JP2007196302A - Index type multi-grinding wheel grinder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To grind a larger number of journal parts than the number of grinding wheels, by using a plurality of grinding wheels with their shafts supported at both ends, while simultaneously indexing a table. <P>SOLUTION: This grinding wheel grinder includes: a grinding wheel shaft unit 20 in which a grinding wheel shaft 21 fitted with a plurality of grinding wheels G1, G2 disposed at the same pitch as the journal parts of a workpiece for grinding the plurality of journal parts of the workpiece at the same time is rotatably supported like twin tong; a table 12 supporting the workpiece and indexing it relatively to the axial direction of the workpiece to the grinding wheel shaft unit; and an index control means 50 for indexing the grinding wheel shaft unit and the table by a predetermined amount. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention grinds a workpiece with high efficiency and high accuracy by relatively indexing a grindstone shaft unit including a plurality of grinding wheels (multi grindstone) and a table supporting the workpiece in the axial direction of the workpiece. The present invention relates to an index type multi-grind grinder.

  As a grinding machine for grinding a workpiece for an automobile part such as a crankshaft or a camshaft having a plurality of journal portions spaced apart in the axial direction, conventionally, for example, as described in Patent Document 1 A method of grinding a plurality of journal portions at once by a multi-grinding wheel grinding machine equipped with a plurality of grinding wheels (multi-grinding wheels) corresponding to the number of journal portions of a workpiece, and grinding with a single grinding wheel A method is known in which the journal portion is sequentially ground one by one while the table is indexed by a disk.

Conventionally, as described in Patent Document 2, for example, two grinding wheels are attached to one end of a grindstone shaft rotatably supported on a grindstone base so that two grinding points can be ground simultaneously. A grinder mounted with a predetermined interval is also known.
JP-A-6-8116 Japanese Patent Laid-Open No. 10-230457

  The multi-grind grinding machine described in Patent Document 1 described above has the advantage that the workpiece can be ground efficiently, but the grinding wheel axis unit is dedicated to the workpiece and lacks flexibility, and the type of workpiece is changed. In such a case, there is a problem that the setup change is difficult and requires a lot of man-hours. On the other hand, in the case where the journal portion of the workpiece is sequentially ground by a single grinding wheel, there is a problem that the cycle time becomes long although there is no problem as in the above-described multi-grind grinding machine.

  On the other hand, in the grinding machine described in Patent Document 2, since the grinding wheel is supported in a cantilever manner, it is difficult to increase the support rigidity of the grinding wheel, and there is a limit in improving the grinding accuracy. Since the touch of the grinding wheel becomes large, there is a problem that it is difficult to maintain the same grinding accuracy at the two grinding points.

  The present invention has been made to solve the above-described conventional problems, and simultaneously grinds a larger number of journal portions than the number of grinding wheels while indexing a table by a plurality of grinding wheels supported by both ends. An index type multi-grind grinding machine is to be provided.

  In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that a workpiece for an automobile part such as a crankshaft or a camshaft having a plurality of journal portions spaced apart in the axial direction is ground. In a grinding machine, the grindstone shaft, which is disposed with the same pitch interval as the journal portion of the workpiece and which grinds the plural journal portions of the workpiece simultaneously, can be rotated by both ends. A grindstone shaft unit supported on the wheel, a table that supports the workpiece and can be indexed relative to the grindstone shaft unit in the axial direction of the workpiece, and the table axis relative to the grindstone shaft unit. This is constituted by index control means for indexing a predetermined amount relative to the direction.

  A feature of the invention according to claim 2 is that, in claim 1, two grinding wheels are attached to the grinding wheel shaft supported by the grinding wheel shaft unit.

  A feature of the invention according to claim 3 is that, in claim 2, the index control means indexes the grindstone shaft unit and the table by approximately twice the pitch interval of the journal portion of the workpiece. It is that you are.

  According to a fourth aspect of the present invention, in the second aspect, the two grinding wheels include a rough grinding wheel and a finish grinding wheel, and the index control means includes the grinding wheel shaft unit and the table. Are sequentially indexed by the pitch interval of the journal portion of the workpiece.

  According to a fifth aspect of the present invention, in any one of the second to fourth aspects, the grindstone shaft is separated from the first and second grindstone shaft portions that can be separated and combined at a central portion in the axial direction. The grinding wheel is removably attached to each of the first and second grinding wheel shafts.

  According to the first aspect of the present invention, the both ends of the grindstone shaft having the plurality of grinding wheels disposed at the same pitch intervals as the journal portions of the workpiece and simultaneously grinding the plurality of journal portions of the workpiece are mounted. A grindstone shaft unit that is rotatably supported by the table, a table that supports the workpiece and can be indexed relative to the grindstone axis unit in the axial direction of the workpiece, and the table axis relative to the grindstone axis unit. Since it is constituted by index control means for indexing a predetermined amount relative to the direction, it is possible to grind the workpiece as compared with a case where a plurality of journal parts of the workpiece are ground one by one with a single grinding wheel. The cycle time can be greatly shortened.

  Moreover, since the grindstone shaft to which a plurality of grinding wheels are attached is supported by both ends of the grindstone shaft unit, the support rigidity of the grinding wheel can be increased, and a plurality of journal parts that are simultaneously ground by the plurality of grinding wheels are provided. Grinding accuracy can be improved.

  According to the second aspect of the present invention, since the two grinding wheels are attached to the grinding wheel shaft supported by the grinding wheel shaft unit, the two wheels attached to the grinding wheel shaft supported by both ends of the grinding wheel shaft unit are supported. A grinding wheel can be arrange | positioned in the position which respectively approached the bearing part of the grinding wheel axis | shaft unit, and the support rigidity of two grinding wheels can be made equal. Thereby, the two journal parts ground simultaneously with two grinding wheels can be ground with high precision with the same grinding accuracy.

  According to the invention of claim 3, since the index control means indexes the grindstone shaft unit and the table by approximately twice the pitch interval of the journal portion of the workpiece, in addition to the effects described above The grinding cycle time of the workpiece can be shortened by half compared to the case where multiple journal parts of the workpiece are ground one by one with a grinding wheel, and it corresponds to the number of journal parts of the workpiece As compared with the case where the workpiece is ground at once by a plurality of grinding wheels, it is possible to relatively easily perform the setup change when the type of the workpiece is changed.

  According to the invention of claim 4, the two grinding wheels are composed of a rough grinding grinding wheel and a finish grinding grinding wheel, and the index control means includes a grinding wheel shaft unit and a table, the pitch of the journal portion of the workpiece. In addition to the above-described effects, the workpiece grinding cycle is compared with the case where rough grinding and finishing grinding are performed on a plurality of journal portions of the workpiece by a single grinding wheel. Time can be cut in half.

  According to the invention which concerns on Claim 5, the grindstone axis | shaft consists of the 1st and 2nd grindstone shaft part which can be isolate | separated and couple | bonded at the axial center part, These 1st and 2nd grindstone shaft parts are Each grinding wheel is detachably mounted, so when the type of workpiece is changed, the grinding wheel shaft can be separated at the center and each grinding wheel can be replaced. It can be done very easily.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings. FIG. 1 shows an entire index-type multi-grind grinding machine 10, and a table 12 is guided and supported on a bed 11 of the multi-grind grinding machine 10 so as to be movable in the horizontal Z-axis direction. A headstock 13 and a tailstock 14 are disposed on the table 12 so as to face each other, and the spindle stock 13 and the tailstock 14 are provided with centers 15 and 16 for supporting the workpiece W. The workpiece W is a crankshaft or a camshaft used as an automobile part, and includes a plurality (four in the embodiment) of journal portions W1 to W4 with an interval in the axial direction. Of the plurality of journal portions W1 to W4, two adjacent journal portions on both sides, that is, the first and second journal portions W1 and W2 and the third and fourth journal portions W3 and W4 are shown in FIG. As described above, the second journal W2 and the third journal portion W3 are arranged at an equal pitch interval P1, and are separated by an interval P2 different from the pitch interval P1. The workpiece W supported by both the centers 15 and 16 has an axis parallel to the moving direction (Z-axis direction) of the table 12 via a driving bracket (not shown) by a spindle driving motor 17 installed on the spindle table 13. It is designed to rotate around.

  On the bed 11, the grindstone shaft unit 20 is guided and supported so as to be movable in the horizontal X-axis direction orthogonal to the moving direction of the table 12. A grinding wheel shaft 21 is supported on the grinding wheel shaft unit 20 so as to be rotatable about an axis parallel to the moving direction (Z-axis direction) of the table 12, and the two grinding wheels G <b> 1 and G <b> 2 are arranged on the grinding wheel shaft 21. They are spaced apart by P1. The grinding wheels G1 and G2 are composed of, for example, super hard CBN abrasive grains bonded to the outer periphery of a disk-shaped metal core with vitrified bonds, and on the outer peripheral surface thereof, the moving direction of the table 12 (Z-axis direction) and The cylindrical grinding surfaces G1a and G2a are parallel and have the same diameter. The grindstone shaft 21 is rotationally connected to an output shaft of a grindstone drive motor 25 mounted on the grindstone shaft unit 20 via a belt transmission device including pulleys 26 and 27 and a belt 28. The grinding wheels G1 and G2 are rotationally driven by a grinding wheel drive motor 25, and simultaneously grind the two adjacent journal portions W1 and W2 of the workpiece W by the cylindrical grinding surfaces G1a and G2a. Two journal portions W3 and W4 are ground simultaneously.

  Next, a specific configuration of the grindstone shaft unit 20 will be described with reference to FIG. In the drawing, a pair of bearing portions 31 and 32 are provided at a front portion of the grindstone shaft unit 20 with a predetermined interval in the Z-axis direction, and the grindstone shaft 21 is supported at both ends by these bearing portions 31 and 32. The workpiece W is supported so as to be rotatable about an axis parallel to the rotation axis of the workpiece W. The grindstone shaft 21 is composed of two (first and second) grindstone shaft portions 21a and 21b that can be divided and joined at the central portion in the axial direction, and the first grindstone shaft portion 21a is one bearing portion 31. The bearing is rotatably and slidably supported by a radial bearing 33 provided on the shaft. The second grindstone shaft portion 21b that is rotationally connected to the grindstone drive motor 25 is rotated only on the same axis as the first grindstone shaft portion 21a by the radial bearing 34 and the thrust bearing 35 provided on the other bearing portion 32. It is supported as possible.

  A taper shaft 21a1 and a taper hole 21b1 that fits and fits the taper shaft 21a1 are formed at the opposing ends of the first and second grindstone shaft portions 21a and 21b, respectively. The taper shaft 21a1 and the taper hole 21b1 The two grindstone shaft portions 21a and 21b are centered and joined by mating and fitting. The taper shaft 21a1 and the taper hole 21b1 are normally integrally coupled by a coupling means (not shown). When the grinding wheels G1 and G2 are replaced, the coupling means is released and the first and second grinding wheel shaft portions 21a and 21b can be separated. It becomes. The taper shaft 21a1 and the taper hole 21b1 constitute a taper coupling portion for centering and coupling the first and second grindstone shaft portions 21a and 21b.

  Flange portions 21a2 and 21b2 are provided on the first and second grindstone shaft portions 21a and 21b, respectively. The flange portions 21a2 and 21b2 are respectively fitted to the first and second grindstone shaft portions 21a and 21b. Grinding wheels G1 and G2 are fixed by bolts 37 and 38. The distance between the two grinding wheels G1 and G2 fixed to the flange portions 21a2 and 21b2 is such that the first and second grinding wheel shaft portions 21a and 21b are centered and coupled. The two journal portions W1 and W2 are set to be kept the same as the pitch interval P1. The two grinding wheels G1 and G2 can be attached and detached from between the opposing ends in a state where the first and second grinding wheel shaft portions 21a and 21b are separated at the central portion in the axial direction. ing.

  Further, a known autobalancer 39 is incorporated in the first grindstone shaft portion 21a, and the two grinding wheels G1 attached to the first and second grindstone shaft portions 21a and 21b by the autobalancer 39, The balance of the rotating system including G2 is automatically corrected.

  As shown in FIG. 1, a truing device 40 having a truing tool 41 for truing two grinding wheels G1 and G2 is disposed on the head stock 13 installed on the table 12. The truing device 40 is configured to true the cylindrical grinding surfaces G1a and G2a of the two grinding wheels G1 and G2 to the same diameter by the cutting advance in the X-axis direction of the grinding wheel shaft unit 20 and the traverse in the Z-axis direction of the table 12. It has become.

  As shown in FIG. 1, the numerical controller 50 that controls the grinding machine 10 mainly includes a central processing unit 51, a memory 52 that stores various control values and programs, and interfaces 53 and 54. The memory 52 stores data necessary for executing the grinding cycle and the truing cycle, the index amount data of the table 12, and the like. Various data are input to the numerical controller 50 via an input device 55. The input device 55 includes a keyboard for inputting data and a display device such as a CRT for displaying data. It has.

  The numerical controller 50 gives a drive signal to an X-axis servo motor 61 that moves the grinding wheel shaft unit 20 in the X-axis direction via the X-axis motor drive unit 60, and is attached to the X-axis servo motor 61. The encoder 62 is configured to send the rotational position of the X-axis servomotor 61, that is, the position in the X-axis direction of the grindstone shaft unit 20 to the X-axis motor drive unit 60 and the numerical controller 50. In addition, the numerical controller 50 gives a drive signal to the Z-axis servomotor 65 that moves the table 12 in the Z-axis direction via the Z-axis motor drive unit 64, and is attached to the Z-axis servomotor 65. The encoder 66 is configured to send the rotational position of the Z-axis servomotor 65, that is, the Z-axis direction position of the table 12 to the Z-axis motor drive unit 64 and the numerical controller 50. The numerical control device 50 described above constitutes the index control means in the claims.

  Next, operations in the first embodiment configured as described above will be described. As shown in FIG. 1, the two grinding wheels G1 and G2 provided in the grinding wheel shaft unit 20 are positioned at the Z-axis direction position corresponding to the first and second journal portions W1 and W2 of the workpiece W. When the start of the grinding cycle is commanded in this state, the grindstone shaft 21 is rotated by the grindstone drive motor 25 and the work supported by the spindles 13 and the centers 15 and 16 of the tailstock 14 is performed. The object W is rotationally driven by the main shaft drive motor 17. Subsequently, the grindstone shaft unit 20 is advanced in the X-axis direction by the X-axis servomotor 61. As shown in FIG. 3A, the two grinding wheels G1 and G2 on the grindstone shaft unit 20 move the workpiece W. The first and second journal portions W1, W2 are ground simultaneously.

  When the first and second journal portions W1 and W2 of the workpiece W are ground to a predetermined dimension, the grindstone shaft unit 20 is retracted in the X-axis direction by the X-axis servomotor 61, and then the numerical controller 50 Based on the command, the table 12 is indexed by a predetermined amount in the Z-axis direction by the Z-axis servomotor 65. That is, the table 12 is indexed by the interval (P1 + P2) between the first journal part W1 and the third journal part W3. As a result, as shown in FIG. 3B, the third and fourth journal portions W3, W4 of the workpiece W are positioned at positions corresponding to the two grinding wheels G1, G2. In this state, as described above, the grindstone shaft unit 20 is advanced in the X-axis direction by the X-axis servomotor 61, and the third and second grinding wheels G1, G2 on the grindstone shaft unit 20 are moved to the third and The fourth journal parts W3 and W4 are ground simultaneously. When the third and fourth journal portions W3 and W4 are ground to a predetermined dimension, the grindstone shaft unit 20 is retracted in the X-axis direction by the X-axis servomotor 61, and the grinding of the workpiece W is finished.

  As described above, since the plurality of journal portions W1 to W4 of the workpiece W are ground at the same time in two places, it is compared with the case where the plurality of journal portions of the workpiece W are ground one by one with a single grinding wheel. Thus, the grinding cycle time of the workpiece W can be greatly shortened.

  In addition, since the grinding wheel shaft 21 to which the two grinding wheels G1 and G2 are attached is supported at both ends by the grinding wheel shaft unit 20, the supporting rigidity of the grinding wheels G1 and G2 can be increased. In this case, since the distance between the two bearing portions 31 and 32 of the grindstone shaft unit 20 can be shortened, the shaft rigidity of the grindstone shaft 21 can be improved, the runout of the grindstone shaft 21 can be reduced, and the grinding accuracy of the workpiece W can be improved. Can be improved. In addition, the grinding wheel shaft 21 to which the two grinding wheels G1 and G2 are attached is supported on both ends by the grinding wheel shaft unit 20, so that the grinding wheels G1 and G2 approach the two bearing portions 31 and 32, respectively. And the supporting rigidity of the two grinding wheels G1 and G2 can be made equal. As a result, the two journal portions W1, W2, W3, and 4 that are simultaneously ground by the two grinding wheels G1 and G2 can be ground with the same grinding accuracy.

  In this type of grinding machine, the taper is adjusted by adjusting the center axis of the tailstock 14 based on the dimensional difference between the two journal parts ground by the two grinding wheels G1 and G2. Although it is well known, the taper adjustment can be performed with high accuracy by making the supporting rigidity of the two grinding wheels G1 and G2 equal as described above.

  Since the difference between the pitch interval P1 and the interval P2 is usually small, if the grindstone width of the grinding wheels G1 and G2 is made larger than the machining width of the journal portions W1 to W4 of the workpiece W, the table 12 is pitched. By indexing twice (P1 × 2) the interval P1, the third and fourth journal portions W3 and W4 can be ground. Accordingly, it should be understood that “approximately twice the pitch interval of the journal portion in the claims” includes the case where the index amount of the table 12 is any of the above cases (“P1 + P2” or “P1 × 2”).

  When the grinding wheels G1 and G2 reach the end of their lives, or when the type of the workpiece W to be ground is changed, the grinding wheels G1 and G2 are replaced. For exchanging the grinding wheels G1 and G2, first, the coupling means (not shown) is released to release the integral coupling between the first grinding wheel shaft portion 21a and the second grinding wheel shaft portion 21b. As shown in FIG. 4, the first grindstone shaft 21a is moved in the left direction in the figure, the first grindstone shaft 21a is separated from the second grindstone shaft 21b, and the first and second grindstone shafts are separated. A space for attaching and detaching the grinding wheel is formed between 21a and 21b. In this state, the bolts 37 and 38 that have fixed the grinding wheels G1 and G2 to the flange portions 21a2 and 21b2 on the grinding wheel shaft portions 21a and 21b are removed, and the grinding wheels G1 and G2 are sequentially moved to the first and the first. It removes from between the 2 grindstone shaft parts 21a and 21b.

  Next, new grinding wheels G1 and G2 are sequentially fitted to the first and second grinding wheel shaft portions 21a and 21b in the reverse order to the above, and fixed to the flange portions 21a2 and 21b2 by bolts 37 and 38, respectively. To do. In this case, when the pitch interval between the two grinding wheels G1 and G2 is changed, a pitch interval is provided by providing a spacer between at least one of the flange portions 21a2 and 21b2 and the grinding wheels G1 and G2. Adjust.

  Thereafter, the first grindstone shaft portion 21a is moved rightward in the drawing, the taper shaft 21a1 is fitted into the taper hole 21b1 of the second grindstone shaft portion 21b, and the taper shaft 21a1 is connected by a coupling means (not shown). The first and second grindstone shaft portions 21a, 21b are integrated with the tapered hole 21b1. At this time, the balance of the rotating system including the grinding wheel shaft 21 and the grinding wheels G1, G2 is automatically corrected by the operation of the autobalancer 39.

  Thereafter, truing of the grinding wheels G1 and G2 newly mounted on the grinding wheel shaft unit 20 is performed. In this truing, first, the table 12 is moved in the Z-axis direction by the Z-axis servomotor 66, and the truing tool 41 of the truing device 40 attached to the headstock 13 is applied to the grinding wheels G 1 and G 2 on the grinding wheel shaft unit 20. Then, the grindstone shaft unit 20 is cut and advanced by the X-axis servomotor 61 to a predetermined position in the X-axis direction. In this state, the table 12 is traversed by a predetermined amount, and the cylindrical grinding surfaces G1a and G2a of the grinding wheels G1 and G2 are trued to the same diameter by the truing tool 41. Note that the truing operation of the grinding wheels G1 and G2 is performed by repeatedly traversing the table 12 several times while cutting the grinding wheel shaft unit 20 by a certain amount.

  According to the first embodiment described above, the two grinding wheels G1 and G2 attached to the grinding wheel shaft 21 supported by the both ends of the grinding wheel shaft unit 20 are mounted on the bearing portions 31 and 32 of the grinding wheel shaft unit 20. Since the two grinding wheels G1 and G2 can be arranged at close positions, the support rigidity of the two grinding wheels G1 and G2 can be made equal, and the two journal parts that are simultaneously ground by the two grinding wheels G1 and G2 can be provided. It becomes easy to perform high-precision grinding with the same grinding accuracy. Accordingly, the grinding cycle time of the workpiece W can be greatly increased without lowering the grinding accuracy as compared with the case where the plurality of journal portions W1 to W4 of the workpiece W are ground one by one with a single grinding wheel. Can be shortened.

  In addition, the number of grinding wheels is reduced by the number of grinding wheels compared to conventional multi-grind grinding machines that grind workpieces at once with multiple grinding wheels corresponding to the number of journal parts of the workpiece. If the grinding wheel shaft 21 is constituted by the first and second grinding wheel shaft portions 21a and 21b that can be separated and combined at the central portion in the axial direction, the type of the workpiece W can be easily changed. When the wheel is changed, the grinding wheel G1, G2 can be replaced very easily, and the pitch interval of the grinding wheels G1, G2 can be easily changed by interposing a spacer or the like.

  FIG. 5 shows a second embodiment of the present invention, which is suitable for grinding a workpiece WA such as a crankshaft or a camshaft used for an engine having a different number of cylinders, for example. That is, the workpiece WA in which two journal portions W11, W12, W13 and W14, W15, W16 arranged at equal pitch intervals P11 are arranged in the axial direction at intervals P12 is ground. In this case, three grinding wheels G11, G12, and G13 are provided at the same interval as the journal portion W so that the three journal portions can be ground simultaneously. Although not shown in FIG. 5, the three grinding wheels G11, G12, and G13 are both supported by the grinding wheel shaft unit (20) via the grinding wheel shaft (21) as in the first embodiment. It is comprised so that. When the first, second, and third journal portions W11, W12, and W13 are ground simultaneously by the three grinding wheels G11, G12, and G13, the table (12) becomes the first journal portion W11 and the fourth journal. The fourth, fifth, and sixth journal portions W14, W15, and W16 are ground at the same time by the three grinding wheels G11, G12, and G13 while being moved by an interval (2 × P11 + P12) from the portion W14.

  According to the second embodiment described above, for example, a workpiece such as a crankshaft or a camshaft used in a 6-cylinder engine is also supported by the three grinding wheels G11, G12, and G13 that are both supported. W can be more efficiently and precisely ground.

  FIG. 6 shows a third embodiment of the present invention, in which one of the two grinding wheels both supported by the grinding wheel shaft unit 20 is a rough grinding wheel G21, and the other is a finishing grinding wheel. By setting the wheel G22 as the wheel G22 and the diameter of the grinding wheel G22 for finishing grinding larger than that of the grinding wheel G21 for roughing grinding, it is possible to perform roughing grinding and finishing grinding simultaneously. is there. In this case, as the rough grinding wheel G21, for example, a grindstone in which superabrasive grains such as CBN and diamond are combined by vitrifado bond is used, and the finish grinding wheel G22 is rough ground by, for example, CBN. The grinding wheel G21 is used by changing the particle size and hardness. The third embodiment can be applied when a plurality of journal portions W21 to W24 on the workpiece WB are arranged at equal pitch intervals P21.

  In the third embodiment, first, as shown in FIG. 6A, the rough grinding wheel G21 is positioned at a position corresponding to the first journal portion W21, and the first journal portion W21 is roughened. Rough grinding is performed by the grinding wheel G21, and then, as shown in FIG. 6B, the table (12) is moved by the pitch interval P21, and the rough grinding wheel G21, the first grinding wheel G21 is moved to the second journal portion W22. The finish grinding wheel G22 is positioned at a position corresponding to the journal portion W21, and the rough grinding and finish grinding of the first and second journal portions W21, W22 are simultaneously performed by the rough grinding wheel G21 and the finish grinding wheel G22. Process. In the same manner, the finish grinding wheel G22 is sequentially associated with the journal portion that has been subjected to rough grinding, and the rough grinding wheel G21 is sequentially associated with the unprocessed journal portion adjacent thereto. The fourth journal portions W22 to W24 are subjected to rough grinding and finish grinding.

  According to the third embodiment described above, since the rough grinding wheel 21 and the finish grinding wheel 23 can simultaneously perform rough grinding and finish grinding on two adjacent journal portions of the workpiece W. The grinding cycle time of the workpiece can be reduced to half compared to the case where rough grinding and finish grinding are performed on a plurality of journal portions on the workpiece by a single grinding wheel.

  In the above-described embodiment, the table 12 is indexed and a plurality of grinding wheels (multi-grinding wheels) are configured to correspond to a plurality of journal portions. However, such an index can be performed on the grinding wheel shaft unit 20 side, The present invention is not limited to the configuration of the grinding machine 10 described in the embodiment.

  Further, in the above-described embodiment, the grindstone shaft 21 can be divided and coupled at the central portion in the axial direction so that the grinding wheel can be easily replaced. However, such a configuration is not necessarily required for the present invention. Instead, the grinding wheel may be replaced for each grinding wheel shaft 21.

It is a top view of the index type multi-grind grinding machine which shows the 1st embodiment of the present invention. It is sectional drawing which shows the grindstone axis | shaft unit in 1st Embodiment. It is a figure which shows the grinding process cycle in 1st Embodiment. It is an operation state figure of Drawing 2 showing the exchange state of a grinding wheel. It is a grinding cycle figure which shows the 2nd Embodiment of this invention. It is a grinding cycle figure which shows the 3rd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Grinding machine, 12 ... Table, 13 ... Spindle head, 14 ... Tailstock, 20 ... Grinding wheel shaft unit, 21 ... Grinding wheel shaft, 21a, 21b ... Grinding wheel Shaft portion, 31, 32 ... Bearing portion, 33, 34 ... Radial bearing, 35 ... Thrust bearing, 21a1, 21b1 ... Taper coupling portion (taper shaft, taper hole), 40 ... Truing Device, 50 ... index control means (numerical control device), G1, G2, G11, G12, G13, G21, G22 ... grinding wheel, W, WA, WB ... workpiece, W1-W4, W11 -W16, W21-W24 ... Journal part.

Claims (5)

  In a grinding machine for grinding a workpiece for an automobile part such as a crankshaft or a camshaft having a plurality of journal portions spaced in the axial direction, the grinder has the same pitch interval as the journal portion of the workpiece. A grindstone shaft unit that supports a grindstone shaft that is rotatably supported with both ends supported by a grindstone shaft mounted with a plurality of grinding wheels that simultaneously grind a plurality of journal portions of the workpiece, and the grindstone shaft unit that supports the workpiece. A table that can be relatively indexed in the axial direction of the workpiece, and index control means for indexing the table relative to the grindstone axis unit by a predetermined amount in the axial direction of the workpiece. Characteristic index type multi-grind grinding machine.   The index type multi-grind grinding machine according to claim 1, wherein two grinding wheels are attached to the grinding wheel shaft supported by the grinding wheel shaft unit.   3. The index type multi-grind grinder according to claim 2, wherein the index control means indexes the grindstone shaft unit and the table by approximately twice the pitch interval of the journal portion of the workpiece.   3. The grinding wheel according to claim 2, wherein the two grinding wheels include a rough grinding grinding wheel and a finish grinding grinding wheel, and the index control means connects the grinding wheel shaft unit and the table to the pitch of the journal portion of the workpiece. An index-type multi-grind grinding machine that is indexed sequentially at intervals.   5. The grindstone shaft according to claim 2, wherein the grindstone shaft includes first and second grindstone shaft portions that are separable and connectable at a central portion in the axial direction. An index type multi-grind grinding machine in which a grinding wheel is detachably attached to each grinding wheel shaft.

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