JPH01270762A - 3-position rotary actuator - Google Patents

Abstract

PURPOSE:To enhance a driving force and to improve responsiveness by providing a buffer member having large elastic force and a rotation limiting member having small elastic force to a rotation limiter. CONSTITUTION:A 3-position rotary actuator has a rotor 2, a base member 20, a stator 40, a yoke 60, etc. The rotor 2 is composed of a dipoled cylindrical permanent magnet 4, a ring 6, a resin bobbin 8 to be integrally molded. A first stopper 10 and a slit are formed at the bobbin 8, a leaf spring is engaged, the rotor 2 is engaged with the rotor movably engaging part 22 of the member 22 to limit the rotating angle of the rotor 2 in cooperation with a second stopper 24 at the time of rotating. Further, a shaft 50 stood at the center is arranged in the stator 40, cores 42-48 and integrally molded with a resin material 52. The rotor 2 and the stator 40 are associated by engaging the shaft 50 with the shaft engaging hole 9. Thus, the first stopper 10 is brought into contact with the second stopper 24 through a high buffer member.

Description

DETAILED DESCRIPTION OF THE INVENTION Purpose of the Invention (Field of Industrial Application) The present invention aims to stabilize one stable point of the rotor due to the field generated by one pair of field poles among four field poles, and The present invention relates to a three-position rotary actuator that can control three positions, with two stable points obtained by blocking rotation immediately before a stable point due to the positive and negative fields generated by the field poles.

(Conventional Technique vgFI) Conventionally, stepping motors have been common as devices for digitally controlling rotational positions, and are used in various fields. However, even if this is a simple system that can obtain three positions, a step motor requires a six-pole field winding, making it unsuitable for use in fields that require miniaturization and weight reduction.

Therefore, the following three-position rotary actuator that can control three positions simply by using four field poles has been proposed. FIG. 8 is a schematic explanatory diagram for explaining the operating principle of the three-position rotary actuator. By turning on the illustrated switch S1, a pair of field poles φIA and φIB spatially opposed to each other among the four field poles are excited to opposite polarities. In this state, the rotor R consisting of a cylindrical permanent magnet is stabilized with its magnetic axis aligned with the magnetic flux lines created by the field poles φIA and φIB, and even after the switch S1 is opened, the rotor R is a permanent magnet, so the rotor R remains stable. Tent torque is generated to maintain a stable state (position 8 in the figure).

When the switch S1 is opened from this state and the switch S2 is turned on, a pair of field poles φ2A and φ2B are excited instead of the field poles φIA and φIB (the direction of the magnetic field at this time is the positive direction). Therefore, a counterclockwise rotational force acts on the rotor R from the stable position B, and the rotor R
attempts to rotate until the magnetic axis of and the lines of magnetic flux created by field poles φ2A and φ2B coincide. However, a rotation limiter is provided between the rotor R and the actuator body to limit the counterclockwise rotation just before the magnetic axis and the magnetic flux lines coincide with each other due to the counterclockwise rotation. After rotating the magnetic shaft to position A, the rotor R stops.

Here, the rotation restricting section is composed of a first restricting member protruding from the rotor R, and a second restricting member protruding from the actuator body on the rotation locus of the first restricting member, so that the rotor R is at the A position. When the rotor R is rotated to the maximum, the first restricting member and the second restricting member come into contact with each other to prevent the rotor R from rotating.

When the switch S3 is turned on instead of the switch S2, a clockwise rotational force acts on the rotor R, but due to the action of the rotation limiter having the same configuration as above, the rotor R rotates to position C in the figure and stops. .

In this way, even with a simple configuration having four field poles and a rotation limiter, a three-position rotary actuator that can be controlled to three positions A, B, and C is realized. This type of three-position rotary actuator has the advantage of being small and lightweight, and is therefore used, for example, as an actuator for vehicles.

(Problems to be Solved by the Invention) However, even with the above three-position rotary actuator, it is still not sufficient, and the following problems remain unsolved.

The 3-position rotary actuator, which obtains three stable points using four poles, forcibly prevents the rotation of the rotor R by the rotation limiter to obtain two stable positions (positions A and C in FIG. 8). That is, every time the three-position rotary actuator is controlled to these two stable positions, a collision occurs between the first limiting member and the second limiting member, which are rotation limiting parts. For this reason,
Problems such as collision noise caused by the collision between the two limiting members and mechanical deterioration of the two limiting members have occurred.

In order to solve these problems, a possible solution is to reduce the rotational force of the rotor R to reduce the collision force between the two limiting members. However, many of the objects for which three-position rotary actuators are used require large drive torque and high responsiveness, so this is not a practical solution.

In addition, in order to solve the above problem without reducing the drive torque and responsiveness of the 3-position rotary actuator, the first
There is a method of forming the limiting member and the second limiting member from a material with high elasticity. However, according to this measure, after the two limiting members come into contact with each other, they are largely deflected due to their mutual elasticity, and the two stable positions of the rotor R cannot be determined with high precision. In this case, the basic performance required as a three-position rotary actuator will be lost.

The present invention has been made to solve the above problems,
A small, lightweight three-position rotary actuator that has a rotation limiter and has three stable points with four poles.It has large drive torque and high responsiveness, and each stable position can be determined with high precision and can be operated easily. The purpose is to provide a three-position rotary actuator that is low in noise and has excellent durability.

Structure of the Invention (Means for Solving the Problems) In order to solve the above problems, the three-position rotary actuator of the present invention has four field poles, one spatially facing each other, a stator in which a pair of field poles are excited to opposite polarities; a rotor that rotates in accordance with the field of the stator;
! The three-position rotary actuator has a rotation limiter that allows rotation from a stable point due to the field generated by the i1 pole to just before a stable point due to the positive and reverse fields generated by the other pair of field poles. The rotation limiting part is formed of a first limiting member formed on the rotor and a member having higher elasticity than the first limiting member, and when the rotor rotates to just before the stable point, the first limiting member a buffer member integrated with the limiting member; and a member having lower elasticity than the buffer member, the buffer member is attached to the stator, and when the rotor rotates just before the stable point, the buffer member The gist thereof includes: a second limiting member that limits rotation of the rotor by coming into contact with the member.

(Function) In the three-position rotary actuator of the present invention, the rotation restriction portion that prevents rotation of the rotor and creates two stable points has the following functions: Consists of three members: two limiting members.

The first limiting member is formed on the rotor and rotates integrally with the rotor. The buffer member functions to become integral with the first limiting member when the rotor rotates just before the stable point, and is formed of a member having higher elasticity than the first limiting member. The second limiting member is attached to the stator and comes into contact with the buffer member when the rotor rotates just before the stable point to limit rotation of the rotor,
The material is a member with lower elasticity than the buffer member.

Therefore, in the rotation restricting portion of the present invention, the first restricting member and the second restricting member come into contact with each other via the buffer member having a higher elastic force than both members.

EXAMPLES Hereinafter, in order to explain the present invention more specifically, examples will be given and explained.

(Embodiment) FIG. 1 is an exploded perspective view of a three-position rotary actuator according to an embodiment, FIG. 2 is a sectional view taken along the line I--I, and FIG. 3 is a view showing the rotor in the direction indicated by the arrow.

The rotor 2 of the three-position rotary actuator consists of a cylindrical permanent magnet 4 magnetized into two poles, a ring 6 molded by annular iron-based sintering, and a resin bobbin 8, and a permanent magnet 11 on the outer periphery. , is integrally formed with a resin bobbin 8 with a ring 6 disposed on the inner periphery.

Therefore, the rotor 2 is a cylindrical member having an inner diameter equal to the inner diameter of the ring 6 and an outer diameter equal to the outer diameter of the permanent magnet 4, and has a shaft-fitting hole 9 formed at the center thereof, which is equal to the inner diameter of the ring 6.

Also, a first stopper part 10 and a slit part 1 protrude from the lower surface of the resin bobbin 8 and regulate the rotation angle of the rotor 2.
2 are integrally formed.

The first stopper part 10 is for restricting the rotation of the rotor 2 within a predetermined angular range, and is formed in a substantially fan shape. Furthermore, a wave-shaped leaf spring 11 having a high elasticity is fitted by cutting out the first stopper part 10. The first stopper portion 10 and the leaf spring 11 configured in this manner are formed in the rotor loosely fitting portion 22 when the rotor 2 is fitted into the rotor loosely fitting portion 22 formed in the base member 20 and rotated as described later. The rotation angle of the rotor 2 is limited by interacting with the second stopper portion 24 . Note that the leaf spring 11 is made of a normal spring material, such as phosphor bronze or stainless steel.

Further, a slit portion 12 formed in the peripheral wall of the shaft-fitting hole 9 at the center of the lower surface of the resin bobbin 8 is used to fit a pin 32 that is press-fitted into one end of a rotating shaft 30 that serves as the output shaft of the three-position rotary actuator. It constitutes a so-called universal joint that transmits rotational force to this.

A rotor loose fitting portion 22 having a diameter slightly larger than the outer diameter of the rotor 2 is formed in the base member 20, and the rotor 2
is loosely fitted. A second stopper part 24 is formed in the rotor loose fitting part 22 and holds a contact member 25 made of hard rubber or the like that comes into contact with the plate spring 11 fitted to the first stopper part 10. In addition, an annular groove 26 that is concentric with the rotor loosely fitting portion 22 and has a larger diameter, and a through hole that is bored in the center of the rotor loosely fitting portion 22 and through which the rotating shaft 30 passes are integrally molded. Further, the whole has a substantially elliptical shape, and bolt holes 29A and 29B are bored near the outer periphery in the major diameter direction, through which bolts for attaching the assembled three-position rotary actuator to the driven member pass. Since such a complicated shape is required, the base member 20 is made of resin.

The stator 40 includes four cores 42 at mutually orthogonal positions.
．． 44, 46, 48 are arranged, and the shaft 50 is placed in the center.
The coils 42C to 48C are wound around the outer periphery of the resin 52 that covers the cores 42 to 4. Coil 42C~4
The end of the winding 8C is wound around the terminal 42T-4BT which is press-fitted into the resin member 52, and then soldered.

The rotor 2 and stator 40 are assembled by inserting the shaft 50 into the shaft-fitting hole 9 formed in the center of the rotor 2. In this state, the inner circumferential portions of the cores 42 to 48 is designed in advance to have a slight gap around its outer periphery. In order to ensure smooth rotation of the rotor 2, the shaft 50 is made of iron-based sintered metal impregnated with lubricating oil.

The yoke 60 is made of a pressed iron plate. The yoke 60 has the above terminals 42T to 48T.
A lead introduction port 64 serves as an introduction port for a lead wire 62 that electrically connects the ends of the coils 42C to 48C attached to the external excitation power source, and a slit 66 for fixing and holding the base member 20 is provided. It is formed. After assembling the above-mentioned members as shown in FIG. 2, the yoke 60 and the base member 20 are integrated by bending the lower part of the yoke 60, where the slit 66 is formed, inward. The attachment portion between this yoke 60 and the base member 20 (I[-I
The enlarged sectional view of FIG. 4 is an enlarged view of the cross section I. As shown in the figure, since a tapered portion 26 is formed at the bottom of the circumferential surface of the base member 20, the yoke 60 and the base member 20 can be brought into close contact by simply bending the yoke 60 at the bottom of the slot 66 inward. It is possible.

Note that a wave washer 70 is provided between the stator 40 and the yoke 60, and acts to press the stator 40 toward the base member 20. A plate 72 provided between each of the coils 42C to 48C of the stator 40 and the yoke 60 is insulating, and insulates the terminals 42T to 48T from the yoke 60. Also,
An O-ring 74 is disposed in the annular groove 26 of the base member 20, and is interposed between the yoke 60 and the base member 20 when they are put together to maintain good waterproofness of the three-position rotary actuator. are doing. The annular sponge rubber 76 attached to the bottom surface of the base member 20 is also attached to the O-ring 74.
Similarly, it is provided to improve the waterproofness of the three-position rotary actuator, and prevents water from entering from the outside.

Next, we will discuss the actions of the first stopper section 10, the leaf spring 11, the second stopper section 24, and the abutment member 25 when the rotor 2 is rotationally driven by appropriately exciting the cores 42 to 48 of the three-position rotary actuator. explain.

FIG. 5 is a view of the rotor 2 loosely fitted in the rotor loosely fitting portion 22, viewed from the base member 20 side.
The second stopper portion 24 and the abutment member 25 formed in the figure are indicated by dotted lines.

FIG. 5(a) is a diagram when the cores 42 and 46 are excited and the rotor 2 is driven so as to stop at an intermediate position among the three stable points. At this time, the first stopper part 10 and the plate spring 11 of the rotor 2 are at substantially intermediate positions within the rotor loose fitting part 22 without coming into contact with the abutting member 25 .

In order to control the rotor 2 from this stable state to another stable position, the cores 44 and 48 are energized (instead of the cores 42 and 46).
The relationship between the rotor 2 and the rotor loose fitting portion 22 is shown in FIG. 5(b) when the direction at this time is defined as the forward direction. When the rotor 2 rotates in the direction of the solid line arrow, the first stopper part 10 and the second stopper part 24 come into contact with each other, and the load FK (dotted line arrow) received from the second stopper part 24 and its rotational force are When the FG reaches equilibrium, it stops and stabilizes in the state shown.

FIG. 6 shows the drive of the rotor 2 from the viewpoint of the balance between the two forces FG and FK.
It shows the relationship between the rotation angle θ of the rotor 2 and the force received by the rotor 2 while the rotation of the rotor 2 is stopped. Note that the dotted lines in the figure indicate the loads generated by each of the leaf spring 11 and the contact member 25 with respect to the rotation angle θ. As shown in the figure, both exhibit an upward-sloping characteristic in which the load generated gradually increases as the rotation angle θ increases.

However, the elastic force of the leaf spring 11 is higher than that of the contact member 25, and the load generated for the same rotation angle θ is small (
Become a detective.

As shown in FIG. 6, the rotor 2 is rotated by receiving the magnetic force FG from the cores 44 and 4. When the rotation angle θ increases due to this force FC, the leaf spring 11, which is highly elastic, is first pushed by the contact member 25 and deflects, thereby generating a load FK on the rotor 2 opposing the magnetic force PC. Since the elastic force of the plate spring 11 is high, the period T1 during which the load FK is generated by the plate spring 11 increases at a small rate with respect to an increase in the rotation angle θ. Then, as shown in FIG. 5(b), the leaf spring 1
1 is bent until it comes into close contact with the stopper portion 10, then the contact member 25 made of hard rubber begins to bend. Since this abutment member 25 has a low elastic force, the load generated increases rapidly as the rotation angle θ increases. That is, even if the rotation angle θ increases only slightly, the load generated by the contact member 250 increases rapidly, and the rotor 2 stops at a position (rotation angle θT) where it is balanced with the magnetic force FG.

The above relationship between the first stopper section 10 and the second stopper section 24 is the same when the cores 44, 48 are excited in the opposite direction and the rotor 2 is rotated counterclockwise.

The three-position rotary actuator of this embodiment configured and operated in this manner clearly has the following effects.

First, the basic configuration of the three-position rotary actuator is the first
As shown in Figures 2 and 3, the four magnetic poles provide three stable rotational positions for the rotor 2.
This is a small and lightweight 3-position actuator.

Further, when operating to three stable positions, the operating noise of the three-position rotary actuator is extremely low, and collision noise is reduced. That is, when the rotor 2 is operated at the center position of the three stable positions, no collision occurs between the structural members and there is no cause of noise. When the rotor 2 is operated to the other two stable positions, a collision between the two stopper portions occurs as shown in FIG. 5(b'). However, at the beginning of this collision, the highly elastic leaf spring 11
It acts as a material and the rotational force is weakened. Therefore, the impact noise caused by the collision is reduced, the impact of the colliding members is alleviated, and durability is improved.

Furthermore, the positional accuracy of the three-position rotary actuator of this embodiment is maintained at a high level of accuracy regardless of the presence of the leaf spring 11. First, when controlling to the stable position shown in FIG. 5(a), the three-position rotary actuator does not cause any collision, and its position accuracy is determined with high precision similar to that of a normal step motor.

Also, in the case where the stable position of the rotor 2 is determined by the collision between both stopper parts (FIG. 5(b)), as explained using FIG. is stable and positional accuracy is extremely high. Furthermore, the positional accuracy exhibits extremely good stability even against fluctuations in the magnetic force FC.

That is, in order to simplify the explanation in FIG. 6, the magnetic force FG applied to the rotor 2 is assumed to be constant, but in reality, the magnitude varies depending on the rotation angle θ.
It varies slightly due to changes over time in the excitation circuit of the permanent magnet 4 and the cores 42 to 48 forming the core. If this relationship is shown in FIG. 6, the magnetic force FG will vary within the range indicated by the arrow in the figure. However, as is clear from the figure, the magnetic force FG
Since the @tpc that opposes the rotation angle θ is generated by a slight change in the rotation angle θ, the positional accuracy of the rotor 2 does not decrease in any way due to the provision of the plate spring 11, and depends only on the elastic force of the contact member 25. However, by adjusting this as appropriate, it is possible to design with desired precision.

Although the above embodiment describes an example in which the leaf spring 11 is attached to the first stopper part 10 formed on the rotor 2, the configuration is not limited to such a structure, and the second stopper part on the base member 20 side A configuration may be adopted in which a leaf spring is disposed at 24.

Furthermore, as is clear from the explanation of FIG. 6, since the rotation angle of the rotor 2 is determined with high precision, the elastic force of the contact member 25 that ultimately prevents the rotation of the rotor 2 is small; A leaf spring 1 is used to absorb the shock when the stopper part collides with the
1 needs to have a large elastic force. However, any configuration may be used as long as it satisfies this elastic force condition. For example, as shown in FIG. 7(a), the first
The second stopper 24 of the stopper part 10 and the base member 20
A movable rubber piece 80 with high elasticity may be built in between. With this configuration, the rubber piece 80 can move between the first stopper part 10 and the second stopper part 24, and when the two stopper parts collide, it can be interposed between them and absorb the impact. can.

Furthermore, as shown in FIG. 7(b), the second stopper portion 24
The abutment member 25 held by the abutment member 25 may be configured as a so-called composite material in which only the tip portion that abuts the first stopper portion 10 has increased elasticity. Using composite materials in this way reduces the number of parts, which is advantageous in terms of manufacturing costs, quality control, etc.

Effects of the Invention As described in detail with reference to embodiments, the three-position rotary actuator of the present invention has a shock absorbing member with a large elastic force and a rotation limiting member with a small elastic force in the rotation limiting portion, and the rotation of the rotor is The angle is determined by a rotation limiting member with small elastic force,
The structure is such that the impact of the collision is absorbed by a binding member with a large elastic force.

Therefore, it is compact and has three stable positions with four magnetic poles.
This is a lightweight 3-position rotary actuator that has large driving force and high responsiveness, has extremely low operating noise, and has an excellent durability of the rotation limiter.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of the 3-position rotary actuator of the embodiment, Fig. 2 is a sectional view taken along the line I-I, Fig. 3 is a view of the rotor in the direction indicated by arrows, and Fig. 4 is a cross section thereof 5(a) and 5(b) are explanatory diagrams for explaining the rotational state of the rotor of the embodiment. FIG. 6 is a characteristic diagram of the force acting on the rotor for explaining the rotation principle. Figure 7 (a), (b)
8 is an explanatory diagram of the configuration of the rotor rotation limiting section of another embodiment.
The figure shows an explanatory diagram of the operation of a conventional three-position rotary actuator.

Claims (1)

[Scope of Claims] A stator having four field poles, in which a pair of spatially opposing field poles are excited to opposite polarities, a rotor that rotates in response to the field of the stator; and a rotation limiter that allows the rotor to rotate from a stable point due to the field generated by one pair of field poles to just before a stable point due to the positive and reverse fields generated by the other pair of field poles. In the rotary actuator, the rotation restricting portion is formed of a first restricting member formed on the rotor and a member having higher elasticity than the first restricting member, and the rotor rotates until just before the stable point. a buffer member that becomes integral with the first limiting member when the buffer member is fixed, and a member having lower elasticity than the buffer member, and is attached to the stator, and the rotor rotates until just before the stable point. A three-position rotary actuator comprising: a second limiting member that comes into contact with the buffer member and limits rotation of the rotor when the rotor is rotated.