JPS62233528A - Actuator - Google Patents

Abstract

PURPOSE:To improve the safety and the reliability by arranging an electromagnetic clutch for driving an output pulley upon excitation coaxially therewith and returning the output pulley to the close position of a throttle pulley when a reduction gear bites a foreign matter. CONSTITUTION:A shaft 2 is secured to an actuator case 1 while brushes 7a, 7b for supplying power to a motor 3, a reduction gear mechanism 4 and an electromagnetic coil 12 are provided. The electromagnetic coil 12 for constituting an electromagnetic clutch 11 is contained in a worm wheel constituting a portion of the reduction gear 4, then an output pulley 20 integral with an armature plate 23 is fitted to the shaft 2 above said coil 12. When the electromagnetic coil 12 is excited, the output pulley 20 is driven and when the excitation is stopped, the output pulley 20 is returned by a return spring 27 to the close position of a throttle valve. Consequently, the safety of the actuator is ensured and the reliability is improved.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) This invention relates to an actuator that drives an output pulley by the rotation of a motor, and is particularly used as a drive source for an automatic vehicle speed control device for automobiles. This relates to actuators.

(Prior Art) Conventionally, actuators used in automatic vehicle speed control devices for automobiles, for example, have been of a negative pressure control type using a negative pressure source or of a motor drive type using a motor.

However, with a negative pressure control type actuator, it is not possible to obtain sufficient negative pressure when supercharging the engine in the case of a supercharged engine, and it is difficult to obtain sufficient and stable pressure in the case of a small displacement engine. Because negative pressure cannot be obtained,
A motor-driven actuator was used.

As such a motor-driven actuator,
For example, there was a structure shown in FIG.

That is, this actuator transmits the rotation of the motor 101 to the worm wheel 104 including the worm 103 that constitutes a part of the deceleration mechanism 102.
It is transmitted to the internal gear body 106 via the planetary gear mechanism 105 that constitutes a part of the . In this state, the electromagnetic coil 1 that constitutes the electromagnetic clutch housed in the clutch case 111
12 is excited, an armature plate 106a constituting an electromagnetic clutch provided on the internal gear body 106 is attracted to the coil 112 and is transmitted to the output shaft 113 fixed to the planetary gear mechanism 105. Then, the output shaft 1
13 is rotated to drive a throttle valve (not shown) according to instructions from a microcomputer serving as a control section.Furthermore, upon receiving a system release command from the driver, a throttle valve (not shown) is driven according to instructions from the microcomputer as a control section. When the excitation of the electromagnetic coil 112 is stopped, the internal gear body 106 becomes rotatable, the rotation of the motor 101 is no longer transmitted to the output shaft 113, and the return spring 115 forces the output valve 9114 to the throttle valve closed position. This ensures safety in the system release state.

(Problems to be Solved by the Invention) However, in the conventional monitor drive type actuator described above, the output pulley 11 is
4 to the throttle valve closed position, it is necessary to rotate the output shaft 113 according to the required angle.
Since the electromagnetic coil 112 is not excited, the M star gear S! corresponds to the rotation of the output shaft 113. The internal gear body 106 is rotated via the mechanism 105, but in this state, foreign matter such as sand or dirt may enter the actuator and cause the foreign matter to interfere with the meshing between the planetary gear mechanism 105 and the internal gear body 106. If the throttle valve becomes jammed, the output shaft 113 may stop at that position, making it impossible to return the output pulley 114 to the throttle valve closed position. This poses a problem in that it significantly impairs safety and reduces the reliability of the system.

Therefore, this invention was made by focusing on the above-mentioned conventional problems, and even if foreign matter such as sand or dirt enters the actuator while it is operating, the output valve can be reliably moved to the throttle valve closed position. The purpose of the present invention is to provide an actuator that can restore the system to the original position, ensure its safety, and improve the reliability of the system.

[Configuration of the Invention j (Means for Solving the Problems) The configuration of the actuator of the present invention for achieving the above object is such that, in an actuator that drives an output pulley by rotation of a motor, the actuator is coaxial with the output pulley. To,
An electromagnetic clutch is provided that interlocks the output pulley by excitation of an electromagnetic coil.

(Example) The present invention will be explained below based on the drawings.

1 to 5 are diagrams showing an embodiment of the present invention. FIG. 1 is a cross-sectional explanatory view showing the structure of an actuator, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is an explanatory plan view of FIG. FIG. 2 is an exploded explanatory diagram of FIG. 1;

In FIG. 1, reference numeral 1 in the figure is an actuator case (hereinafter referred to as "case").

This case 1 has one end of a support shaft 2 fixed as shown in FIG. Each brush 7a supplies power to an electromagnetic coil 12, which will be described later.

7b is provided.

Reference numeral 10 denotes a worm wheel as a final drive member constituting a part of the speed reduction mechanism 4. This worm wheel 10 accommodates therein an electromagnetic coil 12 constituting an electromagnetic clutch 11, and has the brush on its bottom surface. 7a
, 7b to supply power to the electromagnetic coil 12, respectively. Further, a metal bearing 15 is fitted into the insertion hole 14 of the worm wheel 10, and is inserted through the support shaft 12 and supported rotatably.

20 is an output boolean. This output pulley 2G is rotatably supported by the support shaft 2 and is located coaxially with the electromagnetic clutch 11. As shown in FIG. 2, this output pulley 20 is attached with a control wire 22 for driving a throttle valve shaft 21, and is provided with an armature plate 23 constituting the electromagnetic clutch 11 at its lower part. That is, this armature plate 23 is attached to a bin 24 fixed to the output pulley 20 as shown in FIGS. 4 and 5.
3 is engaged with springs 26 fixed with rivets I.25, which are provided at three locations at approximately equal intervals to support the armature plate 23, and when the electromagnetic coil 12 is energized, the electromagnetic coil 12 The output pulley 20 is interlocked with the rotation of the worm wheel 10.

Further, a return spring 27 is provided on the upper part of the output pulley 20, and when the excitation of the electromagnetic coil 12 is stopped by this return spring 27, the output pulley 20 is moved to the throttle valve closed position (throttle valve shaft 21 Return warmly to neutral position).

Reference numeral 30 denotes an inner plate fixed within the case 1 and supporting the other end of the support shaft 2. This inner plate 3
0, there are two stoppers 31 on the output pulley 20 side that restrict the rotation range of the output pulley 20 (from the throttle valve closed position to the throttle valve open position, that is, from the neutral position of the throttle valve shaft 21 to the fully open position). An elastic body 32 (eg, rubber material, etc.) is provided to protect the output pulley 20 when the end of the output pulley 20 comes into contact with the surface of the elastic body 32. Additionally, two limit switches 33 are provided to cut off the power supply to the motor 3 when the output pulley 20 reaches the end of the rotation range (the neutral position or fully open position of the throttle valve shaft 21) by a switch lever 40, which will be described later. It is set up.

A switch lever 40 detects the end of the rotation range of the output pulley 20 and operates the limit switch 33.

50 is a lid that covers the opening of the case 1.

Next, the motor-driven actuator with the above configuration is
A case will be described in which the throttle valve shaft 21 is adjusted by commands from a microcomputer as a control unit of an automatic vehicle speed control device.

First, when the set switch of the automatic vehicle speed control device is turned ON and then turned OFF, the microcomputer memorizes the vehicle speed at the time of the OFF operation from the vehicle speed sensor that outputs a pulse signal proportional to the actual vehicle speed. A set initialization corresponding to the stored vehicle speed is calculated and the actuator is operated. That is, the electromagnetic coil 12 in the worm wheel 10 is excited by instructions from the microcomputer, and the output pulley 20
The armature plate 23 is attracted to the coil 12 side against the restoring force of the spring 26, and the motor 3 rotates according to instructions from the microcomputer to drive the worm wheel 10 as the final drive member. That is, the motor 3 rotates by the number of rotations corresponding to the set initialization calculated by the microcomputer.

At this time, the output pulley 20 is interlocked with the worm wheel 10- via the electromagnetic clutch 11, and the throttle valve shaft 21 is held at a predetermined position to perform constant speed running at the memorized vehicle speed.

Thereafter, when the actual vehicle speed increases or decreases from the stored vehicle speed, the microcomputer rotates the motor 3 in a direction corresponding to the increase or decrease, so that the actual vehicle speed matches the stored vehicle speed, and the vehicle runs at a constant speed.

Then, in a system release state such as a brake operation, the electronic computer stops excitation of the electromagnetic coil 12 in response to this system release signal. As a result, the electromagnetic clutch 11 is released, and the output pulley 20 is forcibly and quickly returned to a position corresponding to the neutral position of the throttle valve shaft 21 by the action of the return spring 27.

That is, when the excitation of the electromagnetic coil 12 is stopped by a command from the microcomputer, the armature plate 23
is returned to the output pulley 20 side by the restoring force of the spring 26. At this time, the output pulley 20 is in a state where it can freely rotate with respect to the support shaft 2, so even if foreign matter such as sand or dirt enters the actuator and the deceleration mechanism 4 gets caught in the foreign matter, the output pulley 20 20 can reliably return the throttle valve shaft 21 to the neutral position by the action of the return spring 27 regardless of the speed reduction mechanism 4, so it can be operated under any conditions according to instructions from a microcomputer, similar to a negative pressure control type actuator. Since it can be used regardless of the negative pressure source that is a problem with negative pressure control type actuators, its range of use is not limited.

[Effects of the Invention] As explained above, according to the actuator of the present invention, in an actuator that drives an output pulley by rotation of a motor, the output pulley is driven coaxially with the output pulley by excitation of an electromagnetic coil. By providing an interlocking electromagnetic clutch, even if foreign matter such as sand or dirt enters the actuator and the deceleration mechanism gets caught in it while the actuator is operating, the electromagnetic coil will not be disconnected in response to system release. By cutting off the power and releasing the electromagnetic clutch, the output boolean can be returned to the throttle valve closed position, which not only ensures the safety of the actuator when the system is released, but also allows the system to An excellent effect of increasing reliability can be obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional explanatory diagram showing the structure of an embodiment of the actuator of the present invention, FIG. 2 is a plan explanatory diagram of FIG. 1, FIG. 3 is an exploded explanatory diagram of FIG. 1, and FIG. 4 is an output boot 5 is a cross-sectional explanatory view showing the structure of a conventional actuator, FIG. 5 is a partially broken explanatory view of the bottom of FIG. 4, and FIG. 6 is a cross-sectional explanatory view showing the structure of a conventional actuator. 2... Support shaft, 3... Motor, 11... Electromagnetic clutch, 12... Electromagnetic coil, 20... Output pulley. Patent Applicant Jidosha Electric Industry Co., Ltd. Representative Patent Attorney Yutaka Oshio 12...tIJ & Coil 20... Muka Pulley -20!1N-- Figure 4 Figure 5

Claims (3)

[Claims] (1) An actuator that drives an output pulley by rotation of a motor, characterized in that an electromagnetic clutch is disposed coaxially with the output pulley and interlocks the output pulley by excitation of an electromagnetic coil. (2) The electromagnetic clutch is characterized in that the electromagnetic coil is housed in the final drive member of the speed reduction mechanism, and the armature plate is provided on the output pulley.
Actuator described in ). (3) The actuator according to claim 1 or 2, wherein the output pulley is rotatably supported by a support shaft fixed in the housing.