JPH0758530A - Motor-driver for driving telescopic antenna - Google Patents

Abstract

PURPOSE:To provide a motor-driver for driving the telescopic antenna provided with a worm gear support mechanism in which a reliable operation is expected with a simple configuration and inexpensive manufacture without an extreme reduction in the drive efficiency and without a play of a meshing part between a worm gear and a worm wheel. CONSTITUTION:The driver is provided with a motor 11, a worm gear 13, a worm wheel 14 and a worm gear support mechanism 20, and the worm gear support mechanism 20 is made of a support plate 21 supporting a tip of a drive shaft extension part 12' on a flat plane orthogonal to the center of a drive shaft 12 and a displacement restriction plate 22 restricting it that the drive shaft extension part 12' is displaced in a direction parted from the worm wheel 1 by press contact of a contact part 23 provided to one end with an outer circumferential face of the drive shaft extension part 12' whose tip is supported by the support plate 21. The contact part 23 of the displacement restriction plate 22 is formed by a notch of V-shape or semi-circular-arc, and is press- contact with the outer circumferential face of the drive shaft extension part 12' in a state that the notch surrounds part of the outer circumference of the drive shaft extension part 12'.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a retractable antenna driving electric device applied to, for example, a retractable antenna for an automobile, and more particularly to an improvement of a worm gear holding mechanism.

[0002]

2. Description of the Related Art FIGS. 2 (a) and 2 (b) are diagrams showing a configuration example of a main part of a conventional telescopic antenna driving electric device. As shown in FIG. 2A, the tip end portion of the extension 2 ′ of the rotary shaft 2 of the motor 1 is supported by the flat support plate 5. The worm gear 3 is press-fitted into the rotary shaft extension 2 '. A worm wheel 4 is meshed with the worm gear 3, and is driven to rotate in the direction of arrow A or B as the motor 1 rotates.

Although not shown, in the usual case, the rotational force of the worm wheel 4 is transmitted to the rope transfer gear through an intermediate gear, and the rotation of the rope transfer gear causes the antenna element with a rack to expand and contract. The rope is transferred in both the forward and reverse directions, and the antenna element is thereby expanded and contracted.

In the structure described above, the motor 1 is rotated in the forward direction in order to drive the antenna element (not shown) to be reduced, and the worm wheel 4 is moved by the worm gear 3 provided in the rotary shaft extension 2'of the motor 1. When rotating in the direction of arrow A, the rotary shaft 2 of the motor 1 receives a thrust load in the direction of arrow Fa. In order to drive the extension of the antenna element, the motor 1 is rotated in the reverse direction,
When the worm wheel 4 is rotated in the direction of arrow B by the worm gear 3 provided on the rotary shaft 2 of
The rotary shaft 2 of 1 receives a thrust load in the direction of arrow Fb.

When the thrust load in the direction of the arrow Fb is extremely large, that is, when the load is high, the rotary shaft extension 2'is long, and therefore the rotary shaft extension 2'is indicated by a broken line in the figure. In addition, the flat support plate at the tip of the rotary shaft extension 2'has been largely displaced in the direction away from the worm wheel 4 (for the sake of convenience of explanation, the amount of displacement is exaggeratedly exaggerated in the drawing). The support point on 5 moves from Pa to Pb. Therefore, the degree of meshing between the worm gear 3 and the worm wheel 4 becomes shallow, and as a result, the rotation transmission efficiency is extremely reduced.

In FIG. 2B, the tip end of the rotary shaft extension 2'is supported by a pivot bearing 6.
The configuration other than this point is the same as that of FIG.
In the structure described above, since the tip of the rotary shaft extension 2'is supported by the pivot bearing 6, the displacement of the rotary shaft extension 2'as shown in FIG. 2A does not occur. Therefore, the situation that the rotation transmission efficiency is extremely lowered does not occur. However, since the support by the pivot bearing 6 prohibits the displacement of the rotary shaft extension 2 ′ almost entirely, it is not possible to absorb the variation in the degree of meshing between the worm gear 3 and the worm wheel 4 and the above variation. There was a problem that rattling of the meshing part due to the above occurred.

[0007]

As described above, in the conventional one supported by the flat support plate 5, a so-called "escape" occurs in the rotary shaft extension 2'at high load, and the degree of meshing becomes shallow. However, the rotation transmission efficiency may be extremely reduced. Further, the conventional bearing supported by the pivot bearing 6 has a problem in that variations in the degree of meshing between the worm gear 3 and the worm wheel 4 are not absorbed, and rattling occurs at the meshing portion.

The object of the present invention is to eliminate the so-called "relief" of the rotary shaft extension when the load is high, so that there is no fear of causing a drastic decrease in the rotation transmission efficiency, and there is a variation in the degree of meshing between the worm gear and the worm wheel. It is an object of the present invention to provide a telescopic antenna driving electric device provided with a worm gear holding mechanism, which does not cause rattling of the meshing part due to it, can be manufactured at low cost in addition to being simple in structure, and can be expected to operate with high reliability. .

[0009]

In order to solve the above problems and achieve the object, the following measures were taken in the present invention. (a) That is, the telescopic antenna driving electric device of the present invention includes a motor, a worm gear provided in an extension portion of the rotary shaft of the motor, a worm wheel rotationally driven by meshing with the worm gear, and the worm wheel. On the other hand, a worm gear holding mechanism that holds the worm gear so as to be in a predetermined meshed state. The worm gear holding mechanism includes a support plate provided to support the tip of the rotary shaft extension on a flat surface orthogonal to the axis of the rotary shaft, and the tip supported by the support plate. The contact part provided at one end contacts the outer peripheral surface of the rotary shaft extension, and the displacement restricting plate is provided so as to restrict displacement of the rotary shaft extension in the direction away from the worm wheel.

(B) In addition, the contact portion of the displacement regulating plate in the electric motor for driving a telescopic antenna according to the present invention is V-shaped,
It is formed by a notch formed in a semi-circular shape or the like, and is formed so as to abut the outer peripheral surface of the rotary shaft extension in a state where the notch partially surrounds the outer circumference of the rotary shaft extension.

[0011]

As a result of taking the above-mentioned means, the following effects occur. (a) A contact portion provided at one end of the displacement regulation plate is in contact with the outer peripheral surface of the rotary shaft extension portion of the motor, and the rotary shaft extension portion regulates displacement in a direction away from the worm wheel. ing. For this reason, even if a large thrust load is applied to the motor rotating shaft under high load, the rotating shaft extension does not largely displace in the direction away from the worm wheel, and so-called "escape" is prevented. For this reason, there is no fear that the rotation transmission efficiency will be extremely lowered. On the other hand, the tip of the rotary shaft extension of the motor is supported by a support plate having a flat surface orthogonal to the axis of the rotary shaft of the motor. Is allowed to be displaced to some extent in the direction orthogonal to the axis of the rotating shaft. Therefore, even if there is a variation in the degree of meshing between the worm gear and the worm wheel, the variation is absorbed by the displacement of the rotary shaft due to some elastic deformation. Therefore, the rattling of the meshing portion due to the variation in the meshing degree does not occur.

(B) The contact portion of the displacement regulating plate, which is a V-shaped or semi-circular cutout portion, surrounds the outer circumference of the rotary shaft extension in a state of partially surrounding the outer circumference of the rotary shaft extension. Abutting. Therefore, although the displacement of the rotary shaft extension portion in the direction away from the worm wheel (including the backward movement in the rearward direction and the sway in the left-right direction) is restricted, the displacement in the worm wheel direction is allowed. That is, the displaceable region and the non-displaceable region are limited to a specific range based on the shape of the cutout portion of the contact portion of the displacement regulation plate. For this reason, the so-called "escape" preventing effect and the effect of absorbing the variation in the meshing degree coexist in a well balanced state.

[0013]

1 (a), 1 (b) and 1 (c) are views showing the structure of an electric apparatus for driving a telescopic antenna according to an embodiment of the present invention. FIG. 1A is a diagram showing a configuration of a main part of a retractable antenna driving electric device including a worm gear holding mechanism. As shown in the figure, a worm gear 13 is press-fitted into an extension 12 'of the rotary shaft 12 of the motor 11. A worm wheel 14 meshes with the worm gear 13. Although not shown in the drawing, the rotational force of the worm wheel 14 is transmitted to the rope transfer gear via the intermediate gear, and the rotation of the rope transfer gear causes the rope for antenna element extension / contraction operation with a rack to move in both forward and reverse directions. And the antenna element is extended or contracted.

Reference numeral 20 is a worm gear holding mechanism. The worm gear holding mechanism 20 is provided with the worm wheel 1
4 is a mechanism for holding the worm gear 13 in a predetermined meshing state. The worm gear holding mechanism 20 supports the tip end of the rotary shaft extension 12 ′ of the motor 11 with a support plate 21 having a flat surface orthogonal to the axis of the rotary shaft 12, and the support plate 21 supports the tip. The rotary shaft extension 12 ′, which is supported by a portion, is composed of a displacement regulating plate 22 that regulates a large displacement in a direction away from the worm wheel 14.

FIG. 1B is a plan view showing a part of the displacement regulation plate 22. As shown in the drawing, a contact portion 23 composed of a V-shaped cutout portion is provided at one end (left end in the drawing) of the displacement regulation plate 22. The contact portion 23 formed of the V-shaped cutout portion is the rotary shaft extension portion 1 described above.
A part of the outer circumference of 2 '(the right half circumference in this figure) is abutted against the outer peripheral surface of the rotary shaft extension 12'.

FIG. 1C is a plan view showing a part of a modified example of the displacement regulating plate 22. As shown in the drawing, a contact portion 24 formed of a semicircular cutout portion is provided at one end (left end in the drawing) of the displacement regulation plate 22. Except for the shape of the contact portion 24, it is the same as the displacement regulation plate 22 shown in FIG. Therefore, in the following description, the description will be made mainly based on the displacement regulating plate 22 shown in FIG.

In the telescopic antenna driving electric device of this embodiment constructed as described above, when the motor 11 rotates in the forward direction, the worm gear 13 provided in the rotary shaft extension 12 'of the motor 11 causes the worm wheel 14 to move in the direction of the arrow. The antenna element (not shown) is rotated in the direction of A to drive it in a reduced size.
In this case, the rotating shaft 12 of the motor 11 receives the thrust load in the direction of arrow Fa.

When the motor 11 rotates in the reverse direction, the motor 1
The worm gear 13 provided on the rotary shaft 12 of No. 1 rotates the worm wheel 14 in the direction of the arrow B, and drives the antenna element (not shown) to extend. In this case, the motor 11
The rotary shaft 12 of is subjected to a thrust load in the direction of arrow Fb.

When the thrust load in the direction of the arrow Fb is extremely large, that is, when the load is high, the rotary shaft extension 12 'is long, and therefore the rotary shaft extension 12' is long.
Tries to make a large displacement in a direction away from the worm wheel 14. However, in the present embodiment, since the contact portion 23 provided at one end of the displacement regulating plate 22 is in contact with the outer peripheral surface of the rotary shaft extension 12 ', the rotary shaft extension 12' moves away from the worm wheel 14. The displacement in the direction is restricted. Therefore, even if a large thrust load is applied to the motor rotating shaft 12 under high load, the so-called "escape" of the rotating shaft extension 12 'is prevented. Therefore, the antenna element can be stably expanded and contracted without causing a drastic decrease in rotation transmission efficiency.

Further, since the tip of the rotary shaft extension 12 'of the motor 11 is supported by the upper surface of the support plate 21 having a flat surface orthogonal to the axis of the rotary shaft 12, it is different from the conventional flat plate. Similarly, the tip of the rotary shaft extension 12 ′ is allowed to be displaced to some extent in the direction orthogonal to the axis of the rotary shaft 12. Therefore, even if the degree of meshing between the worm gear 13 and the worm wheel 14 varies, the variation is absorbed by the displacement of the rotary shaft 12 due to a slight elastic deformation. Therefore, the rattling of the meshing portion due to the variation in the meshing degree does not occur.

Further, the contact portion of the displacement regulating plate 22 which is a V-shaped, semi-circular arc-shaped notch or the like is provided in the rotary shaft extension 12 '.
The rotation shaft extension 12 'is partially surrounded by the outer circumference of
Is in contact with the outer peripheral surface of the. Therefore, the rotary shaft extension 1
2'is restricted in displacement in the direction away from the worm wheel (including receding in the rearward direction and swaying in the left-right direction), but displacement in the worm wheel 14 direction is allowed. That is, the displaceable area and the displaceable area are
It is limited to a specific range based on the shape of the cutout portion of the contact portion 23 of the displacement regulation plate 22. For this reason, the so-called "escape" prevention effect and the effect of absorbing the variation in the meshing degree coexist in a reasonably balanced state.

As is apparent from FIG. 1, the apparatus of this embodiment has an extremely simple structure and there are no difficult parts to manufacture, so that it can be manufactured at low cost and highly reliable operation is expected. It should be noted that the present invention is not limited to the above-described embodiment, but can be modified in various ways as follows.

(1) On the contact surface of the contact portion 23 or 24 of the displacement regulating plate 22 with the rotary shaft extension portion 12 ', a lubricating member having high lubricity may be interposed. By doing so, the contact portion 23 or 24 and the rotary shaft extension 1
Since friction with the outer peripheral surface of 2'is reduced, wear of this portion is reduced and loss of rotational energy of the motor is reduced.

(2) The displacement regulating plate 22 may be provided with a position adjusting mechanism capable of adjusting the position of only the contact portion or the entire plate so as to be movable back and forth. With this configuration, the contact position of the contact portion of the displacement regulating plate 22 with respect to the outer peripheral surface of the rotary shaft extension 12 ′ can be arbitrarily changed, so that the meshing portion of the worm gear 13 and the worm wheel 14 can be changed. It is possible to adjust the degree of meshing between the worm gear 13 and the worm wheel 14 according to the degree of wear, etc.

[0025]

According to the present invention, the presence of the displacement regulating plate regulates the so-called "escape" of the rotary shaft extension, and the presence of the supporting plate absorbs the variation in the degree of meshing between the worm gear and the worm wheel. Therefore, there is no so-called "relief" of the rotary shaft extension at high load, and there is no risk of causing a drastic decrease in rotation transmission efficiency, and there is rattling of the meshing part due to variation in the meshing degree of the worm gear and the worm wheel. It is possible to provide a telescopic antenna driving electric device having a worm gear holding mechanism, which does not occur, and has a simple structure, can be manufactured at low cost, and can be expected to operate with high reliability.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a telescopic antenna driving electric device according to an embodiment of the present invention, and FIG. 1A is a diagram showing a configuration of a main part of the telescopic antenna driving electric device including a worm gear holding mechanism. , (B) is a plan view showing a part of the displacement restricting plate, and (c) is a plan view showing a part of a modification of the displacement restricting plate.

FIG. 2A and FIG. 2B are diagrams showing a configuration example of a retractable antenna driving electric device according to a conventional example, respectively.

[Explanation of symbols]

1, 11 ... Motor 2, 12 ... Rotating shaft 2 ', 12' ... Rotating shaft extension part 3, 13 ... Worm gear 4,14 ... Worm wheel 5 ... Flat plate 6 ... Pivot bearing 20 ... Worm gear holding mechanism 21 ... Holding plate 22 ... Displacement regulation plate 23 ... Contact part consisting of V-shaped notch 24 ... Contact part consisting of semi-circular notch

Claims (2)

[Claims] 1. A motor, a worm gear provided on an extension of a rotary shaft of the motor, a worm wheel rotationally driven by meshing with the worm gear, and a predetermined meshing state of the worm gear with the worm wheel. A worm gear holding mechanism that holds the worm gear holding mechanism so that the worm gear holding mechanism supports the tip of the rotary shaft extension on a flat surface orthogonal to the axis of the rotary shaft. And a contact portion provided at one end abuts the outer peripheral surface of the rotary shaft extension portion whose tip is supported by the support plate, and the rotary shaft extension portion is displaced in a direction away from the worm wheel. An expansion / contraction antenna driving electric device comprising: a displacement restricting plate provided so as to restrict. 2. A contact portion of the displacement regulating plate is a notch portion having a V-shape, a semi-circular arc shape or the like, and the notch portion partially surrounds the outer periphery of the rotary shaft extension portion to rotate the rotary shaft. The telescopic antenna driving electric device according to claim 1, wherein the electric device is for contact with the outer peripheral surface of the shaft extension.