JP2003145396A - Surface grinding method and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface grinding method and its device allowing short and efficient machining for surface grinding requiring high degree of surface roughness. SOLUTION: For surface grinding, grinding wheels 1, 1 are provided with a circular grinding surface 1a of rough machining concentrically with a grinding spindle (x) as a center and a circular grinding surface 1b for finish machining, respectively. In the state of a workpiece (w) being clamped by a clamper 41, a swing arm 51 is swung to the position of the circular grinding surface 1a, where rough machining is performed. When the rough machining is done, the swing arm 51 is swung to the position of the circular grinding surface 1b, where finish machining is performed. Thus, rough to finish machining can be performed with one clamping operation, improving working efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface grinding method and an apparatus therefor, and more particularly, to a grinding technique for performing a grinding process requiring a high quality surface roughness in the surface grinding.

[0002]

2. Description of the Related Art In a surface grinding process using a grindstone having an annular grinding surface a as shown in FIG.
When high-quality surface roughness is required for the surface of the workpiece w to be machined, grinding has been performed so far by two grinding steps, so-called roughing and finishing.

That is, at the time of grinding, two kinds of grinding wheels having different properties of the grinding surface a (specifically, a grinding wheel having a grinding surface for roughing and a grinding wheel having a grinding surface for finishing) are prepared. Then, first, as a first step, grinding processing (rough processing) is performed using a grinding wheel for rough processing, and then, as a second step, grinding for finish processing is performed on a workpiece on which rough processing has been completed. Grinding using a whetstone (finishing)
Was going on.

[0004]

However, such a conventional processing method has the following problems, and its improvement has been desired.

That is, in the grinding process that goes through the two steps of roughing and finishing as described above, the clamp device b that guides the workpiece w to the grinding surface a at the time of shifting from roughing to finishing.
Since it is necessary to change the grip, it is necessary to leave an allowance at the time of finishing in consideration of the change in grip at the stage of rough machining. That is, in the conventional two-step grinding process, there is a problem that the machining allowance at the time of finishing process increases and the work efficiency decreases. In particular, the higher the surface roughness required for finishing, the slower the cutting speed during finishing, and the longer the machining time.

The present invention has been made in view of such conventional problems, and an object of the present invention is to perform efficient machining in a short time in surface grinding which requires high quality surface roughness. It is an object of the present invention to provide a surface grinding method and a device therefor.

[0007]

In order to achieve the above object, a surface grinding method of the present invention is arranged such that a plurality of annular grinding surfaces having different properties are concentrically arranged around a rotation axis of a grinding wheel at predetermined intervals. Then, the workpiece is moved along the annular grinding surface while rotating the grinding wheel, and the workpiece is sequentially ground on each of the plurality of annular grinding surfaces.

Further, the surface grinding apparatus of the present invention rotates a grinding wheel and a grinding wheel in which a plurality of annular grinding surfaces having different properties are concentrically arranged about a rotation axis at predetermined intervals. Grinding wheel rotating means, cutting amount setting means for adjusting the cutting amount of the grinding wheel, work holding means for detachably holding a workpiece, and the work holding means for moving along the surface direction of the annular grinding surface. And a work carrier means.

According to the present invention, in the surface grinding process,
While rotating the grinding wheel formed by arranging a plurality of concentric annular grinding surfaces having different properties at a predetermined interval, the workpiece is moved along the annular grinding surface, and with this movement, the plurality of the grinding wheels are moved. The workpiece is sequentially ground using the annular grinding surface. Therefore, by providing a rough grinding surface for roughing and a finish grinding surface for finishing as the annular grinding surface, it is possible to perform roughing and finishing in one step without changing the grip of the workpiece. You can

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIG.
It will be described in detail with reference to FIG.

FIG. 1 is a perspective view showing a schematic structure of a surface grinding apparatus according to the present invention. In the illustrated example, the present invention is applied to a vertical-axis double-sided surface grinding apparatus.

As shown in the figure, this surface grinding apparatus includes a pair of grinding wheels 1 and 1 arranged to face each other, a grinding wheel rotating means 2 for rotationally driving the grinding wheels 1 and 1, and a cutting of the grinding wheels 1 and 1. The cutting amount setting means 3 for adjusting the amount, the work holding means 4 for detachably holding the workpiece w, and the work holding means 4 in the grinding surface direction of the grinding wheels 1 and 1 (horizontal direction in this embodiment). Work carrier means 5 for moving, discharge truing electrode 6 for truing, electrode driving means 7 for moving the discharge truing electrode 6 in the grinding surface direction of the grinding wheels 1, 1, and operation of each part of the surface grinding machine are controlled. And a control means 8 for performing the operation.

As shown in FIGS. 2 and 3, the grinding wheel 1 has a grinding wheel 11 and a plurality (two in the illustrated example) of grinding wheels 11 and 12 mounted on the grinding wheel 11 as main parts. It is configured. As each grinding wheel 12, an annular wheel having a different diameter is used as shown in the figure,
These are concentrically mounted on the grinding wheel 11 around the rotation axis (grinding wheel axis) x of the grinding wheel 1.

As a result, the grinding wheel 1 has a rotating shaft x
A plurality of annular grinding surfaces (annular grinding surfaces) are concentrically formed (two rows in the illustrated example) around the center. In the following, for convenience of explanation, the outer annular grinding surface is indicated by reference numeral 1a and the inner annular grinding surface is indicated by reference numeral 1b.

The annular grinding surfaces 1a and 1b are
As shown in the figure, they are formed at a predetermined interval, and a single groove 1c is formed between these annular grinding surfaces 1a and 1b (see FIG. 3).

Each of the annular grinding surfaces 1a and 1b constitutes a grinding surface having a different property. Specifically, in this embodiment, the outer annular grinding surface 1a is used for roughing the workpiece w. The rough grinding surface and the inner ring-shaped grinding surface 1b constitute a finish grinding surface for finishing the work w. For example, a whetstone with a large grain size of abrasive grains is used for rough machining on the outer annular grinding surface 1a, and a whetstone with a small grain size of abrasive grains is used for finishing processing on the inner annular grinding face 1b.

Incidentally, here, the above-mentioned annular grinding surfaces 1a, 1b.
May have the same grain size as long as it is a grindstone capable of roughing and finishing. That is, each of the annular grinding surfaces 1a and 1b is in a state suitable for roughing and finishing by dressing or truing even if the grain size of the abrasive grains is the same, for example, by roughing by current control in the discharge truing technique. And a ground surface condition for finishing may be generated.

In the present embodiment, as such a grinding wheel 12, a conductive wheel in which the abrasive grains are bonded by a conductive bonding material is used.

Specifically, the grinding stone 12 has, for example, fine diamond abrasive grains or CBN as the abrasive grains.
So-called superabrasive grains such as (cubic boron nitride) abrasive grains are used, and a metal bond or a conductive resin bond containing a conductive substance is used as a binding material for these abrasive grains.

Although not shown in detail, the grindstone rotating means 2 drives the grindstones 1 and 1 to rotate about the axis of the rotation axis x thereof, and includes a power source and a power transmission mechanism (not shown). The power generated by the power source is transmitted to the grinding wheel 1 through the power transmission mechanism, so that the grinding wheel 1
It is possible to drive the rotation of.

The cutting amount setting means 3 is for adjusting the cutting amount of the grinding wheels 1 and 1, and, like the grinding wheel rotating means 2, is provided with a power source and a power transmission mechanism (not shown). By transmitting the power generated by the power source to the grinding wheel 1 via the power transmission mechanism, it is possible to adjust the cut amount (the operation amount in the x-axis direction) of the grinding wheel 1.

The work holding means 4 holds a work piece in a detachable manner, and in this embodiment, a clamp device 41 of a well-known form for tightening and holding the work w is used as the work holding means 4. . The clamp device 41 includes a power source such as a servo motor (not shown), and is configured so that the work w can be automatically attached / detached under the control of the control means 8 described later.

The work carrier means 5 is means for moving the work holding means 4 in the surface direction (horizontal direction in this embodiment) of the annular grinding surfaces 1a and 1b formed on the grinding wheel 1, and has a tip end. In addition, a swing arm 51 having the work holding means 4 and an arm rotating means 52 for giving a horizontal swinging motion to the swing arm 51 are mainly constituted.

The arm rotating means 52 is an actuator of a known form, and its operation can be controlled by the control means 8. The swing arm 51 is connected to the base end of the swing arm 51 via a power transmission mechanism (not shown), and the swing arm 51 is rotated about the y axis shown in the figure.
By rotating the base end of the swing arm 51
It is configured to impart a horizontal turning motion to the.

The swing arm 51 is composed of a plate-like member arranged horizontally as shown in the figure, and the clamp device 41 is provided at the tip thereof. The swing arm 51 has such a length that the locus drawn by the clamp device 41 provided at the tip of the arm can intersect both of the annular grinding surfaces 1a and 1b when the horizontal swing motion is performed. Have dimensions.

That is, the swing arm 51, as shown in FIG.
The workpiece w clamped to the above is the annular grinding surface 1a, 1b.
It is set so that it can be crossed with both.

As shown in FIG. 5, the swing arm 51 is disposed at a height position between the grinding wheels 1 and 1, that is, when the swing arm 51 is turned, the clamp device 41 is clamped. The formed work w is set so as to be able to pass between the annular grinding surfaces 1a and 1b.

The discharge truing electrode 6 is an electrode for performing discharge truing on the annular grinding surfaces 1a and 1b, and in this embodiment, the rotary electrode 61 is used as this electrode.

Specifically, the rotary electrode 61 is a narrow disk-shaped electrode which is arranged facing the annular grinding surfaces 1a and 1b, and more specifically, an electrode holding base 71 described later.
Is rotatably attached to the tip of an arm (not shown) extending from the rotary electrode 61 via a power transmission mechanism (power transmission belt in the example shown) 72 generated by a power source (not shown). Is transmitted to the rotary electrode 61 so that the rotary electrode 61 can be rotationally driven. The rotary electrode 61 is connected to the DC power supply device 6 via the power supply line 62a.
3 is electrically connected to the negative (-) pole.

On the other hand, the positive (+) pole of the DC power supply device 63 is electrically connected to the grinding wheels 1 and 1 via a power supply line 62b. More specifically, as shown in FIG. 1, a brush-shaped power supply body 64 is provided at the tip of the power supply line 62b,
The power supply body 64 is brought into contact with the grindstone shaft x, whereby the grindstones 1 and 1 (specifically, via the grindstone shaft x).
DC power can be supplied to the grinding wheels 12, 12).

The electrode driving means 7 includes the rotary electrode 31.
Is a device for horizontally turning and moving along the above-mentioned annular grinding surfaces 1a and 1b, although the detailed illustration thereof is omitted,
An electrode holding base 71 configured so as to be able to swivel around the illustrated z-axis as a rotation center, and a power transmission mechanism 72 for transmitting power from a power source (not shown) to the rotary electrode 31 to rotationally drive the rotary electrode 31. Is configured as a main part.

The electrode driving means 7 drives the rotary electrode 61 to rotate under the control of the control means 8 and rotates the electrode holding base 71 about the z-axis to move the rotary electrode 61 to the above-mentioned annular grinding surface. It is possible to traverse horizontally in a range including the outer peripheral edge of 2a and the inner peripheral edge of the annular grinding surface 2b.

When disposing the electrode driving means 7, a position where it does not interfere with the work carrier means 5, that is, the turning radius of the swing arm 51 and the electrode driving means 7 are arranged.
The trajectories of the turning radii of the arms are set so that they do not overlap.

The control means 8 is a control center for controlling the operation of each part of the surface grinding machine, and is specifically composed of a microcomputer which stores a predetermined control program.

That is, the control means 8 controls the respective operations of the grindstone rotating means 2, the cutting amount setting means 3, the arm rotating means 52 and the electrode driving means 7, whereby the rotational speed of the grinding wheel 1 and the like. The cut amount, the movement of the work carrier means 4 and the discharge truing electrode 6 and the application of the voltage to the electrodes can be controlled in association with each other.

A: Grinding of the workpiece w Next, the grinding of the workpiece w using the surface grinding apparatus configured as described above will be described.

In the grinding of the workpiece w, the arm rotating means 52 is driven by the control of the control means 8 so that the clamp device 41 provided at the tip of the swing arm 51 is provided outside the grinding wheels 1 and 1. The swing arm 51 is moved to a predetermined position (the position shown by the solid line in FIG. 4).
This predetermined position is a position where the work w is loaded by a loader device (not shown), and the work w is loaded at this loading position.
Is clamped by the clamp device 41.

Then, at the same time as or after the clamping of the work w, the control means 8 causes the grindstone rotating means 2 to rotate.
Is operated to rotate the grinding wheels 1 and 1, and the arm rotating means 52 is rotated to advance the work w to a position facing the annular grinding surface 1a (see arrow (1) in FIG. 4).

When the workpiece w advances to the position of the annular grinding surface 1a, the control means 8 slows down the swing speed of the swing arm 51, and at the same time, the arm rotating means 52 is used to move the swing arm 51 slightly forward and backward. (Oscillating motion) is performed, and in that state, the grinding wheel 1 is cut by the cutting amount setting means 3 to a preset rough grinding processing position, and the work w is rough processed (see arrow in FIG. 4).
(See (2)).

When the rough machining of the work w is completed in this manner, the control means 8 then causes the grinding wheel setting means 3 to retract the grinding wheels 1 and 1, and the arm rotation means 52 causes the swing arm 51 to move. A horizontal swiveling motion is again applied to advance the work w to the position of the annular grinding surface 1b (see arrow (3) in FIG. 4).

Then, when the work w advances to the position of the annular grinding surface 1b, the control means 8 slows down the swing speed of the swing arm 51 and causes the swing arm 51 to move a minute amount, as in the case of the rough grinding. While performing the forward and backward movement (oscillating movement), the grinding wheels 1 and 1 are cut, and the work w is subjected to finishing processing (Fig. 4 arrow (4)).
reference).

When the finishing process is completed, the control means 8 causes the grinding wheels 1 and 1 to retreat again, and in this state, the arm rotating means 52 is given a horizontal turning motion in the opposite direction to the above. The work w is retracted to a predetermined discharge position (see arrow (5) in FIG. 4).

As described above, according to the surface grinding apparatus of the present invention, a single grinding apparatus can perform a series of grinding processes from roughing to finishing with one clamp without changing the grip of the workpiece w. Therefore, the finishing allowance can be reduced.

B: Truing of Grinding Wheel Grinding Surface Next, the truing of the annular grinding surfaces 1a and 1b will be described. In the surface grinding apparatus of the present invention, the annular grinding surface 1a,
The truing of 1b is performed by the discharge truing electrode 6 without contact with the annular grinding surfaces 1a and 1b.

That is, the control means 8 drives the electric discharge truing electrode 6 to rotate at a predetermined rotational speed during the above-mentioned grinding process or before the start of the grinding process, and the DC power supply device 63 is turned on to turn the grinding wheel 1 on. , 1 and the rotary electrode 61 are applied with a predetermined voltage.

Then, in this state, the control means 8 turns the electrode holding base 71 to traverse the rotary electrode 61 from the outer peripheral edge of the annular grinding surface 1a toward the inner peripheral edge of the annular grinding surface 1b. At that time, the control means 8
Applies a predetermined cutting operation to the grinding wheels 1 and 1 by the cutting amount setting means 3.

That is, when the DC power supply 63 is turned on, a (+) voltage is applied to the annular grinding surfaces 1a and 1b, and a (-) voltage is applied to the rotary electrode 61. When the rotary electrode 61 is advanced in this state, a discharge action occurs between the two electrodes as the electrode 61 advances, the metal bond portions of the grinding wheels 12, 12 are dissolved and removed, and the grinding wheels 1, 1 Is a new annular grinding surface 1a, 1
b is molded. At this time, by adjusting the cutting amount by the cutting amount setting means 3, the annular grinding surface 1
It is possible to true a and 1b into a desired shape.

As described above, according to the surface grinding apparatus of the present embodiment, the truing of the grinding wheels 1 and 1 is the discharge truing which is performed without contact with the annular grinding surfaces 1a and 1b. High-precision truing can be performed on the machine without the need to replace 1.

It should be noted that the above-described embodiment is merely a preferred embodiment of the present invention, and the present invention is not limited to this, and various design changes can be made within the scope thereof.

For example, in the above-described embodiment, the case where the present invention is applied to the vertical-axis double-sided surface grinding machine is shown.
The present invention is applicable not only to the vertical-axis double-sided surface grinding machine but also to the horizontal-axis double-sided surface grinding apparatus. Further, the present invention is not limited to the double-sided surface grinding machine and can be applied to a so-called single-headed surface grinding machine.

In the above embodiment, the case where the rotary electrode is used as the discharge truing electrode 6 has been described.
This discharge truing electrode is an electrode other than the rotary electrode (for example, a fixed electrode that is not driven to rotate).
It is also possible to adopt.

Further, in the above embodiment, the case where the work w and the rotary electrode 61 are moved so as to intersect the annular grinding surfaces 1a and 1b by giving the work carrier means 5 and the electrode holding means 7 a turning motion is shown. However, the work w and the rotary electrode 61 may be configured to advance and retreat in the radial direction of the grinding wheels 1 and 1.

[0053]

As described in detail above, according to the present invention,
In the surface grinding process, the workpiece is moved along the annular grinding surface while rotating the grinding wheel consisting of a plurality of concentric annular grinding surfaces with different properties. Since the roughing and finishing can be performed without changing the grip of the workpiece, the finishing allowance can be reduced during the grinding of the workpiece, and the work efficiency is improved.

Further, along with this, even when a high-quality surface roughness is required and the cutting speed at the time of finishing is slow, grinding can be performed in a short time.

Moreover, since the truing of the grinding wheel is based on electric discharge truing in which the truing of the grinding wheel does not come into contact with the whetstone, the cutting edge of the grinding wheel is not worn and the sharpness of the abrasive grains is not blunted, so that highly accurate truing can be performed. it can.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a surface grinding apparatus according to the present invention.

FIG. 2 is a plan view of a grinding wheel showing a state of a grinding surface of the surface grinding apparatus.

FIG. 3 is a side sectional view of the grinding wheel.

FIG. 4 is an explanatory view showing a procedure of grinding processing by the surface grinding apparatus according to the present invention.

FIG. 5 is a partial side view showing a state of a grinding process of the surface grinding apparatus.

FIG. 6 is an explanatory diagram illustrating a state of conventional surface grinding.

[Explanation of symbols] 1 grinding wheel 1a, 1b Ring grinding surface 11 grinding wheel 12 grinding wheel 2 Wheel rotation means 3 Cutting depth setting means 4 Work holding means 41 Clamp device 5 Work carrier means 51 swing arm 52 Arm rotating means 6 discharge truing electrodes 61 rotary electrode 62a, 62b Power supply line 63 DC power supply 7 electrode drive means 71 Electrode holder 72 power transmission belt 8 Control means x Grindstone axis (rotary axis)

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3C043 BC02 CC04 CC11 CC13                 3C047 AA26                 3C049 AA04 AA09 AA18 AA19 AB01                       CB03                 3C063 AA02 AB05 BA24 BA33 BB02                       BC02 BC03 FF01 FF30

Claims (7)

[Claims] 1. A plurality of annular grinding surfaces having different properties are concentrically arranged around a rotation axis of a grinding wheel at predetermined intervals, and a work is driven along the annular grinding surface while rotating the grinding wheel. The surface grinding method is characterized in that the workpiece is sequentially ground on each of the plurality of annular grinding surfaces. 2. The surface grinding method according to claim 1, wherein when the workpiece passes through the annular grinding surface, the workpiece is oscillated in the surface direction of the annular grinding surface. 3. The electric discharge truing is performed on the annular ground surface during or before grinding of the workpiece by forming the annular grinding surface by a conductive grindstone in which abrasive grains are bonded by a conductive bonding material. The surface grinding method according to claim 1 or 2, further comprising: 4. A grinding wheel comprising a plurality of annular grinding surfaces concentrically different from each other about a rotation axis at predetermined intervals, a grinding wheel rotating means for rotating the grinding wheel, and the grinding wheel. The cutting amount setting means for adjusting the cutting amount of the workpiece, the work holding means for detachably holding the workpiece, and the work carrier means for moving the work holding means along the surface direction of the annular grinding surface. Surface grinding machine characterized by. 5. The work carrier means comprises a swing arm having a work holding means at its tip, and arm rotating means for giving a swinging motion to the swing arm with the base end of the swing arm as a rotation axis. The surface grinding apparatus according to claim 4, wherein. 6. The annular grinding surface of the grindstone is formed by a conductive grindstone in which abrasive grains are bonded by a conductive bonding material, and a discharge truing electrode for truing the annular grinding surface is provided, The surface grinding apparatus according to claim 4 or 5, wherein the truing electrode is arranged so as to face the annular grinding surface and is movable in the surface direction of the annular grinding surface. 7. The surface grinding machine according to claim 6, wherein the discharge truing electrode is in the form of a rotary electrode.