JPH09101192A - Float type liquid level detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a float type liquid level detector compact and lightweight, prevent the easy occurrence of chattering, and ensure a proper detecting function, regardless of the adhesion of sludge or the like to the external surface of a float. SOLUTION: The peripheral part of a vertical hole 7 drilled through the center of the rolling surface 6 of a spherical moving body 4 is formed as an engagement end 10, and the internal surface of the surrounding wall of the moving surface 6 is formed to have an annular groove 5. In addition, a step part 11 is provided near the front end of the moving surface 5. Furthermore, the pressure receiving part 9 of a micro switch 8 laid on the reverse side of the rolling surface 6 is introduced into the vertical hole 7, and the spherical moving body 4 is coupled to the vertical hole 7 from space in the annular groove 5 beyond an annular step part 11. As a result, a pressing force acting on the pressure receiving part 9 is released to reverse the operation of the micro switch 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a relatively small float type liquid level detector used for detecting that the liquid level in a liquid tank has reached a predetermined rising or falling limit. It is a thing.

[0002]

2. Description of the Related Art A float type liquid level detector using a mercury switch as an internal electric switching mechanism has been in existence for a long time. However, since the mercury in the glass tube flows with a slight inclination, it has a drawback that it sensitively reacts to even a slight waviness on the liquid surface to cause chattering. Further, since the opening / closing operation is performed at a small tilt angle based on the horizontal posture, the detection function is lost when the float is tilted deeper than the tilt angle at the opening / closing operation due to the adhesion of sludge or the like. It will be.

On the other hand, a micro switch is used as an electric opening / closing mechanism, and the movable weight for pressing the pressure receiving portion of the micro switch is moved from the front end portion to the rear end portion of the float to activate the micro switch, and the center of gravity moves with the movement of the movable weight. There is also a water level detector configured so that the float is inverted to form a vertical state, and chattering due to the waviness of the liquid surface does not occur. However, in order to invert the float by moving the center of gravity, it is necessary that the movable weight has a large weight, which inevitably increases the size of the float itself.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a float type liquid level detector which can be constructed in a small size and a light weight, is less likely to cause chattering, and does not lose its detection function even when sludge or the like adheres to the outer surface of the float. To provide.

[0005]

In order to achieve the above object, in the float type liquid level detector of the present invention, a space portion for accommodating a spherical movable body is provided in a float having its rear end portion anchored to an electric cable, and the space portion is provided. The front wall surface of the spherical movable body is formed on the rolling surface of the spherical movable body, and the inner peripheral surface of the peripheral wall is formed on an annular groove into which the spherical movable body is fitted. An annular step portion for restricting movement is provided, a vertical hole into which the spherical movable body is fitted is provided in the center of the rolling surface, and the hole edge portion of the vertical hole restricts rolling of the spherical movable body in the peripheral direction. Formed on the locking edge,
A micro switch is installed on the back side of the rolling surface to introduce the pressure receiving part into the vertical hole, and the spherical movable body is pushed from the inside of the annular groove over the annular step into the vertical hole to press the pressure receiving part. The micro switch is actuated, and the spherical movable body is inserted from the inside of the vertical hole over the locking edge into the annular groove to release the pressing of the pressure receiving portion and reversely operate the micro switch. In addition, a space portion for accommodating the spherical movable body is provided in the float having the rear end portion anchored to the electric wire cable, and the front wall surface of the space portion is formed as the rolling surface of the spherical movable body and the inner circumference of the peripheral wall is formed. The surface is formed in an annular groove into which the spherical movable body is fitted, and an annular stepped portion for restricting rolling of the spherical movable body toward the center is provided near the front edge of the annular groove, and at the center of the rolling surface. The vertical hole that the spherical movable body engages with is smaller than the diameter of the spherical movable body. , And the hole edge of the vertical hole is formed as a locking edge that restricts rolling of the spherical movable body in the peripheral direction, and a micro switch is installed on the back side of the rolling surface and the pressure receiving portion is vertical. When the spherical movable body is introduced into the hole and the spherical movable body engages from the inside of the annular groove over the annular stepped portion onto the vertical hole, the pressure receiving portion is pressed to activate the microswitch, and the spherical movable body engages from the vertical hole. The micro switch is reversely actuated by releasing the pressure of the pressure receiving portion by fitting it into the annular groove beyond the toe and further, an air chamber is provided in the front portion in the float and the rear portion is provided. The balance weight is fixed so that the center of gravity of the float is located in the rear part, and the specific gravity of the entire float including interior parts is adjusted to be almost equal to the specific gravity of the liquid to be detected. Characterize.

[0006]

Embodiments will be described below with reference to the drawings of the embodiments.

Reference numeral 1 denotes a float having a rear end portion anchored to an electric wire cable 2 and 3 a casing for forming a space for accommodating the spherical movable body 4, the inner peripheral surface of the peripheral wall of which is the spherical movable body 4. Is formed in the annular groove 5 into which the spherical movable body 4 is fitted, and the front wall surface is inclined from the peripheral portion toward the central portion in a mortar shape to form the rolling surface 6 of the spherical movable body 4. 7 is a vertical hole provided in the central portion of the rolling surface 6, 8 is a micro switch installed on the back side of the rolling surface 6, the pressure receiving portion 9 of which is introduced into the vertical hole 7, and a spherical movable body. When 4 is fitted in the vertical hole 7, the pressure receiving portion 9 is pressed and the micro switch 8 is operated. The hole edge portion of the vertical hole 7 is formed as a locking edge 10 that restricts rolling of the spherical movable body 4 in the peripheral direction, and the diameter of the vertical hole 7 is the spherical movable body 4 as shown in the drawings of the embodiment. The diameter is slightly smaller than the diameter of
The spherical movable body 4 may be engaged with the vertical hole 7 to press the pressure receiving portion 9 of the microswitch 8.
An annular stepped portion 11 for restricting rolling of the spherical movable body 4 toward the center is provided near the front edge of the annular groove 5. An air chamber 12 is secured in the front part of the float 1, and a balancing weight 13 is fixed in the rear part of the float 1 so that the center of gravity of the float 1 is located in the rear part, and the micro switch 8 and Make sure that the specific gravity of the entire float including the interior parts such as the spherical movable body 4 is approximately equal to the specific gravity of the liquid to be detected, for example, when using it in water, the specific gravity of the entire float is approximately 1: 1. Make adjustments.

[0008]

[Operation] Float 1 when the liquid level in the tank is high
2 is in a tilted posture with the front end portion facing upward as shown in FIG. 2A, and the spherical movable body 4 is in the state of FIG. The inclination angle of the float 1 changes as the liquid level begins to descend, and the float 1 is in a downwardly inclined posture with its front end portion facing downward as shown in FIG. Since the stepped portion 11 restricts the rolling in the central direction, the state is as shown in FIG. 4 in which the microswitch 8 is still fitted in the annular groove 5, and the microswitch 8 cannot be operated. However, when the liquid level further lowers and reaches a predetermined lower limit as shown in FIG. 2C, and the float 1 has a constant downward tilt angle, the spherical movable body 4 moves the annular step 11 The state of FIG. 5 in which it rolls over and engages with the vertical hole 7 is reached, and the micro switch 8 is actuated by pressing the pressure receiving portion 9, and it is detected that the liquid level has reached the predetermined lower limit. . Even if the liquid surface undulates in the vicinity of the detected liquid level, the spherical movable member 4 is restricted from rolling in the peripheral direction by the locking edge 10. The switch 8 does not chatter. Further, when the predetermined lower limit liquid level is detected, the float 1 takes a deep downward posture to operate the microswitch 8. Therefore, even if the float 1 is considerably inclined downward due to adhesion of sludge or the like, the above detection is performed. There is no loss of functionality. Since the microswitch 8 is actuated by changing the angle of the float 1 from (B) to (C) in FIG. 2, the lower limit of liquid level detection can be made extremely low.

[0009]

According to the present invention, a float type liquid level detector can be constructed in a small size and a light weight, chattering does not occur due to ripples on the liquid level, and even if sludge or the like adheres to the outer surface of the float. Function is not impaired,
Further, there is an advantage that the lower limit of liquid level detection can be made extremely low.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view of a main part of a float type liquid level detector of the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a liquid level change and a float posture when the float type liquid level detector of the present invention is used.

FIG. 3 is an explanatory view showing a relationship between a spherical movable body and a microswitch in the float type liquid level detector of the present invention, which is a state corresponding to the float posture shown in FIG. 2 (A).

FIG. 4 is an explanatory view showing the relationship between the spherical movable body and the microswitch in the float type liquid level detector of the present invention, which is a state corresponding to the float posture shown in FIG. 2 (B).

5 is an explanatory diagram showing a relationship between a spherical movable body and a microswitch in the float type liquid level detector of the present invention, which is a state corresponding to the float posture shown in FIG. 2 (C).

[Explanation of symbols]

 1 Float 2 Electric Cable 4 Spherical Movable Body 5 Annular Groove 6 Rolling Surface 7 Vertical Hole 8 Micro Switch 9 Pressure Receiving Section 10 Locking Edge 11 Annular Step 12 Air Chamber 13 Balancing Weight

Claims (3)

[Claims] 1. A float type liquid level detector which opens and closes an internal electric switching mechanism according to a change in float posture due to a change in liquid level, and a spherical movable body is housed in a float whose rear end is anchored to an electric wire cable. Is provided, the front wall surface of the space portion is formed on the rolling surface of the spherical movable body, and the inner peripheral surface of the peripheral wall is formed in an annular groove into which the spherical movable body is fitted, and near the front edge portion of the annular groove. An annular stepped portion that restricts rolling of the spherical movable body toward the center is attached to the shaft, and a vertical hole into which the spherical movable body is fitted is provided in the center of the rolling surface, and the hole edge portion of the vertical hole is formed into the spherical movable body. Is formed on the locking edge that restricts rolling in the peripheral direction, and a micro switch is installed on the back side of the rolling surface to introduce the pressure receiving part into the vertical hole, and the spherical movable body moves from the annular groove to the annular shape. When the micro switch is pushed over the stepped portion, the pressure receiving portion is pressed by fitting it into the vertical hole. Is dynamic, so that the pressing of the pressure receiving portion is released to reverse actuating the microswitch by the spherical movable member is fitted into the annular groove beyond the locking edge from the vertical bore,
A float type liquid level detector characterized by being configured. 2. A float type liquid level detector which opens and closes an internal electric switching mechanism according to a change in float posture due to a change in liquid level, and a spherical movable body is housed in a float whose rear end is anchored to an electric wire cable. Is provided, the front wall surface of the space portion is formed on the rolling surface of the spherical movable body, and the inner peripheral surface of the peripheral wall is formed in an annular groove into which the spherical movable body is fitted, and near the front edge portion of the annular groove. An annular stepped portion that restricts rolling of the spherical movable body in the central direction is attached to the shaft, and a vertical hole for engaging the spherical movable body is formed in the central portion of the rolling surface with a diameter smaller than the diameter of the spherical movable body. , The hole edge portion of the vertical hole is formed as a locking edge that restricts rolling of the spherical movable body in the peripheral direction, and a micro switch is installed on the back side of the rolling surface to move the pressure receiving portion into the vertical hole. The spherical movable body is received from the inside of the annular groove by crossing the annular step and engaging with the vertical hole. The part is pressed to operate the micro switch, and the spherical movable body is inserted from above the vertical hole over the locking edge into the annular groove to release the pressing of the pressure receiving part and reversely operate the micro switch. The float type liquid level detector characterized in that 3. An air chamber is provided in the front part of the float, balancing weights are fixed in the rear part of the float so that the center of gravity of the float is located in the rear part, and the specific gravity of the entire float including interior parts is It is characterized in that it is adjusted so as to be approximately equal to the specific gravity of the liquid to be detected. The float type liquid level detector according to claim 1.