JPH06207952A - Moving-iron instrument - Google Patents

Abstract

PURPOSE:To realize a moving-iron instrument employing a butterfly + arcuate fixed iron piece in which adjusting work of sensitivity is simplified and stabilized. CONSTITUTION:In an instrument wherein a movable shaft fixed with a movable iron piece 16 is disposed in a cylinder 30 having a fixed iron piece 20 constituted of a planar butterfly part and an arcuate part extending therefrom, the cylinder member is constituted of a cylindrical body being separated into a plastic cylinder fixed with the iron piece such that the arcuate part is positioned at the opening and a plastic frame member 40 for holding the movable shaft fixed with the movable iron piece. The frame member is mounted rotatably in the cylinder such that the movable shaft is positioned in the cylinder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is a butterfly-shaped fixed iron piece.
The present invention relates to a movable iron piece type instrument using an arc-shaped one.

[0002]

2. Description of the Related Art A conventional example of an iron piece structure used in a movable iron piece type instrument having a narrow angle (a deflection angle of 90 degrees) is shown in FIG.
Shown in (c). (A) is called an arc shape, and the movable iron piece 1 and the fixed iron piece 2 both have an arc shape, and the rotary shaft 3
The arcuate surface of the movable iron piece 1 attached to is rotated along the arcuate surface of the fixed iron piece 2. The arc-shaped iron piece with this configuration has a large torque, and it is easy to deal with the extended scale. There is a drawback that the characteristics tend to vary.

FIG. 2B shows a so-called butterfly shape, in which the fixed iron piece 2 and the movable iron piece 1 attached to the rotary shaft 3 are both flat plates, and the planes of both iron pieces face each other.
This structure has the characteristics that the scale characteristics are close to equal and that the dimensional accuracy of the movable iron piece 1 can be easily increased, but it has a problem that the torque is small and it is difficult to deal with the extended scale.

An intermediate structure between an arc shape and a butterfly shape is an arc shape + butterfly shape. This intermediate structure is shown in (c) and (d) of FIG. As shown in both figures, this intermediate structure has a rotating shaft 3
The movable iron piece 1 attached to is a flat plate, while the fixed iron piece 2 is composed of a flat plate 2a and an arc portion 2b extending from the flat plate portion. With this structure, the torque is generated between the above (a) and (b), the graduation characteristic approaches a uniform graduation, and an extended graduation is possible. Furthermore, the positions of the movable iron piece 1 and the fixed iron piece 2 are in the rotational direction. It has the characteristic that the scale characteristics (eye-out error) are not easily displaced even if it is slightly deviated.

However, in the conventional butterfly-shaped + arc-shaped fixed iron piece, the fixed iron piece 2 has a structure fixed to the frame, and the torque of the control spring varies (usually about ± 5%) or the field coil. In order to adjust variations in sensitivity, the torque of the control spring is adjusted, or the fixed iron piece 2 is rotated for each frame to return only the movable iron piece 1 to the original position and readjust the pointer to the zero point position. In this case, once the frame is rotated and the movable iron piece 1 is returned to the base, it is difficult to adjust because the maximum point checked at the beginning shifts, and it takes time to adjust. Moreover, it was a work that only a skilled worker could do. Further, in the case of the extended scale rating, since the fixed iron piece 2 cannot be rotated and adjusted, separate fixed iron pieces are required for the double scale and triple scale extended scale ratings.

Further, in this type of movable iron piece type instrument,
Generally, a cylinder is used, but the fixed iron piece 2 is attached by spot welding or bonding to the inner wall of an arc-shaped brass holder 4 as shown in FIG. 7 without using the butterfly-shaped + arc-shaped fixed iron piece. A known structure is one in which the holder 4 is inserted inside a fixed coil bobbin (not shown). With this structure, parts are manufactured with high dimensional accuracy.
It has the drawback that it is difficult to assemble, and as a result the instrument has a large variation in graduation characteristics. Note that FIG.
In the figure, reference numeral 41 denotes a rotation convex portion of the fixed iron piece 2.

[0007]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide an instrument using a fixed iron piece with a butterfly shape and an arc shape, which has an improved movable iron piece so that the sensitivity can be adjusted easily and stably. It is to realize a type instrument.

[0008]

According to the present invention, a movable shaft having a movable iron piece is arranged in a cylinder having a fixed iron piece having a flat plate-shaped butterfly portion and an arc portion extending from the butterfly portion. In the instrument, the cylinder member is formed of a cylindrical body having an opening, and a plastic material cylinder to which the fixed iron piece is attached so that an arc portion is located in the opening, and a movable shaft to which the movable iron piece is attached. A frame member made of a plastic material to be held is formed separately, and the frame member is rotatably mounted in the cylinder so that the movable shaft is positioned in the cylinder.

[0009]

According to the present invention as described above, the sensitivity is adjusted by rotating the cylinder to which the fixed iron piece is attached so that the circular arc portion is located at the opening.

[0010]

The present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an embodiment in which a part of a movable iron piece type instrument according to the present invention using a fixed iron piece of butterfly + arc shape is shown in cross section.
In the figure, 10 is a movable part of the instrument, which is a movable shaft 11, a pointer support 12 fixed to this movable shaft, a pointer 13 attached to this support, a zero adjustment arm 14, and a control spring attached to this zero adjustment arm. 15 and a plate-like movable iron piece 16 attached to the movable shaft 11. Reference numeral 20 is a fixed iron piece, and 30 is a cylindrical cylinder to which the fixed iron piece 20 is attached. The structure of the fixed iron piece 20 is shown in FIG. 2, and the structure of the cylinder 30 is shown in FIG.

In FIG. 2, (a) is a perspective view of the fixed iron piece 20 including the movable iron piece 16, and (b) is a side view. As shown in both figures, the fixed iron piece 20 is composed of a butterfly-shaped portion 21 and a circular arc portion 22. The butterfly-shaped portion 21 has a flat plate shape, and the circular arc portion 22 following the flat plate portion 21 has upper and lower surfaces 22a and 22b as indexes. It is functionally cut into an arc shape or a concave shape, and the tip portion 23 is thin. As shown in (a) and (b) of FIG. 2, in the fixed iron piece 20, the width of the butterfly-shaped portion 21 is H, the width of the base of the arc-shaped portion 22 following the butterfly-shaped portion 21 is H1, and the arc-shaped portion 22. When the width of the tip portion 23 is H2, H1 = 0.5H to 1.0H H2 = 0.05H to 0.3H is selected in the embodiment. In the present invention in which the width of each part of the fixed iron piece 20 is selected in this manner, good results are obtained as will be described later in combination with the rotation of the fixed iron piece.

2 (a) and 2 (b) are fixed iron pieces with a normal graduation rating (runout angle of 90 degrees), the fixed iron pieces used in an instrument with an extended graduation rating are shown in FIG. 2 (c). .
(C) As shown in the figure, the fixed scale iron piece 20 having the extended scale rating has a shape in which the rectangular portion 24 is integrally formed at the tip portion 23 of the arc portion 22 of the regular scale rating fixed iron piece.

In the cylinder 30 shown in FIG. 3, (a)
Is a perspective view, (b) is a sectional view taken along line XX 'of (a), (c).
FIG. 7B is a side view from the Y direction in FIG. (I)~
In the figure, the cylinder 30 is made of plastic, the body 31 has a cylindrical shape, and a disc-shaped collar 32 is integrally formed on the upper side. L-shaped protrusions 32 a and 32 b and arc-shaped holes 32 c and 32 d are formed on the upper surface of the collar 32. Bottom 31 of the body 31
A through hole 31b is formed at the center of a. Further, an opening 31c is formed in the body portion 31, and concave portions 31d and 31e are formed in the side wall. The tip portion 23 of the fixed iron piece 20 is fitted into the recess 31d, and the recess 31e
Is the tip portion 2 of the fixed iron piece 20 for the above-mentioned extended scale rating.
The rectangular part 24 formed in 3 is fitted.

FIG. 4 shows a state in which the fixed iron piece 20 is attached to the cylinder 30 having such a structure. That is, the fixed iron piece 2
0 indicates the opening 3 formed by the arc portion 22 on the cylinder body 31
The bent portion of the butterfly portion 21 and the arc portion 22 is attached to the inner wall of the body of the cylinder 30 by an adhesive agent or ultrasonic caulking so as to be located at 1c. In that case, fixed iron piece 2
The leading end 23 of 0 is the recess 3 formed on the side wall of the cylinder 30.
Bonded in 1d. Further, in the case of the extended scale, the flat plate portion 24 formed at the tip of the circular arc portion 22 of the fixed iron piece 20 is positioned inside the recess 31e formed in the side wall of the cylinder 30.

Returning to FIG. 1, reference numeral 40 is a frame for holding the movable shaft 11 to which the movable iron piece 16 is attached, and its structure is shown in FIG. 1 and 5, the frame 40 connects a disc 41 having the same shape as the collar 32 of the cylinder 30 described above, a disc 42 having a small diameter having the same central axis as the disc, and discs 41 and 42. It is composed of a body portion 43 that runs. Disk 4
2 and the body portion 43 are inserted and arranged in the cylinder of the cylinder 30 described above, in which case the disc 42 is inserted in the through hole 31b formed in the center of the bottom surface 31a of the cylinder 30. There is. A bridge 41a and mounting arms 41b and 41c formed on both legs of the bridge are formed on the upper side of the upper disc 41, and a notch 41d reaching the center of the disc 41 and the disc 41 are formed. A pair of arc-shaped holes 41e and 41f are formed along the circumference. A square hole 41g into which the protrusions 32a and 32b formed in the cylinder 30 are inserted into one end of each of the pair of holes.
(41h: 41h is not visible in the figure) is formed.

In the frame member 40 having such a structure, the body portion 43 is used by being fitted in the cylinder of the cylinder member 30. In that case, the holes 41e formed in the upper disc 41 of the frame member 40, Cylinder 3 on 41f
The protrusions 32a and 32b formed on the zero holes are square holes 41g and 41g.
The cylinder 30 is inserted from h and guided by the arcuate holes 41e and 41f so that the cylinder 30 can rotate within the range of the length of the pair of holes. At the center of each of the bridge 41a and the lower disc 42, there are stone screws 51, 52
Screw holes 41i and 42a into which are screwed are respectively formed. Like the cylinder 30, the frame member 40 is integrally made of plastic by precision molding.

Returning to FIG. 1 again, a cylindrical fixed coil 60 is inserted into the cylinder 30 to which the frame member 40 is attached. 70 is a fixed coil 60
Is a shield arranged so as to surround the. The order of the construction of the instrument including the respective parts having such a construction is as follows. (1) The cylinder 30 having the collar 32 is turned or precision molded to form the cylinder 30 shown in FIG. 3, and the fixed iron piece 20 is inserted into the cylindrical portion from the opening 31c, and the cylinder 30 shown in FIG.
The fixed iron piece 20 is attached to the cylindrical body 31 as shown in FIG. Further, the frame member 40 shown in FIG. 4 including the discs 41 and 42, the body portion 43, the bridge 41a, etc. is integrally formed by turning or precision molding, and the bridge 41a and the disc 42 of this frame are provided with stone screws 51, Attach 52 respectively. (2) The movable shaft 11 in the instrument movable portion 10 configured by previously attaching the pointer support 12, the control spring 14, the movable iron piece 16 and the like to the movable shaft 11 is attached to the frame member 4
Stone screws 51 and 52 attached to the frame member 40 with the pivots inserted into both ends of the movable shaft 11 through the notches 41d formed in the upper disk 41 of 0.
And the gap between each pivot and the stone screw is adjusted properly by adjusting both stone screws 51 and 52. (3) Frame member 4 to which the movable instrument 10 is attached
0 is inserted so that the body portion 43 is fitted into the cylinder 30, and a pair of arc-shaped projections 32a and 32b formed on the cylinder 30 are formed on the upper disc 41 of the frame member 40. The holes 41e and 41f are engaged.
In this case, the fixed iron piece 20 and the movable iron piece 1 attached to the cylinder 30 are used to adjust the sensitivity of the instrument or to set the extended scale.
It is determined by the position relative to 6. For that purpose, it is necessary to rotate the cylinder 30 with respect to the frame member 40, but in the instrument of the present invention, the protrusions 32a and 32b formed on the cylinder 30 are the disc 41 of the frame member 40.
Guided by the arcuate holes 41e and 41f formed in the cylinder 30, the cylinder 30 can rotate about the movable shaft 11 with high accuracy. (4) Cylinder 30 to which the frame member 40 is attached
Is mounted in the ring of the fixed coil 60 covered with the shield 70. (5) While supplying the reference current to the fixed coil 60, the cylinder 30 is rotated with respect to the frame member 40 to adjust the sensitivity of the instrument and the like. After the adjustment, the screw 41 (82) is used to form the hole 41 formed in the upper disc 41 of the frame member 40.
The cylinder 30 and the frame member 40 are fixed to the fixed coil 60 via j (41k) and arcuate holes 32c and 32d formed in the flange 32 of the cylinder 30.

[0018]

According to the present invention, by using a structure in which a fixed iron piece of butterfly + arc shape is used and this is rotated,
It is possible to obtain a movable iron piece type instrument that can easily adjust variations in the coil spring, relative displacement between the movable iron piece and the fixed iron piece, or sensitivity changes due to variations in the fixed coil simply by rotating together with the cylinder. Moreover, the scale characteristic of the butterfly-shaped + arc-shaped fixed iron piece structure is close to that of a uniform scale (the scale is not clogged when the input is low), and even if the position of the iron piece changes, there are few eye-opening errors. Even an unfamiliar worker can easily adjust the sensitivity.

FIG. 8 shows the case of using the arcuate shape and the butterfly shape shown in FIG. 6 as the fixed iron piece, and the butterfly shape + arc shape according to the present invention selected according to the above dimensions. It is a graph showing an error in the appearance with respect to the full-scale value when the torque of the control spring is changed by ± 5%.
As is clear from FIG. 8, when the fixed iron piece according to the present invention is adopted, the change in the eye drop is kept to a very small value of 0.3 to 0.5% with respect to the torque change of the control spring of ± 5%. Is possible. Generally, when used in 2.0 to 2.5 class instruments, a control spring having a torque tolerance of about ± 3% or less is required, and a very expensive one is required. By using the fixed iron piece concerned and rotating this, a general spring with a torque tolerance of about ± 5-6% can be used, and printing scales are possible. In addition to the above, according to the present invention, it is possible to obtain a movable iron piece instrument which is very low in cost.

Also, in the conventional internal unit of this type, when the extended scale is rated, separate fixed iron pieces are required for the double and triple scale ratings, but the cylinder is rotated to rotate the fixed iron pieces. By doing so, according to the present invention, it is possible to provide extended scales of various ratings simply by preparing one type of fixed scale iron piece for extended scale. In addition, by mounting a fixed iron piece on the cylinder and adopting a structure in which the cylinder is fitted to the frame, the rotation is stable, and assembly and adjustment with little variation can be performed.
Furthermore, the fixed iron piece can be replaced very easily,
It is possible to obtain a movable iron piece instrument that can easily change the rating (non-extended to extended).

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a movable iron piece instrument of the present invention.

2 is a configuration diagram of a fixed iron piece used in the movable iron piece type instrument of FIG. 1. FIG.

3 is a configuration diagram of a cylinder used in the movable iron piece type instrument of FIG. 1. FIG.

4 is a configuration diagram of a cylinder portion used in the movable iron piece type instrument of FIG. 1. FIG.

5 is a configuration diagram of a frame used in the movable iron piece type instrument of FIG. 1. FIG.

FIG. 6 is a configuration diagram of a movable iron piece and a fixed iron piece used in the movable iron piece type instrument.

FIG. 7 is a configuration diagram of an example of a conventionally used fixed iron piece attachment structure.

FIG. 8 is a diagram showing a projection error due to a change in spring torque when each fixed iron piece is used.

[Explanation of symbols]

 10 Movable part 16 Movable iron piece 20 Fixed iron piece 21 Arc + Butterfly shaped fixed iron piece 30 Cylinder 40 Frame

Claims (3)

[Claims] 1. An instrument in which a movable shaft having a movable iron piece mounted therein is arranged in a cylinder having a fixed iron piece composed of a flat plate-shaped butterfly portion and an arc portion extending from the butterfly portion. The member is formed of a cylindrical body having an opening, the cylinder made of a plastic material to which the fixed iron piece is attached so that the circular arc portion is located in the opening, and the frame of the plastic material holding a movable shaft to which the movable iron piece is attached. A movable iron piece instrument which is configured to be separated into a member and in which the frame member is rotatably mounted in the cylinder so that the movable shaft is located in the cylinder. 2. A fixed iron piece for extended scale, comprising a flat plate-shaped butterfly portion, an arc portion extending from the butterfly portion, and a flat plate portion extending from the tip of the arc portion, the side wall of the cylinder body portion being provided. 2. The movable iron piece type instrument according to claim 1, wherein a concave portion into which the flat plate portion for extension scale extending from the tip of the fixed iron piece is fitted is formed. 3. H, H1 and H2, where H is the width of the butterfly portion of the fixed iron piece, H1 is the width of the base of the arc portion extending from the butterfly portion, and H2 is the width of the tip of the arc portion. The movable iron piece type meter according to claim 1, wherein the relationship is selected as follows. Note H1 = 0.5 to 1.0H H2 = 0.05 to 0.3H