JP5491984B2 - Grinding wheel and boring tool - Google Patents

Description

  The present invention relates to improvement of a grindstone in which a plurality of abrasive grains are bonded to a surface of a base material in a line.

  A grindstone is known in which a plurality of abrasive grains are bonded to the surface of a base material (see, for example, Patent Document 1 (FIG. 5)).

  The grindstone (4) shown in Patent Document 1 (the numbers in parentheses indicate the symbols described in Patent Document 1. The same applies hereinafter) includes a plurality of abrasive grains (3) on the surface of the base material (1). It is bonded in the form of being arranged in pieces. In order to match the height from the surface of the base material (1) to the top of the abrasive grain (4), the upper part of the abrasive grain (4) is removed by truing.

Next, the general manufacturing method and usage pattern of a grindstone are demonstrated.
FIG. 14A is a diagram showing an example of abrasive grains, and the abrasive grains 101 have a polyhedral shape. The abrasive grains 104 are made by arranging the abrasive grains 101 on the surface of the base material 102 as shown in FIG.
As shown to (c), the surface of the to-be-processed object 105 can be shaved by moving the grindstone 104 like the arrow (1).

By the way, the direction of the abrasive grain 101 in (b) is not controlled. That is, there are a form in which the upper surface 106 is parallel to the surface of the base material 102 and an inclined form.
If the upper surface 106 is parallel to the surface of the base material 102, the upper surface 106 contacts the surface 107 of the workpiece 105, so that the grinding resistance increases.
As a result, the processing accuracy and the wheel life are reduced.

  In recent years, further improvement in finishing accuracy has been demanded. Therefore, there is a demand for a grindstone capable of further improving the accuracy of the finished surface by further reducing the grinding resistance.

JP 2001-347453 A

  This invention makes it a subject to provide the grindstone which can improve the precision of a finished surface more by reducing grinding resistance more.

The invention according to claim 1 is a grindstone in which a plurality of abrasive grains are bonded to a surface of a base material in a line, and a clearance angle of a predetermined angle that is the same for all of the plurality of abrasive grains. The flank is a flat grinding surface, and the flank of all the abrasive grains arranged in a row is formed on the same surface. .

  The invention according to claim 2 is characterized in that the grindstone is a grindstone for boring.

According to a third aspect of the present invention, a plurality of abrasive grains are arranged in a line in the axial direction of the shank on the surface of the base material provided at the tip of the shank, and the arrangement of the abrasive grains formed in the axial direction is the shank. A grindstone that is bonded in a form in which a plurality of rows are formed in the circumferential direction, and a relief surface having a relief angle of the same predetermined angle is formed on all the abrasive grains in each row in the axial direction, and the relief surface Is a flat grinding surface, and the relief surfaces of all the abrasive grains arranged in a line are formed on the same surface.
The invention according to claim 4 is a columnar base and a plurality of rows arranged in the axial direction on the columnar base, and the rows of abrasive grains in each row are formed in a row in the axial direction. And a whetstone.

The invention according to claim 5 is a cylindrical tool holder, an arm swingably provided on the tool holder and radially expanded by a diameter expanding mechanism, and a grindstone according to claim 1 provided at the tip of the arm, It is characterized by comprising.

  The invention according to claim 1 is a grindstone in which a plurality of abrasive grains are bonded to a surface of a base material in a line, and a relief angle having a predetermined angle is provided on all of the plurality of abrasive grains. A surface is formed. Since all the abrasive grains are formed with flank surfaces having a predetermined flank angle, the grinding resistance can be further reduced and the accuracy of the finished surface can be further improved.

  In the invention which concerns on Claim 2, a grindstone is a grindstone for boring. In general, inner diameter machining is more difficult than outer diameter machining because the tool shape and peripheral speed are limited. By using the boring grindstone of the present invention for finishing such a hole diameter, the finishing accuracy of the hole can be further improved.

In the invention according to claim 3, flank surfaces having the same predetermined flank angle are formed on all of the rows of abrasive grains in the axial direction, and the flank surfaces are planar grinding surfaces, The flank faces of all the abrasive grains arranged in a row are formed on the same plane. By arranging a plurality of abrasive grains in a row, a flank can be formed by one truing.
In the invention which concerns on Claim 4 , it consists of a cylindrical base and the grindstone of Claim 1 arranged in an axial direction on this cylindrical base. For example, in the case of a cylinder block of 4 cylinders, machining of journal holes in the cylinder block requires processing of 5 bearings, and the tool has a long axis, and depending on the type, there are also those that cut aluminum and iron together. For this reason, it is often difficult to achieve the accuracy of the finished surface. In this regard, by using the boring tool of the present invention, the finishing accuracy of the journal hole can be further improved.

In the invention which concerns on Claim 5 , it consists of the arm spread | stretched to radial direction by a diameter expansion mechanism, and the grindstone of Claim 1 provided in the front-end | tip of an arm. Since the diameter is adjusted by the diameter expansion mechanism, it is possible to cope with finishing with different inner diameters with one boring tool. Therefore, a plurality of boring tools are not required, and the cost of boring tools can be reduced.
For example, in journal hole drilling of a cylinder block, by providing a plurality of diameter expansion mechanisms in the axial direction of the tool, it is possible to enter the tool by reducing the diameter while having a plurality of grinding wheels in the circumferential direction. A plurality of bearings can be processed simultaneously. Therefore, cycle time can be shortened.
Furthermore, it is possible to cope with a reduction in processing diameter due to grinding wheel wear.

It is a figure explaining the manufacturing method of the grindstone concerning the present invention. 1 is a cross-sectional view of a boring tool according to Embodiment 1. FIG. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. It is sectional drawing of an abrasive grain. FIG. 6 is a side view of a boring tool according to a second embodiment. FIG. 6 is a sectional view taken along line 6-6 of FIG. 6 is a cross-sectional view of a line boring bar according to Embodiment 3. FIG. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7. It is a perspective view of the line boring bar which concerns on Example 3. FIG. It is sectional drawing of the grinding device to which the boring tool which concerns on Example 4 is applied. FIG. 6 is a perspective view of a boring tool according to a fourth embodiment. It is sectional drawing of the boring tool which concerns on Example 4. FIG. FIG. 13 is a sectional view taken along line 13-13 of FIG. It is explanatory drawing of the grindstone which concerns on a prior art.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.

First, Embodiment 1 of the present invention will be described with reference to the drawings.
As shown in FIG. 1 (a), the abrasive grains 10 before forming the flank have a polyhedral shape.
In addition, although the abrasive grain 10 which concerns on an Example demonstrates a truncated octahedron to an example, even if it is polyhedral shapes other than a truncated octahedron, it does not interfere.
As shown in (b), the abrasive grains 14 before the flank formation are made by placing the abrasive grains 10 on the surface 12 of the base material 11 and bonding them with electrodeposition or an adhesive 13.

As shown in (c), truing of the abrasive grains 10 is performed with a circular truing grindstone 15. The truing grindstone 15 is brought into contact with the upper side of the abrasive grain 10 in the figure, and the truing grindstone 15 is rotated as indicated by an arrow (2) to grind the abrasive grain 10. Since the diameter of the truing grindstone 15 is larger than the size of the abrasive grain 10, the grinding surface of the abrasive grain 10 is substantially flat.
Then, the flank 16 is formed on the upper side of the abrasive grain 10 as shown in FIG.

Next, a usage example of the grindstone 10 will be described.
As shown in FIG. 2, the boring tool 20 includes a columnar base 21 and three rows of grindstones 14 provided on the outer periphery 22 of the base 21.
Explaining the operation, the inner peripheral surface (machined surface) 24 of the workpiece 23 is ground by rotating the boring tool 20 as shown by the arrow (3).
In the embodiment, the number of rows of the grindstones 14 is three. However, the present invention is not limited to this, and may be appropriately changed according to the material and size of the workpiece 23 such as four rows and five rows. Moreover, the height of the abrasive grains 10 is uniform.

Next, the grindstone 10 will be described based on a cross-sectional view.
As shown in FIG. 3, the grindstone 14 is bonded to the surface 12 of the base material 11 in a form in which a plurality of abrasive grains 10 are arranged in a line. By arranging the plurality of abrasive grains 10 in a line, the flank 16 can be formed by one truing.
In the embodiment, the number of abrasive grains 10 is 11. However, the number of abrasive grains 10 is not limited to this, and may be appropriately changed according to the material and size of the workpiece 23, such as 20 or 30. .

Next, the form of the abrasive grains 10 will be described in detail.
As shown in FIG. 4, in the grindstone 14, the abrasive grains 10 are bonded to the surface 12 of the base material 11. The abrasive grains 10 are constituted by a rake face 25 having a rake angle of an uncontrolled angle α and a flank face 16 having a formed relief angle of a predetermined angle β. All of the abrasive grains 10 shown in FIG. 3 have the same configuration. As indicated by the arrow (4) in FIG. 4, by moving the grindstone 14 and minimizing the scraping contact of the flank 16, the grinding resistance is reduced and the workpiece 23 can be efficiently ground. it can.

Further, since the grinding resistance is reduced, there are effects such as suppression of chattering, suppression of deflection due to insufficient rigidity of the boring tool (reference numeral 20 in FIG. 2) and the workpiece 23, and suppression of burr generation.
Furthermore, since the load applied to the boring tool 20 is reduced, the rigidity and scale of the equipment can be reduced.

Next, a second embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached about the same structure as the structure shown in FIG. 3, and detailed description is abbreviate | omitted.
As shown in FIG. 5, a boring tool 20 is provided at the tip of the shank 26. A plurality of rows of grindstones 14 in which a plurality of abrasive grains 10 are bonded in a line are arranged on the surface 12 of the base material 11 which is the outer periphery of the boring tool 20.

Next, the positional relationship between the boring tool 20 and the workpiece 23 will be described.
As shown in FIG. 6, the abrasive grains 10 provided on the boring tool 20 are in contact with the inner peripheral surface 24 of the workpiece 23.
Explaining the operation, the inner peripheral surface 24 of the workpiece 23 is ground by rotating the boring tool 20 as shown by the arrow (5).
Note that the number of rows of the abrasive grains 10 may be changed as appropriate according to the workpiece 23 and processing conditions.

Next, Embodiment 3 of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached about the same structure as the structure shown in FIG. 2, and detailed description is abbreviate | omitted.
As shown in FIG. 7, the boring tool 20 (line boring bar 20) includes a columnar base 21 and a row of grindstones 14 provided on the outer periphery 22 of the base 21. The journal hole 28 of the cylinder block 27 is ground by rotating the boring tool 20.

Next, the line boring bar 20 will be described based on a cross-sectional view.
As shown in FIG. 8, the line boring bar 20 includes a plurality of grindstones 14 arranged in the axial direction on a columnar base 21. The grindstone 14 is bonded to the surface 12 of the base material 11 in a form in which a plurality of abrasive grains 10 are arranged in a line. By using a plurality of abrasive grains 10 arranged in a row, the journal hole 28 of the cylinder block 27 can be efficiently ground with the grindstone 14.

  As shown in FIG. 9, the cylinder block 27 of the engine has a cylinder 27 and a journal hole 28. For example, in the case of a four-cylinder engine, there are five journal hole 28 bearings. By shifting the axis of the line boring bar 20 to the opposite side of the side where the grindstone 14 is attached, the axis of the line boring bar 20 is moved into the journal hole 28, the axis of the line boring bar 20 is returned to the original, and processed. A plurality of journal holes 28 can be processed simultaneously.

Next, a fourth embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached about the same structure as the structure shown in FIG. 3, and detailed description is abbreviate | omitted.
As shown in FIG. 10, the grinding device 30 has a motor 32 attached to a base 31, a ball screw 33 is rotatably attached to the motor 32, and the ball screw 33 is movably provided on the base 31. The table 34 is moved, and the workpiece 23 is fixed to the table 34.

  Further, a main bearing 35 of the boring tool 20 is fixed to the base 31, a main shaft 36 is rotatably provided on the main bearing 35, and a spindle motor 37 that rotates the main shaft 36 is provided on the main bearing 35. A cylindrical tool holder 38 is attached to one end of the main shaft 36, and the tool holder 38 is configured by connecting a plurality of divided tool holders 41 in the axial direction.

  A draw bar 42 is inserted into the tool holder 38 and the main shaft 36, and a tension member 44 that is moved in the axial direction by a thrust motor 43 is provided at the other end of the main shaft 36. The draw bar 42 is connected to the tension member 44. Yes.

  Further, the opposite side of the main shaft 36 of the tool holder 38 is rotatably held by the support bearing 45. A cutting oil supply unit 46 that supplies cutting oil is attached to the tip of the tool holder 38, and the cutting oil is supplied from the cutting oil supply unit 46 to a cutting oil passage 47 formed in the tool holder 38.

A rail 48 is provided on the base 31 along the axial direction of the main shaft 36. A movable table 51 is movably provided on the rail 48, and a support bearing 45 is supported on the movable table 51.
Further, a boring tool 20 is provided at a position corresponding to the workpiece 23.

  As shown in FIG. 11, the boring tool 20 includes a tool holder 38, a plurality of arms 52 provided on the tool holder 38 so as to be swingable and having a grindstone 14 at a tip portion, and a tool provided on the arms 52. A groove 53 formed parallel to the axis of the holder 38 and a bolt 54 for fixing the arm 52 to the tool holder 38 are provided.

Next, the boring tool 20 will be described based on a cross-sectional view taken along the axial direction.
As shown in FIG. 12, in the boring tool 20, a draw bar 42 is passed inside the tool holder 38. The draw bar 42 is provided with a tapered portion 55 that expands or contracts the arm 52 in the radial direction of the tool holder 38.
The tool holder 38 is provided with a through hole 56 in the radial direction. A pin 57 is slidably accommodated in the through hole 56, and the pin 57 is in contact with the tapered portion 55. Drawbar 42

The arm 52 is provided with a screw hole 61, and an adjustment screw 62 is provided in the screw hole 61. One end of the adjustment screw 62 is in contact with the end of the pin 57.
The tool holder 38 is provided with a jet hole 63 connected to the cutting oil passage 47, and the cutting oil from the cutting oil passage 47 is supplied from the jet hole 63 to the surface to be ground.
In addition, the code | symbol 64 is a screw hole for attaching a grindstone (FIG. 11, code | symbol 14).

  As shown in FIG. 13, the arm 52 has a shape along the outer periphery of the tool holder 38. The arm 52 is attached to the tool holder 38 via a bolt 66 inserted through an attachment hole 65 provided on the base end side. A screw hole for a bolt (FIG. 12, reference numeral 64) for attaching the grindstone 14 is provided on the tip side of the arm 52, and the grindstone 14 is attached to the arm 52 via a bolt.

Since the three arms 52 are provided at equal intervals in the circumferential direction of the draw bar 42, the balance of rotation is maintained. Furthermore, even if the plurality of grindstones 14 are provided apart from each other in the circumferential direction of the draw bar 42, when the grindstone 14 is expanded, the rotating shaft of the tool holder 38 and the grinding surfaces of the plurality of grindstones 14 are kept parallel. Accuracy can be maintained. The diameter expansion mechanism 67 that expands the arm 52 includes a tool holder 38, a draw bar 42, a pin 57 and an adjustment screw 62.
In the embodiment, the number of the arms 52 is three, but the number of arms 52 may be four or five. If the arm 52 can be ground by expanding the diameter, there may be a plurality of arms 52.

The operation of the grinding device 30 described above will be described next.
In FIG. 12, the draw bar 42 is moved to the right in the figure, and the pin 57 is pushed up. Then, the arm 52 in contact with the pin 57 opens around the groove 53, and the diameter of the grindstone 14 is increased. In this manner, the radial protrusion amounts of all the plurality of grindstones 14 are adjusted according to the movement amount of the draw bar 42.
Further, by rotating the adjusting screw 62, the distance between the pin 57 and the arm 52 can be adjusted to adjust the protruding amount of each grindstone 14 in the radial direction.

  After adjusting the protrusion amount of the grindstone 14, the center of the hole of the workpiece 23 placed on the table 34 shown in FIG. After reducing the diameter and allowing the tool to enter, the diameter is expanded to a predetermined diameter, the table 34 is moved along the axis of the rotating tool holder 38, and the inner diameter of the hole in the workpiece 23 is simultaneously ground. To do.

The contents described above are summarized below.
As shown in FIG. 4 above, the grindstone 14 is bonded to the surface 12 of the base material 11 in a form in which a plurality of abrasive grains 10 are arranged in a line, and all of the plurality of abrasive grains 10 have a predetermined value. A relief surface 16 having a relief angle of angle β is formed.

  With this configuration, all the abrasive grains 10 are formed with relief surfaces 16 having a relief angle of a predetermined angle β, so that the grinding resistance can be further reduced and the accuracy of the finished surface can be further improved. .

As shown in FIG. 2 described above, the grindstone 14 is a boring grindstone 14.
In general, inner diameter machining is more difficult than outer diameter machining because the tool shape and peripheral speed are limited. By using the boring grindstone 14 of the present invention for finishing the hole diameter, the hole finishing accuracy can be further improved.

As shown in FIG. 9, it includes a columnar base 21 and a grindstone 14 according to claim 1, which is arranged in a plurality in the axial direction on the columnar base 21.
With this configuration, the processing of the journal hole 28 of the cylinder block 27 requires, for example, processing of five bearings in the case of a four-cylinder cylinder block 27, and the tool has a long axis, and depending on the type, aluminum and iron In some cases, it is difficult to achieve the accuracy of the finished surface. In this respect, the finishing accuracy of the journal hole 28 can be further improved by using the boring tool 20 of the present invention.

As shown in FIG. 13, the arm 52 is expanded in the radial direction by the diameter expansion mechanism 67, and the grindstone 14 according to claim 1 is provided at the tip of the arm 52.
With this configuration, since the diameter is adjusted by the diameter expanding mechanism 67, it is possible to cope with finishing processing of inner diameters having different sizes with one boring tool 20. Therefore, a plurality of boring tools are not required, and the cost of the boring tool 20 can be reduced. Further, for example, in the processing of the journal hole 28 of the cylinder block 27, by providing a plurality of diameter expansion mechanisms 67 in the axial direction of the tool (boring tool 20), the diameter can be increased while having a plurality of grindstones 14 in the circumferential direction. A plurality of bearings can be processed simultaneously by reducing the size of the tool and allowing the tool to enter. Therefore, cycle time can be shortened. Furthermore, it is possible to cope with a reduction in processing diameter due to grinding wheel wear.

  The boring tool 20 of the present invention is applied to the base 21 having a constant outer diameter in the embodiment. However, the diameter of the grindstone 14 is increased with respect to the base 21 and abrasive grains are formed on the inner peripheral surface 24. A boring tool provided with a diameter expanding means for contacting 10 may be used.

  The grindstone of the present invention is suitable for boring of workpieces.

  DESCRIPTION OF SYMBOLS 10 ... Abrasive grain, 11 ... Base material, 12 ... Base material surface, 16 ... Relief surface, 20 ... Boring tool (line boring bar), 21 ... Base, 25 ... Rake face, 28 ... Journal hole, 52 ... Arm , 67 ... Diameter expansion mechanism, α ... Rake angle, β ... Clearance angle.

Claims (5)

A grindstone in which a plurality of abrasive grains are bonded in a row on the surface of a base material,
A relief surface having a relief angle of the same predetermined angle is formed on all of the plurality of abrasive grains ,
The flank is a flat grinding surface, and the flank of all the abrasive grains arranged in a row is formed on the same surface .   The grindstone according to claim 1, wherein the grindstone is a boring grindstone. A plurality of abrasive grains are arranged in a row in the axial direction of the shank on the surface of the base material provided at the tip of the shank, and the arrangement of the abrasive grains formed in the axial direction is arranged in the circumferential direction of the shank. A grindstone that is bonded in the form of multiple rows,
A relief surface having a relief angle of the same predetermined angle is formed on all of the abrasive grains in each row in the axial direction,
The flank is a flat grinding surface, and the flank of all the abrasive grains arranged in a row is formed on the same surface. A grinding wheel according to claim 1 , wherein a plurality of rows are arranged in the axial direction on the columnar base, and the rows of the abrasive grains in each row are formed in a row in the axial direction. Boring tool characterized by that. A cylindrical tool holder, an arm that is swingably provided on the tool holder and is radially expanded by a diameter expansion mechanism, and the grindstone according to claim 1 provided at a tip of the arm. Boring tool to do.

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