Magnetic proximity switch

Abstract

The utility model relates to a magnetic proximity switch, which comprises a shell, an inner cylinder, a trigger assembly and a circuit assembly, the inner cylinder is arranged at the lower section in the shell, the trigger assembly is arranged in the inner cylinder, and the circuit assembly matched with the trigger assembly is arranged at the upper section in the shell. According to the utility model, the normally-closed function is realized through the static magnetic attraction force between the induction magnetic steel and the fixed magnetic steel and the bundle-shaped magnetic steel, and the static magnetic attraction force can resist violent vibration, so that the condition of terminal misoperation is avoided; when the induction target is gradually close to the induction surface, the dynamic magnetic attraction force between the target and the induction magnetic steel is gradually increased and exceeds the static magnetic attraction force at a rated working distance point, and the trigger terminal is conducted with the normally open terminal. According to the proximity switch, violent vibration is avoided in the movement process, the movable contact and the normally-open terminal or the normally-closed terminal have large magnetic attraction force to ensure very low contact resistance, electrical action and mechanical action can reach high stability, and the service life of the proximity switch is further prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of proximity switches and relates to a magnetic proximity switch. Background Art

[0002] In an industrial process control system, a proximity switch is an electrical device used to feedback the state of an actuator and the position of a valve. It is widely used in various actuators and valves in industries such as petrochemical, nuclear power, and new energy. In these industries, proximity switches are often used in harsh environments, such as underwater, ocean, desert, nuclear power plant irradiation, metal chips, dust, explosive gases, corrosive chemicals, high temperature, low temperature and other extremely harsh environments, and even need to be able to work stably during an earthquake.

[0003] In the prior art, the passive proximity switches that can work in some of the above environments are mainly mechanical micro switches and reed tube proximity switches. Even the excellent mechanical micro switches cannot work stably under high temperature and high humidity, salt spray and earthquake conditions, and are prone to problems such as contact corrosion, poor contact or poor breaking; the mechanical switches are extremely prone to an increase in the operating distance due to mechanical wear after long-term operation, and even cannot detect the in-place state. The reed tube proximity switch is prone to the problem of excessive contact resistance at low temperature, and is extremely prone to false operation, such as the normally open contact closing and the normally closed contact opening, under severe vibration; the mechanical operating life of the reed tube proximity switch is generally higher than that of the mechanical proximity switch, but its contact resistance will start to increase significantly after more than 100,000 times, and the electrical operating life is relatively short under the condition of excessive current. Although the mechanical operating life can reach the order of 1 million times, the electrical operating life is only 1 / 10 of it. Summary of the Invention

[0004] The purpose of the utility model is to overcome the deficiencies existing in the prior art, solve the problem that the electrical operating life of the proximity switch is relatively short under the condition of excessive current, and provide a magnetic proximity switch.

[0005] To achieve the above purpose, the following technical solutions are adopted:

[0006] The magnetic proximity switch includes a housing, an inner cylinder, a trigger assembly and a circuit assembly. An inner cylinder is arranged at the lower section inside the housing, a trigger assembly is arranged inside the inner cylinder, and a circuit assembly matched with the trigger assembly is arranged at the upper section inside the housing;

[0007] The triggering component includes a magnet sheath, an induction magnet, a screw rod, a spacer sleeve, a beam-shaped magnet, a fixed magnet, and a movable body. A magnet sheath is provided at the lower end inside the housing, and an induction magnet is provided inside the magnet sheath; a spacer sleeve is provided at the lower end of the inner cylinder. There is a fixed magnet on the outer side of the upper section of the spacer sleeve, and a beam-shaped magnet 9 is screwed on the outer side of the lower section of the spacer sleeve; a screw rod is slidably arranged inside the spacer sleeve. The lower end of the screw rod is connected to the magnet sheath, and the upper end of the screw rod is screwed with a movable body;

[0008] The circuit component includes a movable contact, a copper pressure plate, a fixing member, a normally closed terminal, a normally open terminal, a common terminal, and a fixing plug. A fixing plug is provided at the upper end of the inner cylinder, and a normally closed terminal, a normally open terminal, and a common terminal are connected by connecting wires below the fixing plug. The copper pressure plate and the movable contact are installed at the upper end of the movable body by a fixing member. One end of the movable contact can cooperate with the common terminal, and a triggering terminal is provided at the other end of the movable contact. The upper end of the triggering terminal can cooperate with the normally closed terminal, and the lower end can cooperate with the normally open terminal.

[0009] Preferably, a guiding groove is provided in the middle of the inner cylinder, and a guiding piece that can cooperate with the guiding groove is provided on the outer side of the lower end of the movable body.

[0010] Preferably, a clamping plate is provided at the lower end of the inner cylinder, and a clamping groove that can cooperate with the clamping plate is provided on the spacer sleeve.

[0011] Preferably, an inspection window is provided on the inner cylinder.

[0012] Preferably, the inner cylinder includes a first half cylinder and a second half cylinder, and the first half cylinder and the second half cylinder are connected by a connecting rod.

[0013] Preferably, the inside of the housing at the upper end of the fixing plug is potted with a sealing resin.

[0014] Preferably, a connecting plate is provided at the upper end of the movable body, and a fixing groove for installing the movable contact and the copper pressure plate is provided at the upper end of the connecting plate.

[0015] Preferably, the lower end of the screw rod is fixed to the spacer sleeve by a set screw.

[0016] Preferably, a positioning block is provided on the fixing plug, and a positioning groove that can cooperate with the positioning block is provided on the inner cylinder.

[0017] Compared with the prior art, the utility model has the following advantages:

[0018] The utility model realizes the normally-closed function of the proximity switch through the static magnetic attraction force between the induction magnet and the fixed magnet and the beam-shaped magnet. Since the static magnetic attraction force can resist severe vibration, the situation of misoperation of the terminal is avoided. When the induction target gradually approaches the induction surface, the dynamic magnetic attraction force between the target and the induction magnet gradually increases. After exceeding the static magnetic attraction force at the rated working distance point, the induction magnet drives the sliding component to move towards the target direction, further increasing the dynamic magnetic attraction force, so as to realize the conduction of the normally-open terminal while resisting severe vibration. Whether the target is present or not, there is a large magnetic attraction force between the trigger terminal and the normally-open terminal or the normally-closed terminal to ensure a very low contact resistance, and both the electrical action and the mechanical action have high stability, thereby improving the service life of the proximity switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0020] Figure 2 It is an exploded schematic diagram of the assembly of the trigger component and the circuit component of the utility model.

[0021] Figure 3 It is a schematic diagram of the inner cylinder structure of the utility model.

[0022] Figure 4 It is a schematic diagram of the circuit component structure of the utility model.

[0023] In the figure: 1. housing; 2. inner cylinder; 5. magnet sheath; 6. induction magnet; 7. screw; 8. spacer; 9. beam-shaped magnet; 10. fixed magnet; 11. movable body; 12. movable contact; 13. copper pressure plate; 14. fixing piece; 15. normally-closed terminal; 16. normally-open terminal; 17. common terminal; 18. fixing plug; 19. connecting wire; 20. trigger terminal; 21. guide groove; 22. guide piece; 23. clamping plate; 24. clamping groove; 25. inspection window; 26. first half cylinder; 27. second half cylinder; 28. sealing resin; 29. connecting plate; 30. fixing groove; 31. set screw; 32. positioning block; 33. positioning groove; 34. connecting rod. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the utility model. Obviously, the described embodiments are only a part of the embodiments of the utility model, rather than all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the utility model.

[0025] As Figures 1-4As shown in the figure, a magnetic proximity switch includes a housing 1, an inner cylinder 2, a trigger assembly, and a circuit assembly. The lower part inside the housing 1 is provided with an inner cylinder 2, the inside of the inner cylinder 2 is provided with a trigger assembly, and the upper part inside the housing 1 is provided with a circuit assembly that cooperates with the trigger assembly. When the trigger assembly operates, it can change the on-off state of the circuit assembly;

[0026] The trigger assembly includes a magnet sheath 5, an induction magnet 6, a screw 7, a spacer sleeve 8, a beam-shaped magnet 9, a fixed magnet 10, and a movable body 11. The lower end inside the housing 1 is provided with a magnet sheath 5, and an induction magnet 6 is arranged inside the magnet sheath 5. The induction magnet 6 is fixed inside the magnet sheath 5;

[0027] A spacer sleeve 8 is arranged at the lower end of the inner cylinder 2. There is a fixed magnet 10 on the outer side of the upper section of the spacer sleeve 8, and a beam-shaped magnet 9 is screwed on the outer side of the lower section of the spacer sleeve 8. The magnetic attraction force between the fixed magnet 10 and the beam-shaped magnet 9 and the induction magnet 6 causes the induction magnet 6 to approach the fixed magnet 10 and the beam-shaped magnet 9. The magnetic attraction force can resist severe vibration and avoid misoperation of the contacts;

[0028] A screw 7 is slidably arranged inside the spacer sleeve 8. The lower end of the screw 7 is connected to the magnet sheath 5, and the upper end of the screw 7 is screwed with a movable body 11. The movable body 11 can slide up and down inside the inner cylinder 2;

[0029] The circuit assembly includes a movable contact 12, a copper pressure plate 13, a fixing member 14, a normally closed terminal 15, a normally open terminal 16, a common terminal 17, and a fixing plug 18. A fixing plug 18 is arranged at the upper end of the inner cylinder 2. A normally closed terminal 15, a normally open terminal 16, and a common terminal 17 are connected below the fixing plug 18 by a connecting wire 19. The normally closed terminal 15, the normally open terminal 16, and the common terminal 17 are fixed in position under the action of the fixing plug 18;

[0030] The copper pressure plate 13 and the movable contact 12 are installed at the upper end of the movable body 11 by a fixing member 14. One end of the movable contact 12 can cooperate with the common terminal 17, and a trigger terminal 20 is arranged at the other end of the movable contact 12. The upper end of the trigger terminal 20 can cooperate with the normally closed terminal 15, and the lower end can cooperate with the normally open terminal 16; when the induction magnet 6 approaches the fixed magnet 10 and the beam-shaped magnet 9 under the magnetic attraction force, the trigger terminal 20 is in a state of cooperating with the normally closed terminal 15, and the proximity switch is in a closed state. When the induction target gradually approaches the induction magnet 6, the induction magnet 6 moves downward, driving the screw 7 to move downward, the screw 7 drives the movable body 11 to move downward, and the movable contact 12 on the movable body 11 drives the trigger terminal 20 to move downward. The lower end of the trigger terminal 20 cooperates with the normally open terminal 16, thereby realizing the conduction of the normally open terminal 16. Similar to the avalanche effect, the trigger assembly is attracted near the induction target, ensuring a very low contact resistance, improving the stability of electrical and mechanical actions, and further improving the service life of the proximity switch.

[0031] Further, a guiding groove 21 is provided in the middle of the inner cylinder 2, and a guiding piece 22 that can cooperate with the guiding groove 21 is provided on the outer side of the lower end of the movable body 11. The cooperation between the guiding piece 22 and the guiding groove 21 enables the movable body 11 to move up and down stably.

[0032] Further, a clamping plate 23 is provided at the lower end of the inner cylinder 2, and a clamping groove 24 that can cooperate with the clamping plate 23 is provided on the spacer sleeve 8. The cooperation between the clamping plate 23 and the clamping groove 24 enables the spacer sleeve 8 to be firmly fixed at the lower end of the inner cylinder 2.

[0033] Further, an inspection window 25 is provided on the inner cylinder 2. The inspection window 25 is used to monitor the assembly condition of each terminal during the installation of the tail fixing plug 18. If fine adjustment of the gap between three terminals is required, adjustment can be easily achieved through this inspection window 25 using tools.

[0034] Further, the inner cylinder 2 includes a first half cylinder 26 and a second half cylinder 27, and the first half cylinder 26 and the second half cylinder 27 are connected by a connecting rod 34. The form of the two half cylinders makes the inner cylinder 2 convenient for assembly.

[0035] Further, a sealing resin 28 is potted inside the housing 1 at the upper end of the fixing plug 18. The sealing resin 28 strengthens the overall sealing of the proximity switch and enhances the waterproof and dustproof performance of the proximity switch.

[0036] Further, a connecting plate 29 is provided at the upper end of the movable body 11, and a fixing groove 30 for installing the movable contact 12 and the copper pressure plate 13 is provided at the upper end of the connecting plate 29. The fixing groove 30 enables the movable contact 12 and the copper pressure plate 13 to be better fixed.

[0037] Further, the lower end of the screw rod 7 is fixed to the spacer sleeve 8 by a set screw 31.

[0038] Further, a positioning block 32 is provided on the fixing plug 18, and a positioning groove 33 that can cooperate with the positioning block 32 is provided on the inner cylinder 2. The cooperation between the positioning block 32 and the positioning groove 33 enables the inner cylinder 2 not to rotate.

[0039] Working principle: The utility model replaces the mechanical mechanism with a magnetic attraction structure. Through the magnetic attraction force between the fixed magnet 10 and the beam-shaped magnet 9 on the spacer sleeve 8 and the induction magnet 6, the induction magnet 6 is always close to the fixed magnet 10 and the property magnet 9. This magnetic attraction force can resist severe vibration and avoid misoperation of the contacts;

[0040] When the induction magnet 6 approaches the fixed magnet 10 and the attribute magnet 9 under the magnetic attraction force, the trigger terminal 20 is in a state of cooperating with the normally closed terminal 15, and the proximity switch is in the off state. When the induction target gradually approaches the induction magnet 6, the induction magnet 6 moves downward, driving the screw 7 to move downward. The screw 7 drives the movable body 11 to move downward. The movable contact 12 on the movable body 11 drives the trigger terminal 20 to move downward. The lower end of the trigger terminal 20 cooperates with the normally open terminal 16, thereby realizing the conduction of the normally open terminal 16. Similar to the avalanche effect, the trigger assembly is attracted near the induction target, ensuring a very low contact resistance, improving the stability of electrical and mechanical actions, and further increasing the service life of the proximity switch.

[0041] It can be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principle of the present invention. However, the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims

1. A magnetic proximity switch, comprising a housing (1), an inner cylinder (2), a trigger assembly and a circuit assembly, characterized in that: Inside the lower part of the housing (1), an inner cylinder (2) is provided. Inside the inner cylinder (2), a triggering component is provided. Inside the upper part of the housing (1), a circuit component matching with the triggering component is provided. The triggering component includes a magnet sheath (5), an induction magnet (6), a screw (7), a spacer sleeve (8), a beam-shaped magnet (9), a fixed magnet (10), and a movable body (11). At the lower end inside the housing (1), a magnet sheath (5) is provided, and an induction magnet (6) is arranged inside the magnet sheath (5). At the lower end of the inner cylinder (2), a spacer sleeve (8) is provided. There is a fixed magnet (10) on the outer side of the upper section of the spacer sleeve (8), and a beam-shaped magnet (9) is screwed on the outer side of the lower section of the spacer sleeve (8). A screw (7) is slidably arranged inside the spacer sleeve (8). The lower end of the screw (7) is connected to the magnet sheath (5), and the upper end of the screw (7) is screwed with a movable body (11). The circuit component includes a movable contact (12), a copper pressure plate (13), a fixing member (14), a normally closed terminal (15), a normally open terminal (16), a common terminal (17), and a fixing plug (18). At the upper end of the inner cylinder (2), a fixing plug (18) is provided. Below the fixing plug (18), a normally closed terminal (15), a normally open terminal (16), and a common terminal (17) are connected by a connecting wire (19). The copper pressure plate (13) and the movable contact (12) are installed at the upper end of the movable body (11) by a fixing member (14). One end of the movable contact (12) can cooperate with the common terminal (17). The other end of the movable contact (12) is provided with a triggering terminal (20). The upper end of the triggering terminal (20) can cooperate with the normally closed terminal (15), and the lower end can cooperate with the normally open terminal (16).

2. The magnetic proximity switch according to claim 1, characterized in that: A guiding groove (21) is provided in the middle of the inner cylinder (2). On the outer side of the lower end of the movable body (11), a guiding piece (22) capable of cooperating with the guiding groove (21) is provided.

3. A magnetic proximity switch according to claim 2, characterized in that: A clamping plate (23) is provided at the lower end of the inner cylinder (2). On the spacer sleeve (8), a clamping groove (24) capable of cooperating with the clamping plate (23) is provided.

4. A magnetic proximity switch according to claim 3, characterized in that: An inspection window (25) is opened on the inner cylinder (2).

5. A magnetic proximity switch according to claim 4, characterized in that: The inner cylinder (2) includes a first half cylinder (26) and a second half cylinder (27), and the first half cylinder (26) and the second half cylinder (27) are connected by a connecting rod (34).

6. The magnetic proximity switch according to claim 1, characterized in that: Inside the housing (1) at the upper end of the fixing plug (18), a sealing resin (28) is potted.

7. A magnetic proximity switch according to claim 1, characterized in that: At the upper end of the movable body (11), a connecting plate (29) is provided. On the upper end of the connecting plate (29), a fixing groove (30) for installing the movable contact (12) and the copper pressure plate (13) is opened.

8. A magnetic proximity switch according to claim 1, characterized in that: The lower end of the screw (7) is fixed to the spacer sleeve (8) by a set screw (31).

9. A magnetic proximity switch according to claim 1, characterized in that: On the fixing plug (18), a positioning block (32) is provided. On the inner cylinder, a positioning groove (33) matching with the positioning block (32) is opened.

Images