Patent Description:
A direct current (DC) relay is a device that transmits a mechanical driving signal or a current signal using the principle of an electromagnet. The DC relay is also called a magnetic switch, and is generally classified as an electrical circuit switching device.

Referring to <FIG>, a DC relay <NUM> according to the related art includes a contact part <NUM>, permanent magnets <NUM>, and a core part <NUM>.

The contact part <NUM> includes a fixed contact <NUM> and a movable contact <NUM>. When control power is applied, the movable contact <NUM> is moved toward the fixed contact <NUM> to be brought into contact with the fixed contact <NUM>. Accordingly, the DC relay <NUM> can be electrically connected to external power supply and load.

Driving force for moving the movable contact <NUM> is generated by the core part <NUM>. When control power is applied, coils <NUM> wound around a bobbin <NUM> generates an electromagnetic field. At this time, a fixed core <NUM> is magnetized and attractive force is generated between the fixed core <NUM> and a movable core <NUM>.

Since the fixed core <NUM> is fixed, the movable core <NUM> is moved toward the fixed core <NUM>. At this time, the movable core <NUM> is moved upward together with a shaft <NUM> connected to the movable core <NUM>. Accordingly, the fixed contact <NUM> and the movable contact <NUM> can be brought into contact with each other.

When the control power is not applied any more, the attractive force between the fixed core <NUM> and the movable core <NUM> is eliminated. As the movable core <NUM> is moved upward, a spring <NUM> is compressed and stores restoring force. When the attractive force disappears, the spring <NUM> is tensioned. Accordingly, the fixed contact <NUM> and the movable contact <NUM> are spaced apart from each other, thereby generating arc.

The generated arc is extinguished through a preset path and must be discharged to the outside of the DC relay <NUM>. To this end, the DC relay <NUM> includes the permanent magnets <NUM> for generating an electromagnetic field.

Referring to (a) of <FIG>, a plurality of fixed contacts <NUM> are provided. Current is introduced into an inside of the DC relay <NUM> through a fixed contact 1110a on the right, flows through the movable contact <NUM>, and then is discharged to an outside of the DC relay <NUM> through a fixed contact 1110b on the left.

At this time, the permanent magnets <NUM> are disposed at the outside of the fixed contacts 1110a and 1110b, respectively, to generate magnetic fields.

Referring to <FIG>, directions of flows of current and force generated by the magnetic fields are shown. That is, the current is applied to the right fixed contact 1110a as illustrated in (a) of <FIG>.

In addition, a right permanent magnet 1200a is arranged so that an S pole is located inward, and a left permanent magnet 1200b is arranged so that an N pole is located inward. Accordingly, the magnetic field is generated in a direction from the left to the right.

According to the Fleming's left-hand rule, electromagnetic force, magnetic field, and current are generated at right angles. Accordingly, the electromagnetic force is generated in a direction A by the current application and the arrangement of the permanent magnets <NUM>. As a result, arc is extinguished while moving in the direction A. Conversely, when current is applied to the left fixed contact 1110b, the electromagnetic force is generated in a direction B.

At this time, the electromagnetic forces generated by the permanent magnets <NUM> are inversely proportional to the square of a distance between the permanent magnets <NUM>. Accordingly, when the distance between the permanent magnets <NUM> increases, the electromagnetic forces that are insufficient to form an arc extinguishing path may be generated.

In addition, strength of the magnetic fields generated by the permanent magnets <NUM> is affected by size and thickness of the permanent magnets <NUM>. However, considering a limited space inside the DC relay <NUM>, it is difficult to increase the size and thickness of the permanent magnet <NUM> indefinitely.

Therefore, such space limitation causes lots of limits in designing the size and thickness of the permanent magnets <NUM> and the distance between the permanent magnets <NUM>. Therefore, a method for ensuring magnetic force between the permanent magnets <NUM> is required.

Also, referring to <FIG>, a direction of driving force for moving the movable core <NUM> in response to application of control power is illustrated. At this time, attractive force generated between the fixed core <NUM> and the movable core <NUM> should be greater than elastic force generated due to compression of a return spring <NUM> and the spring <NUM>.

However, there may be a case in which sufficient attractive force is not generated between the fixed core <NUM> and the movable core <NUM> due to factors such as a use environment and the like. This results from that moving force of the movable core <NUM> depends solely on electromagnetic attractive force between the fixed core <NUM> and the movable core <NUM>.

Therefore, a method for sufficiently securing electromagnetic attractive force generated between the fixed core <NUM> and the movable core <NUM> is required.

<CIT> discloses a DC relay including a damping magnet. Specifically, the document discloses a DC relay having a damping magnet that is provided below a movable contact to cancel a magnetic flux induced around the movable contact in order to prevent the movable contact from being arbitrarily separated from a fixed contact when the DC relay is in an ON state.

However, this type of DC relay has a limitation in that there is no consideration on formation of a magnetic flux for extinguishing arc. That is, the arbitrary separation between the contacts can be prevented, but a method for extinguishing arc generated and a method for securing an extinguishing path are not disclosed. In addition, the document does not suggest a method for securing magnetic force between permanent magnets.

<CIT>discloses a DC relay having a structure capable of maintaining permanent magnets at desired positions. Specifically, the document discloses an electromagnetic relay having a structure capable of maintaining positions of permanent magnets by arranging a first plate member and a second plate member around the permanent magnets to support the permanent magnets.

However, this type of electromagnetic relay can maintain the positions of the permanent magnets, but there is a limitation in that any method for changing a direction of a magnetic flux formed by the permanent magnets.

Those types of relays also fail to suggest a method for enhancing driving force for moving the movable contact. In addition, polarities of permanent magnets cause inconvenience in that power source and load applied to fixed contacts are limited in specific directions.

<CIT> discloses an electromagnetic relay that comprises a first stationary terminal and a second stationary terminal that have a first stationary contact part and a second stationary contact part, respectively. The relay further comprises a movable contactor that has a first movable contact part and a second movable contact part. The relay further comprises a first magnet part that is arranged, when viewed from a contact/separation direction, one side of the movable contactor in a direction intersecting the arrangement direction. The relay further comprises a second magnet part and a third magnet part that are arranged respectively on both sides of the movable contactor in the arrangement direction and have the same polarity as each other on their ends toward the movable contactor.

The present disclosure is directed to providing a DC relay having a structure capable of solving those problems and other drawbacks.

First, one aspect of the present disclosure is to provide a DC relay having a structure capable of sufficiently reinforcing (enhancing) strength of magnetic fields generated in an inner space.

Another aspect of the present disclosure is to provide a DC relay having a structure capable of enhancing strength of magnetic fields without excessively changing arrangement of components.

Still another aspect of the present disclosure is to provide a DC relay having a structure capable of generating sufficient magnetic fields without changing positions of permanent magnets provided in an inner space or increasing a size or thickness of the permanent magnets.

Still another aspect of the present disclosure is to provide a DC relay having a structure capable of configuring various moving directions of arc extinguished inside the DC relay.

Still another aspect of the present disclosure is to provide a DC relay having a structure in which a direction of current applied to a fixed contact is not limited according to polarity of a permanent magnet.

Still another aspect of the present disclosure is to provide a DC relay having a structure capable of enhancing driving force for moving a movable contact.

Still another aspect of the present disclosure is to provide a DC relay having a structure capable of reducing magnitude of control power applied to move a movable contact.

In order to achieve these and other advantages and in accordance with the purpose of this specification, as embodied and broadly described herein, there is provided a Direct Current (DC) relay comprising a fixed contactor, a movable contactor extending in a longitudinal direction and having one side located adjacent to the fixed contactor to be brought into contact with or separated from the fixed contactor, a plurality of magnet members located adjacent to both end portions of the movable contact in the longitudinal direction, respectively, to generate magnetic fields, and a magnetic force reinforcing member located between the plurality of magnet members to form magnetic fields together with the plurality of magnet members. The magnetic force reinforcing member is located on another side of the movable contactor opposite to the one side of the movable contactor. The plurality of magnet members comprise a first magnet member located adjacent to one end portion of the movable contactor in the longitudinal direction, and a second magnet member located adjacent to another end portion of the movable contactor opposite to the one end portion of the movable contactor in the longitudinal direction. One side of the first magnet member and one side of the second magnet member facing each other have the same polarity, and one side of the magnetic force reinforcing member facing the movable contactor has a polarity different from that of each one side of the first magnet member and the second magnet member.

The fixed contactor of the DC relay may include a first fixed contactor located on one side of a center of the movable contact, and a second fixed contactor located on another side opposite to the one side of the center of the movable contact.

The magnetic force reinforcing member of the DC relay may be located between the first fixed contactor and the second fixed contactor in the longitudinal direction of the fixed contactor.

One of the first fixed contactor or the second fixed contactor may be electrically connected to an external power supply, and another one of the first fixed contactor and the second fixed contactor may be electrically connected to an external load.

Directions of the magnetic fields generated by the first magnet member, the second magnet member, and the magnetic force reinforcing member of the DC relay may be one of a first direction from the first magnet member and the second magnet member toward the magnetic force reinforcing member, and a second direction from the magnetic force reinforcing member toward the first magnet member and the second magnet member.

According to another implementation of the present disclosure, there is provided a Direct Current (DC) relay that may further include.

a fixed core located at another side opposite to the one side of the fixed contactor to be magnetized when control power is applied, a movable core located at another side of the fixed core opposite to the one side of the fixed core adjacent to the fixed contactor, so as to be moved toward the fixed core when the control power is applied, and a magnetic force reinforcing member located between the fixed contactor and the fixed core to apply attractive force to the movable core in a direction toward the fixed core.

The direct current relay may further include coils disposed to surround the fixed core and the movable core to generate an electromagnetic field when the control power is applied, and the fixed core may be magnetized by the electromagnetic field generated by the coils.

The fixed core may apply attractive force to the movable core in a direction toward the fixed core when the fixed core is magnetized, and the magnetic force reinforcing member may apply attractive force to the movable core in a direction toward the magnetic force reinforcing member.

According to still another implementation of the present disclosure, there is provided a Direct Current (DC) relay that may further include.

a shaft extending in a longitudinal direction, and connected to the fixed contactor so as to be movable toward or away from the fixed contactor together with the fixed contactor, a fixed core located adjacent to another side of the fixed contactor opposite to the one side of the fixed contactor, having the shaft inserted therethrough, and magnetized when control power is applied, a movable core located at another side of the fixed core opposite to the one side of the fixed core adjacent to the fixed contactor to be moved toward the fixed core when the control power is applied, and connected with the shaft, and a magnetic force reinforcing member located between the fixed core and the fixed contactor, having the shaft movably coupled therethrough, and configured to apply attractive force to the movable core.

The direct current relay may further include a plurality of magnet members located adjacent to both end portions of the fixed contactor in the longitudinal direction, respectively, to generate magnetic fields therebetween, and the magnetic force reinforcing member may generate magnetic fields together with the plurality of magnet members.

One side of each of the plurality of magnet members facing each other may have the same polarity, and one side of the magnetic force reinforcing member facing the fixed contactor may have a different polarity from that of the one side of each of the plurality of magnet members.

The magnetic force reinforcing member may have a cylindrical shape extending in the longitudinal direction. A hollow portion may be formed through a center of the magnetic force reinforcing member in the longitudinal direction, and the shaft may be coupled through the hollow portion.

According to the present disclosure, the following effects can be achieved.

First, a magnetic force reinforcing member provided between permanent magnets may reinforce magnetic fields generated by the permanent magnets.

Accordingly, the magnetic fields generated inside the DC relay can be sufficiently reinforced.

The magnetic force reinforcing member may be fitted through a shaft. The magnetic force reinforcing member fitted through the shaft may be located above a fixed core.

This may allow the magnetic force reinforcing member to be simply coupled. In addition, the magnetic force reinforcing member for intensifying strength of the magnetic fields can be provided without excessively changing an internal structure of the DC relay.

The magnetic force reinforcing member can reinforce the magnetic fields generated by the permanent magnets. That is, the magnetic force reinforcing member may be located to generate a magnetic field in the same direction as the magnetic fields generated by the permanent magnets.

Therefore, the magnetic fields can be sufficiently generated without changing positions of the permanent magnets or increasing a size or thickness of the permanent magnets to increase the magnetic forces of the permanent magnets.

In addition, the magnetic fields may be generated inside the DC relay in a direction toward or away from the magnetic force reinforcing member, other than a direction from one of the permanent magnets to the other. That is, directions of magnetic fields generated around fixed contacts, respectively, may be different from each other.

Accordingly, the magnetic fields can be generated in various directions inside the DC relay, and thus arc extinguishing directions can also be diversified.

In addition, the magnetic fields may be generated inside the DC relay in a direction to converge on the magnetic force reinforcing member or a direction to be discharged from the magnetic force reinforcing member. Therefore, based on each fixed contact, arc can receive electromagnetic forces in the same direction.

Even if a direction of current applied to the fixed contact is changed, arc can be induced to be extinguished in the same direction. Thus, since the user does not need to connect the DC relay according to polarities, user convenience can be improved.

The magnetic force reinforcing member may be located adjacent to the fixed core. When the fixed core is magnetized by an electromagnetic field generated as current flows on coils, the magnetic force reinforcing member can also apply attractive force to the movable core.

Therefore, compared to the case where the movable core receives attractive force only by the fixed core, the attractive force applied to the movable core can be increased. As a result, the movable core and the fixed contactor connected to the movable core can be moved smoothly when control power is applied.

In addition, even when control power of the same magnitude is applied, the attractive force applied to the movable core by the magnetic force reinforcing member can be increased.

Therefore, even if the magnitude of the control power for moving the movable core is decreased, the movable core can be moved smoothly, and thus a quantity of power required for driving the DC relay can be reduced.

Hereinafter, a DC relay <NUM> according to an implementation of the present disclosure will be described in detail with reference to the accompanying drawings.

In the following description, descriptions of some components may be omitted to help understanding of the present disclosure.

It will be understood that when an element is referred to as being "connected with" another element, the element can be connected with the another element or intervening elements may also be present.

In contrast, when an element is referred to as being "directly connected with" another element, there are no intervening elements present.

A singular representation used herein may include a plural representation unless it represents a definitely different meaning from the context.

The term "magnetize" used in the following description refers to a phenomenon in which an object exhibits magnetism in a magnetic field.

The term "polarities" used in the following description refers to different properties belonging to an anode and a cathode of an electrode. In one implementation, the polarities may be classified into an N pole or an S pole.

The terms "left", "right", "top", "bottom", "front" and "rear" used in the following description will be understood based on a coordinate system illustrated in <FIG> and <FIG>.

Referring to <FIG> and <FIG>, a DC relay <NUM> according to an implementation of the present disclosure may include a frame part (or frame unit) <NUM>, an opening/closing part <NUM>, a core part <NUM>, and a movable contactor part <NUM>.

In addition, the DC relay <NUM> according to the implementation of the present disclosure includes.

a magnetic force generating part (or magnetism forming unit) <NUM> for forming a path for extinguishing generated arc and increasing driving force for the movable core <NUM>.

Hereinafter, the DC relay <NUM> according to the implementation of the present disclosure will be described with reference to <FIG> and <FIG>, and the magnetic force generating part <NUM> will be described as a separate clause.

The frame part (or frame unit) <NUM> may define appearance of the DC relay <NUM>. A predetermined space may be defined inside the frame part <NUM>. Various devices for the DC relay <NUM> to perform functions for applying or cutting off current may be accommodated in the space. That is, the frame part <NUM> may function as a kind of housing.

The frame part <NUM> may be formed of an insulating material such as synthetic resin. This may prevent inside and outside of the frame part <NUM> from being arbitrarily electrically connected to each other.

The frame part <NUM> may include an upper frame <NUM>, a lower frame <NUM>, an insulating plate <NUM>, and a supporting plate <NUM>.

The upper frame <NUM> may define an upper side of the frame part <NUM>. The opening/closing part <NUM> and the movable contactor part <NUM> may be accommodated in an inner space of the upper frame <NUM>.

The upper frame <NUM> may be coupled to the lower frame <NUM>. The insulating plate <NUM> and the supporting plate <NUM> may be interposed between the upper frame <NUM> and the lower frame <NUM>. The insulating plate <NUM> and the supporting plate <NUM> may electrically and physically isolate the inner space of the upper frame <NUM> and an inner space of the lower frame <NUM> from each other.

A fixed contactor <NUM> of the opening/closing part <NUM> may be provided on one side of the upper frame <NUM>, for example, on an upper side of the upper frame <NUM> in the illustrated implementation. The fixed contactor <NUM> may be partially exposed to the upper side of the upper frame <NUM>, to be electrically connected to an external power supply or a load.

The lower frame <NUM> may define a lower side of the frame part <NUM>. The core part <NUM> may be accommodated in the inner space of the lower frame <NUM>.

The lower frame <NUM> may be coupled to the upper frame <NUM>. The insulating plate <NUM> and the supporting plate <NUM> may be interposed between the lower frame <NUM> and the upper frame <NUM>. The insulating plate <NUM> and the supporting plate <NUM> may electrically and physically isolate the inner space of the lower frame <NUM> and the inner space of the upper frame <NUM> from each other.

The insulating plate <NUM> may be located between the upper frame <NUM> and the lower frame <NUM>. The insulating plate <NUM> may allow the magnetizes upper frame <NUM> and the lower frame <NUM> to be electrically spaced apart from each other.

This may result in preventing arbitrary electric connection between the opening/closing part <NUM> and the movable contactor part <NUM> accommodated in the upper frame <NUM> and the core part <NUM> accommodated in the lower frame <NUM>.

A through hole (not shown) may be formed through a central portion of the insulating plate <NUM>. A shaft <NUM> of the movable contactor part <NUM> may be coupled through the through hole (not shown) to be movable up and down.

The insulating plate <NUM> may be supported by the supporting plate <NUM>.

The supporting plate <NUM> may be located between the upper frame <NUM> and the lower frame <NUM>. The supporting plate <NUM> may allow the magnetizes upper frame <NUM> and the lower frame <NUM> to be electrically spaced apart from each other.

In addition, the support plate <NUM> may be located on a lower side of the insulating plate <NUM> to support the insulating plate <NUM>.

For example, the supporting plate <NUM> may be formed of a magnetic material. In addition, the supporting plate <NUM> can configure a magnetic circuit together with a yoke <NUM> of the core part <NUM>. The magnetic circuit may apply driving force to the movable core <NUM> of the core part <NUM> so as to move toward the fixed core <NUM>.

A through hole (not shown) may be formed through a central portion of the supporting plate <NUM>. The shaft <NUM> may be coupled through the through hole (not shown) to be movable up and down.

Therefore, when the movable core <NUM> is moved toward or away from the fixed core <NUM>, the shaft <NUM> and the movable contactor <NUM> connected to the shaft <NUM> may also be moved in the same direction.

The opening/closing unit <NUM> makes current applied or cut off to the DC relay <NUM> according to an operation of the core part <NUM>. Specifically, the opening/closing part <NUM> allows and blocks an application of current as the fixed contactor <NUM> and the movable contactor <NUM> are brought into contact with or separated from each other.

The opening/closing part <NUM> may be accommodated in the upper frame <NUM>. The opening/closing part <NUM> may be electrically and physically spaced apart from the core part <NUM> by the insulating plate <NUM> and the supporting plate <NUM>.

The opening/closing part <NUM> may include an arc chamber <NUM>, a fixed contactor <NUM>, and a sealing member <NUM>. Also, as will be described later, a first magnet member <NUM> and a second magnet member <NUM> of the magnetic force generating part <NUM> may be accommodated in the opening/closing part <NUM>.

The plurality of magnets <NUM> and <NUM> may generate a magnetic field inside the arc chamber <NUM> to control shape and discharge path of arc generated. A detailed description thereof will be given later.

The arc chamber <NUM> may be configured to extinguish arc generated as the fixed contactor <NUM> and the movable contactor <NUM> are separated from each other. Therefore, the arc chamber <NUM> may also be referred to as an "extinguishing portion".

The arc chamber <NUM> may hermetically accommodate the fixed contactor <NUM> and the movable contactor <NUM>. That is, the fixed contactor <NUM> and the movable contactor <NUM> may be completely accommodated in the arc chamber <NUM>. Accordingly, the arc generated when the fixed contactor <NUM> and the movable contactor <NUM> are separated from each other may not arbitrarily leak to the outside of the arc chamber <NUM>.

The arc chamber <NUM> may be filled with extinguishing gas. The extinguishing gas may extinguish the arc and may be discharged to the outside of the DC relay <NUM> through a preset path.

The arc chamber <NUM> may be formed of an insulating material. In addition, the arc chamber <NUM> may be formed of a material having high pressure resistance and high heat resistance. This is because the generated arc is a flow of electrons of high-temperature and high-pressure. In one implementation, the arc chamber <NUM> may be formed of a ceramic material.

A plurality of through holes (not shown) may be formed through an upper side of the arc chamber <NUM>. The fixed contactor <NUM> may be coupled through each of the through holes (not shown). In the illustrated implementation, the fixed contactor <NUM> may be provided by two, namely, a first fixed contactor 220a and a second fixed contactor 220b. Accordingly, the through holes (not shown) formed through the upper side of the arc chamber <NUM> may also be provided by two.

When the fixed contactor <NUM> is coupled through the through hole (not shown), the through hole (not shown) may be sealed. That is, the fixed contactor <NUM> may be hermetically coupled to the through hole (not shown). Accordingly, generated arc may not be externally discharged through the through hole (not shown).

A lower side of the arc chamber <NUM> may be open. The insulating plate <NUM> may come in contact with the lower side of the arc chamber <NUM>. In addition, the sealing member <NUM> may come in contact with the lower side of the arc chamber <NUM>. That is, the lower side of the arc chamber <NUM> may be sealed by the insulating plate <NUM> and the sealing member <NUM>. Accordingly, the arc chamber <NUM> may be electrically and physically isolated from an outer space of the upper frame <NUM>.

In other words, the arc chamber <NUM> may be sealed by the insulating plate <NUM>, the supporting plate <NUM>, the fixed contactor <NUM>, the sealing member <NUM>, and a housing <NUM> of the movable contactor part <NUM>.

The arc extinguished in the arc chamber <NUM> may be discharged to the outside of the DC relay <NUM> through a preset path.

The fixed contactor <NUM> may be brought into contact with or separated from the movable contactor <NUM>, so as to electrically connect or disconnect the inside and the outside of the DC relay <NUM>.

Specifically, when the fixed contactor <NUM> is brought into contact with the movable contactor <NUM>, the inside and the outside of the DC relay <NUM> may be electrically connected. On the other hand, when the fixed contactor <NUM> is separated from the movable contactor <NUM>, the electric connection between the inside and the outside of the DC relay <NUM> may be released.

As the name implies, the fixed contactor <NUM> does not move. That is, the fixed contactor <NUM> may be fixedly coupled to the upper frame <NUM> and the arc chamber <NUM>. Accordingly, the contact and separation between the fixed contactor <NUM> and the movable contactor <NUM> can be implemented by the movement of the movable contactor <NUM>.

One end portion of the fixed contactor <NUM>, for example, an upper end portion in the illustrated implementation, may be exposed to the outside of the upper frame <NUM>. A power supply or a load may be electrically connected to the one end portion.

The fixed contactor <NUM> may be provided in plurality. In the illustrated implementation, the fixed contactor <NUM> may be provided by two including a first fixed contactor 220a on a left side and a second fixed contactor 220b on a right side.

The first fixed contactor 220a may be located to be biased to one side from a center of the movable contactor <NUM> in the longitudinal direction, namely, to the left in the illustrated implementation. Also, the second fixed contactor 220b may be located to be biased to another side from the center of the movable contactor <NUM> in the longitudinal direction, namely, to the right in the illustrated implementation.

A power supply may be electrically connected to any one of the first fixed contactor 220a and the second fixed contactor 220b. Also, a load may be electrically connected to another one of the first fixed contactor 220a and the second fixed contactor 220b.

The DC relay <NUM> according to the implementation of the present disclosure may be operated regardless of the polarity of the fixed contactor <NUM>. That is, a power supply or a load may be electrically connected to any one of the first fixed contactor 220a and the second fixed contactor 220b. This may result from a direction a magnetic field generated inside the arc chamber <NUM>, and a detailed description thereof will be described later.

Another end portion of the fixed contactor <NUM>, for example, a lower end portion in the illustrated implementation may extend toward the movable contactor <NUM>. When the movable contactor <NUM> is moved toward the fixed contactor <NUM>, namely, upward in the illustrated implementation, the lower end portion of the fixed contactor <NUM> may be brought into contact with the movable contactor <NUM>. Accordingly, the outside and the inside of the DC relay <NUM> can be electrically connected.

The lower end portion of the fixed contactor <NUM> may be located inside the arc chamber <NUM>. That is, the another end portion of the fixed contactor <NUM> may also be sealed by the arc chamber <NUM>.

When control power is cut off, the movable contactor <NUM> may be separated from the fixed contactor <NUM> by elastic force of a return spring <NUM>. At this time, as the fixed contactor <NUM> and the movable contactor <NUM> are separated from each other, arc may be generated between the fixed contactor <NUM> and the movable contactor <NUM>. The generated arc may be extinguished by extinguishing gas inside the arc chamber <NUM> and discharged to the outside.

In this case, a path through which the arc is discharged may be changed according to a direction of a magnetic field generated inside the arc chamber <NUM> and a direction of current applied through the fixed contactor <NUM>. A detailed description thereof will be given later.

The sealing member <NUM> may block communication between the arc chamber <NUM> and an inner space of the upper frame <NUM>. The sealing member <NUM> may seal the lower side of the arc chamber <NUM> together with the insulating plate <NUM> and the supporting plate <NUM>.

In detail, an upper side of the sealing member <NUM> may be coupled to the lower side of the arc chamber <NUM>. A radially inner side of the sealing member <NUM> may be coupled to an outer circumference of the insulating plate <NUM>, and a lower side of the sealing member <NUM> may be coupled to the supporting plate <NUM>.

Accordingly, arc generated in the arc chamber <NUM> and arc extinguished by the extinguishing gas may not flow into the inner space of the upper frame <NUM>.

In addition, the sealing member <NUM> may prevent an inner space of a cylinder <NUM> from communicating with the inner space of the frame part <NUM>.

The core part <NUM> may allow the movable contactor part <NUM> to move upward as control power is applied. In addition, when the control power is not applied any more, the core part <NUM> may allow the movable contactor part <NUM> to move downward again.

The core part <NUM> may be electrically connected to the outside of the DC relay <NUM>. The core part <NUM> may receive control power from the outside through the connection.

The movable core <NUM> may be located below the opening/closing part <NUM>. The core part <NUM> may be accommodated in the lower frame <NUM>. The core part <NUM> and the opening/closing part <NUM> may be electrically and physically spaced apart from each other by the insulating plate <NUM> and the supporting plate <NUM>.

The movable contactor part <NUM> may be located between the core part <NUM> and the opening/closing part <NUM>. The movable contactor part <NUM> may be moved by driving force applied by the core part <NUM>. Accordingly, the movable contactor <NUM> and the fixed contactor <NUM> may be brought into contact with each other so that the DC relay <NUM> can be electrically connected.

The core part <NUM> may include a fixed core <NUM>, a movable core <NUM>, a yoke <NUM>, a bobbin <NUM>, a coil <NUM>, a return spring <NUM>, and a cylinder <NUM>.

The fixed core <NUM> may be magnetized by electromagnetic force generated in the coils <NUM> so as to generate electromagnetic attractive force. The movable core <NUM> may be moved toward the fixed core <NUM> (upward in the illustrated implementation) by the attractive force generated by the fixed core <NUM>.

The fixed core <NUM> may not move. That is, the fixed core <NUM> may be fixedly coupled to the supporting plate <NUM> and the cylinder <NUM>.

The fixed core <NUM> may be implemented as any member that can be magnetized by electromagnetic force. In one implementation, the fixed core <NUM> may be implemented as a permanent magnet or an electromagnet.

The fixed core <NUM> may be partially accommodated in an upper space inside the cylinder <NUM>. Further, an outer circumference of the fixed core <NUM> may come in contact with an inner circumference of the cylinder <NUM>.

The fixed core <NUM> may be located between the supporting plate <NUM> and the movable core <NUM>.

A through hole (not shown) may be formed through a central portion of the fixed core <NUM>. The shaft <NUM> may be coupled through the through hole (not shown) to be movable up and down.

The fixed core <NUM> may be spaced apart from the movable core <NUM> by a predetermined distance. Accordingly, a distance by which the movable core <NUM> can move toward the fixed core <NUM> may be limited to the distance between the fixed core <NUM> and the movable core <NUM>. Accordingly, the predetermined distance may be defined as a "moving distance of the movable core <NUM>".

A recessed portion <NUM> may be formed in a central portion of the fixed core <NUM> by a predetermined distance. Specifically, the recessed portion <NUM> may be recessed by the predetermined distance into one surface of the fixed core <NUM> facing the supporting plate <NUM>.

A magnetic force reinforcing member (or magnetism strengthening member) <NUM> of the magnetic force generating part <NUM> may be accommodated in the recessed portion <NUM>. Accordingly, recessed distance and shape of the recessed portion <NUM> may preferably be determined according to height and shape of the magnetic force reinforcing member <NUM>.

The recessed portion <NUM> may extend radially outward from the through hole (not shown) formed through the central portion of the fixed core <NUM>. The recessed portion <NUM> may be formed to have the same central axis as the through hole (not shown).

One end portion of the return spring <NUM>, namely, a lower end portion in the implementation may be brought into contact with the lower side of the fixed core <NUM>. When the movable core <NUM> is moved upward as the fixed core <NUM> is magnetized, the return spring <NUM> may be compressed and store restoring force.

Accordingly, when the magnetization of the fixed core <NUM> is finished, the movable core <NUM> may be moved downward again.

When control power is applied, the movable core <NUM> may be moved toward the fixed core <NUM> by electromagnetic attractive force generated by the fixed core <NUM>.

As the movable core <NUM> is moved, the shaft <NUM> coupled to the movable core <NUM> may be moved toward the fixed core <NUM>, namely, upward in the illustrated implementation. In addition, as the shaft <NUM> is moved, the movable contactor part <NUM> coupled to the shaft <NUM> may be moved upward.

Accordingly, the fixed contactor <NUM> and the movable contactor <NUM> may be brought into contact with each other so that the DC relay <NUM> can be electrically connected to external power supply and load.

The movable core <NUM> may have any shape capable of receiving attractive force by electromagnetic force. In one implementation, the movable core <NUM> may be formed of a magnetic material or implemented as a permanent magnet or an electromagnet.

The movable core <NUM> may be accommodated inside the cylinder <NUM>. Also, the movable core <NUM> may be moved in the longitudinal direction of the cylinder <NUM> inside the cylinder <NUM>.

Specifically, the movable core <NUM> may be moved toward the fixed core <NUM> (upward in the illustrated implementation) and away from the fixed core <NUM> (downward in the illustrated implementation).

The movable core <NUM> may be coupled to the shaft <NUM>. The movable core <NUM> may move integrally with the shaft <NUM>. When the movable core <NUM> moves upward or downward, the shaft <NUM> may also move upward or downward.

The movable core <NUM> may be located below the fixed core <NUM>. The movable core <NUM> may be spaced apart from the fixed core <NUM> by a predetermined distance. The predetermined distance may be defined as the moving distance of the movable core <NUM>, as aforementioned.

A predetermined space may be defined inside the movable core <NUM>. Specifically, the movable core <NUM> may extend in a longitudinal (lengthwise) direction, and a hollow portion may be recessed into the movable core <NUM> in the longitudinal direction by a predetermined distance (depth).

The return spring <NUM> and the shaft <NUM> coupled through the return spring <NUM> may be partially accommodated in the hollow portion.

Specifically, the hollow portion may accommodate a portion, adjacent to the movable core <NUM>, of a shaft body portion <NUM> of the shaft <NUM>, and a shaft tail portion <NUM> of the shaft <NUM>.

The yoke <NUM> may form a magnetic circuit as control power is applied. The magnetic circuit formed by the yoke <NUM> may control a direction of the electromagnetic field generated by the coils <NUM>.

Accordingly, when control power is applied, the coils <NUM> may generate an electromagnetic field in a direction in which the movable core <NUM> moves toward the fixed core <NUM>. The yoke <NUM> may be formed of a conductive material capable of allowing electrical connection.

The yoke <NUM> may be accommodated inside the lower frame <NUM>. The yoke <NUM> may surround the coils <NUM>. The coils <NUM> may be accommodated in the yoke <NUM> with being spaced apart from an inner circumferential surface of the yoke <NUM> by a predetermined distance.

Also, the bobbin <NUM> may be accommodated in the yoke <NUM>. That is, the yoke <NUM>, the coils <NUM>, and the bobbin <NUM> on which the coils <NUM> are wound may be sequentially located radially inward from an outer circumference of the lower frame <NUM>.

An upper side of the yoke <NUM> may come in contact with the supporting plate <NUM>. In addition, the outer circumference of the yoke <NUM> may come in contact with an inner circumference of the lower frame <NUM> or may be located to be spaced apart from the inner circumference of the lower frame <NUM> by a predetermined distance.

As will be described later, the DC relay <NUM> according to the implementation of the present disclosure may include a magnetic force reinforcing member <NUM>. The magnetic force reinforcing member <NUM> may strengthen (reinforce, enhance) a magnetic circuit formed by the yoke <NUM>. A detailed description thereof will be given later.

The coils <NUM> may be wound around the bobbin <NUM>. The bobbin <NUM> may be accommodated inside the yoke <NUM>.

The bobbin <NUM> may include upper and lower portions formed in a flat shape, and a cylindrical pole portion extending in the longitudinal direction to connect the upper and lower portions. That is, the bobbin <NUM> may have a bobbin shape.

An upper portion of the bobbin <NUM> may come in contact with the lower side of the supporting plate <NUM>. In addition, a lower portion of the bobbin <NUM> may be supported by a protrusion protruding from the lower side to the upper side of the lower frame <NUM>.

The coils <NUM> may be wound around the pole portion of the bobbin <NUM>. A wound thickness of the coils <NUM> may be the same as a diameter of the upper and lower portions of the bobbin <NUM>.

A hollow portion may be formed through the pole portion of the bobbin <NUM> extending in the longitudinal direction. The cylinder <NUM> may be accommodated in the hollow portion.

The pole portion of the bobbin <NUM> may be disposed to have the same central axis as the fixed core <NUM>, the movable core <NUM>, and the shaft <NUM>.

The coils <NUM> may generate an electromagnetic field as control power is applied. The fixed core <NUM> may be magnetized by the electromagnetic field generated by the coils <NUM> and thus apply attractive force to the movable core <NUM>.

The coils <NUM> may be wound around the bobbin <NUM>. Specifically, the coils <NUM> may be wound around the pole portion part of the bobbin <NUM> and stacked on a radial outside of the pole portion. The coils <NUM> may be accommodated inside the yoke <NUM>.

When control power is applied, the coils <NUM> may generate an electromagnetic field. In this case, strength and direction of the electromagnetic field generated by the coils <NUM> may be controlled by the yoke <NUM>. The fixed core <NUM> may be magnetized by the electromagnetic field generated by the coils <NUM>.

When the fixed core <NUM> is magnetized, the movable core <NUM> may receive electromagnetic force, namely, attractive force in a direction toward the fixed core <NUM>. Accordingly, the movable core <NUM> may be moved toward the fixed core <NUM>, namely, upward in the illustrated implementation.

The return spring <NUM> may apply driving force for the movable core <NUM> to be moved away from the fixed core <NUM> when control power is not applied any more after the movable core <NUM> is moved to the fixed core <NUM>.

The return spring <NUM> may be compressed and store restoring force as the movable core <NUM> is moved toward the fixed core <NUM>.

At this time, the restoring force stored by the return spring <NUM> may preferably be smaller than the attractive force exerted by the magnetized fixed core <NUM> to the movable core <NUM>. Accordingly, while control power is applied, the movable core <NUM> may not be returned to its original position by the return spring <NUM>.

As will be described later, the DC relay <NUM> according to the implementation of the present disclosure includes a magnetic force reinforcing member <NUM>. The magnetic force reinforcing member <NUM> may apply electromagnetic force to the movable core <NUM> together with the fixed core <NUM>.

Therefore, in the implementation, the restoring force stored by the return spring <NUM> may preferably be greater than the attractive force exerted by the magnetic force reinforcing member <NUM> to the movable core <NUM>, but smaller than the sum of the attractive force exerted by the magnetized fixed core <NUM> to the movable core <NUM> and the attractive force exerted by the magnetic force reinforcing member <NUM> to the movable core <NUM>.

When control power is not applied any more, only the restoring force by the return spring <NUM> may be applied to the movable core <NUM>. Accordingly, the movable core <NUM> can be moved away from the fixed core <NUM> to be returned to the original position.

The return spring <NUM> may be provided in any form capable of storing restoring force by being compressed in response to the movement of the movable core <NUM>. In one implementation, the return spring <NUM> may be configured as a coil spring.

A shaft <NUM> may be coupled through the return spring <NUM>. The shaft <NUM> may move up and down regardless of the return spring <NUM> in a coupled state to the return spring <NUM>. That is, the shaft <NUM> may serve to support the return spring <NUM>.

The return spring <NUM> may be accommodated in the hollow portion formed through the inside of the movable core <NUM>. In addition, one end portion of the return spring <NUM> facing the fixed core <NUM>, namely, an upper end portion in the illustrated implementation may be supported with coming in contact with a lower surface of the fixed core <NUM>.

In addition, one end portion of the return spring <NUM> facing the fixed core <NUM>, namely, an upper end portion in the illustrated implementation may be supported with coming in contact with a lower surface of the magnetic force reinforcing member <NUM>.

The cylinder <NUM> may accommodate the fixed core <NUM>, the movable core <NUM>, and the return spring <NUM>. Inside the cylinder <NUM>, the movable core <NUM> may be moved upward and downward.

The cylinder <NUM> may be located in the hollow portion formed through the pole portion of the bobbin <NUM>. An upper end portion of the cylinder <NUM> may come in contact with a lower surface of the supporting plate <NUM>. In addition, a side surface of the cylinder <NUM> may come in contact with an inner circumferential surface of the pole portion of the bobbin <NUM>, and an upper opening of the cylinder <NUM> may be sealed by the fixed core <NUM>. A lower surface of the cylinder <NUM> may come in contact with an inner circumferential surface of the lower frame <NUM>.

The cylinder <NUM> may accommodate the shaft <NUM>. Inside the cylinder <NUM>, the shaft <NUM> may be moved upward or downward together with the movable core <NUM>.

The movable contactor part <NUM> inlcudes the movable contactor <NUM> and components for moving the movable contactor <NUM>. The movable contactor part <NUM> may allow the DC relay <NUM> to be electrically connected to external power supply and load.

The movable contactor part <NUM> may be accommodated in the frame part <NUM>, specifically, in the inner space of the upper frame <NUM>. In detail, the movable contactor part <NUM> may be accommodated in the arc chamber <NUM> within the upper frame <NUM>.

The fixed contactor <NUM> may be located above the movable contactor part <NUM>. The movable contactor part <NUM> may be accommodated in the arc chamber <NUM> to be movable toward and away from the fixed contactor <NUM> (i.e., movable up and down in the illustrated implementation).

The core part <NUM> may be located below the movable contactor part <NUM>. The movable contactor part <NUM> may be accommodated to be movable toward and away from the fixed contactor <NUM> (i.e., movable up and down in the illustrated implementation), in response to the movement of the movable core <NUM>.

The movable contactor part <NUM> includes the movable contactor <NUM>.

The movable contactor <NUM> may be brought into contact with or separated from the fixed contactor <NUM> in response to the movement of the movable core <NUM> of the core part <NUM>.

In the illustrated implementation, the movable contactor part <NUM> may include a housing <NUM>, a cover <NUM>, a movable contactor <NUM>, a shaft <NUM>, and an elastic portion <NUM>.

Also, although not illustrated, the movable contactor part <NUM> may include a yoke (not illustrated) for preventing the movable contactor <NUM> from being arbitrarily separated from the fixed contactor <NUM>. The yoke (not illustrated) may cancel the electromagnetic repulsive force generated between the fixed contactor <NUM> and the movable contactor <NUM>.

The housing <NUM> may accommodate the movable contactor <NUM> and the elastic portion <NUM> elastically supporting the movable contactor <NUM>.

In the illustrated implementation, the housing <NUM> may be formed such that one side and another side opposite to the one side are open. The movable contactor <NUM> may be inserted through the openings.

In the illustrated implementation, the housing <NUM> may include a base defining a lower surface, and side surfaces protruding from both ends of the base toward the fixing contacts <NUM>, respectively. When the movable contactor <NUM> is inserted, the side surfaces of the housing <NUM> may surround the movable contactor <NUM>.

The cover <NUM> may be provided on a top of the housing <NUM>. The cover <NUM> may cover an upper surface of the movable contactor <NUM> accommodated in the housing <NUM>.

The housing <NUM> and the cover <NUM> may preferably be formed of an insulating material to prevent unexpected electrical connection. In one implementation, the housing <NUM> and the cover <NUM> may be formed of synthetic resin or the like.

A bottom of the housing <NUM> may be connected to the shaft <NUM>. When the movable core <NUM> connected to the shaft <NUM> is moved upward or downward, the housing <NUM> may also be moved upward or downward.

The housing <NUM> and the cover <NUM> may be coupled by arbitrary members. In one implementation, the housing <NUM> and the cover <NUM> may be coupled by a coupling member (not illustrated) such as a bolt and a nut.

In this case, the cover <NUM> may be fitted to the housing <NUM>. To this end, grooves (not illustrated) may be recessed in upper end portions of the both side surfaces of the housing <NUM>, and protrusions (not illustrated) to be inserted into the grooves may be formed on the cover <NUM>.

The movable contactor <NUM> may come in contact with the fixed contactor <NUM> when control power is applied, so that the DC relay <NUM> can be electrically connected to external power supply and load. When control power is not applied, the movable contactor <NUM> may be separated from the fixed contactor <NUM> such that the DC relay <NUM> can be electrically disconnected from the external power supply and load.

The movable contactor <NUM> may be located adjacent to the fixed contactor <NUM>.

An upper side of the movable contactor <NUM> may be covered by the cover <NUM>. In one implementation, the upper side of the movable contactor <NUM> may come in contact with one surface of the cover <NUM> facing the movable contactor <NUM>, namely, a lower surface in the illustrated implementation.

A lower side of the movable contactor <NUM> may be elastically supported by the elastic portion <NUM>. In order to prevent the movable contactor <NUM> from being arbitrarily moved downward, the elastic portion <NUM> may elastically support the movable contactor <NUM> in a restored state to some extent after being compressed.

Accordingly, when the elastic portion <NUM> applies elastic force to the movable contactor <NUM> in a direction toward the cover <NUM>, the movable contactor <NUM> may be stably maintained in a contact state with the fixed contactor <NUM>.

The movable contactor <NUM> may extend in the longitudinal direction, namely, in left and right directions in the illustrated implementation. That is, a length of the movable contactor <NUM> may be longer than its width.

Accordingly, when the movable contactor <NUM> is accommodated in an inner space of the housing <NUM>, both end portions of the movable contactor <NUM> in the longitudinal direction may be exposed to the outside of the housing <NUM>. Contact protrusions <NUM> may protrude from the both end portions.

The contact protrusions <NUM> of the movable contactor <NUM> may be portions brought into contact with the fixed contactor <NUM>. The contact protrusions <NUM> may protrude by a predetermined distance from one surface of the movable contactor <NUM> facing the fixed contactor <NUM>, namely, from an upper surface in the illustrated implementation.

In the illustrated implementation, the fixed contactor <NUM> may include a first fixed contactor 220a on a left side and a second fixed contactor 220b on a right side. Accordingly, the contact protrusions <NUM> may be formed on end portions of the movable contactor <NUM> corresponding to positions of the respect fixed contacts <NUM>.

The contact protrusions <NUM> can reduce a distance by which the movable contactor <NUM> has to be moved to come into contact with the fixed contactor <NUM>.

Other portions of the movable contactor <NUM>, except for the contact protrusions <NUM>, may not come into contact with the fixed contactor <NUM>. Since the contact protrusions <NUM> protrude from the movable contactor <NUM>, the contact protrusions <NUM> of the movable contactor <NUM> may be portions closest to the fixed contactor <NUM>.

A width of the movable contactor <NUM> may be the same as a spaced distance between the side surfaces of the housing <NUM>. That is, when the movable contactor <NUM> is accommodated in the housing <NUM>, both side surfaces of the movable contactor <NUM> in a width direction may be brought into contact with inner sides of the side surfaces of the housing <NUM>.

Accordingly, the state where the movable contactor <NUM> is accommodated in the housing <NUM> can be stably maintained.

The shaft <NUM> may transmit driving force, which is generated in response to the operation of the core part <NUM>, to the movable contactor part <NUM>. Specifically, the shaft <NUM> may be connected to the movable core <NUM> and the movable contactor <NUM>. When the movable core <NUM> is moved upward or downward, the movable contactor <NUM> may be moved upward or downward.

The shaft <NUM> may extend in the longitudinal direction, namely, in the up and down (vertical) direction in the illustrated implementation.

The shaft <NUM> may be coupled to the movable core <NUM>. When the movable core <NUM> is moved up and down, the shaft <NUM> may also be moved up and down together with the movable core <NUM>.

The shaft <NUM> may be coupled to the housing <NUM>. When the shaft <NUM> is moved up and down, the housing <NUM> may also be moved up and down together with the shaft <NUM>.

The shaft <NUM> may be coupled through the fixed core <NUM> and the magnetic force reinforcing member <NUM> to be movable up and down. The shaft <NUM> may be inserted into the movable core <NUM>. In addition, the return spring <NUM> may be fitted through the shaft <NUM>.

The shaft <NUM> may include a shaft body portion <NUM>, a shaft head portion <NUM>, and a shaft tail portion <NUM>.

The shaft body portion <NUM> may define the body of the shaft <NUM>. In the illustrated implementation, the support body portion <NUM> may be formed in a cylindrical shape having a circular cross section and extending in the longitudinal direction.

The shaft head portion <NUM> may be located on one end portion of the shaft body portion <NUM> coupled to the housing <NUM>, namely, on an upper end portion in the illustrated implementation. The shaft head portion <NUM> may be coupled to the housing <NUM>. The shaft head portion <NUM> may be formed to have a larger diameter than the shaft body portion <NUM>.

The shaft head portion <NUM> and the housing <NUM> may be integrally formed with each other. In one implementation, the shaft head portion <NUM> and the housing <NUM> may be formed through insert-injection molding.

The shaft tail portion <NUM> may be located on one end portion of the shaft body portion <NUM> inserted into the movable core <NUM>, namely, on a lower end portion in the illustrated implementation. The shaft tail portion <NUM> may be coupled to the movable core <NUM>. The shaft tail portion <NUM> may be formed to have a larger diameter than the shaft body portion <NUM>.

The coupled states between the shaft <NUM> and the housing <NUM> and between the shaft <NUM> and the movable core <NUM> can be stably maintained by the shaft head portion <NUM> and the shaft tail portion <NUM>.

The elastic portion <NUM> may elastically support the movable contactor <NUM>. When the movable contactor <NUM> comes into contact with the fixed contactor <NUM>, the movable contactor <NUM> may tend to be separated from the fixed contactor <NUM> by electromagnetic repulsive force.

At this time, the elastic portion <NUM> may elastically support the movable contactor <NUM> to prevent the movable contactor <NUM> from being arbitrarily separated from the fixed contactor <NUM>.

The elastic portion <NUM> may be formed in any shape capable of being compressed or stretched to store restoring force and transmitting the stored restoring force to another member. In one implementation, the elastic portion <NUM> may be configured as a coil spring.

One end portion of the elastic portion <NUM> facing the movable contactor <NUM>, namely, an upper end portion in the illustrated implementation, may come in contact with the lower side of the movable contactor <NUM>. In addition, another end portion of the elastic portion <NUM> opposite to the one end portion, namely, an upper side of the housing <NUM> may come in contact with the upper side of the housing <NUM>.

The elastic portion <NUM> may elastically support the movable contactor <NUM> in a state of storing the restoring force by being compressed by a predetermined length. Accordingly, even if electromagnetic repulsive force is generated between the movable contactor <NUM> and the fixed contactor <NUM>, the movable contactor <NUM> and the fixed contact <NUM> may not be separated from each other by the elastic portion <NUM>.

A protrusion (not illustrated) to which the elastic portion <NUM> can be fitted may protrude from the lower side of the movable contactor <NUM> to enable stable coupling of the elastic portion <NUM>. Similarly, a protrusion (not illustrated) to which the elastic portion <NUM> can be fitted may protrude from the top of the housing <NUM>.

Referring back to <FIG>, the DC relay <NUM> according to the implementation includes a magnetic force generating part (or magnetism forming unit) <NUM>.

The magnetic force generating part <NUM> may generate a magnetic field for forming a movement path of arc generated inside the arc chamber <NUM>. In addition, the magnetic force generating part <NUM> may increase driving force for moving the movable core <NUM> toward the fixed core <NUM> as control power is applied.

Hereinafter, the magnetic force generating part <NUM> provided in the DC relay <NUM> according to the implementation will be described with reference to <FIG>.

In the illustrated implementation, the magnetic force generating part <NUM> includes a first magnet member <NUM>, a second magnet member <NUM>, and a magnetic force reinforcing member <NUM>.

The first magnet member <NUM> may generate a magnetic field that forms a path for extinguishing arc generated inside the arc chamber <NUM>.

Specifically, arc may be generated when the fixed contactor <NUM> and the movable contactor <NUM> are separated from each other after current can flow in response to the movable contactor <NUM> being in contact with the fixed contactor <NUM>.

In this case, the first magnet member <NUM> may generate a magnetic field in the arc chamber <NUM>. The magnetic field generated by the first magnet member <NUM> and the current may generate electromagnetic force for guiding the arc. A direction of the electromagnetic force may be defined by the Fleming's left-hand rule.

In the illustrated implementation, the first magnet member <NUM> may be accommodated in the upper frame <NUM>. In addition, the first magnet member <NUM> may be located at the left side outside the arc chamber <NUM>. This may prevent the first magnet member <NUM> from being damaged due to the arc generated inside the arc chamber <NUM>.

Also, the first magnet member <NUM> may come in contact with a left inner surface of the upper frame <NUM>. The first magnet member <NUM> may be fixed to the inner surface of the upper frame <NUM>. To this end, a fixing member (not illustrated) for fixing the first magnet member <NUM> may be provided.

According to the invention, the first magnet member <NUM> is located adjacent to one end portion of the movable contactor <NUM> in the longitudinal direction, namely, a left end portion in the illustrated implementation.

The first magnet member <NUM> may be formed in any shape capable of generating a magnetic field. In one implementation, the first magnet member <NUM> may be implemented as a permanent magnet.

The magnetic field generated by the first magnet member <NUM> is reinforced by the second magnet member <NUM> and the magnetic force reinforcing member <NUM>.

Further referring to <FIG>, the first magnet member <NUM> may include a first inner portion <NUM> and a first outer portion <NUM>.

The first inner portion <NUM> may be defined as one side of the first magnet member <NUM> facing the fixed contactor <NUM>. That is, if it is defined that the fixed contactor <NUM> is located at an inner side and the upper frame <NUM> is located at an outer side, the first inner portion <NUM> may be a portion of the first magnet member <NUM> facing the inner side.

One surface of the first inner portion <NUM> that is the closest to the fixed contactor <NUM> may be defined as a first inner surface 511a.

The first outer portion <NUM> may be defined as one side of the first magnet member <NUM> facing the inner surface of the upper frame <NUM>. In other words, the first outer portion <NUM> may be defined as a portion of the first magnet member <NUM> opposite to the first inner portion <NUM>.

One surface of the first outer portion <NUM> that is the closest to the inner surface of the upper frame <NUM> may be defined as a first outer surface 512a.

The first inner portion <NUM> and the first outer portion <NUM> may have different polarities. That is, when the first inner portion <NUM> has an N pole, the first outer portion <NUM> may have an S pole. On the other hand, when the first inner portion <NUM> has an S pole, the first outer portion <NUM> may have an N pole.

The second magnet member <NUM> may generate a magnetic field that forms a path for extinguishing arc generated inside the arc chamber <NUM>.

Specifically, arc may be generated when the fixed contactor <NUM> and the movable contactor <NUM> are separated from each other after current flows in response to the movable contactor <NUM> being in contact with the fixed contactor <NUM>.

In this case, the second magnet member <NUM> may generate a magnetic field in the arc chamber <NUM>. The magnetic field generated by the second magnet member <NUM> and the current may generate electromagnetic force for guiding the arc. A direction of the electromagnetic force may be defined by the Fleming's left-hand rule.

In the illustrated implementation, the second magnet member <NUM> may be accommodated in the upper frame <NUM>. In addition, the second magnet member <NUM> may be located at the right side outside the arc chamber <NUM>. This may prevent the second magnet member <NUM> from being damaged due to the arc generated inside the arc chamber <NUM>.

Also, the second magnet member <NUM> may come in contact with a right inner surface of the upper frame <NUM>. The second magnet member <NUM> may be fixed to the inner surface of the upper frame <NUM>. To this end, a fixing member (not illustrated) for fixing the second magnet member <NUM> may be provided.

According to the invention, the second magnet member <NUM> is located adjacent to one end portion of the movable contactor <NUM> in the longitudinal direction, namely, a right end portion in the illustrated implementation.

The second magnet member <NUM> may be formed in any shape capable of generating a magnetic field. In one implementation, the second magnet member <NUM> may be implemented as a permanent magnet.

The magnetic field generated by the second magnet member <NUM> is reinforced by the first magnet member <NUM> and the magnetic force reinforcing member <NUM>.

Further referring to <FIG>, the second magnet member <NUM> may include a second inner portion <NUM> and a second outer portion <NUM>.

The second inner portion <NUM> may be defined as one side of the second magnet member <NUM> facing the fixed contactor <NUM>. That is, if it is defined that the fixed contactor <NUM> is located at an inner side and the upper frame <NUM> is located at an outer side, the second inner portion <NUM> may be a portion of the second magnet member <NUM> facing the inner side.

One surface of the second inner portion <NUM> that is the closest to the fixed contactor <NUM> may be defined as a second inner surface 521a.

The second outer portion <NUM> may be defined as one side of the second magnet member <NUM> facing the inner surface of the upper frame <NUM>. In other words, the second outer portion <NUM> may be defined as a portion of the second magnet member <NUM> opposite to the second inner portion <NUM>.

One surface of the second outer portion <NUM> that is the closest to the inner surface of the upper frame <NUM> may be defined as a second outer surface 522a.

The second inner portion <NUM> and the second outer portion <NUM> may have different polarities. That is, when the second inner portion <NUM> has an N pole, the second outer portion <NUM> may have an S pole. On the other hand, when the second inner portion <NUM> has an S pole, the second outer portion <NUM> may have an N pole.

The first magnet member <NUM> and the second magnet member <NUM> may be spaced apart from each other with the arc chamber <NUM> interposed therebetween. The first inner portion <NUM> of the first magnet member <NUM> and the second inner portion <NUM> of the second magnet member <NUM> may be disposed to face each other.

The first inner portion <NUM> of the first magnet member <NUM> and the second inner portion <NUM> of the second magnet member <NUM> may have the same polarity. Likewise, the first outer portion <NUM> of the first magnet member <NUM> and the second outer portion <NUM> of the second magnet member <NUM> may have the same polarity.

In addition, the first inner portion <NUM> of the first magnet member <NUM> and the second inner portion <NUM> of the second magnet member <NUM> may have a different polarity from polarity of a first portion <NUM> of the magnetic force reinforcing member <NUM>.

With the configuration, magnetic fields emitted from the first magnet member <NUM> and the second magnet member <NUM> may converge on the magnetic force reinforcing member <NUM>. On the other hand, a magnetic field emitted from the magnetic force reinforcing member <NUM> may converge on the first magnet member <NUM> and the second magnet member <NUM>. A detailed description thereof will be given later.

In the illustrated implementation, the first magnet member <NUM> and the second magnet member <NUM> may have a rectangular shape that has a rectangular cross section and extends in the longitudinal direction, namely, in the back and forth direction in the illustrated implementation. The first magnet member <NUM> and the second magnet member <NUM> may be formed in any shape capable of generating magnetic fields.

In addition, although not illustrated, additional magnet members for generating magnetic fields in the arc chamber <NUM> may be provided. The additional magnet members (not illustrated) may be provided at the front and the rear outside the arc chamber <NUM> to generate the magnetic fields.

The magnetic force reinforcing member <NUM> reinforces the magnetic fields generated by the first magnet member <NUM> and the second magnet member <NUM>. Accordingly, the electromagnetic forces generated by the current, which can flow in response to the electric connection between the fixed contactor <NUM> and the movable contactor <NUM>, and the magnetic fields can be reinforced, thereby effectively forming an arc extinguishing path.

In addition, the magnetic force reinforcing member <NUM> may control a direction of the magnetic fields generated by the first magnet member <NUM> and the second magnet member <NUM>. Accordingly, an external power supply and an external load can be arbitrarily electrically connected to the fixed contactor <NUM> without the need to maintain directionality.

That is, the power supply may be electrically connected to one of the first fixed contactor 220a and the second fixed contactor 220b and the load may be electrically connected to the other.

Furthermore, the magnetic force reinforcing member <NUM> may reinforce driving force for moving the movable core <NUM>, which is generated as control power is applied to the core part <NUM>. Accordingly, even when control power of a smaller magnitude is applied, a driving force sufficient to move the movable core <NUM> can be secured.

The magnetic force reinforcing member <NUM> may generate a magnetic field in the arc chamber <NUM>. In addition, the magnetic force reinforcing member <NUM> may apply electromagnetic attractive force to the movable core <NUM>.

The magnetic force reinforcing member <NUM> is located below the lower side of the movable contactor part <NUM>. Specifically, the magnetic force reinforcing member <NUM> may be located at the lower side of the housing <NUM> with being spaced apart from the housing <NUM> by a predetermined distance.

In other words, the magnetic force reinforcing member <NUM> is located at another side opposite to one side of the movable contactor <NUM> adjacent to the fixed contactor <NUM>.

Also, the magnetic force reinforcing member <NUM> may be located at the center of the movable contactor <NUM> in the longitudinal direction. As described above, the first fixed contactor 220a and the second fixed contactor 220b may be located to be biased from the center of the movable contactor <NUM> in the longitudinal direction of the movable contactor <NUM>. Therefore, it may be said that the magnetic force reinforcing member <NUM> is located between the first fixed contactor 220a and the second fixed contactor 220b.

The magnetic force reinforcing member <NUM> may be inserted into the fixed core <NUM>. Specifically, the magnetic force reinforcing member <NUM> may be inserted and seated in the recessed portion <NUM> of the fixed core <NUM>.

The shaft <NUM> may be coupled through the magnetic force reinforcing member <NUM>. The shaft <NUM> may be moved up and down while being coupled through the magnetic force reinforcing member <NUM>. In this case, the magnetic force reinforcing member <NUM> may be maintained in an inserted state in the fixed core <NUM>, irrespective of the movement of the shaft <NUM>.

In the illustrated implementation, the magnetic force reinforcing member <NUM> may have a cylindrical shape with a hollow portion <NUM> formed therethrough in a height direction. The magnetic force reinforcing member <NUM> may be formed in any shape that is coupled to the fixed core <NUM> so as to reinforce magnetic fields and reinforce driving forces, as described above.

The magnetic force reinforcing member <NUM> may be formed in any shape capable of generating magnetic field and magnetic force. In one implementation, the magnetic force reinforcing member <NUM> may be implemented as a permanent magnet.

The magnetic force reinforcing member <NUM> may include a first portion <NUM>, a second portion <NUM>, an outer circumferential surface <NUM>, an inner circumferential surface <NUM>, and a hollow portion <NUM>.

The first portion <NUM> may define an upper side of the magnetic force reinforcing member <NUM>. The first portion <NUM> may be defined as one side of the magnetic force reinforcing member <NUM> facing the movable contactor <NUM>.

The first portion <NUM> may have a predetermined polarity. In one implementation, the first portion <NUM> may have any one of N pole and S pole.

The second portion <NUM> may be located beneath the first portion <NUM>. The second portion <NUM> may define a lower side of the magnetic force reinforcing member <NUM>. The second portion <NUM> may be defined as one side of the magnetic force reinforcing member <NUM> facing the fixed core <NUM> or the movable core <NUM>.

The second portion <NUM> may have a predetermined polarity. In one implementation, the second portion <NUM> may have any one of N pole and S pole.

The first portion <NUM> and the second portion <NUM> may be configured to have opposite polarities. That is, when the first portion <NUM> has an N pole, the second portion <NUM> may have an S pole. Conversely, when the first portion <NUM> has an S pole, the second portion <NUM> may have an N pole.

The first portion <NUM> has a polarity opposite to that of the first inner portion <NUM> of the first magnet member <NUM> and the second inner portion <NUM> of the second magnet member <NUM>. In other words, the second portion <NUM> has the same polarity as the first inner portion <NUM> and the second inner portion <NUM>.

The outer circumferential surface <NUM> may define a side surface of the magnetic force reinforcing member <NUM>. In the illustrated implementation, the magnetic force reinforcing member <NUM> may have a cylindrical shape, and thus the outer circumferential surface <NUM> may be referred to as a side surface.

When the magnetic force reinforcing member <NUM> is inserted into the recessed portion <NUM> of the fixed core <NUM>, the outer circumferential surface <NUM> may be brought into contact with the inner circumferential surface of the fixed core <NUM> surrounding the recessed portion <NUM>. In addition, the outer circumferential surface <NUM> may be brought into contact with an inner circumferential surface of the supporting plate <NUM>.

Accordingly, the magnetic force reinforcing member <NUM> can be stably seated on the fixed core <NUM>.

The inner circumferential surface <NUM> may define an inner surface of the magnetic force reinforcing member <NUM>. A space surrounded by the inner circumferential surface <NUM> may be defined as the hollow portion <NUM>.

The hollow portion <NUM> may be a space formed through the inside of the magnetic force reinforcing member <NUM> in the height direction. The shaft <NUM> may be coupled through the hollow portion <NUM> to be movable up and down.

The hollow portion <NUM> may be defined as a space surrounded by the inner circumferential surface <NUM>. A diameter of the hollow portion <NUM> may be slightly larger than a diameter of the shaft body portion <NUM>.

Accordingly, the magnetic force reinforcing member <NUM> can be maintained in a fixed state regardless of the vertical movement of the shaft <NUM>.

The DC relay <NUM> according to the implementation may generate electromagnetic force for forming an arc discharge path by using flows of magnetic fields and current.

The current may be applied in response to the movable contactor <NUM> being brought into contact with the fixed contactor <NUM>. In addition, the magnetic fields may be generated by the magnetic force generating part <NUM>.

Hereinafter, a process of forming an arc discharge path in the DC relay <NUM> according to the implementation will be described in detail with reference to <FIG>.

In the following description, the first inner portion <NUM> of the first magnet member <NUM>, the second inner portion <NUM> of the second magnet member <NUM>, and the second portion <NUM> of the magnetic force reinforcing member <NUM> have the same magnetism.

In addition, the first outer portion <NUM>, the second outer portion <NUM>, and the first portion <NUM> have the same magnetism opposite to the above magnetism.

As described above, the first magnet member <NUM> and the second magnet member <NUM> may be located adjacent to the left inner surface and the right inner surface of the upper frame <NUM>. In addition, the magnetic force reinforcing member <NUM> may be located between the first magnet member <NUM> and the second magnet member <NUM>.

The first fixed contactor 220a and the second fixed contactor 220b may be located between the first magnet member <NUM> and the second magnet member <NUM>. The magnetic force reinforcing member <NUM> may be located between the first fixed contactor 220a and the second fixed contactor 220b with the same distance from each fixed contactor 220a and 220b.

Similarly, the magnetic force reinforcing member <NUM> may be located with being spaced apart by the same distance from the first magnet member <NUM> and the second magnet member <NUM>.

In addition, current carrying (electric connection) conditions may be classified into two types.

That is, as illustrated in (a) of <FIG>, a condition may be considered in which current is introduced through the second fixed contactor 220b located at the right side, flows through the movable contactor <NUM>, and is discharged through the first fixed contactor 220a located at the left side. Hereinafter, the above condition may be referred to as a "first electric connection (current-carrying) condition".

That is, as illustrated in (b) of <FIG>, a condition may be considered in which current is introduced through the first fixed contactor 220a located at the left side, flows through the movable contactor <NUM>, and is discharged through the second fixed contactor 220b located at the right side. Hereinafter, the above condition may be referred to as a "second electric connection condition".

Hereinafter, a process of forming an arc discharge path when the first portion <NUM> of the magnetic force reinforcing member <NUM> has an S pole will be described with reference to (a) of <FIG>, and <FIG>.

Referring to (a) of <FIG>, an implementation in which an S pole is formed in the first portion <NUM> of the magnetic force reinforcing member <NUM> is illustrated. Although not illustrated, an N pole may be formed in the second portion <NUM> as aforementioned.

<FIG> illustrates flows (paths) (M. P) of magnetic fields generated in the first electric connection condition and a direction (F1) of electromagnetic forces generated accordingly.

In the illustrated implementation, since the first portion <NUM> has the S pole, the first inner portion <NUM> and the second inner portion <NUM> may have the N pole. Considering that the direction of the magnetic field is from the N pole to the S pole, the flows (paths) M. P of the magnetic fields emitted from the first magnet member <NUM> and the second magnet member <NUM> may converge to the magnetic force reinforcing member <NUM> (refer to a first direction A in <FIG>).

In the first electric connection condition, current C. P may be introduced through the second fixed contactor 220b. When applying the Fleming's left-hand rule in the vicinity of the second fixed contactor 220b, the electromagnetic forces may be generated in the direction F1 (upward in the illustrated implementation).

Also, the current C. P may flow out through the first fixed contactor 220a. When applying the Fleming's left-hand rule in the vicinity of the first fixed contactor 220a, the electromagnetic forces may be generated in the direction F1 (upward in the illustrated implementation).

<FIG> illustrates flows (paths) (M. P) of magnetic fields generated in the second electric connection condition and a direction F1 of electromagnetic forces generated accordingly.

In the first electric connection condition, the current C. P may be introduced through the first fixed contactor 220a. When applying the Fleming's left-hand rule in the vicinity of the first fixed contactor 220a, the electromagnetic forces may be generated in the direction F1 (downward in the illustrated implementation).

Also, the current C. P may flow out through the second fixed contactor 220b. When applying the Fleming's left-hand rule in the vicinity of the second fixed contactor 220b, the electromagnetic forces may be generated in the direction F1 (downward in the illustrated implementation).

That is, the electromagnetic forces generated in the first fixed contactor 220a and the second fixed contactor 220b may be applied in the same direction F1. Accordingly, compared to the case where the directions of the electromagnetic forces generated in the respective fixed contacts 220a and 220b are different from each other, arc extinguishing and discharge paths can be effectively formed.

This may result from that the paths M. P of the magnetic fields emitted from the first magnet member <NUM> and the second magnet member <NUM> proceed toward the magnetic force reinforcing member <NUM> located therebetween.

That is, the paths M. P of the magnetic fields emitted from the first magnet member <NUM> and the second magnet member <NUM> may not be biased to any one side. Accordingly, even if the direction of the current in the first fixed contactor 220a and the second fixed contactor 220b is changed, the electromagnetic forces may be applied in the same direction.

Hereinafter, a process of forming an arc discharge path when the first portion <NUM> of the magnetic force reinforcing member <NUM> has an N pole will be described with reference to (b) of <FIG>, and <FIG>, <FIG>, and <FIG>.

Referring to (b) of <FIG>, an implementation in which an N pole is formed in the first portion <NUM> of the magnetic force reinforcing member <NUM> is illustrated. Although not illustrated, an S pole may be formed in the second portion <NUM> as aforementioned.

<FIG> illustrates flows (paths) (M. P) of magnetic fields generated in the first electric connection condition and a direction F2 of electromagnetic forces generated accordingly.

In the illustrated implementation, since the first portion <NUM> has the N pole, the first inner portion <NUM> and the second inner portion <NUM> may have the S pole. Considering that the direction of the magnetic field is from the N pole to the S pole, the flows (paths) M. P of the magnetic fields emitted from the magnetic force reinforcing member <NUM> may converge respectively to the first magnet member <NUM> and the second magnet member <NUM> (refer to a second direction B in <FIG>).

In the first electric connection condition, current C. P may be introduced through the second fixed contactor 220b. When applying the Fleming's left-hand rule in the vicinity of the second fixed contactor 220b, the electromagnetic forces may be generated in the direction F2 (downward in the illustrated implementation).

Also, the current C. P may flow out through the first fixed contactor 220a. When applying the Fleming's left-hand rule in the vicinity of the first fixed contactor 220a, the electromagnetic forces may be generated in the direction F2 (downward in the illustrated implementation).

<FIG> illustrates flows (paths) (M. P) of magnetic fields generated in the second electric connection condition and a direction F2 of electromagnetic forces generated accordingly.

In the second electric connection condition, the current C. P may be introduced through the first fixed contactor 220a. When applying the Fleming's left-hand rule in the vicinity of the first fixed contactor 220a, the electromagnetic forces may be generated in the direction F2 (upward in the illustrated implementation).

Also, the current C. P may flow out through the second fixed contactor 220b. When applying the Fleming's left-hand rule in the vicinity of the second fixed contactor 220b, the electromagnetic forces may be generated in the direction F2 (upward in the illustrated implementation).

That is, the electromagnetic forces generated in the first fixed contactor 220a and the second fixed contactor 220b may be applied in the same direction F2. Accordingly, compared to the case where the directions of the electromagnetic forces generated in the respective fixed contacts 220a and 220b are different from each other, arc extinguishing and discharge paths can be effectively formed.

This may result from that the paths M. P of the magnetic fields emitted from the magnetic force reinforcing member <NUM> may proceed toward the first magnet member <NUM> and the second magnet member <NUM>.

The DC relay <NUM> according to the implementation of the present disclosure may generate driving force for moving the movable core <NUM> toward the fixed core <NUM>. The driving force may be generated when the fixed core <NUM> is magnetized by a magnetic field formed by the coils <NUM> as control power is applied.

The DC relay <NUM> according to the implementation of the present disclosure includes the magnetic force reinforcing member <NUM>. The magnetic force reinforcing member <NUM> may reinforce the driving force for moving the movable core <NUM> toward the fixed core <NUM>.

Hereinafter, a process of strengthening the driving force of the movable core <NUM> in the DC relay <NUM> according to the implementation of the present disclosure will be described in detail with reference to <FIG>.

As described above, the core part <NUM> may be electrically connected to an external power supply (not illustrated) to receive control power. When control power is applied, the coils <NUM> may generate an electromagnetic field.

The fixed core <NUM> may be magnetized by the electromagnetic field generated by the coils <NUM>. The magnetized fixed core <NUM> may apply electromagnetic attractive force to the movable core <NUM> (see solid arrows in <FIG>). The movable core <NUM> may be accommodated inside the cylinder <NUM> to be movable up and down.

Accordingly, the movable core <NUM> may be moved up toward the fixed core <NUM>. At this time, the return spring <NUM> may store the restoring force by being compressed, as described above.

In this case, the magnetic force reinforcing member <NUM> may be located in the recessed portion <NUM> of the fixed core <NUM>. The magnetic force reinforcing member <NUM> may be implemented as a permanent magnet capable of generating a magnetic field by itself. That is, the magnetic force reinforcing member <NUM> may also apply electromagnetic attractive force to the movable core <NUM> (see dotted arrows in <FIG>).

Accordingly, the movable core <NUM> may receive the electromagnetic attractive force in a direction toward the fixed core <NUM> by the magnetized fixed core <NUM> and the magnetic force reinforcing member <NUM>. As a result, compared to the case where the movable core <NUM> is moved only by the electromagnetic attractive force generated by the fixed core <NUM>, stronger electromagnetic attractive force can be applied to the movable core <NUM>.

The electromagnetic attractive force applied by the magnetized fixed core <NUM> to the movable core <NUM> may be proportional to strength of the magnetic field generated by the coils <NUM>. In addition, the strength of the magnetic field generated by the coils <NUM> may be proportional to magnitude of control power applied from the outside, for example, magnitude of current or voltage.

Accordingly, the magnitude of control power to be applied to the coils <NUM> to apply the same electromagnetic attractive force to the movable core <NUM> can be reduced.

A magnetic force generating part <NUM> according to an implementation of the present disclosure includes a first magnet member <NUM> and a second magnet member <NUM>. In addition, a magnetic force reinforcing member <NUM> is located between the first magnet member <NUM> and the second magnet member <NUM>.

A first inner portion <NUM> and a second inner portion <NUM> of the first magnet member <NUM> and the second magnet member <NUM> that face each other have the same polarity. In addition, a first portion <NUM> of the magnetic force reinforcing member <NUM> has different polarity from the first inner portion <NUM> and the second inner portion <NUM>.

Accordingly, a path M. P of magnetic fields generated by the magnetic force generating part <NUM> may proceed in a direction from the first magnet member <NUM> and the second magnet member <NUM> toward the magnetic force reinforcing member <NUM>, or vice versa.

That is, a distance by which the path M. P of the magnetic fields moves within the arc chamber <NUM> can be reduced by the magnetic force reinforcing member <NUM>. This may result in reinforcing the flow M. P of the magnetic fields generated inside the DC relay <NUM>.

In addition, the magnetic force reinforcing member <NUM> may be coupled through a shaft <NUM>. The magnetic force reinforcing member <NUM> may be inserted into a recessed portion <NUM> which is recessed in an upper side of a fixed core <NUM>.

Accordingly, the magnetic force reinforcing member <NUM> can be provided without excessively changing an internal structure of the DC relay <NUM>.

In addition, the magnetic force reinforcing member <NUM> reinforces paths (flows) M. P of magnetic fields generated by the first magnet member <NUM> and the second magnet member <NUM>.

Accordingly, the paths M. P of the magnetic fields having sufficient strength can be formed without increasing volumes of the first magnet member <NUM> and the second magnet member <NUM>.

Also, the paths M. P of the magnetic fields generated in an arc chamber <NUM> can be formed to proceed from the first magnet member <NUM> and the second magnet member <NUM> toward the magnetic force reinforcing member <NUM>. Alternatively, the paths M. P of the magnetic fields can be formed to proceed from the magnetic force reinforcing member <NUM> toward the first magnet member <NUM> and the second magnet member <NUM>.

Accordingly, the flows M. P of the magnetic fields generated in the vicinity of fixed contacts 220a and 220b, respectively, can proceed in different directions. This may facilitate the change in direction for extinguishing arc according to an environment in which the DC relay <NUM> is provided. This may result in improving user convenience.

In addition, the flows M. P of the magnetic fields generated by the first magnet member <NUM>, the second magnet member <NUM>, and the magnetic force reinforcing member <NUM> can generate electromagnetic forces in the same direction near the respective fixed contacts 220a and 220b.

Therefore, even if a direction of current applied to each of the fixed contacts 220a and 220b is changed, arc generated in each of the fixed contacts 220a and 220b can receive electromagnetic forces all flowing toward any one of the front and the rear of the DC relay <NUM>. Accordingly, the user does not need to connect a power supply and a load to the DC relay <NUM> according to polarities, thereby increasing the user convenience.

In addition, when current flows on coils <NUM> and the fixed core <NUM> is magnetized, the fixed core <NUM> can apply electromagnetic attractive force to the movable core <NUM>. At this time, the magnetic force reinforcing member <NUM> can also apply electromagnetic attractive force to the movable core <NUM>.

Therefore, compared to a case where only electromagnetic attractive force by the fixed core <NUM> is applied to the movable core <NUM>, driving force applied to the movable core <NUM> can be increased. This may result in improving reliability of an operation of the DC relay <NUM>.

Even if magnitude of control power applied to the coils <NUM> is decreased, electromagnetic attractive force corresponding to the decrease can be compensated for by the magnetic force reinforcing member <NUM>. Accordingly, magnitude of control power for moving the movable core <NUM> can be decreased, resulting in improving power efficiency of the DC relay <NUM>.

Claim 1:
A Direct Current (DC) relay (<NUM>) comprising:
a fixed contactor (<NUM>);
a movable contactor (<NUM>) extending in a longitudinal direction and having one side located adjacent to the fixed contactor (<NUM>) to be brought into contact with or separated from the fixed contactor (<NUM>);
a plurality of magnet members (<NUM>, <NUM>) located adjacent to both end portions of the movable contact (<NUM>) in the longitudinal direction, respectively, to generate magnetic fields; and
a magnetic force reinforcing member (<NUM>) located between the plurality of magnet members (<NUM>, <NUM>) to form magnetic fields together with the plurality of magnet members (<NUM>, <NUM>),
wherein the plurality of magnet members (<NUM>, <NUM>) comprise:
a first magnet member (<NUM>) located adjacent to one end portion of the movable contactor (<NUM>) in the longitudinal direction; and
a second magnet member (<NUM>) located adjacent to another end portion of the movable contactor (<NUM>) opposite to the one end portion of the movable contactor (<NUM>) in the longitudinal direction,
wherein one side of the first magnet member (<NUM>) and one side of the second magnet member (<NUM>) facing each other have the same polarity, characterized in that the magnetic force reinforcing member (<NUM>) is located on another side of the movable contactor (<NUM>) opposite to the one side of the movable contactor (<NUM>), and
wherein one side of the magnetic force reinforcing member (<NUM>) facing the movable contactor (<NUM>) has a polarity different from that of each one side of the first magnet member (<NUM>) and the second magnet member (<NUM>).