JPH1151973A - Electric instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric instrument of a simple structure to dispense with a soldering process and to allow an instrument main body to be electrically connected to a printed circuit board with easy operation. SOLUTION: A moving magnet 6 is fixed to a hand spindle 5 with a pointer 4. An instrument main body 1 with a bobbin 3 having a winding of a coil 2 in a periphery of the moving magnet 6, and a printed circuit board 15 assembled with electric parts or the like to impress a signal to the main body 1 are provided. A terminal 14 connected electrically to a terminal part of the coil 2 in the main body 1 is arranged in the main body 1, and a coupling means 16 to be connected to the terminal 14 and to be connected electrically and mechanically to the printed circuit board 15 by turning the main body 1 around an axial center of the hand spindle 5 as a base point is also provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an instrument body such as a movable magnet instrument or a stepping motor instrument having a movable magnet fixed to a pointer shaft having a pointer attached thereto and a coil wound around the movable magnet. Is electrically connected to a printed circuit board.

[0002]

2. Description of the Related Art Generally, a movable magnet type instrument as an electric instrument of this type is, for example, a synthetic resin bobbin having a movable magnet built therein, as disclosed in Japanese Utility Model Publication No. 3-2862. A coil is wound, and an upper end of a pointer shaft provided on the movable magnet is protruded from the bobbin, and a pointer is attached to the distal end.

[0003] This conventional electric instrument has a structure in which a surface opposite to a surface on which hands are mounted is connected to a printed circuit board provided on a lower surface side of a bobbin which is an instrument main body, as an electric routing structure with the outside. Alternatively, a structure is adopted in which a terminal connected to the end of the coil provided at an appropriate position on the bobbin is fixedly connected to the terminal from outside the case for accommodating the instrument body by using a screw or a nut.

As another electrical connection means, as disclosed in Japanese Patent Application Laid-Open Nos. 7-139977 and 8-5667, a female or male connector is provided between the instrument main body and a printed circuit board. In some cases, electrical connection can be made with one touch by inserting and fitting each other with a connector member.

Another example of an electric instrument in a stepping motor instrument is disclosed in, for example, Japanese Patent Laid-Open No. 9-149.
A conventional stepping motor as disclosed in Japanese Patent No. 619 is provided with an upper and lower coaxial resin bobbin around which a coil is wound, extending along the axis of the bobbin and fixing a pointer at an upper portion. A movable magnet fixed to the pointer shaft is rotatably arranged in the hollow portion of the bobbin, and a metallic comb-shaped yoke formed over the bobbin to apply a magnetic field of the coil to the movable magnet is provided at the upper and lower stages. Each of the bobbins is provided with a metal upper plate and a lower plate which are stacked on the yoke and accommodate the movable magnet.

A terminal is provided on the bobbin flange. An end of the bobbin coil is wound around one end of the terminal and soldered, and the other end of the terminal is formed to hang down toward the printed circuit board. The terminals are soldered directly to the printed circuit board to supply a current from the printed circuit board to the bobbin.

[0007]

As described above, in the conventional movable magnet type instrument, the number of screws and nuts corresponding to the number of coils pulled out from the bobbin is electrically and mechanically connected. Due to the configuration, it is necessary to perform a tightening operation of screws and nuts corresponding to the number of the coils to be pulled out, and the workability is poor. Also, male,
When the electrical connection means consisting of a female connector is adopted, workability is somewhat improved, but it is necessary to provide electrical connection parts such as male terminals or female terminals on both the instrument body side and the printed circuit board side, and it is structurally complicated It was easy to become.

[0008] In a stepping motor, a method is generally used in which a terminal hanging downward from a flange portion of a bobbin is inserted into a hole of a land portion formed on a printed circuit board and soldered. There was also a demand that the attaching process be omitted.

Accordingly, an object of the present invention is to provide an electric instrument which can eliminate the soldering process with a simple configuration and can electrically connect the instrument body to a printed circuit board with one touch with good workability. Things.

[0010]

In order to achieve the above object, the present invention provides an instrument in which a movable magnet is fixed to a pointer shaft having a pointer attached thereto, and a bobbin formed by winding a coil around the movable magnet is provided. A main body, and a printed circuit board on which electric components for applying signals to the instrument main body are assembled. The instrument main body is provided with a terminal electrically connected to a coil end of the instrument main body, and the terminal Is electrically connected to
A connecting means is provided for electrically and mechanically connecting to the printed circuit board by rotating the instrument main body with the axis of the pointer shaft as a base point.

Further, a positioning means is provided at an opposing portion between the instrument main body and the printed circuit board so as to be engaged at a predetermined rotation position of the instrument main body.

The coupling means has an upper holding piece and a lower holding piece, and the printed circuit board is held between the upper holding piece and the lower holding piece. Things.

[0013] An annular or columnar boss portion centering on the pointer shaft is provided around the pointer shaft at a portion of the instrument body facing the printed circuit board, and the boss portion is provided on the printed circuit board. A guide portion that can be inserted is provided.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS For example, an instrument body composed of a stepping motor will be described as an example. This stepping motor is provided with a resin bobbin around which a coil is wound coaxially at an upper stage and a lower stage, and the bobbin has a shaft center. A movable magnet fixed to a pointer shaft that extends along and is fixed to a pointer at the top is rotatably arranged in a hollow portion of the bobbin, and a metal formed over the bobbin to apply a magnetic field of a coil to the movable magnet. An instrument configured by providing a comb-shaped yoke for each of the upper and lower bobbins, and providing a synthetic resin upper plate and a metal lower plate that are stacked on the yokes and house the movable magnets. The main body is provided.

A terminal is provided on the flange portion of the bobbin. An end of the coil of the bobbin is wound around one end of the terminal and soldered, and the other end of the terminal stands upright toward the top plate. Has formed. The upper surface plate is provided with joining means for electrically and mechanically connecting to the printed board, and the joining means is provided at the other end of the terminal formed downward from the flange of the bobbin toward the upper surface plate. And an electric relay portion which is connected by soldering through the portion, an upper holding piece and a lower holding piece for holding and fixing the printed circuit board thereabove are provided above and below the upper and lower bobbins of the stepping motor. A number of coupling means corresponding to the number of coils to be drawn are insert-molded on the upper plate.

An insertion hole is provided in the printed circuit board at a position corresponding to the coupling means, and a land portion is provided around the insertion hole to be connected to predetermined electric components, circuits, etc. of the printed circuit board. By inserting an upper holding piece serving as a coupling means into the insertion hole, and then rotating a stepping motor serving as an instrument body by a predetermined angle around the axis of the pointer shaft, the upper holding piece and the lower holding piece are rotated. The instrument body and the printed circuit board are electrically and mechanically connected to each other by the attachment piece holding and holding the printed board and the upper holding piece being in contact with the land portion.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 5 illustrate the first embodiment of the present invention, taking as an example an electric instrument main body 1 composed of a stepping motor. The instrument main body 1 composed of this stepping motor is provided with a resin bobbin 3 around which a coil 2 is wound, coaxially provided at an upper stage and a lower stage, extending along the axis of the bobbin 3 and fixing a pointer 4 at an upper portion. A movable magnet 6 fixed to a pointer shaft 5 is rotatably disposed in a hollow portion 7 of the bobbin 3, and a metallic comb formed over the bobbin 3 to apply a magnetic field of the coil 2 to the movable magnet 6. -Shaped yokes 8 are provided for the upper and lower bobbins 3, respectively. An upper plate 9 made of synthetic resin and a lower plate 10 made of metal are provided on the yokes 8 and accommodate the movable magnets 6, and are provided on the yokes 8. 9
The pointer shaft 5 is supported by bearings 11 and 12 provided on the lower plate 10.

On the flange portion 13 of the upper bobbin 3, four L-shaped terminals 14 are provided by insert molding corresponding to the coils 2 of the upper and lower bobbins 3, and one of these terminals is provided. The terminal 14a corresponds to the upper bobbin 3, and the terminal 14b on the other side is provided corresponding to the lower bobbin 3. One end of these terminals 14a and 14b is connected to the end of the coil 2 of the bobbin 3. The other ends of the terminals 14a and 14b are formed so as to rise vertically toward the upper surface plate 9 by being wound around and soldered. A printed board 15 is provided on the upper surface plate 9.
5 is provided for electrically and mechanically connecting the bobbin 3 to the upper surface plate 9 from the flange portion 13 of the bobbin 3 as shown in FIG. An electric relay section 18 which is connected to the other end of each of the terminals 14a and 14b by soldering by being inserted into the hole 17;
Above it, an upper holding piece 19 and a lower holding piece 20 for holding and fixing the printed circuit board 15 are integrally press-molded by a conductive member, so that the upper and lower bobbins 3 of the instrument main body 1 are pressed. Coupling means 16 of a number corresponding to the number of end portions of the coil 2 to be drawn out are arranged on the upper surface plate 9 concentrically with the pointer shaft 5 as a base point and insert-molded.
Each of the upper holding piece 19 and the lower holding piece 20 is provided with a bent portion 21 having a U-shape protruding toward the printed circuit board 15 side.
It is formed in a rigid shape so as to increase the contact force with the printed board 15.

The printed circuit board 15 is made of a hard wiring board having an electric component and a circuit pattern (not shown) for applying a signal to the instrument main body 1.
A generally arcuate insertion hole 22 centered on the pointer shaft 5 is provided at a position corresponding to the coupling means 16, and the insertion hole 22 is formed by an inlet portion 22a into which the upper clamping piece 19 is inserted and an inlet portion 22a. A narrow fixing portion 22b is formed, and a land portion 23 connected to a predetermined electric component or circuit (not shown) of the printed circuit board 15 is provided on the upper surface side of the insertion hole 22 so that the insertion hole 22 is formed. Connecting means 16 to the entrance 22a
Is inserted, and then the instrument body 1
Is rotated by a predetermined angle about the axis of the pointer shaft 5, so that the upper holding piece 19 and the lower holding piece 20 hold and hold the land 23 around the fixing portion 22b of the printed circuit board 15 while holding the same. The instrument body 1 and the printed circuit board 15 are electrically and mechanically connected by the upper holding piece 19 being in contact with the land portion 23.

With the above configuration, the instrument body having the coupling means 16 is simply inserted into the insertion hole 22 of the printed circuit board 15 so as to match the same, and the instrument body 1 is rotated by a predetermined angle to the printed circuit board 15 of the instrument body 1. Mechanical fixing and electrical connection can be achieved, and the assembling operation can be performed with a single touch without soldering with a relatively simple structure.

Since the coupling means 16 has the upper holding piece 19 and the lower holding piece 20, only when the land 23 is on the upper surface side of the printed circuit board 15 as in the first embodiment described above. Alternatively, although not shown, electrical connection can be made even when the land portion is only on the lower surface side of the printed circuit board 15. In this case, the lower sandwiching piece 20 comes into contact with the land portion on the lower surface side of the printed circuit board 15. An electrical connection is made.

Thus, the joining means 16 of the instrument body 1
The electrical connection can be made even when the land portion 23 is located only on the upper surface side of the printed circuit board 15 or when it is located only on the lower surface side, thereby improving versatility.

In particular, with regard to the stepping motor, according to the conventional stepping motor structure, the electric connection is carried to the solder tank together with the printed circuit board and soldered, so that it receives heat during the soldering process. As a result, the movable magnet housed inside the instrument body also receives heat, and this heat may decrease the magnetic force and reduce the rotational torque. However, according to the present invention, the soldering process is performed. Since the main body of the instrument can be assembled without the need for mounting specified electrical components on a printed circuit board,
By assembling the instrument body after soldering, it is possible to prevent a decrease in rotational torque due to heat at the time of soldering as in the related art.

FIG. 6 shows a second embodiment of the present invention. Positioning means 24 is provided at an opposing portion between the instrument body 1 and the printed circuit board 15 so as to engage with the instrument body 1 at a predetermined rotation position. When the instrument main body 1 is attached to the printed circuit board 15, the instrument main body 1 is rotated by a predetermined angle so that the upper holding piece 19 corresponds to the land portion 23 of the printed circuit board 15. In this embodiment, a hole 26 is provided in the printed board 15 at a position corresponding to the projection 25.

By doing so, the printed circuit board 15
When the instrument main body 1 is turned by a predetermined angle when the instrument main body 1 is assembled to the main body 1, the convex portion 25 of the upper surface plate 9 engages with the hole 26 of the printed circuit board 15, so that the operator can turn the predetermined It can be recognized that the instrument main body 1 has been rotated to the position, and the upper holding piece 19 of the engaging means 16 is in the proper land portion 2.
3 are set at corresponding positions.

Also, since the positioning means 24 can prevent rattling of the instrument body 1 and the printed circuit board 15 in the assembled state, the instrument body 1 is displaced in the direction of rotation with respect to the printed circuit board 15 due to, for example, vibration of the vehicle, and the upper pinch is held. It is also possible to prevent a situation in which the attachment piece 19 is displaced from the land portion 23 of the printed circuit board 15 to cause a contact failure.

Further, in the second embodiment, an annular boss portion 27 centering on the pointer shaft 5 is provided around the pointer shaft 5 at the portion of the instrument main body 1 facing the printed circuit board 15 to perform printing. The board 15 is provided with a guide portion 28 through which the boss portion 27 can be inserted. The guide portion 28 of the printed board 15 is provided with an annular boss portion 27 formed on the upper surface plate 9 on the instrument body 1 side. The instrument body 1 is rotated while the upper holding piece 19 of the coupling means 16 is inserted into the insertion hole 22 while being inserted, so that the boss portion 27 and the guide portion 28
, The instrument main body 1 can be smoothly rotated about the pointer shaft 5 without the rotational axis thereof being deviated, and the upper holding piece 19 of the coupling means 16 is properly formed on the printed circuit board 15. It is rotated to a predetermined position while being guided toward the land 23 that has been set. The boss 27 and the guide 28 allow the upper holding piece 19 of the coupling means 16 to be relatively easily inserted into the insertion hole 22 of the printed circuit board 1.

In each of the embodiments, a plurality of coupling means 16 having the structure shown in FIG. 5 are provided on the concentric circle of the pointer shaft 5, but a structure in which the boss portion 27 is provided as in the second embodiment. In this configuration, the joining means 16 may be provided on the outer periphery of the boss portion 27 and the land portion 23 may be formed on the periphery of the guide portion 28 of the printed circuit board 15 to join the two. The formation position can be set freely.

In the above-described embodiment, a stepping motor has been described as an example of the instrument main body 1.
It goes without saying that the present invention can be similarly applied to a cross-coil movable magnet type instrument.

Although only the example in which the meter main body 1 is provided on the lower surface of the printed circuit board 15 is shown, the instrument body 1 may be provided on the upper surface of the printed circuit board 15; What is necessary is just to provide the coupling means 16 in the bottom part of 1.

The printed circuit board 15 is not limited to a rigid printed circuit board, and a flexible F
A printed circuit board made of PC is installed alongside this case and F
An insertion hole is formed in the PC, the connecting means of the instrument main body is inserted, and the instrument main body is rotated with respect to the case to mechanically and electrically connect to the land provided on the FPC. Is also good.

The positioning means 24 is provided between the upper surface plate 9 and the printed circuit board 15 which are components of the stepping motor in the above-described embodiment. Although it is provided, it may be provided between the joining means 16 and the printed circuit board 15, and it is not limited to the positioning means 24 by the engagement of the projection 25 and the hole 26, and other It may be by means.

[0033]

As described above, according to the present invention, it is possible to provide an electric instrument which can eliminate the soldering process with a simple structure and can electrically connect the instrument body to a printed circuit board with one touch with good workability. Can be.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an instrument main body used in a first embodiment of the present invention.

FIG. 2 is a sectional view showing a first embodiment of the present invention before assembly.

FIG. 3 is a perspective view showing a first embodiment of the present invention.

FIG. 4 is a sectional view after assembling showing the first embodiment of the present invention.

FIG. 5 is a perspective view showing a main part of the first embodiment of the present invention.

FIG. 6 is a perspective view showing a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Instrument main body 2 Coil 3 Bobbin 4 Pointer 5 Pointer shaft 6 Movable magnet 14 Terminal 15 Printed circuit board 16 Joining means 19 Upper holding piece 20 Lower holding piece 24 Positioning means 27 Boss 28 Guide part

Claims (4)

[Claims] 1. An instrument body having a movable magnet fixed to a pointer shaft on which a pointer is attached, a bobbin formed by winding a coil around the movable magnet, an electric component for applying a signal to the instrument body, and the like. And a printed circuit board on which the terminal is electrically connected to a coil end of the meter main body, and the terminal is electrically connected to the terminal, with the axis of the pointer shaft as a base point. An electric instrument comprising a coupling means for electrically and mechanically connecting to the printed circuit board by rotating the instrument main body. 2. An electric instrument according to claim 1, wherein a positioning means is provided at an opposing portion between said instrument main body and said printed circuit board so as to engage with said instrument main body at a predetermined rotational position. 3. The coupling means has an upper clamping piece and a lower clamping piece, and the printed circuit board has an upper clamping piece,
The electric instrument according to claim 1, wherein the electric instrument is held between the lower holding piece and the holding piece. 4. An annular or cylindrical boss portion centered on the pointer shaft is provided around the pointer shaft at a portion of the instrument main body facing the printed circuit board, and the boss portion is provided on the printed circuit board. 2. The electric instrument according to claim 1, further comprising a guide portion that can be inserted.