JP2007190648A - Drum core grinding machine and method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drum core grinding machine capable of machining a workpiece into a product with quality better than that of an integrally molded article without requiring machining for a long period of time, and to provide a drum core grinding method. <P>SOLUTION: The grinding machine 1 has a rotary grinding wheel 2, a workpiece retainer 4, and a revolving machine 3 for driving the workpiece retainer. The grinding machine is composed so as to allow the revolving machine to execute the following operation to the workpiece retainer. The workpiece retainer is moved by the revolving machine toward at least one place on the outer periphery of the rotary grinding wheel, and then, revolved around the rotary grinding wheel along the outer periphery, and finally, seceded from the outer periphery of the rotary grinding wheel. The workpiece is attachably/detachably fixed to the workpiece retainer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a structure of a grinding machine and a grinding method for grinding a side surface of a workpiece (working material) having a cylindrical shape, a rectangular parallelepiped shape, or the like, while leaving the upper and lower ends thereof to be processed into a drum core shape. .

  For example, a typical shape of a drum core, which is one of electronic components wound around a coil, is formed by a coil winding shaft around which the coil is wound and flanges formed at both ends of the coil winding shaft. ing. In most cases, the material is a mixture of calcined ferrite powder and a synthetic resin binder, which is obtained by molding press, drum processing, and firing. However, since the coil winding shaft is generally thin, it is difficult to integrally form and fire it so as to provide flanges at both ends.

  Therefore, in general, a method is adopted in which a product that is shaped as a product shape is first formed as a material as long as it is ground to form a coil winding shaft. ing. 5 to 7 show an outline of the grinding process.

  FIG. 5 shows the workpiece W to be ground by the processing machine and the product G after grinding. The workpiece W of this example has a rectangular parallelepiped shape with a long and short side length, and a side surface thereof is ground by a width b so as to leave a thickness a so as to be a product G. As a result, the drum core has a rectangular parallelepiped flange portion having a thickness a at the upper and lower ends of a cylinder having a height b. Other than the rectangular parallelepiped shown in the figure, the shape of the product includes a cylindrical shape, a hexagonal column or an octagonal column, and a chamfered shape of such a shape (not shown). ).

  FIG. 6 is a front view showing an outline of a conventional grinding machine. Four cages B are arranged on the outer edge of the disk A that rotates intermittently by 90 degrees, and revolves around the rotation axis of the disk A according to the intermittent rotation. The retainer B is provided with a recess that matches the shape of the workpiece W in order to fit and grip the workpiece W. In the case of a conventional processing machine, the retainer B rotates as will be described later, so the posture of the recess is not fixed. Therefore, in the case of automation, it is necessary to “position” the concave portion so as to match the posture of the workpiece W. Generally, a method is adopted in which the cage B is formed in a disc shape, rotated by a separately provided drive source, and a projection provided at one location around the disc is detected by a phototube arranged outside. ing. Then, it takes about 2 seconds to set the work W. Further, a disc-shaped rotating grindstone C is disposed at a position substantially in contact with the outer periphery of the disk A, and the outer periphery of the rotating grindstone C is brought close to or away from the outer periphery of the disk A by controlling the servo motor D. The material w conveyed from the parts feeder (not shown) and arranged on the disk A at the position p reaches the product discharge section s through the positions q and r, and the grinding operation itself is performed at the position q. It will be. The discharged work W is then subjected to final firing, and if necessary, the product G is completed through other processes. However, since the discharge is not a main part of the present invention, the description thereof is omitted.

At position q, a motor E that contacts and rotates the cage B is arranged in a state where it does not co-operate (that is, does not revolve) with the rotation of the disk A. The workpiece W arranged in the holder B rotates together with the holder B when it contacts the motor E. When the rotating grindstone C is moved to the workpiece W side in this state, it contacts the workpiece W and further grinds it. FIGS. 7A to 7C schematically show the state of this grinding over time, and the hatched portion in the drawing shows the ground portion. That is, one of four ridges (four vertices of a rectangle in the figure) that separates the four side surfaces of the workpiece W having a rectangular parallelepiped shape is in contact with the rotating grindstone C [FIG. a)], grinding starts in the state of repeated contact / separation between the rotating grindstone C and the workpiece W [FIG. (b)], and the state where the grinding does not take place [FIG. (c)]. It becomes. Grinding is continued thereafter, and the work is completed in a state where the grinding has progressed to the core diameter depth of the product G in FIG.

  As described above, the method of grinding the material in the calcined state to obtain the desired shape and then firing the material has facilitated the manufacture of the drum core, but the conventional method still has some problems. It was not ideal. For example, from the state of FIG. 7A to the state of FIG. 7C, the rotating grindstone C and the workpiece W are repeatedly contacted and separated as long as the workpiece W is not cylindrical. There is a possibility that a material that is in a state before being fired just after being molded and pressed will be damaged by an impact at the time of contact. 7 (a) to 7 (c) in which contact / separation is repeated, this is dealt with by reducing the cutting speed. However, as a matter of course, the time spent for machining increases. Moreover, unfortunately, in reality, it is impossible in many cases to reduce the grinding speed until the occurrence of breakage can be resolved due to the demand for maintaining productivity. That is, the processing time is long and the processing method cannot eliminate the risk of breakage.

Alternatively, there has been proposed a method in which such a problem is originally integrated but formed into two parts and combined. However, it is not easy to provide a product with a quality higher than that of a completely integrated product, whether it is integrated by bonding or by utilizing the difference in shrinkage during firing. I didn't get it.
JP2003-092215

  In view of the present situation as described above, the inventor has finally made the present invention as a result of intensive research for many years. The feature of the present inventor is that in a device for grinding into a drum core shape while leaving both ends of a workpiece, A grinder, a work holder, and a revolving machine for driving the work holder, and a processing machine configured to revolve the work holder along the outer periphery of the rotating grindstone .

  That is, in the processing machine according to the present invention, the workpiece first approaches a grindstone that rotates at high speed, and revolves around the grindstone when the distance from the center of rotation of the grindstone approaches a preset position. Will be ground. Once contacted with the grindstone, it is not separated from the grindstone until the grinding process is completed. Therefore, the machining time can be easily reduced and the possibility of breakage is extremely small.

  The structure of the “rotary grindstone” is not particularly limited in the present invention. There is no significant difference from the rotating grindstone used in conventional processing machines, and it can be used as it is. The rotating grindstone has a disk-like outer edge having a width that matches the width of the groove to be ground, and is therefore appropriately replaced according to processing changes due to material changes and the like. The outer edge portion of the rotating grindstone is composed of a “circumferential surface” and an “end surface”. In the processing machine of the present invention, the entire peripheral surface and a part of the end surface are used.

  The “work holder” is a member attached to a “circulator” described later, and holds the work during the grinding process. At the stage around the grindstone, a part of it exists inside the outer edge of the grindstone, but it is designed so that only the gripping work material is ground and it does not come in contact with the grindstone.・ It is arranged. Further, the work holder itself does not rotate (rotate) while orbiting (revolving) around the grindstone. Therefore, as described above, it is not necessary to “position” the concave portion of the cage so as to match the workpiece posture. Therefore, equipment (projections, motors, phototubes, etc.) and time (about 2 seconds) related to posture detection and control can be omitted.

  The “circulator” is a member for bringing the work holder closer to the rotating grindstone, revolving around the rotating grindstone, and finally separating from the rotating grindstone. The workpiece is set in the workpiece holder before being brought close to the rotating grindstone, the grindstone grinds the workpiece during revolution, and the workpiece is discharged from the workpiece holder after separation. Thereafter, the orbiting machine returns the work holder to the work set position, and thereafter repeats the above operation. Such an operation can be performed by a robot arm whose joint angle is accurately controlled, but a member that slides in a direction different from the sliding direction (for example, a right angle) on a member that slides parallel to the rotating surface of the rotating grindstone. Is attached and the sliding amount of both members is controlled, the work holder (and the work) moves on a specific plane parallel to the rotating surface of the rotating grindstone, so that the control is two-dimensional and the efficiency is high. However, even if a mechanism other than such a mechanism is adopted, it is included in the present invention, and the structure of the orbiting machine is not particularly limited.

  While the apparatus is in operation, the work holder holds the work for most of the time. However, it is not easy to reliably and effectively hold the work ground on the grindstone rotating at high speed. Therefore, a support plate is arranged at a position parallel to and close to the end face of the rotating grindstone on the opposite side of the rotating grindstone from the side on which the circling machine is arranged, and the work grinder approaches the rotating grindstone by the circling machine. If the free end of the work is brought into contact with the support plate at this stage, the gripping during the grinding process (that is, during the revolution around the grindstone) is ensured.

When grinding is performed in this manner, according to the conventional processing machine, the processing time required for one piece is shortened to 2 to 3 seconds instead of 4 to 8 seconds. Will be drastically reduced.

The drum shape grinding machine according to the present invention is an extremely advanced invention having the following effects.
(1) It can be manufactured by integral molding.
(2) Unlike conventional processing machines in which the workpiece and the grindstone are repeatedly contacted and separated, once contacted, they do not separate until the end of grinding, so they are not easily damaged.
(3) Since the workpiece is not easily damaged even when it is rotated at high speed, the time required for machining can be easily reduced.
(4) Conventionally, since the work holder was rotated and ground, the shape of the core portion was limited to a cylindrical shape. However, in the case of the present invention that revolves around the rotating grindstone without rotating itself, The core part can be made into a shape other than a cylinder only by changing the position control by.
(5) When machining a square workpiece, “positioning”, which was necessary in the past, is unnecessary.

  Hereinafter, the present invention will be described in more detail with reference to the drawings.

  FIG. 1 schematically shows an essential part of an example of a drum core grinding machine 1 (hereinafter referred to as “the present invention machine 1”) according to the present invention. As is apparent from the drawing, the processing machine 1 of the present invention has a rotating grindstone 2 and a rotating machine 3 disposed in the vicinity thereof. The rotating grindstone 2 rotates with a horizontal rotation axis, and thus the rotation becomes a vertical plane. The orbiting machine 3 includes an X-axis rail body 31, an X-axis slide body 32 that slides horizontally on the X-axis rail body 31, a Y-axis rail body 33 that is fixed to the X-axis slide body 32, A Y-axis slide body 34 that slides on the Y-axis rail body 33 in the vertical direction and a work holder 4 fixed on the Y-axis slide body 34 are configured. By comprehensively controlling the slide amount in the X-axis (horizontal) direction and the Y-axis (vertical) direction, the work holder 4 can move almost freely on one vertical plane. In the figure, depiction of a mechanism for controlling these devices or devices for driving is omitted.

  The work holder 4 is a member that holds the grinding work W. Since it is fixed to the Y-axis slide body 34, the work holder 4 moves in the X-axis (horizontal) direction and the Y-axis (vertical) direction according to the behavior of the orbiting machine 3. However, in the case of this example, the work holder 4 itself turns around without rotating.

  FIG. 2 schematically shows the movement of the work holder 4 and the depiction of the orbiting machine 3 is omitted. The work holder 4 is initially located at a position (A) slightly away from the rotating grindstone 2, and the work W is set here. This setting method does not limit the present invention. Thereafter, the work holder 4 is moved closer to the rotating grindstone 2. In the middle of the approach, the workpiece W comes into contact with the rotating grindstone 2 and begins to be ground. Then, from the position (b) ground to a predetermined depth, the work holder 4 revolves around the rotating grindstone 2 (clockwise in this example). Although the work holder 4 itself does not rotate (rotate), it continues to be ground as it revolves, and when it reaches one position after rotating once (1), the grinding is finished. It moves to the discharge position (c) of the subsequent workpiece W. After moving and discharging the workpiece W, it returns to the position (A) again, and this operation is repeated thereafter.

  FIG. 3 shows an example of a method for holding the material w. A support disk 5 slightly wider than the rotating grindstone 2 is disposed on the back side of the rotating grindstone 2 (the side opposite to the side where the orbiting machine 3 is disposed). When the workpiece W is set at the position (A) shown in FIG. 2, the suction portion 6 of the suction device (not shown) provided in the workpiece holder 4 sucks the workpiece W, and the suction is performed. Although the workpiece W is held by force, the free end of the workpiece W rides on the support disk 5 when it approaches the revolution start position (b), and during the revolution, the workpiece holder 4 and the support disk 5 It functions as a support plate that holds the workpiece W in a sandwiched manner. The presence of the support disk 5 facilitates a grinding operation with higher accuracy. However, the presence of the support disk 5 itself does not limit the present invention.

FIG. 4 shows another example of the form of grinding. A part of the trajectory (basically “circle”) around which the workpiece W revolves is made a “straight line”, so that the shape of the core part is a cross section. “D” shaped. According to the method of the present invention, it is possible to obtain such a “D” shape, or various other shapes which are not shown.

It is a perspective view which shows roughly the principal part of the structure of the drum core grinding machine which concerns on this invention. It is a front view which shows roughly an example of a motion of the workpiece holder in the drum core grinding machine which concerns on this invention. It is a top view which shows roughly an example of the holding | maintenance method of the workpiece | work in the drum core grinding machine which concerns on this invention. It is the top view which carried out the cross section which shows a part which shows the other example regarding the form of grinding in the drum core grinding machine which concerns on this invention. (A) And (b) is a perspective view which shows an example of the workpiece | work which is a processing material ground with a processing machine, and the shape of the product after the grinding, respectively. It is a front view which shows the outline of an example of the conventional grinding machine. (A) thru | or (c) is the schematic which shows the mode of the workpiece grinding in the conventional grinding machine over time.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drum core grinding machine 2 Rotary grindstone 3 Circulator 31 X-axis rail body 32 X-axis slide body 33 Y-axis rail body 34 Y-axis slide body 4 Work holder 5 Supporting disk 6 Adsorption part W Work G Product ( Drum core)
A disk (conventional example)
B Cage (conventional example)
C Rotary whetstone (conventional example)
D Servo motor (conventional example)
E Motor (conventional example)

Claims (5)

  In an apparatus for grinding into a drum core shape while leaving both ends of a work, a processing machine comprising a rotating grindstone, a work holder, and a revolving machine for driving the work retainer, the revolving machine comprising the work A drum core grinding machine characterized in that a cage is revolved along the outer periphery of the rotating grindstone.   The orbiting machine consists of a member that slides parallel to the end face of the rotating grindstone, and is attached to a member that is also parallel to the end face of the rotating grindstone and slides in a direction different from the sliding direction, The drum core grinding machine according to claim 1, wherein the work holder is revolved in a circular orbit by a combination of slides of both members.   The drum core grinding machine according to claim 1 or 2, wherein a support plate for supporting the workpiece between the rotating grindstone and the workpiece holder is arranged on the side opposite to the side on which the orbiting machine is arranged.   A method of grinding into a drum core shape while leaving both ends of a work, wherein the work holder includes a rotating grindstone, a work holder, and a circulator that drives the work holder. A drum core grinding method comprising: moving the wheel toward at least one point on the outer periphery of the rotating grindstone, then revolving 360 ° along a circular orbit along the outer periphery, and then separating from the circular orbit.   The drum core grinding method according to claim 4, wherein the workpiece is supported and processed with a workpiece holder by a support disk disposed on the opposite side of the rotating grinder.

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