JP5181227B2 - Centerless grinding machine - Google Patents

Description

  The present invention relates to a technique for adjusting a centerless grinding machine according to a diameter dimension when performing centerless grinding on a plurality of types of workpieces having different diameter dimensions, and is particularly practical when performing through-feed grinding. The effect is remarkable.

FIG. 4 is a schematic front view shown for explaining the basic structure and function of centerless grinding.
The workpiece 5 having a cylindrical surface to be processed is supported by the blade 4 and the adjusting grinding wheel 2 on the surface to be processed.
The adjusting grinding wheel is rotated in the direction of arrow d by a drive mechanism (not shown), and the workpiece 5 in contact therewith is rotated in the direction of arrow e.
The grinding wheel 3 is rotationally driven in the direction of the arrow f by a drive mechanism (not shown), and rotates at a peripheral speed faster than the peripheral speed of the workpiece 5 while contacting and grinding the workpiece 5. The illustrated angle α is the apex angle of the blade 4 and the dimension H is the center height.
The angle β is the center angle for the grinding wheel, the angle γ is the center angle for the adjusting wheel, and the angle (β + γ)
Is called heart high angle.
These numerical values must be strictly controlled in order to perform high-precision centerless grinding, but it is difficult to calculate the appropriate values using mathematical formulas, and adjustments are made by experts with advanced knowledge and many years of experience. This is the current situation.

The center of the grinding wheel 3 is designated as G, the center of the adjustment grinding wheel 2 is designated as R, and a straight line connecting these points is designated as GR line 1. In general centerless grinding, the GR line 1 is not necessarily horizontal.
The rotation center line of the grinding wheel 3 passes through the point G and is perpendicular to the paper surface. The rotation center line of the adjusting grinding wheel 2 is basically perpendicular to the paper surface through the point R, but in the case of through-feed grinding, a feed angle is given.
The above feed angle is a slight angle of inclination in the direction in which the adjustment grinding wheel 2 is rotated around the GR line 1, but is not related to the effects of the present invention, so the feed angle is ignored in the following description. Shall.

FIG. 5 is a front view showing a conventional example of a centerless grinding machine. A grinding wheel base 6 installed on the bed 8 supports the grinding wheel 3 in the Z-axis direction (perpendicular to the paper surface) (the rotational drive mechanism of the grinding wheel 3 is not shown in the drawings and the same applies hereinafter).
A lower slide mechanism 10 is mounted on the bed 8, and an upper slide mechanism 9 is mounted thereon. Further, an adjustment grinding wheel base 7 is installed thereon to support the adjustment grinding wheel 2.
The lower slide mechanism 10 is driven by a servo motor 10a and slides in the direction of a reciprocating arrow aa ′. The upper slide mechanism 9 is driven by the servo motor 9a and slides in the reciprocating arrow bb ′ direction.

A work rest 16 is mounted on the lower slide mechanism 10 and supports the blade 4. For this reason, when the lower slide mechanism 10 is operated, the adjusting grinding wheel 2 and the blade 4 move in parallel with the GR line 1 while maintaining the relative positions.
The reason for this is that the workpiece 5 is supported by the blade 4 and the adjusting grinding wheel 2 as can be understood from FIG. 4 (basic structure), so that the workpiece can be processed while keeping this supported state constant. This is for bringing the object 5 close to the grinding wheel 3 (that is, cutting and feeding).
For comparison with the present invention to be described later, please remember that “the conventional example has a structure in which the relative position of the adjusting grinding wheel 2 and the blade 4 is kept constant”.

If necessary for adjustment or maintenance, the upper slide mechanism 9 is operated to retract the adjusting grindstone table 7 in the direction of the arrow b 'and then return to the direction of the arrow b.
There is also an example in which a horizontal swivel 11 is disposed between the lower slide mechanism 10 and the upper slide mechanism 9. In this way, in the case of a three-story structure, it is actually difficult to ensure the supporting rigidity of the adjusting grinding wheel 2.

FIG. 6 is a front view showing a conventional centerless grinding machine different from the above.
Differs from the relative 5 supra, lower slide surface 10b of the lower slide mechanism 10 has angularly φ inclined with respect to the horizontal axis X, thus the upper slide surface 9b also water Flat Shaft X of the upper slide mechanism 9 The angle φ is inclined with respect to the angle.
The reason for this is that, as can be understood from FIG. 4 (basic structure), the workpiece 5 is supported by the blade 4 and the adjusting grinding wheel 2, so that the workpiece 5 is tilted as shown in FIG. The support of the workpiece 5 is stabilized.
Furthermore, when the accuracy of the material of the workpiece is poor and the rotation is asymmetric, the workpiece 5 is pressed against the adjusting grinding wheel 2 due to the inclination, and is easily rotated (by the action of gravity) .

FIG. 7 is a schematic plan view of a main part in a state where through-feed grinding is performed using the centerless grinding machine according to the conventional example of FIG. 5 or FIG.
In through-feed grinding (through-feed grinding), the workpiece material 5A is guided by the inlet guide plate 12a and the inlet guide plate 12b and supplied in the direction of the arrow i, and between the adjusting grinding wheel 2 and the grinding wheel 3 The processed product 5B, which has been ground while passing, is sent out in the direction of the arrow j while being guided by the outlet guide plate 13a and the outlet guide plate 13b.
This through-feed grinding method has the advantage that centerless grinding can be performed automatically and continuously with high efficiency while supplying a large number of workpiece materials sequentially, but is widely used. It is very difficult to adjust the position and posture of the inlet guide plates 12a and 12b and the outlet guide plates 13a and 13b.
This adjustment is difficult to automatically control by assigning a numerical value to an arithmetic expression, and requires a high degree of skill and a great deal of labor.

Regarding improvement around the adjusting wheel of the centerless grinding machine, as disclosed in Patent Document 1, JP 2006-88333 A “Centerless Grinding Machine” in which a screw-like groove is provided on the outer periphery of the adjusting wheel, and Patent Document Japanese Patent Laid-Open No. 2002-86333, “Centerless Grinding Method and Apparatus”, which improves the grinding efficiency and accuracy by setting the machining allowance as mentioned above, is known, but corresponds to the change in the diameter dimension of the workpiece. No special consideration has been given to the structure of the centerless grinding machine that makes the setup change easy.
JP 2006-88333 A JP 2002-86333 A

As described above with reference to FIG. 7, adjustment of the guide plate in through-feed grinding requires a high degree of skill and a great deal of time and labor. This problem appears as an important defect in the case of so-called setup change. That is, when the finishing dimension of the workpiece (specifically, the finishing dimension of the diameter) is changed, a great amount of time and labor are required to correct the adjustment, so that the work efficiency is lowered and the machining cost is increased.
FIG. 8 is a view for explaining a problem associated with the setup change adjustment. The relative positional relationship among the blade, the adjustment grinding wheel, and the workpiece in the centerless grinding is expressed by a small-diameter workpiece Wa.
FIG. 2 is a front view schematically illustrating a workpiece and a large-diameter workpiece Wb.

Reference numeral 1 indicates a GR line (described above) that connects the center of the adjustment grinding wheel and the center of the grinding wheel.
Considering the case of centerless grinding of a small-diameter workpiece Wa drawn with a solid line by the through-feed method, the adjusting grinding wheel is located at the forward position 2A drawn with a solid line, and the center of the adjusting grinding wheel is Ra. .
W1 is the center of the workpiece Wa having a small diameter.
Next, to change the setup so that the workpiece Wb having a large diameter drawn by the phantom line is centerless ground, the adjusting grinding wheel must be moved to the retracted position 2B drawn by the phantom line.
W2 is the center of the workpiece Wb having a large diameter.

According to the conventional centerless grinding machine shown in FIGS. 5 and 6, the center of the adjustment grinding wheel is retreated along the GR line 1 from Ra to Rb. Next, adjustment of the guide plate accompanying this operation will be described.
For convenience of explanation (see FIG. 7), the outlet guide plate 13b will be described.
(See also FIGS. 7 and 8) The line where the small-diameter workpiece Wa is in contact with the adjustment grinding wheel 2A at the forward position is the pass line Pa. This pass line Pa passes through the point Pa shown in the figure and is perpendicular to the paper surface.
The guide plate is adjusted so as to contact the workpiece Wa having a small diameter in the pass line Pa, and the relative position with respect to the adjusting grinding wheel 2A is fixed (specifically, the adjusting wheel base 7 (see FIGS. 5 and 6)). Fixed against).

Next, considering the position of the guide plate with respect to the large-diameter workpiece Wb, the adjusting grinding wheel is set to the retreat position 2B, and the center thereof is the point Ra shown in the figure. In this state, the guide plate is adjusted so as to come into contact with the workpiece Wb having a large diameter along the pass line Pb.
Comparing before and after the above adjustment work, the pass line moves from Pa to Pb as indicated by an arrow m. On the other hand, the center of the adjustment grinding wheel moves along the GR line 1 from Ra to Rb.
Since the movement direction of the pass line (arrow m) and the movement direction of the adjusting grinding wheel (GR line) intersect at an angle ψ, the position and posture of the guide plate must be adjusted again.
However, as described above, the adjustment of the guide plate requires a high degree of skill and a great deal of time and labor.

  The present invention has been made in view of the above circumstances, and its purpose is that when the diameter of the workpiece changes, the center angle does not change without readjusting the blade, and the guide plate is readjusted. It is to provide centerless grinding technology that is not required.

The basic principle of the present invention created to achieve the above object will be briefly described with reference to FIG. 1 corresponding to one embodiment thereof.
A. The adjusting grindstone bed 7 is moved back and forth in the horizontal direction by the horizontal slide mechanism 15.
B. The grinding wheel 3 is arranged higher than the adjusting wheel 2, and a line connecting the center G of the grinding wheel 3 and the center R of the adjusting wheel 2 with respect to the forward / backward direction (horizontal) of the adjusting wheel base 7. Tilt.
C. The grinding wheel 3 and the blade 4 are fixedly installed.

The configuration of the centerless grinding machine according to the first aspect of the invention will be described with reference to FIG. 1 depicting one embodiment thereof. However, although reference numerals are added for easy comparison with FIG. 1, the reference numerals do not limit the configuration of claim 1.
Assuming horizontal orthogonal two axes X and Z and a vertical Y axis,
A grinding wheel head (6) that supports the grinding wheel (3) is fixedly installed on the flat bed (14), and
On the flat type bed, a horizontal slide mechanism (15) that slides in the X-axis direction is provided, and an adjustment grindstone stand (7) that supports the adjustment grindstone (2) is mounted.
In addition, a height difference h is provided between the center G of the adjusting grinding wheel and the center R of the grinding wheel,
When the horizontal slide (15) mounted with the adjusting grindstone base (7) is moved according to the diameter of the workpiece (5), the contact point between the workpiece and the adjusting grindstone can always be kept constant. It has become.

The configuration of the centerless grinding machine that does not use the inclined slide according to the invention of claim 2 is in addition to the configuration requirements of the inventive device of claim 1,
A blade for supporting a workpiece in cooperation with the grinding wheel is fixedly installed on the bed.

The configuration of the centerless grinding machine not using the inclined slide according to the invention of claim 3 is in addition to the configuration requirements of the inventive device of claim 2,
Plural kinds of blades are attached, and the blades can be attached and detached as needed.

An adjustment method of a centerless grinding machine that does not use an inclined slide according to the invention of claim 4
In the method of adjusting the centerless grinding machine corresponding to the diameter dimension of the workpiece,
In advance, the center position R of the adjustment grinding wheel is set lower than the center position G of the grinding wheel,
The center position R of the grinding wheel is slid in the horizontal direction without changing the center position G of the grinding wheel.

The adjustment method of the centerless grinding machine that does not use the inclined slide according to the invention of claim 5 is in addition to the configuration requirements of the method of the invention of claim 4,
Prepare multiple types of blades in advance,
When the center position R of the grinding wheel is slid in the horizontal direction, the blade is attached and detached as necessary.

When the invention apparatus of claim 1 is applied, the center position R of the adjustment grinding wheel is set lower than the center position G of the grinding wheel,
Since the GR line connecting the center positions of both grinding wheels is inclined with respect to the X axis,
Even if the adjusting grinding wheel is slid in the horizontal direction according to the diameter of the workpiece, the change in the center angle is small.
For this reason, within the range of normal working conditions, it is possible to perform the setup change adjustment only by the horizontal slide of the adjusting grinding wheel without moving the position of the grinding wheel. Therefore, it is possible to perform high-efficiency and low-cost centerless grinding by changing the setup quickly and easily without requiring any special knowledge or skill.

  When the invention device of claim 2 is applied together with the invention device of claim 1, it is possible to quickly and easily without changing the position of the blade by simply sliding the adjusting grinding wheel in the horizontal direction according to the diameter size of the workpiece. A setup change can be made.

  When the invention device of claim 3 is applied together with the invention device of claim 2, the change in the height of the center when the adjusting grinding wheel is slid in the horizontal direction can be made finer.

According to the method of the invention of claim 4, within the range of normal working conditions, it is possible to perform the setup change adjustment only by the horizontal slide of the adjusting grinding wheel without moving the position of the grinding wheel.
Therefore, it is possible to perform high-efficiency and low-cost centerless grinding by changing the setup quickly and easily without requiring any special knowledge or skill.

  When the inventive method of claim 5 is carried out in combination with the inventive method of claim 4, high-precision centerless grinding can be performed by further minimizing the change in the center height.

FIG. 1 is a front view schematically illustrating one embodiment of a centerless grinding machine that does not use an inclined slide according to the present invention.
5 and 6 showing the conventional example, the difference in appearance is not the two-story or three-story structure in which the upper slide mechanism 9 and the lower slide mechanism 10 are stacked, but only the horizontal slide mechanism 15. This is a single layer structure. Therefore, naturally, the supporting grinding wheel 2 has a high support rigidity, and high-precision centerless grinding is possible.
High support rigidity is an indirect effect of the present invention, but for a centerless grinder pursuing submicron order high accuracy, the practical value of high support rigidity of the grinding wheel is great.

A horizontal slide mechanism 15 is installed on a horizontal flat bed 14 on the top surface.
The slide surface 15b is along a horizontal auxiliary axis χ.
The adjusting grinding wheel 2 is supported by an adjusting grinding wheel base 7, which is mounted on the horizontal slide mechanism 15 and slid in the horizontal direction.
A work rest 16 is fixed to the top surface of the flat bed 14, and the blade 4 is fixedly attached so as to be detachable and replaceable.

A grinding wheel base 6 is mounted on the top surface of the flat type bed 14 directly or via a work rest 16, and the grinding wheel base 6 moves the grinding wheel 3 in the Z-axis direction (perpendicular to the paper surface). I support it. In short, the structure of the grinding wheel 3 is unchanged.
The center R of the adjustment grinding wheel 2 is arranged lower than the center G of the grinding wheel 3. That is, the GR line 1 is inclined with respect to the horizontal slide surface 15b (the inclination is a direction in which the center R of the grinding wheel 2 is lowered).
In the figure, the X axis is a horizontal axis passing through the center G of the grinding wheel 3. The dimension h is a height difference between the center R of the adjustment grinding wheel 2 and the center G of the grinding wheel 3.
In the present embodiment, as described above, the distance between the axis R of the adjusting grinding wheel (2) and the bed (14) is such that the axis G of the grinding wheel (3) and the bed (14). It arrange | positions so that it may become smaller than the distance between.

Next, the operation of the present invention will be described with reference to FIG.
The general arrangement of the adjustment grinding wheel 2, the grinding wheel 3, and the blade 4 depicted in FIGS. 2A and 2B is the same as that in the embodiment shown in FIG. Reference numeral G denotes the center of the grinding wheel 3 and reference numeral 1 denotes a GR line.
FIG. 2A shows a state where a small-diameter workpiece Wa is centerless-ground, and FIG. 2B shows a state where a large-diameter workpiece Wb is centerless-ground.
In both figures (A) and (B), the Y axis is common and the X axis is the horizontal axis.

In FIG. 2A, the center of the adjustment grinding wheel 2 that is in contact with the small-diameter workpiece Wa is Ra, which is lower than the center point G of the grinding wheel 3 by a dimension h.
The small-diameter workpiece Wa is supported involuntarily by the adjusting grinding wheel 2 and the blade 4, and the center thereof is W1.
The heart height is expressed with reference to the GR line 1.
The center height in this state is Ha, the center angle of the adjustment grinding wheel is γa, and the vertical axis passing through the center of the adjustment grinding wheel 2 is y ′.

As described above, from the state of FIG. 2 (A) corresponding to the small-diameter workpiece Wa, the setup change to correspond to the large-diameter workpiece Wb is performed by using the horizontal auxiliary shaft at the center of the adjustment grinding wheel 2. A dimension L is moved to the right of the drawing along x ', as shown in FIG. The center of the adjusted grinding wheel 2 in the moved state is defined as Rb.
The center height in this state (corresponding to the large-diameter workpiece Wb) is Hb, and the center height angle related to the adjusting grinding wheel is γb. W2 is the center of the workpiece Wb having a large diameter.

As described above, when the adjustment is changed from FIG. 2A corresponding to the small-diameter workpiece Wa to FIG. 2B corresponding to the large-diameter workpiece Wb, due to the structure of the apparatus of the present invention, The adjusting grinding wheel 2 moves along the horizontal line (auxiliary axis x ′) lower than the grinding wheel 3 by a predetermined dimension h without moving along the GR line 1 ”.
as a result,
γa = γb …………………………… (1)
Ha ≒ Hb ………………………… (2)
It becomes.
That is, it is possible to cope with a change in the diameter of the workpiece by moving the adjusting grinding wheel 2 without moving the grinding wheel 3 and the blade 4, and the center angle is not changed.
Specifically, the center angle γ relating to the adjustment grinding wheel is so small that it can be regarded as unchanged, and the change in the center height H is so small that it can be ignored under normal working conditions.

FIG. 2A and FIG. 2B are overlapped and drawn as shown in FIG.
Γa = γb and Ha≈Hb so that the drawing can be convinced.
Referring to the FIG. 3 Judging considered when as follows.

Suppose, and replacing the workpiece Wa of small diameter workpiece Wb of larger diameter.
B. The diameter of the workpiece on the blade 4 is increased, thereby increasing the heart high.
B. As the diameter dimension of the workpiece increases , the center moves from W1 to W2 to the right in the figure, so that the contact point between the workpiece and the blade also moves to the right in the figure. However, since the top surface of the blade is inclined downward to the right, the workpiece slides down along the inclined surface. This lowers the heart.

By appropriately setting the dimension h shown in the figure and the apex angle α of the blade and moving the adjusting grinding wheel horizontally, the rise factor of the above item B and the decrease factor of the term B are offset, and the center height is changed. Absent.
When the present invention is implemented, the apex angle α of the blade is an important design factor for stabilizing the workpiece and enabling ultra-high accuracy centerless grinding. Therefore, the apex angle α of the blade cannot be arbitrarily set in order not to change the center height.
In this embodiment, (a) the optimum apex angle α of the blade for stable grinding is set, and (b) the height difference dimension h of the adjusting grinding wheel is selected so that the change in center height can be almost zero. did.

Next, an application example of the present invention will be described with reference to FIG.
The centerless grinding machine that does not use the inclined slide of this embodiment is suitable for grinding by a through feed method. In the case of through-feed grinding, if the position of the adjusting grinding wheel 2 is adjusted according to the diameter size of the workpiece 5, then a number of workpieces are continuously ground without changing the position of the adjusting grinding wheel. can do.
However, in-feed grinding can also be performed using the slide in the X-axis direction by the horizontal slide mechanism 15.

Further, an application example other than the above will be described with reference to FIG.
In order to give further versatility to the centerless grinding machine that does not use the inclined slide of this embodiment, it is impossible to interpose a horizontal slide mechanism (not shown) between the flat bed 14 and the grinding wheel head 6. is not.
Even if it is the structure which interposed the slide mechanism (not shown) without fixing the grinding wheel head 6 on the flat type bed 14,
If the adjustment grinding wheel 2 is arranged at a position lower than the grinding wheel 3 and the adjustment grinding wheel base 7 is mounted on the horizontal slide mechanism 15, the setup change adjustment shown in FIG. It belongs to the technical scope of the present invention.
That is, even if a slide mechanism that is not necessarily used is additionally installed, the conflict with the present invention cannot be avoided.

In the embodiment shown in FIG. 1, a plurality of types of blades are prepared as accessories. The work rest 16 is fixed to the top surface of the flat bed 14 and the blade 4 is attached to and detached from the work rest. It has a structure to obtain.
When the present invention is applied, the changeover can be adjusted by simply sliding the adjustment grinding wheel 2 in the horizontal direction within the normal working condition range. However, for some reason (for example, the rate of change in the diameter dimension of the workpiece is extremely large, It is very convenient if the blade can be replaced with an optimum blade 4 according to a special type of blade for centerless grinding of a minute workpiece.
In the present embodiment, the mounting surface of the blade 4 with respect to the work rest 16 is inclined by an angle θ with respect to the horizontal plane. Although the value of the angle θ can be set as appropriate, it is desirable that the angle θ be a minute angle of about several degrees.

In this way, even if the blade can be removed and replaced,
If the adjustment grinding wheel 2 is arranged at a position lower than the grinding wheel 3 and the adjustment grinding wheel base 7 is mounted on the horizontal slide mechanism 15, the setup change adjustment shown in FIG. It belongs to the technical scope of the present invention.
That is, even if a replacement blade that is not necessarily used is combined, the conflict with the present invention cannot be avoided.

1 is a schematic front view illustrating an embodiment of a centerless grinding machine that does not use an inclined slide according to the present invention. (A) is a schematic diagram of a state where a small-diameter workpiece is centerless-ground, and (B) is a schematic diagram of a state where a large-diameter workpiece is centerless-ground. Fig. 2 (A) and Fig. 2 (B), which are the above-mentioned drawings, are combined to show a schematic enlarged detail of the main part. Schematic drawing depicting the basic structure of a centerless grinding machine Schematic front view depicting a conventional centerless grinding machine Schematic front view depicting a conventional centerless grinding machine with an inclined slide mechanism Schematic plan view for explaining the arrangement of guide plates in through-feed grinding Schematic front view for explaining technical problems in the centerless grinding machine of the conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... GR line 2 ... Adjustment grinding wheel 3 ... Grinding grinding wheel 4 ... Blade 5 ... Workpiece 5a ... Workpiece material 5b ... Processed product 6 ... Grinding wheel base 7 ... Adjustment wheel base 8 ... Bed 9 ... Top slide Mechanism 9a ... Servo motor 9b ... Upper slide surface 10 ... Lower slide mechanism 10a ... Servo motor 10b ... Lower slide surface 11 ... Horizontal swivel 12a, 12b ... Inlet guide plate 13a, 13b ... Outlet guide plate 14 ... Flat type bed 15 ... Horizontal slide mechanism 15b ... Horizontal slide surface ...
16. Work rest

Claims (2)

A grinding wheel support for supporting the grinding wheel is fixedly installed on the flat type bed, and a blade set at an apex angle for stable grinding to support the workpiece in cooperation with the grinding wheel. , Fixedly installed on the flat type bed,
A horizontal slide mechanism that slides in the horizontal direction is provided on the flat type bed, and an adjustment grindstone stand that supports the adjustment grindstone is mounted on the horizontal slide mechanism,
And, the center of the adjustment grinding wheel is set lower than the center of the grinding wheel with respect to the upper surface of the flat type bed,
Even if the horizontal slide equipped with the adjustment wheel head is moved according to the workpiece diameter, the height of the center of the work piece is always based on the straight line connecting the center of the grinding wheel and the center of the adjustment wheel. A centerless grinding machine characterized in that the height of the center of the adjusting grinding wheel relative to the center of the grinding wheel is set so that a certain center height hardly changes . The centerless grinding machine according to claim 1, wherein a plurality of types of blades are attached, and can be attached and detached as necessary.

Images