JPH03234464A - Grinding method and grinder - Google Patents

Abstract

PURPOSE:To prevent a feeding mark by the abrasive grain of a grindstone from appearing on the grinding face of a work by reciprocating a grindstone and/or table in the direction crossed with the tangential direction of the same grindstone. CONSTITUTION:A driving cylinder and a motor 7 for driving a saddle are driven in the state of a grindstone G and table 10 being brought into contact with each other, the table 10 is reciprocated in the right and left direction on a rail 9 and the surface of a work W is subjected to grinding by the grindstone G by moving the saddle 3 forward by the feeding length B at the reversal time of this table 10. At this grinding time the saddle 3 is reciprocated in the fore and aft direction which is the direction orthogonal with the tangential direction of the grindstone G, and the amplitude A thereof is set slightly larger than the diameter of the abrasive grain of the grindstone G. Consequently, even in the case of the surface of the work W being scratched by the abrasive grain of this grinding grindstone G, it does not appear as the feeding mark linearly extending continuously and is inconspicuous. So, the surface of the work W can be finished smoothly and beautifully.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention brings a rotationally driven grinding wheel and a work fixed on a table into contact with each other, and connects the grinding wheel and the table to the tangent line of the grinding wheel. The present invention relates to a grinding method and a grinding machine for grinding the surface of a workpiece by relative movement in the direction.

[Prior Art] Conventionally, as shown in FIG. 8, this type of grinding method involves bringing a rotationally driven grinding wheel G and a workpiece W fixed on a table (not shown) into contact with each other. In this state, the table and workpiece W are reciprocated in the tangential direction of the grinding wheel G as shown by the arrow in the figure, and when reversed, are moved forward (diagonally to the upper right in the figure) by a predetermined feed length. There is a traverse grinding method. This method is suitable for grinding a workpiece W having a grinding surface with a width larger than the width of the grinding wheel G.

Further, as shown in FIG. 9, using a grinding wheel G having a width larger than the width of the grinding surface of the workpiece W, and with the two in contact with each other, the workpiece W is moved to the grinding wheel G as shown by the arrow in the figure. A plunge grinding method in which the grinding material is moved in the tangential direction has also been adopted.

[Problems to be Solved by the Invention] However, in both the traverse grinding method and the plunge grinding method, since grinding is performed by moving the table and workpiece W in the tangential direction of the grinding wheel G, When the grinding surface of the work W is scratched by the abrasive grains constituting the grinding wheel G, the scratches appear in a continuous line and may remain as feed marks.

Therefore, it may not be possible to obtain a smooth and clean ground surface.

An object of the present invention is to provide a grinding method and a grinding machine that can reliably finish the grinding surface of the workpiece neatly without causing feed marks due to the abrasive grains of the grindstone on the grinding surface of the workpiece. It is in.

[Means for Solving the Problem] Therefore, in order to achieve the above object, the first invention brings a rotationally driven grinding wheel into contact with a workpiece fixed on a table, and the grinding wheel and the table are brought into contact with each other. A grinding method in which the surface of a workpiece is ground by relatively moving the grinding wheel in the tangential direction of the grinding wheel, the grinding wheel and/or the table being reciprocated in a direction intersecting the tangential direction of the grinding wheel. The gist is the grinding method.

In addition to the first invention, the second invention also includes a grinding wheel and/or
Alternatively, the gist is a grinding method in which the amplitude of the reciprocating motion of the table is set slightly larger than the diameter of the abrasive grains of the grinding wheel.

Furthermore, a third invention provides a grinding wheel rotationally driven by a grinding wheel drive motor, a workpiece fixed on a table and brought into contact with the grinding wheel, and the grinding wheel and table relative to each other in a tangential direction of the grinding wheel. The gist of the present invention is a grinding machine equipped with a driving means for reciprocating the grinding wheel and/or table in a direction intersecting a tangential direction of the grinding wheel.

In a fourth aspect of the present invention, in addition to the third aspect, the driving means includes a pair of protrusions provided at the lower part of the table, protruding in opposite directions and extending in the tangential direction of the grinding wheel.
a pair of rails disposed near each of the protrusions and provided with a guide groove into which the protrusions are slidably inserted; and an oil pocket formed in each of the protrusions from between the protrusions and the guide grooves. The gist is a grinding machine consisting of an oil pump that supplies pressure oil and controls the pressure of the pressure oil.

[Function] In the first invention, with the grinding wheel and the table in contact with each other, the grinding wheel is relatively moved in the tangential direction.
When the grinder grinds, the surface of the workpiece is ground. At this time,
- Since the grinding wheel and/or the table are reciprocated in a direction that intersects the tangential direction of the grinding wheel, even if the surface of the work is scratched by the abrasive grains of the grinding wheel, it will continue to extend linearly. It does not appear as a feed mark.

In particular, in the second invention, since the amplitude of the reciprocating motion of the grinding wheel and/or the table is set to be slightly larger than the diameter of the abrasive grains of the grinding wheel, the appearance of the feed mark is reliably prevented.

Furthermore, in the third invention, when the grinding wheel rotationally driven by the grinding wheel drive motor and the workpiece fixed on the table are in contact with each other, and the moving means relatively moves the grinding wheel in the tangential direction of the grinding wheel. , the workpiece surface is ground. At this time, the grinding wheel and/or the table are reciprocated by the driving means in a direction that intersects the tangential direction of the grinding wheel, so even if the grinding surface of the workpiece is scratched by the abrasive grains, the grinding wheel and/or table will continue to move. It does not appear as a linear feed mark and is not noticeable.

In the fourth invention, since the driving means is constituted by the pair of protrusions, the pair of rails, and the oil pump, the pressure oil from the oil pump is supplied between the protrusions and the guide groove through the oil pocket. Therefore, static pressure due to pressure oil acts between each protrusion and the guide groove, and the table slides with the protrusion separated from the inner surface of the guide groove by the thickness of the oil film.

At this time, by controlling the pressure of the pressure oil to the oil pocket in one protrusion and the pressure of pressure oil to the oil pocket in the other protrusion, the table is moved in a direction that intersects the tangential direction of the grinding wheel. It is possible to move it back and forth.

[First Embodiment] A first embodiment embodying the grinding method and grinding machine of the present invention will be described below with reference to FIGS. 1 and 2.

First, a grinding machine used in the grinding method of this embodiment will be explained. As shown in FIG. 1, a saddle 3 is supported on the upper surface of a frame 1 of the grinding machine so as to be able to reciprocate in the front and back direction by a guide rail 2 that extends back and forth (left and right in the figure). A connecting portion 4 is protruded from the lower surface of the saddle 3, and a front and rear feed screw 5 supported by the frame l is connected to the connecting portion 4.
is screwed into. A saddle drive motor 7 is connected to the front end of the longitudinal feed screw 5 via a gear mechanism 6.

The connecting portion 4, the front-rear feed screw 5, the gear mechanism 6, and the saddle drive motor 7 constitute a moving means, and when the saddle drive motor 7 is rotated forward and backward, The saddle 3 is driven back and forth.

A pair of front and rear rails 9 extending in the left-right direction (direction perpendicular to the paper) is provided on the upper surface of the saddle 3, and a table 10 is supported on both rails 9 so as to be able to reciprocate. The upper surface of the table 10 serves as a mounting surface 10a for holding the workpiece W by magnetic force or the like. Further, the lower part of the table 10 is connected to a piston rod 11 that protrudes and retracts from a drive cylinder (not shown), and the table 10 is reciprocated in the left-right direction by the operation of the piston rod 11.

A column 12 is erected at the rear of the frame 1, and a vertically extending vertical feed screw 13 is supported on the upper surface of the column 12 so as to be movable in the vertical direction by the screw action of the vertical feed screw 13. A grindstone head 14 is fixed to the lower end of the vertical feed screw 13, and a grinding wheel G is rotatably attached to the front end of the grindstone head 14 via an arm portion 15 so as to be positioned above the table 10. ing. Further, a grindstone driving motor 16 for rotationally driving the grinding wheel G is attached to the rear part of the grindstone head 14.

A head drive motor 17 is installed at the top of the column 12, and as the head drive motor 17 rotates forward and backward, the grindstone head 1 is moved through the vertical feed screw 13.
4 is designed to move up and down.

Incidentally, an NC control device 8 is connected to the saddle drive motor 7 and the drive cylinder.

This NC control device 8 stores in advance a control program for operating the saddle drive motor 7 and the drive cylinder. The forward and reverse rotation of the saddle drive motor 7 and the protrusion movement of the piston rod 11 in the drive cylinder are controlled based on this rotation program.

FIG. 2 shows a movement trajectory of the workpiece W, and control is performed by the NC control device 8 so that the workpiece W moves on this trajectory. That is, when the table 10 reciprocates in the left-right direction due to the protruding action of the piston rod 11, the saddle 3 moves with an amplitude A slightly larger than the diameter of the abrasive grains of the grinding wheel G due to the forward and reverse rotation of the saddle drive motor 7. It reciprocates in the front-back direction, which is a direction perpendicular to the tangential direction of the grinding wheel G. Further, when the moving direction of the table 10 is reversed, the table 10 moves forward by a predetermined feed length B.

Here, the reason why the amplitude A of the saddle 3 is set slightly larger than the diameter of the abrasive grain is because if the same amplitude A is smaller than the diameter of the abrasive grain, feed marks similar to those in the prior art may still appear. This is because if the amplitude A is made extremely larger than the diameter of the abrasive grain, the grinding efficiency will decrease. This amplitude A needs to be determined according to the grain size of the abrasive grains of the grinding wheel G.
In practice, it is preferably in the range of 0.5 to 1 mm. In this embodiment, the amplitude A of this saddle 3 is approximately 0.5 mm.
is set to .

Next, a method of grinding using the grinding machine will be explained. First, the workpiece W is placed on the mounting surface 10a of the table 10.
is fixed and the head drive motor 17 is operated to adjust the vertical height of the grinding wheel G so that it comes into contact with the workpiece W. Thereafter, the grinding wheel drive motor 16 is operated to rotate the grinding wheel G. drive. Subsequently, when the drive cylinder and saddle drive motor 7 are operated based on the machine program stored in advance in the NC control device 8, the table 10 reciprocates in the left and right direction on the rail 9, and the table 10 is reversed. When saddle 3 is sent forward for a length B
As a result, the surface of the workpiece W is ground by the grinding wheel G.

During this grinding, the saddle 3 is reciprocated in the front-rear direction, which is a direction perpendicular to the tangential direction of the grinding wheel G, and the amplitude A is set to be slightly larger than the diameter of the abrasive grains of the grinding wheel G. Even if the surface of the workpiece W is scratched by the abrasive grains, it will not appear as a continuous linear feed mark and will not be noticeable. Therefore, according to this embodiment, unlike the prior art, the surface of the workpiece W can be finished smoothly and neatly.

[Second Embodiment] Next, a second embodiment of the present invention will be described based on FIG.
A pair of front and rear (left and right in FIG. 3) rails 9 extending in the direction of the rails 9 are arranged at a predetermined interval, and guide grooves 18 extending in the longitudinal direction are formed in opposing surfaces of both rails 9. A pair of protrusions 19 extending in the left-right direction are provided on both front and rear sides of the inverted table 10 on which the workpiece W is placed and fixed, and each protrusion 19 is slidably inserted into the guide groove 18 of each rail 9. It is fitted.

Each protrusion 19 has a plurality of oil pockets 20.2.
1 are bored at predetermined intervals in the left-right direction, and pressure oil is supplied to these oil pockets 20 and 21 from an oil pump (not shown). Therefore, each protrusion 19
Static pressure due to the pressure oil acts between the guide groove 18 and the guide groove 18, and the table IO is slid with the protrusion 19 spaced apart from the inner surface of the guide groove 18 by the thickness of the oil film.

In this embodiment, the rail 9, the protrusion 19 and the oil pump constitute a driving means, and the pressure of the pressure oil to the oil pocket 20 on the protrusion 19 on the front side and the oil pocket 21 on the protrusion 19 on the rear side are By controlling the pressure of the pressurized oil to It is designed to be reciprocated in the front-rear direction with an amplitude of about 20 μm. The configuration other than the above is the same as the first embodiment.

Therefore, in this embodiment, as in the first embodiment,
The table IO can be reciprocated back and forth, and the surface of the workpiece W can be ground smoothly and neatly. Further, in the first embodiment, the saddle drive motor 7
Both forward and reverse rotations of the table 10 are used to control both the feed when reversing the table 10 and the reciprocating motion, but in this embodiment, these are driven separately, making it easier to control the needles.

[Third Example] Next, a third embodiment of the present invention will be described with reference to FIG.

This embodiment differs greatly from the first embodiment in that the saddle 3 is not reciprocated back and forth, but the grinding wheel G is reciprocated back and forth (left and right in FIG. 4). That is, a bearing sleeve 22 is fitted into the arm portion 15 of the grinding machine, and a main shaft 23 is rotatably inserted into a holding hole 22a extending through the bearing sleeve 22.

Covers 24 and 25 are attached to the front and rear of the bearing sleeve 22, a grinding wheel G is attached to the front end of the main shaft 23 protruding from the front cover 24, and the rear end of the main shaft 23 protruding from the rear cover 25. is connected to the grindstone drive motor 16 via a coupling 26.

The inner peripheral surface of the holding hole 22a and the front and rear force bars 24°25
Oil pockets 27 and 28 are formed on the inner surfaces of the cylinders, respectively, and pressure oil is supplied to these oil pockets 27 and 28 from an oil pump (not shown). By controlling the pressure of the pressure oil to the oil pockets 27 and 28, the main shaft 23 and the grinding wheel G are
The grinding wheel G can be reciprocated in the front-back direction, which is a direction orthogonal to the tangential direction of the grinding wheel G.

Therefore, this embodiment also provides the same functions and effects as the second embodiment.

It should be noted that the present invention is not limited to the configuration of the embodiments described above, and may be modified as desired without departing from the spirit of the invention, for example, as described below.

(1) As shown in FIG. 5, when grinding the bottom surface 29a of the groove 29 of the workpiece W, the grinding wheel G is in contact with the bottom surface 29a, and the grinding wheel G is perpendicular to the tangential direction of the grinding wheel G. It reciprocates in the left and right direction. Further, when grinding the side surface 29b of the groove 29, the grinding wheel G is reciprocated in the vertical direction while being in contact with the side surface 29b.

Furthermore, as shown in FIG.
When grinding the inclined surface 30a of 0, the grinding wheel G is reciprocated obliquely as shown by the arrow in a state in which it is in contact with the inclined surface 30a. Even in this case, the same operation and effect as in the third embodiment can be achieved.

Moreover, instead of reciprocating the grinding wheel G in FIGS. 5 and 6, the workpiece W may be reciprocated, or both may be reciprocated. In any of the above cases, it is desirable to set the amplitude A of the reciprocating motion to be slightly larger than the diameter of the abrasive grain in order to prevent the occurrence of feed marks.

(2) In the first embodiment, the workpiece W and/or the grinding wheel G may be reciprocated with an amplitude A while reciprocating in a zigzag manner as shown in FIG.

(3) In the first embodiment, the saddle 3 may be reciprocated back and forth by using a crank mechanism in place of the front and back feed screw 5.

[Effects of the Invention] As detailed above, according to the grinding method and grinding machine of the first and third inventions, when grinding a workpiece, a feed mark due to the abrasive grains of the grindstone appears on the ground surface of the workpiece. You can prevent it from happening.

Moreover, according to the second invention, it is possible to reliably prevent the appearance of feed marks on the workpiece, and it is possible to finish the grinding surface of the workpiece more neatly.

Furthermore, according to the fourth invention, the feeding and reciprocating motion of the grinding wheel and/or table can be driven separately, making it easier to control the reciprocating motion.

[Brief explanation of drawings]

1 and 2 show a first embodiment embodying the present invention, FIG. 1 is a partially cutaway side view of the grinding machine, FIG. 2 is a schematic perspective view showing the trajectory of the workpiece, and FIG. 3 is a partial side view showing a grinding machine according to a second embodiment of the present invention, and FIG. 4 is a partial sectional view showing a drive mechanism for a grinding wheel according to a third embodiment of the present invention.
5 and 6 are partially enlarged side views showing the state of contact between the workpiece and the grinding wheel, FIG. 7 is a diagram showing the separate locus of movement of the workpiece during grinding, FIGS. 8 and 9 show the prior art, and FIG. The figure is a schematic perspective view of a workpiece and a grinding wheel in a traverse grinding method, and FIG. 9 is a schematic perspective view of a workpiece and a grinding wheel in a plunge processing method. 4... Connecting portion forming part of the moving means, 5... Front and rear feed screw forming part of the moving means, 6... Gear mechanism forming part of the moving means, 7... Saddle drive motor forming part of the moving means, 9... Rail forming part of the driving means, 10... Table, 16...
Grindstone drive motor, 18...Guide groove, 19...Protrusion constituting a part of drive means, 20.21...Oil pocket, G...Grinding whetstone, W...Work.

Claims (1)

[Claims] 1. A rotationally driven grinding wheel (G) and a table (10
), and the grinding wheel (G) and the table (10) are brought into contact with the workpiece (W) fixed on the grinding wheel (G).
By relatively moving the workpiece (W) in the tangential direction of
A grinding method in which a surface is ground, wherein the grinding wheel (G) and/or the table (10) are reciprocated in a direction intersecting a tangential direction of the grinding wheel (G). 2. The grinding method according to claim 1, wherein the amplitude of the reciprocating motion of the grinding wheel (G) and/or the table (10) is set to be slightly larger than the diameter of the abrasive grains of the grinding wheel (G). 3. A grinding wheel (G) rotationally driven by a grinding wheel drive motor (16), a workpiece (W) fixed on a table (10) and in contact with the grinding wheel (G), and the grinding wheel ( G) and table (10) with a grinding wheel (
In a grinding machine equipped with moving means (4 to 7) for relatively moving the grinding wheel (G) and/or the table (10) in the tangential direction of the grinding wheel (G), A grinding machine equipped with a drive means for reciprocating in the direction of 4. The driving means includes: a pair of protrusions (19) provided at the bottom of the table (10), protruding in opposite directions and extending in the tangential direction of the grinding wheel (G); and each of the protrusions (19). It is arranged in a nearby position, and the same protrusion (1
A pair of rails (9) each having a guide groove (18) into which the oil pocket (2) is slidably inserted;
4. The grinding machine according to claim 3, further comprising an oil pump that supplies pressurized oil from the protrusions (19) and the guide grooves (18), and controls the pressure of the pressurized oil.