38A electromagnetic three-normally-closed alternating current contactor and application thereof

Abstract

The invention discloses a 38A electromagnetic type three-normally-closed alternating current contactor and application thereof, and belongs to the field of low-voltage electric appliances. The three-normally-closed alternating current contactor comprises a contact system unit and an electromagnetic system unit, in the contact system unit, a three-phase main loop static current-carrying contact is fixed on an upper shell, a three-phase main loop movable current-carrying contact is located below the three-phase main loop static current-carrying contact, the three-phase main loop movable current-carrying contact is installed on a movable supporting frame, and the movable supporting frame can move up and down. In the electromagnetic system unit, a static electromagnet is fixed to the lower shell, a movable electromagnet is located above the static electromagnet and installed at the bottom of the movable supporting frame, a coil is located between the static electromagnet and the movable electromagnet, and a first counter-force spring is arranged between the coil and the movable electromagnet. The three-normally-closed alternating current contactor can be used for on-load star sealing control of equipment such as elevators and the like, can also be used for operation control of long-term working equipment, and achieves the zero-power-consumption and energy-saving effects.

Description

Technical Field

[0001] The invention belongs to the field of low-voltage electrical appliances, and in particular relates to a 38A electromagnetic three-normally closed AC contactor and an application thereof. Background Art

[0002] The main circuit forms of existing AC contactor contact systems are mostly normally open or two-open and two-closed.

[0003] The main circuit of the contact system is a normally open AC contactor. After the coil is energized, the electromagnetic system is excited, and the electromagnetic attraction overcomes the tower-shaped reaction spring and the electric repulsion of the contact, so that the contact is reliably connected, the product contact resistance is small, and the contact temperature rise is low; after the coil is de-energized, the electromagnetic system disappears, and the tower-shaped reaction spring of the magnetic system and the columnar reaction spring of the contact system are used to react, so that the contact system is in a disconnected state. At this time, the tower-shaped reaction spring and the columnar reaction spring of the contact act at the same time, and their reaction force only needs to overcome the gravity of the movable parts. The contact breaking speed is fast, the arcing time is short, and the arc is easy to extinguish. After the coil is de-energized, the electromagnetic system is not excited, and the arc is not attracted by the electromagnetic attraction. Therefore, this type of product has a high switching capacity of AC-3 690V, and is mostly used for AC-3 and AC-4 heavy load on-off control. However, when it is used to control long-term working equipment, the coil needs to be energized for a long time, and the coil power consumption is large, resulting in energy waste. At the same time, there is a risk of coil burning.

[0004] The main circuit of the contact system is a two-open and two-closed contactor. When the coil is energized, the two-phase normally open current-carrying contacts are in a closed state, and the two-phase normally closed current-carrying contacts are in an open state; when the coil is de-energized, the two-phase normally open current-carrying contacts are in an open state, and the two-phase normally closed current-carrying contacts are in a closed state; in the process of the contactor coil gaining and losing power, since the states of the two-phase normally open current-carrying contacts and the two-phase normally closed current-carrying contacts are opposite, the action characteristics and product connection reliability of this type of contactor are easy to achieve. However, since it has two normally closed contacts, when the coil is energized, if the normally closed current-carrying contact is disconnected under load, electromagnetic attraction is likely to occur, which can easily attract the disconnected arc to the electromagnetic system, causing a short circuit between the contact system and the electromagnetic system, or a short circuit between the normally closed current-carrying contacts, resulting in product failure. Therefore, this type of product can only be used in AC-1 380V light loads, and the normally closed current-carrying contacts cannot be disconnected under load. When this type of product is used to control a three-phase circuit, since there are only two-phase normally closed or normally open current-carrying contacts, the contacts are easily burned due to three-phase imbalance.

[0005] As a special equipment for rail transit, elevators have high safety requirements. In order to prevent safety accidents such as rapid falling or rapid rushing to the top of the elevator when the elevator brake fails, the elevator traction machine can be controlled by "sealing the star" to balance the elevator. At present, the elevator star-sealing scheme generally uses relays or auxiliary contact groups or contact systems with two normally open and two normally closed contactors. There is a problem of contact burning due to insufficient contact capacity or three-phase imbalance when the elevator stops unexpectedly, and it does not meet the requirements of the revised "Elevator Type Test Rules" approved and issued by the State Administration for Market Regulation in 2022. The provisions of Clause H6.12 are added: "The components of other electrical braking devices should be able to withstand the impact of unexpected shutdowns of elevators when running at rated speeds. If a star-sealing contactor is used, the normal start of the elevator should be prevented when its contacts are sticky. The device can be inoperative when the elevator power supply fails." Summary of the invention

[0006] The purpose of the present invention is to provide a 38A electromagnetic three-normally closed AC contactor.

[0007] Another object of the present invention is to provide an application of a 38A electromagnetic three normally closed AC contactor.

[0008] The technical solution of the present invention is: a 38A electromagnetic three-normally closed AC contactor, comprising an upper shell and a lower shell, wherein the upper shell and the lower shell are connected to form a shell space inside, and a contact system unit and an electromagnetic system unit are arranged in the shell space; The contact system unit includes a three-phase main circuit static current-carrying contact and a three-phase main circuit movable current-carrying contact. The three-phase main circuit static current-carrying contact is fixed on the upper shell, and the three-phase main circuit movable current-carrying contact is located below the three-phase main circuit static current-carrying contact. The three-phase main circuit movable current-carrying contact is installed on a moving support frame, and the moving support frame can move up and down; The electromagnetic system unit includes a stationary electromagnet, a movable electromagnet and a coil. The stationary electromagnet is fixed on the lower shell, the movable electromagnet is located above the stationary electromagnet, the movable electromagnet is installed at the bottom of the moving support frame, the coil is located between the stationary electromagnet and the movable electromagnet, and a first reaction spring is provided between the coil and the movable electromagnet.

[0009] As a further improvement of the present invention, a second reaction spring is provided between the moving support frame and the movable current-carrying contact of the three-phase main circuit.

[0010] As a further improvement of the present invention, an arc extinguishing device is provided on the inner wall of the upper shell, the arc extinguishing device is located below the static current-carrying contacts of the three-phase main circuit, and an arc striking foot is provided on the arc extinguishing device.

[0011] As a further improvement of the present invention, the arc extinguishing device is provided with a first arc discharge port, the inner wall of the upper shell is provided with a second arc discharge port, and the second arc discharge port is arranged side by side opposite to the first arc discharge port.

[0012] As a further improvement of the present invention, an insulating plate is provided on the moving support frame.

[0013] As a further improvement of the present invention, a phase-to-phase insulating groove is provided on the moving support frame, and a phase-to-phase insulating rib matching the phase-to-phase insulating groove is provided on the top of the upper shell body, and the phase-to-phase insulating rib is slidably inserted in the phase-to-phase insulating groove.

[0014] The invention discloses an application of a 38A electromagnetic three-normally closed AC contactor in elevator on-load star-sealing control.

[0015] The invention discloses an application of a 38A electromagnetic three-normally closed AC contactor in the operation control of long-term working equipment.

[0016] The beneficial effects of the present invention are as follows: the present invention breaks through the technical bottleneck of the existing contact system normally open structure or two normally open and two normally closed structure AC contactor, realizes the normally closed connection function of the three-phase main circuit after the coil loses power through the electromagnetic system suction and reaction force balance matching structure design, and at the same time, the arc isolation, arc starting and arc discharge structure design of the arc extinguishing device composed of the insulating plate, the phase-to-phase insulating groove and the phase-to-phase insulating convex ribs isolates the arcing risks between the three-phase circuits and between the contact system unit and the electromagnetic system unit, can quickly extinguish the arc, improve the arc insulation performance between the contact system units and the electromagnetic insulation performance between the contact system unit and the electromagnetic system unit, improve the arc extinguishing performance, electrical insulation and safety of the product, and realize a 38A electromagnetic three-normally closed AC contactor with high insulation, high arc extinguishing ability, high switching ability (AC-3 690V) and zero power consumption. The 38A electromagnetic three-normally closed AC contactor of the present invention can be used for load-sealing control of equipment such as elevators, and can also be used for operation control of long-term working equipment to achieve zero power consumption and energy saving effects, and can also be used for load-breaking AC-3 380V equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a 38A electromagnetic three-normally closed AC contactor of the present invention; Figure 2 It is a state diagram of the coil of the 38A electromagnetic three-normally closed AC contactor of the present invention when it is energized; Figure 3 It is a state diagram of the coil of the 38A electromagnetic three-normally closed AC contactor of the present invention when it loses power; Figure 4 It is a schematic diagram of the structure of the static current-carrying contact of the three-phase main circuit and the movable current-carrying contact of the three-phase main circuit in the present invention; Figure 5 It is a structural schematic diagram of the arc extinguishing device in the present invention; Figure 6 It is a working principle diagram of the arc extinguishing device in the present invention; Figure 7 It is a schematic diagram of the structure of the interphase insulation groove and the interphase insulation convex rib in the present invention; Figure 8 The present invention is a circuit connection diagram of the 38A electromagnetic three-normally closed AC contactor used for elevator on-load star-sealing control.

[0018] In the figure: 1-1 is a stationary current-carrying contact of a three-phase main circuit; 1-2 is a movable current-carrying contact of a three-phase main circuit; 1-3 is a moving support frame; 1-4 is an interphase insulating groove; 1-5 is an insulating plate; 1-6 is a second reaction spring; 2-1 is a coil; 2-2 is a stationary electromagnet; 2-3 is a movable electromagnet; 2-4 is a first reaction spring; 3 is an upper shell; 3-2 is a second arc discharge port; 3-3 is an interphase insulating rib; 3-4 is an arc extinguishing device; 3-5 is an arc starting foot; 3-6 is a first arc discharge port; 4 is a lower shell. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with specific implementation modes.

[0020] like Figure 1-7 As shown, a 38A electromagnetic three-normally closed AC contactor includes an upper shell 3 and a lower shell 4. The upper shell 3 and the lower shell 4 are connected up and down by fasteners to form a shell space inside. A contact system unit and an electromagnetic system unit are arranged in the shell space; The contact system unit includes a three-phase main circuit static current-carrying contact 1-1 and a three-phase main circuit movable current-carrying contact 1-2, the three-phase main circuit static current-carrying contact 1-1 is fixed on the upper shell 3, the three-phase main circuit movable current-carrying contact 1-2 is located below the three-phase main circuit static current-carrying contact 1-1, and the three-phase main circuit movable current-carrying contact 1-2 is installed on a moving support frame 1-3, and the moving support frame 1-3 can move up and down; The electromagnetic system unit includes a stationary electromagnet 2-2, a movable electromagnet 2-3 and a coil 2-1, wherein the stationary electromagnet 2-2 is fixed on the lower housing 4, the movable electromagnet 2-3 is located above the stationary electromagnet 2-2, the movable electromagnet 2-3 is installed at the bottom of the motion support frame 1-3, the coil 2-1 is fixed on the lower housing 4, the coil 2-1 is located between the stationary electromagnet 2-2 and the movable electromagnet 2-3, and a first reaction spring 2-4 is provided between the coil 2-1 and the movable electromagnet 2-3. The first reaction spring 2-4 is a tower-shaped reaction spring, and the first reaction spring 2-4 is sleeved on the movable electromagnet 2-3.

[0021] A second reaction spring 1-6 is provided between the moving support frame 1-3 and the movable current-carrying contact 1-2 of the three-phase main circuit. The second reaction spring 1-6 is a columnar reaction spring.

[0022] An arc extinguishing device 3-4 is embedded in the inner wall of the upper shell 3. The arc extinguishing device 3-4 is located below the static current-carrying contact 1-1 of the three-phase main circuit. An arc striking foot 3-5 is provided on the arc extinguishing device 3-4.

[0023] The arc extinguishing device 3-4 is provided with a first arc discharge port 3-6, which is located below the arc striking foot 3-5. The inner wall of the upper shell 3 is provided with a second arc discharge port 3-2, which is arranged side by side with the first arc discharge port 3-6.

[0024] An insulating plate 1-5 is provided on the moving support frame 1-3.

[0025] The moving support frame 1-3 is provided with an interphase insulating groove 1-4, and the top of the upper shell 3 is provided with an interphase insulating rib 3-3 matching the interphase insulating groove 1-4, and the interphase insulating rib 3-3 is slidably inserted in the interphase insulating groove 1-4.

[0026] like Figure 2 As shown, when the coil 2-1 is energized, the movable electromagnet 2-3 and the stationary electromagnet 2-2 are energized, and the generated electromagnetic attraction overcomes the reaction force of the first reaction spring 2-4 and the second reaction spring 1-6, and the movable electromagnet 2-3 and the stationary electromagnet 2-2 attract each other, and the movable electromagnet 2-3 drives the moving support frame 1-3 to move downward, and the movable current-carrying contact 1-2 of the three-phase main circuit moves downward with the moving support frame 1-3 and is disconnected from the stationary current-carrying contact 1-1 of the three-phase main circuit.

[0027] The working principle of the arc extinguishing device is as follows Figure 6 As shown, the static current-carrying contact 1-1 of the three-phase main circuit is disconnected from the movable current-carrying contact 1-2 of the three-phase main circuit, generating a powerful breaking arc ( Figure 6 The shaded part in the middle), if the arc cannot be extinguished quickly, the silver contact of the contact will be burned, causing the product to be damaged and unusable. The present invention provides an arc-starting foot 3-5 on the arc-extinguishing device 3-4, and the arc-starting foot 3-5 can quickly attract the broken arc to the arc-extinguishing device 3-4 to accelerate the arc cooling; at the same time, the first arc-discharging port 3-6 cooperates with the second arc-discharging port 3-2 to use the air flow principle to make the broken arc move quickly from the contact position to the arc-extinguishing device 3-4 ( Figure 6 This quick arc extinguishing structure accelerates the extinguishing of the breaking arc when the three-phase main circuit is disconnected on load when the coil 2-1 loses power, reduces contact burns, and increases product life.

[0028] When the 38A electromagnetic three-phase normally closed AC contactor of the present invention disconnects the normally closed device under load, the movable current-carrying contact 1-2 of the three-phase main circuit moves downward, generating a powerful breaking arc, and the phase arcs attract each other, which is easy to form phase-to-phase arcing, resulting in the risk of short circuit. Therefore, an interphase insulating groove 1-4 is provided on the moving support frame 1-3, and the interphase insulating rib 3-3 on the upper shell 3 is always nested and matched with each other to form a closed arc extinguishing cavity to avoid phase-to-phase arcing. At the same time, since the coil 2-1 is in the energized state when the three-phase main circuit of the 38A electromagnetic three-phase normally closed AC contactor is disconnected, the magnetic system excitation generates magnetic force, and the magnetic force attracts the breaking arc to spray toward the magnetic system, which is easy to cause a short circuit between the contact system unit and the electromagnetic system unit. Therefore, an insulating plate 1-5 is provided on the moving support frame 1-3, and the insulating plate 1-5 is located between the movable electromagnet 2-3 and the movable current-carrying contact 1-2 of the three-phase main circuit, isolating the contact system unit from the electromagnetic system unit, and avoiding the breaking arc spraying toward the magnetic system.

[0029] When the 38A electromagnetic three-normally closed AC contactor of the present invention is used to disconnect normally closed equipment under load, the rapid arc extinguishing structure formed by the arc extinguishing device 3-4 and its arc-starting foot 3-5 and the first arc discharge port 3-6 and the second arc discharge port 3-2, as well as the reinforced insulation structure formed by the insulating plate 1-5, the phase-to-phase insulating groove 1-4, and the phase-to-phase insulating rib 3-3 can achieve rapid disconnection, arc extinguishing, phase-to-phase arc insulation, and arc insulation between the contact system unit and the electromagnetic system unit, thereby improving the product's switching capacity and extending the product's service life.

[0030] like Figure 3 As shown, when the coil 2-1 loses power, the movable electromagnet 2-3 and the stationary electromagnet 2-2 lose their magnetic force. Under the reaction force of the first reaction spring 2-4, the movable electromagnet 2-3 drives the moving support frame 1-3 to move upward, and the movable current-carrying contact 1-2 of the three-phase main circuit moves upward with the moving support frame 1-3, and closes with the stationary current-carrying contact 1-1 of the three-phase main circuit. The second reaction spring 1-6 is in a compressed state, and the reaction force is exerted on the stationary current-carrying contact 1-1 of the three-phase main circuit, so that the stationary current-carrying contact 1-1 of the three-phase main circuit and the movable current-carrying contact 1-2 of the three-phase main circuit are in a reliable contact and closed state.

[0031] The 38A electromagnetic three-way normally closed AC contactor of the present invention can be used for elevator load-carrying star-sealing control. Figure 8As shown, the main circuit of the 38A electromagnetic three normally closed AC contactor of the present invention is connected in series to the front end of the elevator control motor winding, and forms a split star-sealing contactor with the three normally open AC contactors. The three normally open AC contactor is used as the running contactor, and the 38A electromagnetic three normally closed AC contactor of the present invention is used as the star-sealing contactor. Its star-sealing current-carrying contact capacity is equal to the current-carrying contact capacity of the running contactor, and can withstand a short-term withstand current shock of 8 times the rated current for 10 seconds. It can be used when the load star-sealing occurs due to various reasons leading to unexpected shutdown, and at the same time meets the requirements of the new "Elevator Type Test Rules". The two contactor coils are controlled by the same control system. When the system is powered, the two contactor coils are energized at the same time, the magnetic system is closed, the three-phase main circuit current-carrying contacts of the three normally open AC contactor are closed, and the elevator runs normally. The three-phase main circuit static current-carrying contacts 1-1 of the 38A electromagnetic three normally closed AC contactor of the present invention are disconnected from the three-phase main circuit movable current-carrying contacts 1-2, and do not work in the elevator control system. When the elevator stops, the three-phase main circuit current-carrying contact of the three-normally open AC contactor 5 is disconnected, and the three-phase main circuit static current-carrying contact 1-1 of the 38A electromagnetic three-normally closed AC contactor of the present invention is closed with the three-phase main circuit movable current-carrying contact 1-2, and reliably contacts under the reaction force of the second reaction spring 1-6, thereby short-circuiting the motor winding in a "star" shape. At this time, if the brake fails, the car will move unexpectedly, and the motor rotor will rotate to cut the magnetic flux lines, generating a reverse braking torque in the opposite direction to the movement direction of the car, hindering the acceleration of the car, and finally making the car reach a uniform speed state, and no accidents of "hitting the top" or "piercing the ground" will occur, thereby protecting the safety of passengers. At the same time, the present invention uses a 38A electromagnetic three-normally closed AC contactor for star-sealing control, and the star-sealing contact capacity is equal to the running contact capacity, avoiding the risk of contact burning caused by insufficient star-sealing contact capacity, and having higher safety and reliability.

[0032] The 38A electromagnetic three-phase normally closed AC contactor of the present invention can be used for the operation control of long-term working system equipment. When used to control the operation of long-term working system equipment, the system does not need to supply power to the coil 2-1, and the three-phase main circuit is in a closed state. Only when the equipment is under maintenance or failure, the coil 2-1 is supplied with power to disconnect the equipment, thereby achieving zero power consumption and energy saving effect, and solving the problem of easy burning of the coil under long-term working system.

Claims

1. A 38A electromagnetic three-phase normally closed AC contactor, characterized in that: It comprises an upper shell (3) and a lower shell (4), wherein the upper shell (3) and the lower shell (4) are connected to form a shell space inside, and a contact system unit and an electromagnetic system unit are arranged in the shell space; The contact system unit comprises a three-phase main circuit static current-carrying contact (1-1) and a three-phase main circuit movable current-carrying contact (1-2); the three-phase main circuit static current-carrying contact (1-1) is fixed on the upper housing (3); the three-phase main circuit movable current-carrying contact (1-2) is located below the three-phase main circuit static current-carrying contact (1-1); the three-phase main circuit movable current-carrying contact (1-2) is mounted on a moving support frame (1-3); and the moving support frame (1-3) can move up and down; The electromagnetic system unit comprises a stationary electromagnet (2-2), a movable electromagnet (2-3) and a coil (2-1); the stationary electromagnet (2-2) is fixed on a lower housing (4); the movable electromagnet (2-3) is located above the stationary electromagnet (2-2); the movable electromagnet (2-3) is installed at the bottom of a moving support frame (1-3); the coil (2-1) is located between the stationary electromagnet (2-2) and the movable electromagnet (2-3); and a first reaction force spring (2-4) is provided between the coil (2-1) and the movable electromagnet (2-3).

2. A 38A electromagnetic three-normally closed AC contactor according to claim 1, characterized in that: A second reaction force spring (1-6) is provided between the moving support frame (1-3) and the three-phase main circuit movable current-carrying contact (1-2).

3. A 38A electromagnetic three-normally closed AC contactor according to claim 1 or 2, characterized in that: An arc extinguishing device (3-4) is provided on the inner wall of the upper housing (3); the arc extinguishing device (3-4) is located below the static current-carrying contact (1-1) of the three-phase main circuit; and an arc striking foot (3-5) is provided on the arc extinguishing device (3-4).

4. A 38A electromagnetic three-normally closed AC contactor according to claim 3, characterized in that: The arc extinguishing device (3-4) is provided with a first arc discharge opening (3-6), the inner side wall of the upper shell (3) is provided with a second arc discharge opening (3-2), and the second arc discharge opening (3-2) and the first arc discharge opening (3-6) are arranged side by side opposite to each other.

5. A 38A electromagnetic three-normally closed AC contactor according to claim 4, characterized in that: An insulating plate (1-5) is provided on the moving support frame (1-3).

6. A 38A electromagnetic three-normally closed AC contactor according to claim 5, characterized in that: The motion support frame (1-3) is provided with an interphase insulating groove (1-4), the top of the upper shell (3) is provided with an interphase insulating convex rib (3-3) matching the interphase insulating groove (1-4), and the interphase insulating convex rib (3-3) is slidably inserted in the interphase insulating groove (1-4).

7. Application of the 38A electromagnetic three-normally closed AC contactor according to any one of claims 1 to 6 in elevator on-load star-sealing control.

8. Application of the 38A electromagnetic three-way normally closed AC contactor according to any one of claims 1 to 6 in the operation control of long-term working equipment.

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