JPH0535219Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a clutch mechanism used, for example, in an electric antenna device for an automobile, and is particularly applicable to clutch mechanisms when two corresponding clutch plates are stuck to each other. Regarding coping methods.

[Conventional technology]

Generally, in a clutch mechanism used in an electric vehicle antenna device, a first clutch plate receives rotational force from a drive source such as a motor, and a second clutch plate receives rotational force from a drive source such as a motor.
The clutch plates are pressed into contact with each other, and the rotational force that is frictionally transmitted from the first clutch plate to the second clutch plate is output to the load. Thus, if an overload condition occurs when the antenna completes extension or contraction, the clutch may disengage and the drive source side may idle.

[Problem that the invention attempts to solve]

The conventional clutch mechanism having the above structure has the following problems. That is, the pressure contact surfaces between the first and second clutch plates may become stuck due to freezing or adhesion of sticky substances. If this happens, the clutch will not be released when the antenna element is fully extended or retracted, and an excessive amount of current will flow through the motor. In a typical electric antenna device, when the antenna element completes its expansion and contraction operations, an upper limit switch or a lower limit switch operates to automatically turn off the power to the motor. Therefore, even if an excessive current flows temporarily due to the above-mentioned sticking phenomenon between the clutch plates, it does not pose a serious problem. However, if the clutch mechanism is stuck and the antenna element malfunctions during the extension/retraction operation for some reason and stops, the limit switch will not work and the motor will suffer a large amount of damage. Overload current continued to flow, and there was a high risk of burnout of the motor windings. However, conventionally, no effective means have been taken to avoid such a situation.

Therefore, the present invention eliminates the risk of burning out the motor windings even if the clutch plates become stuck between each other due to freezing or adhesion of adhesive substances under conditions where the limit switch etc. do not work. The purpose of the present invention is to provide a clutch mechanism that is highly safe and does not cause new problems such as continuous noise generation.

[Means for solving problems]

The present invention is characterized by taking the following measures in order to solve the above problems and achieve the objectives. That is, in the clutch mechanism of the present invention, one side of the input side rotating body, such as a worm wheel, which is rotationally driven by a drive source such as a motor, is connected to one side of the input side rotating body by engagement of a ball and a recess. A first clutch plate is provided so as to rotate together with the first clutch plate, and a second clutch plate is connected at one side to the other side of the first clutch plate through planar contact and is configured to frictionally transmit rotational force from the first clutch plate. The present invention is characterized in that a plate is provided, and an output side rotating body is provided so as to rotate integrally with the second clutch plate and output rotational force to the load. In particular, the coupling force between the input rotating body and the first clutch plate is set to be larger than the coupling force between the first clutch plate and the second clutch plate, and the input rotating body The present invention is characterized in that the motor power source is cut off when the first clutch plate and the first clutch plate slip.

[Effect]

As a result of taking the above measures, if a stuck state occurs between the clutch plates due to icing or adhesion of sticky substances, and the load side becomes locked, the input side rotating body and the first clutch plate become stuck. The ball interposed therebetween is disengaged from the recess, a slip occurs between the input rotating body and the first clutch plate, and the drive source side is allowed to idle. At this time, the motor power is cut off.

[Example of idea]

1 to 3 are views showing an embodiment in which the present invention is applied to an electric antenna, and FIG. 1 is a sectional view of the main part. As shown in FIG. 1, inside the case 10 molded with hard synthetic resin, etc.
A clutch mechanism 1, which will be described later, is connected to a motor 11 and a worm 12 provided on the rotating shaft of the motor 11.
3 and an antenna element extension/retraction mechanism 14 operated by the rotational force transmitted via the clutch mechanism 13. Furthermore, the antenna element expansion/contraction mechanism 1
4 is a first bolt fixed to the output end of the clutch mechanism 13.
a gear roller 21, and second and third gear rollers provided so as to be interlocked with this first gear roller 21.
By means of the rollers 22 and 23, the single small-diameter rod antenna element 15 is transported, for example, as shown by the arrow.

FIG. 2 is a sectional view taken along the line A--A in FIG. 1 and showing only the clutch mechanism 13. FIG. 3 is an exploded perspective view of the clutch mechanism 13. In Figures 2 and 3, 3
1 is a flange portion 31a and a flat cut surface 31
b, 31c. A worm wheel 32 as an input side rotating body is rotatably fitted into the cylindrical part on one side of the flange part 31a of the rotating shaft 31, and the teeth of the worm wheel 32 are rotatably driven by the motor 11. It meshes with the Three cylindrical recesses 32a, 32b, 32c are provided on one side of the worm wheel 32 at intervals of 120°, and a portion of the recesses 32a, 32b, 32c is fitted into a steel ball 33a. ,33b,3
3c are arranged respectively. On one side of the worm wheel 32 where the steel balls 33a, 33b, 33c are arranged, there are three engagement holes 41a, 41 provided so as to be able to engage with the steel balls 33a, 33b, 33c, respectively.
One side of the first clutch plate 41 having the numbers b and 41c is press-fitted and is provided to rotate together with the worm wheel 32. A second clutch plate 42 is provided on the other side of the first clutch plate 41.
One side of the worm wheel 32 is pressure-welded by planar contact, and is provided so that the rotational force is frictionally transmitted from the worm wheel 32. This second clutch plate 42
is fitted into the flat cut surface 31b forming portion of the rotary shaft 31 so as to be slidable in the axial direction but not rotatable. Note that a washer 34 is provided on the back side of the second clutch plate 42.
For example, a pressing force of approximately 13 kg is applied from the disc spring 35 via the disc spring 35. The pressing force of the disc spring 35 is adjusted by a nut 36 screwed onto the rotating shaft 31. A flat cut surface 31c on the opposite side of the flange portion 31a of the rotating shaft 31 is provided with a rotary shaft such that the rotational output transmitted to the second clutch plate 42 is applied as a driving output to the single narrow diameter rod antenna element 15, which is a load. A feed roller 37 and a connecting gear 38 as an output side rotating body are integrally fitted into the rotary shaft 31 in a non-rotatable state. Note that the feed roller 37 and the connecting gear 38 correspond to the first gear roller 21 shown in FIG.

Next, the operation and effects of this embodiment configured as described above will be explained. First, when the motor 11 is rotated in the forward direction when the antenna is extended, the rotational force is transmitted to the worm wheel 32 via the worm 12. Therefore, the worm wheel 32, which is the input side rotating body, is driven to rotate. Then, the steel balls 33a to 33c and the engagement holes 4 are formed on one side of the worm wheel 32.
1a to 43c rotates the first clutch plate 41, which is coupled with a coupling force of about 7.8 kg. Therefore, it comes into pressure contact with the first clutch plate 41, and approximately
The rotational force is frictionally transmitted to the second clutch plate 42, which is coupled with a coupling force of 4.8 kg, and the second clutch plate 42 also rotates. Therefore, the rotating shaft 31
rotates, and the feed roller 37, which is the first gear roller 21, and the connecting gear 38 rotate. Therefore, the second and third gear rollers 22 and 23 also rotate in conjunction with each other, and the single small diameter rod antenna element 15
is transferred in the direction of the arrow in FIG. 1 while being held under pressure by the first to third gear rollers 21 to 23, and the antenna element 15 is extended. When the antenna element 15 completes extension and transfer is stopped, the load side of the clutch mechanism 13 becomes overloaded, and the load exceeds the clutch coupling force of 4.8 kg between the first clutch plate 41 and the second clutch plate 42. As a result, a slip occurs between the first and second clutch plates 41 and 42, and the clutch mechanism 13 becomes disengaged. Therefore, the drive source side, that is, the motor 1
1, worm 12, worm wheel 32, first
Clutch plate 41 rotates idly. After this, a limit switch (not shown) operates and motor 1
The rotation of 1 stops.

When the motor 11 is rotated in the opposite direction when the antenna is contracted, the worm 12, the worm wheel 32, the first and second clutch plates 41, 42, and the first to third gear rollers 21 to 23 rotate as described above. In all cases, the rotation is in the opposite direction, the antenna element 15 is moved in the direction opposite to the arrow in FIG. 1, and the antenna element 15 is reduced. When the reduction is completed, the clutch mechanism 13 is disengaged as in the case described above, and then the motor 11 stops rotating, and the operation is completed.

Now, suppose that the first and second clutch plates 41 and 42 become stuck together due to freezing or adhesion of sticky substances. Moreover, suppose that in such a state, the antenna element stops in the middle of an expansion/contraction operation in which the limit switch does not work.
In this state, the load side of the clutch mechanism 13 is locked, so under normal conditions, slipping should occur between the first and second clutch plates 41 and 42, but as described above, Since the first and second clutch plates 41 and 42 are fixed to each other, the first clutch plate 41, which is originally on the driving source side, also stops rotating together with the second clutch plate 42. In this case, a force exceeding the 7.8 kg force generated by the engagement between the steel balls 33a to 33c and the engagement holes 41a to 41c is exerted between the worm wheel 32 and the first clutch plate 41. As a result, the engagement is disengaged, and the worm wheel 32, worm 12, and motor 11 are allowed to idle. This prevents locking on the drive source side,
Even if the above-mentioned condition continues for a while, the winding burnout accident of the motor 11 can be avoided. Note that in the above state, the steel balls 33a to 33c
Since the engagement and disengagement between the and the engagement holes 41a to 41c occur intermittently, the above-mentioned fixed state may be released due to vibrations accompanying the engagement and disengagement. It is desirable to provide means for detecting the occurrence of a stuck state and to immediately cut off the motor power. Note that instead of providing a means for directly detecting the stuck state, a worm wheel 32 which is an input side rotating body and a first clutch plate 4 are used.
It is more practical to provide a means for detecting the slip operation of motor 1 and cutting off the motor power supply accordingly.

Note that the present invention is not limited to the above embodiment. For example, in the above embodiment, the present invention was applied to an electric antenna using a single small-diameter rod antenna element 11 as the rod antenna element. Of course, the present invention can also be applied to electric antennas using multi-stage telescoping antenna elements, and can also be widely applied to antennas other than electric antennas. Further, in the above embodiment, the first clutch plate 41 is provided with the engagement holes 41a to 41c as recesses for engaging the steel balls 33a to 33c, but depressions may be provided instead of the engagement holes. All that is required is to provide a recess that engages the ball. Furthermore, in the above embodiment, the balls and recesses are arranged at three locations, but the number of balls and recesses to be arranged may be arbitrary. Further, in the above embodiment, the worm wheel 32 is used as the input side rotating body, and the gear roller 21 consisting of the feed roller 37 and the connecting gear 38 is used as the output side rotating body, but these are devices that can input and output rotational force. If so, it may be of any structure such as gears, rollers, pulleys, etc. It goes without saying that various other modifications can be made without departing from the gist of the present invention.

[Effect of idea]

According to the present invention, the following effects can be expected.

Under normal conditions, a normal clutch section consisting of a joint between a first clutch plate and a second clutch plate is used. If the clutch part, that is, the joint part between the first clutch plate and the second clutch plate, becomes stuck due to freezing or adhesion of adhesive substances, and the load side becomes rodded for some reason, , the connection between the ball and the recess in the emergency clutch section interposed between the input-side rotating body and the first clutch plate is released. As a result, a slip occurs between the input-side rotating body and the first clutch plate, allowing the drive source side to idle.
Therefore, it is possible to avoid various troubles caused by an abnormal situation occurring in the normal clutch portion. Further, as described above, when the normal clutch becomes stuck and slip occurs between the input rotating body and the first clutch plate, the motor power is automatically cut off. As a result, it is possible to avoid the disadvantage that the engagement and disengagement operations of the abnormality clutch portion as described above continue indefinitely, resulting in continuous generation of noise.

Therefore, even if the clutch plates become stuck between each other due to ice formation or adhesion of adhesive substances under conditions where the limit switch etc. do not operate, there is no risk of burnout of the motor windings, resulting in extremely safe operation. It is possible to provide a clutch mechanism that has a high level of noise and does not cause new problems such as continuous noise generation.

[Brief explanation of the drawing]

Figures 1 to 3 are diagrams showing an embodiment in which the present invention is applied to an electric antenna. Figure 1 is a sectional view of the main part, and Figure 2 is a cross-sectional view of Figure 1 taken along line A-A. FIG. 3 is a sectional view showing only a portion of the clutch mechanism, and FIG. 3 is an exploded perspective view of the clutch mechanism. DESCRIPTION OF SYMBOLS 10... Case, 11... Motor, 12... Worm, 13... Clutch mechanism, 14... Antenna element expansion/contraction mechanism, 15... Single small diameter rod antenna element, 21-23... First to third Gear roller, 31... Rotating shaft, 32... Worm wheel, 32a to 32c... Cylindrical recess, 33a
~33c...steel ball, 34...washia, 35...disc spring, 36...nut, 37...
Feed roller, 38... Connection gear, 41, 42...
First and second clutch plates, 41a to 41c...engagement holes.

Claims (1)

[Scope of claim for utility model registration] An input-side rotating body rotationally driven by a motor,
A first clutch plate whose one side is connected to one side of the input side rotary body by engagement of a ball and a recess and which rotates together with the input side rotary body; A second clutch plate whose one side is connected by contact and to which the rotational force of the first clutch plate is transmitted by friction, and an output side rotation unit that rotates integrally with the second clutch plate and outputs the rotational force to a load. and a coupling force between the input-side rotating body and the first clutch plate is set to be larger than a coupling force between the first clutch plate and the second clutch plate. and a clutch mechanism configured such that when the input-side rotating body and the first clutch plate slip, the power to the motor is cut off.