Contact device capable of resisting short-circuit current

Abstract

The invention discloses an anti-short-circuit current contact device, and relates to the technical field of relays, the anti-short-circuit current contact device comprises an insulating shell, an electromagnet assembly is installed in the insulating shell, and a first armature is arranged at the position, above the electromagnet assembly, in the insulating shell; the inner wall of the top end of the insulating shell is fixedly connected with an insulating column in sliding fit with the first armature, a first spring is fixedly connected between the inner wall of the top end of the insulating shell and the top end of the first armature, and a conductive block is arranged at the position, located on one side of the first armature, in the insulating shell. Two groups of first contacts are symmetrically mounted at the bottom of the conductive block, two groups of second contacts corresponding to the two groups of first contacts are arranged at the bottom ends of the two groups of first contacts respectively, and a compensation mechanism used for driving the two groups of second contacts to move longitudinally is arranged in the insulating shell. And when the working circuit is short-circuited, the working circuit can be disconnected in time.

Description

Technical Field

[0001] The invention relates to the technical field of relays, in particular to a contact device capable of resisting short-circuit current. Background Art

[0002] A relay is an electrical control device. When the change in the input quantity reaches the specified requirement, it 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 used in automated control circuits. The relay is mainly composed of an electromagnet, an armature, a spring, and contacts. When the coil is energized, the electromagnet generates magnetism, attracts the armature, and causes the contacts to shift. The contact contacts make the circuit conductive. When the coil is de-energized, the electromagnet loses its 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, the circuit is disconnected and the contacts are separated, which will form an arc 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, causing a large arc to form when the contacts are separated, and the contacts are prone to ablation. After the contacts are ablated, a gap will be generated when they make contact next time, resulting in poor contact of the contacts. If the contact pressure of the contacts is insufficient, the resistance will increase, thereby generating excessive 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 that is significantly different from the existing technologies. Specifically, the purpose of the present invention is to provide a contact device that can resist short-circuit current to solve the problem raised in the above background technology that large current in a short-circuit situation can cause contact burnout and poor contact.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a short-circuit current resistant contact device, comprising an insulating shell, an electromagnet assembly is installed inside the insulating shell, and a first armature is arranged inside the insulating shell above the electromagnet assembly, an insulating column slidingly matched with the first armature is fixedly connected to the top inner wall of the insulating shell, and a first spring is fixedly connected between the top inner wall of the insulating shell and the top of the first armature, a conductive block is arranged on one side of the first armature inside the insulating shell, two groups of first contacts are symmetrically installed at the bottom of the conductive block, two groups of second contacts corresponding thereto are respectively arranged at the bottom ends of the two groups of first contacts, and the two groups of second contacts are arranged to be slidably connected to the insulating shell, a compensation mechanism for driving the two groups of second contacts to move longitudinally is arranged inside the insulating shell, and a connecting 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 shell, a sliding rod slidably matched with the support plate is arranged inside the support plate, a stop block is fixedly connected to the top of the sliding rod and the bottom of the first armature, a second spring located on the outside of the sliding rod is fixedly connected between the stop block and the support plate, and an auxiliary drive assembly is arranged on one side of the lower end of the sliding rod.

[0007] Preferably, the auxiliary drive assembly includes a fixed shell fixedly arranged on the outer wall of an insulating shell, a gear rotatably connected to the fixed shell is arranged on one side outer wall of the fixed shell, a tooth block meshing with the gear is arranged on the outer wall of the sliding rod, a threaded rod rotatably connected to the fixed shell is arranged on the other side outer wall of the fixed shell, a ratchet mechanism located inside the fixed shell is arranged between the gear and the threaded rod, a moving block threadably matched with the thread is arranged on the outer wall of the threaded rod, two groups of connecting rods are symmetrically hinged on the outer wall of the two groups of connecting rods, and the other ends of the two groups of connecting rods are hinged to insulating plates fixedly arranged on the outer walls of the lower ends of the two groups of 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 connecting groove connecting the first inner cavity with the second inner cavity is arranged inside the first armature, one end of the connecting groove is located at the lower end of the first inner cavity, and the other end of the connecting 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, one end of the third spring is fixedly connected to a piston slidably matched with the second inner cavity, an insulating rod is fixedly connected to the outer wall of the piston and passes through the outer wall of the first armature, and one end of the insulating rod is fixedly connected to the outer wall of the conductive block.

[0009] Preferably, the outer wall of the second armature is provided with a sealing ring which fits with the inner wall of the first inner cavity, and the top and the bottom of the first armature are respectively provided with air holes which communicate with the first inner cavity and the second inner cavity.

[0010] Preferably, a limiting rod slidably matched with the first armature is arranged inside the first armature above the second inner cavity, one end of the limiting rod passes 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 present invention has the following beneficial effects: The present invention is provided with a compensation mechanism. When the load in the working circuit is too large, after the first contact and the second contact become shorter due to ablation, the downward movement stroke of the first contact will increase, so that the downward movement position of the first armature will increase, and the first armature will press the stopper to make the slide bar move downward synchronously, and the slide bar will drive 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, and the moving block pushes the insulating plate upward through the connecting rod, and the insulating plate pushes the second contact upward, wherein the thread density of the threaded rod is set to match the downward movement stroke of the stopper, so that the downward movement position of the stopper The displacement of the first contact and the second contact is the same as the displacement of the second contact upward. After compensating the burnt length, the second contact ensures that adaptive compensation can be performed according to the burnt conditions of the first contact and the second contact each time the power is turned on after power failure, and after compensation, the first armature can restore the downward position of the first armature to the initial position when power is turned on, and the second spring reset pushes the stopper to reset to the bottom of the first armature, and the stopper drives the slide bar to move upward and reset, and the slide bar drives the gear to reverse. In this rotation direction, the gear will not drive the threaded rod to rotate through the ratchet mechanism, so the compensation can be continued on the basis of the compensation movement of the second contact during the next compensation. The present invention is provided with a connecting mechanism. When a short circuit occurs in the working circuit, the current passing through the electromagnet assembly in the control circuit becomes larger, so that the generated magnetic force increases. The first armature is limited after the first contact contacts the second contact, and the magnetic force pulls the second armature to slide down in the first inner cavity. The second armature presses the air in the first inner cavity into the second inner cavity through the connecting groove, pushing the piston to slide leftward in the second inner cavity and pulling the third spring. The piston pushes the insulating rod to move leftward, and the insulating rod drives the conductive block to move leftward. The conductive block drives the first contact at the bottom to move leftward and separate from the second contact. The first contact on the right side moves to the left side of the second contact on the left side, 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, the generation of arcs can be reduced in the manner of lateral movement to disconnect the first contact and the second contact.

[0012] In summary, after the first contact and the second contact are ablated, adaptive compensation can be performed according to the burning situation to avoid poor contact between the first contact and the second contact, and the working circuit can be disconnected in time when a short circuit occurs in the working circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a front cross-sectional structural schematic diagram of the present invention; Figure 2 For the present invention Figure 1 A in the enlarged view; Figure 3 It is a schematic diagram of the front cross-sectional structure of the fixed shell of the present invention; Figure 4 It is a right side structural schematic diagram of the ratchet mechanism of the present invention; Figure 5 It is a schematic diagram of the top view of the structure of the moving block, the connecting rod and the insulating plate of the present invention; Figure 6 It is a schematic diagram of the front cross-sectional structure of the first armature of the present invention.

[0014] In the figure: 1. insulating shell; 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 rod; 11. block; 12. second spring; 13. fixed shell; 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. DETAILED DESCRIPTION

[0015] 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.

[0016] See also Figure 1-6 The present invention provides a technical solution: a short-circuit current resistant contact device, comprising an insulating shell 1, an electromagnet assembly 2 is installed inside the insulating shell 1, and a first armature 3 is arranged inside the insulating shell 1 above the electromagnet assembly 2, an insulating column 4 slidingly matched with the first armature 3 is fixedly connected to the top inner wall of the insulating shell 1, and a first spring 5 is fixedly connected between the top inner wall of the insulating shell 1 and the top of the first armature 3, a conductive block 6 is arranged on one side of the first armature 3 inside the insulating shell 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 thereto are respectively arranged at the bottom ends of the two groups of first contacts 7, and the two groups of second contacts 8 are arranged to be slidably connected with the insulating shell 1, a compensation mechanism for driving the two groups of second contacts 8 to move longitudinally is arranged inside the insulating shell 1, and a connecting mechanism is arranged inside the first armature 3.

[0017] The compensation mechanism includes a support plate 9 fixedly arranged on the inner wall of the insulating shell 1, a slide rod 10 slidably matched with the support plate 9 is arranged inside the support plate 9, a stopper 11 is fixedly connected to the top of the slide rod 10 at the bottom of the first armature 3, a second spring 12 located on the outside of the slide rod 10 is fixedly connected between the stopper 11 and the support plate 9, and an auxiliary drive assembly is arranged on one side of the lower end of the slide rod 10.

[0018] 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 the outer wall of one side of the fixed shell 13, a tooth block meshing with the gear 14 is arranged on the outer wall of the sliding rod 10, a threaded rod 15 rotatably connected to the fixed shell 13 is arranged on the outer wall of the other side of the fixed shell 13, a ratchet mechanism 16 located inside the fixed shell 13 is arranged between the gear 14 and the threaded rod 15, a moving block 17 threadably matched with the threaded rod 15 is arranged on the outer wall of the threaded rod 15, and two groups of connecting rods 18 are symmetrically hinged on the outer wall of the moving block 17, and the other ends of the two groups of connecting rods 18 are hinged to insulating plates 19 fixedly arranged on the outer walls of the lower ends of the two groups of second contacts 8.

[0019] 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 connecting groove connecting the first inner cavity 20 with the second inner cavity 22 is arranged inside the first armature 3, one end of the connecting groove is located at the lower end of the first inner cavity 20, and the other end of the connecting 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 outer wall of the piston 24 is fixedly connected to an insulating rod 25 penetrating the outer wall of the first armature 3, and one end of the insulating rod 25 is fixedly connected to the outer wall of the conductive block 6.

[0020] The outer wall of the second armature 21 is provided with a sealing ring which fits with 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 .

[0021] A limiting rod slidably matched with the first armature 3 is arranged above the second inner cavity 22 , one end of the limiting 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 limiting rod is made of insulating material.

[0022] Working principle: When using the short-circuit current resistant contact device, first, the electromagnet assembly 2 is connected to the control circuit, and the bottoms of the two groups of second contacts 8 are connected to the working circuit. The control circuit and the working circuit do not interfere with each other. After the two groups of first contacts 7 come into contact with the second contacts 8, a loop is formed and the working circuit is turned on. Otherwise, the working circuit is turned off.

[0023] Then, the electromagnet assembly 2 generates magnetism when energized, and the generated magnetic force pulls the first armature 3 downward to slide on the outer wall of the insulating column 4, and 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, wherein the elastic force of the third spring 23 in the connecting mechanism is greater than that of the first spring 5, and the conductive block 6 drives the first contact 7 to move and contact the second contact 8, and the working circuit is turned on; conversely, after the electromagnet assembly 2 is powered off, under the action of the first spring 5, the first contact 7 moves up and separates from the second contact 8, and the working circuit is disconnected, and when the first contact 7 contacts the second contact 8, the bottom of the first armature 3 just contacts the top surface of the stopper 11.

[0024] When the load in the working circuit is too large, a large arc will be generated when the first contact 7 and the second contact 8 are separated, causing ablation of the contact portion of the first contact 7 and the second contact 8. If the first contact 7 and the second contact 8 become shorter due to ablation, then when power is on, the downward stroke of the first contact 7 will increase, causing the downward 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 block 11, and the block 11 drives the slide bar 10 to move downward in the support plate 9 while squeezing the second spring 12, and the slide bar 10 drives the gear 14 to rotate. In this rotation direction, the ratchet mechanism 16 will not rotate on its own, and the gear 14 drives the threaded rod 15 to rotate, and the threaded rod 15 drives the moving block 17 to move to the left, and the moving block 17 pushes the insulating plate 1 upward through the connecting rod 18. 9, the insulating plate 19 pushes the second contact 8 to move upward, wherein the thread density of the threaded rod 15 is set to match the downward travel of the stopper 11, so that the downward displacement of the stopper 11 is the same as the upward displacement of the second contact 8. Then, after compensating the burnt length, the second contact 8 ensures that adaptive compensation can be performed according to the burnt conditions of the first contact 7 and the second contact 8 each time the power is turned on after power failure, and after compensation, the downward position of the first armature 3 can be restored to the initial position when the power is turned on, and the second spring 12 resets and pushes the stopper 11 to reset to the bottom of the first armature 3, and the stopper 11 drives the slide rod 10 to move upward and reset, and the slide rod 10 drives the gear 14 to reverse, and the gear 14 will not drive the threaded rod 15 to rotate through the ratchet mechanism 16 in this rotation direction, so the compensation can be continued on the basis of the compensation movement of the second contact 8 during the next compensation; Finally, when a short circuit occurs in the working circuit, the current controlled by the control circuit to pass through the electromagnet assembly 2 becomes larger, so that the generated magnetic force increases, and the first armature 3 is limited after the first contact 7 contacts the second contact 8, and the magnetic force pulls the second armature 21 to slide down in the first inner cavity 20, and the second armature 21 slides in a sealed manner through the sealing ring of the outer wall, and the second armature 21 presses the air in the first inner cavity 20 into the second inner cavity 22 through the connecting groove, pushing the piston 24 to slide to the left in the second inner cavity 22 and pulling the third spring 23, and the piston 24 pushes the insulating rod 25 to move to the left, and the insulating rod 25 drives the conductive block 6 to move to the left, and the conductive block 6 moves through the outer wall The limit rod slides inside the first armature 3 to limit the position and prevent rotation. The conductive block 6 drives the first contact 7 at the bottom to move to the left and separate from the second contact 8. The first contact 7 on the right side moves to the left side of the second contact 8 on the left side, so that the circuit is disconnected to prevent the short-circuit current from continuing to affect the electrical equipment in the working circuit. At the same time, the first contact 7 and the second contact 8 are disconnected by lateral movement to reduce the generation of arcs. Then, after the staff cuts off the power when repairing the short-circuit condition, 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 power is turned on.

[0025] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in 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 slides with the first armature (3) is fixedly connected to the inner wall at the top end of the insulating housing (1), and a first spring (5) is fixedly connected between the inner wall at the top end of the insulating housing (1) and the top end of the first armature (3); a conductive block (6) is arranged inside the insulating housing (1) on one side of the first armature (3); two groups of first contacts (7) are symmetrically installed at the bottom of the conductive block (6); two groups of second contacts (8) corresponding thereto are respectively arranged at the bottom ends of the two groups of first contacts (7), 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), and a connecting mechanism is arranged inside the first armature (3).

2. A short-circuit current resistant contact device according to claim 1, characterized in that: The compensation mechanism comprises a support plate (9) fixedly arranged on the inner wall of the insulating housing (1), a slide bar (10) slidably matched therewith is arranged inside the support plate (9), a stopper (11) is fixedly connected to the top of the slide bar (10) located at the bottom of the first armature (3), a second spring (12) located outside the slide bar (10) is fixedly connected between the stopper (11) and the support plate (9), and an auxiliary drive assembly is arranged on one side of the lower end of the slide bar (10).

3. A short-circuit current resistant contact device according to claim 2, characterized in that: The auxiliary drive assembly comprises a fixed shell (13) fixedly arranged on the outer wall of an 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), a tooth block meshing with the gear (14) is arranged on the outer wall of the sliding rod (10), a threaded rod (15) rotatably connected to the fixed shell (13) is arranged on the other side of the outer wall of the fixed shell (13), a ratchet mechanism (16) located inside the fixed shell (13) is arranged between the gear (14) and the threaded rod (15), a moving block (17) threadably engaged with the threaded rod (15) is arranged on the outer wall of the threaded rod (15), two groups of connecting rods (18) are symmetrically hinged on the outer wall of the moving block (17), and the other ends of the two groups of connecting rods (18) are hinged to insulating plates (19) fixedly arranged on the outer walls of the lower ends of the two groups of second contacts (8).

4. 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).

5. A short-circuit current resistant contact device according to claim 4, 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).

6. A short-circuit current resistant contact device according to claim 4, 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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