JPH0440253Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This device is a solenoid, mainly for attaching and detaching heads,
This relates to an improvement to a noise-reducing solenoid used in products where the impact noise generated when the plunger constituting the solenoid is attracted, such as when a pressure plate is attached or detached, is a problem.

[Conventional technology]

Conventionally, a solenoid shown in FIG. 7 has been known as a solenoid designed to suppress noise as described above. That is, FIG. 7 is a cross-sectional view showing the structure of a conventional solenoid 1. In the figure, 2 is a cylinder made of non-magnetic material such as brass, and both ends are connected to guide plates 3 and 4.
A spool 5 fixed to is formed, and a winding 6 is wound around this spool 5 in the direction in which the suction force is applied. The suction end of this spool 5 is fixed to the bottom part 8 of a bottomed cylindrical yoke 7 provided on the outside of the spool 5, and the other end is fixed to a stop plate 9 fitted into the opening of the yoke 7. The stop plate 9 forms a closed magnetic path. On the other hand, the reference numeral 10 in the figure is a plunger made of a bar-shaped iron material, and this plunger 10 has one end protruding from the cylinder 2 toward the stop plate 9, and has a connecting portion 10 to other parts.
a, a scraped-off portion 10b is formed at the tip of this connecting portion 10a, and a pin 11 is provided perpendicularly to the scraped-off portion 10b.
In addition, the gap between the plunger 10 and the cylinder 2 is made as small as possible to suppress air circulation. Therefore, in order to vent air when the plunger 10 is sucked, a ventilation groove 12 is provided on the outer surface of the plunger 10 along the axial direction. is formed from the tip to the scraped-off portion 10b of the connecting portion 10a.

Furthermore, a rubber washer 13 for cushioning the impact force during suction is attached to the connecting portion 10a of the plunger 10.
It is fixed by a retaining ring 14, and the clearance A is maintained in the suction state so that the suction end of the plunger 10 does not come into contact with the guide plate 3.

[Problems to be solved by the invention] However, in the conventional solenoid 1 described above, the rubber washer 13 is used as a stopper to buffer the impact force when the plunger 10 sucks. ,
Since the amount of plastic deformation differs depending on the length of the latching time, the clearance A must be configured taking into account the difference in the amount of deformation, and the latching force decreases accordingly, and the rubber washer 13 itself Since it does not have the effect of reducing the impact force, but merely buffers it, it is not practical as a countermeasure against sound during a collision.

Further, in order to fix the rubber washer 13 to the plunger 10, an E-type retaining ring 14 is required,
The number of assembly steps also increases.

Therefore, the present invention has been devised by focusing on the problems of the related art, and it solves these problems by alleviating the impact itself when the plunger is sucked, thereby reducing the impact sound, and also reduces the latching force. The purpose of the present invention is to provide a solenoid that increases the efficiency, eliminates the number of assembly steps, and achieves miniaturization and energy savings.

[Means for trying to solve problems]

In order to achieve this object, the solenoid according to the present invention is a solenoid having a plunger having a ventilation groove formed along the axial direction on the outer surface, in which the ventilation groove is formed halfway up the plunger, and the ventilation groove is formed halfway up the plunger. It is characterized by forming a damper part following the groove.

[Effect]

By forming the damper part continuously by extending the ventilation groove formed in the plunger to the middle of the plunger as described above, it is possible to reduce the impact itself when the plunger is sucked, and therefore to reduce the impact noise. Additionally, there is no need to provide special clearance, which increases the latch force, and the rubber washer and the E-type retaining ring that fixes the rubber washer are also no longer required, reducing the number of assembly steps.
Further, by setting the same latch force as the conventional one, it is possible to reduce the size and save energy by eliminating the clearance.

〔Example〕

Next, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 6.

FIG. 1 is a sectional view of a solenoid 20 according to a first embodiment of the present invention, in which reference numeral 21 denotes a cylinder made of non-magnetic material such as brass, and a spool whose both ends are fixed to guide plates 22 and 23. 24 is formed, and a winding 25 is wound around this spool 24 in the direction in which the suction force is applied. Also, this spool 24
The guide plate 22 which becomes the suction end of the spool 2
The guide plate 23 is fixed to the bottom part 26a of a bottomed cylindrical yoke 26 provided on the outside of the yoke 4, and the guide plate 23 at the other end is in pressure contact with a stop plate 27 fitted into the opening of the yoke 26. A closed magnetic path is formed by the stop plate 27.

On the other hand, reference numeral 28 in the figure is a plunger made of a bar-shaped iron material, and this plunger 28 has a connecting part 28a with other parts that projects toward the stop plate 27 at one end, and the tip of this connecting part 28a is A scraped-off portion 28b is formed, and a pin 29 is provided perpendicularly to the scraped-off portion 28b. In addition, the gap between the plunger 28 and the cylinder 21 is made as small as possible to suppress air circulation. Therefore, in order to vent air when the plunger 28 is sucked, a ventilation groove is provided on the outer surface of the plunger 28 along the axial direction. 30 is formed. This ventilation groove 300
is formed approximately halfway from the suction end of the plunger 28, and the rear end communicates with a communication hole 31 that is orthogonal to the axial direction of the plunger 28. One end is opened in the communication hole 31, and the connecting portion 28a of the plunger 28 is connected to the connecting portion 28a of the plunger 28. A small-diameter cylindrical hole 32 is formed as a damper portion, penetrating through it and having the other end open at the scraped-off portion 28b.
That is, according to the solenoid 20 according to the first embodiment, when the plunger 28 is sucked, the air inside the cylinder 21 flows from the ventilation groove 30 to the communication hole 3.
1 and is constricted by the cylindrical hole 32 and exhausted, thereby alleviating the impact caused by the suction of the plunger 28. In addition, since the suction end of the plunger 28 acts as a stopper and there is no need to set a special clearance, the latching force is increased by the clearance compared to the conventional one, as shown in Fig. 3.
As shown in FIG. 4, the impact force (or acceleration) of the plunger 28 draws a gentle curve.

FIG. 5 shows a second embodiment of the present invention, which is a plan view of the plunger 33. This plunger 33 forms a connecting portion 33a;
Form a scraped part 33b on the line 3a and insert the pin 2.
9 is provided in the vertical direction, but the ventilation groove 34 is formed in a triangular shape with the suction end side being widest and gradually narrowing, and continuous with the ventilation groove 34 as a damper part. The orifice is narrowed down to 35.

Further, FIG. 6 shows a third embodiment of the present invention, and is a sectional view of the plunger 36. This plunger 36 is a modification of the first embodiment, in which a ventilation groove 30 and a communication hole 31 are formed, and a cylindrical hole 32a that opens at one end to the communication hole 31 is made slightly wider, so that an air can be left inside the cylindrical hole 32a. A sintered metal 37 having holes is press-fitted, and the sintered metal 37
is made to face the scraped-off portion 36b of the connecting portion 36a.

[Effect of idea]

As described above, according to the solenoid according to the present invention, by forming the damper portion with a narrow passage following the ventilation groove, the impact during suction of the plunger is alleviated, so the impact noise is reduced, and
Latching force is increased without the need for special clearance. Furthermore, if the latch force is set as before, the product will be smaller due to the lack of clearance.
Energy saving can also be achieved. Further, the rubber washer and the E-shaped retaining ring for fixing the rubber washer are also unnecessary, and the number of assembly steps is also reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a solenoid showing the first embodiment of the present invention, Fig. 2 is a sectional view of the same plunger, and Fig. 3 is a sectional view of the solenoid according to the first embodiment of the present invention.
The figure is a graph comparing the latching force of the product of the present invention and the conventional product. Figure 4 is a graph comparing the impact force or acceleration of the plunger. Figure 5 is a plan view of the plunger showing the second embodiment. The figure is a sectional view of a plunger showing the third embodiment, and FIG. 7 is a sectional view of a solenoid showing a conventional example. 20...Solenoid, 21...Cylinder, 2
4...Spool, 25...Winding, 26...Yoke, 28, 33, 36...Plunger, 30,3
4... Ventilation groove, 31... Communication hole, 32, 32a...
... cylinder hole, 35 ... orifice, 37 ... sintered metal.

Claims (1)

[Claims for Utility Model Registration] (1) In a solenoid having a plunger having a ventilation groove formed along the axial direction on its outer surface, the ventilation groove is formed halfway up the plunger,
A solenoid characterized by forming a damper part following the ventilation groove. (2) The solenoid according to claim 1, wherein the damper portion is a cylindrical hole with a small diameter formed in the plunger through a communication hole that communicates with the rear end of the ventilation groove. (3) The solenoid according to claim 1, wherein the damper portion is continuous with a ventilation groove whose width gradually becomes narrower, and is constricted into a generally triangular shape. (4) The damper portion has the cylindrical hole with a slightly wide diameter;
The solenoid according to claim 2, characterized in that the solenoid is press-fitted with a sintered metal having holes inside.