External triangular prism type liquid level sensor

Abstract

The invention discloses an external triangular prism type liquid level sensor which comprises a water pipe, the surface of the middle of the water pipe is connected with one end of a shell, a PCB is installed in the shell, an infrared emitting lamp bead, an infrared receiving lamp bead and a triode are arranged on the PCB, an inverted-trapezoid-shaped boss is arranged on the outer side face of the connecting position of the water pipe and the shell, the boss is an external triangular prism, and the included angle between the two inclined faces of the external triangular prism is 90 degrees. Wherein one inclined plane is arranged on the inner side face of the water pipe, infrared light of the infrared emission lamp bead is reflected to the infrared receiving lamp bead through the boss, one end of the triode is connected with the infrared receiving lamp bead, the other end of the triode is connected with the signal line, and the triode performs reverse level conversion on the infrared light received by the infrared receiving lamp bead. Whether water exists in the water pipe or not is judged according to whether the boss can reflect infrared rays or not and the level output by the signal line, whether water shortage exists in the water tank or not is monitored in real time, the inner side face of the water pipe is smooth, liquid is not prone to remaining, and incrustation or deterioration of edible liquid is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of liquid level sensors, and in particular to an external prism type liquid level sensor. Background Art

[0002] Nowadays, household appliances or industrial equipment with water tanks need to monitor whether there is water shortage in the water tank in real time. Float and other detection devices are used to detect the water level, but such a structure takes up a lot of space and is difficult to use on small household appliances or equipment. In addition, when using small-volume pipe liquid level sensors on the market to detect the water level, a boss is installed on the inside of the water pipe connected to the sensor to act as a prism to detect whether there is liquid. In the case of long-term water flow or other viscous liquids, the boss is prone to scale or liquids with reverse viscosity are more likely to adhere to the surface, especially edibles such as juice and milk will cause deterioration. In addition, the existing liquid level sensors have the problem of their operation being interfered by the lamp beads themselves. Therefore, in order to solve this problem, some sensors add components such as light shielding sheets, thereby increasing the structural complexity of the sensor. Summary of the invention

[0003] The object of the present invention is to provide an external prism type liquid level sensor, which utilizes the reflection of a boss as an external prism to realize the reception of infrared light, and the boss is arranged on the outer surface of the connection between the shell and the water pipe, and one of the inclined surfaces is arranged on the inner surface of the water pipe, so that the inner surface of the water pipe is flat, so as to solve the problems raised in the above-mentioned background technology.

[0004] In order to achieve the above objectives, the technical solution adopted by the present invention is:

[0005] An external prism type liquid level sensor comprises a water pipe, wherein the left and right ends of the water pipe are provided with a water inlet end and a water outlet end, the water inlet end of the water pipe is connected to a water tank through a hose, and the water pipe is arranged at the bottom of the water tank or below the bottom of the water tank, the water outlet end of the water pipe is connected to a water-using component, the middle surface of the water pipe is connected to one end of a shell, a PCB board is installed in the shell, an infrared emitting lamp bead, an infrared receiving lamp bead, a triode and a resistor are arranged on the PCB board, the emitting end of the infrared emitting lamp bead and the receiving end of the infrared receiving lamp bead penetrate the PCB board and face vertically to one side of the water pipe, and the shell and the water pipe are connected. An integrated arrangement is provided, and an inverted trapezoidal boss is provided on the outer side surface of the connection between the water pipe and the shell, the boss is an external prism with two inclined surfaces at 90 degrees, wherein the first inclined surface is provided on the inner side surface of the water pipe, and the second inclined surface is provided directly below the shell, the infrared light of the infrared emitting lamp bead is reflected to the infrared receiving lamp bead through the boss serving as a prism, and wires are welded on the surface of the PCB board, the wires have three wires, including two power lines and one signal line, one end of the transistor is connected to the infrared receiving lamp bead, and the other end is connected to the signal line, and the transistor performs reverse level conversion on the infrared light received by the infrared receiving lamp bead.

[0006] As a further solution of the present invention: the water inlet end and the water outlet end of the water pipe are both provided with steps, and the water inlet end of the water pipe is connected to the hose through the step.

[0007] As a further solution of the present invention: two longitudinally distributed convex ribs are respectively arranged on the inner surfaces of two opposite sides of the shell, and two grooves corresponding to the convex ribs are respectively arranged on the outer surfaces of two opposite sides of the PCB board.

[0008] As a further solution of the present invention: the convex rib and the concave groove are respectively and correspondingly arranged at positions off-center on the inner side surface of the protective shell and the outer side surface of the PCB board.

[0009] As a further solution of the present invention: PCB potting glue is distributed inside the shell on the outside of the PCB board, and a through hole for the wire to pass through is opened on the PCB potting glue.

[0010] Compared with the prior art, the present invention has the following beneficial effects: the present invention reflects the infrared light of the infrared emitting lamp bead to the infrared receiving lamp bead arranged side by side through the boss serving as an external prism, and the transistor performs reverse level conversion on the infrared light received by the infrared receiving lamp bead, that is, when there is water in the water pipe passing through the connection with the outer shell, the infrared light emitted by the infrared emitting lamp bead enters the boss serving as the external prism and cannot be reflected to the infrared receiving lamp bead, the input signal sent by the infrared receiving lamp bead to the transistor is a high level, the transistor is turned on, and the output signal of the signal line is a low level (<0.8V); when there is no water in the water pipe passing through the connection with the outer shell, the infrared light emitted by the infrared emitting lamp bead enters the boss serving as the external prism and is reflected to the infrared receiving lamp bead, the input signal of the infrared receiving lamp bead to the transistor is a low level, the transistor is turned on, and the output signal of the signal line is a low level (<0.8V); The signal line outputs a high level signal (<4.5V) when the projection is turned off, thereby utilizing whether the projection can reflect infrared rays and the level of the signal line output to determine whether there is water in the water pipe, thereby realizing real-time monitoring of whether there is a lack of water in the water tank. The device has a simple structure and does not need to occupy a large space. It is suitable for small household appliances or equipment. The projection as an external prism is arranged on the outer surface of the connection between the outer shell and the water pipe, and the inclined surface is arranged on the inner side of the water pipe, so that the inner side of the water pipe is flat, there are no concave and convex surfaces, and it is not easy to retain liquid, thus avoiding the formation of scale or the deterioration of edible liquid. In addition, the transmitting end of the infrared emitting lamp bead and the receiving end of the infrared receiving lamp bead pass through the PCB board and face vertically toward one side of the water pipe, thereby preventing the side-by-side lamp beads from being interfered with by themselves without increasing their structural complexity. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a three-dimensional diagram of the external prism liquid level sensor of this embodiment.

[0012] Figure 2 1 is an exploded view of the external prism liquid level sensor of this embodiment.

[0013] Figure 3 4 is a cross-sectional view of the external prism liquid level sensor of this embodiment.

[0014] Figure 4 This is a light diagram between the infrared emitting lamp beads and the infrared receiving lamp beads when there is water in the water pipe in this embodiment.

[0015] Figure 5 This is a light diagram between the infrared emitting lamp beads and the infrared receiving lamp beads when the water pipe is dry in this embodiment.

[0016] Figure 6 This is a working principle diagram of the external prism liquid level sensor of this embodiment.

[0017] Figure 7 4 is a circuit schematic diagram of the external prism liquid level sensor of this embodiment.

[0018] The accompanying drawings are marked as: water pipe 1, water inlet end 101, water outlet end 102, shell 2, PCB board 3, infrared emitting lamp bead 4, infrared receiving lamp bead 5, transistor 6, resistor 7, boss 8, inclined plane 1 801, inclined plane 2 802, power line 9, signal line 10, convex rib 11, groove 12, PCB potting glue 13, step 14. DETAILED DESCRIPTION

[0019] The following further describes the specific embodiments of the present invention in conjunction with the accompanying drawings to make the technical solutions and beneficial effects of the present invention clearer and more specific.

[0020] like Figures 1 to 7 As shown, this embodiment provides an external prism type liquid level sensor, including a water pipe 1, with a water inlet end 101 and a water outlet end 102 at the left and right ends of the water pipe 1, the water inlet end 101 of the water pipe 1 is connected to the water tank through a hose, and the water pipe 1 is arranged at the bottom of the water tank or below the bottom of the water tank, the water outlet end 102 of the water pipe 1 is connected to the water-using component, the middle surface of the water pipe 1 is connected to one end of the shell 2, a PCB board 3 is installed in the shell 2, an infrared emitting lamp bead 4, an infrared receiving lamp bead 5, a triode 6 and a resistor 7 are arranged on the PCB board 3, the emitting end of the infrared emitting lamp bead 4 and the receiving end of the infrared receiving lamp bead 5 pass through the PCB board 3 and are vertically toward one side of the water pipe 1, the shell 2 is integrated with the water pipe 1, and the outer side surface of the connection between the water pipe 1 and the shell 2 is provided with an inverted trapezoidal boss 8, the boss 8 is an external prism with two inclined surfaces at 90 degrees, wherein the first inclined surface 801 is arranged on the inner side surface of the water pipe 1, and the second inclined surface 802 is arranged directly below the shell 2, the infrared light of the infrared emitting lamp bead 4 is reflected to the infrared receiving lamp bead 5 through the boss 8 as a prism, the surface of the PCB board 3 is welded with wires, and the wires have three wires, including two power lines 9 and a signal line 10, one end of the transistor 6 is connected to the infrared receiving lamp bead 5, and the other end is connected to the signal line 10, and the transistor 6 performs reverse level conversion on the infrared light received by the infrared receiving lamp bead 5.

[0021] In this embodiment, if Figure 1 As shown, both the water inlet end 101 and the water outlet end 102 of the water pipe 1 are provided with steps 14 , and the water inlet end 101 of the water pipe 1 is connected to the hose via the step 14 .

[0022] Specifically, the step 14 is provided to prevent the hose from falling off and to provide a better seal with the hose.

[0023] In this embodiment, if Figure 2 As shown, two longitudinally distributed ribs 11 are respectively arranged on the inner surfaces of two opposite sides of the housing 2 , and two grooves 12 corresponding to the ribs 11 are respectively arranged on the outer surfaces of two opposite sides of the PCB board 3 .

[0024] Specifically, the two groups of convex ribs 11 and the grooves 12 cooperate with each other to prevent the PCB board 3 from floating up during potting, thereby ensuring the infrared emitting lamp beads 4 and the infrared receiving lamp beads 5 to emit and receive infrared rays.

[0025] In this embodiment, if Figure 2 As shown, the rib 11 and the groove 12 are respectively disposed at the inner side surface of the housing and the outer side surface of the PCB board 3 at positions off-center, so as to achieve fool-proofing during assembly.

[0026] In this embodiment, if Figures 1 to 3 As shown, a PCB potting compound 13 is distributed on the outer side of the PCB board 3 in the housing 2, and a through hole for the wire to pass through is opened on the PCB potting compound 13.

[0027] Specifically, the PCB potting glue 13 is provided to provide waterproof and moisture-proof effect to the PCB board 3 .

[0028] like Figures 4 to 7 As shown, the working principle of the above external prism liquid level sensor is:

[0029] (1) Use the power line (VCC-GND) to power the PCB board 3. When there is water in the water tank, since the water pipe 1 connected to the water tank is at the bottom of the water tank or below the bottom of the water tank, the water in the water tank flows into the water pipe 1. The boss 8 on the outer side of the connection between the housing 2 and the water pipe 1, which serves as an external prism, cannot reflect the infrared light emitted by the infrared emitting lamp bead (IR1) to the infrared receiving lamp bead (PT1). The infrared receiving lamp bead (PT1) without infrared reception sends an input signal to the transistor (Q1), so that point A maintains a high level of 5V, so that the transistor (Q1) is turned on, and the voltage at point B output by the transistor (Q1) to the signal line (OUT) is low (<0.8V);

[0030] (2) When there is no water in the water tank, there is no water flowing through the water pipe 1. The boss 8 as an external prism on the outer side of the connection between the housing 2 and the water pipe 1 can reflect the infrared light emitted by the infrared emitting lamp bead (IR1) to the infrared receiving lamp bead (PT1). The infrared receiving lamp bead (PT1) receives the infrared light and sends an input signal to the transistor (Q1), which reduces the voltage at point A to a low level (<0.5V), making the transistor (Q1) unable to conduct. The voltage at point B output by the transistor (Q1) to the signal line (OUT) is a high level (>4.5V).

[0031] The above are only preferred specific implementations of this embodiment, but the protection scope of this embodiment is not limited to this. Any technician familiar with the technical field can make equivalent replacements or changes based on the technical solution and inventive concept of this embodiment within the technical scope disclosed in this embodiment, which should be covered by the protection scope of this embodiment.

Claims

1. An external prism type liquid level sensor, comprising a water pipe (1), wherein the water pipe (1) is provided with a water inlet end (101) and a water outlet end (102) at both ends, the water inlet end (101) of the water pipe (1) is connected to a water tank through a hose, and the water pipe (1) is arranged at or below the bottom of the water tank, the water outlet end (102) of the water pipe (1) is connected to a water-using component, the middle surface of the water pipe (1) is connected to one end of a housing (2), a PCB board (3) is installed in the housing (2), an infrared emitting lamp bead (4), an infrared receiving lamp bead (5), a triode (6) and a resistor (7) are arranged on the PCB board (3), the emitting end of the infrared emitting lamp bead (4) and the receiving end of the infrared receiving lamp bead (5) both penetrate the PCB board (3) and face vertically to one side of the water pipe (1), and the external The shell (2) and the water pipe (1) are integrally arranged, and a boss (8) in the shape of an inverted trapezoid is provided on the outer side surface of the connection between the water pipe (1) and the shell (2), wherein the boss (8) is an external prism with two inclined surfaces at 90 degrees, wherein the first inclined surface (801) is arranged on the inner side surface of the water pipe (1), and the second inclined surface (802) is arranged directly below the shell (2), and the infrared light of the infrared emitting lamp bead (4) is reflected to the infrared receiving lamp bead (5) through the boss (8) as a prism, and the surface of the PCB board (3) is welded with wires, and the wires have three wires, including two power lines (9) and a signal line (10), one end of the transistor (6) is connected to the infrared receiving lamp bead (5), and the other end is connected to the signal line (10), and the transistor (6) performs reverse level conversion on the infrared light received by the infrared receiving lamp bead (5).

2. A pipeline liquid level sensor according to claim 1, characterized in that: The water inlet end (101) and the water outlet end (102) of the water pipe (1) are both provided with steps (14), and the water inlet end (101) of the water pipe (1) is connected to the hose via the step (14).

3. The external prism type liquid level sensor according to claim 1, characterized in that: Two longitudinally distributed convex ribs (11) are respectively arranged on the inner surfaces of two opposite sides of the housing (2), and two grooves (12) corresponding to the convex ribs (11) are respectively arranged on the outer surfaces of two opposite sides of the PCB board (3).

4. The external prism type liquid level sensor according to claim 3, characterized in that: The convex rib (11) and the concave groove (12) are respectively arranged at positions deviating from the center on the inner side surface of the protective shell and the outer side surface of the PCB board (3).

5. The external prism type liquid level sensor according to claim 1, characterized in that: A PCB potting glue (13) is distributed inside the housing (2) and outside the PCB board (3), and a through hole for a wire to pass through is provided on the PCB potting glue (13).

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