JP3910935B2 - Work grinding method and grinding apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a workpiece grinding method and a grinding machine for performing planar and spherical grinding on an optical member such as an optical element or a lens mold member.
[0002]
[Prior art]
Conventionally, in a spherical grinding process using an optical member as a workpiece, a glass lens grinding method using a curve generator (CG) as disclosed in, for example, Japanese Patent Publication No. 61-33665 is generally employed. .
[0003]
The grinding method will be described with reference to FIGS. FIG. 7 shows an outline of a spherical grinding apparatus by CG processing.
[0004]
In FIG. 7, reference numeral 103 denotes a work created with a curvature radius R 0, which is held on the work shaft by the work chuck 104. Reference numeral 105 denotes a workpiece shaft main body, and a mechanism (not shown) is incorporated so as to cut in the direction of arrow E while rotating the workpiece 103. Further, in order to adjust the thickness of the workpiece 103, the workpiece shaft main body 105 is configured to be movable and adjusted in the e direction by a handle (not shown). In FIG. 7, reference numeral 101 denotes a cup-type grinding wheel, and reference numeral 102 denotes a grindstone shaft main body.
[0005]
As shown in the principle diagram of CG processing in FIG. 8, the processing method by the spherical grinding apparatus having the above configuration is as follows. First, assuming that the processing diameter of the cup-type grinding wheel 101 for creating the workpiece 103 having the curvature radius R0 is D, the grinding wheel shaft The main body 102 is tilted by an angle θ 0 corresponding to sin θ 0 = D / (2 · R 0), and the grindstone axis is set so that the machining diameter D coincides with the workpiece axis center line a and the point P at the position where the cutting in the E direction is completed. The main body 102 is moved and adjusted in the direction of the arrow f by a handle (not shown).
[0006]
After this adjustment is completed, the E direction is actually cut while the workpiece 103 and the cup-type grinding wheel 101 are rotated. Next, while the workpiece 103 makes at least one rotation at the cutting completion position in the E direction, the shaft movement of the grindstone shaft and the workpiece shaft is stopped so that there is no uncut portion of the workpiece 103 (spark-out process). By completing the processing as described above and detaching the workpiece 103 from the cup-type grinding wheel 101, a spherical surface having a desired radius of curvature O0P (= R0) can be created.
[0007]
[Patent Document 1]
Japanese Patent Publication No. 61-33665
[0008]
[Problems to be solved by the invention]
However, the above-described Patent Document 1 has the following problems. In the conventional setting of the processing conditions, the processing diameter D of the cup-type grinding wheel 101 is measured with a caliper or a tool microscope, and the processing conditions are set based on the measured value. Generally, the tip of the wheel is manufactured with high accuracy. Therefore, it is difficult to measure this accurately.
[0009]
Further, the work of making the machining diameter D of the cup-type grinding wheel 101 coincide with the workpiece axis center line a and the point P is performed by adjusting the movement of the grinding wheel shaft main body 102 in the direction of arrow f, but the workpiece axis center line which is the workpiece rotation axis. Since a is an imaginary line, it is difficult to see the point P at the position of the processing diameter D of the cup-type grinding wheel 101, so that it is difficult to make it coincide with each other with a single adjustment.
[0010]
When the workpiece 103 is machined in a state in which the position of the workpiece axis center line a and the machining diameter D is deviated, as shown in FIG. Called) is created. Note that FIG. 9B shows the workpiece 103 without the navel 103a. As shown in FIG. 10, the knives 103 a of the workpiece 103 have an outer velocities shown in FIG. 10A because of the processing trajectory 103 b of the cup-type grinding wheel 101 (the trajectory that is actually very difficult or invisible). (As shown in FIG. 10 (b), the navel 103a generated when the workpiece axis center line a is outside the processing diameter D of the cup-type grinding wheel 101) and the inner navel (FIG. 10 (c)). As shown in d), there is a navel 103 a) that occurs when the workpiece axis center line a is inside the machining diameter D of the cup-type grinding wheel 101.
[0011]
In general, when the workpiece having the bulge 103a is subjected to fine grinding and polishing, which are post-processing, an excessive load is applied to the fine grinding grindstone and pitch grinding grindstone formed so that the bulge 103a faces the workpiece 103. The problem arises that the shape of the workpiece 103 is deteriorated by deteriorating the shape, and the durability of the precision grinding wheel and the pitch grinding wheel is adversely affected.
[0012]
Therefore, in order to remove the bulge 103a, that is, in order to make the workpiece axis center line a coincide with the machining diameter D of the cup-type grinding wheel 101, the workpiece 103 is machined, and the workpiece shaft body 105 is moved in the direction of arrow e. The processing conditions are corrected by adjusting the movement. In general, this correction work has been performed several times to several tens of times even by skilled technicians. The main reason for the time required for this correction work is that it is difficult to distinguish whether the navel 103a is an external chin or an internal chin. For example, if it is actually determined that it is an internal velocities, even though it was an internal velocities, the grindstone shaft main body 102 is processed again under that condition in order to correct the movement adjustment in the direction of arrow f in the reverse direction. In the center of the workpiece 103, a larger inner velvet than the previous time occurs. As described above, since it is impossible to determine whether the navel 103a generated at the center of the workpiece 103 machined under each condition is an outer navel or an inner navel, the correction work takes time.
[0013]
The skilled technician sees the slight streak of grinding traces remaining on the surface of the workpiece 103 and corrects it based on experience and intuition. The grinding trajectory 103b described above is also the type of workpiece 103, cup-type grinding. Depending on the bonding material of the grindstone 101 and the abrasive mesh (abrasive grain size), there may be no residue. In such a case, even a skilled technician cannot determine the outer and inner navels at all, and spends a considerable amount of time on trial processing (processing set to be thicker than the medium thickness of the target workpiece 103). In some cases, there has been a problem that an excessive load is applied to the cup-type grinding wheel 101 due to a correction error of the bulge 103a.
[0014]
The present invention has been made in view of the above circumstances, and can easily determine the outer and inner navels, can accurately correct the navel, and can reduce the correction time of processing, that is, the setup time. It is an object of the present invention to provide a workpiece grinding method and a grinding device capable of effectively preventing an excessive load from being applied to a grindstone due to a correction error.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, the workpiece grinding method according to the present invention as set forth in claim 1 is a workpiece grinding method in which a workpiece is held on a workpiece axis and rotated, and the workpiece is ground with a rotating cup-type grinding wheel. Then, after the workpiece is sparked out, the rotation of the workpiece is stopped, and either one of the workpiece and the cup-type grinding wheel is cut slightly to form a machining mark on the workpiece, and the workpiece is created. It is characterized in that the relative position of the remaining uncut shaving protrusion with respect to the processing mark is determined, and correction processing is performed based on the determination result.
[0016]
According to a second aspect of the present invention, there is provided a workpiece grinding apparatus comprising: a workpiece rotatably held on a workpiece axis; a cup-type grinding wheel rotatably held for grinding the workpiece; and the cup-type grinding wheel In the workpiece grinding device provided with the grinding control means for controlling the grinding of the workpiece by the above, the grinding control means stops the rotation of the workpiece after the workpiece is sparked out, and the workpiece and the cup type Cut a small amount of one of the grinding wheels into the above workpiece. Shows the relative position between the remaining uncut projection and the cup-type grinding wheel Shape the machining mark Complete It is characterized by that.
[0017]
That is, in the workpiece grinding method according to the first aspect of the present invention, the workpiece is held and rotated on the workpiece axis, and the workpiece is ground by the rotating cup type grinding wheel. At this time, after the workpiece is sparked out, the rotation of the workpiece is stopped, and one of the workpiece and the cup-type grinding wheel is cut into a minute amount to form a machining mark on the workpiece. The relative position of the portion with respect to the processing mark is determined, and correction processing is performed based on the determination result.
[0018]
In the workpiece grinding apparatus according to the second aspect of the present invention, the grinding control means controls the grinding of the workpiece held rotatably on the workpiece axis by the cup-type grinding wheel held rotatably. At this time, after the workpiece is sparked out, the grinding control means stops the rotation of the workpiece, and cuts a small amount of either the workpiece or the cup-type grinding wheel into the workpiece. Shows the relative position between the remaining uncut projection and the cup-type grinding wheel Shape the machining mark Complete The
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 show a first embodiment of the present invention, FIG. 1 is a front view showing a part of a spherical grinding device in cross section, and FIG. 2 is an enlarged view showing a state in which knurls are generated in a work part. It is explanatory drawing.
[0020]
In FIG. 1, reference numeral 1 denotes an optical member (work) created with a curvature radius R 0, and the work 1 is held by a work chuck 2. The work chuck 2 is rotatably held on the work spindle 3 with the work axis W as a central axis.
[0021]
The work spindle 3 is connected to a work spindle rotation motor 4 that rotationally drives the work spindle 3. Further, the work spindle 3 is fixed to a work spindle linear motion mechanism 5 using a work spindle linear motion control motor 6 as a drive source, and is configured to be movable in a direction parallel to the workpiece axis W. The work spindle linear motion mechanism 5 is fixed to a gantry 7 of the apparatus main body.
[0022]
On the other hand, in FIG. 1, reference numeral 8 denotes a cup-shaped grinding wheel for grinding the workpiece 1 on a spherical surface. The cup-shaped grinding wheel 8 rotates on a grinding wheel spindle 9 with a grinding wheel axis T as a central axis. It is held freely.
[0023]
Further, the grindstone spindle 9 is connected to a grindstone spindle rotation motor 10 that rotationally drives the grindstone spindle 9. Further, the grindstone spindle 9 is fixed to a grindstone spindle linear motion mechanism 12 using a grindstone spindle linear motion control motor 11 as a drive source, and is configured to be movable in a direction perpendicular to the grindstone axis T.
[0024]
The grindstone spindle linear motion mechanism 12 is placed on a fan-shaped base 13, and the base 13 is disposed on a stand 7 of the apparatus main body and is rotated by a base movement control motor 14 around a rotation center 13a. It is free to move.
[0025]
In FIG. 1, reference numeral 15 denotes each control motor, that is, a work spindle linear motion control motor 6, a grindstone spindle direct motion control motor 11, a base movement control motor 14, and each rotary motor, that is, a work spindle rotational motor. 4 is a control device as grinding control means for controlling the grinding wheel spindle rotation motor 10.
[0026]
Then, the control device 15 stops the rotation of the workpiece 1 after the spark-out processing of the workpiece 1, as will be described in detail in a later-described machining method, and either one of the workpiece 1 and the cup-type grinding wheel 8 is made minute. Cut into work 1 The relative position between the created hem 1b and the cup-type grinding wheel 8 is shown. Forms machining mark 1a To do. And The relative position of the hem 1b created on the workpiece 1 with respect to the machining mark 1a But Judgment Is , Correction processing based on the judgment result Is It has become so.
[0027]
That is, in the processing method using the spherical grinding machine configured as described above, first, assuming that the processing diameter of the cup-type grinding wheel 8 that creates the workpiece 1 having the curvature radius R0 is D, sin θ0 = D / (2 · R0). The base 13 is rotated about the rotation center 13a by the base movement control motor 14 by an angle θ0 (an angle formed by the workpiece axis W and the grindstone axis T) corresponding to the angle θ0.
[0028]
Next, at a position where the cutting in the workpiece axis W direction is completed, the machining diameter D matches the workpiece axis W and the point P (machining end point) (this step is a problem to be solved by the above-described invention. As explained, it is actually difficult to match in the first machining.) The grindstone spindle linear motion control motor 11 moves the grindstone spindle linear motion mechanism 12 in the direction perpendicular to the grindstone axis T.
[0029]
Then, after the movement is completed, the workpiece 1 actually cuts in the workpiece axis W direction while rotating the workpiece 1 and the cup-type grinding wheel 8. Note that a grinding fluid is supplied to the workpiece 1 and the cup-type grinding wheel 8 from a grinding fluid supply device (not shown) from the start to the completion of processing.
[0030]
Next, the workpiece 1 rotates at least once at the cutting completion position in the workpiece axis W direction. During this time, the movement in the workpiece axis W direction is stopped so that there is no uncut portion of the workpiece 1 (spark-out machining step). Each movement described above is controlled and executed by the control device 15.
[0031]
Next, according to a command from the control device 15, the work spindle rotation motor 4 is stopped and the rotation of the work spindle 3 is stopped. As a result, the workpiece 1 is brought into a stopped state.
[0032]
Thereafter, the workpiece 1 is cut by a minute amount in the workpiece axis W direction, and then the workpiece 1 is moved back in the workpiece axis W direction to complete the machining. Here, the minute amount is preferably 0.005 mm to 0.1 mm. This is because, when the depth of cut is 0.005 mm or less, there is a possibility that the navel cannot be discriminated because the processing marks of the cup-type grinding wheel 8 are small. In addition, when the depth of cut is 0.1 mm or more, the load of the depth of cut is applied and the cup-type grinding wheel 8 is unevenly worn, adversely affects the subsequent spherical grinding, or the processing of the cup-type grinding wheel 8 This is because there is a risk that the navel will be scraped off by the marks.
[0033]
In this way, the processed surface of the workpiece 1 that has been processed is in a state in which the processing marks 1a of the cup-type grinding wheel 8 and the navel 1b remain in the center as shown in FIG.
For example, when the workpiece 1 has a convex shape, in the case of FIG. 2A, the point P of the machining diameter D of the cup-type grinding wheel 8 is shifted upward by H1 from the workpiece axis W, so It becomes. The judgment of the outer velcro can be easily distinguished from the fact that the velvet 1b is outside the processing mark 1a of the cup-type grinding wheel 8 as shown in FIG.
[0034]
In this correction, the controller 15 is instructed to finely adjust the cup-type grinding wheel 8, that is, the grinding wheel spindle linear movement mechanism 12, downward by H1 / cos θ0.
[0035]
Further, in the case of FIG. 2C, the point P of the processing diameter D of the cup-type grinding wheel 8 is shifted downward by H2 from the workpiece axis W, so that the velvet 1b becomes an internal velvet. The judgment of the inner velvet can be easily distinguished from the fact that the velvet 1b is inside the processing mark 1a of the cup-type grinding wheel 8 as shown in FIG.
[0036]
In this correction, the controller 15 is commanded to finely adjust the cup-type grinding wheel 8, that is, the grinding wheel spindle linear motion mechanism 12, upward by H 2 / cos θ 0.
[0037]
As described above, since the outer and inner navels can be determined based on the positional relationship between the machining mark 1a and the navel 1b, the navel can be corrected accurately once. That is, the workpiece axis W and the point P of the processing diameter D of the cup-type grinding wheel 8 can coincide with each other, and a processing surface having no knurl can be easily obtained with high accuracy in the second grinding process.
[0038]
On the other hand, when the workpiece 1 has a concave shape, the grindstone spindle is set so that the machining diameter D coincides with the workpiece axis W and the Q point (machining end point: see FIG. 1) at the position where the cutting in the workpiece axis W direction is completed. The movement control motor 11 moves the grinding wheel spindle linear movement mechanism 12 in the direction perpendicular to the grinding wheel axis T.
[0039]
Then, after the movement is completed, the workpiece 1 actually cuts in the workpiece axis W direction while rotating the workpiece 1 and the cup-type grinding wheel 8. Note that a grinding fluid is supplied to the workpiece 1 and the cup-type grinding wheel 8 from a grinding fluid supply device (not shown) from the start to the completion of processing.
[0040]
Next, the workpiece 1 rotates at least once at the cutting completion position in the workpiece axis W direction. During this time, the movement in the workpiece axis W direction is stopped so that there is no uncut portion of the workpiece 1 (spark-out machining step). Each movement described above is controlled and executed by the control device 15.
[0041]
Next, according to a command from the control device 15, the work spindle rotation motor 4 is stopped and the rotation of the work spindle 3 is stopped. As a result, the workpiece 1 is brought into a stopped state.
[0042]
Thereafter, the workpiece 1 is cut in a minute amount (preferably 0.005 mm to 0.1 mm) in the workpiece axis W direction, and then the workpiece 1 is moved back in the workpiece axis W direction to complete the machining.
[0043]
The second grinding process is performed by accurately correcting the kinks by correcting the machining surface of the workpiece 1 that has been machined in this way by correcting upward by H1 / cosθ0 at the outer knives and downward by H2 / cosθ0 at the inner knives. Therefore, it is possible to easily obtain a machined surface having no bulge with high accuracy.
[0044]
As described above, according to the first embodiment of the present invention, it is possible to easily determine the outer and inner navels and to accurately correct the navel, so that the processing correction time can be shortened, that is, the setup can be performed. It is possible to shorten the time and effectively prevent an excessive load from being applied to the grindstone due to a correction error.
[0045]
In the first embodiment described above, when the base 13 is rotated so that the angle formed between the workpiece axis W and the grindstone axis T is 0 °, the processed surface of the workpiece 1 can be planar. it can. FIG. 3 is a front view showing, in section, a part of the surface grinding apparatus in which the base 13 and the base movement control motor 14 are removed in the first embodiment.
[0046]
The heel correction by the surface grinding apparatus can be performed by moving the grindstone spindle linear movement mechanism 12 in the downward direction by H1 for the outer velocities and in the upward direction by H2 for the inner velocities. Thus, the present invention can be applied not only to spherical grinding but also to surface grinding.
[0047]
Further, even if the tip shape of the cup-type grinding wheel 8 is an R shape, the same effect can be obtained by performing the correction as described above.
[0048]
Furthermore, it can be said that the same effect can be obtained by carrying out the same machining method regardless of the direction (parallel, vertical, or inclined direction) of the workpiece axis W with respect to the ground. Not too long.
[0049]
Next, FIG. 4 is a front view showing a part of a spherical grinding apparatus in section according to the second embodiment of the present invention.
[0050]
That is, the second mode of the present invention is that the work spindle linear motion mechanism 5 and the work spindle linear motion control motor 6 in the first mode are abolished, and the work spindle 3 is fixed to the gantry 7 of the apparatus main body. 9 is fixed to the second grindstone spindle linear motion mechanism 17 using the second grindstone spindle linear motion control motor 16 controlled by the control device 15 as a drive source, and is movable in a direction parallel to the grindstone axis T. The second grindstone spindle linear motion mechanism 17 is fixed to the grindstone spindle linear motion mechanism 12 using the grindstone spindle linear motion control motor 11 as a drive source, and is movable in the direction perpendicular to the grindstone axis T. In other respects, the other configuration is the same as that of the first embodiment. Therefore, the same reference numeral is given to the same configuration, and the description is omitted.
[0051]
Therefore, in the machining method by the spherical grinding machine of the second embodiment configured as described above, first, assuming that the machining diameter of the cup-type grinding wheel 8 that creates the workpiece 1 having the curvature radius R0 is D, sin θ0 = D / ( The base 13 is rotated about the rotation center 13a by the base movement control motor 14 and tilted by an angle θ0 (angle formed by the workpiece axis W and the grindstone axis T) corresponding to 2 · R0).
[0052]
Next, at the position where the cutting in the direction parallel to the grindstone axis T is completed, the machining diameter D coincides with the workpiece axis W and the P point (machining end point). Actually, it is difficult to coincide with the first machining as described in the above problem.) The second grindstone spindle linear motion control motor 16 moves the second grindstone spindle linear motion mechanism 17 horizontally with the grindstone axis T. Commands the control device 15 to move in the direction.
[0053]
The cup-type grinding wheel 8 actually cuts in a direction parallel to the grinding wheel axis T while rotating the workpiece 1 and the cup-type grinding wheel 8. Note that a grinding fluid is supplied to the workpiece 1 and the cup-type grinding wheel 8 from a grinding fluid supply device (not shown) from the start to the completion of processing.
[0054]
Next, the workpiece 1 rotates at least once at the cutting completion position in the direction parallel to the grinding wheel axis T. During this time, the movement in the direction parallel to the grinding wheel axis T is stopped so that there is no uncut portion of the workpiece 1 (spark-out processing step). Each movement described above is controlled and executed by the control device 15.
[0055]
Next, according to a command from the control device 15, the work spindle rotation motor 4 is stopped and the rotation of the work spindle 3 is stopped. As a result, the workpiece 1 is brought into a stopped state.
[0056]
Thereafter, a small amount (preferably 0.005 mm to 0.1 mm) of the cup-type grinding wheel 8 is cut in a direction parallel to the grinding wheel axis T, and then the cup-type grinding wheel 8 is parallel to the grinding wheel axis T. Retract to complete processing.
[0057]
In this way, the processed surface of the workpiece 1 that has been processed is in a state in which the processing marks 1a of the cup-type grinding wheel 8 and the chin 1b remain in the center as shown in FIG.
For example, when the workpiece 1 has a convex shape, in the case of FIG. 2A, the point P of the machining diameter D of the cup-type grinding wheel 8 is shifted upward by H1 from the workpiece axis W, so It becomes. In this correction, the controller 15 is instructed to finely adjust the cup-type grinding wheel 8, that is, the grinding wheel spindle linear movement mechanism 12, downward by H1 / cos θ0.
[0058]
Further, in the case of FIG. 2C, the point P of the processing diameter D of the cup-type grinding wheel 8 is shifted downward by H2 from the workpiece axis W, so that the velvet 1b becomes an internal velvet. In this correction, the controller 15 is commanded to finely adjust the cup-type grinding wheel 8, that is, the grinding wheel spindle linear motion mechanism 12, upward by H 2 / cos θ 0.
[0059]
As described above, since the outer and inner navels can be determined based on the positional relationship between the machining mark 1a and the navel 1b, the navel can be corrected accurately once. That is, the workpiece axis W and the point P of the processing diameter D of the cup-type grinding wheel 8 can coincide with each other, and a processing surface having no knurl can be easily obtained with high accuracy in the second grinding process.
[0060]
Therefore, according to the second embodiment of the present invention, even if the work spindle 3 is fixed and the grindstone spindle 9 is a grinding device having a linear motion mechanism in two directions, the same effect as in the first embodiment is obtained. be able to.
[0061]
Next, FIG. 5 is a front view showing, in section, a part of a spherical grinding apparatus according to a third embodiment of the present invention.
[0062]
That is, the third embodiment of the present invention eliminates the grindstone spindle linear motion mechanism 12 and the grindstone spindle linear motion control motor 11 in the first embodiment, and the grindstone spindle 9 is controlled by the control device 15. The third grindstone spindle linear motion mechanism 19 is fixed to a third grindstone spindle linear motion mechanism 19 having a spindle linear motion control motor 18 as a drive source, and is movable in a direction parallel to the grindstone axis T. Since the other structure is the same as that of the first embodiment except that it is fixed to the base 13, the same reference numeral is given to the same structure, and the description is omitted.
[0063]
Therefore, in the machining method by the spherical grinding machine of the third embodiment configured as described above, first, assuming that the machining diameter of the cup-type grinding wheel 8 that creates the workpiece 1 having the curvature radius R0 is D, sin θ0 = D / ( The base 13 is rotated about the rotation center 13a by the base movement control motor 14 and tilted by an angle θ0 (angle formed by the workpiece axis W and the grindstone axis T) corresponding to 2 · R0).
[0064]
Next, at the position where the cutting in the direction parallel to the grindstone axis T is completed, the machining diameter D coincides with the workpiece axis W and the P point (machining end point). As explained in the above problem, it is difficult to match with the first machining in practice.) The third grindstone spindle linear motion control motor 18 moves the third grindstone spindle linear motion mechanism 19 horizontally with the grindstone axis T. Commands the control device 15 to move in the direction.
[0065]
The cup-type grinding wheel 8 actually cuts in a direction parallel to the grinding wheel axis T while rotating the workpiece 1 and the cup-type grinding wheel 8. Note that a grinding fluid is supplied to the workpiece 1 and the cup-type grinding wheel 8 from a grinding fluid supply device (not shown) from the start to the completion of processing.
[0066]
Next, the workpiece 1 rotates at least once at the cutting completion position in the direction parallel to the grinding wheel axis T. During this time, the movement in the direction parallel to the grinding wheel axis T is stopped so that there is no uncut portion of the workpiece 1 (spark-out processing step). Each movement described above is controlled and executed by the control device 15.
[0067]
Next, according to a command from the control device 15, the work spindle rotation motor 4 is stopped and the rotation of the work spindle 3 is stopped. As a result, the workpiece 1 is brought into a stopped state.
[0068]
Thereafter, a small amount (preferably 0.005 mm to 0.1 mm) of the cup-type grinding wheel 8 is cut in a direction parallel to the grinding wheel axis T, and then the cup-type grinding wheel 8 is parallel to the grinding wheel axis T. Retract to complete processing.
[0069]
Thus, the processed surface of the workpiece 1 that has been processed is in a state in which the processing marks 1a of the cup-type grinding wheel 8 and the knives 1b remain in the center as shown in FIG.
For example, when the workpiece 1 has a convex shape, in the case of FIG. 2A, the point P of the machining diameter D of the cup-type grinding wheel 8 is shifted upward by H1 from the workpiece axis W, so It becomes. In this correction, the work spindle linear motion mechanism moves the cup grinding wheel 8 downward by H1 / sin θ0, that is, in the direction in which the cup grinding wheel 8 advances toward the workpiece 1 by the third grinding wheel spindle linear motion mechanism 19. 5, the controller 15 is instructed to finely adjust the workpiece 1 in a direction in which the workpiece 1 moves backward by H 1 / tan θ 0 toward the cup-type grinding wheel 8.
[0070]
Further, in the case of FIG. 2C, the point P of the processing diameter D of the cup-type grinding wheel 8 is shifted downward by H2 from the workpiece axis W, so that the velvet 1b becomes an internal velvet. In this correction, the work spindle linear movement mechanism is moved upward by H2 / sin θ0, that is, in a direction in which the cup grinding wheel 8 moves backward toward the work 1 by the third grinding wheel spindle linear movement mechanism 19. 5, the control device 15 is instructed to finely adjust the workpiece 1 in a direction to advance the workpiece 1 toward the cup-type grinding wheel 8 by H 2 / tan θ 0.
[0071]
As described above, since the outer and inner navels can be determined based on the positional relationship between the machining mark 1a and the navel 1b, the navel can be corrected accurately once. That is, the workpiece axis W and the point P of the processing diameter D of the cup-type grinding wheel 8 can coincide with each other, and a processing surface having no knurl can be easily obtained with high accuracy in the second grinding process.
[0072]
Therefore, according to the third embodiment of the present invention, the work spindle linear motion mechanism 5 in which the work spindle 3 moves in a direction parallel to the work axis W, and the grindstone spindle 9 moves in a direction parallel to the grindstone axis T. Even with the grinding device having the third grindstone spindle linear motion mechanism 19, the same effect as in the first embodiment can be obtained.
[0073]
When the workpiece 1 is actually ground with the cup-type grinding wheel 8, the cup-type grinding wheel 8 is moved and cut, but the position where the point P of the cup-type grinding wheel 8 and the workpiece axis W coincide with each other. The same effect can be obtained by cutting the workpiece 1 by moving the workpiece 1 in the direction parallel to the workpiece axis W of the workpiece spindle linear motion mechanism 5 with the cup-type grinding wheel 8 moved to the maximum.
[0074]
Next, FIG. 6 is a front view showing a part of a spherical grinding apparatus in section according to the fourth embodiment of the present invention.
[0075]
In other words, the fourth embodiment of the present invention eliminates the grindstone spindle linear motion mechanism 12 and the grindstone spindle linear motion control motor 11 in the first embodiment, and the grindstone spindle 9 is directly fixed to the base 13. The linear motion mechanism 5 is fixed to the second work spindle linear motion mechanism 21 using the second work spindle linear motion control motor 20 controlled by the control device 15 as a drive source, and moves in a direction perpendicular to the workpiece axis W. Since the second work spindle linear motion mechanism 21 is fixed to the frame 7 of the apparatus main body and the other configurations are the same as those of the first embodiment, the same reference numerals are used for the same configurations. The description is omitted.
[0076]
Therefore, in the machining method by the spherical grinding machine of the fourth embodiment configured as described above, first, assuming that the machining diameter of the cup-type grinding wheel 8 that creates the workpiece 1 having the curvature radius R0 is D, sin θ0 = D / ( The base 13 is rotated about the rotation center 13a by the base movement control motor 14 and tilted by an angle θ0 (angle formed by the workpiece axis W and the grindstone axis T) corresponding to 2 · R0).
[0077]
Next, at a position where the cutting in the workpiece axis W direction is completed, the machining diameter D matches the workpiece axis W and the point P (machining end point) (this step is a problem to be solved by the above-described invention. As explained, it is actually difficult to match in the first machining.) The second workpiece spindle linear motion control motor 20 moves the second workpiece spindle linear motion mechanism 21 in the direction perpendicular to the workpiece axis W. To do.
[0078]
After the movement is completed, the workpiece 1 is actually cut in the workpiece axis W direction while rotating the workpiece 1 and the cup-type grinding wheel 8. Note that a grinding fluid is supplied to the workpiece 1 and the cup-type grinding wheel 8 from a grinding fluid supply device (not shown) from the start to the completion of processing.
[0079]
Next, the workpiece 1 rotates at least once at the cutting completion position in the workpiece axis W direction. During this time, the movement in the workpiece axis W direction is stopped so that there is no uncut portion of the workpiece 1 (spark-out machining step). Each movement described above is controlled and executed by the control device 15.
[0080]
Next, according to a command from the control device 15, the work spindle rotation motor 4 is stopped and the rotation of the work spindle 3 is stopped. As a result, the workpiece 1 is brought into a stopped state.
[0081]
Thereafter, the workpiece 1 is cut in a minute amount (preferably 0.005 mm to 0.1 mm) in the workpiece axis W direction, and then the workpiece 1 is moved back in the workpiece axis W direction to complete the machining.
[0082]
Thus, the processed surface of the workpiece 1 that has been processed is in a state in which the processing marks 1a of the cup-type grinding wheel 8 and the knives 1b remain in the center as shown in FIG.
For example, when the workpiece 1 has a convex shape, in the case of FIG. 2A, the point P of the machining diameter D of the cup-type grinding wheel 8 is shifted upward by H1 from the workpiece axis W, so It becomes. In this correction, the controller 15 is instructed to finely adjust the cup-type grinding wheel 8, that is, the second work spindle linear motion mechanism 21 downward by H 1.
[0083]
Further, in the case of FIG. 2C, the point P of the processing diameter D of the cup-type grinding wheel 8 is shifted downward by H2 from the workpiece axis W, so that the velvet 1b becomes an internal velvet. In this correction, the controller 15 is instructed to finely adjust the cup-type grinding wheel 8, that is, the second workpiece spindle linear motion mechanism 21, upward by H2.
[0084]
As described above, since the outer and inner navels can be determined based on the positional relationship between the machining mark 1a and the navel 1b, the navel can be corrected accurately once. That is, the workpiece axis W and the point P of the processing diameter D of the cup-type grinding wheel 8 can coincide with each other, and a processing surface having no knurl can be easily obtained with high accuracy in the second grinding process.
[0085]
If the workpiece 1 has a concave shape, the heel 1b is accurately corrected by correcting the outer chin by H1 upward and the inner heel by H2 downward. The processed surface can be easily obtained with high accuracy.
[0086]
Therefore, according to the fourth embodiment of the present invention, even when the workpiece spindle 3 is a grinding mechanism having a linear motion mechanism in which the work spindle 3 moves in two directions and the grindstone spindle 9 has a rotation mechanism, the same as in the first embodiment. The effect of can be obtained.
[0087]
The grindstone spindle 9 is directly fixed to the gantry 7 of the apparatus main body, and the base 13 holding the base movement control motor 14 so as to be rotatable is mounted on the work spindle 3 side. Even if the workpiece spindle linear motion mechanism 21 is fixed to the gantry 7 via the base 13, the relative positional relationship between the workpiece 1 and the cup-type grinding wheel 8 does not change, and the same effect can be obtained.
[0088]
[Appendix]
According to the embodiment of the present invention as described above in detail, the following configuration can be obtained.
[0089]
(1) In a grinding method for a workpiece in which a workpiece is held and rotated on a workpiece axis, and is ground by being brought into contact with a rotating cup-type grinding wheel.
Machining progresses, and after sparking out, the rotation of the work is stopped, and the work or the cup-type grinding wheel is slightly cut to leave a work mark on the work. A method for grinding a workpiece, wherein correction is performed by the amount of the chin.
[0090]
(2) In a workpiece grinding apparatus for holding and rotating a workpiece on a workpiece axis and grinding the workpiece by bringing it into contact with a rotating cup-type grinding wheel,
A workpiece spindle that holds the workpiece rotatably;
A grinding wheel spindle that rotatably holds the cup-type grinding wheel;
A base for pivotably holding either the work spindle or the grindstone spindle;
A linear motion mechanism movable in two intersecting directions;
A workpiece grinding apparatus comprising: a base, a linear motion mechanism, a workpiece spindle, and a control device for controlling rotation of a grinding wheel spindle.
[0091]
【The invention's effect】
As described above, according to the present invention, it is possible to easily identify the outer and inner velocities, and to accurately correct the velocities, shortening the processing correction time, that is, shortening the setup time. In addition, it is possible to effectively prevent an excessive load from being applied to the grindstone due to a correction error.
[Brief description of the drawings]
FIG. 1 is a front view showing, in section, a part of a spherical grinding apparatus according to a first embodiment of the present invention.
FIG. 2 is an enlarged explanatory view partially showing a state in which a knurl is generated in the workpiece,
FIG. 3 is a front view showing, in section, a part of a surface grinding apparatus to which the first embodiment of the present invention is applied.
FIG. 4 is a front view showing a part of a spherical grinding apparatus in section according to a second embodiment of the present invention.
FIG. 5 is a front view showing, in section, a part of a spherical grinding device according to a third embodiment of the present invention.
FIG. 6 is a front view showing, in section, a part of a spherical grinding apparatus according to a fourth embodiment of the present invention.
FIG. 7 is a schematic explanatory diagram of a spherical grinding apparatus using CG processing according to a conventional technique.
[Fig. 8] Same as above, principle of CG processing
FIG. 9 is an explanatory view of the workpiece after CG machining is completed, as described above.
FIG. 10 is an enlarged explanatory view partially showing a state in which a knurl is generated in the workpiece, in the same manner as above.
[Explanation of symbols]
1 Work
1a processing mark
1b Navel (unfinished protrusion)
8 Cup type grinding wheel
15 Control device (grinding control means)

Claims (2)

In a grinding method of a workpiece that rotates while holding the workpiece on the workpiece axis and grinding with a cup-type grinding wheel that rotates the workpiece,
After the workpiece is sparked out, rotation of the workpiece is stopped, and either the workpiece or the cup-type grinding wheel is cut into a minute amount to form a machining mark on the workpiece, which is created in the workpiece. A method for grinding a workpiece, comprising: determining a relative position of an uncut projection part with respect to the machining mark and performing correction processing based on the determination result. A workpiece held rotatably on the workpiece axis;
A cup-type grinding wheel that is rotatably held to grind the workpiece;
In a workpiece grinding apparatus provided with a grinding control means for controlling grinding of the workpiece by the cup-type grinding wheel,
The grinding control means stops the rotation of the work after the work is sparked out, and cuts one of the work and the cup-type grinding grindstone into a minute amount to create an uncut remaining projection created on the work. parts and grinding apparatus of the workpiece, characterized in Rukoto forming form a machining mark indicating the relative position between the cup-shaped grinding wheel.

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