JPH0235518Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial field of application> The present invention relates to the improvement of a template, which is a kind of drafting ruler used to draw a prescribed perfect circle, ellipse, etc. The present invention is characterized in that an error caused by a deviation in the center position between the center axis and the drafting hole can be instantly and easily confirmed, and it can be easily determined whether the error is within an allowable range or not.

<Prior art> Generally, when manufacturing a template, which is a type of drafting ruler, each center axis line is printed on the surface of a plastic plate, and then the center is aligned with the intersection of the printed lines. Holes are machined for drafting, such as perfect circles and ellipses. Theoretically, the drafting template manufactured in this way is required to have the printed center axis line and the center of the drafting hole coincident with each other. However, as mentioned above, the printing process for each central axis line and the drilling process for the drafting holes are performed in separate processes, making it extremely difficult to align the points of the two.
In reality, a certain degree of centering error occurs due to reasons such as expansion and contraction of the plastic plate itself occurring between the printing process and the hole drilling process. Such a centering error is allowed to some extent as unavoidable in this industry, and the allowable range of such centering error is set within 0.15 mm in this industry.

However, it is possible to instantly and easily check the centering error due to the deviation in the center position of the drawing hole and the center axis line that lost its intersection during the drilling process of the drawing hole, and check whether the centering error is within the allowable range. It is extremely difficult to easily determine whether this is the case.

<Purpose of the invention> In view of the above-mentioned circumstances, the present invention has been developed to instantly and easily confirm the center error caused by the deviation of the center position of the center axis line due to the printing process, which has lost its intersection point due to the hole processing process, with the center position of the drafting hole. Furthermore, it is an object of the present invention to provide a drafting template that allows it to be easily determined whether or not the center error is within a permissible range.

<Structure of the invention> In order to achieve the above object, the drafting template according to the invention has the following structure. That is, a large number of center axes are printed at appropriate intervals on the surface of a plastic plate, and a through hole for drafting is formed in the shape of a perfect circle, ellipse, or equilateral triangle, with the intersection of the center axes as the center position. In the drafting template formed by drilling holes in the drafting template, during the printing process of the central axis line, dividing lines for error confirmation are printed at two or more positions on the plate, and furthermore, the holes in the drafting through-holes are printed at two or more positions on the plate. During processing, a small hole for error confirmation is formed that is set around the center position of each of the error confirmation partition lines and has an area smaller than the error confirmation partition line, and is formed between the error confirmation partition lines and the error confirmation The present invention is characterized in that an error in the center position between the drawing hole and the central axis, which has lost its intersection, is determined by checking the deviation of the center position relative to the small hole.

<Example> Hereinafter, an example of the present invention will be explained based on the drawings.

Fig. 1 is a front view showing a drafting template of the present invention, Fig. 2 is a front view showing an enlarged main part of the invention, Fig. 3 is a vertical cross-sectional view taken along the - line of Fig. 2, 4A and 4B are front views of main parts showing the manufacturing process of the drafting template of the present invention.

1 in the figure shows the template body of the present invention. The configuration and manufacturing process of the central axis 2 printed on one side of the template body 1 and the elliptical drafting hole 3 having its center at the intersection of the central axis 2 and the central axis 2 are based on conventionally known conventional drafting. This is the same as the template for That is, in the drafting template of the present invention, after printing a large number of center axes 2 at appropriate intervals on one surface of a plastic plate as shown in FIG. 4A, each of the central axes 2 is printed as shown in FIG. It is formed by drilling various elliptical drafting holes 3 whose center position is the intersection of the central axes 2.

A feature of the drafting template according to the present invention is that, during the printing process of the central axis 2, dividing lines 4 for error confirmation are placed at two or more positions on the plate as shown in FIG. 4A and FIG. When printing and further drilling the drafting through-hole 3, as shown in FIG. 4B and FIG. Error confirmation small hole 5 having an area smaller than 4
was formed. The error confirmation marking line 4
In this embodiment, as shown in FIG. 1, these are printed near the opposing corners. Further, in this embodiment, the error confirmation marking line 4 is formed of a perfectly circular annular line. Next, in the case of this embodiment, the small hole 5 for error confirmation is machined into a perfect circular shape like the division line 4 for error confirmation.

The relationship between the error confirmation marking line 4 made of the perfectly circular annular line and the error confirmation small hole 5, which is also perfectly circular, is as described above. The center positions of the small holes 5 for error confirmation having a diameter smaller than the dividing line 4 are set to coincide with each other. As shown in FIG. 2 and FIG. It was confirmed that there was no center error between the center axis 2 and the drafting hole 3 that was processed in a separate process. The radial distance (L) to the periphery of the small hole 5 is defined as an allowable range of center error. Therefore, as shown in FIG. 5B, although the periphery of the small hole 5 for error confirmation is in contact with the inscribed line of the partition line 4 for error confirmation, the partition line 4 for error confirmation does not contact the small hole 5 for error confirmation. Therefore, if there is no notch, it can be instantly and easily confirmed that the permissible error limit is reached, and as shown in FIG. If the drawing hole 3 is notched, the center position of the drafting hole 3 with respect to the central axis 2 is formed to exceed the allowable error.

Incidentally, FIGS. 6A, B, C, and D show other embodiments of the error confirmation partition line 4 and the error confirmation small hole 5. However, the relationship between the error confirmation partition line 4 and the error confirmation small hole 5 shown in this embodiment is as follows.
Compared to the relationship between the error confirmation partition line 4 and the error confirmation small hole 5 shown in FIGS. 1 to 5, the distance from the inscribed error confirmation partition line 4 to the periphery of the error confirmation small hole 5 is Since the values are different, it is not possible to uniformly determine the allowable error, which is not preferable from this point of view.

<Effects of the invention> As described above, the drafting template according to the present invention has marking lines for error confirmation printed at two or more positions on the plate during the printing process of the center axis line, and also has through-holes for drafting. When machining the hole, a small hole for error confirmation is formed that is set around the center position of each of the error confirmation partition lines and has a smaller area than the error confirmation partition line, and The feature of the structure is that the error in the center position of the drafting hole and the center axis, which has lost its intersection, is determined by checking the deviation of the center position relative to the small hole for error confirmation. Therefore, it has the following effects.

In other words, it is possible to instantly and easily check the centering error caused by the misalignment of the center position of the drawing hole and the center axis that lost the intersection point during the hole machining process, and it is also easy to check whether the centering error is within the allowable range or not. It has an effect that can be judged as follows.

[Brief explanation of the drawing]

Fig. 1 is a front view showing a drafting template of the present invention, Fig. 2 is a front view showing an enlarged main part of the invention, Fig. 3 is a vertical cross-sectional view taken along the - line of Fig. 2, Figures 4A and B are front views of the main parts showing the manufacturing process of the drafting template of the present invention, and Figures 5A, B, and C show the positional relationship between the error confirmation marking line and the error confirmation small hole. Each explained front view, Figure 6A,
B, C, and D are front views showing examples of other relationships between the error confirmation partition lines and the error confirmation small holes. 1...Template body, 2...Center axis line, 3
...Drawing hole, 4... Compartment line for error confirmation, 5...
...Small hole for error confirmation.

Claims (1)

[Claims for Utility Model Registration] (1) A large number of central axes are printed at appropriate intervals on the surface of a plastic plate, and a predetermined perfect circle, ellipse, or Alternatively, in a drafting template formed by drilling a drafting hole such as an equilateral triangle,
During the printing process of the central axis line, marking lines for error confirmation are printed at two or more positions on the plate, and furthermore, when drilling the drafting holes, the center of each marking line for error checking is printed at two or more positions on the plate. A small hole for error confirmation is formed with the position as the center and has an area smaller than the partition line for error confirmation, and the deviation in the relative center position of the partition line for error confirmation and the small hole for error confirmation is formed. A drafting template characterized in that an error in the center position of the drafting hole and the center axis line that has lost the intersection point is determined by checking the above. (2) The drafting template according to claim 1, wherein the error confirmation marking line and the error confirmation small hole are perfectly circular.