JP2000164124A - Manufacturing device of shadow mask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately and symmetrically form a curved surface of a long size upper end surface by vertically moving a shaving blade to a tangent of a circular arc formed of an arc-shaped rail, and reciprocating an edge so as to abut to the long size upper end surface. SOLUTION: A mask frame 4 is fixed to a pedestal 8. A shaving blade lifting part 10 is moved up to one end of a long size upper end surface 2 of the mask frame 4. A shaving blade 32 is lowered on a vertical straight line so that an edge 33 is allowed to abut to a lower position cuttable from the corner of one end of an upper end surface 2. A work arm 17 is circularly moved with the center of a circle formed of a circular arc so that both corners of the long size upper end surface 2 is cut in a round shape in the same shape as an arc- shaped rail 16 by the edge 33 of the shaving blade 32. Then, the work arm 17 is inversely circularly moved to be returned up to one end of the long size upper end surface 2 to lower the shaving blade 32 so that both corner parts of the long size upper end surface 2 are cut further in a round shape in the same shape as the arc-shaped rail 16. This operation is repeated to be cut in the same shape as a circular arc of the arc-shaped rail 16 toward the center from both end sides of the long size upper end surface 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a shadow mask used for a flat cathode ray tube of a television, for cutting a long upper end face of a mask frame.

[0002]

2. Description of the Related Art As is well known, a conventional shadow mask having a slit for color selection has a three-dimensional curved surface.

FIG. 6 is a perspective view for explaining a method of assembling a shadow mask having a three-dimensional curved surface. Reference numeral 41 denotes a three-dimensional curved mask having a color selecting slit formed by an aperture die press. A mask frame 43 formed by pressing is a spot welding portion (welding point).

In a conventional shadow mask, as shown in FIG. 6A, a three-dimensionally curved mask 41 is fitted on a mask frame 42, and as shown in FIG. The three-dimensional curved surface mask 41 and the mask frame 42 are fixed by spot welding the peripheral portion of the curved surface mask 41.

[0005] In the spot welding, for example, a welding electrode horizontally moving in the opposite direction from the inside of the peripheral portion of the three-dimensionally curved mask 41 and the outside of the side wall portion of the mask frame 42 disclosed in Japanese Patent No. 2665760. Means has been adopted in which the rod is clamped so as not to change the support state of the spot welding portion, and then a welding current is applied to perform welding.

[0006]

In the conventional shadow mask, the three-dimensional curved surface mask 41 and the mask frame 42 are formed by die molding. Because of the three-dimensional curved surface, the distortion caused by spot welding did not appear on the curved surface of the mask.

However, in recent years, the demand for televisions using flat CRTs having substantially flat curved surfaces has been increasing, and the production of curved CRTs has been switched to the production of flat CRTs. The shadow mask used for this flat cathode ray tube is based on the shadow mask assembling method shown in FIG.

More specifically, as shown in FIG. 5A, side plates 3 having a long upper end surface 2 on the upper surface thereof are provided on both side ends of the frame form 1.
3 are erected in correspondence with each other, and the upper end surface 2 is elongated on both sides.
Is formed. Next, as shown in FIG. 5B, the long upper end surfaces 2, 2 of the side plates 3, 3 are formed.
To form a curved surface of the same shape. Subsequently, a thin flat rectangular mask 5 having a slit for color selection as shown in FIG. 5C is placed on the mask frame 4 and corresponding both ends of the mask 5 are curved to form a long upper end surface 2. , 2 by spot welding to obtain a shadow mask 6 shown in FIG.

In the mask frame 4 of such a shadow mask 6, since the side plates 3 and 3 having the long upper end surface 2 on the upper surface correspond to both side edges of the frame 1 by spot welding. It is said that the distortion caused by welding causes the mask frame 4 to be twisted, and it is difficult to form the mask frame 4 with high accuracy.

In addition, although the curved surface processing of the long upper end surface 2 is generally performed by an end mill, the side plates 3 and 3 vibrate by the end mill rotating at a high speed, and once the vibration occurs, the vibration cannot be stopped. The processing surface of the scale-shaped upper end surface 2 is rough, so that the processing accuracy cannot be obtained, and the two side plates 3, 3
There is a problem that the curved surfaces of the long upper end surfaces 2 and 2 are not symmetrical.

Further, if the both ends of the mask 5 are spot-welded to the long upper end surfaces 2 and 2 having rough processing surfaces where the processing accuracy is not high, a shadow mask 6 having a distorted color selecting slit can be obtained. There was a problem of becoming.

Therefore, the present invention makes it possible to form a curved mask of the long upper end surfaces 2 and 2 accurately and symmetrically even with a mask frame 4 of low precision, thereby producing a shadow mask without distortion. It is an object of the present invention to provide a shadow mask manufacturing apparatus that can perform the above operation.

[0013]

The technical problem can be solved by the present invention as described below.

That is, in the shadow mask manufacturing apparatus according to the present invention, a flat rectangular mask having a slit for color selection is placed on a mask frame having a long upper end surface on both sides, and the corresponding two ends of the flat rectangular mask are provided. A shadow mask manufacturing apparatus for cutting a long upper end surface of the mask frame of a shadow mask having sides fixed to the long upper end surface,
A pedestal for fixing the mask frame and an arc-shaped rail disposed in the vicinity of the pedestal following the elongate upper end surface of the mask frame fixed to the pedestal and the cutting edge of the cutting blade facing the elongate upper end surface. A fixed cutting blade elevating means and reciprocating means for reciprocating the cutting blade elevating means along the arc-shaped rail, wherein the cutting blade is vertically moved up and down with respect to a tangent line of an arc formed by the arc-shaped rail. The elongated upper end face is positioned on the elongated upper end face, and is cut into the same shape as the arc of the arc-shaped rail by the reciprocating movement of the cutting edge of the cutting blade in contact with the elongated upper end face. It is.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic front view showing a shadow mask manufacturing apparatus according to the present invention. FIG. 2 is a side view of the shadow mask manufacturing apparatus shown in FIG.
The mask frame is shown in longitudinal section. 3 and 4 are views for explaining the operation of the shadow mask manufacturing apparatus shown in FIG.

In these figures, the same reference numerals as those in FIG. 5 denote the same or corresponding parts, and 7 denotes a shadow for cutting the long upper end surfaces 2 and 2 of the mask frame 4 shown in FIG. This is a mask manufacturing apparatus.
A reciprocating unit (reciprocating means) 9 for reciprocating in the same direction as the longitudinal direction in which the elongated upper end surface 2 of the mask frame 4 fixed to the pedestal 8 runs; A cutting blade raising / lowering unit (sharpening blade raising / lowering means) 10 fixed to the reciprocating unit 9 and cutting the long upper end surface 2 into a curved surface.

The pedestal 8 is mounted on the mask frame 4.
And a leg portion 13 supporting the table 11 and fixed to the floor surface 12. On the upper surface of the table 11, L-shaped brackets 14, 14 for fixing the frame 1 of the mask frame 4 are screwed. It has been stopped.

The reciprocating part 9 is arranged so as to follow the drive part 15 arranged below the table 11 of the pedestal 8 and the elongated upper end surface 2 of the mask frame 4 fixed to the pedestal 8. And a work arm 17 that reciprocates around the center of a circular arc formed by the arc-shaped rail 16 while being controlled by the arc-shaped rail 16 by the operation of the drive unit 15.

The drive unit 15 includes a drive motor 18 fixed to the floor 12 and a reciprocating motion mounted on a rotating shaft of the drive motor 18 in the same direction as the longitudinal direction in which the elongated upper end surface 2 runs. The ball screw 19 is supported by bearing angles 20, 20 having both ends fixed to the floor surface 12. The arc-shaped rail 16 is screwed at both ends to washers 21, 21 fixed to the floor surface 12.

A long hole 22 is formed in the lower portion of the work arm 17, and a slide roller 24 pivotally mounted on a block 23 screwed to the ball screw 19 is fitted in the long hole 22, and intersects the arc-shaped rail 16. Arc-shaped rail in the center of the work arm 17
Three copying rollers 25, 2 arranged in a triangle so as to sandwich 16
5 and 25 are mounted on the shaft, and the above-mentioned cutting blade elevating unit 10 is mounted on the upper part of the work arm 17.

The cutting blade raising / lowering unit 10 is mounted on a lifting / lowering control motor 27 fixed to the work arm 17 via a support angle 26 and a rotating shaft of the lifting / lowering control motor 27 downward. A lifting ball screw 29 supported by bearings 28, 28, and a block 30 screwed to the lifting ball screw 29
And a cutting blade 32 screwed to a base plate 31 fixed to the base plate 31. The cutting blade 32 is positioned on a vertical line A (see FIG. 3) with respect to a tangent line of an arc formed by the arc-shaped rail 16, and a lift control motor When the cutting blade 32 moves up and down on the vertical line A by the drive of 27, the cutting edge 33 of the cutting blade 32 comes into contact with the elongated upper end surface 2.

The block 30 is a ball screw for raising and lowering.
It moves up and down along a guide plate (not shown) provided between the bearings 28 at both ends so as not to rotate by the rotation of 29.

Next, the operation will be described.

First, as shown in FIG. 1, the mask frame 4 is fixed to the pedestal 8 by L-shaped fittings 14 and 14. continue,
Power is supplied to the drive motor 18 and the reciprocating ball screw 19 is rotated while controlling the drive of the motor 18 to move the cutting blade elevating unit 10 to one end of the elongated upper end surface 2 of the mask frame 4.

Next, power is supplied to the elevation control motor 27,
While controlling the driving of the motor 27, the ball screw 29 for raising and lowering is rotated to lower the cutting blade 32 on the vertical line A.
The blade edge 33 of 32 is brought into contact with a lower position a (see FIG. 3) at which the edge of the elongated upper end surface 2 can be cut from the corner of the one end.

Thereafter, the reciprocating ball screw 19 is rotated to cause the work arm 17 to make a circular motion in the direction of arrow C about the center B of the circle formed by the arc as shown in FIG. Due to the circular movement of the arm 17, the cutting edge 33 of the cutting blade 32 cuts both corners a and b of the elongated upper end surface 2 into an R shape having the same shape as the arc-shaped rail 16.

Subsequently, the ball screw 19 for reciprocating motion is reversely rotated while controlling the driving of the motor 18, and the work arm 17 is circularly moved in the direction of arrow D to return to the one end of the elongated upper end surface 2, and again. Then, while controlling the drive of the motor 27, the lifting ball screw 29 is rotated to lower the cutting blade 32 on the vertical line A, and abut the cutting position below the position a. Is rotated again to cause the work arm 17 to circularly move in the direction of arrow C about the center B, and the two corners of the elongated upper end surface 2 cut into an R shape are further formed into the same shape as the arc rail 16. To cut.

By repeating the above operation, as shown in FIG. 4A, the round shape of the elongated upper end surface 2 gradually widens.
Thus, every time the long upper end surface 2 is cut, the cutting blade 32
When the cutting edge 33 is gradually lowered downward on the vertical line A, as shown in FIG. 4 (b), the long upper end surface 2 is located at the center from both ends of the long upper end surface 2. Is cut into a curved surface having the same shape as the arc formed by the arc-shaped rail 16.

In the present invention, the shaving blade 32 for cutting the long upper end surface 2 of the mask frame 4 is always on the vertical line A to the tangent of the arc formed by the arc-shaped rail 16 even when the work arm 17 moves. Since the cutting edge 33 does not change its direction with respect to the arc formed by the arc-shaped rail 16, the elongated upper end surface 2 is cut into the same shape as the curved surface of the arc.

The cutting edge 33 of the shaving blade 32 has a long upper end surface 2.
The mask frame 4 does not vibrate as in the case of using an end mill because
The long upper end surfaces 2 on both sides can be accurately curved into the same shape.

Furthermore, if the shadow mask manufacturing apparatus 7 is installed symmetrically, the long upper end surfaces 2 on both sides of the mask frame 4 can be simultaneously and accurately cut.

Further, the arc-shaped rail may be a grooved rail in which a groove is formed in an arc shape. When the grooved rail is used, if the copying roller of the work arm runs in the arc-shaped groove. Good.

Since the arc-shaped rails can be replaced, it is possible to obtain a mask frame having an elongate upper end surface having a curved shape as required with high accuracy.

[0035]

According to the present invention, even if the accuracy of the mask frame is not high, the long upper end surfaces on both sides can be precisely and symmetrically curved, so that a shadow mask without distortion can be efficiently produced. Can be manufactured.

Therefore, it can be said that the industrial applicability of the present invention is very high.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing a shadow mask manufacturing apparatus according to the present invention.

FIG. 2 is a side view of the shadow mask manufacturing apparatus shown in FIG.

FIG. 3 is a diagram for explaining the operation of the shadow mask manufacturing apparatus shown in FIG.

FIG. 4 is a view for explaining the operation of the shadow mask manufacturing apparatus shown in FIG.

FIG. 5 is a perspective view illustrating a method of assembling a shadow mask having a flat curved surface.

FIG. 6 is a perspective view illustrating a method of assembling a shadow mask having a three-dimensional curved surface.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 frame form 2 long upper end surface 3 side plate 4 mask frame 5 thin flat rectangular mask 6 shadow mask 7 shadow mask manufacturing device 8 pedestal 9 reciprocating unit 10 cutting blade elevating unit 15 driving unit 16 arc-shaped rail 17 work arm Reference Signs List 18 drive motor 19 reciprocating ball screw 27 elevating control motor 29 elevating ball screw 32 cutting blade 33 cutting edge

Claims (1)

[Claims] 1. A flat rectangular mask having a slit for color selection is placed on a mask frame having an elongated upper end face on both sides, and both ends of the rectangular rectangular mask are fixed to the elongated upper end face. An apparatus for manufacturing a shadow mask for cutting a long upper end surface of a mask frame of a shadow mask comprising: a pedestal for fixing the mask frame; and a long upper end surface of a mask frame fixed to the pedestal. And a reciprocating motion for reciprocating the shaving blade elevating means, which is fixed to the arc-shaped rail disposed near the pedestal, the cutting edge of the shaving blade toward the elongated upper end face, and the shaving blade elevating means along the arc-shaped rail. The cutting blade is vertically moved with respect to a tangent line of an arc formed by the arc-shaped rail to be positioned on the long upper end surface, and the cutting edge of the cutting blade contacts the long upper end surface. Reciprocate in contact The apparatus for manufacturing a shadow mask, wherein the long upper end surface is cut into the same shape as the arc of the arc-shaped rail.