JP3407650B2 - Cross-coil indicating instrument - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cross coil type indicating instrument used in vehicles and general industrial equipment.

[0002]

2. Description of the Related Art Heretofore, as a cross-coil type indicating instrument of this type, there is one shown in Japanese Utility Model Publication No. 62-17714. This cross-coil type indicator has two cross-coils wound around the outer wall of a hollow bobbin, a pointer shaft coaxially and rotatably supported in the bobbin and extending through a dial, and a bobbin inside the bobbin. Disk-shaped magnet that is coaxially supported by the pointer shaft, and a pointer that is supported by the tip of the pointer shaft and that indicates and displays on the dial as the pointer shaft rotates.
And a magnetic shield casing that houses the bobbin from its bottom wall.

Here, a part of the outer peripheral wall of the magnetic shield casing is formed in a radially different shape from the outer peripheral wall. Then, when the electromagnetic force of both crossing coils has disappeared, the magnet is magnetically attracted by the deformed portion of the outer peripheral wall of the magnetic shield casing by the magnetic attracting portion formed on the outer peripheral wall of the magnet to rotate. It gives a zeroing effect to the pointer. Therefore, the pointer returns to the zero indication position and is held as it is.

[0004]

However, in the above-mentioned cross-coil type indicator, in order that the deformed portion of the magnetic shield casing maintains the specified zero holding force for the magnetized portion of the magnet, Must be formed by largely deforming a part of the outer peripheral wall of the magnetic shield casing inward over the entire axial width thereof.

For this reason, it hinders the reduction of the outer diameter and the flattening of the outer diameter of the magnetic shield casing. In order to cope with such a situation, the present invention devises a zero-return structure between the magnetic shield casing and the magnet to ensure flatness and downsizing, while maintaining a proper zero-retention force. An object is to provide a coil type indicating instrument.

[0006]

In order to solve the above-mentioned problems, according to the invention described in claim 1, the cross coil type indicator is wound around a resin housing (10) and an outer wall of the housing. Both the cross coils (20) and the dial (4) supported coaxially and rotatably in the housing.
0) extending through the pointer shaft (30), and a disk magnet supported coaxially with the pointer shaft in the housing, the disk magnet having a magnetic pole portion formed on the outer peripheral wall thereof. (50), a pointer (60) supported by the tip of the pointer shaft and indicating and indicating on a dial plate as the pointer shaft rotates, and a housing is housed from its bottom wall (15). A magnetic shield casing (70).

Then, the housing has a magnetic wall on its bottom wall.
Formed to face the bottom wall (71) of the air shield casing
The magnetic shield casing is provided with at least one recess (15a) formed therein , and the bottom portion of the magnetic shield casing projects toward the bottom wall of the housing and is fitted into the recess (74).
Is equipped with. In the present invention thus configured, when the magnet rotates together with the pointer shaft so as to zero the pointer, the magnet is magnetically attracted by the magnetic pole portion to the convex portion of the magnetic shield casing, It is held at a position facing the convex portion.

By thus projecting the convex portion of the magnetic shield casing toward the bottom wall of the housing, the zeroing action of the pointer is secured, so that the magnetic shield casing is subjected to the conventional variant forming process. Without this, it is possible to easily achieve flattening of the cross-coil type indicating instrument, and also to ensure the zeroing action of the pointer with high accuracy .

[0009]

According to a second aspect of the present invention, in the crossed coil type indicating instrument according to the first aspect , the housing has a bottom wall in which the recess is formed symmetrically with respect to the pointer axis. I have two. Also, the magnetic shield casing is
The bottom wall is provided with two protrusions which are located corresponding to the two recesses and are fitted into these recesses. As described above, by providing two recesses and two projections symmetrically corresponding to each other, the invention according to claim 1 can be achieved in a well-balanced manner with respect to the action and effect.

Further, according to the invention described in claim 3 , in the cross coil type indicating instrument according to claim 1 or 2 ,
The convex portion is fitted in the recess immovably in the circumferential direction. As a result, the function and effect of the invention described in claim 1 or 2 can be achieved, and the magnetic shield casing can be prevented from rotating by the housing. Also, the claims
According to a fourth aspect of the present invention, in the crossed coil type indicator according to any one of the first to third aspects, the convex portion is a concave portion that is projected from the bottom wall of the magnetic shield casing toward the bottom wall of the housing. It may be a tongue fitted in place.

According to a fifth aspect of the present invention, in the cross coil type indicating instrument according to any one of the first to fourth aspects, the housing also serves as a winding line separator for the cross coil. It is provided with a terminal holder part (11, 12) to fulfill. The recess is formed in the bottom wall side end of the magnetic shield casing of the terminal holder part.

As a result, the projection is fitted in the recess of the terminal holder portion which also functions as a winding line separator for the crossed coils. Therefore, the effects of the invention according to claims 1 to 4 are achieved. Of course, it is possible to prevent the convex portion and the concave portion from interfering with the cross coil.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 show a cross-coil type indicating instrument for a vehicle according to the present invention, and the cross-coil type indicating instrument is arranged on an instrument panel in a vehicle compartment of a vehicle. The cross coil type indicator is a hollow bobbin 1 as a housing made of a resin material (for example, Duracon).
It has 0. This bobbin 10 is constructed by assembling upper and lower bobbin members 10a and 10b with each other.
The bobbin 10 is housed in a magnetic shield casing 70 described later. The bobbin member 10b is inserted into a central hole portion 71a provided in the bottom wall 71 of the magnetic shield casing 70 at a central tubular portion formed in the bottom wall 15 thereof.

As shown in FIGS. 1 and 2, the bobbin 10 is provided with both terminal holder portions 11 and 12, and these terminal holder portions 11 and 12 are provided on the outer peripheral portion of the bobbin 10 and their shafts are provided. It is formed along the direction. Here, both terminal holder portions 11 are symmetrically positioned with reference to a pointer shaft 30 described later, while both terminal holder portions 12 are symmetrically positioned with respect to the pointer shaft 30 and both terminals. It is located orthogonal to the line connecting the holder portions 11. It should be noted that each of the terminal holder portions 11 and 12 also plays a role as a winding line separator for both cross coils 20 described later at the upper end portion thereof.

Further, both terminals 13 are inserted in both terminal holder portions 11 along the axial direction thereof,
On the other hand, both terminals 14 are both terminal holder parts 1
It is inserted in 2 along the axial direction. The terminals 13 and 14 are made of a non-magnetic conductive material such as phosphor bronze. Both crossing coils 20 are wound around the outer wall of the bobbin 10 so as to cross each other. The crossing coils 20 are driven by a driving circuit (not shown) to generate a combined electromagnetic force. The both cross coils 20 are connected to the upper ends of the terminals 13 and 14 at their connection terminals.

The pointer shaft 30 is coaxially and rotatably supported inside the bobbin 10 and extends upward through a through hole portion of the dial 40. The pointer shaft 30 is a disc magnet. It rotates in conjunction with 50. The lower end of the pointer shaft 30 is located inside the central tubular portion of the bobbin member 10b. The pointer shaft 30 is made of a steel material or the like.

The disk-shaped magnet 50 is coaxially supported inside the bobbin 10 while being partially immersed in the silicone oil contained in the lower bobbin 10b, at an intermediate portion of the pointer shaft 30. The magnet 50 is rotated by the combined electromagnetic force of the two crossing coils 20. Here, on the outer peripheral wall of the magnet 50, both magnetic pole portions 51 and 52 are magnetized so as to be positioned symmetrically with respect to the axial center of the pointer shaft 30. The magnetic pole portion 51 is an N pole, and the magnetic pole portion 52
Is the south pole. The magnet 50 is formed of a ferrite permanent magnet.

The pointer 60 is supported by the tip end portion of the pointer shaft 30, and the pointer 60 rotates in conjunction with the rotation of the pointer shaft 30 to display an instruction on the dial 40. The magnetic shield casing 70 is made of a soft magnetic material such as permalloy or Ni—Fe alloy and has a substantially U-shaped cross section as shown in FIG.
It forms a magnetic circuit together with the magnet 50 and plays a role of shielding disturbance magnetic energy.

The magnetic shield casing 70 is provided at its bottom wall 71 with square openings 72 and square openings 73, as illustrated in FIGS. 3 and 4. Both openings 72 are different from the central hole 71a of the bottom wall 71 in the bottom wall 7
1 is symmetrically formed on the outer peripheral portion of the base wall 1. On the other hand, both openings 73 are formed symmetrically with respect to the central hole portion 71a of the bottom wall 71 and orthogonal to the line connecting both openings 72. There is.

Both terminal holder portions 11 of the bobbin 10 are press-fitted into the respective opening portions 72 at their lower end portions 11a, while both terminal holder portions 12 of the bobbin 10 are fitted into the respective opening portions 73. , Is press-fitted at its lower end 12a. It should be noted that both terminals 13 extend outwardly from their respective lower end portions 11a of both terminal holder portions 11 at their respective lower end portions 13a, while both terminals 14 are
At each lower end portion 14a, both terminal holder portions 12
From each lower end 12a of the.

Further, the magnetic shield casing 70 has, on the bottom wall 71 thereof, both tongue pieces 74 having a square cross section as shown in FIGS. 2 to 4, and these both tongue pieces 74 are
The holding torque after the zeroing of the pointer 60 acts on the magnet 50. Of these both tongue pieces 74, the left side tongue piece 74 shown in FIG. 3 is the central hole portion 71 a of the left side opening portion 72.
The left side tongue piece 74 is formed by cutting and bending from the side inner wall portion toward the inside of the magnetic shield casing 70 in an L shape.
The tip portion 74a is fitted into the left side recess 15a formed in the lower bobbin 10b.

Here, the left recess 15a is formed in the lower end portion 11a of the left terminal holder portion 11 in a square cross section. On the other hand, the right tongue piece 74 is formed by cutting and bending toward the inside of the magnetic shield casing 70 in an L-shape from the inner wall portion of the right side opening 72 on the side of the central hole 71a. At the lower bobbin 10b
It is fitted in the right side recess 15a formed in the.

Here, the right recess 15a is formed in the lower end portion 11a of the right terminal holder portion 11 in a square cross section. The holding torque is determined by the shape and size of the magnetic shield casing 70, the distance h between the bottom wall of the magnet 50 and the tip of each tongue piece 74, the axis of the pointer shaft 30 and each tongue piece 74.
It is properly set by selecting the radial distance r from the outer wall of the tip end portion 74a, the plate thickness t and the width w (see FIG. 2) of the tip end portion 74a of each tongue piece 74. In addition, the tip portion 74a of each tongue piece 74
The width w of each of the recesses 15a is fittable and substantially coincides with the circumferential width n (see FIG. 2) of each recess 15a.

In the present embodiment configured as described above, the magnet 50 receives the combined electromagnetic force from both the crossing coils 20 generated by being driven by the drive circuit, and rotates together with the pointer shaft 30, so that the pointer 60 is moved. It is assumed that the pointer is rotated in association with the pointer shaft 30 and the instruction is displayed on the dial 40. In such a state, when the drive circuit generates a combined electromagnetic force (hereinafter referred to as a forced zero-reduction electromagnetic force) forcibly returning the pointer 60 to zero from both crossing coils 20,
The magnet 50 rotates in the direction of the arrow shown in FIG. 5 together with the pointer shaft 30 so as to zero the pointer 60 by receiving the forced zero-reduction electromagnetic force.

Along with this rotation, the pointing position of the pointer shaft 60 reaches the zero pointing position, and the magnet 50 causes the respective magnetic pole portions 5 to move.
1, 52, both tongue pieces 7 of the magnetic shield casing 70
4 is rotated to a position facing the respective tip portions 74a of the No. 4 magnetic poles and the forced zero-reduction electromagnetic force disappears, the magnetic pole portions 51 and 52 are magnetically applied to the respective tip portions 74a of both tongues 74 under the holding torque. Is sucked into each. Here, the holding torque is properly set as described above.

Therefore, the magnet 50 stops its rotation, and is properly held by the magnetic pole portions 51 and 52 at the positions facing the respective tip portions 74a of the tongue pieces 74 (see FIG. 6). ). As a result, the pointer 60 can be accurately stopped and held at the zero return position. Here, each tongue piece 74 of the magnetic shield casing 70 is cut and bent into an L shape inside the magnetic shield casing 70 to form each recess 1 of the lower bobbin 10b.
Since the zeroing action of the pointer 30 is ensured by fitting the needle 30 in the 5a, the magnetic shield casing 70 and the bobbin 10 are secured.
It is possible to shorten the axial length of the.

As a result, the axial length of the cross-coil type indicating instrument can be easily shortened, that is, the cross-coil type indicating instrument can be easily flattened without carrying out the conventional modification processing on the magnetic shield casing 70. At the same time, the zeroing action of the pointer 60 can be accurately ensured. In this case, as described above, since the magnetic shield casing 70 is not subjected to the conventional deforming process, the cylindricity of the magnetic shield casing 70 is not changed when the magnetic shield casing 70 is formed (for example, by press working). It can be secured accurately.

Further, as described above, the tip portions 74a of the tongue pieces 74 are fitted in the recesses 15a, respectively,
In addition, the width w of the tip portion 74a of each tongue piece 74 is determined by
Approximately fits in the circumferential width n of the above. For this reason, the tip end portion 74a of each tongue piece 74 can be held immovably in the circumferential direction in each recess 15a. This is the bobbin 10
Means that the magnetic shield casing 70 has a rotation preventing function.

Further, as described above, since the tip end portions 74a of the respective tongue pieces 74 are fitted in the respective recesses 15a of both terminal holder portions 11 having the role of the winding line separator, the respective tongue pieces 74 are formed. Even if the recesses 15a are provided, these do not interfere with the cross coil 20. If there is no such an obstacle, each tongue piece 74
The position where the recess 15a is provided may be changed.

In the above embodiment, an example in which both tongue pieces 74 are formed by cutting and bending on the bottom wall 71 of the magnetic shield casing 70 has been described. Substantially the same effect can be achieved. Further, in carrying out the present invention, both tongue pieces 74
Is not limited to both openings 72 of the bottom wall 71 of the magnetic shield casing 70, and both tongue pieces 74 are formed in both openings 73, and the lower end portions 12 of both terminal holder portions 12 are formed.
Recesses (similar to the recess 15a) are formed in a, and the tongue pieces 7 formed in both openings 73 are formed in these recesses.
4 may be fitted. In this case, both openings 7
Instead of 2, the tongue pieces 74 may be formed in both openings 73.

In implementing the present invention, both tongue pieces 74
Is not limited to a square cross section, but may be changed to a circular cross section or the like. Further, in carrying out the present invention, the bottom wall 71 of the magnetic shield casing 70 is punched out as a convex portion toward the inside of the magnetic shield casing 70 at a portion corresponding to the tongue pieces 74, and the both tongue pieces 74 are eliminated. May be.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a cross-coil type indicating instrument according to the present invention with a pointer and a dial removed.

FIG. 2 is a sectional view taken along line 2-2 in FIG.

3 is a perspective view of the magnetic shield casing of FIG. 1. FIG.

FIG. 4 is a bottom view of the cross-coil indicating instrument of FIG. 1 viewed from the bottom wall side of the magnetic shield casing.

FIG. 5 is a plan view showing a rotation direction of a magnet and a pointer shaft with respect to a forced zero electromagnetic force.

FIG. 6 is a plan view showing a state in which a magnet has been rotated to a zero return position.

[Explanation of symbols]

10 ... Bobbin, 10a ... Upper bobbin member, 10b ... Lower bobbin member, 11, 12 ... Terminal holder part, 11
a, 12a ... lower end, 15 ... bottom wall, 15a ... recess, 20
... crossing coil, 30 ... pointer axis, 40 ... dial, 50 ... magnet, 51, 52 ... magnetic pole section, 60 ... pointer, 70 ... magnetic shield casing, 71 ... bottom wall, 72, 73 ... opening, 74 ... tongue Piece, 74a ... Tip.

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01R 5/16

Claims (5)

(57) [Claims] 1. A resin housing (10) and a double cross coil (2) wound around an outer wall of the housing.
0), a pointer shaft (30) coaxially and rotatably supported in the housing and extending through the dial (40), and coaxially supported by the pointer shaft in the housing. A disc magnet (50) having a magnetic pole portion formed on its outer peripheral wall, and a disc magnet (50) supported by the tip end portion of the pointer shaft and rotating on the dial shaft as the pointer shaft rotates. In a cross-coil type indicator instrument comprising a pointer (60) for indicating and displaying by means of, and a magnetic shield casing (70) accommodating the housing from its bottom wall (15), the housing has a bottom wall. , At least one recess (15a) formed so as to face the bottom wall (71) of the magnetic shield casing, wherein the magnetic shield casing faces the bottom wall of the housing at its bottom wall. Issued by cross coil type indicating instrument, characterized in that it includes a projection (74) fitted into said recess. 2. The housing is provided with two recesses on the bottom wall thereof symmetrically with respect to the pointer shaft, and the magnetic shield casing is provided on the bottom wall with the protrusions. and positioned so as to correspond to the two recesses cross coil type indicating instrument according to claim 1, characterized in that it comprises two fitted thereto recesses. Wherein the convex portions claim 1 or, characterized in that fitted to immovable in the circumferential direction in said recess
The cross-coil type indicator as described in 2 . 4. The tongue piece according to claim 1, wherein the convex portion is a tongue piece that protrudes from the bottom wall of the magnetic shield casing toward the bottom wall of the housing and is fitted into the recess . The crossed coil type indicating instrument described in any one of the above. 5. The housing is provided with a terminal holder portion (11, 12) which also functions as a winding line separator for the cross coil, and the recess is provided in the magnetic shield casing of the terminal holder portion. The cross coil type indicating instrument according to any one of claims 1 to 4 , wherein the cross coil type indicating instrument is formed in an end portion on the bottom wall side.