JPH0628700Y2 - Cross coil type indicator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a cross-coil type indicator, and more particularly to a cross-coil type indicator suitable for a vehicle speedometer, tachometer, fuel gauge, and the like.

[Conventional technology]

Generally, a predetermined current supplied to the cross coil rotates the magnet rotor in the direction of the combined magnetic field that combines the magnetic fields generated by the coils, and the indicator needle fixed to the rotating shaft of the magnet rotor rotates by a predetermined amount for measurement. A cross-coil type indicator instrument for displaying a quantity is known.

FIG. 2 shows an automobile instrument that uses the above-mentioned cross-coil type indicator instrument. In the instrument case 1 integrally molded with synthetic resin, a speedometer and a rotation indicator are provided together with a lighting bulb (not shown), various warning lights, etc. Various instrument units 2 such as fuel gauges and fuel gauges are placed and fixed on the support posts 3 via the screw portions 4, and a flexible printed wiring board (FPC) 5 is provided on the lower surface of the instrument case 1. It is provided. The instrument case 1 constitutes a combination meter as a whole, and the combination meter is attached to an instrument panel of a vehicle.

The instrument unit 2 is provided with an IC, a resistor (not shown) on the upper surface, and has electrical wiring (not shown) on the lower surface,
Hard wiring board (HPC) 7 provided with soldering part 6 and the like
And a dial 9 fixed on the HPC 7 with a screw portion 8 and a dial 11 placed and fixed on the movement 9 via a light guide plate 10 acting as a prism. Reference numeral 8 also functions as a terminal terminal for supplying a predetermined current to the movement 9 as described later.

The movement 9 includes a coil bobbin 13 housed inside a case body 12 having a cylindrical shape and one end of which is open. A direction in which a pair of coils 14 and 14 are orthogonal to each other is provided outside the coil bobbin 13. A disk-shaped magnet rotor 15 is disposed inside the coil bobbin 13 while being wound. Further, a terminal terminal 8a for energizing each of the coils 14 is arranged on the peripheral portion of the coil bobbin 13, and the light guide plate 1 is also provided.
A flange 16 for mounting and fixing 0 on the upper surface is formed to project. A rotary shaft 17 extending in the axial direction of the coil bobbin 13 is attached to the center of the magnet rotor 15, and the magnet rotor 15 is attached.
Is energized to each coil 14 via the terminal terminal 8a so that it can be rotated by a predetermined angle. An indicator needle 18 is fixed to the tip of the rotary shaft 17, and the indicator needle 18 rotates by a prescribed amount to display a prescribed measured amount.
Further, a hairspring 19 whose one end is connected to the coil bobbin 13 is fixed to a middle portion of the rotary shaft 17, and the urging force of the hairspring 19 causes the pointer needle 18 to return to the 0 position. ing.

In the instrument unit 2 described above, when measurement signals such as vehicle speed and remaining fuel amount are input to the FPC 5 via a wire harness (not shown) or the like and are input to the HPC 7 from the FPC 5 via the screw portion 4, the HPC 7 determines a predetermined value. Is performed and a predetermined current corresponding to a predetermined measurement amount as a drive signal is supplied to each coil 14 via the terminal terminal 8a. Then, the magnet rotor 15 rotates in the direction of the synthetic magnetic field of the magnetic field generated by each coil 14 by the predetermined current supplied to each coil 14, at an angle corresponding to the above-mentioned measured amount. As a result, the rotating shaft 17 rotates, and the pointer 18 rotates on the dial 11 to display the measured amount. At this time, the hairspring 19 has the rotating shaft 1
It is in a state where it is caught by the rotation of 7 and the biasing force is accumulated.

Then, when the automobile is stopped, etc., each of the coils 14
The magnet rotor 15 is allowed to rotate freely in a state in which no current is applied to the
It is adapted to be rotated by the urging force of the balance spring 19 applied to 7 to return to the 0 position.

By the way, in the movement 9, the magnetic shield for preventing the influence of the magnetic field generated in the magnet rotor 15 and the coils 14 from reaching the outside of the movement 9 and preventing the influence of the geomagnetism from affecting the movement 9. As a result, a case body for shielding the movement 9 is required, and conventionally, the case body 12 for accommodating the coil bobbin 13 is made of a ferromagnetic material so as to be magnetically shielded. And this case body 12
The bottom plate 12a is configured to be fixed at a predetermined position by being sandwiched between the coil bobbin 13 and the HPC 7 by the screw portion 8 that fixes the movement 9, and in order to fix the case body 12. Is the bottom plate 12a
Was needed.

[Problems to be solved by the device]

However, in the above-described cross-coil type movement 9, the magnetic field generated by each coil 14 works mainly in the direction of the axis of each wound coil 14 which is perpendicular to the axial direction of the coil bobbin 13, and the above magnetic fields are combined. It has been found that the direction of the magnetic field also acts in a direction perpendicular to the axial direction of the coil bobbin 13, and from the viewpoint of a magnetic shield, the conventional case body 12 has an additional bottom plate 12a unrelated to the magnetic shield. Was prepared for. Since the ferromagnetic material that is the material of the case body 12 is generally expensive, its price increases as the surface area of the case body 12 increases, and the extra bottom plate 12a on the magnetic shield causes the case body 12 to have a large amount. There was a problem that the manufacturing cost increased.

Therefore, the present invention solves the above-mentioned problems of the prior art, and provides a cross-coil type indicator instrument capable of magnetically shielding only a necessary portion and having a magnetic shield case body which is very inexpensive and favorable in manufacturing cost. The purpose is to

[Means for Solving the Problems]

In order to achieve the above object, the present invention forms a cross coil by winding a pair of coils in directions orthogonal to each other on the outside of a coil bobbin, and generates electricity inside the coil bobbin by energizing each coil. The movement is constructed by disposing a magnet rotor that rotates a predetermined angle around the rotation axis in the direction of the combined magnetic field of the magnetic fields to be arranged, and the movement is arranged on the wiring board that energizes each of the coils. In a cross-coil type indicator instrument having an indicator needle attached to its tip, a cylindrical magnetic shielding case body having both ends opened in the axial direction is used, and the coil of the coil bobbin is coiled so that the axial direction extends along the direction of the rotation axis. It is characterized in that it is arranged around the winding part, and one end of the case body is held and fixed by the coil bobbin and the other end by the wiring board.

[Action]

According to the present invention, a magnetic shielding case body whose both ends are opened in the axial direction is arranged around the coil winding portion of the coil bobbin, and one end portion of the case body is held by the coil bobbin,
While fixing, the other end of the case body is held by the wiring board,
Since it is fixed, the magnetic shield can be performed only in the direction perpendicular to the axial direction of the coil bobbin, and the bottom plate portion for fixing the case body is not necessary.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. The same parts as those of the related art will be designated by the same reference numerals and the description thereof will be omitted.

In FIG. 1, reference numeral 21 denotes a coil bobbin, and a pair of coils 14, 14 are wound outside the coil bobbin 21 in directions orthogonal to each other, and the coil bobbin 2 is provided.
A magnet rotor 15 is arranged inside the unit 1. The magnet rotor 15 includes the coil 14
When the coil 14 is not energized, each coil 14 is freely rotatable about the rotary shaft 17 and is energized to each coil 14 through the pin terminals 22 provided upright at diametrically symmetrical positions on the outer peripheral edge of the coil bobbin 21. Thus, it can be rotated by a predetermined angle. A balance spring 19 is fixed to the rotary shaft 17, and an urging force of the balance spring 19 causes an indicator needle (not shown) fixed to the rotary shaft to return to the 0 position.

Further, on the outer peripheral portion of the coil bobbin 21, four posts for winding the pair of coils 14 and 14 orthogonally to each other are formed at intervals of 90 °, and the posts are opposed to each other. One pair of posts 23a,
23b is formed to be higher than the other pair of posts (not shown). And the pair of posts 2
The positioning pin 24 formed at the tip of one of the posts 23a out of 3a and 23b fits into the positioning hole 25 formed in the light guide plate 10 and the other post 23b.
The front end of the light guide plate 10 is fitted into the positioning groove 27 formed by the pair of protrusions 26 provided on the lower surface of the light guide plate 10, so that the light guide plate 10 is positioned and placed on the coil bobbin 21. Has been done.

Further, guide grooves 28, 28 having an arc-shaped cross section extending upward from the lower surface of the coil bobbin are formed between the pin terminal 22 and the post 23 at diametrically symmetrical positions on the outer peripheral portion of the coil bobbin 21. Cage, this guide groove 28,
A part of a cylindrical magnetic shielding case body 29, which is made of a ferromagnetic material and is open at both ends, is inserted into the case 28. Then, the case body 29 is arranged around the winding portion of each coil 14 of the coil bobbin 21, and the coil bobbin 21 is inserted in the state where the case body 29 is inserted.
Is fixed on the HPC 7 with a fixing screw 30, the upper end of the case body 29 is fixed to the bottom plate 28a of the guide groove 28.
Is held and fixed by the bottom of the case body 29 at the H level.
It will be held and fixed by the PC 7.

Next, the operation of this embodiment will be described.

In the present embodiment, the pin terminal 22 is
By supplying a predetermined current to each coil 14 via, the direction of the synthetic magnetic field of the magnetic field generated by each coil 14,
The magnet rotor 15 rotates by an angle corresponding to the above measured amount. At this time, the rotary shaft 17 rotates and an indicator needle (not shown) rotates to display the measured amount. At this time, the balance spring 19 is caught by the rotation of the rotary shaft 17 and the biasing force is accumulated.

Then, when the automobile is stopped, etc., each of the coils 14
In a state in which the magnet rotor 15 is not energized, the magnet rotor 15 is allowed to freely rotate, and the pointer needle is rotated by the urging force of the balance spring 19 applied to the rotating shaft 17 to return to the 0 position.

Therefore, in this embodiment, a cylindrical case body 29 made of a ferromagnetic material and having both ends open in the axial direction is arranged around the winding portion of each coil 14 of the coil bobbin 21, and the case body 29 is formed. The upper end of the coil bobbin 21 is held and fixed, and the lower end of the case body 29 is held and fixed by the HPC 7. Therefore, only the periphery of the coil winding portion requiring magnetic shielding should be covered with a ferromagnetic material. You can
Further, since the bottom plate of the case body, which was conventionally required to fix the magnetic shielding case body that houses the coil bobbin around the coil bobbin, can be omitted, the ferromagnetic pipe material is simply cut into a predetermined length. A magnetic shield case body 29
Therefore, the magnetic shielding case body can be easily manufactured at low cost.

[Effect of device]

As is apparent from the above description, the present invention has a magnetic shielding case body, which has a wall surface substantially parallel to the rotation axis and whose both ends are open in the axial direction, disposed around the coil bobbin, and one end portion of the case body. Since the coil bobbin holds and fixes the case body, and the other end of the case body is held and fixed by the wiring board, only the necessary part can be magnetically shielded, and the bottom plate for fixing the case body as in the past Parts are unnecessary, and as a result,
The case body can be easily manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a partial vertical sectional view of a movement portion of a cross coil type indicating instrument according to the present invention, and FIG. 2 is a vertical sectional view showing a conventional indicating instrument. 1 ... Instrument case, 7 ... Wiring board (HPC), 9 ... Movement, 10 ... Light guide plate, 12, 29 ... Magnetic shielding case body, 13, 21 ... Coil bobbin, 14 ... Coil, 15 ...... Magnet rotor, 17 ...... Rotary shaft, 18
...... Indicator needle, 19 ...... Hairspring, 28 ...... Guide groove

Claims (1)

[Scope of utility model registration request] 1. A pair of coils are wound outside the coil bobbin in a direction orthogonal to each other to form a cross coil, and inside the coil bobbin, a direction of a synthetic magnetic field of magnetic fields generated by energizing the coils. In addition, a magnet rotor that rotates a predetermined angle around the rotation axis is arranged to form a movement, and this movement is arranged on a wiring board that energizes each coil, and an indicator needle is provided at the tip of the rotation axis. In the cross-coil indicator that is installed, put a cylindrical magnetic shielding case body with both ends open in the axial direction around the coil winding part of the coil bobbin so that the axial direction is along the direction of the rotation axis. A cross-coil type indicator instrument characterized in that one end of the case body is held and fixed by the coil bobbin and the other end is held by the wiring board.