JPS61199454A - Rotary drive mechanism - Google Patents

Abstract

PURPOSE:To facilitate to improve starting and stopping characteristics by increasing the width of a rotary armature type stator magnet in the rotating direction larger than that of the pole of a rotor, and increasing a distance from the center to the stator magnet at both ends from the center. CONSTITUTION:A core 11 made of a ferromagnetic material is secured to a rotational shaft 10, the core 11 has four poles 11a-11d including outer periph eral surfaces of the same distance from the shaft 10, a coil 12 is wound on the poles 11a, 11c, and a coil 13 is wound on poles 11b, 11d. Permanent magnets 21, 22 of opposite polarity magnetized radially are secured to the inner periphery of the case 17. The central angle theta1 of the widths of the magnets 21, 22 in the rotating direction is increased larger than the width theta2 of the poles 11a-11d. The thicknesses of the magnets 21, 22 are larger at the center than both ends. Thus, the distances from both ends of the pole 11 to the magnets 21, 22 are short at the starting time, the centers of the magnets 21, 22 are approached to the poles 11 at stopping time, thereby smoothly starting and stopping.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rotary drive mechanism, and more particularly, to a rotary armature type rotary drive mechanism in which a core having a coil wound therein is provided within a field of a stator magnet. .

BACKGROUND OF THE INVENTION Conventionally, there have been shock absorbers using dash boards. In this shock absorber, the buffering efficiency changes depending on the diameter of the communication hole installed in the piston of the Datsushiko pot. By utilizing this phenomenon, for example, as shown in FIG.

30b and 30c with the reel tube 3o (D tube 3o)
There is a mechanism for varying the buffering efficiency with a rotating member 31 provided inside. This one rotates the rotating part +A'31 every 90 degrees to select - of the communication holes 30a-30c, and selects one of the cylinders leading to the inside of the pipe 30 pulled by screws 1 to 11. The buffering efficiency is varied by varying the amount of fluid flowing between the chamber and the other chamber of the cylinder that communicates with the outside of the tube 3°.

Conventional rotational drive mechanisms for the rotating member 31 include a so-called geared motor, which uses a gear to reduce the rotation speed of a motor and transmits the reduced speed to the rotating member 31, and a step motor, which directly rotates the rotating member 31.

Problems to be Solved by the Invention The geared A7 motor requires a gear in addition to the motor and has a complicated configuration, and also requires a rotational position detection sensor or a rotational stop position of the rotating member 31 to detect when the motor stops. There is a problem that a stopper mechanism is required to ensure accuracy, and assembly workability is also poor.

In addition, when the rotational drive mechanism is placed inside the cylinder,
The step motor has an output of 1 because the outer diameter size is regulated.
Since the torque is small and the output 1 to large, the multi-stage step motor has a multiple 911 configuration.Furthermore, the step motor requires a rotational drive control circuit and is expensive.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotary drive mechanism that solves the above-mentioned problems by selecting a rotary armature type stator magnet shape.

Means for Solving the Problems The present invention is of a rotating armature type, in which the width of the stator magnet in the rotational direction is larger than the width of the magnetic pole, and the distance from the center of rotation of the stator magnet is at the center. It is considered human at both ends.

Function Since the present invention is of a rotating armature type, the structure is simple and a large amount of torque can be output.

In addition, the width of the stator magnet in the rotational direction is wider than the width of the magnetic pole pieces, improving starting performance. The stability of time is in the spotlight.

Embodiment FIGS. 1 and 2 are a longitudinal cross-sectional view and a cross-sectional view taken along the line ■-■, respectively, of an embodiment of the rotary drive mechanism according to the present invention. In both figures, 10 is a rotating shaft, and a ferromagnetic material 11 is fixed to this rotating shaft 10. ] Core 1 is rotating shaft 10
'', four magnetic pole pieces 11 having outer peripheral surfaces with the same distance
a, 11b.

The coil 12 is wound so that the magnetic poles 11a and 11C facing each other become negative electromagnets when energized, and the 11 poles 11b and 11d act as negative electromagnets when energized. The coil 13 is wound so that =1 both ends 12a, 12b of coil 12 and] both ends 13a of coil 3.

131) Each is connected to a relay board 14 fixed to the rotating shaft 10, and a flexible lead wire 15 is connected to the relay board 14 from the relay board 14.
a to 15 (j) are connected to contacts on the external board 16 through each one.

The above rotating shaft 10. Core 11. ] The rotor consisting of the coil 1213 and the relay board 1/I is inserted into a bottomed cylindrical case 17 that functions as a yoke, and
is provided at the center of the bottom of the case 17 and is rotatably supported by an I-shaped bearing 18 and a bearing 20 provided at the center of one of the brackets 1 to 1 mounted in the opening of the case 17.

On the inner wall of the case 17 are fixed permanent magnets as stators (stator magnet>21,22, respectively).
'1 is magnetized so that, for example, the surface facing the magnetic pole pieces 11a to 11a to lid is the north pole, and the surface that abuts the case 17 is the south pole. Its cross-sectional shape is as shown in Fig. 2, with rotation @10
The angular width θ1 (for example, 90 degrees) centered on the core 11
The angular m width θ2 of each of the magnetic pole pieces 11a to 11d is larger than the width θ2, and the central part of the cross section has a maximum thickness of 21, and the culm that is displaced toward both ends becomes thinner, and both ends have a thickness of f! , 2 is considered to be the minimum. Accordingly, the distance from the rotating shaft 10 to the permanent magnet 21 is longer at both ends of the width in the rotational direction than at the center of the width in the rotational direction of the permanent magnet 21. Further, the permanent magnet 22 has the same cross-sectional shape as the permanent magnet 21, and the surface that comes into contact with the case 17 is N 14i
The permanent magnets 21 and 22 have a rotational angle of 180 degrees with respect to the rotating shaft 10. In other words, the rotational drive nMjtt4 of the present invention
is of the rotating armature type.

Here, the first mode is when the magnetic pole piece facing the permanent magnet 21 is 11a as shown in the second diagram;
b is the second mode, and 11C is the third mode. When shifting from the first mode to the second mode, a current is passed through the coil 13 with one end 13a of the coil 13 as a positive electrode and the other end 13b as a negative electrode. For this! The i-ladder 11b is magnetized to the S pole, and the VT1 pole 11d is magnetized to the N pole, so that the magnetic poles 11b and 116 are attracted to the permanent magnets 21 and 22, respectively, and the rotating shaft 10 is rotated 90 degrees clockwise.

At this time, the angular width θ1 of each of the permanent magnets 21 and 22 is larger than the angular width θ2 of each of the magnetic pole pieces 11a and 11c, so the distance from both ends of the magnetic pole pieces 11b and 11d to the permanent magnets 21 and 22 is short. Thus, 1 = Ruku at startup is a dog. The magnetic pole piece 11b is driven as described above.

11 (after each of the magnetic poles 11a and 11c shown in the second figure has rotated, the current in the coil 13 is cut off and -b
, (i1i pole 11b) of the core 11 which is a ferromagnetic material.

11 [1] are attracted to the permanent magnets 21 and 22, respectively.

At this time, each of the permanent magnets 21 and 22 has a thickness P at the center of the cross section.
lζ where l is maximum, this cross-sectional center part and the magnetic pole piece 111
), 11d, and the magnetic pole pieces 11b,
The center line passing through the rotating shaft 10 of 11d is the permanent magnet 21.22
The magnetic pole pieces 11b and 11d are stably stationary at a position spaced apart from the central portion having a thickness e+.

By the way, after the rotary shaft 13 starts rotating due to the energization of the coil 13, a current is passed for a short time in the direction from the -dWj 12a of the coil 2 to the other end 121, and the Ia pole 1
It is also possible to increase the 1-lux at the start of the rotation 1'l1113 by repelling the permanent magnets 21 and 22, respectively.

FIG. 3 shows the direction of current in each of the coils 12 and 13 for causing mode transition between the first to third modes. In other words, when transitioning from the second mode to the third mode, one end 12a of the coil 12 is connected to the positive electrode, and the other end 121
) is used as a negative electrode, and a current is passed through the coil 12. Also, the third (
When transitioning from the second (first) mode to the second (first) mode, the negative terminal 13a (12b) of the coil 13 (12) is connected to the positive terminal.

Connect the other end 13h (12a> to the negative terminal of the coil 13 (12
). The operation in these cases is exactly the same as the transition from the first mode to the second mode, and the explanation thereof will be omitted.

In this way, since there is a rotating armature type C, while keeping the outer diameter of the case 17 constant, the armature 1 and the permanent magnet 2 are
1.22 As shown in Figure 1 of each figure, [By increasing the lateral strength, the output power per herk can be increased,
The configuration is also simple. Further, the width of the permanent magnets 21, 22 in the rotational direction is larger than the width of each of the magnetic pole pieces 118 to 11d in the rotational direction, thereby improving starting performance. Also, permanent magnet 21.2
2. Since the distance from each rotation 1lIll110 is d5 at both ends compared to the center of the width in the rotational direction of the magnet, the stability of the rotation 'I'l1110 when the rotation is stopped is constant, and the rotational position can be detected. It is possible to construct the structure at low cost without requiring a lens or a stopper mechanism.

Note that a slip ring (flat sliding contact) may be provided on the relay board 14, and a brush may be used in place of the lead wires 15a to 15d, so that the rotation 1111110 can be rotated by more than 360 degrees.

Further, the rotational drive mechanism of the present invention may be applied to any device other than a shock absorber, and is not limited to the above embodiment.

Effects of the Invention 1 As mentioned in 1, the rotary drive mechanism according to the present invention is of the rotating armature type, so the structure is simple and the output can be increased by 1 to 1 torque, and the starting performance is good, and the rotation can be stopped easily. It has advantages such as good stability during operation, no need for a rotational position detection sensor or stopper mechanism like the conventional one, no need for a drive control circuit, simple construction and low cost.

10-

[Brief explanation of drawings]

1 and 2 are cross-sectional views of one embodiment of the rotational drive mechanism according to the present invention, FIG. 3 is a diagram for explaining the drive of the mechanism shown in FIG. 1, and FIG. 4 is a diagram of a shock absorber. FIG. 3 is a diagram for explaining an example of a variable buffer efficiency mechanism. 10... Rotating shaft, 11... Core, 11a to 11d.
・・till pole, 12.13・T]-1'/l/, 1
7-K:1. ．． 21.22...Permanent magnet.

Claims (1)

[Claims] A rotary armature-type rotational drive mechanism in which a core with a coil wound thereon is provided in a field generated by a stator magnet, and the width of the stator magnet in the rotational direction is greater than the width of the magnetic pole at the tip of the core in the rotational direction. A rotary drive mechanism characterized in that the distance from the center of rotation to the stator magnet is larger at both ends than at the center of the width of the stator magnet in the rotational direction.