A heavy-load reed switch structure

Abstract

The present invention belongs to the technical field of reed switches, and in particular to a large-load reed switch structure, comprising a glass tube and a short pin and a long pin encapsulated at both ends of the glass tube, wherein the short pin and the long pin are both sealed and connected to the glass tube, and a pole shoe is provided at one end of the short pin extending into the glass tube, wherein the pole shoe is integrally formed with the short pin; the present invention adopts a design structure in which a magnetic circuit is separated from an electric circuit, and adopts a high-conductivity reed to reduce the on-resistance of the circuit, thereby reducing the resistance heating of a large-load current that causes demagnetization of the magnetic circuit and causes unreliable switching action; a snap-on armature magnetic circuit structure is adopted, which eliminates the inherent elastic restoring reaction force of the magnetic reed of a traditional reed switch while ensuring that the armature can produce a suction action under the action of a magnetic field, and the restoring reaction force required for the disconnecting contact is provided solely by a copper alloy elastic conductive reed, thereby creating conditions for increasing the cross-sectional area of ​​the copper alloy elastic reed of the circuit and reducing the circuit resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of reed switches, and in particular relates to a heavy-load reed switch structure. Background Art

[0002] A reed switch is also called a dry reed pipe. It is an electric switch operated by an applied magnetic field. The basic type is to seal two magnetic reeds in a glass tube. Although the two reeds overlap, there is a small air gap in the middle. When there is an external magnetic field, the two reeds will be attracted and contacted, so that the current flows through the reeds to achieve contact connection. Once the magnetic field moves away from the switch or disappears, the reeds return to their initial state under the action of their own elastic reaction force, so that the overlapping part of the two reeds re-forms an air gap, and the contacts are disconnected, thereby disconnecting the circuit. Therefore, the traditional reed switch is a structure that combines the magnetic circuit and the circuit into one. The working principle of the reed switch is very simple. Two overlapping soft magnetically sealed alloy reeds (usually composed of iron and nickel) are sealed in a glass tube. The two reeds are overlapped and separated by a small air gap (only about tens to hundreds of microns). The contacts on the two reeds are plated with a layer of very hard precious metal, usually rhodium and ruthenium. This layer of hard precious metal greatly improves the switching life and contact reliability. The glass tube is filled with high-purity inert gas. In order to improve its high-voltage performance, some reed switches will even make the interior into a high vacuum state.

[0003] As a core part of magnetic proximity switch (magnetic sensor) and reed relay, reed switch is widely used in various fields such as household appliances, transportation equipment, monitoring equipment, aerospace and national defense due to its simple and reliable structure, good adaptability to airtight environment of contacts, good safety and long life. High-load reed switch and reed relay are ideal switch components for electrical control systems of equipment such as short-wave communication, electric trains and explosion-proof electrical appliances. When traditional reed switch is connected to a large load current, due to the high resistivity of the soft magnetic reed, the current will easily heat the reed, resulting in high-temperature demagnetization of the magnetic circuit and unreliable contact. Summary of the invention

[0004] In order to solve the problems mentioned in the background technology, the present invention provides a large-load reed switch structure to solve the above problems.

[0005] To achieve the above-mentioned purpose, the present invention provides a technical solution for separating the magnetic circuit and the electric circuit. The specific technical solution is: a large-load reed switch structure, including a glass tube and a short pin and a long pin encapsulated at both ends of the glass tube, the short pin and the long pin are both sealed and connected to the glass tube, the end of the short pin extending into the glass tube is provided with a pole shoe, the pole shoe and the short pin are integrally formed, a static reed sheet is installed on the pole shoe, one end of the static reed sheet is riveted and fixed to the pole shoe, and a static contact is fixedly installed at the other end, the end of the long pin extending into the short pin is provided with a U-shaped magnetic pole, the U-shaped magnetic pole is integrally formed with the long pin, The long tube pin is riveted to one end of a moving spring, and the other end of the moving spring is riveted to the armature with the help of the tail of the moving contact. The inherent elastic force of the curved structure of the moving spring causes one end of the armature to bend upward to form a working air gap in the magnetic circuit, and also forms a contact gap between the static contact and the moving contact, while the other end contacts the U-shaped magnetic pole to form a snap-fit ​​structure of a rotating hinge, which can make the armature rotate around the U-shaped magnetic pole under the action of the magnetic field, thereby driving the moving contact and the movement to realize the closing and opening action with the static contact.

[0006] Preferably, rivets are provided between the pole shoe and the static spring sheet, and between the long tube foot and the dynamic spring sheet, and they are fixed by riveting.

[0007] Preferably, the dynamic reed and the static reed are elastic copper alloy reeds.

[0008] Preferably, the contact surface between the static contact and the static reed is a silver alloy contact.

[0009] Preferably, the magnetic pole is a U-shaped structure, so that a snap-fit ​​magnetic circuit structure is formed between the pole shoe and the armature, and a restoring reaction force is generated by the movable spring.

[0010] Preferably, the movable spring piece and the armature are fixed by riveting the tail of the movable contact.

[0011] Preferably, the short pin and the long pin are both soft magnetic glass sealing alloy structures, and the short pin and the long pin are respectively melt-sealed and sealed with the two ends of the glass tube.

[0012] Preferably, the glass tube is a glass tube or a ceramic tube.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. The magnetic circuit is separated from the electric circuit, which greatly reduces the adverse effect of unreliable contact caused by heating of contacts and reeds when large load current occurs.

[0015] 2. The copper alloy reed is used for conducting electricity, and its resistivity is much lower than the resistivity of the Kovar alloy of ordinary reed switches, so that the reed switch can conduct and switch loads with larger currents.

[0016] 3. Composite contacts are used, and the thickness of the silver alloy is not less than 0.1mm. The contacts of ordinary reed switches are precious metal coatings with a thickness of only about 1um, and the contact resistance to electrical burning is far inferior to this product. Therefore, this product has a larger load current switching capability.

[0017] 4. The snap-on armature magnetic circuit structure eliminates the elastic reaction force of the soft magnetic reed of the ordinary reed switch, improves the magnetic circuit efficiency, and makes the magnetic circuit armature action range larger but does not increase the reed switch action AT value, which is beneficial to increase the contact gap and improve the contact withstand voltage and current breaking capacity.

[0018] 5. The dynamic and static reeds use high elasticity and high conductivity elastic copper alloy strips verified by the relay industry to provide contact recovery reaction force and overtravel. The performance is more stable and better than that of ordinary reed switch reeds.

[0019] 6. This structure has the advantages of simple and reliable structure of reed switch and large load capacity of power relay. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2 It is a schematic diagram of the structure of the present invention.

[0023] In the figure: 1, short pin; 11, pole shoe; 2, glass tube; 3, armature; 4, moving contact; 5, moving reed; 6, rivet; 7, long pin; 71, U-shaped magnetic pole; 8, static contact; 9, static reed. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] See also Figure 1-2The present invention provides the following technical solutions: a large-load reed switch structure, comprising a glass tube 2 and a short pin 1 and a long pin 7 encapsulated at both ends of the glass tube 2, the short pin 1 and the long pin 7 are both sealed and connected to the glass tube 2, the end of the short pin 1 extending into the glass tube 2 is provided with a pole shoe 11, the pole shoe 11 and the short pin 1 are integrally formed, a static reed sheet 9 is installed on the pole shoe 11, one end of the static reed sheet 9 is riveted and fixed to the pole shoe 11, and a static contact 8 is fixedly installed on the other end, a hinge 71 is provided at one end of the long pin 7 extending into the short pin 1, the U-shaped magnetic pole 71 is integrally formed with the long pin 7, and the long pin 7 is riveted One end of the movable spring piece 5 is fixed to the armature 3, and the other end of the movable spring piece 5 is riveted and fixed to the armature 3 by means of the tail of the movable contact 4. The inherent elastic force of the curved structure of the movable spring piece 5 causes one end of the armature 3 to bend upward to form a magnetic circuit working air gap, and also a contact gap is formed between the static contact 8 and the movable contact 4, while the other end contacts the U-shaped magnetic pole 71 to form a snap-fit ​​structure of a rotating hinge, which can make the armature 3 rotate around the U-shaped magnetic pole 71 under the action of the magnetic field, thereby driving the movable contact 4 and the movement to realize the closing and opening action with the static contact 8.

[0026] In this embodiment, the short pin 1 is riveted to the static spring piece 9 with a rivet 6 and a static contact 8 is installed thereon. The long pin 7 is riveted to the moving spring piece 5 with a rivet 6, and the moving contact 4 rivets the moving spring piece 5 and the armature 3 into one body. A section of the long pin 7 inside the glass tube 2 is bent into a U-shaped magnetic pole 71, which overlaps with the armature 3 to form a hinge for the rotation of the armature 3 in a snap-fit ​​magnetic circuit structure. The hinge contact portion can keep the armature 3 in contact with the long pin 7 at all times, which can keep its position stable under vibration and impact conditions, and can also make the working air gap formed by the armature 3 and the pole shoe 11 at one end of the glass tube 2 of the short pin 1 the only gap in the magnetic circuit, thereby reducing the magnetic resistance of the magnetic circuit and improving the efficiency of the magnetic circuit. The moving spring piece 5 and the static spring piece 9 are elastic copper alloy spring pieces, and the moving contact 4 and the static contact 8 are contact surfaces. The contacts are made of silver alloy. When the reed switch is in the magnetic field, the magnetic field flowing through the magnetic circuit generates suction at the air gap between the pole shoe 11 and the armature 3, causing the armature 3 to rotate along the hinge, and the moving contact 4 is driven to move through the moving spring 5. When the moving contact 4 contacts the static contact 8, it pushes the static contact 8 to move, causing the static spring 9 to begin to deform and generate a reaction force. The reaction force increases with the increase in the deformation of the static spring 9, reducing the rotation linear speed of the armature 3, thereby reducing the collision energy when the armature 3 and the pole shoe 11 are fully attracted, and reducing the probability of the sealing part of the long tube pin 7 and the glass tube 2 being broken.

[0027] Specifically, rivets 6 are provided between the pole shoe 11 and the static spring sheet 9, and between the long tube pin 7 and the dynamic spring sheet 5, and they are riveted and fixed by the rivets 6 to increase the stability of the connection mechanism.

[0028] Specifically, the moving reed 5 and the static reed 9 are elastic copper alloy reeds. The moving reed 5 and the static reed 9 use high-elasticity, high-conductivity copper alloy elastic copper strips verified by the relay industry to provide contact recovery reaction force and overtravel. The performance is more stable and better than that of ordinary reed switch reeds.

[0029] Specifically, the contact surface between the static contact 8 and the static reed piece 9 is a silver alloy contact, and a composite contact is used, and the thickness of the silver alloy is not less than 0.1mm. The contact of the ordinary reed switch is a precious metal plating with a thickness of only about 1um, and the contact's resistance to electrical burning is far inferior to that of this product. Therefore, this product has a larger load current switching capability.

[0030] Specifically, a snap-fit ​​structure is formed between the U-shaped magnetic pole 71 and the armature 3, and the elastic force of the movable spring 5 can keep the armature 3 in contact with the U-shaped magnetic pole 71 at all times, thereby maintaining its position stable under vibration and impact conditions, and can also make the working air gap formed by the armature 3 and the pole shoe 11 at one end of the short pin 1 glass tube 2 become the only gap in the magnetic circuit, thereby reducing the magnetic resistance of the magnetic circuit and improving the efficiency of the magnetic circuit.

[0031] Specifically, the short pin 1 and the long pin 7 are both soft magnetic glass sealing alloy structures. The short pin 1 and the long pin 7 are respectively melt-sealed and sealed with the two ends of the glass tube 2. The glass tube 2 is a glass tube or a ceramic tube, which can ensure the structural strength and sealing of the reed switch.

[0032] The working principle and use process of the present invention are as follows: After the present invention is installed, when the reed switch is in the magnetic field, the magnetic field flowing through the magnetic circuit generates suction at the air gap between the pole shoe 11 and the armature 3 to rotate the armature 3 along the U-shaped magnetic pole 71 hinge, and the moving contact 4 is driven to move through the moving spring piece 5. When the moving contact 4 contacts the static contact 8, it pushes the static contact 8 to move so that the static spring piece 9 begins to deform and generates a reaction force. The reaction force increases with the increase of the deformation of the static spring piece 9, thereby reducing the rotation linear speed of the armature 3, thereby reducing the collision energy when the armature 3 and the pole shoe 11 are fully attracted, and reducing the probability of the sealing part of the long tube pin 7 and the glass tube 2 being broken.

[0033] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A heavy-load reed switch structure, characterized in that: The invention comprises a glass tube (2) and a short tube pin (1) and a long tube pin (7) sealed at both ends of the glass tube (2); the short tube pin (1) and the long tube pin (7) are both sealedly connected to the glass tube (2); one end of the short tube pin (1) extending into the glass tube (2) is provided with a pole shoe (11); the pole shoe (11) and the short tube pin (1) are integrally formed; a static reed sheet (9) is mounted on the pole shoe (11); one end of the static reed sheet (9) is riveted and fixed to the pole shoe (11); and a static contact (8) is fixedly mounted on the other end; one end of the long tube pin (7) extending into the glass tube (2) is provided with a U-shaped magnetic pole (71); the magnetic pole (71) and the long tube pin (7) are integrally formed. The long tube pin (7) is riveted to fix one end of a moving spring (5), and the other end of the moving spring (5) is riveted to fix on the armature (3) by means of the tail of the moving contact (4). The elastic force inherent in the curved structure of the moving spring (5) causes one end of the armature (3) to bend upward to form a magnetic circuit working air gap, which also forms a contact gap between the static contact (8) and the moving contact (4), while the other end contacts the U-shaped magnetic pole (71) to form a snap-fit ​​structure of a rotating hinge, so that the armature (3) can rotate around the U-shaped magnetic pole (71) under the action of the magnetic field, thereby driving the moving contact (4) and the moving contact (8) to achieve a closing and opening action with the static contact (8); The movable reed (5) and the static reed (9) are elastic copper alloy reeds, which provide contact reset reaction force and contact overtravel for the reed switch; the magnetic pole (71) is a U-shaped structure, so that a snap-fit ​​magnetic circuit structure is formed between the long tube pin (7) and the armature (3); the short tube pin (1) and the long tube pin (7) are both soft magnetic sealing alloy structures, and the short tube pin (1) and the long tube pin (7) are respectively melt-sealed and sealed with the two ends of the glass tube (2).

2. A heavy-load reed switch structure according to claim 1, characterized in that: The pole shoe (11) and the stationary spring sheet (9), the long tube foot (7) and the moving spring sheet (5), and the moving spring sheet (5) and the armature (3) are all riveted and fixed.

3. A heavy-load reed switch structure according to claim 1, characterized in that: The contact surface between the static contact (8) and the static reed sheet (9) is a silver alloy contact.

4. A heavy-load reed switch structure according to claim 1, characterized in that: The glass tube (2) is a glass tube or a ceramic tube.

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