JPH047663Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an electric actuator that controls the rotational position of an output shaft, and is suitable for use, for example, in adjusting an orifice in a hydraulic shock absorber.

(Prior Art) Conventionally, as this type of electric actuator, one shown in FIG. 6 has been known.

In FIG. 6, a pinion 31 fixed to a rotating shaft (not shown) of a reversible motor is connected to an output gear 3 connected to an output shaft 32 connected to a drive shaft of a damping force adjustment valve having a plurality of orifices (not shown).
It meshes with 3. This output gear 33 is provided with a semi-circular stopper hole 34 through which a pin 36 connected to a movable plunger (not shown) of a solenoid passes through. Further, a recess 35 is provided in the center of the stopper hole 34, into which a pin 36 is inserted when the solenoid is energized.

When the reversible motor is driven when the solenoid is shut off, the output gear 33 rotates in the direction of the arrow C or the direction of the arrow D, and the output gear 33 rotates in the direction of the arrow C or the direction of the arrow D.
4b collides with the pin 36, the output gear 33
stops, and the output shaft 33 is controlled to the 2nd position.

Furthermore, when the solenoid is energized, the movable plunger is attracted, so the pin 36 is pressed against the outer arcuate surface 34c of the stopper hole 34, and when the concave portion 35 reaches the position of the pin 36 due to the rotation of the output gear 33, the pin 36 is moved as indicated by the dotted line. As shown in the figure, the output gear 33 enters the recess 35, so the output gear 33 stops and the output shaft 32 is controlled to an intermediate position between the two positions.

(Problem to be solved by the invention) However, in the conventional electric actuator as described above, the output shaft 32 is located at the intermediate position.
Since the pin 36 is inserted into the recess 35 in order to control the
It is necessary to increase the width dimension of the output shaft 32 to ensure that the output shaft 32 is inserted therein, which causes backlash and makes it impossible to accurately position the output shaft 32. Furthermore, if the rotational speed of the output gear 33 is increased, the pin 36 may not be able to enter the recess 35, so the rotational speed of the output gear 33 is restricted, resulting in poor responsiveness in positioning the output shaft 32. The dot was hot.

Furthermore, since the pin 36 is pressed against the outer arcuate surface 34c of the stopper hole 34 until it enters the recess 35, there is a problem in that the motor load increases due to frictional resistance. Here, in order to avoid increasing the motor load, the timing of energizing the solenoid can be adjusted so that when the recess 35 reaches the pin position, the movable plunger is sucked and the pin 36 enters the recess 35. In this case, a new timing device is required, resulting in a problem of increased costs.

The present invention was devised to solve the above-mentioned conventional problems, and it enables highly accurate positioning of the output shaft, improves the responsiveness of output shaft positioning, and increases the motor load. The purpose of the present invention is to provide an electric actuator that is free from problems.

(Means for Solving the Problems) An electric actuator according to the present invention transmits the rotation of a reversible motor to an output shaft via a gear reduction mechanism and controls the rotational position of the output shaft. A drive device 1 consisting of a reversible motor 3 and one gear reduction mechanism 5 including a first output gear 9; a drive device 2 consisting of the other gear reduction mechanism 6 including a reversible motor 4 and a second output gear 10; A pair of levers are provided on the first output gear 9, which is constructed from a case 11 that houses each of the drive devices 1 and 2, and which are not connected to the output shaft 19, for setting the left and right rotation limit positions of the gear. 14, 15, and the pair of levers 14, 15 provided in the case 11.
a pair of stoppers 16 and 17 that come into contact with one of the stoppers 16 and 17 to restrict the rotation range of the first output gear 9;
The second output gear 10 of the drive device 2 is connected to the output shaft 19 by a connecting pin 21, and is disposed between the pair of levers 14 and 15 and selectively engaged with each of the levers 14 and 15. Then, the second
An engagement member 22 that restricts the rotation range of the output gear 10
It is characterized by having the following.

(Example) Hereinafter, the electric actuator according to the present invention will be explained as follows.
An explanation will be given based on an embodiment shown in FIGS. 5 to 5.

In FIGS. 1 to 3, reference numerals 1 and 2 represent a pair of drive devices housed in a case 11. As shown in FIG. One drive device 1 includes a reversible motor 3 and a reversible motor 3.
The motor includes a worm 7 fixed to an armature shaft 3a, and a first output gear 9 that meshes with the worm 7. This worm 7 and the first output gear 9 constitute one gear reduction mechanism 5, so that the gear reduction mechanism 5 cannot be rotated from the output stage side, that is, from the first output gear 9 side. ing. Similarly, the other drive device 2 includes a reversible motor 4, a worm 8 fixed to an armature shaft 4a of the motor 4, and a second output gear 10 that meshes with the worm 8. 8 and the second output gear 10 constitute the other gear reduction mechanism 6.

As shown in FIG. 3, the case 11 has a stepped boss 1 integrally formed inwardly projecting from its bottom surface.
2, the large diameter portion 12a and the small diameter portion 1 of the boss 12.
2b, the first output gear 9 and the second output gear 1, respectively.
0 is rotatably supported. Note that 13 is a cover that closes off the case 11.

On the upper surface of the first output gear 9 in FIG. 2, a pair of levers 14 and 15 for setting the left and right rotation limit positions of the gear 9 are integrally provided at a predetermined interval. . A pair of stoppers 16 and 17 are provided on the case 11 and are made of an elastic material and come into contact with one of the pair of levers 14 and 15 to restrict the range of rotation of the first output gear 9. The stopper 16 is disposed within the thick wall portion 11a of the case 11 that supports each bearing 18 that rotatably supports the tip portions of the armature shafts 3a, 4a. It projects outward from the thick portion 11a so that the lever 14 can come into contact with its distal end surface 16a. Also, stopper 17
is a case 1 that supports the reversible motors 3 and 4;
1 and is integral with the case 11.
1b, the tip of the stopper 17 projects outward from the support frame 11b, so that the lever 15 can come into contact with its tip surface 17a.

19 is a gear reduction mechanism 6 of the other drive device 2
The output shaft is connected to the second output gear 10 constituting the boss 12, and is rotatably supported in a through hole 12c bored in the axis of the boss 12, as shown in FIG.
Both ends of the output shaft 19 protrude from the through hole 12c, and are prevented from coming off the boss 12 in the axial direction by a washer 20 engaged near the lower end of the output shaft 19. Both ends of the connecting pin 21, which is inserted into a radial through hole drilled near the upper end of the output shaft 19 and has both ends protruding, are provided on one surface of the second output gear 10 and are opposed to each other. A pair of connecting members 10a, 10a having engagement grooves 10c formed by protrusions 10b, 10b.
(See FIG. 1), the second output gear 10 and the output shaft 19 are connected in a relatively unrotatable manner. A drive shaft (not shown) of a damping force adjustment valve having, for example, a plurality of orifices is connected to the lower end of the output shaft 19.

22 is the second output gear 10 shown in FIG.
The pair of levers 1 are provided protruding from the lower surface in the figure.
4 and 15 and selectively engages with the levers 14 and 15 to restrict the rotation range of the second output gear 10.
It consists of a protruding shaft 22a integral with the protruding shaft 22a and an elastic sleeve 22b attached to the protruding shaft 22a.

FIG. 4 is a drive circuit diagram of the electric actuator, and 23 is a DC power source whose negative electrode side is grounded.
R ₁ , R ₂ , R ₃ , and R ₄ are relays with one end grounded, respectively, and movable contact pieces R ₁₁ , R ₁₂ , R ₁₃ ,
R ₁₄ and grounded normally closed contacts R ₂₁ , R ₂₂ ,
R ₂₃ , R ₂₄ and normally open contacts R ₃₁ , R ₃₂ , R ₃₃ , R ₃₄ connected to the positive electrode of the DC power supply 23, respectively.

24 is an operation switch, and automatic return operators 25a, 25b, 25c, 25d, 25e, 2
5f and fixed contacts 26a, 26b, 26c, 25d, 26 connected to the positive electrode of the DC power supply 23, respectively.
e, 26f, fixed contacts 27a, 27c connected to the other end of the relay _R1 , fixed contacts 27b connected to the other end of the relay _R3 , and the relay
Fixed contacts 27d and 27f connected to the other end of _R2
and a fixed contact 27e connected to the other end of the relay _R4 . The operator 25a and the operator 2
5b, the operator 25d, and the operator 25e are interlocked with each other. When the operator 25a is turned on, the fixed contacts 26a, 27a are electrically connected via the operator 25a, and the fixed contacts 26b, 27b are connected via the operator 25b. is becoming conductive. Similarly, when the operator 25d is turned on, the fixed contacts 26d, 27d are electrically connected via the operator 25d, and the fixed contacts 26e, 27e are connected via the operator 25e.
conducts.

One end of the reversible motor 3 is connected to a movable contact piece _R13 , and the other end is connected to a movable contact piece _R14 . Further, one end of the reversible motor 4 is connected to a movable contact piece _R11 , and the other end is connected to a movable contact piece _R12 .

Next, the operation of the electric actuator of this embodiment having the above configuration will be explained based on the operation explanatory diagrams shown in FIGS. 5A, 5B, 5D, and 4 and FIG.

First, turn the operation switch 24 in the position shown in Fig. 5A.
When the operator 25c is turned on, the relay _R1 is energized, its movable contact _R11 is switched to the normally open contact _R31 side, and the reversible motor 4 rotates forward. Due to the forward rotation of the motor 4, the second output gear 10 is
rotates clockwise together with the output shaft 19, so the engagement member 2
When the lever 2 leaves the lever 14 and reaches the position shown in FIG. 5B, it engages with the other lever 15. At this time, the gear reduction mechanism 5 composed of the worm 7 and the first output gear 9 is connected to the output stage side, that is, the pair of levers 1
4 and 15, the second output gear 10 is restrained at the position where the engaging member 22 engages with the lever 15, that is, the position shown in FIG. The shaft 19 is rotationally controlled from the position shown in FIG. 5A to the position shown in FIG. 5B. When you release your hand from the operator 25c, the operator 25c automatically returns, so the relay _R1 becomes de-energized, and its movable contact _R11
is switched to the normally closed contact _R21 side, and the drive circuit of the remoter 4 is opened.

Next _, when the operator _25a is turned on at the position shown in FIG _.
R ₁₃ switches to the normally open contact R ₃₁ and R ₃₃ side, and the reversible motors 4 and 3 rotate forward, respectively. The forward rotation of the motor 3 causes the first output gear 9 to
rotates clockwise, and the second output gear 10 also rotates clockwise via the worm 8 due to the forward rotation of the motor 4. When the first output gear 9 reaches the position shown in FIG.
7a, the output gear 9 is prevented from further clockwise rotation and is restrained. On the other hand, since the engaging member 22 engages with the lever 15, the second output gear 10 is similarly restrained at the position shown in FIG.
9 is rotationally controlled from the position shown in FIG. 5B to the position shown in FIG. 5C. When you release your hand from the operator 25a, the relay
R ₁ and R ₃ are de-energized and the drive circuits of the motors 4 and 3 are opened.

Next, when the operator _25f is turned on at _the position shown in _FIG . The output gear 10 rotates to the left. Therefore, when the engaging member 22 separates from the lever 15 and reaches the position shown in FIG. The shaft 19 is controlled to rotate from the position shown in FIG. 5C to the position shown in FIG. 5D. When you release your hand from the operator 25f, relay _R2 becomes de-energized and motor 4
The drive circuit of is open.

In this embodiment, in order to control the rotation of the output shaft 19 to three positions, the rotational position of the output shaft 19 when driven from the position A in FIG. 5 to the position B in FIG. The positions of the pair of stoppers 16 and 17 are determined so that the rotational position of the output shaft 19 when driven from the position shown in FIG. 5C to the position shown in FIG. 5D coincides with each other. In other words, one of the pair of levers 14 and 15 is connected to the stopper 1 of the pair of levers 14 and 15.
6, 17 and the stopper 16, 1
When the engagement member 22 engages with the other lever 15 or 14 that is not in contact with the second output gear 10 and the second output gear 10 is restrained, the rotational position of the output shaft 19 is the clockwise rotation position of the second output gear 10. The arrangement positions of the pair of stoppers 16 and 17 are determined so that they match during the rotation operation and the counterclockwise rotation operation. Therefore, in this example, the fifth
The drive from FIG. 5B to FIG. 5D and from FIG. 5D to FIG. 5B is unnecessary.

Next _, when the operator 25d is turned on at _the position _D in FIG _.
is switched to the normally open contact R ₁₂ and R ₃₄ side, and the reversible motors 4 and 3 rotate in reverse, so the first output gear 9
and the second output gear 10 rotates to the left. When the first output gear 9 reaches the position shown in FIG. 5A, the lever 14
Since the output gear 9 contacts the tip 16a of the stopper 16, further left rotation of the output gear 9 is prevented and restrained. On the other hand, since the engaging member 22 engages with the lever 14, the second output gear 10 is similarly restrained at the position shown in FIG. 5A, and the output shaft 19 moves from the position shown in FIG. rotation is controlled.

Similarly, moving from the position A in FIG. 5 to the position C in FIG. 5 is achieved by inserting the operator 25a.
The reverse is done by turning on the operator 25d. Further, moving from the position shown in FIG. 5B to the position shown in FIG. 5A is performed by inserting the operator 25f, and moving from the position shown in FIG. 5D to the position shown in FIG.

In this way, each operator 25a, 25 of the operating switch 24 can be operated from each position shown in FIGS. 5A to 5D.
By selectively turning on the output shafts c, 25d, and 25f, the output shaft 19 is rotationally controlled in three positions, and the orifice can be switched in three stages by controlling the rotational position of the drive shaft of the damping force adjustment valve. can.

The electric actuator of this embodiment has an output shaft 19
When controlling the rotation to an intermediate position, that is, the position shown in FIG. 5B or the position shown in FIG.
A lever 15 is provided with an engaging member 22 protruding from the first output gear 9 within the rotation locus of the engaging member 22.
Or, because of the structure that engages with the side surface of 14, there is no backlash like in the conventional example shown in FIG.
Therefore, the output shaft 19 can be positioned with high precision. Further, both output gears 9 and 10 can be rotated at high speed, and the responsiveness of positioning the output shaft 19 is improved, and the motor load does not increase.

In this embodiment, a pair of stoppers 1
6 and 17 are arranged at predetermined positions so that the output shaft 19 can be rotationally controlled in three positions in particular, but the output shaft 19 can be rotationally controlled in four positions depending on the use of the controlled member. Of course, it is also possible to do so.

Further, the one gear reduction mechanism 5 is a mechanism that is not rotated from the output stage side, and in this embodiment is composed of a worm 7 and a first output gear 9 that meshes with the worm 7, but it is rotated from the output stage side. For example, a differential gear mechanism that does not move may be used. Furthermore,
The other gear reduction mechanism 6 is also composed of a worm 8 and a second output gear 10 that meshes with the worm 8, and is not rotated from the output stage side. However, this gear reduction mechanism 6 is composed of, for example, a train of spur gears. It may also be rotatable from the output stage side.

(Effects of the invention) As explained above, according to the electric actuator according to the invention, it is possible to control the positioning of the output shaft with high precision, improve the responsiveness of the positioning of the output shaft, and reduce the motor load. It has the effect of not increasing.

[Brief explanation of the drawing]

1 to 5 show an embodiment of the electric actuator according to the present invention, in which FIG. 1 is a partially cutaway plan view, FIG. 2 is a sectional view taken along line A-A in FIG. 1, and FIG. Fig. 1 is a sectional view taken along line B-B, Fig. 4 is a drive circuit diagram,
Figure 5 A, B, C, and D are explanatory diagrams of the operation, and Figure 6
The figure is a plan view showing a conventional example. 1, 2... A pair of drive devices, 3, 4... Reversible motor, 5... One gear reduction mechanism, 6... The other gear reduction mechanism, 9... First output gear, 10...
Second output gear, 11... Case, 14, 15...
1 pair of levers, 16, 17... 1 pair of stoppers,
19... Output shaft, 21... Connection pin, 22... Engagement member.

Claims (1)

[Claims for Utility Model Registration] 1. An electric actuator that transmits the rotation of a reversible motor to an output shaft via a gear reduction mechanism and controls the rotational position of the output shaft. A first drive device 1 comprising a first gear reduction mechanism 5 including one output gear 9; and a second gear reduction mechanism 6 including a second reversible motor 4 and a second output gear 10. a second drive device 2, and each of the first and second drive devices 1, 2;
The first output gear 9 is provided with a case 11 that houses the output gear 9, and an output shaft 19, and is provided on the first output gear 9 that is not connected to the output shaft 19, and sets the left and right rotation limit positions of the first output gear 9. a pair of first and second levers 14 and 15 provided in the case 11 and in contact with one of the pair of first and second levers 14 and 15, respectively, and the first output gear 9; a pair of first, which regulates the rotation range of the
second stoppers 16 and 17 and the output shaft 19
is provided on the second output gear 10 of the second drive device 2 connected by a connecting pin 21 and is disposed between the pair of first and second levers 14 and 15. An electric actuator comprising: an engaging member 22 that selectively engages with the levers 14 and 15 to restrict the rotation range of the second output gear 10. 2. 14 and 15 of the pair of first and second levers
either one of the first and second stoppers 16, 17 comes into contact with the pair of first and second stoppers 16, 17;
When the engagement member 22 engages with the other first lever 14 or second lever 15 that is not in contact with the second stopper 14, 15 and the second output gear 10 is restrained. The pair of first and second stoppers 16 and 17 are arranged so that the rotational position of the output shaft 19 is the same when the second output gear 10 is rotated clockwise and when it is rotated counterclockwise. The electric actuator according to claim 1, characterized in that the installation position is determined.