JPS5911393Y2 - Float switch for detecting the second position of liquid level - Google Patents

Description

[Detailed Description of the Invention] (1) Purpose of the Invention The present invention relates to a float switch for detecting two positions of a predetermined upper limit and a predetermined lower limit of a liquid level.

Conventionally, there have been float switches that use the inclination of the float to move a movable magnet to open and close the contacts of an internal reed switch, but the conventional ones have a sliding guide tube 4' and movable magnets 1 and 9'. Since the fitting portion has a simple fitting structure as shown in FIG. 5, there is a problem especially when the control width is wide.

That is, when the liquid has not yet reached the predetermined amount and the float 1' is only slightly inclined, the movable magnet 9' will slide and actuate the reed switch 8'. This results in early activation of the barrier.

In addition, in the conventional float switch described above, the movable magnet 9' is fitted to the outer periphery of the sliding guide tube 4' which also serves as a switch holding tube. Furthermore, even if a small amount of water intrudes into the float 1' to the extent that it does not impair the buoyancy of the float, there is a drawback that the sliding operation of the movable magnet 9' will be immediately hindered. .

The purpose of this invention is to eliminate these conventional drawbacks, provide excellent operational stability, ensure the ability to detect the second position of the liquid level, and prevent buoyancy from being lost even if water enters the float. An object of the present invention is to provide a flow 1 switch which does not interfere with the sliding operation of a movable magnetic strip.

(2) Structure of the invention In the float switch for detecting the second position of the liquid level according to the invention,
A switch holding cylinder is installed inside a sliding guide cylinder installed vertically inside a hollow sealed float whose buoyancy position changes as the liquid level increases and decreases, and an annular groove is formed on the outer periphery of the cylinder. a fixed magnet is disposed near the outer circumferential surface of the annular groove or the groove end, and a reed switch that is normally closed by the action of the fixed magnet is accommodated in the switch holding tube;
In addition, a movable magnetic cylinder that can be fitted into the annular groove is housed in a sliding guide cylinder, and the movable magnetic cylinder moves in a direction approaching the reed switch and the fixed magnet due to a change in the attitude of the float as the liquid level increases or decreases. In a structure in which the contacts of the reed switch are opened and the contacts of the reed switch are closed or returned by moving in the opposite direction to the above, the cylinder end of the sliding guide cylinder housing the movable magnetic cylinder and By attaching a protruding brake element facing h and having a slight arc-shaped or inclined deleted part on the outer periphery of the cylinder end of the movable magnetic cylinder facing the raised brake element, the deleted part can be removed. A sliding starting point is formed between the opposing surfaces of the raised brake element and the raised brake element.

To explain the drawings, 1 is a hollow hermetic float that is moored by an electric wire 3 inserted from an electric wire insertion port 2 and whose floating position changes as the liquid level increases; It is a vertically installed sliding guide tube, and in order to smooth the sliding movement of the movable magnetic tube 9 described later, a material with good sliding properties such as nylon resin is pasted on the inner peripheral surface.

5 is a switch holding tube installed inside the sliding guide tube 4 so as to communicate with the wire insertion port 2 opened at one end, 6 is an annular groove formed on the outer periphery of the switch holding tube 5, and 7 is an annular groove. A fixed magnet 6 is disposed near the outer peripheral surface or the groove end, and 8 is a reed switch housed in the switch holding cylinder 5 so as to be kept in a normally closed state by the action of the fixed magnet 7. It is connected to the core wires 3a and 3b of the inserted electric wire 3 within the switch holding tube 5.

Reference numeral 9 denotes a movable magnetic cylinder which is housed within the sliding guide cylinder 4 so as to fit into the annular groove 6 and is movable along the guide cylinder 4 in the axial direction.

A raised brake 10 is attached to the inner circumferential surface of the sliding guide cylinder 4 at a predetermined position so as to face the end of the movable magnetic cylinder 9. Magnetic cylinder 9
The outer periphery of the cylindrical end is provided with a slight arcuate or inclined cutout 11, and a sliding start point 12 is formed between the cutout 11 and the facing surface of the raised brake element 10. This prevents the movable magnetic cylinder 9 from operating prematurely.

Furthermore, reference numeral 13 designates an internal auxiliary float that is provided around the outer periphery of the sliding guide cylinder 4 within the hollow hermetic float 1, and is made of a single-hole foamed resin, foamed rubber, or the like.

The node switch 8 is connected to the core wires 3a and 3b of the inserted electric wire 3 and separately communicated with a control engine.

The electric wire 3 is fixed at a predetermined position in the liquid tank with a suitable fixture, and the flexibility of the wire from the fixed part to the neck of the float 1 is used to move the float 1 up and down in response to increases and decreases in the liquid level. Alternatively, the electric wire 3 may be inserted into a tubular arm (not shown) rotatably supported at a predetermined position in the liquid tank, so that the tubular arm tilts as the liquid level increases or decreases. The float 1 may be tilted up and down using the support point of the arm as a fulcrum.

When the liquid level in the liquid tank reaches a predetermined lowering limit l1, the float 1 is in a downwardly inclined state as shown in FIGS. 1 and 4A, and the movable magnetic cylinder 9 is connected to the reed switch 8 and Since the reed switch 8 is located away from the magnet 7, the contacts of the reed switch 8 are kept closed by the magnetic force of the magnet 7.

However, as the liquid level begins to rise, float 1 also gradually rises,
As the float 1 approaches a predetermined rise limit, the float 1 tilts upward, and when the liquid level approaches the predetermined rise limit, the removed portion 11 of the movable magnetic cylinder 9 attempts to exceed the sliding start point 12, as shown in FIG. do.

Then, the liquid level reaches a predetermined rise limit 1. At the same time, the movable magnetic tube 9 moves in the direction approaching the reed switch 8 and the magnet 7 as shown in FIGS. 2 and 4B.
The magnetic lines of force of the magnet 7 are blocked, and the contacts of the reed switch 8 become open.

Next, when the liquid level starts to fall again, float 1 will also gradually fall.
As the float 1 approaches a predetermined lower limit, the float 1 tilts downward, and when the liquid level approaches the predetermined lower limit, the removed portion 11 of the movable magnetic cylinder 9 attempts to exceed the sliding start point 12.

As soon as the liquid level reaches a predetermined lowering limit l1, the movable magnetic cylinder 9 moves in a direction away from the reed switch 8 and the magnet 7 as shown in FIGS. 1 and 4A, and the magnetic force of the magnet 7 causes the reed switch to Contact point 8 returns to the closed state.

In this way, the liquid level reaches the predetermined lowering limit l1 or rising limit l.
A single float switch detects when the liquid level reaches 2 and controls the liquid level to the 2nd level.

(3) Effects of the invention In the float switch of the invention, since the movable magnetic cylinder 9 is housed in the sliding guide cylinder 4, the float 1
Even if a small amount of water enters the inside, it will not interfere with the sliding movement of the movable magnetic cylinder 9.

In addition, raised brakes 10 are attached to the inner circumferential surface of the sliding guide tube 4 at required positions to prevent premature activation of the movable magnetic tube 9. Even when the control width is wide, the liquid level detection function is accurate, and the upper and lower limits of the liquid level can be reliably detected with a single float switch.

[Brief explanation of drawings]

Figure 1 is a longitudinal side view of the float switch of the present invention in a downwardly tilted state, Figure 2 is a longitudinal side view of the float switch of the present invention in an upwardly tilted state, and Figure 3 is the start of sliding of the movable magnetic tube in the float switch of the present invention. Longitudinal side view showing points;
FIG. 4 is an explanatory diagram showing the operating state of the float switch of the present invention, where A indicates the lower limit operation and B indicates the upper limit operation. FIG. 5 is a longitudinal sectional side view of the main part showing the operating state of a conventional float switch, with A showing the downward tilting operation and B showing the upward tilting operation. 1...Hollow sealed float, 4...Sliding guide tube, 5...Switch holding tube, 6...
...Ring groove, 7...Fixed magnet, 8...
...Reed switch, 9...Movable magnetic cylinder, 10
. . . Raised brake, 11 . . . Slight deletion, 12 . . . Sliding start point.

Claims (1)

[Scope of utility model registration request] A switch holding cylinder 5 is installed inside a sliding guide cylinder 4 installed vertically in a hollow sealed float 1 whose buoyancy attitude changes as the liquid level increases and decreases, and an annular groove 6 is installed on the outer periphery of the sliding guide cylinder 4. A fixed magnet 7 is disposed on the outer peripheral surface of the annular groove 6 or near the groove end, and a reed switch 8 which is normally closed by the action of the fixed magnet 7 is accommodated in the switch holding tube 5. , and a movable magnetic cylinder 9 that can be fitted into the annular groove 6 is accommodated in the sliding guide cylinder 4, and the movable magnetic cylinder 9 is fixed to the reed switch 8 by changing the attitude of the float 1 as the liquid level increases or decreases. In a structure in which the movable magnetic tube 9 is configured to open the contacts of the reed switch 8 by moving toward the magnet 7 and to close or return the contacts of the reed switch 8 by moving in the direction away from the magnet 7. A raised brake 10 facing the cylinder end of the movable magnetic cylinder 9 is attached at a required position on the inner circumferential surface of the sliding guide cylinder 4 that accommodates the movable magnetic cylinder 9. By providing a slight arcuate or inclined removed portion 11 on the outer peripheral edge of the cylinder end, a sliding starting point 12 is formed between the removed portion 11 and the facing surface of the raised brake element 10. Float switch for detecting the second position of liquid level.