A device mainly based on a reed switch capable of fine-tuning a liquid level switch

Abstract

The present invention belongs to the liquid level switch measurement technology, a device mainly composed of a reed switch that can be fine-tuned in the liquid level switch. It includes a socket, a liner, a push rod, a magnet, an end cover, a shell, a float, and a reed switch; the end cover is fixed to the shell by screws to form a cavity, and the float is enclosed inside the cavity. The float can move up and down inside the cavity, and the magnet is fixed inside the float by silicone rubber. The socket and the liner are fixed to the shell by screws, and the push rod is connected to the liner by a central thread. At the same time, the two side threads on the push rod are screwed to fix the push rod and the liner, and the reed switch is fixed in the groove on the end face of the push rod with silicone rubber. The cost is low, the position adjustment of the reed switch does not require glue removal, and it is well protected, so the damage of the reed switch during product debugging, installation and use is avoided, and unnecessary losses are reduced. The application range is wide, the position of the reed switch is adjustable, and the float is light in weight, so that the liquid level switch can adapt to a variety of different measurement media and can be widely used in different scenarios.

Description

Technical Field

[0001] The invention belongs to the liquid level switch measurement technology and relates to a device mainly composed of a fine-tunable reed switch in the liquid level switch. Background Art

[0002] A reed switch is a magnetic reed switch. The basic type is to seal two magnetic reed sheets in a glass tube. Although the two sheets overlap, there is a small gap in the middle. When the external magnetic field reaches a certain intensity, the two magnetic reed sheets will deform and attract each other, and the circuit will be connected. When the magnetic field weakens or disappears, the reed sheets will separate their contact surfaces due to their own elasticity, and the circuit will be disconnected.

[0003] Since the on and off of the reed switch is only affected by the magnetic field, it has a strong anti-interference ability to other signals. It can be used in conjunction with permanent magnets such as magnets. When the magnet approaches, the reed switch is attracted, and when the magnet moves away, the reed switch is disconnected, thereby achieving the purpose of distance switch control.

[0004] In the aviation field, people use reed switches and magnets as the core devices of position sensors. For example, in liquid level switches, the magnets are wrapped with materials with lower density so that the magnets move with the rise and fall of the liquid level, fixing the reed switches in the corresponding positions, thereby realizing the on and off of the circuit at a specific position.

[0005] In actual application, the following problems mainly exist: the reed switch is sensitive to the induction of magnetic field. Due to the inconsistency between batches of magnets and reed switches, the fixed position of the reed switch needs to be adjusted multiple times to achieve the on and off of the liquid level switch at a specific liquid level.

[0006] The basic type of reed switch is two magnetic reeds sealed in a glass tube. The reed switch itself is relatively fragile and easily damaged by external forces. When used in the aviation field as part of a liquid level switch, it often needs to bear mechanical loads such as vibration, impact, and acceleration. In order to prevent external mechanical loads from damaging the reed switch, soft glue is often used to fix the reed switch. If you want to adjust the position of the reed switch, you need to remove the glue, which increases the workload and the loss rate of the reed switch. Summary of the invention

[0007] The purpose of the present invention is to provide a liquid level switch structure with an adjustable reed switch, which is used to meet the scenario where the position of the reed switch needs to be changed multiple times.

[0008] The technical solution of the present invention is: a device mainly based on a reed switch that can be fine-tuned in a liquid level switch of the present invention comprises a socket, an inner lining, a push rod, a magnetic steel, an end cover, a shell, a float, and a reed switch;

[0009] The end cover is fixed to the shell by screws to form a cavity, which encloses the buoy inside the cavity. The buoy can move up and down inside the cavity. The magnet is fixed inside the buoy by silicone rubber. The socket and the liner are fixed to the shell by screws. The push rod is connected to the liner through the center thread. At the same time, the two side threads on the push rod are fixed to the push rod and the liner with screws. The reed switch is fixed in the groove on the end face of the push rod with silicone rubber.

[0010] The material of the push rod is aluminum alloy.

[0011] The lining material is austenitic stainless steel.

[0012] The height of the groove should be greater than or equal to the diameter of the reed switch.

[0013] The lining and the shell are clearance-fitted, and the roughness is Ra3.2.

[0014] The buoy consists of an outer shell and a round cover, and the round cover is in point contact with the outer shell.

[0015] The buoy material is polyetheretherketone

[0016] The inner lining is provided with a wire harness passing hole.

[0017] The advantages of the present invention are:

[0018] 1. Small size, the overall length is 93mm, the diameter of the measuring part is 19.4mm, which can meet the current requirements of miniaturization of sensors in the aviation field.

[0019] 2. Light weight, the overall weight can be controlled within 120g, which can meet the current requirements for lightweight sensors in the aviation field.

[0020] 3. Strong sealing, the circuit part is completely isolated from the float part, eliminating the risk of short circuit caused by interference from the measuring medium. There are two sealing ring grooves on the surface, which can effectively prevent the oil tank from leaking at the installation point of the liquid level switch when the product is installed on the oil tank.

[0021] 4. The position of the reed switch can be adjusted multiple times without removing the glue, which effectively reduces the workload during the debugging process.

[0022] 5. High precision. Due to the adjustable position of the reed switch, the operability, standardization and consistency of the debugging process are guaranteed, thereby improving the accuracy of the liquid level switch.

[0023] 6. Low cost. The position of the reed switch does not require glue removal and is well protected, thus avoiding damage to the reed switch during product debugging, installation and use, and reducing unnecessary losses.

[0024] 7. Wide range of applications, adjustable reed switch position and light float weight enable the liquid level switch to adapt to a variety of different measuring media and can be widely used in different scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the present invention;

[0026] Figure 2 It is a three-dimensional diagram of the innovative part of the present invention;

[0027] Figure 3 is a three-dimensional diagram of the present invention;

[0028] Figure 4 This is a schematic diagram of the installation of the liquid level switch. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below with reference to the accompanying drawings.

[0030] A device mainly based on a reed switch that can be fine-tuned in a liquid level switch comprises a socket 1, an inner lining 2, a push rod 3, a magnetic steel 4, an end cover 5, a shell 6, a float 7, and a reed switch 8;

[0031] The end cover 5 is fixed to the shell 6 by screws to form a cavity, enclosing the buoy 7 inside the cavity. The buoy 7 can move up and down inside the cavity. The magnet 4 is fixed inside the buoy 7 by silicone rubber. The socket 1 and the liner 2 are fixed to the shell 6 by screws. The push rod 3 is connected to the liner 2 through the center thread. At the same time, the two side threads on the push rod 3 are screwed to fix the push rod 3 and the liner 2. The reed switch 8 is fixed in the groove on the end face of the push rod with silicone rubber.

[0032] The material of the ejector rod 3 is aluminum alloy, mainly for the following reasons:

[0033] 1. The structural strength of the ejector rod. Aluminum alloy is a commonly used material in the aviation field. Under the current structure, it can meet the mechanical load borne by the liquid level switch.

[0034] 2. The magnetic properties of the top rod. Aluminum alloy is non-magnetic and will not affect the effect of the reed switch.

[0035] 3. The weight of the top rod, the density of aluminum alloy is only 2.7g / cm 3 , which can effectively reduce weight and meet the increasing weight requirements in the aviation field.

[0036] The push rod 3 is used to provide an installation position for the reed switch, and is used in conjunction with the liner 2 to achieve the mobility of the reed switch.

[0037] The material of the lining 2 is austenitic stainless steel, mainly for the following reasons:

[0038] 1. Structural strength of the lining. Stainless steel is a commonly used material in the aviation field. Under the current structure, it can meet the mechanical load borne by the liquid level switch.

[0039] 2. The magnetic properties of the push rod. Austenitic stainless steel is non-magnetic. After solution treatment, the residual magnetism generated during the processing can be removed and will not affect the effect of the reed switch.

[0040] The lining 2 is used in conjunction with the ejector rod 3 to achieve the mobility of the reed switch and provide installation space for internal circuit cables and the like.

[0041] The height of the groove should be greater than or equal to the diameter of the reed switch 8. The main reason is that the groove is used to install the reed switch. Because the glass shell of the reed switch is fragile, it needs to be completely installed in the groove to prevent it from colliding with the external metal structure and being damaged. However, if the groove is too deep, it will cause the reed switch to be away from the magnetic field generated by the lower magnet, reducing the adjustment space.

[0042] The lining 2 and the shell 6 are clearance fit, and the roughness is Ra3.2. During the debugging process of the liquid level switch, the lining 2 needs to be taken out several times to adjust the position of the reed switch, so the lining 2 and the shell need to be clearance fit, and the shell diameter is limited by the surface sealing ring groove and the internal reed switch size, and the thinnest wall thickness is only 0.7mm, so the lining needs to be matched with it to form a structural reinforcement. Therefore, a clearance fit is used here, but the fit is tight and the roughness requirement is high to prevent assembly difficulties.

[0043] The float 7 is composed of an outer shell and a round cover, and the round cover is in point contact with the shell 6. In the aviation field, liquid level switches are often used to detect the liquid level of media such as hydraulic oil or fuel. Such media have high viscosity and surface tension. Point contact can effectively prevent the float from being bonded to the shell by the surface tension of the medium, causing the liquid level switch to fail to work properly.

[0044] The buoy 7 is made of polyetheretherketone for the following reasons:

[0045] 1. The mechanical strength of the buoy. As a moving part, the buoy will inevitably collide with the metal shell during operation. Polyetheretherketone has high strength and can withstand the corresponding mechanical load.

[0046] 2. The magnetic properties of the buoy. Polyetheretherketone, as a non-metallic material, is non-magnetic and will not affect the effect of the reed switch.

[0047] 3. The weight of the float. As a sensitive element for sensing the liquid level, the float needs to float on the liquid surface and move with the rise and fall of the liquid level. The density of polyetheretherketone is only 1.3g / cm 3 , which can meet the weight requirements.

[0048] The inner lining 2 is provided with a wiring harness through hole, which is mainly used for the passage of cables at both ends of the reed switch, so that the signal of the reed switch can be transmitted to the socket for output.

[0049] Liquid level switch debugging process:

[0050] 1. As shown in the figure below, install the liquid level switch on the fixture and connect it to the multimeter. Adjust the buzzer mode of the multimeter.

[0051] 2. Inject lubricating oil into the fixture until the multimeter beeps, record the current liquid level, if it is higher than the preset value, remove the lining and the ejector rod, adjust the ejector rod and the lining installation threads to reduce the distance between the two, if it is lower than the preset value, adjust the ejector rod and the lining installation threads to increase the distance between the two, until the liquid level is consistent with the preset value when the buzzer alarm sounds. Continue to add lubricating oil to cover the preset page.

[0052] 3. Release the lubricating oil until the beeping sound of the multimeter stops, and record the current liquid level position from the installation surface. If it is higher than the preset value, remove the lining and the ejector rod, and adjust the ejector rod and the lining installation threads to reduce the distance between the two. If it is lower than the preset value, adjust the ejector rod and the lining installation threads to increase the distance between the two, until the liquid level is consistent with the preset value when the buzzer alarm stops.

[0053] 4. Tighten the two slotted cylindrical head screws between the liner and the top rod to fix the distance between them.

[0054] Working process of the liquid level switch: when the liquid level rises, the float inside the liquid level switch rises with the liquid level, and the magnet continues to approach the reed switch. When it rises to the predetermined liquid level, the magnetic field strength generated by the magnet reaches the attraction strength of the reed switch. The reed switch is affected by the magnetic field of the magnet inside the float and becomes on, and the liquid level switch outputs a conduction signal; when the liquid level drops, the float inside the liquid level switch drops with the liquid level. When it drops to the predetermined liquid level, the magnetic field strength generated by the magnet is less than the attraction strength of the reed switch, the reed switch becomes off, and the liquid level switch outputs a disconnection signal.

Claims

1. A debugging method based on a fine-tunable reed switch in a liquid level switch, characterized in that: The debugging device is realized based on the debugging device, which comprises a socket (1), an inner lining (2), a top rod (3), a magnetic steel (4), an end cover (5), a shell (6), a buoy (7), and a reed switch (8); The end cover (5) is fixed to the housing (6) by screws to form a cavity, and the buoy (7) is enclosed in the cavity. The buoy (7) can move up and down in the cavity. The magnetic steel (4) is fixed to the buoy (7) by silicone rubber. The socket (1) and the liner (2) are fixed to the housing (6) by screws. The push rod (3) is connected to the liner (2) by a central thread. At the same time, the threads on both sides of the push rod (3) are screwed to fix the push rod (3) and the liner (2). The reed switch (8) is fixed in the groove on the end face of the push rod (3) by silicone rubber. The debugging method is as follows: Step 1. Install the liquid level switch on the fixture and connect it to the multimeter. Adjust the buzzer mode of the multimeter. Step 2. Inject lubricating oil into the fixture until the multimeter beeps, record the current liquid level position, if it is higher than the preset value, remove the liner and the ejector rod, adjust the ejector rod and the liner mounting threads to reduce the distance between them, if it is lower than the preset value, adjust the ejector rod and the liner mounting threads to increase the distance between them, until the liquid level is consistent with the preset value when the buzzer alarm sounds; continue to add lubricating oil to cover the preset liquid level; Step 3. Release the lubricating oil until the beeping sound of the multimeter stops, record the current position of the liquid level from the installation surface, if it is higher than the preset value, take out the liner and the ejector rod, and adjust the installation threads of the ejector rod and the liner to reduce the distance between them, if it is lower than the preset value, adjust the installation threads of the ejector rod and the liner to increase the distance between them, until the liquid level is consistent with the preset value when the beeping alarm stops; Step 4. Tighten the two slotted cylindrical head screws between the liner and the top rod to fix the distance between them; Working process of the liquid level switch: when the liquid level rises, the float inside the liquid level switch rises with the liquid level, and the magnet continues to approach the reed switch. When it rises to the predetermined liquid level, the magnetic field strength generated by the magnet reaches the attraction strength of the reed switch. The reed switch is affected by the magnetic field of the magnet inside the float and becomes on, and the liquid level switch outputs a conduction signal; when the liquid level drops, the float inside the liquid level switch drops with the liquid level. When it drops to the predetermined liquid level, the magnetic field strength generated by the magnet is less than the attraction strength of the reed switch, the reed switch becomes off, and the liquid level switch outputs a disconnection signal.

2. The debugging method according to claim 1, characterized in that: The material of the push rod (3) is aluminum alloy.

3. The debugging method according to claim 1, characterized in that: The material of the lining (2) is austenitic stainless steel.

4. The debugging method according to claim 1, characterized in that: The height of the groove should be greater than or equal to the diameter of the reed switch (8).

5. The debugging method according to claim 1, characterized in that: The lining (2) and the shell (6) are clearance-fitted, and the roughness is Ra3.

2.

6. The debugging method according to claim 1, characterized in that: The buoy (7) is composed of an outer shell and a round cover, and the round cover is in point contact with the shell (6).

7. The debugging method according to claim 1, characterized in that: The material of the buoy (7) is polyetheretherketone.

8. The debugging method according to claim 1, characterized in that: The inner lining (2) is provided with a wire harness passing hole.

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