JP5728251B2 - Grinding method for long workpiece - Google Patents

Description

  In the present invention, a long work piece having a length of 5 to 10 m such as a T-die for resin film molding, a T-die for melting, or a T-die for forming a liquid curtain curtain is applied to a grinding wheel, a flat grinding wheel (PCD). The present invention relates to a method of grinding a long workpiece with a flat and small warp using a grinding (polishing) tool such as a grindstone, a cup wheel grindstone, or a pitch polisher.

  It is known to machine the surface of a long workpiece into a T-die without a tool locus island pattern by unidirectional grinding with a pitch polisher.

  For example, Japanese Patent Laying-Open No. 2006-7373 (Patent Document 1) discloses a work table 4 provided on a frame 6 shown in FIG. 2, a polishing tool holding plate supported on the lower end of a spindle shaft of a polishing head 10, and the polishing A pitch polishing tool 3 affixed to the surface of the tool holding plate, a rotation driving device of the spindle shaft that supports the pitch polishing tool, a right and left movement driving device, a lifting device, and a work surface placed on the work table; A pitch polishing apparatus 100 including an abrasive supply nozzle, a dresser 12 and a numerical controller 8 for supplying an abrasive between the pitch polishing tool surfaces facing this is proposed.

  Using this pitch polishing apparatus, a pitch polishing tool affixed to a surface of a metal plating block (work) fixed to a work table 6 provided on a frame 6 on a polishing tool holding plate supported at the lower end of a spindle shaft 3 is pressed and moved in one direction while rotating the pitch polishing tool while supplying an abrasive between the workpiece surface and the pitch polishing tool surface facing the workpiece surface, and performs one-direction pitch polishing of the workpiece. The grinding wheel streak traces remaining on the workpiece are eliminated, and the surface roughness value is 1/4 to 1/6 times smaller than that of a workpiece that has been precisely polished using a precision grinding device that uses a grinding wheel. An improved polishing mirror surface can be exhibited.

  Moreover, it replaces with the said pitch grinding | polishing tool, and Unexamined-Japanese-Patent No. 2006-315088 (patent document 2) is a disk-shaped diamond baking of 5-20 mm in diameter and 1-10 mm in height on one surface of a disk shaped base. A disk-shaped grinding wheel provided with a plurality of concatenated pellets spaced apart by at least 3 mm at equal intervals on a concentric circle, wherein the disk-like diamond sintered pellet has an average particle size of 1 PCD pellet grinding wheel formed of diamond sintered pellets obtained by sintering diamond particles having a diameter of -6 μm and JIS particle size of 2,500 to 8,000 bonded with resin binder and molded into pellets This is attached to the spindle shaft so that the PCD pellet layer faces the bottom surface, and the surface of the cemented carbide workpiece placed on the work table of the grinding machine While supplying the abrasive, press the PCD pellet of the PCD pellet grinding wheel rotating around the spindle axis against the workpiece surface, and cut the workpiece while feeding the PCD pellet in one direction to make the cemented carbide alloy workpiece surface We propose a grinding method.

The applicant of the present patent application discloses a slide main body for guiding a work table 4 provided in Japanese Patent Application Laid-Open No. 2006-102867 (Patent Document 3) on a frame (machine frame) 6 shown in FIG. And a hydrostatic linear motion guide device comprising a guide body, an hydrostatic linear motion guide device for guiding a saddle 7 reciprocally movable in the front-rear direction provided orthogonal to the work table 4, the numerical control device 8, A column 9 fixed upright on a saddle 7; a hydrostatic pressure linear motion guide device that moves up and down a sliding body to which a grinding wheel head 10 having a grinding wheel shaft 10 bearing a grinding wheel shaft 3 is fixed; The precision surface grinding apparatus 100 provided with the grinding wheel rotation drive mechanism was proposed.

  The straightness in the front-rear direction of a workpiece obtained by surface grinding a workpiece having a lateral length of 4250 mm and a front-rear width of 800 mm using the ultraprecision surface grinding apparatus 100 described in Patent Document 3 is 0.3 μm, and the straightness in the left-right direction is It can be said to be an ultra-precision surface grinding device that is as small as 1.3 μm and is suitable for precision grinding of long workpieces.

  The pitch polishing apparatus described in Patent Document 1, the planar polishing apparatus described in Patent Document 2, and the planar description apparatus described in Patent Document 3 are warped if the length of the long workpiece is about 5000 mm. A workpiece that is ground (polished) with a mirror surface without a gap is provided. However, in a long workpiece having a length of 7000 to 12000 mm, the workpiece is warped and the straightness in the left and right longitudinal directions is 1.3 to The reason why 2.5 μm and the straightness in the front-rear direction are larger than 0.1 to 0.3 μm is that the tool diameter is 250 to 360 mm, or the grinding wheel diameter is 200 to 360 mm, and the grinding wheel width is When the width is 25 to 60 mm, the surface of the workpiece part far away from the grinding action point is the left and right reciprocal reaction of the work table when the amount of the grinding fluid supplied to the processing point where the tool and the workpiece come into contact with each other. It was inferred that the surface temperature of the workpiece being machined was not constant due to drying during rolling.

The patent applicant of the present application uses an ultra-precise surface grinder “UPG” (trade name) (see Japanese Patent Application No. 2011-030387 (Patent Document 4)) for a cooling water jet nozzle for cooling the workpiece and table shown in FIG. Attached to Okamoto Machine Tool Co., Ltd. catalog “UPG Series”, printed in April 2007)
a) a work table provided so as to be able to reciprocate in the left-right direction on a guide rail provided in the left-right direction on the machine frame;
b) Workpiece surface coolant supply mechanism in which a pair of coolant supply pipes provided with a plurality of jet nozzles are attached to the machine frame before and after the worktable;
c) A grinding wheel supported by a tool shaft attached to the column so as to be movable up and down,
d) a grinding fluid supply nozzle that is provided in the vicinity of the grinding wheel and supplies a grinding fluid to a processing point where the grinding wheel and the workpiece come into contact;
Using a surface grinding machine comprising
A work is fixed on the work table, and the work table is reciprocally reversed in the left-right direction. The coolant liquid is supplied from the pair of work surface coolant supply mechanisms to the work surface to form a coolant liquid film over the entire work surface. Along with, supplying the grinding fluid from the grinding fluid supply nozzle toward the grinding tool,
The grinding wheel rotating at a peripheral speed of 150 to 380 m / min is lowered and brought into contact with a workpiece surface fixed on a work table that is reciprocally reversed at a speed of 6 to 10 m / min in the left-right direction. Started grinding,
A long workpiece grinding method was proposed in which the workpiece surface is ground by a grinding wheel by the relative movement of the workpiece and the grinding wheel.

JP 2006-7373 A JP 2006-315088 A JP 2006-102867 A Japanese Patent Application No. 2011-030387

Catalog of Okamoto Machine Tool Works "Ultra-precision surface grinder" UPG Series "", April 2007

  In the surface grinding method described in Patent Document 4, a coolant liquid film is always formed on the entire surface of the work table during grinding, and the temperature of the work table can be kept constant. A ground workpiece with a straightness of 0.3 μm in the direction and a straightness of 0.6 μm in the horizontal direction of the workpiece could be obtained.

  The inventor of the present application provides a diamond grinding wheel having a grinding number of 2,000 to 3,000 and a small abrasive grain size in the final grinding stage in order to obtain a workpiece having a straightness value of about 0.1 μm and smaller. It was thought that this could be achieved by reducing the peripheral speed of the diamond grinding wheel to about 20 to 40 m / min.

Claim 1 of the present invention provides
a). A work table provided to be able to reciprocate in the left-right direction on a guide rail provided in the left-right direction on the machine frame;
b). A workpiece surface coolant liquid supply mechanism in which a pair of coolant liquid supply pipes provided with a number of jets in a pair of coolant liquid supply pipes having a length longer than the length of the lateral movement width of the work table is attached to a machine frame before and after the work table;
c). Diamond grinding wheel supported by a grinding wheel shaft that can be moved up and down on the column,
d). A grinding fluid supply nozzle that is provided in the vicinity of the diamond grinding wheel and supplies a grinding fluid to a processing point where the diamond grinding wheel and the workpiece come into contact with each other.
Using a grinding device comprising
The work is fixed to the upper surface of the electromagnetic chuck on the work table, and the work table is reciprocally reversed in the left-right direction. The coolant is supplied from the plurality of jets of the pair of work surface coolant liquid supply mechanisms to the upper surface and the side of the work and the electromagnetic chuck. A coolant liquid film is formed over the entire surface of the electromagnetic chuck and supplied to the surface, and the grinding liquid is supplied from the grinding liquid supply nozzle toward the diamond grinding wheel,
The rotating diamond grinding wheel is lowered and brought into contact with the workpiece surface fixed on the work table that is reciprocally reversed in the left-right direction to start grinding the workpiece surface. In the method of grinding a long workpiece, the surface of the workpiece is ground with a diamond grinding wheel by a simple movement.
The long workpiece grinding stage is divided into a rough grinding stage with a machining allowance of 1.5 to 15 μm and a finish grinding stage with a machining allowance of 0.05 to 1.0 μm. Surface grinding is performed using a diamond grinding wheel of No. 500 and a peripheral speed of the diamond grinding wheel of 150 to 380 m / min, and diamond grinding wheels of grinding numbers 2,000 to 3,000 are used on the finish grinding stage. The present invention provides a method for grinding a long workpiece characterized in that the surface finish grinding is performed at a peripheral speed of a grinding wheel of 20 to 40 m / min.

  During the grinding process, a coolant liquid film is always formed on the entire worktable surface, and the worktable temperature can be kept constant, so it is possible to produce a grinding work piece with less warpage and less variation in straightness. it can. Further, since the rotational peripheral speed of the grinding wheel at the finish grinding stage is performed at a low speed of about 1/10 to 1/15 of the peripheral speed of the grinding wheel at the rough grinding stage, about Rx is about 0.01 μm, A processed workpiece having a mirror surface with Ry of 0.09 to 0.12 μm could be obtained.

FIG. 1 is a perspective view showing a state in which a coolant liquid film is formed over the entire work surface. FIG. 2 is a front view of the pitch polishing apparatus. FIG. 3 is a perspective view of an ultra-precision surface grinding apparatus.

  The grinding apparatus for carrying out the present invention is characterized in that the grinding apparatus includes a workpiece surface coolant liquid supply mechanism 20 in which a pair of coolant liquid supply pipes 20a and 20b provided with a plurality of jet nozzles are attached to the machine frame before and after the work table. Except for this, the above-described Patent Document 1, Patent Document 2, and Patent Document 3 and the known column-type, saddle-type, and portal-type surface grinding apparatuses 100 can be used.

  As the grinding wheel 3, a diamond grinding wheel having a grinding number of 800 to 1,500 is used in the rough grinding stage, and surface grinding is performed at a peripheral speed of the diamond grinding wheel of 150 to 380 m / min. In the finish grinding stage, a diamond grinding wheel having a grinding number of 2,000 to 3,000 is used, and the surface grinding is performed with the peripheral speed of the diamond grinding wheel being 20 to 40 m / min.

  In FIG. 1, a workpiece surface coolant liquid supply mechanism 20 includes a pair of coolant liquid supply pipes 20a and 20b each having a diameter of 8 to 15 mm provided with a plurality of jet holes 20d having a hole diameter of 2 to 5 mm at intervals of 30 cm. The coolant liquid supply pipes 20 a and 20 b are attached to the frame 2, and the length of the coolant liquid supply pipes 20 a and 20 b is slightly longer by 10 to 20 cm than the lateral movement width of the work table 4. The ends of the pair of coolant liquid supply pipes 20a and 20b are coupled to a branch pipe 20c. Coolant liquid is supplied to the branch pipe from a coolant liquid tank by a pump, and a jet 20e is supplied from an outlet 20d to the upper surface of the workpiece w and the electromagnetic chuck 13. Supplied to the side. The drilling position on the coolant supply pipe of the jet outlet 20d is provided so that the coolant liquid jetted from the jet outlet at a rate of 10 to 250 liters / minute reaches the surface of the electromagnetic chuck 13 on the work table 4. The supplied coolant liquid forms a liquid film over the entire surface of the upper surface of the electromagnetic chuck 13 by moving the work table 4 left and right, and also droops on the work table 4 or a jet 20e of the coolant is applied to the work table 4. Then, the electromagnetic chuck 13 is cooled. Furthermore, the work table 4 is also cooled.

In the vicinity of the diamond grinding wheel 3, there is provided a grinding fluid supply nozzle 11 for supplying a grinding fluid to a processing point where the diamond grinding wheel 3 and the workpiece w are in contact, and the grinding fluid (coolant fluid) is 2 to 30 liters / minute. Supplied in proportion.

  The coolant liquid and the grinding liquid are stored in separate coolant liquid tanks, and their storage temperatures are kept at substantially the same temperature as the coolant liquid for cooling the column 9, the work table 4, and the electromagnetic chuck.

Example 1
A pair of coolant liquid supply pipes having a diameter of 12 mm and a length of 12050 mm, in which a plurality of jet holes with a hole diameter of 4 mm are provided at intervals of 30 cm on the machine frame 6 before and after the work table 4 of a column type ultra-precision surface grinder “UPG12000” (trade name). 20a and 20b are attached, one end of these coolant liquid supply pipes is connected to the branch pipe, the tip of the branch pipe faces the coolant liquid tank, and the coolant liquid can be supplied to the branch pipe by the pump.

  As the grinding wheel 3, a rough grinding diamond grinding wheel having a grinding wheel diameter of 300 mm and a grinding wheel width of 50 mm and a finishing grinding diamond grinding wheel having a grinding number of 2,000 is used. The front and rear width is 150 mm, the left and right length is 2500 mm, and the height is high. A work w having a size of 40 mm was fixed via an electromagnetic chuck 13 on the work table 4.

  The work table 4 is reciprocally moved back and forth in the left-right direction at a speed of 9 m / min, and the coolant liquid from the pair of work surface coolant supply mechanisms 20 is transferred onto the magnetic chuck at a rate of 40 liters / min from one ejection hole. A coolant liquid film is formed on the surface of the workpiece to be fixed to form a coolant liquid film over the entire surface of the work, and a grinding liquid of 10 liters / minute is supplied from the grinding liquid supply nozzle 11 toward the grinding wheel 3 with the grinding number 1,000. Supplied.

  The grinding wheel 3 rotating at a peripheral speed (v) of 370 m / min is lowered by a cutting amount of 0.5 μm, reciprocally reversed at a table speed of 9 m / min in the left-right direction, and moved back and forth at a longitudinal feed speed of 10 mm / min. Grinding of the workpiece surface was started by bringing the grinding wheel 3 into contact with the workpiece surface fixed to the magnetic chuck on the workpiece table 4.

  The surface of the workpiece is roughly ground by the grinding wheel 3 by the relative movement of the workpiece w and the grinding wheel 3 (front and rear, left and right, up and down), the total amount of 15.0 μm is removed, and the straightness of the workpiece in the longitudinal direction is zero. A rough-grinded workpiece with a thickness of 3 μm and a straightness in the left-right direction of the workpiece of 0.6 μm was obtained.

  Next, the grinding wheel is replaced with a finish grinding diamond grinding wheel with a grinding number of 2,000, and the grinding conditions of the rough grinding work are as follows: grinding wheel cutting depth 0.1 μm, total machining allowance 0.5 μm, finish grinding diamond Finish grinding is performed in the same manner except that the peripheral speed (v) of the grinding wheel is 34 m / min, the horizontal moving table speed of the work table 4 is 6 m / min, and the longitudinal feed speed of the work table 4 is 0.4 mm / min. , Rx was 0.098 to 0.10 μm, and Ry was 0.12 to 0.16 μm.

Example 2
A pair of coolant liquid supply pipes having a diameter of 12 mm and a length of 12050 mm, in which a plurality of jet holes with a hole diameter of 4 mm are provided at intervals of 30 cm on the machine frame 6 before and after the work table 4 of a column type ultra-precision surface grinder “UPG12000” (trade name). 20a and 20b are attached, one end of these coolant liquid supply pipes is connected to the branch pipe, the tip of the branch pipe faces the coolant liquid tank, and the coolant liquid can be supplied to the branch pipe by the pump.

  As the grinding wheel 3, a rough grinding diamond grinding wheel having a grinding wheel diameter of 300 mm and a grinding wheel width of 50 mm with a grinding number of 1,000, a medium finish grinding diamond grinding wheel with a grinding number of 1,500, or a finishing grinding diamond grinding wheel with a grinding number of 3,000. Using a vehicle, a workpiece w having dimensions of 150 mm in the front and rear width, 2500 mm in the left and right length, and 40 mm in height was fixed via the electromagnetic chuck 13 on the work table 4.

  The work table 4 is reciprocally moved back and forth in the left-right direction at a speed of 9 m / min, and the coolant liquid from the pair of work surface coolant supply mechanisms 20 is transferred onto the magnetic chuck at a rate of 40 liters / min from one ejection hole. A coolant liquid film is formed on the entire surface of the workpiece by supplying it onto the fixed workpiece surface, and 10 liters / minute of grinding fluid is applied from the grinding fluid supply nozzle 11 toward the grinding wheel 3 of the grinding number 1,000. Supplied.

  The grinding wheel 3 rotating at a peripheral speed (v) of 370 m / min is lowered by a cutting amount of 1.0 μm, reciprocally reversed at a table speed of 9 m / min in the left-right direction, and moved back and forth at a forward / backward feed speed of 10 mm / min. Grinding of the workpiece surface was started by bringing the grinding wheel 3 into contact with the workpiece surface fixed to the magnetic chuck on the workpiece table 4.

  The surface of the workpiece is roughly ground by the grinding wheel 3 by the relative movement of the workpiece w and the grinding wheel 3 (front and rear, left and right, up and down), and the total amount of 12.0 μm is removed, and the straightness of the workpiece in the front and rear direction is zero. A rough-grinding work piece having a thickness of .36 μm and a straightness in the left-right direction of the work of 0.68 μm was obtained.

  Next, the grinding wheel is replaced with a medium finish grinding diamond grinding wheel with a grinding number of 1,500, and the grinding conditions of the rough grinding workpiece are as follows: grinding wheel cutting depth 0.2 μm, total machining allowance 2.0 μm, medium finishing Grinding diamond grinding wheel circumferential speed (v) 80m / min, left and right moving table speed of work table 4 6m / min, forward / backward feed speed of work table 4 0.4mm / min. Processing was performed to obtain a semi-finished grinding workpiece having a mirror surface with Rx of 0.010 to 0.012 μm and Ry of 0.14 to 0.18 μm.

  Subsequently, the grinding wheel is replaced with a finish grinding diamond grinding wheel with a grinding number of 3,000, and the grinding conditions of the above-mentioned intermediate finish grinding work are as follows: grinding wheel cutting depth 0.1 μm, total machining allowance amount 0.5 μm, finishing Grinding diamond grinding wheel peripheral speed (v) 34m / min, horizontal movement table speed of work table 4 6m / min, forward / backward feed speed of work table 4 0.4mm / min. A finish-grinding work piece having a mirror surface with Rx of 0.009 to 0.010 μm and Ry of 0.09 to 0.12 μm was obtained.

  The long workpiece grinding method of the present invention can produce a mirror-polished T-die with low warpage.

DESCRIPTION OF SYMBOLS 100 Surface grinding apparatus w Work 3 Grinding wheel 4 Work table 5 Work stage 6 Machine frame 7 Saddle 9 Column 10 Grinding head 11 Grinding liquid supply nozzle 13 Magnetic chuck 20a, 20b Coolant liquid supply pipe

Claims (1)

a). A work table provided to be able to reciprocate in the left-right direction on a guide rail provided in the left-right direction on the machine frame;
b). A workpiece surface coolant liquid supply mechanism in which a pair of coolant liquid supply pipes provided with a number of jets in a pair of coolant liquid supply pipes having a length longer than the length of the lateral movement width of the work table is attached to a machine frame before and after the work table;
c). Diamond grinding wheel supported by a grinding wheel shaft that can be moved up and down on the column,
d). A grinding fluid supply nozzle that is provided in the vicinity of the diamond grinding wheel and supplies a grinding fluid to a processing point where the diamond grinding wheel and the workpiece come into contact with each other.
Using a grinding device comprising
The work is fixed to the upper surface of the electromagnetic chuck on the work table, and the work table is reciprocally reversed in the left-right direction. The coolant is supplied from the plurality of jets of the pair of work surface coolant liquid supply mechanisms to the upper surface and the side of the work and the electromagnetic chuck. A coolant liquid film is formed over the entire surface of the electromagnetic chuck and supplied to the surface, and the grinding liquid is supplied from the grinding liquid supply nozzle toward the diamond grinding wheel,
The rotating diamond grinding wheel is lowered and brought into contact with the workpiece surface fixed on the work table that is reciprocally reversed in the left-right direction to start grinding the workpiece surface. In the method of grinding a long workpiece, the surface of the workpiece is ground with a diamond grinding wheel by a simple movement.
The long workpiece grinding stage is divided into a rough grinding stage with a machining allowance of 1.5 to 15 μm and a finish grinding stage with a machining allowance of 0.05 to 1.0 μm. Surface grinding is performed using a diamond grinding wheel of No. 500 and a peripheral speed of the diamond grinding wheel of 150 to 380 m / min, and diamond grinding wheels of grinding numbers 2,000 to 3,000 are used on the finish grinding stage. A grinding method for a long workpiece, wherein surface grinding is performed at a peripheral speed of a grinding wheel of 20 to 40 m / min.

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