JP4604280B2 - Wide hysteresis type float switch - Google Patents

Description

  The present invention relates to a wide hysteresis type float switch, and more particularly to a wide hysteresis type float switch that has a simple structure and can be provided at low cost.

  Conventionally, in this type of float switch, a combination of a reed switch and a float with a magnetic body (hereinafter referred to as a float) is often used. The reed switch used in this float switch has a short difference between ON and OFF (hysteresis) of about 1 mm to 5 mm. Therefore, for example, when the control depth in the water tank is 100 mm, a reed switch for detecting full water and a reed switch for detecting drought are arranged, and the flow moves between these reed switches. It has been. The full output signal and the dry output signal are each transmitted to a control device such as a programmable controller, and an output signal is generated from the programmable controller as a final output signal by a logic circuit and connected to the final load.

  For example, Patent Document 1 describes a float switch that detects the amount of ink in an ink tank. This float switch uses at least three or more reed switches arranged in the upper, middle, and lower positions in the ink tank, and the combination of ON / OFF of each reed switch that changes depending on the position of the float with respect to these reed switches. It is a system which a remaining amount determination part determines based on.

In addition, the liquid level sensor described in Patent Document 2 shows a float switch using a detection coil unit. According to this float switch, a magnetic body with a float that moves following a change in the level of the liquid surface, and a magnetic field that accompanies the movement of the magnetic body with the float is disposed along the movement process area of the magnetic body with the float. And a detection coil section for detecting a change in the above. According to this float switch, a transmission circuit for transmitting a change in the magnetic field detected by the detection coil unit as a signal, a diagnosis circuit for receiving the transmitted signal, and a detection circuit for detecting a position from the received signal are provided. Yes.
Japanese Patent No. 3518460 JP 2001-194213 A

  Conventional float switches require complex equipment and configurations such as control devices such as programmable controllers, or various circuits associated with logic circuits and detection circuits, which complicates the overall configuration of the liquid level control system and is inexpensive. Also difficult to provide.

  For example, according to Patent Document 1, it is necessary to provide a remaining amount determination unit having a function of determining the remaining amount of ink based on the combination of ON and OFF of each reed switch. In Patent Document 2, various circuits such as a transmission circuit, a diagnosis circuit, and a detection circuit must be prepared.

  As described above, in the conventional liquid level control system, the configuration of the switch is inevitably complicated, and it is difficult to provide the switch at a low cost. Therefore, the present invention was created to solve the above-described problems, and an object of the present invention is to provide a wide hysteresis type float switch that has a simple structure and can be provided at low cost.

In order to achieve the above object, the present invention slides along the liquid level between the full water detection reed switch 2 for detecting full water, the drought detection reed switch 3 for detecting drought, and the two reed switches. A float switch having a float 4 is provided with a reed relay 1 including a magnetic coil 1B that generates a magnetic field according to the open / closed state of each reed switch and a reed switch attached to the magnetic coil 1B. Has a configuration in which a coil 1B is wound around a drought detection reed switch 3 having a NO contact, the full water detection reed switch 2 and the drought detection reed switch 3 are connected to the coil 1B, and a current flows through the coil 1B. And the solenoid valve 5 is set to open, and the full water detection reed switch 2 is an NC contact reed switch. Further, the drought detection reed switch 3 is a NO contact reed switch, and the solenoid valve 5 is opened and closed according to the open / closed state of the reed relay 1 according to the position of the float 4 provided with a magnet. The reed switch 2 is provided to cut off the energization of the reed relay 1 when the float 4 is lowered and to energize the reed relay 1 when the float 4 is raised .

  According to the present invention, a reed relay 1 that generates a magnetic field according to the open / closed state of each reed switch is provided, and the reed relay 1 is set to open and close the electromagnetic valve 5 on the water supply side. The liquid level control system has a simple structure and can be provided at low cost.

Further , by changing the positions of the full water detection reed switch 2 and the drought detection reed switch 3, the design of the operating water level and the return water level can be arbitrarily changed. As a result, it is easy to freely expand the measurement range of the float switch.

Further , by using the reed relay 1, a reliable operation is possible with a simple configuration.

  As described above, according to the present invention, it is possible to provide a simple and inexpensive structure, and it is possible to provide various beneficial effects such as easy expansion of the operating range of the float switch.

  In the best mode of the float switch of the present invention, a reed relay 1 that generates a magnetic field according to the open / close state of each reed switch is provided, and the reed relay 1 is set to open and close the electromagnetic valve 5 on the water supply side. In the reed relay 1, a coil 1B is wound around a drought detection reed switch 3 having a NO contact, the full water detection reed switch 2 and the drought detection reed switch 3 are connected to the coil 1B, and a current is supplied to the coil 1B. It sets so that the said solenoid valve 5 may open when it flows. The full water detection reed switch 2 is an NC contact reed switch, and the drought detection reed switch 3 is a NO contact reed switch. The electromagnetic valve 5 is set to open and close depending on the open / close state of the reed relay 1 according to the position of the float 4. The full water detection reed switch 2 achieves the original purpose by providing the reed relay 1 so as not to energize the reed relay 1 when the float 4 is lowered, but to energize the reed relay 1 when the float 4 is raised.

  An embodiment of the present invention will be described below. The present invention is a float switch having a float 4 that slides along the liquid surface between two upper and lower reed switches. The upper and lower reed switches include a full water detection reed switch 2 that detects full water and a drought detection reed switch 3 that detects drought.

  A reed relay 1 is connected to each reed switch. That is, the full water detection reed switch 2 and the drought detection reed switch 3 are connected to the coil 1 </ b> B of the reed relay 1. The reed relay 1 generates a magnetic field in accordance with the open / closed state of the full water detection reed switch 2 and the drought detection reed switch 3, and opens / closes the water supply side electromagnetic valve 5 in the open / closed state of the reed relay 1. It is set as follows.

  For example, the full water detection reed switch 2 is an NC contact reed switch, and the drought detection reed switch 3 is a NO contact reed switch. The electromagnetic valve 5 is opened and closed according to the open / closed state of the reed relay 1 according to the position of the float 4.

At this time, the full water detection reed switch 2 is provided so that the reed relay 1 is not energized when the float 4 is lowered after the full water is detected, and the reed relay 1 is energized when the float 4 is elevated after the detection of drought. For example, as shown in FIG. 3 , an ON region such as a shaded portion is set between red and black of the lead wire 6, and when the full water detection reed switch 2 is lowered, it is not energized, and full water detection is energized when it is raised. A reed switch 2 is provided.

An embodiment of the present invention is shown in FIG. In this embodiment, a reed relay 1 is configured by winding a coil 1B around a drought detection reed switch 3. The float 4 moves up and down between the full water detection reed switch 2 and the drought detection reed switch 3. The resistance value of the coil 1B at this time is 2000Ω, but the resistance value can be changed arbitrarily.

FIG. 2 shows an operation simulation showing the open / close state of the solenoid valve 5 according to the embodiment of the present invention . The float 4 moves up and down between the full water detection reed switch 2 and the drought detection reed switch 3. Description will be made in order from the left in the figure. When the float 4 is at the uppermost position, the NC contact is located on the full water detection reed switch 2 side, so that the full water detection reed switch 2 and the NO contact dry water detection reed switch 3 are both turned OFF. As a result, no current flows through the reed relay 1 and the solenoid valve 5 is closed. This state continues until the float 4 starts to move down and moves to the drought detection reed switch 3 side.

  When the float 4 is at the lowermost position, it is located on the side of the drought detection reed switch 3 for the NO contact, and the full contact detection reed switch 2 and the drought detection reed switch 3 for the NC contact are both turned ON. As a result, a current flows through the coil 1B of the reed relay 1 provided integrally with the drought detection reed switch 3, and the electromagnetic valve 5 is activated to start water supply.

  While the float 4 rises from the bottom, the water supply state continues. That is, even if the float 4 moves away from the drought detection reed switch 3 and the drought detection reed switch 3 is turned off, the full water detection reed switch 2 is not changed while the float 4 is raised. Since it is provided so as to be ON, the energized state of the reed relay 1 continues, and the electromagnetic valve 5 continues to supply water as it is.

  When the float 4 moves to the uppermost position, the full contact detection reed switch 2 at the NC contact is turned off, so that the reed relay 1 is not energized, the electromagnetic valve 5 is closed, and the water supply is finished. Thus, the solenoid valve 5 can be operated only by the movement of the float 4.

It shows the structure of the float 4 used in Example 3. In the figure, reference numeral 4A denotes a magnet, reference numeral 7 denotes a stem, and reference numeral 8 denotes a stopper for limiting the movement range of the float 4.

  Note that the present invention is not limited to the illustrated example, and the coil magnetic field and the magnet 4A magnetic field in the float 4 are representative examples, and can be operated by other magnetic field combinations. It can be freely changed without changing the gist.

It is a connection diagram which shows the Example of this invention. It is explanatory drawing which shows the operation | movement simulation shown in FIG. It is a front view which shows one Example of the float used by this invention.

DESCRIPTION OF SYMBOLS 1 Reed relay 1B Coil 2 Reed switch for full water detection 3 Reed switch for drought detection 4 Float 4A Magnet 5 Solenoid valve 6 Lead wire 7 Stem 8 Stopper

Claims (1)

In a float switch having a full water detection reed switch that detects full water, a drought detection reed switch that detects drought, and a float that slides along the liquid level between the two reed switches, each reed switch is opened and closed. A reed relay comprising a magnetic coil that generates a magnetic field according to the state and a reed switch attached to the magnetic coil is provided, and the reed relay is configured such that the coil is wound around a NO contact drought detection reed switch. The full water detection reed switch and the drought detection reed switch are connected to the coil, the solenoid valve is set to open when a current flows through the coil, and the full water detection reed switch is connected to the NC contact reed switch. The drought detection reed switch is a NO contact reed switch, The solenoid valve is set to open and close depending on the open / closed state of the reed relay according to the float position. Wide hysteresis type float switch, which is provided to energize .

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