Contact coil structure and arc extinguish chamber contact

Abstract

The utility model relates to the technical field of arc extinguish chambers, in particular to a contact coil structure which comprises a front-turn coil and a rear-turn coil, the front-turn coil and the rear-turn coil are both in an unclosed circular ring shape, one end of the front-turn coil extends towards the circle center to form a front connecting end, and one end of the rear-turn coil extends towards the circle center to form a rear connecting end. The bottom face of the front-turn coil abuts against the top face of the rear-turn coil, the front connecting end and the rear connecting end are in relative clearance fit, and a limiting mechanism for limiting radial displacement of the front-turn coil and the rear-turn coil when the front-turn coil and the rear-turn coil rotate in the circumferential direction is arranged between the front-turn coil and the rear-turn coil. Therefore, the heating capacity of the contact can be effectively reduced, post-arc insulation strength recovery is optimized, the breaking capacity of the contact is improved, the structure is simple, installation and positioning are more convenient and accurate, the longitudinal magnetic field intensity and distribution uniformity are ensured, the local serious melting phenomenon is avoided, and the service life of the contact is prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of arc extinguishing chambers and relates to a contact coil structure and an arc extinguishing chamber contact. Background Art

[0002] The main function of the vacuum interrupter contact structure is to form a transverse magnetic field or a longitudinal magnetic field between the contacts when the vacuum interrupter interrupts the short-circuit current, thereby limiting the formation of anode spots on the contact surface and improving the interrupter's breaking capacity. There are two main ways for the contact structure to form the required magnetic field: one is to form the required magnetic field by changing the direction of the current; the other is to form a magnetic field in the required direction by setting magnetic materials to gather the magnetic lines of force. Commonly used contact structures include disc-shaped flat plate contacts, transverse magnetic field contacts, and longitudinal magnetic field contacts.

[0003] Chinese utility model patent application number CN200520072205.7 discloses a double-turn longitudinal magnetic field contact for a vacuum interrupter, comprising a conductive rod, a current coil, and a contact piece. The current coil is arranged between the conductive rod and the contact piece, wherein the current coil is a double-turn coil, and the two ends of the coil are located at the axial center position to form two concentric connecting ends.

[0004] Chinese utility model patent application number CN201811320948.X discloses a coil-type longitudinal magnetic field contact assembly, including a conductive rod and a contact sheet, a contact base and a freewheeling contact disc are fixedly connected between the conductive rod and the contact sheet, and the contact base and / or the freewheeling contact disc are provided with at least two curved current arms extending outward. When assembling the longitudinal magnetic field contact assembly, the conductive rod and the contact base are first welded, the support bar and the freewheeling contact disc are welded, and the support bar, the freewheeling contact disc and the contact pad, which are welded into one, are welded together, and the copper-chromium contact is welded.

[0005] The above-mentioned prior art is two different forms of double-turn longitudinal magnetic field contacts, and their basic structure is composed of a double-turn coil and a conductive plate arranged between the double-turn coils. The conductive plate is used to support and connect the double-turn coils in series. The above-mentioned prior art has the following problems:

[0006] First, when the current remains constant, the more turns the coil has, the greater the magnetic field strength it generates. However, the coil resistance will increase with the increase in the number of turns, which will cause the current to decrease when the voltage is constant, thus affecting the strength of the magnetic field. If the conductor diameter used in the double-wire coil remains unchanged, the increase in the number of turns will cause the resistance to increase and the current to decrease, which will not only offset part of the magnetic field enhancement effect brought about by the increase in the number of turns, but the increase in resistance will cause the contacts to heat up and reduce the contact breaking capacity;

[0007] Secondly, the double-turn coil must be highly overlapped during assembly. The above-mentioned prior art double-turn coil assembly is prone to radial deviation, resulting in uneven distribution of the longitudinal magnetic field, which in turn easily leads to uneven distribution of arc spots on the surface of the electrode contact, and ultimately causes local severe melting on the contact surface, which reduces the service life of the contact. Utility Model Content

[0008] The utility model aims to solve the above problems in the prior art and proposes a contact coil structure.

[0009] The purpose of the utility model can be achieved through the following technical solutions: a contact coil structure, including a front turn coil and a rear turn coil, the front turn coil and the rear turn coil are both in an open circular shape, one end of the front turn coil extends toward the center of the circle to form a front connecting end, and one end of the rear turn coil extends toward the center of the circle to form a rear connecting end, the bottom surface of the front turn coil and the top surface of the rear turn coil are installed in abutment with each other, the front connecting end and the rear connecting end are matched with a relative gap, and a limiting mechanism is provided between the front turn coil and the rear turn coil to limit the radial displacement of the two when the two rotate circumferentially.

[0010] Preferably, the limiting mechanism comprises an annular limiting rib protruding along the inner side edge of the rear turn coil, and the inner side of the front turn coil is provided with a boss abutting and slidingly cooperating with the limiting rib.

[0011] Preferably, a positioning block protruding upward and abutting against the boss is provided on one side close to the rear connecting end. When the boss abuts against the positioning block, the projection surfaces of the front connecting end and the rear connecting end coincide, and a Z-shaped fracture is formed around the front turn coil and the rear turn coil.

[0012] Preferably, the limiting mechanism comprises a limiting groove in an annular shape provided on the inner side of the rear turn coil, and the inner side of the front turn coil is provided with an insert block inserted into the limiting groove and slidingly engaged with the limiting groove.

[0013] Preferably, a block is provided near the rear connecting end to block the side of the limiting groove, and when the plug and the block abut against each other, the projection surfaces of the front connecting end and the rear connecting end coincide, and a Z-shaped fracture is formed around the front turn coil and the rear turn coil.

[0014] Preferably, grooves for mounting the coil support are formed on the inner sides of the front connecting end and the rear connecting end.

[0015] Preferably, the outer side surface of the front connecting end protrudes outward to form a fixed end, and the fixed end is cylindrical with an outer end surface edge chamfered.

[0016] Preferably, a notch is provided at the front connecting end adjacent to the front turn coil, a notch is provided at the rear connecting end adjacent to the rear turn coil, the width of the front connecting end is greater than that of the front turn coil, and the width of the rear connecting end is greater than that of the rear turn coil.

[0017] An arc extinguishing chamber contact includes the contact coil structure, and also includes a conductive rod, a contact shielding cover, a coil support, a coil support, a reinforcing plate and a contact piece. The contact shielding cover is sleeved and fixed outside the conductive rod, the bottom surface of the rear turn coil is fixedly connected to the conductive rod, the coil support is sleeved outside the conductive rod and fixedly attached to the bottom surface of the rear turn coil, the coil support is fixed between the front connecting end and the rear connecting end, the reinforcing plate is fixed to the top surface of the front turn coil, and the contact piece is fitted and fixedly connected to the reinforcing plate and connected in series with the front turn coil.

[0018] Preferably, the coil support is fixed in the groove, the reinforcing plate is sleeved and fixed on the outer end surface of the fixed end, and the contact piece is clamped and fixedly connected to the outer end surface of the reinforcing plate, and its bottom surface abuts against the outer end surface of the fixed end.

[0019] Compared with the prior art, the utility model has the following advantages:

[0020] 1. In the process of current conduction, the cross-sectional diameter of the conductor of the contact coil structure changes from a single-layer coil to a double-layer coil and then to a single-layer coil. In this design, the resistance becomes smaller and the current becomes larger under the condition of constant voltage. This not only enables the longitudinal magnetic field to maintain sufficient strength, but also accelerates the movement of charges, which greatly reduces the heat generated by the contacts and is very beneficial to the recovery of insulation strength after arcing, so as to effectively improve the breaking capacity of the contacts;

[0021] 2. The setting of the limit mechanism makes it unnecessary for workers to deliberately calibrate and keep the outer circumference of the front turn coil and the rear turn coil consistent during assembly, so as to improve the assembly efficiency and prevent the radial deviation of the double turn coil. Under the action of sufficient and evenly distributed longitudinal magnetic field, the arc spots are evenly distributed on the surface of the electrode contact, and the contact surface will not produce local serious melting phenomenon, which greatly improves the service life of the contact;

[0022] 3. The contact coil has a simpler structure, more convenient installation, more accurate positioning, and is widely applicable;

[0023] 4. The contact coil and contact have high assembly efficiency and high structural strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the contact current flow.

[0025] Figure 2 It is an axonometric diagram of the contact assembly structure.

[0026] Figure 3 It is a schematic diagram of the contact structure of the first embodiment.

[0027] Figure 4 It is a schematic diagram of the cross-sectional structure of the contact in the first embodiment.

[0028] Figure 5 It is a schematic diagram of the contact structure of the second embodiment.

[0029] Figure 6 It is a schematic diagram of the cross-sectional structure of the contact of the second embodiment.

[0030] Figure 7 It is a schematic diagram of the cross-sectional structure of the front turn coil and the rear turn coil when they are installed in coordination with each other in the first embodiment.

[0031] Figure 8 It is a schematic diagram of the cross-sectional structure of the arc extinguishing chamber contact.

[0032] Fig. 9 It is a schematic diagram of the arc extinguishing chamber contact split structure.

[0033] In the figure, 1, front turn coil; 11, front connecting end; 111, fixed end; 2, rear turn coil; 21, rear connecting end; 3, limiting mechanism; 31, limiting rib; 32, boss; 33, positioning block; 34, limiting groove; 35, insert block; 36, block; 4, groove; 5, conductive rod; 51, contact shielding cover; 6, coil support; 7, coil bracket; 8, reinforcement plate; 81, contact piece. DETAILED DESCRIPTION

[0034] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0035] like Figure 1 , Figure 2 As shown, a contact coil structure includes a front turn coil 1 and a rear turn coil 2, wherein the front turn coil 1 and the rear turn coil 2 are both in an open circular ring shape, one end of the front turn coil 1 extends toward the center of the circle to form a front connecting end 11, and one end of the rear turn coil 2 extends toward the center of the circle to form a rear connecting end 21, the bottom surface of the front turn coil 1 and the top surface of the rear turn coil 2 are installed in abutment with each other, the front connecting end 11 and the rear connecting end 21 are fitted with a relative clearance, and a limiting mechanism 3 is provided between the front turn coil 1 and the rear turn coil 2 to limit the radial displacement of the two when the two rotate circumferentially.

[0036] In this embodiment, if Figure 1The arrow direction is the current transmission direction. In the arc extinguishing chamber, two contacts with the same structure are used to disconnect the short-circuit current. In this scheme, one of the contact structures is used. The rear turn coil 2 is used to connect the conductive rod. During the current conduction process, the contact first flows from the single-layer rear connection end 21 to the double-layer structure formed by the front turn coil 1 and the rear turn coil 2, and then flows to the single-layer structure of the front connection end 11. The front connection end 11 is used to install the contact piece. The two contacts are turned on and off in coordination. The relationship between current and charge is that the current is formed by the directional movement of the charge. The current can be calculated by dividing the charge amount Q by the time T. The formula is I =Q / T, where I represents the current. The magnitude of the current depends on the number of charges moving in a certain direction per unit time. The more charges flow through the unit time, the greater the current. During the current conduction process of this contact, the cross-sectional area of ​​the conductor changes from a single-layer coil to a double-layer coil and then to a single-layer coil. In this design, the resistance becomes smaller and the current becomes larger under the condition of constant voltage. Compared with the traditional contacts in the prior art, when the longitudinal magnetic field can maintain sufficient strength, the resistance becomes smaller and the heat generation is greatly reduced, and the charge movement has an accelerated process, which is very beneficial to the recovery of insulation strength after arcing and effectively improves the contact breaking capacity.

[0037] In this embodiment, if Figure 3 , Figure 4 , Figure 7 As shown, the limiting mechanism 3 includes an annular limiting rib 31 protruding along the inner side edge of the rear turn coil 2 , and the inner side of the front turn coil 1 is provided with a boss 32 that abuts and slides with the limiting rib 31 .

[0038] After the bottom surface of the front coil 1 and the top surface of the rear coil 2 are abutted and installed, the raised limiting edge 31 abuts against the boss 32. At this time, the front coil 1 and the rear coil 2 can rotate circumferentially and limit the radial deviation of the two, ensuring that the circumferential surfaces of the front coil 1 and the rear coil 2 are aligned, so as to improve the uniformity of the longitudinal magnetic field distribution;

[0039] A positioning block 33 is provided on one side near the rear connecting end 21, which protrudes upward and can abut against the boss 32. When the boss 32 abuts against the positioning block 33, the projection surfaces of the front connecting end 11 and the rear connecting end 21 coincide with each other, and the front connecting end 11 and the rear connecting end 21 are relatively clearance-matched. Therefore, after installation, a strip-shaped gap is formed between the front connecting end 11 and the rear connecting end 21. When the bottom surface of the front turn coil 1 and the top surface of the rear turn coil 2 are abutted and installed, the front turn coil 1 and the rear turn coil 2 are both in the form of an open circular ring. Therefore, a gap penetrating the strip-shaped gap is formed adjacent to the front connecting end 11 and the rear connecting end 21, and finally a Z-shaped fracture is formed on the peripheral sides of the front turn coil 1 and the rear turn coil 2, so that when the current is transmitted, a Z-shaped fracture is formed. Figure 1 Spiral transmission in the direction of the arrow shown.

[0040] Rotate the front turn coil 1 or the rear turn coil 2 until the boss 32 abuts against the positioning block 33. At this time, the projection surfaces of the front connecting end 11 and the rear connecting end 21 coincide with each other, ensuring that the circumferential surfaces of the front connecting end 11 and the rear connecting end 21 are aligned, thereby improving the installation efficiency and positioning accuracy, making the longitudinal magnetic field evenly distributed, and thus making the arc spots evenly distributed on the surface of the electrode contact, avoiding local severe melting on the contact surface, and increasing the service life of the contact.

[0041] In this embodiment, if Figure 5 , Figure 6 As shown, the limiting mechanism 3 includes a ring-shaped limiting groove 34 arranged on the inner side of the rear turn coil 2, and an insert block 35 is inserted into the limiting groove 34 and slidably matched with the limiting groove 34 is provided on the inner side of the front turn coil 1.

[0042] After the inner side surfaces of the front coil 1 and the rear coil 2 are abutted against each other, the insert block 35 is inserted into the limiting groove 34. At this time, the front coil 1 and the rear coil 2 can rotate circumferentially and limit the radial deviation of the two, thereby ensuring that the circumferential surfaces of the front coil 1 and the rear coil 2 are aligned.

[0043] A stopper 36 is provided near the rear connecting end 21 to block the side of the limiting groove 34. When the insert block 35 abuts against the stopper 36, the projection surfaces of the front connecting end 11 and the rear connecting end 21 coincide with each other, and a Z-shaped fracture is formed around the front turn coil 1 and the rear turn coil 2. The formation principle of the Z-shaped fracture is the same as that of the previous embodiment and will not be repeated here.

[0044] The front coil 1 or the rear coil 2 is rotated until the stopper 36 abuts against the inserting block 35 , and the projection surfaces of the front connecting end 11 and the rear connecting end 21 coincide with each other, ensuring that the circumferences of the front connecting end 11 and the rear connecting end 21 are aligned.

[0045] In this embodiment, if Figure 3 , Figure 5 As shown, the inner side surfaces of the front connection end 11 and the rear connection end 21 are provided with grooves 4 for installing coil supports. In the prior art patent application number CN200520072205.7, the front turn coil and the rear turn coil of the application are connected in series through a conductive plate, and the front turn coil and the rear turn coil are arranged in an overhead structure that is unstable. The coil support 6 is arranged between the front connection end and the rear connection end to play the role of insulation and support. In the present application, the conductive plate structure is cancelled between the front turn coil 1 and the rear turn coil 2, and the bottom surface of the front turn coil 1 and the top surface of the rear turn coil 2 are attached to each other to form a support. The groove 4 is used to install the coil support. The coil support 6 in this solution mainly plays an insulating role, so the structure is simpler and the structural strength is improved.

[0046] like Figure 2As shown, the outer side of the front connection end 11 protrudes outward to form a fixed end 111. The fixed end 111 is cylindrical and its outer end edge is chamfered. The fixed end 111 is used to connect and install the contact piece, and the chamfering of its outer end edge can improve the installation efficiency.

[0047] The front coil 1 is provided with a notch adjacent to the front connection end 11, and the rear coil 2 is provided with a notch adjacent to the rear connection end 21. The width of the front connection end 11 is greater than that of the front coil 1, and the width of the rear connection end 21 is greater than that of the rear coil 2. It has the excellent characteristics of low arc voltage and small arc energy, which is very beneficial for the recovery of insulation strength after arcing and improving the breaking capacity.

[0048] like Figure 8 , Fig. 9 As shown, in this embodiment, an arc extinguishing chamber contact includes the contact coil structure, and also includes a conductive rod 5, a contact shielding cover 51, a coil support 6, a coil support 7, a reinforcing plate 8 and a contact piece 81, wherein the contact shielding cover 51 is sleeved and fixed outside the conductive rod 5, the bottom surface of the rear turn coil 2 is fixedly connected to the conductive rod 5, the coil support 7 is sleeved outside the conductive rod 5 and fixedly attached to the bottom surface of the rear turn coil 2, the coil support 6 is fixed between the front connecting end 11 and the rear connecting end 21, the reinforcing plate 8 is fixed on the top surface of the front turn coil 1, and the contact piece 81 is fitted and fixedly connected to the reinforcing plate 8 and connected in series with the front turn coil 1.

[0049] The contact shielding cover 51 is sleeved on the conductive rod 5 and welded to the conductive rod 5, the bottom surface of the rear turn coil 2 is welded to the conductive rod 5, the coil support 7 is sleeved outside the conductive rod 5, welded to the conductive rod 5 and fixed to the bottom surface of the rear turn coil 2, the coil support 7 supports the rear turn coil 2, the coil support 6 is fixed between the front connecting end 11 and the rear connecting end 21 to play an insulating and supporting role, the contact piece 81 is fit and fixedly connected with the reinforcing plate 8 and connected in series with the front turn coil 1, and the reinforcing plate 8 plays a structural supporting and reinforcing role for the contact piece 81.

[0050] When the current is connected or disconnected, an arc is generated on the surface of the contact piece 81. The arc lines repel each other due to their respective transverse magnetic fields, resulting in unstable movement. This movement will cut the magnetic lines of force of the longitudinal magnetic field and be subjected to the reverse force generated by the longitudinal magnetic field, making the arc stable and concentrated. The electric field distribution on the surface of the contact piece 81 is evenly concentrated, and coupled with the uniform longitudinal magnetic field, the service life of the contact piece 81 and the arc extinguishing chamber contacts is effectively improved.

[0051] Furthermore, the coil support 6 is fixed in the groove 4, the reinforcing plate 8 is sleeved and fixed on the outer end surface of the fixed end 111, and the contact piece 81 is clamped and fixedly connected to the outer end surface of the reinforcing plate 8, and its bottom surface abuts against the outer end surface of the fixed end 111. The groove 4 has a limiting effect on the coil support 6, ensuring the stability of the contact coil structure after the coil support 6 is installed, the reinforcing plate 8 is sleeved on the outer end surface of the fixed end 111 and is welded and fixed thereto, and the contact piece 81 is clamped and welded to the outer end surface of the reinforcing plate 8 to prevent the two contact pieces 81 from abutting and rubbing against each other when the current is turned on, causing the contact piece 81 and the front turn coil 1 to be displaced, and the reinforcing plate 8 can improve the connection strength between the contact piece 81 and the fixed end 111.

[0052] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A contact coil structure, comprising a front coil (1) and a rear coil (2), characterized in that: The front coil (1) and the rear coil (2) are both in the shape of an open circular ring; one end of the front coil (1) extends toward the center of the circle to form a front connecting end (11); one end of the rear coil (2) extends toward the center of the circle to form a rear connecting end (21); the bottom surface of the front coil (1) and the top surface of the rear coil (2) are mounted in contact with each other; the front connecting end (11) and the rear connecting end (21) are fitted with a relative clearance; and a limiting mechanism (3) is provided between the front coil (1) and the rear coil (2) for limiting radial displacement of the two when the two rotate in a circumferential direction.

2. A contact coil structure according to claim 1, characterized in that: The limiting mechanism (3) comprises an annular limiting rib (31) protruding along the inner side edge of the rear coil (2), and the inner side of the front coil (1) is provided with a boss (32) that abuts and slides against the limiting rib (31).

3. A contact coil structure according to claim 2, characterized in that: A positioning block (33) is provided on one side close to the rear connecting end (21) and protrudes upwards and can abut against the boss (32). When the boss (32) abuts against the positioning block (33), the projection surfaces of the front connecting end (11) and the rear connecting end (21) overlap, and a Z-shaped fracture is formed on the circumference of the front turn coil (1) and the rear turn coil (2).

4. A contact coil structure according to claim 1, characterized in that: The limiting mechanism (3) comprises a limiting groove (34) in an annular shape provided on the inner side of the rear coil (2), and an insert block (35) is provided on the inner side of the front coil (1) and is inserted into the limiting groove (34) and slidably matched with the limiting groove (34).

5. A contact coil structure according to claim 4, characterized in that: A stopper (36) is provided on one side close to the rear connecting end (21) to block the side of the limiting groove (34); when the inserting block (35) and the stopper (36) are in contact, the projection surfaces of the front connecting end (11) and the rear connecting end (21) overlap, and a Z-shaped fracture is formed on the circumference of the front turn coil (1) and the rear turn coil (2).

6. A contact coil structure according to any one of claims 1 to 5, characterized in that: The inner sides of the front connecting end (11) and the rear connecting end (21) are both provided with grooves (4) for installing the coil support (6).

7. A contact coil structure according to any one of claims 1 to 5, characterized in that: The outer side of the front connecting end (11) protrudes outward to form a fixed end (111), and the fixed end (111) is cylindrical and has a chamfered outer end edge.

8. A contact coil structure according to any one of claims 1 to 5, characterized in that: The front coil (1) is provided with a notch adjacent to the front connecting end (11), and the rear coil (2) is provided with a notch adjacent to the rear connecting end (21); the width of the front connecting end (11) is greater than that of the front coil (1), and the width of the rear connecting end (21) is greater than that of the rear coil (2).

9. An arc extinguishing chamber contact, characterized in that: The invention comprises a contact coil structure as described in any one of claims 1 to 8, and further comprises a conductive rod (5), a contact shielding cover (51), a coil support (6), a coil support (7), a reinforcing plate (8) and a contact piece (81), wherein the contact shielding cover (51) is sleeved and fixed outside the conductive rod (5), the bottom surface of the rear turn coil (2) is fixedly connected to the conductive rod (5), the coil support (7) is sleeved outside the conductive rod (5) and fixedly attached to the bottom surface of the rear turn coil (2), the coil support (6) is fixed between the front connecting end (11) and the rear connecting end (21), the reinforcing plate (8) is fixed on the top surface of the front turn coil (1), and the contact piece (81) is fitted and fixedly connected to the reinforcing plate (8) and connected in series with the front turn coil (1).

10. An arc extinguishing chamber contact according to claim 9, characterized in that: The coil support (6) is fixed in the groove (4), the reinforcing plate (8) is sleeved and fixed on the outer end surface of the fixed end (111), and the contact piece (81) is clamped and fixed on the outer end surface of the reinforcing plate (8) and its bottom surface abuts against the outer end surface of the fixed end (111).

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