JP2005169530A - Grinding machine and grinding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grinding machine and a grinding method for improving productivity and enhancing workpiece machining accuracy. <P>SOLUTION: The grinding machine is provided with a table 2; a headstock 3 and a tailstock 4 provided at the table 2 to support a camshaft W rotatably; a grinding wheel 5 moving in an X-axis direction orthogonal to a Z-axis which is a rotation axis of the camshaft W to grind the camshaft W; a runout preventer 13 moving in the X-axis direction orthogonal to the Z-axis which is the rotation axis of the camshaft W to contact and separate from the camshaft W; a load generating part 16 applying a workpiece pressing load to the runout preventer 13; and a load detecting part 18 for detecting the workpiece pressing load. The runout preventer 13 is formed as a clamping part provided with a machining roller 11 capable of forming micro unevenness on the camshaft W, and a roller support part 12 supporting the machining roller 11 and contacting and separating from the camshaft W. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a grinding machine and a grinding method used for grinding a workpiece, and particularly to a grinding machine and a grinding method suitable for grinding a camshaft.

  When the workpiece to be ground is a camshaft, both the journal and the cam lobe are ground, and in particular, the journal is also processed to form fine irregularities.

  Conventionally, when a camshaft is ground by a grinder, the journal is first ground into a cylindrical shape, then the cam lobe is ground by a grinder different from this grinder, and then the journal is again applied to the journal. Thus, for example, fine irregularities are formed by processing such as shot peening.

  Here, when the cam lobe is ground by cutting the camshaft supported by the headstock and tailstock with a grinding wheel, it is rotated with respect to the journal to prevent the shaft from bending. The steady rest is pressed in the direction orthogonal to the shaft.

JP 2000-227119 A

  However, in the past, when a single workpiece is subjected to grinding processing or processing to form fine irregularities, a processing machine corresponding to each of the plurality of processes must be used, which increases productivity. In addition, there is a problem that it is difficult to adjust the pressing force of the steady rest so that the processing accuracy of the workpiece is optimized during grinding. Solving these problems has been a conventional problem.

  The present invention has been made by paying attention to the above-described conventional problems, and even if it is a case where a grinding process or a process for forming fine irregularities is performed on one work, the other 1 is used without using another grinding machine. To provide a grinding machine and a grinding method that can perform both of the processes on the table, and as a result, can improve productivity, and can also increase the machining accuracy of the workpiece. It is aimed.

  The present invention includes a table, a spindle stock and a tailstock that are provided on the table and rotatably support the workpiece, a grinding wheel that moves the workpiece in a direction orthogonal to the rotation axis of the workpiece, and grinds the workpiece, The steady rest includes a steady rest that moves in a direction perpendicular to the rotation axis of the workpiece and contacts and separates the workpiece, a load generating section that applies a workpiece pressing load to the steady rest, and a load detection section that detects the workpiece pressing load. However, it is characterized by having a function capable of forming fine irregularities on the workpiece, and the structure of this grinding machine is used as a means for solving the above-described conventional problems.

  According to the grinding machine of the present invention, it is possible to realize an excellent effect that productivity can be improved and the machining accuracy of the workpiece can be greatly improved.

  In the grinding machine of the present invention, the steady rest includes a steady stop roller that contacts and separates from the workpiece and a roller support portion that supports the steady stop roller, and fine irregularities can be formed on the workpiece by the steady stop roller. The structure and the steady rest include a processing roller capable of forming fine irregularities on the workpiece, and a roller support portion that supports the processing roller, and the steady rest portion that contacts and separates the roller support portion from the workpiece. The configuration described above can be adopted.

  If the above configuration is adopted, in the case of a cam grinder, one unit can perform fine uneven processing of the journal by a roller or roller support after grinding the cam lobe. In the case of a crank grinder, one unit grinds the crank pin. Later, the roller and roller support can be used to process the fine unevenness of the journal. On the other hand, during cam lobe grinding, it functions as a steady rest for the workpiece and can provide an optimum load for the steady rest. The bending of the workpiece (camshaft) can be suppressed to a small extent, and as a result, the machining accuracy is improved.

  Further, in the grinding machine of the present invention, the roller can be moved in a direction perpendicular to the rotation axis of the workpiece, and the roller support portion can be projected and retracted in the direction perpendicular to the rotation axis of the workpiece. In the extended state, the tip of the roller support portion can be positioned closer to the workpiece than the roller. In this case, the productivity can be improved and the workpiece machining accuracy can be improved. It can be greatly improved.

  Further, in the grinding machine of the present invention, the steady rest, the load generating portion, and the load detecting portion constitute one unit, and the whole steady rest unit is configured to be movable in a direction perpendicular to the workpiece rotation axis. It is possible.

  Furthermore, in the grinding machine of the present invention, it is possible to adopt a configuration in which the entire steadying unit can be moved in the direction of the rotation axis of the workpiece. For example, in the case of a cam grinding machine, the steadying during cam lobe grinding is possible. Further, the fine unevenness processing of the journal can be performed by one steadying unit, and further, for example, the case where the journal position of the camshaft is different in the same grinding machine can be dealt with.

  Furthermore, in the grinding machine of the present invention, it is possible to adopt a configuration including a plurality of steadying units, and in this case, it becomes possible to perform micro-processing on a plurality of journals at the same time. The property is further improved.

  Furthermore, in the grinding machine of the present invention, the roller support part that functions as a steadying part can be provided with a separate contact body with the workpiece, and the contact body with the workpiece is a roller. In the former case, since the contact body with the workpiece can be exchanged, carbide, diamond, ceramics, etc. with excellent wear resistance can be used, and it is excellent in economic efficiency. In the latter case, for example, at the time of cam processing, a roller as a contact body comes into contact with the journal, so that friction is reduced and scratches are less likely to occur.

  On the other hand, in the grinding method of the present invention, when the workpiece is ground by the grinding machine according to any one of claims 1 to 10, grinding processing by a grinding wheel that is performed while pressing a steady rest against the workpiece, It is possible to adopt a configuration that continuously performs fine unevenness forming processing that is performed by stopping, which can improve productivity and greatly improve workpiece processing accuracy Is possible.

  Further, in the grinding method of the present invention, based on the workpiece pressing load obtained by the load detection unit, a configuration for controlling the workpiece pressing load applied from the load generating unit to the steady rest to suppress the amount of bending of the workpiece to a small amount is adopted. In this case, since the bending of the workpiece can be suppressed, the processing accuracy at the time of grinding is improved.

  Furthermore, in the grinding method of the present invention, the amount of movement and / or the grinding wheel in the direction orthogonal to the rotation axis of the work piece of the steady rest is determined based on the work pressing load obtained by the load detecting unit when grinding with the grinding wheel. In this case, since the force applied to the part other than the grinding part can be detected during grinding, finer control than the above grinding method is possible, and machining accuracy can be controlled. Can be further improved. In addition, the pressing force of the steady rest can be automatically optimized when machining different types of workpieces. Since the force applied to the workpiece during grinding can be estimated, it is possible to perform processing with stable quality on all grinding surfaces by changing the cutting so that the processing force during grinding is constant. .

  Furthermore, in the grinding method of the present invention, it is possible to adopt a configuration in which the grinding conditions are changed to suppress the workpiece pressing load below a preset load when grinding with a grinding wheel. Then, for example, during cam lobe grinding, it is possible to prevent excessive grinding resistance from occurring by changing the depth of cut and workpiece rotation speed based on the load detected by the load detection unit. And grinding with excellent internal quality.

  Furthermore, in the grinding method of the present invention, when the grinding machine of the grinding machine according to claim 7 is ground by the grinding wheel, the whole steady rest unit is arranged with the rotational axis direction and the rotational axis of the workpiece while the steady rest is in contact with the workpiece. In addition to being able to adopt a structure that moves in both directions orthogonal to each other, the steady rest unit is in contact with the workpiece while forming the fine unevenness by the steady rest of the grinding machine according to claim 7. It is possible to adopt a configuration that moves the whole in the direction of the rotation axis of the workpiece. In the former case, the periphery of the roller support can be configured compactly, so that interference between the workpiece and the steady rest can be avoided. Since it is possible to perform fine unevenness processing with a narrow roller, the force required for fine unevenness processing can be reduced, and the amount of bending of the workpiece is reduced. Degree is improved.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example.

  As shown in FIG. 1, a grinding machine 1 in this embodiment includes a table 2, a spindle stock 3 and a tailstock 4 provided on the table 2 and rotatably supporting a camshaft (workpiece) W, a cam A grinding wheel 5 for grinding the camshaft W by moving in a direction (X axis) orthogonal to the rotation axis (Z axis) of the shaft W, and a rotation axis of the camshaft W attached to the table 2 via the slider 6. A plurality of steady-rest units 10 that move in a direction perpendicular to the camshaft W and come into contact with and away from the camshaft W are provided. The steady-rest units 10 are also movable in the Z-axis direction.

  As shown in FIG. 2, the steady rest unit 10 includes a processing roller 11 capable of forming fine irregularities on the camshaft W and a steady rest 13 having a roller support portion 12 that supports the processing roller 11. .

  The processing roller 11 of the steady rest 13 has a cylindrical shape made of a high-hardness material such as cemented carbide or ceramics. As shown in FIG. It is formed by grinding, brazing or press fitting.

  On the other hand, the roller support portion 12 of the steady rest 13 has a contact body with the camshaft W, that is, a contact body 12a made of a member having excellent wear resistance such as carbide, attached to the tip (upper end in FIG. 2). . A cylinder 12b is provided at the base end (lower end in FIG. 2) of the roller support portion 12, and the processing roller 11 is held at the tip of the roller support portion 12 by holding the rotation shaft 11b of the processing roller 11 so as to be movable in the X-axis direction. Can be haunted from.

  In this case, the tip end portion of the shaft 15 whose base end portion is slidably fitted to the housing 14 is connected to the roller support portion 12. The housing 14 is provided with a load generating portion 16 that applies a load to the roller support portion 12 and the processing roller 11 via the shaft 15, and the load is applied via the preload adjusting portion 17 that prevents the shaft 15 from rattling. A detection unit 18 is provided, and both the load generation unit 16 and the load detection unit 18 together with the steady rest 13 constitute a steady rest unit 10.

  In this embodiment, as shown in FIG. 2, the shaft 15 is linearly moved in the X-axis direction. However, for example, a load is applied to the roller support portion 12 and the processing roller 11 by an arc motion other than the linear motion. It is also possible to employ a mechanism as given. In this embodiment, a coil spring is shown as the load generating unit 16, but hydraulic pressure or pneumatic pressure may be used as another configuration.

  Next, a grinding method using the grinding machine 1 will be described. First, as shown in FIG. 1, a camshaft W whose journal Wb has been previously cylindrically ground in the previous process is sandwiched between the headstock 3 and the tailstock 4, and the camshaft W is rotated by a motor built in the headstock 3. Let The headstock 3 and the tailstock 4 are mounted on the table 2 and linearly move together with the table 2 in the rotation axis direction (Z-axis direction in the drawing) of the camshaft W.

  The above-described steadying unit 10 has a housing 14 attached to the table 2 via a slider 6 and can move relative to the table 2 in the illustrated X-axis direction.

  The grinding portion of the camshaft W is rotated after the tip of the grinding wheel 5 approaches the surface of the processing portion by the movement of the grinding wheel 5 in the X-axis direction and the movement of the table 2 in the Z-axis direction. In addition, the grinding wheel 5 is processed by being cut by the movement of the grinding wheel 5 in the X-axis direction.

  The operation of the steady rest unit 10 until it is ground will be described with reference to FIG. 4. First, as shown in FIG. 4A, the cylinder 12b provided at the base end of the roller support portion 12 is contracted so that the processing is performed. The roller 11 is in a state of being sunk from the tip of the roller support portion 12. Further, the steady rest unit 10 is retracted relative to the table 2 by the slider 6 in the X-axis direction, so that the shaft 15 is pushed forward in the X-axis by the load applied from the load generating unit 16. It has become.

  Subsequently, as shown in FIG. 4B, the steady rest unit 10 is advanced in the X-axis direction by the slider 6, and the surface of the journal Wb in which the contact body 12 a attached to the tip of the roller support portion 12 is previously ground. To touch.

  Next, as shown in FIG. 4C, when the steady rest unit 10 moves forward by the slider 6, the shaft 15 moves backward while the contact body 12a is kept in contact with the surface of the journal Wb. When the coil spring 16 is contracted, a pressing load is generated on the surface of the journal Wb. This pressing load can be set in advance according to the amount of movement of the slider 6, but as shown in the present embodiment, it can be measured by a load detection unit 18 incorporated behind the load generation unit 16, and this Setting based on load is possible. In this way, the grinding process is performed on the grinding part in the state where the contact body 12a of the roller support 12 is in contact with the journal Wb.

  According to such a grinding method, it is possible to set the load so that the deformation (bending) of the workpiece W during processing is minimized, and during processing based on a signal from the load detection unit 18. It is possible to change the pressing load of the steady rest, and it is possible to always perform the optimum steady rest in response to changes in the processing force such as when the cutting amount of the grinding wheel 5 is changed.

  Therefore, it is possible to perform grinding with excellent accuracy, and in addition, it is possible to measure the variation of the processing force by the load detection unit 18 incorporated in the steady rest unit 10. It is also possible to capture changes in machining force caused by progress, and realize grinding with stable quality.

  Next, a method of processing a fine uneven surface on the journal Wb by the above-described grinding machine 1 will be described with reference to FIG.

  First, after the processing of the grinding portion Wa is completed, as shown in FIG. 5A, the steadying unit 10 is retracted in the X-axis direction by the slider 6, and at the same time, the cylinder 12b is extended, whereby the processing roller 11 protrudes from the tip of the roller support 12 and is in a rotatable state.

  At this time, the shaft 15 is in an extended state, and the pressing load by the load generator 16 is minimized.

  Next, as shown in FIG. 5B, the steadying unit 10 is advanced by the slider 6, and the processing roller 11 comes into contact with the surface of the journal Wb. Further, as shown in FIG. As the stop unit 10 is moved forward, the coil 15 that is the load generating portion 16 contracts simultaneously with the shaft 15 moving backward, and a load is applied from the processing roller 11 to the surface of the journal Wb.

  At this time, the pressing load can be controlled by the amount of movement of the slider 6 or the load detected by the load detector 18 as in the previous grinding process, and a load different from that in the previous grinding process should be set. Can do.

  In this way, when the camshaft W is rotated by the main shaft while the front end of the outer peripheral portion of the processing roller 11 is pressed against the journal Wb, fine irregularities 11a are formed on the outer peripheral surface of the processing roller 11. 6 can be easily performed on the surface of the journal Wb as shown in FIG. 6, and the other grinding portion Wa can be processed with only the single grinding machine 1 described above. Therefore, it is not necessary to attach and detach the workpiece, and the time required for processing can be reduced by that amount, and the capital investment can be reduced. Therefore, it is possible to provide an inexpensive rotating part with excellent friction performance.

  According to the above-described embodiment, the contact body 12a made of a member having excellent wear resistance such as carbide is attached to the tip of the roller support portion 12, but the contact body is attached to the tip of the roller support portion 12. Alternatively, a roller made of a member having excellent wear resistance such as super hard metal may be provided.

  Further, the cylinder 12b attached to the roller support portion 12 holds the rotating shaft 11b of the processing roller 11 so that the processing roller 11 protrudes and protrudes from the tip of the roller support portion 12. However, as another configuration, the roller support A similar effect can also be obtained by providing a member capable of linear movement at the tip of the portion 12 so that the member moves relative to the roller support portion 12.

  Further, after the steady rest unit 10 is moved relative to the table 2 in the Z-axis direction, it is linearly moved in the X-axis direction perpendicular to the table 2 so that only one end of the roller support portion 12 contacts the journal Wb. It is also possible to make it happen.

  Furthermore, in addition to the configuration in which a plurality of the steady rest units 10 are provided corresponding to the plurality of journals Wb, one steady rest unit 10 is moved relative to the table 2 in both the X-axis direction and the Z-axis direction. The same effect can be obtained also.

It is a plane explanatory view showing one example of a grinding machine of the present invention. (Example 1) It is a cross-sectional explanatory view (a) of the steadying unit of the grinding machine in FIG. 1 and a partial side explanatory view (b) of the steadying. It is the plane explanatory drawing (a) and side surface explanatory drawing (b) of the processing roller in the steadying unit of the grinding machine shown in FIG. It is operation | movement explanatory drawing (a)-(c) of the steadying unit until it grinds at the time of grinding using the grinder in FIG. It is operation | movement explanatory drawing (a)-(c) of the steadying unit at the time of processing a fine uneven surface using the grinder in FIG. It is plane explanatory drawing of the journal in which the fine unevenness | corrugation was formed using the grinding machine in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Grinding machine 2 Table 3 Headstock 4 Tailstock 5 Grinding wheel 10 Stabilization unit 11 Processing roller 12 Roller support part (stabilization part)
12a contact body 13 steady rest 16 load generation part 18 load detection part
W Camshaft (work)

Claims (16)

  A table, a headstock and a tailstock that are provided on the table and rotatably support the workpiece, a grinding wheel that moves in a direction orthogonal to the workpiece rotation axis to grind the workpiece, and a workpiece rotation shaft A steady rest that moves in an orthogonal direction and contacts and separates from the workpiece, a load generating section that applies a workpiece pressing load to the steady rest, and a load detection section that detects the workpiece pressing load. A grinding machine having a function capable of forming fine irregularities.   2. The grinding according to claim 1, wherein the steady rest comprises a steady stop roller that contacts and separates from the workpiece, and a roller support portion that supports the steady stop roller, and the workpiece can be formed with fine irregularities by the steady stop roller. Board.   2. The steady rest includes a processing roller capable of forming fine irregularities on the workpiece and a roller support portion that supports the processing roller, and the roller support portion is a steady stop portion that contacts and separates the workpiece. Grinding machine.   The grinding machine according to claim 3, wherein the roller is movable in a direction perpendicular to the rotation axis of the workpiece and protrudes and retracts with respect to the roller support portion.   The grinding machine according to claim 3, wherein the roller support portion can be expanded and contracted in a direction perpendicular to the rotation axis of the workpiece, and the tip of the roller support portion is positioned closer to the workpiece than the roller in the extended state.   The steady rest, the load generating portion, and the load detecting portion constitute one unit, and the whole steady rest unit can be moved in a direction perpendicular to the rotation axis of the workpiece. The grinding machine described.   The grinding machine according to claim 6, wherein the entire steadying unit is movable in the direction of the rotation axis of the workpiece.   The grinding machine according to claim 6 or 7, comprising a plurality of steady rest units.   The grinding machine according to any one of claims 3 to 8, wherein a contact body with the workpiece is provided separately on the roller support portion that functions as a steady rest portion.   The grinding machine according to claim 9, wherein a contact body with the workpiece is a roller.   When grinding a workpiece by the grinding machine according to any one of claims 1 to 10, grinding by a grinding wheel that is performed while pressing the steady rest against the workpiece, and formation of fine unevenness caused by the steady rest A grinding method characterized in that the processing is performed continuously.   The grinding method according to claim 11, wherein the workpiece pressing load applied to the steady rest from the load generating unit is controlled based on the workpiece pressing load obtained by the load detection unit so as to suppress a bending amount of the workpiece to a small amount.   13. The amount of movement and / or the amount of cutting of the grinding wheel is controlled in a direction orthogonal to the rotation axis of the work piece of the steady rest based on the workpiece pressing load obtained by the load detection unit during grinding with the grinding wheel. The grinding method described in 1.   The grinding method according to claim 13, wherein the grinding conditions are changed in order to suppress the workpiece pressing load below a preset load during grinding with the grinding wheel.   8. The grinding apparatus according to claim 7, wherein the entire steadying unit is moved both in the direction of the rotation axis of the workpiece and in the direction perpendicular to the rotation axis while the steadying is in contact with the workpiece during grinding with the grinding wheel of the grinding machine. The grinding method according to any one of items 11 to 14.   The whole of the steady rest unit is moved in the direction of the rotation axis of the workpiece while the steady rest is brought into contact with the workpiece when forming the fine unevenness by the steady rest of the grinding machine according to claim 7. The grinding method as described in one term.

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