JPH045233Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a cylindrical grinder that grinds the cylindrical surface of a stepped cylindrical workpiece and the stepped end surface following the cylindrical surface.

``Problems to be solved by conventional techniques and ideas'' When grinding the cylindrical surface and step end surface of a stepped cylindrical workpiece, as shown in Fig. Angle θ with the feeding direction) After feeding and grinding the step end surface 1b and cylindrical surface 1a of the workpiece 1 with the mutually perpendicular outer circumferences 2b and 2a of the grindstone 2, the workpiece 1 is removed, reversed, and reinstalled on the grinding machine. Step end face 1 of workpiece 1
d and the cylindrical surface 1c, or as shown in FIG. After that, remove the workpiece 1, turn it around, reinstall it on the grinding machine, and then remove the step end face 1 of the workpiece 1.
d and the cylindrical surface 1c were being ground.

In either case, it takes time to turn the workpiece 1 over, and furthermore, it is difficult to keep the depth of the center hole constant, so the position of the step end surface varies. If the accuracy of the center hole is not good, the accuracy of the machined surface will be poor.

As shown in Fig. 1, in the case of grinding using an angular slide grinder that grinds the workpiece 1 by feeding the grindstone 2 obliquely, the grinding wheel 2 and the workpiece 1 are at a constant angle θ, so the workpiece 1 Step end surfaces 1b, 1d and cylindrical surfaces 1a, 1c
With respect to the depth of cut, a constant relationship of cosθ and sinθ is established, and the
An expensive dressing mechanism for dressing a at a constant ratio of cos θ:sin θ is required, making the entire grinding machine expensive and complicated.

As mentioned above, since the depth of cut is constant, it is impossible to select the depth of cut for each of the cylindrical surface and the end surface.

When grinding the stepped end surfaces 1b and 1d of the workpiece 1 with the cylindrical grindstone 3 as shown in FIG. 2, both side surfaces 3b of the cylindrical grindstone 3 become thinner, so the cylindrical surface must be largely dressed after a certain amount of use.

In the case of Fig. 2, in which grinding is performed using the cylindrical grindstone 3, grinding debris is removed from the step end surfaces 1b and 1d of the workpiece 1 during the grinding process.
It has the disadvantage that it is easy to touch, and if it comes into contact with it, smooth and good grinding cannot be achieved.

Figure 1 and column 8 of Special Publication No. 47-27311
Lines 42 to 9th column, line 3 describe the use of both sides of a disc grindstone having a trapezoidal cross section to grind the stepped end face opposite to the direction of the stepped shaft. This makes it possible to solve the above problems. However, the invention disclosed in this publication has a complicated structure because it includes a device for dressing the outer periphery and both sides of the grindstone. In particular, the dressing devices on both sides of the grindstone are complicated, and dressing on both sides of the grindstone is time consuming.

The present invention is a cylindrical grinding machine that can completely process a stepped workpiece with steps on both sides without reversing and reinstalling it.The cutting of the grindstone into the workpiece can be efficiently selected, and the dressing of the grindstone is simple. The object of the present invention is to provide a cylindrical grinder that can perform grinding with high precision.

``Means for Solving the Problems'' The present invention is a numerically controlled cylindrical grinding machine that is equipped with a cylindrical grindstone with a cylindrical surface dressed on the outer periphery of the grindstone, and that processes a stepped shaft. It is equipped with a disc-shaped grindstone with a trapezoidal radial cross section that widens toward the outer circumference at approximately 20 degrees, and a grindstone head that is driven in the Y direction, which is the same direction as the table movement direction, and in the X direction, which is perpendicular to the Y direction. The main axis of the grinding wheel is installed so that it is parallel to the moving direction Y of the table of the grinding machine, and the grinding wheel is equipped with a numerical control device that drives the grinding wheel head to enable diagonal cutting through simultaneous XY-axis control movement. This is a numerically controlled cylindrical grinding machine characterized by being able to simultaneously grind the end face of a stepped shaft and the cylindrical surface by constantly keeping an acute corner on the outer periphery of the grinding wheel using only diameter dressing.

"Example" Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a plan view showing an embodiment of the present invention,
FIG. 4 is an enlarged plan view of section A in FIG. 3. A table 5 is installed on the upper surface of the front part of the bed 4 of the grinding machine so as to be able to slide in the direction of the arrow Y along a slide not visible in the figure, and a grindstone head 6 is installed in a stepped manner on the upper surface of the rear part of the bed 4 in the direction of the arrow X. It is provided so as to be slidable along an XY slide provided in the direction of arrow Y perpendicular to the X direction.

X-direction pulse motor 7, Y-direction pulse motor 8
is connected to the grindstone head 6 by arrow X via a ball screw (not shown).
The table 5 is slid in the direction of arrow Y and positioned at a predetermined position, and the table 5 is slid by a pulse motor 9 fixed to the bed 4 and positioned at a predetermined position. A grindstone 10 attached to a main shaft of the grindstone parallel to the moving direction of the table 5 is rotatably driven by a drive motor (not shown) on the grindstone table 6.

A headstock 11 and a tailstock 12 are provided on the table 5, and centers 13 and 14 move the workpiece 1
5 is supported by the center hole of the workpiece 15, and the headstock 1
The workpiece 15 is rotationally driven by a drive motor (not shown) provided inside the workpiece 1 through a celery 16. Reference numeral 17 is a manual table feed handle for manually sliding and setting the table 5, and reference numeral 18 is a manual grindstone cutting handle for manually sliding the grindstone head 6 in the direction of arrow X.

The whetstone 10 is a disc-shaped whetstone with both sides 10b1,1
0b2 is at an angle α (α = 15°
~25°), and the center side surfaces 10c1 and 10c2 are parallel to each other, and the cylindrical surface 10a is a true cylindrical surface.

The cylindrical surface 15a of the work 15 is the cylindrical surface 10a of the grindstone 10, and the step end surface 15b of the work 15 is the cylindrical surface 10a of the grindstone 10.
A grinding wheel 10 is placed on the stepped end surface 15d and the cylindrical surface 15c of the workpiece 15 so as to be ground by the edge 10c of the workpiece 15.
The workpiece 15 is ground so that the edge 10d and the cylindrical surface 10a face each other. Whetstone 10
In order to dress the cylindrical surface 10a, a known cylindrical surface dressing device (not shown) is provided. Or, remove the grindstone 10 from the device and grind the cylindrical surface 1.
Dressing 0a.

First, move the table 5 and the grindstone head 6 to a position facing the step end face 15b and the cylindrical face 15a of the workpiece 15 using the table manual feed handle 17 and the grindstone manual cut handle 18, and move the side face 10b1 and the cylindrical face 10 of the whetstone 10
a is approached and slightly moved by the numerical control device, and the grindstone 10 moves to the origin position.

Next, the grinding wheel 10 and the workpiece 15 rotate, and the pulse motor 7 is driven by the data built into the numerical control device.
and 8 are driven to move the grindstone head 6 in the direction of arrow X and arrow Y.
While grinding the cylindrical surface 15a and step end surface 15b of the workpiece 15 while performing cutting depths x and y in the directions, the pulse motor 8 stops and the diameter of the cylindrical surface 15a
_{The pulse} motor 7 moves _the grinding wheel head 6 in the _X direction (in the 3), and the pulse motor 7 also stops.

Next, the pulse motor 9 is started, and the thickness of the grinding wheel 10 is
The table 5 is moved by the drive of the pulse motor 9 by a distance equal to the sum of L ₂ and the length L ₁ of the central cylindrical part of the workpiece 15 (L ₁ +L _{2 )} and the amount of cut y into the stepped end surface 15d of the workpiece 15. After moving to the right, the pulse motor 9 stops.

Next, by driving the pulse motor 7, the grinding wheel head 6 is moved by a distance of half (D ₂ − D ₃ )/ ₂ of the difference between the diameter D ₃ of the cylindrical surface 15c of the workpiece 15 and the diameter D 2 of the center part, and then is driven by the pulse motors 7 and 8 to grind the cylindrical surface 15c and step end surface 15d of the workpiece 15 while executing cutting depths x and -y, and when finished, the pulse motor 8 stops, Pulse motor 7
Due to the drive of (D ₂ - D ₃ )/2 + ΔD, the grinding wheel head 6
When the pulse motor 7 returns and the pulse motor 7 stops, the table 5 is moved to the left by a distance of L ₁ +L ₂ +y by the pulse motor 9, the pulse motor 9 stops, and then the grinding wheel head 6 is returned to the origin position by the drive of the pulse motor 7. The rotation of the grinding wheel 10 and workpiece 15 is stopped, and one cycle of the grinding process is completed.

The workpiece 15 that has been ground is removed from the centers 13, 14 and the kelly 16.

In the above explanation, the diameter of the central cylindrical part of the workpiece 15 D ₂
Of course, if the grinding work for ₃ parts of diameter D is included in the data of the numerical control device, it is possible to grind ₂ parts of diameter D.

In addition, although we have shown an example in which the workpiece 15 has only cylindrical surfaces with diameters D ₁ , D ₂ , and D ₃ , it is possible to create a stepped cylinder with many different diameters by repeatedly expanding or contracting the diameter from one cylindrical surface. Of course, even for shaped workpieces, grinding can be completed in one set.

It should be noted that dressing of the grindstone 10 adopted in the present invention is sufficient if it is performed on the cylindrical surface 10a, and dressing on the side surfaces 10b1 and 10b2 is not necessary.

Also, the width of the grinding wheel 10 with the dressing amount corrected.
It is known that a numerical controller controls the process described above for L ₂ or diameter.

Here, a comparison will be made between the conventional dish-shaped grindstone and the grindstone 10 of the present invention for grinding the cylindrical surface 15a and stepped end surface 15b of the workpiece 15. 5 and 6 show the state of wear of the conventional dish-shaped grindstone 30, and FIGS. 7 and 8 show the state of wear of the grindstone 10 of the present invention. In the present invention, the shape of the grindstone after the corrected dressing is a cylindrical surface 10a, side surfaces 10b1, 10b2, and side surfaces 10b1, 10b2.
Dressing is performed during production of the grindstone, resulting in an accurate conical surface, and dressing is not performed again due to wear of the grindstone. Only the cylindrical surface 10a is shaped by dressing as the grindstone wears. A conventional dish-shaped grindstone has a cylindrical surface 100a and a side surface 100b1,1.
00b2, and as the grinding wheel wears, the cylindrical surface becomes 100
a, side surfaces 100b1 and 100b2 are formed by dressing.

In FIGS. 5 and 7, the portion indicated by the upward-right sectional line indicates wear of the grindstone, and the cutting state of the dressing tool in dressing the grindstone in the portion indicated by the downward-right sectional line.

The upper right section line in Figures 6 and 8 is the grindstone 3.
0 and 10 respectively indicate the width of the grinding action GW acting on the step end surface 15b of the workpiece 15. FIG. 6 of the conventional example shows that when the step end surface 15b is plunge-cut, the grinding width is always the same as the radial width of the step end surface 15b, and in the present invention, the grinding action width GW is zero after dressing with the grindstone (actually, due to the depth of cut). The width rapidly increases to a certain width), and increases to the grinding action width GW, which is the shape in which the grinding wheel correction shown in FIG. 7 is to be performed.

In the conventional example, the cylindrical surface 15a of the workpiece 15 is ground by sending the dish-shaped grindstone 30 in the axial direction, and then the step end surface 15b is ground by a plunge cut (tool path T2 in FIG. 5). direction, the step end surface 1b is ground with the side surface of the whetstone, and the cylindrical surface 1
Plunge cut a with the outer periphery of the grinding wheel (not shown)
You can do it the way you want. In this invention, the grindstone 1
0 is the cylindrical surface 15 of the workpiece 15 simultaneously in the XY direction
a, it is sent toward the corner of the step end surface 15b with an oblique cut T1, and the cylindrical surface 15a and the step end surface 15b of the workpiece 15 are simultaneously ground by a plunge cut.

Therefore, in the grinding action, the axial cutting feed force applied to the step end face 15b is small because the radial grinding action width GW on the side surface of the grinding wheel is small in the present invention, and the radial cutting action width GW on the side surface of the grinding wheel is small in the conventional plunge cut. In the conventional example, when the sharpness of the grindstone decreases, it becomes significantly large, causing grinding burns and deterioration of surface roughness due to increased grinding resistance. In addition, in the present invention, since the grindstone cuts diagonally, the cutting ratio in each of the X and Y directions can be adjusted, so the cutting depth can be selected to obtain the best grinding accuracy and surface roughness.

The combination of the grinding wheel and diagonal cut of the present invention has a very effective grinding effect, and in the conventional example, when the step end surface 15b is ground with a plunge cut, the grinding force increases, grinding burn, and surface roughness worsens, and the step end surface 1b When the side surface of the grindstone is fed in the radial direction, the outer circumferential side of the grindstone side surface participates in the grinding action longer than the inner circumferential side, which has a remarkable effect of reducing the fact that the outer circumferential side of the grindstone side surface wears out more.

Cylindrical surfaces 10a, 100 on the outer periphery of the grindstones 10, 30
Assuming that the wear in the radial direction of a is equal, grinding wheel 1
Radial wear width R3, R30 of side surface of 0,30
is R3<R30. The three-dimensional wear shape is a complement to the shape in which the step end surface 15b has a minute umbrella shape.

Here, the conventional grindstone 30 dresses the outer periphery with a total cutting depth of ΔD30, and the present invention dresses the outer periphery with a total cutting depth of ΔD3. ΔD3＞ΔD3
0, but the conventional dish-shaped grindstone 30 has both sides 10
It is necessary to dress near the outer periphery on the 0b1 and 100b2 sides. Since this radial dressing width ΔW30 is large, dressing takes a long time. Although the dressing conditions for the cylindrical surface are constant, when dressing the side surface of the grindstone, the circumferential speed of the grindstone changes, so it is difficult to ensure precision when correcting the side surface of the grindstone perpendicular to the axis. This dressing device must be installed on both sides of the grinding wheel, making the grinding machine complicated and expensive. In contrast, in the present invention, a numerically controlled cylindrical grinder with simultaneous two-axis control and cylindrical surface dressing are sufficient.

[Effect of idea]

As explained above, this invention is a numerically controlled cylindrical grinding machine that is equipped with a cylindrical grinding wheel with a cylindrical surface dressed on the outer circumference of the grinding wheel and that processes a stepped shaft. The grindstone is equipped with a disc-shaped grindstone with a trapezoidal radial cross section that widens toward the outer periphery, and the grindstone head is driven in the Y direction, which is the same direction as the table movement direction, and the X direction, which is perpendicular to the Y direction, respectively. The grinding wheel is installed so that it is parallel to the moving direction Y of the grinding machine table, and the grinding wheel is equipped with a numerical control device that drives the grinding wheel head to enable diagonal cutting through simultaneous XY-axis control movement. Since the numerically controlled cylindrical grinder is characterized by having an acute corner on the outer periphery of the grinding wheel and being able to simultaneously grind the end face of the stepped shaft and the cylindrical surface, it is possible to simultaneously grind the end face of the stepped shaft and the cylindrical surface. When grinding a cylindrical surface that continues from the end surface to the corner is completed in one grinding without reversing the workpiece, the outer circumference and both sides of the grinding wheel are Since there is no need to dress the surface, the grindstone only needs to be corrected on the outer periphery, dressing the grindstone is simple, and it is also simple to provide a dressing device. Since the grinding wheel has a trapezoidal radial cross section with the side surface at an angle of approximately 20 degrees (15 to 25 degrees) with respect to the plane perpendicular to the grinding wheel axis and widening toward the outer periphery, radial grinding of the side surface of the grinding wheel due to wear of the side surface of the grinding wheel. The increasing speed of the working width is small because the angle of the side surface of the grinding wheel is large, and unlike conventional dish-shaped cylindrical grinding wheels, the radial width of the grinding action does not increase significantly due to slight wear on the side surface of the grinding wheel, and the workpiece can be stepped. When grinding the end face, it is possible to prevent grinding burn or deterioration of surface roughness due to increased grinding resistance, and is durable. In addition, in this invention, the numerical control device with simultaneous XY control is used to cut diagonally toward the corner of the step end surface and cylindrical surface of the workpiece, so the cutting ratio to the cylindrical surface and step end surface of the workpiece can be freely set, making it easier to grind. It has good accuracy and surface roughness, and the grindstone shape suppresses the increase in grinding force by simultaneously cutting into the step end face and cylindrical face of the workpiece, so the work time is fast. Further, compared to an angular slide grinder or a cylindrical grinder equipped with dressing devices on both sides, the machine cost can be greatly reduced.

[Brief explanation of the drawing]

Figures 1 and 2 are plan views showing conventional processing;
Fig. 3 is a plan view showing an embodiment of the present invention, Fig. 4 is an enlarged plan view of section A in Fig. 3, and Fig. 5 is a grinding wheel used in grinding the cylindrical surface and step end surface of a workpiece using a conventional dish-shaped grindstone. 6 is a right side view of FIG. 5; FIG. 7 is a radial sectional view showing wear of the grinding wheel and the notch of dressing of the present invention; FIG. FIG. 3 is a right side view of the figure. 5...Table, 6...Whetstone stand, 7, 8, 9...
...Pulse motor, 10... Grindstone, 15... Workpiece, X, Y... Arrow, x, y... Amount of cut, α...
…angle.

Claims (1)

[Scope of utility model registration request] In a numerically controlled cylindrical grinding machine that is equipped with a cylindrical grindstone with a cylindrical surface dressed on the outer periphery of the grindstone and processes a stepped shaft, the side surface is at an angle of approximately
The grindstone head is equipped with a disk-shaped grindstone with a trapezoidal radial cross section that widens toward the outer circumference at 20 degrees, and is driven in the Y direction, which is the same direction as the table movement direction, and the X direction, which is perpendicular to the Y direction. The main axis of the grinding wheel is installed so that it is parallel to the moving direction Y of the table of the grinding machine,
The whetstone is equipped with a numerical control device that drives the whetstone head to enable diagonal cutting through simultaneous XY-axis control movement, and by simply dressing the outside diameter of the whetstone, it constantly creates an acute corner on the outside of the whetstone and cuts the end face of the stepped shaft and the cylindrical surface. A numerically controlled cylindrical grinder that is capable of simultaneous grinding.