Overcurrent protection relay

Abstract

The invention provides an overcurrent protection relay, and relates to the field of relays. The over-current protection relay comprises a relay body, an iron core and a lock catch connecting rod which are installed in the relay body, and further comprises a supporting rod and an armature which are installed in the relay body, connecting pieces are installed between the supporting rod and the armature, and an elastic piece is installed between fixing parts of the two connecting pieces. The gravity of the armature cooperates with the elastic sheet to form an included angle between the fixed part and the movable part of the connecting piece; according to the over-current protection relay, the armature and the iron core form surface contact, the adsorption efficiency of the iron core is improved, the response time is shortened, the lug boss is eccentrically arranged, the radius is gradually increased along the rotation direction, and the eccentric arrangement enables the arm of force to be lengthened along with the increase of the angle when the lug boss rotates; in the rotating process, the thrust on the lock catch connecting rod is continuously amplified, even if lubricating grease carbonization and friction problems exist in a fulcrum, the lock catch connecting rod can still be rapidly pushed, the response time is further shortened, and motion lag of the armature is prevented.

Description

Technical Field

[0001] The present invention relates to the field of relays, in particular to an overcurrent protection relay. Background Art

[0002] An overcurrent protection relay is a relay device that can automatically detect and trigger protective action when an abnormal situation occurs in a circuit or electrical equipment that exceeds its rated current. By monitoring the current size, when the current exceeds the preset threshold, it will quickly cut off the circuit or send an alarm signal to prevent the equipment from being damaged by overcurrent; the relay current transformer is used to convert the large current in the main circuit into a small current in proportion so that the relay can detect it. It is usually put on the wire of the main circuit and works on the principle of electromagnetic induction. The coil of the relay is connected to the current transformer, and a magnetic field is generated by the current. The number of turns and wire diameter of the coil are designed according to the rated current and sensitivity of the relay. There is a certain air gap between the iron core and the armature of the relay. When current passes through the coil, the iron core generates a magnetic field to attract the armature. The reaction spring of the relay is used to provide a reaction force to balance the electromagnetic attraction. When the electromagnetic attraction is greater than the effect of the reaction spring When the force is applied, the armature moves; when the armature moves, the moving contact and the static contact close or open, thereby controlling the on and off of the circuit. The contact system usually has two types of contacts: normally open contacts and normally closed contacts. The normally open contact is open when the relay is not actuated and closed when actuated, while the normally closed contact is the opposite. When the overcurrent protection is actuated, the tripper is linked with the lever mechanism. After the tripper, such as the electromagnetic tripper or the thermal tripper, is triggered, the force is transmitted to the driven end through the lever. The driven end pushes the tripping half-shaft or the tripping lock to open the relay. After the relay is triggered and the power is cut off, the coil remains energized. At this time, the iron core and the armature are in the attracted state, but the contacts have cut off the main circuit instead of cutting off the control circuit where the coil is located. The coil is usually connected in series in the control circuit, and the contacts are connected in series in the main circuit. When the main circuit overcurrent occurs, the contacts cut off the main circuit, but the coil in the control circuit is still energized, maintaining the armature attracted state until it is manually reset or the control circuit power is manually cut off after the fault is eliminated.

[0003] When a traditional relay activates overcurrent protection, the iron core attracts the armature to drive the lever to move. The fulcrum, active end and driven end of the lever form a mechanical transmission structure. Among them, the driven end is used to push the tripping locking mechanism, such as the tripping half-shaft or locking link, to release the mechanical lock of the moving contact, so that the moving contact is quickly disconnected under the drive of the trip spring, realizing circuit disconnection protection.

[0004] According to measured data, when the relay is in long-term operation, the carbonization of grease at the fulcrum will extend the time it takes for the iron core to adsorb the armature from 12ms to 45ms. In addition, environmental dust or copper chips generated by disconnection entering the fulcrum gap will cause foreign matter to accumulate, and oxidation and rusting of the metal surface, such as caused by humidity or corrosive gases, will further increase frictional resistance. The fulcrum serves as the axis of rotation of the lever. Increased fulcrum friction will directly hinder the transmission of the lever, resulting in prolonged adsorption time and delayed armature movement, which will ultimately delay the action of the locking link and cause delayed or refusal of the overcurrent protection action. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides an overcurrent protection relay, which solves the problem that the increased friction of the fulcrum hinders the lever transmission, resulting in prolonged adsorption time and delayed armature movement.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: an overcurrent protection relay, including a relay body and an iron core and a locking rod installed in the relay body, and also including a support rod and an armature installed in the relay body, with a connecting piece installed between the two, and an elastic sheet installed between the fixed parts of the two connecting pieces. The gravity of the armature cooperates with the elastic sheet to form an angle between the fixed part and the movable part of the connecting piece, and the movement trajectory of the armature is limited to moving perpendicular to the end face of the iron core.

[0007] One end of one of the connectors close to the support rod has a "6"-shaped protrusion, the radius of which increases successively along the rotation direction from the starting point to the ending point, and the protrusion of the connector contacts the locking link.

[0008] Preferably, the connecting member includes a fixing member and a sling fixed to each other, the fixing member is installed on the support rod through a cylinder, and the sling is installed on the armature through a cylinder.

[0009] Preferably, a plurality of the fixing members and the slings are provided, and the plurality of the slings are distributed in a matrix.

[0010] Preferably, the elastic sheet is curved in an initial state, and both ends of the elastic sheet are rotatably connected to the adjacent fixing members via a connecting rod.

[0011] Preferably, a gap is left between the armature and the iron core in an initial state, and when the iron core attracts the armature, surface contact is formed between the armature and the iron core.

[0012] Preferably, a groove conjugate with the outer peripheral contour of the raised portion is provided in the raised portion of the connector, and the locking link is located in the groove and contacts the groove in the raised portion.

[0013] Preferably, the armature is colinear with the central axis of the core.

[0014] Preferably, the protrusion of the connecting member is eccentrically arranged with respect to the support rod, and the support rod is close to the end with a smaller radius of the protrusion.

[0015] Compared with the prior art, the present invention has the following beneficial effects: the armature is collinear with the central axis of the iron core, and the elastic sheet and gravity cooperate to limit the vertical motion trajectory, so that the armature and the iron core form surface contact, thereby improving the iron core adsorption efficiency and shortening the response time. The protrusion adopts an eccentric setting, and the radius increases along the rotation direction. The eccentric setting makes the force arm longer as the angle increases when the protrusion rotates. In conjunction with the increase in the radius of the protrusion, the thrust on the lock link is continuously amplified during the rotation process. Even if there are problems of grease carbonization and friction at the fulcrum, the lock link can still be pushed quickly, further shortening the response time and preventing the armature movement from lagging. The protrusion is in direct contact with the lock link to eliminate the energy loss at the moment of collision, reduce the kinetic energy loss of the transmission link, and improve the transmission efficiency. At the same time, the contact transmission is evenly stressed, avoiding plastic deformation caused by frequent collisions and uneven stress, ensuring the accuracy and stability of long-term use, and improving the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of a relay body of the present invention;

[0017] Figure 2 A schematic diagram of the internal structure of the overall frame of the relay body of the present invention;

[0018] Figure 3 A top view of a portion of the structure of the present invention;

[0019] Figure 4 This is a front view of the entire iron core after it absorbs the armature;

[0020] Figure 5 It is a front view of the connecting piece of the present invention;

[0021] Figure 6 A sectional view of the front view of the connector of the present invention;

[0022] Figure 7 This is a partial schematic diagram of the iron core before it absorbs the armature;

[0023] Figure 8 This is a partial schematic diagram of the iron core after adsorbing the armature according to the present invention;

[0024] Figure 9 A top view of the connector of the present invention;

[0025] Figure 10 It is a structural schematic diagram of the connecting piece and the raised portion of the present invention.

[0026] Among them, 1. relay body; 101. iron core; 102. locking link; 103. armature; 2. support rod; 3. connecting piece; 301. fixing piece; 302. sling; 303. protrusion; 4. elastic sheet; 5. groove. DETAILED DESCRIPTION

[0027] like Figures 1-10 As shown, an overcurrent protection relay includes a relay body 1 and an iron core 101 and a locking link 102 installed in the relay body 1, and also includes a support rod 2 and an armature 103 installed in the relay body 1, and a connecting piece 3 is installed between the two. The connecting piece 3 includes a fixed fixing piece 301 and a sling 302, the fixing piece 301 is installed on the support rod 2 through a cylinder, and the sling 302 is installed on the armature 103 through a cylinder. The fixing piece 301 serves as the fixed part of the connecting piece 3, and the sling 302 serves as the movable part of the connecting piece 3. The fixing piece 301 and the sling 302 are both fixed to the cylinder close to each other. A plurality of fixing pieces 301 and slings 302 are provided, and the plurality of slings 302 are distributed in a matrix, so that the armature 103 is more stable. The protrusion 303 of the connecting piece 3 is provided with There is a groove 5 which is conjugate with the outer peripheral contour of the raised portion 303, that is, the radius of the groove 5 also increases successively along the rotation direction. The locking link 102 is located in the groove 5 and contacts the groove 5 in the raised portion 303. The armature 103 is collinear with the central axis of the iron core 101. An elastic sheet 4 is installed between the fixed parts of the two connecting parts 3. The elastic sheet 4 is curved in the initial state. Both ends of the elastic sheet 4 are rotatably connected to the fixed parts 301 close to it through a connecting rod. The gravity of the armature 103 cooperates with the elastic sheet 4 to form an angle between the fixed part and the movable part of the connecting part 3, and the movement trajectory of the armature 103 is limited to moving perpendicular to the end face direction of the iron core 101. In the initial state, there is a gap between the armature 103 and the iron core 101. When the iron core 101 attracts the armature 103, surface contact is formed between the two.

[0028] One of the connectors 3 has a "6"-shaped protrusion 303 at one end close to the support rod 2, the radius of which increases successively along the rotation direction from the starting point to the end point, and the protrusion 303 of the connector 3 contacts the lock link 102, and the radius growth rate of the protrusion 303 is constant, so that when the iron core 101 attracts the armature 103, the protrusion 303 rotates around the support rod 2 as the axis, pushing the lock link 102 to move linearly through the spiral arc surface, thereby releasing the lock of the moving contact in the relay body 1. The protrusion 303 of the connector 3 is eccentrically arranged with respect to the support rod 2, and the support rod 2 is close to the end with the smaller radius of the protrusion 303.

[0029] In use, if overcurrent occurs in the circuit, the current will flow through the coil on the iron core 101. With the passage of the current, a magnetic field is immediately generated around the coil. Due to the high magnetic conductivity of the iron core 101, the magnetic field is concentrated and amplified, so that the magnetism of the iron core 101 is enhanced. The enhanced magnetic field forms a magnetic flux loop between the iron core 101 and the armature 103. The armature 103 is also made of a magnetic conductive material. Under the action of the magnetic field, the armature 103 is magnetized and becomes a temporary magnet. According to the basic properties of the magnet, opposite poles attract each other. The magnetic field force between the iron core 101 and the armature 103 will overcome the elastic force of the elastic sheet 4 and the gravity of the armature 103, and generate an attractive force pointing to the iron core 101. Since the armature 103 and the center axis of the iron core 101 are collinear, and the connecting piece 3 is connected to the armature 103 and the support rod 2 at both ends, respectively, the gravity of the elastic sheet 4 and the armature 103 forms a fixed included angle at both ends of the connecting piece 3. When the armature 103 moves, this included angle acts like a track, allowing the armature 103 to move perpendicular to the end surface of the armature 103, so that the magnetic field force can uniformly act on the armature 103, ensuring that the armature 103 is stably stressed, avoiding the uneven distribution of the magnetic field and the loss of the attractive force due to the deviation of the armature 103, so that the iron core 101 can adsorb the armature 103 with higher efficiency. With the continuous increase of the current, the magnetic field strength is continuously enhanced. When the magnetic field force is sufficient to overcome the elastic force of the elastic sheet 4, the armature 103 starts to move along the direction perpendicular to the end surface of the iron core 101, and the air gap between the iron core 101 and the armature 103 gradually decreases, until they are in close contact, forming a surface contact state. In the surface contact state, the contact area between the iron core 101 and the armature 103 is the largest, which can maximize the effect of electromagnetic attraction, ensuring that the armature 103 is reliably adsorbed, which is conducive to the subsequent unlocking and breaking action.

[0030] Next, as Figure 7 and Figure 8As shown, when the iron core 101 absorbs the armature 103, the armature 103 will drive the connecting piece 3 connected thereto to move, and one end of the connecting piece 3 is sleeved on the support rod 2 through the fixing piece 301, and the connecting piece 3 rotates around the support rod 2. One end of one of the connecting pieces 3 close to the support rod 2 has a "6"-shaped protrusion 303. At this time, the protrusion 303, as the end of the connecting piece 3 close to the support rod 2, will follow the connecting piece 3 to rotate with the support rod 2 as the axis; when the protrusion 303 rotates with the support rod 2 as the axis, its radius increases from the starting point to the end point along the rotation direction, and the protrusion 303 of the connecting piece 3 contacts the bottom end of the lock link 102, and the protrusion 303 The arc surface of the groove 5 will continue to push the lock link 102 to make a linear motion. The lock link 102 originally locked the moving contact, but will be unlocked after being pushed. The moving contact quickly disconnects the circuit under the elastic force of the trip spring to achieve overcurrent protection. It should be noted that during the whole process, the rotation of the protrusion 303 is like the handle of a switch. The electromagnetic force pulling the armature 103 is the power to turn the handle. The eccentric setting of the protrusion 303 and the support rod 2 and the radius of the protrusion 303 increase successively, so that the thrust of the protrusion 303 on the lock link 102 gradually increases. In this process, the two cooperate to overcome the fulcrum friction, ensuring smooth rotation and timely protection, more labor-saving and more efficient.

[0031] Next, it should be noted that the protrusion 303 and the support rod 2 are eccentrically arranged, and the support rod 2 is close to the end of the small radius of the protrusion, which makes the rotation center of the protrusion not in the center of the protrusion 303, but biased to the small radius side, just like using an eccentric key to open a door, which will generate greater twisting force when turning. When the protrusion rotates around the support rod 2, the distance from the support rod 2 to the center of the protrusion will form a lever arm. As the protrusion rotates, the lever arm gradually becomes longer, thereby amplifying the thrust on the lock link 102, which can easily overcome the fulcrum friction; the radius of the protrusion 303 gradually increases from the starting point to the end point, like the texture of a snail shell. When the protrusion starts to rotate, the small radius end first contacts the lock link 102. As the rotation angle becomes larger, the radius of the protrusion gradually increases, just like using an increasingly larger key. The longer the lever pushes the lock link 102, the greater the thrust of the protrusion 303 on the lock link 102 during the rotation process. Even if there is friction at the fulcrum, such as carbonization of grease, the lock link 102 can be pushed by the increasing thrust of the protrusion. The lever mechanism used in traditional relays collides with the lock link 102 through swinging. The impact force at the moment of collision is large, resulting in energy loss. Long-term frequent collisions and uneven force, coupled with fulcrum friction and vibration, make the lever prone to plastic deformation, reduce transmission accuracy, and affect relay performance and service life. The protrusion 303 of the device contacts the lock link 102, and the transmission is collision-free, which reduces energy loss. The contact transmission is evenly stressed, reduces the probability of deformation, and extends service life.

[0032] Finally, when the locking link 102 completes its movement, the lock on the moving contact in the relay body 1 is released, and the moving contact quickly disconnects the circuit under the drive of the trip spring to realize the overcurrent protection function. After the circuit fault is eliminated and the current returns to normal, the relay needs to be reset. After the power is cut off, the magnetic field of the iron core 101 disappears, and the restoring force of the elastic sheet 4 and the gravity of the armature 103 work together to make the connector 3 rotate in the opposite direction and return to the initial state, waiting for the next work.

[0033] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An overcurrent protection relay, comprising a relay body (1), an iron core (101) and a locking link (102) installed in the relay body (1), characterized in that: It also includes a support rod (2) and an armature (103) installed in the relay body (1), with a connecting piece (3) installed between the two, and an elastic piece (4) installed between the fixed parts of the two connecting pieces (3). The gravity of the armature (103) cooperates with the elastic piece (4) to form an angle between the fixed part and the movable part of the connecting piece (3), and the movement trajectory of the armature (103) is limited to move perpendicular to the end face direction of the iron core (101); One end of one of the connecting pieces (3) close to the support rod (2) has a "6"-shaped protrusion (303), the radius of which increases in sequence along the rotation direction from the starting point to the ending point, and the protrusion (303) of the connecting piece (3) contacts the locking connecting rod (102).

2. The overcurrent protection relay according to claim 1, characterized in that: The connecting member (3) comprises a fixing member (301) and a sling (302) fixed to each other, the fixing member (301) is mounted on the support rod (2) via a cylinder, and the sling (302) is mounted on the armature (103) via a cylinder.

3. The overcurrent protection relay according to claim 2, characterized in that: A plurality of the fixing members (301) and the slings (302) are provided, and the plurality of slings (302) are distributed in a matrix.

4. The overcurrent protection relay according to claim 2, characterized in that: The elastic sheet (4) is in a curved shape in an initial state, and both ends of the elastic sheet (4) are rotatably connected to the adjacent fixing members (301) via connecting rods.

5. The overcurrent protection relay according to claim 1, characterized in that: In an initial state, a gap is left between the armature (103) and the iron core (101); when the iron core (101) attracts the armature (103), surface contact is formed between the two.

6. The overcurrent protection relay according to claim 1, characterized in that: A groove (5) conjugated with the outer peripheral contour of the raised portion (303) is provided in the raised portion (303) of the connecting member (3); the locking link (102) is located in the groove (5) and contacts the groove (5) in the raised portion (303).

7. The overcurrent protection relay according to claim 1, characterized in that: The armature (103) is colinear with the central axis of the iron core (101).

8. The overcurrent protection relay according to claim 1, characterized in that: The raised portion (303) of the connecting member (3) is eccentrically arranged with respect to the support rod (2), and the support rod (2) is close to the end with the smaller radius of the raised portion (303).

Images