JPH07167680A - Hair spring mounting structure for resetting needle to zero - Google Patents

Abstract

PURPOSE:To reduce the hysteresis of designation by forming a structure in which a contact overcrowded part between wires of a hair spring is so set as to be eccentrically deviated toward an outer end locking part with a rotary shaft as a boundary. CONSTITUTION:A crank-shaped bent part having a first bent 14, a second bent 15 and a third bent 16 is formed at the locking end of a housing of a spiral hair spring 12, and further a pair of protrusions 17A, 17B in contact with a first bent side end and a third bent side end of the bent 15 to energize to lock the spring 12 are formed in the housing. At the time of mounting an instrument of the spring 12, when the inclination of the bent 15 is controlled by the protrusions 17A, 17B and a needle is rotated against elasticity of the spring and wound to reduce its diameter, the wires of the spring is not brought into contact with one another, and hysteresis of designation by an operation of the needle is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for a hairspring for zeroing pointers incorporated in an analog type instrument such as a cross coil type instrument.

[0002]

2. Description of the Related Art As a conventional analog type instrument structure, there is a structure as shown in FIGS. 1 and 2, for example. That is,
Reference numeral 1 denotes a movable magnet magnetized with two poles. The movable magnet 1 is fixed to a rotating shaft 2 and is rotatably supported by an upper housing 3 and a lower housing 4. Reference numerals 5 and 6 are coils wound around the outer periphery of the combination of the upper housing 3 and the lower housing 4 which also serve as coil bobbins,
As shown in FIG. 2, the inner coil 5 and the outer coil 6 are wound in contact with the inner coil 5 at right angles. The coil terminal is wound around the terminal 10 (3 to 4 places) and fixed by soldering or the like. The direction of the composite magnetism changes depending on the magnitude of the current flowing through the coils 5 and 6, and the movable magnet 1 rotates following the change to cause the pointer 7 fixed to the rotary shaft 2 to be pointed to a desired position, and the power source When cut, the pointer 7 is returned to the zero position by the hair spring 8 fixed to the rotary shaft 2. In addition, 9 is a shield for eliminating the influence of the external magnetic field.
It is a case. A spiral hairspring 8 provided for zeroing the pointer has its inner end fixed to the rotating shaft 2 and its outer end locked in a locking groove 11 provided in the housing 3. It is what That is, as shown in FIG. 2, the hairspring 8 for returning to the pointer is mounted in the instrument by fixing the inner end of the hairspring 8 having a substantially concentric shape to the rotating shaft and the outer end of the hairspring 8 to the housing 3. It is what

[0003]

Therefore, when the pointer 7 provided with the hair spring 8 is rotated against the elastic force of the hair spring 8, the spiral hair spring 8 has the form thereof. As shown in FIG. 3, the hair spring 8 has a line contact overcrowded portion 8 ′ at the portion opposite to the outer end with the rotating shaft 2 as a boundary, due to the fact that the hair is wound and the diameter is reduced. As a result, the line contact overcrowding portion 8 ′ hinders the smooth pivotal movement of the pointer 7 and causes a hysteresis of the indication, and there is a problem that the movement of the pointer 7 is caught. .

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, in which a hair spring is attached to reduce the hysteresis of an instruction by a pointer and to cause a smooth movement of the pointer. It provides the structure. That is, in the present invention, when the hairspring is set on the instrument, the shrinkage amount of the spiral of the hairspring due to the rotation of the pointer is taken into consideration, and the line contact overcrowded portion of the hairspring has an outer end engagement with the rotation axis as a boundary. (EN) Provided is a hairspring mounting structure for instrument zero return, which has a structure which can be set so as to be eccentric in the direction of the stop portion, so that the pointer can be smoothly rotated and the hysteresis of the instruction can be reduced. .

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on the embodiments shown in the drawings. The same parts as the structure of this embodiment and the structure described in the conventional example are designated by the reference numerals used in the conventional example. Then, the structural description of the same structural part is omitted.

That is, FIGS. 4 and 5 are characterized in that the crossing coil type instrument having the same structure as that described in the conventional example is provided with the hairspring 12 for zeroing, which is an embodiment of the present invention. In the unitary structure of the spiral hair spring 12 in this embodiment, as shown in FIG. 6, the inner end of the hair spring 12 is formed into the hook-shaped rotary shaft locking portion 13, and the outer end thereof is The bent portion 14, the second bent portion 15, and the third bent portion 16 are formed in a crank-shaped locking portion. Further, the housing 3 is locked by shifting the outer end of the hair spring 12 from the chain line to the left side shown by the solid line in FIGS. 5 and 7 in anticipation of the contraction amount of the spiral of the hair spring accompanying the rotation of the pointer. A locking projection 17 for this is formed integrally with the housing 3, and this locking projection 17 is formed on the second bent portion 15 of the crank-shaped locking portion as shown in FIG. 7, for example. The first protrusion 17A abutting on the inner surface of the end on the side of the third bent portion 16
And a second projecting portion 17B that is in contact with the outer surface of the end of the second bent portion 15 on the side of the first bent portion.

As described above, the shapes of the first protrusion 17A and the second protrusion 17B are such that both ends of the second bent portion 15 can be brought into contact with and locked to each other. Therefore, as shown in FIG. 7, both protrusions 17A, 17A
The locking surface of B is tapered, or, as shown in FIG. 8, a pair of protrusions 17A, 1
7B, or as shown in FIG. 9, the protrusions 17A and 17B having a hook-shaped cross section may be formed symmetrically in the oblique direction.

Each of the protrusions 17A and 17B is made of resin integrally formed with the upper housing 3, and after the outer ends of the hair springs 12 are locked between the protrusions 17A and 17B, The tips of the protrusions 17A and 17B are heat-welded as shown in FIG. 10 to prevent the outer ends of the hair springs from coming off.

In the above embodiment, the inner surface of the spiral hair spring is locked by the projection 17A and the outer surface of the spiral hair spring is locked by the projection 17B. However, the invention is not limited to this. As shown in FIG. 11, the outer side surface of the hair spring is locked by the protrusion 17A, and the inner side surface thereof is protruded by the protrusion 17A.
Even if it is locked by B, the same effect as that of the above embodiment can be obtained.

As described above, in this embodiment, when fixing the outer end of the spiral hair spring 12 to the housing, the crank-shaped engaging portion formed on the outer end of the hair spring is used as a pointer. Since a pair of protrusions 17A and 17B are provided to allow the spiral hair spring to contract while being biased and biased in the direction in which the spiral hair spring is rolled in, while allowing the spiral hair spring to shrink while being rotated. Due to the locking action of the protrusions 17A and 17B, for example, in the conventional protrusion of FIG. 12, the spiral force of the spiral hair spring causes a downward spiral in the drawing. As shown in FIG.
The second bent portion 1 is formed by the pair of protrusions 17A and 17B.
Since the inclination of 5 is regulated in a substantially vertical direction, the downward sagging of the spiral is eliminated, whereby when the pointer is rotated against the elasticity of the hair spring and is rolled in to reduce the diameter, It is possible to regulate the mounting shape so as not to cause the line contact.

Although the hair spring 12 having the above structure is mounted between the rotary shaft 2 provided on the movable magnet 1 and the housing 3 in the above embodiment, the present invention is not limited to this. For example, FIG. 13 and FIG.
As shown in FIG. 4, the present invention can be applied to an eccentric type cross-coil type instrument having a rotary shaft 2 attached to a movable magnet 1 and an eccentric rotary shaft 18 arranged in parallel. That is, the upper housing 3 is provided with a locking projection 17 similar to that in the above embodiment, that is, a pair of projections 17A and 17B,
By providing the spiral hair spring 12 between the locking projection 17 and the eccentric rotation shaft 18, it is possible to obtain the same effect as that of the above embodiment.

[0012]

As described above, according to the present invention, in the cross coil type instrument in which the spiral hair spring for returning the pointer is mounted between the rotary shaft on which the pointer is mounted and the housing, the spiral hair spring is provided. A crank-shaped fold consisting of a first fold 14, a second fold 15, and a third fold 16 is formed at the housing-side locking end of the housing. Second bent portion 1
The pair of protrusions 17A and 17B, which are respectively abutted to the first bent portion side end and the third bent portion side end of 5 to bias and lock the spiral hair spring in the winding direction, Since the hair spring mounting structure is formed, the pair of protrusions 1 is attached when the spiral hair spring is mounted on the instrument.
The inclination of the second bent portion 15 is regulated by 7A and 17B, so that when the pointer is rotated against the elasticity of the hair spring to be rolled up and the diameter is reduced, the line contact in the hair spring is prevented. Therefore, the hysteresis of the pointer due to the pointer movement can be reduced, and thus the pointer movement can be smoothly performed, and an analog type instrument having excellent pointing characteristics can be obtained.

[Brief description of drawings]

FIG. 1 is a structural explanatory view showing a conventional cross coil type instrument.

FIG. 2 is an explanatory plan view showing a conventional cross-coil type instrument.

FIG. 3 is an explanatory view of a hair spring used in a conventional cross coil type instrument.

FIG. 4 is a structural explanatory view of a cross coil type instrument having a hair spring mounting structure according to the present invention.

FIG. 5 is an explanatory plan view of a crossed coil type instrument having a hair spring attachment structure according to the present invention.

FIG. 6 is an explanatory diagram of a hair spring according to an embodiment of the present invention.

FIG. 7 is an explanatory view of attaching the hair spring according to the embodiment of the present invention.

FIG. 8 is an explanatory view of the structure of a hair spring locking portion of another embodiment of the present invention.

FIG. 9 is a structural explanatory view of a hair spring locking portion according to still another embodiment of the present invention.

FIG. 10 is an explanatory view of a crimping structure according to the embodiment of the present invention.

FIG. 11 is a plan view of a main portion showing another embodiment of the shape of the hair spring locking portion.

FIG. 12 is an operation explanatory view of a conventional hair spring.

FIG. 13 is an explanatory diagram showing a state in which the hair spring mounting structure of the present invention is applied to an eccentric cross coil.

14 is an explanatory plan view of FIG.

[Explanation of symbols]

12 ... Hair spring 13 ... Rotating shaft locking part 14 ... 1st bending part 15 ... 2nd bending part 16 ... 3rd bending part 17 ... Locking protrusion 17A ... 1st protrusion part 17B ... Projection 2 18 ... Eccentric rotation shaft

Claims (2)

[Claims] 1. A cross-coil type instrument in which a spiral hair spring for zeroing the pointer is mounted between a rotary shaft to which a pointer is mounted and a housing, wherein a housing-side locking end portion of the spiral hair spring is provided. , The first bent portion (1
4), the second bent portion (15), the third bent portion (1
6) is formed into a crank-shaped bend, and the housing is further provided with a first bent part side end and a third bent part side end of the second bent part (15). A hairspring attachment structure for zero hands, characterized in that a pair of protrusions (17A) and (17B) that are respectively brought into contact with each other to bias and lock the spiral hairspring in the winding direction are formed. 2. The hairspring mounting structure for zero hands according to claim 1, wherein the rotary shaft for mounting the pointer is arranged in parallel with the rotary shaft for supporting the movable magnet at an eccentric position.