Electromagnetic contact device

Abstract

An electromagnetic contact device according to one embodiment of the present invention comprises: a coil wound around a bobbin; the movable iron core is driven along the axial direction under the action of the coil; a pair of fixed contacts for applying a DC power source; a movable contact seat which operates in conjunction with the movable iron core, moves up and down in a reciprocating manner, and can be in contact with the pair of fixed contacts; a yoke made of a magnetic material and configured so as to surround at least a part of the outside of the coil; a yoke plate fixedly disposed on the upper side of the yoke; a fixed iron core which is made of a magnetic body, passes through the central part of the bobbin, and is fixedly arranged by the yoke; and an annular permanent magnet arranged on the upper side of the fixed iron core, wherein the suction force of the movable iron core is increased by the magnetic flux generated by the coil and the magnetic flux generated by the permanent magnet.

Description

Technical Field

[0001] The present invention relates to an electromagnetic contact device, and more particularly, to an electromagnetic contact device having a structure that improves the suction force of a movable iron core by superimposing the magnetic flux of an electromagnet and the magnetic flux of a permanent magnet. Background Art

[0002] DC switch contact devices can be used in DC power transmission systems such as electric vehicles, slow charging devices, and fast charging devices that utilize battery energy. In recent years, due to problems such as battery fires in energy storage devices, electric buses, and fast charging systems, higher requirements have been placed on reliability. The contact reliability of the contacts is related to human life and safety, so it is very important to precisely control the battery system to ensure safety.

[0003] In recent years, with the increase in the energizing current, the volume of DC switch contact device products has been continuously increasing, posing higher requirements for the contact reliability of the contact portion of the movable contact and the contact portion of the fixed contact. A contact device that can handle battery short circuits is needed. In electric vehicle applications, multiple limiting conditions such as performance, safety, size, weight, and operating power consumption also need to be met. The electromagnetic repulsive force between the contacts generated by the short-circuit current will exceed the compression force of the contact pressure spring of the contacts. If the electromagnetic suction force generated by the coil excitation current cannot overcome the electromagnetic repulsive force caused by the short circuit, the contact pressure spring will exceed its limit, causing the contacts to separate. This phenomenon may lead to product burnout, explosion, or fire, making it difficult to achieve the protection coordination of electrical safety devices.

[0004] Based on such problems, in order to increase the magnetomotive force of the excitation coil, enhance the contact pressure of the contacts, and increase the elastic force of the contact pressure spring of the contacts, inefficient products that increase the power consumption of the excitation coil to improve the suction force of the iron core and enhance the strength of the contact pressure spring are used.

[0005] In a general DC relay contact device, if the coil is energized using the electromagnet of the coil, the movable iron core moves axially due to the magnetic force of the electromagnet. The pivot pin integrally connected to the movable iron core drives the movable contact seat to move up and down reciprocally. During this process, the movable contact and the fixed contact come into contact to connect the electrical circuit. When the power supply of the coil is cut off, the movable contact seat that was originally in contact with the fixed contact is reset under the reset action of the return spring compressed axially downward, thereby cutting off the electrical circuit.

[0006] In a traditional DC contact device, a coil is wound around a spool to form an electromagnet, a movable iron core is made of a magnetic material, a permanent magnet is provided on a fixed iron core, or an auxiliary magnetic yoke of a magnetic material is made on the magnetic pole surface of the permanent magnet, and a permanent magnetic body is provided at the central part of the fixed iron core and the movable iron core, thus generating a leakage magnetic flux of the permanent magnet. In addition, a certain distance (gap) is maintained between the fixed iron core and the movable iron core, and the magnetic fluxes of the movable iron core reciprocating axially and the annular permanent magnet provided with a certain gap cannot achieve the best efficiency. In addition, as the combined magnetic flux generated by the electromagnet made of a coil and the permanent magnet, there is a lot of leakage magnetic flux during use, and there are also problems of an increase in the number of components used and an increase in the working hours.

[0007] In addition, in order to enhance the suction force of the movable iron core, a primary coil and a secondary coil are wound around the same spool. When the primary coil is working, a large amount of current flows through it in a short time to make the movable iron core operate. After the movable iron core is adsorbed to the fixed iron core, only the secondary coil bears the current required to maintain its adsorbed state, and at the same time, the current of the primary coil is cut off. In order to implement such primary and secondary coils, electronic components are used, or an auxiliary normally closed contact is used for switching, or in order to reduce energy consumption, a control element composed of Pulse Width Modulation electronic components is also used.

[0008] In addition, recently, in order to ensure the compact size and safety of a high-voltage relay for electric vehicles, a contact device is made on an airtight contact box, which can prevent the arc generated when the contact is opened and closed from being released outward. Therefore, in order to prevent battery fires and protect new energy devices, a structure is currently being developed, that is, an insulating gas is sealed inside the airtight contact device, and a permanent magnet for driving the arc is used to quickly guide, cool and diffuse the arc to make it easy to cut off.

[0009] The electromagnet of the traditional contact device is manufactured and used in the following way: according to the rated current flowing through, the size of the product is increased, and at the same time, the size of the excitation coil provided inside is increased to increase the operating effect and suction force of the movable iron core.

[0010] In addition, in order to increase the volume and contact pressure of the movable contact seat, the fixed iron core, the spool, the movable iron core, etc. must be increased proportionally according to the current flowing through the contact seat. Therefore, a contact device that increases the excitation current generated by the reciprocating motion of the movable iron core up and down has been used.

[0011] Therefore, there is a need for a new, economical and practical structure of a contact device that can achieve the maximum synthetic magnetic flux through the efficient arrangement of permanent magnets and electromagnets, thereby reducing the overall size of the product and lowering power consumption. Summary of the Invention

[0012] (Problems to be Solved by the Invention)

[0013] The present invention is a technical solution for solving the problems of the above-mentioned prior art. Its purpose is to provide a miniaturized electromagnetic contact device. As a method for realizing the miniaturization of an electromagnet and reducing power consumption, this device can ensure that the movable iron core has a stronger suction force by making the magnetic flux of the exciting coil and the magnetic flux of the permanent magnet act synergistically to synthesize the magnetic flux.

[0014] Furthermore, the purpose of the present invention is to provide a contact device that can effectively utilize the synthetic magnetic flux of the magnetic flux Φ1 of the electromagnet and the magnetic flux Φ2 of the permanent magnet. The magnetic flux generated in the coil by applying the rated voltage to the coil is combined with the magnetic flux of the permanent magnet, so that the synthetic magnetic flux is utilized during the operation of the movable iron core, and it can increase the initial suction force of the movable iron core and the holding force after the movable iron core operates, reduce power consumption, reduce the size, and miniaturize the electromagnet of the exciting coil and the electromagnet device of the permanent magnet that increase the suction force.

[0015] Furthermore, the purpose of the present invention is to provide a contact device used during the charging and discharging of a battery. This device can increase the contact force between the fixed contact and the movable contact seat, thereby expanding the volume of the energized contact seat to increase the capacity. It can also enhance the compression force of the contact pressure spring for maintaining the contact pressure, and as the contact pressure increases, the repulsive force generated between the contacts due to battery short - circuit can be suppressed.

[0016] Furthermore, the purpose of the present invention is to provide a contact device that can generate a strong suction force that overlaps the magnetic fluxes of the electromagnet and the permanent magnet. Insert a circular - ring - shaped permanent magnet into the upper - side end of the assembled fixed iron core and make it adsorb on the yoke plate. Assemble by pasting a circular plate - shaped washer made of magnetic material on its upper part, and then install the yoke plate on the left and right sides of the yoke, and fix the yoke plate by bending the yoke.

[0017] Furthermore, the purpose of the present invention is to provide a contact device with a structure that reduces the driving range of an electric vehicle. In the hermetic contact device included in a high - voltage contact switch device applicable to fields such as new energy, electric vehicles, DC power control, and battery power control, it achieves lower power consumption that is more economical than the energizing current and minimizes the volume.

[0018] The problems to be solved by the present invention are not limited to the above-mentioned content. Other technical problems not mentioned can be clearly understood by those of ordinary skill in the art from the following description.

[0019] (Measures for solving the problems)

[0020] An electromagnetic contact device according to an embodiment of the present invention includes: a coil wound around a bobbin; a movable iron core axially driven by the coil; a pair of fixed contacts for applying a DC power supply; a movable contact seat that operates in conjunction with the movable iron core and reciprocates up and down to be able to contact the pair of fixed contacts; a yoke made of a magnetic material and configured to surround at least a part of the outside of the coil; a yoke plate fixedly disposed on the upper side of the yoke; a fixed iron core made of a magnetic material, passing through the central portion of the bobbin and fixedly disposed by the yoke; and an annular permanent magnet disposed on the upper side of the fixed iron core, increasing the suction force of the movable iron core through the magnetic flux generated by the coil and the magnetic flux generated by the permanent magnet.

[0021] In addition, the permanent magnet may have a magnetization surface in the axial direction.

[0022] In addition, the permanent magnet may be mounted on the upper end face of the fixed iron core.

[0023] In addition, a plate-shaped washer made of a magnetic material may be mounted on the upper layer portion of the permanent magnet.

[0024] In addition, a closed loop of magnetic flux may be formed without a gap between the yoke, the fixed iron core, the permanent magnet, the washer, and the yoke plate.

[0025] (Effects of the invention)

[0026] According to the present invention, there is provided a contact device capable of remotely controlling a switch using an electromagnet. The exciting coil of the switch contact device used during battery charging and discharging and the exciting coil are optimally combined with a permanent magnet to increase the suction force of the movable iron core, increase the contact pressure of the contacts, and minimize power consumption. As such a contact device, using the magnetic fluxes of the electromagnet and the permanent magnet, the movable contact driven by the coil power supply can associate the enhanced suction force with the contact pressure of the contacts even when the operating coil has low power consumption, thereby ensuring the contact reliability of the contacts and an increase in the current flowing through the contacts.

[0027] In addition, according to the present invention, there can be provided a contact device as follows: that is, an annular permanent magnet is adsorbed and combined to the upper end face of the fixed iron core, so that the leakage magnetic flux of the permanent magnet can be reduced, and the operating suction force formed by the coil and the permanent magnet can be increased, thereby increasing the contact pressure of the contacts.

[0028] In addition, according to the present invention, the polarities of the exciting coil for operating the coil part by a DC power supply and the permanent magnet need to be set in the same direction, and the power supply of the exciting coil becomes a contact device with current directivity due to the polarity of the internally provided permanent magnet, enabling a contact device that can be made inoperable when the polarity of the terminal led out from the coil is reversed and power is input.

[0029] In addition, according to the present invention, a contact device can be provided as follows: that is, when power is applied to the exciting coil, magnetic flux flows from the fixed iron core to the internal movable iron core, then from the movable iron core to the yoke plate, and then from the yoke plate to the left and right sides of the yoke, thus forming a loop to constitute a closed circuit, so that the movable iron core can exert the maximum suction force. At this time, a part of the magnetic flux starts from the N pole of the permanent magnet, passes through the movable iron core and the yoke plate, and reaches the S pole of the permanent magnet to form a loop of the magnetic closed circuit, thereby doubling the adsorption holding force of the movable iron core on the yoke plate.

[0030] The effects of the present invention are not limited to the above-mentioned content, and other effects not mentioned can be clearly understood by those of ordinary skill in the art from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 An assembly drawing for explaining the structure of a DC contact device according to an embodiment of the present invention.

[0032] Figure 2 A sectional view for explaining the structure and operation of an exciting coil part and a permanent magnet according to an embodiment of the present invention.

[0033] Figure 3 A schematic diagram for explaining the assembly sequence of an electromagnet including a permanent magnet capable of exerting a combined force of an exciting coil and magnetic flux.

[0034] Figure 4 A schematic diagram for explaining the form in which a permanent magnet provided at the axial end of a fixed iron core and a plate-shaped washer made of a magnetic material adsorbed and attached by the magnetic force of the axial permanent magnet fix the yoke plate to the yoke.

[0035] Figures 5a to 5h A schematic diagram for explaining the force of the combined magnetic flux generated by the magnetic flux Φ1 of an electromagnet and the magnetic flux Φ2 of a permanent magnet according to the operating distance of a movable iron core in an embodiment of the present invention.

[0036] Figure 6 A schematic diagram for explaining a closed loop of the combined magnetic flux of the magnetic flux Φ1 generated by the exciting current of a coil and the magnetic flux Φ2 of a permanent magnet in an embodiment of the present invention for a movable iron core.

[0037] Figure 7 A schematic diagram of a closed loop showing the distribution of the magnetic flux Φ2 generated by a permanent magnet before power is applied to the coil.

[0038] Figure 8 A schematic diagram showing the magnetic flux distribution generated only by the magnetic flux of the electromagnet without a permanent magnet in the initial state when power is applied to the coil.

[0039] Figure 9 A schematic diagram showing the magnetic flux distribution in which the magnetic flux Φ1 of the coil part and the magnetic flux Φ2 of the permanent magnet are combined to double the suction force after power is applied to the coil according to an embodiment of the present invention. Detailed implementation mode

[0040] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art to which the present invention pertains can easily implement the present invention. However, the present invention can be implemented in various different forms and is not limited to the embodiments described herein.

[0041] The terms used in this specification are for explaining the embodiments and are not intended to limit the present invention. In this specification, unless specifically mentioned in the sentence, the singular form also includes the plural form.

[0042] The "comprises" and "comprising" used in this specification mean that the mentioned constituent elements, steps, actions, and / or elements do not exclude the existence or addition of one or more other constituent elements, steps, actions, and / or elements.

[0043] In addition, ordinal terms such as first and second used in the present invention can be used to describe constituent elements, but the constituent elements should never be limited by these terms. Such terms are only used to distinguish one constituent element from other constituent elements. Additionally, when explaining the present invention, if it is determined that a detailed description of related well-known technologies may obscure the gist of the present invention, then its detailed description will be omitted.

[0044] In addition, each constituent component shown in the embodiments of the present invention is independently drawn and shown for the purpose of embodying mutually different characteristic functions, and this does not mean that each constituent component is composed of mutually separate constituent units. That is to say, each constituent component is listed and described as an independent constituent component for the convenience of explanation, and at least two of the constituent components can be combined into one constituent component, or one constituent component can be divided into multiple constituent components to perform corresponding functions. As long as the integrated embodiments and separated embodiments of these constituent components do not deviate from the essence of the present invention, they are also included in the protection scope of the present invention.

[0045] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The structure of the present invention and the resulting effects will be clearly understood through the following detailed description.

[0046] Figure 1 An assembly drawing for explaining the constitution of a DC contact device according to an embodiment of the present invention Figure 2 A sectional view for explaining the constitution and operation of an exciting coil part and a permanent magnet according to an embodiment of the present invention.

[0047] Referring to Figure 1 and Figure 2 When observing the assembly process of the contact device according to an embodiment of the present invention, a coil 02 is wound around a bobbin 01, and the starting wire and the end wire of the electromagnetic coil winding part are respectively electrically connected to a coil terminal 21 to form an electromagnet. A fixed iron core 22 integrally and fixedly provided at the central part of a yoke 06 can be inserted into the lower center of the hollow part of the bobbin 01 around which the coil is wound. Among them, the fixed iron core 22 can penetrate through a hollow cylindrical tube structure at the center of the bobbin 01 and is made of a magnetic material.

[0048] An annular permanent magnet 03 is provided at the upper side end 22-a in the axial direction (the up-and-down direction) of the fixed iron core 22, and a plate-shaped washer 04 made of a magnetic material can be placed and assembled on the S pole 03-a which is the axial upper side magnetic pole surface of the permanent magnet 03. Among them, the upper surface of the permanent magnet 03 is the S pole 03-a, and the lower surface is the N pole 03-b. The permanent magnet can have a magnetization surface in the axial direction of the fixed iron core 22 and the movable iron core 08. In addition, various types of permanent magnets can be used for the permanent magnet 03. For example, it can include permanent magnets made of various materials such as ferritic or rare earth types. In addition, the permanent magnet is not circular, and can also be square, semi-circular, composed of multiple blocks, adsorbed on the upper side end in the axial direction of the fixed iron core 22 by the magnetic force of the permanent magnet, and formed in a shape surrounding a cylinder 07.

[0049] In addition, the axial polarity of the permanent magnet can also be changed by changing the current direction of the electromagnet to change the directions of the N pole and the S pole.

[0050] At this time, the permanent magnet 03 is completely and tightly attached to the upper side surface in the axial direction of the fixed iron core 22 without a gap, and is adsorbed under the action of the magnetic force to extend its length. A plate-shaped washer 04 made of a magnetic material is installed on the upper layer of the permanent magnet 03, thereby being able to prevent the leakage flux of the permanent magnet 03.

[0051] Among them, the yoke 06 is made of a magnetic material and is configured to surround at least a part of the outside of the coil 02. The yoke plate 05 is fixedly provided on the upper side of the yoke 06. In addition, the yoke plate 05 and the yoke 06 can be fixed by processing to embed the yoke plate 05 into the left side 06a and the right side 06-b of the yoke 06. The yoke 06 is made of a magnetic metal and can have, for example, a U-shaped form including a lower panel and two side panels. Through such a structure and assembly, the exciting coil operation unit coil including the permanent magnet can be completed. Thus, a circular groove is made in the center of the lower surface of the U-shaped yoke 06 made of a magnetic material, and the fixed iron core 22 is tightly fixed in the groove, and the yoke assembly can be completed. The yoke assembly can first wind the coil 02 on the bobbin 01, electrically connect the starting wire and the end wire of the coil to the coil terminal by welding, fusing, etc. on the coil terminal, then embed the fixed iron core 22 into the through groove in the center of the bobbin 01, and then assemble it onto the yoke 06.

[0052] In addition, as Figure 2 shown, the permanent magnet 03 is mounted on the fixed iron core 22, and the center of the movable iron core 08 disposed inside the cylindrical body 07 of the airtight contact device is penetrated and the shaft pin 08 is fixedly disposed therein. The shaft pin is combined with the movable contact seat bracket 09 and fixed by the movable contact seat molded product 10 formed by insert molding of plastic resin. And the contact pressure spring 11 is sleeved on the contact pressure spring placement protrusion 10-a located on the upper side of the insert-molded movable contact seat molded product 10, and then the spring is compressed to integrate the contact pressure spring 11 with the lower protrusion of the movable contact seat 12 for assembly. The whole movable contact seat bracket 09 can be in an inverted U shape, and can include on both sides curved surfaces protruding in a protruding shape and sliding portions 11-a protruding in an R shape. As Figure 2 shown, it can include a pair of sliding portions 11-b located at the lower ends of both sides, or two pairs of sliding portions respectively formed at the upper end and the lower end thereof, and multiple plates stacked on the upper side of the inverted U shape, so as to be able to realize a method of increasing the contact suction force in response to the electronic repulsive force generated at the contact when the battery is short-circuited.

[0053] In addition, the contact pressure spring 11 and the movable contact base 12 housed in the movable contact base holder 09 of the "∩"-shaped movable contact base housing part 09 are restricted within the "∩"-shaped movable contact base holder 09 to prevent detachment, and will operate along the axial direction according to the contact pressure over-travel (O / T) amount in the up and down directions. When contacting the fixed contact 13, the contact pressure spring 11 is compressed by the O / T amount to push the movable contact base 12 upward, and the compression force of the compressed spring becomes the contact pressure at the contact part between the fixed contact 13 and the movable contact base 12. Among them, the movable contact base holder 09 can be made of a magnetic metal material, and through the structure of the sliding part in the form of a protruding curved surface, it can have a structure that can move up and down by sliding with the exposed surface of the guide plate 15 formed on the arc base 14.

[0054] In addition, a cylindrical body 07 of the hermetic contact device can be fixedly installed at the lower part of the yoke plate 05 on which the movable contact base housing part 09 is fixed by means of airtight welding.

[0055] After the internal assembly of such a hermetic contact device is completed, the flange of the sealing cup 17 fixed to the lower part of the ceramic housing 16 is airtight welded to the yoke plate 05 in a hydrogen mixed gas environment to isolate the inside of the device from the outside, so that a hermetic contact device filled with an insulating gas can be manufactured.

[0056] In addition, the cylindrical body part of the hermetic contact device can be embedded in the central groove of the coil bobbin 01 assembled on the yoke 06, and the yoke 06 and the yoke plate 05 are fixed by caulking, that is, a pair of protruding parts 06-a and 06-b integrally formed on the yoke 06 are fixed to the yoke plate 05 by caulking.

[0057] In addition, a pair of permanent magnets 18 for arc extinguishing are provided in the longitudinal direction of the ceramic housing 16 on the left and right sides of the pair of fixed contacts 13 for applying a DC power supply, and the permanent magnets 18 for arc extinguishing are surrounded by the permanent magnet holder 19 for arc extinguishing to reduce the leakage of the magnetic field to the outside. As a method of guiding the arc generated by the opening and closing of the contacts to the diagonal direction of the movable contact base 12 and elongating it to extinguish the arc by providing a pair of permanent magnets 18 for arc guiding paths, a permanent magnet for arc extinguishing can be provided.

[0058] According to the above solution of the present invention, the following DC contact device can be provided: that is, in the DC contact device, the magnetic flux generated in the excitation coil 02 for achieving low power consumption and the magnetic flux of the permanent magnet 03 installed on the upper side of the fixed iron core 22 are used to increase the suction force on the movable iron core with the doubled magnetic flux, so as to realize the light weight of the product and an economical DC contact device with airtight sealing of the insulating gas.

[0059] Refer again to Figure 1 and Figure 2 to explain the operation of the contact device. When the coil operating power supply is applied (on) to the coil terminal 21 led out from the exciting coil 02, according to the principle of the electromagnet, the magnetic flux of the electromagnet will flow from the fixed iron core 22 to the movable iron core 08. In addition, the magnetic flux starting from the fixed iron core 22 will independently flow to the permanent magnet 03, and will also move from the permanent magnet 03 towards the movable iron core 08. Eventually, the two magnetic fluxes Φ1 and Φ2 merge, doubling the magnetic force to drive the device to operate. At the moment when the movable iron core 08 stops running and contacts the yoke plate, the Φ1 magnetic flux generated by the coil 02 in the electromagnet will form a closed loop in the order of the fixed iron core 22, the movable iron core 08, the yoke plate 05, and the yoke 06. And the Φ2 magnetic flux generated from the permanent magnet 03 will start from the N pole 03-b of the permanent magnet 03 along the inner direction of the permanent magnet 03, pass through the movable iron core 08 and the yoke plate 05, and finally return to the S pole 03-a of the permanent magnet 03 to form a closed loop.

[0060] On the other hand, when the operating power supply of the coil 02 is turned off (off), contrary to the above actions, the movable iron core 08 will separate from the fixed iron core 22 and move downward under the action of the return spring 20. At this time, the movable iron core 08 linked with the movable contact seat 12 moves downward, and the electrical contact state of the contacts can be changed to the open state.

[0061] Through the actions of such open and closed states, the contact separates from the contact part between the fixed contact 13 as the main contact and the movable contact seat 12.

[0062] Figure 3 It is a drawing for explaining the assembly sequence of an electromagnet including a permanent magnet that can exert the combined force of the exciting coil and the magnetic flux.

[0063] Refer to Figure 3 , it can be configured to integrally combine with the yoke 06 and install a circular ring-shaped permanent magnet 03 on the upper side of the axial direction of the fixed iron core 22 that fixes the lower part of the yoke plate 05. At this time, the polarity of the permanent magnet 03 is magnetized along the axial direction. A plate-shaped washer 04 made of a magnetic material is interposed between the upper side of the permanent magnet 03 and the yoke plate 05, so as to obtain the effect of reducing the magnetic flux leakage of the permanent magnet 03.

[0064] In addition, the fixed iron core 22 is fixed to the lower part of the yoke 06, inserted and assembled into the central through-hole of the bobbin 01 of the coil part. A permanent magnet 03 is provided on the upper part of the fixed iron core 22, and the plate-shaped washer 04 and the yoke plate 05 are placed on the left and right sides of the yoke 06 and fixed by caulking or the like.

[0065] Figure 4It is a schematic diagram for explaining the form of a permanent magnet provided at the axial end of a fixed iron core, a plate-shaped washer made of a magnetic material adsorbed and attached by the magnetic force of the axial permanent magnet, and fixing a yoke plate to a yoke.

[0066] Figure 4 It shows another method of the assembly sequence of the permanent magnet 03, and is a diagram for explaining the following situation: a plate-shaped washer 04 made of a magnetic material is sleeved on the cylindrical body 07 of a contact device in which an insulating gas is hermetically sealed. After assembling the permanent magnet, the assembly is embedded in the central part of a bobbin. The edges on the left and right sides of the yoke plate 05 are placed at the groove parts 06-a and 06b of the yoke 06, and then fixed and installed by caulking.

[0067] Refer to Figure 4 , after sleeving a plate-shaped washer 04 and a permanent magnet 03 on the upper side of the cylindrical body 07 of a contact device in which a fixed contact 13, a sealing cup 17, a yoke plate 05 and the cylindrical body 07 are hermetically welded to a ceramic housing 16 and an insulating gas is filled inside, then it is embedded into the central through hole of the bobbin 01 for assembly.

[0068] Such a contact device assembly is to embed the cylindrical body 07 part of the contact device with the insulating gas sealed into the central part of the bobbin 01, and then embed and place it in the stepped groove parts of the left protrusion 06-a and the right protrusion 06-b on both sides of the U-shaped yoke 06, and fix the protrusion parts 06a and 06b of the yoke 06 by caulking.

[0069] In addition, for example, the permanent magnet 03 and the plate-shaped washer 04 are installed on the yoke plate 05 to prevent falling off. Since they are sleeved and assembled outside the cylindrical body 07, when the contact device is erected and embedded into the center of the bobbin 01, there is an effect that there is no need to worry about the assembled parts being misaligned or falling off.

[0070] Figure 5 is a schematic diagram for explaining the combined suction force generated by the magnetic flux of an electromagnet and the magnetic flux of a permanent magnet according to the operating distance of a movable iron core in an embodiment of the present invention.

[0071] First, refer to Figure 5a, when the operating distance d, which is the interval between the movable iron core 22 and the yoke plate 05, is 3.0 millimeters (mm), the resultant suction force is 8.3 Newton - meters (Nm); when the interval is 2.5 mm, the resultant suction force is 11.5 Nm; when the interval is 2.0 mm, the resultant suction force is 16.1 Nm; when the interval is 1.5 mm, the resultant suction force is 22.1 Nm; when the interval is 1.0 mm, the resultant suction force is 32.8 Nm; when the interval is 0.5 mm, the resultant suction force is 58.3 Nm; when the interval is 0.05 mm, the resultant suction force is 153.7 Nm. Thus, it can be confirmed that the closer the movable iron core 22 is to the yoke plate 05, the stronger the resultant magnetic flux will be generated, and furthermore, the contact pressure will increase.

[0072] In addition, the volume of the permanent magnet 03 is adjusted to obtain the optimal suction force. In order to minimize the leakage magnetic flux of the electromagnet and the leakage magnetic flux of the permanent magnet 03, the permanent magnet 03 can be arranged on the upper side section 22 - a of the fixed iron core 22, and a contact device can be realized, that is, the volume of the electromagnet of the excitation coil part of the electromagnet using both the electromagnet and the permanent magnet 03 simultaneously is reduced, and the power consumption is lowered.

[0073] Figures 5b to 5h The flow directions of the resultant suction forces generated by the magnetic flux of the electromagnet and the magnetic flux of the permanent magnet are respectively shown when the operating distance d, which is the interval between the movable iron core 22 and the yoke plate 05, is 3.0 mm, 2.5 mm, 2.0 mm, 1.5 mm, 1.0 mm, 0.5 mm, and 0.05 mm.

[0074] Thus, for the resultant magnetic flux of the excitation coil 02 and the permanent magnet 03, while applying the power supply of the excitation coil 02, magnetic fluxes are respectively generated and synthesized, thereby playing the role of reducing the operating voltage of the movable iron core 08, and increasing the magnetic flux as the movable iron core 08 gets closer to the yoke plate 05.

[0075] Figure 6 It is a schematic diagram of the closed - loop of the resultant magnetic flux of the coil and the permanent magnet at the initial stage when the coil power is applied to the movable iron core in an embodiment for explaining the present invention.

[0076] When a coil operating power supply is applied to the coil terminal 21 extending from the sub-excitation coil 02, according to the principle of the electromagnet, the magnetic flux of the electromagnet will flow from the fixed iron core 22 to the movable iron core 08. In addition, the magnetic flux starting from the fixed iron core 22 will flow to the permanent magnet 03, and will also move in the direction of the movable iron core 08 from the permanent magnet 03. Finally, the two magnetic fluxes Φ1 and Φ2 are combined to double the magnetic suction force and operate. At the moment when the movable iron core 08 stops operating and abuts against the yoke plate, the Φ1 magnetic flux generated by the electromagnet of the coil part will form a closed loop in the order of the fixed iron core 22, the movable iron core 08, the yoke plate 05, and the yoke 06. The Φ2 magnetic flux generated from the permanent magnet 03 will follow the inner direction of the permanent magnet 03, starting from the N pole 03-b below the permanent magnet 03, passing through the fixed iron core 22, the movable iron core 08, and the yoke plate 05, and returning to the S pole 03-a of the permanent magnet 03, thus forming a closed loop.

[0077] On the other hand, when the operation power supply of the coil 02 is turned off, contrary to the above action, the movable iron core 08 will separate from the fixed iron core 22 and move downward under the action of the return spring 20. At this time, the movable iron core 08 linked with the movable contact seat 12 moves downward, and the electrical contact state of the contact can be changed to an open state. At this time, the yoke 06, the fixed iron core 22, the permanent magnet 03, the washer 04, and the yoke plate 05 are connected together without gaps, and a closed loop of magnetic flux can be formed.

[0078] Figure 7 It is a schematic diagram showing a closed loop of the magnetic flux Φ2 distribution generated by the permanent magnet before applying power to the coil.

[0079] Referring to Figure 7 It can be seen that this is a completely closed loop formed without gaps from the N pole to the S pole of the permanent magnet 03, then from the S pole through the magnetic washer 04, passing through the yoke plate 05, the yoke 06, and the fixed iron core 22, and finally returning to the N pole of the permanent magnet 03.

[0080] Figure 8 It is a schematic diagram showing the magnetic flux distribution generated only by the magnetic flux of the electromagnet without the permanent magnet in the initial state when power is applied to the coil.

[0081] Referring to Figure 8 It can be seen that in the state without the permanent magnet, only the Φ1 magnetic flux generated by the electromagnet of the coil part exists, and the Φ2 magnetic flux generated by the permanent magnet does not exist, and the suction force of the movable iron core 08 is weak.

[0082] Figure 9A schematic diagram showing the magnetic flux distribution in which the magnetic flux Φ1 of the coil part and the magnetic flux Φ2 of the permanent magnet are combined to double the suction force after applying power to the coil according to an embodiment of the present invention.

[0083] Referring to Figure 9 As can be seen, the figure shows a closed loop of the combined magnetic flux after the Φ1 magnetic flux distribution generated by the electromagnet of the coil part and the Φ2 magnetic flux generated by the permanent magnet are combined after the movable iron core 08 has completed its full operation by moving upward. Thus, it can be seen that after the magnetic flux Φ1 of the coil part and the magnetic flux Φ2 of the permanent magnet are combined, the suction force is doubled.

[0084] At the moment when the movable iron core 08 stops operating and abuts against the yoke plate 05, the magnetic flux Φ1 generated by the coil 02 forms a closed loop in the order of the fixed iron core 22, the movable iron core 08, the yoke plate 05, and the yoke 06, while the Φ2 magnetic flux generated by the permanent magnet 03 starts from the N pole 03-b below the permanent magnet 03 along the inner direction of the permanent magnet 03, passes through the fixed iron core 22, the movable iron core 08, and the yoke plate 05, and returns to the S pole 03-a of the permanent magnet 03 to form a closed loop.

[0085] The embodiments disclosed in the specification of the present invention are merely examples, and the present invention is not limited thereto. The protection scope of the present invention should be interpreted according to the appended claims, and all technologies within the equivalent scope thereof should also be interpreted as being included in the protection scope of the present invention.

Claims

1. An electromagnetic contact device, characterized in that, the electromagnetic contact device includes: a coil wound around a bobbin; a movable iron core axially driven under the action of the coil; a pair of fixed contacts for applying a DC power supply; a movable contact holder that operates in linkage with the movable iron core and reciprocates up and down to be able to contact the pair of fixed contacts; a yoke made of a magnetic material and configured to surround at least a part of the outside of the coil; a yoke plate fixedly disposed on the upper side of the yoke; a fixed iron core made of a magnetic material, passing through the central portion of the bobbin and fixedly disposed by the yoke; and an annular permanent magnet disposed on the upper side of the fixed iron core, increasing the suction force of the movable iron core through the magnetic flux generated by the coil and the magnetic flux generated by the permanent magnet.

2. The electromagnetic contact device according to claim 1, wherein, the permanent magnet has a magnetization surface in the axial direction.

3. The electromagnetic contact device according to claim 1, wherein, the permanent magnet is mounted on the upper end face of the fixed iron core.

4. The electromagnetic contact device according to claim 3, wherein, a plate-shaped washer made of a magnetic material is mounted on the upper layer portion of the permanent magnet.

5. The electromagnetic contact device according to claim 4, wherein, a closed loop of magnetic flux is formed without gaps between the yoke, the fixed iron core, the permanent magnet, the washer and the yoke plate.

6. The electromagnetic contact device according to claim 1, wherein, the permanent magnet is composed of a plurality of blocks.

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