Electromagnetic three-normally-closed alternating current contactor

Abstract

The utility model relates to the technical field of electricity, discloses an electromagnetic type three-normally-closed alternating current contactor, and solves the problems that when the conventional 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 applied to 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] This utility model relates to the field of electrical technology, specifically to an electromagnetic three normally closed AC contactor. Background Technology

[0002] Currently, most AC contactors on the market have three normally open, four normally open, or two open-two closed main circuit configurations. When these contactors are used in a three-phase main circuit, after the coil in the electromagnetic mechanism is de-energized, the return spring's reaction force causes the contact mechanism, along with the moving iron core, to move upwards and reset. The three-phase active contacts move upwards with the contact mechanism for a certain distance before stopping under the limiting action of the three-phase main stationary contacts, i.e., the three-phase main contacts close. The three-phase active contact springs compress, and the upward movement of the three-phase active contacts generates an electric repulsion force with the three-phase main stationary contacts. This electric repulsion force, the contact spring's reaction force, and the gravity of the contact mechanism and the moving iron core prevent the contact mechanism and the moving iron core from resetting upwards, thus causing the contacts to not close properly. The contactor suffers from reliability issues, high contact resistance, and high contact temperature. Furthermore, when the coil in the electromagnetic mechanism is energized, the normally closed contacts of the three-phase main circuit open. An electric arc is generated at the instant the normally closed contacts open, and the arc moves downwards with the contact mechanism, eventually impacting the electromagnetic mechanism. At this point, the electromagnetic mechanism is energized, generating electromagnetic attraction. This attraction makes arc extinguishing more difficult and increases the risk of a short circuit between the arc and the electromagnetic mechanism. Because the return spring is close to the coil, the arc, moving downwards with the contact mechanism and short-circuiting the moving iron core, can further cause a short circuit and burn out the coil, leading to product failure. Therefore, this type of contactor can only be used in control circuits with lower loads and fewer normally closed contacts, significantly limiting its applicability. Utility Model Content

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

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] An electromagnetic three-normally closed AC contactor includes an upper insulating shell and a lower insulating shell. A contact mechanism is housed within the upper insulating shell, and an electromagnetic mechanism is housed within the lower insulating shell. Multiple main stationary contacts are arranged side-by-side on one side of the upper insulating shell, and auxiliary stationary contacts are arranged parallel to the main stationary contacts on the other side of the upper insulating shell. The contact mechanism includes a contact support, active contacts, and auxiliary moving contacts. The contact support and the upper insulating shell are movably connected at intervals. The active contacts are evenly distributed and connected to the contact support. The auxiliary moving contacts are located on the contact support parallel to the active contacts. The active contacts are located on the upper insulating shell... Below the stationary contact, the auxiliary moving contact is located above the auxiliary stationary contact. The contact support is also equipped with a magnetic shielding plate, and the magnetic shielding plate is located below the active contact and the auxiliary moving contact. The electromagnetic mechanism includes a fixed iron core, a movable iron core, and a coil. The fixed iron core and the lower insulating shell are fixedly connected. The coil is sleeved on the middle boss of the fixed iron core. The movable iron core is located directly above the fixed iron core. A return spring is sleeved on the middle boss of the movable iron core. The return spring presses against the top of the middle boss of the fixed iron core. The contact support is fixedly installed on the top of the movable iron core.

[0006] Furthermore, an active contact spring is connected between the magnetic shielding plate and the active contact, and an auxiliary moving contact spring is connected between the auxiliary moving contact and the magnetic shielding plate.

[0007] Furthermore, the coil has a coil terminal on its outer side, and the outer side of the coil terminal is covered with electromagnetic insulating adhesive.

[0008] Furthermore, the contact support is provided with multiple guide isolation grooves, and the inner side of the upper insulating shell is provided with multiple guide insulating ribs, which are all slidably engaged in the guide isolation grooves.

[0009] Furthermore, arc-venting ports are provided on the upper insulating shell located between the guide insulating ribs.

[0010] Furthermore, the non-polar surfaces of both the fixed iron core and the movable iron core are coated with electromagnetic insulating varnish.

[0011] This utility model has the following beneficial effects:

[0012] In this invention, the upper insulating shell is designed as a structure with insulating ribs and inserted into the contact bracket. A matching magnetic shielding plate is then set at the bottom of the contact bracket, and an arc-extinguishing port is opened on its side, thereby forming an arc-extinguishing cavity in the direction of arc movement. This effectively blocks the influence of the electromagnetic attraction generated by the electromagnetic mechanism on the arc, thereby improving the electromagnetic insulation between the contact head and the electromagnetic mechanism, and thus significantly improving the arc-extinguishing performance, electrical insulation and safety of the AC contactor.

[0013] This utility model provides an electromagnetic three normally closed AC contactor. By using reset, active and auxiliary moving contact springs to support and press the contacts tightly, the three-phase main circuit achieves a three normally closed structure after the coil is de-energized. This effectively ensures the reliability of the contact, thereby reducing the contact resistance and temperature rise, ensuring the three-phase main circuit can operate under load even when the coil is de-energized. This also avoids the phenomenon of easy burnout due to continuous coil energization and improves the service life of the contactor.

[0014] When the coil of this invention is de-energized and applied to a three-phase main circuit, the three-phase moving contacts only move upward under the support of the reaction force of the return spring, keeping the three-phase main circuit in a closed state. At the same time, the compression and squeezing action of the auxiliary moving contact spring on the moving contacts ensures the reliability of the moving contact contact. This allows the contactor to control continuously operating equipment without the need for the coil to be continuously energized, thus achieving the load operation of the three-phase main circuit. This breaks the limitation of existing three normally open contactors on the market, which require three sets of main contacts to control the normal operation of equipment under the condition that the coil is continuously energized, and effectively reduces the operating energy consumption of the three-phase main circuit. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0016] Figure 2 This is a partial schematic diagram of the contact mechanism when the electromagnetic mechanism is energized in this utility model.

[0017] Figure 3 This is a partial schematic diagram of the contact mechanism when the electromagnetic mechanism loses power in this utility model.

[0018] Figure 4 This is a schematic diagram of the upper insulating shell arc-extinguishing cavity in this utility model.

[0019] Figure 5 This is a schematic diagram showing the magnetic shielding plate arrangement of the contact mechanism in this utility model.

[0020] Figure 6 This is a schematic diagram of the arc-venting port of the upper insulating shell in this utility model.

[0021] Figure 7 This is a schematic diagram of the coil terminal before electromagnetic insulation encapsulation in this utility model.

[0022] Figure 8 This is a schematic diagram of the electromagnetic insulation encapsulation of the coil terminals in this utility model.

[0023] Figure 9 This is a schematic diagram of the electromagnetic insulation setup of the iron core in this utility model.

[0024] The meanings of the reference numerals in the attached figures are as follows:

[0025] 1. Electromagnetic mechanism; 2. Contact mechanism; 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 adhesive; 1-6. Electromagnetic insulating varnish; 2-1. Active contact; 2-2. Auxiliary moving contact; 2-3. Contact support; 2-4. Return spring; 2-5. Active contact spring; 2-6. Auxiliary moving contact spring; 2-7. Guide isolation groove; 2-8. Magnetic shielding plate; 3-1. Main stationary contact; 3-2. Auxiliary stationary contact; 3-3. Guide insulating rib plate; 3-4. Arc venting port. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0027] 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 contact mechanism 2 is housed within the upper insulating shell 3, and an electromagnetic mechanism 1 is housed within the lower insulating shell 4. Multiple main stationary contacts 3-1 are arranged side-by-side on one side of the upper insulating shell 3, while auxiliary stationary contacts 3-2 are arranged parallel to the main stationary contacts 3-1 on the other side of the upper insulating shell 3. The contact mechanism 2 includes a contact support 2-3, active contacts 2-1, and auxiliary moving contacts 2-2. The contact support 2-3 and the upper insulating shell 3 are movably connected at intervals. The active contacts 2-1 are evenly distributed and connected to the contact support 2-3. The auxiliary moving contacts 2-2 are located on the contact support 2-3 parallel to the active contacts 2-1. The active contacts 2-1 are located on the main stationary contacts 3-1. Below, the auxiliary moving contact 2-2 is located above the auxiliary stationary contact 3-2. The contact support 2-3 is also provided with a magnetic shielding plate 2-8, and the magnetic shielding plates 2-8 are all located below the active contact 2-1 and the auxiliary moving contact 2-2. The electromagnetic mechanism 1 includes 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 the middle boss of the fixed iron core 1-1. The movable iron core 1-2 is located 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 presses on the top of the middle boss of the fixed iron core 1-1. The contact support 2-3 is fixedly installed on the top of the movable iron core 1-2.

[0028] An active contact spring 2-5 is connected between the magnetic shielding 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 shielding plate 2-8.

[0029] like Figure 1 , 2 The coil terminals 1-4 shown in Figures 7 and 8 are provided on the outside of the coil terminals 1-3, and electromagnetic insulating glue 1-5 is provided on the outside of the coil terminals 1-4.

[0030] like Figure 4 As shown, multiple guide isolation grooves 2-7 are evenly distributed on the contact bracket 2-3, and multiple guide insulation ribs 3-3 are evenly distributed on the inner side of the upper insulating shell 3, and the guide insulation ribs 3-3 are all slidably locked in the guide isolation grooves 2-7.

[0031] like Figure 6 As shown, arc-venting ports 3-4 are provided on the upper insulating shell 3 located between the guide insulating ribs 3-3.

[0032] like Figure 9 As shown, the non-polar surfaces of both the fixed iron core 1-1 and the movable iron core 1-2 are coated with electromagnetic insulating varnish 1-6.

[0033] When coil 1-3 in electromagnetic mechanism 1 is energized, the electromagnetic attraction overcomes the reaction forces of reset spring 2-4, active contact spring 2-5, and auxiliary moving contact spring 2-6, attracting the moving iron core 1-2 towards the fixed iron core 1-1. The contact mechanism 2, which is linked to the moving iron core 1-2, moves downward, causing the three-phase active contact 2-1 and the main stationary contact 3-1 to be in the open state. When coil 1-3 in electromagnetic mechanism 1 is de-energized, the electromagnetic attraction disappears, and the reaction forces of reset spring 2-4, active contact spring 2-5, and auxiliary moving contact spring 2-6 cause the moving iron core 1-2 to be released. The contact mechanism 2 moves upward to reset, and the three-phase active contact 2-1 and the main stationary contact 3-1 are in the closed state.

[0034] like Figure 1 , 3 As shown, after the coil in electromagnetic mechanism 1 is de-energized, the reaction force of the reset spring 2-4 causes the contact mechanism 2 to move the moving iron core 1-2 upward to reset. The three-phase active contact 2-1 moves upward with the contact mechanism 2 for a certain distance and then stops under the limiting action of the three-phase main stationary contact 3-1, that is, the three-phase main contacts close. The three-phase active contact spring 2-5 is compressed. During the upward movement of the three-phase active contact 2-1, an electric repulsion force is generated between it and the three-phase main stationary contact 3-1. The electric repulsion force of the contacts and the reaction force of the contact springs... The force and gravity of the contact mechanism 2 and the moving iron core 1-2 prevent the contact mechanism 2 and the moving iron core 1-2 from moving upwards to reset. Under the combined action of the return spring 2-4, the attraction and reaction force of the contact spring and the electromagnetic attraction force of the electromagnetic mechanism 1, the contact between the three-phase active contact 2-1 and the three-phase main stationary 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 and reducing the contact temperature rise.

[0035] like Figure 4 , 5As shown, the upper insulating shell 3 also includes three sets of guide insulating ribs 3-3. The contact support 2-3 in the contact mechanism 2 has three sets of guide isolation grooves 2-7. The three sets of guide insulating ribs 3-3 are inserted into the three sets of guide isolation grooves 2-7, which isolate the three-phase main circuit into independent arc extinguishing cavities. Through the design of the arc extinguishing cavity and arc extinguishing channel, the arc extinguishing capability during the contactor switching process is effectively improved.

[0036] like Figure 5 As shown, a magnetic shielding plate 2-8 is installed on the contact support 2-3 in the contact mechanism 2. The magnetic shielding plate 2-8 is located between the electromagnetic mechanism 1 and the contact mechanism 2, which insulates the electromagnetic mechanism 1 and the contact mechanism 2, blocking the influence of the electromagnetic attraction generated by the electromagnetic mechanism 1 on the electric arc, and effectively improving the electrical safety and insulation of the contact mechanism 2 and the electromagnetic mechanism 1.

[0037] like Figure 6 As shown, the three main stationary contacts 3-1 and one auxiliary stationary contact 3-2 on the upper insulating shell 3 are all provided with dedicated arc venting ports 3-4. By utilizing the principle of air flow, the arc can be moved quickly from the product contact position to the outside of the product, accelerating arc extinguishing, reducing the risk of contact burn-out, and improving the product's electrical life.

[0038] like Figure 7 As shown, the coil terminals 1-4 in the electromagnetic mechanism 1 are sealed with electromagnetic insulating glue 1-5, which effectively prevents the electric arc from moving downward with the contact mechanism 2 and short-circuiting the moving iron core 1-2, and further causing the coil 1-3 to short-circuit and burn out through the reset spring 2-4.

[0039] like Figure 3 , 9 As shown, the fixed iron core 1-1 and the movable iron core 1-2 in the electromagnetic mechanism 1 are coated with electromagnetic insulating varnish 1-6 except for the iron core pole surface. This effectively avoids the risk of the electric arc following the contact mechanism 2 downward and eventually spraying onto the electromagnetic mechanism 1, which would cause a short circuit between the electric arc and the electromagnetic mechanism 1.

[0040] like Figure 1 , 2 As shown in Figure 3, when the auxiliary moving contact 2-2 and auxiliary stationary contact 3-2 units of this contactor are normally open, when the coil 1-3 in the electromagnetic structure 1 is energized, a set of auxiliary moving contacts 2-2 and a set of auxiliary stationary contacts 3-2 of the normally closed contactor of the three-phase main circuit are closed. Conversely, when the coil 1-3 in the electromagnetic structure 1 is de-energized, a set of auxiliary moving contacts 2-2 and a set of auxiliary stationary contacts 3-2 of the normally closed contactor of the three-phase main circuit are open. At this time, they can be used as mirror contacts of the auxiliary contact unit to connect feedback signals and detect the opening and closing status of the main circuit unit in a timely manner.

Claims

1. An electromagnetic three-normally closed AC contactor, comprising an upper insulating shell (3) and a lower insulating shell (4), wherein a contact mechanism (2) is provided inside the upper insulating shell (3), and an electromagnetic mechanism (1) is provided inside the lower insulating shell (4); a plurality of main stationary contacts (3-1) are arranged side by side on one side inside the upper insulating shell (3), and auxiliary stationary contacts (3-2) are arranged parallel to the main stationary contacts (3-1) on the other side inside the upper insulating shell (3), characterized in that: The contact mechanism (2) includes a contact support (2-3), an active contact (2-1), and an auxiliary moving contact (2-2). The contact support (2-3) and the upper insulating shell (3) are movably connected at intervals. The active contacts (2-1) are evenly distributed and connected on 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 stationary contact (3-1), and the auxiliary moving contact (2-2) is located above the auxiliary stationary contact (3-2). The contact support (2-3) is also provided with a magnetic shielding plate (2-8), and the magnetic shielding plates (2-8) are all located on the active contact. Below the head (2-1) and auxiliary moving contact (2-2), the electromagnetic mechanism (1) includes 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 the middle boss of the fixed iron core (1-1). The movable iron core (1-2) is set 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) presses on the top of the middle boss of the fixed iron core (1-1). The contact bracket (2-3) is fixedly set on the top of the movable iron core (1-2).

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

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

4. An electromagnetic three-normally closed AC contactor according to claim 1, characterized in that: Multiple guide isolation grooves (2-7) are evenly distributed on the contact support (2-3), and multiple guide insulation ribs (3-3) are evenly distributed on the inner side of the upper insulating shell (3), and the guide insulation ribs (3-3) are all slidably locked in the guide isolation grooves (2-7).

5. An electromagnetic three-normally closed AC contactor according to claim 4, characterized in that: Arc vents (3-4) are provided on the upper insulating shell (3) located between the guide insulating ribs (3-3).

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

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