Subminiature proximity switch sensor

Abstract

The utility model discloses super small proximity switch sensor relates to sensor technical field, including tubular shell, be equipped with circuit board in the shell, the back end of circuit board is connected with wire, the back end of shell passes through threaded connection plug, the inboard of back end of shell is equipped with conical ring, wire passes through plug and conical ring, wire outside is equipped with sealing washer, sealing washer is clamped between plug and conical ring, first sealing adhesive layer is established between the back end surface of shell and plug, the inboard of plug and wire is equipped with second sealing adhesive layer, the utility model discloses through plug extruding sealing washer, can make sealing washer extrude conical ring and wire simultaneously, seal the clearance between wire and shell inside, and form the periphery sealing through first sealing adhesive layer and second sealing adhesive layer, reach the effect of double -layer sealing, make sensor have good sealing property.

Description

Technical Field

[0001] This utility model relates to the field of sensor technology, and in particular to an ultra-miniature proximity switch sensor. Background Technology

[0002] Conventional proximity switches have large outer diameters and long lengths, failing to meet the demands of factory development, especially in miniaturized and precision equipment. Ultra-miniature proximity switches, on the other hand, are compact, non-contact detection elements requiring minimal installation space. With high-precision sensing capabilities, they can quickly identify the approach and departure of targets at close range, triggering signals without physical contact. They are widely used in precision instruments, small equipment, automated production lines, and other scenarios where installation space is limited, providing reliable support for precise positioning, counting, and safety protection. Their compact design saves installation space and adapts to complex working environments, meeting the automation control needs of various miniaturized equipment. Ultra-miniature proximity switches mainly consist of a housing, a probe core, an integrated circuit board, and wires, as exemplified by the patented ultra-miniature proximity switch with publication number CN207250349U. The sealing of ultra-miniature proximity switch sensors needs to be adapted to their compact structure and the application requirements of multiple scenarios. It should have a good sealing effect to avoid signal distortion or component damage caused by sealing failure. For example, ultra-miniature proximity switch sensors have a rigid housing and flexible wires. The connection between the wires and the housing is a weak point in the seal, especially in the case where the ultra-miniature proximity switch sensor moves with the device. Utility Model Content

[0003] The purpose of this invention is to provide an ultra-miniature proximity switch sensor in order to solve at least one of the problems in the prior art mentioned above.

[0004] To achieve the above objectives, this utility model provides the following technical solution: An ultra-miniature proximity switch sensor includes a tubular housing; a circuit board is provided inside the housing, and a wire is connected to the rear end of the circuit board. A plug is connected to the rear end of the housing via a thread. A conical ring is provided on the inner side of the rear end of the housing. The wire passes through the plug and the conical ring. A sealing ring is sleeved on the outer side of the wire. The sealing ring is clamped between the plug and the conical ring. A first sealing layer is provided between the rear end face of the housing and the plug. A second sealing layer is provided between the inner side of the plug and the wire.

[0005] Furthermore, the conical ring has a conical annular surface facing outwards from the rear end of the housing, and the sealing ring contacts the conical annular surface.

[0006] Furthermore, a magnetic core is connected to the front end of the circuit board, and a front cover that shields the magnetic core is connected to the front end of the housing via a threaded connection.

[0007] Furthermore, a first retaining ring is provided on the inner side of the front end of the outer shell, and a third sealing layer is provided between the front side of the first retaining ring and the rear end of the front cover.

[0008] Furthermore, the magnetic core passes through the first retaining ring, and a second retaining ring is provided on the inner side of the outer casing. A sealing gasket is provided on the front side of the second retaining ring to contact the rear side of the magnetic core.

[0009] Furthermore, the front edge of the front cover is evenly distributed with several grooves.

[0010] Furthermore, an indicator light is connected to the circuit board, and a lamp hole corresponding to the indicator light is provided on the side wall of the housing. A cylindrical light cover is connected to the inside of the lamp hole through a fourth sealing adhesive layer.

[0011] Furthermore, the light cover does not protrude from the outside of the lamp hole, and the light cover is filled with transparent sealant columns, the upper end of which is connected to the inner wall of the lamp hole.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention uses a plug to compress the sealing ring, which simultaneously compresses the conical ring and the wire, sealing the gap between the wire and the inside of the housing. Furthermore, it forms an outer seal through a first and a second sealing layer, achieving a double-layer seal and giving the sensor excellent sealing performance.

[0013] The front cover of this invention limits the magnetic core while achieving a double-layer sealing effect at the front end through the contact between the front cover and the third sealing layer, and the contact between the magnetic core and the sealing gasket. This invention also achieves a double-layer sealing effect for the lamp hole by bonding the cylindrical photomask to the lamp hole and sealing the outer end of the photomask with the sealing column, thereby improving the sealing effect and the comprehensiveness of the sealing. Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0015] Figure 2 This is a schematic diagram of the internal structure of this utility model.

[0016] Figure 3 for Figure 2 Enlarged diagram of point A in the middle.

[0017] Figure 4 for Figure 2 Enlarged diagram of point B in the middle.

[0018] Figure 5 for Figure 2 Enlarged diagram of point C in the middle.

[0019] Figure 6 This is an exploded view of the present invention.

[0020] Figure 7 This is a schematic diagram of the front cover of this utility model in disassembled state.

[0021] Figure 8 This is a three-dimensional structural diagram of the threaded outer shell of this utility model.

[0022] In the diagram: 1. Outer shell; 2. Wire; 3. Circuit board; 4. Magnetic core; 5. Indicator light; 6. Plug; 7. Conical ring; 8. Sealing ring; 9. First sealant layer; 10. Second sealant layer; 11. Front cover; 12. First retaining ring; 13. Third sealant layer; 14. Second retaining ring; 15. Sealing gasket; 16. Groove; 17. Potting compound; 18. Lamp hole; 19. Photomask; 20. Fourth sealant layer; 21. Sealing column. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings. The drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0024] Specific embodiments of the ultra-miniature proximity switch sensor provided by this utility model: Please see Figures 1-8 An ultra-miniature proximity switch sensor includes a tubular housing 1, which is a metal housing, preferably a stainless steel housing, which protects the internal structure and forms a shielding layer.

[0025] The outer casing 1 contains a circuit board 3. The rear end of the circuit board 3 is connected to a wire 2, the front end of the circuit board 3 is connected to a magnetic core 4, and an indicator light 5 is connected to the circuit board 3. The indicator light 5 is a surface-mount LED.

[0026] The rear end of the outer casing 1 is connected to the plug 6 via a thread. A conical ring 7 is provided on the inner side of the rear end of the outer casing 1. The inner side of the rear end of the outer casing 1 has an internal thread section. The conical ring 7 is the front side of the internal thread section. The wire 2 passes through the plug 6 and the conical ring 7. A sealing ring 8 is tightly fitted on the outer side of the wire 2. The sealing ring 8 is clamped between the plug 6 and the conical ring 7. The conical ring 7 has a conical annular surface facing the outer side of the rear end of the outer casing 1. The sealing ring 8 is in contact with the conical annular surface.

[0027] The front side of the conical ring 7 is an annular plane. The inner diameter of the conical ring 7 is larger than the outer diameter of the wire 2, allowing the wire 2 to pass through. The plug 6 has a through hole in the center for the wire 2 to pass through. During the process of rotating the plug 6 to close the rear port of the outer shell 1, the inner end of the plug 6 squeezes the sealing ring 8. The sealing ring 8 is squeezed onto the conical ring surface. The inner diameter of the conical ring surface at the front end becomes smaller, causing the sealing ring 8 to deform forward and towards the center, sealing the gap between the conical ring 7 and the wire 2.

[0028] The rear part of the plug 6 is approximately hemispherical, the front part of the plug 6 is studded, the outer diameter of the rear front end of the plug 6 is large and forms a step with the stud section, an annular first sealing layer 9 is provided between the rear end face of the outer shell 1 and the plug 6, and a second sealing layer 10 is provided between the inner side of the plug 6 and the wire 2.

[0029] The front end of the outer casing 1 is threadedly connected to a front cover 11 that shields the magnetic core 4. To ensure a flat front end, the front cover 11 can be completely moved inside the outer casing 1. The inner side of the front end of the outer casing 1 has an internal thread section that mates with the front cover 11, and the outer side of the front cover 11 has an external thread. Several arc-shaped grooves 16 are evenly distributed around the circumference of the front edge of the front cover 11. The front cover 11 can be rotated by inserting a tweezer-like tool into the grooves 16, thus enabling the front cover 11 to be installed or removed.

[0030] A first retaining ring 12 is provided on the inner side of the front end of the outer casing 1, and a third sealing layer 13 is provided between the front side of the first retaining ring 12 and the rear end of the front cover 11. A second retaining ring 14 is provided on the inner side of the outer casing 1. The inner diameter of the second retaining ring 14 is smaller than that of the first retaining ring 12. The second retaining ring 14 is located behind the first retaining ring 12. The magnetic core 4 passes through the first retaining ring 12. A sealing gasket 15 is provided on the front side of the second retaining ring 14, which contacts the rear side of the magnetic core 4. The sealing gasket 15 is annular in shape, made of rubber, and is adhered to the front side of the second retaining ring 14.

[0031] An indicator light 5 is connected to the circuit board 3. A lamp hole 18 corresponding to the indicator light 5 is provided on the side wall of the housing 1. The inner half of the lamp hole 18 is connected to a cylindrical photomask 19 via a fourth sealant layer 20. The fourth sealant layer 20 is located on the outer side of the upper end of the photomask 19. The photomask 19 does not protrude beyond the outer side of the lamp hole 18 and has a gap with the outer edge of the lamp hole 18. A transparent sealant column 21, which is a transparent UV adhesive, is filled inside the photomask 19. The upper end of the sealant column 21 is connected to the outer half of the inner wall of the lamp hole 18. A potting compound 17, which is a low-viscosity UV-curable adhesive or epoxy resin, is filled on the outer side of the photomask 19 between the circuit board 3 and the housing 1.

[0032] Packaging process: A sealing ring 8 and a plug 6 are fitted on the outside of the wire 2. The circuit board 3 is connected to the wire 2 and the connection is insulated with heat shrink film. Then the circuit board 3 and the wire 2 are passed through the outer shell 1. The circuit board 3 protrudes from the front end of the outer shell 1 and the front end of the circuit board 3 is connected to the magnetic core 4. Apply a layer of sealant to the front side of the first retaining ring 12, and attach a sealing gasket 15 to the front side of the second retaining ring 14. Pull the wire 2 and the circuit board 3 backward so that the rear end of the magnetic core 4 is attached to the front side of the sealing gasket 15. Install the front cover 11 so that the rear end of the front cover 11 presses against the sealing layer in front of the first retaining ring 12, and at the same time, the front cover 11 makes the magnetic core 4 stick to the front of the sealing gasket 15. Apply a sealant layer to the front side of the plug 6 or the rear end of the housing 1, apply a sealant layer to the outside of the wire 2 at the rear end of the housing 1, and screw the plug 6 tightly onto the rear end of the housing 1. Fill the lamp hole 18 with potting compound 17, then apply a sealant layer to the outer side of the upper end of the photomask 19, so that the photomask 19 enters the lamp hole 18, with the inner end corresponding to the outer side of the indicator light 5. The upper end of the photomask 19 is bonded to the inside of the lamp hole 18, and the potting compound 17 inside the photomask 19 is cleaned out. Finally, transparent sealant is injected into the inside of the photomask 19. After curing, the outer side of the transparent sealant is polished to form a sealant column 21.

[0033] In some embodiments, the outer ring side of the housing 1 is a smooth surface, while in other embodiments, the outer ring side of the housing 1 is provided with external threads; adaptable to different installation and fixing occasions.

[0034] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still make modifications to the technical solutions described in the foregoing embodiments without creative effort, or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An ultra-miniature proximity switch sensor, comprising a tubular housing (1); characterized in that, The outer casing (1) is provided with a circuit board (3), and the rear end of the circuit board (3) is connected to a wire (2). The rear end of the outer casing (1) is connected to a plug (6) by a thread. The inner side of the rear end of the outer casing (1) is provided with a conical ring (7). The wire (2) passes through the plug (6) and the conical ring (7). The outer side of the wire (2) is provided with a sealing ring (8). The sealing ring (8) is clamped between the plug (6) and the conical ring (7). The rear end face of the outer casing (1) and the plug (6) are provided with a first sealing layer (9). The inner side of the plug (6) and the wire (2) are provided with a second sealing layer (10).

2. The ultra-miniature proximity switch sensor according to claim 1, characterized in that, The conical ring (7) has a conical annular surface facing the outer rear end of the housing (1), and the sealing ring (8) is in contact with the conical annular surface.

3. The ultra-miniature proximity switch sensor according to claim 1, characterized in that, The circuit board (3) is connected to a magnetic core (4) at the front end, and the front end of the outer casing (1) is connected to a front cover (11) that shields the magnetic core (4) by a thread.

4. The ultra-miniature proximity switch sensor according to claim 3, characterized in that, The outer shell (1) has a first retaining ring (12) on the inner side of the front end, and a third sealing layer (13) is provided between the front side of the first retaining ring (12) and the rear end of the front cover (11).

5. The ultra-miniature proximity switch sensor according to claim 4, characterized in that, The magnetic core (4) passes through the first retaining ring (12), and the inner side of the outer shell (1) is provided with a second retaining ring (14). The front side of the second retaining ring (14) is provided with a sealing gasket (15) that contacts the rear side of the magnetic core (4).

6. The ultra-miniature proximity switch sensor according to claim 3, characterized in that, The front cover (11) has several grooves (16) evenly distributed around its front edge.

7. The ultra-miniature proximity switch sensor according to claim 1, characterized in that, The circuit board (3) is connected to an indicator light (5), and the side wall of the housing (1) is provided with a lamp hole (18) corresponding to the indicator light (5). The inner side of the lamp hole (18) is connected to a cylindrical light cover (19) through a fourth sealant layer (20).

8. The ultra-miniature proximity switch sensor according to claim 7, characterized in that, The light cover (19) does not protrude from the outside of the lamp hole (18). The light cover (19) is filled with a transparent sealant column (21), and the upper end of the sealant column (21) is connected to the inner wall of the lamp hole (18).

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