JPS6348919Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a float switch for measuring the liquid level, and more specifically, it is a switch holding type float that eliminates hunting of the switch due to floating of the float due to the wave motion of the liquid level. It's about the switch.

As shown in FIG. 1, a conventional general float switch has an annular magnet 2 installed inside an annular hollow float 1, and as the liquid level rises and falls, this float 1 moves a stopper 4 of a hollow float guide 3.
When moving up and down along the guide, the reed switch 5 installed inside the float guide 3
The structure is such that an electrical signal is generated by opening and closing.

However, in the case of the above-mentioned structure, the float 1 hunts up and down when the liquid level fluctuates as shown in FIG. If the float 1 approaches the reed switch 5 in such a state, the contact point of the reed switch 5 will also hunt in the same way. This results in various problems such as the lifespan of the contacts and the need to provide an electrical delay holding circuit on the load side.

In order to eliminate such drawbacks, for example,
As shown in Publication No. 52-113250, a reed switch is installed inside the rod, and an annular magnet is attached via a magnetic member to the outside of the reed switch attachment point at a position where the reed switch is moved, and the buoyancy of the float lowers the liquid level. The magnetic shield plate is connected with a string so that it moves up and down as the liquid level rises, and the shield plate is inserted between the magnet and the reed switch at the upper limit position of the liquid level, and the shield plate is held by the magnet. As the float descends, the float rides on the plate and the mass of the float, plate, and string is applied to the plate, and the magnetic shield plate is removed from the magnet. A liquid level switch that prevents hunting has been proposed. However, the configuration of this switch makes it difficult to operate smoothly due to slack and inclination between the string and float and between the plate and rod, and current flows through the reed switch contacts while the liquid level is not above the upper level, which is not energy efficient. There are drawbacks such as.

This invention aims to eliminate the above-mentioned drawbacks, and its features include a ring-shaped float, a float core that is inserted into the float, and has a float stopper formed at each upper and lower part and a magnet mounted thereon. , a core guide which is inserted into the core and has a core stopper formed near each of the upper and lower ends, and a magnetic sensing element is installed therein; a magnet is attached to the lower part of the upper stopper of each of the core stoppers; The present invention provides a float switch characterized in that a magnetic material is attached to the upper part of the upper stopper. An embodiment of this invention shown in the drawings will be described in detail below.

The float switch for a liquid level gauge of this invention has a hollow annular float 11 and a float stopper 1 inserted in the float at the upper and lower ends, as shown in Fig. 3.
3a and 13b, and a cylindrical float core 12 made of a lightweight non-magnetic material such as synthetic resin, with an annular magnet 14 inside or connected to a part thereof.
, a hollow core guide 15 made of synthetic resin that is inserted into the core and has core stoppers 16a and 16b attached near the upper and lower ends, and has a reed switch 17 inside, a magnetic member 18 attached to the float stopper 13a, and a core stopper. 16a
It consists of a magnet 19 attached to the.

The float switch 20 of this invention is constructed as described above, and as shown in FIG.
It is inserted into the container through the opening 23 in the ceiling plate 22 and fixed with the flanges 24a and 24b.

FIG. 3 shows a state in which the liquid level in the container has fallen and the core 12 is in contact with the core stopper 16b and the float 11 is in contact with the float stopper 13b. 17 is not closed.

After passing through the state shown in FIG. 4, the liquid level rises, and as shown in FIG. 5, the float stopper 1 of the core 12
The float 1 contacts the core 3a, and the core 12 is raised along the core guide 15 by the buoyancy of the float, and the magnet 1 is moved at a position where the float stopper 13a of the core contacts the core stopper 16a.
More of the magnetic lines of force No. 4 pass through the reed made of magnetic material constituting the reed switch 17 to close the reed switch 17 and notify that the liquid level has reached the upper limit.

In this state, the core 12 is attracted and restrained by the magnet 19 via the magnetic member 18, and even if the float 11 hunts up and down due to the wave motion of the liquid level, the core 12 with the magnet 14 inside is held by the float stopper 13a. Therefore, the reed switch 17 remains closed and does not hunt.

After this, the liquid level drops as shown in Figure 6,
Even if the unrestrained float 11 hunts as shown by the chain line in the figure as the liquid level falls, the reed switch 17 remains closed. When the liquid level falls further from this point, the sum of the weights of the float 11 and the core 12 becomes larger than that of the magnet 19 and the magnetic member 1.
As shown in FIG. 3, the magnet 19 and the magnetic member 18 are disengaged from each other and the core 12 descends along the core guide 15. switch 17
is opened and the core 12 is opened as shown in FIG.
The float 11 is in contact with the core stopper 16b and the float stopper 13b. Note that a magnetic sensing element such as a Hall element may be used in place of the reed switch 17.

As mentioned above, this idea consists of an annular float, a float core that is inserted into the float and has a float stopper formed at each upper and lower part and a magnet mounted thereon, and a core stopper that is inserted into the core and has a core stopper formed near each of the upper and lower ends. The core guide is equipped with a magnetic sensing element, and a magnet is attached to the lower part of the upper stopper of each of the core stoppers, and a magnetic material is attached to the upper part of the upper stopper of each of the float stoppers. Since the provided core is adsorbed and restrained by the magnet of the core stopper, hunting of the reed switch will not occur even if the float is hunted due to wave motion on the liquid level.As a result, the life of the reed switch will be extended, malfunctions will be less likely to occur, and the float stop will be prevented from hunting. Since the par is integrated with the float core, it does not tilt with respect to the core guide, and both the float core and the float operate smoothly.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional float switch, Fig. 2 is an explanatory diagram of the hunting phenomenon caused by a conventional float switch, and Figs. 3 to 6 are cross-sectional views showing the structure and operation of the float switch of this invention. It is. 11...Float, 12...Float core,
13a, 13b...Float stopper, 14,
19...Magnet, 15...Core guide, 1
6a, 16b... Core stopper, 17... Reed switch (magnetic sensing element), 18... Magnetic member,
20...Float switch.

Claims (1)

[Scope of utility model registration request] An annular float 11 and float stoppers 13a, 13 inserted into the float 11 and provided at upper and lower parts.
It consists of a float core 12 with a magnet 14 mounted thereon, and a core guide 15 which is inserted into the core 12 and has core stops 16a and 16b formed near each of the upper and lower ends, and has a magnetic sensing element 17 installed therein. A float switch characterized in that a magnet 19 is attached to the lower part of the upper stopper 16a of the core stoppers 16a and 16b, and a magnetic material 18 is attached to the upper part of the upper stopper 13a of the respective float stops 13a and 13b.