CN212062322U - High-current-carrying movable contact spring of electromagnetic relay capable of avoiding abrupt increase of counter force - Google Patents
High-current-carrying movable contact spring of electromagnetic relay capable of avoiding abrupt increase of counter force Download PDFInfo
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- CN212062322U CN212062322U CN202020774322.2U CN202020774322U CN212062322U CN 212062322 U CN212062322 U CN 212062322U CN 202020774322 U CN202020774322 U CN 202020774322U CN 212062322 U CN212062322 U CN 212062322U
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Abstract
The utility model discloses an electromagnetic relay movable contact spring that high current-carrying just can avoid the counter-force to increase steeply, this movable contact spring are equipped with a plurality of parallel to each other's narrow grooves along the direction of current, and narrow groove one end is close to the movable terminal other end and is close to the movable contact. In the overtravel stage, it is necessary to reduce the stress in the peripheral region of the contact position of the pusher and the movable spring, which is caused by the elastic deformation of the movable spring. The area between the two narrow grooves is not limited by surrounding materials after the grooves are opened due to the fact that the area is close to the contact point of the push sheet and the elastic sheet, and becomes the main area of elastic deformation of the movable spring sheet in the overtravel stage, and the distance between the two narrow grooves is the width of the main deformation area. Only by designing a proper width, the proper elastic force can be guaranteed to be provided, the contact closing is not influenced by too much elasticity, and the contact closing is not too small, so that reliable contact pressure can be provided.
Description
Technical Field
The utility model relates to an electromagnetic relay, in particular to high current-carrying just can avoid electromagnetic relay movable contact spring that the counter-force sharply increases.
Background
Because the relay has unique electrical and physical characteristics in the control circuit, high insulation resistance in an off state and low on resistance in an on state, any other electronic components cannot be compared with the relay, and the relay has the advantages of high standardization degree, good universality, capability of simplifying circuits and the like, so the relay is widely applied to various electronic equipment in aerospace, military electronic equipment, information industry and national economy.
With the miniaturization of industrial equipment and the development of integrated circuits, the requirements for the overall dimensions of electronic components are higher and higher. For the equipment circuit board, the relay is an important component and plays an important role in opening and closing the circuit. On the basis of unchanged relay volume, if the load capacity is improved, the whole power of the equipment has improved space, and the board distribution area on the circuit board does not need to be additionally increased, so that more surplus space is provided for the development and design of the circuit board. Therefore, a multi-elastic-piece laminated fit solution is provided, and meanwhile, a solution is provided for the problem of product parameters which can occur in the solution. As shown in fig. 1, a relay generally includes an electromagnetic assembly a, a stationary terminal assembly B, and a moving terminal assembly C. The electromagnetic component A mainly comprises an electromagnetic coil 1 and an iron core 2 penetrating through the interior of the electromagnetic coil 1, the arrangement direction of the iron core 2 is along the direction of a magnetic line of force inside the electromagnetic coil 1 after the electromagnetic coil 1 is electrified, one end of the electromagnetic coil 1 is provided with an armature 3, and the armature 3 is over against one end of the iron core 2. The movable end component B is arranged on the outer side of the armature 3 and mainly comprises a movable terminal 4, one end of the movable terminal 4 is connected with an external circuit, a movable spring 5 is fixed at the other end of the movable terminal 4, the movable spring 5 is an elastic conductive metal sheet, the movable spring 5 is provided with a movable contact 51, and the movable spring 5 is connected with the armature 3 through a push piece 7; the static end component C is arranged on the outer side of the movable end component B, the static end component C comprises a static terminal 6, the static terminal 6 is connected with an external circuit, a static contact 61 is arranged on the outer side of the static terminal 6, the static contact 61 corresponds to the movable contacts 51 one by one, and the movable contacts 51 are separated from the static contact 61 under the elastic action of the movable reed 5. When the electromagnetic coil 1 is energized, the armature 3 is attracted by magnetism generated by the iron core 2 to rotate towards the iron core 2 and drive the push piece 7 to push the movable reed 5 contacted with the armature to move, so that the movable contact 51 is contacted with the fixed contact 61, and the effect of conducting connection between a load and a power supply is achieved.
The design of a typical relay leaves a margin for contact wear. During the action of the relay, the action process is generally divided into two stages, the process that the driven contact just touches the static contact is called a gap stage, and the process that the armature continues to move until the armature contacts the iron core is called an overtravel stage. During the overtravel phase, the increase in the reaction force is amplified because the reaction force slope is greater than the reaction force slope during the lash phase. For the movable spring, after the contact is closed, one fulcrum is added in an overtravel stage, and the counterforce is increased sharply. The counter force is too big in the overtravel stage, probably can lead to armature and iron core contactless, and the sound contact can not stably be closed, has the risk that the product became invalid.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a high current-carrying just can avoid the electromagnetic relay movable contact spring that the counter-force sharply increases.
According to the utility model discloses an aspect provides a high current-carrying and can avoid the electromagnetic relay movable contact spring that the counter-force sharply increases, and this movable contact spring is equipped with a plurality of slots that are parallel to each other along the direction of current, and slot one end is close to the movable terminal other end and is close to the movable contact, and the slot position is symmetrical with the contact point of push jack and movable contact spring.
From ansys simulation analysis, stress is concentrated in a region close to a riveting point for riveting a movable terminal at a clearance stage, and the region is also a root region for generating reaction force; and during the overtravel phase, stress concentration begins to occur in the region where the push piece contacts the movable spring. This is also the source of the steep increase in reaction force during the overtravel phase.
In the overtravel stage, it is necessary to reduce the stress in the peripheral region of the contact position of the pusher and the movable spring, which is caused by the elastic deformation of the movable spring. The area between the two narrow grooves is not limited by surrounding materials after the grooves are opened due to the fact that the area is close to the contact point of the push sheet and the elastic sheet, and becomes the main area of elastic deformation of the movable spring sheet in the overtravel stage, and the distance between the two narrow grooves is the width of the main deformation area. Only a narrow groove with a proper width needs to be designed, so that proper elastic force can be guaranteed to be provided, the contact closing is not affected by too large force, and the contact pressure is not too small, so that reliable contact pressure can be provided. The narrow groove width is required to be as small as possible, so that the current-carrying sectional area is ensured to the greatest extent, the premise is that the punch forming process is met, the service life of a cutter is ensured, and the groove width can offset the influence of staggered slotting positions of the plurality of elastic sheets caused by the position deviation of the groove.
The width of the same narrow groove at different parts of the movable spring plate is required to be consistent as much as possible. Thereby, the stress distribution of the movable spring plate in the main deformation area is more uniform.
Furthermore, the two ends of the narrow groove close to the movable terminal and the movable contact are both arc-shaped. Whereby the accumulation of stress in the portions at both ends of the narrow groove can be avoided.
Furthermore, the movable spring plate is formed by laminating and attaching a plurality of metal spring plates.
Generally, the fixed terminal part of the load end is stronger and uses a material with high electric conductivity, while the movable spring plate is generally thin due to the requirements of deformation and movement, and uses an alloy material, so that the electric conductivity is relatively small, and the effective current-carrying sectional area is small. The current carrying bottleneck at the load end is generally concentrated at the movable spring portion. The current-carrying capacity of the product is improved, and the emphasis is on improving the current-carrying capacity of the movable spring plate, namely improving the effective current-carrying sectional area.
There are three ways to increase the effective current carrying area: and the width of the movable spring plate is increased, the conductivity of the movable spring plate is increased or the thickness of the movable spring plate is increased.
The width of the movable spring is increased, generally limited by the product volume, the change amplitude is limited, and the lifting is not obvious.
The movable reed alloy generally uses copper alloy with higher conductivity, and the range of improving the conductivity is also limited. Thus, the most significant way to increase the effective current carrying area is to increase the thickness of the movable spring plate.
The known formula for calculating the spring force of the movable spring is W ═ h (b ═ h)3*E*)/(4*L3)
Wherein, b is the width of the movable spring plate, h is the thickness of the movable spring plate, E is the elastic modulus and is the deformation, and L is the length of the force arm.
As can be seen from the calculation formula, directly increasing the thickness of the movable spring plate can cause the elastic force to sharply increase by a multiple of a cube. The sharp increase of the elastic force requires a larger coil attraction force, which means that the volume of the magnetic circuit needs to be increased and the product volume needs to be increased.
Assuming that the thickness h, width b and conductivity of the movable spring are 100%, the effective current-carrying cross-sectional area of the movable spring is S ═ b ═ h, and the spring force of the movable spring is W ═ b ═ h3*E*)/(4*L3)。
The following two schemes can be adopted for increasing the current-carrying sectional area:
the first scheme is as follows: the thickness of the movable spring is directly increased to 1.6h, the width is unchanged, the effective current-carrying cross section area is b, 1.6h is 1.6S, and the elasticity of the movable spring is [ b, 1.6h)3*E*]/(4*L3)＝4.096W
Scheme II: two metal spring sheets with the thickness of 80% h and the width of b are used for replacing the original movable spring sheet, so that the effective current carrying area is 2 × b 0.8h ═ 1.6S, and the elastic force of the movable spring sheet is simply calculated to be 2 × b (0.8h)3*E*]/(4*L3)＝1.024W。
From the comparison, the effective current-carrying sectional area can be improved by 60% by using the bimetal spring plate with the thickness of 80% h, and the elastic force of the movable spring plate is only increased by 2.4%, so that the magnetic circuit part does not need to be changed greatly.
Therefore, the form of the bimetal spring plate or the three-metal spring plate can obviously improve the loading capacity of the product, and meanwhile, the magnetic circuit part does not need to be changed too much.
The width of the movable spring plate perpendicular to the current direction can be properly designed according to the matching electromagnetic attraction and the guarantee of the current-carrying sectional area.
Preferably, the movable spring plate is formed by laminating two metal spring plates with identical shapes. Therefore, stress can be uniformly distributed between the two metal elastic sheets.
Specifically, the two metal elastic sheets are at least provided with two narrow grooves, and the position of the narrow groove in each metal elastic sheet is symmetrical to the contact point of the push sheet and the metal elastic sheet, so that the force balance of the metal elastic sheets in the movement process is ensured. In the case of the double-acting spring or triple-acting spring, the reaction force gradient is larger than that in the gap stage in the overtravel stage, and the increase in the reaction force is amplified. Through setting up a plurality of slots, can reduce the counter force greatly.
Furthermore, the positions of the narrow grooves of the two metal elastic sheets correspond to each other.
Or one of the two metal elastic sheets is provided with a plurality of narrow grooves.
Drawings
Fig. 1 is a schematic structural view of an electromagnetic relay.
Fig. 2 is a schematic structural diagram of a movable contact spring of an electromagnetic relay with high current carrying capability and capable of avoiding a sudden increase in reaction force according to an embodiment of the present invention.
Fig. 3 is a schematic structural diagram of a movable contact spring of an electromagnetic relay with high current carrying capability and capable of avoiding a sudden increase in reaction force according to another embodiment of the present invention.
Fig. 4 is an exploded view of the movable spring of the electromagnetic relay shown in fig. 3, which has high current carrying capacity and can avoid a steep increase in the reaction force.
Fig. 5 is an exploded view of a movable spring of an electromagnetic relay with high current carrying capability and capable of avoiding a sudden increase in reaction force according to another embodiment of the present invention.
Fig. 6 is an exploded view of a movable spring of an electromagnetic relay with high current carrying capability and capable of avoiding a sudden increase in reaction force according to another embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
Example 1
Fig. 2 schematically shows an electromagnetic relay movable contact spring with high current carrying capability and capable of avoiding a sudden increase in reaction force according to an embodiment of the present invention.
As shown in the figure, the movable contact spring 5 is provided with two parallel narrow grooves 52 along the current direction, and one end of the narrow groove 52 is close to the movable contact 51 and the other end is close to the movable terminal 4.
The narrow groove 52 is positioned symmetrically to the contact point of the push piece and the movable spring 5.
From ansys simulation analysis, in the gap stage, stress is concentrated in a region close to a riveting point for riveting the movable terminal 4, which is also a root region for generating a reaction force; and during the overtravel phase, stress concentration begins to occur in the region where the push piece contacts the movable spring 5. This is also the source of the steep increase in reaction force during the overtravel phase.
In the overtravel stage, it is necessary to reduce the stress in the peripheral region of the contact position of the pusher with the movable spring 5, which is caused by the elastic deformation of the movable spring. The area between the two narrow grooves 52 is a main area of the movable spring 5 in the overtravel stage, because the area is close to the contact point of the push sheet and the movable spring 5 and is not limited by surrounding materials after the grooves are opened, and the distance between the two narrow grooves 52 is the width of the main deformation area. Only by designing a proper width, the proper elastic force can be guaranteed to be provided, the contact closing is not influenced by too much elasticity, and the contact closing is not too small, so that reliable contact pressure can be provided.
Specifically, the same narrow groove 52 has the same width at different portions of the movable spring 5. Thereby, the stress distribution of the movable spring 5 in the main deformation region is more uniform.
Both ends of the narrow groove 52 near the movable terminal 4 and the movable contact 51 are rounded. Whereby the stress can be prevented from being accumulated in the portions at both ends of the narrow groove 52.
Example 2
Fig. 3 and 4 schematically show an electromagnetic relay movable contact spring having high current carrying capability and capable of avoiding a sudden increase in reaction force according to another embodiment of the present invention. The difference from embodiment 1 is that the movable spring 5 is formed by laminating two metal spring pieces (5a, 5 b).
Generally, the fixed terminal part of the load end is stronger and uses a material with high electric conductivity, while the movable spring plate is generally thin due to the requirements of deformation and movement, and uses an alloy material, so that the electric conductivity is relatively small, and the effective current-carrying sectional area is small. The current carrying bottleneck at the load end is generally concentrated at the movable spring portion. The current-carrying capacity of the product is improved, and the emphasis is on improving the current-carrying capacity of the movable spring plate, namely improving the effective current-carrying sectional area.
There are three ways to increase the effective current carrying area: and the width of the movable spring plate is increased, the conductivity of the movable spring plate is increased or the thickness of the movable spring plate is increased.
The width of the movable spring is increased, generally limited by the product volume, the change amplitude is limited, and the lifting is not obvious.
The movable reed alloy generally uses copper alloy with higher conductivity, and the range of improving the conductivity is also limited. Thus, the most significant way to increase the effective current carrying area is to increase the thickness of the movable spring plate.
The known formula for calculating the spring force of the movable spring is W ═ h (b ═ h)3*E*)/(4*L3)
Wherein, b is the width of the movable spring plate, h is the thickness of the movable spring plate, E is the elastic modulus and is the deformation, and L is the length of the force arm.
As can be seen from the calculation formula, directly increasing the thickness of the movable spring plate can cause the elastic force to sharply increase by a multiple of a cube. The sharp increase of the elastic force requires a larger coil attraction force, which means that the volume of the magnetic circuit needs to be increased and the product volume needs to be increased.
Assuming that the thickness h, width b and conductivity of the movable spring are 100%, the effective current-carrying cross-sectional area of the movable spring is S ═ b ═ h, and the spring force of the movable spring is W ═ b ═ h3*E*)/(4*L3)。
The following two schemes can be adopted for increasing the current-carrying sectional area:
the first scheme is as follows: the thickness of the movable spring is directly increased to 1.6h, the width is unchanged, the effective current-carrying cross section area is b, 1.6h is 1.6S, and the elasticity of the movable spring is [ b, 1.6h)3*E*]/(4*L3)＝4.096W
Scheme II: two metal spring sheets with the thickness of 80% h and the width of b are used for replacing the original movable spring sheet, so that the effective current carrying area is 2 × b 0.8h ═ 1.6S, and the elastic force of the movable spring sheet is simply calculated to be 2 × b (0.8h)3*E*]/(4*L3)＝1.024W。
From the comparison, the effective current-carrying sectional area can be improved by 60% by using the bimetal elastic sheets (5a, 5b) with the thickness of 80% h, and the elastic force of the movable spring sheet is only increased by 2.4%, so that the magnetic circuit part does not need to be changed greatly.
Therefore, the form of the bimetal shrapnel can obviously improve the loading capacity of the product, and meanwhile, the magnetic circuit part does not need to be changed too much.
Preferably, the movable spring 5 is formed by laminating two metal elastic sheets (5a, 5b) with the same shape. The stress can thus be distributed evenly between the two metal domes (5a, 5 b).
In the present embodiment, two metal spring pieces (5a, 5b) are provided with two narrow grooves 52.
The positions of the narrow grooves 52 of the two metal elastic sheets (5a, 5b) correspond to each other.
The position of the narrow groove 52 arranged in each metal elastic sheet is symmetrical to the contact point of the push sheet and the metal elastic sheet.
When a double-acting reed structure is used, the increase in the reaction force is amplified during the overtravel period because the reaction force slope is greater than the reaction force slope during the clearance period. By providing a plurality of narrow grooves 52, the reaction force can be greatly reduced.
In other embodiments, the movable spring 5 can also be formed by laminating three or more metal spring pieces.
Example 3
Fig. 5 schematically shows an electromagnetic relay movable contact spring with high current carrying capability and avoiding a sudden increase in reaction force according to another embodiment of the present invention. The difference from embodiment 2 is that two narrow grooves 52 are provided on the upper metal dome 5a of the movable spring 5, and the lower metal dome 5b is not provided with the narrow grooves 52.
Example 4
Fig. 6 schematically shows an electromagnetic relay movable contact spring with high current carrying capability and avoiding a sudden increase in reaction force according to another embodiment of the present invention. The difference from embodiment 3 is that two narrow grooves 52 are provided on the lower metal dome 5b of the movable spring 5, and the upper metal dome 5a is not provided with the narrow grooves 52.
What has been described above are only some embodiments of the invention. For those skilled in the art, without departing from the inventive concept, several modifications and improvements can be made, which are within the scope of the invention.
Claims (7)
1. The movable contact spring of the electromagnetic relay is characterized in that a plurality of parallel narrow grooves are formed in the movable contact spring along the current direction, one end of each narrow groove is close to a movable terminal, the other end of each narrow groove is close to a movable contact, and the positions of the narrow grooves are symmetrical to the positions of contact points of a push piece and the movable contact spring.
2. The movable contact spring for an electromagnetic relay having high current carrying capability and avoiding a steep increase in reaction force according to claim 1, wherein both ends of said narrow groove near said movable terminal and said movable contact are rounded.
3. The movable contact spring for an electromagnetic relay according to claim 1, wherein said movable contact spring is formed by laminating a plurality of metal contact pieces.
4. The movable contact spring for an electromagnetic relay, which has high current carrying capability and can avoid a steep increase in reaction force, according to claim 3, wherein the movable contact spring is formed by laminating two metal contact springs having the same shape.
5. The movable contact spring of an electromagnetic relay with high current carrying capability and capable of avoiding the abrupt increase of the counterforce as claimed in claim 3 or 4, wherein at least two narrow grooves are formed in the two metal spring pieces, and the position of the narrow groove in each metal spring piece is symmetrical to the contact point of the push piece and the metal spring piece.
6. The movable contact spring for an electromagnetic relay, which has high current carrying capability and can avoid a steep increase in reaction force, according to claim 5, wherein a plurality of the narrow grooves of the two metal spring pieces are located in correspondence.
7. The movable contact spring for an electromagnetic relay according to claim 5, wherein one of said two metal spring pieces is provided with a plurality of said narrow grooves.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020774322.2U CN212062322U (en) | 2020-05-12 | 2020-05-12 | High-current-carrying movable contact spring of electromagnetic relay capable of avoiding abrupt increase of counter force |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202020774322.2U CN212062322U (en) | 2020-05-12 | 2020-05-12 | High-current-carrying movable contact spring of electromagnetic relay capable of avoiding abrupt increase of counter force |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114743835A (en) * | 2021-01-07 | 2022-07-12 | 厦门台松精密电子有限公司 | Contact spring sheet structure of electromagnetic relay |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114743835A (en) * | 2021-01-07 | 2022-07-12 | 厦门台松精密电子有限公司 | Contact spring sheet structure of electromagnetic relay |
| CN114743835B (en) * | 2021-01-07 | 2023-12-01 | 厦门台松精密电子有限公司 | Contact spring plate structure of electromagnetic relay |
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