JPH0518214B2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Field of Application of the Invention The present invention relates to a sealed switch, particularly a switch that uses a conductive liquid such as mercury, an alkali metal alloy, or a gallium alloy as a contact point. It is possible to open and close an electric circuit by tilting the body in any direction from the normal posture, and in this case, the angular difference between the operating angle and the return angle can be selected in advance according to the purpose, and the movement of the conductive liquid. The purpose is to expand the use of this type of switch by applying the influence of surface tension to the component force of gravity to ensure stability and eliminate inconveniences such as chattering.

(2) Conventional technology and problems Conventionally, in this type of switch, a closed body is constituted by, for example, a mortar-shaped container and a lid plate that closes the upper opening end of the container, and a conductive liquid is placed inside the closed body. It is extremely difficult to select the difference between the operating angle and the return angle depending on the purpose, and the difference in angle is very small. There were disadvantages such as a chattering state occurring when the sexual liquid came into contact with or separated, resulting in abnormal heat generation. In contrast, a device as shown in FIG. 8 has been known to improve the tilting operation in a specific direction. That is, in FIG. 8, a cylindrical glass container 81 with both ends closed is bent into a dogleg shape at its central portion 82, and a conductive liquid 8 is contained inside.
8 and a pair of electrodes 83 and 84 are sealed and fixed to the right end. In the illustrated state, this switch is open between the integrated electrodes, but when the right end is tilted downward, that is, clockwise, the bottom 85 on the left side of the center portion 82 becomes horizontal, and beyond this, the conductive liquid 88 The conductive liquid 88 begins to move to the right and a portion of the conductive liquid 88 exceeds the central portion 82. The conductive liquid 88 suddenly accelerates and completes its movement so as to close the pair of electrodes 83 and 84 in a snap-like manner. It is easy to understand that a snap-like motion can be obtained even when the switch is tilted counterclockwise. However, in the case of a switch that operates by tilting in any direction rather than a switch that operates by tilting in a specific direction, the shape of the container is different from the closed container shown in FIG. This requires a different technical concept from that of the past.

(3) Structure of the invention and means for solving problems The tilt-operated switch of the present invention has a contact that is closed in the normal position (hereinafter referred to as normally closed type).
or open (hereinafter referred to as normally open type), and when the operating angle is tilted from the normal posture to a preset angle, for example 45 degrees, in any direction, the normally closed type will open. In addition, if the normally open type is closed, then if the angle difference is set in advance, for example, 15 degrees, the normally closed type will close or In the case of a normally open type, a narrow part is formed in the middle of the path through which the conductive liquid flows so that the influence of surface tension acts, so that the force that causes the conductive liquid to move due to the component force of gravity is combined with the force that causes the conductive liquid to move. It provides stable and reliable movement through its working effect.

(4) Embodiments and operations of the invention As shown in the longitudinal section in FIG. 1, a hole 12 is bored in the center of a cover plate 11 made by drawing and forming a relatively thick iron plate, and a hole 12 is formed in the center of the cover plate 11, and a hole 12 is formed in the center of the cover plate 11, and a material such as glass or ceramic is inserted into the cover plate 11. An electrode 14 hermetically sealed with an electrically insulating filler 13 is provided, and the lid plate 11 has an intermediate portion 15 in the radial direction formed from the inner surface of a mortar-shaped container 16 made of a relatively thin iron plate. It has a stepped shape that approaches. The lid plate 11 and the container 16 are joined to each other near the outer periphery 17 by a method such as ring projection welding to form a hermetically sealed container. 18 is injected and placed in an atmosphere such as an inert gas or hydrogen that prevents contamination such as oxidation of mercury, and the sealing process by bonding described above is performed.

When a droplet is placed on a solid surface, the droplet 68 does not wet the fixed surface 66 (that is, the contact angle Θ ₁ is an obtuse angle) and has a nearly spherical shape on the solid surface 66, as shown in FIG. In some cases, the droplet 78 takes the shape of a solid surface 76 and spreads out (the contact angle Θ ₂ is an acute angle) as shown in FIG. This takes advantage of the dry condition. In order to create a state in which the droplets do not get wet, it is preferable that the container be made of a material that does not easily form an alloy with the conductive liquid, and that the surface of the container that comes into contact with the conductive liquid be roughened.

Rolling droplets have little loss, so even if they are tilted slightly (for example, by 1 degree) from horizontal, they will move lower. However, when the switch in the normal position shown in Figure 1 is tilted to the right, In this case, even if the mortar-shaped right inclined surface passes through the horizontal reference line 29 as shown in FIG. Doesn't flow. This is because the rightward propulsive force, which is a component of gravity acting on the mercury droplet 18, does not exceed the surface tension acting on the narrow portion 15 at the right end of the mercury droplet 18, which opposes this force. When the switch is tilted further clockwise and the angle A in Fig. 2 becomes, for example, 7 to 8 degrees, the component of gravity, that is, the propulsive force, is absorbed by the surface tension and once the mercury drop 1
When the right end of the mercury droplet 8 passes through the narrow part 15, the mercury droplet 18 suddenly increases its speed and moves to the right end of the container as shown by the dotted line in FIG. That is, even if the switch is tilted very slowly, its contacts will snap open from the closed state. In other words, once the right end of the mercury drop passes through the narrow part 15, its surface tension acts on the wide part, so the force that opposes the propulsive force decreases rapidly, and the left end of the mercury drop becomes narrower and the surface tension acting there This is because it adds to the propulsion force. This condition increases as the droplet moves to the right, so even if the inclination angular velocity of the switch is extremely small, the movement of the droplet is stable and reliable, and chattering of the contacts can be prevented. Next, in the process of returning the switch to its normal position, the process is completely reversed to that described above, and the slope of the mortar on the right side of the switch container 16 exceeds the horizontal reference line 29, for example, from 7 to 7.
When the temperature passes 8 degrees, the left end of the mercury droplet 18 is the narrow part 1.
5, its movement is accelerated, and it moves steadily and reliably toward the center, and the contact is closed again, although this is not shown in the figure, but it can be easily understood. The operating angle of this switch mainly depends on the angle of the mortar-shaped slope, and the difference between the operating angle and the return angle depends on the gap size of the narrow part. If the droplet wets the fixed surface very well (as shown in Figure 7), even if the narrow part is made extremely narrow, there will be almost no difference in angle between movement and return, and the droplet will simply pass through the narrow part. As the time becomes longer, the effect of the present invention in preventing contact chatter cannot be expected at all.

The switch shown in FIG. 3 is another embodiment of the present invention and differs from the switch shown in FIG. 1 in the shape of the cover plate. The center of the lid plate 31 shown in FIG. 3 is easier to draw than that shown in FIG. 1. Narrow part 35 in this case
This corresponds to the outer periphery of the end face of the central hole 32. An electrode 34 is sealed in the central hole 32 with an electrically insulating filler 33. Conductive liquid 3
The container 36 in which the 8 is housed and the lid plate 31 are joined together near the outer periphery 37 using the same method as described above to form a sealed container body. The switch of this embodiment allows a large creepage distance of the electrically insulating filler 33 and is suitable for manufacturing a small switch.

The other embodiment shown in FIG. 4 differs in the shape of the container compared to the one in FIG. That is, while the mortar of the container 36 shown in FIG. 3 has a substantially straight generatrix, the mortar in FIG.
Even if the gap between the actuator and the container 46 is made wider than that shown in FIG. 3, the difference between the operating angle and the return angle can be selected to be large. Although not shown in the drawings, as another embodiment which provides a similar effect, the shape of the container may be shaped like a mortar, with the generatrix being a straight line with different angles above and below the narrow part. The symbols shown in FIG. 4 indicate that an electrode 44 is sealed in a central hole 42 of a cover plate 41 with an electrically insulating filler 43, and that the cover plate 41 and the container 46 are connected to each other near their respective outer peripheries 47. They are joined together to form a hermetically sealed body, in which a conductive liquid 48 is housed.

In another embodiment shown in FIG. 5, the electrode 54 has an annular portion 54A along a portion substantially near the outer periphery of the sealing body, and this is arranged to be electrically insulated from the sealing body. When the conductive liquid 58 is in its normal position, it is placed in the recess at the center of the container 56 as shown in the figure, so there is a gap between the contacts, which closes when tilted at a predetermined angle in any direction. As shown in the figure, a hole 52 is formed in the cover plate 51 near the outer periphery, and an electrode 54 is sealed and fixed therein with an electrically insulating filler 53. The shape of the container 56 is convenient for accommodating the electrode having the annular portion 54A in a non-contact manner. The lid plate 51 having the narrow portion 55 and the outer circumferential portion 57 of the container 56 are joined to each other to form a single closed container body. This embodiment is a so-called normally open type switch.

As mentioned above, the shape of the container can be various, such as a mortar shape, a morning glory shape, or a shape with different inclination angles above and below the narrow part, but the present invention is applicable as long as the shape widens upward from the center part toward the outer periphery. It is possible to apply the gist of

(5) Effects of the Invention As described above, the present invention provides a conductive device that performs a switch operation when tilted at a predetermined angle in all directions from a normal posture, and the switch is returned when returning to the original normal posture. In a tilt-operated switch using a liquid, it is possible to preselect an arbitrary angular difference between the operating angle and the return angle, and furthermore, it is possible to prevent contact chattering during operation and return. This is extremely effective in expanding the range of uses.

[Brief explanation of the drawing]

FIG. 1 shows a longitudinal sectional view of an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view illustrating the operation of the embodiment of FIG. FIGS. 3 to 5 are longitudinal cross-sectional views showing other different embodiments. FIGS. 6 and 7 are side views for explaining the wettability of a conductive liquid on a solid surface. FIG. 8 is a side view for explaining the operation of a conventionally known switch. 11, 31, 41, 51... Lid plate, 12, 3
2, 42, 52... hole, 13, 33, 43, 53
... Filler, 14, 34, 44, 54 ... Electrode,
15, 35, 45, 55... Narrow area, 16, 3
6,46,56...container, 17,37,47,5
7... Near the outer periphery, 18, 38, 48, 58... Conductive liquid.

Claims (1)

[Claims] 1. A conductive liquid is contained in a sealed container body in which a container having a portion that expands upward from the center toward the outer periphery and a lid plate that closes the upper opening end of the container are hermetically joined near the outer periphery of each container. The cover plate is provided with a hole, and an electrode hermetically sealed with an electrically insulating filler is fixed in the hole, and the conductive electrode is fixed inside the sealing body. The liquid is selected to have an almost free surface except for the lower side in contact with the sealed vessel body, and the area in contact with the electrode is selected such that the liquid has an almost free surface, and a part corresponding to the middle of the range in which the liquid moves is located between the inner surface of the container and the lid. The space between the inner surface of the plate is narrowed, and when the conductive liquid moves across this narrow portion, the free surface area of one side increases and the free surface area of the other side decreases. Due to the surface tension of the conductive liquid, the conductive liquid performs a snap-like motion when it comes into contact with or separates from the electrode, giving a preselected angular difference between the operating angle and the return angle and stable and reliable movement. A tilt-operated switch characterized by: