Electromagnetic three-normally-closed alternating current contactor

Abstract

The invention relates to the technical field of electricity, discloses an electromagnetic three-normally-closed alternating-current contactor, and solves the problem that when the current three-normally-open, four-normally-open and two-open and two-closed alternating-current contactors are applied to a three-phase main loop, the contactor structure is lack of an effective arc extinguishing and insulating mechanism, and the current three-normally-open, four-normally-open and two-open and two-closed alternating-current contactors cannot be used for controlling the three-phase main loop and the problems of poor arc extinguishing of the contact, short circuit of the electromagnetic mechanism and failure of the contactor are solved. According to the contactor, spaced guide insulation rib plates are arranged on the inner side of an upper insulation shell, the upper insulation shell is integrally inserted into a guide isolation groove of a contact support, a magnet vane corresponding to a moving contact and a static contact is arranged on the bottom side of the contact support, and an arc discharge port is formed in the side portion of the magnet vane. After the coil loses power, the three-phase main loop is of a three-normally-closed structure through the clinging, extruding and contacting of the active and auxiliary moving contact springs to the moving and static contacts, so that an arc extinguishing cavity is formed in the moving direction of the arc, and the influence of electromagnetic attraction force generated by an electromagnetic mechanism on the arc is effectively blocked. And the electromagnetic insulativity of the contact mechanism head and the electromagnetic mechanism is improved.

Description

Technical Field

[0001] The invention relates to the field of electrical technology, and in particular to an electromagnetic three-normally closed AC contactor. Background Art

[0002] At present, the main circuit forms of AC contactors on the market are mostly three-normally open, four-normally open or two-open and two-closed. When the three-normally open, four-normally open and two-open and two-closed contactors are used in the three-phase main circuit, after the coil in the electromagnetic mechanism loses power, the reaction force of the reset spring causes the contact mechanism to move the moving iron core upward and reset. The three-phase active contact moves upward with the contact mechanism for a distance and then stops moving under the limiting action of the three-phase main static contact. That is, the three-phase main contact is closed, the three-phase active contact spring is compressed, and the process of the three-phase active contact moving upward generates electric repulsion with the three-phase main static contact. The electric repulsion of the contact, the reaction force of the contact spring and the gravity of the contact mechanism and the moving iron core prevent the contact mechanism and the moving iron core from resetting upward, resulting in contact failure. The problem of reliability, large contact resistance and increased contact temperature is that when the coil in the electromagnetic mechanism is energized, the normally closed contacts of the three-phase main circuit are disconnected, and the contactor generates an arc at the moment when the normally closed contacts of the three-phase main circuit are disconnected. The arc moves downward with the contact mechanism and finally sprays toward the electromagnetic mechanism. At this time, the electromagnetic mechanism is energized to generate electromagnetic attraction, which makes it more difficult to extinguish the arc and the arc is very likely to short-circuit with the electromagnetic mechanism. In addition, since the reset spring is close to the coil, the arc moves downward with the contact mechanism and short-circuits the moving iron core, and then further causes the coil to short-circuit and burn, and the product fails, through the reset spring. Therefore, this type of contactor can only be used in control circuits with lower loads and fewer normally closed contacts, which greatly affects the applicability of this type of contactor. Summary of the invention

[0003] The present invention provides an electromagnetic three-normally-closed AC contactor to solve the problems of poor contact arc extinguishing, electromagnetic mechanism short circuit and contactor failure in three-phase main circuit applications of three-normally-open, four-normally-open and two-open-two-closed AC contactors in the above background due to the lack of effective arc extinguishing and insulation mechanism in the contactor structure itself.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: An electromagnetic three-normally closed AC contactor comprises an upper insulating shell and a lower insulating shell. A plurality of main static contacts are arranged side by side on one side of the upper insulating shell, and auxiliary static contacts are arranged parallel to the main static contacts on the other side of the upper insulating shell. The upper insulating shell and the lower insulating shell are detachably connected to form a shell space inside, and a contact mechanism and an electromagnetic mechanism are arranged in the shell space.

[0005] The contact mechanism includes a contact bracket, multiple active contacts and auxiliary moving contacts. The contact bracket and the upper insulating shell are movably connected. The active contacts are all connected to the contact bracket. The auxiliary moving contacts are located on the contact bracket parallel to the active contacts. The active contacts are located below the main static contacts. The auxiliary moving contacts are located above the auxiliary static contacts. A magnetic isolation plate is also provided on the contact bracket, and the magnetic isolation plate is located below the active contacts and the auxiliary moving contacts.

[0006] The electromagnetic mechanism includes a fixed iron core, a movable iron core and a coil. The fixed iron core is fixedly connected to the lower insulating shell. The coil is sleeved on the middle boss of the fixed iron core. The movable iron core is arranged directly above the fixed iron core. A reset spring is sleeved on the middle boss of the movable iron core. The reset spring is pressed on the top of the middle boss of the fixed iron core. The contact bracket is fixedly arranged on the top of the movable iron core.

[0007] Furthermore, an active contact spring is connected between the magnetic isolation plate and the active contact, and an auxiliary moving contact spring is connected between the auxiliary moving contact and the magnetic isolation plate.

[0008] Furthermore, a coil terminal is provided on the outer side of the coil, and the outer side of the coil terminal is covered with electromagnetic insulating glue.

[0009] Furthermore, guide isolation grooves are provided between the active contacts of the contact bracket, guide insulating ribs are provided between the main static contacts of the upper insulating shell, and the guide insulating ribs are slidably clamped in the guide isolation grooves.

[0010] Furthermore, arc discharge openings are provided on the upper insulating shells located between the guiding insulating ribs.

[0011] Furthermore, the non-polar surfaces of the fixed iron core and the movable iron core are coated with electromagnetic insulating paint.

[0012] The present invention has the following beneficial effects: In the present invention, the upper insulating shell is designed as a structure with insulating ribs and is inserted into the contact bracket, and then a matching magnetic isolation plate is arranged at the bottom of the contact bracket at the contact, and an arc discharge port is opened on its side, thereby forming an arc extinguishing cavity in the direction of arc movement, effectively blocking the influence of the electromagnetic suction force generated by the electromagnetic mechanism on the arc, thereby improving the electromagnetic insulation between the contact head and the electromagnetic mechanism, and further significantly improving the arc extinguishing performance, electrical insulation and safety of the AC contactor.

[0013] The present invention provides an electromagnetic three-phase normally closed AC contactor, which supports and squeezes the contacts tightly through the reset, active and auxiliary moving contact springs, so that after the coil is de-energized, the three-phase main circuit is realized as a three-phase normally closed structure, effectively ensuring the reliability of contact contact, thereby reducing the contact resistance and temperature rise of the contacts, ensuring the loaded operation of the three-phase main circuit under the condition of coil de-energization, thereby avoiding the phenomenon that the coil is easily burned due to continuous power-on, and improving the service life of the contactor.

[0014] When the coil is in the de-energized state and is used in a three-phase main circuit, the three-phase moving contact only moves upward under the support of the reaction force of the reset spring, so that the three-phase main circuit is in a closed state. At the same time, under the compression and squeezing action of the auxiliary moving contact spring on the moving contact, the contact reliability of the moving contact is guaranteed, so that when the contactor controls the continuously running equipment, the three-phase main circuit can be operated with load without the need for continuous power supply to the coil, breaking the limitation of the existing market that only three groups of main contacts can control the normal operation of the equipment under the condition that the coils of the three normally open contactors are continuously energized, and effectively reducing the operating energy consumption of the three-phase main circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0016] Figure 2 It is a partial schematic diagram of the contact mechanism when the electromagnetic mechanism in the present invention is energized.

[0017] Figure 3 It is a partial schematic diagram of the contact mechanism when the electromagnetic mechanism loses power in the present invention.

[0018] Figure 4 It is a schematic diagram of the arc extinguishing chamber of the upper insulating shell in the present invention.

[0019] Figure 5 It is a schematic diagram of the arrangement of the magnetic isolation plate of the contact mechanism in the present invention.

[0020] Figure 6 It is a schematic diagram of the arc discharge port of the upper insulating shell in the present invention.

[0021] Figure 7 This is a schematic diagram of the coil terminal before electromagnetic insulation packaging in the present invention.

[0022] Figure 8 This is a schematic diagram of the coil terminal after electromagnetic insulation packaging in the present invention.

[0023] Fig. 9 It is a schematic diagram of the electromagnetic insulation setting of the iron core in the present invention.

[0024] The meanings of the reference numerals are as follows: 3. Upper insulating shell; 4. Lower insulating shell; 1-1. Fixed iron core; 1-2. Moving iron core; 1-3. Coil; 1-4. Coil terminal; 1-5. Electromagnetic insulating glue; 1-6. Electromagnetic insulating paint; 2-1. Active contact; 2-2. Auxiliary moving contact; 2-3. Contact bracket; 2-4. Reset spring; 2-5. Active contact spring; 2-6. Auxiliary moving contact spring; 2-7. Guide isolation groove; 2-8. Magnetic isolation plate; 3-1. Main static contact; 3-2. Auxiliary static contact; 3-3. Guide insulating rib plate; 3-4. Arc discharge port. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0026] like Figure 1-2 As shown, an electromagnetic three-normally closed AC contactor includes an upper insulating shell 3 and a lower insulating shell 4. A plurality of main static contacts 3-1 are arranged side by side on one side of the upper insulating shell 3, and auxiliary static contacts 3-2 are arranged parallel to the main static contacts 3-1 on the other side of the upper insulating shell 3. The upper insulating shell 3 and the lower insulating shell 4 are detachably connected to form a shell space inside, and a contact mechanism and an electromagnetic mechanism are arranged in the shell space.

[0027] The contact mechanism includes a contact bracket 2-3, three groups of active contacts 2-1 and a group of auxiliary moving contacts 2-2. The contact bracket 2-3 and the upper insulating shell 3 are movably connected at intervals. The active contacts 2-1 are evenly connected to the contact bracket 2-3. The auxiliary moving contacts 2-2 are located on the contact bracket 2-3 parallel to the active contacts 2-1. The active contact 2-1 is located below the main static contact 3-1, and the auxiliary moving contact 2-2 is located above the auxiliary static contact 3-2. A magnetic isolation plate 2-8 is also provided on the contact bracket 2-3, and the magnetic isolation plate 2-8 is located below the active contact 2-1 and the auxiliary moving contact 2-2.

[0028] The electromagnetic mechanism includes a fixed iron core 1-1, a movable iron core 1-2 and a coil 1-3. The fixed iron core 1-1 is fixedly connected to the lower insulating shell 4. The coil 1-3 is sleeved on the middle boss of the fixed iron core 1-1. The movable iron core 1-2 is arranged directly above the fixed iron core 1-1. A reset spring 2-4 is sleeved on the middle boss of the movable iron core 1-2. The reset spring 2-4 is pressed on the top of the middle boss of the fixed iron core 1-1. The contact bracket 2-3 is fixedly arranged on the top of the movable iron core 1-2.

[0029] An active contact spring 2-5 is connected between the magnetic isolation plate 2-8 and the active contact 2-1, and an auxiliary moving contact spring 2-6 is connected between the auxiliary moving contact 2-2 and the magnetic isolation plate 2-8.

[0030] like Figure 1 , 2, 7 and 8, the outer side of the coil 1-3 is provided with a coil terminal 1-4, and the outer side of the coil terminal 1-4 is covered with an electromagnetic insulating glue 1-5.

[0031] like Figure 4 As shown, guide isolation grooves 2-7 are provided between the active contacts 2-1 of the contact bracket 2-3, guide insulating ribs 3-3 are provided between the main static contacts 3-1 of the upper insulating shell 3, and the guide insulating ribs 3-3 are slidably clamped in the guide isolation grooves 2-7.

[0032] like Figure 6 As shown, arc discharge openings 3 - 4 are provided on the upper insulating shell 3 between the guiding insulating ribs 3 - 3 .

[0033] like Fig. 9 As shown, the non-polar surfaces of the fixed iron core 1-1 and the movable iron core 1-2 are coated with electromagnetic insulating paint 1-6.

[0034] When the coil 1-3 in the electromagnetic mechanism is energized, the electromagnetic attraction overcomes the reaction force of the reset spring 2-4, the active contact spring 2-5 and the auxiliary moving contact spring 2-6 to attract the moving iron core 1-2 to the fixed iron core 1-1, and the contact mechanism 2 linked to the moving iron core 1-2 moves downward, so that the three-phase active contact 2-1 and the main static contact 3-1 are in the disconnected state; when the coil 1-3 in the electromagnetic mechanism loses power, the electromagnetic attraction disappears, and the reaction force of the reset spring 2-4, the active contact spring 2-5 and the auxiliary moving contact spring 2-6 releases the moving iron core 1-2, the contact mechanism moves upward to reset, and the three-phase active contact 2-1 and the main static contact 3-1 are in the closed state.

[0035] like Figure 1 , 3 As shown, after the coil in the electromagnetic mechanism 1 loses power, the reaction force of the reset spring 2-4 causes the contact mechanism to move the moving iron core 1-2 upward and reset. The three-phase active contact 2-1 moves upward with the contact mechanism for a distance and then stops moving under the limiting action of the three-phase main static contact 3-1, that is, the three-phase main contact is closed, and the three-phase active contact spring 2-5 is compressed. The process of the three-phase active contact 2-1 moving upward generates an electric repulsion force with the three-phase main static contact 3-1, and the electric repulsion force of the contact and the reaction force of the contact spring The acting force and the gravity of the contact mechanism and the moving iron core 1-2 prevent the contact mechanism and the moving iron core 1-2 from returning to the original position. Under the joint action of the return spring 2-4, the suction and reaction force characteristics of the contact spring and the electromagnetic suction force of the electromagnetic mechanism, the contact between the three-phase active contact 2-1 and the three-phase main static contact 3-1 reaches a dynamic balance, which satisfies the good holding characteristics of the contactor, thereby ensuring the reliable connection of the normally closed contacts of the three-phase main circuit, reducing the contact resistance of the contacts and reducing the temperature rise of the contacts.

[0036] like Figure 4 , 5As shown, the upper insulating shell 3 also includes three groups of guiding insulating ribs 3-3, and three groups of guiding isolation grooves 2-7 are opened on the contact bracket 2-3 in the contact mechanism. The three groups of guiding insulating ribs 3-3 are inserted into the three groups of guiding isolation grooves 2-7 to isolate the three-phase main circuit into independent arc extinguishing chambers. Through the design of the arc extinguishing chamber and the arc extinguishing channel, the arc extinguishing ability of the contactor during the on-off process is effectively improved.

[0037] like Figure 5 As shown, a magnetic isolation plate 2-8 is installed on the contact bracket 2-3 in the contact mechanism. The magnetic isolation plate 2-8 is located between the electromagnetic mechanism and the contact mechanism 2, which insulates the electromagnetic mechanism and the contact mechanism, blocks the influence of the electromagnetic attraction generated by the electromagnetic mechanism on the arc, and effectively improves the electrical safety and insulation of the contact mechanism and the electromagnetic mechanism.

[0038] like Figure 6 As shown, three groups of main static contacts 3-1 and one group of auxiliary static contacts 3-2 on the upper insulating shell 3 are each provided with a dedicated arc discharge port 3-4 on the side, which, in conjunction with the principle of air flow, allows the arc to quickly move from the product contact position to the outside of the product, thereby accelerating arc extinguishing, reducing the risk of contact burning, and increasing the electrical life of the product.

[0039] like Figure 7 As shown, the coil terminal 1-4 in the electromagnetic mechanism is sealed with electromagnetic insulating glue 1-5, which effectively prevents the arc from moving downward with the contact mechanism and short-circuiting the moving iron core 1-2, and further causing the coil 1-3 to short-circuit and burn through the reset spring 2-4.

[0040] like Figure 3 , 9 As shown, the fixed iron core 1-1 and the movable iron core 1-2 in the electromagnetic mechanism are coated with electromagnetic insulating paint 1-6 except for the core pole surface, which effectively avoids the risk of the arc following the contact mechanism to move downward and finally spraying toward the electromagnetic mechanism, causing a short circuit between the arc and the electromagnetic mechanism.

[0041] like Figure 1 , 2 As shown in Figure 3, when the auxiliary moving contact 2-2 and auxiliary static contact 3-2 units provided in the contactor are normally open, when the coil 1-3 in the electromagnetic structure is energized, a group of auxiliary moving contacts 2-2 and a group of auxiliary static contacts 3-2 of the three-phase main circuit normally closed contactor are closed, and conversely, when the coil 1-3 in the electromagnetic structure is energized, a group of auxiliary moving contacts 2-2 and a group of auxiliary static contacts 3-2 of the three-phase main circuit normally closed contactor are disconnected. At this time, they can be used as mirror contacts of the auxiliary contact unit, connect feedback signals, and timely detect the opening and closing status of the main circuit unit.

Claims

1. An electromagnetic three-way normally closed AC contactor, characterized by: The invention comprises an upper insulating shell (3) and a lower insulating shell (4), wherein a plurality of main static contacts (3-1) are arranged side by side on one side of the upper insulating shell (3), and auxiliary static contacts (3-2) are arranged parallel to the main static contacts (3-1) on the other side of the upper insulating shell (3), and the upper insulating shell (3) and the lower insulating shell (4) are detachably connected to form a shell space inside, and a contact mechanism and an electromagnetic mechanism are arranged in the shell space; The contact mechanism comprises a contact support (2-3), a plurality of active contacts (2-1) and an auxiliary moving contact (2-2); the contact support (2-3) and the upper insulating shell (3) are movably sleeved at intervals; the active contacts (2-1) are all connected to the contact support (2-3); the auxiliary moving contact (2-2) is located on the contact support (2-3) parallel to the active contact (2-1); the active contact (2-1) is located below the main static contact (3-1); the auxiliary moving contact (2-2) is located above the auxiliary static contact (3-2); a magnetic isolation plate (2-8) is also provided on the contact support (2-3); and the magnetic isolation plate (2-8) is located below the active contact (2-1) and the auxiliary moving contact (2-2); The electromagnetic mechanism comprises a fixed iron core (1-1), a movable iron core (1-2) and a coil (1-3); the fixed iron core (1-1) and the lower insulating shell (4) are fixedly connected; the coil (1-3) is sleeved on a middle boss of the fixed iron core (1-1); the movable iron core (1-2) is arranged directly above the fixed iron core (1-1); a return spring (2-4) is sleeved on the middle boss of the movable iron core (1-2); the return spring (2-4) is pressed on the top of the middle boss of the fixed iron core (1-1); and the contact bracket (2-3) is fixedly arranged on the top of the movable iron core (1-2).

2. The electromagnetic three-normally closed AC contactor according to claim 1 is characterized in that: An active contact spring (2-5) is connected between the magnetic isolation plate (2-8) and the active contact (2-1), and an auxiliary moving contact spring (2-6) is connected between the auxiliary moving contact (2-2) and the magnetic isolation plate (2-8).

3. The electromagnetic three-normally closed AC contactor according to claim 1 is characterized in that: The outer side of the coil (1-3) is provided with a coil connection terminal (1-4), and the outer side of the coil connection terminal (1-4) is covered with electromagnetic insulation glue (1-5).

4. The electromagnetic three-normally closed AC contactor according to claim 1 is characterized in that: Guide isolation grooves (2-7) are provided between the active contacts (2-1) of the contact support (2-3), guide insulation ribs (3-3) are provided between the main static contacts (3-1) of the upper insulation shell (3), and the guide insulation ribs (3-3) are slidably clamped in the guide isolation grooves (2-7).

5. The electromagnetic three-normally closed AC contactor according to claim 4 is characterized in that: Arc discharge openings (3-4) are provided on the upper insulating shell (3) located between the guiding insulating rib plates (3-3).

6. The electromagnetic three-phase normally closed AC contactor according to claim 1 is characterized in that: The non-polar surfaces of the fixed iron core (1-1) and the movable iron core (1-2) are both coated with electromagnetic insulating paint (1-6).

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