JP2012032201A - Driving device for instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an instrument drive device in which a zero point indicated value is hardly shifted even when an impact force is inputted from the outside.
[Solution]
A case main body 12, a pivotally supported by the case main body 12, a part of which protrudes to the outside, an output shaft 6, a coil 9, and a rotor magnet 2 that drives the output shaft 6 by energizing the coil 9; In the instrument drive device 1 including the first stopper member 15 provided on the output shaft 6 and the case main body 12, the first stopper member 15 is brought into contact with the first stopper member 15 to determine the rotation range of the output shaft 6. A second stopper member 16, and either one of the first stopper member 15 or the second stopper member 16 is a projecting piece having a first contact portion 15a and a first wall portion 15b. The other is composed of a storage part having a second contact part 16a with which the first contact part 15a contacts and a second wall part 16b opposite to the first wall part 15b, and the viscous liquid 18 is contained in the storage part. It is provided.
[Selection] Figure 2

Description

  The present invention relates to an instrument drive device, and more particularly to an instrument drive device having a feature in a stopper mechanism that determines a zero point position of a pointer.

  As a conventional instrument driving device, one disclosed in Patent Document 1 is known. This instrument drive device is an instrument drive device that transmits the power of a movement having a permanent magnet to a pointer shaft provided with a pointer to rotate the pointer, and the output gear provided with the pointer shaft has a first The stopper member is provided, a second stopper member is provided in the case for housing the output gear, and the pointer indicates the zero point in a state in which the first and second stopper members are in contact with each other. Is.

JP-A-6-38497

  However, such an instrument driving device generates a repulsive force between the first and second stopper members when receiving an impact from the outside when the first and second stopper members are in contact with each other. The repulsive force generates a force for rotating the output gear. As a result, there is a problem that the pointer shaft rotates and the pointer is displaced from the position indicating the zero point.

  Therefore, the present invention pays attention to the above-mentioned problems, and an object thereof is to provide an instrument drive device in which the pointer is not easily displaced from the position indicating the zero point even when an impact is applied from the outside.

  In order to solve the above-described problems, the present invention provides a case main body, and a case pivotally supported by the case main body, a part of which protrudes to the outside, an output shaft, a coil, and the output shaft by energizing the coil. And a rotor magnet for driving the first and second stopper members provided on the output shaft and the case main body, contacting the first stopper member and contacting the first stopper member. A second stopper member that defines a rotation range, and either one of the first stopper member or the second stopper member comprises a projecting piece having a first contact portion and a first wall portion. And the other comprises a storage portion having a second contact portion that contacts the first contact portion and a second wall portion that faces the first wall portion, and a viscous liquid is provided in the storage portion. It is a thing.

  In addition, the storage portion is provided with two second wall portions so as to surround the protruding piece, and the second contact portion is provided between the second wall portions.

  The first contact portion and the second contact portion are in line contact or point contact.

  ADVANTAGE OF THE INVENTION According to this invention, the intended objective can be achieved, and even if it receives an impact from the outside, the instrument drive device can be provided in which the pointer is not easily displaced from the position indicating the zero point.

The top view of the instrument drive device of one Embodiment of this invention. Sectional drawing of the AA line in FIG. The upper side figure of the instrument drive device which removed the upper case of the same embodiment and notched a part. The front view of the instrument apparatus using the stepping motor of the embodiment. The expanded sectional view of the 1st, 2nd stopper member of the embodiment. The expanded sectional view of the 1st, 2nd stopper member of the modification of the same invention. The expanded sectional view of the 1st, 2nd stopper member of the other modification of the invention.

  The instrument drive device 1 of this embodiment is a stepping motor that is used in the instrument device M and rotates a pointer.

  The stepping motor 1 of the present embodiment is provided on the same axis as the rotor magnet 2, the rotor gear 3 fixed to the rotor magnet 2, the first gear 4a meshing with the rotor gear 3, and the first gear 4a. An intermediate gear 4 having a second gear 4b, an output gear 5 meshing with the second gear 4b of the intermediate gear 4, two coils 9 for generating a rotating magnetic field and applying a rotational force to the rotor magnet 2, and a rotor A metal first rotation shaft 10 that is the rotation center of the magnet 2, a metal second rotation shaft 11 that is the rotation center of the intermediate gear 4, and a metal output shaft that is the rotation center of the output gear 5. 6, a rotor magnet 2, a rotor gear 3, an intermediate gear 4, an output gear 5, an output shaft 6, a coil 9, a first rotating shaft 10, and a case member 12 that houses a second rotating shaft 11. is there.

  The rotor magnet 2 is made of a synthetic resin having magnetism called a so-called plastic magnet, has a circular shape, and has a donut shape with a through hole in the center. The rotor gear 3 and the first rotating shaft 10 pass through this through hole. The rotor magnet 2 only needs to have at least one N pole and one S pole. In this embodiment, the rotor magnet 2 includes four magnetic poles, two N poles and two S poles. Centering on the rotation axis of the magnet 2, it is provided so that it may become equal to the radial direction. Accordingly, multipolar magnetization is performed along the rotational direction on the outer circumferential surface of the rotor magnet 2 with the first rotation shaft 10 as a central axis.

  The rotor gear 3 is made of a synthetic resin not having magnetism, is provided coaxially with the rotor magnet 2, and rotates as the rotor magnet 2 rotates. Further, the first rotating shaft 10 passes through the rotor gear 3.

  The intermediate gear 4 is made of a synthetic resin not having magnetism, and integrally includes a first gear 4a and a second gear 4b. The first gear 4 a meshes with the rotor gear 3. Further, the second gear 4 b meshes with the output gear 5. Further, the intermediate gear 4 is provided with a second rotation shaft 11 serving as a rotation center.

  Similarly to the rotor gear 3 and the intermediate gear 4, the output gear 5 is made of a synthetic resin not having magnetism, and meshes with the second gear 4 b of the intermediate gear 4. The output gear 5 is provided with an output shaft 6 serving as a rotation center.

  The output shaft 6 is pivotally supported by the case body 12 and a part of the output shaft 6 protrudes to the outside.

  In FIG. 2, a protruding piece constituting the first stopper member 15 is integrally provided on the lower surface of the output gear 5. The first stopper member 15 is in contact with a second stopper member 16 provided on the case member 12 to be described later, stops the rotation of the output shaft 6 at a predetermined position, and determines the rotation range of the output shaft 6. Yes, it is provided on the output shaft 6 via the output gear 5.

  The first stopper member 15 includes a first contact portion 15a and a first wall portion 15b. The cross-sectional shape of the first contact portion 15a is a semicircular convex portion, and is in line contact. In addition, the 1st contact part 15a is not limited to a line contact, A point contact may be sufficient. The cross-sectional shape of the first wall portion 15b located on the output shaft 6 side is an arc-shaped concave surface, and the cross-sectional shape of the first wall portion 15b located on the side opposite to the output shaft 6 is an arc-shaped convex surface. is there.

  In the present embodiment, a reduction mechanism comprising an intermediate gear 4 and an output gear 5 is provided, and the rotation of the rotor magnet 2 is reduced and transmitted.

  The coil 9 is obtained by winding a conductive metal wire such as copper around a bobbin 9a made of a synthetic resin. The coil 9 is connected to a control means (not shown) via a terminal 9b provided on the bobbin 9a.

  The bobbin 9a is a cylindrical body having a through hole having a rectangular cross-sectional shape. And the coil 9 is arrange | positioned around the rotor magnet 2, and a part of disk surface of the rotor magnet 2 and the said through-hole are in the state which a part of rotor magnet 2 entered in the said through-hole of the bobbin 9a. The inner circumference faces each other.

  Then, the drive waveforms output from the control means are input to the two coils 9, whereby a rotating magnetic field is generated in the rotor magnet 2, a rotational force is applied to the rotor magnet 2, and the output shaft 6 is To drive.

  The case member 12 is made of a synthetic resin that does not have magnetism, and is divided into upper and lower parts. The case member 12 divided in the vertical direction is fixed by hooking a locking claw 12a provided on each case member 12. The case member 12 supports the first rotating shaft 10, the second rotating shaft 11, and the output shaft 6 in a rotatable manner. The case member 12 is integrally provided with a second stopper member 16 that contacts the first stopper member 15 provided on the output gear 5.

  The 2nd stopper member 16 consists of the storage part 16c provided with the 2nd contact part 16a with which the 1st contact part 15a contacts, and the 2nd wall part 16b facing the 1st wall part 15b. The storage portion 16c is provided with two second wall portions 16b so as to surround the first stopper member 15 and a second contact portion 16a between the second wall portions 16b.

  The cross-sectional shape of the second contact portion 16a is a straight plane, and the cross-sectional shape of the second wall portion 16b located on the output shaft 6 side inside the storage portion 16c is an arc-shaped convex surface. It faces the wall portion 15b. The cross-sectional shape of the second wall portion 16b located on the side away from the output shaft 6 inside the storage portion 16c is an arc-shaped concave surface.

  The storage portion 16 c stores the first stopper member 15. A liquid 18 having a viscosity, for example, a liquid having a viscosity such as silicon oil or glue is provided in the storage portion 16c.

  In the present embodiment, the first contact portion 15a and the second contact portion 16b are in line contact. Further, a slight gap is provided between the first wall portion 15b and the second wall portion 16b, and the first stopper member 15 and the second stopper member 16 are movable. In addition, since the liquid 18 is provided in the storage portion 16c by application or the like, when the first contact portion 15a and the second contact portion 16b are separated from the contact state due to viscous frictional force, the liquid 18 is rotated. Provided is an instrument drive device 1 that can apply a dynamic load and that makes it difficult for the output shaft 6 to rotate even when an impact is applied from the outside, so that a pointer that will be described later is difficult to deviate from a position indicating 0 point. be able to.

  FIG. 4 shows the stepping motor 1 used in the instrument device M. The instrument device M of the present embodiment displays the speed of the vehicle using the pointer 14.

  The pointer 14 is attached to the output shaft 6. Behind the pointer 14 is provided a display board 17 provided with indicator portions 17a such as scales and characters indicated by the pointer 14. The pointer 14 is held at a predetermined position, in the present embodiment, at a position indicating “0” of the vehicle speed by the first stopper member 15 and the second stopper member 16 provided in the stepping motor 1.

  Further, the second stopper member 16 includes the storage portion 16c, but it is not necessary to form the storage portion 16c. As shown in FIG. 6, as a modified example of the present invention, the second contact portion 16a Alternatively, a single second wall portion 16b may be used. A viscous liquid 18 is applied to the second contact portion 16a and the second wall portion 16b. Also with the above configuration, it is possible to obtain the same operational effects as in the above embodiment.

  In the first embodiment, the cross-sectional shape of the first contact portion 15a is a semicircular convex portion, and the cross-sectional shape of the second contact portion 16a is a straight plane. As shown in FIG. 7, as another modification of the present invention, the cross-sectional shape of the first contact portion 15c is a straight plane, and the cross-sectional shape of the second contact portion 16d is as shown in FIG. It is good also as a triangular convex part. Also with the above configuration, it is possible to obtain the same operational effects as in the above embodiment.

  Moreover, in the said embodiment, the 1st stopper member 15 which is a protrusion piece was provided in the output shaft 6 (output gear 5), and the 2nd stopper member 16 which is 16c which is an accommodating part was provided in the case member 12. However, the 1st stopper member 15 which is a protrusion piece may be provided in the case member 12, and the 2nd stopper member 16 which is the accommodating part 16c may be provided in the output shaft 6 (output gear 5).

  The present invention can be used for an instrument drive device provided with a stopper mechanism for determining the zero point position of the pointer.

1 Stepping motor (Instrument drive)
2 Rotor magnet 5 Output gear 6 Output shaft 9 Coil 12 Case member 14 Pointer 15 First stopper member (projecting piece)
15a, 15c First contact portion 15b First wall portion 16 Second stopper member 16a, 16d Second contact portion 16b Second wall portion 16c Storage portion 18 Liquid

Claims (3)

An instrument comprising a case main body, a pivotally supported by the case main body, a part of which protrudes to the outside, an output shaft, a coil, and a rotor magnet that drives the output shaft by energizing the coil A first stopper member provided on the output shaft; and a second stopper member provided on the case main body and in contact with the first stopper member to define a rotation range of the output shaft. Wherein either one of the first stopper member or the second stopper member is a projecting piece having a first contact portion and a first wall portion, and the other is in contact with the first contact portion. An instrument driving device comprising: a storage portion including a second contact portion and a second wall portion facing the first wall portion, wherein a viscous liquid is provided in the storage portion. The said accommodating part provided the said 2nd wall part so that the said protrusion piece might be enclosed, and provided the said 2nd contact part between the said 2nd wall parts, The said 2nd wall part is provided. Instrument drive. The instrument driving device according to claim 1, wherein the first contact portion and the second contact portion are in line contact or point contact.

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