JPH1054740A - Pointer instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pointer instrument which reduces a friction torque generated in a surface bearing and has a small indication error. A shaft 3 made of a magnetic material, a pointer 2 and a shaft 3 are supported. In the pointer instrument provided with the surface bearing 61a, the shaft 3 and the shaft 3 are disposed above the surface bearing 61a.
The magnets 10a are provided at a small interval from. This magnet 10
The shaft 3 is sucked in a direction repelled by gravity by the suction force a. Thus, the load applied to the surface bearing 61a is reduced, and the friction torque generated on the surface bearing 61a is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pointer instrument for displaying information by rotating a pointer, and is suitably used for an automobile meter.

[0002]

BACKGROUND OF THE INVENTION With a few exceptions, pointer instruments are used in an inclined position. Therefore, the bearing holds the load such as the weight of the pointer and the shaft. At this time, the above-mentioned load is large because the pointer gauge is used at an angle, and when the pointer and the shaft rotate, a friction torque proportional to this load is generated in the bearing portion. Since this friction torque causes a pointing error, in order to reduce the friction torque, there are some bearings using bearings and lubricating oil applied to surface bearings such as journal bearings.

[0003]

However, when a surface bearing is used for the bearing portion of the shaft of the pointer instrument, the contact area is large because the shaft is held on the surface, resulting in a large friction torque. Even when lubricating oil is applied to the bearing portion, the load on the pointer and the shaft is large, so that the friction torque cannot be sufficiently reduced, and a large pointing error occurs.

[0004] In view of the above problems, it is an object of the present invention to provide a pointer instrument which reduces friction torque generated in a surface bearing and has a small pointing error.

[0005]

In order to achieve the above object, the following technical means are employed. According to the first aspect of the present invention, the rotating shaft (3) and the pointer (2)
And a pointer instrument provided with a surface bearing (61a) for holding the shaft (3), the shaft suction means (10a, 1) for sucking the pointer (2) and the shaft (3) in the antigravity direction.
0b, 20a, 20b).

As described above, by applying a force for moving the pointer (2) and the shaft (3) in the anti-gravity direction, the pointer (2) and the shaft are applied to the surface bearing (61a) holding the shaft (3). The load of (3) is reduced. Thereby, the friction torque generated in the surface bearing (61a) can be reduced, and the pointing error can be reduced. According to the second aspect of the invention, the shaft (3) made of a magnetic material, the pointer (2), and the surface bearing (61) holding the shaft (3) are provided.
a) is provided with a magnet (10a) at a predetermined distance from the shaft (3) in the antigravity direction from the shaft (3) and the surface bearing (61a), and the shaft (3) in the antigravity direction. It is characterized by sucking.

As described above, since the shaft (3) made of a magnetic material is attracted in the antigravity direction by the magnet (10a), the pointer (2) and the shaft (3) on the surface bearing (61a) are attracted. Load can be reduced. Thereby, the same effect as the first aspect can be obtained. According to the third aspect of the present invention, the shaft (3) of the shaft (3) of the pointer instrument according to the second aspect is shifted from the surface bearing (61a).
Is characterized in that a magnet (20a) is provided axially above.

Thus, the magnet (2) is also provided on the shaft (3).
By providing 0a), the magnets (10a, 20a) attract each other and the attraction force increases, and the load on the pointer (2) and the shaft (3) on the bearing (61a) can be greatly reduced. Thus, for example, even if the pointer (2) is made large, the same effect as that of the first aspect can be obtained. According to a fourth aspect of the present invention, one of the magnets (10a, 20a) provided in the pointer instrument of the third aspect is replaced with a soft magnetic material (10a, 20b). As a feature, the same effect as the first aspect is obtained.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. (First Embodiment) FIG. 1 is an embodiment of the present invention, and is a simplified side sectional view using a cross-coil pointer instrument. Further, this figure is a diagram in which this pointer meter is used for an automobile meter, and is attached to an instrument panel in a vehicle with such inclination.

The configuration of the pointer meter shown in FIG. 1 will be described.
The basic structure of the cross-coil pointer instrument is the same as that generally known. As shown in FIG. 1, there is an instrument panel 1 provided with a speed scale, and a pointer shaft of a pointer 2 is disposed in a hole provided in the center of the instrument panel 1, and the pointer 2 is provided with a magnetic material shaft through this hole. 3 is attached.
A rotor 4 is attached to the shaft 3.

The shaft 3 is held by surface bearings 61a and bearing portions 62a of bobbins 61 and 62 which are housings made of resin. And this bobbin 6
Reference numerals 1 and 62 each include an upper bobbin member 61 and a lower bobbin member 62, and the rotor 4 is incorporated in an internal space formed when the upper bobbin member 61 and the lower bobbin member 62 are fixed.

The bobbins 61 and 62 have a rotor 4
, And four coils 5 are wound in a cross shape. In order to eliminate the influence of an external magnetic field, a shield case 7 made of a permalloy-based material that is a
62. The instrument panel 1 and the upper bobbin member 61 are fixed with screws 8. FIG. 2 is a partially exploded perspective view of the pointer meter according to the present embodiment. As shown in FIG.
Substantially circular plate-shaped magnet fixing housing 9 about the axis
Are fixed above the surface bearing 61a of the upper bobbin member 61. Notches are provided at both ends in the diameter direction of the magnet fixing housing 9, and the magnet fixing housing 9 is fitted into and fixed to the upper bobbin member 61 from the notches.

The magnet fixing housing 9 is provided with magnet fixing grooves 9a divided in eight directions corresponding to the notches, and one of the magnet fixing grooves 9a is provided with a magnet 10a.
a is adhered. It should be noted that the magnet fixing grooves 9a are provided in all directions to provide design flexibility, but the magnet 10a attracts the shaft 3 in the antigravity direction when the pointer instrument is mounted on the instrument panel. The magnet 10a is arranged in the suction groove 9a.

The magnet 10a is fixed at a predetermined distance from the shaft 3 so as not to always contact the shaft 3. Also, the magnet fixing housing 9
Shaft 3 so that it does not always touch the shaft 3
It is arranged at an interval from. A hole is provided at the bottom of the shield case 7, and electric wiring to the coil 5 is provided through the hole.

The operation of the pointer meter in this embodiment will be described. Although not shown, the drive mechanism for driving the pointer instrument of the present embodiment is composed of a vehicle speed sensor and a drive circuit, and is connected to an ignition switch and a battery. When the ignition switch is turned on, the vehicle speed sensor detects the rotation speed of the output shaft of the vehicle transmission and generates a vehicle speed pulse. Then, the drive circuit controls the drive current to each coil 5 according to the vehicle speed pulse. A magnetic field is generated in each of the coils 5 based on the driving current.

The shaft 3 is rotated by the action of the magnetic field and the magnetic force of the rotor 4. When the ignition switch is turned off, the spring force of a return spring (not shown) acts to return the shaft 3 to its original position. At this time, since the pointer instrument is used in an inclined state, the weight of the pointer 2 and the shaft 3 (particularly, the weight of the pointer 2) becomes the load of the surface bearing 61a. Therefore, when the shaft 3 rotates, the hands 2
And the weight of the shaft 3, the radius of the shaft 3, the surface bearing 6
A friction torque proportional to the friction coefficient of the bearing 1a and the bearing 62b is generated in the surface bearing 61a.

In this embodiment, since the shaft 3 is attracted in the antigravity direction by the magnet 10a, the weights of the pointer 2 and the shaft 3, which cause a friction torque, are reduced. Further, as described above, the moment is increased by forming the magnet 10a above the surface bearing 61a, and the shaft 3 is effectively attracted. Thereby, the friction torque generated in the surface bearing 61a can be reduced, and the pointing error can be reduced.

The magnet 10a has such a magnetic force that the magnetic force does not affect the magnetic field generated in the coil 5. (Second Embodiment) The pointer gauge shown in FIG. 3 has a cylindrical magnet 20a provided axially above the magnet 10a in the shaft 3 of the shaft 3 of the pointer meter in the first embodiment. The magnet 20a is fixed around the shaft 3 and rotates together with the shaft 3. The magnet 20a is arranged according to the magnetic pole of the magnet 10a so as to increase the force of the magnet 10a for attracting the shaft 3.
That is, as shown in FIG. 3, if the direction toward the shaft 3 is the south pole of the magnet 10a, the bottom side of the cylindrical magnet 20a is turned to the north pole and directed toward the magnet 10a.
They are arranged to attract each other.

The magnet 20a is always connected to the magnet 10a.
The magnet 20a is provided at a distance of, for example, about 1 mm from the magnet 10a and the magnet fixing housing 9 so as not to come into contact with the magnet fixing housing 9.
At this time, since the magnet 10a and the magnet 20a attract each other, the attraction force is increased, and the shaft 3 is attracted with a strong force in the antigravity direction. Therefore, the load of the pointer 2 and the shaft 3 on the surface bearing 61a can be greatly reduced. Thereby, for example, even if the pointer 2 having a large weight is used, the friction torque generated in the surface bearing 61a can be reduced, and the pointing error can be reduced.

Since the magnets 10a and 20a are used, the magnets 10a and 20a are attracted to each other even if they are slightly apart from each other. (Third Embodiment) A pointer instrument shown in FIG. 4 is obtained by replacing the magnet 10a in the second embodiment with a soft magnetic material 10b. Generally, a soft magnetic material generates a strong magnetic force when approaching a magnet. The magnetic force of the soft magnetic material 10b strengthened by the magnet 20a and the magnetic force of the magnet 10a interact, and the shaft 3
The suction force increases.

As a result, the friction torque generated on the surface bearing 61a can be reduced, and the pointing error can be reduced. Note that the attractive force between the soft magnetic material and the magnet is stronger than the force of the magnet attracting the magnetic material and weaker than the attractive force between the magnets. Therefore, the soft magnetic material 10b used in the present embodiment can be set according to the weight of the pointer 2 to be applied. (Fourth Embodiment) The pointer instrument shown in FIG. 5 is obtained by replacing the magnet 20a in the second embodiment with a soft magnetic material 20b. The magnetic force of the soft magnetic material 20b strengthened by the magnet 10a and the magnetic force of the magnet 10a interact, and the shaft 3
The suction force increases. (Other Embodiments) In Embodiments 2 to 4, a magnetic material is used as the material of the shaft 3, but an insulating material may be used.

In the first to fourth embodiments, the magnet 10
a, the soft magnetic body 10b is attached to the magnet fixing housing 9, but is not limited to this. A place where the shaft 3 can be sucked upward in the direction of gravity, for example, the back surface of the instrument panel 1 or the upper bobbin member 61 It may be attached to. However, even in the case of mounting in these places, the number of parts required for mounting such as the magnet 10a increases, so that the use of the magnet fixing housing 9 is effective.

In the first to fourth embodiments, a cross-coil type pointer meter is used as the pointer meter. However, the present invention is not limited to this, and another type of motor may be used. However, the present invention may be used for an engine speed meter, a fuel meter, a water temperature meter, and the like.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a pointer meter according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of a pointer meter according to one embodiment of the present invention.

FIG. 3 is a side sectional view of a pointer meter according to a second embodiment of the present invention.

FIG. 4 is a side sectional view of a pointer meter according to a third embodiment of the present invention.

FIG. 5 is a side sectional view of a pointer meter according to a fourth embodiment of the present invention.

[Explanation of symbols]

2 ... pointer, 3 ... shaft, 9 ... magnet fixing housing,
9a: magnet fixing groove, 10a: magnet, 10b: soft magnetic material, 20a: magnet, 20b: soft magnetic material, 61: upper bobbin member, 61a: surface bearing, 62: lower bobbin member,

Claims (4)

[Claims] 1. A rotating shaft (3), a pointer (2) attached to the shaft (3), and a surface bearing (6) rotatably holding the shaft (3).
1a), wherein the shaft suction means (10a, 10b, 20a, 2a) sucks the shaft (3) in the antigravity direction of the pointer (2).
0b). 2. A rotating shaft (3) formed of a magnetic material, a pointer (2) attached to the shaft (3), and a surface bearing (6) rotatably holding the shaft (3).
1a); and a magnet (10a) provided at a predetermined distance from the shaft (3) in the direction of antigravity from the shaft (3) and attracting the shaft (3). Instrument. 3. A rotating shaft (3), a pointer (2) attached to the shaft (3), and a surface bearing (6) rotatably holding the shaft (3).
1a) and a magnet (10a) provided at a predetermined distance from the shaft (3) in a direction of antigravity from the shaft (3).
And the shaft (3) is provided above the surface bearing (61a) in the axial direction of the shaft (3);
a pointer magnet comprising: a) a magnet for attracting a). 4. A magnet (10a) provided at a predetermined interval from said shaft (3) and a magnet (20a) provided on said shaft (3) are made of a soft magnetic material (20). The pointer instrument according to claim 3, wherein the pointer instrument is replaced with 20a, 20b).