Patent Description:
An electromagnetic switch is an electrical appliance that can frequently switch on/off, carry, and turn on/off a normal current and a specified overload current. A working principle of the electromagnetic switch is that a current flows through coils to generate a magnetic field to switch on/off a contact, thereby controlling a load. The electromagnetic switch usually includes a contactor and a relay.

Currently, a voltage of a battery pack in most electric vehicles reaches <NUM> VDC. Voltages of some battery packs reach <NUM> VDC to <NUM> VDC. A surge voltage, electrical spacing, and a creepage distance corresponding to a high/low-voltage system and a component of an entire vehicle correspondingly increase. Currently, isolation is not implemented between a high voltage and a low voltage of an electromagnetic switch of a conventional epoxy package and some ceramic packages. After a moving contact is connected to a fixed contact, a moving iron core, a fixed iron core, and a magnet yoke of an electromagnetic system are all charged. As a result, electrical spacing and a creepage distance between a high-voltage contact system and a low-voltage coil system do not meet a basic insulation requirement. There is a high safety risk. Therefore, a relatively large safety accident is likely to occur.

The document <CIT> discloses a pushing mechanism for relays and a relay comprising the pushing mechanism.

The document <CIT> discloses a DC contactor with adjustable structures of insulating bushing and insulating washer.

The document <CIT> discloses a reversing contactor for commutation control of current.

The document <CIT> Al discloses a relay with auxiliary conduction and detection structures.

Embodiments of this application provide a contact apparatus and an electromagnetic switch, to reduce a safety risk and improve safety reliability.

According to a first aspect, this application provides a contact apparatus applied to an electromagnetic switch. The contact apparatus includes a fixed contact and a moving contact component. The moving contact component includes a push rod, a contact bracket, an insulated sleeve, a moving contact, and a contact spring. The insulated sleeve is fixedly sleeved on a first end of the push rod. A second end of the push rod is configured to connect a drive apparatus. The contact bracket is fixedly sleeved on the insulated sleeve. The moving contact and the contact spring are both flexibly sleeved on the insulated sleeve. The contact spring elastically abuts between the moving contact and the contact bracket. The moving contact and the fixed contact are disposed relative to each other in an extension direction of the push rod. The moving contact can be driven by the push rod to be connected to the fixed contact.

Because the insulated sleeve is sleeved on the first end of the push rod, and the moving contact is sleeved on the insulated sleeve, the insulated sleeve can insulate the push rod from the moving contact. When driven by the drive apparatus, the push rod connects the moving contact to the fixed contact. The insulated sleeve can fully isolate the push rod from a high-voltage contact loop in the electromagnetic switch. In this way, when the electromagnetic switch switches a large-current and direct-current high-voltage load, a low-voltage coil part of the electromagnetic switch is not affected and damaged by a large current and a high voltage, thereby avoiding a safety problem caused by a breakdown between a high voltage and a low voltage, that is, improving safety reliability of the electromagnetic switch.

According to the first aspect, the contact bracket includes a frame structure comprising a first support kit and a second support kit that are disposed relative to each other. A first connection hole is disposed on the first support kit. A second connection hole is disposed on the second support kit. The first end of the push rod fixedly passes through the first connection hole and the second connection hole. The moving contact is located between the first support kit and the contact spring. The contact spring is located between the moving contact and the second support kit.

The insulated sleeve extends from the first connection hole of the first support kit to the second connection hole of the second support kit along the push rod. The moving contact can move along an outer wall of the insulated sleeve, to improve an overrun of the moving contact.

With reference to the first aspect, in a first possible implementation of the first aspect, the first connection hole is a through hole passing through the first support kit. The insulated sleeve includes a guide part and an abutting flange disposed on an end of the guide part. The guide part fixedly passes through the first connection hole and the second connection hole. The abutting flange abuts against a side of the first support kit away from the second support kit, to conveniently mount the insulated sleeve on the contact bracket and prevent the insulated sleeve from being separated from the contact bracket.

With reference to any one of the first aspect or the first possible implementation of the first aspect, in a second possible implementation of the first aspect, the first connection hole includes a first installation section and a second installation section. The first installation section is disposed on an end of the first connection hole away from the second support kit. An aperture of the first installation section is greater than an aperture of the second installation section. The abutting flange is fixedly accommodated in the first installation section and abuts against a bottom wall of the first installation section, to conveniently mount the insulated sleeve on the contact bracket.

With reference to any one of the first aspect or the first to the second possible implementations of the first aspect, in a third possible implementation of the first aspect, the contact apparatus further includes a circlip. A slot is disposed on the first end of the push rod. The slot is located on the side of the first support kit away from the second support kit. The circlip is clamped into the slot and abuts against the abutting flange, to prevent the insulated sleeve from moving in an axial direction of the push rod.

With reference to any one of the first aspect or the first to the third possible implementations of the first aspect, in a fourth possible implementation of the first aspect, the contact apparatus further includes a gasket. The gasket is located between an abutting part and the circlip, to prevent looseness between the insulated sleeve and the circlip and also prevent damage of the circlip to the insulated sleeve, thereby prolonging a service life of the insulated sleeve.

With reference to any one of the first aspect or the first to the fourth possible implementations of the first aspect, in a fifth possible implementation of the first aspect, the second support kit includes a board body and a convex part disposed on the board body facing the first support kit. The contact spring is sleeved outside the convex part. The contact spring elastically abuts between the moving contact and the board body.

With reference to any one of the first aspect or the first to the fifth possible implementations of the first aspect, in a sixth possible implementation of the first aspect, the contact apparatus further includes a base. The fixed contact is fixed to the base. At least a part of the fixed contact is located in the base. The first end of the push rod extends into the base. The contact bracket, the insulated sleeve, the contact spring, and the moving contact bracket are all located in the base. The second end of the push rod is exposed outside the base. The base can protect the fixed contact and the moving contact, and prevent external interference to movement of the moving contact component.

With reference to any one of the first aspect or the first to the sixth possible implementations of the first aspect, in an seventh possible implementation of the first aspect, the push rod includes a rod body and a convex limiting part disposed in a circumferential direction of the rod body. The insulated sleeve is sleeved on a first end of the rod body. The limiting part is exposed outside the base to abut against a first abutting part in the first insertion through hole of the fixed iron core, to prevent the push rod from deviating from an original position in a process of returning to the original position.

According to a second aspect, this application further provides an electromagnetic switch, including the foregoing contact apparatus and a drive apparatus. A base is fixedly connected to the drive apparatus. The drive apparatus includes a magnet yoke, a coil skeleton, coils, a fixed iron core, a moving iron core, and a reset spring. The coil skeleton is fixedly accommodated in the magnet yoke. The coils are sleeved outside the coil skeleton. The fixed iron core and the moving iron core are accommodated in the coil skeleton along an axial direction of the coil skeleton. The fixed iron core is fixed on an end of the coil skeleton close to the contact bracket. A second end of the push rod is fixedly connected to the moving iron core. The push rod flexibly passes through the fixed iron core and the magnet yoke. The reset spring is sleeved on the push rod. The reset spring abuts between the fixed iron core and the moving iron core. The fixed iron core can be magnetized after the coils are charged to generate suction force, so that the moving iron core moves towards the fixed iron core under a function of the suction force.

When the moving contact is connected to the fixed contact, the coils, the magnet yoke, the fixed iron core, the moving iron core, and the push rod are all charged. The coils are provided with a low-voltage (for example, <NUM> V) current. The magnet yoke, the fixed iron core, the moving iron core, and the push rod form a high-voltage push rod loop. The moving contact and the fixed contact form a high-voltage contact loop. Because an insulated sleeve is fixedly sleeved on a first end of the push rod, the moving contact is flexibly sleeved on the insulated sleeve, so that electrical insulation is well maintained between the moving contact and the push rod, and the high-voltage contact loop is fully isolated from the low-voltage coils. In this way, when the electromagnetic switch switches a large-current and direct-current high-voltage load, the low-voltage coils of the electromagnetic switch is not affected and damaged by a large current and a high voltage, thereby avoiding a safety problem caused by a breakdown between a high voltage and a low voltage, that is, improving safety reliability of the electromagnetic switch.

With reference to the second aspect, in a first possible implementation of the second aspect, a first insertion through hole is disposed on the fixed iron core. A first convex abutting part is disposed on an inner wall of the first insertion through hole. A second insertion through hole is disposed on the moving iron core. The first insertion through hole and the second insertion through hole are coaxially disposed. A second convex abutting part is disposed on an inner wall of the second insertion through hole. The reset spring abuts between the first abutting part and the second abutting part. The push rod passes through the first insertion through hole and the second insertion through hole. The first insertion through hole and the second insertion through hole can limit and guide movement of the push rod.

With reference to the second aspect or the first possible implementation of the second aspect, in a second possible implementation of the second aspect, the magnet yoke includes an enclosure and a cover. The enclosure has an opening. The cover fixedly covers the opening of the enclosure. A mounting hole is disposed on an end of the enclosure away from the cover. The magnet yoke further includes a convex positioning part on an inner wall of the enclosure. The positioning part is disposed around the mounting hole. The coil skeleton is of a hollow structure. An abutting step is disposed on an inner wall of the coil skeleton. The coil skeleton is sleeved on the positioning part. The positioning part abuts against the abutting step, to prevent the coil skeleton from moving in the magnet yoke.

With reference to any one of the second aspect or the first and the second possible implementations of the second aspect, in the second possible implementation of the second aspect, the drive apparatus further includes a sealing sleeve. The sealing sleeve is accommodated in the coil skeleton and covers the fixed iron core and the moving iron core in a sealing manner, to seal the coil skeleton.

An electromagnetic switch in the embodiments of this application is an electrical appliance that can frequently switch on/off, carry, and turn on/off a normal current and a specified overload current. A working principle of the electromagnetic switch is that a current flows through coils to generate a magnetic field to switch on a contact, thereby controlling a load. The electromagnetic switch usually includes a contactor and an electromagnetic relay.

A direct-current contactor is used as an example for description in the embodiments of this application.

With reference to <FIG>, an electromagnetic switch <NUM> provided in an implementation of this application includes a drive apparatus <NUM> and a contact apparatus <NUM> disposed on the drive apparatus <NUM>. The electromagnetic switch <NUM> shown in <FIG> generally further includes a housing. For example, the contact apparatus <NUM> and the drive apparatus <NUM> are accommodated in the hollow square housing. The schematic diagram shows the electromagnetic switch <NUM> without the housing in the embodiments of this application. The drive apparatus <NUM> uses an electromagnetic field generated by coils to drive and control on/off of the contact apparatus <NUM>. The electromagnetic switch <NUM> in this implementation is a normally open contactor whose initial status is that a contact is disconnected. The electromagnetic switch <NUM> in another implementation may alternatively be a normally closed contactor whose initial status is that a contact is connected.

With reference to <FIG>, the drive apparatus <NUM> includes a coil skeleton <NUM>, coils <NUM>, a magnet yoke <NUM>, a fixed iron core <NUM>, a moving iron core <NUM>, a sealing sleeve <NUM>, and a reset spring <NUM>.

Specifically, the coil skeleton <NUM> includes a hollow cylindrical body part <NUM>. Convex flange parts <NUM> are formed on two ends in an axial direction of the body part <NUM> to a radial direction. The axial direction is a direction of a rotation central axis of an object (for example, a cylinder), that is, a direction parallel to the central axis. The radial direction is perpendicular to the axial direction, that is, a direction of a radius or a diameter of an end-face circle of the cylinder.

The coils <NUM> are wound on the body part <NUM> of the coil skeleton <NUM> and are located between the two convex flange parts <NUM> on the two ends of the body part <NUM>. It may be understood that the two ends of the coils <NUM> are further connected to coil terminals (not shown in the figure). For example, the coil terminals may be made of a conductive material such as copper. In this way, the coils <NUM> may be charged by using the coil terminals to drive the contact apparatus <NUM>.

The magnet yoke <NUM> is made of a magnetic material and covers the coil skeleton <NUM>. In an implementation of this application, the magnet yoke <NUM> is approximately in a rectangle shape. The magnet yoke <NUM> includes an enclosure <NUM> and a cover <NUM>. The enclosure <NUM> has an opening. The cover <NUM> fixedly covers the opening of the enclosure <NUM>. A mounting hole <NUM> is disposed on an end of the enclosure <NUM> away from the cover <NUM>. The magnet yoke <NUM> further includes a convex positioning part <NUM> on an inner wall of the enclosure <NUM>. The positioning part <NUM> is disposed around the mounting hole <NUM>. The body part <NUM> is of a hollow structure. An abutting step <NUM> is disposed on an inner wall of the body part <NUM>. The body part <NUM> is sleeved on the positioning part <NUM>. The positioning part <NUM> abuts against the abutting step <NUM>, to prevent the coil skeleton <NUM> from moving in the magnet yoke <NUM>. One convex flange part <NUM> abuts against a face of the cover <NUM> facing the enclosure <NUM>. The other convex flange part <NUM> abuts against the inner wall of the enclosure <NUM>. It may be understood that the enclosure <NUM> and the positioning part <NUM> may be integrally formed, or may be separately manufactured. A structure of the magnet yoke <NUM> is not limited. For example, the mounting hole <NUM> and the positioning part <NUM> may be removed from the magnet yoke <NUM>. The coil skeleton <NUM> is directly fastened to the magnet yoke <NUM>. A structure of the coil skeleton <NUM> is not limited. Ends of the body part <NUM> abut against the cover <NUM> and the enclosure <NUM>.

The sealing sleeve <NUM> fixedly passes through the body part <NUM>, to form enclosed space in the body part <NUM>. In this implementation, the sealing sleeve <NUM> is made of a non-ferromagnetic material.

The fixed iron core <NUM> and the moving iron core <NUM> are disposed in the sealing sleeve <NUM> in the axial direction of the body part <NUM> of the coil skeleton <NUM>. The fixed iron core <NUM> is fixedly disposed in the sealing sleeve <NUM> and is close to an upper cover <NUM>. There is a gap between the fixed iron core <NUM> and the moving iron core <NUM>, to reserve specific moving space for the moving iron core <NUM>. After the coils <NUM> are charged, the fixed iron core <NUM> is magnetized to generate suction force, and the moving iron core <NUM> moves towards the fixed iron core <NUM> under a function of the suction force. In this implementation, the fixed iron core <NUM> and the moving iron core <NUM> are generally cylindrical. It may be understood that shapes of the fixed iron core <NUM> and the moving iron core <NUM> are not limited.

In this embodiment of this application, outer diameters of the fixed iron core <NUM> and the moving iron core <NUM> are approximately the same as an inner diameter of the sealing sleeve <NUM>. The fixed iron core <NUM> is disposed on an opening side of the sealing sleeve <NUM>. The moving iron core <NUM> moves in the sealing sleeve <NUM>. It may be understood that the sealing sleeve <NUM> may be alternatively removed. For example, the coil skeleton <NUM> is directly set to a structure that is sealed on one end. The fixed iron core <NUM> and the moving iron core <NUM> are accommodated in the coil skeleton <NUM>.

The reset spring <NUM> is sandwiched between the fixed iron core <NUM> and the moving iron core <NUM>. The reset spring <NUM> is configured to impose, on the moving iron core <NUM>, driving force whose direction is opposite to a direction of the suction force generated by the fixed iron core <NUM>, so that the moving iron core <NUM> is driven to be returned to an original position when the coils <NUM> are discharged, that is, the moving iron core <NUM> of the drive apparatus <NUM> is driven to move to a bottom end of the sealing sleeve <NUM> away from the cover <NUM>.

It should be noted that in this embodiment of this application, a first insertion through hole <NUM> is disposed on the fixed iron core <NUM>, and a first convex abutting part <NUM> is disposed on an inner wall of the first insertion through hole <NUM>. A second insertion through hole <NUM> is disposed on the moving iron core <NUM>. The first insertion through hole <NUM> and the second insertion through hole <NUM> are coaxially disposed. A second convex abutting part <NUM> is disposed on an inner wall of the second insertion through hole <NUM>. Two ends of the reset spring <NUM> respectively abut between the first abutting part <NUM> and the second abutting part <NUM>.

With reference to <FIG>, the contact apparatus <NUM> includes a base <NUM>, a fixed contact <NUM>, and a moving contact component <NUM>.

The base <NUM> is fastened to the cover <NUM> of the magnet yoke <NUM>. A through hole <NUM> is disposed on the top of the base <NUM> away from the drive apparatus <NUM>. The fixed contact <NUM> passes through the corresponding through hole <NUM> and fixedly extends into the base <NUM>. In this embodiment of this application, the base <NUM> is made of a heat-resistant material (for example, ceramic). The fixed contact <NUM> is made of a conductive material such as a copper material.

The moving contact component <NUM> includes a push rod <NUM>, an insulated sleeve <NUM>, a contact bracket <NUM>, a moving contact <NUM>, and a contact spring <NUM>.

A first end of the push rod <NUM> is located in the base <NUM>. A second end of the push rod <NUM> extends into and passes through the fixed iron core <NUM>, and is fixedly connected to the moving iron core <NUM>, to implement connection to the drive apparatus <NUM>. The insulated sleeve <NUM> is fixedly sleeved on the first end of the push rod <NUM> and is accommodated in the base <NUM>. The contact bracket <NUM> is fixedly sleeved outside the insulated sleeve <NUM>. The moving contact <NUM> and the contact spring <NUM> are both flexibly sleeved on the insulated sleeve <NUM> and are located in the contact bracket <NUM>. The contact spring <NUM> elastically abuts between the moving contact <NUM> and the contact bracket <NUM>. The moving contact <NUM> and the fixed contact <NUM> are disposed relative to each other in an extension direction of the push rod <NUM>. The moving contact <NUM> can be driven by the push rod <NUM> to be connected to the fixed contact <NUM>.

When the moving contact <NUM> is connected to the fixed contact <NUM>, the coils <NUM>, the magnet yoke <NUM>, the fixed iron core <NUM>, the moving iron core <NUM>, and the push rod <NUM> are all charged. The coils <NUM> are provided with a low-voltage (for example, <NUM> V) current. The magnet yoke <NUM>, the fixed iron core <NUM>, the moving iron core <NUM>, and the push rod <NUM> form a high-voltage push rod part (shown by using a relatively thin dashed-line part in <FIG>). The moving contact <NUM> and the fixed contact <NUM> form a high-voltage contact loop (shown by using a relatively thick dashed-line in <FIG>). Because the insulated sleeve <NUM> is fixedly sleeved on the first end of the push rod <NUM>, the moving contact <NUM> is flexibly sleeved on the insulated sleeve <NUM>, so that electrical insulation is well maintained between the moving contact <NUM> and the push rod <NUM>, and the high-voltage contact loop is fully isolated from the low-voltage coils <NUM>. In this way, when the electromagnetic switch <NUM> switches a large-current and direct-current high-voltage load, the low-voltage coils <NUM> of the electromagnetic switch <NUM> is not affected and damaged by a large current and a high voltage, thereby avoiding a safety problem caused by a breakdown between a high voltage and a low voltage, that is, improving safety reliability of the electromagnetic switch <NUM>.

More specifically, the push rod <NUM> includes a rod body <NUM> and a convex limiting part <NUM> disposed in a circumferential direction of the rod body <NUM>. The second end of the rod body <NUM> passes through the first insertion through hole <NUM> of the fixed iron core <NUM> and fixedly passes through the second insertion through hole <NUM> of the moving iron core <NUM>. In this way, the first insertion through hole <NUM> and the second insertion through hole <NUM> can guide and limit movement of the push rod <NUM>. The first end of the rod body <NUM> is exposed outside the magnet yoke <NUM> and extends into the base <NUM>. The limiting part <NUM> is configured to abut against a side of the first abutting part <NUM> away from the moving iron core <NUM>, to abut against the first abutting part <NUM> when the push rod <NUM> moves toward the moving iron core <NUM> and returns to the original position, thereby preventing the push rod <NUM> from being deviated from the original position.

The insulated sleeve <NUM> is fixedly sleeved on the first end of the push rod <NUM> and is accommodated in the base <NUM>. The contact bracket <NUM> is fixedly sleeved on the insulated sleeve <NUM>. The moving contact <NUM> and the contact spring <NUM> are both flexibly sleeved on the insulated sleeve <NUM>. The contact spring <NUM> elastically abuts between the moving contact <NUM> and the contact bracket <NUM>.

The contact bracket <NUM> is approximately a frame structure. The contact bracket <NUM> includes a first support kit <NUM> and a second support kit <NUM> that are disposed relative to each other. The second support kit <NUM> is disposed close to the magnet yoke <NUM>. The second support kit <NUM> is made of an insulating material. It may be understood that the contact bracket <NUM> may be all made of an insulating material, or may be disposed according to an actual requirement. A first connection hole <NUM> is disposed on the first support kit <NUM>. A second connection hole <NUM> is disposed on the second support kit <NUM>. The insulated sleeve <NUM> fixedly passes through the first connection hole <NUM> and the second connection hole <NUM>. In other words, the insulated sleeve <NUM> extends from the first connection hole <NUM> to the second connection hole <NUM> along the rod body <NUM>. The moving contact <NUM> can move along an outer wall of the insulated sleeve <NUM>, to improve an overrun of the moving contact <NUM>.

In this implementation, the first connection hole <NUM> includes a first installation section <NUM> and a second installation section <NUM>. The first installation section <NUM> is disposed on an end of the first connection hole <NUM> away from the second support kit <NUM>. An aperture of the first installation section <NUM> is greater than an aperture of the second installation section <NUM>. The insulated sleeve <NUM> includes a guide part <NUM> and an abutting flange <NUM> disposed on an end of the guide part <NUM>. The guide part <NUM> fixedly passes through the first connection hole <NUM> and the second connection hole <NUM>. The abutting flange <NUM> is fixedly accommodated in the first installation section <NUM> and abuts against a bottom wall of the first installation section <NUM>. The second support kit <NUM> includes a board body <NUM> and a convex part <NUM> disposed on the board body <NUM> facing the first support kit <NUM>. The second connection hole <NUM> passes through the board body <NUM> and the convex part <NUM>. The contact spring <NUM> is sleeved outside the convex part <NUM>. The contact spring <NUM> elastically abuts between the moving contact <NUM> and the board body <NUM>.

It may be understood that the first connection hole <NUM> may be not a through hole passing through the first support kit <NUM>. The first connection hole <NUM> is a blind hole disposed on a side of the first support kit <NUM> facing the second support kit <NUM>. The abutting flange <NUM> is located on a side of the first support kit <NUM> away from the second support kit <NUM> and abuts against the first support kit <NUM>.

A slot <NUM> is disposed on the first end of the push rod <NUM>. The slot <NUM> is located on the side of the first support kit <NUM> away from the second support kit <NUM>. The moving contact component <NUM> further includes a circlip <NUM> and a gasket <NUM>. The circlip <NUM> is clamped into the slot <NUM>. The gasket <NUM> is sleeved on the push rod <NUM>. The gasket <NUM> is located between the circlip <NUM> and the abutting flange <NUM>. The circlip <NUM> is configured to: prevent the insulated sleeve <NUM> from leaving the push rod <NUM>, and prevent the insulated sleeve <NUM> from moving in the axial direction of the push rod <NUM>. The gasket <NUM> is configured to: prevent looseness between the insulated sleeve <NUM> and the circlip <NUM>, and prevent damage of the circlip <NUM> to the insulated sleeve <NUM>, thereby prolonging a service life of the insulated sleeve <NUM>.

Claim 1:
A contact apparatus (<NUM>) applied to an electromagnetic switch (<NUM>), wherein the contact apparatus (<NUM>) comprises a fixed contact (<NUM>) and a moving contact component (<NUM>), the moving contact component (<NUM>) comprises a push rod (<NUM>), a contact bracket (<NUM>), an insulated sleeve (<NUM>), a moving contact (<NUM>), and a contact spring (<NUM>), the insulated sleeve (<NUM>) is fixedly sleeved on a first end of the push rod (<NUM>), a second end of the push rod (<NUM>) is configured to connect a drive apparatus (<NUM>), the contact bracket (<NUM>) is fixedly sleeved on the insulated sleeve (<NUM>), the moving contact (<NUM>) and the contact spring (<NUM>) are both flexibly sleeved on the insulated sleeve (<NUM>), the contact spring (<NUM>) elastically abuts between the moving contact (<NUM>) and the contact bracket (<NUM>), the moving contact (<NUM>) and the fixed contact (<NUM>) are disposed relative to each other in an extension direction of the push rod (<NUM>), and the moving contact (<NUM>) is capable of being driven by the push rod (<NUM>) to be connected to the fixed contact (<NUM>), characterised in that the contact bracket (<NUM>) comprises a frame structure comprising a first support kit (<NUM>) and a second support kit (<NUM>) that are disposed relative to each other, a first connection hole (<NUM>) is disposed on the first support kit (<NUM>), a second connection hole (<NUM>) is disposed on the second support kit (<NUM>), the first end of the push rod (<NUM>) fixedly passes through the first connection hole (<NUM>) and the second connection hole (<NUM>), the moving contact (<NUM>) is located between the first support kit (<NUM>) and the contact spring (<NUM>), and the contact spring (<NUM>) is located between the moving contact (<NUM>) and the second support kit (<NUM>).