JP2008023650A - Grinding device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grinding device and method capable of greatly improving the productivity by contour-machining a workpiece corresponding to a plurality of works. <P>SOLUTION: The workpiece 1 formed in advance with a plurality sets of slope faces 1c-1f corresponding to the shapes of the both end parts of the works 5 and 6 is contour-machined with a contour-machining grinding wheel. The contour machining for a plurality of works is collectively executed on the workpiece 1 by the grinding wheel while conveying the workpiece 1 with its respective slope faces 1c-1f supported to the slope face of a conveying rail, and when separating it into the respective works, this grinding device executes the contour-machining while supporting at least the lower ends of the slope faces 1d and 1e corresponding to the slope face in the work side adjoining to the work positioned outermost side by a slip prevention mechanism. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a grinding apparatus and a grinding method used for contour processing of a rare earth sintered magnet, for example.

  With the demand for miniaturization of various electric parts such as motors and the demand for improvement in the characteristics of magnets corresponding to the demand, development of high-performance small magnets is required. In such a situation, for example, an R-T-B system such as an Nd-Fe-B magnet (R is one or more rare earth elements. T is essential for Fe and contains other metal elements). Magnets have advantages such as excellent magnetic properties, Nd, which is a main component, and abundant resources, and are relatively inexpensive. Therefore, demand for magnets has been increasing in recent years.

  As a method for producing a rare earth sintered magnet, powder metallurgy is known and widely used because it can be produced at low cost. In order to produce a rare earth sintered magnet by powder metallurgy, first, a raw material alloy ingot is roughly pulverized and finely pulverized to obtain a raw material alloy powder having a particle size of about several μm. The raw material alloy powder thus obtained is oriented in a magnetic field and molded in a magnetic field. After molding in a magnetic field, the compact is sintered and aged in a vacuum or in an inert gas atmosphere. Furthermore, processes such as machining and surface treatment are performed.

  In the production of rare earth sintered magnets by the powder metallurgy method described above, a desired shape (for example, an arc shape or a ring shape) is formed by molding in a magnetic field, and a cutting process or the like is performed after heat treatment (sintering and aging). It is common to arrange the shape. However, along with the demand for downsizing, it has become difficult to form R-T-B type raw material alloy powder having poor fluidity into a small arc shape or ring shape.

  Therefore, for example, when producing an arc-shaped rare earth sintered magnet, it is formed into a rectangular shape that is one size larger in the magnetic field molding, or is formed into a block shape that is large enough to take a plurality of the arc shapes. In addition, after producing a sintered body by heat treatment, an attempt has been made to process it into a desired arc shape by contour processing using a grindstone (see, for example, Patent Document 1).

  In Patent Document 1, a conveyance path that guides a magnet member to be ground in one direction, a conveyance means that urges a plurality of magnet members in the conveyance direction in the conveyance direction and continuously sends them to the conveyance path, and a conveyance path And a pair of grinding means for grinding the opposite surfaces of the conveyed magnet member, and an urging means for urging the magnet member in the direction opposite to the conveying direction downstream of the grinding means. An apparatus for processing a magnet member is disclosed.

  In order to process the segment shape, it is necessary to perform processing using a general-purpose grindstone (contour processing grindstone) having a grinding surface (contour processing surface) equivalent to the final product shape. For example, in the case of a C shape, It is necessary to grind the outer R surface and the inner R surface with a grindstone that matches each shape. As described above, when the outer R surface and the inner R surface are each ground with the general-purpose grindstone, the workpieces must be interchanged in the middle, and it is difficult to process them continuously. Therefore, the invention described in Patent Document 1 has means for grinding each of the opposite surfaces of the magnet member, and means for urging the magnet member in the direction opposite to the conveying direction downstream of the grinding means, The outer R surface and the inner R surface are ground simultaneously.

  By adopting such a configuration, continuity is improved. However, if the productivity is further increased, there is a great difficulty. For example, if the productivity is to be doubled, it is necessary to install two processing apparatuses having the above-described configuration in parallel, which requires a large capital investment. Further, when two processing devices are installed in parallel, it is necessary to double the workpieces to be input, and there is a problem that efficiency cannot be achieved in this respect.

In order to greatly improve productivity while simplifying the equipment, for example, as described in Patent Document 2, it can be considered that two systems can be processed by one unit, but the number of devices themselves is reduced. Even if it is possible, the apparatus configuration becomes complicated, and a large capital investment is required. Moreover, the problem that the workpieces to be input must be doubled cannot be solved, and there remains a problem in terms of efficiency.
JP 11-347900 A JP-A-9-248744

  As described above, in the prior art, it is a basic stance to perform contour processing corresponding to one workpiece with one total-type grindstone for one workpiece, which greatly improves productivity. It is a big obstacle on the top.

  The present invention has been proposed in view of such a conventional situation, and enables contour processing corresponding to a plurality of workpieces to one workpiece, for example, without greatly changing the apparatus configuration. It is an object of the present invention to provide a grinding apparatus and a grinding method capable of dramatically improving productivity.

  In order to improve productivity, it is considered advantageous to process a plurality of workpieces from one workpiece. However, when machining a plurality of workpieces from one workpiece, for example, there may be a difference in dimensions between the location where the contouring is started by the contouring grindstone of the workpiece and the location where the contouring is finished. is there. This is because one grinding object (workpiece) is processed into a plurality of workpieces and finally separated into each workpiece, so the force (grinding resistance, etc.) received during grinding is separated into each workpiece. This is considered to be caused by the fact that the workpiece is misaligned between the conveying rail and the contouring grindstone.

  Therefore, when separating a plurality of workpieces from a single workpiece, it is necessary to eliminate dimensional variations in the grinding direction (contour processing start location and contour processing end location) and improve dimensional accuracy. . The inventors of the present invention have repeatedly studied measures that can improve not only productivity but also dimensional accuracy, and have reached the present invention.

  That is, the grinding apparatus of the present invention includes a conveyance rail that conveys a workpiece in which a plurality of sets of inclined surfaces are formed in advance corresponding to the shape of both end portions of the workpiece, and the workpiece that is conveyed by the conveyance rail. A contouring grindstone for contouring the contouring grindstone, the contouring grindstone is a single electrodeposition grindstone having a plurality of contouring surfaces corresponding to a workpiece shape, and the conveying rail is formed of the workpiece. A plurality of sets of inclined surfaces extending in the conveying direction corresponding to each inclined surface, and at least a contouring grindstone of an inclined surface corresponding to a workpiece-side inclined surface adjacent to at least the outermost workpiece; An anti-slip mechanism is provided at the opposing portion, and each workpiece is transported in a state where each inclined surface of the workpiece is supported by each inclined surface of the conveying rail, and a plurality of workpieces are separated from the workpiece by the contouring grindstone. Contour processing of all at once It is, characterized in that it is separated into a workpiece.

  The grinding method of the present invention is a grinding method in which contour processing is performed with a contour processing grindstone on a workpiece on which a plurality of sets of inclined surfaces are formed in advance corresponding to the shapes of both end portions of the workpiece. In addition, the contouring for a plurality of workpieces is collectively performed on the workpiece by the contouring grindstone while conveying the inclined surfaces of the workpiece while being supported by the inclined surfaces of the conveying rails. In the separation, the contour machining is performed while at least the lower end portion of the inclined surface corresponding to the workpiece-side inclined surface adjacent to the outermost workpiece is supported by a non-slip mechanism.

  In the grinding apparatus and grinding method of the present invention, the contouring grindstone in which a plurality of contoured surfaces corresponding to the workpiece shape are formed on a single electrodeposition grindstone is used. The contour processing is performed all at once. For example, if a plurality of arc-shaped surfaces are formed on a pair of contouring grindstones, a plurality of C-shaped workpieces are collectively formed. Therefore, the production amount by one-time processing increases dramatically, such as double or triple, and the productivity is greatly improved. At this time, it is only necessary to change the shape of the electrodeposition grindstone, and it is not necessary to significantly change the configuration of the grinding apparatus.

  Furthermore, in the grinding apparatus of the present invention, since the shape of the transport rail for transporting the workpiece is devised, it is also possible to realize highly accurate contour processing. That is, in the grinding apparatus of the present invention, the workpiece having an inclined surface corresponding to the shape of each workpiece is conveyed by a conveyance rail having a plurality of sets of inclined surfaces, and the inclined surfaces of both end portions of the workpiece are obtained. Is ground with a pair of inclined surfaces of the transport rail being supported. In this case, when the workpiece is placed on the conveyance rail, the inclined surfaces facing each other are brought into contact with each other by gravity, and the position is inevitably determined. This positioning state is maintained at a high level, and as a result, highly accurate grinding is stably realized. In addition, no clearance is required between the transport rail and the workpiece, and no clearance is formed by abutment between the inclined surfaces due to the gravity. Therefore, the occurrence of positional deviation of the workpiece during machining due to the clearance does not become a problem.

  However, in the above-described contour machining, the force received during grinding when the workpiece is separated into each workpiece is released, and this causes a positional shift in the workpiece, for example, the contour machining starts. There may be a difference in size between the portion to be processed and the portion where the contour processing is completed. As a result of detailed investigations on the occurrence of misalignment by the present inventors, when the contour processing on the workpiece proceeds and separated into each workpiece, the inner portion of the workpiece (adjacent in the arrangement direction of the workpiece) It has been found that the part on the workpiece side) is pushed downward, resulting in less grinding of the inner part compared to the outer part, resulting in a dimensional difference. Therefore, in the present invention, an anti-slip mechanism is installed at least on the portion of the inclined surface corresponding to the inner inclined surface (adjacent workpiece-side inclined surface) of the outermost workpiece facing the contouring grindstone. After the separation, the contour processing is performed while the inner lower end portion of the workpiece is supported by the front slip prevention mechanism. Thereby, the positional deviation of the workpiece is eliminated, and in the finally obtained workpiece, the dimensional difference between the location where the contour machining is started and the location where the contour machining is finished is suppressed.

  According to the grinding apparatus and the grinding method of the present invention, it is possible to collectively perform contour processing corresponding to a plurality of workpieces on one workpiece, for example, without greatly changing the apparatus configuration. It is possible to dramatically improve the performance. Further, according to the grinding apparatus and the grinding method of the present invention, even when a plurality of workpieces are separated from a single workpiece, dimensional variations in the grinding direction (contour processing start location and contour processing end location) are eliminated. It is possible to improve the dimensional accuracy of the obtained workpiece.

  Hereinafter, embodiments of a grinding apparatus and a grinding method to which the present invention is applied will be described in detail with reference to the drawings.

  In the grinding apparatus and grinding method of the present embodiment, the workpiece is a rare earth sintered magnet, and the workpiece is a workpiece having two arc-shaped sections (C-shaped). First, a process for grinding a rare earth sintered magnet into a circular arc shape using a set of contouring grindstones will be described.

  The contouring grindstone performs, for example, a grinding process (so-called contouring process) in which a rare earth sintered magnet is machined into a predetermined shape. For example, an electrodeposition surface serving as a grinding part is provided on the outer peripheral surface of a disk-shaped base metal. It is formed. The contouring grindstone is mounted on a grinding apparatus by inserting and fixing a rotating shaft into a grindstone mounting hole of the disc-shaped base metal, for example, and is rotated at a high speed by the rotating shaft, and is an electrodeposited surface that is the outer peripheral surface Grinding (contouring) is performed by contacting the workpiece with the workpiece. At this time, the peripheral speed is determined by the grindstone diameter and the rotational speed. In the grinding process, the peripheral speed is preferably 800 to 3000 m / min, and more preferably 1000 to 2500 m / min. If the peripheral speed is less than or equal to the above range, the grinding resistance increases. Conversely, if the peripheral speed exceeds the above range, machining defects due to vibration or slip may occur.

  The electrodepositing surface of the contouring grindstone is configured by electrodepositing and fixing abrasive grains on the outer peripheral surface of the disk-shaped base metal. Examples of the abrasive grains include diamond and boron nitride cubic (CBN). Superabrasive grains are used. These abrasive grains are fixed to the electrodeposition surface by an electrodeposition metal such as Ni. Further, the shape of the electrodeposition surface of the contouring grindstone has a shape corresponding to the contour shape of the workpiece. For example, when the workpiece is C-shaped, the inner arc surface (referred to as the inner R surface) or the like. Corresponding to the outer arc surface (referred to as the outer R surface), the cross section is arcuate.

  FIG. 1 shows a grinding process in the case where two C-shaped workpieces are collectively formed. FIG. 2 shows a contouring grindstone set (a pair of contouring grindstones) used in the grinding process.

  For example, when grinding a rectangular parallelepiped workpiece 1 as shown in FIG. 1A to two C-shaped workpieces, first, two inner R surfaces as shown in FIG. The first grinding is performed using the first contouring grindstone 3 having the arcuate surfaces 3a and 3b corresponding to 2 and the inclined surfaces 3c corresponding to the inclined surfaces on both sides thereof. Here, the circular arc surfaces 3a and 3b have a shape corresponding to the contour shape of the workpiece, and each has an arc surface shape in which a central portion protrudes. In the case of this embodiment, arc surfaces 3a and 3b corresponding to two inner R surfaces are formed adjacent to each other so as to correspond to two C-shaped workpieces.

  Further, the inclined surface 3c is a contour processed surface for forming inclined surfaces on both sides of the two inner R surfaces, and the inclined surfaces formed thereby become both end surfaces of the C-shaped workpiece. The formed inclined surface is formed at an angle substantially coincident with the normal line at both ends of the inner R surface formed by the arc surfaces 3a and 3b. Here, in the first contouring grindstone 3, the region between the inclined surfaces 3c adjacent to each other between the circular arc surfaces 3a and 3b is formed as a convex portion 3d, and the grinding allowance for the tip is as follows. It is larger than the grinding allowance required for forming the inclined surface of the workpiece.

  By performing the first grinding process (contour processing) using the first contouring grindstone 3, as shown in FIG. 1B, the workpiece 1 has two inner R surfaces 1a and 1b, Inclined surfaces 1c, 1d, 1e, 1f on both sides of each inner R surface 1a, 1b are formed. The inner R surface 1a and the inclined surfaces 1c and 1d on both sides thereof correspond to the contour shape of one workpiece, and the inner R surface 1b and the inclined surfaces 1e and 1f on both sides thereof correspond to the contour shape of the other workpiece. .

  Further, in this first grinding process, the height of the end inclined surface required for forming the C-shape at the intermediate position between the inner R surfaces 1a and 1b by the convex portion 3d of the first contouring grindstone 3 is set. Groove processing is performed to a height (depth) of more than this. The groove S thus formed serves as a boundary that separates the two C-shaped workpieces during outer R surface grinding. The first grinding process can also be performed in two stages: rough grinding and fine grinding. By using two stages, it is possible to reduce the grinding amount to be processed at one time, and it is possible to reduce the load applied to the contouring grindstone 3 and the workpiece 1.

  Next, the second grinding is performed using the second contouring grindstone 4 having two arcuate surfaces 4a and 4b corresponding to the outer R surface as shown in FIG. Processing. The contouring grindstone 4 used for the second grinding process has the two arcuate surfaces 4a and 4b, and these arcuate surfaces 4a and 4b are part of the contour shape of the C-shaped workpiece (outside This is a contour processing surface corresponding to the (R surface). Further, the second contouring grindstone 4 has a convex portion 4c between the two arcuate surfaces 4a and 4b, and the grinding processing allowance of the tip portion of the convex portion 4c is the first contour processing. It is set to overlap with the grinding allowance for the convex portion 3d of the grinding wheel 3 for use.

  This second grinding process is preferably performed in two stages: rough grinding shown in FIG. 1C and fine grinding shown in FIG. In the second grinding step, the convex portion 4c must be provided at the center of the second contouring grindstone 4, and when the workpiece 1 is a hard material such as a rare earth sintered magnet, Heavy grinding results in particularly severe wear. If the two-stage grinding is performed, it is possible to reduce the grinding amount to be processed at one time, and it is possible to suppress wear during the heavy grinding. In addition, when the outer R surface is roughly ground, the R surface boundary region is wide, unlike the inner R surface. Therefore, in the rough grinding shown in FIG. Alternatively, it is preferable to grind into a flat shape.

  In precision grinding shown in FIG. 1 (d), the outer R surfaces 1g and 1h are ground into circular arc surfaces, and two workpieces 5 having the two inner R surfaces 1a and 1b and the outer R surfaces 1g and 1h are further obtained. , 6 cut. The cutting into the two workpieces 5 and 6 is performed by the convex portion 4 c of the second contour processing grindstone 4. As described above, the grinding allowance of the second contouring grindstone 4 is set so that the outer R surfaces 1g and 1h are formed, but the grinding allowance of the convex portion 4c at this time is The depth reaches the groove S formed by the convex portion 3 d of the first contouring grindstone 3. Therefore, at the time when grinding of the outer R surfaces 1g and 1h to the circular arc surface is completed in the final stage of the second grinding, the tip of the convex portion 4c of the second contouring grindstone 4 is the groove. S has reached S, and the two workpieces 5 and 6 are cut and completely separated.

  Although the two workpieces 5 and 6 can be collectively formed by the above-described grinding (contour processing), the number of workpieces that can be collectively formed is not limited to this, for example, the first contour By increasing the number of arcuate surfaces corresponding to the inner R surface and the outer R surface formed on the processing grindstone 3 and the second contouring grindstone 4, three workpieces, four workpieces Further, it is possible to perform contour processing of a larger number of workpieces at once. Therefore, productivity can be dramatically improved. In addition, when the number of circular arc surfaces is increased as described above, it is possible to cut and separate all workpieces by forming convex portions 3d or convex portions 4c between the circular arc surfaces. is there.

  Further, the above-described grinding (contour processing) is effective not only for improving productivity but also for improving the accuracy of contour processing. For example, by taking a plurality of workpieces, such as two, three, etc., the workpiece 1 becomes larger and its weight increases, so that the installation state becomes stable, and the workpiece 1 is misaligned. It is suppressed and processing accuracy improves. In particular, when the shape of each contour processing surface of the contouring grindstone is asymmetrical, the machining accuracy is greatly improved by using the plurality of (especially even number). When the contouring surface of the contouring grindstone is asymmetrical, for example, the amount of shaving is large at one side of the contouring grindstone, and the amount of shaving is small at the opposite side. The balance may be greatly lost. The loss of the balance of the amount of cutting leads to uneven wear or the like of the contouring grindstone, and greatly impairs the processing accuracy. When a plurality of contour processing surfaces (particularly even numbers) are formed corresponding to a plurality of contouring grindstones as described above, even if the individual contour processing surfaces are asymmetrical, they are arranged symmetrically. Thus, the shape of the entire contouring grindstone can be made symmetrical. Therefore, a well-balanced cutting can be performed, the uneven wear of the contouring grindstone can be eliminated, and the machining accuracy can be maintained for a long time.

  A series of grinding processes of the workpiece 1 can be performed by mounting the above-described contouring grindstone on a grinding apparatus. As described above, the workpiece 1 uses the first contouring grindstone 3 to grind the inner R surfaces 1a and 1b and the inclined surfaces 1c to 1f, and then uses the second contouring grindstone 4 to grind. The outer R surfaces 1g and 1h are ground. Therefore, the grinding process of the inner R surfaces 1a and 1b and the inclined surfaces 1c to 1f is a first grinding process, and the grinding process of the outer R surfaces 1g and 1h is a second grinding process, and the first contour machining is used. By sequentially arranging the grindstone 3 and the second contouring grindstone 4, it is possible to perform the first grinding process and the second grinding process as a series of steps.

  Therefore, in the following, as an embodiment of a grinding apparatus to which the present invention is applied, an example of a grinding apparatus applied to a grinding apparatus that continuously performs the first grinding process and the second grinding process will be described. In the grinding apparatus according to the present embodiment, in the second grinding process, a plurality of workpieces are processed with respect to the workpiece by the contouring grindstone while conveying each inclined surface of the workpiece supported by the inclined surface of the conveying rail. Minute contour processing is performed at once and separated into each workpiece.

  FIG. 3 shows a schematic configuration of a grinding apparatus that continuously performs the first grinding process and the second grinding process. This grinding apparatus can be broadly divided into a first area and a second area. In this first area, a first grinding process (grinding of the inner R surfaces 1a and 1b and the inclined surfaces 1c to 1f) is performed. A second grinding process (the outer R surface 1g, 1h grinding process and separation by cutting the workpieces 5 and 6) is performed in the two areas.

  Here, the first area is composed of the first conveyance rail 11, the first grinding wheel 12 provided in the middle of the first conveyance rail 11, and the support jig 13 disposed to face the first grinding wheel 12. It is configured. The first transport rail 11 transports the rectangular parallelepiped workpiece 1 and has a rectangular guide groove 11a as shown in FIGS. 4 (a) and 4 (b). The first grinding wheel 12 is a general-purpose grindstone for grinding the inner R surfaces 1a and 1b and the inclined surfaces 1c to 1f of the object 1 to be ground. For example, the same contour processing as shown in FIG. Use a grinding wheel. The first grinding wheel 12 performs grinding on the lower surface of the workpiece 1 from an opening (not shown) provided in the transport rail 11. The support jig 13 plays a role of pressing and holding the workpiece 1 from above when the lower surface of the workpiece 1 is ground by the first grinding wheel 12. In the first area, the workpiece 1 having a width wider than the traveling direction is transported on the transport rail 11. That is, the width of the workpiece 1 is set to be larger than that in the case of taking a single workpiece, and as a result, the contact area with the conveyance rail 11 may increase and the conveyance resistance may increase. Therefore, in the grinding apparatus of the present embodiment, a plurality of auxiliary grooves 11b extending in the transport direction are formed on the bottom surface of the transport groove 11a where the transport rail 11 is formed, and the workpiece 1 and the transport rail 11 during transport are formed. The contact resistance is reduced.

  The second area is composed of a second conveyance rail 21 and a second grinding wheel 22, and the same grinding wheel for contouring as shown in FIG. 2B is used as the grinding wheel 22. The second grinding wheel 22 performs grinding of the outer R surfaces 1 g and 1 h on the upper surface of the workpiece 1. The second transport rail 21 supports and transports the workpiece 1 on which the inner R surfaces 1a and 1b and the inclined surfaces 1c to 1f are formed by the first grinding process, and FIG. As shown to (b), it has the inclined surfaces 21a-21d corresponding to the said inclined surfaces 1c-1f. In the case of this example, an auxiliary rail that supports the back side of the workpiece 1 is provided at the central portion of the transport rail 21 (between the inclined surfaces 21a and 21b and between the inclined surfaces 21c and 21d). Portions 21e and 21f are formed. The auxiliary rail portions 21 e and 21 f correspond to auxiliary members that support the back surface side of the workpiece 1 during grinding by the second grinding wheel 22.

  When the workpiece 1 is ground into a C shape by the grinding apparatus having the above configuration, first, the workpiece 1 is placed on the first transport rail 11 for transporting the workpiece 1. At this time, the workpiece 1 is conveyed in a state where both side surfaces of the workpiece 1 are guided by the side walls of the guide groove 11 a of the first conveyance rail 11, but between the side walls of the guide groove 11 a and both sides of the workpiece 1. A slight clearance is provided for. Thereby, conveyance is performed smoothly. It should be noted that the clearance does not cause a center position shift between the inner R surfaces 1a and 1b and the outer R surfaces 1g and 1h in the C-shape of the workpiece 1 that is finally processed.

  The workpiece 1 placed on the first conveyance rail 11 is composed of conveyance means (for example, conveyance using a roller covered with a material having elasticity, or a belt member having elasticity, two rollers). The first grinding wheel 12 is transported along the guide groove 11a of the first transport rail 11 and rotated in the direction opposite to the direction in which the workpiece 1 is transported. Contact with. The workpieces 1 are supplied one after another, and the second and third workpieces 1 are continuously conveyed behind the first workpiece 1.

  In the conveying means, when the workpiece 1 is a rare earth sintered magnet, it is preferable that the conveying means R1 has a pair of upper and lower structures because the grinding resistance is very large. The feed speed of the workpiece 1 is appropriately set mainly depending on the cutting amount, the material of the workpiece 1 and the required value of the grindstone life, and is usually set to about 10 to 3000 mm / min. In particular, when the workpiece 1 is a rare earth sintered magnet, the feed rate is preferably 50 to 1000 mm / min. When the feed rate is 50 mm / min or less, there is no merit of efficiency improvement by continuous machining. Conversely, when the feed rate is 1000 mm / min or more, there is a possibility that a thermal crack may occur in the workpiece 1.

  The workpiece 1 is brought into contact with the first grinding wheel 12 so that the inner R surfaces 1a and 1b and the inclined surfaces 1c to 1f are ground. The inclined surfaces 1c to 1f are preferably inclined surfaces that are inclined, for example, by 20 ° to 80 ° with respect to the vertical direction. In the grinding process, the workpiece 1 is ground while being supported by the support jig 13. The support jig 13 serves as a guide for conveying the so-called workpiece 1. Moreover, it is set as the mechanism in which position adjustment is possible in order to make the workpiece 1 into desired thickness.

  The workpiece 1 on which the inner R surfaces 1a and 1b and the inclined surfaces 1c to 1f are formed in the first area is then conveyed to the second area, and the outer R surfaces 1g and 1h are ground. The workpiece 1 is transferred from the first area to the second area by conveying the workpiece 1 from the first conveyance rail 11 to the second conveyance rail 21. At this time, at the joint between the first transport rail 11 and the second transport rail 21, the end of the second transport rail 21 is made equal to or less than the end of the first transport rail 11. Preferably, a minute step is provided so that the end of the second conveyance rail 21 is slightly lowered, so that the workpiece 1 is conveyed from the first conveyance rail 11 to the second conveyance rail 21. Can be performed smoothly.

  In the 2nd conveyance rail 21, it conveys in the state supported by the inclined surfaces 21a-21d which have the inclination angle corresponding to this to the inclined surfaces 1c-1f of the said workpiece 1, and performs a 2nd grinding process. The shape of the second transport rail 21 may be a shape that matches not only the inclined surfaces 1 c to 1 f of the workpiece 1 but also the inner R surfaces 1 a and 1 b of the workpiece 1. The inclined surfaces 1c to 1f at both ends of the workpiece 1 are supported by the inclined surfaces 21a to 21d that match this, and the inner R surfaces 1a and 1b and the transport rail 21 have a gap. Positioning can be performed with accuracy only on the inclined surfaces 21a to 21d, and processing accuracy in grinding of the outer R surfaces 1g and 1h can be improved.

  In addition, when conveying the workpiece 1 using the conveyance rail 21, the conveyance mechanism (for example, conveyance roller) R2 may be used for conveyance, but the workpiece 1 is conveyed as the conveyance mechanism R2. A single roller that is urged so as to be pressed against the inclined surfaces 21 a to 21 d of the rail 21 can be used. However, when the workpiece 1 is a material having a large grinding resistance, or is formed of a material having low mechanical strength, it is preferable to use a pair of upper and lower rollers. Further, when the workpiece 1 is held by the transport rail 21, it is preferable to hold the workpiece 1 so that at least the lower ends of the inclined surfaces 1c to 1f are positioned 0.5 mm or more above the lower ends of the inclined surfaces 21a to 21d. . The transport mechanism R2 can be installed next to the first area or can be omitted.

  Here, the second conveyance rail 21 will be described. As described above, in the second conveyance rail 21, the inclined surface 21a that supports the inclined surfaces 1c to 1f of the workpiece 1 formed in the first area. , 21b, 21c, 21d, and auxiliary rail portions 21e that support the back side of the workpiece 1 between the inclined surfaces 21a and 21b and between the inclined surfaces 21c and 21d, 21f is formed. The inclined surface 21a and the inclined surface 21b, and the inclined surface 21c and the inclined surface 21d are formed so as to extend in the transport direction in a state of facing each other.

6A and 6B schematically show the inclined surfaces 21a to 21d and the inclined surfaces 1c to 1f of the work piece 1, respectively. As shown in FIG. 6A, the inclined surfaces 1c to 1f of the workpiece 1 are normal lines h ₁ and h that radiate radially through the centers of the circles corresponding to the inner R surfaces 1a and 1b. ₂ or an angle corresponding to the normals h ₃ and h ₄ , and the opening angle θ ₁ between the inclined surfaces 1 c and 1 d and the opening angle θ ₂ between the inclined surfaces ₁ e and ₁ f are normal lines h ₁ , h _The angle corresponds to the center angle between the _two or the center angle between the normals h ₃ and h ₄ . For example, when the processed shape of the workpiece 1 (the shapes of the workpieces 5 and 6) is a C-shape obtained by dividing a cylindrical shape into three equal angular intervals, the opening angles (center angles) θ ₁ and θ ₂ are respectively 120 °. When the processed shape of the workpiece 1 is a shape obtained by dividing a cylindrical shape into four at equal angular intervals, the opening angles (center angles) θ ₁ and θ ₂ are each 90 °.

The opening angle θ ₁ between the inclined surfaces 1c and 1d of the workpiece ₁ and the opening angle θ ₂ between the inclined surfaces 1e and 1f are not limited to this, for example, the opening angles θ ₁ and θ ₂ = 15 ° to 150 °. It is possible to set arbitrarily within the range. However, if the opening angles θ ₁ and θ ₂ are less than 15 °, the inclined surfaces 1c to 1f are close to a vertical surface, and smooth conveyance may be difficult. On the other hand, if the opening angles θ ₁ and θ ₂ exceed 150 °, the inclined surfaces 1c to 1f are close to a horizontal plane, which may make positioning in the horizontal direction difficult.

The inclined surfaces 21 a to 21 d of the transport rail 21 are formed at an angle corresponding to the inclined surfaces 1 c to 1 f of the workpiece 1. That is, when the inclined surfaces 1c to 1f of the workpiece 1 are formed corresponding to the normal lines of the inner R surfaces 1a and 1b, the inclined surfaces 21a to 21d are also inclined at the same angle. and by the inclined surface 21a, the opening angle theta ₃ and the inclined surface 21c between 21b, also open angle theta ₄ between 21d, the workpiece 1 of the inclined surface 1c, open between 1d angle theta ₁ and the inclined surface 1e, It is set equal to the opening angle θ ₂ between 1f.

  When transporting the workpiece 1 on the transport rail 21, the inclined surfaces 1 c and 1 d of the workpiece 1 are inclined by the gravity as shown in FIG. 6B. The inclined surfaces 1e and 1f of the workpiece 1 are supported by the inclined surfaces 21c and 21d of the conveyance rail 21, and the inclined surfaces 1c to 1f of the workpiece 1 are inclined of the conveyance rail 21. By sliding on the surfaces 21a to 21d, the workpiece 1 is conveyed, and grinding by the grinding wheel 22 is performed.

  Here, the support state is inevitably determined by the action of gravity and is extremely excellent in stability. Moreover, in this state, the workpiece 1 is supported without clearance and is positioned with high accuracy. For example, when the processed shape of the workpiece 1 is a C-shape, the center position is uniquely determined by the placement on the transport rail 21. Therefore, if the workpiece 1 is ground by the grinding wheel 22 while being transported by the transport rail 21, it is possible to stably perform highly accurate grinding without causing a decrease in processing accuracy due to misalignment. It is.

  In the above example, the inclined surfaces 1c to 1f of the workpiece 1 and the inclined surfaces 21a to 21d of the transport rail 21 are all left-right symmetric. However, the present invention is not limited to this, and the inclined surfaces 1c and 1d and the inclined surfaces are inclined. The surfaces 21a, 21b, or the inclined surfaces 1e, 1f and the inclined surfaces 21c, 21d may be asymmetrical. The positioning can be performed in the same manner even when the left and right are asymmetric, and highly accurate grinding can be stably performed.

  Further, as shown in FIGS. 5A and 5B, auxiliary rail portions 21 e and 21 f are formed on the transport rail 21, and these auxiliary rail portions 21 e and 21 f are formed by the grinding wheel 22. It functions as an auxiliary member that supports the back surface side of the workpiece 1 at the grinding position. The auxiliary rail portions 21e and 21f do not need to positively bias the back surface side of the workpiece 1 and may be installed so that the tip contacts or slightly separates the back surface of the workpiece 1. . In this case, the front end surfaces of the auxiliary rail portions 21e and 21f may be arcuate surfaces that substantially coincide with the inner R surfaces 1a and 1b of the work piece 1, but from the viewpoint of slidability, the auxiliary rail portions 21e. 21f is preferably less than or equal to 1/2 of the width of the workpiece 1, and the radius of curvature of the arc of the tip surface is the curvature of the inner R surfaces 1a and 1b of the workpiece 1. It is preferably smaller than the radius.

  When the workpiece 1 is ground into, for example, a C shape, the inclined surfaces 21 a to 21 d of the transport rail 21 support both ends of the inner R surfaces 1 a and 1 b of the workpiece 1. If an excessive force is applied when a force is applied to the central portion of each inner R surface 1a, 1b, there is a risk of damage or breakage. If the auxiliary rail portions 21e and 21f are installed and the workpiece 1 is supported from the back side, damage or breakage of the workpiece 1 due to excessive force applied can be avoided. Further, when the workpiece 1 is a rare earth sintered magnet or the like, the workpiece 1 may be bent due to the pressing force of the grinding wheel 22, but the auxiliary rail portions 21 e and 21 f prevent the bending and prevent the workpiece 1 being conveyed from being conveyed. It also demonstrates the function of preventing rampage. The function is effective for processing a C-type rare earth magnet having a thickness of about 0.5 to 3 mm.

  As described above, by using the grinding apparatus shown in FIG. 3, a series of grinding processes from the inner R surfaces 1a, 1b to the outer R surfaces 1g, 1h can be performed continuously, and the inner R surface 1a, It is possible to perform high-precision grinding without any deviation of the center position between 1b and the outer R surfaces 1g and 1h.

  By the way, in the above-described grinding apparatus and grinding method, the contour processing proceeds from the end of the workpiece 1 in the second area, and is processed into two workpieces having a circular arc cross section. FIG. 7 shows the progress of grinding in the second area. In the second area, contour processing is performed on the upper surface of the workpiece 1 in which the inner R surfaces 1a and 1b are formed on the bottom surface side as shown in FIG. At this time, as shown in FIG. 7B, the outer R surfaces 1h and 1g are processed from the end portion (contour processing start side end portion A) of the workpiece 1, and the workpiece 5, Separation between 6 progresses. When the contour processing of the outer R surfaces 1h and 1g proceeds to the opposite end (contour processing end side end B) of the workpiece 1, the workpiece 1 is 2 as shown in FIG. The two workpieces 5 and 6 are completely separated.

  In the above-described grinding of the workpiece 1, the contour forming start side end portion A and the cutting process are started. However, since a lot of grinding allowance is left in the initial stage of grinding, the workpiece is left. The rigidity of 1 is maintained. However, as machining progresses and cutting progresses, the grinding cost is reduced and the rigidity is lowered, and the machining accuracy deteriorates. In particular, when the workpiece 1 is separated into two workpieces 5, 6, the grinding resistance is suddenly released, so that the workpiece 1 is violated between the transport rail 21 and the grinding wheel 22, and the dimensions are reduced. It tends to decrease accuracy.

  FIG. 8A schematically shows the state of positional deviation of the workpiece 1 (the workpieces 5 and 6) at this time. If the workpiece 1 (the workpieces 5 and 6) is at the position indicated by the solid line, accurate machining is performed. On the other hand, when the grinding resistance is abruptly released, the direction of the force applied by the central convex portion of the grinding wheel 22 responsible for cutting to the workpiece 1 (shown by an arrow in the figure), as shown by a one-dot chain line in FIG. The workpiece 1 is displaced (sinks) with respect to the direction. When such positional deviation occurs, the grinding amount decreases in the submerged portion, and the grinding amount increases on the opposite side. In the workpiece 1, the thickness dimension t2 of the inner end portion is larger than the thickness dimension t1 of the outer end portion of each of the workpieces 5 and 6, as shown in FIG. Therefore, in the workpieces 5 and 6 after grinding, a difference in the thickness dimension occurs at the contour processing end side end B, and there is a dimensional difference between the contour processing start side end A and the contour processing end side end B. Arise.

  The present inventors have studied in detail about the cause of such a positional shift. As a result, when the smoothness of the inclined surfaces 21a to 21d of the transport rail 21 is high, it was found that the workpiece 1 slips slightly when the force in the direction of the arrow in FIG. The transport rail 21 is finished so that the surface is close to a mirror surface in order to smoothly transport the workpiece 1. The smoothing of the transport rail 21 is effective in terms of transporting the workpiece 1, but causes the positional deviation.

  Therefore, in order to eliminate the positional deviation of the workpiece 1 (workpieces 5 and 6), in the grinding apparatus of the present embodiment, a non-slip mechanism is provided at least in a portion facing the grinding wheel 22 of the transport rail 21. ing. By providing a non-slip mechanism, it is possible to avoid displacement due to the workpiece 1 (the workpieces 5 and 6) sinking.

  In consideration of the mechanism of occurrence of the positional deviation, the anti-slip mechanism has an inclined surface on the adjacent workpiece side of the two workpieces 5 and 6 of the workpiece 1, that is, an inner side in the arrangement direction of the workpieces 5 and 6. It is necessary to provide on the inclined surfaces 21b and 21c of the conveyance rail 21 corresponding to the inner inclined surfaces 1d and 1e located at the same position. In the case where three or more pieces are taken (when three or more workpieces are processed simultaneously), the anti-slip mechanism is provided on the inclined surface corresponding to the inner inclined surface of the outermost workpiece. An anti-slip mechanism may be provided on the inclined surface corresponding to the inclined surface of the workpiece located inside, and in an extreme case, it is possible to provide an anti-slip mechanism on all the inclined surfaces of the transport rail.

  The form of the anti-slip mechanism is arbitrary, and any form may be used as long as it functions as an anti-slip to the workpiece 1 and can prevent the positional deviation. In FIG. 9, step surfaces 21g and 21h for supporting the lower end E of the inclined surfaces 1d and 1e of the workpiece 1 are provided at the bottoms of the inclined surfaces 21b and 21c of the transport rail 21, and these step surfaces 21g and 21h are provided. It is a non-slip mechanism. As shown in FIGS. 10 (a) and 10 (b), the stepped surfaces 21g and 21h are formed at a height corresponding to the normal position of the lower end E, whereby each inclined surface 1d of the workpiece 1 is formed. 1e has a lower end E placed on the stepped surfaces 21g and 21h, and while the workpiece 1 is processed from the workpiece 1 to the workpieces 5 and 6, the lower end E is the stepped surface 21g, It will be in the state supported by 21h. Therefore, even if the machining progresses and the workpieces 5 and 6 are separated from each other and the grinding resistance is suddenly released, the sinking of the workpiece 1 is suppressed, and the displacement is avoided. As a result, there is no difference in thickness between the contour processing start side end A and the contour processing end side end B of the workpieces 5 and 6.

  As the form of the stepped surfaces 21g and 21h, for example, as shown in FIG. 11, the shape on the inclined surfaces 21b and 21c side of the auxiliary rail portions 21e and 21f is imitated to the inner R surfaces 1a and 1b of the workpiece 1. It is also possible. However, if the shape of the transport rail 21 is matched with the shape of the lower surface of the work piece 1, it becomes difficult to discharge shavings and the like, which leads to a decrease in dimensional accuracy. As described above, it is preferable to form such that a part of the space is formed on the lower surface of the workpiece 1.

  The step surfaces 21g and 21h may be formed in the vicinity of the portion of the transport rail 21 that faces the grinding wheel 22 but may be formed over the entire length of the transport rail 21. The steps 21g and 21h are easier to process if they are formed over the entire length of the transport rail 21. Further, when the step surfaces 21g and 21h are formed only on the portion facing the grinding wheel 22, the end portions of the step surfaces 21g and 21h on the side where the workpiece 1 enters are R surfaces, and the workpiece 1 is formed. It is preferable that the can enter smoothly.

  Alternatively, as the anti-slip mechanism, the inclined surfaces 21b and 21c can be roughened as shown in FIG. By roughening the inclined surfaces 21b and 21c, the contact resistance with respect to the workpiece 1 is increased, the sinking of the workpiece 1 is suppressed, and the displacement is avoided. At the time of the roughening, as shown in FIG. 13, rubbing with a file or the like in the direction of the arrow in the figure (direction substantially parallel to the conveying direction of the workpiece 1 on the conveying rail 21), a minute scratch is formed. It is preferable to roughen only in the direction orthogonal to the direction. As a result, the lower end E of the workpiece 1 is locked to a minute scratch and is not displaced downward, and the increase in friction can be minimized in the conveying direction.

  When the anti-slip mechanism is formed by roughening as described above, the vicinity of the portion of the transport rail 21 that faces the grinding wheel 22 (the grinding wheel from the position where the workpiece 1 comes into contact with the grinding wheel 22 and processing starts). It is preferable to form it only on the conveyance rail portion to the position where the processing by 22 is finished and become the two workpieces 5 and 6.

  As described above, by providing the anti-slip mechanism for supporting the lower end E of the workpiece 1 on the transport rail 21, in the grinding process for simultaneously machining and cutting a plurality of workpieces, machining accuracy (especially grinding) (Thickness dimensional accuracy in the direction) can be improved.

  The above-described grinding apparatus and grinding method are suitable for application to grinding of rare earth sintered magnets, for example. In this case, the above-mentioned grinding is performed using a rare earth sintered magnet as a workpiece.

  The rare earth sintered magnet has, for example, a rare earth element R, a transition metal element T, and boron as main components. However, the magnet composition is not particularly limited, and may be arbitrarily selected according to the application. For example, the rare earth element R specifically means Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu. 1 type (s) or 2 or more types can be used. Among these, it is preferable that the main component as the rare earth element R is Nd because it is abundant in resources and relatively inexpensive. Moreover, as the transition metal element T, any conventionally used transition metal element can be used. For example, one or more of Fe, Co, Ni and the like can be used. Among these, from the viewpoint of magnetic properties, Fe is the main component, and it is particularly preferable to add Co that is effective in improving the Curie temperature and improving the corrosion resistance of the grain boundary phase. In addition to the rare earth element R, transition metal element T, and boron B, the inclusion of other elements is allowed. For example, elements such as Al, Cu, Zr, Ti, Bi, Sn, Ga, Nb, Ta, Si, V, Ag, and Ge can be appropriately contained. On the other hand, it is desirable to reduce impurity elements such as oxygen, nitrogen, and carbon as much as possible. In particular, the amount of oxygen that impairs magnetic properties is preferably 7000 ppm or less, more preferably 5000 ppm or less. This is because when the amount of oxygen is large, the rare-earth oxide phase, which is a nonmagnetic component, increases and the magnetic properties are deteriorated. The rare earth sintered magnet to be cut is not limited to the RTB-based rare earth sintered magnet. For example, the rare earth sintered magnet may be an SmCo-based sintered magnet or the like, and it is effective to apply the present invention also to these.

  Rare earth sintered magnets are produced by powder metallurgy, but the manufacturing process basically consists of an alloying process, coarse pulverization process, fine pulverization process, molding process, sintering process, and aging process. . In order to prevent oxidation, most of the steps after sintering are performed in a vacuum or in an inert gas atmosphere (in a nitrogen gas atmosphere, an Ar gas atmosphere, etc.).

  In the alloying step, a raw material metal or alloy is blended according to the composition of the desired rare earth alloy powder, and melted in a vacuum or an inert gas, for example, Ar atmosphere, and cast to form an alloy. As the casting method, any method can be adopted, but the strip casting method (continuous casting method) in which a molten high-temperature liquid metal is supplied onto a rotating roll and the alloy thin plate is continuously cast is a viewpoint of productivity and the like. From the viewpoint of the form of the resulting alloy.

  As the raw material metal (alloy) used in the alloying, pure rare earth elements, rare earth alloys, pure iron, ferroboron, and alloys thereof can be used. As the alloy, a single alloy having almost the final magnet composition may be used, or a plurality of types of alloys having different compositions may be mixed so as to have the final magnet composition.

  In the coarse pulverization step, the previously cast raw alloy thin plate, ingot, or the like is pulverized until the particle size is about several hundred μm. As the pulverizing means, a stamp mill, a jaw crusher, a brown mill, or the like can be used. In order to improve the coarse pulverization property, it is effective to perform coarse pulverization after occlusion of hydrogen and embrittlement.

  After the above-described coarse pulverization step is completed, a lubricant is added to the coarsely pulverized raw material alloy powder as necessary. As the lubricant, for example, a fatty acid-based compound can be used, and in particular, by using a fatty acid or a fatty acid amide having a melting point of 60 ° C. to 120 ° C. as a lubricant, good magnetic properties, particularly high orientation and high A rare earth sintered magnet having magnetization can be obtained, and the strength of the compact can be adjusted to a predetermined value depending on the type and amount of addition.

  After the coarse pulverization step, a fine pulverization step is performed. This fine pulverization step is performed using, for example, an airflow pulverizer. The conditions for fine pulverization may be appropriately set according to the airflow pulverizer to be used, and the raw material alloy powder is finely pulverized until the average particle size becomes about 1 to 10 μm, for example, 3 to 6 μm. A jet mill or the like is suitable as the airflow pulverizer.

  After the pulverization step, the raw material alloy powder is formed in the magnetic field in the magnetic field forming step. Specifically, the raw material alloy powder obtained in the fine pulverization step is filled in a mold in which an electromagnet is arranged, and is molded in a magnetic field in a state where crystal axes are oriented by applying a magnetic field. The forming in the magnetic field may be either a parallel magnetic field forming in which the forming pressure and the magnetic field direction are parallel, or an orthogonal magnetic field forming in which the forming pressure and the magnetic field direction are orthogonal to each other. Further, a pulse power source and an air-core coil can be employed as the magnetic field applying means. The forming in the magnetic field may be performed in a magnetic field of 700 to 1600 kA / m, for example, at a pressure of 30 to 300 MPa, preferably about 130 to 160 MPa.

  After forming into a predetermined shape by the forming step, a sintering process is performed on the formed body in the sintering step. In the sintering process, the compact is sintered in a vacuum or in an inert gas atmosphere (such as in an Ar gas atmosphere). The sintering temperature needs to be adjusted according to various conditions such as composition, pulverization method, difference in particle size and particle size distribution, etc. For example, sintering may be performed at 1000 to 1200 ° C. for about 1 to 10 hours. It is preferable to do. In addition, in a sintering process, it is preferable to perform a degreasing process prior to sintering as needed.

  After the sintering, the obtained sintered body is preferably subjected to an aging treatment. This aging treatment is an important step in controlling the coercive force Hcj of the obtained rare earth magnet. For example, the aging treatment is performed in an inert gas atmosphere or in a vacuum. As the aging treatment, a two-stage aging treatment is preferable, and in the first aging treatment step, the temperature is maintained at a temperature of about 800 ° C. for 1 to 3 hours. Next, a first quenching step is provided for quenching to room temperature to 200 ° C. In the second stage aging treatment step, the temperature is maintained at about 600 ° C. for 1 to 3 hours. Next, a second quenching step for quenching to room temperature is provided. Since the coercive force Hcj is greatly increased by heat treatment at around 600 ° C., when aging treatment is performed in a single stage, it is preferable to perform aging treatment at around 600 ° C.

  In this way, for example, a block-shaped (cuboid-shaped) rare earth sintered magnet is manufactured. This block-shaped rare earth sintered magnet is used as a workpiece, and contoured according to the shape of the final workpiece (for example, C-shaped). Processing. At this time, by using the grinding apparatus and the grinding method, it is possible to dramatically improve the productivity and to realize a highly accurate grinding process. For example, when a rare earth sintered magnet is manufactured by a powder metallurgy method, a fine powder is formed in a magnetic field. At this time, the rare earth alloy powder as a raw material has poor fluidity. Therefore, it is difficult to mold a thin and small-sized one. The present invention is particularly effective when applied to a final workpiece (rare earth sintered magnet) having a thickness of about 0.5 to 5 mm from a rectangular parallelepiped sintered body having a thickness of 1 to 50 mm. In addition, after processing into a product shape by the processing method of the present invention, it is possible to further adjust to a desired dimension by cutting or the like.

  As mentioned above, although the embodiment of the grinding apparatus and the grinding method to which the present invention is applied has been described, it goes without saying that the present invention is not limited to these embodiments, and various modifications can be made without departing from the scope of the present invention. Is possible.

  Next, specific examples of the present invention will be described.

Example A rectangular block-shaped rare earth sintered magnet of 50 mm × 20 mm × 3 mm was used as a workpiece, and contour processing was performed into a C shape using the grinding apparatus shown in FIG. When grinding, a plurality of rare earth sintered magnet blocks are arranged on the first conveyance rail, and the inner R surface and the inclined surface are ground while being conveyed by the conveyance roller, and then conveyed by the second conveyance rail. The outer R surface was ground while carrying out the above. Therefore, in this embodiment, the inclined surfaces of the rare earth sintered magnet block are supported by the inclined surfaces of the second transport rail in the second grinding process. Further, the step surface shown in FIGS. 9 and 10 is formed on the inner inclined surface of the second transport rail, and the lower end portion of the inner inclined surface of the workpiece is supported by this step surface.

  As the grinding wheels (the first contouring grindstone and the second contouring grindstone), an electrodeposition grindstone electrodeposited with diamond abrasive grains was used. Each contouring grindstone corresponds to two pieces, and as shown in FIGS. 2 (a) and 2 (b), the first contouring grindstone includes two inner grindstones corresponding to two inner R surfaces. The second contouring grindstone has two arc surfaces corresponding to the two outer R surfaces. The grain size of the diamond abrasive grains was 100 to 500 μm. The rotational speed of the grindstone during grinding was 3000 rpm, and the feed rate of the rare earth sintered magnet block was 200 mm / min.

The step surface (anti-slip mechanism) shown in FIGS. 9 and 10 was not formed on the transport rail of the comparative example, and grinding was performed using the same grinding apparatus as in the examples.

Measurement of dimensional accuracy In the C-type rare earth sintered magnet after contour processing, the center positions of the inner R surface and the outer R surface and the thicknesses of both ends were measured. The measurement was performed on the front end portion, the central portion, and the rear end portion in the conveyance direction of the C-type rare earth sintered magnet, and the dimensional accuracy of the example and the comparative example were compared. The results are shown in Table 1. In Table 1, “total” is a value obtained by measuring the thickness of the center position and both end portions and arithmetically averaging, and “only the end portion” is the thickness of only the both end portions. It is a measurement result.

  As is apparent from Table 1, it is understood that the dimensional accuracy at both ends is greatly improved by providing the step surface on the transport rail.

It is a figure which shows the grinding process in the case of taking two C type | mold shapes, (a) is a to-be-processed object, (b) is an inner R surface and an inclined surface formation state, (c) is outer R surface rough grinding. The state (d) shows the separated state. FIG. 2 shows an example of the shape of a contouring grindstone used in the grinding process shown in FIG. 1, (a) shows the shape of the contouring grindstone for forming the inner R surface and the inclined surface, and (b) shows the outer R shape. The shape of the contouring grindstone for surface formation and separation is shown. It is a figure which shows an example of the grinding device which performs a series of outline processing continuously. FIG. 4 shows a first transport rail used in the grinding apparatus shown in FIG. 3, (a) is a schematic perspective view, and (b) is a schematic cross-sectional view. The 2nd conveyance rail used for the grinding device shown in FIG. 3 is shown, (a) is a schematic perspective view, (b) is a schematic sectional drawing. (A) is a figure which shows the inclined surface of a workpiece, and the inclined surface of a conveyance rail, (b) is a figure which shows the mounting state to the conveyance rail of a workpiece. It is a schematic perspective view explaining the progress of grinding, (a) is before grinding, (b) is in the middle of grinding, (b) shows the end of grinding. (A) is a figure which shows typically the mode of the position shift of a workpiece (workpiece), (b) is a figure which shows the thickness dimension of a workpiece end part. It is a schematic perspective view of the part in which the level | step difference surface of the conveyance rail was formed. It is a figure which shows the support state of the to-be-processed object by the level | step difference surface of a conveyance rail, (a) is the time of the contour processing start, (b) is the time of the contour processing end. It is a figure which shows the example which changed the shape of the auxiliary rail part and was set as the anti-slip | skid mechanism. It is a figure which shows the example made into the anti-slip | skid mechanism by roughening the inclined surface of a conveyance rail. It is a figure which shows the direction of roughening.

Explanation of symbols

1 Workpiece, 1a, 1b Inner R surface, 1c, 1d, 1e, 1f Inclined surface, 1g, 1h Outer R surface, E Lower edge, 3 Contouring grindstone, 3a, 3b Arc surface, 3c Inclined surface, 3d Convex part, 4 Contouring grindstone, 4a, 4b Arc surface, 4c Convex part, 5, 6 Workpiece, 11 1st conveyance rail, 12 1st grinding wheel, 13 Support jig, 21 2nd conveyance rail 21a, 21b, 21c, 21d Inclined surface, 21e, 21f Auxiliary rail portion, 21g, 21h Step surface, 22 Second grinding wheel

Claims (9)

A conveying rail for conveying a workpiece on which a plurality of sets of inclined surfaces are formed in advance corresponding to the shape of both end portions of the workpiece; and a contouring grindstone for contouring the workpiece conveyed by the conveying rail; With
The contouring grindstone is a single electrodeposition grindstone having a plurality of contoured surfaces corresponding to the workpiece shape,
The conveying rail has a plurality of sets of inclined surfaces extending in the conveying direction corresponding to each inclined surface of the workpiece, and at least corresponds to a workpiece-side inclined surface adjacent to the outermost workpiece. Having a non-slip mechanism on at least a portion of the inclined surface facing the contouring grindstone,
Each inclined surface of the workpiece is conveyed in a state supported by each inclined surface of the conveying rail, and the contour processing for a plurality of workpieces is collectively performed on the workpiece by the contour processing grindstone, A grinding apparatus characterized by being separated into workpieces.   The grinding apparatus according to claim 1, wherein the anti-slip mechanism is formed as a support portion that supports a lower end portion of an inclined surface of the workpiece.   The grinding apparatus according to claim 2, wherein the support portion has a shape along a part of a bottom surface of the workpiece.   The grinding apparatus according to claim 1, wherein the anti-slip mechanism is formed by roughening an inclined surface of the transport rail.   5. The grinding apparatus according to claim 4, wherein fine scratches are formed in substantially the same direction as the conveying direction, and the surface is roughened in a direction substantially perpendicular to the conveying direction.   The grinding apparatus according to claim 1, wherein the anti-slip mechanism is formed over the entire length of the transport rail.   The grinding apparatus according to any one of claims 1 to 5, wherein the anti-slip mechanism is formed only at a portion facing the contouring grindstone of the transport rail and in the vicinity thereof. A grinding method for performing contouring with a contouring grindstone on a workpiece in which a plurality of sets of inclined surfaces are formed in advance corresponding to the shapes of both end portions of the workpiece,
Contour processing of a plurality of workpieces is collectively performed on the workpiece by the contouring grindstone while conveying each inclined surface of the workpiece supported by the inclined surface of the conveyance rail, and each workpiece is processed. When separating
A grinding method, wherein the contour machining is performed while supporting at least a lower end portion of an inclined surface corresponding to an adjacent workpiece-side inclined surface of an outermost workpiece by an anti-slip mechanism. The grinding method according to claim 8, wherein the workpiece is a rare earth sintered magnet.

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