JPS641271B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polishing device configured to efficiently and automatically polish a curved surface to be processed.

Traditionally, the curved surface to be machined can be polished by copy polishing using a grindstone or by using a rotating elastic tool, but when using a grindstone, there is a limit to the profiling polishing range, and when using a rotating elastic tool This method has the disadvantage that the amount of polishing varies depending on the position of the curved surface.

FIGS. 1 and 2 show how a curved surface is polished by tracing it with a reciprocating grindstone. As shown in the figure, a grindstone 3 is attached to the tip of a polishing head 2 via a universal joint 4.
Workpiece 1 is vibrated at high speed in the direction of the arrow.
is sent in the direction of the arrow, and the grindstone 3 polishes the curved surface 5 which is the surface to be machined. However, surface 5
There is no particular problem when the whetstone 3 is copying and polishing the bottom curved surface part 6 of the whole, but when the whetstone 3 is copying and polishing the side curved part 7, there is a limit to the inclination angle of the universal joint 4, so the upward It becomes difficult to efficiently polish the extended side curved surface portion 7. For this reason, when copying and polishing the side curved surface part 7, it is proposed to place a tilting table 8 on the table 9 as shown in FIG. 2 and copying and polishing the entire workpiece 1 in an inclined state. However, this method has disadvantages in that it is difficult to automate copy polishing, and the inclination state of the tilting table 8 must be changed depending on the copy polishing position, which is cumbersome.

On the other hand, when polishing is performed by rotating the elastic tool 10 while supplying abrasive liquid as shown in FIG. 3, there is a drawback that the polishing amount varies depending on the scanning polishing position. That is, at position A, which is the bottom curved surface portion 6, not only is it difficult for the abrasive liquid to intervene between the bottom surface of the elastic tool 10 and the curved surface 5, but also the average circumference of the bottom surface is The speed decreases,
The amount of polishing is small.

In addition, at position B, the corner of the elastic tool 10 has a curved surface 5.
Since the contact area of the elastic tool 10 with the curved surface 5 is small due to the point contact with the curved surface 5, not only is the polishing pressure high, but also the amount of abrasive liquid involved is large, so the amount of wear is the largest, but at the C position Since the side surface of the elastic tool 10 comes into contact with the curved surface by a considerable amount, the contact area becomes larger, and the amount of polishing becomes smaller. Figure 4 shows these circumstances. As is clear from this figure, in copy polishing using the elastic tool 10, there are variations in the polishing amount depending on the copy polishing position, and there is a drawback that the curved surface 5 cannot be uniformly polished.

The object of the present invention is to be able to uniformly and automatically polish all curved surfaces without variation in polishing amount, whether it is copy polishing using a grindstone or a rotating elastic tool. Our purpose is to provide automatic polishing equipment.

For this purpose, the present invention uses a conventional oscillating polishing head to trace and polish a curved surface while oscillating a polishing tool such as a grindstone or an elastic tool in the X direction or Y direction with a constant amplitude. During copy polishing, the height of the curved surface is detected by a detector attached to the oscillating polishing head, and the oscillating tool of the grindstone or rotating elastic tool is detected by the oscillating direction detector. It is characterized by a configuration in which the rotation of the polishing head itself or the workpiece is controlled based on these detection signals so that the relative angle between the axial direction of the polishing tool and the curved surface is always within a certain range. shall be.

The present invention will be explained below with reference to FIGS. 5 to 11.

First, referring to FIGS. 5 and 6, these figures show the mechanical structure of an example of an automatic polishing device according to the present invention. As shown in the figure, this device consists of a mechanism centered around a swing polishing head 14 and a workpiece 1.
It is roughly divided into a mechanism that rotationally drives 9. Of these, the entire oscillating polishing head 14 is attached to the workpiece 1.
By following the curved surface of 9, a predetermined polishing load can be achieved.It is attached to and supported by the hydraulic cylinder 27 so as to be able to move up and down, and at the bottom thereof, as a polishing tool, is driven by a driving means as shown in FIGS. 1 to 3. An elastic tool 13 (or grindstone) that is rotated or reciprocated is attached. and hydraulic cylinder 27
is activated to lower the swinging polishing head 14, and when the tip of the polishing tool 13 comes into contact with the curved surface of the workpiece 19, the polishing tool 13 receives a reaction force and is supported to move up and down as shown in FIG. Then, the detection shaft 29 to which a spring load is applied downward from the upper end is pushed upward, and the displacement of the detection shaft 29 is detected by the magnetic sensor 15. The hydraulic cylinder 27 is controlled so that the displacement of the detection axis 29 detected by the magnetic sensor 15 shows a certain predetermined value, and as the table 26 moves, the polishing tool 13 follows the curved surface of the workpiece 19. It is then polished under a constant load. This elastic tool 13 is oscillated in the direction of the arrow, and this oscillation is driven by oscillating motors 11 and 12 attached to an oscillating polishing head 14. For example, when the swing motor 11 is rotated, the plate 28 to which the docks 24 and 25 are attached is reciprocated and linearly driven in the horizontal direction, and the rotating elastic tool 13 is moved through the plate by a predetermined width in the horizontal X direction. The other swing motor 12 is a rotary elastic tool 13.
This is to linearly reciprocate in the horizontal Y direction with a predetermined width. However, according to the present invention, it is necessary to detect the swing direction and the height state of the curved surface. In this example, the rocking direction is detected by limit switches 16 and 17. dock 2
The limit switch 16,
17 is controlled to open and close, and when the limit switches 16 and 17 are each closed, it is detected that the rotary elastic tool 13 is also at the swing end position in the corresponding direction. Further, the height state is detected by the magnetic sensor 15 and the detection shaft 29 as a displacement detector in this example. The magnetic sensor 15 detects relative height displacement with respect to the detection shaft 29.

On the other hand, the rotational drive mechanism for the workpiece 19 rotates the rotary table 18 on which the workpiece 19 is placed onto the rotary shaft 2.
3. Direct current motor 20 via worm reducer 21
It is constructed so that forward and reverse rotation can be controlled by.
The support 22 is for rotatably supporting the rotating shaft 23. Control over the DC motor 20 will be described later.

Now, the operation of the automatic polishing device constructed as described above will be explained as follows. That is, in order to polish the curved surface 30 of the workpiece 19 with this device, the table 26 is moved in the direction of the arrow, while the swing motor 11 is rotated to convert the eccentric rotational motion into linear reciprocating motion, thereby improving rotational elasticity. body tool 13
This is done while the is being swung in the direction of the arrow. The swinging conditions of the rotating elastic body tool 13 are, for example, 20~
40 cycles/min, amplitude 5 mm (both amplitudes).
In this way, the oscillating polishing head 14, that is, the elastic tool 1, moves at a faster speed than the response speed of the hydraulic cylinder 27, which operates based on the output signal of the magnetic sensor 15.
3 is oscillated, a signal indicating the height difference of the workpiece depending on the oscillation speed is obtained from the magnetic sensor 15 as shown in FIG. 7A. For example, when the elastic tool 13 is polishing the bottom curved surface part 31 or its vicinity among the curved surfaces 30 to be machined, the magnetic sensor 1
The level of the output waveform a from 5 becomes small. However, after the workpiece 26 is further moved by the feeding of the table 26 and the detection shaft 29 is raised to become the output waveform b, the right curved surface portion 3 shown in FIG.
2, the output waveform of the magnetic sensor 15 becomes like the output waveform c. Conversely, when the rotary elastic tool 13 is polishing the left curved surface portion 33 on the opposite side in FIG. 6, the machin sensor 15 outputs an output as shown in the output waveform d. In this case, the level of the output waveform indicates the polishing position height of the curved surface 30, so if the level of the output waveform exceeds a certain level, the workpiece 19 is rotated and the output waveform is adjusted. It is necessary to polish so that the size of the level falls within a certain range. At that time, is the elastic tool 13 located on the right side of the curved surface 30 of the workpiece 19?
It is unclear whether it is located on the left side. Therefore, when the elastic tool 13 is located on the right curved surface portion 32 in FIG. A signal c is obtained.
That is, when the elastic tool 13 swings to the right end, the curved surface becomes high, so the output of the magnetic sensor 15 becomes +, and when the elastic tool 13 swings to the left end, the curved surface becomes low, so the output of the magnet sensor 15 becomes -. Become. On the other hand, when the elastic tool 13 is located on the left curved surface portion 33, as the swinging polishing head 14, that is, the elastic tool 13 swings, the magnetic sensor 15 outputs a signal d as shown in FIG. 7A. is obtained.
On the other hand, the oscillating polishing head 14, that is, the elastic tool 13
When the polishing head 14, that is, the elastic tool 13, swings to the left end, the switch 16 closes and the white output signal shown in FIG. 7B is obtained. , an output signal indicated by diagonal lines as shown in FIG. 7B is obtained. As a result, for example, when a signal is detected from the switch 16, if a + signal exceeding E _A is detected from the magnetic sensor 15, the elastic tool 13 moves to the right side curved portion 32, that is, the right side is higher and the left side is lower. It turns out that it is a curved surface that is curved, and it turns out that it is necessary to rotate the workpiece clockwise. For example, when a signal is detected from the switch 17, if a + signal exceeding E _A is detected from the magnet sensor 15, the elastic tool 13
It can be seen that this is the left side curved surface portion 33, that is, a curved surface that is higher on the left side and lower on the right side, and that it is necessary to rotate the workpiece counterclockwise. Therefore, the direction of rotation of the workpiece 19 is controlled by the outputs of the limit switches 16 and 17. Figure 7B
As shown in the figure, each time the rotary elastic tool 13 reaches the swing end position, outputs are obtained alternately from the limit switches 16 and 17 (the output of the limit switch 17 is indicated by diagonal lines), so this is used to control the rotation direction. It is. FIG. 8 shows a block diagram of a forward/reverse rotation control circuit for the DC motor 20 that rotationally drives the workpiece 19. As shown in the figure, the level comparison circuit 35 compares the output 34 of the magnetic sensor 15 and the reference voltage E _A , and as a result of the comparison, the reference voltage
If it is larger than E _A , limit switch 16,
The tilt direction determination circuit 36 based on the output 38 of 17
The direction of inclination is determined by the determination output, and the DC motor 20 is rotated in a predetermined direction via the control circuit 37, and the output of the magnetic sensor 15 is set to the reference voltage E _A
It is something that is controlled so that it exists within the body. Reference voltage
When the output of the magnetic sensor 15 falls within E _A , the rotation of the DC motor 20 is stopped, and the curved surface 30 of the workpiece 19 is polished in this state. Therefore, for example, when the elastic tool 13 polishes the right curved surface portion 32, the workpiece 19 is placed so that the bottom surface of the elastic tool 13 is almost parallel to the polishing surface of the workpiece 19, as shown in FIG. In other words, they are tilted so that they are in surface contact.

In this example, as explained above, the magnetic sensor 15
The output of DC motor 2 should be within the reference voltage E _A.
0, but such control is preferable when using a grindstone with a universal joint as a polishing tool, but when using a rotary elastic body tool 13, since the amount of polishing is small, it is not appropriate control. I can't say that. Therefore, control as shown in FIG. 10 is generally performed on rotating elastic tools. That is, the output of the magnetic sensor 15 is the reference voltage E _A , E _B (a value that is a certain voltage higher than E _A ).
The DC motor 20 is controlled so that the curved surface of the workpiece is tilted to a certain extent, the contact area is reduced and the polishing pressure per unit area is increased, and the elastic tool 13 Curved surface 3
I made it possible to polish by increasing the polishing amount of 0. For example, when polishing the right curved surface portion 32 with the elastic tool 13 as shown in FIG. The output of the magnetic sensor 15 is made to exist between the reference voltages E _A and E _B by rotating it counterclockwise and clockwise. Elastic tool 1 as long as it remains between the reference voltages E _A and E _B
3, the curved surface 30 is polished with a large amount of polishing. Further, in this embodiment, the workpiece 19 is rotated by the rotary shaft 23 via the rotary table 18, but as shown in FIG. 12, for example, another rotary table 40 is mounted on the rotary table 18. If the table 40 is rotated by another rotating shaft 41 whose axial direction is perpendicular to the rotating shaft 23, similar control can be achieved in the Y direction as well. That is, the DC motor 42, the worm reduction crosspiece 43, the support 44, etc. are naturally placed on the rotary table 18. In this case, just as limit switches 16 and 17 are provided for the swing motor 11, a pair of similar limit switches are provided for the swing motor 12 as well. In short, in the case of a cylindrical concave surface, it is sufficient to rotate the table 18 in one axis direction, and in the case of a general curved surface, when the table 18 is rotated in one axis direction and machining is completed in one axis direction, the It is clear that the workpiece 19 can also be manually rotated through 90 degrees and placed on the table 18. Furthermore, in the case of a curved surface close to a spherical surface, it is obvious that the workpiece 19 may be constructed so as to be rotatable on the table 18. Furthermore, in this example, the workpiece is rotated with the swinging head fixed, but since the point is relative, the swinging head is rotated with the workpiece fixed. It is clear that the objective will be achieved.

As explained above, the present invention detects the height state of the curved surface and the rocking direction of the polishing tool while the polishing tool that is driven to swing is copying and polishing the curved surface to be machined. Based on these detections, the rotation of the workpiece or the swinging head is automatically controlled so that the polishing condition of the polishing tool on the curved surface is always optimal. Therefore, according to the present invention, in the case of copy polishing using a grindstone, it is possible to copy and polish the entire curved surface,
Furthermore, in the case of copy polishing using a rotating elastic tool, it is possible to always keep the contact area small and polish the entire curved surface with a large polishing amount.

[Brief explanation of drawings]

Figures 1 to 4 are explanatory diagrams of conventional copy polishing using a grindstone or a rotary elastic tool, and Figures 5 and 6 are perspective views showing the mechanical configuration of an example of the automatic polishing device according to the present invention. Figures and sectional views, Figure 7A,
B is a diagram showing the relationship between the output of a magnetic sensor as a displacement detector and the output of a limit switch, and FIG.
FIG. 5 is a block diagram of the forward/reverse rotation control circuit of the DC motor; FIG. 9 is a state diagram of the workpiece being polished in an inclined state according to the present invention; and FIG.
11 and 11 are explanatory diagrams for polishing a curved surface by reducing the contact area with a rotary elastic tool, and FIG.
The figure is a perspective view showing another embodiment of the automatic polishing device of the present invention. 11, 12... Swinging motor, 13... Elastic tool, 14... Swinging polishing head, 15... Magne sensor (displacement detector), 16, 17... Limit switch, 18... Rotating table, 20... ...DC motor, 23...Rotating axis, 27...Hydraulic cylinder, 29...Detection axis, 35...Level comparison circuit,
36...Inclination direction determination circuit, 37... Control circuit.

Claims (1)

[Claims] 1. A drive means for supporting and rotating or reciprocating a polishing tool such as a grindstone or an elastic tool, a detection shaft supported to move up and down in conjunction with the movement of the polishing tool, and a load applied to the detection shaft. A rocking device configured to reciprocate a polishing head having a load applying means and a displacement detector for detecting vertical displacement of the detection shaft in a horizontal direction with a predetermined width by a rocking drive means. The polishing head is configured to be moved up and down with respect to the main body by a hydraulic cylinder, etc., and the table on which the workpiece is placed is moved in the horizontal direction, and the detection axis is detected by the displacement detector at a constant displacement. In an automatic profile polishing device that polishes the polishing tool by controlling the hydraulic cylinder etc. so that a certain profile load is detected so that the polishing tool follows the curved surface of the workpiece, the left and right positions of the polishing head relative to the oscillating polishing head are used. a polishing head motion detector for detecting position;
When a signal of the left or right position of the polishing head detected from the polishing head movement detector is detected, depending on whether the signal detected from the displacement detector indicates a signal upward or downward of the detection axis. an inclination determination circuit that determines to which side, left or right, the curved surface of the workpiece is inclined; a rotational drive mechanism that changes the inclination of one of the swing polishing head and the workpiece in the left-right direction; The direction of inclination is determined based on the signal obtained from the inclination discrimination circuit, and the rotation is performed so that the signal indicating the maximum upward displacement of the detection axis detected by the displacement detector satisfies a preset reference value. An automatic polishing device characterized by comprising a control circuit for controlling a drive mechanism.