JPH04109855A - Direct drive electromagnetic actuator - Google Patents

Abstract

PURPOSE:To realize high speed driving of a miniature motor by disposing a linear drive moving body movably through a predetermined gap against a coil core such that the coil core interlinks approximately in normal to the flux thereby forming a closed magnetic path integrally of a yoke and the coil core. CONSTITUTION:An exciting coil 32 is wound around the lower part of a coil core composed of a core material disposed in the center of two yokes 10a, 10b comprising U-shaped magnetic bodies arranged oppositely. A moving body 40 is composed of an annular core material having outer diameter slightly shorter than the inner diameter of a through-hole 30a. Consequently, the moving core 40a is magnetically coupled strongly with the coil core 30. When an exciting current is fed to the exciting coil 32, the moving core 40a repels against any one of pole pieces 50a, 50b and attracts to the other. Consequently, the moving core 40a is attracted with a strong force to any one of the pole pieces 50a, 50b and moved. In other words, an actuator 40b moves, linearly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a highly versatile linear drive electromagnetic actuator, and more particularly to a high performance linear drive electromagnetic actuator that is compact and capable of high-speed drive.

[Prior Art] Linear drive type electromagnetic actuators have been used in a wide range of sectors because linear drive electromagnetic actuators are easy to use because they drive moving bodies in a straight line.

FIG. 4 is an explanatory diagram of the structural concept of such a linear drive type electromagnetic actuator. As shown in the figure, in the linear drive type electromagnetic actuator, an excitation coil FC is wound around the moving body MS. The drawing is driven in a straight line in the left and right direction.

In addition, in order to switch the moving position of the mobile MS at high speed, 1
The mobile body MS has excitation coils FC1 and F wound oppositely to each other.
e2 is wound, and an excitation current is passed to either excitation coil PCI or FC2 depending on the direction of movement.

The linear drive type electromagnetic actuator having the above structure allows the moving body M SLL to be linearly driven and to switch the moving position at high speed.

[Problems to be Solved by the Invention] In a conventional linear drive type electromagnetic actuator, an excitation coil FC is wound around a moving body MS. For this reason, a large space is required around the mobile body MS, making it impossible to downsize the area around the mobile body. This tendency is particularly noticeable in the case where two excitation coils PCI and FC2 are wound in order to switch the movement position at high speed.

Further, as is easily understood, in order to obtain a large force during one movement, it is necessary to increase the size of the exciting coil FC. However, the moving body MS needs to pass through the excitation coil FC, and increasing the size of the excitation coil FC results in the length and weight of the moving body MSO.

For this reason, it was not possible to provide a high-speed and small linear drive type electromagnetic actuator, and it was not possible to develop new application fields.The present invention was made to solve the above problem E, and can be used in a wide range of sectors. It is an object of the present invention to provide a linear drive type electromagnetic actuator that is easy to use, has excellent characteristics such that the movable body part is miniaturized, and can be driven at high speed.

[Means for Solving the Problems] In order to solve the above problems, the linear drive electromagnetic actuator of the present invention has a linear drive type electromagnetic actuator that moves a moving body made of a magnetic material in a straight line by an electromagnetic force generated by passing an exciting current to an exciting coil. In a linearly driven electromagnetic actuator, the actuator is provided inside a yoke made of a magnetic material so as to be substantially orthogonal to a coil core around which the excitation coil is wound and a magnetic flux that makes the coil core a magnetic path. and a movable body that is movably arranged with a certain gap from the coil core and forms a closed magnetic path integrally with the yoke and the coil core; The present invention is characterized by comprising: a biasing member that applies a biasing force different from the electromagnetic force caused by the coil.

[Operation] The linear drive type electromagnetic actuator of the present invention has a coil core inside the yoke, and the excitation coil is wound around this coil core.

A linearly driven moving body (a linearly driven moving body) that is movably arranged so as to be substantially orthogonal to the magnetic flux with the coil core as a magnetic path and with a certain gap from the coil core. form.

In other words, the moving body (magnetically speaking, it only acts as one magnetic path and is configured separately from the excitation coil that generates magnetomotive force. Therefore, the space around the moving body in which the excitation coil is arranged is This becomes unnecessary, and the degree of freedom in designing the moving body increases.

If an excitation current is passed through the excitation coil configured as above (the melon moving body will be attracted to the side where the magnetic resistance is smaller with respect to the yoke, forming one closed magnetic path.And since that position is the most stable, If this continues, the next movement will be impossible.Therefore, a biasing member is separately provided that applies a biasing force different from the electromagnetic force produced by the excitation coil in the moving direction of the moving body.For example, (as a song biasing member) (It is also possible to use either a permanent magnet that applies an urging force without contacting the surface moving body or a spring that makes contact with it.

EXAMPLES Hereinafter, in order to explain the present invention more specifically, the present invention will be described in detail with reference to Examples.

[Example] FIG.
) Figure is its plan view, (B) Figure is its front view, (C)
The figure shows its right side view.

As shown in the figure, the linear drive type electromagnetic actuator (A) of this embodiment uses two yokes 10a and 10b made of mouth-shaped magnetic bodies arranged opposite to each other as aggregates, and on the sides of each yoke 10a and 10b, By screwing the side plates of the opening-shaped top plate 14, the side plates of the opening-shaped bottom plate 16, and the side plates of the U-shaped partition plate 56 made of non-magnetic material with bolts 18a to 18h and 54a to 54. It is housed in a formed housing 10.

A rectangular plate member 20 is placed on the bottom plate 16 of the casing 1o formed in this way (to reinforce the strength and improve magnetic permeability).A coil core 30 made of a magnetic core material is erected in the center of the rectangular plate member 20. The lower part of the coil magnetic core 30 has a cylindrical shape, and the excitation coil 32 is wound around that part.The outer shape of the upper part of the coil magnetic core 30 is a square prism, and a large diameter through hole 30a is formed in the center. The coil core 30 having such a shape is screwed into the bottom of the casing 0 using bolts 181 so as to be firmly integrated with the bottom plate 16 and the plate material 20.

Excitation coil 32 arranged on the lower surface of coil iron core 30
is arranged on an annular elastic seat 22 placed on the plate material 20. Note that the excitation coil 32 is configured by combining two excitation coils 32a and 32b that constitute mutually independent electric circuits.

The through hole 30a drilled in the upper part of the coil core 30 has a
The moving body 40 is loosely fitted in a non-contact state. That is, the movable body 40 has window holes 42a and 42 in yokes 10a and 10b.
Both ends of the coil core 30 are slidably supported by annular bushes 44a and 44b fitted to
It is only magnetically coupled to the through hole 30a through a certain gap.

Note that the bushes 44a and 44b refer to the moving body 40.
It plays the role of a sliding part for smooth sliding, and a sealing part that separates the casing 10 from the outside.

The moving body 40 is composed of two members: a moving core 40a and an actuator 40b. The movable iron core 40a is a portion loosely fitted into the through hole 30a at the center of the movable body 40, and is constituted by an annular magnetic core material having an outer diameter slightly smaller than the inner diameter of the through hole 30a. Therefore, the moving core 40a exhibits high magnetic coupling with the coil core 30. The actuator 40b is a rod-shaped body fitted into the central hole of the movable core 40a, and both ends of the actuator 40b protrude from the housing 10 through the bushes 44a and 44b as described above.

It should be noted that a urethane cushioning material 4 is attached to the side surface of the moving core 40a (1) in order to absorb the impact upon collision with the magnetic pole pieces 50a and 50b (described later) and to weaken the magnetic coupling force upon contact.
0c is attached.

The actuator 40b is attached to the inner wall surface of each yoke 10a, 10b through which the actuator 40b penetrates.
Washers 46a and 46b are installed to loosely fit the.

These washers 46a, 46bl & serve as pedestals for permanent magnets 48a, 48b and magnetic pole pieces 50a, 50b into which a similar actuator 40b is loosely fitted. In this way, the washer 46
Pole pieces 50a, 50b[t stacked on the permanent magnets 48a, 48b and the magnetic pole pieces 50a, 50b[t protrude from the yokes 10a, 10b to a position facing the movable iron core 40a in the neutral position with a fixed gap as shown in the figure. .

In addition, a permanent magnet 48a and a magnetic pole piece 50a [a hole having a larger diameter than that of the other permanent magnet 48b and magnetic pole piece 50a] are provided in the actuator 40b into which the permanent magnet 48a and the magnetic pole piece 50a are fitted.
2 are fitted.

Furthermore, the linear drive type electromagnetic actuator (mountain yokes 10a, 10b) of this embodiment is fitted with the core 30 in the center of the partition plate 56 attached to the side surfaces of the yokes 10a, 10b at ports 54a to 54d and penetrated through the housing 10. The movable body 40 located at the upper part of the movable body 40 can be operated in a dust-proof state, and the excitation coil 32 can be securely fixed.

The linear drive type electromagnetic actuator of this embodiment configured as described above has the following excellent effects.

Moving iron core 40 when excited and magnetic current is passed through excitation coil 32
A repulsive force acts on one of the magnetic pole pieces 50a, 50b, and an attractive force acts on the other. Therefore, moving iron core 40a
is one of the magnetic pole pieces 50 a, 50 on which the attractive force acts.
The card is drawn to b with great force and moves until it comes into contact with it. That is, the actuator 40b moves linearly, and is a linear drive type electromagnetic actuator that can be easily used in a wide range of sectors.

Moreover, the excitation coil 32 that generates magnetomotive force through the excitation current is arranged in a space different from the movable body 40 serving as a moving part. Therefore, the degree of freedom in designing the moving part 40 is increased, and the length, diameter, material, etc. of the moving core 40a and the actuator 40b can be freely selected regardless of the excitation coil 32. Therefore, by reducing the weight of the moving body 40, it is possible to easily manufacture a linear drive type electromagnetic actuator that is faster than the conventional one.

Further, there is no need for a space for arranging the excitation coil 32 on the surface of the moving body 40, and the moving body 40 can be miniaturized and the field of application can be further expanded.

In addition, the upper space of the casing]O in which the moving body 40 is arranged is
The bushes 44a, 44b and the partition plate 56 provide the minimum necessary dust-proof space. Therefore, the linear drive type electromagnetic actuator of this embodiment operates with high reliability even under harsh operating conditions with a lot of wind and dust, and is extremely easy to maintain.

Furthermore, in the linear drive type electromagnetic actuator of this embodiment, a buffer material 40c is attached to the side surface of the movable core 40a to prevent the movable core 40a from coming into direct contact with the magnetic pole pieces 50a, 50b. Therefore, the rising characteristics when switching the movable core 40a from one stable position to the other stable position are improved, and high-speed driving of the negative layer is possible. The material and thickness of the edge brace 40c are design matters that are determined while balancing the requirements for high-speed drive and the requirement for a holding force that continues to hold the movable core 40a in a stable position, as described above. .

Speeding up the linear drive type electromagnetic actuator can also be achieved by dividing the excitation coil 30 into two. That is, in order to switch the stable position of the moving core 40a at high speed, it is necessary to change the polarity of the magnetic flux guided to the coil core 30 at high speed. However, since the excitation coil generally has a large inductance component, it has the property of preventing sudden changes in current. Therefore, the excitation coils 32 are replaced with independent excitation coils 3
This problem can be solved by dividing it into two parts, 2a and 32bl.

Note that the linear drive type electromagnetic actuator having the above configuration can adjust the strength of the return spring 52 so that when the excitation of the excitation coil 32 is interrupted, the movable iron core 4 that has moved toward the magnetic pole piece 50a side can be adjusted.
0a is pushed back toward the magnetic pole piece 50b side by a springing elastic force, and an operation mode in which there is one stable position can be created. Therefore, in this case, there is no need to divide the excitation coil 32 into two parts, which has the effect of simplifying the power supply. In this way, the operation mode of the linear drive electromagnetic actuator of this embodiment can be freely designed by applying various techniques used in conventional electromagnetic actuators. For example, the configuration may be such that the return spring 52 is omitted.

Next, a linear drive type electromagnetic actuator which is another embodiment of the present invention will be described with reference to FIG.

FIG. 2 is an orthogonal projection view showing a partial cross section of a linear drive type electromagnetic actuator according to another embodiment, (A) is a plan view thereof, (B) is a front view thereof, and (C) The figure shows its right side view.

As is clear from the figure, many of the components of the linear drive electromagnetic actuator of this embodiment are the same as those of the first embodiment described above. Therefore, in order to avoid duplication of explanation between the first embodiment and the linear drive electromagnetic actuator of this embodiment, the same components will be given the same reference numerals and their explanation will be omitted.

Unique components of the linear drive type electromagnetic actuator of this embodiment are a coil core 70 that serves as a magnetic flux path due to the magnetomotive force of the excitation coil 32, a movable core 80 magnetically coupled to the coil core, and a partition plate 90.

As shown in the figure, the coil core 70 of this embodiment has a housing]O
There are three types: a fixed part 72 fixed to the bottom surface of the fixed part 72, a swinging part 74 that can swing by being loosely fitted to the fixed part 72, and two coupling springs 76a and 76b attached to both ends of the swinging part. It is composed of the following members.

The fixing part 72 is fixed to the bottom surface of the housing 10 by bolts 81, and has a loose fitting hole 72a in its upper surface for loosely fitting the swinging part 74 and the coupling spring 76a. The swinging portion 74 is a rod-shaped body made of a magnetic material, and both ends thereof are configured to have a slightly smaller diameter in order to accommodate coil-shaped coupling springs 76a and 76b. Then, one end of the swinging part 74 equipped with the coupling spring 72a is inserted into the loose fitting hole 72a of the fixed part 72. Further, a coupling spring 76b is attached to the other end of the swinging portion 74 and is inserted into a coupling hole 80a drilled in the lower part of the movable iron core 80.

In order to prevent the swinging of the swinging portion 74 from being restricted, the partition plate 90 of this embodiment has a hole that is the same as the inner diameter of the excitation coil 32.

According to the linear drive type electromagnetic actuator of another embodiment configured as described above, the actuator 40b can be efficiently
This embodiment has many effects similar to those of the previous embodiment, such as being able to drive linearly.

Furthermore, the linear drive type electromagnetic actuator of this embodiment has the following unique effects because the coil core 70 is composed of a plurality of members.

The actuator 40b is linearly driven by passing an appropriate excitation current through the excitation coil 32, and at this time the coil core 70 of this embodiment operates as shown in FIGS. 3(A) to 3(C). As can be easily understood from this Figure 3, the moving iron core 4
Even if Oa slides linearly, the swinging portion 74 of the coil core 70 is always magnetically coupled to the coupling hole 80a drilled in the center of the lower part of the movable core 40a. Therefore, the degree of magnetic coupling between the coil core 70 and the moving core 40a becomes extremely high, and electrical energy is efficiently converted into kinetic energy.

Further, by appropriately adjusting the elastic force of the coupling springs 76a and 76b, the operating speed and stability of the actuator 40b can be easily improved.

[Effects of the Invention] As described in detail with reference to a plurality of embodiments, in the linearly driven electromagnetic actuator of the present invention, the linearly driven moving body is substantially orthogonal to the magnetic flux with the coil core as a magnetic path, and is spaced from the coil core with a constant gap. It is configured to be movably arranged with a yoke and a coil core to form a closed magnetic path. A biasing member that applies a biasing force different from the electromagnetic force produced by the excitation coil in the direction of movement of the moving body is separately provided, so that the excitation coil that generates the magnetomotive force through the excitation current and the movable body are located in different spaces. The degree of freedom in designing the movable body increases, and the length, diameter, material, etc. of the movable body can be freely selected regardless of the excitation coil. Therefore, by reducing the weight of the moving body, it is possible to easily manufacture a linear drive type electromagnetic actuator that is faster than the conventional one.

Further, there is no need for a space for arranging an excitation coil on the surface of the moving body, and the size of the moving body can be reduced to further expand the field of private use.

[Brief explanation of the drawing]

Fig. 1 (A) to C) is an orthogonal projection view showing a partial cross section of the linear drive electromagnetic actuator of the first embodiment, and Fig. 2 is a partial cross section of the linear drive electromagnetic actuator of the second embodiment. FIG. 3 is an explanatory diagram of the operation of the second embodiment, and FIG. 4 is an explanatory diagram of the principle of a conventional linear drive type electromagnetic actuator. 10b...Yoke 30.70...Coil core 40a, 80...Moveable core 40b...Actuator 40c...Buffer material 48a, 48b...Permanent magnet 50a, 50b...-Magnetic pole piece 56. 90... Partition plate 72 - Fixed part 74... - Swinging part 76a, 76b... Connection spring

Claims (1)

[Scope of Claims] 1. In a linear drive electromagnetic actuator that linearly drives a moving object made of a magnetic material by an electromagnetic force generated by passing an exciting current to an exciting coil, the actuator is provided inside a yoke made of a magnetic material, a coil core around which an excitation coil is wound; and a coil core arranged so as to be movable substantially perpendicular to a magnetic flux having a magnetic path around the coil core and with a certain gap between the yoke and the coil. A moving body that forms a closed magnetic path integrally with an iron core, and a moving direction of the moving body,
A linear drive electromagnetic actuator comprising: a biasing member that applies a biasing force different from the electromagnetic force produced by the excitation coil.