JPS63202252A - Actuator - Google Patents

Abstract

PURPOSE:To miniaturize the outer diameter of an actuator and improve the response property of the same, by a method wherein an attracting force as well as an repulsive force are applied simultaneously into the pivoting direction of a rotor by electromagnets, main permanent magnets and sub-permanent magnets. CONSTITUTION:An actuator is equipped with a casing 20, an output shaft 21, a rotor 22 and a stator 23. The rotor 22 is equipped with a main shaft 37 and main permanent magnets 38, 39 while sub-permanent magnets 59, 60 are arranged at the both peripheral sides of the main permanent magnets 38, 39 respectively. A plurality of electromagnets 46-51 are arranged on the rotor 22 separately with an equal interval in the peripheral direction of the rotor 22 and are fixed in the casing 20 through a mount base 45. The electromagnets 46-51 are excited selectively whereby attraction forces and repulsive forces are applied simultaneously by the electromagnets 46-51, main permanent magnets and sub-permanent magnets 59, 60 into the rotating direction of the rotor 22.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an actuator used in a variable damping force type hydraulic shock absorber or the like.

2. Description of the Related Art As a suspension device for an automobile, a so-called variable damping force hydraulic shock absorber is known which can adjust the damping force of the hydraulic shock absorber according to the driving condition of the automobile. This is because the piston, which divides the cylinder filled with hydraulic fluid into two liquid chambers, moves in the cylinder as it extends (the piston rod extends, the piston moves upward in the cylinder, and the hydraulic shock absorber During the pressure stroke (the piston rod is compressed, the piston moves downward in the cylinder, and the vertical length of the hydraulic shock absorber is shortened), the hydraulic fluid is pumped between each fluid chamber. It includes a damping force generation mechanism that generates a damping force by displacing and circulating the damping force, and a damping force variable mechanism that bypasses a portion of the hydraulic fluid that would otherwise pass through the damping force generation mechanism between each liquid chamber.

This variable damping force mechanism includes a bypass passage formed in a piston rod to which a piston is fixed, and an adjuster housed in the bypass passage, and this adjuster is rotated by an actuator connected via a control rod. , by selecting one of the plurality of orifices of different diameters formed in the regulator,
Adjust the bypass amount of hydraulic fluid flowing through the bypass passage,
For example, you can set damping force variable modes of soft, medium, and hard.

By the way, some of the actuators described in 1ii7 have an output that connects a table fitted to the upper end of the piston and an adjuster for varying the damping force, as shown in Japanese Utility Model Application Publication No. 58-72546. A rotor having a shaft, a rotor having a permanent magnet fixed to the outer periphery of the output shaft, and a stator having a plurality of electromagnets fixed to the table spaced apart from each other in the circumferential direction of the rotor, the plurality of electromagnets being selectively activated. There is a device in which the permanent magnet is attracted by being excited to rotate the output shaft, thereby rotating the regulator relative to the bypass passage.

Problems to be Solved by the Invention However, in the above-mentioned actuator, only the electromagnet located at the rotation destination of the permanent magnet among the plurality of electromagnets is excited so that the magnetic field attracted by the permanent magnet is generated. The rotor is rotated by attracting the permanent magnets, so the variable damping force mode can be set to soft mode, for example.
When switching between medium and hard, at the beginning of the rotation of the rotor, the magnetic field that acts as an attractive force between the permanent magnet and the electromagnet, which are facing each other at the stop position, acts as a rotation resistance. Therefore, it is necessary to increase the output (torque) at the initial stage of rotation. However, in order to increase the output at the initial stage of rotation, the magnetic field of the electromagnet must be strengthened, which results in an increase in the external size of the electromagnet. As a result, when the actuator is attached to the vehicle body, the area occupied by the actuator becomes large, which poses a problem in that it poses a problem in attaching other functional parts.

In addition, in order to increase the output (torque) of this actuator, ■ increase the cross-sectional area of the permanent magnet, ■ increase the length of the permanent magnet, that is, the distance from the output shaft to the outer end of the permanent magnet, ■ increase the electromagnet It is necessary to strengthen the magnetic field. For this reason, the higher the output of the actuator is, the larger the actuator becomes in the radial direction, which causes trouble in attaching other functional parts.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a casing, an output shaft rotatably mounted in the casing,
a rotor having a main permanent magnet fixed to the outer periphery of the output shaft; a stator having a plurality of electromagnets spaced apart in the circumferential direction and fixed in a casing; when the rotor is driven;
magnetic field switching means for selectively exciting the plurality of electromagnets so that the electromagnet located at the rotation destination of the main permanent magnet among the plurality of electromagnets generates an attractive magnetic field of the main permanent magnet;
On both sides of the main permanent magnet in the circumferential direction are sub permanent magnets whose magnetic field direction is set opposite to that of the main permanent magnet, and which generates a repulsive force in the rotational direction of the rotor with the selective excitation electromagnet. It has a structure with magnets installed.

EXAMPLES Hereinafter, examples of the present invention will be described in detail based on the drawings. This embodiment shows an actuator applied to a variable damping force type hydraulic shock absorber.

1 to 6 show the first embodiment, and in these figures, l is a variable damping force type hydraulic shock absorber, and a cylinder 2 filled with hydraulic fluid and the inside thereof are shown. A piston 5 defined in the two liquid chambers 3 and 4, a damping force generating mechanism 6 provided on the piston 5 and generating a damping force when the piston 5 moves within the cylinder 2, and a damping force generating mechanism 6 provided at one end of the piston 5. A variable damping force that adjusts the bypass amount of hydraulic fluid that can be exchanged and circulated between the two liquid chambers 3 and 4 via the piston rod 7 attached to the side and the damping force generation mechanism 6 provided on the piston rod 7. It is equipped with a mechanism 8. The damping force generation mechanism 6 includes a plurality of passages 6a that are spaced apart in the circumferential direction of the piston 5 and penetrate in the vertical direction, and a damping force generation mechanism 6 that connects at least one of the plurality of passages 6a provided on the upper surface of the piston 5 with liquid. A slit 6b that communicates with the chamber 3; a slit 6c provided on the lower surface of the piston 5 that communicates at least one of the plurality of passages 6a with the liquid chamber 4;
An extension side valve body 6d is disposed on the lower surface of the piston 5 and covers the plurality of passages 6a during the compression stroke and opens during the extension stroke; It is equipped with a pressure side valve body 6e that opens during the extension stroke and the pressure stroke, and as the piston 5 moves within the cylinder 2, the damping force is reduced by displacing and circulating the hydraulic fluid between the fluid chambers 3 and 4. It's starting to happen. Damping force variable mechanism 8
A bypass passage 9 is formed in the piston rod 7 and communicates the two liquid chambers 3 and 4 by bypassing the damping force generating mechanism 6, and an adjuster 10 is rotatably housed in the bypass passage 9. It is equipped with An actuator 12 is connected to the regulator 1G via a control rod 11 inserted into the axial center of the piston rod 7, and the actuator 12 allows a plurality of orifices 10a of different diameters provided in the regulator 10 to be connected. By selectively communicating one of the orifices log to the communication hole 13 provided in the circumferential wall of the bypass passage 9 of the piston rod 7, the regulator l
O adjusts the bypass amount of the working fluid flowing through the bypass passage 9. The other end (upper end) of the piston rod 7 that sealingly passes through the cylinder 2 is attached to an upper mount insulator 15 . That is, the nut 16 is fastened to a threaded portion of the piston rod 7 that passes through the upper mount insulator 15 and projects upward from the upper mount insulator 15 .

This upper mount insulator 15 is attached to the vehicle body using a known structure.

Here, the actuator 12 includes a casing 20, an output shaft 21, a rotor 22, and a stator 23, as shown in detail in FIGS. 2-6. The casing 20 is composed of a base plate 24 and a cover 25 in the shape of a closed cylinder. The opening periphery of the cover 25 is attached to the base plate 2.
By fitting and mounting the output shaft 21.4 onto the outer peripheral edge of the casing 20. A space 26 is formed to accommodate the rotor 22 and the stator 23.

As shown in FIG. 1, a plurality of flanges 27 are provided on the outer peripheral edge of the lower surface of the base plate 24 and extend horizontally outward in the radial direction. These flanges 27 are fixed to an actuator bracket 28 provided on the upper mount insulator 15 with bolts 29. Second time again
Returning to FIG. 6, a boss 30 is provided at the center of the lower surface of the base plate 24 to protrude downward. A recess 31 is formed in the center of the upper surface of the base plate 24, excluding the protrusion 31a of the portion facing the stator 23 in FIG. is formed. An insertion hole 33 is formed in the lower part of the boss 30 so as to face downward. The upper end of the piston rod 7 is fitted into the insertion hole 33 with a seal member 34 interposed therebetween. This insertion hole 33 and bearing hole 32
are communicated with each other through a through hole 35 having a smaller diameter than these. A bearing hole 36 is formed in the top wall surface of the cover 25 and is open downward. This bearing hole 36 corresponds in position to the bearing hole 32 of the base plate 24 in the vertical direction. The output shaft 21 is connected to the casing 2 via the rotor 22.
It is rotatably mounted inside the 0. The lower part of this output shaft 21 passes through the through hole 35 of the base plate 24 and passes through the insertion hole 3.
The upper part of the control rod 11 is fitted into the lower axial center of the output shaft 21 so as to rotate together with the output shaft 21, and the regulator 10 is connected to the output shaft 21 through the control rod 11. are connected. The rotor 22 includes a support shaft 37 and main permanent magnets 38 and 39. The upper and lower ends of the support shaft 37 are rotatably fitted into the bearing hole 36 of the cover 25 and the bearing hole 32 of the base plate 24 via bushings 40, 41, respectively. A hollow hole 42A is provided vertically through the axial center of the support shaft 37, and a stepped portion 42 is provided above the intermediate portion of the hollow hole 42A.
B is formed. The output shaft 21 is inserted into the hollow hole 42A.
is inserted, and the force at both ends of the pin 42G radially inserted through the upper part of the output shaft 21 (in the vertical groove 42D formed in the hole wall surface of the portion above the stepped portion 42B of the hollow hole 42A) is inserted. The output shaft 21 is fitted and received on the upper surface of the auxiliary portion 42B, and the output shaft 21 is assembled to the support shaft 37 of the rotor 22 via a pin 42C so as to rotate integrally with the support shaft 37 of the rotor 22.

A flange portion 43 is provided horizontally protruding outward in the radial direction at an intermediate portion in the vertical direction of the outer circumferential surface of the support shaft 37 . The main permanent magnet 3
8.39 is formed into a fan-shaped flat plate, and a plurality of, for example, two, are provided, and are disposed on the radially outer side of the support shaft 37, facing each other with the support shaft 37 in between. These two main permanent magnets 38.3
9 each include a flange 43 of the support shaft 37 and an annular stay plate 44 externally fitted and fixed to a portion below the flange 43.
It is held in a sandwich-like manner and fixed to the support shaft 37. That is, these main permanent magnets 38 and 39 are fixed to the outer periphery of the output shaft 21 via the support shaft 37. The diverging outer peripheral portions of the main permanent magnets 38 and 39 protrude outward from the flange portion 43 and the stay plate 44, and are slightly separated from the upper surface of the base plate 24. The stay plate 44 is located within the four parts 31 of the base plate 24. The direction of the magnetic field of these main permanent magnets 38 and 39 is the third
．． As shown by arrow X in FIG. 5, it is set parallel to the rotation center of the output shaft 21 and upward. The stator 23 includes a mount base 45 constituting a wiring board and a plurality of electromagnets 46 to 51. The mount base 45 is formed in an annular shape, is located at a vertically intermediate portion of the inner peripheral surface of the cover 25, and is fixed onto the base plate 24 via a stay 52. This mount base 45 is located slightly above the flange 43 of the support shaft 21. The plurality of electromagnets 46 to 51 are six in this embodiment, and are arranged at equal intervals in the circumferential direction of the rotor 22 and are fixed in the casing 1 via a mount base 45. Each of the six electromagnets 46 to 51 includes a magnetic core 46a to 51a, and a solenoid 46c wound around the outside of the vertically intermediate portion of the magnetic core through a bobbin 46b to 51b.
~StC, and rivets 53 protruding from the lower flanges of the bobbins 46b to 51b are caulked to the mount base 45. These electromagnets 46 to 51 are the main permanent magnets 38.3
The permanent magnets 38 and 39 are disposed above the main permanent magnets 38 and 39 with a required gap around the circle within a range facing the direction of the magnetic field of the magnets 38 and 39. Specifically, when the main permanent magnet 38.39 rotates around the output shaft 21, the lower surfaces of the magnet cores 46a to 51a of the six electromagnets 46 to 51 are connected to the main permanent magnet 38.3.
It is designed to be in a state where it is released from the outer peripheral part of 9. The upper portions of the magnet cores 46a to 51a are tightly fitted into a receiving portion 54 formed on the top wall surface of the cover 25.

The upper flanges of the bobbins 46b to 51b are in contact with the top wall surface of the cover 25. Moreover, among the six electromagnets 46 to 51,
Electromagnets 46 facing each other across the center of rotation of the output shaft 21.
Groups 49, 47.50, and 48.51 are electrically made up of two pairs. The solenoids 46c to StC of the six electromagnets 46 to 51 are connected to a magnetic field switching means 55° and a fuse 56, as shown in FIG. It is connected to a battery 58 as a power source via an ignition switch 57. The magnetic field switching means 55 is a selection switch having a plurality of damping force variable mode setting contacts, for example, a soft mode setting contact S, a hard mode setting contact H, and a medium mode setting contact M. The plurality of electromagnets 46 to 51 are selectively excited so that an electromagnet located at the rotation destination of the main permanent magnets 38 and 39 among the electromagnets 46 to 51 generates an attractive magnetic field of the main permanent magnets 38 and 39. It is composed of

Soft mode setting contact S. Hard mode setting contact! 1.
Each medium mode setting contact M is turned on by a mode setting signal from a damping force variable controller (not shown). In this embodiment, the solenoid 4 is a set of two of the six electromagnets 46 to 51.
6c and 49c are connected in series, and one solenoid 46 of the pair of solenoids 46c and 49c
One end of C9 is connected to the soft mode setting contact S of the magnetic field switching means 55, and the other end of the other solenoid 49c is connected to the negative pole of the battery 58. In addition, another solenoid 4 which is a set of two of the six electromagnets 46 to 51
7c and 50c are connected in series, and one solenoid 47 of the pair of solenoids 47c and 50c
One end of c is the hard mode setting contact H of the magnetic field switching means 55.
The other end of the other solenoid 50c is connected to the negative electrode of the battery 58. Further, another set of two solenoids 48C151C among the six electromagnets 46 to 51 are connected in series, and one end of one solenoid 48c of the set of two solenoids 48c and 51c is connected in series. It is connected to the medium mode setting contact M of the magnetic field switching means 55, and the other end of the other solenoid 51c is connected to the negative pole of the battery 58. On the other hand, on both sides of the main permanent magnets 38 and 39 in the circumferential direction are sub permanent magnets 5.
9 and 60 are arranged. These secondary permanent magnets 59°6
The direction of the magnetic field of the main permanent magnets 38 and 39 is set to be opposite to the direction of the magnetic field of the main permanent magnets 38 and 39, as shown by the arrow Y in FIG.

These auxiliary permanent magnets 59.60- are, for example, 2°5.6
As shown in the figure, when the circumferential center part of the main permanent magnet 38.39 is located directly below the electromagnet 46.49, it is placed astride the electromagnets 47.48 on both sides and the electromagnets 50.51 on both sides, The rotor 2
It is designed to generate a repulsive force in the direction of rotation of 2.

These auxiliary permanent magnets 59, 60 are fixed to the support shaft 37 by a collar 43 and a stay plate 44, similarly to the main permanent magnets 38, 39. In addition, 61 shown in FIG. 2-3 is a harness to the solenoids 46c to 51c of the six electromagnets 46 to 51, and 62 shown in FIG. This is a seal that seals the inside of 20.

According to the structure of the above embodiment, the ignition switch 5
When one of the soft mode setting contact S1 or the hard mode setting contact H or the medium mode setting contact M of the magnetic field switching means 55 is turned on while the solenoid 7 is turned on, a set of two solenoids 4 are turned on from the battery 58.
6c, 49c or 47c.

An excitation current is supplied to 50C, 48c, and 51c, and a set of two magnet cores 46a, 49a, or 47a.

50a and 48a and 51a are marked with arrow Z in Fig. 3.5.
Generates a magnetic field in the direction shown. Now, in the state shown by the solid line in Fig. 5.6, the magnetic field switching means 55 is switched from the soft mode setting contact S to the hard mode setting contact H, cutting off the excitation current of the electromagnets 46 and 49, and switching the electromagnets on the right. 4
7.50, the main permanent magnet 38.39 is attracted to the excited electromagnet 47.50, and the auxiliary permanent magnet 59.60 is attracted to the excited electromagnet 47.50. The initial starting torque is obtained through repulsion. In this way, the main permanent magnet 38.
39 is attracted and the auxiliary permanent magnets 59 and 60 are repelled, the output shaft 21 is rotated via the support shaft 37, and the regulator lO connected to this output shaft 21 via the control rod 11 is rotated. One orifice 10a of the plurality of orifices loa of different diameters of the adjuster 10 is communicated with the communication hole 13 of the piston rod 7, and the amount of bypass of the variable damping force mechanism 8 is adjusted. The rotation of the output shaft 21 is caused by the lines of magnetic force Y of the magnetic cores 46a, 49a or 47a, 50a, 48a, 51a, which are selectively excited via the magnetic field switching means 57, connected to the main permanent magnet 311.39. It is stopped where it becomes parallel to the magnetic field lines, that is, where the magnetic field is in the strongest coupling state.

FIG. 7 shows a second embodiment of the present invention, in which a pair of solenoid 46c and a solenoid 49c are connected in parallel, and a pair of solenoid 47c and solenoid 50 are connected in parallel.
c are connected in parallel, and a set of two solenoids 48c and 510 are connected in parallel, so that even if one of the two solenoids is disconnected, the rotor 22 can be It is designed to be able to be driven.

Although illustration is omitted in the present invention, an electromagnet may be placed below the main permanent magnet, or two or more main permanent magnets, sub permanent magnets, and electromagnets may be provided, or after the damping force variable mode switching is completed. Even if the output shaft 21
It is also possible to prevent the reversibility of

Effects of the Invention As described above, according to the present invention, when the rotor rotates, the magnetic field switching means can generate an attractive magnetic field of the main permanent magnet in the electromagnet at the rotation destination of the main permanent magnet. The selectively excited electromagnets, the main permanent magnets, and the auxiliary permanent magnets can simultaneously exert an attractive force and a repulsive force in the rotating direction of the rotor. As a result, compared to the conventional structure in which the attractive magnetic field of the permanent magnet is generated only in the electromagnet that is located at the rotation destination of the permanent magnet among multiple electromagnets, the radial outer shape of the actuator can be made smaller. Therefore, when the actuator is installed on the vehicle body, the area occupied by the actuator can be reduced.
It will not interfere with the installation of other functional parts. Moreover, at the beginning of the rotation of the rotor, the repulsive force acting between the auxiliary permanent magnet and the excited electromagnet acts as a rotational auxiliary force, which improves the responsiveness of the actuator. effective.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG.
Figure 3 is a cross-sectional view taken along line ■-■ in Figure 2, Figure 4 is a cross-sectional view taken along line IV-■ in Figure 3, and Figure 5 is a cross-sectional view taken along line IV-■ in Figure 3. FIG. 6 is an electric circuit diagram of the same embodiment, and FIG. 7 is an electric circuit diagram of a different example of the present invention. 20...Casing, 21...Output shaft, 22...
Rotor, 38°39... Main permanent magnet, 48~53...
- Electromagnet, 57... Magnetic field switching means, 59.60...
Secondary permanent magnet. 2 people outside

Claims (1)

[Claims] A casing, an output shaft rotatably mounted within the casing, a rotor having a main permanent magnet fixed to the outer periphery of the output shaft, and a plurality of electromagnets spaced apart in the circumferential direction and fixed within the casing. a stator having a stator, and selectively exciting the plurality of electromagnets so that, when the rotor is driven, an electromagnet located at a rotation destination of the main permanent magnet among the plurality of electromagnets generates an attractive magnetic field of the main permanent magnet. magnetic field switching means, the direction of the magnetic field is set to be opposite to the direction of the magnetic field of the main permanent magnet on both sides in the circumferential direction of the main permanent magnet, and the direction of the magnetic field is set to be opposite to the direction of the magnetic field of the main permanent magnet, and the direction of the magnetic field is set to be opposite to the direction of the magnetic field of the main permanent magnet, and the direction of the magnetic field is set to be opposite to the direction of the magnetic field of the main permanent magnet. An actuator characterized in that an auxiliary permanent magnet is provided that generates a repulsive force.