JPH0115205Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to the invention of an electric antenna extension/retraction operation mechanism, which improves the operability of the antenna extension/retraction operation mechanism driven by a motor, appropriately avoids the noise generation of the clutch mechanism, and furthermore, The aim is to obtain a mechanism that reduces load generation.

Automatic extension and retraction using a motor has been common practice in car antennas, etc., but it is essential to employ a clutch mechanism in such devices, that is, fully extended or fully extended. After retraction, the clutch mechanism is actuated to prevent wire breakage and other mechanical damage caused by continued motor drive.Of course, in recent years, the motor power switch has been turned on and off to control the motor operation. Although the clutch is automatically stopped, it is necessary to drive the motor by a certain amount larger than the predetermined amount, and to avoid incomplete extension or retraction, the clutch should be stopped automatically. It is essential to establish an operational relationship that incorporates the operation of the mechanism. However, the engagement relationship between the engaging protrusion provided on the drum side and the engaging protrusion provided on the clutch plate, which is generally adopted in the conventional electric antenna extension/retraction mechanism incorporating the clutch mechanism in this way, is In the case of the one used, even after the motor drive starts, until the engaging parts engage with each other (three or more of the engaging parts as described above are arranged in an equiangular relationship, and the expansion and contraction of the antenna is In this case, the motor drive direction is alternately reversed, so the clutch plate engaging protrusion that was engaged with one drum engaging protrusion in the previous stroke rotates in the opposite direction in the next stroke and slips, causing the clutch plate to engage with the other drum engaging protrusion. Therefore, the antenna (which comes into contact with the engaging protrusion) will not be expanded or contracted, and the timing of the antenna expansion and contraction operation cannot be obtained appropriately. Therefore, in order to properly complete expansion and contraction using a limit switch, it is necessary to set the limit switch so that it operates while taking into account the time due to slip. In addition, when the clutch mechanism as described above is activated, the elastic restoring action of the spring that presses the clutch plate against the side of the drum generates a clicking noise between the clutch plate and the drum, which is disadvantageous in that it gives an unpleasant audible sensation. Furthermore, the motor torque needed to operate the clutch over the various engagement parts between the clutch plate and the drum as described above is quite large, which not only causes large power loss but also causes damage due to heat generated by the motor. There are disadvantages such as

The present invention was devised after consideration to eliminate the disadvantages of the conventional ones as described above, and the embodiment thereof is explained as shown in the attached drawings. A drive gear 2 that engages with the worm 1 coaxial with the worm 1 is rotatably inserted into a central shaft 11 provided on the base body 10, and a drive gear 2 is connected to one side of the drive gear 2 through the shaft cylinder part 20. A nut-shaped rectangular protrusion 21 and a threaded shaft portion 22 are integrally protruded, and a plurality of hole-shaped engaging portions 23 are arranged on the circumferential side of the shaft cylinder portion 20. It is set up. Further, a washer plate 3, a drum 4 serving as a wire-operated rotating body, and a clutch plate 5 having a square engagement portion 51 are attached to the shaft cylinder portion 20 as described above. That is, the washer plate 3 is made of a metal plate or the like, and is designed to allow smooth relative rotation between the drive gear 2 and the drum 4, which are made of a synthetic resin material. The one made by Washashi Plate 3 is like this.
An engaging protrusion 33 shallower than a clutch engaging protrusion 44 described later, which is capable of engaging and disengaging with the engaging part 23, is formed on the joint surface with the drive gear 2, and also on the joint surface with the drum 4. A relatively shallow engaging protrusion 32, which is as shallow as the engaging protrusion 33 that engages with and disengages from the engaging recess 42 of the drum 4, is disposed on the opposite surface at an intermediate position between the engaging protrusions 33, 33. That is, each engaging protrusion 3
2 and 33 are disposed at intermediate positions with respect to each other, the angle at which they are disposed is one-half of the angle at which the clutch engaging protrusion 44 of the drum 4, which will be described later, is disposed. The rest of the configuration of the drum 4 is as conventionally known, including a wire 9 that is telescopically operated on one side.
A groove 41 for winding up is formed in a spiral shape, and clutch engaging protrusions 44 are provided on the other side.
The clutch engagement protrusion 54 of the clutch plate 5, which has a square engagement part 51 in the center thereof, is exposed, and is connected to the threaded shaft part 22 via the spring 6 and the washer 7, as in the conventional case. By screwing the nut 8 into the clutch plate 5, the clutch plate 5 is brought into pressure contact with the other side surface of the drum 4 with appropriate elasticity. When assembling the washer plate 3, drum 4 and clutch plate 5 as described above, the engaging protrusion 3
2, 33 and the engaging recess 42 portion, the engaging protrusion 3
2 and 33 are assembled in a stable state by fitting into the recesses 23 and 42,
It goes without saying that these parts should be assembled by fitting them into each other, as shown in FIG. 1 by imaginary lines, and in FIG. 2 in an assembled state. On the other hand, since the clutch engaging protrusions 44 and 54 are both protrusions and do not form a fitting relationship, the distance between the respective engaging protrusions 54 or 44 on the clutch plate 5 or the drum 4 is simply an intermediate position. It is enough to be located in

To explain the operation of the device according to the present invention as described above, the relatively shallow engaging protrusions 32 and 33 of the washer plate 3 and the engaging parts 23 and 42 of the drive gear 2 and the drum 4 are It is designed so that either one of the engagement relationships can be released when a rotational force of, for example, about 2 kg is generated due to the pressing force of the spring 6, and the clutch engagement portion between the clutch plate 5 and the drum 4 is The engagement between 44 and 54 is similarly designed to be released by the action of the spring 6 with a torque larger than the above-mentioned rotational force of, for example, about 5 kg. However, in a device assembled as described above with such a relationship of engagement and disengagement, when the rotational force of the motor 20 is transmitted to the drive gear 2, the drum 4 is simultaneously rotated via the washer plate 3 as described above. Although it will move,
In this case, there is no engagement or disengagement between the engagement protrusion 54 of the clutch plate 5 and the engagement protrusion 44 of the drum 4 (that is, no clutch operation). That is, when the assembled state is formed as described above, and the engaging protrusions 32 and 33 are fitted into the engaging recess 42 of the engaging part 23, the rotation of the drive gear 2 causes the drum 4 to move through the washer plate 3. In contrast, when the engaging protrusions 54 of the clutch plate 5 are located between the engaging protrusions 44 of the drum 4, when four of them are arranged as shown in the figure, the maximum This is because the drum 4 is connected to the engaging protrusion 44 and does not rotate until the drum 4 has been rotated through nearly 90 degrees. That is, in normal operation, as the drive gear 2 rotates, the clutch plate 5 also rotates in the same way, but since there is no connection between the engaging protrusions 54 and 44, the limit switch operates with a light torque within the operating range. The clutch mechanism via the washer plate 3 preferentially rotates the drum 4, and the clutch mechanism between the clutch plate 5 and the drum 4 does not operate. In other words, the antenna telescoping wire 9 is operated in and out by the clutch mechanism via the washer plate 3 from the initial stage of starting the motor 20, and the antenna can be extended and retracted with a sharp start-up timing.

In addition, in the case where the antenna that is extended and contracted in this manner reaches the extension limit or is caught on another object, the engagement relationship via the washer plate 3 is applied with a relatively low torque of about 2 kg as described above. The clutch is released (clutched off), which indicates that the motor load is low even when the extension limit is reached. However, even after the engagement relationship via the washer plate 3 is released (clutched off) in this way, the driving force from the drive gear 2 is continuously transmitted to the clutch plate 5 via the square engagement part 51, and the clutch plate As described above, the clutch engaging protrusions 54 of No. 5 slip on the surface of the drum 4 and engage with the clutch engaging protrusions 44, and eventually these engaging protrusions 4
When a relatively large torque of around 5 kg is generated between 4 and 54, the clutch will be operated (engaged and disengaged). In other words, the rotational force during such slip action and clutch action is always relatively large, and the amount of torque is also large. 15 is rotated intermittently, and a switch operation cam body 16 provided integrally with the gear 15 turns off the power circuit switch for the motor 20 to stop the motor drive, taking into account rotational inertia. Completely stopping the motor drive is easy in terms of design by directly rotating the drum 4 with the washer plate 3 as described above.
Therefore, in general, rotation by the motor drive can be completely stopped while no clutch action is obtained between the clutch engaging projections 44, 54. That is, in the conventional one, the clutch engagement protrusion 5 of the clutch plate 5
4 engages with the clutch engaging portion 44 of the drum 4 in the direction of rotation, and then the drum rotates, so there is a delay in the timing of the antenna expansion/contraction operation, as described above, and the antenna expansion/contraction limit When reaching the clutch engaging protrusion 4, the
4 and 54 (clutch operation), so naturally clutch operation was required to turn off the motor switch and eliminate rotational inertia as described above, but in contrast to this According to the invention, in the case of normal operation, the antenna expansion/contraction stopping action is achieved which does not substantially require the clutch action between the clutch engaging protrusions 44 and 54 (via the washer plate 3), as described above. The clutch operation between the clutch engaging protrusions 44 and 54 functions as a safety mechanism in a special case where an abnormality occurs in the washer plate 3 or the switch system, as in the conventional case.

According to the present invention as explained above, the operating characteristics at the start of this type of electric antenna expansion/contraction are improved by rotating the drum from the beginning via the washer plate, and moreover, by the operation of the clutch mechanism with a double structure. It can significantly reduce or eliminate noise generation, and also has the effect of reducing motor drive power or heat generation in the motor during normal use by operating the clutch mechanism. This is a highly effective idea in practical terms.

[Brief explanation of the drawing]

The drawings show embodiments of the invention,
FIG. 1 is a perspective view showing an exploded state of the operating mechanism according to the present invention, and FIG. 2 is a cutaway side view of the assembled state.
FIG. 3 shows a front view of the gear and washer plate portions. However, in these drawings, 1 is a worm,
2 is a drive gear, 3 is a washer plate, 4 is a drum which is a wire-operated rotating body, 5 is a clutch plate, 6 is a spring, 7 is a washer, 8 is a nut, 9 is a wire,
10 is a base body, 11 is a central shaft, 15 is a gear,
16 is a switch operation cam body, 20 is a shaft cylinder portion, 2
1 is a square protrusion, 22 is a threaded shaft portion, 23 is an engaging portion,
Reference numerals 32 and 33 indicate engagement protrusions, 42 an engagement recess, and 44 and 54 clutch engagement protrusions, respectively.

Claims (1)

[Scope of utility model registration request] A clutch plate is attached to which the wire for extending and contracting the antenna element is engaged with a drive gear driven by a motor to rotate, and the antenna element is rotated by a wire-operated rotating body such as a drum or pulley. , a clutch engagement portion that engages with each other is disposed between the wire-operated rotary body and the clutch plate, and a washer plate interposed between the wire-operated rotary body and the drive gear is provided with a clutch engaging portion that engages the wire-operated rotary body and the clutch plate; 1. An electric antenna extension/retraction operation mechanism, characterized in that a locking portion is provided which engages with the body and the drive gear and is released by a rotational torque less than the rotational torque between the clutch engagement portions.