A contact device against short-circuit current

Abstract

The present invention discloses a contact device against short-circuit current, which relates to the technical field of relays. The contact device includes an insulating housing, an electromagnet assembly is installed inside the insulating housing, and a first armature is arranged above the electromagnet assembly inside the insulating housing. An insulating column that is slidably matched with the first armature is fixedly connected to the inner wall of the top end of the insulating housing, and a first spring is fixedly connected between the inner wall of the top end of the insulating housing and the top end of the first armature. A conductive block is arranged on one side of the first armature inside the insulating housing. Two groups of first contacts are symmetrically installed at the bottom of the conductive block. Two groups of second contacts corresponding to the two groups of first contacts are respectively arranged at the bottom ends of the two groups of first contacts. A compensation mechanism for driving the two groups of second contacts to move longitudinally is arranged inside the insulating housing. The present invention can perform adaptive compensation according to the burning damage situation, and can timely disconnect the working circuit when a short circuit occurs in the working circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of relays, and specifically to a contact device resistant to short-circuit current. Background Art

[0002] A relay is an electrical control device. When the change of the input quantity reaches the specified requirement, it is an electrical appliance that causes a predetermined step change in the controlled quantity in the electrical output circuit. It has an interactive relationship between the control system and the controlled system and is usually applied to an automatic control circuit. A relay mainly consists of an electromagnet, an armature, a spring, contacts, etc. When the coil is energized, the electromagnet generates magnetism, attracts the armature, causes the contacts to produce displacement actions, and the contacts contact to make the circuit conduct. When the coil is de-energized, the electromagnet loses magnetism, and the armature resets under the action of the spring, causing the contacts to separate.

[0003] When the contact device of the existing relay is in use, when the circuit is disconnected and the contacts are separated, an arc will be formed between the contacts. When the circuit is short-circuited, the current in the circuit suddenly increases, and the relay itself cannot perform short-circuit protection. If the contacts of the relay cannot be disconnected in time, the short-circuit current will affect the electrical equipment in the circuit. Secondly, a large current will be formed in the case of a short circuit, resulting in a large arc when the contacts are separated, and the contacts are prone to ablation. When the contacts are ablated and then make the next contact, a gap will be generated, resulting in poor contact between the contacts. If the contact pressure of the contacts is insufficient, the resistance will increase, generating too much heat and causing more serious ablation. Summary of the Invention

[0004] The technical solution of the present invention aims at the technical problem that the existing technical solutions are too single, and provides a solution significantly different from the existing technology. Specifically, the purpose of the present invention is to provide a contact device resistant to short-circuit current to solve the problem that large current in the case of short circuit will cause contact damage and poor contact as mentioned in the above background art.

[0005] To achieve the above object, the present invention provides the following technical solution: A contact device resistant to short-circuit current, including an insulating housing, an electromagnet assembly is installed inside the insulating housing, and a first armature is arranged above the electromagnet assembly inside the insulating housing. An insulating column slidably matched with the first armature is fixedly connected to the inner wall of the top end of the insulating housing, and a first spring is fixedly connected between the inner wall of the top end of the insulating housing and the top end of the first armature. A conductive block is arranged on one side of the first armature inside the insulating housing. Two groups of first contacts are symmetrically installed at the bottom of the conductive block. Two groups of second contacts corresponding to the two groups of first contacts are respectively arranged at the bottom ends of the two groups of first contacts, and the two groups of second contacts are slidably connected to the insulating housing. A compensation mechanism for driving the two groups of second contacts to move longitudinally is arranged inside the insulating housing, and a connection mechanism is arranged inside the first armature.

[0006] Preferably, the compensation mechanism includes a support plate fixedly arranged on the inner wall of the insulating housing. A slide bar slidably matched with the support plate is arranged inside the support plate. A stop block is fixedly connected to the bottom of the first armature at the top of the slide bar. A second spring located outside the slide bar is fixedly connected between the stop block and the support plate. An auxiliary driving assembly is arranged on one side of the lower end of the slide bar.

[0007] Preferably, the auxiliary driving assembly includes a fixed housing fixedly arranged on the outer wall of the insulating housing. A gear rotatably connected to the fixed housing is arranged on the outer wall of one side of the fixed housing. A tooth block meshed with the gear is arranged on the outer wall of the slide bar. A threaded rod rotatably connected to the fixed housing is arranged on the outer wall of the other side of the fixed housing. A ratchet mechanism is arranged inside the fixed housing between the gear and the threaded rod. A moving block threadedly matched with the threaded rod is arranged on the outer wall of the threaded rod. Two groups of connecting rods are symmetrically hinged on the outer wall of the moving block. The other ends of the two groups of connecting rods are hinged to an insulating plate fixedly arranged on the outer wall of the lower ends of the two second contacts.

[0008] Preferably, the connecting mechanism includes a first inner cavity arranged inside the first armature. A second armature slidably matched with the first inner cavity is arranged inside the first inner cavity. A second inner cavity is opened on one side of the first inner cavity inside the first armature. A communication groove for communicating the first inner cavity with the second inner cavity is arranged inside the first armature. One end of the communication groove is located at the lower end of the first inner cavity, and the other end of the communication groove is located at the bottom of one end of the second inner cavity. A third spring is fixedly connected to the inner wall of one end of the second inner cavity. A piston slidably matched with the second inner cavity is fixedly connected to one end of the third spring. An insulating rod penetrating through the outer wall of the first armature is fixedly connected to the outer wall of the piston. One end of the insulating rod is fixedly connected to the outer wall of the conductive block.

[0009] Preferably, a sealing ring fitting the inner wall of the first inner cavity is arranged on the outer wall of the second armature. Air holes communicating with the first inner cavity and the second inner cavity are respectively opened at the top and bottom of the first armature.

[0010] Preferably, a limiting rod slidably matched with the first armature is arranged above the second inner cavity inside the first armature. One end of the limiting rod penetrates through the outer wall of the first armature and is fixedly connected to the outer wall of the conductive block, and the limiting rod is made of insulating material.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] In the present invention, a compensation mechanism is provided. When the load in the working circuit is too large and the first contact and the second contact become shorter due to ablation, the downward movement stroke of the first contact will increase, causing the downward movement position of the first armature to increase. The first armature then presses the stopper to synchronously move the slide rod downward, and the slide rod drives the gear to rotate. In this rotation direction, the gear drives the threaded rod to rotate through the ratchet mechanism, and the threaded rod drives the moving block to move leftward. The moving block then pushes the insulating plate upward through the connecting rod, and the insulating plate pushes the second contact upward. The thread density of the threaded rod is set to match the downward movement stroke of the stopper, so that the displacement of the stopper downward is the same as the displacement of the second contact upward. After the second contact compensates for the burned length, it ensures that each time power is restored after power-off, it can be adaptively compensated according to the ablation conditions of the first contact and the second contact. After compensation, the downward movement position of the first armature can be restored to the initial position when powered on, and the second spring resets to push the stopper back to the bottom of the first armature. The stopper then drives the slide rod to move upward and reset, and the slide rod drives the gear to reverse. In this rotation direction, the gear will not drive the threaded rod to rotate through the ratchet mechanism, so that the next compensation can be continued on the basis of the compensated movement of the second contact;

[0013] In the present invention, a connection mechanism is provided. When a short circuit occurs in the working circuit, the current passing through the electromagnet assembly in the control circuit is increased, so that the generated magnetic force is increased. The first armature is limited after the first contact and the second contact come into contact, and the magnetic force pulls the second armature to slide downward in the first inner cavity. The second armature then presses the air in the first inner cavity into the second inner cavity through the communication groove, pushing the piston to slide leftward in the second inner cavity and pulling the third spring. The piston then pushes the insulating rod to move leftward, the insulating rod drives the conductive block to move leftward, and the conductive block drives the first contact at the bottom to move leftward to separate from the second contact. The first contact on the right moves to the left of the second contact on the left, so that the circuit is disconnected, preventing the short-circuit current from continuously affecting the electrical equipment in the working circuit. At the same time, in the way of horizontally moving to disconnect the first contact and the second contact, the generation of electric arcs can be reduced.

[0014] In summary, after ablation occurs on the first contact and the second contact, it can be adaptively compensated according to the ablation conditions, avoiding the phenomenon of poor contact between the first contact and the second contact. When a short circuit occurs in the working circuit, the working circuit can be disconnected in time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a front sectional structure schematic diagram of the present invention;

[0016] Figure 2 is for the present invention Figure 1 an enlarged view of part A;

[0017] Figure 3 is a front sectional structure schematic diagram of the fixed housing of the present invention;

[0018] Figure 4 This is a schematic right side view structure diagram of the ratchet mechanism of the present invention;

[0019] Figure 5 This is a schematic top view structure diagram of the moving block, connecting rod and insulating plate of the present invention;

[0020] Figure 6 This is a schematic front sectional view structure diagram of the first armature of the present invention.

[0021] In the figure: 1. Insulating housing; 2. Electromagnet assembly; 3. First armature; 4. Insulating column; 5. First spring; 6. Conductive block; 7. First contact; 8. Second contact; 9. Support plate; 10. Slide bar; 11. Stopper; 12. Second spring; 13. Fixed housing; 14. Gear; 15. Threaded rod; 16. Ratchet mechanism; 17. Moving block; 18. Connecting rod; 19. Insulating plate; 20. First inner cavity; 21. Second armature; 22. Second inner cavity; 23. Third spring; 24. Piston; 25. Insulating rod. Specific embodiments

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0023] Please refer to Figure 1-6 , the present invention provides a technical solution: a contact device for resisting short-circuit current, including an insulating housing 1, an electromagnet assembly 2 is installed inside the insulating housing 1, and a first armature 3 is arranged above the electromagnet assembly 2 inside the insulating housing 1. An insulating column 4 slidably matched with the first armature 3 is fixedly connected to the inner wall of the top end of the insulating housing 1, and a first spring 5 is fixedly connected between the inner wall of the top end of the insulating housing 1 and the top end of the first armature 3. A conductive block 6 is arranged on one side of the first armature 3 inside the insulating housing 1. Two groups of first contacts 7 are symmetrically installed at the bottom of the conductive block 6. Two groups of second contacts 8 corresponding to the two groups of first contacts 7 are respectively arranged at the bottom ends of the two groups of first contacts 7, and the two groups of second contacts 8 are slidably connected to the insulating housing 1. A compensation mechanism for driving the two groups of second contacts 8 to move longitudinally is arranged inside the insulating housing 1, and a connection mechanism is arranged inside the first armature 3.

[0024] The compensation mechanism includes a support plate 9 fixedly arranged on the inner wall of the insulating housing 1. A slide bar 10 slidably matched with the support plate 9 is arranged inside the support plate 9. A stop block 11 is fixedly connected to the top of the slide bar 10 at the bottom of the first armature 3. A second spring 12 located outside the slide bar 10 is fixedly connected between the stop block 11 and the support plate 9. An auxiliary driving component is arranged on one side of the lower end of the slide bar 10.

[0025] The auxiliary driving component includes a fixed housing 13 fixedly arranged on the outer wall of the insulating housing 1. A gear 14 rotatably connected to the outer wall of the fixed housing 13 is arranged on one side of the outer wall of the fixed housing 13. A tooth block meshing with the gear 14 is arranged on the outer wall of the slide bar 10. A threaded rod 15 rotatably connected to the outer wall of the fixed housing 13 is arranged on the other side of the outer wall of the fixed housing 13. A ratchet mechanism 16 located inside the fixed housing 13 is arranged between the gear 14 and the threaded rod 15. A moving block 17 threadedly matched with the threaded rod 15 is arranged on the outer wall of the threaded rod 15. Two connecting rods 18 are symmetrically hinged on the outer wall of the moving block 17. The other ends of the two connecting rods 18 are hinged to an insulating plate 19 fixedly arranged on the lower outer wall of the two second contact heads 8.

[0026] The connecting mechanism includes a first inner cavity 20 arranged inside the first armature 3. A second armature 21 slidably matched with the first inner cavity 20 is arranged inside the first inner cavity 20. A second inner cavity 22 is opened on one side of the first inner cavity 20 inside the first armature 3. A communication groove for communicating the first inner cavity 20 with the second inner cavity 22 is arranged inside the first armature 3. One end of the communication groove is located at the lower end of the first inner cavity 20, and the other end of the communication groove is located at the bottom of one end of the second inner cavity 22. A third spring 23 is fixedly connected to the inner wall of one end of the second inner cavity 22. One end of the third spring 23 is fixedly connected to a piston 24 slidably matched with the second inner cavity 22. An insulating rod 25 penetrating the outer wall of the first armature 3 is fixedly connected to the outer wall of the piston 24. One end of the insulating rod 25 is fixedly connected to the outer wall of the conductive block 6.

[0027] A sealing ring fitting the inner wall of the first inner cavity 20 is arranged on the outer wall of the second armature 21. Air holes communicating with the first inner cavity 20 and the second inner cavity 22 are respectively opened at the top and bottom of the first armature 3.

[0028] A limiting rod slidably matched with the first armature 3 is arranged above the second inner cavity 22 inside the first armature 3. One end of the limiting rod penetrates the outer wall of the first armature 3 and is fixedly connected to the outer wall of the conductive block 6, and the limiting rod is made of insulating material.

[0029] Working principle: When using the contact device for resisting short-circuit current, first, the electromagnet assembly 2 is connected to the control circuit, and the bottoms of the two second contact heads 8 are connected to the working circuit. The control circuit and the working circuit do not interfere with each other. After the two first contact heads 7 are in contact with the second contact heads 8, a loop is formed and the working circuit is turned on. Conversely, the working circuit is turned off.

[0030] Then, the electromagnet assembly 2 generates magnetism when energized. The generated magnetic force pulls the first armature 3 downward to slide on the outer wall of the insulating column 4. The first armature 3 pulls the first spring 5, and the first armature 3 drives the conductive block 6 to move synchronously through the connecting mechanism. The elastic force of the third spring 23 in the connecting mechanism is greater than that of the first spring 5. The conductive block 6 drives the first contact 7 to move into contact with the second contact 8, and the working circuit is turned on. On the contrary, after the electromagnet assembly 2 is powered off, under the action of the first spring 5, the first contact 7 moves upward to separate from the second contact 8, and the working circuit is turned off. When the first contact 7 contacts the second contact 8, the bottom of the first armature 3 just touches the top surface of the stop block 11.

[0031] In the case of excessive load in the working circuit, when the first contact 7 separates from the second contact 8, a large arc will be generated, causing ablation of the part where the first contact 7 contacts the second contact 8. If the first contact 7 and the second contact 8 become shorter due to ablation, then when energized, the downward movement stroke of the first contact 7 will increase, causing the downward movement position of the first armature 3 to increase. Since the magnetic force formed by the normal current is greater than the elastic force of the second spring 12, the first armature 3 presses the stop block 11. While squeezing the second spring 12, the stop block 11 drives the slide rod 10 to move downward in the support plate 9. The slide rod 10 drives the gear 14 to rotate. In this rotation direction, the ratchet mechanism 16 will not rotate internally. The gear 14 drives the threaded rod 15 to rotate. The threaded rod 15 drives the moving block 17 to move leftward. The moving block 17 pushes the insulating plate 19 upward through the connecting rod 18. The insulating plate 19 pushes the second contact 8 upward. The thread density of the threaded rod 15 is set to match the downward movement stroke of the stop block 11, so that the downward displacement of the stop block 11 is the same as the upward displacement of the second contact 8. Then, after the second contact 8 compensates for the burned length, it ensures that each time after power-off and then power-on, it can adaptively compensate according to the ablation situation of the first contact 7 and the second contact 8. And after compensation, the downward movement position of the first armature 3 can be restored to the initial position when energized. The second spring 12 resets and pushes the stop block 11 to reset to the bottom of the first armature 3. The stop block 11 drives the slide rod 10 to move upward and reset. The slide rod 10 drives the gear 14 to reverse. In this rotation direction, the gear 14 will not drive the threaded rod 15 to rotate through the ratchet mechanism 16. Then, the next compensation can be continued on the basis of the compensated movement of the second contact 8.

[0032] Finally, when a short circuit occurs in the working circuit, the current passing through the electromagnet assembly 2 in the control circuit increases, resulting in an increase in the generated magnetic force. The first armature 3 is limited after the first contact 7 contacts the second contact 8. The magnetic force then pulls the second armature 21 to slide downward in the first inner cavity 20. The second armature 21 slides in a sealed manner through the sealing ring on the outer wall. The second armature 21 presses the air in the first inner cavity 20 into the second inner cavity 22 through the communication groove, pushing the piston 24 to slide leftward in the second inner cavity 22 and pulling the third spring 23. The piston 24 then pushes the insulating rod 25 to move leftward, and the insulating rod 25 drives the conductive block 6 to move leftward. When the conductive block 6 moves, it is limited by the limiting rod on the outer wall and slides inside the first armature 3 to prevent rotation. The conductive block 6 drives the first contact 7 at the bottom to move leftward and separate from the second contact 8. The first contact 7 on the right moves to the left of the second contact 8 on the left, disconnecting the circuit and preventing the short-circuit current from continuously affecting the electrical equipment in the working circuit. At the same time, in the way of horizontally moving to disconnect the first contact 7 and the second contact 8, the generation of electric arcs can be reduced. Then, after the short-circuit condition is repaired and the power is cut off, the first contact 7 is reset under the action of the third spring 23. If the first contact 7 and the second contact 8 are ablated due to the short-circuit current, they can be adaptively compensated by the compensation mechanism after being powered on.

[0033] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A short-circuit current resistant contact device, comprising an insulating housing (1), characterized in that: An electromagnet assembly (2) is installed inside the insulating housing (1), and a first armature (3) is arranged inside the insulating housing (1) above the electromagnet assembly (2); an insulating column (4) that slidably cooperates with the first armature (3) is fixedly connected to the top inner wall of the insulating housing (1), and a first spring (5) is fixedly connected between the top inner wall of the insulating housing (1) and the top of the first armature (3); a conductive block (6) is arranged inside the insulating housing (1) on one side of the first armature (3), and a conductive block (6) is symmetrically arranged at the bottom of the conductive block (6). Two groups of first contacts (7), the bottom ends of the two groups of first contacts (7) are respectively provided with two groups of second contacts (8) corresponding thereto, and the two groups of second contacts (8) are arranged to be slidably connected to the insulating housing (1), a compensation mechanism for driving the two groups of second contacts (8) to move longitudinally is arranged inside the insulating housing (1), a connecting mechanism is arranged inside the first armature (3), the compensation mechanism comprises a support plate (9) fixedly arranged on the inner wall of the insulating housing (1), and a slide rod (10) slidably matched therewith is arranged inside the support plate (9). The top of the slide bar (10) is located at the bottom of the first armature (3) and is fixedly connected to a stopper (11); a second spring (12) located outside the slide bar (10) is fixedly connected between the stopper (11) and the support plate (9); an auxiliary drive assembly is arranged on one side of the lower end of the slide bar (10); the auxiliary drive assembly includes a fixed shell (13) fixedly arranged on the outer wall of the insulating shell (1); a gear (14) rotatably connected to the fixed shell (13) is arranged on one side of the outer wall of the fixed shell (13); and a gear (14) rotatably connected to the fixed shell (13) is arranged on the outer wall of the slide bar (10). 4) meshing tooth blocks, the outer wall of the other side of the fixed shell (13) is provided with a threaded rod (15) rotatably connected thereto, a ratchet mechanism (16) located inside the fixed shell (13) is provided between the gear (14) and the threaded rod (15), the outer wall of the threaded rod (15) is provided with a moving block (17) threadably matched thereto, the outer wall of the moving block (17) is symmetrically hinged with two groups of connecting rods (18), and the other ends of the two groups of connecting rods (18) are hinged with insulating plates (19) fixedly arranged on the outer walls of the lower ends of the two groups of second contacts (8).

2. A short-circuit current resistant contact device according to claim 1, characterized in that: The connecting mechanism comprises a first inner cavity (20) arranged inside the first armature (3), a second armature (21) slidably matched with the first inner cavity (20) being arranged inside the first inner cavity (20), a second inner cavity (22) being opened inside the first armature (3) on one side of the first inner cavity (20), a connecting groove for connecting the first inner cavity (20) with the second inner cavity (22) being arranged inside the first armature (3), one end of the connecting groove being located at the lower end of the first inner cavity (20), and the other end of the connecting groove being located at the bottom of one end of the second inner cavity (22), a third spring (23) being fixedly connected to the inner wall of one end of the second inner cavity (22), one end of the third spring (23) being fixedly connected to a piston (24) slidably matched with the second inner cavity (22), an outer wall of the piston (24) being fixedly connected to an insulating rod (25) penetrating the outer wall of the first armature (3), one end of the insulating rod (25) being fixedly connected to the outer wall of the conductive block (6).

3. A short-circuit current resistant contact device according to claim 2, characterized in that: The outer wall of the second armature (21) is provided with a sealing ring which fits the inner wall of the first inner cavity (20), and the top and bottom of the first armature (3) are respectively provided with air holes which communicate with the first inner cavity (20) and the second inner cavity (22).

4. A short-circuit current resistant contact device according to claim 2, characterized in that: A limit rod slidably matched with the first armature (3) is arranged above the second inner cavity (22) inside the first armature (3), one end of the limit rod passes through the outer wall of the first armature (3) and is fixedly connected to the outer wall of the conductive block (6), and the limit rod is made of insulating material.

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