JP5457329B2 - Brush grinding apparatus and brush grinding method - Google Patents

Description

  The present invention relates to a brush grinding apparatus and a brush grinding method for grinding a workpiece using a grinding brush formed by bundling abrasive strands containing abrasive grains.

  For example, when R processing is performed on both side ends (edge portions) of a metal ring before rolling used for manufacturing a drive belt for a continuously variable transmission, a grinding brush formed by bundling brush strands containing abrasive grains is used. It is done. In this case, the length of the free portion (hereinafter referred to as “trim length”) on the tip side of the restraining portion in the grinding brush affects the grinding force of the grinding brush, and the metal ring end portion obtained as a result of the R processing This greatly affects the accuracy of the shape and dimensions.

  For this reason, the bushing of the same length is provided as a restraining part of each grinding brush so that the grinding force by each grinding brush becomes constant, and the trim length in each grinding brush is set to the same value. Further, since the grinding brush is worn during machining, machining is performed while the grinding brush is displaced toward a metal ring as a workpiece to be machined sequentially by a certain distance as the wear progresses (for example, see Patent Document 1). ).

  Further, the trim length is one of the important factors in the grinding conditions as described above, and is set so that both end portions of the metal ring can achieve the accuracy required as a product. The set value is constant in one grinding shot for grinding one end of the metal ring, or is changed during the machining in one grinding shot.

Japanese Patent No. 4554589

  However, according to the above prior art, it is necessary to set the trim length for each grinding brush to a constant value as a processing condition so that the R processing by the grinding brush can achieve a predetermined processing accuracy. For this reason, in processing, a certain processing time corresponding to the trim length is required.

  If the trim length is shortened in order to shorten the processing time, the curvature of the end of the metal ring becomes too large, and the edge is formed at the side R portion where the end surface having the curvature and the side of the metal ring are connected. As a result, a predetermined machining accuracy cannot be achieved. Therefore, the machining efficiency cannot be improved by changing the trim length.

  An object of the present invention is to provide a brush grinding apparatus and method with improved processing efficiency in view of the problems of the prior art.

  In order to achieve this object, the brush grinding apparatus of the present invention is formed by bundling a table for holding a workpiece, a brush holder provided opposite to the table, and a plurality of abrasive strands containing abrasive grains. The brush holder is held between the table and the brush holder, and is rotated integrally with the brush holder, with the root portion held by the brush holder and the bristle direction extending toward the workpiece held by the table. And a support plate disposed so as to be positionally adjustable relative to the brush holder in the direction of separation, and an intermediate portion of the grinding brush provided on the support plate and held by the brush holder is restrained. In a brush grinding apparatus that includes a restraining portion and performs grinding by bringing the tip of the grinding brush into contact with a workpiece by rotation of the brush holder, The first grinding brush in which the length from the bundle portion to the tip is set to the first length, and the length from the restraint portion to the tip is set to the second length that is longer than the first length. A second grinding brush, and the first grinding brush and the second grinding brush are mixed on the brush holder.

  In this brush grinding apparatus, the first grinding brush in which the length from the restricting portion to the tip is set to the first length acts in a hard contact with the workpiece and has a relatively strong grinding force. The second grinding brush in which the length from the restricting portion to the tip is set to the second length acts in soft contact with the workpiece, and the grinding force is weaker than that of the first grinding brush.

  Therefore, when the grinding is performed by rotating the brush holder in which the first grinding brush and the second grinding brush are mixed, the grinding according to the grinding characteristics of the first grinding brush and the second grinding brush is performed. Progress at the same time. At that time, it is not necessary to change the characteristics of the grinding brush in the middle of the grinding process as in the prior art. Further, the machining accuracy can be controlled by the set values of the first length and the second length and the ratio of the number of the first and second grinding brushes. Thereby, the grinding which satisfy | fills required precision can be performed with high grinding efficiency.

  In this invention, the said restraint part is comprised by the cylindrical member which restrains the said intermediate part with a cylindrical inner wall, and the cylindrical member of the said restraint part which restrains a said 2nd grinding brush is said 1st grinding | polishing. The difference between the first length and the second length may be shorter than the cylindrical member of the restraining portion that restrains the brush.

  According to this, the position of the brush root side end portion of the cylindrical member that restrains the first grinding brush is aligned with the position of the brush root side end portion of the cylindrical member that restrains the second grinding brush. By simply restraining the first and second grinding brushes with the corresponding cylindrical members, the lengths from the restraining portion to the tip of the first and second grinding brushes are respectively set to the first length and the second length. Can be set.

  The brush grinding method of the present invention comprises a grinding brush formed by bundling a plurality of abrasive strands containing abrasive grains, the root portion being held by the brush holder, and the direction of the bristles extending toward the workpiece, and the brush holder integrally A support plate that is rotated and positioned so as to be relatively adjustable in the contact / separation direction with respect to the brush holder; and an intermediate portion of the grinding brush provided on the support plate and held by the brush holder. In a brush grinding method for performing grinding by using a brush grinding mechanism having a restraining portion for restraining, and performing grinding by bringing the tip of the grinding brush into contact with a workpiece by rotation of the brush holder, As the grinding brush held by the brush holder, a first grinding brush having a first length from the restraining portion to the tip, and a length from the restraining portion to the tip are the first length. Characterized by using those second grinding brush is longer second length than are mixed.

  According to this, as in the case of the brush grinding apparatus of the present invention, it is possible to perform grinding that satisfies the required accuracy with high grinding efficiency.

1 is a perspective view schematically showing a brush grinding apparatus according to an embodiment of the present invention. It is a fragmentary sectional view which shows the brush holder and indicator plate in the apparatus of FIG. It is a top view of the ring holding means in the apparatus of FIG. It is explanatory drawing for demonstrating the principal part in the apparatus of FIG. It is a figure which shows arrangement | positioning of the grinding brush in the brush holder of the apparatus of FIG. It is a figure which shows the difference of an effect | action of a grinding brush with a long trim length, and a short grinding brush.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view schematically showing a brush grinding apparatus according to an embodiment of the present invention, and FIG. 2 is a partial sectional view showing a brush holder of the brush grinding apparatus. As shown in these drawings, the brush grinding apparatus 1 includes a disc-shaped brush holder 3 in which a plurality of grinding brushes 2 are provided on the circumference, and a plurality (six in this embodiment) of metal rings as workpieces. And a table 4 for holding W.

  The metal ring W is formed in a thin plate-like endless belt shape and is used for an endless belt of a continuously variable transmission. The grinding brush 2 is formed by bundling a plurality of brush strands made of nylon wire containing abrasive grains and bundling the base with a cap-shaped binding tool 5.

  As shown in FIG. 2, the brush holder 3 supports the root portion of the grinding brush 2 via the binding tool 5 of the grinding brush 2. A disk-shaped support plate 6 is provided below the brush holder 3. The support plate 6 includes an insertion hole 7 through which the grinding brush 2 is inserted, and a bush 9 in which a tapered hole 8 is formed is inserted into the insertion hole 7. The tapered hole 8 is formed in a shape that gradually decreases in diameter downward. There are two types of bushes 9 having different lengths as will be described later.

  In a state where the grinding brush 2 is attached to the brush holder 3, the grinding brush 2 is inserted into the insertion hole 7 through the bush 9 from the tip side. At this time, the intermediate portion near the tip of the grinding brush 2 is restrained by the bush 9. A restraint 10 is constituted by the bush 9.

  The support plate 6 is provided with a connecting rod 11 extending upward. The connecting rod 11 penetrates the brush holder 3 in the vertical direction through a sliding hole 12 formed in the brush holder 3, and the collar portion 14 is attached to the cylindrical rotary shaft 13 positioned above the brush holder 3. Are connected through. The rotary shaft 13 is rotationally driven by a drive motor (not shown). The rotation of the rotating shaft 13 is transmitted to the brush holder 3 and the support plate 6 by the connecting rod 11. Thereby, the brush holder 3 and the support plate 6 are integrally rotated.

  The brush holder 3 is connected to a substantially cylindrical lifting shaft 15 slidably inserted into a cylindrical rotating shaft 13. The brush holder 3 moves up and down as the elevating shaft 15 is slid in the axial direction by elevating means (not shown). As the brush holder 3 moves up and down, the position of the support plate 6 can be adjusted in the vertical direction relative to the brush holder 3. The table 4 includes a plurality (six in this embodiment) of ring holding means 16 that hold the metal ring W from the inside.

  FIG. 3 is a plan view of the ring holding means 16. As shown in the figure, the ring holding means 16 is formed by a plurality (six in this embodiment) of contact members 17. When the metal ring W is placed around the contact members 17 in a state where the contact members 17 are close to each other, the ring holding means 16 separates the contact members 17 to contact the inner peripheral surface of the metal ring W. The metal ring W is held.

  When grinding the metal rings W, each ring holding means 16 is rotated by a motor (not shown) to rotate each metal ring W in the circumferential direction indicated by an arrow 31. Each grinding brush 2 rotates integrally in the direction of arrow 32 as the brush holder 3 rotates.

  The table 4 is provided with a plurality (six in this embodiment) of injection nozzles 18 and injection nozzles 19 having different injection angles. The injection nozzles 18 and 19 are nozzles for injecting the grinding liquid onto the metal ring W or the like held by the ring holding means 16, and are provided to smoothly remove the abrasive chips and abrasive grains separated from the grinding brush 2. It has been.

  FIG. 4 is an explanatory diagram for explaining the main part of the brush grinding apparatus in more detail. As shown in the figure, the bush 9 constituting the restraining portion 10 is constituted by a cylindrical member that restrains the intermediate portion of the grinding brush 2 by a cylindrical inner wall.

  As the bush 9, bushes 9a and 9b having different lengths are provided. The bush 9b has a length comparable to the thickness of the support plate 6, and the bush 9a is longer than this. As the grinding brush 2, there are a grinding brush 2a restrained by a bush 9a and a grinding brush 2b restrained by a bush 9b.

  L1 in the figure is the brush length, which is the length from the lower end of the binding tool 5 to the tip of the grinding brush 2 in the grinding brush 2. The brush length L1 is the same in each grinding brush 2a and 2b. L2 is the depth of cut, which means the distance from the level of the upper end of the metal ring W during grinding to the level of the tip of the grinding brush 2 positioned below that level.

  L3 and L4 in the figure are trim lengths of the grinding brushes 2a and 2b, respectively. The trim length L3 is a distance from the lower end of the bush 9a to the tip of the grinding brush 2a restrained by the bush 9a. The trim length L4 is a distance from the lower end of the bush 9b to the tip of the grinding brush 2b restrained by the bush 9b.

  The lower end of the bush 9 a is positioned at a level considerably lower than the lower surface of the support plate 6, and the lower end of the bush 9 b is positioned at the same level as the lower surface of the support plate 6. Accordingly, the trim length L3 of the grinding brush 2a is shorter than the trim length L4 of the grinding brush 2b by the level difference between the lower ends of the bush 9a and the bush 9b. That is, the bush 9b is shorter than the bush 9a by the difference between the trim lengths L3 and L4.

  As shown on the left side of the figure, when the metal ring W is processed, the lower end of the grinding brush 2 is located above the contact member 17 of the ring holding means 16, so that it contacts the contact member 17. There is nothing.

  FIG. 5 shows the arrangement of the grinding brushes 2 a and 2 b in the brush holder 3. As shown in the figure, the grinding brushes 2a and 2b are evenly arranged without deviation. This is because the action based on the grinding characteristics of the grinding brushes 2a and 2b having different trim lengths is uniformly distributed over the entire circumference of the end of the metal ring W. For example, the ratio of the number of grinding brushes 2a and 2b is 1: 2, and one grinding brush 2a is arranged for every two grinding brushes 2b.

  FIG. 6 shows the difference in action between a grinding brush with a long trim length and a short grinding brush. FIG. 2A shows a state in which the end portion of the metal ring W is R-processed using only the grinding brush 2a set to L3 having a short trim length as the grinding brush 2. In this case, since the grinding brush 2a acts in a hard contact with the metal ring W, the grinding force is strong.

  Therefore, the cross-sectional shape of the end portion of the metal ring W after the R processing has a flat shape with a large curvature at the center portion 61 of the end portion, as shown in FIG. Presents a small edge shape. Since the length cut by grinding is long, the length L5 of the tip portion of the processed metal ring W is relatively short.

  FIG. 2C shows a state in which the end portion of the metal ring W is R-processed using only the grinding brush 2b set to L4 having a long trim length as the grinding brush 2. In this case, since the grinding brush 2b acts softly against the metal ring W, the grinding force is weak.

  Therefore, the cross-sectional shape of the end portion of the metal ring W after the R processing is a sharp shape with a large curvature at the center portion 61 of the end portion, as shown in FIG. It has a gentle shape. Since the length cut by grinding is short, the length L6 of the tip portion of the processed metal ring W is relatively long.

  Therefore, as shown in FIG. 5, when the grinding process is performed by arranging the grinding brush 2a having a short trim length and the grinding brush 2b having a long trim length, the end shapes of FIGS. 6B and 6D are synthesized. The end shape of the metal ring W having such a shape can be obtained. At that time, by adjusting the trim lengths L3 and L4 of the grinding brushes 2a and 2b and the ratio of the number of the grinding brushes 2a and 2b, the obtained end shape can be made desired.

  In this configuration, when grinding the metal rings W, first, the metal rings W are attached to the ring holding means 16 one by one. At this time, each edge located above each metal ring W is located on the same plane, and the plane is perpendicular to the axis of the rotation shaft 13.

  Next, rotation of each ring holding means 16 in the direction of arrow 31 in FIG. 3 is started. Further, the brush holder 3 is lowered so that the tip of each grinding brush 2 is positioned at the edge of each metal ring W, and the rotation of the brush holder 3 in the direction of arrow 32 is started. As a result, each metal ring W starts to rotate (rotate) in the direction of arrow 31, and each grinding brush 2 starts to rotate integrally (revolution) in the direction of arrow 32.

  At this time, the cutting amount L2 (FIG. 4) is set so that the tip of each grinding brush 2 is located at an appropriate position lower than the edge located above each metal ring W. This setting is performed by adjusting the vertical position of the brush holder 3. The cutting depth L2 is the same for each metal ring W. As a result, each grinding brush 2 rotates along a circumferential track such that the tip portion traverses each rotating metal ring W from the outside to the inside and further from the inside to the outside. One edge is ground into an R shape.

  That is, since the grinding brush 2 is a bundle of plastic wires containing abrasive grains, the edge of the metal ring W is ground by the action of the abrasive grains and chamfered into an R shape. At this time, since the grinding brush 2 is an aggregate of wire rods, it acts on the metal ring W in a flexible manner, not as a rigid body. For this reason, the edge part of the edge part of the end surface of the metal ring W is mainly ground and processed into R shape.

  At the time of this grinding, the tip of each grinding brush 2 is also worn at the same time by an impact force or the like when crossing each metal ring W. In accordance with this wear, the vertical position of the brush holder 3 is adjusted, and the cut amount L2 is adjusted to be constant.

  Further, during grinding, the grinding brush 2a is set to L3 having a short trim length, so that it comes into contact with the metal ring W with a relatively large impact force, and as shown in FIG. The center part of the end of W is also ground strongly. Since the grinding brush 2b is set to L4 having a long trim length, the grinding brush 2b contacts the metal ring W with a relatively small impact force, and as shown in FIG. The center portion is not so much ground, and contributes relatively greatly to the grinding on both sides of the end portion of the metal ring W.

  Therefore, in the past, the trim length was first set short, and grinding was performed mainly including the center part of the end of the metal ring, and then the trim length was set long and the curvatures on both sides of the end of the metal ring were mainly set. However, in this embodiment, these separate processes are performed simultaneously by the grinding brushes 2a and 2b.

  When the predetermined time elapses or when the predetermined number of rotations of the rotating shaft 13 is completed, the brush holder 3 is raised to a predetermined position, and the rotation of the ring holding means 16 and the rotating shaft 13 is stopped. Thereby, the grinding process about one edge of each metal ring W, that is, one-shot grinding process is completed.

  Since the ratio of the trim lengths L3 and L4 of the grinding brushes 2a and 2b and the number of grinding brushes 2a and 2b is set so that the end shape of the metal ring W after processing satisfies the required specifications, When the grinding process is finished, the shape of the edge of the processed metal ring W satisfies the required specification.

  According to the present embodiment, as the grinding brush 2, the grinding brush 2a in which the short trim length L3 is set and the grinding brush 2b in which the long trim length L4 is set are mixedly arranged on the brush holder 3, and grinding is performed. Since the processing is performed, grinding can be performed with the grinding brush 2a with a strong grinding force, and grinding with the grinding brush 2b with a weak grinding force.

  That is, it is possible to perform grinding while simultaneously performing grinding according to the grinding characteristics of the grinding brush 2a and the grinding brush 2b. At that time, it is not necessary to change the characteristics of the grinding brush during the grinding process as in the conventional case. The machining accuracy can be controlled by the set values of the trim lengths L3 and L4 and the ratio of the number of grinding brushes 2a and 2b. Therefore, the edge of the metal ring W can be ground to satisfy the required accuracy with high grinding efficiency.

  Further, the restraining portion 10 is configured by the bush 9a or 9b, and the bush 9b is shorter than the bush 9a by the difference between the trim lengths L3 and L4, so that the position of the brush root side end portion of the bush 9a, The trim lengths of the grinding brushes 2a and 2b are set to the trim lengths L3 and L4, respectively, only by restraining the grinding brushes 2a and 2b with the bushes 9a or 9b while keeping the position of the brush root side end of the bush 9b. be able to.

  The present invention is not limited to the above-described embodiment, and can be appropriately modified and implemented. For example, in the above description, the case where the metal ring W is an object to be ground has been described, but the object to be processed is not limited to this, and may be another object requiring R processing. Even in this case, efficient grinding can be performed by simultaneously performing grinding according to each grinding characteristic by using two kinds of grinding brushes having different trim lengths.

  W ... Metal ring (workpiece), 4 ... Table, 3 ... Brush holder, 2 ... Grinding brush, 2a ... Grinding brush (first grinding brush), 2b ... Grinding brush (second grinding brush), 6 ... Support plate 10 ... restraint part, 9 ... bush (cylindrical member).

Claims (3)

A table that holds the workpiece,
A brush holder provided opposite to the table and rotating;
A grinding brush formed by bundling a plurality of abrasive strands containing abrasive grains, the root portion being held by the brush holder, and the hair direction extending toward the work held by the table;
A support plate that is positioned between the table and the brush holder, is rotated integrally with the brush holder, and is disposed so as to be relatively position-adjustable with respect to the brush holder in the direction of separation.
A restraining portion for restraining an intermediate portion of the grinding brush provided on the support plate and held by the brush holder;
In a brush grinding apparatus that performs grinding by bringing the tip of the grinding brush into contact with a workpiece by rotation of the brush holder,
As the grinding brush, a first grinding brush in which the length from the restraining portion to the tip is set to a first length, and a second in which the length from the restraining portion to the tip is longer than the first length. And a second grinding brush set to the length of the brush grinding device, wherein the first grinding brush and the second grinding brush are mixed on the brush holder. The restraining portion is constituted by a cylindrical member that restrains the intermediate portion by a cylindrical inner wall,
2. The brush grinding apparatus according to claim 1, wherein a cylindrical member of the restraining portion that restrains the second grinding brush is shorter than a cylindrical member of the restraining portion that restrains the first grinding brush. A grinding brush that is formed by bundling a plurality of abrasive strands containing abrasive grains, the root portion is held by a brush holder, and the hair foot direction extends toward the workpiece,
A support plate that is rotated integrally with the brush holder and is disposed so as to be relatively position-adjustable in the contact / separation direction with respect to the brush holder;
The tip of the grinding brush is moved by the rotation of the brush holder by using a brush grinding mechanism provided with a restraining portion provided on the support plate and restraining an intermediate portion of the grinding brush held by the brush holder. In the brush grinding method that abuts on and grinds,
When grinding, the grinding brush held by the brush holder includes a first grinding brush having a first length from the restraint to the tip, and a length from the restraint to the tip. A brush grinding method comprising using a mixture of a second grinding brush having a second length longer than the first length.

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