JPH0342322Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a structure for reducing the height of a magnetic scale in a digital caliper that digitally displays measured values of an object to be measured.

Some digital calipers use magnetism as a means of obtaining measurement signals. As shown in FIG. 1, this consists of a magnetic scale 3 that is fixed in a groove 1a provided in the main scale 1 via a mounting rod 2, and an upper and lower slider portion that constitutes a slider portion that is close to and opposite to the magnetic scale 3. The amount of movement of the vernier 6 is magnetically detected using a magnetic sensor 7 housed in the cases 4 and 5 and fixed to the vernier 6.

In such a digital caliper, the magnetic scale 3 and the magnetic sensor 7 must be placed close to each other, and the distance between them is very small, and furthermore, it is necessary to keep the distance constant. Ta.

Conventionally, in digital calipers, the distance between the magnetic scale 3 and the magnetic sensor 7 has been kept constant by maintaining the height of the magnetic scale 3 accurately.

This magnetic scale 3, as shown in FIG.
It is fixed in the groove 2a of the mounting rod 2 so that about 1/3 of its cross-sectional diameter protrudes. The mounting rod 2 to which the magnetic scale 3 is fixed is fixed in the groove 1a of the main scale 1 in this way. It is often difficult to keep the height of the magnetic scale 3 constant due to errors in the external dimensions of the rod 2. In particular, it is very difficult to determine the depth of the grooves with high accuracy, so it has been difficult to maintain a constant height of the magnetic scale 3 with respect to the top surface of the main scale 1.

Therefore, conventionally, as shown in Fig. 3, the mounting rod 2
A spacer 8 was inserted between the magnetic scale 3 and the bottom surface of the groove 1a of the main scale 1, and the height of the magnetic scale 3 was adjusted to be constant and then fixed.

However, since the depth of the groove is not constant,
Spacers 8 of various heights must be prepared, which not only impedes mass production but also increases the number of parts.

In addition, there is no point in inserting the spacer 8 unless its precision is good, so the spacer 8
There were also many restrictions on materials and processing, which caused prices to rise.

The present invention solves the drawbacks of the conventional example by fixing the mounting rod to which the magnetic scale is fixed in the groove of the main scale and then grinding the magnetic scale, the mounting rod, and the main scale at the same time to adjust the height of the magnetic scale. The aim is to solve this problem and provide a digital caliper with excellent mass productivity.

4 and 5 are cross-sectional views showing one embodiment of the structure of the present invention.

Note that the symbols are assigned based on those assigned to the digital caliper shown in FIG.

The height of the mounting rod 2 in this embodiment is set to be slightly higher than the depth of the groove 1a provided in the main scale 1.

In the groove 2a provided in this mounting rod 2,
The cross section of the magnetic scale 3 is 1/1 from the top surface of the mounting rod 2.
It is fixed by appropriate means such as adhesion or welding so that it protrudes by about 3 degrees.

As shown in FIG. 4, the upper part of the mounting rod 2 to which the magnetic scale 3 is fixed protrudes slightly from the groove 1a of the main scale 1, and the magnetic scale 3 further protrudes from the mounting rod 2. .

The mounting rod 2 and magnetic scale 3 fixed in this manner are ground together with the upper surface 1b of the main scale 1 so as to be aligned on the same plane as the upper surface 1b.

In this way, main scale 1, mounting rod 2, magnetic scale 3
By removing the magnetic scale 3, the height of the magnetic scale 3 relative to the main scale 1 can be kept constant, and the height can be set freely.

Incidentally, as shown in FIG. 6, it is also possible to perform grinding so that the heights of the magnetic scale 3 and the mounting rod 2 are slightly lower than the upper surface 1b of the main scale 1.

7 and 8 are sectional views showing other embodiments of the present invention.

In the embodiment described above, the groove 1a of the main scale 1 was also used as the depth bar groove on which the depth bar 9 for depth measurement attached to the vernier scale 6 shown in FIG. The magnetic scale 3 was fixed through it.

In this embodiment, a depth bar groove 1d is provided on the lower surface 1c side of the main scale 1, and a groove 1e for accommodating and fixing the magnetic scale 3 is provided on the upper surface 1b side. In this groove 1e, the magnetic scale 3 is 1/3 of its cross-sectional diameter.
The depth is set so that it protrudes from the groove 1e.

In this way, the magnetic scale 3 is placed in the groove 1e of the main scale 1.
is fixed, and then the magnetic scale 3 is ground together with the upper surface 1b of the main scale 1, so that the upper surface thereof is set to be the same as or slightly lower than the upper surface 1b of the main scale 1.

As described above, according to the present invention, the height of the magnetic scale with respect to the top surface of the main scale can be determined with high precision, thereby improving the accuracy of the interval between the magnetic sensor of the slider section attached to the main scale and the magnetic scale. I can do it.

In addition, the height of the magnetic scale is not affected by errors in the depth of the grooves on the main scale, so the accuracy of the depth of the grooves formed on the main scale is not necessary and can be easily formed in manufacturing. be able to.

Furthermore, there is no need to use spacers or the like to adjust the height, and since it is sufficient to simply fix the magnetic scale to the main scale, the number of parts can be reduced, and the present invention has significant practical effects.

[Brief explanation of the drawing]

Figure 1 is an exploded perspective view of a digital caliper, Figure 2 is a sectional view showing a conventional magnetic scale and mounting rod, and Figure 3 is a structure for attaching the conventional magnetic scale and mounting rod shown in Figure 2 to the main scale. 4 and 5 are cross-sectional views showing one embodiment of the present invention, and FIG.
The figure shows a partially modified example of the structure shown in FIG. 5, and FIGS. 7 and 8 are sectional views showing other embodiments of the present invention. 1...Main scale, 1a, 1e...Groove, 2...Mounting rod, 2a...Groove, 3...Magnetic scale.

Claims (1)

[Scope of utility model registration request] A digital caliper that digitally displays measured values includes a main scale having a groove on the top surface, and a magnetic scale fixed to the groove of the main scale directly or via a mounting rod so that the upper part protrudes from the top surface of the main scale. A structure for cutting a magnetic scale in a digital caliper, characterized in that the height of the magnetic scale is determined by grinding both the upper surface of the main scale and the magnetic scale.