JPH06190696A - Grinding device - Google Patents

Abstract

PURPOSE:To reduce grinding resistance and improve cylindricity and surface roughness of a work by providing a means to form the outer circumference of a grinding wheel at the grinding point of a work into a straight form in parallel with the rotary axis of the work and a taper form inclined against the axis, and the like. CONSTITUTION:A table 11 is horizontally movably supported on a bed 10, a head stock 13 and a tailstock 14 are oppositely provided on the table 11, and a work W is supported with them at both ends. A wheel spindle 15 is supported on the bed 10 horizontally movably in the direction meeting at right angles with the moving direction of the table 11, and a grinding wheel 16 is rotatably borne with the wheel spindle stock 15. Further the grinding wheel 16 is with a motor 17, and the table 11 and the wheel spindle stock 15 are with respective servo motors 20, 21 respectively driven, and the respective servo motors 20, 21 are respectively numerically controlled with the NC device 23. The outer circumference of the grinding wheel 16 at the grinding point of the work W, is formed out of a straight part 30 in parallel with the rotary axis of the work W. and a taper part 31 inclined against the same rotary axis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding device for cylindrically grinding a work.

[0002]

2. Description of the Related Art In some of the above-mentioned grinding machines, a grindstone is moved forward at one end of the work, then the work is moved in the direction of the rotation axis, and the grindstone is moved backward at the other end of the work, thereby making the cylinder of the work cylindrical. Some grind. In this grinding device, when the work is moved in the direction of the rotation axis, rough grinding of the work is performed by the taper shape of the outer circumference of the grindstone,
Then, there is one that finish-grinds the work with a straight shape on the outer periphery of the grindstone.

[0003]

When the above-described cylindrical grinding is performed, there is an advantage that the grinding time can be shortened because rough grinding and finish grinding can be performed in one step. However, there is a problem that the cylindricity of the work and the surface roughness of the work are not sufficiently satisfied.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the outer circumference of the grindstone at the grinding point for grinding the work of the grindstone has a straight shape parallel to the work rotation axis. This is a portion in which the workpiece is cylindrically ground prior to the straight shape, and has a taper shape which is inclined with respect to the axis of rotation of the work, and the taper shape is set to an inclination angle corresponding to the diameter of the work. Further, the truing device is provided for truing the taper shape at an inclination angle that decreases as the diameter of the work increases. Further, the inclination angle with respect to the work rotation axis of the tapered shape is selected from 1 degree to 20 degrees according to the diameter of the work. Further, the length of the straight-shaped work in the rotation axis direction is 5 mm or more immediately after truing regardless of the work diameter. Furthermore, the length of the straight shape in the rotation axis direction of the work is set to 2 mm or more immediately before truing, regardless of the work diameter.

[0005]

Function: While rotating the work and the grindstone respectively, the grindstone is relatively moved with respect to the work in the direction of the work rotation axis, the work is roughly ground by the taper shape of the outer circumference of the grindstone, and the finish grinding is performed by the straight shape. Since the inclination angle of the taper shape is set to the optimum value according to the workpiece diameter, the grinding resistance is reduced and the cylindricity of the workpiece is improved. Further, since the length of the straight shape is set to the optimum value, the surface roughness of the work is improved.

[0006]

Embodiments of the present invention will be described with reference to the drawings.
In FIG. 1, reference numeral 10 denotes a bed on which a table 11 is guided and supported so as to be horizontally movable. A headstock 13 and a tailstock 14 are installed on the table 11 so as to face each other, and both ends of the work W are supported by the headstock 13 and the tailstock 14 so that the work rotation axis is parallel to the moving direction of the table 11. The work W is rotationally driven by the headstock 13. A grindstone 15 is guided and supported on the bed 10 in a horizontal direction orthogonal to the moving direction of the table 11, and the grindstone 1 is mounted on the grindstone 10.
6 is rotatably supported around an axis parallel to the moving direction of the table 11. This grindstone 16 is a grindstone drive motor 1
7 is driven to rotate via a pulley and a belt (not shown). The table 11 is moved by a servo motor 20 provided on the bed 10, and the grindstone base 15 is moved by a servo motor 21 provided on the bed 10. The servomotors 21 and 22 are NC controlled by the NC device 23. A truing device 50 is attached to the side surface of the headstock 13 on the grindstone 15 side. A measuring device 51 for measuring the outer diameter of the work W is mounted on the table 11, and the measuring device 51 is connected to the NC device 23. The NC device 23 stores a table showing the relationship between the outer peripheral diameter d of the work W and the inclination angle θ as shown in FIG. 10, and in order to relatively move the truing device 50 and the grindstone 16 as shown in FIG. 11 during truing. Required data Z1 (= 5mm), Z2 (= 5
mm) is stored, and a machining program for controlling the entire grinding device according to the flowchart of FIG. 12 and a truing program for performing truing according to the flowchart of FIG. 13 are stored.

The grindstone 16 is a disk-shaped grindstone core 40 having a grindstone layer 41 provided on the outer periphery thereof. The grindstone layer 41 is made of CBN abrasive grains bonded by vitrified bonds. On the outer periphery of the grindstone 16 at the grinding point for grinding the work W of the grindstone 16, a straight portion 30 formed in a straight shape parallel to the work rotation axis and a taper portion 31 formed in a tapered shape inclined with respect to the work rotation axis. And are provided.

Next, the operation of the entire grinding machine will be described based on the above-mentioned configuration. When the worker sets the work W between the headstock 14 and the tailstock 14 and presses the machining start button of the NC device 23, the machining program shown in FIG. 12 starts.
In step S1, the outer diameter d of the work W is measured by the measuring device 50, and in step S2, it is compared with the previously measured outer diameter d of the work W for comparison. If they are different, truing is performed in step S3, and then grinding is performed in step S4. If they are the same, the process jumps to step S4 to perform grinding.

The truing performed in step S3 will be described with reference to FIG. In step S10, the inclination angle θ corresponding to the outer diameter d of the workpiece W measured this time is selected according to the table of FIG. In step S11, X in FIG. 11 is calculated based on the equation X = Z2 × tan θ based on the tilt angle θ selected in step S10 and the data Z2 stored in the NC device 23. Step S
The table 11 and the grindstone base 15 are moved by 12 to make the truing device 51 correspond to the left end of the grindstone 16. Step S
At 13, the table 11 is moved rightward by Z1 and the straight portion 30 of the grindstone 16 is trued. In step S14, the table 11 is moved rightward by Z2, and at the same time, the grindstone 15 is moved.
Is advanced by X to true the taper portion 31 so that the taper portion 31 has an inclination angle θ corresponding to the outer peripheral diameter d of the work W.

The cylindrical grinding processing of the work performed in step S4 will be described. The table 11 is moved to a position where the grindstone 16 corresponds to the left end of the work W, and the grindstone 16 and the work W are rotated. Subsequently, the whetstone base 15 is advanced, and the advancement of the whetstone mount 15 is stopped at a predetermined position. In this state, the table 11 is moved to the left, the outer circumference of the work is roughly ground by the taper portion 31 of the grindstone 16, and then the outer circumference of the work is finish-ground by the straight portion 30. When the grindstone 16 has passed the right end of the work, the table 11 is stopped from moving to the left and the grindstone base 15 is retracted to complete the cylindrical grinding of the work W.

In the graph on the left side of FIG. 3, the diameter of the grindstone 16 to the outer periphery is 400 mm, the width of the grindstone 16 is 10 mm, the length of the straight portion 30 in the direction of the work rotation axis is 5 mm, the grindstone peripheral speed is 160 m / S, and the work is This shows how the cylindricity changed when the workpiece W was cylindrically ground under the condition of the diameter of 45 mm and the inclination angle of the taper portion 31 was changed, and the grinding resistance was small when the inclination angle was 5 degrees. . That is, since the variation of the escape amount of the work W between the both ends and the middle of the work W is small, the cylindricity of the work is improved when the inclination angle is 5 degrees. The graph on the right side of FIG. 3 shows that the diameter of the grindstone 16 up to the outer circumference is 400 mm, the width of the grindstone 16 is 10 mm, and the tapered portion 3
The workpiece W is cylindrically ground under the conditions of an inclination angle of 1 with respect to the work rotation axis of 5 degrees, a grindstone peripheral speed of 160 m / S, and a work diameter of 45 mm, and the surface roughness is obtained when the length of the straight portion 30 in the work rotation axis direction is changed. It shows that the surface roughness changes, and it can be seen that the surface roughness is small when it is 5 mm or more. FIG. 4 is a graph when the workpiece diameter is 5 mm under the same conditions as FIG. 3, and when the inclination angle of the taper portion 31 is 20 degrees, the cylindricity becomes small and the length of the straight portion 30 is 5 mm or more. When it is set, the surface roughness becomes small. FIG. 5 shows a workpiece diameter of 25 m under the same conditions as in FIG.
It is a graph when m is set, and when the inclination angle of the taper portion 31 is 15 degrees, the cylindricity becomes small, and when the length of the straight portion 30 is 5 mm or more, the surface roughness becomes small. 6 shows a workpiece diameter of 100 mm under the same conditions as in FIG.
It is a graph when it is set, and the inclination angle of the tapered portion 31 is 1
The degree of cylindricity becomes smaller as
When the length is 5 mm or more, the surface roughness becomes small. From this, the workpiece diameter exceeds 5 mm and 100 m
It can be seen that when the angle is m or less, there is a tendency that the inclination angle decreases as the diameter of the work increases, and the inclination angle may be selected from more than 1 degree and less than 20 degrees. This is stored in the NC device 23 in the form of the table shown in FIG.

The length of the straight portion 30 is shortened by abrasion by grinding a large number of works W, as shown in FIG. FIG. 7 shows a grindstone 16 having a straight portion 30 having a length of 5 mm immediately after truing and having a diameter of 5 mm.
It is a graph showing how the surface roughness changes due to the change in the length of the straight portion 30 when the workpiece W having a size of mm is repeatedly ground. From FIG. 7, the straight part 3
Straight part 30 when the length of 0 is from 5 mm to 2 mm
There is a sufficient action to reduce the tool mark of each abrasive grain due to the large number of abrasive grains, and the length of the straight portion 30 is 2 mm.
It can be seen that when the amount is less than the above, the effect of reducing the tool mark of the abrasive grains is rapidly reduced and the surface roughness is deteriorated. Further, by decreasing the length of the straight portion 30 from 5 mm to 2 mm, the action of reducing the tool mark of the abrasive grains is reduced, but conversely, the surface roughness of the abrasive grains of the straight portion 30 is smaller than that in FIG. As shown in FIG. 9, the surface roughness of the work W can be kept constant because it becomes smaller.

An operator measures the length of the straight portion 30 with a measuring means such as a caliper, and when the length becomes 2 mm, a truing device (not shown) provided in the grinding device is used.
The straight portion 30 is trued so that the straight portion 30 is 5 mm or more and the taper portion 31 has an inclination angle corresponding to the diameter of the work W. As described above, according to the present invention, the grinding angle is reduced and the cylindricity of the work is improved by selecting the optimum inclination angle of the taper portion 31 according to the work diameter. In addition, by selecting the optimum value for the length of the straight portion 30 immediately after truing in the workpiece rotation axis direction,
Surface roughness is improved.

In the above-mentioned embodiment, the example in which the taper portion 31 is trued by the truing device 51 so that the taper portion 31 of the grindstone 16 has the inclination angle θ according to the outer peripheral diameter d of the work W has been described. , The grindstone 16 having an inclination angle θ according to the outer peripheral diameter d of the work W may be replaced.

[0015]

As described above, according to the present invention, the outer periphery of the grindstone at the grinding point for grinding the work of the grindstone has a straight shape parallel to the rotation axis of the work and a portion for cylindrically grinding the work prior to this straight shape. Since the taper shape is inclined with respect to the axis of rotation of the work and the taper shape is set to the inclination angle according to the diameter of the work, the effect of improving the cylindricity of the work can be obtained. Further, since the length of the straight shape in the direction of the rotation axis of the work is 5 mm or more immediately after truing regardless of the work diameter and 2 mm or more immediately before truing regardless of the work diameter, the effect of improving the surface roughness of the work is obtained. To be

[Brief description of drawings]

FIG. 1 is an overall plan view of a grinding device according to the present invention.

FIG. 2 is a cross-sectional view showing the shape of a grindstone used in the present invention.

FIG. 3 is a diagram showing a change in cylindricity and a change in surface roughness when a work diameter is 45 mm.

FIG. 4 is a diagram showing a change in cylindricity and a change in surface roughness when a work diameter is 5 mm.

FIG. 5 is a diagram showing a change in cylindricity and a change in surface roughness when a work diameter is 25 mm.

FIG. 6 is a diagram showing a change in cylindricity when a work diameter is 100 mm.

[Fig. 7] When a workpiece having a diameter of 5 mm is ground,
The figure showing the change of surface roughness with respect to the change of the length of a straight part.

FIG. 8 is a state diagram showing the properties of a grindstone immediately after truing.

FIG. 9 is a state diagram showing the properties of a grindstone immediately before truing.

FIG. 10 is a table showing the relationship between the outer peripheral diameter d of the work and the inclination angle θ.

FIG. 11 is a truing operation diagram.

FIG. 12 is a flowchart showing the contents of a machining program.

FIG. 13 is a flowchart showing the contents of a truing program.

[Explanation of symbols]

 16 Whetstone 30 Straight part 31 Tapered part 30 NC device W work

Claims (5)

[Claims] 1. A grinder that grinds a workpiece in a grinding device, which is configured to perform cylindrical grinding of a workpiece by rotating the workpiece and the grindstone relative to the workpiece in the direction of the workpiece rotation axis. The outer circumference of the grindstone at the grinding point is a straight shape that is parallel to the work rotation axis and a portion that performs cylindrical grinding of the work prior to this straight shape and has a tapered shape that is inclined with respect to the work rotation axis. A grinding device characterized in that the inclination angle is set according to the diameter. 2. A grinder that grinds a workpiece in a grinding device that performs cylindrical grinding of the workpiece by moving the grindstone relative to the workpiece in the direction of the workpiece rotation axis while rotating the workpiece and the grindstone, respectively. The outer circumference of the grindstone at the grinding point is a straight shape that is parallel to the work rotation axis and a portion that performs cylindrical grinding of the work prior to this straight shape and has a tapered shape that is inclined with respect to the work rotation axis. A grinding machine provided with a truing device for truing at an inclination angle that decreases as the diameter increases. 3. A grinder which grinds a workpiece in a grinding device, wherein the grindstone is moved relative to the workpiece in the direction of the workpiece rotation axis while rotating the workpiece and the grindstone, respectively. The outer circumference of the grindstone at the grinding point is a straight shape parallel to the work rotation axis and a part that performs cylindrical grinding of the work prior to this straight shape and has a taper shape inclined with respect to the work rotation axis. Is selected from 1 to 20 degrees according to the diameter of the work. 4. A grinder that grinds a workpiece in a grinding device that performs cylindrical grinding of the workpiece by rotating the workpiece and the grindstone relative to the workpiece in the direction of the workpiece rotation axis. The outer circumference of the grindstone at the grinding point is a straight shape parallel to the work rotation axis and a part that performs cylindrical grinding of the work prior to this straight shape and has a taper shape inclined with respect to the work rotation axis. Is selected from 1 degree to 20 degrees according to the diameter of the work, and the length of the straight shape in the direction of the work rotation axis is 5 mm or more immediately after truing regardless of the work diameter. 5. A grinder that grinds a workpiece in a grinding device that performs cylindrical grinding of the workpiece by rotating the workpiece and the grindstone relative to the workpiece in the direction of the workpiece rotation axis. The outer circumference of the grindstone at the grinding point is a straight shape parallel to the work rotation axis and a part that performs cylindrical grinding of the work prior to this straight shape and has a taper shape inclined with respect to the work rotation axis. Is selected from 1 degree to 20 degrees according to the diameter of the work, and the length of the straight shape in the direction of the rotation axis of the work is set to 2 mm or more immediately before truing regardless of the work diameter.