JP3796942B2 - Cross coil type indicator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cross coil type indicating instrument.
[0002]
[Prior art]
Conventionally, in a cross coil type indicator, a hollow bobbin that supports a pointer shaft and incorporates a magnet is usually assembled in a shield casing.
In this assembly, in order to keep the bobbin immovable in the shield casing, the plurality of protrusions protruding from the outer peripheral portion of the bottom wall of the bobbin are inserted into the plurality of through holes formed in the bottom wall of the shield casing and then heated. It is caulking.
[0003]
[Problems to be solved by the invention]
However, the cross coil type indicating instrument requires a process of heat caulking as described above. For this reason, not only a dedicated facility for heat caulking is required, but also time and work for heat caulking are required. Therefore, the problem that the product cost increases is caused.
[0004]
Therefore, in order to cope with such a situation, the present invention is to devise a structure for assembling the housing with respect to the shield casing in the cross coil type indicating instrument, so that the housing is fixedly assembled into the shield casing by a simple operation. An object of the present invention is to provide a cross coil type indicating instrument.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a cross coil type indicating instrument according to the invention described in claims 1 to 3,
A magnetic metal shield casing (20);
A housing (10) that is assembled in the shield casing and has at least two flanges (12) extending radially outward from the opening side end of the shield casing in the outer peripheral wall;
A dial (70) fixed to the end surface of the opening of the shield casing of each flange so as to be opposed to and parallel to the opening;
A pointer shaft (60) supported coaxially and rotatably in the housing and extending through the dial;
A magnet (80) coaxially supported in the middle of the pointer shaft in the housing;
Both cross coils (40) wound around the outer wall of the housing;
And a pointer (90) that is supported by the tip of the pointer shaft and displays instructions on the dial.
[0006]
Each flange includes a columnar protrusion (13) protruding from the end surface opposite to the opening side end surface along the axial direction of the pointer shaft toward the bottom wall (22) side of the shield casing.
Each of the protrusions is provided with a gap (G) between each protrusion and the outer peripheral wall portion of the shield casing facing the protrusion, and is provided with a retaining portion (14) protruding into the gap. ,
The shield casing is a retaining piece that extends from the outer peripheral wall portion on the opening portion side facing each of the gaps to the retaining portion via the gaps, and is provided at each tip (21a). Each retaining portion (21) is provided so as to face the retaining portion so as to be retained.
[0007]
As a result, when the housing is assembled in the shield casing, each retaining piece is inserted into each of the above-mentioned gaps and faces each retaining portion at its tip so as to be retained. As a result, the housing can be easily assembled to the shield casing so that it cannot escape in the axial direction as well as in the radial direction.
According to the second aspect of the present invention, each retaining piece is opposed to the end face (14c) formed on the dial side of each retaining part at each tip.
[0008]
Thereby, the effect of the invention of claim 1 can be further improved.
According to the third aspect of the present invention, the housing is made of resin. The housing is formed on the outer peripheral portion of the bottom wall and ribs (15a, 15b) which are raised from the opposing portions corresponding to the protrusions on the outer peripheral wall and engage with the inner peripheral surface of the shield casing. And a projection (16) that engages with each through hole (22a) formed on the outer peripheral portion of the bottom wall of the shield casing.
[0009]
Each retaining piece is opposed to an end surface (14c) formed on the dial side of each retaining part at each tip.
According to this, the housing can be held in the shield casing in a relative movement in the radial direction by the engagement between the inner peripheral surface of the housing and each rib and the engagement with each through-hole portion of each protrusion. In this case, since each protrusion does not need to be caulked to each through hole, the axial length of the cross coil type indicator can be further reduced.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1 and 2 show an example in which the present invention is applied to a cross coil type indicator for a vehicle.
This cross coil type indicator is provided with a hollow bobbin 10 as a housing and a shield casing 20 having a U-shaped cross section for housing the bobbin 10. Here, in the present embodiment, the bobbin 10 is molded from a thermoplastic resin material such as Duracon or PBT, and the shield casing 20 is press-molded from a soft magnetic metal material such as permalloy. The shield casing 20 forms a magnetic circuit together with a magnet 90 described later.
[0011]
The bobbin 10 is composed of a lower bobbin member 10a and an upper bobbin member 10b. The bobbin 10 is assembled in the shield casing 20 with the lower bobbin member 10a on the lower side of the shield casing 20. . The bobbin 10 is attached to a circuit board (not shown) together with the shield casing 20.
[0012]
In addition, a cross-over coil 40 (made of coated copper wire) is wound around the hollow axial center wall portion 11 of the bobbin 10, and each terminal 41 of the cross-coil 40 has an outer periphery of the bobbin 10. Are connected to the upper end of each terminal 50 (made of phosphor bronze or the like) inserted through the section.
The pointer shaft 60 is coaxially and rotatably supported in the bobbin 10, and the pointer shaft 60 extends upward from the bobbin 10 through the through hole portion 71 of the scale plate 70 at the upper end portion thereof. I'm out. The scale plate 70 is assembled on a pair of flanges 10c (described later) of the bobbin 10.
[0013]
The magnet 80 (see FIG. 2) is coaxially supported at the intermediate portion of the pointer shaft 60 in the hollow axial center wall portion 11 of the bobbin 10. The pointer shaft 60 is rotated by receiving the combined electromagnetic force.
The pointer 90 is supported at the tip of the pointer shaft 60, and the pointer 90 displays instructions on the scale plate 70 in conjunction with the rotation of the pointer shaft 60.
[0014]
Next, the assembly structure of the bobbin 10 to the shield casing 20 will be described in detail with reference to FIGS.
The bobbin 10 includes a pair of flanges 10c, and both the flanges 10c are formed so as to protrude radially outward from both opposing portions of the outer peripheral wall of the upper bobbin member 10b through the opening of the shield casing 20.
[0015]
Of the two flanges 10c, the lower flange 10c shown in FIG. 1 is provided with a columnar pedestal 12. The pedestal 12 is pointed from one of the opposing portions of the outer peripheral wall of the upper bobbin member 10b to the scale plate 70 side. Projecting parallel to 60. The pedestal 12 has a screw hole 12a (see FIG. 2).
Further, the lower flange 10 c includes a columnar protrusion 13, and this protrusion 13 protrudes in parallel to the pointer shaft 60 from the lower surface of the pedestal 12 downward.
[0016]
Here, the protrusion 13 protrudes downward from the left side shown in FIG. 2 in the lower surface of the pedestal 12, and between the outer peripheral surface of the protrusion 13 and the portion facing the part of the outer peripheral surface of the shield casing 20. In the formed gap G, a retaining portion 14 is formed so as to protrude from the facing surface portion toward a part of the outer peripheral surface of the shield casing 20.
An interval between the outer end surface 14a of the retaining portion 14 and a part of the outer peripheral surface of the shield casing 20 facing the outer end surface 14a is set so that a retaining piece 21 (to be described later) of the shield casing 20 can be passed against the elasticity. Has been.
[0017]
Further, the retaining portion 14 includes a guide surface 14b. The guide surface 14b resists the retaining piece 21 against its elasticity, and the shield casing that opposes the outer end surface 14a of the retaining portion 14. As shown in FIG. 2, the protrusion 13 is formed in an inclined shape so as to be guided between a part of the outer peripheral surface 20 and the outer surface 14 a from the facing surface portion of the protrusion 13.
[0018]
Further, the retaining portion 14 includes a seating surface 14c. The seating surface 14c is perpendicular to the axis of the pointer shaft 60, as shown in FIG. It extends toward a part of the outer peripheral surface of the shield casing 20 from the facing surface portion.
Further, as shown in FIG. 1, the upper flange 10 c is formed in a configuration symmetrical to the lower flange 10 c with respect to the axis of the pointer shaft 60.
[0019]
The outer diameter of the bobbin 10, that is, the outer diameters of both the bobbin members 10 a and 10 b are slightly smaller than the inner diameter of the shield casing 20. In addition, ribs 15a are formed on each of the outer peripheral surfaces of the bobbin member 10a facing each of the protrusions 13 so as to protrude in the longitudinal direction and parallel to the axis of the pointer shaft 60, and the bobbin member 10b A rib 15b is formed on each of the outer peripheral surfaces facing each of the protrusions 13 so as to protrude in a longitudinal direction and parallel to the axis of the pointer shaft 60. Further, the distance between the outer ends of both ribs 15 a and the distance between the outer ends of both ribs 15 b are slightly larger than the inner diameter of the shield casing 20.
[0020]
The shield casing 20 includes a pair of retaining pieces 21, and these retaining pieces 21 are substantially inverted L-shaped from both opposing portions of the opening of the shield casing 20 at positions corresponding to both flanges 10 c. It extends to.
Here, for each of both of the retaining pieces 21, the distance between the distal end portion 21 a of the retaining piece 21 and the opposing portion of the outer peripheral surface of the shield casing 20 is between the opposing surface portions of the protrusion 13 and the shield casing 20. It is narrower than the interval and wider than the interval between the outer end surface 14 a of the retaining portion 14 and the outer peripheral surface portion of the shield casing 20 corresponding thereto.
[0021]
Further, as will be described later, when the bobbin 10 is assembled in the shield casing 20, the retaining pieces 21 are arranged so that the leading end portions 21 a of the retaining pieces 21 are locked and seated on the seating surfaces 14 c of the retaining portions 14. The extension length from the opening of the shield casing 20 is set.
In the bobbin 10 and the shield casing 20 configured as described above, the scale plate 70 is assembled on each pedestal 12 of the bobbin 10 by fastening each screw 72 to each through hole 12a. Moreover, each retaining piece 21 is engaged with the seating surface 14c of the retaining portion 14 of each protrusion 13 at the tip portion 21a. The bobbin 10 is engaged with each through hole 22a formed in the bottom wall 22 of the shield casing 20 at each protrusion 16 provided on the outer peripheral portion of the bottom wall.
[0022]
In the present embodiment configured as described above, the bobbin 10 is assembled to the shield casing 20 as follows.
The bobbin 10 including the magnet 80, the pointer shaft 60, and the two crossing coils 40 is prepared.
Then, the bobbin 10 is accommodated in the shield casing 20 by press-fitting from the lower bobbin member 10a. At this time, the housing is performed while plastically deforming both ribs 15 a and 15 b of the bobbin 10 by the peripheral wall of the shield casing 20. For this reason, the bobbin 10 can be held in the shield casing 20 so as not to be relatively movable. In addition, each protrusion 16 of the bobbin 10 is engaged in each through hole 22 a of the shield casing 20.
[0023]
Further, in the housing process, the retaining pieces 21 are inserted between the projections 13 and the shield casing 20, that is, in the gaps G, via the retaining portions 14.
Here, each retaining piece 21 is guided by the guide surface 14 b and is inserted into each gap G through each retaining portion 14 against its elasticity. When this insertion is completed, each retaining piece 21 returns to its original shape and is seated and engaged on the seating surface 14c at its tip 21a.
[0024]
As a result, each retaining piece 21 is fixed and secured by each retaining portion 14.
As described above, the bobbin 10 can be easily assembled to the shield casing 20. Therefore, it is not necessary to heat caulk each protrusion 16 of the bobbin 10 to each through hole 22a of the shield casing 20, and to match that this heat caulking is unnecessary, each through hole 22a of each protrusion 16 is provided. Therefore, the axial length of the pointer device is further shortened.
[0025]
In this case, the tip 21 a of each retaining piece 21 is only seated and engaged on each seating surface 14 c and is not in contact with the opposing surface of each projection 13. Therefore, although the load is applied in the direction parallel to the axis of the pointer shaft 60 at the engaging portion between each retaining piece 21 and each retaining portion 14, no load is generated in the radial direction.
After the bobbin 10 is assembled to the shield casing 20 as described above, the scale plate 70 is fixed on each pedestal 12 of the bobbin 10 with each screw 72. Thereafter, the pointer 90 is supported on the tip of the pointer shaft 60.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment in which the present invention is applied to a cross coil type indicator.
2 is a view of the light guide plate of FIG. 1 viewed from the back side.
[Explanation of symbols]
G: Gap, 10 ... Bobbin, 10c ... Flange, 12 ... Base part, 13 ... Projection,
14 ... Retaining part, 14c ... Seating surface, 20 ... Shield casing,
21 ... retaining piece, 21a ... tip, 22 ... bottom wall, 22a ... through hole,
40 ... cross coil, 60 ... pointer shaft, 70 ... scale plate, 80 ... magnet,
90 ... Guidelines.

Claims (3)

A magnetic metal shield casing (20);
A housing (10) that is assembled in the shield casing and has at least two flanges (12) extending radially outward from the opening side end of the shield casing in the outer peripheral wall;
A dial (70) fixed to the opening side end surface of the shield casing of each flange so as to be positioned in parallel to face the opening;
A pointer shaft (60) that is coaxially and rotatably supported in the housing and extends through the dial;
A magnet (80) coaxially supported in an intermediate portion of the pointer shaft in the housing;
Both cross coils (40) wound around the outer wall of the housing;
A cross coil type indicating instrument comprising a pointer (90) supported by the tip of the pointer shaft and displaying an indication on the dial,
Each flange includes a columnar protrusion (13) that protrudes from the end surface opposite to the end surface on the opening side along the axial direction of the pointer shaft toward the bottom wall (22) of the shield casing.
Each of the protrusions is provided with a gap (G) between each protrusion and the outer peripheral wall portion of the shield casing that faces the protrusion, and includes a retaining portion (14) that protrudes into the gap.
The shield casing is a retaining piece extending from the outer peripheral wall portion on the opening portion side facing the gap to the retaining portion via the gap, and is attached to each distal end portion (21a). A cross coil type indicating instrument provided with each retaining piece (21) facing each retaining part so as to prevent the retaining part. 2. The cross coil according to claim 1, wherein each retaining piece is opposed to an end surface (14 c) formed on the dial side of each retaining member at each tip portion thereof. 3. Type indicating instrument. The housing is made of resin,
The housing is formed on each of the ribs (15a, 15b) which are raised from the facing portions corresponding to the protrusions on the outer peripheral wall and engage with the inner peripheral surface of the shield casing, and on the outer peripheral portion of the bottom wall. Each protrusion (16) that engages with each through hole (22a) formed in the outer peripheral portion of the bottom wall of the shield casing,
2. The cross coil according to claim 1, wherein each retaining piece is opposed to an end surface (14 c) formed on the dial side of each retaining member at each tip portion thereof. 3. Type indicating instrument.

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