JPH0656297B2 - Optical position adjustment method for machine tool structures - Google Patents

Description

The present invention relates to an optical position adjusting method for a machine tool structure, which is useful for adjusting the axial center position of the machine tool structure.

<Prior Art> In a machine tool, in order to align the axes of both of a pair of structures, at least one of which rotates, to align them in a straight line, conventionally, referring to FIGS. The method shown was used.

FIG. 5 shows a position adjusting method using a test indicator. As shown in the figure, the end surface of the rotating body 2 supported by the bearing 1 and the end surface of the rotating body 4 supported by the bearing 3 face each other. To adjust the position so that the axis l ₁ of the rotating body ₂ and the axis l ₂ of the rotating body 4 are aligned on a straight line,
And the test bar 7 are coaxially provided on the rotating body 4, and the probe 6a of the test indicator 6 is brought into contact with the peripheral surface of the test bar 7. When the rotating body 2 and the test indicator 6 are rotated in this state,
The amount of deflection of the pointer of the test indicator 6 at this time indicates the amount of axis deviation. Therefore, if the position of the rotating body 2 or the rotating body 4 is shifted so that the amount of deflection of the pointer becomes zero, they become coaxial. Also,
By moving the rotating body 2 or the rotating body 4 so that the amount of deflection of the pointer of the indicator 6 when the rotating body 2 is reciprocated in the direction along the axis l ₁ (direction A) is zero,
The axes l ₁ and l ₂ can be parallel. In this way, the positions of the axes l ₁ and l ₂ can be adjusted so that they are aligned. According to this method, by increasing the accuracy of the test indicator 6 and the test bar 7, highly accurate position adjustment can be quantitatively performed.

FIG. 6 shows a visual position adjustment method using a test bar. In this method, the test bar 8 having a sharp conical tip is provided coaxially with the rotating body 2, and the test bar 9 having the same shape is provided coaxially with the rotating body 4. Then, the tip ends of the test bars 8 and 9 are observed with a microscope, and the position of the rotating body 2 or the rotating body 4 is adjusted so that the both ends coincide with each other. In this method, highly accurate position adjustment can be performed by increasing the magnification of the microscope.

FIG. 7 shows a position adjusting method using a centering microscope. In this method, the centering microscope 10 is provided coaxially with the rotating body 2 and the test bar 11 is provided coaxially with the rotating body 4.
In the field of view of the centering microscope 10, as shown in FIG.
Template 12 cross-shaped template intersection 1
2'is visible, and the position of the rotating body 2 or the rotating body 4 is adjusted so that the image 11 'at the tip of the test bar 11 overlaps with the intersection point position of the template intersection line 12'. With this method, highly accurate position adjustment can be performed by increasing the magnification of the centering microscope.

<Problems to be Solved by the Invention> By the way, the above-mentioned prior art has the following problems.

The conventional method shown in FIG. 5 is a machine tool to which the test indicator 6 cannot be attached, that is, the rotating bodies 2, 4
It is not applicable to machine tools where the space between the two is very narrow or there is no space for rotating the test indicator 6.

In the conventional method shown in FIG. 6, the magnification of the microscope must be increased in order to adjust the position with high accuracy.
The apex of 9 must be approached, and there is a risk of collision between the microscope and the test bars 8 and 9. In addition, a space that can be observed with a microscope must be secured between the rotating bodies 2 and 4.

In the conventional technique shown in FIG. 7, similar to the conventional technique shown in FIG. 6, there is a risk of collision between the centering microscope and the test bar 11, and there is also a space problem.

The present invention has been made in view of the above-described conventional art, and an object of the present invention is to provide an optical position adjusting method for a machine tool structure capable of performing position adjustment safely and with high accuracy even if a space between the structures of the machine tool is narrow.

<Means for Solving Problems> In the present invention for achieving the above object, an optical fiber is installed at each of axial positions of a pair of structures of a machine tool so that an optical loss passing through both optical fibers is minimized. The point is to move at least one of the structures.

<Examples> Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. As shown in the figure, in the machine tool, a rotating body 22 supported by bearings 21,
Both end faces of the rotating body 24 supported by the bearing 23 are arranged so as to face each other.

The tip end of the transmitting optical fiber 25 is coaxially fixed to the sleeve 26, and the axial misalignment of both is 0.5 μm or less and the axial misalignment is 0.3 ° or less. Such high-precision processing can be realized very easily with today's optical connector manufacturing technology. Further, the end faces of the transmitting optical fiber 25 and the sleeve 26 are polished together and processed so that the end faces are orthogonal to the axis. Further sleeve 26
Is machined so that the outer periphery thereof has a highly accurate cylindrical shape. The sleeve 26 is used for the hole 22 of the rotary member 22.
It is fitted in a. Of course, the hole 22a is processed with high precision. Therefore, the tip of the transmitting optical fiber 25 is accurately positioned at the axial center position of the rotating body 22. A light source 27 is connected to the base of the transmitting optical fiber 25.

On the other hand, the receiving optical fiber 28 has its tip end coaxially fixed to the sleeve 29, and the axial misalignment between them is 0.5.
The axis center angle deviation is set to 0.3 ° or less at μm or less. Further, the end faces of the receiving optical fiber 28 and the sleeve 29 are polished together and processed so that the end faces are orthogonal to the axis. Further, the sleeve 29 is processed so that the outer periphery thereof has a highly accurate cylindrical shape. And this sleeve 29
Is fitted into the hole 24 a of the rotating body 24. Hole 2 of course
4a is processed with high precision. Therefore, the tip of the receiving optical fiber 28 is accurately positioned at the axial center position of the rotating body 24. A light receiver 30 is connected to the base of the receiving optical fiber 28.

In order to align the axes of the rotating bodies 22 and 24, a constant amount of light is incident on the transmitting optical fiber 25 from the light source 27. This light passes through the transmitting optical fiber 25 and the receiving optical fiber 2
It is incident on 8. Further, the light passing through the receiving optical fiber 28 reaches the light receiver 30, and the light amount is detected by the light receiver 30. Then, in order to maximize the detected light amount, in other words, the transmitting optical fiber 25 and the receiving optical fiber 2
The position of at least one of the rotating bodies 22 and 24 is moved so that the light loss at the connection point with 8 is minimized. When the detected light amount becomes maximum in this way, the rotating body 22,
The axes of 24 are aligned.

In the above embodiment, the alignment may be performed while rotating at least one of the rotating bodies 22 and 24. By doing so, it is possible to extremely reduce the influence of the axial deviation between the sleeves 26 and 29 and the optical fibers 25 and 28 and the axial center angle deviation.

Further, the axis alignment accuracy can be selected according to the types of the optical fibers 25 and 28 and the core diameter. For reference, the core diameter is 50
FIG. 2 shows the splice loss characteristics of a μm graded index type multimode optical fiber, and FIG. 3 shows the splice loss characteristics of a single mode optical fiber having a core diameter of 10 μm. For example, it can be seen from FIG. 3 that the optical loss is 0.3 dB (7%) when the axis deviation is 1 μm and the axial center angle deviation is 1 °. When the optical fiber is used as described above, the loss is large even if the deviation is slight, so that the axis alignment can be performed with high accuracy.

FIG. 4 shows an embodiment in which the present invention is applied to a lathe. As shown in the figure, the main spindle rotating spindle 32 supported by a bearing 31 has a chuck 33. Further, the cylindrical drill head 34 has a chuck 35. Chuck 3
The reproducibility of 3, 35 is 1 μm or less if the object to be chucked is highly accurately finished.

The transmission optical fiber 36, which is a single-mode optical fiber (core diameter 10 μm, cladding diameter 125 μm), is fixed to the sleeve 37 with a coaxiality of 0.5 μm or less.
The receiving optical fiber 38, which is a single-mode optical fiber (core diameter 10 μm, cladding diameter 125 μm), is fixed to the sour rib 39 with a coaxiality of 0.5 μm or less. The sleeves 37 and 39 have a surface roughness of 0.5 μm or less,
The roundness is finished to 1 μm or less. Each sleeve 3
7 and 39 were fixed by chucks 33 and 35, respectively, and the distance between the sleeves 37 and 39 was narrowed to within 3 μm. Optical fiber (core diameter 50μm, cladding diameter 125μm)
Light having a wavelength of 1.3 μm was incident on the transmitting optical fiber 36 through the optical fiber 40 and the optical rotary joint 41.
Then, the amount of light passing through the receiving optical fiber 38 was detected. The results are shown below.

(B) The optical output incident on the transmitting optical fiber 36 is -10.
It was 5 dBm.

(B) When the connection state of FIG. 4 is established, the receiving optical fiber 3
The output of the light that passed through 8 was -12.0 dBm.

(C) While rotating the main spindle rotating spindle 32,
When the position of the drill head 34 was moved three-dimensionally so that the fluctuation of the light output was minimized and the average amount of received light was maximized, the received light output was -10.6 dBm ± 0.1 dBm.

(D) The optical output incident on the transmitting optical fiber 36 was measured again and found to be -10.4 dBm. This variation in the optical output on the transmitting side is due to the variation in the interval between the sleeps 37 and 39.

(E) Therefore, the loss generated between the sleeves 37 and 39, that is, between the optical fibers 36 and 38 is 0.2 ± 0.1 dBm.
Becomes From this, referring to FIG. 3, it can be confirmed that the central axes of the main spindle rotating spindle 32 and the chuck 35 have an axial deviation of 1.3 μm and an axial center angular deviation of 1.7 ° or less.

In this way, the spindle rotating spindle 32 and the chuck 35
When the drill is mounted on the main spindle rotating spindle 32 in a state where the axial center positions of and are accurately aligned, the axes of the drill and the main spindle rotating spindle 32 are accurately aligned. For this reason, the diameter of the formed hole matches the diameter of the drill without touching the drill even when drilling. Thus, submicron-order fine drilling can be performed with high precision. Also, because the drill does not touch, it does not cause excessive load on the drill,
Drill damage is prevented and drill life is extended.

<Effects of the Invention> According to the present invention as specifically described with reference to the above embodiments, since the position of the structure of the machine tool is adjusted by using the optical fiber, the margin space between the structures is reduced. Position adjustment can be done quantitatively even if it is small. Further, by selecting an optical fiber, the position can be adjusted with an appropriate resolution. Of course, since the optical fiber is used, it is not disturbed by electrical noise.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a characteristic diagram showing connection loss characteristics of a graded index type multimode optical fiber, and FIG. 3 is a connection loss characteristic of a single mode optical fiber. FIG. 4 is a characteristic diagram, FIG. 4 is a sectional view showing an embodiment in which the present invention is applied to a lathe, FIGS. 5 to 7 are configuration diagrams showing various conventional techniques, and FIG. 8 is a conventional technique shown in FIG. It is explanatory drawing which shows the image seen by the centering microscope of FIG. In the drawings, 22 and 24 are rotating bodies, 25 is a transmitting optical fiber, 26 and 29 are sleeves, 27 is a light source, 28 is a receiving optical fiber, 30 is a light receiver, 32 is a main spindle, and 33 and 35 are chucks. , 34 is a drill head, 36 is a transmitting optical fiber, 37 and 39 are sleeves, and 38 is a receiving optical fiber.

Claims (2)

[Claims] 1. A method for adjusting a position of a machine tool structure such that both axial centers of a pair of structures whose end faces are opposed to each other and at least one of which is rotated are aligned on a straight line. The optical fiber for transmission is coaxially installed at the axial center position of the structure 1 and the optical fiber for reception is coaxially installed at the axial center position of the second structure so that a certain amount of light is transmitted to the optical fiber for transmission. As it enters
The light that has passed through the transmitting optical fiber is incident on the receiving optical fiber, passes through the receiving optical fiber, and the amount of light that passes through the receiving optical fiber is detected. An optical position adjusting method for a machine tool structure, characterized in that the position of at least one structure is moved. 2. A method of performing position adjustment so that the axes of both of a pair of structures of a machine tool structure, the end faces of which face each other and at least one of which rotates, are aligned. The transmitting optical fiber is coaxially installed at the axial center position of the first structure, and the receiving optical fiber is coaxially installed at the axial center position of the second structure so that the transmitting optical fiber has a certain amount of light. Incident on
The light that has passed through the transmitting optical fiber is incident on the receiving optical fiber, passes through the receiving optical fiber, and the amount of light that passes through the receiving optical fiber is detected. As described above, the optical position adjusting method for a machine tool structure, wherein the position of at least one structure is moved while rotating at least one structure around its axis.