JP2001041188A - Removable liquid level detector for automatic operation of submerged motor-driven pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a removable liquid level sensor for automatic operation for using a non-automatic submerged motor-driven pump as an automatic operation type, effectively functioning even under a non-conductive liquid with excellent maintenability. SOLUTION: A water passing window 4 communicating with a lower surface opening part 5 is opened in the wall surface of a sensor cover 3 guided downward along the outer periphery of an outer cover 2 of a submerged motor-driven pump 1 to open at the lower surface, and a photoelectric sensor 6 is mounted to face on the water passing window 4 from the inside of the sensor cover 3. The automatic operation circuit 9 of a pump motor is accommodated in a fitting holder 8 connected to the upper part of the sensor cover 3 and projected laterally to be opposite to the upper surface of the outer cover 2, and subjected to resin molding 10, and the base 8a of the fitting holder 8 is formed on the fitting part and provided with a lead-out hole 12 opposite to an outlet 11 for a power supply cord.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a removable liquid level detector for automatic operation of a submersible electric pump.

[0002]

2. Description of the Related Art Conventionally, in an automatic submersible electric pump that drives a pump at a predetermined limit of liquid level rise, an automatic operation circuit of a pump motor is provided in a motor casing. It needs to be designed, and it is extremely difficult to attach a liquid level detector to an existing non-automatic submersible electric pump and convert it to an automatic type. In addition, a float type or an electrode type is often used as a liquid level detection mechanism, but a float type easily causes an operation failure or damage to a lead wire in a movable portion, and an electrode type has a conductive type. In bad liquids, the detection function will be impaired.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a demountable liquid level detector for automatic operation for automatically using a non-automatic underwater electric pump not equipped with a liquid level detector. Another object of the present invention is to provide a product which functions effectively even in a liquid and has excellent maintainability.

[0004]

In the detachable liquid level detector for automatic operation of a submersible electric pump according to the present invention, the lower surface is attached to the wall surface of a sensor cover which is guided along the outer periphery of the outer cover of the submersible electric pump in the form of a lower surface opening. A water sensor window is opened from the inside of the sensor cover to face the water window from the inside of the sensor cover. The automatic operation circuit of the pump motor is accommodated in a mounting holder that is protruded so as to face the upper surface of the outer cover,
The base of the mounting holder is formed on a mounting portion which is superimposed on a power cord outlet on the upper surface of the submersible electric pump and is detachably mounted by a fixing tool, and the mounting portion leads out a lead wire from the automatic operation circuit. A hole is provided vertically, the outlet hole is aligned with the power cord outlet, and the lead wire from the automatic operation circuit is separably connected to the split core wire of the power cord and the motor-side lead wire by connection terminals. ,and,
The sensor cover is fixed along the outside of the outer cover by mounting the mounting holder base on the outlet in a state where the power cord is led out from the lead-out hole via the watertight structure.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments will be described below with reference to the drawings.

1 is a submersible electric pump to which the liquid level detecting device of the present invention is attached, 2 is an outer cover of the submersible electric pump 1, and 3 is a sensor cover guided downwardly along the outside of the outer cover 2 so as to have a lower surface opening. Reference numeral 4 denotes a water passage window opened in the wall surface of the sensor cover 3 so as to communicate with the lower surface opening 5. The water passage window 4 has an interval in one place or in the vertical direction corresponding to the number of photoelectric sensors 6 described later in the sensor cover 3. It is opened in several places at a distance. The photoelectric sensor 6 has a light-emitting element and a light-receiving element arranged side by side at a predetermined interval and opposed to one surface 7a of the prism 7, and emits light while the convex back surfaces 7b and 7c of the prism 7 are exposed to the air. The optical signal emitted from the element is refracted in the prism 7 and reaches the light receiving element, and the convex back surfaces 7b and 7
When c is immersed in the light-transmissive liquid, the optical signal from the light emitting element is transmitted through the prism 7 and does not reach the light receiving element. Then, the photoelectric sensor 6 is mounted from the inside of the sensor cover 3 so as to face the water flow window 4, and a lead wire derived from the photoelectric sensor 6 is connected to an input side of an automatic operation circuit 9 described later. Reference numeral 8 denotes a mounting holder which is connected to the upper portion of the sensor cover 3 and protrudes laterally so as to face the upper surface of the outer cover 2. 10 to give a strong watertight structure. The base 8a of the mounting holder 8 is formed in a mounting portion that overlaps with the power cord outlet 11 on the upper surface of the submersible electric pump 1, and the mounting portion guides a lead wire from the automatic operation circuit 9 and connects the power cord. A lead-out hole 12 for vertically guiding is provided vertically.

[0007] In order to equip the non-automatic submersible electric pump 1 'as shown in Fig. 5 with the liquid level detecting device of the present invention, each divided core wire of the power cord 14 is separated from the motor-side lead wire and the power cord 14 is separated. 6 and the outlet hole 12 vertically provided in the mounting holder 8 is aligned with the power cord outlet 11, and the power cord 14 once extracted is used again for automatic operation. The lead wire from the circuit 9 is connected to the split core wire of the power cord and the motor-side lead wire so as to be separable by connection terminals, respectively, and the power cord 14 is led from the outlet hole 12 through the watertight structure 16 on the stopper. In this state, if the outside of the mounting holder base 8a is fixed by a fixing tool 17 such as a tightening bolt, a liquid level detecting tool is provided in a state in which the sensor cover 3 is guided along the outside of the outer cover 2. And The non-automatic submersible electric pump 1 ′ is converted to the automatic submersible electric pump 1. The derivation and connection of the grounding core wire is a well-known matter and is not the main point of the present invention, so that illustration and description are omitted.

When the liquid level in the pump installation tank rises, the prism 7
Is submerged in the liquid, the optical path is turned off and a liquid level detection signal is output, and if the prism 7 is exposed to the air as the liquid level drops, the optical path is turned on and the liquid level detection signal is not output. ,
For automatic operation of the pump motor based on the switching of the detection signal, when two upper and lower photoelectric sensors 6A and 6B are mounted, for example, a circuit configuration as shown in FIG. 9 is adopted. In this circuit configuration, as shown in FIG. 10, even if the liquid level gradually rises and the prism 7 of the lower photoelectric sensor 6B sinks in the liquid and a liquid level detection signal is output, the upper photoelectric sensor 6
While the prism 7 of A is exposed to the air, since the liquid level detection signal is not output from the upper photoelectric sensor 6A, the control circuit turns off the power supply circuit of the pump motor and the pump motor continues to be stopped. I do. When the liquid level further rises and the prism 7 of the upper photoelectric sensor 6A is also immersed in the liquid and a liquid level detection signal is output, the control circuit turns on the power supply circuit of the pump motor and the pump motor is driven to drive the underwater electric motor. Drainage by the pump 1 is performed. Even if the liquid level gradually drops due to the progress of the drainage and the prism 7 of the upper photoelectric sensor 6A comes out of the liquid and is exposed to the air, the submersible electric pump is used until the output of the liquid level detection signal from the lower photoelectric sensor 6B stops. In order to continue the operation of No. 1, the control circuit unit controls the power supply circuit of the pump motor to maintain the self-holding state. When the liquid level continues to fall and the prism 7 of the lower photoelectric sensor 6B is exposed to the air and the output of the liquid level detection signal from the lower photoelectric sensor 6B stops, the pump motor stops and the submersible electric pump 1 is stopped.
The drainage effect due to is not performed. Even if the liquid level rises while the pump motor is stopped and the prism 7 of the lower photoelectric sensor 6B is immersed in the liquid, the pump motor is kept open while the prism 7 of the upper photoelectric sensor 6A is exposed. Is stopped, but when the liquid level further rises and the prism 7 of the upper photoelectric sensor 6A is immersed in the liquid, the pump motor is driven again and the submersible electric pump 1 drains water. As described above, the submersible electric pump 1 repeats the operation and stop according to the rise and fall of the liquid level in the pump installation tank, and is synchronized with the rise and fall of the liquid level through the upper and lower water passage windows 4 and 4 and the lower opening 5. Water introduction into the sensor cover 3
As the drainage is repeated, the air is not exhausted from the inside of the sensor cover 3 to form an air pocket.
The liquid level change in the sensor cover 3 that matches the liquid level change in the pump installation tank is performed smoothly, and the wave prevention effect by the wall surface of the sensor cover 3 is combined, so that accurate liquid level detection without malfunction is achieved. Done. At the time of maintenance,
4, the condition of the prism reflecting surface can be easily inspected visually, and when an adhering substance is visually recognized on the prism reflecting surface, the prism surface can be cleaned directly from the water flow windows 4, 4 without removing the sensor cover 3. It is.

When a single photoelectric sensor 6 is mounted,
When the liquid level in the pump installation tank rises and the prism 7 of the photoelectric sensor 6 is immersed in the liquid, the pump motor starts immediately and the water is drained by the submersible electric pump 1. Even if the prism 7 of 6 is exposed to the air, the pump motor is not stopped immediately, but is stopped after, for example, operation is continued for about 10 minutes so that the drainage operation by the submersible electric pump 1 is not performed with time. I will keep it.

When the submersible electric pump 1 equipped with the liquid level detector of the present invention is used as a non-automatic type, the base 8a of the mounting holder 8 is removed from the outlet 11 as shown in FIG.
In addition, if the power cord 14 is led out from the outlet 11 through the watertight structure 16 in a state where the split core wire of the power cord 14 is separably connected to the motor-side lead wire by a connection terminal, the non-automatic The submersible electric pump 1 'is configured.

[0011]

The liquid level detecting device according to the present invention does not cause an operational failure of the movable portion or damage to the lead wire unlike the conventional float type device, and is different from the conventional electrode type device. Works effectively in non-conductive liquids, and
Prevention of foreign matter adhesion and wave prevention effect by the sensor cover wall surface, and accurate flow level detection without malfunction due to the flow inside the sensor cover are performed. Inspection is possible, and even when an adhering matter is visually recognized on the prism reflection surface, it can be cleaned directly from the water passage window without removing the sensor cover, and the maintenance is excellent. Furthermore, the present non-automatic submersible electric pump can be immediately used as an automatic submersible electric pump only by attaching the liquid level detecting device of the present invention to the ready-made non-automatic submersible electric pump. There is an advantage that you can also.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view of a liquid level detector according to the present invention.

FIG. 2 is a plan view of a liquid level detector according to the present invention.

FIG. 3 is a front view of the liquid level detector according to the present invention.

FIG. 4 is an explanatory diagram showing the formation of the optical path of the optical signal of the photoelectric sensor in the liquid level detector according to the present invention.

FIG. 5 is a longitudinal sectional side view of a main part of a non-automatic underwater electric pump to which a liquid level detecting device according to the present invention is attached.

FIG. 6 is a vertical sectional side view showing a state where a power cord is extracted from the non-automatic underwater electric pump of FIG. 5;

7 is a vertical sectional side view of a main part of an automatic submersible electric pump constructed by mounting the liquid level detecting device according to the present invention from the state of FIG. 6;

8 is an external side view of the automatic submersible electric pump shown in FIG.

FIG. 9 is an example of an electric circuit diagram of an automatic submersible electric pump configured by mounting the liquid level detector of the present invention.

FIG. 10 is a flowchart showing an operation state of the automatic submersible electric pump having the circuit configuration of FIG. 9;

[Explanation of symbols]

 Reference Signs List 1 underwater electric pump 2 outer cover 3 sensor cover 4 water passage window 5 bottom opening 6 photoelectric sensor 7 prism 8 mounting holder 8a base of mounting holder 9 automatic operation circuit 10 resin mold 11 outlet 12 outlet hole 16 watertight structure 17 fixing Ingredient

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F014 FA02 3H020 AA01 AA08 BA08 CA07 DA01 EA04

Claims (1)

[Claims] 1. A water flow window communicating with the lower surface opening is opened in a wall surface of a sensor cover guided in a lower surface opening shape along the outer cover outer surface of a submersible electric pump, and a light emitting element and a light receiving element are arranged on one surface of a prism. The photoelectric sensors arranged side by side to face each other are installed facing the water flow window from inside the sensor cover, and connected to the upper part of the sensor cover, and the pump is placed in the mounting holder that protrudes out so as to face the upper surface of the outer cover. The base of the mounting holder is formed on a mounting portion which is detachably mounted by a fixing tool by being superimposed with a power cord outlet on the upper surface of the submersible electric pump. A vertically extending lead-out hole for leading out the lead wire from the automatic driving circuit, the lead-out hole is aligned with the power cord outlet, and the lead wire from the automatic driving circuit is divided into a core wire of a power cord and And the motor-side lead wire is connected to each other in a separable manner by a connection terminal, and in a state where the power cord is led out from the outlet hole through the watertight structure, the mounting holder base is mounted on the outlet,
A detachable liquid level detector for automatic operation of a submersible electric pump, wherein the sensor cover is fixed along the outside of the outer cover.