Connection structure

Abstract

This connection structure comprises a conductive connection member in which at least one of both axial end parts has a sleeve shape, and a seal structure that is disposed inside the connection member. The connection member includes a first connection part that is formed at one end side and is connectable to a first conductive member, a second connection part that is formed at the other end side and is connectable to a second conductive member, and a separation part which is formed between the first connection part and the second connection part and separates the first conductive member and the second conductive member inside the connection member. The seal structure is disposed in the separation part whereby the inside of the connection member is sealed.

Description

Connection structure

[0001] The present invention relates to a connection structure for conductive members.

[0002] Conventionally, an electrical connection method using a bus bar has been commonly used as a means for electrically connecting an electronically controlled automatic transmission of a vehicle with a control unit, etc. For example, Patent Document 1 discloses an electrical connection structure in which a spring function component is provided between a base end extension and a tip end extension of a bus bar. Meanwhile, Patent Document 2 discloses a technology for enhancing the waterproofing of an electrical connection structure using a connector by injecting a photocurable resin into a gap that should be waterproofed to seal the gap.

[0003] Patent No. 3488998 Patent No. 2650547

[0004] For example, a connection structure for electrically connecting equipment that is subject to fluid pressure, such as hydraulic equipment or water hydraulic equipment, to other equipment is required to prevent fluid leakage into or out of the equipment. In particular, a connection structure with higher sealing performance is desired for application to equipment that generates vibrations during operation.

[0005] The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a technique capable of improving sealing performance in a connection structure for electrically connecting conductive members to each other.

[0006] In order to solve the above problems, the connection structure according to the present invention employs the following configuration. That is, the gist of the present invention is as follows: [1] A connection structure for electrically connecting conductive members, comprising: a connecting member that is conductive and at least one of both axial ends of which is sleeve-shaped; and a seal structure disposed inside the connecting member, wherein the connecting member has a first connection portion formed on one end side and capable of connecting a first conductive member, a second connection portion formed on the other end side and capable of connecting a second conductive member, and a separation portion formed between the first connection portion and the second connection portion and separating the first conductive member and the second conductive member inside the connecting member, and the seal structure is disposed in the separation portion to seal the inside of the connecting member. [2] The connection structure according to [1], wherein at least one of the first connection portion and the second connection portion is formed on an axial end of the connecting member as a crimp portion that is connected to the conductive member by crimping. [3] The connection structure according to [2], wherein L1 is the axial distance between the tip of the crimped portion and the seal structure, and H1 is the height of the crimped portion in the crimping direction before crimping, and L1 ≧ H1 × 0.88. [4] The connection structure according to [2], wherein a slit is formed in the connection member between the crimped portion and the seal structure. [5] The connection structure according to [4], wherein L2 is the axial distance between the tip of the crimped portion and the seal structure, and H2 is the height of the crimped portion in the crimping direction before crimping, and S1 is the depth of the slit in the crimping direction, and L2 ≧ H2 × 0.68 and 0.25 ≦ S1 / H2 ≦ 0.67. [6] The connection structure according to any of [1] to [5], wherein the seal structure is formed by an elastic body fitted in the separation portion. [7] The connection structure according to any one of [1] to [5], wherein the seal structure is formed integrally with the connection member as a partition wall that closes the separation portion. [8] The connection structure according to any one of [1] to [5], wherein the seal structure is formed by a resin molded body that fills the separation portion.[9] The connection structure according to any one of [1] to [8], further comprising an outer periphery seal member arranged on an outer periphery of the connection member, wherein the outer periphery seal member seals the outer periphery of the connection member by continuously covering at least a part of the outer periphery in the axial direction of the connection member in a circumferential direction.

[10] The connection structure according to any one of [1] to [9], wherein the connection member is arranged so as to be subjected to the pressure action of a fluid on at least one end side in the axial direction.

[0007] According to the present invention, it is possible to improve the sealing performance in a connection structure for electrically connecting conductive members to each other.

[0008] FIG. 1 is an overall perspective view of a connection structure according to an embodiment. FIG. 2 is a cross-sectional view of the connection structure according to an embodiment. FIG. 3 is a side view showing a state before crimping of the connection member according to the embodiment. FIG. 4 is a side view schematically showing a state in which a lead wire is crimped to the connection member according to the embodiment. FIG. 5 is a cross-sectional view of a separation portion before and after crimping of the connection member according to the embodiment. FIG. 6 is a side view showing a state before crimping of the connection member according to Modification 1 of the embodiment. FIG. 7 is a top view showing a state before crimping of the connection member according to Modification 1 of the embodiment. FIG. 8 is a perspective view showing a state before crimping of the connection member according to Modification 2 of the embodiment. FIG. 9 is a cross-sectional view of a connection structure according to Modification 3 of the embodiment. FIG. 10 is a cross-sectional view of a connection structure according to Modification 4 of the embodiment. FIG. 11 is a diagram showing simulation results of an example.

[0009] Specific embodiments of the present invention will be described below with reference to the drawings. The dimensions, materials, shapes, and relative positions of the components described in the following embodiments are not intended to limit the technical scope of the present invention unless otherwise specified.

[0010] One embodiment of the present invention is a connection structure for electrically connecting conductive members. Specifically, the connection structure is attached to a device that is subject to fluid pressure, and electrically connects a first cable (conductive member) provided inside the device with a second cable (conductive member) provided outside the device. The connection structure includes a conductive connection member having a sleeve-shaped end at least on one of its axial ends, a seal structure disposed within the connection member, and a peripheral seal member. That is, the connection member may have a sleeve-shaped connection portion on both axial ends, or may have a sleeve-shaped connection portion on only one end. The connection member is formed in a cylindrical shape and has a first connection portion at one longitudinal end to which a first cable can be connected, a second connection portion at the other longitudinal end to which a second cable can be connected, and a separation portion between the first and second connection portions that separates the first and second cables. The connection member is inserted into a mounting hole that penetrates the device from the inside to the outside. The seal structure is disposed in the separation portion of the connection member to seal the interior of the connection member. The outer periphery seal member is disposed so as to cover the outer periphery of the connection member, thereby sealing the outer periphery of the connection member.

[0011] Here, the term "fluid" is not limited to liquid and may also be gas. Furthermore, "fluid pressure" may include pressure acting from inside the device (internal pressure) and pressure acting from outside the device (external pressure). The connection structure according to the present invention can be applied to devices that are subject to fluid pressure, but the device to which the connection structure is attached is not particularly limited. Examples of devices to which the connection structure is applied include hydraulic devices that operate using hydraulic pressure and water hydraulic devices that operate using water pressure. Furthermore, the device to which the connection structure is applied may be, for example, a liquid-cooled electric motor (rotating electric machine) in which cooling water or oil is supplied to the motor case. Furthermore, the "second conductive member" may be a cable provided in a device (another device) other than the device to which the connection structure is applied, or a cable provided in the device to which the connection structure is applied.

[0012] [Overall Configuration] Hereinafter, as an embodiment, a description will be given of an aspect in which a connection structure according to the present invention is applied to an electric motor. Fig. 1 is an overall perspective view of a connection structure 100 according to the embodiment. Fig. 2 is a cross-sectional view of the connection structure 100 according to the embodiment. Figs. 1 and 2 show a state in which lead wires 10, 20 are crimped to a connection member 1 and are electrically connected.

[0013] 2, the connection structure 100 is attached to the motor 200. More specifically, the connection structure 100 is attached to a case 200a that is the housing of the motor 200.

[0014] The motor 200 is a three-phase motor used as a driving power source for, for example, hybrid vehicles, electric vehicles, etc. In FIG. 2 , the symbol IS indicates the internal space of the case 200a (i.e., the interior of the motor 200), and the symbol ES indicates the external space of the case 200a (i.e., the exterior of the motor 200). The internal space IS of the case 200a accommodates a stator, coils, a rotor, a shaft, etc. The motor 200 is liquid-cooled, and cooling oil is supplied to the internal space IS of the case 200a. Therefore, the pressure of the cooling oil acts on the motor 200 from the internal space IS side. As shown in FIG. 2 , the case 200a is formed with an attachment opening 200b for attaching the connection structure 100. The attachment opening 200b penetrates from the inside to the outside of the case 200a.

[0015] The motor 200 also has three lead wires 10 (an example of a "first conductive member" according to the present invention) that are cables for inputting three-phase AC to the coils. The three lead wires 10 are arranged in the internal space IS of the case 200a (i.e., inside the motor 200), and each lead wire 10 corresponds to a coil of each phase. The lead wires 10 also include a conductive wire 101 made of a conductive material and an insulating tube 102 made of an electrically insulating material that covers the conductive wire 101. The tip of the conductive wire 101 is exposed from the insulating tube 102, thereby forming the tip of the lead wire 10.

[0016] Additionally, three lead wires 20 (an example of a "second conductive member" according to the present invention) connected to an inverter, which is an external device (other device) of the motor 200, are disposed in the external space ES of the case 200a (i.e., outside the motor 200). The lead wires 20 are cables that are electrically connected to the lead wires 10 of the motor 200 to supply AC current generated by the inverter to the lead wires 10 of the motor 200. Each of the three lead wires 20 corresponds to a respective lead wire 10. The lead wires 20 include a conductive wire 201 formed from a conductive material and an insulating tube 202 formed from an electrically insulating material and covering the conductive wire 201. The tip of the conductive wire 201 is exposed from the insulating tube 202, thereby constituting the tip of the lead wire 20.

[0017] In this embodiment, the conductive wire 101 of the lead wire 10 and the conductive wire 201 of the lead wire 20 are formed as twisted wires in which multiple metal (e.g., copper) linear conductors are bundled and twisted together. However, the present invention is not limited to this. The first conductive member and the second conductive member according to the present invention may be formed as twisted wires or as single wires (single-core) consisting of a single linear conductor. Furthermore, the first conductive member and the second conductive member need not be electric wires (lead wires) as long as they are capable of transmitting electricity. The first conductive member and the second conductive member may be, for example, bus bars or electric wires with terminal-shaped conductors provided at the ends thereof. Furthermore, the number of the first conductive member and the second conductive member may be multiple or not multiple.

[0018] The connection structure 100 according to this embodiment is configured to electrically connect a lead wire 10 provided inside a motor 200 to a lead wire 20 provided outside the motor 200, and to seal the inside and outside of the motor 200. As shown in Figure 2, the connection structure 100 includes a connection member 1, a seal structure 2, a holder 3, a multiple grommet 4 (an example of an "outer peripheral seal member" according to the present invention), a gasket 5, and a bolt 6. Each component of the connection structure 100 will be described below.

[0019] [Holder, Gasket, and Bolt] The holder 3 is a component that holds the connection member 1 and is attached to the mounting opening 200b of the motor 200. The holder 3 is made of an electrically insulating material and has electrical insulation properties. The material of the holder 3 is not particularly limited, but examples include resin materials such as PPS (polyphenylene sulfide). The holder 3 has a fitting portion 31 and a plate portion 32. The fitting portion 31 is formed in a cylindrical shape and fits into the mounting opening 200b. The plate portion 32 is formed in a plate shape perpendicular to the axial direction of the fitting portion 31 and is provided at the end of the fitting portion 31 on the external space ES side. The plate portion 32 has a closing portion 32a that closes the end of the fitting portion 31 and a fixing portion 32b that protrudes outward beyond the fitting portion 31. The fixing portion 32b abuts against the surface of the case 200a on the external space ES side and is fixed to the case 200a with bolts 6. The holder 3 has a recess 3a, which is a space surrounded by the fitting portion 31 and the closing portion 32a. The recess 3a is recessed relative to the internal space IS of the case 200a. A multiple grommet 4 is attached to the recess 3a. The closing portion 32a also has a mounting hole 3b into which the connecting member 1 is inserted. The mounting hole 3b is connected to the recess 3a and penetrates the inside and outside of the case 200a (i.e., the inside and outside of the motor 200).

[0020] The gasket 5 is made of an elastic material and is attached to the outer periphery of the fitting portion 31 of the holder 3 to seal between the outer periphery of the fitting portion 31 and the inner wall surface of the mounting opening 200b. The material of the gasket 5 is not particularly limited, but examples include rubber such as ACM (acrylic rubber), resin materials, etc. The gasket 5 may also be made of metal.

[0021] The bolt 6 is a fastening member that fastens the fixing portion 32b of the holder 3 to the case 200a, thereby fixing the connection structure 100 to the motor 200.

[0022] [Connection Member] The connection member 1 is formed in a cylindrical shape and configured as crimp terminals to which electric wires can be crimped at both ends. In other words, the connection member 1 is configured as a crimp sleeve. The connection member 1 is inserted into a mounting hole 3b that penetrates the interior and exterior of the motor 200. Here, with respect to the connection member 1, the direction in which the central axis A1 of the connection member 1 extends (i.e., the extension direction of the connection member 1) is defined as the "axial direction," the radial direction of the connection member 1 is defined as the "radial direction," and the direction around the axis of the connection member 1 is defined as the "circumferential direction." Both ends of the connection member 1 are crimped by plastic deformation such that they are crushed by pressure applied from the radial outside. Note that although the connection member 1 according to this embodiment is formed in a cylindrical shape, it may also be formed in a rectangular tube shape. The connection member 1 is positioned so that at least one axial end thereof is subjected to the pressure action of a fluid.

[0023] The connection member 1 can crimp the lead wires 10, 20 to their respective ends by crimping the conductive wires 101, 201 of the lead wires 10, 20 inserted into each end. The connection member 1 is made of metal and is conductive. Therefore, the conductive wires 101 and 201 are electrically connected via the connection member 1, and the lead wires 10 and 20 are electrically connected. Examples of materials for the connection member 1 include metal materials such as copper, aluminum, and silver. The material of the connection member according to the present invention is not particularly limited, and may be any material that is conductive and can be crimped. The connection member according to the present invention does not need to be entirely conductive, as long as at least a portion of it is conductive. For example, the connection member may be a metal tubular member whose outer periphery is coated with a resin material.

[0024] The connection structure 100 according to this embodiment includes three connection members 1, corresponding to the number of combinations of lead wires 10 and 20 to be connected to each other. However, the number of connection members according to the present invention is not limited to a plurality. The number of connection members can be changed as appropriate depending on the number of pairs of first conductive members and second conductive members to be connected.

[0025] 2, the connection member 1 has a sleeve-shaped first connection portion 11 at one end in the axial direction, a sleeve-shaped second connection portion 12 at the other end in the axial direction, and a hollow separation portion 13 between the first connection portion 11 and the second connection portion 12. The connection member 1 is inserted into the mounting hole 3b of the holder 3 so that the first connection portion 11 is located in the internal space IS of the case 200a, the second connection portion 12 is located in the external space ES of the case 200a, and the separation portion 13 is located in the mounting hole 3b of the holder 3.

[0026] The first connection portion 11 and the second connection portion 12 according to this embodiment are both formed in a sleeve-like shape having a hollow structure and are formed at the axial end of the connection member 1 as crimping portions, which are portions connected to conductive members by crimping. However, the present invention is not limited thereto, and at least one of the first connection portion and the second connection portion may be sleeve-shaped. In other words, the connection member may have at least one of its axial ends in a sleeve-shaped configuration. Furthermore, the present invention also allows at least one of the first connection portion and the second connection portion to be formed as a crimping portion, and does not require both the first connection portion and the second connection portion to be crimping portions. For example, one of the first connection portion and the second connection portion may be configured as a sleeve-shaped crimping portion, while the other may not be sleeve-shaped and may be configured so that a conductive member such as a bus bar can be connected to the end opposite the sleeve by screwing or the like. Hereinafter, when the first connection portion 11 and the second connection portion 12 are described without distinction, they will be simply referred to as "crimping portions."

[0027] The first connection portion 11 is formed by one end portion of the connection member 1, and is capable of connecting the lead wire 10. When the conductive wire 101, which is the tip portion of the lead wire 10, is inserted into the first connection portion 11, the first connection portion 11 is crimped, whereby the lead wire 10 is crimped to the first connection portion 11.

[0028] The second connection portion 12 is formed by the other end portion of the connection member 1, and is capable of connecting a lead wire 20. When the second connection portion 12 is crimped with the conductive wire 201, which is the tip portion of the lead wire 20, inserted into the second connection portion 12, the lead wire 20 is crimped to the second connection portion 12.

[0029] As shown in FIG. 2, the lead wires 10 and 20 are crimped to the connection member 1 while being spaced apart from each other inside the connection member 1 .

[0030] The separation portion 13 is formed hollow at a portion between both ends of the connection member 1. By interposing the separation portion 13 between the first connection portion 11 and the second connection portion 12, the lead wires 10 and 20 are separated from each other, creating a non-contact state. The separation portion 13 is sealed internally by disposing the seal structure 2 therein. The separation portion 13 is also sealed at its outer periphery by being covered by the multiple grommet 4. Note that, in this embodiment, the separation portion 13 is formed at the central position of the connection member 1 in the axial direction, but the present invention is not limited thereto. The position of the separation portion 13 does not have to be the central position of the connection member 1 in the axial direction.

[0031] Here, the radial direction of the connection member 1 in which the crimping portions (first connection portion 11 and second connection portion 12) are pressurized for crimping is referred to as the "crimping direction." The crimping direction of the first connection portion 11 is referred to as the "first crimping direction," and the crimping direction of the second connection portion 12 is referred to as the "second crimping direction." In the connection member 1 according to this embodiment, the first crimping direction and the second crimping direction are the same. However, as in Modification 2 described below, the first crimping direction and the second crimping direction may be different.

[0032] FIG. 3 is a side view showing the state of the connection member 1 according to the embodiment before crimping. FIG. 3 illustrates the connection member 1 before plastic deformation due to crimping, as viewed in a direction perpendicular to the first crimping direction (second crimping direction) and the axial direction. FIG. 4 is a side view schematically illustrating the state in which the lead wires 10 and 20 are crimped to the connection member 1 according to the embodiment. FIGS. 3 and 4 illustrate the state in which the seal structure 2 is disposed in the separation portion 13. As shown in FIG. 4 , the crimping process causes the crimping portions (the first connection portion 11 and the second connection portion 12) to be crushed in the crimping direction and plastically deformed, so that the conductive wire 101 of the lead wire 10 is crimped to the first connection portion 11, and the conductive wire 201 of the lead wire 20 is crimped to the second connection portion 12.

[0033] Here, since the separation portion 13 is a portion whose outer periphery is sealed by the multiple grommet 4 as described below, from the viewpoint of improving the adhesion between the separation portion 13 and the multiple grommet 4 and improving the sealing performance of the outer periphery, it is preferable to suppress plastic deformation of the separation portion 13 as much as possible during the crimping process of the connecting member 1. If the amount of deformation of the separation portion 13 due to the plastic deformation of the crimped portion is large, it is necessary to increase the axial length of the separation portion 13 and seal the outer periphery at a position sufficiently distant from the crimped portion (i.e., a position where the amount of deformation of the separation portion 13 is small) in order to ensure the sealing performance of the outer periphery.

[0034] FIG. 5 is a cross-sectional view of the separation portion 13 before and after crimping of the connection member 1 according to the embodiment. FIG. 5 illustrates a cross-section of the separation portion 13 before the lead wires 10 and 20 are crimped to the connection member 1, and a cross-section of the separation portion 13 after the lead wires 10 and 20 are crimped to the connection member 1. The cross-section shown in FIG. 5 is a cross-section perpendicular to the axial direction. In the example shown in FIG. 5, the separation portion 13 is crushed in the crimping direction and deformed into an ellipse due to the influence of plastic deformation of the crimped portion during crimping. Here, the outer diameter of the separation portion 13 before crimping is defined as DB, and the minor axis (outer diameter in the short direction) of the elliptical deformed separation portion 13 after crimping is defined as DA. The amount of deformation, which is the difference between DB and DA, is defined as DX. That is, DX = DB - DA. In this case, from the viewpoint of improving the sealing performance of the outer periphery, DX is preferably 0.085 mm or less. In other words, it is preferable that the connecting member 1 is configured so that DX≦0.085 mm. By keeping DX of the separation portion 13 at 0.085 mm or less, the sealing performance of the outer periphery at the separation portion 13 can be improved. Furthermore, the axial length of the separation portion 13 is sufficient as long as it is long enough to ensure space in which the seal structure 2 can be arranged, and it is not necessary to make it large in consideration of plastic deformation of the separation portion 13. This allows the length of the separation portion 13 to be set short, thereby realizing space-saving and cost-saving of the connecting member 1.

[0035] As shown in FIG. 3 , no slit 14 (see FIG. 6 ) is formed between the crimped portion and the separation portion 13 of the connection member 1 (i.e., between the crimped portion and the seal structure 2), as in the modified example 1 described below. Instead, the connection member 1 is continuous in the axial and circumferential directions. In this case, the axial distance between the tip of the crimped portion and the seal structure 2 is defined as L1. Specifically, L1 is the axial distance from the axially most distal point of the crimped portion (i.e., the point farthest from the seal structure 2) to the point on the seal structure 2 closest to the crimped portion. Furthermore, the height of the crimped portion in the crimping direction before crimping (before plastic deformation) is defined as H1. In this case, it is preferable that L1 ≥ H1 × 0.88. This reduces the effect of plastic deformation of the crimped portion on the separation portion 13, thereby suppressing plastic deformation of the separation portion 13. This allows the deformation amount DX of the separation portion 13 to be kept to 0.085 mm or less. As a result, the sealing performance of the outer periphery of the separation portion 13 can be further improved. Furthermore, from the viewpoint of space saving, it is preferable that L1 ≦ H1 × 6, and it is more preferable that L1 ≦ H1 × 4. By doing so, it is possible to prevent the connection member 1 from becoming large, and to achieve space saving.

[0036] Furthermore, the thickness (radial thickness) of the connecting member 1 at the first connecting portion 11 is T1, the thickness of the connecting member 1 at the second connecting portion 12 is T2, and the thickness of the connecting member 1 at the separation portion 13 is T3. In this case, T1 < T3 and T2 < T3 may be set. That is, the thickness of the separation portion 13 may be set to be greater than the thickness of the crimped portion. By forming the separation portion 13 thicker than the crimped portion, the crimped portion can be made more easily deformed than the separation portion 13. As a result, in the crimping process of the connecting member 1, the first connecting portion 11 and the second connecting portion 12 undergo plastic deformation preferentially over the separation portion 13, and therefore plastic deformation of the separation portion 13 can be suppressed.

[0037] [Sealing Structure] As shown in Fig. 2 , the sealing structure 2 according to this embodiment is a spherical plug made of an elastic material, and is disposed in the separation portion 13 to seal the interior of the connecting member 1. The sealing structure 2 is made of rubber, such as ACM (acrylic rubber), and is elastically deformable. The sealing structure 2 is fitted into the separation portion 13 while being compressed in the radial direction of the connecting member 1. The restoring force of the sealing structure 2 brings the surface of the sealing structure 2 into contact with the inner surface of the separation portion 13 without any gaps, thereby closing the separation portion 13 and sealing the interior of the connecting member 1. This prevents fluid from passing through the interior of the connecting member 1 and leaking.

[0038] The shape of the seal structure according to the present invention is not limited to a sphere. The seal structure may be cylindrical or a truncated cone with a tapered outer periphery, and may have elastically deformable protrusions or irregularities formed on the outer periphery. The periphery may also be chamfered. The material of the seal structure is not limited to rubber. Examples of materials for the seal structure include, but are not limited to, elastic materials such as rubber, cured materials such as resin materials and adhesives, and metal materials. The seal structure may also be a resin molded body integrally molded with the connecting member by resin insert molding, as in Variation 4 described below. Furthermore, the seal structure according to the present invention does not need to be electrically insulating and may be conductive as long as it can seal the interior of the connecting member. Forming the seal structure from a conductive material allows current to flow not only through the connecting member but also through the seal structure, thereby improving the electrical conductivity of the entire connection structure. Furthermore, when the seal structure is formed from a conductive material, it is preferable that the seal structure be arranged so as to contact both the first conductive member and the second conductive member. This allows current to flow more easily between the first and second conductive members through the seal structure, further improving electrical conductivity. When the seal structure is made of metal, the seal structure may be a metal partition plate that is arranged perpendicular to the axial direction and divides the internal space of the connection member in the axial direction, and is fixed to the connection member by brazing, for example. In addition, in this embodiment, the seal structure is configured as the seal structure 2, which is a separate component from the connection member 1, but the seal structure may also be configured as an integral component with the connection member. In other words, the seal structure may be part of the connection member. In this case, the seal structure may be formed as a metal partition wall that is arranged approximately perpendicular to the axial direction and divides the internal space of the connection member 1 in the axial direction, as in Variation 3 described below.

[0039] 2 , the multiple grommet 4 is formed in a plate shape from an elastic and electrically insulating material, and is disposed in the recess 3a of the holder 3 so as to cover the outer periphery of the connection member 1, thereby sealing the outer periphery of the connection member 1. More specifically, the multiple grommet 4 continuously covers the outer periphery of a portion of the connection member 1 in the axial direction, including the separation portion 13. However, in the present invention, the portion of the connection member 1 that is covered by the outer periphery seal member is not particularly limited. The outer periphery seal member according to the present invention may be one that continuously covers at least a portion of the outer periphery of the connection member in the axial direction, but is not limited thereto.

[0040] The multiple grommet 4 has a through hole 4a formed therein that extends along the axial direction of the connecting member 1. The connecting member 1 is inserted through the through hole 4a. In this embodiment, three through holes 4a are formed, corresponding to the number of connecting members 1. As a result, the multiple grommet 4 has a structure in which multiple grommets (three in this example) are integrated. The material of the multiple grommet 4 is not particularly limited, but examples include rubber such as ACM (acrylic rubber) and resin materials.

[0041] A protrusion 41 is formed on the outer periphery of the multiple grommet 4, and a protrusion 42 is formed on the inner wall of the through hole 4a. The protrusions 41, 42 are formed as annular protrusions that are continuous in the circumferential direction and are elastically deformable. The multiple grommet 4 is fitted into the recess 3a of the holder 3 with the protrusion 41 crushed and compressed. The restoring force of the protrusion 41 brings the outer surface of the multiple grommet 4 into contact with the inner surface of the recess 3a without any gaps, thereby sealing the gap between the multiple grommet 4 and the holder 3. The connecting member 1 is inserted into the through hole 4a so as to crush and compress the protrusion 42. The restoring force of the protrusion 42 brings the outer surface of the connecting member 1 into contact with the inner wall surface of the through hole 4a without any gaps, thereby sealing the gap between the connecting member 1 and the multiple grommet 4. In this way, the multiple grommet 4 seals the gap between the connecting member 1 and the holder 3. As a result, the outer periphery of the connecting member 1 is sealed. This prevents fluid from leaking past the outer periphery of the connecting member 1 .

[0042] In this embodiment, a multiple grommet 4, in which multiple grommets are integrated, is used as the peripheral seal member, but the peripheral seal member according to the present invention is not limited to this. The peripheral seal member may be a single grommet or a single O-ring that seals the periphery of each connecting member. Furthermore, as long as electrical insulation between multiple connecting members is ensured, the peripheral seal member according to the present invention does not need to be electrically insulating and may be conductive. Furthermore, the peripheral seal member may be a resin molded body integrally molded with the connecting members and holder by resin insert molding.

[0043] [Operations and Effects] As described above, the connection structure 100 according to this embodiment is attached to the motor 200, which is subjected to fluid pressure, and electrically connects the lead wire 10 provided inside the motor 200 to the lead wire 20 provided outside the motor 200. The connection structure 100 includes a connecting member 1 that is conductive and has at least one sleeve-shaped axial end, and a seal structure 2 disposed within the connecting member 1. The connecting member 1 has a first connection portion 11 formed on one end thereof and to which the lead wire 10 can be connected, a second connection portion 12 formed on the other end thereof and to which the lead wire 20 can be connected, and a separation portion 13 formed between the first connection portion 11 and the second connection portion 12 and that separates the lead wire 10 and the lead wire 20 within the connecting member 1. The seal structure 2 is disposed in the separation portion 13 to seal the interior of the connecting member 1.

[0044] The connection structure 100 configured as described above can electrically connect the lead wire 10 and the lead wire 20 by connecting the lead wire 10 to the first connection portion 11 and the lead wire 20 to the second connection portion 12. Furthermore, by disposing the seal structure 2 in the separation portion 13 and sealing the interior of the connection member 1, it is possible to prevent fluid from passing through the interior of the connection member 1 and leaking. In this embodiment, the conductive wires 101 of the lead wire 10 and the conductive wires 201 of the lead wire 20 are twisted together. This may allow oil to penetrate into the interior of the lead wires 10 and 20 due to capillary action. However, because the lead wires 10 and 20 are isolated from each other by the seal structure 2 within the connection member 1, this also prevents oil from leaking through the interior of the lead wires 10 and 20. As described above, this embodiment can prevent oil from leaking from the internal space IS of the motor 200 through the interior of the connection member 1 and into the external space ES of the motor 200. As a result, this embodiment can improve the sealing performance of the connection structure 100.

[0045] Furthermore, the connection structure 100 according to this embodiment employs a simple structure in which a sealing member is disposed inside the connection member 1, and is therefore relatively inexpensive, and can provide a reliable seal even when applied to equipment that generates vibrations during operation, such as the motor 200. As a result, the connection structure 100 according to this embodiment can reliably achieve improved sealing performance with a relatively inexpensive structure.

[0046] In this embodiment, the mounting holes 3b are formed in the holder 3 that is attached to the case 200a of the motor 200, but the present invention is not limited to this. The holder 3 is not an essential component of the present invention, and the mounting holes according to the present invention may be formed in, for example, the housing of the device.

[0047] In this embodiment, at least one of the first connection portion 11 and the second connection portion 12 is formed as a crimping portion that is connected to a conductive member by crimping at an axial end of the connection member 1. By forming at least one of the first connection portion 11 and the second connection portion 12 as a crimping portion with a relatively simple structure, conductive members can be electrically connected to each other with a relatively inexpensive structure. However, in the present invention, the connection method of the first connection portion and the second connection portion is not limited to crimping.

[0048] Furthermore, the seal structure 2 according to this embodiment is formed by an elastic body fitted into the spaced portion 13. This allows the inside of the connection member 1 to be reliably sealed.

[0049] The connection structure 100 according to this embodiment also includes a multiple grommet 4 disposed on the outer periphery of the connection member 1. The multiple grommet 4 seals the outer periphery of the connection member 1 by continuously covering at least a portion of the outer periphery of the connection member 1 in the axial direction. Thus, sealing the outer periphery of the connection member 1 with the multiple grommet 4 prevents fluid from passing through the outer periphery of the connection member 1 and leaking. In other words, oil in the internal space IS of the motor 200 is prevented from passing through the outer periphery of the connection member 1 and leaking into the external space ES of the motor 200. In this way, the connection structure 100 according to this embodiment can seal the interior of the connection member 1 with the seal structure 2 and seal the outer periphery of the connection member 1 with the multiple grommet 4. As a result, while electrically connecting the inside and outside of the motor 200, it is possible to prevent oil in the internal space IS of the motor 200 from leaking into the external space ES of the motor 200. Note that the peripheral seal member is not a required component of the present invention.

[0050] [Modifications] Modifications of the connecting member according to this embodiment will be described below. In the following description of the modifications, differences from the connecting member 1 described using Figures 1 to 5 will be mainly described, and the same components as those of the connecting member 1 will be assigned the same reference numerals and detailed description will be omitted. [Modification 1]

[0051] FIG. 6 is a side view showing a state of the connection member 1A according to Modification 1 of the embodiment before crimping. FIG. 6 illustrates the connection member 1A before plastic deformation by crimping, as viewed along a direction perpendicular to the first crimping direction and the axial direction. In Modification 1, the first crimping direction and the second crimping direction are the same. FIG. 7 is a top view showing a state of the connection member 1A according to Modification 1 of the embodiment before crimping. FIG. 7 illustrates the connection member 1A before plastic deformation by crimping, as viewed along the first crimping direction (second crimping direction). FIGS. 6 and 7 illustrate a state in which the seal structure 2 is disposed in the separation portion 13. As shown in FIGS. 6 and 7, slits 14, which are notches penetrating the connection member 1A, are formed between the first connection portion 11 and the separation portion 13 and between the second connection portion 12 and the separation portion 13 in the connection member 1A. That is, a slit 14 is formed in the connection member 1A between the crimping portion and the seal structure 2. As shown in FIG. 7 , the slit 14 is formed linearly and extends in a direction substantially perpendicular to the crimping direction and the axial direction. When viewed in the crimping direction, the slit 14 extends across the central axis A1 of the connection member 1A and is formed axially symmetrical with respect to the central axis A1. The slit 14 divides the connection member 1A into a first connection portion 11, a separation portion 13, and a second connection portion 12. Hereinafter, the slit 14 formed between the first connection portion 11 and the separation portion 13 may be denoted by the reference numeral 141, and the slit 14 between the second connection portion 12 and the separation portion 13 may be denoted by the reference numeral 142.

[0052] The shape of the slit according to the present invention is not limited to a linear shape. The slit according to the present invention may be an elliptical shape whose major axis is substantially perpendicular to the axial direction of the connection member 1A, or a polygonal shape whose longitudinal direction is substantially perpendicular to the axial direction of the connection member 1A. Examples of polygonal shapes include a triangular shape, a rectangular shape, and a diamond shape. The inclination angle of the slit with respect to the axial direction is not limited to approximately 90°. The slit may be inclined with respect to the axial direction and the radial direction. However, the slit is not essential for the connection member according to the present invention. Furthermore, when a slit is formed in the connection member according to the present invention, it is sufficient that the slit is formed between the crimp portion and the seal structure of at least one of the first connection portion and the second connection portion, and it is not necessary that the slit is formed in both.

[0053] Here, the region of the crimped portion adjacent to the slit 14 in the axial direction is referred to as the "slit-adjacent region" and is represented by a dot pattern in Figures 6 and 7. Hereinafter, the slit-adjacent region of the first connecting portion 11 may be denoted by the reference symbol 11a, and the slit-adjacent region of the second connecting portion 12 may be denoted by the reference symbol 12a. The slit-adjacent regions 11a and 12a are adjacent to the slit 14, making them more susceptible to deformation than other portions of the connecting member 1A. Therefore, when the first connecting portion 11 and the second connecting portion 12 are pressurized in the crimping direction during the crimping process of the connecting member 1A, the slit-adjacent regions 11a and 12a undergo plastic deformation preferentially over the separation portion 13. This allows for better suppression of plastic deformation of the separation portion 13.

[0054] The crimping process causes the slit-adjacent regions 11a, 12a to be crushed and plastically deformed in the crimping direction, so that the conductive wire 101 of the lead wire 10 is crimped to the first connection portion 11 and the conductive wire 201 of the lead wire 20 is crimped to the second connection portion 12.

[0055] As described above, according to the first modification, the slit 14 is formed between the crimped portion of the connection member 1A and the seal structure 2, thereby suppressing plastic deformation of the separation portion 13 during the crimping process of the connection member 1A. As a result, the sealing performance of the outer periphery of the separation portion 13 can be improved.

[0056] Here, as shown in Figure 6, the axial distance between the tip of the crimped portion and the seal structure 2 is defined as L2. Specifically, L2 is the axial distance from the axially most distal point of the crimped portion where the slit 14 is formed between the crimped portion and the seal structure 2 (i.e., the point farthest from the seal structure 2) to the point on the seal structure 2 closest to the crimped portion. Also, the height of the crimped portion in the crimping direction before crimping (before plastic deformation) is defined as H2. Also, the depth of the slit 14 in the crimping direction is defined as S1. The depth S1 is the distance from the opening of the slit 14 to the end when the connecting member 1A is visually observed in a direction perpendicular to the crimping direction and the axial direction.

[0057] In this case, it is preferable that L2 ≧ H2 × 0.68 and 0.25 ≦ S1 / H2 ≦ 0.67. By satisfying 0.25 ≦ S1 / H2 and L2 ≧ H2 × 0.68, the influence of plastic deformation of the crimped portion on the separation portion 13 can be reduced, thereby suppressing plastic deformation of the separation portion 13. This allows the deformation amount DX of the separation portion 13 to be kept to 0.085 mm or less. As a result, the sealing performance of the outer periphery of the separation portion 13 can be further improved. Furthermore, by satisfying S1 / H2 ≦ 0.67, the cross-sectional area of ​​the connection member 1A at the portion where the slit 14 is formed can be secured, thereby ensuring the conductive performance of the connection member 1A. Furthermore, from the perspective of space saving, it is preferable that L2 ≦ H2 × 6, and more preferably that L2 ≦ H2 × 4. This prevents the connection member 1A from becoming too large, thereby achieving space saving.

[0058] [Modification 2] Figure 8 is a perspective view showing a state of a connection member 1B according to Modification 2 of the embodiment before crimping. As shown in Figure 8, the connection member 1B according to Modification 2 differs from the connection member 1A described above in that the slit 141 formed on the first connection portion 11 side and the slit 142 formed on the second connection portion 12 side are formed at different positions in the circumferential direction. In other words, the slit 141 and the slit 142 are arranged offset around the central axis A1 of the connection member 1B. In other words, the slit-adjacent region 11a of the first connection portion 11 and the slit-adjacent region 12a of the second connection portion 12 are arranged at an angle to each other around the central axis A1. Therefore, the first crimping direction of the first connection portion 11 and the second crimping direction of the second connection portion 12 are different. By differentiating the first crimping direction of the first connection portion 11 and the second crimping direction of the second connection portion 12, the direction in which the first connection portion 11 is crushed during the crimping process can be different from the direction in which the second connection portion 12 is crushed. This reduces the effect on the separation portion 13 of plastic deformation of the first connection portion 11 and the second connection portion 12 during the crimping process. As a result, plastic deformation of the separation portion 13 can be suppressed.

[0059] Here, the angle of deviation between the slits 141 and 142 around the central axis A1, i.e., the minor angle between the first crimping direction and the second crimping direction, is defined as θ1. From the viewpoint of suppressing plastic deformation of the separation portion 13, it is preferable that θ1 be 30°≦θ1≦180°, but this is not limited thereto.

[0060] [Modification 3] Fig. 9 is a cross-sectional view of a connection structure 100C according to Modification 3 of the embodiment. As shown in Fig. 9, the connection structure 100C according to Modification 3 differs from the above-described connection structure 100 in that the seal structure 2C is formed by a part of the connection member 1C. The seal structure 2C according to Modification 3 is formed integrally with the connection member 1C as a metal partition wall that closes the separation portion 13. The seal structure 2C is disposed approximately perpendicular to the axial direction, and the internal space of the connection member 1C is divided in the axial direction by the seal structure 2C. According to Modification 3, the interior of the connection member 1C can be reliably sealed.

[0061] [Modification 4] Figure 10 is a cross-sectional view of a connection structure 100D according to Modification 4 of the embodiment. As shown in Figure 10, the connection structure 100D according to Modification 4 differs from the connection structure 100 described above in that the seal structure 2D is formed of a resin molded body filled in the separation portion 13. The seal structure 2D according to Modification 4 is integrally molded with the connection member 1 by, for example, resin insert molding. The resin molded body forming the seal structure 2D may be a molded body of a thermoplastic resin or a cured product of a thermosetting resin such as an adhesive. As shown in Figure 10, the seal structure 2D may fill the interiors of the first connection portion 11 and the second connection portion 12 to secure the conductive wires 101, 201 of the lead wires 10, 20. According to Modification 4, the interior of the connection member 1 can be reliably sealed.

[0062] [Simulation and Test] The deformation amount of the connection member according to the present embodiment when subjected to crimping was simulated by CAE analysis. A leakage test was also conducted on the connection structure. Note that the present invention is not limited to the examples described below.

[0063] For Examples 1 to 8, 13, 14, 16, 17, 19, and 20 and Comparative Example 1, analytical models were created that had slits corresponding to the connecting member 1A of Modified Example 1. For Examples 9 to 12, 15, 18, 21, and 22 and Comparative Examples 2 and 3, analytical models were created that did not have slits corresponding to the connecting member 1. Table 1 shows the conditions, simulation results, and leakage test results for Examples 1 to 22 and Comparative Examples 1 to 3. Note that h1 is the seal length, which represents half the axial length of the seal structure (see FIGS. 3 and 6).

[0064] In the simulation, a pressure was applied to the analytical model from the crimping direction, which was equivalent to the pressure applied when crimping the lead wire, and the deformation DX of each part of the analytical model was analyzed. The material of the analytical model was copper. The pressure applied to the crimped part was set to the pressure expected when crimping using an appropriate crimping tool that was compatible with the dimensions of the connecting member.

[0065] 11A and 11B are diagrams showing the simulation results of Example 1. Fig. 11A is a perspective view of the analytical model. Fig. 11B is a cross-sectional view of the separation portion 13 of the analytical model, perpendicular to the axial direction. The gradation scales shown in Figs. 11A and 11B represent the amount of deformation.

[0066] As shown in Table 1, when there are no slits (Examples 9 to 12, 15, 18, 21, and 22), it was found that the deformation amount DX was 0.085 or less by satisfying L1 ≧ H1 × 0.88 as in Examples 9 to 12 and 15. Furthermore, when there are slits (Examples 1 to 8, 13, 14, 16, 17, 19, and 20), it was found that the deformation amount DX was 0.085 or less by satisfying 0.25 ≦ S1 / H2 and L2 ≧ H2 × 0.68 as in Examples 1 to 8, 13, 14, 16, and 17.

[0067] For the leakage test, the connection structures shown in Figures 1 and 2 were actually fabricated for Examples 1, 2, 3, 19, 20, and 21 and Comparative Examples 1 to 3, and a fluid leakage test was conducted under specified conditions. Note that in Comparative Examples 1 to 3, a seal structure was not provided inside the connection member. In the leakage test, the presence or absence of fluid leakage was confirmed for both the interior and outer periphery of the connection member. A rating of "Good" was given when no fluid leakage occurred, a rating of "Average" was given when a relatively small amount of fluid leakage was observed, and an rating of "Poor" was given when a relatively large amount of fluid leakage was observed. As shown in Table 1, for Examples 1, 2, 3, 19, 20, and 21, which had a seal structure, no liquid leakage occurred from the interior. For Comparative Examples 1 to 3, which did not have a seal structure, fluid leakage occurred from the interior. For Examples 1, 2, and 3 and Comparative Example 1, no fluid leakage from the outer periphery occurred, while for Examples 19, 20, and 21 and Comparative Example 2, very small amounts of fluid leakage from the outer periphery were observed. Leakage from the outer periphery was observed in Comparative Example 3. This shows that the sealing performance on the outer periphery can be further improved by suppressing the deformation amount DX to 0.085 mm or less.

[0068] <Others> Although the embodiments of the connection structure according to the present invention have been described above, each aspect disclosed in this specification can be combined with any other feature disclosed in this specification.

[0069] DESCRIPTION OF SYMBOLS 1 Connection member 2 Sealing structure 3 Holder 4 Multiple grommet (an example of a peripheral sealing member) 5 Gasket 6 Bolt 10, 20 Lead wire (an example of a first conductive member and a second conductive member) 11 First connecting portion 12 Second connecting portion 13 Separating portion 100 Connection structure

Claims

1. A connection structure for electrically connecting conductive members, comprising: a connecting member that is conductive and at least one of both axial ends of which is sleeve-shaped; and a seal structure arranged inside the connecting member, wherein the connecting member has a first connection portion formed on one end side and capable of connecting a first conductive member, a second connection portion formed on the other end side and capable of connecting a second conductive member, and a separation portion formed between the first connection portion and the second connection portion and separating the first conductive member and the second conductive member inside the connecting member, and the seal structure is arranged in the separation portion to seal the inside of the connecting member.

2. The connection structure according to claim 1, wherein at least one of the first connection portion and the second connection portion is formed at an axial end portion of the connection member as a crimp portion that is connected to the conductive member by crimping.

3. The connection structure according to claim 2, wherein L1 is the axial distance between the tip of the crimped portion and the seal structure, and H1 is the height of the crimped portion in the crimping direction before crimping, and L1 ≧ H1 × 0.

88.

4. The connection structure according to claim 2, wherein a slit is formed in the connection member between the crimping portion and the seal structure.

5. The connection structure according to claim 4, wherein L2 is the axial distance between the tip of the crimped portion and the seal structure, H2 is the height of the crimped portion in the crimping direction before crimping, and S1 is the depth of the slit in the crimping direction, L2 ≧ H2 × 0.68 and 0.25 ≦ S1 / H2 ≦ 0.

67.

6. A connection structure as claimed in claim 1 or 2, wherein the sealing structure is formed by an elastic body fitted into the spaced apart portion.

7. A connection structure as claimed in claim 1 or 2, wherein the sealing structure is formed integrally with the connection member as a partition that closes the spaced apart portion.

8. A connection structure according to claim 1 or 2, wherein the sealing structure is formed by a resin molding filled in the space.

9. A connection structure as described in claim 1 or 2, further comprising an outer periphery seal member arranged on the outer periphery of the connection member, the outer periphery seal member sealing the outer periphery of the connection member by continuously covering at least a portion of the outer periphery in the axial direction of the connection member in the circumferential direction.

10. A connection structure as claimed in claim 1 or 2, wherein the connection member is arranged so as to be subjected to the pressure action of a fluid on at least one end side in the axial direction.

Images