JPH071310A - Grinding machine - Google Patents

Abstract

PURPOSE:To carry out grinding from rough grinding to finishing by using grinding wheels appropriate for each grinding process without interrupting machining. CONSTITUTION:A rough grinding wheel 2 and a finish grinding wheel 3 are provided concentrically with the wheel rotational center serving as the center. The rough grinding wheel 2 is mounted on a rotational drive shaft 4, and the finish grinding wheel 3 is provided by a spring 5 in the cup-shape recession of the rough grinding wheel 2 so that the finish grinding wheel 3 can progress/ withdraw. Rough grinding is carried out by having the rough grinding wheel 2 and the finish grinding wheel 3 abutted on a work 6. Machining pressure is applied to the finish grinding wheel 3 by no more than a specific level by the activation of the spring 5. The rough grinding work is primarily carried out by the rough grinding wheel 2. When the rough grinding is finished, the rough grinding wheel 2 is withdrawn, and finish grinding is continued only by the finish grinding wheel 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding machine for grinding highly brittle materials such as glass and ceramics used for optical elements into curved surfaces.

[0002]

2. Description of the Related Art Conventionally, in a grinding machine for grinding a workpiece into a curved shape, a cup-type grinding wheel that performs rough grinding to finish grinding is disclosed in Japanese Patent Laid-Open No. 4-2238.
It is disclosed in Japanese Patent Publication No. 59.

FIG. 6 is a sectional view showing the cup type grinding wheel 40. The cup-shaped grinding wheel 40 includes a cup-shaped annular grinding wheel 41 and a cylindrical annular grinding wheel 42. The ring-shaped grinding wheel 41 is attached to a rotary drive shaft (not shown), and the ring-shaped grinding wheel 42 is
The ring-shaped grinding wheel 41 is mounted inside the cup-shaped recess via a screw 43 so as to be movable in the axial direction of the rotary drive shaft.
Then, the annular grinding wheel 42 has a spacer 44 interposed between the annular grinding wheels 41 and 42 in the initial state of processing so that the tip portion 42a of the annular grinding wheel 42 is more than the tip portion 41a of the other annular grinding wheel 41. Is also provided so as to project forward. In this case, the annular grinding wheel 41
Is a grinding wheel for finish grinding, and the annular grinding wheel 42 is a grinding wheel for rough grinding.

The grinding process by the grinding wheel 40 is
While rotating the grinding wheel 40 via the rotary drive shaft, first, the tip portion 42a of the annular grinding wheel 42 is brought into contact with the workpiece to perform rough grinding. Then, after the rough grinding process is completed, the spacer 44 is removed and the tip portion 42a of the ring-shaped grinding wheel 42 is retracted from the tip portion 41a of the other ring-shaped grinding wheel 41 to perform the finishing grinding process by the ring-shaped grinding wheel 41. To do.

[0005]

The grinding wheel 40 described above is to be solved.
In such a case, after the rough grinding process is completed, it is necessary to temporarily interrupt the process and perform an operation of advancing and retracting the annular grinding stone 42, and further, it is necessary to remove the spacer 44 when advancing and retracting. Due to the complexity, there are problems such as a reduction in processing efficiency and a complicated processing apparatus.

[0006] Usually, in finish grinding, it is possible to obtain a highly accurate finished surface by using a high-mesh abrasive grain grindstone as much as possible, but in order to reduce the influence on the deterioration of the machined surface precision due to the grind of the grindstone, For high-mesh abrasive stones, it is more stable to apply lapping with springs or air pressure. Therefore, when the same processing method is used for both the rough grinding process and the finish grinding process as in the configuration of the conventional example, it is difficult to perform highly accurate processing stably with high efficiency.

The present invention has been made in view of the above-mentioned problems of the prior art. When performing curved surface generation processing using a plurality of annular grinding wheels, a series of rough grinding processing to finish grinding processing is performed by a simple mechanism. It is an object of the present invention to provide a grinding apparatus which can be stably and highly accurately performed in the step of.

[0008]

FIG. 1 is a conceptual diagram showing a main part of a grinding apparatus of the present invention. The cup type grinding wheel 1 includes a rough grinding wheel 2 and a finish grinding wheel 3.
And is attached to the rotary drive shaft 4 of the grinding apparatus. The rough grinding wheel 2 and the finish grinding wheel 3 are concentrically arranged around the wheel rotation center (rotational drive shaft 4).
Is movably provided in the rough grinding wheel 2 by a spring 5 in the axial direction of the rotary drive shaft 4. Reference numeral 6 denotes a work as a workpiece, which is rotatably provided around the rotary drive shaft 7.

[0009]

According to the above construction, first, in the rough grinding step, the grinding wheel 1 is moved in the direction of the arrow Y as shown in FIG. 2 (A) to move the rough grinding wheel 2 and the finish grinding wheel 3. Both end surfaces (working surfaces) are brought into contact with the work 6. At this time, the processing surface of the finish grinding wheel 3 is not subjected to a processing pressure of a certain pressure or more due to the action of the spring 5, and therefore the work 6 mainly produced by the rough grinding wheel 2 is used.
Rough grinding is performed. Next, in the finish grinding process step, as shown in FIG. 2B, the grinding wheel 1 is moved by a small amount in the arrow-Y direction to continue the process. At this time, only the rough grinding wheel 2 separates from the work 6 and the work 6
On the other hand, only the finish grinding wheel 3 acts with a substantially constant working pressure by the pressure of the spring 5, and the finish grinding of the work 6 is performed. As a result, rough grinding to finish grinding can be continuously performed in a series of steps.

[0010]

[Embodiment 1] FIG. 3 is a partially cutaway plan view showing Embodiment 1 of a grinding apparatus according to the present invention, showing a state of rough grinding. In the drawing, 10 is a work, and a holder 11 And is rotatably provided by a drive device (not shown) and is also provided so as to be movable back and forth in the axial direction of the rotation axis A (direction of arrow X). A cup-shaped grinding wheel 12 is provided in front of the work 10 via a spindle 13 so as to be rotatable about a rotation axis B by a drive device (not shown).

The grinding wheel 12 comprises a cup-shaped rough grinding wheel 14 and a cup-shaped finishing wheel 15 disposed in the rough grinding wheel 14, and the rough grinding wheel 14 and the finish grinding wheel 15 are provided. Are arranged concentrically around the rotation axis B. The rough grinding wheel 14 is attached to the spindle 13 and has a key groove 16 in the axial direction of the rotary shaft B therein.
Is provided. On the other hand, finish grinding wheel 15
A key 17 slidably engaged with the key groove 16 is provided on the outer periphery of the key. That is, the finish grinding wheel 15 is mounted in the rough grinding wheel 14 with the key groove 16 and the key 17 engaged with each other, is rotatable with the rotation of the rough grinding wheel 14, and is guided to the key groove 16. It is held so as to be movable in the axial direction of the rotating shaft B. A spring 18 is provided between the bottom surface of the cup-shaped recess of the rough grinding wheel 14 and the finish grinding wheel 15, and the finish grinding wheel 15 is constantly pressed at a constant pressure in the arrow Y direction (axial direction of the rotation axis B). Pressing with.

The grinding wheel 12 is arranged at a required angle with respect to the rotation axis A of the work 10, sets the relative angle θ between the rotation axis A and the rotation axis B, and moves the work 10 in the arrow X direction. The movement of the spindle 13 and the spindle 13 in the arrow Y and -Y directions can be arbitrarily set and moved by a driving device (not shown).

In the grinding apparatus having the above structure, the rough grinding wheel 14, the finish grinding wheel 15 and the work 10 are rotated, and the work 10 is moved in the arrow X direction or the spindle 13 in the arrow Y direction. As a result, the grinding wheel 12 and the work 10 are brought into contact with each other to process the work 10.

First, when the work 10 is roughly ground, both the rough grinding wheel 14 and the finish grinding wheel 15 are brought into contact with the work 10, and the work is carried out.
At this time, the finish grinding wheel 15 is operated by the spring 18 when the work 10 receives a certain pressure or more.
Since it retreats in the Y direction, it does not directly contribute to rough grinding,
Highly efficient rough grinding is performed by the rough grinding wheel 14.

When finish grinding the work 10, the spindle 13 is slightly moved in the -Y direction to move the rough grinding wheel 14 away from the work 10 when the rough grinding is completed. Due to the action, only the finish grinding wheel 15 is brought into contact with the workpiece 10, and at the same time, the angle θ is set so that one end of the finish grinding wheel 15 intersects the rotation axis A. As a result, the finish grinding process is performed by the finish grinding wheel 15 by the constant pressure processing method.

According to this embodiment, the work from the rough grinding to the finish grinding of the work 10 can be efficiently and stably performed in a series of steps without attaching or detaching the grindstone according to the type of the work.

[0017]

[Embodiment 2] FIG. 3 is a partially cutaway plan view showing Embodiment 2 of the grinding apparatus according to the present invention, showing a state of finish grinding. The same members as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. The grinding apparatus of the present embodiment is configured so that electrolytic in-process dressing can be performed on the finish grinding wheel.

In the figure, 19 is a cup-shaped grinding wheel. The grinding wheel 19 includes a cup-shaped rough grinding wheel 20 mounted on a spindle 13 and a rough grinding wheel 20 having a rough axis centered on a rotation axis B on the outer periphery thereof. Finishing grinding wheel 2 arranged concentrically with grinding wheel 20
1 and 1. A key groove 22 is provided on the outer circumference of the rough grinding wheel 20 in the axial direction of the rotary shaft B, and a key 23 slidably engaged with the key groove 22 is provided on the inner circumference of the finish grinding wheel 21. Is provided. That is, the finish grinding wheel 21 has the key groove 2
Wheel 2 for rough grinding with the key 2 and the key 23 engaged with each other.
No. 0, which is rotatable with the rotation of the rough grinding wheel 20 and is held by being guided by the key groove 22 so as to be movable in the axial direction of the rotating shaft B. Further, a spring 24 is provided between the flange portion 20a formed at the rear end of the rough grinding wheel 20 and the rear end of the finish grinding wheel 21, and an arrow is always provided to the finish grinding wheel 21. A constant pressure in the Y direction is applied.

Wheel 21 for finish grinding having conductivity
The processed portion 21a of C is composed of abrasive grains such as diamond powder and C
It is formed of a sintered alloy obtained by specially blending metal powders such as u, Sn, and Fe and heat-treating them. At the outer peripheral portion of the finish grinding wheel 21, a (+) pole of a power supply device 25 provided outside the grinding device is electrically connected via a brush 26. A dress electrode 27 is electrically connected to the (−) pole of the power supply device 25.

The dressing electrode 27 is formed in a shape similar to the processed surface of the finish grinding wheel 21, and the dressing electrode 27 and the finish grinding wheel are provided at a position where the contact between the finish grinding wheel 21 and the workpiece 10 is not hindered. It is held by the dress electrode holding member 28 so that the gap between the processed surface of 21 and 0.1 mm to 0.3 mm. In addition, 29 is a nozzle for supplying the weakly electric coolant 30 to a processing area from a coolant supply device (not shown).

In the present embodiment, the grinding wheel 19 and the work 10 are rotationally driven to perform rough grinding to finish grinding in the same manner as in Embodiment 1, and at the same time, the weak electric coolant 30 is supplied from the nozzle 29. A voltage is applied between the dressing electrode 27 and the processed surface of the finish grinding wheel 21 by the power supply device 25 through the weak electric coolant 30 to electrolytically dress the processed surface of the finish grinding wheel 21.

According to the present embodiment, in addition to the effect of the first embodiment, even if a # 1000 or more superabrasive grindstone is used for the finish grinding wheel 21, the surface to be machined is electrolytically dressed. Stable spherical surface grinding can be performed with high accuracy and without causing clogging.

[0023]

[Embodiment 3] FIG. 5 is a partially cutaway plan view showing Embodiment 3 of a grinding apparatus according to the present invention, showing a state of rough grinding. The same members as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

A feature of this embodiment is that a compressive fluid such as air is used instead of the spring 18 provided in the first embodiment. That is, the space 31 formed by the bottom surface of the cup-shaped recess of the rough grinding wheel 14 and the finish grinding wheel 15.
A compressive fluid 32 made of air or the like is sealed in, and the finish grinding wheel 15 is always loaded with a constant pressure in the arrow Y direction by the pressure of the compressive fluid 32.

Workpiece 10 by the grinding apparatus of this embodiment
Since the grinding method of No. 1 is the same as that of the first embodiment, its description is omitted. According to the present embodiment, in addition to the effect of the first embodiment, the processing pressure at the time of finish grinding is obtained by the pressure of the compressive fluid 32, so that it is not affected by mechanical vibration during processing. Highly accurate and stable spherical generation grinding can be performed.

[0026]

As described above, according to the present invention, the rough grinding wheel and the finish grinding wheel are provided so as to be relatively movable back and forth, and after the rough grinding by the rough grinding wheel is finished, the grinding is performed. The tip of the finish grinding wheel can be made to protrude from the tip of the rough grinding wheel without interruption, and the finish grinding wheel is brought into contact with the work piece with a constant spring pressure or fluid pressure for finish grinding. Since it can be processed, it becomes possible to stably and efficiently perform high-precision processing in a series of continuous steps.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a main part of a grinding apparatus of the present invention.

FIG. 2 is a cross-sectional view of an essential part showing a processing step by the grinding apparatus of the present invention.

FIG. 3 is a partially cutaway plan view of the first embodiment of the present invention.

FIG. 4 is a partially cutaway plan view showing Embodiment 2 of the present invention.

FIG. 5 is a partially cutaway plan view showing a third embodiment of the present invention.

FIG. 6 is a sectional view showing a conventional cup-type grinding wheel.

[Explanation of symbols]

 1 Cup type grinding wheel 2 Rough grinding wheel 3 Finish grinding wheel 4 Rotation drive shaft 5 Spring 6 Work piece

Claims (1)

[Claims] 1. A grinding machine for performing curved surface creation using a cup-type grinding wheel in which a rough grinding wheel and a finish grinding wheel are concentrically arranged with respect to a wheel rotation center, in the grinding machine. A grinding apparatus comprising a mechanism for supporting a wheel by spring pressure or fluid pressure so as to be able to move back and forth relative to the rough grinding wheel.