JPH09177715A - Rotary actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary actuator capable of multistage rotation. SOLUTION: A rotary actuator 1 is provided with a first cylinder 4 provided with a piston 10 integrally formed with a rod 12 engagingly installed to a first magnetic screw 21, a piston 11 integrally formed with a rod 13 inserted into the first cylinder 4 in order to press the piston 10 of the first cylinder 4 in axial direction, and a second cylinder 5, the stroke of which is formed shorter than that of the first cylinder 4. When the first magnetic screw 21 is moved in axial direction, by the sliding of the respective pistons 10, 11, a second magnetic screw 22 receives magnetism of the first magnetic screw 21 to be rotated at different angles of rotation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary actuator for converting a linear motion of a rod projecting from a cylinder having a magnetic screw to a rotary motion of a rotary member having a magnetic screw, and more particularly to a rotary actuator. The present invention relates to a rotary actuator that can be rotated at multiple angles.

[0002]

2. Description of the Related Art Conventionally, various rotary actuators that use a fluid such as compressed air as a drive source have been used. However, the conventional vane type rotary actuator and the rack and pinion type rotary actuator have a problem that the body extends in a direction orthogonal to the rod and the rotary actuator becomes large. Further, the vane type rotary actuator has a problem that fluid leaks between the seal and the vane. Therefore, in order to solve these problems, the applicant of the present application proposed to employ a magnetic screw in Japanese Patent Laid-Open No. 62-46005. FIG. 8 is an exploded perspective view showing a rotary actuator using the magnetic screw, and FIG. 9 is a sectional view thereof.

The conventional rotary actuator 51 shown in the figure has the following construction. Cylinder covers 55, 55 are vertically fitted on a thick-walled cylinder body 54 having an upper port 52 and a lower port 53, and a rod 56 is rotatable so as to penetrate the center of the cylinder covers 55, 55. It has been inserted. Further, guide pins 57, 57 are fitted in the cylinder body 54 at symmetrical positions with the rod 56 sandwiched therebetween.
A piston 58 pierced by 7 and the rod 56 is slidably inserted. A rod 56 that penetrates the cylinder body 54 has a stepped portion at the center thereof, and a spiral magnetized band 59 whose outer peripheral surface is alternately magnetized to have N poles and S poles is formed on the surface of the stepped portion. . On the other hand, two permanent magnet guide magnets 61, 61 are embedded and fixed in the grooves 60, 60 formed in the shaft core of the piston 58. The inner peripheral surfaces of the guide magnets 61, 61 are both N poles.

Therefore, the rotary actuator 51 having such a structure operates as follows. First, when a working fluid such as compressed air or working oil is supplied from the upper port 52, the piston 58 is guided by the guide pins 57, 57 and descends in the cylinder body 54 without rotating downward. On the other hand, when the working fluid is supplied from the lower port 53, the piston 58 rises inside the cylinder body 54. When the piston 58 moves up and down in the cylinder body 54 in this manner, the guide magnets 61, 61 embedded in the piston 58 also move linearly up and down along the magnetizing band 59. At this time, since the inner peripheral surfaces of the guide magnets 61, 61 are N poles, repulsion and attraction are repeated between the N poles and S poles of the magnetizing band 59, and the magnets are magnetized in a spiral shape. The rod 56 integral with the band 59 will rotate. Specifically, as shown in the figure, when the magnetizing band 59 is rising to the right, it rotates counterclockwise when the piston 58 descends, and rotates clockwise when it rises.

In such a conventional rotary actuator 51, one of the permanent magnets attracting each other is made to have a spiral shape so that the rod 56, which is the output shaft, is caused to rotate. The maximum rotation angle of the output shaft can be set to 360 degrees or more by reducing the lead of No. 1 or by lengthening the cylinder body 54 in the axial direction.

[0006]

In the conventional rotary actuator as described above, the magnetizing band 5 is used as described above.
The rotation angle of the rod 56 can be increased by reducing the lead of the spiral of No. 9 or increasing the axial dimension of the cylinder body 54. On the contrary, it is possible to reduce the rotation angle of the rod 56 by enlarging the spiral lead of the magnetizing band 59 or shortening the axial dimension of the cylinder body 54. Therefore, if a predetermined design change is made to the rotary actuator 51, it is possible to obtain a rotation output from the rod 56 at an arbitrary rotation angle.

However, in the structure of the conventional rotary actuator 51 as described above, even if a rotation of an arbitrary angle can be obtained by a design change, the rotary output of only one angle is output to one rotary actuator 51. Can't get That is, when the rotation angle is set to 180 degrees, it is impossible to accurately stop the rotation at the intermediate point of 90 degrees. Therefore, for example, when the rotary actuator 51 is used as a product conveying device, the product can be conveyed only within a certain rotation angle, and a plurality of rotary actuators are required for distribution.

Therefore, it is an object of the present invention to provide a rotary actuator capable of rotating in multiple stages in order to solve the above-mentioned conventional problems.

[0009]

A rotary actuator according to the present invention comprises a hermetically sealed hollow cylinder having a piston integral with a rod projecting to the outside, and a helical magnetizing band provided on the rod. One magnetic screw and a rotatable second magnetic screw disposed with respect to the first magnetic screw formed of a spiral magnetized band, and the piston is slid to move the first magnetic screw to a shaft. The second magnetic screw is rotated by the magnetic force of the first magnetic screw when moved in a direction, and the cylinder is provided with a piston integral with a rod attached to the first magnetic screw. A cylinder and a second cylinder formed with a stroke shorter than that of the first cylinder, the piston being integral with a rod inserted into the first cylinder to axially press the piston of the first cylinder. And wherein the door.

Further, in the rotary actuator of the present invention, the second cylinder has a predetermined number of cylinders arranged coaxially in series, and the second cylinder is arranged at the rear of two cylinders which are continuous in the front and rear. The rear cylinder is equipped with a piston that is integrated with a rod that is inserted into the front cylinder in order to axially press the piston of the front cylinder that is arranged in the front, and is formed with a stroke shorter than that of the front cylinder. Is desirable. Further, the rotary actuator of the present invention has a stopper that is engaged with a projecting portion of a rod that projects from the second cylinder to the opposite side of the first cylinder and that can adjust the distance to the contact surface of the second cylinder. It is desirable to be one.

Further, in the rotary actuator of the present invention, the first magnetic screw is a male magnetic screw having a spiral magnetizing band formed on the outer periphery thereof, and the second magnetic screw is spirally magnetized on the inner periphery thereof. It may be a female magnetic screw formed with a band. Further, in the rotary actuator of the present invention, the first magnetic screw is a female magnetic screw in which a spiral magnetizing band is formed on the inner circumference, and the second magnetic screw is forming a spiral magnetizing band on the outer circumference. It may be a male magnetic screw.

In the rotary actuator of the present invention having the above-mentioned structure, the piston is given a driving force by the pressure of the working fluid supplied to the cylinder and slides in the cylinder, and the first rod is integrally provided with the piston. When the one magnetic screw moves in the axial direction, the second magnetic screw arranged with respect to the first magnetic screw rotates due to the magnetic force received from the first magnetic screw, so that the driving force of the piston sliding in the cylinder is increased. It is output as rotation. At this time, when the piston slides in the first cylinder, the piston moves the first magnetic screw along the second magnetic screw for a long distance. Therefore, the rotation amount of the second magnetic screw is large, and the rotation angle is increased accordingly. It will be a large output. On the other hand, when the piston slides in the second cylinder formed with a stroke shorter than that of the first cylinder, the rod integrated with the piston pushes the piston in the first cylinder. Also the moving distance of the second magnetic screw becomes shorter, and the amount of rotation of the second magnetic screw becomes smaller. Therefore, the first cylinder is driven by the second cylinder.
It is possible to obtain an output equal to or less than the rotation angle by driving the cylinder, and it is possible to rotate in two stages with one rotary actuator.

Further, in the rotary actuator of the present invention, when a piston of one of the second cylinders in which a predetermined number of cylinders are coaxially arranged in series is slid, a rod integral with the piston moves forward. The piston in the front cylinder arranged in series is pushed, and finally the piston in the first cylinder is pushed, but the moving distance is the one cylinder which is the drive source. It is possible to obtain an output of a rotation angle that is equal to or less than the rotation angle by driving the first cylinder, depending on the stroke. Therefore, one rotary actuator can rotate in multiple stages. Further, in the rotary actuator of the present invention, the stopper provided on the protruding portion of the rod protruding from the second cylinder to the opposite side of the first cylinder is provided with a distance from the stopper to the contact surface of the second cylinder. By adjusting, it is possible to adjust the rotation angle that is output by limiting the distance of the piston that slides in the cylinder, and it is possible to install it in different devices and make fine adjustments.

Further, in the rotary actuator of the present invention, the first magnetic screw is a male magnetic screw having a spiral magnetic band on the outer circumference, and the second magnetic screw has a spiral magnetic band on the inner circumference. If the female magnetic screw has, the female magnetic screw receives magnetic force from the male magnetic screw due to the sliding of the piston, and when the rotating shaft rotates, the rotation of the rotating shaft is smooth and uneven rotation occurs. There is no. Further, in the rotary actuator of the present invention, the first magnetic screw is a female magnetic screw having a spiral magnetizing band on the inner circumference, and the second magnetic screw has a spiral magnetizing band on the outer circumference. If the male magnetic screw is
The male magnetic screw receives a magnetic force from the female magnetic screw due to the sliding of the piston, and when the rotating shaft rotates, the rotating shaft rotates smoothly and uneven rotation does not occur.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a rotary actuator according to the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing a rotary actuator according to the first embodiment. The rotary actuator 1 is configured by connecting a magnetic screw portion 3 and a cylinder portion 2 in series. First, the configuration of the cylinder portion 2 will be described. In the cylinder portion 2, two closed hollow cylinders 4 and 5 are coaxially fixed. The two cylinders 4 and 5 have the same configuration, and the left end of the hollow cylindrical cylinder tube body 6 and 7 is the end cover 8 and
9, the pistons 10 and 11 are slidably fitted in the hollow portions of the cylinder tube bodies 6 and 7, and the rods 12 and 13 are inserted into the pistons 10 and 11, respectively.
Are fixed so that they are located on the same axis. In order to supply compressed air as a working fluid, the cylinder tube body 6 is formed with air ports 14 and 15, and the cylinder tube body 7 is formed with air ports 16 and 17, respectively. Since the air port 17 is used only for venting air, only pores are formed.

In the cylinders 4 and 5 having the same structure as described above, the magnetic screw described later is fitted to the tip of the rod 10 extending to the magnetic screw portion 3, and the magnetic screw to be described later is fitted to the cylinder 4. It constitutes a first cylinder that transmits the drive directly to the section 3. On the other hand, the cylinder 5 has its rod 1
1 penetrates the cylinder tube main body 7 and the end cover 8 and is brought into contact with the piston 10, and the magnetic screw portion 3 constitutes a second cylinder for indirectly transmitting drive through the cylinder 4 which is the first cylinder. ing. Then, as will be described later, the linear motion of the pistons 10 and 11 of the cylinders 4 and 5 is converted into the rotational motion of the magnetic screw portion 3, and the rotation angle is determined by the stroke of the pistons 10 and 11.

That is, in the rotary actuator 1 in which the cylinders 4 and 5 are connected in series like the rotary actuator 1 of the present embodiment, the maximum rotation angle (for example, 180 degrees) is generated by the piston stroke of the cylinder 4 directly connected to the magnetic screw portion 3. ) Is obtained, and the piston 11 of the cylinder 5 indirectly transmits the driving force to the magnetic screw portion 3 by pressing the piston 10.
Can move within the sliding range of the piston 10, so that an intermediate rotation angle (for example, 90 degrees) within the maximum rotation angle due to the sliding of the piston 10 can be obtained. Therefore, the axial dimension of the cylinder tube main bodies 6 and 7 is determined by the rotation angle to be obtained by the magnetic screw portion 3, and between the cylinders 4 and 5, the cylinder tube main body 6 that generates a large rotation angle is determined. Is designed to be longer than the cylinder tube body 7.

Next, the structure of the magnetic screw portion 3 will be described. Here, description will also be made with reference to FIG. 2, which is a cross-sectional perspective view showing a part of the magnetic screw. Magnetic screw part 3 is cylinder 4
A male magnetic screw 21 is fitted to the tip of a rod 12 extending from the rod 12, and a hollow cylindrical female magnetic screw 22 is rotatably provided so as to surround the male magnetic screw 21. Further, in the magnetic screw part 3, a cylindrical guide 26 is fixed to the cylinder 4, and a female magnetic screw 22 and a turntable 27 screwed to the end of the female magnetic screw 22 are fixed to the guide 26. It is rotatably held via bearings 29 and 30.

The male magnetic screw 21 forming the magnetic screw portion 3 is a male spiral cylindrical magnet fitted and bonded to the rod 12. The rod 12 is formed of a highly magnetically permeable material (for example, iron, iron oxide, nickel, cobalt, an alloy containing these as a main component, or another compound). The male magnetic screw 21 is a cylindrical magnet, and has a plurality of magnetizing bands 23 formed in a spiral shape. The adjacent magnetized bands 23 have opposite polarities of magnetization. That is, if the N pole is magnetized on the outer surface of a certain magnetizing band 23, the S pole is magnetized on the outer surface of the adjacent magnetizing band 23. Therefore, on the surface of the male magnetic screw 21, a magnetizing band 23 in which N poles and S poles are alternately magnetized in a spiral shape is formed orderly.

On the other hand, the female magnetic screw holder 24, which is rotatably held by the bearings 29 and 30, is formed from a highly magnetically permeable material (for example, iron, iron oxide, nickel, cobalt or alloys and compounds containing these as main components). The female magnetic screw 22 is a hollow cylindrical female spiral cylindrical magnet fixed to the inner circumference of the female magnetic screw holder 24. A magnetizing band 25, in which N poles and S poles are alternately magnetized in a spiral shape, is also formed on the inner circumference of the female magnetic screw 22.

The male magnetic screw 21 and the female magnetic screw 22 having the above-described structure have a mechanical strength increased by inserting a strength member into the hollow portion or by covering the circumference with a strength member. That is, the male magnetic screw 21 and the female magnetic screw 22 are
The rods 12 and 13 and the female magnetic screw holder 24 correspond to such a strength member. With this strength member, the male magnetic screw 21 and the female magnetic screw 2 formed of a ferrite-based or rare-earth-based material that is excellent as a magnet material but is brittle in terms of material quality
The mechanical strength of 2 is secured. If the strength member is made of a highly magnetically permeable material, the strong magnetic forces of the male magnetic screw 21 and the female magnetic screw 22 can be used more effectively.

Next, the operation of the rotary actuator 1 having such a configuration will be described. The rotary actuator 1 of the present embodiment is divided into, for example, two types of operations for obtaining 180 ° rotation by the cylinder 4 and 90 ° rotation by the cylinder 5. Therefore, when trying to obtain a rotation of 180 degrees, the cylinder 4 is driven. That is, when compressed air is supplied from the air port 14 into the cylinder tube body 6, the piston 10 is slid in the cylinder tube body 6 to the right side in the drawing together with the integrated rod 12 by the air pressure as shown in FIG. Move. Then, the male magnetic screw 21 fitted to the tip of the rod 12 moves along the female magnetic screw 22.

When the male magnetic screw 21 moves in a straight line in the female magnetic screw 22 without rotating in this way, the magnetizing band 2 constituting the male magnetic screw 21 or the female magnetic screw 22 is formed.
Since the north and south poles of 3, 25 repeat repulsion and attraction with each other and are magnetized in a spiral shape, the female magnetic screw 22 rotates with respect to the male magnetic screw 21 moving on a straight line. Becomes Then, in this way, the female magnetic screw 22 receives the force in the rotational direction by the magnetic force, and the bearings 29, 3
When the inside of the guide 26 is rotated through 0, the turntable 27 screwed to the female magnetic screw holder 24 is also turned, and the device (not shown) provided on the turntable 27 is turned. In this case, the female magnetic screw holder 24 rotates in proportion to the distance that the male magnetic screw 21 moves, and the cylinder 4
In the case of, it will rotate 180 degrees.

On the other hand, when the supply of compressed air is switched by an electromagnetic valve (not shown) and compressed air is supplied from the air port 15 into the cylinder tube body 6, the piston 10
Will slide to the left in the drawing, and will return to the state of FIG. Therefore, when the male magnetic screw 21 moves the female magnetic screw 22 in the opposite direction, the female magnetic screw holder 24 and the turntable 2 are moved.
7 rotates in the reverse direction and returns to the original rotation position. Here, an integral male magnetic screw 21 provided on the rod 12
Has a spiral magnetizing band 23 around the entire outer circumference, and also has an integral female magnetic screw 22 provided in a female magnetic screw holder 24.
However, since it has a spiral magnetizing band 25 around the entire inner circumference,
Due to the sliding of the piston 10, the female magnetic screw 22 receives a magnetic force from the male magnetic screw 21 to rotate smoothly,
No uneven rotation occurs.

Then, when it is desired to obtain a rotation of 90 degrees, the cylinder 5 is driven. That is, when compressed air is supplied from the air port 16 into the cylinder tube body 6, the piston 11 is compressed by air pressure as shown in FIG.
, But slides together with the integrated rod 13 in the cylinder tube body 7 to the right in the drawing. Then, since the rod 13 is in contact with the piston 10, the piston 10 and the rod 12 are moved to the right in the drawing. Therefore, the male magnetic screw 21 formed of the magnetized band 23 formed by the fitting of the rod 12 moves along the female magnetic screw 22 formed on the inner peripheral surface of the female magnetic screw holder 24. However, since it is driven by the piston 11 this time, it moves only by the piston stroke of the cylinder tube body 7.

Therefore, as described above, the male magnetic screw 21
Alternatively, the N magnetic poles and the S magnetic poles of the magnetizing bands 23 and 25 constituting the female magnetic screw 22 repeatedly repel and attract each other, and the female magnetic screw 22 rotates. Therefore, the female magnetic screw holder 24 and the turntable 27 rotate in the guide 26 via the bearings 29 and 30, but the female magnetic screw 22 rotates in proportion to the distance the male magnetic screw 21 moves. When the cylinder 5 is driven, it rotates 90 degrees. On the other hand, when the rotation is returned, the supply of the compressed air is switched by the solenoid valve (not shown), and the compressed air is supplied from the air port 15 of the cylinder 4 into the cylinder tube body 6. Therefore, the piston 10 slides to the left in the drawing, and at the same time, the piston 10 presses the rod 13 to slide the piston 11 to the left in the drawing and return to the state of FIG. Therefore, when the male magnetic screw 21 moves the female magnetic screw 22 in the opposite direction, the turntable 27 reversely rotates and returns to the original rotation position.

As described above, according to the rotary actuator 1 of the present embodiment, the cylinders 4 and 5 having different piston strokes are serially arranged in series, and the respective cylinders 4 and 5 are driven, so that the male magnetic screw 21 becomes the female magnetic screw 22. It was possible to set the rotation angle of the turntable 27 screwed to the female magnetic screw 22 and the female magnetic screw holder 24 in two stages by changing the distance moved along.

Next, a second embodiment of the rotary actuator according to the present invention will be described with reference to the drawings. FIG. 5 is a sectional view showing the rotary actuator of the present embodiment. Since the rotary actuator of the present embodiment has the same configuration as that of the first embodiment described above, the same reference numerals are given to the configuration and the description thereof is omitted. The rotary actuator 31 of the present embodiment is similar to the rotary actuator 31 of the above-mentioned embodiment in that the magnetic screw portion 3 is used.
And the cylinder portion 2, and the cylinder portion 3 is also composed of the cylinders 4 and 5. The characteristic feature of the cylinder portion 3 is that the piston 11 of the cylinder 5 is further provided with a rod 32 fixed through the axial center thereof. It is provided so as to penetrate the end cover 9. An adjusting stopper 33 is screwed to the rod 32 together with a lock nut 34 so as to cover the tip portion of the rod 32.

In the rotary actuator 31 of the present embodiment as described above, the operation of the cylinder 4 is similar to that of the first embodiment, but the characteristic feature is that of the cylinder 5. That is, the position of the rod 32 is changed by rotating the adjustment stopper 33, and the distance L from the contact surface 33a of the adjustment stopper 33 to the end cover 9 is adjusted. Therefore, when the distance L is larger than the piston stroke P of the piston 11, the adjustment stopper 33 does not act at all, and the rotary actuator 31 acts in the same manner as in the first embodiment.
On the other hand, when the distance L is smaller than the piston stroke P, the contact surface 33a of the adjustment stopper 33 contacts the end cover 9 as shown in the figure, and the sliding of the piston 11 is restricted. Therefore, as described above, according to the action of the cylinder 5, the turntable 27 is rotated 90 degrees, but in the present embodiment, it is possible to obtain a rotation of less than 60 degrees, for example.

According to the rotary actuator 31 of the present embodiment having such a configuration, the adjustment stopper 3
By changing the position of 3, the rotation angle determined at the design stage of the cylinder portion 2 can be changed to an arbitrary angle. Therefore, without using a different rotary actuator for each desired rotation angle, it is possible to cope with any case within the stroke of the piston provided with the adjustment stopper. Further, after the rotary actuator 31 is attached, the rotation angle can be finely adjusted.

The present invention is not limited to the above embodiment, and various changes can be made without departing from the gist of the present invention. For example, both the first and second embodiments show the case where two cylinders are connected in series, but the number of cylinders is not limited to two, and three cylinders are further provided.
One, four or more units may be connected in series so that one rotary actuator can output in multiple stages. However, in this case, it is necessary to reduce the size of the piston stroke in order from the magnetic screw portion side. Further, for example, the male magnetic screw 2 is attached to the rod 12 so that the drive from the cylinder portion is transmitted to the magnetic screw.
1, the female magnetic screw 43 is engaged with the rod 42 of the cylinder 41 as shown in FIG.
3 is moved linearly without rotating, and the male magnetic screw 44
May be rotated. Further, although compressed air is used as the working fluid for sliding the piston in the above embodiment, there is no problem in using working oil or the like.

[0032]

According to the present invention, a cylinder constituting a rotary actuator is a first cylinder having a piston integral with a rod fixed to a magnetic screw, and the piston of the first cylinder is axially pressed. Since the first cylinder has a second cylinder formed with a stroke shorter than that of the first cylinder, the first cylinder provides an output having a large rotation angle while the rod is inserted into the first cylinder. By driving the second cylinder, it is possible to obtain an output with a rotation angle equal to or less than the rotation angle by driving the first cylinder, and one rotary actuator can output in two stages.

Further, in the present invention, the second cylinder constituting the rotary actuator has a predetermined number of cylinders arranged coaxially in series, and the second cylinder is arranged at the rear of the two cylinders which are continuous in the front and rear. A rear cylinder that is provided with a piston that is integrated with a rod that is inserted into the front cylinder in order to axially press the piston of the front cylinder that is disposed in front, and is formed with a stroke shorter than that of the front cylinder Therefore, the moving distance can be determined by the cylinder that is the drive source, and by obtaining the output of the rotation angle equal to or less than the rotation angle by the drive of the first cylinder, it becomes possible to output in multiple stages with one rotary actuator. It was Also,
According to the present invention, the stopper provided on the protruding portion of the rod protruding from the second cylinder to the opposite side of the first cylinder is provided, so that the distance of the piston sliding in the cylinder is limited and the rotation is output. It has become possible to provide a rotary actuator that can adjust the angle.

Further, according to the present invention, the first magnetic screw is a female magnetic screw having a spiral magnetizing band on the inner circumference, and the second magnetic screw is a male magnetic screw having a spiral magnetizing band on the outer circumference. Since a screw is used, the male magnetic screw receives magnetic force from the female magnetic screw due to sliding of the piston, and when the rotating shaft rotates, the rotating shaft rotates smoothly, providing a rotary actuator that does not cause uneven rotation. It became possible to do. In the present invention, the first magnetic screw is a male magnetic screw having a spiral magnetizing band on the outer circumference, and the second magnetic screw is a female magnetic screw having a spiral magnetizing band on the inner circumference. Therefore, when the piston slides, the female magnetic screw receives magnetic force from the male magnetic screw, and when the rotating shaft rotates, the rotating shaft rotates smoothly.
It has become possible to provide a rotary actuator that does not cause uneven rotation.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a rotary actuator according to a first embodiment.

FIG. 2 is a partial cross-sectional perspective view showing a magnetic screw of the rotary actuator according to the first embodiment.

FIG. 3 is a cross-sectional view showing the rotary actuator according to the first embodiment when the first cylinder is driven.

FIG. 4 is a cross-sectional view showing the rotary actuator of the first embodiment when the second cylinder is driven.

FIG. 5 is a cross-sectional view showing a rotary actuator according to a second embodiment.

FIG. 6 is a cross-sectional view showing a rotary actuator according to a second embodiment when a second cylinder is driven.

FIG. 7 is a sectional view showing a rotary actuator according to another embodiment.

FIG. 8 is an exploded perspective view showing a conventional rotary actuator.

FIG. 9 is a sectional view showing a conventional rotary actuator.

[Explanation of symbols] 1 rotary actuator 2 cylinder part 3 magnetic screw part 4,5 cylinder 10 and 11 piston 12 and 13 rod 21 male magnetic screw 22 female magnetic screw 24 female magnetic screw holder 27 turntable

Claims (5)

[Claims] 1. A hermetically sealed hollow cylinder having a piston integral with a rod protruding to the outside, a first magnetic screw provided on the rod, the spiral magnetizing band, and a spiral magnetizing band. A second magnetic screw that is rotatable with respect to the first magnetic screw, and the second magnetic screw moves to the first magnetic screw when the first magnetic screw moves in the axial direction by sliding of the piston. In a rotary actuator that rotates by receiving the magnetic force of one magnetic screw, the cylinder includes a first cylinder that includes a first piston integrated with a rod that is engaged with the first magnetic screw, and a piston of the first cylinder. First to push in the axial direction
A rotary actuator, comprising: a rod inserted into the cylinder; and a piston, the second cylinder having a stroke shorter than that of the first cylinder. 2. The rotary actuator according to claim 1, wherein the second cylinder is one in which a predetermined number of cylinders are coaxially arranged in series, and the rear of two cylinders that are continuous in the front and rear. The rear cylinder disposed in the front cylinder is provided with a piston integrated with a rod inserted into the front cylinder to axially press the piston of the front cylinder disposed in the front, and is formed with a stroke shorter than that of the front cylinder. Rotary actuator characterized by being 3. The rotary actuator according to claim 1, wherein the second cylinder is abutted on a protruding portion of a rod protruding from the second cylinder to the opposite side of the first cylinder. A rotary actuator having a stopper capable of adjusting a distance to a surface. 4. The rotary actuator according to claim 1, wherein the first magnetic screw is a male magnetic screw having a spiral magnetized band formed on an outer periphery thereof, and the second magnetic screw is provided. A rotary actuator, wherein the screw is a female magnetic screw having a spiral magnetized band formed on the inner circumference. 5. The rotary actuator according to claim 1, wherein the first magnetic screw is a female magnetic screw having a spiral magnetized band formed on an inner circumference thereof. A rotary actuator, wherein the magnetic screw is a male magnetic screw having a spiral magnetized band formed on the outer circumference.