JP4405830B2 - Motor casing - Google Patents

Description

  The present invention relates to a motor casing in which a rotation mechanism having a rotation shaft is provided and supported by projecting the rotation shaft.

  For example, there is a stepper motor as a motor used for an automobile speedometer, various accumulators, and the like. As is well known, this stepper motor rotates a rotating shaft based on an inputted electric pulse signal. A moving mechanism is built in the motor casing.

  Conventionally, the motor casing is generally fitted with an upper casing and a lower casing, and is made of a synthetic resin member in consideration of productivity, cost, and the like.

  As described above, the motor casing is made of a synthetic resin member. Particularly, when this stepper motor is used for an automobile instrument or the like, the motor casing is made of a synthetic resin member as described above. There are also problems.

  For example, if the upper wall of the wiring board or motor casing increases or decreases in thickness due to thermal expansion or contraction due to an increase or decrease in ambient temperature, or if distortion occurs in the thickness direction, the wiring between the connection terminal of the stepper motor and the wiring board There is a problem in that the soldered portion between the two portions receives a large shearing force and generates a crack, leading to poor conduction between the connection terminal of the step motor and the wiring board.

  In view of this, it has been proposed to provide a protrusion on the peripheral edge of the upper wall of the motor casing to form a gap between the wiring board and the upper wall, and to absorb thermal deformation through the gap (see, for example, Patent Document 1). ).

Further, in order to improve the attachment property to the wiring board, a stepper motor in which an elastically deformable claw is projected from the motor casing and locked to the wiring board is the same application as the applicant of the above-mentioned Patent Document 1. A person has proposed in Patent Document 2, but this document also has a protrusion on the peripheral edge of the upper wall of the motor casing (see Patent Document 2).
Japanese Patent Laid-Open No. 2002-39805 (second page, FIG. 2) JP 2002-333344 A (page 4, FIG. 2)

  As described above, the stepper motor described above is considered to be effective as a solution to each of the problems to be solved. However, the problem still remains because the motor casing is composed of a synthetic resin member. Yes.

  That is, if the motor casing is manufactured from a synthetic resin member, warping and undulation often occur in the motor casing, although it is a little. In other words, the angle between the motor casing and the rotating shaft must be a right angle (of course, there is an allowable value), but this cannot be maintained.

  If it is attached to the wiring board as a stepper motor with the “warping” occurring, a sufficient perpendicularity between the wiring board and the rotating shaft cannot be obtained as shown in FIG. Accordingly, the display pointer P3 attached to the tip of the rotation shaft S is also inclined. Naturally, this results in a defective product as a display.

  Even if a protrusion is provided on the peripheral edge of the upper wall of the motor casing as disclosed in the preceding stepper motor as described above, since the entire motor casing is warped and undulated, there is no solution. It does n’t come.

  Therefore, according to the present invention, even when the entire motor casing is warped or swelled, the angle formed by the motor casing and the rotating shaft is maintained within a tolerance and is normally attached to the wiring board. An object of the present invention is to provide a motor casing that can be used.

In order to solve the above problems, the motor casing according to the present invention has the following technical means.
That is, the motor casing according to claim 1 includes a rotation mechanism provided with a rotation shaft and a projection provided with a projection for projecting the rotation shaft, wherein the projection is the motor casing installation surface. Protruding portions that are provided above and projectingly contact with the mounted member are provided at a required position adjacent to or adjacent to the protruding portion and a required position spaced from the protruding portion, and the protruding portion An engagement portion that engages with a member to be attached such as a wiring board is provided at a required position facing the portion across the portion, and the engagement portion is on a horizontal axis that passes through the rotation axis center with the motor casing interposed therebetween. The convex portions are respectively provided on the motor casing installation surface located on one side and the other side across the horizontal axis. To do.
According to a second aspect of the present invention, there is provided a motor casing in which a rotating mechanism having a rotating shaft is provided and a protruding portion for projecting the rotating shaft is provided. A member to be attached to each of a required position on the opposite surface adjacent to or adjacent to the axial line of the protruding portion and a required position on the opposite surface spaced from the axial line of the protruding portion; An engaging portion is provided to project the projecting portion to be abutted and to engage with a member to be attached such as a wiring board at a required position facing the projecting portion, and the engaging portion includes the motor casing. The projections are provided so as to face each other on the horizontal axis passing through the rotation axis center, and the convex portions are provided on the opposite surfaces located on one side and the other side across the horizontal axis, respectively. characterized in that it has been To.
A motor casing according to a third aspect is the motor casing according to the first or second aspect, wherein the convex portions are arranged so as to be line-symmetric.
A motor casing according to a fourth aspect of the present invention is the latch according to any one of the first to third aspects, wherein the motor casing is formed of a synthetic resin member and can be elastically deformed so as to have a substantially portal shape in a side view. The arm protrudes from the motor casing installation surface side.

  According to the present invention, even if the attached member is warped or swelled, the protrusion provided in the vicinity or adjacent position with respect to the protruding portion is contacted with the attached member. When the projection is used as a reference, the engagement portion is provided at a required position facing the projecting portion at the same time while minimizing the amount of deformation to be expanded based on the distance away from the projecting portion. However, the normal casing can be maintained with respect to the mounted member, and the motor casing can be attached to the mounted member in a normal state.

  Next, embodiments of the present invention will be described with reference to the drawings. In addition, the motor casing 1 concerning this Embodiment has illustrated what was applied to the stepper motor.

  As shown in FIGS. 1 and 2, the stepper motor according to the present embodiment includes a motor casing 1 and a rotation mechanism (not shown).

  The motor casing 1 is formed of a synthetic resin member, and has an upper case 11 on which a boss (projection) 1a and a guide pin 1b are provided to guide and support a rotation shaft 2 of a rotation mechanism described later, The lower case 12 is formed in a substantially box shape with the lower case 12 fitted to the case 11 and faces the horizontal axis X passing through the center of the rotating shaft 2 with the motor casing 1 interposed therebetween. A pair of substantially U-shaped latching arms 1c (engagement portions) project from the lower edge of 12 so as to cross the side surface, and are formed in a substantially portal shape in side view.

  The component surface on the upper case 11 side is the motor casing installation surface 1d. The pair of latching arms 1c described above can be elastically deformed by the elasticity of the synthetic resin member, and the latching claws facing outward from each other at the tip of the substantially U-shaped latching arm 1c. 1e is provided.

  As shown in FIGS. 1 and 2, the top surface of the upper case 11 has a round shaft shape with a flat top surface above the center of the boss 1a adjacent to the boss 1a (on the vertical axis Y passing through the center of the rotating shaft 2). And a pair of convex portions 1f are provided below the boss 1a so as to be line symmetric with respect to the vertical axis Y passing through the center of the rotation shaft 2. It has a three-point support structure.

  The rotation mechanism (not shown) is configured to rotate the rotation shaft 2 projecting from the boss 1a of the upper case 11 based on the input electric pulse signal, and the motor casing 1 described above. Decorated in. In addition, since the structure and the principle of operation of the mechanism part are known, detailed description is abbreviate | omitted.

  As shown in FIG. 2, the stepper motor according to the present embodiment configured as described above is configured such that the boss 1 a, the guide pin 1 b, and the tip of the latching arm 1 c are respectively connected from the front surface side of the wiring board P. Each of the mounting holes (engaged with the boss 1a: not shown) provided in the plate P, the insertion hole pa (engaged with the latching arm 1c), and the insertion hole pb (engaged with the guide pin 1b) are associated with each other. After positioning the stepper motor so as to match, the stepper motor is pushed into the wiring board P.

  At this time, since the convex portion 1f protrudes in the vicinity of the rotation shaft 2 of the stepper motor, the base side of the rotation shaft 2 contacts the surface of the wiring board P at a desired squareness, and the motor Even if warpage or undulation occurs in the casing 1 as a whole, it is normally attached to the wiring board P. As a result, as shown by a two-dot chain line in FIG. 2, the rotating shaft 2 protrudes on the display board P2 arranged in parallel with the wiring board P with a desired squareness (relative to the display board P2). The display pointer P3 is fitted to the tip of the protruding rotating shaft 2 to complete the assembly as a normal display.

  That is, by shortening the distance between the boss 1a and the convex portion 1f, when the boss 1a (projecting portion) is used as a reference, the deformation amount that expands based on the distance away from the boss 1a is minimized, Since the latch arm 1c provided on the horizontal axis X (of the rotation shaft 2) of the boss 1a (left and right in FIG. 1) latches the wiring board P, the motor casing 1 and the rotation shaft 2 are formed. The stepper motor is attached to the wiring board P in a normal state while maintaining the squareness within the allowable value.

  The stepper motor according to this embodiment has been described above. However, the above-described embodiment shows an example of a preferred embodiment of the present invention, and the present invention is not limited thereto. Various modifications can be made without departing from the scope of the invention.

  For example, the component surface opposite to the projecting direction of the rotation shaft 2 may be the motor casing installation surface 1d. In this case, a required position near or adjacent to the axis Z of the rotation shaft 2 of the motor casing installation surface 1d; Protrusions 1f are projected from the required positions separated from the axis Z of the rotation shaft 2 on the motor casing installation surface 1d.

  For example, in the case where the component surface opposite to the projecting direction of the rotation shaft 2 is the motor casing installation surface 1d and is supported at four points, as shown in FIGS. 3 and 4, the rotation shaft 2 of the upper case 11 The convex portion 1f is symmetrical with respect to the vertical axis Y passing through the center of the rotating shaft 2 at a position close to the left and right direction across the boss 1a in the opposite direction and a position below the boss 1a. May be provided to provide four-point support. In this case, the pair of substantially U-shaped latching arms 1c are provided so as to cross the side surface from the upper edge of the upper case 11 and on the horizontal axis X passing through the center of the rotating shaft 2. .

  Although not shown, a convex portion 1f may be provided at the base of the boss 1a that guides and supports the rotating shaft 2, and the boss 1a may protrude from the convex portion 1f.

It is a front view of the stepper motor to which the motor casing concerning this Embodiment is applied. FIG. It is a rear view of the stepper motor to which the motor casing of another aspect is applied. It is a left view of the stepper motor to which the motor casing of another aspect is applied. It is a left view of the conventional stepper motor which the curvature produced.

Explanation of symbols

1 Motor casing 1a Boss (protruding part)
1b Guide pin 11 Upper case 12 Lower case 1c Latching arm 1d Motor casing installation surface 1e Latching claw 1f Protruding part 2 Rotating axis P Wiring board P2 Display board P3 Display pointer Y Vertical axis X Horizontal axis Z Z axis pa Insertion hole pb insertion hole

Claims (4)

In the motor casing provided with a projecting portion for projecting the rotating shaft while incorporating a rotating mechanism having a rotating shaft,
The projecting portion is provided on the motor casing installation surface, and is brought into contact with the mounted member at a required position near the projecting portion or adjacent to the projecting portion and a required position separated from the projecting portion. While projecting the convex part,
An engagement portion that engages with a member to be attached, such as a wiring board , is provided at a required position facing the projecting portion ,
The engaging portion protrudes so as to oppose a horizontal axis passing through the rotation axis center across the motor casing,
The motor casing, wherein the convex portions are respectively provided on the motor casing installation surface located on one side and the other side across the horizontal axis . In the motor casing provided with a projecting portion for projecting the rotating shaft while incorporating a rotating mechanism having a rotating shaft,
The protrusion is provided on a surface opposite to the motor casing installation surface, and is located on the opposite surface adjacent to or adjacent to the opposite surface of the protrusion, and on the opposite surface spaced from the axis of the protrusion. In each of the required positions, a projecting portion that abuts against the attached member protrudes,
An engagement portion that engages with a member to be attached, such as a wiring board , is provided at a required position facing the projecting portion ,
The engaging portion protrudes so as to oppose a horizontal axis passing through the rotation axis center across the motor casing,
The motor casing according to claim 1, wherein the convex portion is provided on each of the opposite surfaces located on one side and the other side across the horizontal axis .   The motor casing according to claim 1, wherein the convex portions are arranged so as to be line symmetric.   The motor casing is formed of a synthetic resin member, and an elastically deformable latching arm is provided so as to be opposed to the motor casing installation surface side so as to have a substantially portal shape in a side view. The motor casing according to any one of claims 1 to 3, characterized in that

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