Contact relay

Abstract

This invention discloses a contact relay that enables space-saving in the heat dissipation structure and shortening and lowering the thermal resistance of the heat dissipation path. [Solution] The contact relay 10 comprises an electromagnet device 20 that attracts the movable element 18 to the stator 16 by passing current through the excitation coil 14, thereby moving the movable element 18; a contact device 26 having a fixed contact 22 provided on the stator 16 and a movable contact 24 provided on the movable element 18, and switching between a closed state in which the movable contact 24 is in contact with the fixed contact 22 and an open state in which the movable contact 24 is away from the fixed contact 22 as the movable contact 24 moves as the movable element 18 moves; a bus bar 28 connected to the fixed contact 22; an insulating case 32 that houses the electromagnet device 20, the contact device 26 and the bus bar 28 and has a contact portion 30 for heat dissipation; and a relay terminal 34 connected to the fixed contact 22 and exposed outside the case 32, wherein the bus bar 28 has a thermal connection portion 36 and the thermal connection portion 36 is thermally connected to the contact portion 30.

Description

Technical Field

[0001] The present disclosure relates to a contact relay.

Background Art

[0002] Conventionally, in vehicles equipped with a battery composed of a high-voltage secondary battery such as an electric vehicle or a hybrid vehicle, the battery and in-vehicle loads are connected via a contact relay (hereinafter sometimes simply referred to as a relay), and by controlling the relay with a control signal from a control unit, the electrical connection state between the battery and the in-vehicle loads is switched. In recent years, due to the increase in the current of vehicles, the contact heat generation of the relay has increased, and it has become essential to take heat dissipation measures for the relay. For example, in Patent Document 1, a bus bar connected to a relay terminal exposed on the outer surface of the relay case is thermally contacted with a metal battery case to be cooled via an insulating heat conduction sheet, and a structure for transferring heat from the relay to the heat dissipation target is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional heat dissipation structure of a relay, it is necessary to extend the bus bar connected to the relay terminal toward the heat dissipation target, and an increase in the size of the relay itself including the heat dissipation structure is inevitable. In addition, it is necessary to route the bus bar extending from the relay terminal to the heat dissipation target around the relay, and there is a limit to shortening the heat transfer path. Furthermore, since the heat generated by the relay is transferred in the order of the heat conduction sheet, bus bar, heat conduction sheet, and heat dissipation target from the relay case, the heat resistance increases accordingly, and there is a possibility that a sufficient heat dissipation effect cannot be obtained.

[0005] Therefore, we disclose a contact relay that can achieve space savings in the heat dissipation structure and shorten and reduce the thermal resistance of the heat dissipation path. [Means for solving the problem]

[0006] The contact relay of this disclosure comprises an electromagnet device that attracts a movable element to a stator and moves the movable element by passing an electric current through an excitation coil provided on the outer circumference of a magnetic material; a contact device having a fixed contact provided on the stator and a movable contact provided on the movable element, wherein the movable contact moves as the movable element moves, switching between a closed state in which the movable contact is in contact with the fixed contact and an open state in which the movable contact is away from the fixed contact; a busbar connected to the fixed contact; an insulating case housing the electromagnet device, the contact device and the busbar, and having a contact portion for heat dissipation; and a relay terminal connected to the fixed contact and exposed outside the case, wherein the busbar has a thermal connection portion, and the thermal connection portion is thermally connected to the contact portion. [Effects of the Invention]

[0007] The contact relay of this disclosure makes it possible to reduce the space required for the heat dissipation structure and shorten and lower the thermal resistance of the heat dissipation path. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view showing a contact relay according to Embodiment 1 in a partially transparent state. [Figure 2] Figure 2 is a plan view showing the contact relay shown in Figure 1 with the upper case removed. [Figure 3] Figure 3 is a vertical cross-sectional view of the contact relay shown in Figure 1, and corresponds to the III-III cross-section in Figure 2. [Figure 4] Figure 4 is a cross-sectional view taken along line IV-IV in Figure 3. [Figure 5] Figure 5 is an exploded perspective view of the contact relay shown in Figure 1. [Figure 6] Figure 6 is a plan view showing the relay body portion, which includes the electromagnet device and contact device, in the contact relay shown in Figure 1. [Figure 7] Figure 7 is a perspective view showing a contact relay according to Embodiment 2 in a partially transparent state. [Figure 8] Figure 8 is a vertical cross-sectional view of the contact relay shown in Figure 7, and corresponds to Figure 2. [Figure 9] Figure 9 is a planar perspective view showing the contact relay according to Embodiment 3 in a partially transparent state. [Figure 10] Figure 10 is a perspective view from the bottom of the contact relay shown in Figure 9. [Figure 11] Figure 11 is a cross-sectional view taken along line XI-XI in Figure 10. [Figure 12] Figure 12 is a perspective view showing a contact relay according to Embodiment 4 in a partially transparent state. [Figure 13] Figure 13 is a cross-sectional view taken along line XIII-XIII in Figure 12. [Figure 14] Figure 14 is a perspective view showing a contact relay according to another aspect of the present disclosure in a partially transparent state. [Modes for carrying out the invention]

[0009] <Description of Embodiments in this Disclosure> First, embodiments of this disclosure will be listed and described. The contact relay disclosed herein is (1) An electromagnet device that attracts a movable element to a stator and moves the movable element by passing an electric current through an excitation coil provided on the outer circumference of a magnetic material; a contact device having a fixed contact provided on the stator and a movable contact provided on the movable element, wherein the movable contact moves as the movable element moves, switching between a closed state in which the movable contact is in contact with the fixed contact and an open state in which the movable contact is away from the fixed contact; a busbar connected to the fixed contact; an insulating case housing the electromagnet device, the contact device and the busbar, and having a contact portion for heat dissipation; and a relay terminal connected to the fixed contact and exposed outside the case, wherein the busbar has a thermal connection portion, and the thermal connection portion is thermally connected to the contact portion.

[0010] According to the contact relay of this disclosure, an electromagnet and contact device, along with a busbar connected to a fixed contact, are housed inside an insulating case, and the thermal connection portion of the busbar is in thermal contact with the contact portion of the case that is used to dissipate heat. As a result, heat generated on the relay contacts and excitation coil can be efficiently transferred to the contact portion of the insulating case that is used to dissipate heat via the busbar connected to the fixed contact, and a heat dissipation path can be configured to transfer heat generated inside the relay to the heat dissipation object simply by bringing the contact portion of the contact relay case into contact with the heat dissipation object, such as a battery housing. Consequently, compared to conventional structures in which it was necessary to extend the busbar connected to the relay terminal toward the heat dissipation object, the heat dissipation structure can be provided inside the relay, and the heat dissipation structure of the relay can be provided in a space-saving manner. Furthermore, compared to conventional structures in which a busbar extending from the relay terminal to the contact area of ​​the heat dissipation target was routed around the outside of the relay, the busbar of this disclosure only needs to have a length that extends between the fixed contact and the contact area within the relay case, thus shortening the heat dissipation path and, consequently, reducing the thermal resistance of the heat dissipation path. In addition, since the thermal connection portion of the busbar is thermally in contact with the contact area of ​​the heat dissipation target on the insulating case, an insulating heat dissipation path can be constructed simply by bringing the contact area of ​​the case into direct contact with the heat dissipation target. As a result, compared to the conventional structure in which heat from the relay is transferred in the order of relay case, thermal conductive sheet, busbar, thermal conductive sheet, and heat dissipation target, it is possible to reduce the number of components interposed between the busbar and the heat dissipation target, further reducing the thermal resistance of the heat dissipation path.

[0011] Furthermore, "busbars connected to fixed contacts" includes both configurations in which busbars, separate from the fixed contacts, are fixed to the fixed contacts by any method such as welding or bolting and are interconnected, and configurations in which the fixed contacts and busbars are provided integrally and are interconnected.

[0012] Furthermore, the thermal connection portion of the busbar only needs to be thermally connected to the contact portion of the case, and may be embedded in the contact portion, or it may be superimposed on the contact portion and covered with an insulating cover or the like.

[0013] (2) In the above (1), it is preferable that the thermal connection portion of the bus bar is embedded in the contact portion of the case. Since the thermal connection portion of the bus bar is embedded in the contact portion of the case, the insulation of the thermal connection portion of the bus bar can be ensured without requiring other members. As a result, members intervening in the heat dissipation path can be advantageously reduced, and further reduction of the thermal resistance of the heat dissipation path can be achieved.

[0014] (3) In the above (1) or (2), the thermal connection portion is provided on one end side of the bus bar, the relay terminal is integrally provided on the other end side of the bus bar, and the fixed contact provided separately from the bus bar is connected to the middle region of the bus bar by welding. This is preferable. Since the thermal connection portion is provided at one end of the bus bar connected to the fixed contact and the relay terminal is integrally provided at the other end, the bus bar can also be used as an energization path in addition to the heat dissipation path, reducing the number of parts and simplifying the structure. Moreover, since a separate fixed contact can be connected to the middle region of the bus bar by welding, the connection between the fixed contact and the bus bar can be easily and surely made.

[0015] (4) In the above (1) or (2), it is preferable that the relay terminal is provided on one end side of the bus bar and the fixed contact is integrally provided on the other end side of the bus bar. Since the fixed contact is integrally provided on the other end side of the bus bar provided with the relay terminal on one end side, the number of parts can be reduced and the structure can be simplified. Moreover, since the fixed contact and the relay terminal are constituted by using a single bus bar, further reduction of the thermal resistance of the heat dissipation path can be achieved.

[0016] (5) In (4) above, it is preferable that the busbar comprises a first busbar having the relay terminal at one end and a second busbar having the fixed contact at one end, and that the stator is formed by the second busbar, and that the other ends of the first busbar and the second busbar are overlapped and welded together to form a single unit. Since the busbar can be formed by welding the other ends of the first busbar and the second busbar together to form a single unit, it is possible to reduce the contact resistance of the heat dissipation path while improving the freedom of routing the heat dissipation path.

[0017] <Details of the embodiments of this disclosure> Specific examples of the contact relays of this disclosure will be described below with reference to the drawings. However, this disclosure is not limited to these examples, and is intended to include all modifications within the meaning and scope equivalent to the claims as shown in the claims.

[0018] <Embodiment 1> Hereinafter, the contact relay 10 of Embodiment 1 of this disclosure will be described with reference to Figures 1 to 6. This contact relay 10 is installed inside an electrical connection box (not shown) in, for example, an electric vehicle or a hybrid vehicle, and is used to switch ON and OFF in an electrical circuit. The contact relay 10 can be positioned in any orientation within the vehicle, but in the following, "upper" will be described as the upper part in Figure 3, "lower" as the lower part in Figure 3, "left" as the left part in Figure 2, "right" as the right part in Figure 2, "front" as the upper part in Figure 2, and "rear" as the lower part in Figure 2. In addition, for multiple identical components, reference numerals may be assigned to only some of the components, while the reference numerals for other components may be omitted. For clarity, some components are shown transparently in the drawings. For example, in Figure 1, the upper case 72, ceramic case 58, and excitation coil 14, which will be described later, are shown transparently, and in Figure 2, the ceramic case 58, excitation coil 14, and iron core member 12 are shown transparently.

[0019] <Contact Relay 10> The contact relay 10 of Embodiment 1 includes an electromagnet device 20 that attracts the movable element 18 to the stator 16 and moves the movable element 18 by passing an electric current through an excitation coil 14 provided on the outer circumference of an iron core member 12 which is a magnetic material. The contact relay 10 also includes a contact device 26 that has a fixed contact 22 provided on the stator 16 and a movable contact 24 provided on the movable element 18, and switches between a closed state (state shown by the dashed line in Figure 4) where the movable contact 24 is in contact with the fixed contact 22 as the movable element 18 moves, and an open state (state shown by the solid line in Figure 4) where the movable contact 24 is away from the fixed contact 22. Furthermore, the contact relay 10 includes a busbar 28 connected to a fixed contact 22 (stator 16), and an insulating case 32 that houses the electromagnet device 20, the contact device 26, and the busbar 28, and has contact points 30 to a heat dissipation object (e.g., an electrical junction box or battery pack housing) not shown. The contact relay 10 also includes relay terminals 34 connected to the fixed contact 22 and exposed outside the case 32. The busbar 28 has a thermal connection portion 36, which is thermally connected to the contact points 30 inside the case 32.

[0020] <Magnetic material (iron core member 12)> The iron core member 12 is a substantially cylindrical member made of iron, and in Embodiment 1, the inner bore of the iron core member 12 is positioned to extend in the front-rear direction. A metal shaft 38 extending in the front-rear direction is fixed in place through the inner bore of the iron core member 12, and this shaft 38 extends forward of the iron core member 12. A disc-shaped portion 40 is integrally formed at the front end of the shaft 38, and the outer circumference of the disc-shaped portion 40 protrudes outward from the shaft 38. By providing the disc-shaped portion 40 at the front end of the shaft 38, the forward displacement of the movable element 18, which is externally fitted onto the shaft 38 as described later, can be restricted. Since the shaft 38 is also made of metal, the magnetic material provided on the inner circumference side of the excitation coil 14 may include the shaft 38 in addition to the iron core member 12.

[0021] Furthermore, a metal flat plate member 42 is positioned extrapolated to the middle portion of the shaft 38 in the longitudinal direction (front-to-back direction), that is, in front of the iron core member 12. The flat plate member 42 is rectangular in shape as a whole, and a through hole 44 is formed in its central part, penetrating in the front-to-back direction. A substantially cylindrical displacement restricting member 46 is fixed to the rear end face of the flat plate member 42. This displacement restricting member 46 is a rigid member made of, for example, synthetic resin, and has predetermined dimensions in the front-to-back direction. The inner hole of the displacement restricting member 46 communicates with the through hole 44 in the flat plate member 42 in the front-to-back direction, and the shaft 38 is inserted through these through hole 44 and the inner hole of the displacement restricting member 46. As will be described later, the shaft 38 is displaceable in the front-to-back direction relative to the flat plate member 42 and the displacement restricting member 46, and the iron core member 12 provided at the rear end of the shaft 38 comes into contact with the displacement restricting member 46, thereby limiting further forward displacement of the shaft 38. In other words, the amount of displacement of the shaft 38 in the longitudinal direction can be adjusted by the longitudinal dimension of the displacement restricting member 46.

[0022] Furthermore, a coil spring 48 is externally attached to the shaft 38 between the displacement restricting member 46 and the iron core member 12 in the front-rear direction. One end of the coil spring 48 is fixed to the displacement restricting member 46, and the other end of the coil spring 48 is fixed to the iron core member 12. As shown in Figure 2, etc., in the open state where the movable contact 24 and the fixed contact 22 are separated, the coil spring 48 is at its natural length. On the other hand, in the closed state shown by the dashed line in Figure 4, the coil spring 48 is compressed in the front-rear direction. When the excitation coil 14 is not energized, the elastic restoring deformation of the coil spring 48 causes the shaft 38 to be displaced in a direction that separates the displacement restricting member 46 and the iron core member 12 from each other, causing the movable contact 24 and the fixed contact 22, which were in the closed state, to open.

[0023] Furthermore, on the shaft 38, a movable element 18 is externally mounted in front of the flat plate member 42, and an annular spring seat 50 protruding outward is fixed between the flat plate member 42 and the movable element 18 in the front-rear direction. Therefore, the movable element 18 is displaceable in the front-rear direction between the disc-shaped portion 40 on the shaft 38 and the spring seat 50. In particular, a coil spring 52 is externally mounted on the shaft 38 between the movable element 18 and the spring seat 50 in the front-rear direction, with one end of the coil spring 52 fixed to the movable element 18 and the other end of the coil spring 52 fixed to the spring seat 50. As shown in Figure 2, etc., in the open state where the movable contact 24 and the fixed contact 22 are separated, the coil spring 52 is at its natural length, while in the closed state shown by the dashed line in Figure 4, the coil spring 52 is under tension in the front-rear direction. When the excitation coil 14 is not energized, the elastic restoring deformation of the coil spring 52 causes the movable element 18 to be displaced in a direction approaching the spring seat 50, causing the movable contact 24 and the fixed contact 22, which were in a closed state, to open.

[0024] <Excitation coil 14> The excitation coil 14, provided on the outer circumference of the magnetic material (iron core member 12), is a coil made of known electric wire and is wound around the central axis of the iron core member 12, which extends in the front-rear direction. The excitation coil 14 may be wound along the outer surface of the iron core member 12, or it may be wound at a position spaced outward from the iron core member 12. Although not shown in the figures, both ends of the excitation coil 14 extend outside the contact relay 10 and are connected to an electrical circuit not shown, allowing power to be supplied to the excitation coil 14 from this electrical circuit. In Embodiment 1, the excitation coil 14 is covered and protected on three sides: the left and right sides and the rear. The front ends of the left and right side walls constituting the protective wall 54 are fixed to both ends of the flat plate member 42. In Embodiment 1, the excitation coil 14 wound at a position spaced outward from the iron core member 12 is held and fixed in the central part of the rear wall constituting the protective wall 54. As will be described later, the movable element 18 is attracted to the stator 16 and moved when power is supplied to the excitation coil 14. Therefore, in Embodiment 1, the electromagnet device 20 is configured to include a magnetic material (iron core member 12) and an excitation coil 14.

[0025] <Stator 16> In Embodiment 1, a pair of stators 16, 16 are provided separately from the busbar 28, and each stator 16, which is the same shape as the others, is arranged to be spaced apart from each other in the left-right direction. Each stator 16 is a substantially cylindrical member that extends in the front-rear direction as a whole, and is made of a metal with excellent conductivity such as copper (including copper alloys). In particular, in Embodiment 1, an enlarged diameter portion 56 is provided at the front end of each stator 16, with an outer diameter larger than that of other parts. As will be described later, the front end surface of each stator 16 becomes the overlapping surface (welding surface) with the intermediate region 69 of the busbar 28, so by providing an enlarged diameter portion 56 at the front end of each stator 16, a large contact area (welding area) is secured between each stator 16 and the busbar 28. In addition, the rear end surface of each stator 16 constitutes a fixed contact 22 that contacts each movable contact 24 of the movable element 18. Then, by welding each stator 16 to each busbar 28, each fixing contact 22 on the rear end face of each stator 16 is connected to the intermediate region 69 of each busbar 28.

[0026] Each of these stators 16 is held in an insulating ceramic case 58. The ceramic case 58 is a roughly rectangular box shape that opens to the rear, and comprises a roughly rectangular plate-shaped front wall portion 60 and a peripheral wall portion 62 that protrudes rearward from the outer peripheral edge of the front wall portion 60. Through holes 64 through which each stator 16 is inserted are formed in the front wall portion 60, spaced apart from each other in the left-right direction and penetrating in the front-rear direction. Each stator 16 is held in the ceramic case 58 by being inserted into these through holes 64, with the front end surface of each stator 16 positioned in front of the ceramic case 58 and exposed to the outside, and the rear end surface (each fixing contact 22) of each stator 16 exposed inside the ceramic case 58. Each stator 16 and the ceramic case 58 can be fixed together by known means such as adhesive or welding, as needed. The rear end of the ceramic case 58 is overlapped and fixed to the front end surface of the flat plate member 42. As a result, the front portion of the shaft 38 that protrudes forward from the flat plate member 42 and the movable element 18 are housed inside the ceramic case 58. The method of fixing the rear end of the ceramic case 58 to the flat plate member 42 is not limited, but in Embodiment 1, they are fixed by brazing.

[0027] The movable element 18 is a substantially rectangular plate-shaped member that extends in the left-right direction as a whole, and is made of a metal with excellent conductivity such as copper (including copper alloys). A thickened portion 66 is provided in the central part of the movable element 18 in the left-right direction, and a through hole 67 is formed in the central part of this thickened portion 66 that penetrates in the front-rear direction. The aforementioned shaft 38 is inserted through this through hole 67. The inner diameter of the through hole 67 is larger than the outer diameter of the shaft 38, allowing the movable element 18 to be smoothly displaced in the front-rear direction relative to the shaft 38. As shown by the dashed line in Figure 4, the front end surface of the thickened portion 66 of the movable element 18 abuts against the disc-shaped portion 40 provided at the front end of the shaft 38, thereby restricting the forward displacement of the movable element 18 relative to the shaft 38. In addition, one end of the aforementioned coil spring 52 is fixed to the rear end surface of the thickened portion 66. As shown by the dashed line in Figure 4, in the closed state, both left and right ends of the movable element 18, which extends in the left-right direction, contact the fixed contacts 22 of each stator 16, and the front end surfaces of both left and right ends of the movable element 18 constitute each movable contact 24. As will be described later, the switching between the closed and open states is achieved not only by supplying and releasing power to the excitation coil 14, but also by the displacement of the shaft 38 and the deformation of each coil spring 48, 52. Therefore, in Embodiment 1, the contact device 26 is composed not only of each stator 16 and movable element 18, but also of the shaft 38 and each coil spring 48, 52.

[0028] <Bus Bar 28> In Embodiment 1, a pair of busbars 28, 28 are provided, spaced apart from each other in the left-right direction. Each of these busbars 28 has a similar shape and extends in the front-rear direction as a whole, with relay terminals 34 protruding outward in the left-right direction from the front end of each busbar 28. In short, the relay terminal 34 protrudes to the right from the front end of the right busbar 28, and the relay terminal 34 protrudes to the left from the front end of the left busbar 28. Each of these busbars 28 is made of a metal with excellent conductivity, such as copper (including copper alloys) or aluminum (including aluminum alloys). Furthermore, each of these busbars 28 can be formed, for example, by press-forming a metal sheet, and can be formed with a substantially constant thickness.

[0029] Specifically, as shown in Figure 3, each busbar 28 has a roughly L-shaped portion, with a portion extending in the front-to-back direction and a portion extending in the up-to-down direction connected at a bent portion 68. In other words, a bent portion 68 is provided at the front end of the portion extending in the front-to-back direction, and a portion extending in the up-to-down direction protrudes upward from this bent portion 68. At the front end of each busbar 28, each relay terminal 34 protrudes outward in the left-to-right direction from the portion extending in the up-to-down direction. In Embodiment 1, a thermal connection portion 36 is formed by the portion extending in the front-to-back direction of each busbar 28. That is, a thermal connection portion 36 is provided at one end (rear end) of each busbar 28, and a relay terminal 34 is integrally formed at the other end (front end and outward in the left-to-right direction) of each busbar 28. In each busbar 28, the portion extending in the up-to-down direction between the thermal connection portion 36 and the relay terminal 34 is the intermediate region 69 of the busbar 28. Each relay terminal 34 has a bolt insertion hole 70 through which a bolt for connecting to an external busbar or the like (not shown) is inserted.

[0030] In particular, in Embodiment 1, as shown in Figure 5, each busbar 28 is integrally formed with the lower case 74, which will be described later and constitutes the case 32. That is, the lower case 74 is formed as an integrally molded product 76 comprising each busbar 28. In this integrally molded product 76, the thermal connection portion 36 of each busbar 28 is embedded inside the lower case 74, and the portion above the bent portion 68 protrudes outward from the lower case 74.

[0031] <Case 32> In Embodiment 1, the case 32 is composed of an upper case 72 and a lower case 74 that can be assembled and disassembled in the vertical direction. As described above, the lower case 74 is formed as an integrally molded product 76 equipped with each busbar 28. These upper case 72 and lower case 74 are made of an insulating synthetic resin.

[0032] The upper case 72 is a roughly rectangular box shape that opens downwards as a whole, and comprises a rectangular flat upper bottom wall portion 78 and an upper circumferential wall portion 80 that protrudes downwards from the outer peripheral edge of the upper bottom wall portion 78. In the front wall portion that constitutes the upper circumferential wall portion 80, an insulating projection 82 is provided in the central portion in the left-right direction, which is inserted between each bus bar 28 in the left-right direction to ensure insulation between each bus bar 28, and protrudes toward the rearward direction toward the inside of the upper case 72. In addition, insertion grooves 84 are formed at the rear ends of the left and right walls that constitute the upper circumferential wall portion 80, into which each relay terminal 34 that protrudes outward in the left-right direction on each bus bar 28 is inserted. Through these insertion grooves 84, each relay terminal 34 on each bus bar 28 protrudes outward in the left-right direction from the case 32. Furthermore, at the lower ends of the left and right walls that constitute the upper circumferential wall portion 80, notches 86 are formed at predetermined positions in the front-rear direction into which the legs 88 of the lower case 74, which will be described later, are inserted.

[0033] The lower case 74 is a roughly rectangular flat plate sized to cover the lower opening of the upper case 72. At both the left and right ends of the lower case 74, legs 88 for fixing the contact relay 10 to an electrical junction box (not shown) are integrally formed, protruding outward in the left and right directions at predetermined positions in the front-rear direction, and nuts 90 are arranged inside each of these legs 88. In Embodiment 1, when molding the lower case 74, the lower case 74 is formed as an integrally molded product 76 equipped with each bus bar 28 and each nut 90 by setting each bus bar 28 and each nut 90 in the molding cavity of the lower case 74. By fixing such a contact relay 10 to the housing that constitutes the electrical junction box with bolts inserted through each leg 88 (each nut 90), the lower case 74, which is roughly flat in the lower part of the case 32, comes into contact with the housing of the electrical junction box that is to be subjected to heat dissipation, so that the contact area 30 is formed by substantially the entire lower case 74. Furthermore, the thermal connection portion 36 of each busbar 28 is embedded in this contact portion 30.

[0034] <Assembly of Contact Relay 10> The following describes a specific example of how to assemble the contact relay 10. However, the assembly method of the contact relay 10 is not limited to the configuration described below.

[0035] First, the movable element 18, coil spring 52, and spring seat 50 are fitted onto the shaft 38 in order from below, fixing the spring seat 50 at a predetermined position in the front-rear direction relative to the shaft 38, and fixing the coil spring 52 to the movable element 18 and spring seat 50. Then, the shaft 38 is inserted from the front of the flat plate member 42 and the displacement restricting member 46, and the coil spring 48 and the iron core member 12 are fixed to the rear end of the shaft 38. Next, the ceramic case 58 that holds each stator 16 is brought closer from the front of the shaft 38, and the overlapping portion of the ceramic case 58 and the flat plate member 42 is fixed by brazing. In addition, the protective wall portion 54, on which the excitation coil 14 is fixed to the inner surface of the rear wall portion, is brought closer from the rear of the shaft 38, and the overlapping portion of the protective wall portion 54 and the flat plate member 42 is fixed. As a result, the relay body portion 92, which includes the electromagnet device 20 and the contact device 26, is constructed as shown in Figure 6.

[0036] Furthermore, as shown in Figure 5, the upper case 72 and the lower case 74 are formed separately. As described above, the lower case 74 is formed as an integrally molded product 76 that integrally includes each bus bar 28. First, the relay body 92 is placed on top of the integrally molded product 76 from above, so that the front end faces of each stator 16 exposed to the outside in the relay body 92 and the intermediate regions 69 of each bus bar 28 in the integrally molded product 76 are aligned in the front-rear direction. Then, laser welding is performed from the outside (front) of each bus bar 28 to fix the front end faces of each stator 16 and the intermediate regions 69 of each bus bar 28 by welding. This electrically and thermally connects each stator 16 and each bus bar 28. Subsequently, the upper case 72 is placed on top of the assembly of the relay body 92 and the integrally molded product 76 from above, fixing the upper case 72 and the lower case 74 (integrally molded product 76). Furthermore, the method of fixing the upper case 72 and the lower case 74 is not limited, and known fixing methods such as adhesive bonding, welding, press-fitting, and interlocking can be used. This completes the contact relay 10.

[0037] The contact relay 10 manufactured in this manner is, for example, placed on the bottom surface of the housing of an electrical junction box (for example, the lower case that makes up the housing) and fixed to the housing by bolts inserted through each leg portion 88 provided on the case 32. In addition, each relay terminal 34 protrudes outward in the left and right directions from the contact relay 10, and for example, a busbar placed inside the electrical junction box is placed on each relay terminal 34 in the front-to-back direction and fixed by bolts inserted through each bolt insertion hole 70. Furthermore, as described above, both ends of the excitation coil 14 extend to the outside of the contact relay 10 and are connected to an electrical circuit not shown. Note that in the initial state when no current is flowing through the excitation coil 14, each coil spring 48, 52 is at its natural length, and as shown in Figure 2, each movable contact 24 and each fixed contact 22 are in an open state, separated from each other.

[0038] When current is passed through the excitation coil 14 in such a contact relay 10, the iron core member 12, which is a magnetic material located on the inner circumference side of the excitation coil 14, is magnetized. As a result, the shaft 38, spring seat 50, coil spring 52, and movable element 18 connected to the iron core member 12 are also magnetized. Consequently, the movable element 18 is attracted to each stator 16, which is made of metal, and the connection changes to a closed state in which each movable contact 24 and each fixed contact 22 come into contact with each other, as shown by the dashed line in Figure 4. In other words, in the open state, each movable contact 24 and each fixed contact 22 are separated from each other, and the connection between each busbar 28 is electrically interrupted, resulting in an OFF state for the electrical circuit. However, when the excitation coil 14 is energized, it is closed, causing each movable contact 24 and each fixed contact 22 to come into contact with each other, and the connection between each busbar 28 is energized, resulting in an ON state for the electrical circuit. Furthermore, when power is stopped to the excitation coil 14, the magnetization of the iron core member 12 and the movable element 18 connected to it is also released. As a result, the shaft 38 and the movable element 18 are displaced back to their initial positions due to the elastic restorative deformation of the coil springs 48 and 52. This causes the movable contacts 24 and fixed contacts 22 to return to an open state, separated from each other.

[0039] In the contact relay 10 of Embodiment 1, which has the structure described above, the heat generated when current is supplied to the contact relay 10 is dissipated to the heat dissipation target, such as the housing of an electrical junction box, through the thermal connection portion 36 of each busbar 28 and the contact portion 30 of the case 32 (lower case 74) that is thermally connected to the thermal connection portion 36. In particular, in the conventional structure, the busbars were connected from outside the relay housing, and the thermal connection portion of the busbars was also exposed to the outside of the relay housing. However, in Embodiment 1, each busbar 28 is provided integrally with the lower case 74, the connection between each stator 16 and each busbar 28 is realized inside the case 32, and the thermal connection portion 36 of each busbar 28 is also provided inside the case 32. As a result, the contact relay 10 can be made smaller, and the heat dissipation path from the heat-generating part to the heat dissipation target is shortened, improving heat dissipation performance.

[0040] The thermal connection portion 36 of each busbar 28 is embedded in the contact portion 30 of the case 32. This ensures insulation at the thermal connection portion 36, preventing short circuits in the electrical circuit caused, for example, by each busbar 28 unintentionally coming into contact with other components. Furthermore, by positioning the thermal connection portion 36 of each busbar 28 near the contact portion 30 of the case 32, the heat dissipation path can be further shortened, thereby further improving heat dissipation performance.

[0041] A thermal connection portion 36 is provided at one end (rear end) of each busbar 28, and relay terminals 34 are integrally formed at the other end (front end and outward side in the left-right direction) of each busbar 28. Furthermore, each fixed contact 22 (each stator 16) is welded to the intermediate region 69 between the thermal connection portion 36 and the relay terminal 34 of each busbar 28. This eliminates the need to separately provide a heat dissipation busbar that is thermally connected to the heat-generating part of the relay, and a current-carrying busbar that electrically connects the relay to an external busbar, thus reducing the number of parts. In addition, since each stator 16 and each busbar 28 are connected at the intermediate region 69 of each busbar 28, both the current-carrying path from each stator 16 to each relay terminal 34 and the heat-dissipation path from each stator 16 to each thermal connection portion 36 can be shortened, improving both conductivity and heat dissipation performance.

[0042] <Embodiment 2> Hereinafter, the contact relay 100 of Embodiment 2 of this disclosure will be described with reference to Figures 7 and 8. The basic structure of the contact relay 100 of Embodiment 2 is the same as that of Embodiment 1, but the shape of each busbar 102 used in the contact relay 100 is different from that of Embodiment 1. Therefore, in the following description, the differences from Embodiment 1 will be explained, and components and parts that are substantially the same as those in Embodiment 1 will be denoted by the same reference numerals in the figures as in Embodiment 1, and detailed explanations will be omitted.

[0043] <Bus Bar 102> In Embodiment 1, each relay terminal 34 protruded outward in the left-right direction from the front end of each bus bar 28, but in Embodiment 2, the bus bar 102 extends in the front-rear direction along its entire length. Specifically, each bus bar 102 extends behind the rear end of the upper case 72, and the rear end of each bus bar 102 is exposed to the outside from the lower case 104 to form a relay terminal 106. A bolt insertion hole 108 is formed in the central part of each relay terminal 106, and a nut 110 is superimposed below each relay terminal 106, with each bolt insertion hole 108 and the inner hole of each nut 110 communicating with each other in the vertical direction. In Embodiment 2, the lower case 104 is formed as an integrally molded product 112 that integrally includes each bus bar 102 and each nut 90, 110.

[0044] Here, as shown in Figure 8, at the front end of each busbar 102, an upward projection 114 that protrudes upward via a bent portion 68 is the part where the front end surface of each stator 16 is welded by laser welding. Also, as described above, each relay terminal 106 is formed at the rear end of each busbar 102. A thermal connection portion 36 is formed by the intermediate region between each upward projection 114 and each relay terminal 106 in the front-rear direction. In other words, in Embodiment 2, each relay terminal 106 is provided at one end (rear end) of each busbar 102, and each fixed contact 22 (each stator 16) is integrally provided at the other end (front end) of each busbar 102 by welding. Furthermore, a thermal connection portion 36 is provided in the intermediate region of each busbar 102.

[0045] In the contact relay 100 of Embodiment 2, which has the structure described above, the only difference from Embodiment 1 is the location where the relay terminals 106 are provided on each busbar 102, so the same effects as in Embodiment 1 can be achieved. In particular, in Embodiment 2, since the bolt insertion holes 108 in each relay terminal 106 pass through in the vertical direction, the external busbars can be overlapped vertically with each relay terminal 106 and bolted together, thereby improving the work efficiency of assembling the contact relay 100 into the electrical junction box.

[0046] <Embodiment 3> Hereinafter, the contact relay 120 of Embodiment 3 of this disclosure will be described with reference to Figures 9 to 11. The basic structure of the contact relay 120 of Embodiment 3 is the same as that of Embodiment 2, but in Embodiment 2, the section from the welded portion of the stator 16 to each relay terminal 106 was composed of one busbar, whereas in Embodiment 3, the section from the fixed contact 122 to the relay terminal 106 is composed of two busbars, a first busbar 124 and a second busbar 126. In Embodiments 1 and 2, each stator 16 having each fixed contact 22 was substantially cylindrical in shape, whereas in Embodiment 3, a fixed contact 122 is provided at one end (upper end) of each second busbar 126, and the stator is composed of the second busbars 126. In the following description, the differences from Embodiment 2 will be explained, and for components and parts that are substantially the same as those in Embodiment 2, the same reference numerals will be used in the figures, and detailed explanations will be omitted.

[0047] <Bus Bar 124> The first busbar 124 is a member that extends in the front-rear direction throughout its entire length. One end (front end) of the first busbar 124 is a relay terminal 106, and the other end (rear end) is a thermal connection portion 36. Each of these first busbars 124 is formed integrally with the lower case 128, similar to embodiments 1 and 2, and substantially the entirety of each first busbar 124 is embedded in the lower case 128.

[0048] <2nd Bus Bar 126> The second busbar 126 is a member that is bent in a roughly L-shape, with one end (upper end) extending vertically and the other end (rear end) extending in the front-to-back direction, and these vertically extending portion and front-to-back extending portion are connected at the bent portion 68. The vertically extending portion of the second busbar 126 protrudes into the interior of the ceramic case 58 through an insertion hole 130 provided in the lower part of the ceramic case 58, and when the excitation coil 14 is energized and the movable element 18 is magnetized, the movable element 18 is attracted to and makes contact with the vertically extending portion of the second busbar 126. Therefore, in embodiment 3, the vertically extending portion at one end (upper end) of the second busbar 126 constitutes the fixed contact 122.

[0049] Furthermore, in the assembled state of the contact relay 120, the other end of the second busbar 126 (the portion extending in the front-rear direction) is superimposed vertically on the other end of the first busbar 124 (the thermal connection portion 36), and these are welded together by laser welding. That is, in Embodiment 3, the busbar is composed of a first busbar 124 with a relay terminal 106 provided at one end (rear end) and a second busbar 126 with a fixed contact 122 provided at one end (upper end). The other ends of the first busbar 124 and the second busbar 126 are superimposed on each other and welded together to form a single unit. As also shown in Figure 10, through holes 132 are formed in the lower part of the lower case 128 at positions corresponding to these welding locations, and laser welding is performed through these through holes 132. After laser welding, the through holes 132 are covered by a cover member 134 to ensure the insulation of the first busbar 124.

[0050] <Assembly of Contact Relay 120> The contact relay 120 of Embodiment 3 is assembled, for example, by the following assembly method. That is, the assembly method of the relay body 136 is the same as in Embodiment 1, but the ceramic case 58 is placed on top of the shaft 38 and the movable element 18 from the front and fixed to the flat plate member 42, and then one end (the part extending in the vertical direction) of the second bus bar 126 is inserted through the insertion hole 130 provided in the lower part of the ceramic case 58. After that, the ceramic case 58 and the second bus bar 126 are fixed by brazing (brazing 138). This completes the relay body 136.

[0051] Next, the relay body 136 is placed on top of the lower case 128, which integrally houses the first busbar 124, from above, so that the other end of the first busbar 124 (thermal connection portion 36) and the other end of the second busbar 126 (the portion extending in the front-rear direction) overlap each other. Then, laser welding is performed through the through hole 132 provided in the lower part of the lower case 128 to weld the other end of the first busbar 124 and the other end of the second busbar 126. After this laser welding, the through hole 132 is covered with the cover member 134. With this, the assembly of the relay body 136 and the lower case 128 is completed, and the contact relay 120 of Embodiment 3 is completed by placing the upper case 72 on top of the lower case 128 from above and fixing it in place.

[0052] The contact relay 120 of Embodiment 3 is constructed with a first busbar 124 and a second busbar 126 instead of the busbar 102 used in Embodiment 2, and therefore can achieve the same effects as Embodiment 2. In particular, by adopting this structure, a fixed contact 122 is formed at one end (upper end) of the second busbar 126, so there is no need to use a stator 16 with a special shape as in Embodiments 1 and 2, thus simplifying the structure and reducing costs.

[0053] <Embodiment 4> Hereinafter, the contact relay 140 of Embodiment 4 of this disclosure will be described with reference to Figures 12 and 13. The basic structure of the contact relay 140 of Embodiment 4 is the same as that of Embodiment 3, but the shapes of the first busbar 142 and the second busbar 144 of the contact relay 140 are different from those of Embodiment 3. In the following description, the differences from Embodiment 3 will be explained, and components and parts that are substantially the same as those in Embodiment 3 will be denoted with the same reference numerals as in Embodiment 2 in the figures, and detailed explanations will be omitted.

[0054] <1st Bus Bar 142> The shape of the first busbar 142 in Embodiment 4 is the same as that of the busbar 102 in Embodiment 2. That is, the first busbar 142 extends in the front-rear direction along its entire length, and the relay terminal 106 is formed at the rear end, which is one end of the first busbar 142. At the front end, which is the other end of the first busbar 142, an upward projection 114 protrudes upward via a bent portion 68. The thermal connection portion 36 is formed by the intermediate region between the upward projection 114 and the relay terminal 106 in the front-rear direction.

[0055] <2nd Bus Bar 144> The second busbar 144 is a member that is bent in a roughly U-shape, with one end (rear end) and the other end (front end) both extending in the vertical direction, and these vertically extending portions are connected to each other at their respective lower ends. The portion of the second busbar 144 that extends in the vertical direction at the rear end protrudes into the inside of the ceramic case 58 through an insertion hole 130 provided in the lower part of the ceramic case 58, and when the excitation coil 14 is energized and the movable element 18 is magnetized, the movable element 18 is attracted to and makes contact with the portion of the second busbar 144 that extends in the vertical direction at the rear end. Therefore, in Embodiment 4, the fixed contact 146 is formed by the portion of the second busbar 144 that extends in the vertical direction at one end (rear end).

[0056] Furthermore, in the assembled state of the contact relay 140, the portion of the second busbar 144 that extends vertically at the other end (front end) is superimposed in the front-to-back direction on the other end (upward projection 114) of the first busbar 142, and these are welded together by laser welding. In other words, in Embodiment 4, the busbar is composed of a first busbar 142 with a relay terminal 106 provided at one end (rear end) and a second busbar 144 with a fixed contact 146 provided at one end (rear end). The other ends of the first busbar 142 and the second busbar 144 are superimposed on each other and welded together to form a single unit.

[0057] The assembly method for the contact relay 140 in Embodiment 4 is the same as in Embodiment 3. That is, as shown in Figures 12 and 13, a through hole 148 is formed in the front of the upper case 72 at a position corresponding to the welding location of the first bus bar 142 and the second bus bar 144, and laser welding is performed through this through hole 148. After laser welding, the through hole 148 is covered by a cover member 150 to ensure the insulation of the first bus bar 142.

[0058] The contact relay 140 of Embodiment 4, which has the structure described above, differs from Embodiment 3 in that the overlapping direction of the other ends of the first busbar 142 and the second busbar 144 is different, thereby changing the direction of laser irradiation during laser welding. As a result, it can achieve the same effects as Embodiment 3. In other words, in Embodiment 4, welding of the first busbar 142 and the second busbar 144 can be achieved by irradiating with a laser from the front, thereby improving the efficiency of assembly work.

[0059] <Variation> While Embodiments 1 to 4 have been described in detail above as specific examples of the present disclosure, the present disclosure is not limited by these specific descriptions. Modifications, improvements, etc., to the extent that they can achieve the objectives of the present disclosure are included in the present disclosure. For example, the following modifications of embodiments are also included in the technical scope of the present disclosure.

[0060] (1) For example, as shown in Figure 14, the ceramic case 58 covering each fixed contact 122 and each movable contact 24 is not required inside the case 32, as in the contact relay 160 shown in Figure 14. The contact relay 160 shown in Figure 14 is the contact relay 120 of Embodiment 3 with the ceramic case 58 removed, but embodiments 1, 2, and 4 may also adopt a configuration in which no ceramic case is provided.

[0061] (2) In Embodiment 1, the lower case 74 was formed as an integrally molded product 76 comprising each bus bar 28, but the invention is not limited to this embodiment, and the lower case and bus bars may be formed separately and then fixed in place. Also, the thermal connection portion 36 of each bus bar 28 does not need to be embedded in the lower case 74. For example, the thermal connection portion of the bus bar may be exposed to the outside on the lower surface of the lower case, and a thermal conductive member having electrical insulation and thermal conductivity may be provided over substantially the entire lower surface of the lower case. The same applies to Embodiments 2 to 4.

[0062] (3) In embodiments 1 and 2, each busbar 28, 102 and each stator 16 were welded by laser welding, but the method of fixing the busbars and stators is not limited, and they may be fixed with bolts, for example, or they may be formed as a single unit. Similarly, in embodiments 3 and 4, the fixing of the first busbars 124, 142 and the second busbars 126, 144 does not have to be by laser welding, and they may be fixed with bolts, for example. [Explanation of symbols]

[0063] 10 Contact relay (Embodiment 1) 12. Iron core component (magnetic material) 14 Excitation coil 16 Stator 18 Mover 20 Electromagnetic device 22 Fixed contacts 24 Movable contacts 26 Contact device 28 Bus Bar 30 Contact area 32 cases 34 Relay terminals 36 Thermal connection 38 shafts 40 Disc-shaped part 42 Flat plate member 44 Through holes 46 Displacement restricting member 48 Coil Springs 50 Spring seat 52 Coil Springs 54 Protective wall 56 Expanded diameter part 58 Ceramic Case 60 Front wall 62 Peripheral wall part 64 Through hole 66 Thick wall part 67 Through hole 68 Bending section 69 Intermediate area 70 bolt insertion holes 72 Upper Case 74 Lower Case 76 Integrally molded product 78 Upper bottom wall 80 Upper peripheral wall 82 Insulating protrusion 84 Insertion groove 86 Notches 88 Legs 90 Nut 92 Relay main unit 100 Contact relay (Embodiment 2) 102 Bus Bar 104 Lower Case 106 Relay terminals 108 Bolt insertion holes 110 Nut 112 Integrally molded product 114 Upper protrusion 120 Contact Relay (Embodiment 3) 122 Fixed contacts 124 First Bus Bar 126 Second bus bar (stator) 128 Lower Case 130 Through hole 132 Through hole 134 Lid component 136 Relay main unit 138 Row 140 Contact Relay (Embodiment 4) 142 First Bus Bar 144 Second Bus Bar 146 Fixed contacts 148 Through holes 150 Lid member 160 Contact relay (Figure 14)

Claims

1. An electromagnet device that moves a movable element by attracting it to a stator by passing an electric current through an excitation coil provided on the outer circumference of a magnetic material, A contact device having a fixed contact provided on the stator and a movable contact provided on the movable element, wherein as the movable element moves, the movable contact moves, switching between a closed state in which the movable contact is in contact with the fixed contact and an open state in which the movable contact is separated from the fixed contact, A busbar connected to the aforementioned fixed contact, An insulating case housing the electromagnet device, the contact device, and the busbar, and having contact points for the heat dissipation object, It comprises a relay terminal connected to the fixed contact and exposed outside the case, The busbar has a thermal connection portion, and the thermal connection portion is thermally connected to the contact portion. Contact relay.

2. The contact relay according to claim 1, wherein the thermal connection portion of the busbar is embedded in the contact portion of the case.

3. The thermal connection portion is provided on one end of the busbar, and the relay terminal is integrally provided on the other end of the busbar. The contact relay according to claim 1 or claim 2, wherein the fixed contact, which is provided separately from the busbar, is welded to the intermediate region of the busbar.

4. The contact relay according to claim 1 or claim 2, wherein the relay terminal is provided on one end of the busbar and the fixed contact is integrally provided on the other end of the busbar.

5. The contact relay according to claim 4, wherein the busbar comprises a first busbar having the relay terminal at one end and a second busbar having the fixed contact at one end, the stator is formed by the second busbar, and the other ends of the first busbar and the second busbar are overlapped and welded together to form a single unit.

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