JP2006135050A - Linear actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear actuator which is simple in structure and wherein an movable element can be held still even during no energization. <P>SOLUTION: The linear actuator is provided with a stator 10 having four pole plates 1N, 2S, 3S, and 4N and a movable element 20 that a first electromagnet 1E and a second electromagnet 2E are coupled in parallel state. The first electromagnet 1E is provided with a first fork-shaped end 1G which pinches the first pole plate 1N and the third pole plate 3S and exclusively touches either of their external sides, and a second fork-shaped end 2G which pinches the second pole plate 2S and the fourth pole plate 4N and exclusively touches either of their external sides. The second electromagnet 2E is provided with a third fork-shaped end 3G which pinches the first pole plate 1N and the third pole plate 3S and exclusively touches either of their external sides, and a fourth fork-shaped end 4G which pinches the second pole plate 2S and the fourth pole plate 4N and exclusively touches either of their external sides. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a linear actuator suitable for use in a zoom adjustment mechanism and a focus adjustment mechanism of a camera.

  For example, in a zoom adjustment mechanism of a camera, a motor is used to move the camera lens linearly, and the shaft of the motor is a screw shaft that is screwed into a nut on the camera lens side. However, when using a motor, a screw shaft that converts the rotational movement of the motor into the linear movement of the lens is required, so the development of a simple linear actuator is required to reduce the number of parts and reduce the cost. Has been.

  Conventionally, various linear actuators have been proposed, but many of them are energized even when the mover is held stationary, and it is not possible to reduce power consumption.

  Therefore, in view of the above problems, an object of the present invention is to provide a simple linear actuator that can hold a movable element stationary even when no power is supplied.

  In the linear actuator according to the present invention, the first magnetic pole surface and the third magnetic pole surface of the counter electrode, the second magnetic pole surface of the counter electrode and the fourth magnetic pole surface are aligned in one direction, and the first magnetic pole surface and the fourth magnetic pole surface are aligned. A stator having a north pole and a second magnetic pole face and a third magnetic pole face being an S pole; and a mover having a first electromagnet and a second electromagnet connected to be separated in the one direction; 1 electromagnet sandwiches the first magnetic pole surface and the third magnetic pole surface and exclusively contacts one of the first magnetic sandwich surface and the second magnetic pole surface and the fourth magnetic pole surface. A first core having a second sandwiching portion for performing the first coil and a first coil for exciting the first sandwiching portion and the second sandwiching portion with different polarities from each other. A third sandwiching portion for sandwiching the three magnetic pole faces and making an exclusive contact with either one; A second core having a fourth sandwiching portion for sandwiching the pole surface and the fourth magnetic pole surface and exclusively contacting either of them, and a third core for exciting the third sandwiching portion and the fourth sandwiching portion with different polarities from each other. It has two coils, and is characterized by comprising current control means for switching the current application direction to the first coil and the second coil or to make it non-energized.

  When the first and second coils are not energized, the inner surface of one half of the sandwiched portion (four locations) of the first and second cores is the first magnetic pole surface and the second magnetic pole surface or the third magnetic pole surface and the second magnetic pole surface. Since the magnetic poles are magnetically attracted to the four magnetic pole surfaces and the mover is held stationary with respect to the stator in the following first to fourth postures, power can be saved.

  Here, there are four magnetic adsorption postures with respect to the four magnetic pole surfaces of the mover. That is, the first posture is that both the inner surface of one half of the first sandwiching portion in the first core and the inner surface of one half of the third sandwiching portion in the second core are magnetically attracted to the first magnetic pole surface. At the same time, the inner surface of one half of the second sandwiching portion in the first core and the inner surface of one half of the fourth sandwiching portion in the second core are both in a parallel posture in a state of being magnetically attracted to the second magnetic pole surface. . In the second posture, the inner surface of one half of the first sandwiching portion in the first core is magnetically attracted to the first magnetic pole surface, and the inner surface of the other half of the third sandwiching portion in the second core is the third magnetic pole. At the same time, the inner surface of one half of the second sandwiching portion of the first core is magnetically attracted to the second magnetic pole surface and the inner surface of the other half of the fourth sandwiching portion of the second core is the fourth. It is an inclined posture in a state of being magnetically attracted to the magnetic pole surface. In the third posture, the inner surface of the other half of the first sandwiching portion in the first core and the inner surface of the other half of the third sandwiching portion in the second core are both magnetically attracted to the third magnetic pole surface, The inner surface of the other half of the second sandwiching portion in the first core and the inner surface of the other half of the fourth sandwiching portion in the second core are both in a parallel posture in a state of being magnetically attracted to the fourth magnetic pole surface. The fourth posture is that the inner surface of the other half of the first sandwiching portion in the first core is magnetically attracted to the outer surface of the third magnetic pole plate, and the inner surface of the one half of the third sandwiching portion in the second core is Simultaneously magnetically attracting to the first magnetic pole surface, the inner surface of the other half of the second sandwiched portion of the first core is magnetically attracted to the fourth magnetic pole surface, and the inner surface of the first half of the fourth sandwiched portion of the second core. Is an inclined posture in a state of being magnetically attracted to the second magnetic pole surface. The first to fourth postures occur cyclically as described below.

  When the first and second coils are in a non-energized state and the mover is in the first posture, the second coil is energized by the current control means, and the third sandwiching portion of the second core is set to the N pole, the fourth When the sandwiching portion is excited to become the S pole, the inner surface of one half of the first sandwiching portion in the first core is the first magnetic pole surface, and the inner surface of the first half of the second sandwiching portion is the second magnetic pole plate. The inner surface of one half of the third sandwiching portion (N pole) in the second core is magnetically repelled from the first magnetic pole surface (N pole) while the inner surface of the other half is first While magnetically attracting to the three magnetic pole surfaces (S pole), the inner surface of one half of the fourth sandwiching portion (S pole) in the second core is magnetically repelled from the second magnetic pole surface (S pole) and at the same time the other half Since the inner surface of the first magnetic core is magnetically attracted to the fourth magnetic pole surface (N pole), With the inner edge of one half of the second sandwiching portion as the instantaneous center, in the forward direction until the inner edge of the other half of the third and fourth sandwiching portions of the second core hits the third and fourth magnetic pole surfaces It turns and changes to the 2nd posture.

Here, the distance between the first magnetic pole surface (second magnetic pole surface) and the third magnetic pole surface (fourth magnetic pole surface) is T, D is the distance between all the sandwiched portions, and the first sandwiched portion is overlapped (second sandwiched portion). ) And the third sandwiching portion (fourth sandwiching portion) are both L, and the swivel angle of the mover is θ, the following equation is established and θ is given.
T = D cos θ−L sin θ
Next, when the second coil is turned off by the current control means, the first coil is energized to excite the first sandwiched portion of the first core to the N pole and the second sandwiched portion to the S pole. The inner surface of the other half of the third sandwiched portion of the second core is magnetically attracted to the third magnetic pole surface, and the inner surface of the other half of the fourth sandwiched portion is magnetically attracted to the fourth magnetic pole surface. The inner surface of one half of the first sandwiching portion (N pole) magnetically repels the first magnetic pole surface (N pole), and at the same time the inner surface of the other half body magnetically attracts to the third magnetic pole surface (S pole). The inner surface of one half of the second sandwiching portion (S pole) in the first core is magnetically repelled to the second magnetic pole surface (S pole), and at the same time, the inner surface of the other half is the fourth magnetic pole surface (N pole). The other half of the third and fourth sandwiching portions of the second core. Rotating in the opposite direction with the inner edge of the inner center of the first core as the instantaneous center until the inner surface of the other half of the first and second sandwiching portions of the first core hits the third and fourth magnetic pole faces, and transitioned to the third posture To do.

Here, the amount of stepping p in one direction from the first posture to the third posture of the mover is approximately given by the following equation.
p = Dsin θ + L cos θ−L
In order to change the mover from the second position to the third position, it is necessary to stop energization of the second coil and to supply power to the first coil. However, after the mover changes to the third position, The energization of one coil may be stopped, and the energization of the first coil during the transition can be completed with a trigger pulse.

  Next, when the first coil is turned off by the current control means, the second coil is energized to excite the third sandwiching portion of the second core to the S pole and the fourth sandwiching portion to the N pole, The inner surface of the other half of the first sandwiched portion of the first core is magnetically attracted to the third magnetic pole surface, and the inner surface of the other half of the second sandwiched portion is magnetically attracted to the fourth magnetic pole surface. While the inner surface of the other half of the third sandwiching portion (S pole) is magnetically repelled from the third magnetic pole surface (S pole), the inner surface of the other half is magnetically attracted to the first magnetic pole surface (N pole). The inner surface of the other half of the fourth sandwiching portion (N pole) in the second core is magnetically repelled from the fourth magnetic pole surface (N pole), and at the same time, the inner surface of the other half is the second magnetic pole surface (S pole). Other than the first and second sandwiching portions in the first core With the inner edge of the half as an instantaneous center, the inner edge of one half of the third and fourth sandwiching portions in the second core pivots in the opposite direction until it hits the outer surface of the first and second magnetic pole faces, Transition to the fourth posture.

  Next, when the second coil is turned off by the current control means, and the first coil is energized to excite the first sandwiching portion of the first core to the S pole and the second sandwiching portion to the N pole, The inner surface of one half of the third sandwiching portion of the second core is magnetically attracted to the first magnetic pole surface, and the inner surface of one half of the fourth sandwiching portion is magnetically attracted to the second magnetic pole surface. While the inner surface of the other half of the first sandwiching portion (S pole) is magnetically repelled from the third magnetic pole surface (S pole), the inner surface of the one half is magnetically attracted to the first magnetic pole surface (N pole). The inner surface of the other half of the second sandwiching portion (N pole) in the first core is magnetically repelled from the fourth magnetic pole surface (N pole) and at the same time, the inner surface of the first half is the second magnetic pole surface (S pole). One of the third and fourth sandwiching portions in the second core. With the inner edge of the half body as the instantaneous center, the inner surface of one half of the first and second sandwiching portions in the first core turns in the positive direction until it contacts the outer surface of the first and second magnetic pole faces, Transition to 1 posture.

  In order to change the mover from the fourth position to the first position, it is necessary to stop energization of the second coil and to supply power to the first coil. However, after the mover changes to the first position, The energization of one coil may be stopped, and the energization of the first coil during the transition can be completed with a trigger pulse.

  In this way, the mover performs a 1-cycle movement from the first posture → the second posture → the third posture → the fourth posture → the first posture, and linearly moves in one direction by the lead P = 2p. To do. Further, since the mover can reversely transit from the first posture → the fourth posture → the third posture → the second posture → the first posture, forward / reverse movement can be realized.

  For this reason, since the mover is magnetically attracted to the magnetic pole surface and held stationary even when no current is applied, a simple linear actuator with low power consumption can be obtained. When the mover moves, the mover does not slide on the magnetic pole surface, but rather moves forward and backward by absorption and repulsion, so that wear can be suppressed and the life can be extended. High responsiveness is obtained by absorption and repulsion. Note that the magnetic pole surface may be slightly curved as long as the movable element can be rotated in the forward and reverse directions within the gap (= DT) between the inner side surface of the sandwiched portion and the magnetic pole surface. It is also possible to cause the mover to perform a curved motion in a three-dimensional space.

  According to the present invention, a simple linear actuator with low power consumption can be realized because the mover is magnetically attracted to the magnetic pole plate and held stationary even when no current is applied. In addition, when the mover is moved, the mover does not slide on the magnetic pole surface, but rather moves forward and backward by absorption and repulsion, so wear can be suppressed and the life can be extended. At the same time, high responsiveness can be realized by absorption and repulsion.

  Next, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing a linear actuator according to an embodiment of the present invention.

  The linear actuator of this example includes a stator 10, a mover 20 that moves linearly by a saddle movement along the stator 10, and current control means (not shown) that controls current of the mover 20 in the forward / reverse linear movement. ing.

The stator 10 includes a pair of first yoke plate 2 and second yoke plate 3 that extend in parallel by connecting at least one end side, a first pole plate 1N having a counter electrode superimposed on the front and back surfaces of the first yoke plate 2, and It has a third magnetic pole plate 3S, a second magnetic pole plate 2S and a fourth magnetic pole plate 4N that are counter electrodes superimposed on the front and back surfaces of the second yoke plate 3, and these four magnetic pole plates 1N, 2S, 3S, 4N are The center of the cross-sectional view is aligned with the vertices P _{1 to} P ₄ of the rectangle and oriented in the normal ν direction. The first magnetic pole plate 1N and the fourth magnetic pole plate 4N in the first diagonal relationship are magnetized in the N pole, and the second magnetic pole plate 2S and the third magnetic pole plate 3S in the second diagonal relationship are magnetized in the S pole, respectively. Has been. The outer surface of the first magnetic pole plate 1N is the first magnetic pole surface of the N pole, the outer surface of the second magnetic pole plate 2S is the second magnetic pole surface of the S pole, and the outer surface of the third magnetic pole plate 3S is the S pole. The outer surface of the fourth magnetic pole plate 4N corresponds to the third magnetic pole surface and corresponds to the fourth magnetic pole surface of N pole.

  The mover 20 includes a first electromagnet 1 </ b> E and a second electromagnet 2 </ b> E that are separated from each other in the normal ν direction and connected in parallel via a spacer 6. The first electromagnet 1E sandwiches the first magnetic pole plate 1N and the third magnetic pole plate 3S, and contacts the first bifurcated end 1G and the second magnetic pole plate 2S with the fourth magnetic plate 2S. A first core 1K including a second bifurcated end 2G for sandwiching the magnetic pole plate 4N and exclusively contacting any one of the outer surfaces, and a first constricted portion of the first core 1K are wound around the first second core 1K. Moreover, it has the 1st coil 1C for exciting the shape end part 1G and the 2nd forked shape end part 2G mutually differently. Further, the second electromagnet 2E includes the third bifurcated end 3G and the second magnetic pole plate 2S for exclusively contacting the outer surface with the first magnetic pole plate 1N and the third magnetic pole plate 3S interposed therebetween. A second core 2K having a fourth bifurcated end 4G for sandwiching the fourth magnetic pole plate 4N and exclusively contacting any one of the outer surfaces and the second core 2K is wound around the central constricted portion of the second core 2K. 3 has a second coil 2C for exciting the bifurcated end 3G and the fourth bifurcated end 4G to different polarities.

  The spacer 6 sandwiches the first magnetic pole plate 1N and the third magnetic pole plate 3S with a margin gap and the one side bifurcated end 6a, and the second magnetic pole plate 2S and the fourth magnetic pole plate 4N with a margin gap. It has the other side bifurcated end portion 6b and an action portion 6c projecting from the side surface. This action part 6c drives a driven mechanism as a driving arm part. In addition, this operation part may be a recessed part.

  FIGS. 2A to 2E are side views showing the transition postures of the mover 20 in the linear actuator as viewed from the first yoke plate 2 side.

  There are four magnetic adsorption postures of the mover 20 with respect to the four magnetic pole plates 1N, 2S, 3S, 4N. That is, as shown in FIGS. 2A and 2E, the first posture is such that the inner surface of one half (left side in the drawing) of the first bifurcated end 1G of the first core 1K and the second core 2K. At the same time, the inner surface of one half (the left side in the figure) of the third bifurcated end 3G of the first magnetic pole is magnetically attracted to the outer surface of the first magnetic pole plate 1N, and at the same time, the second bifurcated end 2G of the first core 1K. Both of the inner side surfaces of the first half body and the inner side surface of one half body of the fourth bifurcated end portion 4G of the second core 2K are in a parallel posture in a state where they are magnetically attracted to the outer side surface of the second magnetic pole plate 2S.

  As shown in FIG. 2B, the second posture is such that the inner surface of one half (the left side in the drawing) of the first bifurcated end portion 1G of the first core 1K is magnetized to the outer surface of the first magnetic pole plate 1N. At the same time as the inner surface of the other half (right side in the figure) of the third bifurcated end 3G in the second core 2K is magnetically attracted to the outer surface of the third magnetic pole plate 3S, the second second in the first core 1K. The inner surface of one half of the end 2G is magnetically attracted to the outer surface of the second magnetic pole plate 2S, and the inner surface of the other half of the fourth bifurcated end 4G in the second core 2K is the fourth magnetic pole. The inclined posture is in a state of being magnetically attracted to the outer surface of the plate 4N.

  As shown in FIG. 2C, the third posture is such that the inner surface of the other half (right side in the drawing) of the first bifurcated end 1G of the first core 1K and the third bifurcated shape of the second core 2K. Both the inner surface of the other half (the left side in the figure) of the end 3G is magnetically attracted to the outer surface of the third magnetic pole plate 3S, and at the same time, the other half of the second bifurcated end 2G of the first core 1K. Both the side surface and the inner surface of the other half of the fourth bifurcated end 4G of the second core 2K are in a parallel posture in a state of being magnetically attracted to the outer surface of the fourth magnetic pole plate 4N.

  As shown in FIG. 2D, the fourth posture is such that the inner surface of the other half (right side in the drawing) of the first bifurcated end portion 1G of the first core 1K is magnetized to the outer surface of the third magnetic pole plate 3S. The inner surface of one half (the left side in the figure) of the third bifurcated end 3G in the second core 2K is magnetically attracted to the outer surface of the first magnetic pole plate 1N, and at the same time, the second second in the first core 1K. The inner surface of the other half of the second end 2G is magnetically attracted to the outer surface of the fourth magnetic pole plate 4N, and the inner surface of one half of the fourth bifurcated end 4G of the second core 2K is the second magnetic pole. The inclined posture is in a state of being magnetically attracted to the outer surface of the plate 2S. The first to fourth postures occur cyclically as described below.

When the first and second coils 1C and 2C are in a non-energized state and the mover 20 is in the first posture as shown in FIG. 2A, the second coil 2C is energized by the current control means, When the third bifurcated end 3G of the two cores 2K is excited to have the N pole and the fourth bifurcated end 4G to be the S pole, one half of the first bifurcated end 1G of the first core 1K is excited. The inner surface of the body (left side in the figure) is magnetically attracted to the outer surface of the first magnetic pole plate 1N, and the inner surface of one half of the second bifurcated end 2G is magnetically attracted to the outer surface of the second magnetic pole plate 2S. The inner surface of one half (left side in the figure) of the third pole-shaped third bifurcated end 3G of the second core 2K is magnetically repelled from the outer surface of the first magnetic pole plate 1N having the N pole, and the other half ( (The right side in the figure) is magnetically attracted to the outer surface of the third magnetic pole plate 3S having the S pole, and the fourth bifurcated S pole in the second core 2K. The inner surface of one half of the end 4G is magnetically repelled from the inner surface of the second magnetic pole plate 2S having the S pole, and at the same time, the inner surface of the other half is magnetically attracted to the outer surface of the fourth magnetic pole plate 4N having the N pole. Therefore, as the center the first and second bifurcated shaped end 1G in the first core 1K, the inner edge O ₁ of one half of the 2G moment, the third and fourth fork-shaped end of the second core 2K ₂ turns counterclockwise until the inner edge O2 of the other half contacts the outer surface of the third and fourth magnetic pole plates 3S, 4N, and transitions to the second posture shown in FIG. .

Here, the distance between the outer surface of the first magnetic pole plate 1N (second magnetic pole plate 2S) and the outer surface of the third magnetic pole plate 3S (fourth magnetic pole plate 4N) is T, and the gap between the bifurcated ends is D, The total thickness of the overlapped first bifurcated end 1G (second bifurcated end 2G) and third bifurcated end 3G (fourth bifurcated end 4G) is L, and the mover 20 If the turning angle is θ, the following equation is established and θ is given.
T = D cos θ−L sin θ
Next, in the second posture shown in FIG. 2 (b), the second coil 2C is made non-energized by the current control means, and the first coil 1C is energized to supply the first bifurcated end 1G of the first core 1K. When the second bifurcated end 2G is excited to be the S pole, the inner surface of the other half (right side in the figure) of the third bifurcated end 3G of the second core 2K is the third side. The first surface of the N pole in the first core 1K is magnetically adsorbed on the outer surface of the magnetic pole plate 3S and the inner surface of the other half of the fourth bifurcated end 4G on the outer surface of the fourth magnetic pole plate 4N. The inner surface of one half (left side in the figure) of the bifurcated end 1G is magnetically repelled on the outer surface of the first magnetic pole plate 1N having N pole, and at the same time, the inner side surface of the other half (right side in the figure) is S pole. While being magnetically attracted to the outer surface of the three magnetic pole plate 3S, one half of the second bifurcated end 2G of the S pole in the first core 1K Since the surface magnetically repels the outer surface of the second magnetic pole plate 2S having the S pole, the inner surface of the other half is magnetically attracted to the outer surface of the fourth magnetic pole plate having the N pole (N pole). third and the 4 forked-shaped end 3G, and inner edge O ₂ of the other half of 4G around the moment, the first and second bifurcated shaped end 1G in the first core, the other half of the 2G Is turned clockwise by θ until the inner side surface of the first and second magnetic pole plates 3S, 4N comes into contact with the outer side surface of the third and fourth magnetic pole plates 3S, 4N, and transitions to the third posture shown in FIG.

Here, the step amount p translated in the normal direction from the first posture (FIG. 2A) to the third posture (FIG. 2C) of the mover 20 is approximately given by the following equation. .
p = Dsin θ + L cos θ−L
In order to change the mover 20 from the second posture (FIG. 2B) to the third posture (FIG. 2C), the current to the second coil 2C is stopped and the first coil 1C is energized. Although it is necessary, the energization of the first coil 1C may be stopped after the mover 20 transitions to the third posture, and the energization of the first coil 1C at the time of the transition can be completed with a trigger pulse.

Next, in the third posture shown in FIG. 2C, the first coil 1C is deenergized by the current control means, and the second coil 2C is energized to supply the third bifurcated end 3G of the second core 2K. And the fourth bifurcated end 4G are excited to be the N pole, the inner surface of the other half (right side in the figure) of the first bifurcated end 1G in the first core 1K is third. The third side of the S pole of the second core 2K is magnetically attracted to the outer surface of the magnetic pole plate 3S and the inner surface of the other half of the second bifurcated end 2G is magnetically attracted to the outer surface of the fourth magnetic pole plate 4N. The inner side surface of the other half (right side in the figure) of the forked end 3G is magnetically repelled from the outer side surface of the third magnetic pole plate 3S having S pole, and at the same time, the inner side surface of one half (left side in the figure) is N pole. While magnetically attracting to the outer surface of one magnetic pole plate 1N, the other half of the N-pole fourth bifurcated end 4G of the second core 2K Since the side surface magnetically repels from the outer surface of the fourth magnetic pole plate 4N having the N pole, the inner surface of one half thereof is magnetically attracted to the outer surface of the second magnetic pole plate 2S having the S pole. and second bifurcated shaped end 1G, as the moment about the inner edge O ₃ of the other half of 2G, inside of the third and fourth fork-shaped end portion 3G, one half of the 4G in the second core 2K edge O ₄ the first and second pole plate 1N, turning only θ clockwise until it hits the outer surface of the 2S, transitions to the fourth position shown in Figure 2 (d).

Next, in the fourth posture shown in FIG. 2 (d), the second coil 2C is made non-energized by the current control means, and the first coil 1C is energized to make the first bifurcated end 1G of the first core 1K. When the second bifurcated end 2G is excited to be the N pole, the inner surface of one half (the left side in the figure) of the third bifurcated end 3G of the second core 2K is the first side. The first side of the first S pole in the first core 1K while the inner side surface of one half of the fourth bifurcated end 4G is magnetically attracted to the outer side surface of the second magnetic pole plate 2S on the outer side surface of the magnetic pole plate 1N. The inner side surface of the other half (right side in the figure) of the forked end 1G is magnetically repelled from the third magnetic pole plate 3S having S pole, and at the same time, the first magnetic pole plate in which the inner side surface of one half (left side in the figure) is N pole. The inner surface of the other half of the second bifurcated end 2G of the N pole in the first core 1K is magnetically attracted to the outer surface of 1N. At the same time as the magnetic repulsion from the fourth pole plate 4N of the pole, the inner surface of one half thereof is magnetically attracted to the outer surface of the second pole plate 2S of the S pole, so that the third and fourth bifurcated shapes in the second core 2K around the ends 3G, of one half of the 4G inner edge O ₄ moment, the first and second bifurcated shaped end 1G in the first core 1K, the inner surface of one half of the 2G first and second 2 turns counterclockwise until it hits the outer surface of the two magnetic pole plates 1N, 2S, and transitions to the first posture shown in FIG.

  In order to change the mover 20 from the fourth position (FIG. 2D) to the first position (FIG. 2E), the energization of the second coil 2C is stopped and the first coil 1C is energized. Although it is necessary, after the mover 20 transitions to the first posture (FIG. 2 (e)), the energization to the first coil 1C may be stopped as shown in FIG. 2 (a). Energization of one coil 1C can be completed with a trigger pulse.

  In this way, the mover 20 has the first posture (FIG. 2A) → the second posture (FIG. 2B) → the third posture (FIG. 2C) → the fourth posture ( 2 (d)) → First posture (FIG. 2 (e)) and one cycle motion are performed, and the lead P = 2p is linearly moved in the normal ν direction. Further, since the mover 20 can be reversely transferred from the first posture → the fourth posture → the third posture → the second posture → the first posture, the forward / reverse movement can be realized.

  For this reason, since the movable element 20 is magnetically attracted to the magnetic pole plates 1N, 2S, 3S, and 4N and held stationary even when no current is applied, a simple linear actuator with low power consumption can be obtained. When the mover 20 is in the non-energized state in the inclined posture of the second posture or the fourth posture, the mover 20 may transition to the parallel posture of the first posture or the third posture. By incorporating a current control means for prohibiting the non-energized state in the fourth posture, it can be used as a linear actuator with a stepping amount p. In such a case, the movable element 20 is in the first posture in the non-energized state. Alternatively, the stator 10 is held in a parallel posture of the third posture.

  When the mover 20 is moved, the mover 20 does not slide on the magnetic pole plates 1N, 2S, 3S, 4N, but rather moves forward and backward by absorption and repulsion. The life can be extended and high responsiveness can be obtained by absorption and repulsion. If the movable element 20 can be rotated in the forward and reverse directions within the gap (= DT) between the inner surface of the bifurcated ends 1G to 4G and the outer surface of the magnetic pole plates 1N, 2S, 3S, 4N, the magnetic pole The plates 1N, 2S, 3S, 4N may be slightly curved. For this reason, it is also possible to cause the movable element 20 to perform a curved motion in a three-dimensional space by using a gradually bent magnetic pole plate.

  In FIG. 1, the rectangle 4 may be a square, a parallelogram, a rhombus, or an unequal side quadrilateral depending on the cross-sectional shape of the magnetic pole plate. The first magnetic pole plate 1N (second magnetic pole plate 2S) and the third magnetic pole plate 3S (fourth magnetic pole plate 4N) may be displaced in the plate width direction, and the thicknesses of the respective magnetic pole plates may be different. This is because it is sufficient to adjust the gap between the two forked ends. Moreover, you may connect the 1st electromagnet 1E and the 2nd electromagnet 2E in a non-parallel state as needed.

It is a perspective view which shows the linear actuator which concerns on one Embodiment of this invention. (A)-(e) is a side view which shows the state which looked at each transition attitude | position of the needle | mover in the linear actuator from the 1st yoke board side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Stator 20 ... Movable element 2 ... 1st yoke board 3 ... 2nd yoke board 4 ... Rectangle 6 ... Spacer 6a ... One side bifurcated end part 6b ... Other side bifurcated end part 6c ... Action part 1N ... First magnetic pole plate 2S ... second magnetic pole plate 3S ... third magnetic pole plate 4N ... fourth magnetic pole plate 1E ... first electromagnet 2E ... second electromagnet 1K ... first core 2K ... second core 1G ... first bifurcated end part 2G ... second forked-shaped end 3G ... third fork-shaped end portion 4G ... fourth fork-shaped end portion 1C ... first coil 2C ... vertex [nu ... law second coil _P 1 to P 4 _... Rectangular Lines O _{1 to} O ₄ ... Inner edge D... L between the forked ends L. Total thickness T of the overlapping first and second forked ends T. Out of the first magnetic pole plate. Distance θ between the side surface and the outer surface of the third magnetic pole plate: The turning angle of the mover

Claims (2)

The first magnetic pole surface and the third magnetic pole surface of the counter electrode, the second magnetic pole surface of the counter electrode and the fourth magnetic pole surface are aligned in one direction, the first magnetic pole surface and the fourth magnetic pole surface are N poles, A stator having two magnetic pole faces and a third magnetic pole face that are S poles, and a mover having a first electromagnet and a second electromagnet that are connected to be spaced apart from each other in the one direction, and the first electromagnet includes a first magnetic pole face, A first sandwiching portion for sandwiching the third magnetic pole surface and making an exclusive contact with either one and a second sandwiching portion for sandwiching the second magnetic pole surface and the fourth magnetic pole surface and making an exclusive contact with each other are provided. A first coil for exciting the first core and the first sandwiching portion and the second sandwiching portion with different polarities, and the second electromagnet sandwiches the first magnetic pole surface and the third magnetic pole surface; The third sandwiching portion for exclusive contact and the second magnetic pole surface and the fourth magnetic pole surface are sandwiched. A second core having a fourth sandwiching portion for contact with the other and a second coil for exciting the third sandwiching portion and the fourth sandwiching portion with different polarities from each other, the first coil and the second coil A linear actuator characterized by comprising current control means for switching the energization direction of the current to or de-energizing. 2. The linear actuator according to claim 1, wherein the first electromagnet and the second electromagnet are connected with a spacer interposed therebetween, and an action portion is provided on the spacer.

Images