JP3530633B2 - Centering adjustment method of laser length measuring machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centering adjusting method for a laser length measuring machine.

[0002]

2. Description of the Related Art A laser length measuring machine is known as a device for accurately measuring a linear movement distance of a machine tool or an XY table. This type of laser length measuring device includes a laser head having a light transmitting portion and a light receiving portion, and a target prism that reflects the laser light. The target prism is attached to the length-measuring object side to move and move. The length is measured by utilizing the interference effect of laser light corresponding to the distance.

In the length measuring machine having such a structure, in order to improve the accuracy of measurement, it is extremely important to first perform the so-called centering adjustment, that is, the laser head and the target prism are positioned on the same optical axis. In the past, centering adjustment was performed by repeating the following procedure a plurality of times. At the position close to the target prism, align the optical axis of the laser head with a predetermined position on the target prism, then move the target prism to the separated position, and then in this state, move the laser head according to the amount of deviation of the optical axis. It is oscillated vertically and horizontally so that the optical axis is adjusted to match the predetermined position of the target prism. Next, the target prism is moved to a close position, and if the optical axis is displaced from the predetermined position of the target prism, the laser head is moved in parallel vertically and horizontally, and the optical axis,
Match the target prism. However, such a conventional centering adjustment method has the technical problems described below.

[0004]

That is, even with the above-described centering adjustment method, even a person skilled in the art can achieve the target until the optical axis of the laser head and the predetermined position of the target prism are completely aligned with each other. Normally, the prism must be reciprocated five times or more, and it is an adjustment work that depends on experience and intuition. Especially, when the measurement distance is 10 m or more, it takes a long time to perform the centering adjustment work. It was

[0005] Incidentally, the actual development 4-
As shown in Japanese Patent No. 126104, an auxiliary target having a scale displayed from the center is set on the front surface of a target prism, and a laser beam from a laser head is irradiated on this surface to give a rough guideline for the amount of deviation from the center. Some of them are easy to attach, but even if such an auxiliary target is used, since substantial centering adjustment was performed with experience and intuition similar to the above-mentioned conventional method, it is troublesome for the initial setting work. It remained the same and did not become a fundamental solution.

The present invention has been made in view of such conventional problems, and an object of the present invention is to perform centering adjustment work without requiring skill and to shorten the adjustment work time. It is to provide a method for adjusting the centering of a laser length measuring machine.

[0007]

In order to achieve the above-mentioned object, the present invention provides a laser head supported on a support so as to be swingable and movable in parallel, and to be capable of approaching and separating so as to face the laser head. Arranged, comprising a target for centering adjustment to receive the emitted laser light from the laser head,
The target is provided with a display section showing the center point O, and the optical axis of the emitted laser light is made to coincide with the movement locus of the center point O of the target by the following procedure. Step, at a position close to the laser head of the target, after matching the irradiation position of the emitted laser light on the target with the center point O, the target is retracted to a predetermined separation position, and at this separation position A displacement amount A between the irradiation position on the target and the center point O is measured. In the step, the laser head is swung back and forth and left and right at the separated position to match the irradiation position on the target with the center point O, and then the target is moved again to the close position to move the target. A displacement amount B between the upper irradiation position and the center point O is measured. From the process and the displacement amounts A and B, the length C to which the laser head should be translated is calculated based on the following equation. C = A × B / A−B step, the target is retracted to the separated position again, and the laser head is swingably adjusted in the front-rear direction and the left-right direction at the separated position to move the irradiation position from the center point O to the parallel movement distance. Move to the position corresponding to C. Step, the laser head is translated in the vertical and horizontal directions by the translation distance C. In this case, the target may be provided with a cross-shaped line indicating the center point O and a plurality of concentric circular scales spaced from the center point O by a unit interval.

[0008]

According to the centering adjustment method of the laser length measuring machine having the above-described structure, the parallel movement distance C calculated from the process equation is such that the optical axis of the laser beam is parallel to the movement locus of the center point O of the target. Is the value to do. Therefore, after adjusting the irradiation position of the laser beam to the position of the parallel movement distance C obtained in the process,
By moving the laser head in parallel in the vertical and horizontal directions by the amount corresponding to the parallel movement distance C according to the calculation result, the optical axis of the laser light can be matched with the center point movement locus of the target. The number of reciprocating movements of the target required for the work is once and a half to two times.

[0009]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a diagram for explaining the principle of the method of the present invention in a two-dimensional manner.
(F) is an explanatory view of the adjustment procedure, and (a) to (f) of FIG.
It is explanatory drawing which shows the relationship between the target and the irradiation position P of a laser beam in the same adjustment procedure.

In FIG. 2, a laser head 1 has a swinging mechanism which can be vertically swung on a tripod 2 which serves as a support.
It is supported via an up-and-down mechanism that can move up and down and left and right in parallel and a left and right moving mechanism. A target 4 for centering adjustment is fixed on a moving body 3 facing the laser head 1 via a height adjuster 5 capable of height adjustment.

As shown in FIG. 4, the height adjuster 5 includes a flat base 5a placed on the moving body 3, and
A post 5b vertically provided at the center of the base 5a, and a post 5
It is composed of a main body 5c movably supported by b on the vertical direction and an adjusting screw 5d provided on the main body 5c. By turning the adjusting screw 5d, the main body 5c moves up and down along the axial direction of the post 5b. It is like this.

As shown in FIG. 3, the target 4 is a substantially square flat plate composed of a metal plate of aluminum or the like which has been subjected to a satin finish, and its center point O is displayed. At the same time, radial cross lines 4a are drawn at 45 ° intervals from the center point O, and concentric circular scales 4b are drawn from the center point O at unit intervals of 1 mm, for example. The center of the target 4 is attached to the height adjust 5 so as to coincide with the laser beam incident position on the target prism.

The size of the target 4 is arbitrary, but for measuring short distances, for example, a relatively small diameter may be used.
A large-diameter one is used for long-distance measurement up to 0 m or more, but in short, the irradiation position of the laser beam is the target 4
If it is large enough to prevent it from coming off,
As one example, one having a side of about 150 mm is used, and for example, it is detachably attached to the front surface of the main body 5c of the height adjuster 5 by adsorption by a magnet or screwing.

The moving body 3 is, for example, a moving table of a machine tool, and reciprocates through the tripod 2 so as to move closer to and away from the laser head 1 installed at a fixed position. When adjusting the centering of the laser head 1, the length L1 between the laser head 1 and the target 4 at the proximity position X1 and the length L2 between the target 4 and the laser head 1 at the separation position X2 are kept constant. After the above, the centering adjustment work is performed by the following procedure.

It should be noted that the length L2 of the separated position X2 does not have to extend to the entire length of the moving distance of the moving body 3, but if it is too short, the error becomes large, and if it is too long, the working time becomes long. It is desirable to set the length taking these into consideration. Step: First, the optical axis of the laser head 1 is installed and fixed so as to be substantially aligned with the center of the moving direction of the target 4 via the tripod 2. Then, first, as shown in FIG. 2A, the target 4 is moved to the proximity position X1. In this state,
The irradiation position P of the laser beam emitted from the laser head 1 on the target 4 is adjusted by the swinging mechanism of the tripod 2 so as to irradiate the center point O as shown in FIG. Adjust the height by adjusting the height adjuster 5.

Next, as shown in FIG. 2B, the moving body 3
Is retracted and stopped at a predetermined separation position X2. In this state, the locus of movement of the center point O is generally off the optical axis, so that the irradiation position P of the laser beam deviates from the center point O as shown in FIG. It is in the position. Therefore, first, the displacement amount A between the irradiation position P and the center point O is measured using a concentric circle scale, and P
Write from end to end of line segment L that passes through and O.

When the process and the measurement of the displacement amount A are completed, the laser head 1 is swingably adjusted by the swinging mechanism at the same separation position X2 as shown in FIGS. 2 (c) and 3 (c). The operation of making the irradiation position P coincide with the center point O again is performed. Then, the moving body 3 is driven again to move the target 4 to the proximity position X1 and stop it. Then
In this manner, as shown in FIGS. 2D and 3D, the displacement amount B of the irradiation position P from the center point O is measured. The irradiation position P at this time is on the extension of the line segment L.

From the process and the obtained displacement amounts A and B, the parallel movement distance C is calculated based on the following equation. C = A × B / A−B This formula is intended to obtain an optical axis parallel to the movement locus of the center point O of the target 4 from the similarity of the triangles in the principle explanatory diagram shown in FIG. The terms of lengths L1 and L2 are deleted on the way, and the parallel movement distance C is derived only from the measured displacement amounts A and B.

Step, then, as shown in FIGS. 2 (e) and 3 (e), the target 4 is retracted to the separated position X2,
The irradiation position P of the laser head 1 is operated by swinging the swing mechanism.
Is moved from the center point O to the position corresponding to the parallel movement distance C on the line segment L. This position is also an extension of the line segment L. By this operation, the optical axis is corrected to a position which is completely parallel to the movement locus of the center point O of the target and deviates by the parallel movement distance C.

Process, and finally, FIG. 2 (f) and FIG. 3 (f)
As shown in, the target 4 is moved to the proximity position X1 again, and after confirming that the irradiation position P coincides with the position corresponding to the parallel movement distance C, the elevating mechanism is operated to move the parallel position. The laser head 1 is moved in the vertical direction by a size corresponding to the vertical component of the moving distance C, and the horizontal moving mechanism is operated to move the laser head 1 in the horizontal direction by a size corresponding to the horizontal component of the parallel moving distance C. When the irradiation position P is made to coincide with the center point O by performing parallel movement with respect to, the optical axis coincides with the movement locus of the center point O, and the centering work is completed.

It should be noted that the proximity operation in the process is not always necessary, and after the rocking operation in the process, after confirming that the irradiation position P matches the parallel movement distance C at an arbitrary position of the target 4, the parallel movement is performed. You may perform parallel adjustment work according to the distance C. After that, the target 4 fixed to the height adjuster 5 is removed, and the target prism used for the measurement is attached to the height adjuster 5, whereby the length can be measured.

The adjusting principle in the above centering adjusting method will be described with reference to FIG. In FIG. 1, the laser head 1 is fixedly installed at a point a, and the length L is measured from this point a.
The position of 1 is the proximity position X1, and the position of the same length L2 is the separation position X2. First, the target 4 has the proximity position X.
In 1, the irradiation position P is made to coincide with the center point O, then the target 4 is moved to the separated position X2, and the displacement amount between the center point O and the irradiation position P at this time is A (the above process). .

In this state, the optical axis of the laser beam emitted from the laser head 1 is at the position indicated by l ₁ in FIG. Then, in the process, the irradiation position P
Is aligned with the center point O, so the optical axis is changed from l ₁ to l ₂ . Then, the target 4 is moved to the proximity position X1 in the same process, and the irradiation position P at this position is set.
And the displacement amount B between the center point O and the center point O is measured.

At this time, as can be seen from FIG. 1, assuming a parallel line segment l ₀ passing through the point a with respect to the movement locus L ₃ of the center point of the target 4, the parallel movement distance between them is assumed. If C can be obtained, the optical axis can be made to coincide with the movement locus l ₃ of the center point of the target 4 by moving the laser head 1 in parallel by the amount corresponding to the parallel movement distance C.

Therefore, in the present invention, the parallel movement distance C is calculated based on the displacement amounts A and B. The parallel movement distance C is obtained by a similarity relationship of triangles. First, △
According to the similarity relationship between cag and Δdae, B / A = L1 / L2 ... by the same Δgab∽Δeaf, ef / C = L1 / L2 ... by the same Δdeg∽Δfea, ef / B = L1 / (L1- L2) From the formula, EF = L1 · C / L2… Substituting the formula into the formula, L1 · C / L2 · B = L1 /
It becomes L2-L1, and when this formula is converted, it becomes C / B = L2 / L2-L1 ... And from the formula, L1 = L2 · B / A, so if this is substituted into the formula and transformed, C / B = A / Becomes AB,
If this is further modified, C = A × B / A−B,
The parallel movement distance C is obtained regardless of the lengths L1 and L2.

The parallel movement distance C thus obtained
When the irradiation position P is adjusted to the position corresponding to the parallel movement distance C on the basis of the above, the optical axis of the laser head 1 is changed from l ₂ to l ₀ , and thereafter, the laser head is changed. When 1 is translated by a distance corresponding to the translation distance C, the optical axis is changed from l ₀ to l ₃ . As a result, the optical axis of the laser head 1 completely coincides with the movement trajectory of the center point O of the target 4.

In the above embodiment, the scales 4b having unit intervals are displayed on the target 4 and used as a guide for measuring the amount of displacement, but the scales 4b are not always necessary. Further, in the above-mentioned embodiment, the displacement amount was measured based on the scale using the jig plate such as aluminum as the target 4, but instead of this, for example, a large number of CCD elements are arranged on the front surface side of the target and irradiation is performed. The coordinate value of position P is CCD
It is also possible to provide means for calculating the parallel movement distance C by applying the detection value to the above-mentioned calculation formula by detecting with the element, and means for displaying the calculation result.

Further, if the program corresponding to the procedure of the centering adjustment method based on these detected values automatically controls the swinging mechanism, the lifting mechanism and the horizontal moving mechanism of the tripod, the adjustment work can be automated. It will be possible.

[0029]

As described in detail in the above embodiments, in the centering method of the laser length measuring machine according to the present invention, the target is moved to the close position and the separated position so that the optical axis and the center point of the target are moved. If you calculate the amount of parallel movement with the movement locus and move the optical axis in parallel by the amount equivalent to this amount of parallel movement, the centering of the optical axis will be completed, so you will have no experience with adjustment work as in the past. No need for intuition. Further, since the number of movements of the target necessary for the centering adjustment is one and a half or two times of reciprocating movement, the working time can be greatly shortened as compared with the conventional case. Further, in the method of the present invention, the amount of parallel movement required for centering can be automatically displayed, and it is possible to further develop it and automate the adjustment work itself.

[Brief description of drawings]

FIG. 1 is a two-dimensional principle explanatory view of a centering adjustment method for a laser length measuring machine according to the present invention.

FIG. 2 is an explanatory diagram sequentially showing an adjustment procedure of a centering adjustment method for a laser length measuring machine according to the present invention.

FIG. 3 is an explanatory diagram showing a relationship between a target and a laser beam irradiation position in the adjustment procedure shown in FIG.

FIG. 4 is a side view and a plan view of a height adjuster equipped with a target used in the adjusting method of the present invention.

[Explanation of symbols]

1 laser head 2 tripod (support base) 3 moving bodies 4 targets 4a crosshair 4b scale O center point P irradiation position A, B displacement C parallel distance

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01B 11/00-11/30 G01C 15/00

Claims (2)

(57) [Claims] 1. A laser head supported on a support so as to be swingable and movable in parallel, and a centering unit which is arranged so as to face the laser head and is capable of approaching and separating from it, and which receives laser light emitted from the laser head. With a target for adjustment,
The target is provided with a display section showing the center point O, and the optical axis of the emitted laser light is made to coincide with the movement trajectory of the center point O of the target by the following procedure: Step, proximity of the target to the laser head At the position, after the irradiation position of the emitted laser light on the target is matched with the center point O, the target is retracted to a predetermined separation position, and the irradiation position on the target and the center point at the separation position. The displacement amount A with respect to O is measured. In the step, the laser head is swung back and forth and left and right at the separated position to match the irradiation position on the target with the center point O, and then the target is moved again to the close position to set the target. A displacement amount B between the upper irradiation position and the center point O is measured. Step, the distance C to which the laser head should be translated is calculated from the displacement amounts A and B based on the following equation. C = A × B / A−B step, the target is retreated to the separated position again, and the laser head is adjusted to swing at the separated position so that the irradiation position corresponds to the parallel movement distance C from the center point O. Move to the position. Step, the laser head is translated by the translation distance C. A method for adjusting the centering of a laser length measuring machine, which is characterized in that 2. The target has a cross-shaped line indicating the center point O, and a plurality of concentric circular scales spaced from the center point O by a unit interval.
The centering adjustment method for the laser length measuring machine described.