Multi-contact self-sequence on-off control relay arc extinguishing method
By combining a multi-contact self-sequential on/off control relay with an external surge absorption network, the arcing problem of the relay under inductive and capacitive loads is solved, achieving low-cost and efficient arc extinguishing effect and extending the service life of the relay.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-05
- Publication Date
- 2026-03-27
AI Technical Summary
In existing technologies, relays are prone to arcing when controlling inductive and capacitive loads, leading to contact erosion and shortened service life. Existing arc extinguishing solutions are either costly or complex, and cannot effectively solve this problem.
Design a multi-contact self-sequential on/off control relay. By adjusting the difference in contact gaps, the on/off timing is naturally formed. Combined with an external surge absorption network, the automatic sequential engagement and disengagement of contacts is achieved, suppressing electric arcs.
It achieves low-cost and efficient arc extinguishing, significantly reduces contact erosion and material loss, improves relay reliability and lifespan, and is suitable for frequent switching applications.
Smart Images
Figure CN121748223A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of relays, and in particular to an arc extinguishing method for a multi-contact self-sequence on-off control relay. BACKGROUND
[0002] As a commonly used electric control switch element, relays are widely used in various electrical control systems, especially in controlling inductive loads (such as motors, solenoid valves, etc.) and capacitive loads (such as filter capacitors, switching power supplies, etc.). During the on-off process of the contacts, electric arcs are easily generated, which seriously affects the working reliability and service life of the relay.
[0003] When the relay controls an inductive load, a high induced voltage will be generated across the contacts due to the sudden change of current at the moment of disconnection. If the voltage exceeds the dielectric breakdown voltage between the contacts, an electric arc will be triggered. When the relay controls a capacitive load, a surge current will be generated due to the charging of the capacitor at the moment of closure. The excessive instantaneous current will cause the local temperature of the contacts to rise too high, the metal to vaporize and sputter, and a sputtering arc to be formed. In either case, the electric arc will exacerbate the contact ablation, material transfer, and the increase of contact resistance, which will eventually lead to the failure of the relay.
[0004] The common solutions for arc extinguishing in the prior art mainly fall into two categories: The first category is to parallel a passive absorption network, such as an RC absorption circuit, a varistor, a transient voltage suppression diode, etc., across the contacts of the relay. This type of solution uses the bypass network to absorb the overvoltage energy generated when the contacts are disconnected, or to limit the voltage rise rate. Although the structure is simple and the cost is low, the protection effect is limited: on the one hand, the absorption network needs to be activated after the voltage accumulates to a certain value, and the response is delayed; on the other hand, the suppression capability for the surge current generated when the capacitive load is closed is weak, and the electric arc cannot be completely eliminated. The second category is to series-connect a solid-state electronic switch in the contact circuit of the relay, and to realize soft switching operation through an external control circuit, so that the voltage and current stress in the on-off process are transferred to the solid-state switch. Although this solution can effectively suppress the electric arc, it requires additional driving circuit, isolation circuit, and control timing circuit, which leads to a complex system, a significant increase in cost, and the reliability is affected by the performance of the additional electronic components, which limits its application in industrial environments. SUMMARY
[0005] In view of the above, the existing first type is to connect a passive absorption network, such as an RC absorption circuit, a pressure-sensitive resistor, a transient voltage suppression diode, etc., in parallel across the relay contacts, which uses the bypass network to absorb the overvoltage energy generated when the contacts are opened, or limits the voltage rise rate, although the structure is simple and the cost is low, but the protection effect is limited, and the second type is to connect a solid-state electronic switch in series in the relay contact circuit, and to realize soft switching operation through an external control circuit, so that the voltage and current stress in the on-off process is transferred to the solid-state switch, which can effectively suppress the arc, but requires additional drive circuit, isolation circuit and control timing circuit, resulting in a complex system and a significant increase in cost.
[0006] Therefore, the purpose of the present application is to provide a multi-contact self-sequence on-off control relay arc extinguishing method, which aims to realize the automatic sequence on-off of the contacts through the design of the relay structure itself, and to realize high-efficiency and low-cost arc extinguishing effect by cooperating with an external simple surge absorption network.
[0007] To solve the above technical problems, the present application provides the following technical scheme: a multi-contact self-sequence on-off control relay arc extinguishing method, comprising a relay with two pairs of contacts, the relay comprising: a first static contact, a first moving contact corresponding to the first static contact, a second static contact, a second moving contact corresponding to the second static contact, and a coil for driving the moving contact to act; Wherein, the static gap of the first contact pair composed of the first static contact and the first moving contact is greater than the static gap of the second contact pair composed of the second static contact and the second moving contact; the method comprises the following steps: When the coil is energized and attracted, the second static contact and the second moving contact are contacted first, and after a certain time interval, the first static contact and the first moving contact are contacted later; When the coil is de-energized and released, the first static contact and the first moving contact are disconnected first, and after a certain time interval, the second static contact and the second moving contact are disconnected later; The first static contact and the first moving contact of the relay and the second static contact and the second moving contact are connected to an external working circuit, wherein the second static contact and the second moving contact are connected in series with a surge absorption network, and then connected in parallel with the first static contact and the first moving contact before being connected to a load; By attracting and releasing the two contacts in the above sequence, and cooperating with the surge absorption network, the surge current is limited when the capacitive load is connected, and the overvoltage is suppressed when the inductive load is disconnected.
[0008] As a preferred scheme of the multi-contact self-sequence on-off control relay arc extinguishing method of the present application, wherein: the surge absorption network comprises at least one or a combination of an RC absorption circuit, a pressure-sensitive resistor, and a transient voltage suppression diode.
[0009] As a preferred scheme of the arc extinguishing method of the multi-contact self-sequence on-off control relay of the present application, wherein: the first time and the second time are determined by the gap difference between the first static contact and the first moving contact and the second static contact and the second moving contact and the mechanical action characteristics of the relay, without intervention of external control circuit.
[0010] As a preferred scheme of the relay of the arc extinguishing method of the present application, wherein: a coil; a moving iron core or armature mechanism driven by the coil; a first static contact and a first moving contact, the first moving contact being linked with the moving iron core or armature mechanism; a second static contact and a second moving contact, the second moving contact being linked with the moving iron core or armature mechanism; wherein the static gap between the first static contact and the first moving contact is greater than the static gap between the second static contact and the second moving contact, when the coil controls the moving iron core or armature mechanism to act, the second static contact and the second moving contact are closed first, and the first static contact and the first moving contact are disconnected first.
[0011] As a preferred scheme of the relay of the present application, wherein: the relay further comprises a first contact terminal and a second contact terminal for connecting external wires, the first moving contact and the second moving contact are connected to a common moving contact terminal, the first contact terminal is electrically connected to the first static contact, the common moving contact terminal is connected to the first moving contact and the second moving contact, and the second contact terminal is electrically connected to the second static contact.
[0012] As a preferred scheme of the electrical control system of the present application, wherein: the relay as claimed or described; a load, the load being a capacitive load or an inductive load; a surge absorption network; wherein the common contact of the relay is connected to a power supply, the first static contact is connected to one end of the load, the second static contact of the relay is connected to one end of the surge absorption network, and the other end of the surge absorption network is connected to the same end of the load to which the first static contact of the relay is connected.
[0013] As a preferred scheme of the electrical control system of the present application, wherein: when the load is a capacitive load, the surge absorption network pre-charges the load during the period when the second static contact and the second moving contact are closed first, so as to limit the surge current when the first static contact and the first moving contact are subsequently closed.
[0014] As a preferred scheme of the electrical control system, when the load is an inductive load, during the first stationary contact and the first moving contact are disconnected first, the surge absorption network absorbs the inductive overvoltage generated by the load through the subsequently disconnected second stationary contact and the second moving contact connected to the surge absorption network.
[0015] Compared with the prior art, the present application has at least the following beneficial effects: 1. The present application adjusts the gap difference of the two pairs of contacts in the relay, uses the mechanical action to naturally form the on-off timing, does not need to add a complex electronic control circuit, significantly reduces the system complexity and manufacturing cost, and can inhibit the arc of two typical loads by connecting the absorption network in advance to suppress the overvoltage when the inductive load is disconnected, and by pre-charging to limit the surge current when the capacitive load is closed.
[0016] 2. The present application reduces the electrical stress in the on-off process of the contacts, significantly reduces the ablation and material loss of the contacts, improves the electrical life and reliability of the relay, is suitable for frequent on-off application scenarios, and the external surge absorption network can be flexibly configured according to the specific load type, thereby enhancing the applicability and adjustability of the scheme and facilitating the popularization and application in different electrical environments.
[0017] 3. The present application does not need external timing control, uses the mechanical characteristics of the relay to realize the sequence of contact action, does not need additional controllers and power devices controlled by the controllers, and improves the reliability and anti-interference ability of the system. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 The present application is a schematic diagram of the relay circuit structure of the multi-contact self-sequence on-off control relay arc extinguishing method. Figure 2 The present application is a schematic diagram of the electrical control system circuit connection of the multi-contact self-sequence on-off control relay arc extinguishing method.
[0019] MARKED DESCRIPTION: 1. First stationary contact; 2. Second stationary contact; 3. First moving contact; 4. Second moving contact; 5. Coil; 6. Load; 7. Second contact terminal; 8. First contact terminal; 9. Surge absorption network; 10. Common moving contact terminal. DETAILED DESCRIPTION
[0020] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings.
[0021] Example one, refer to Figure 1For the first embodiment of the present application, the relay mainly comprises a coil 5, a moving iron core or armature mechanism (not separately marked in the figure, but a general component for driving the contact to act), a first stationary contact 1, a first moving contact 3, a second stationary contact 2, a second moving contact 4, the first moving contact 3 and the second moving contact 4 are both fixed on a common contact support linked with the moving iron core, and synchronously move with the on-off of the coil 5.
[0022] The static gap between the first stationary contact 1 and the first moving contact 3 (i.e. the distance between the two when the relay is not in action) is designed to be greater than the static gap between the second stationary contact 2 and the second moving contact 4. This gap difference can be realized by adjusting the installation height of the first stationary contact 1 and the second stationary contact 2, or adjusting the installation height of the first moving contact 3 and the second moving contact 4. Figure 1 In the embodiment, for the convenience of connecting external wires, the relay is further provided with a first contact terminal 8 and a second contact terminal 7; According to a preferred connection mode, the first contact terminal 8 is electrically connected with the second stationary contact 2, and the second contact terminal 7 is electrically connected with the first stationary contact 1.
[0023] The self-sequence on-off working principle of the relay is as follows: The attraction process: when the coil 5 is powered on, the moving iron core drives the common contact support to move towards the stationary contact. Since the gap between the second stationary contact 2 and the second moving contact 4 is small, the second moving contact 4 will first contact and conduct with the second stationary contact 2, and the common contact support continues to move, and after a short time delay (i.e. the first time, determined by the gap difference and the movement speed), the first moving contact 3 with a larger gap will contact and conduct with the first stationary contact 1.
[0024] The release process: when the coil 5 is powered off, the moving iron core drives the common contact support to return under the action of a return spring (not shown in the figure), at this time, the first moving contact 3 first separates and disconnects from the first stationary contact 1, and the common contact support continues to return, and after a short time delay (i.e. the second time), the second moving contact 4 will separate and disconnect from the second stationary contact 2.
[0025] Referring to Figure 2 , a schematic diagram of the circuit connection of an electrical control system applying the arc extinguishing method of the present application is shown. The system comprises the above-mentioned relay, a load 6 and a surge absorption network 9; The common terminal 10 of the relay is connected to a power supply, the first contact terminal 8 is connected to one end of the load 6; the second contact terminal 7 is connected to the surge absorption network 9, and the other end of the surge absorption network 9 is connected to the same end of the load 6 as the first contact terminal 8.
[0026] For the working process and arc extinguishing principle of different load types: When load 6 is a capacitive load (such as a switching power supply, frequency converter / inverter, etc.): During the relay activation process, the second stationary contact 2 and the second moving contact 4 are connected first; at this time, the current path is: power supply → first stationary contact 1 (not connected at this time) → second moving contact 4 → surge absorption network 9 → load 6; The surge absorption network 9 (e.g., an RC circuit with a current-limiting resistor in series) begins to pre-charge the capacitive load 6 with a current limit, thus limiting the magnitude of the initial charging current (surge current).
[0027] After the first time delay, the first stationary contact 1 and the first moving contact 3 are connected to provide the main power supply path for the load 6. At this time, since the load 6 has been precharged to near the power supply voltage, the current flowing through the first stationary contact 1 and the first moving contact 3 when they are closed is very small, effectively avoiding contact metal vaporization and sputtering arc caused by the surge current during closure.
[0028] When load 6 is an inductive load (such as a motor, solenoid valve, relay coil, etc.): During the relay release (disconnection) process, the first stationary contact 1 and the first moving contact 3 disconnect first; at this time, the inductive load 6 will generate a very high induced electromotive force (reverse voltage) because its current cannot change abruptly; this induced electromotive force attempts to maintain the current, and its release path is: load 6 → surge absorption network 9 → second stationary contact 2 → second moving contact 4 → power supply or ground; Surge absorption network 9 (such as a varistor or RC snubber circuit) can absorb or clamp the induced overvoltage, dissipating its energy or limiting it to a safe range.
[0029] After a second time delay, the second stationary contact 2 and the second moving contact 4 disconnect. At this time, since most of the induced energy has been consumed by the surge absorption network 9, the voltage across the second stationary contact 2 and the second moving contact 4 has been greatly reduced. Therefore, the arc generated during disconnection is extremely weak or even non-existent, effectively protecting the contacts.
[0030] The surge absorption network 9 can be configured and its parameters matched according to the specific characteristics (capacitive or inductive) of the load 6 in the actual application. For example, for capacitive loads, an RC circuit with a large series resistance can be used to limit the pre-charge current; for inductive loads, a varistor or transient voltage suppressor diode (TVS) with a suitable clamping voltage can be used to absorb overvoltage.
[0031] Example 2: This example provides a relay as described in Example 1; like Figure 1As shown, the specific structure of the relay is as described above, and the key to manufacturing the relay is to ensure that the static gap between the first static contact 1 and the first moving contact 3 is accurately larger than the static gap between the second static contact 2 and the second moving contact 4. This design makes the relay a standard component with intelligent timing action characteristics, and the user does not need to design a complex control circuit when applying it. Figure 2 This design makes the relay a standard component with intelligent timing action characteristics, and the user does not need to design a complex control circuit when applying it.
[0032] In embodiment three, an electrical control system is provided, as shown. Figure 2 The system integrates the relay of embodiment two, the load 6 and the surge absorption network 9; the working process of the system has been described in detail in embodiment one. The advantage of the system is that the core control logic realized by the mechanical characteristics of the relay makes the whole system structure simple, reliable and low in cost, and is especially suitable for occasions with high requirements for relay life and reliability and frequent on-off of capacitive or inductive loads, such as industrial control, new energy, household appliances and the like.
[0033] In summary, the present application internalizes the complex timing control logic in the relay itself through a clever mechanical structure design of the relay, and only needs to cooperate with a simple and general surge absorption network to effectively deal with the two major problems of capacitive load closing surge and inductive load opening overvoltage, realizes the arc extinguishing target of low cost and high reliability, and prolongs the service life of the relay.
[0034] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application, and they should be covered in the scope of the claims of the present application.
Claims
1. A method of arc extinction for a multi-contact self-sequence on-off control relay, characterized by, The application relates to a relay with two pairs of contacts, which comprises a first static contact (1), a first movable contact (3) corresponding to the first static contact (1), a second static contact (2), a second movable contact (4) corresponding to the second static contact (2), and a coil (5) driving the movable contact to act; Wherein, the static gap of the first contact pair formed by the first static contact (1) and the first movable contact (3) is larger than the static gap of the second contact pair formed by the second static contact (2) and the second movable contact (4); the method comprises the following steps: When the coil (5) is energized and attracted, the second static contact (2) and the second movable contact (4) are first contacted, and after a certain time interval, the first static contact (1) and the first movable contact (3) are contacted; When the coil (5) is de-energized and released, the first static contact (1) and the first movable contact (3) are first disconnected, and after a certain time interval, the second static contact (2) and the second movable contact (4) are disconnected; The first static contact (1) and the first movable contact (3) of the relay and the second static contact (2) and the second movable contact (4) are connected to an external working circuit, wherein the second static contact (2) and the second movable contact (4) are connected in series with a surge absorption network (9), and then connected in parallel with the first static contact (1) and the first movable contact (3) and connected to a load; By attracting and releasing the two contacts in the above order, and cooperating with the surge absorption network (9), the surge current is limited when the capacitive load is connected, and the overvoltage is suppressed when the inductive load is disconnected.
2. The arc quenching method for a multi-contact self-sequence on-off control relay according to claim 1, characterized in that: The surge absorption network (9) comprises at least one or a combination of an RC absorption circuit, a pressure-sensitive resistor and a transient voltage suppression diode.
3. The arc quenching method for a multi-contact self-sequence on-off control relay according to claim 1, characterized in that: The first time and the second time are determined by the gap difference between the first static contact (1) and the first movable contact (3) and the second static contact (2) and the second movable contact (4) and the mechanical action characteristics of the relay, without the intervention of an external control circuit.
4. A relay for implementing the arc extinguishing method according to any one of claims 1 to 3, characterized in that, It comprises: a coil (5); a movable iron core or armature mechanism driven by the coil (5); a first static contact (1) and a first movable contact (3) linked with the movable iron core or armature mechanism; a second static contact (2) and a second movable contact (4) linked with the movable iron core or armature mechanism; Wherein, the static gap between the first static contact (1) and the first movable contact (3) is larger than the static gap between the second static contact (2) and the second movable contact (4), so that when the coil (5) acts, the second static contact (2) and the second movable contact (4) are closed before the first static contact (1) and the first movable contact (3), and the first static contact (1) and the first movable contact (3) are disconnected before the second static contact (2) and the second movable contact (4).
5. The relay of claim 4, wherein: The relay further comprises a first contact terminal (8) and a second contact terminal (7) for connecting external wires, the first movable contact (3) and the second movable contact (4) are connected to a common movable contact terminal (10), the first contact terminal (8) is electrically connected to the first stationary contact (1), the common movable contact terminal (10) is connected to the first movable contact (3) and the second movable contact (4), and the second contact terminal (7) is electrically connected to the second stationary contact (2).
6. An electrical control system, characterized by Comprise: The relay according to claim 4 or 5; A load (6), which is a capacitive load or an inductive load; A surge absorption network (9); Wherein, the common movable contact terminal (10) of the relay is connected to a power supply, the first contact terminal (8) is connected to one end of the load (6); the second contact terminal (7) is connected to the surge absorption network (9), and the other end of the surge absorption network (9) is connected to the same end of the load (6) to which the first contact terminal (8) is connected.
7. The electrical control system of claim 6, wherein, When the load (6) is a capacitive load, during the first closing of the second stationary contact (2) and the second movable contact (4), the surge absorption network (9) precharges the load (6) to limit the inrush current when the first stationary contact (1) and the first movable contact (3) are subsequently closed.
8. The electrical control system of claim 6, wherein, When the load (6) is an inductive load, during the first opening of the first stationary contact (1) and the first movable contact (3), the surge absorption network (9) absorbs the induced overvoltage generated by the load (6) through the subsequently opened surge absorption network (9) connected by the second stationary contact (2) and the second movable contact (4).