Electrical connection unit

Abstract

The purpose of the present invention is to obtain high connection reliability between a connection member and a mating connection member, and to enable easy connection work. The electrical connection unit is connected to a counterpart-side connection member, and is provided with: a connection member that can be brought into contact with the counterpart-side connection member; and a biasing member that imparts a contact pressure between the counterpart connecting member and the connecting member, the biasing member being configured from a shape memory alloy, the shape of the shape memory alloy being memorized so that the contact pressure is increased by temperature rise.

Description

Technical Field

[0001] The invention relates to an electrical connection unit. Background Art

[0002] Patent document 1 discloses a zero insertion force connector, which includes a female pin and a shape memory spring. In Patent document 1, when the shape memory spring is energized and heated, the female pin is opened by the shape restoring force of the shape memory spring. As a result, the installation force when inserting the male pin into the female pin can be made zero. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 8-167456 Summary of the invention Problems to be solved by the invention

[0004] However, in order to improve vibration resistance and suppress contact heating, it is considered that the contact pressure of the contact part needs to be increased. However, if the contact pressure is increased, the force required for connection becomes larger, and there is a possibility that the connection workability will deteriorate. In the technology disclosed in Patent Document 1, it is necessary to turn on the power to heat the shape memory spring when inserting the male pin, which makes the connection operation troublesome.

[0005] Therefore, an object of the present disclosure is to obtain high connection reliability between a connecting member and a counterpart connecting member and to facilitate the connection work. Solutions to Solve Problems

[0006] The electrical connection unit disclosed in the present invention is connected to a connecting member on the other side, and the electrical connection unit comprises: a connecting member capable of contacting the connecting member on the other side; and a force-applying member for applying contact pressure between the connecting member on the other side and the connecting member, wherein the force-applying member is composed of a shape memory alloy, and the shape memory alloy memorizes its shape in a manner that increases the contact pressure by increasing the temperature. Effects of the Invention

[0007] According to the present disclosure, high connection reliability between the connection member and the counterpart connection member can be obtained, and the connection work can be easily performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 Schematic diagram showing a mechatronic unit according to the embodiment. Figure 2 is a perspective view showing an electrical connection unit. Figure 3 It is a perspective view showing the outer connecting end and the urging member. Figure 4 It is a side view showing the outer connecting end and the urging member. Figure 5 It is a partially cutaway perspective sectional view showing the outer connecting end and the urging member. Figure 6 It is an explanatory diagram showing an example of a work of connecting a bus bar to an electrical connection unit. Figure 7 It is an explanatory diagram showing the operation of the electrical connection unit in a use state. DETAILED DESCRIPTION

[0009] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be described below.

[0010] The electrical connection unit of the present disclosure is as follows.

[0011] (1) An electrical connection unit connected to a connecting member on the other side, the electrical connection unit comprising: a connecting member capable of contacting the connecting member on the other side; and a force applying member for applying contact pressure between the connecting member on the other side and the connecting member, the force applying member being composed of a shape memory alloy, the shape memory alloy memorizing a shape in such a way as to increase the contact pressure by increasing the temperature.

[0012] According to the present disclosure, the connection operation can be easily performed by performing the connection operation between the other side connection member and the electrical connection unit before the temperature is raised. In addition, the contact pressure between the connection member and the other side connection member is increased by the temperature increase after the connection, so that high connection reliability can be obtained.

[0013] (2) In the electrical connection unit of (1), the urging member may be in contact with the connection member in a connected state of the counterpart connection member.

[0014] In this case, when the temperature of the connection member rises due to Joule heat, the heat is easily transferred to the urging member, thereby increasing the temperature of the urging member and the contact pressure.

[0015] (3) In the electrical connection unit of (2), the urging member may be in contact with the connection member from a side opposite to a contact portion between the counterpart connection member and the connection member.

[0016] Considering that Joule heat is likely to be generated at the contact portion between the other-side connection member and the connection member, the heat generated at the contact portion is effectively transferred to the urging member, and the temperature of the urging member is likely to rise.

[0017] (4) In the electrical connection unit of any one of (1) to (3), the urging member may memorize the shape so as to increase the contact pressure by increasing the temperature from a temperature range of 25 degrees Celsius ±15 degrees Celsius to 50 degrees Celsius or higher.

[0018] In this case, the connection operation can be easily performed by performing the connection operation of the other side connection member and the electrical connection unit within a temperature range of 25 degrees Celsius ± 15 degrees Celsius. When the force application member is heated to 50 degrees Celsius due to Joule heat, etc., the contact pressure between the connection member and the other side connection member increases, thereby achieving high connection reliability.

[0019] (5) In any one of the electrical connection units of (1) to (4), the connecting member may include: a first contact portion, which contacts the connecting member on the other side; a second contact portion, which contacts the connecting member on the other side from the side opposite to the first contact portion; and a spring portion, which generates an elastic force that sandwiches the connecting member on the other side between the first contact portion and the second contact portion.

[0020] In this case, even in the state before the temperature rises, the mating connection member and the connection member can be maintained in a stably connected state by the spring portion of the connection member.

[0021] (6) In the electrical connection unit of (5), the force-applying member may include: a first force-applying contact portion, which contacts the first contact portion from a side opposite to the first contact portion between the first contact portion and the other-side connecting member; a second force-applying contact portion, which contacts the second contact portion from a side opposite to the second contact portion between the second contact portion and the other-side connecting member; and an intermediate spring portion, which generates an elastic force that applies force to the first force-applying contact portion and the second force-applying contact portion in a direction toward each other.

[0022] Considering that Joule heat is easily generated at the first contact portion and the second contact portion, the heat generated at these contact portions is effectively transferred to the force applying member, and the force applying member is easily heated. In addition, the heated force applying member can effectively press the first contact portion and the second contact portion toward the other side connecting member through the first force applying contact portion and the second force applying contact portion.

[0023] (7) In the electrical connection unit of (6), the intermediate spring portion may include an additional contact portion that contacts the connection member.

[0024] Thus, the heat of the connection member is easily transferred to the urging member through the additional contact portion, and the urging member is effectively heated. The heat can be effectively transferred to the intermediate spring portion through the first urging contact portion, the second urging contact portion and the additional contact portion, and the intermediate spring portion is effectively heated.

[0025] (8) In the electrical connection unit of (7), the first contact portion and the second contact portion may have a positioning protrusion, the intermediate spring portion may have a positioning recess, the positioning protrusion is inserted into the positioning recess, and the positioning protrusion contacts the intermediate spring portion when embedded in the positioning recess.

[0026] Thus, the heat of the connection member is easily transferred to the urging member through the positioning structure of the urging member.

[0027] (9) In the electrical connection unit according to any one of aspects (1) to (8), the urging member may be a Ni—Ti alloy or a Ni—Ti—Cu alloy.

[0028] Thus, the original shape can be restored by shape memory by temperature rise, and the elastic coefficient can be increased to increase the contact pressure between the connecting member and the other connecting member.

[0029] [Details of the embodiments of the present disclosure] Specific examples of the electrical connection unit of the present disclosure are described below with reference to the drawings. In addition, the present disclosure is not limited to these examples, but is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0030] [Implementation Method] The following is a description of the electrical connection unit of the embodiment. The electrical connection unit is a unit connected to the connecting member on the other side. In this embodiment, the electrical connection unit is installed in the rotating motor to connect the coil wire in the rotating motor to the electrical device. The electrical device is, for example, an inverter that drives and controls the rotating motor. Such an electrical connection unit may also be referred to as a terminal block unit.

[0031] <About the overall structure of the mechatronic unit having the electrical connection unit> For the sake of convenience, the overall structure of a mechatronic unit that integrates a rotating electrical machine and an inverter will be described. Figure 1 1 is a schematic diagram showing the mechatronic unit 10 . The mechatronic unit 10 includes a rotating electrical machine 20 and an inverter 12 .

[0032] The rotating electrical machine 20 is a rotating electrical machine including a housing 22, an armature 24, and a field magnet. Figure 1, an example is shown in which an armature 24 as a stator is fixed in a cylindrical housing 22. The excitation is arranged in the armature 24 as a rotor. The excitation rotates by the magnetic field generated by the armature 24, or the armature 24 generates an electromotive force by the rotation of the excitation. In this embodiment, it is assumed that the rotating electric machine 20 is a rotating electric machine that can be used as a three-phase AC motor. In addition to operating as a motor, the rotating electric machine can also operate as a generator on this basis or instead. The rotating electric machine 20 can also be used as an electric motor for driving a vehicle.

[0033] The armature 24 includes a stator core and a plurality of coil wires 26 (see Figure 2 ). The stator core includes a plurality of teeth, and the plurality of teeth are arranged in a manner to surround the rotating shaft. Each coil wire 26 is wound around one or more teeth. At least a portion of the plurality of ends of the plurality of coil wires 26 is a connection end that is led out from between the plurality of teeth toward one end side of the armature 24 in the axial direction and is electrically connected to the inverter 12.

[0034] The inverter 12 is a device having an inverter circuit. It is assumed that the inverter 12 is integrated with the rotating electric machine 20. For example, the inverter 12 is integrated with the housing 22 of the rotating electric machine 20 by bolt fixing or the like.

[0035] The inverter 12 includes a bus bar 18 connected to the output end of the inverter circuit. The bus bar 18 is a thin and long plate-shaped member formed of a metal plate such as copper or copper alloy. In the present embodiment, three bus bars 18 corresponding to three extend in parallel from the inverter 12 toward the rotating electric machine 20 at intervals. The top end of the bus bar 18 may be formed to gradually become thinner toward the top end side (see Figures 3 to 5 ).

[0036] The electrical connection unit 30 is incorporated into the rotating electrical machine 20 as a component constituting the rotating electrical machine 20, for example. The electrical connection unit 30 includes a connection composite member 40. One end of the connection composite member 40 is connected to the end of the coil wire 26, and the other end is supported at a position that can be connected to the end of the bus bar 18 of the inverter 12.

[0037] When the inverter 12 is integrated with the rotating electric machine 20 in which the electrical connection unit 30 is incorporated, the bus bar 18 is arranged at a position where it can be connected to the other end of the connection composite component 40. Thus, the bus bar 18 is connected to the corresponding connection composite component 40. The bus bar 18 is an example of a connecting member on the other side that is a connection target of the connection composite component 40.

[0038] The electrical connection unit 30 will be described in more detail. Figure 2 is a perspective view showing the electrical connection unit 30. Figure 1 and Figure 2As shown, the electrical connection unit 30 includes a connection composite component 40. In the present embodiment, the electrical connection unit 30 includes three connection composite components 40 corresponding to the three phases, respectively.

[0039] The composite connection component 40 is a component connected to the bus bar 18. The composite connection component 40 includes a connection member 42 and a biasing member 60. The connection member 42 is a member that contacts the bus bar 18 and serves as a main current path. The biasing member 60 is a member that applies contact pressure between the connection member 42 and the bus bar 18.

[0040] More specifically, the connection member 42 is an integrated structure of the inner connection end 44, the outer connection end 50, and the intermediate conductor portion 46 interposed between the inner connection end 44 and the outer connection end 50. In the present embodiment, the connection member 42 is formed by punching a sheet of metal plate to form the inner connection end 44, the outer connection end 50, and the intermediate conductor portion 46. Since the connection member 42 is a portion that becomes a current path, it is preferably formed of a metal having better conductivity than the urging member 60. The connection member 42 is formed of, for example, copper or a copper alloy.

[0041] The inner connection terminal 44 is connected to the end of the coil wire 26. For example, the coil wire 26 is composed of a flat conductor, and the end of the flat coil wire 26 and the inner connection terminal 44 are arranged to overlap each other. In this state, the end of the coil wire 26 and the inner connection terminal 44 are tightened and fixed by screws and nuts. Alternatively, the terminal is connected to the end of the coil wire 26 by crimping or welding. The terminal overlaps with the inner connection terminal 44 and is tightened and fixed by screws and nuts.

[0042] The connection structure between the inner connection end 44 and the coil wire 26 is not particularly limited, and may be welding, press-fit connection, crimp connection, etc. The ends of a plurality of coil wires 26 may be connected to the connection composite member 40 .

[0043] The intermediate conductor part 46 is formed in an elongated shape. The intermediate conductor part 46 may be straight or bent in the middle. An inner connection end 44 is provided at one end of the intermediate conductor part 46, and an outer connection end 50 is provided at the other end.

[0044] The electrical connection unit 30 includes a support base 32. The support base 32 holds a plurality of connection composite components 40 at a certain position in a mutually insulated state. In the present embodiment, the support base 32 is formed in a square plate shape. For example, the support base 32 is formed by mold-molding the intermediate conductor portion 46 as an embedded component. The support base 32 may also be a structure in which a plurality of components are combined in a manner that a portion of the connection composite component 40 is supported internally. The inner connection end 44 extends from one end of the intermediate conductor portion 46 and protrudes from the surface of the support base 32 on the side of the armature 24. Thus, the inner connection end 44 is arranged at a position where it can be connected to the end of the coil wire 26. The outer connection end 50 is exposed to the outside from the support base 32. In the present embodiment, it protrudes radially outward from the side of the support base 32 opposite to the armature 24 toward the outside of the armature 24.

[0045] The support base 32 is fixed to the housing 22 of the rotary electric machine 20 by screw fastening or an embedding structure, etc. Thus, the electrical connection unit 30 is held at a certain position in the rotary electric machine 20 .

[0046] In addition, in the connection member 42, the structure for connecting the inner connection end 44 to the connection partner member is arbitrary. In addition, the structure for holding the connection member 42 is also arbitrary.

[0047] The outer connection end 50 protrudes from the support base 32 toward the outside of the rotating electrical machine 20 and is connected to the bus bar 18. In the present embodiment, the outer connection end 50 is configured to clamp the bus bar 18. The biasing member 60 increases the contact pressure when the outer connection end 50 clamps the bus bar 18.

[0048] <About the external connection terminal> The outer connecting end 50 and the urging member 60 of the connecting member 42 will be described in more detail. Figure 3 It is a perspective view showing the outer connecting end 50 and the urging member 60 . Figure 4 It is a side view showing the outer connecting end 50 and the urging member 60 . Figure 5 FIG. 2 is a partially cutaway perspective view showing the outer connecting end 50 and the biasing member 60. Figures 3 to 5 The busbar 18 is partially shown in FIG.

[0049] The outer connection end 50 has a first clamping portion 53A and a second clamping portion 53B. The first clamping portion 53A and the second clamping portion 53B face each other in the thickness direction of the intermediate conductor portion 46. The end of the bus bar 18 is arranged between the first clamping portion 53A and the second clamping portion 53B.

[0050] The first clamping portion 53A is a portion formed by press working of a metal plate, and includes a first base portion 54A, a first spring portion 55A, and a first contact portion 56A.

[0051] The first base portion 54A includes: a square plate-like portion bent from the edge of the other end of the intermediate conductor portion 46 toward one side in the thickness direction of the intermediate conductor portion 46; and a square plate-like portion extending from the top edge of the square plate-like portion toward a direction away from the intermediate conductor portion 46 in a posture parallel to the intermediate conductor portion 46. When the outer connecting terminal 50 is viewed from the side, the first base portion 54A is a plate-like portion bent into an L shape.

[0052] The first spring portion 55A is a portion extending from the top of the first base portion 54A toward the second clamping portion 53B side and bent back into a U-shape by the intermediate conductor portion 46. In the present embodiment, the first clamping portion 53A includes a plurality of (here, two) first spring portions 55A. The two first spring portions 55A are bent back in a state of having a gap therebetween. That is, there is a slit S between the two first spring portions 55A, and each first spring portion 55A can be elastically deformed without interfering with each other. The slit S may also extend in a manner of entering the first base portion 54A side. The slit S may also be omitted.

[0053] The first contact portion 56A is a portion that contacts the bus bar 18. Here, the first contact portion 56A extends from the top end of the first spring portion 55A toward the intermediate conductor portion 46. Here, a plurality of (two) first contact portions 56A extend from the first spring portion 55A, respectively. The first contact portion 56A is bent so as to be closest to the second clamping portion 53B in the middle portion from the base end side toward the top end side. More specifically, the middle portion of the long side direction of the first contact portion 56A is bent at an obtuse angle, and the bent portion is convex toward the second clamping portion 53B side.

[0054] The first contact portion 56A has a partial protrusion 57A that partially protrudes toward the bus bar 18 to be clamped. The partial protrusion 57A only needs to be a protrusion when viewed from the bus bar 18 to be clamped. For example, the partial protrusion 57A is formed by stamping a metal plate. Therefore, the partial protrusion 57A is a protrusion when viewed from the bus bar 18 to be clamped, but may be a recessed portion when viewed from the opposite side.

[0055] In the present embodiment, a partial protrusion 57A is formed at the widthwise center of the curved portion of the first contact portion 56A. The partial protrusion 57A is formed in a partially spherical shape that is elongated along the extending direction of the first contact portion 56A, for example.

[0056] The first spring portion 55A is elastically deformable so that the first contact portion 56A approaches the first base portion 54A. The first contact portion 56A is urged toward the second clamping portion 53B by the elastic force of the first spring portion 55A to restore the original shape.

[0057] A positioning protrusion 58A extends from the tip of the first contact portion 56A. The positioning protrusion 58A is formed to have a width narrower than that of the first contact portion 56A.

[0058] The second clamping portion 53B is a portion formed by press working of a metal plate, and includes a second base portion 54B, a second spring portion 55B, and a second contact portion 56B.

[0059] Here, the intermediate conductor portion 46 is a structure in which two plate-like portions 46a overlap each other. For example, the two plate-like portions 46a are bent by the bent-back portion 46b so as to overlap each other (see Figure 3 ). The two plate-like parts 46a are kept in an overlapping state by the bent folded part 46b. By forming the first clamping part 53A on one plate-like part 46a and forming the second clamping part 53B on the other plate-like part 46a, the first clamping part 53A and the second clamping part 53B can be formed by bending a single metal plate. In addition, the first clamping part 53A and the second clamping part 53B can also be joined and integrated by welding, a tightening structure or screw fastening.

[0060] The second base portion 54B, the second spring portion 55B, and the second contact portion 56B are configured to have mirror symmetry with respect to the first base portion 54A, the first spring portion 55A, and the first contact portion 56A on an imaginary plane passing through the center in the thickness direction of the clamped bus bar 18 .

[0061] That is, the second base portion 54B includes a rectangular plate portion bent from the edge of the one plate portion 46 a toward the side opposite to the first base portion 54A and a plate portion extending from the rectangular plate portion in a direction away from the intermediate conductor portion 46 .

[0062] The second spring portion 55B is a portion that extends from the top end of the second base portion 54B toward the second clamping portion 53B and the intermediate conductor portion 46 is bent back into a U-shape. The second contact portion 56B extends from the top end of the second spring portion 55B toward the intermediate conductor portion 46. Just as the first clamping portion 53A includes a plurality of sets of first spring portions 55A and first contact portions 56A, the second clamping portion 53B includes a plurality of sets of second spring portions 55B and second contact portions 56B. The second contact portion 56B is disposed at a position opposite to the first contact portion 56A, and can contact the bus bar 18 from the side opposite to the first contact portion 56A in the thickness direction of the bus bar 18.

[0063] The curved shapes of the second spring portion 55B and the second contact portion 56B are the same as those of the first spring portion 55A and the first contact portion 56A. The second contact portion 56B has a partial protrusion 57B and a positioning convex portion 58B, similarly to the first contact portion 56A.

[0064] The minimum gap between the first contact portion 56A and the second contact portion 56B in the initial state is smaller than the thickness of the bus bar 18. Before the bus bar 18 is sandwiched, the first contact portion 56A and the second contact portion 56B may or may not be in contact.

[0065] When the bus bar 18 is inserted between the first contact portion 56A and the second contact portion 56B, the first spring portion 55A and the second spring portion 55B are elastically deformed in a manner that increases the gap between the first contact portion 56A and the second contact portion 56B. When the bus bar 18 is arranged between the first contact portion 56A and the second contact portion 56B, the first contact portion 56A and the second contact portion 56B are urged toward each other by the elastic force of the first spring portion 55A and the second spring portion 55B to restore the original shape, and the first contact portion 56A and the second contact portion 56B clamp the bus bar 18. That is, the first spring portion 55A and the second spring portion 55B function as spring portions that generate an elastic force that clamps the bus bar 18 between the first contact portion 56A and the second contact portion 56B.

[0066] The structural example of the spring portion that generates the elastic force for clamping the bus bar 18 between the first contact portion 56A and the second contact portion 56B is not limited to the above example. For example, the spring portion may be a structure that supports only one of the first contact portion and the second contact portion so that it can be elastically displaced. In addition, the outer connection end 50 does not necessarily have to have a spring portion.

[0067] The urging member 60 is a member that applies contact pressure between the connecting member 42 and the bus bar 18 .

[0068] In the present embodiment, the urging member 60 is formed by pressing a metal plate or the like, and includes a first urging contact portion 62 , a second urging contact portion 64 , and an intermediate spring portion 66 .

[0069] The intermediate spring portion 66 includes a pair of curved extensions bent at an acute angle from both ends of the plate-like base toward one main surface of the plate-like base. For example, in a side view of the urging member, the intermediate spring portion 66 is formed into a shape including the base of an isosceles triangle and the corners at both ends of the base.

[0070] The first force contact portion 62 extends from one end of the intermediate spring portion 66, and the second force contact portion 64 extends from the other end of the intermediate spring portion 66. The first force contact portion 62 and the second force contact portion 64 move toward a direction approaching each other as they move away from the intermediate spring portion 66. The top ends of the first force contact portion 62 and the second force contact portion 64 are bent outward and folded back into a ring shape. In addition, corresponding to the plurality of (here two) first contact portions 56A being separated by the slit S, the plurality of (here two) first force contact portions 62 are separated by the slit. Similarly, corresponding to the plurality of (here two) second contact portions 56B being separated by the slit S, the plurality of (here two) second force contact portions 64 are separated by the slit S.

[0071] The first urging contact portion 62 and the second urging contact portion 64 can be opened while elastically deforming the intermediate spring portion 66. The first urging contact portion 62 and the second urging contact portion 64 can be urged in the approaching direction by the elastic force of the intermediate spring portion 66 to restore.

[0072] A positioning recess 66H is formed in the middle spring portion 66, and the positioning protrusions 58A and 58B can be inserted into the positioning recess 66H. Here, the positioning recess 66H is a hole that penetrates the middle spring portion 66 in the thickness direction, and a plurality of (four in this case) positioning recesses 66H are formed corresponding to the plurality of (four in this case) positioning protrusions 58A and 58B.

[0073] In the initial state before the bus bar 18 is connected, the urging member 60 is attached to the connecting member 42 as follows.

[0074] That is, in the space between the first base portion 54A and the second base portion 54B, the urging member 60 is externally fitted to the first contact portion 56A and the second contact portion 56B from the distal end sides of the first contact portion 56A and the second contact portion 56B.

[0075] At this time, the closest portion of the first force-applying contact portion 62 and the second force-applying contact portion 64 is arranged at the recessed portion of the outer surface of the first contact portion 56A and the second contact portion 56B. The recessed portion of the outer surface of the first contact portion 56A and the second contact portion 56B is located on the opposite side of the most protruding portion of the inner surface (i.e., the opposing surface) of the first contact portion 56A and the second contact portion 56B. The most protruding portion of the inner surface (i.e., the opposing surface) of the first contact portion 56A and the second contact portion 56B is the portion that contacts the bus bar 18. Therefore, the force-applying member 60 can contact the contact portions 56A and 56B from the side opposite to the contact portion of the contact portions 56A and 56B of the connecting member 42 and the bus bar 18. Furthermore, when viewed along the direction in which the contact pressure between the contact portions 56A, 56B and the bus bar 18 acts, at least a portion of the contact area between the urging member 60 and the contact portions 56A, 56B overlaps with at least a portion of the contact area between the contact portions 56A, 56B and the bus bar 18 .

[0076] In addition, the positioning protrusions 58A and 58B can be embedded in the above-mentioned positioning recess 66H. As a result, the biasing member 60 is difficult to be displaced laterally relative to the first contact portion 56A and the second contact portion 56B. In the state where the positioning protrusions 58A and 58B are embedded in the above-mentioned positioning recess 66H, the positioning protrusions 58A and 58B can also contact the intermediate spring portion 66. The portion 66P where the positioning protrusions 58A and 58B contact the intermediate spring portion 66 can function as the following additional contact portion 66P: the intermediate spring portion 66 contacts the connecting member 42 at a different place from the portion where the first biasing contact portion 62 and the second biasing contact portion 64 contact the first contact portion 56A and the second contact portion 56B.

[0077] The minimum gap between the first force-applying contact portion 62 and the second force-applying contact portion 64 in the initial state is preferably smaller than the minimum width between the outer surfaces of the first contact portion 56A and the second contact portion 56B in the initial state. Thus, in the initial state before the bus bar 18 is connected, the first contact portion 56A and the second contact portion 56B can be clamped between the first force-applying contact portion 62 and the second force-applying contact portion 64 by the elastic force of the intermediate spring portion 66.

[0078] The urging member 60 is made of a shape memory alloy that memorizes a shape so that the contact pressure between the connection member 42 and the bus bar 18 increases as the temperature rises.

[0079] The temperature before the contact pressure increases is, for example, the temperature at which the bus bar 18 and the connection member 42 are connected, and is, for example, a room temperature. Room temperature is, for example, 25 degrees Celsius ± 15 degrees Celsius. When referring to temperatures below, the temperature is in Celsius.

[0080] The temperature at which the contact pressure increases is a temperature higher than the temperature at which the operation of connecting the bus bar 18 to the connecting member 42 is performed. The temperature at which the contact pressure increases may be, for example, a temperature exceeding room temperature. The temperature at which the contact pressure increases may be, for example, a temperature at which the influence of heating such as Joule heat is added to the ambient temperature of the use environment of the electrical connection unit 30. The temperature at which the contact pressure increases may be, for example, a temperature of 50 degrees or more.

[0081] That is, the urging member 60 may memorize the shape so that the contact pressure increases by increasing the temperature from the temperature range of 25 degrees ± 15 degrees to 50 degrees or more.

[0082] The memorized form may be memorized in such a way that the contact pressure is increased by changing the shape or changing the physical property value due to temperature increase.

[0083] For example, it is considered that the urging member 60 memorizes the shape in such a way that the minimum gap after the contact pressure is increased becomes smaller than the minimum gap between the first urging contact portion 62 and the second urging contact portion 64 at the temperature before the contact pressure is increased. That is, the minimum gap between the first urging contact portion 62 and the second urging contact portion 64 becomes smaller by the temperature increase.

[0084] In addition, for example, the urging member 60 may memorize the shape so that the elastic coefficient, which is an example of a physical property value, increases due to a temperature increase, thereby increasing the spring load.

[0085] The shape memory alloy may be, for example, a Ni-Ti alloy or a Ni-Ti-Cu alloy. If it is a Ni-Ti alloy or a Ni-Ti-Cu alloy, the shape can be memorized by further increasing the elastic coefficient by changing the shape when the temperature changes from a temperature range of 25 degrees ± 15 degrees to above 50 degrees. Thus, by increasing the temperature, the force applied by the force contact parts 62 and 64 to the contact parts 56A and 56B in the approaching direction can be increased.

[0086] Furthermore, the shape memory alloy may be an alloy other than the Ni—Ti alloy or the Ni—Ti—Cu alloy.

[0087] <About the Operation of the Electrical Connection Unit> The operation of the electrical connection unit 30 will be described.

[0088] In the initial state, the urging member 60 is attached to the outer connecting end 50 of the connecting member 42. In addition, before the temperature rises (for example, at room temperature), the gap between the urging contact parts 62 and 64 is relatively wide. Therefore, the urging member 60 can be easily attached to the outer connecting end 50.

[0089] like Figure 6As shown, the bus bar 18 is connected to the outer connection end 50. That is, the bus bar 18 is inserted between the contact parts 56A and 56B. Then, the bus bar 18 contacts the opposing parts of the contact parts 56A and 56B, and here, the parts of the protrusions 57A and 57B. The contact parts 56A and 56B are pushed apart in the direction of separation from each other so that a gap corresponding to the thickness of the bus bar 18 is formed between the contact parts 56A and 56B. At this time, the force F1 of the spring load of the spring parts 55A and 55B and the force F2 of the spring load of the biasing member 60 act on the contact parts 56A and 56B. Therefore, during the insertion operation of the bus bar 18, the contact pressure generated by the combined force of the force F1 and the force F2 acts between the contact parts 56B and 56B and the bus bar 18. Therefore, the friction force proportional to the combined force of the force F1 and the force F2 acts between the contact parts 56B and 56B and the bus bar 18.

[0090] The force F2 is smaller than the force F3 after the temperature rises. Therefore, the force required to connect the bus bar 18 can be reduced. In addition, by reducing the contact pressure during the connection operation, the plating wear of the bus bar 18 and the contact parts 56A and 56B can be suppressed. As a result, in the connection state of the composite component 40 and the bus bar 18, the anti-oxidation and corrosion-resistant plating function can be exerted, and high connection reliability can be obtained.

[0091] Even when the insertion work of the bus bar 18 is completed, if the temperature is normal, the contact pressure due to the combined force of the force F1 and the force F2 acts between the contact portions 56B, 56B and the bus bar 18 .

[0092] When the electrical connection unit 30 is used as a relay connection part of a circuit, Figure 7 As shown, it can be considered that a power source 80 is electrically connected to one of the bus bar 18 and the connection member 42 , and a load 82 is electrically connected to the other. Therefore, current flows through the bus bar 18 and the connection member 42 .

[0093] When current flows through the bus bar 18 and the connecting member 42, the bus bar 18 and the connecting member 42 are heated up due to Joule heat. It is also considered that the contact portion between the bus bar 18 and the connecting member 42 is easily heated up due to Joule heat. The heat of the bus bar 18 and the connecting member 42 is transferred to the force member 60, and the force member 60 is also heated up. As a result, the force member 60 is deformed into a memorized shape, or the physical properties such as the elastic coefficient of the force member 60 are changed, and the spring load of the force member 60 becomes higher. As a result, the force F3 of the force member 60 becomes larger than the above-mentioned force F2. Therefore, the contact pressure between the bus bar 18 and the connecting member 42 also becomes larger. As a result, the bus bar 18 and the connecting member 42 are maintained in a stable contact state even under vibration conditions. In addition, the resistance of the bus bar 18 and the connecting member 42 is reduced, which can suppress excessive heat generation at the contact portion.

[0094] For example, when the electrical connection unit 30 is applied to a power supply circuit or a circuit to which a high voltage is applied, heat generation due to Joule heat is expected. The high voltage is, for example, 60V or more, and more preferably 90V or more.

[0095] However, the electrical connection unit 30 may also be applicable to a signal circuit or a circuit to which a low voltage is applied.

[0096] The temperature increase of the connection member 42 may be caused by heat other than Joule heat in the bus bar 18 and the connection member 42. For example, the connection member 42 may be heated by heat of a control device or a drive circuit around the electrical connection unit 30, heat of an internal combustion engine, or heat of a battery.

[0097] <Effects, etc.> The electrical connection unit 30 constructed as described above comprises: a connection member 42 capable of contacting the bus bar 18; and a force applying member 60 for applying contact pressure between the bus bar 18 and the connection member 42, wherein the force applying member 60 is made of a shape memory alloy that memorizes its shape in such a way as to increase the contact pressure by increasing the temperature.

[0098] Therefore, by performing the connection operation of the bus bar 18 and the electrical connection unit 30 in the state before the temperature is raised, the connection operation can be easily performed with a low insertion force. In addition, since the contact pressure between the bus bar 18 and the connection member 42 is smaller than that after the temperature is raised, the plating wear of the bus bar 18 and the connection member 42 can be suppressed. Therefore, in the connection state of the bus bar 18 and the connection member 42, the plating function can be exerted, and the connection reliability of the bus bar 18 and the connection member 42 can be ensured.

[0099] In addition, after the temperature is raised, the contact pressure between the connecting member 42 and the bus bar 18 is increased, and vibration resistance can be ensured. In addition, the resistance between the connecting member 42 and the bus bar 18 is reduced, and the heat generation of their contact parts can be suppressed. As a result, high connection reliability can be obtained in the heated state. In addition, when returning to normal temperature, since the contact pressure between the bus bar 18 and the connecting member 42 returns to a relatively low state, maintenance accompanied by the insertion and removal of the bus bar 18 relative to the connecting member 42 can be easily implemented.

[0100] For example, in order to improve vibration resistance and suppress heat generation at the contact point, it is assumed that the spring load of the terminal is increased. In this case, the force required for connection becomes larger, and there is a possibility that the connection workability will deteriorate. In order to improve the connection workability, it is considered to install a rod using the principle of a lever, or a structure using the tightening force of a bolt. In these cases, there is a possibility of increasing weight, size, and complexity.

[0101] According to the present electrical connection unit 30, it is possible to suppress the increase in weight, size, and size, and to improve the ease of connection work and the connection reliability. In addition, in the electrical connection unit 30, the connection structure using the above-mentioned rod or bolt can also be applied.

[0102] In addition, when the bus bar 18 and the connection member 42 are connected, the urging member 60 is in contact with the connection member 42, so when the temperature of the connection member 42 rises due to Joule heat, the heat is easily transferred to the urging member 60. Therefore, when the electrical connection unit 30 is in use, the temperature of the connection member 42 is easily increased, and the contact pressure can be effectively increased.

[0103] In addition, it is considered that Joule heat is easily generated at the contact portion between the bus bar 18 and the connection member 42. Therefore, if the urging member 60 contacts the connection member 42 from the side opposite to the contact portion between the bus bar 18 and the connection member 42, the heat generated at the contact portion is effectively transferred to the urging member 60. As a result, when the electrical connection unit 30 is in use, the temperature of the connection member 42 is more likely to rise, and the contact pressure can be more effectively increased.

[0104] If the urging member 60 memorizes the shape in such a way that the contact pressure is increased by heating from the temperature range of 25 degrees ± 15 degrees to 50 degrees or more, the connection workability can be easily performed by performing the connection work of the bus bar 18 and the electrical connection unit 30 within the temperature range of 25 degrees ± 15 degrees. When the urging member 60 is heated to 50 degrees due to Joule heat, etc., the contact pressure between the bus bar 18 and the connection member 42 is increased, so that high connection reliability can be obtained.

[0105] Furthermore, if the urging member 60 is a Ni—Ti alloy or a Ni—Ti—Cu alloy, it can restore its original shape by shape memory when heated, and can increase the elastic coefficient to increase the contact pressure between the connecting member 42 and the bus bar 18 .

[0106] Furthermore, since the connection member 42 includes the first contact portion 56A, the second contact portion 56B, and the spring portions 55A and 55B, the bus bar 18 and the connection member 42 can be maintained in a stably connected state by the spring portions 55A and 55B of the connection member 42 even before the temperature rises.

[0107] In addition, the urging member 60 includes a first urging contact portion 62, a second urging contact portion 64, and an intermediate spring portion 66. The first urging contact portion 62 contacts the first contact portion 56A from the side opposite to the first contact position between the first contact portion 56A and the bus bar 18, and the second urging contact portion 64 contacts the second contact portion 56B from the side opposite to the contact position between the second contact portion 56B and the bus bar 18. Since Joule heat is assumed to be easily generated at the first contact position and the second contact position, the heat generated at those contact positions is effectively transferred to the urging member 60. In addition, the urging member 60 with increased temperature can effectively press the first contact portion 56A and the second contact portion 56B toward the bus bar 18 through the first urging contact portion 62 and the second urging contact portion 64. As a result, in the use state of the electrical connection unit 30, the contact pressure can be effectively increased, and the connection reliability can be improved.

[0108] In addition, the intermediate spring portion 66 includes an additional contact portion 66P that contacts the connection member 42, so that the heat of the connection member 42 is also easily transferred to the urging member 60 through the additional contact portion 66P. Thus, heat is transferred to the urging member 60 via the first urging contact portion 62, the second urging contact portion 64, and the additional contact portion, and the intermediate spring portion 66 is effectively heated.

[0109] In addition, the first contact portion 56A and the second contact portion 56B have positioning protrusions 58A and 58B, and the intermediate spring portion 66 has a positioning recess 66H, and the positioning protrusions 58A and 58B are inserted into the positioning recess 66H. In addition, the positioning protrusions 58A and 58B are in contact with the intermediate spring portion 66 in a state of being embedded in the positioning recess 66H. Therefore, the heat energy of the connecting member 42 is easily transferred to the urging member 60 by the positioning structure.

[0110] [Modifications] In the present embodiment, an example in which the electrical connection unit 30 is a terminal base unit is described, but the structure of the electrical connection unit 30 can be applied to various electrical connection parts other than the terminal base unit.

[0111] In addition, the respective configurations described in the above-mentioned embodiment and the respective modifications can be appropriately combined as long as they do not contradict each other. Description of Reference Numerals

[0112] 10Mechatronics Unit 12 Inverter 18 Bus bar (connecting member on the other side) 20 Rotary motor 22 Shell 24 Armature 26 coil wire 30 electrical connection units 32 Support base 40 Connecting composite parts 42Connecting components 44 Inner connection end 46 Intermediate conductor 46a plate part 46b Bend return portion 50 Outer connection end 53A 1st clamping part 53B Second clamping part 54A 1st base 54B 2nd base 55A 1st spring part (spring part) 55B 2nd spring part (spring part) 56A 1st contact part 56B Second contact part 57A, 57B part of the protrusion 58A, 58B positioning convex parts 60 force member 62 1st force application contact part 64 Second force-applying contact portion 66 Intermediate spring part 66H positioning recess 66P additional contact 80 Power Supply 82 load S-slit

Claims

1. An electrical connection unit connected to a connecting member on the other side, The electrical connection unit comprises: a connecting member capable of contacting the other-side connecting member; and a force applying member for applying contact pressure between the other connecting member and the connecting member, The urging member is made of a shape memory alloy that memorizes a shape so as to increase the contact pressure by increasing the temperature.

2. The electrical connection unit according to claim 1, wherein: In the connected state of the counterpart connection member, the urging member is in contact with the connection member.

3. The electrical connection unit according to claim 2, wherein: The urging member contacts the connecting member from a side opposite to a contact portion between the counterpart connecting member and the connecting member.

4. The electrical connection unit according to any one of claims 1 to 3, wherein: The urging member memorizes a shape so as to increase the contact pressure by raising the temperature from a temperature range of 25 degrees Celsius ±15 degrees Celsius to 50 degrees Celsius or more.

5. The electrical connection unit according to any one of claims 1 to 3, wherein: The connecting member includes: a first contact portion that contacts the other-side connecting member; a second contact portion that contacts the other-side connecting member from a side opposite to the first contact portion; and a spring portion that generates an elastic force that sandwiches the other-side connecting member between the first contact portion and the second contact portion.

6. The electrical connection unit according to claim 5, wherein: The force-applying member includes: a first force-applying contact portion, which contacts the first contact portion from a side opposite to the first contact portion between the first contact portion and the other-side connecting member; a second force-applying contact portion, which contacts the second contact portion from a side opposite to the second contact portion between the second contact portion and the other-side connecting member; and an intermediate spring portion, which generates an elastic force that applies force to the first force-applying contact portion and the second force-applying contact portion in a direction toward each other.

7. The electrical connection unit according to claim 6, wherein: The intermediate spring portion includes an additional contact portion that contacts the connecting member.

8. The electrical connection unit according to claim 7, wherein: The first contact portion and the second contact portion have positioning protrusions, The intermediate spring portion has a positioning recess, and the positioning protrusion is inserted into the positioning recess. The positioning protrusion contacts the intermediate spring portion in a state where the positioning protrusion is fitted into the positioning concave portion.

9. The electrical connection unit according to any one of claims 1 to 3, wherein: The urging member is a Ni-Ti alloy or a Ni-Ti-Cu alloy.

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