JP2023046520A - Surface grinding method - Google Patents

Abstract

To provide a surface grinding method capable of correctly determining completion of surface grinding of grinding a surface of a workpiece by removing a case that is hard to determine and due to magnitude of a power value or noise generated when the power value is set to a reference value of the determination.SOLUTION: A surface grinding method according to the present invention is a surface grinding method of grinding a surface of a cylindrical workpiece 100 including, while grinding the surface of the workpiece 100 using a grind stone 120, causing probes 132, 142 of dimension measurement devices 130, 140 to contact with the surface being ground to detect deviation of the dimension of the surface, and determining that the surface grinding is completed when the deviation of the dimension of the surface during grinding of the surface of the workpiece 100 is within a first predetermined value.SELECTED DRAWING: Figure 3

Description

The present invention relates to a surface grinding method for grinding the surface of a cylindrical work.

Conventionally, in order to remove the distortion of the workpiece and the oxide film (black scale) on the surface of the workpiece, surface grinding (black scale grinding) is performed at a slower cutting speed than the main grinding. Thereafter, after a predetermined time has passed, the cutting speed for surface grinding is switched to the cutting speed for main grinding (rough machining), and main grinding is performed.

However, there are variations in the magnitude of distortion on the work surface to be machined. For this reason, if a sufficiently long time is set as the surface grinding time assuming a work with large distortion, even a work with small distortion that does not need to spend a long time for surface grinding can be ground in the same way as a work with large distortion. A long surface grinding time will be provided. As a result, a useless surface grinding time is set for a work having a small distortion, resulting in an increase in cycle time.

Therefore, for example, in the grinding method of Patent Document 1, a value (electric power) corresponding to the grinding resistance is detected during surface grinding, and fluctuations in the detected value are monitored. At the time of determination, the cutting feed speed is switched from the cutting feed speed for surface grinding to the cutting feed speed for main grinding. According to Patent Literature 1, such a method can effectively suppress damage to the grindstone at the start of grinding while shortening the cycle time.

Japanese Patent Application Laid-Open No. 2002-292560

When electric power is used as the detected value corresponding to the grinding resistance as in Patent Document 1, if the electric power value is extremely small, it is difficult to determine that the amplitude of the fluctuation of the detected value has fallen below a certain level. For example, in the case of raceway surface grinding (R shape), the determination is difficult because the power fluctuation immediately after contact with the grindstone is small.

Further, in Patent Document 1, the difference between the maximum detected value stored during surface grinding and the updated detected value is sequentially calculated. Then, when the difference (power difference) is equal to or less than a preset allowable value for a predetermined determination time or longer, it is determined that the amplitude of the variation in the detected value has become equal to or less than a certain value. However, with such a configuration, the maximum value increases incorrectly when the power value is noisy. Since the maximum value is no longer updated after that, it becomes impossible to determine whether or not the amplitude of the variation in the detected value has become equal to or less than a certain value.

In view of such problems, the present invention excludes cases where determination is difficult due to the magnitude of the power value and noise that occur when the power value is used as a reference value for determination, and grinds the surface (black scale) of the work. It is an object of the present invention to provide a surface grinding method capable of accurately judging completion of surface grinding.

In order to solve the above problems, a representative configuration of the surface grinding method according to the present invention is a surface grinding method for grinding the surface of a cylindrical work, wherein the surface of the work is ground with a grindstone while grinding. The probe of the dimension measuring device is brought into contact with the surface of the workpiece to detect the deviation of the dimension of the surface, and when the deviation of the dimension of the surface during grinding of the surface of the work falls within the first predetermined value, the surface is ground. is completed.

It is preferable that the probe of the dimension measuring device is in contact with the surface of the cylindrical workpiece at two axially symmetrical locations, and the deviation of the dimension of the surface is detected by adding the displacements at the two locations.

Before grinding with the grindstone, it is preferable to detect the dimensional deviation of the surface with a dimension measuring device while rotating the work, and to determine that the product is nonconforming if the dimensional deviation of the surface is equal to or greater than a second predetermined value.

Before grinding with the grindstone, it is preferable to detect the dimensional deviation of the surface with a dimension measuring device while rotating the work, and reduce the cutting speed of the grindstone as the deviation of the surface dimension increases.

After the surface grinding is completed, main grinding is performed with a higher cutting speed than surface grinding, and finish grinding is performed with a lower cutting speed than main grinding. is determined to be a nonconforming product when the deviation of the dimension of is equal to or greater than a third predetermined value.

According to the present invention, it is possible to accurately determine the completion of surface grinding for grinding the surface of the workpiece by excluding cases where determination is difficult due to the magnitude of the power value or noise that occurs when the power value is used as the reference value for determination. It is possible to provide a surface grinding method capable of

FIG. 2 is a schematic diagram of a usage mode of the surface grinding method according to the present embodiment; 5 is a graph illustrating the relationship between the dimensional deviation of the surface of the workpiece and the time during surface grinding. 5 is a graph illustrating the relationship between the dimensional deviation of the surface of the workpiece and the time during surface grinding. 5 is a graph illustrating the relationship between the dimensional deviation of the surface of the workpiece and the time during surface grinding. 5 is a graph illustrating the relationship between the measured runout value of the surface dimension of the workpiece and the surface grinding completion time;

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in these embodiments are merely examples for facilitating understanding of the invention, and do not limit the invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are given the same reference numerals to omit redundant description, and elements that are not directly related to the present invention are omitted from the drawings. do.

FIG. 1 is a schematic diagram of a usage of a surface grinding method (black scale grinding method) in this embodiment. FIG. 1(a) illustrates the case of grinding an outer surface 100a of a cylindrical workpiece 100. FIG. FIG. 1(b) illustrates the case where the inner surface 100b of the cylindrical work 100 is ground. In the surface grinding method of this embodiment, the surface of a cylindrical workpiece 100 as shown in FIGS. 1(a) and 1(b) is ground.

When grinding the outer surface 100a of the cylindrical workpiece 100, as shown in FIG. The probes 132 and 142 of the measuring devices 130 and 140 are placed on the outer surface 100a of the workpiece 100. As shown in FIG. When grinding the inner surface 100b of the cylindrical workpiece 100, as shown in FIG. The probes 132, 142 of the devices 130, 140 are placed on the inner surface 100b of the workpiece 100. As shown in FIG.

A so-called sizing device can be used as the dimension measuring device. In the present invention, the term "fluctuation of surface dimensions" is synonymous with "fluctuation of surface position" or "fluctuation width of surface position".

In the surface grinding method of the present embodiment, while grinding the surface of the workpiece 100 (see FIGS. 1A and 1B) with the grindstone 120, the surface being ground (outer surface 100a or inner surface 100b) The probes 132 and 142 of the dimension measuring devices 130 and 140 are brought into contact with each other to detect the deviation of the dimension of the surface. Then, it is determined that the surface grinding is completed when the deflection of the surface dimension during grinding the surface of the workpiece 100 is within the first predetermined value.

Particularly in this embodiment, two dimension measuring devices 130 and 140 are arranged with respect to the workpiece 100, and the probes 132 and 142 of the dimension measuring devices 130 and 140 are positioned at two axially symmetrical positions of the cylindrical workpiece 100. is in contact with the surface of the workpiece 100, and the displacement of the two points is added to detect the dimensional deflection of the surface of the workpiece 100. FIG. This makes it possible to reliably detect the dimensional deviation of the surface.

FIGS. 2, 3, and 4 are graphs illustrating the relationship between the dimensional deviation of the surface of the workpiece 100 and time during surface grinding. The workpiece 100 to be surface-ground has an outer diameter of φ62.8 mm, an inner diameter of φ55.0 mm, and a width of 24.0 mm. In the example shown in FIGS. 2 to 4, the set time (t1-t2) for surface grinding is set to 2 seconds, and the first predetermined value of surface dimensional deflection for judging the completion of surface grinding is set to 10 μm.

In FIGS. 2-4, the surface grinding is performed during the time t1-t2 (2 seconds). Then, at time t2, the cutting speed for surface grinding is switched to the cutting speed for main grinding, and main grinding is performed until time t3. When the main grinding is finished, the cutting speed for main grinding is switched to the cutting speed for finishing, and finish grinding is performed during time t3-t4. After finish grinding is completed, zero cut processing is performed during time t4-t5.

FIG. 2 shows an example of surface grinding of a work 100 having a surface dimensional runout of 17 μm before surface grinding. For the workpiece 100 having a surface dimensional deviation of 17 μm before surface grinding, that is, the workpiece 100 having a small surface dimensional deviation, surface grinding is started (t1) as shown in FIG. is less than or equal to the first predetermined value. Therefore, in the case of a workpiece whose surface has a dimensional deviation of 17 μm before surface grinding, surface grinding is completed in time “t1−tA”. Therefore, it can be seen that the time between "tA-t2" can be reduced.

FIG. 3 shows an example of surface grinding of a workpiece having a surface dimensional deviation of 35 μm before surface grinding. For the work 100 having a surface dimensional deviation of 35 μm before surface grinding, that is, the work 100 having a certain degree of surface dimensional deviation, surface grinding is started (t1) as shown in FIG. At time tB, which is earlier than the end time t2 of , the dimensional deflection of the surface of the workpiece 100 becomes equal to or less than the first predetermined value. Therefore, in the case of a workpiece whose surface has a dimensional deviation of 35 μm before surface grinding, surface grinding is completed in time “t1−tB”. Therefore, it can be understood that the time between "tB-t2" can be reduced.

FIG. 4 shows an example of surface grinding of a workpiece having a surface dimensional deviation of 50 μm before surface grinding. For the work 100 having a surface dimensional deviation of 50 μm before surface grinding, that is, the work 100 having a large surface dimensional deviation, surface grinding is started (t1) as shown in FIG. 4, and the set end time of surface grinding At time tC after t2 has elapsed, that is, during the main grinding, the dimensional deflection of the surface of the workpiece 100 becomes equal to or less than the first predetermined value. Therefore, in the case of the work 100 having a surface dimensional deviation of 50 μm before surface grinding, it may be necessary (insufficient) to perform surface grinding for a time longer than the set time (t1-t2: 2 seconds, for example). Recognize.

FIG. 5 is a graph illustrating the relationship between the measured runout value of the surface dimension of the workpiece 100 and the surface grinding completion time. FIG. 5 plots the dimensional run-out of the surface of several samples and the time to complete surface grinding when the present invention is applied. In FIG. 5, the ideal line is the line when the grinding speed is 15 μm.

As shown in FIG. 5, the average deflection of the samples in this experiment was 29.6 μm. Since the intersection of the approximation curve of the grinding completion time and the runout average value of 29.6 μm is 1.5 seconds, it can be said that the average grinding completion time is 1.5 seconds. As a result, it can be seen that the total time can be shortened by 0.5 seconds compared to the case where the set time for surface grinding is fixed at 2 seconds. Since the number of works to be processed in one day is extremely large, if the cycle time can be shortened by 0.5 seconds, the number of work that can be processed can be greatly increased.

In addition, it is significant for improving the accuracy of the next main grinding to be able to lengthen the grinding completion time when the deflection is large. That is, it is possible to optimize the time required for surface grinding according to the fluctuation of the surface dimension, and to improve the manufacturing efficiency.

As described above, according to the surface grinding method of the present embodiment, the workpiece 100 is measured using the dimensional deviation of the surface detected by the dimension measuring devices 130 and 140, that is, analog values, instead of conventional electric power values, that is, digital values. , and based on that value, it is determined whether or not the surface treatment has been completed. Therefore, it is possible to accurately determine the completion of surface grinding for grinding the surface of the workpiece 100 by excluding cases where determination is difficult due to the magnitude of the power value and noise that occur when the power value is used as the reference value for determination. becomes.

Further, according to the surface grinding method of the present embodiment, it is possible to grasp the time required for surface grinding according to the dimensional deviation of the surface of the workpiece 100 before surface grinding. As a result, the surface grinding time, which is conventionally set uniformly regardless of the magnitude of the dimensional fluctuation of the surface of the work, can be set according to the dimensional fluctuation of the surface of the work 100.例文帳に追加Therefore, it is possible to optimize the time required for surface grinding and improve manufacturing efficiency.

Preferably, before grinding by the grindstone 120, that is, before the time t1 at which surface grinding is started, while rotating the workpiece 100, the dimension measuring devices 130 and 140 detect the deviation of the dimension of the surface, and the deviation of the dimension of the surface is detected by the dimension measuring devices 130 and 140. 2 If it is equal to or greater than a predetermined value, it should be determined that the product is nonconforming. As a result, it is possible to preliminarily exclude the workpiece 100 having a significantly large surface dimensional fluctuation from the object to be processed.

In addition, before grinding with a grindstone, that is, before the time t1 at which surface grinding is started, while rotating the workpiece 100, the dimension measurement devices 130 and 140 detect the deviation of the surface dimension, and according to the deviation of the surface dimension, The cutting speed of the grindstone should be decreased as the runout increases. When the surface of the workpiece 100 has a large dimensional deviation, a high cutting speed causes a large amount of damage to the grindstone. Therefore, by decreasing the cutting speed of the grindstone 120 as the dimensional deviation of the surface increases as in the above configuration, it is possible to suitably prevent wear and damage of the grindstone 120 during the subsequent grinding process.

Furthermore, as described above, in the surface grinding method of the present embodiment, when surface grinding is completed (time t2), main grinding is performed at a higher cutting speed than surface grinding (time t2-t3). Finish grinding is performed at a slow speed (time t3-t4). Preferably, after finish grinding (time t3-t4), the dimensional deviation of the surface is detected by the dimension measuring devices 130 and 140, and when the dimensional deviation of the surface is equal to or greater than a third predetermined value It should be judged as a nonconforming product. This makes it possible to exclude products that do not meet the desired specifications after finish grinding.

That is, when the grinding resistance (electric power) is detected as in Patent Document 1, only the variation during grinding can be observed, but when the dimensions are obtained as in the present invention, the surface changes before and after grinding. can know the status. As a result, it is possible to exclude nonconforming products before grinding and nonconforming products after grinding, and to change the cutting speed in accordance with dimensional deviation, so that manufacturing efficiency can be further improved.

Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It is obvious that a person skilled in the art can conceive of various modifications or modifications within the scope described in the claims, and these also belong to the technical scope of the present invention. Understood.

INDUSTRIAL APPLICABILITY The present invention can be used as a surface grinding method for grinding the surface of a cylindrical work.

DESCRIPTION OF SYMBOLS 100... Work, 100a... Surface, 100b... Surface, 120... Grindstone, 130... Dimension measuring device, 132... Probe, 140... Dimension measuring device, 142... Probe

Claims (5)

A surface grinding method for grinding the surface of a cylindrical work,
While grinding the surface of the work with a grindstone, contacting a probe of a dimension measuring device to the ground surface to detect dimensional deviation of the surface,
A surface grinding method, wherein it is determined that the surface grinding is completed when the dimensional deviation of the surface during grinding of the surface of the workpiece is within a first predetermined value. The probe of the dimension measuring device is in contact with the surface of the cylindrical work at two axially symmetrical points,
2. A surface grinding method according to claim 1, wherein the deviation of said surface dimension is detected by adding said two displacements. Before grinding with the grindstone, while rotating the workpiece, the dimension measuring device detects the deviation of the dimension of the surface,
3. A surface grinding method according to claim 1 or 2, wherein the product is determined to be a nonconforming product if the dimensional deviation of the surface is greater than or equal to a second predetermined value. Before grinding with the grindstone, while rotating the workpiece, the dimension measuring device detects the deviation of the dimension of the surface,
4. The surface grinding method according to any one of claims 1 to 3, wherein the cutting speed of the grindstone is reduced as the deviation of the dimension of the surface increases. After the surface grinding is completed,
Performing main grinding with a higher cutting speed than the surface grinding,
After performing finish grinding with a lower cutting speed than the main grinding, the dimension measuring device detects the dimensional deviation of the surface,
5. The surface grinding method according to any one of claims 1 to 4, wherein the product is determined to be nonconforming when the dimensional deviation of the surface is equal to or greater than a third predetermined value.

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