CN212648145U

CN212648145U - Movable contact propulsion structure and relay thereof

Info

Publication number: CN212648145U
Application number: CN202021743508.8U
Authority: CN
Inventors: 于国飞; 郑翔; 袁仲林; 吕芃锦; 叶龙
Original assignee: Xiamen University of Technology
Current assignee: Xiamen University of Technology
Priority date: 2020-08-19
Filing date: 2020-08-19
Publication date: 2021-03-02
Anticipated expiration: 2030-08-19

Abstract

The utility model provides a movable contact propulsion structure and a relay thereof, which comprises a movable reed, a movable contact, a push rod, a movable iron core, a positioning plate, a return spring and a thrust spring; the outer side wall of the pushing rod is provided with a fixed seat, the fixed seat is positioned between the positioning plate and the movable spring piece, the pushing spring is a nonlinear spring piece, and two ends of the nonlinear spring piece are respectively abutted against the upper surface of the fixed seat and the lower surface of the movable spring piece; the non-linear spring piece comprises a first linear spring with the initial length of L31 and a second linear spring with the initial length of L32, and the spring length of the non-linear spring piece is L33 when the relay is in a normally open state, wherein L31 is larger than L33, and L32 is smaller than or equal to L33. Therefore, even if the contact material has a wear gap, the movable spring piece can be pushed to rise to the height required by the excessive stroke under the pushing of the nonlinear spring piece with a larger elastic coefficient, so that the movable contact and the fixed contact are tightly closed.

Description

Movable contact propulsion structure and relay thereof

Technical Field

The utility model relates to a high voltage direct current relay field particularly, relates to a movable contact impels structure and relay thereof.

Background

The high-voltage direct-current relay of the new energy automobile has a plurality of factors, such as contact resistance between contacts, pressure between the contacts and the like, which influence the service life of the high-voltage direct-current relay, and the relay cannot be used when the characteristic parameters exceed the limit values specified by the standards.

In the process of repeatedly pushing, contacting and resetting the movable contact of the relay, materials between the fixed contact and the movable contact can be transferred and disappear, so that the gap between the fixed contact and the movable contact is enlarged, namely the abrasion gap of the relay is larger as the relay works for a longer time. When the abrasion gap between the fixed contact and the movable contact is increased, the contact of the relay is poor, and the resistance value between the contacts is increased, so that the relay is required to stop using.

SUMMERY OF THE UTILITY MODEL

Utility model people discover at the in-process of implementing high voltage direct current relay, when the wearing and tearing clearance increase between the contact, if the movable contact will closely combine with the stationary contact, then need the catch bar with the ascending bigger height of movable contact spring, again because the existence of return spring, the pulling force of the return spring that needs the opposition also is big more after the wearing and tearing clearance increase when closed.

Traditional movable contact impels structure adopts linear spring as the thrust spring between catch bar and the movable contact spring, consequently, need more rise a stroke height than initial condition just can make the movable contact combine closely with the stationary contact when the movable contact spring, actually need the catch bar to rise the stroke of 1.5 times or more multiples and just can make this thrust spring meet the thrust of opposition return spring.

However, in the actual pushing process, the pushing rod is driven by the movable iron core to move up and down, and the stroke of the driven pushing rod is limited by the magnitude of the magnetic field force of the coil of the relay and the pullback spring, so that the larger the height of the lifted pushing rod is, the smaller the pushing force is. When the wear gap increases, a larger height needs to be raised and a larger urging force is given to the urging spring.

However, due to the limitation of the magnitude of the magnetic field force of the coil and the pull-back spring, the traditional propelling structure of the movable contact cannot generate enough ascending stroke and pushing force to eliminate the increased gap between the contacts under the scene that the abrasion gap is increased, so that the two contacts are not tightly combined, the resistance value is increased to exceed a limited value, the contact failure of the relay is caused, and the service life of the relay is short.

The utility model provides a movable contact impels structure and relay thereof aims at solving the work working process of relay, and its contact material loss and lead to the clearance grow, leads to the increase of resistance value between the contact and surpasss the problem of limiting value.

The utility model discloses a realize like this: a movable contact propulsion structure comprises a movable reed, a movable contact, a push rod, a movable iron core, a positioning plate, a return spring and a thrust spring.

The movable contact is arranged on the upper surface of the movable spring piece, the movable spring piece is vertically arranged at the upper end of the push rod in a sliding mode, the positioning plate is located below the movable spring piece, a positioning plate through hole which penetrates through the positioning plate up and down for the push rod to pass through is formed in the positioning plate, and two ends of the return spring are connected with the movable spring piece and the positioning plate respectively.

The outer side wall of the pushing rod is provided with a fixed seat, the fixed seat is positioned between the positioning plate and the movable spring piece, the pushing spring is a nonlinear spring piece, and two ends of the nonlinear spring piece are respectively abutted against the upper surface of the fixed seat and the lower surface of the movable spring piece; the movable iron core is used for driving the push rod to move up and down in a reciprocating manner; the nonlinear spring piece is used for compressing the movable spring piece to push the movable spring piece to move upwards to close the movable contact and the fixed contact when the pushing rod moves upwards.

The non-linear spring piece comprises a first linear spring with the initial length of L31 and a second linear spring with the initial length of L32, and the spring length of the non-linear spring piece is L33 when the relay is in a normally open state, wherein L31 is larger than L33, and L32 is smaller than or equal to L33.

In the preferred embodiment of the present invention:

as a further improvement, the first linear spring and the second linear spring are sleeved on the push rod, wherein the inner diameter of the first linear spring is larger than the outer diameter of the second linear spring, or the inner diameter of the second linear spring is larger than the outer diameter of the first linear spring.

As a further improvement, the inner diameter of the first linear spring is larger than the outer diameter of the second linear spring, and the L32 is smaller than the L33; and the upper end and the lower end of the second linear spring are respectively and fixedly connected to the upper surface of the fixed seat and the lower surface of the movable reed.

As a further improvement, the inner diameter of the first linear spring is larger than the outer diameter of the second linear spring, and the L32 is smaller than the L33; the lower end of the second linear spring is fixed on the upper surface of the fixing seat, and the upper end of the second linear spring and the lower surface of the movable reed are arranged in a clearance mode.

As a one-step improvement, two ends of the first linear spring are respectively fixed on the upper surface of the fixed seat and the lower surface of the movable spring.

As a further improvement, the inner diameter of the first linear spring is larger than the outer diameter of the second linear spring, and the L32 is smaller than the L33; the lower end of the second linear spring is fixed on the upper surface of the movable spring plate, and the upper end of the second linear spring is arranged in a gap with the upper surface of the fixed seat.

As a further improvement, the return spring comprises a first return spring and a second return spring, the upper end of the first return spring is connected with one end of the movable spring, the upper end of the second return spring is connected with the other end of the movable spring, the lower end of the first return spring and the lower end of the second return spring are both connected with the positioning plate, and the movable contact comprises a first movable contact and a second movable contact.

The utility model also provides a relay, including relay casing, coil, stationary contact subassembly and as above the movable contact impels the structure.

Furthermore, the positioning plate further comprises a yoke, and the positioning plate is fixedly arranged above the yoke.

The utility model has the advantages that: when the relay is in a normally open state, a certain distance needs to be kept between the fixed contact and the movable contact, and if the elastic coefficient of the thrust spring is too large, the distance between the fixed contact and the movable contact when the relay is in the normally open state is difficult to control. If the elastic coefficient of the thrust spring is too small, a larger magnetic field is required to drive the push rod, thereby increasing the cost and the weight of the relay. Therefore, the elastic coefficient of the thrust spring is controlled between a reasonable balance value, but the clearance between the fixed contact and the movable contact is gradually increased during the working process of the relay, and if the larger thrust does not push the movable spring piece to rise to a larger height to eliminate the increased clearance between the contacts, the resistance value between the contacts is increased to exceed the limit value.

In this application, adopt nonlinear spring part, this nonlinear spring part is when being in the normally open state of relay, and its elastic coefficient is less, therefore this nonlinear spring part produces great compressed volume under the effect of movable contact spring gravity and the spring tension that returns to make the interval between stationary contact and the movable contact far away. When the relay is in normally closed state, thereby the catch bar shifts up and further compresses this nonlinear spring part, make this nonlinear spring part compression produce bigger impetus to resist the pulling force that the return spring increases, however, because the coefficient of elasticity of the nonlinear spring part at this moment is bigger, thereby only need less compressive capacity can produce bigger impetus, thereby even wear clearance has appeared in the contact material, but under the promotion of the nonlinear spring part of bigger coefficient of elasticity, also can promote the movable spring piece and rise bigger height, make the movable contact closely closed with the stationary contact.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a relay according to an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of FIG. 1;

fig. 3 is a first perspective structural diagram of a portion of the structure of the moving contact advancing structure of fig. 1;

fig. 4 is a second perspective structural schematic diagram of a portion of the structure of the moving contact advancing structure of fig. 1;

FIG. 5 is a graph illustrating the compression amount versus the thrust of a non-linear spring versus a linear spring.

Icon:

the movable contact spring comprises a movable contact spring piece 1, a movable contact 2, a push rod 3, a fixed seat 31, a movable iron core 4, a positioning plate 5, a return spring 6, a thrust spring 7, a first linear spring 81, a second linear spring 81, a relay shell 9, a coil 91 and a fixed contact 92.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the drawings of the embodiments of the present invention are combined to clearly and completely describe the technical solutions of the embodiments of the present invention, and obviously, the described embodiments are some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention. Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and to simplify the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

Example 1:

referring to fig. 1 to 5, a pushing structure of a movable contact 2 includes a movable spring 1, a movable contact 2, a pushing rod 3, a movable iron core 4, a positioning plate 5, a return spring 6 and a pushing spring 7.

The movable contact 2 is arranged on the upper surface of the movable spring piece 1, the movable spring piece 1 is vertically arranged at the upper end of the push rod 3 in a sliding manner, the positioning plate 5 is positioned below the movable spring piece 1, a through hole of the positioning plate 5 which is vertically penetrated for the push rod 3 to pass through is formed in the positioning plate 5, and two ends of the return spring 6 are respectively connected with the movable spring piece 1 and the positioning plate 5.

The outer side wall of the pushing rod 3 is provided with a fixed seat 31, the fixed seat 31 is located between the positioning plate 5 and the movable spring leaf 1, the pushing spring 7 is a nonlinear spring part, and two ends of the nonlinear spring part are respectively abutted to the upper surface of the fixed seat 31 and the lower surface of the movable spring leaf 1.

The fixing seat 31 may be a protrusion integrally formed with the push rod 3, or an independent ring-shaped member fixedly connected to the outer sidewall of the push rod 3, without affecting the use thereof. For example, in the present embodiment, the fixing seat 31 is a separate annular member.

In order to maintain the position of the movable spring plate 1 relative to the positioning plate 5 stable, in an embodiment, the movable spring plate 1 is provided with a through hole in sliding fit with the top end of the push rod 3, and the top end of the push rod 3 is located in the through hole.

The movable iron core 4 is used for driving the push rod 3 to move up and down in a reciprocating manner; the nonlinear spring element is used for compressing the spring element to push the movable contact spring 1 to move upwards when the pushing rod 3 moves upwards so as to enable the movable contact spring 2 to be closed with the fixed contact 92.

The nonlinear spring member includes a first linear spring 81 having an initial length of L31, and a second linear spring 81 having an initial length of L32, and the spring length is L33 when the relay is in a normally open state.

Referring to fig. 4 and 5, in the present embodiment, L31 is greater than L33, and L32 is equal to L33. Let the elastic coefficient of the first linear spring 81 be K1 and the elastic system of the second linear spring 81 be K2. Then, when the relay is in the normally open state, the elastic coefficient is K1. The spring constant of the nonlinear spring is K1+ K2 in the stroke when the moving contact 2 pushes the spring 1 in the pushing structure to make the moving contact 2 close to the fixed contact 92.

Therefore, in the pushing-up stroke, the nonlinear spring part can obtain larger pushing force through smaller compression amount, so that even if the contact material has abrasion clearance, the movable spring piece 1 can be pushed to rise to a larger height under the pushing of the nonlinear spring part with larger elastic coefficient, and after the contact clearance is increased, the movable spring piece 1 needs to rise for excessive stroke, so that the movable contact 2 and the fixed contact 92 are tightly closed.

To traditional high voltage direct current relay, material wearing and tearing lead to contact clearance increase back between the contact, the stroke of the stroke spring that movable contact spring 1 needs to rise more is the overtravel action, and its thrust spring 7 often leads to the magnetic attraction not enough because can't accomplish the overtravel action, can not compress tightly movable contact 92, and both can not combine closely. Therefore, the non-close contact of the two materials can increase the contact resistance value between the two, and additionally consume power and energy. In the present embodiment, the compression force (magnetic attraction force) of the thrust spring 7 is increased in a non-linear manner, thereby compensating for the compression force required for the overtravel action.

Specifically, the driving force and driving stroke of the pushing rod 3 come from the plunger 4, and the pushing force of the plunger 4 comes from the magnetic field produced by the coil 91, and the rising height of the plunger 4 is limited by the pulling force of the pullback spring.

The magnetic field force produced by the coil 91 is limited by the current and the number of the coil 91, if the current is too large, the energy consumption of the normally closed state of the relay is increased, and if the number of the coil 91 is increased, the weight of the coil is increased, which will finally result in the increase of the weight and energy consumption of the product, which is contrary to the development requirement of new energy conservation.

Although the reduction in the elastic modulus of the pullback spring can reduce the pullback force on the movable iron core 4 in the same stroke, thereby increasing the pushing force of the movable iron core 4 in the stroke, the reduction in the elastic modulus also causes the reduction in the pullback speed of the movable iron core 4 when the magnetic field generated by the coil 91 disappears. However, if the force for separating the contacts is not large enough, the contacts are not separated completely and quickly, a severe arc discharge phenomenon (generally, an arc discharge phenomenon occurs under normal conditions) will occur in the process of separating the moving and static contacts 92, a more severe contact ablation phenomenon will occur between the moving and static contacts 92, the material loss between the contacts will be more severe, a vicious circle phenomenon will result, and the service life of the relay will also be finished. Therefore, it is inconvenient to raise the urging force of the plunger 4 in the overtravel by lowering the spring constant of the pullback spring.

In the relay, under the drive of the movable iron core 4, the pushing rod 3 rises higher, and the pushing force is smaller; accordingly, when a linear spring is used as the thrust spring 7, the higher the push rod 3 is raised, the smaller the compression amount of the thrust spring 7.

Therefore, in fact, in the normally open state of the relay, the tension force of the thrust spring 7, which is mainly required to oppose the return spring 6 in order to support the movable contact 1, is F11, the compression amount corresponding to the thrust spring 7 at this time is L11, and the distance between the movable contact 2 and the stationary contact 92 at this time is L1.

The functional effects of the linear spring and the nonlinear spring on the increase of the contact material wear gap of the relay were analyzed with the same L1 as the starting point and the same magnitude of the magnetic field of the coil 91 and the elastic coefficient of the pullback spring as the limit.

Then, for the linear spring, in the normally closed state of the unworn relay, the pushing rod 3 rises by the height of H1, the pushing force corresponds to F21, the compression amount of the linear spring is L2 at this time, the pulling force F12 of the return spring 6 at this time is deducted, and the pressure between the fixed contact 92 and the movable contact 2 is F1 at this time.

The pressure force F1 is limited due to the design of the primary coil 91 and the constraints of the pullback spring, the return spring 6, etc. If the abrasion gap between the movable contact 2 and the fixed contact 92 is increased, the movable spring leaf 1 needs to be lifted to a higher height, so that the push rod 3 needs to move upwards continuously, the compression amount of the linear spring is correspondingly reduced, and the tension of the return spring 6 is gradually increased. Therefore, the pressure between the fixed contact 92 and the movable contact 2 is continuously reduced, so that the fixed contact 92 and the movable contact 2 cannot be tightly closed, and therefore, poor contact occurs, and the resistance value between the contacts is increased, so that the relay must stop being used.

For the non-linear spring of the present application, in the normally closed state of the unworn relay, the pushing rod 3 rises by the height of H2, the pushing force corresponds to F22, the compression amount of the non-linear spring at this time is L3, the pulling force F13 of the return spring 6 at this time is deducted, and the pressure between the fixed contact 92 and the movable contact 2 at this time is F2.

Because the elastic coefficient of the nonlinear spring in the ascending stroke of the push rod 3 is K1+ K2 and is greater than the elastic coefficient K1 of the linear spring, the compression amount L3 of the nonlinear spring is smaller than the compression amount L2 of the linear spring under the same condition, so that the ascending stroke H2 of the push rod 3 is smaller than the ascending stroke H1 of the push rod 3 of the linear spring, namely the pushing force F22 of the nonlinear spring is greater than the pushing force F21 of the linear spring; since the movable spring piece 1 is in the same position, the return spring 6 has the same tension, and therefore F13 becomes F12. Thus, F2 is greater than F1.

Since F2 is larger than F1 and H2 is smaller than H1, the nonlinear spring of the present application can provide more over-stroke margin than a linear spring as the thrust spring 7, so that even if the wear gap between the movable contact 2 and the stationary contact 92 increases to a certain extent, the push lever 3 can continue to move upward by the over-stroke margin provided by the nonlinear spring, and the pushing force thereof is sufficient to close the movable contact 2 and the stationary contact 92 tightly while releasing more stroke to move the movable spring 1 upward.

When the normally closed state of the switching relay is the normally open state, the magnetic field produced by the coil 91 disappears, and the push rod 3 descends, so that the compression amount of the compression spring is reduced, and further the pushing force is reduced, until the critical point when the pressure between the fixed contact 92 and the movable contact 2 is 0, the fixed contact 92 and the movable contact 2 start to be separated formally. Because the elastic coefficient of the nonlinear spring in the stroke of the section is larger than that of the linear spring, the descending driving force of the nonlinear spring is larger in the same descending stroke of the push rod 3, so that the movable contact 2 is separated more quickly, and the phenomenon of serious arc discharge in the separation process of the movable contact 92 and the fixed contact 92 is avoided.

From another point of view, if the pushing rod 3 of the non-linear spring is lifted and the pushing force of the non-linear spring is the same as that of the linear spring serving as the pushing spring 7 in the normally closed state of the unworn relay, the distance between the movable contact 2 and the fixed contact 92 of the relay is definitely larger than that of the linear spring serving as the pushing spring 7 in the normally open state of the relay, so that the movable contact 2 is separated more thoroughly, and the safety is higher.

The extent of the wear gap over which the non-linear spring can act is related to the spring constant of L1 and the second linear spring 81. Among them, the elastic coefficient K2 of the second linear spring 81 is preferably in the range of 0.5 to 2K 1. Wherein the larger the value of K2, the larger the overstroke that can be brought about and the larger the wear gap that can be acted on.

In the present embodiment, the elastic coefficient K2 of the second linear spring 81 has a value of 0.8K 1. In an embodiment, the elastic coefficient K2 of the second linear spring 81 has a value of 0.2K1 or 2K 1.

In other embodiments, the elastic coefficient K2 of the second linear spring 81 may also be 0.4K1 or 3K1, and is set according to the size of the wear gap to be compensated in a specific relay, which is not limited herein.

In this embodiment, the first linear spring 81 and the second linear spring 81 are both sleeved on the pushing rod 3, wherein the inner diameter of the first linear spring 81 is larger than the outer diameter of the second linear spring 81.

In other embodiments, the inner diameter of the second linear spring 81 may be larger than the outer diameter of the first linear spring 81.

In this embodiment, the return spring 6 includes a first return spring 6 and a second return spring 6, the upper end of the first return spring 6 is connected to one end of the movable spring 1, the upper end of the second return spring 6 is connected to the other end of the movable spring 1, the lower end of the first return spring 6 and the lower end of the second return spring 6 are both connected to the positioning plate 5, and the movable contact 2 includes a first movable contact 2 and a second movable contact 2.

The present embodiment also provides a relay including the relay housing 9, the stationary contact 92 assembly, the coil 91, and the movable contact 2 pushing structure as described above.

In addition, the relay is also provided with a yoke iron which is an optional part on the electromagnet and used for enhancing the attraction force of the electromagnetic coil 91 and sealing the magnetic force lines generated by the electromagnetic coil 91 inside so as to improve the efficiency of the electromagnet. Wherein, the locating plate 5 is fixedly arranged above the yoke iron.

In other embodiments, the positioning plate 5 may also be made of a yoke material, and is used as a yoke in a relay.

Example 2

The embodiment of the present invention provides a device, which has the same technical effects as those of embodiment 1, and for the sake of brief description, the embodiment does not mention, and reference can be made to the corresponding contents of embodiment 1.

In the present embodiment, the initial length L32 of the second linear spring 81 is smaller than the spring length L33 when the relay is in the normally open state. In addition, when the abrasion gap is λ, the relay is in a normally closed state, and the movable contact 2 and the stationary contact 92 are tightly combined, the spring length is L34, so that L32 is at least greater than L34, and the second linear spring 81 can exert force in the ascending stroke of the push rod 3, and a greater elastic coefficient is given to the nonlinear spring member, that is, the nonlinear spring member can obtain the same pushing force, and needs a smaller compression amount, so that the movable spring member 1 can be pushed higher. Or the nonlinear spring element can obtain larger pushing force under the condition of the same compression amount, so that the movable contact 2 and the fixed contact 92 are pressed more tightly.

Therefore, in the range of the abrasion gap lambda, even if the abrasion gap lambda belongs to the overtravel range relative to the linear spring, under the boosting action of the second linear spring 81, the movable contact 2 and the fixed contact 92 can be tightly closed, so that the resistance value between the contacts is in a reasonable range, and the service life of the relay is prolonged.

In this embodiment, the lower end of the second linear spring 81 is fixed to the upper surface of the fixed seat 31, and the upper end of the second linear spring 81 is spaced from the lower surface of the movable spring plate 1. Therefore, when the relay is in a normally open state, a gap is formed between the upper end of the second linear spring 81 and the lower surface of the movable spring leaf 1, and when the push rod 3 moves upwards, the upper end of the second linear spring 81 is abutted against the lower surface of the movable spring leaf 1, so that the compression amount is obtained, and the pushing force of the thrust spring 7 in the same stroke is increased.

In other embodiments, the upper end of the second linear spring 81 may be fixed to the lower surface of the movable spring plate 1, and the lower end of the second linear spring 81 may be spaced from the upper surface of the fixed seat 31. When the pushing rod 3 moves upwards, the lower end of the second linear spring 81 abuts against the upper surface of the fixed seat 31, so that the compression amount is obtained, and the pushing force of the pushing spring 7 in the same stroke is increased.

In an embodiment, preferably, the upper end and the lower end of the second linear spring 81 are fixedly connected to the upper surface of the fixed seat 31 and the lower surface of the movable spring 1, respectively, so that when the relay is in the normally open state, the second linear spring 81 has a force of pulling down the movable spring 1, thereby increasing the total compression amount of the nonlinear spring element when the relay is in the normally open state, and further increasing the interval between the movable contact 2 and the stationary contact 92 when the relay is in the normally open state. And, when the pushing rod 3 moves upwards, the second linear spring 81 will gradually return to the original length to eliminate the pulling force, and will obtain the compression amount when the pushing upwards continues, so that the elastic coefficient of the nonlinear spring in the stroke is equal to K1+ K2. The urging force of the urging spring 7 is increased in the same stroke.

And the two ends of the first linear spring 81 are respectively fixed on the upper surface of the fixed seat 31 and the lower surface of the movable spring plate 1, and are matched with the arrangement of the second linear spring 81. Or the two ends of the first linear spring 81 are respectively positioned on the upper surface of the fixed seat 31 and the clamping grooves on the lower surface of the movable spring plate 1, so that the first linear spring 81 and the second linear spring 81 are prevented from interfering with each other.

Wherein, the size of the wear gap λ is related to the elastic coefficient of the first linear spring 81 and the initial length, wherein, the larger the elastic coefficient of the first linear spring 81 is, the larger the wear gap λ that can keep the moving contact 2 and the stationary contact 92 tightly closed is; the larger the initial length of the first linear spring 81 is, the larger the wear gap λ that can keep the movable contact 2 and the stationary contact 92 tightly closed.

With the support of the above description, a person skilled in the art can set the elastic coefficient and the initial length of the first linear spring 81 according to specific needs to obtain a suitable over travel to compensate for the contact material wear problem during the use of the relay.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A movable contact propulsion structure is characterized by comprising a movable reed, a movable contact, a push rod, a movable iron core, a positioning plate, a return spring and a thrust spring;

the movable contact is arranged on the upper surface of the movable spring plate, the movable spring plate is vertically arranged at the upper end of the pushing rod in a sliding manner, the positioning plate is positioned below the movable spring plate, a positioning plate through hole which penetrates through the positioning plate up and down for the pushing rod to pass through is formed in the positioning plate, and two ends of the return spring are respectively connected with the movable spring plate and the positioning plate;

the outer side wall of the pushing rod is provided with a fixed seat, the fixed seat is positioned between the positioning plate and the movable spring piece, the pushing spring is a nonlinear spring piece, and two ends of the nonlinear spring piece are respectively abutted against the upper surface of the fixed seat and the lower surface of the movable spring piece; the movable iron core is used for driving the push rod to move up and down in a reciprocating manner; the nonlinear spring piece is used for compressing the spring piece to push the movable spring piece to move upwards until the movable contact is closed with the fixed contact when the push rod moves upwards;

2. A moving contact pushing structure as claimed in claim 1 wherein the first and second linear springs are both fitted over the push rod, wherein the inner diameter of the first linear spring is larger than the outer diameter of the second linear spring, or the inner diameter of the second linear spring is larger than the outer diameter of the first linear spring.

3. A movable contact advancing structure according to claim 2, characterized in that the inner diameter of the first linear spring is larger than the outer diameter of the second linear spring, the L32 is smaller than L33; and the upper end and the lower end of the second linear spring are respectively and fixedly connected to the upper surface of the fixed seat and the lower surface of the movable reed.

4. A movable contact advancing structure according to claim 2, characterized in that the inner diameter of the first linear spring is larger than the outer diameter of the second linear spring, the L32 is smaller than L33; the lower end of the second linear spring is fixed on the upper surface of the fixing seat, and the upper end of the second linear spring and the lower surface of the movable reed are arranged in a clearance mode.

5. A moving contact push structure according to claim 3 or 4, characterized in that both ends of the first linear spring fix the fixed seat upper surface and the moving spring piece lower surface respectively.

6. A movable contact advancing structure as claimed in claim 2, characterized in that the inner diameter of the first linear spring is larger than the outer diameter of the second linear spring, the L32 is smaller than L33; the lower end of the second linear spring is fixed on the upper surface of the movable spring plate, and the upper end of the second linear spring is arranged in a gap with the upper surface of the fixed seat.

7. A moving contact push structure as claimed in claim 1, wherein let K1 be the elastic coefficient of the first linear spring and K2 be the elastic system of the second linear spring, where K2 is 0.5-2K 1.

8. A moving contact push structure according to claim 1, characterized in that the return spring comprises a first return spring and a second return spring, the upper end of the first return spring is connected with one end of the movable spring, the upper end of the second return spring is connected with the other end of the movable spring, the lower end of the first return spring and the lower end of the second return spring are both connected with the positioning plate, and the moving contact comprises a first moving contact and a second moving contact.

9. A relay comprising a relay housing, a coil, a stationary contact assembly, and the movable contact advancing structure of any one of claims 1 to 7.

10. The relay according to claim 9, further comprising a yoke, wherein the positioning plate is fixedly disposed above the yoke.