuum suction holes (not shown) opened on the upper surface of the table. The workpiece (work) and the linear table unit 210 as an additional stage are vacuum-pressed on the upper surface of the table. A vacuum suction chuck for suction holding is configured by. The vacuum pressure is supplied to the vacuum suction chuck by a hollow hole 46 of the table rotation drive shaft 33, a rotary joint 47 provided between the upper end of the table rotation drive shaft 33 and the rotary table 30.
Can be done by

(Upper Structure) As shown in FIG. 4, the upper structure 60 includes a column portion 61 and a cross rail portion 6.
2 is integrally formed by an integrally cast product, and the lower end of the column portion 61 is rigidly fastened and fixed to the base 10 and the side extending portion 17 of the integrally cast member by bolts 64 to form an open side column. It has the form of a vertical lathe.

Since the upper structure 60 is an integrally cast product having the column portion 61 and the cross rail portion 62 integrally, high rigidity is obtained, and the lower end portion of the column portion 61 is integrally cast with the base 10. By being fixed on the extension part 17, high mounting (assembly) position accuracy can be obtained.

(Saddle) As shown in FIGS. 4 to 9, the cross rail portion 62 has two upper and lower portions parallel to each other.
It has two linear guide portions 65 and 66, and a hollow portion 67 is provided between the two linear guide portions 65 and 66. The saddle 90 straddles the hollow portion 67 and is supported on both sides by two linear guide portions 65 and 66. Linear guide section 6
The linear guide of the saddle 90 in 5 and 66 is a finite type V
-V rolling guide 68. With this structure, an unbalanced load is not applied to the cross rail portion 62 due to the weight of the saddle / ram, and the cross rail portion 62 is not twisted and deformed.

As a result, the movement accuracy of the X-axis movement of the saddle 90 is improved, and it becomes possible to perform ultra-precision turning, which requires a high degree of processing accuracy, such as turning of the Fresnel lens molding die.

The finite V-V rolling guide 68 is a roller holding cage 69 having a V-shaped cross section having a predetermined length in the moving direction.
The plurality of needle rollers 70 arranged at equal intervals are sandwiched between the cross rail portion 62 and the V-shaped linear guide rails 62A and 90A of the saddle 90 which are engaged with each other.

By applying the finite type V-V rolling guide 68, with respect to the X-axis movement of the saddle 90, it is possible to obtain high motion accuracy with high rigidity and low friction and less microwaviness as compared with the circular rolling guide. This also makes it possible to perform ultra-precision turning, which requires a high degree of processing accuracy, such as turning of the Fresnel lens molding die.

On the cross rail portion 62, an X-axis feed screw rod 73 having a ball screw whose both ends are rotatably supported by bearing brats 71 and 72 is provided. A ball nut 91 is attached to the saddle 90 by a parallel spring member 92. The ball nut 91 is screwed onto the X-axis feed screw rod 73. The X-axis feed screw rod 73 is drivingly connected to an X-axis servomotor 74 mounted on the cross rail portion 62, and is rotationally driven by the X-axis servomotor 74. As a result, the saddle 90 moves to the X-axis servomotor 7
4 moves in the X-axis direction.

The parallel spring member 92 has high rigidity in the axial feed direction due to its thick wall, and has a thin bridge portion 9 on the upper, lower, left and right sides.
It is a kind of flexible coupling that is elastically deformed by the shake movement by 3 and absorbs the bending of the ball screw and the misalignment between the X-axis feed screw rod 73 and the ball nut 91, and is generated by the rotation of the ball screw. Reduces rocking.

(Ram) As shown in FIG. 8, a rectangular tube-shaped ram guide member 94 is suspended and fixed to the lower bottom portion of the saddle 90 by bolts 95. The ram guide member 94 is located in the hollow portion 67 between the left and right linear guide portions (X-axis VV guide surfaces) 65 and 66, and houses the ram 120 therein.

Z-axis guide rails 121 and 122 are fixed to both sides of the ram 120, and inside the ram guide member 94 is a circulating type rolling guide or the like that engages with each of the Z-axis guide rails 121 and 122. The linear guide members 96 and 97 are fixed. This allows the ram 12
0 is guided by the linear guide members 96 and 97 and moves in the Z-axis direction.

The saddle 90 rotatably supports a Z-axis feed screw rod 99 by a ball screw by a bearing member 98. A ball nut 123 is attached to the ram 120, and the ball nut 123 is screwed onto the Z-axis feed screw rod 99. The Z-axis feed screw rod 99 is drivingly connected to a Z-axis servomotor 100 mounted on the saddle 90,
It is rotationally driven by the axis servomotor 100. As a result, the ram 120 is moved to the Z-axis by the Z-axis servomotor 100.
Move in the axial direction.

Two balance cylinder devices 101 and 102 (see FIG. 5) are attached to the saddle 90, and the piston rod 103 of each of the balance cylinder devices 101 and 102 is connected to the upper end of the ram 120. . As a result, the ram 120 is suspended by the two balance cylinder devices 101 and 102, and the straightness of the ram 120 can be guaranteed by the individual operations of the two balance cylinder devices 101 and 102.

(Swivel Head and Tool Holder) As shown in FIGS. 8 to 13, a swivel head housing 152 is fixed to the lower end of the ram 120.
The swivel head housing 152 includes an aerostatic bearing 15
3, the tool holder shaft 154 is rotatably supported around a horizontal axis (B axis), and the tool holder 151 is fixedly attached to one end of the tool holder shaft 154. As a result, the tool holder 151 can rotate on the B axis.

The aerostatic bearing 153 is the tool holder shaft 1
Two flanged bearing bushes 15 fixedly arranged on both sides of an intermediate flange portion 155 formed in the intermediate portion of 54.
6, 157, and radial air static pressure portions 158, 159 and thrust air static pressure portions 160, 161 are formed on the bearing bushes 156, 157, respectively.

The thrust air static pressure portions 160 and 161 are opposed to each other with the intermediate flange portion 155 in between, and both thrust air static pressure portions 16 are rotated when the B-axis rotates (when the tool holder rotates).
0, 161 is supplied with air pressure, and when the B-axis is clamped, air pressure is supplied only to the thrust air static pressure portion 160 or 161 on one side, and the tool holder 151 is clamped at an arbitrary rotation angle position by the air pressure of the static pressure bearing portion. It also functions as holder clamping means.

A worm wheel 162 is fixedly attached to the tool holder shaft 154. A B-axis servomotor 163 is mounted on the swivel head housing 152, and a worm 165 is attached to an output shaft 164 of the B-axis servomotor 163. The worm 165 meshes with the worm wheel 162, and the B-axis servomotor 163 rotationally drives the tool holder 151 to an arbitrary rotation angle position.

The tool holder 151 is provided with four tool mounting portions 166 in a radial pattern, and the tool holder 151 is a turret disk so that four kinds of bite tools T can be simultaneously mounted. The tool mounting portions 166 are
The wedge member 168 moved by the adjusting screw 167 can finely adjust the mounting position of the cutting tool T in the Y-axis direction, and the lock screw 169 can mount the cutting tool T at an arbitrary mounting position in the Y-axis direction. Also, each tool mounting part 1
The 66 is provided with an adjusting screw 170 for finely adjusting the position of the bite tool T in the length direction.

The position of the cutting edge of the cutting tool T can be finely adjusted by the adjusting screws 167 and 170. This fine adjustment of the position of the cutting edge can be performed with high precision while visually checking the position of the cutting edge of the cutting tool T by the microscope 63. You can

(Cross Rail Support Device) As shown in FIGS. 1 to 3, the cross rail support device 180 is a post support 181 arranged near the base 10.
Vertical post 1 rotatably mounted around a vertical axis
82 and a horizontal arm 183 provided at the upper end of the vertical post 182, and a height adjusting member 184 is attached to the tip of the horizontal arm 183.

The horizontal arm 183 is, as shown by the reference numeral A in FIG. 3, a retracted position away from the main body of the vertical lathe (the rotary table 30 and the cross rail portion 62) and a reference numeral B. In addition, the height adjustment member 184 is fixed to the tip of the cross rail portion 62, and the auxiliary bracket 1
It is turnable between a support position for engaging with 04 and supporting it from below.

As a result, the horizontal arm 183 is pivotally moved to the support position B, whereby the cross rail portion 62 is
While the tip end portion of the cross rail portion 62 is held, and the workability of loading and unloading the work to and from the rotary table 30 is good, the apparent rigidity of the cross rail portion 62 can be improved during actual processing while utilizing the features of the open side column type.

The height adjusting member 184 is like a fluid pressure type or electric type precision jack, and the height dimension can be finely adjusted by an external signal.

(Linear Table Unit) The linear table unit 210 is added on the rotary table 30 during the planing process, and is removed on the rotary table 30 as shown in FIGS. 14 to 16. It has a fixed base 211 which is fixed as possible. The fixed base 211 has two linear guide portions 212 parallel to each other,
213 is formed, and the linear guide portions 212, 21 are formed.
A linear table 214 is reciprocally provided on the table 3.

The linear guides of the linear table 214 in the linear guide portions 212 and 213 are composed of a finite VV rolling guide 215. The finite V-V rolling guide 215 is the finite V-V rolling guide 6 described above.
8, a plurality of needle rollers (not shown) arranged at equal intervals by a roller holding cage 216 having a V-shaped cross section having a predetermined length in the moving direction, are fixed to the fixed base 211 and the linear base that engage with each other. The table 214 is sandwiched between the V-shaped linear guide rails 211A and 214A.

By applying the finite type VV rolling guide 215, with respect to the movement (Y-axis movement) of the linear table 214, high rigidity and low friction, and a high motion accuracy with less microwaviness than the rolling type rolling guide are provided. Is obtained.

On the fixed base 211, there are provided feed screw rods 219 by ball screws whose both ends are rotatably supported by bearing brats 217 and 218. A ball nut 221 is attached to the linear table 214 by a parallel spring member 220. Ball nut 2
21 is screwed to the feed screw rod 219. Feed screw rod 2
Reference numeral 19 is drivingly connected to a servo motor 222 mounted on the fixed base 211, and is rotationally driven by the servo motor 222. As a result, the linear table 214 is axially moved by the servo motor 222.

The parallel spring member 220 is equivalent to the above-mentioned parallel spring member 92, has high rigidity in the axial feed direction due to its thick wall, and has a thin bridge portion 223 in the vertical and horizontal directions.
It is a kind of flexible coupling that elastically deforms due to shaking motion due to bending, ball screw bending and feed screw rod 2
The core misalignment between the ball screw nut 19 and the ball nut 221 is absorbed, and the swing generated by the rotation of the ball screw is reduced.

A large number of vacuum suction holes 224 are opened on the upper surface of the linear table 214, and a vacuum suction chuck for sucking and holding a work material (workpiece) by vacuum pressure is configured on the table upper surface.

(Example of Use of Vertical Lathe) Next, as an example of use of the vertical lathe having the above-described structure, a process of manufacturing a Fresnel lens molding die by turning will be described. (1) The length (tool length) of the bite tool T attached to the tool attachment portion 166 of the tool holder 151 is determined by the microscope 63.
To measure.

(2) Center of rotation of the work material (center of rotation of the rotary table 30) and the tool mounting portion 16 of the tool holder 151
The bite tool T attached to 6 is aligned.

(3) Cross rail support device 180
With the horizontal arm 183 of FIG.
The material (work material) of the Fresnel lens molding die is loaded onto the rotary table 30, and the work material is fixed at a prescribed position by the vacuum suction chuck of the rotary table 30.

(4) Cross rail support device 180
The horizontal arm 183 is moved to the support position B, and the height adjusting member 184 holds the tip of the cross rail 62. In this case, as the X-axis position of the saddle 90 is closer to the tip of the cross rail portion 62, the height adjusting member 184 is
Can be extended to strengthen the support of the cross rail portion 62 of the cross rail support device 180.

(5) In the unclamped state, the rotation angle of the tool holder 151 is adjusted by the B-axis servo motor 163, the angle of the bite tool T is adjusted to the lens surface (Fresnel surface) inclination angle of the Fresnel lens, and the tool holder shaft is rotated. 154
(B axis) is clamped, and the rotary table 30 is rotationally driven at a predetermined rotational speed by the table driving motor 42.
The X-axis servo motor 74 sets the X-axis position of the saddle 90, the Z-axis servo motor 100 feeds the ram 120 in the Z-axis (cut feed), and starts turning the Fresnel lens molding die.

(6) Since the lens surface (Fresnel surface) inclination angle of the Fresnel lens changes depending on the radial position of the Fresnel lens molding die, depending on the X-axis position of the saddle 90, as in the case of (5), The rotation angle of the tool holder 151 is adjusted by the B-axis servomotor 163, the angle of the bite tool T is changed according to the lens surface (Fresnel surface) inclination angle of the Fresnel lens, and the Z-axis servomotor 100 feeds the ram 120 to the Z-axis. Then, the Fresnel lens molding die is turned. Turning of the Fresnel lens forming die is performed from the center of the table turning toward the outside.

(Example of use of a vertical lathe to which a linear table unit is added) In the case of performing a planing process such as a linear Fresnel lens molding die or a windshield light guide plate molding die, the planing process shown in FIGS. As shown, the fixed base 211 of the linear table unit 210 is fixed on the rotary table 30, and the rotary table 30 is rotated to rotate the linear table 214 of the linear table unit 210.
Axis moving direction, that is, the linear guide portions 212, 21
3 is adjusted in the Y-axis direction orthogonal to the X-axis direction.

When this adjustment is completed, the hydrostatic bearing 11
The hydraulic pressure is supplied only to the static pressure pockets 14 or 15 on one side, and the rotary table 30 is non-rotatably clamped on the base 10 by the hydraulic pressure of the static pressure bearing portion.

The work material is the linear table unit 21.
It is installed on the linear table 214 of 0, and the work piece is sucked and held on the linear table 214 by the vacuum suction chuck of the linear table 214.

In machining using the linear table unit 210, the saddle 90 is moved in the X-axis, the linear table 214 is moved in the Y-axis, the ram 120 is moved in the Z-axis, and the tool holder shaft 154 is rotated in the B-axis. The planing process can be performed in such a manner that the angle can be changed.

[0056]

As can be understood from the above description, according to the vertical lathe according to the present invention, the saddle is supported by the two linear guide portions on both sides across the hollow portion between the two linear guide portions. Since the ram hangs down through its hollow part, the weight of the saddle and ram acts evenly on the two linear guide parts, and the cross rail does not have an unbalanced load due to the weight of the dollar ram. The torsional deformation does not occur in the
It becomes possible to perform ultra-precision turning that requires a high degree of processing accuracy, such as turning of the Fresnel lens molding die.

[Brief description of drawings]

FIG. 1 is a front view showing the overall configuration of a vertical lathe according to the present invention.

FIG. 2 is a side view showing the overall configuration of a vertical lathe according to the present invention.

FIG. 3 is a plan view showing the overall structure of a vertical lathe according to the present invention.

FIG. 4 is a base of a vertical lathe according to the present invention, a rotary table,
It is an assembly drawing of an upper structure.

FIG. 5 is a plan view of a cross rail portion of the vertical lathe according to the present invention.

FIG. 6 is a front view of a saddle shaft feeder of the vertical lathe according to the present invention.

FIG. 7 is a perspective view of a linear guide portion of a saddle of a vertical lathe according to the present invention.

FIG. 8 is a vertical sectional view of a saddle and a ram portion of a vertical lathe according to the present invention.

FIG. 9 is a front view of a ram lower end portion and a swivel head portion of a vertical lathe according to the present invention.

FIG. 10 is a half sectional view of a swivel head portion of a vertical lathe according to the present invention.

FIG. 11 is a vertical sectional view of a swivel head portion of a vertical lathe according to the present invention.

FIG. 12 is a front view of a tool holder portion of a vertical lathe according to the present invention.

FIG. 13 is a side view of a tool holder portion of a vertical lathe according to the present invention.

FIG. 14 is a plan view of a linear table unit used in the vertical lathe according to the present invention.

FIG. 15 is a plan view of the feed portion of the shaft of the linear table unit used in the vertical lathe according to the present invention.

FIG. 16 is a front view of the feed portion of the shaft of the linear table unit used in the vertical lathe according to the present invention.

[Explanation of symbols]

10 bases 30 turntable 60 Upper structure 61 Column section 62 Cross rail part 63 microscope 65, 66 Linear guide section 67 Hollow part 68 Finite type VV rolling guide 90 saddle 120 ram 150 swivel head 151 tool holder 180 Cross rail support device 210 linear table unit 211 fixed base 214 linear table

Claims (2)

[Claims] 1. A horizontally arranged rotary table, a saddle axially movable on a cross rail portion extending in the radial direction of the rotary table, a ram vertically provided on the saddle, and a ram In a vertical lathe having a tool holder fixedly attached to a lower end portion thereof, the cross rail portion has two linear guide portions parallel to each other on an upper surface portion thereof, and a space between the two linear guide portions is hollow. In the vertical lathe, the saddle is supported by the two linear guide portions on both sides across the hollow portion, and the ram extends in the vertical direction through the hollow portion. 2. The linear guide of the saddle is a finite type V-
The vertical lathe according to claim 1, which is a V rolling guide.