JPS6328575Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an actuator for a door lock, and more particularly to an actuator for a device that automatically locks and unlocks an automobile door using an electrically operated switch.

Devices that automatically lock and unlock doors using electrically operated switches have been put to practical use mainly in luxury cars. The model of this door lock device is
Although there are various types, the one described in the Automotive Engineering Handbook (edited by the Society of Automotive Engineers of Japan) is known as a common one.

In other words, the rod attached to the actuator shaft is fixed to the hook on the door side,
When this hook engages with a so-called hinge attached to the body, it becomes locked and unlocked. A torsion bar and a coil spring are attached to the hook, and their movement is moderated during the locking and unlocking process.

Therefore, both locking and unlocking are designed to prevent reversal once this moderation is overcome. Normally, the operating distance of the actuator shaft until it overcomes this moderation is set to less than half of the total stroke, and the actuator is required to have a thrust that can overcome the moderation during the above distance.

Although there are various types of actuators, the electromagnetic solenoid type actuator described in Figure 2-398 of the Automotive Engineering Handbook is often used. Although this electromagnetic solenoid type actuator has excellent responsiveness, it has the following drawbacks. That is, in this method, thrust is generated based on the electric attractive force between the movable core and the end faces of the yoke that face each other in the axial direction.

Figure 1 shows the relationship between this generated thrust and the operating stroke of the movable iron core. As shown in the figure, the generated thrust increases as it approaches the end of the action, and therefore the operating noise at the end of the action becomes louder. , and shocking.

Therefore, if a sound absorbing material is attached to the end face of the yoke or the end face of the movable iron core in order to absorb this operating noise, the length of the gap that generates the electromagnetic attraction force becomes longer and the generated thrust force decreases. Furthermore, since separate electromagnetic coils are required for locking and unlocking operations, there is a drawback that both capacity and weight are large.

By the way, as an electromagnetic actuator,
For example, a movable magnet type as described in US Pat. No. 3,149,255 is also known.
However, this electromagnetic motor receives a commercial AC power source as an input and is used in pumps and vibration equipment, and does not receive a DC power source like a door lock actuator. Further, this electromagnetic motor is characterized in that the air gap overlaps the magnetic pole piece in order to effectively utilize the magnetic flux of the permanent magnet, and no particular consideration is given to thrust-stroke characteristics.

SUMMARY OF THE INVENTION An object of the present invention is to provide a small and lightweight actuator for a door lock, which overcomes the drawbacks of the prior art described above and provides desired thrust-stroke characteristics.

The feature of this invention is that two electromagnetic coils are disposed via a coil bobbin in a yoke whose longitudinal end face in a plane including the axis is formed into a substantially E shape, so that the same polarity occurs in adjacent parts. A door lock actuator is equipped with a reciprocating drive means in which a movable element having an axially magnetized permanent magnet and a pair of magnetic pole pieces provided at both ends is attached to the center of the yoke so as to be movable in the axial direction. In the door lock actuator, a stepped portion is formed on the inner outer peripheral surface of the pair of magnetic pole pieces provided at both ends of the permanent magnet of the movable element.

Embodiments of the present invention will be described below based on the drawings.

Here, FIG. 2 is a longitudinal sectional front view showing one embodiment of the door lock actuator of the present invention.

In FIG. 2, a central magnetic pole piece 2 made of a soft magnetic material is fixed in the center of a cylindrical yoke 1 made of a soft magnetic material, and end magnetic pole pieces 3, 3a are provided on both sides of the central magnetic pole piece 2. Side plates 5 and 5a each made of a soft magnetic material are fixed, and these members make the longitudinal end surface in a plane including the shaft approximately E.
A shaped fixed yoke 4 is formed.

Two electromagnetic coils 7, 7a housed in coil bobbins 6, 6a are disposed within the fixed yoke 4, and these coils 7, 7a are connected in series or arranged so that the same polarity occurs in adjacent parts. wired in parallel. A movable element 8 is located in the center of the fixed yoke 4.
The movable element 8 is supported by the side plates 5, 5a by a shaft 9 provided on the movable element 8 via bearings 10, 10a, respectively. The mover 8 is formed by attaching magnetic pole pieces 12, 12a to both ends of a ring-shaped permanent magnet 11 magnetized in the axial direction. Here, 13, 13a
is a stop ring for fixing the magnetic pole piece.

The magnetic pole pieces 12, 12a have annular portions 14, 12a, respectively.
14a and truncated conical portions 15, 15a. Moreover, the inner peripheral surface of the end magnetic pole pieces 3, 3a is
They are each formed in a substantially similar shape to the truncated conical portions 15 and 15a.

The operation of the actuator with the above configuration is as follows. First, in the electromagnetic coils 7 and 7a,
When the magnetic pole pieces 12 and the magnetic pole pieces of the end magnetic pole pieces 3 are energized so that an S pole is generated in the magnetic pole part of the central magnetic pole piece 2 and an N pole is generated in the magnetic pole parts of the end magnetic pole pieces 3 and 3a. On the other hand, the magnetic pole piece 12a is
It is magnetically attracted to the magnetic pole portion of the end magnetic pole piece 3a.
From this, a thrust force is applied to the movable element 8 in the direction of the arrow X shown in the figure. In addition, the electromagnetic coils 7, 7a
When the direction of energization is switched, a magnetic relationship opposite to that described above occurs, and a thrust force is applied to the movable element 8 in the direction of the arrow Y in the figure.

Here, the magnitude of the thrust changes depending on the relative positional relationship between the magnetic pole portion of the fixed yoke and the movable magnetic pole piece. In other words, the generated thrust is of course proportional to the amount of magnetic flux of the permanent magnet and the magnitude of the current flowing through the electromagnetic coil, but in addition to this, the thrust at each stroke position is affected by the above relative positional relationship. .

That is, the stroke position where the maximum thrust is obtained is the position where the change in permeance of the magnetic circuit is maximum. The position is such that the magnetic pole piece of the mover and the edge portion of the fixed yoke magnetic pole part face each other with different polarities. In the above actuator, this positional relationship is set to provide the optimum thrust characteristic necessary and efficient for locking and unlocking the door, so moderation is overcome in the first half of the total operating distance as shown in Figure 5. The thrust characteristic is that the thrust force is small in the second half, where the thrust force is large and the thrust force is not needed.

In this case, in order to obtain the thrust characteristics shown in FIG. 5, it is necessary to set the dimensional relationship between the fixed yoke and the mover as follows. FIG. 3 is an enlarged sectional view of the main part of FIG. 2 for explaining this dimensional relationship. In FIG. 3, A is the axial length between the end pole pieces 3 and 3a of the fixed yoke 4, B is the axial length of the central pole piece 2 of the fixed yoke 4, and C is the mover pole piece. 12, 12a, D is the outer axial length of the mover pole pieces 12, 12a, lg
1 and 2 show the gap dimensions between the fixed yoke 4 and the movable magnetic pole pieces 12, 12a, respectively.

Between these dimensional elements, the following formula (1) and
Setting the dimensional relationship expressed by equation (2) is necessary to obtain efficient thrust characteristics necessary for locking and unlocking the door.

D, A>C ...(1) B≧C≧lg ...(2) In addition, in order to obtain a more suitable thrust pattern and magnitude, the following considerations should be made regarding the mover 8. preferable.

Here, Fig. 4A shows the positional relationship between the mover magnetic pole piece without a stepped part and the fixed yoke magnetic pole piece, and Fig. 4B shows the positional relationship between the mover magnetic pole piece and the fixed yoke magnetic pole piece with a stepped part. FIG. 3 is an enlarged schematic diagram of the main parts of FIG. 2 for explaining the positional relationship between the two.

When the magnetic pole pieces 12, 12a provided at both ends of the permanent magnet 11 of the mover 8 are shaped without stepped parts as shown in FIG. 4A, a steep peak like the E curve in FIG. 6 is formed. However, the magnetic pole pieces 1 provided at both ends of the permanent magnet 11 of the mover 8 as shown in FIG.
By providing a stepped portion on the inner outer periphery of the thrusters 2 and 12a, a smooth thrust-stroke characteristic as shown by the F curve in FIG. 6 can be obtained.

In Fig. 4A, the magnetic pole piece edge portion u of the mover 8 and the center magnetic pole piece 2 when the mover 8 is at the right end.
The distance from the magnetic pole piece edge y to the magnetic pole piece edge part y is a, and in FIG. Let the distance be b. First, in FIG. 4A, the thrust force is generated when the movable element 8 moves in the direction of the arrow shown in the figure, and the magnetic pole piece edge part u of the movable element 8 and the magnetic pole piece edge part y of the central magnetic pole piece 2 face each other with different polarities. of
If Fa, the gap length is shorter than when the magnetic pole piece edge part u of the mover 8 and the magnetic pole piece edge part y of the center magnetic pole piece 2 face each other with different polarities at other positions, so the thrust force Fa is Showing the maximum value, the 6th
As shown by curve E in the figure, although the maximum thrust is large, smooth characteristics cannot be obtained.

In this way, the magnitude of the thrust changes depending on the relative positional relationship between the magnetic pole part of the fixed yoke and the movable element magnetic pole piece. In other words, the generated thrust is of course proportional to the amount of magnetic flux of the permanent magnet and the magnitude of the current flowing through the electromagnetic coil, but in addition to this, the thrust at each stroke position is affected by the above relative positional relationship. . That is, the stroke position where the maximum thrust is obtained is the position where the change in permeance of the magnetic circuit is maximum. This position is such that the edge portions of the magnetic pole piece of the mover and the magnetic pole piece of the yoke are opposite to each other and have different polarities.

Next, in FIG. 4B, where stepped portions are provided on the magnetic pole pieces 12, 12a of the mover 8, when the magnetic pole piece edge portion z of the mover 8 and the magnetic pole piece edge portion y of the central magnetic pole piece 2 are opposed to each other, The thrust of Fb is the magnetic pole piece edge part w of the mover 8 and the magnetic pole piece stepped edge part y of the central pole piece 2.
If the thrust when they face each other is Fc, then this thrust
Since the maximum thrust is generated at the two points Fb and Fc, a smooth and good thrust-stroke characteristic as shown in the curve F in FIG. 6 can be obtained.

In addition, in the above actuator, the permanent magnet is demagnetized by the influence of the demagnetizing field generated in the electromagnetic coil, so in order to obtain a predetermined thrust,
It is preferable to keep demagnetization to a minimum. For this purpose, for example, it is preferable to use a rare earth magnet with a BHc of 78000e or more, and it is particularly preferable to use an RC _05- based rare earth magnet. This rare earth magnet has a higher maximum energy product and higher residual magnetic flux density than other permanent magnets, so it is effective in reducing the size and weight of the drive device.

As described above, the present invention can be expected to provide a door lock actuator that provides the following effects as a whole, and can be said to be a device with excellent practical effects.

(1) Necessary and sufficient thrust characteristics can be obtained for a door lock actuator, and it can also be made smaller and lighter.

(2) Since the thrust at the end of the operation can be set small,
Operator is small.

[Brief explanation of the drawing]

Fig. 1 is a thrust characteristic diagram of a conventional electromagnetic solenoid door lock actuator, Fig. 2 is a longitudinal sectional front view showing an embodiment of the door lock actuator of the present invention, and Fig. 3 is the main part of Fig. 2. The enlarged cross-sectional view in Figure 4A shows the positional relationship between the mover magnetic pole piece without a stepped part and the fixed yoke, and Figure 4B shows the positional relationship between the mover magnetic pole piece with a stepped part and the fixed yoke. Fig. 2 is an enlarged schematic diagram of the main parts to explain the above, Fig. 5 is a diagram showing the thrust force characteristics necessary for locking the door, and Fig. 6 is a diagram showing the thrust force characteristics necessary for locking the door. FIG. 3 is a diagram showing thrust characteristics of a door lock actuator according to an embodiment of the invention. 1... Cylindrical yoke, 2... Central magnetic pole piece, 3, 3
a...End magnetic pole piece, 4...Fixed yoke, 5, 5a
... Side plate, 6, 6a ... Coil bobbin, 7, 7a ... Electromagnetic coil, 8 ... Mover, 9
... shaft, 11 ... permanent magnet, 12, 12a ... magnetic pole piece.

Claims (1)

[Claims for Utility Model Registration] (1) In a yoke whose longitudinal end face in a plane including the axis is formed into a substantially E shape, two electromagnetic coils are connected via a coil bobbin so that the same polarity occurs in adjacent parts. A reciprocating drive means is provided in which a movable element having an axially magnetized permanent magnet and a pair of magnetic pole pieces provided at both ends is attached to the center of the yoke so as to be movable in the axial direction. 1. A door lock actuator comprising: a stepped portion formed on the inner outer peripheral surface of a pair of magnetic pole pieces provided at both ends of the permanent magnet of the movable member. (2) The actuator for a door lock according to claim 1 of the utility model registration, characterized in that the dimensional relationship between the yoke and the mover is determined as follows. D, A>C B≧C≧lg However, A: Axial length between the end magnetic pole pieces of the fixed yoke B: Axial length of the central pole piece of the fixed yoke C: Axial length between the end magnetic pole pieces on the outer peripheral surface of the mover D: Axial length of mover lg: Gap between E-type fixed yoke inner circumferential surface and mover outer circumferential surface