Terminal connection structure

Abstract

To provide a terminal connection structure that suppresses contact sliding between female and male terminals while reducing the amount of heat generated at each contact portion.SOLUTION: A terminal connection structure 1 includes a cylindrical female terminal 2 having an inner wall portion 20b formed with a protruding portion 27, a male terminal structure 3 including a pin-shaped male terminal 30 inserted into the female terminal 2 and multiple elastic members 31 arranged cylindrically around a second central axis AX2 of the male terminal 30, each pressing the outer wall portion 20a of the female terminal 2 with the male terminal 30 inserted in a direction toward the second central axis AX2 of the male terminal 30, and a plate spring portion 4 held on the inner wall portion 20b of the female terminal 2, which presses the male terminal 30 inserted into the female terminal 2 against a protruding portion 27.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a terminal connection structure. [Background technology]

[0002] Conventionally, there are many types of terminal connection structures that allow a female terminal and a male terminal to be freely connected. Patent Document 1 discloses a technology relating to an electrical connector that ensures reliable electrical contact between the male terminal and the female terminal by clamping the male terminal with both leaf spring portions provided on the female terminal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-76341 Summary of the Invention [Problem to be solved by the invention]

[0004] In the electrical connector disclosed in Patent Document 1, when the female terminal and the male terminal are connected, the electrical circuit is established only through the contact points between the female terminal and the male terminal. Therefore, when the electrical connector is connected to an electric wire carrying a relatively high current, there is a concern that heat generated when electricity is passed through the contact points between the female terminal and the male terminal may be concentrated at the contact points, which may result in the connector being inappropriate for connection to the electric wire.

[0005] The present invention has been made in view of the problems inherent in the prior art, and an object of the present invention is to provide a terminal connection structure that suppresses contact sliding between the female terminal and the male terminal while suppressing the amount of heat generated at each contact point. [Means for solving the problem]

[0006] A terminal connection structure according to an embodiment of the present invention comprises a cylindrical female terminal having an inner wall portion on which a protrusion is formed, a pin-shaped male terminal to be inserted into the female terminal, a male terminal structure including a plurality of elastic portions arranged cylindrically around the central axis of the male terminal and each of which presses the outer wall portion of the female terminal into which the male terminal is inserted in a direction toward the central axis of the male terminal, and a leaf spring portion held on the inner wall portion of the female terminal and pressing the male terminal inserted into the female terminal against the protrusion. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a terminal connection structure that suppresses contact sliding between a female terminal and a male terminal while suppressing the amount of heat generated at each contact portion. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of a terminal connection structure according to one embodiment before connection; [Figure 2] FIG. 2 is a perspective view of a terminal connection structure according to one embodiment after connection; [Figure 3] 3 is a cross-sectional view of the terminal connection structure taken along line III-III in FIG. 2. FIG. [Figure 4] FIG. 4 is a cross-sectional view of the female terminal and the leaf spring portion extracted from FIG. 3. [Figure 5] FIG. 4 is a cross-sectional view of the male terminal structure extracted from FIG. 3. [Figure 6] FIG. 2 is a conceptual cross-sectional view of the terminal connection structure according to the embodiment after connection. DETAILED DESCRIPTION OF THE INVENTION

[0009] A terminal connection structure according to one embodiment will be described in detail below with reference to the drawings. Note that the dimensional proportions in the drawings are exaggerated for the sake of convenience and may differ from the actual proportions.

[0010] 1 and 2 are perspective views of a terminal connection structure 1 according to one embodiment. Fig. 1 shows the terminal connection structure 1 before a female terminal 2 and a male terminal structure 3 are connected. Fig. 2 shows the terminal connection structure 1 after the female terminal 2 and the male terminal structure 3 are connected.

[0011] The terminal connection structure 1 is a structure for connecting a female terminal 2 and a male terminal structure 3 including a male terminal 30. The terminal connection structure 1 is employed, for example, as an in-vehicle connector compatible with high current, for electrically connecting between a power source and a device or between devices. The female terminal 2 is electrically connected to one device, etc., and the male terminal structure 3 is electrically connected to the other device, etc. The terminal connection structure 1 also includes a leaf spring portion 4 held by the female terminal 2.

[0012] Hereinafter, the direction in which the male terminal structure 3 is connected to the female terminal 2 is defined as the Z direction. The Z direction is also the direction along the axial direction of each of the female terminal 2 and the male terminal structure 3. Hereinafter, the Z direction may be referred to as "front" or "rear" for each female terminal 2 or male terminal structure 3. The X direction and the Y direction are each perpendicular to the Z direction and perpendicular to each other, and are directions along the width direction of each of the female terminal 2 and the male terminal structure 3. Hereinafter, the X direction may be referred to as "left" or "right," and the Y direction may be referred to as "up" or "down."

[0013] Fig. 3 is a cross-sectional view of the terminal connection structure 1 taken along line III-III in Fig. 2. For convenience, Fig. 3 assumes that the first central axis AX1, which is the central axis of the female terminal 2, and the second central axis AX2, which is the central axis of the male terminal structure 3, are coaxial. In this case, according to the above-mentioned directional definition, the cross section of the male terminal 30 in Fig. 3 is a virtual YZ plane including the first central axis AX1 and the second central axis AX2.

[0014] Fig. 4 is a cross-sectional view of the female terminal 2 and the leaf spring portion 4 extracted from the terminal connection structure 1 shown in Fig. 3. The female terminal 2 shown in Fig. 4 is in a state prior to being connected to the male terminal structure 3. Although not shown, a first imaginary plane is assumed to be an XZ plane including the first central axis AX1, and a second imaginary plane is assumed to be a YZ plane including the first central axis AX1 and perpendicular to the first imaginary plane.

[0015] The female terminal 2 is a conductive metal member formed into a cylindrical shape. In this embodiment, the female terminal 2 is a cylindrical body formed with an outer wall portion 20a and an inner wall portion 20b based on a first center axis AX1. Hereinafter, the diameter of the outer wall portion 20a will be referred to as "D1." However, the female terminal 2 does not need to be a perfect cylinder, and may have a separation groove 21 that separates the outer wall portion 20a and the inner wall portion 20b in a portion of the circumferential direction.

[0016] The female terminal 2 also has a first open end 22 and a second open end 23 that face each other in the Z direction along the first central axis AX1. The first open end 22 is an open end through which the male terminal 30 is inserted into the internal space of the female terminal 2. The first open end 22 has a locking groove 24 that locks a portion of the leaf spring portion 4 from the outside toward the inside of the female terminal 2 along the Z direction. The second open end 23 is an open end to which an electric wire or device (not shown) is connected. The second open end 23 has a notch 25 that exposes a portion of the leaf spring portion 4 in a partial direction radially from the first central axis AX1. The female terminal 2 also has a locking hole 26 through which a portion of the leaf spring portion 4 enters.

[0017] The inner wall portion 20b has, on one side facing the first imaginary plane, multiple protrusions 27 that serve as contact points with the male terminal 30 inserted into the female terminal 2. Referring to FIG. 4 , the side of the inner wall portion 20b facing the first imaginary plane corresponds to a semi-cylindrical inner wall portion located below the first center axis AX1 in the Y direction. In this embodiment, there are four protrusions 27. If the first opening end 22 is the front side and the second opening end 23 is the rear side along the Z direction, two of the protrusions 27 are front protrusions 27a and the remaining two are rear protrusions 27b. In other words, the front protrusions 27a and the rear protrusions 27b are spaced apart from each other along the first center axis AX1. The two front protrusions 27a are symmetrical with respect to each other with respect to the second imaginary plane. Similarly, the two rear protrusions 27b have symmetrical shapes with respect to the second imaginary plane. When a male terminal 30 is inserted into the female terminal 2, the base side of the male terminal 30 contacts the front protrusion 27a, and the tip side of the male terminal 30 contacts the rear protrusion 27b. For example, the contact area of ​​the rear protrusion 27b with the male terminal 30 may be set larger than the contact area of ​​the front protrusion 27a with the male terminal 30 so as to be able to withstand tilt displacement of the male terminal 30 with respect to the first center axis AX1. Furthermore, to improve ease of insertion of the male terminal 30, the protrusion 27 may have an inclined surface aligned with at least the Z direction along the insertion direction of the male terminal 30.

[0018] When there are a plurality of protrusions 27 other than four, at least two protrusions 27 selected from the plurality of protrusions 27 may be spaced apart from each other along the first central axis AX1. Also, there may be only one protrusion 27. Furthermore, when there are a plurality of protrusions 27 other than four, at least two protrusions selected from the plurality of protrusions 27 may have shapes symmetrical with respect to the second imaginary plane.

[0019] The leaf spring 4 is a metal member that is held by the inner wall 20b and presses the male terminal 30 inserted into the female terminal 2 against the protrusions 27. In the example of this embodiment, four protrusions 27 are provided on one side of the inner wall 20b that faces the first imaginary plane and corresponds to a side below the first center axis AX1 in the Y direction. In this case, as shown in FIG. 4, the leaf spring 4 is held on the other side of the inner wall 20b that faces the first imaginary plane and corresponds to a side above the first center axis AX1 in the Y direction.

[0020] For example, the leaf spring portion 4 includes a plurality of leaf springs 40, a front support frame 41, and a rear support frame 42. In this embodiment, there are five leaf springs 40. When the leaf spring portion 4 is held by the female terminal 2, each leaf spring 40 extends along the first center axis AX1 and deforms convexly from the inner wall portion 20b toward the first center axis AX1. At the same time, the leaf springs 40 are maintained in parallel with each other at a predetermined interval in the circumferential direction along the wall surface of the inner wall portion 20b. The front support frame 41 is a semi-annular frame that curves along the wall surface of the inner wall portion 20b and supports the front ends of all the leaf springs 40. The rear support frame 42 has a shape similar to that of the front support frame 41 and supports the rear ends of all the leaf springs 40. When the male terminal 30 is inserted into the female terminal 2, the convexly curved side portions of all the leaf springs 40 come into contact with and press against the male terminal 30, so that the male terminal 30 is pressed against each of the protrusions 27.

[0021] The leaf spring portion 4 has a first engagement portion 43 and a second engagement portion 45, each of which is supported by the front support frame 41. The first engagement portion 43 and the second engagement portion 45 are each supported by the front support frame 41 on the side opposite to the side on which the plurality of leaf springs 40 are supported. The tip of the first engagement portion 43 is bent outward, and when the leaf spring portion 4 is held by the female terminal 2, it faces the locking groove 24 formed in the female terminal 2 in the Z direction. In this embodiment, there are two combinations of the first engagement portion 43 and the locking groove 24 with which the first engagement portion 43 is locked. The tip of the second engagement portion 45 is bent outward, and when the leaf spring portion 4 is held by the female terminal 2, a portion of the second engagement portion 45 enters the locking hole 26 formed in the female terminal 2. That is, when the leaf spring 4 is held by the female terminal 2, movement of the leaf spring 4 toward the first opening end 22 is restricted by the engagement of the second engagement portion 45 with the locking hole 26, and movement of the leaf spring 4 toward the second opening end 23 is restricted by the engagement of the first engagement portion 43 with the locking groove 24. This prevents the leaf spring 4 from falling off the female terminal 2. Furthermore, the leaf spring 4 may have a protrusion 44 supported by the rear support frame 42. The protrusion 44 is exposed to the outside through the cutout 25 of the female terminal 2 so that it can be touched by an operator when the leaf spring 4 is held by the female terminal 2.

[0022] Fig. 5 is a cross-sectional view of the male terminal structure 3 extracted from the terminal connection structure 1 shown in Fig. 3. The male terminal structure 3 shown in Fig. 5 is in a state prior to being connected to the female terminal 2.

[0023] The male terminal structure 3 is a conductive metal member including a male terminal 30, a plurality of elastic portions 31, and a support portion 32. The male terminal structure 3 may be integrally molded to include the male terminal 30, the plurality of elastic portions 31, and the support portion 32 in advance, or may be integrally formed by separately manufacturing some of them and finally joining them together.

[0024] The male terminal 30 is a pin-shaped terminal that is inserted into the female terminal 2. In this embodiment, the male terminal 30 is a cylindrical body with the second central axis AX2 as its central axis. The tip portion 30a of the male terminal 30 is the end that is inserted into the female terminal 2 and has a tapered surface to make it easier to insert. On the other hand, the base end of the male terminal 30 is integrally supported by the support portion 32.

[0025] Each of the multiple elastic portions 31 is arranged cylindrically around the second center axis AX2 and presses the outer wall portion 20a of the female terminal 2 into which the male terminal 30 is inserted in a direction toward the second center axis AX2. In this embodiment, there are eight elastic portions 31, which are equally spaced along the circumferential direction based on the second center axis AX2. The eight elastic portions 31 have the same shape. Each elastic portion 31 is generally flat and rod-shaped, and includes a first rod-shaped portion 31a and a second rod-shaped portion 31b. The first rod-shaped portion 31a and the second rod-shaped portion 31b are continuous with each other.

[0026] The first rod-shaped portion 31a is a rod-shaped portion having one end continuous with one end of the second rod-shaped portion 31b and the other end integrally supported by the support portion 32. In this embodiment, the extension direction of the first rod-shaped portion 31a is along the second central axis AX2.

[0027] The second rod-shaped portion 31b has one end defined as an open end 31c that forms an opening through which the female terminal 2 is inserted, and the other end is a rod-shaped portion that is continuous with one end of the first rod-shaped portion 31a. In this embodiment, the extension direction of the second rod-shaped portion 31b is inclined with respect to the second central axis AX2 so that the shortest distance from the open end 31c to the male terminal 30 is narrower than the shortest distance from the other end connected to the first rod-shaped portion 31a to the male terminal 30. Here, assuming that the male terminal 30 is not inserted into the female terminal 2, the inner diameter of the opening including the open end 31c of each elastic portion 31 is denoted as "D2." The inner diameter D2 is smaller than the diameter D1 of the outer wall portion 20a of the female terminal 2. The length of the second rod-shaped portion 31b is set longer than the length of the first rod-shaped portion 31a. Furthermore, since the open end 31c is the end on the side through which the female terminal 2 is inserted, it has a tapered surface to facilitate insertion.

[0028] When the eight elastic portions 31 are viewed as a whole, they can be regarded as having a shape in which eight slots are formed in a cylindrical body based on the second central axis AX2.

[0029] The support portion 32 supports the male terminal 30 and the multiple elastic portions 31. In this embodiment, the support portion 32 is a rectangular parallelepiped block body that integrally supports the male terminal 30 and the base ends of all of the elastic portions 31 on a support surface 32a. However, the shape of the support portion 32 is not particularly limited as long as it is a shape that can electrically connect the male terminal 30 and the elastic portions 31.

[0030] Next, the operation and effects of the terminal connection structure 1 will be described.

[0031] The terminal connection structure 1 includes a cylindrical female terminal 2 having an inner wall portion 20b on which a protrusion 27 is formed, and a male terminal structure 3. The male terminal structure 3 includes a pin-shaped male terminal 30 to be inserted into the female terminal 2. The male terminal structure 3 also includes a plurality of elastic portions 31 that are cylindrically arranged around the second center axis AX2 of the male terminal 30 and each presses the outer wall portion 20a of the female terminal 2 into which the male terminal 30 is inserted in a direction toward the second center axis AX2 of the male terminal 30. The terminal connection structure 1 also includes a leaf spring portion 4 that is held by the inner wall portion 20b of the female terminal 2 and presses the male terminal 30 inserted into the female terminal 2 against the protrusion 27.

[0032] FIG. 6 is a conceptual cross-sectional view of the terminal connection structure 1 for explaining the operation and effect of the terminal connection structure 1. FIG. 6 shows the terminal connection structure 1 after the female terminal 2 and the male terminal structure 3 are connected. FIG. 6 also shows, in a single cross-sectional view, a state in which the protrusion 27 of the female terminal 2 contacts the male terminal 30 and the open end 31c of each elastic portion 31 contacts the outer wall portion 20a of the female terminal 2. Here, the protrusion 27 is illustrated as one front protrusion 27a and one rear protrusion 27b. The open end 31c is illustrated as two open ends 31c facing each other across the male terminal 30. Thus, for convenience, the cross sections of the female terminal 2 and the male terminal structure 3 are illustrated in a different state from the actual state shown in FIG. 3, and the leaf spring portion 4 is not illustrated.

[0033] First, let us consider a state in which the female terminal 2 and the male terminal structure 3 are connected to each other in the terminal connection structure 1. We will focus on the portion where the male terminal 30 is inserted into the female terminal 2, i.e., the connection portion inside the female terminal 2. When the male terminal 30 is inserted into the female terminal 2, it is pressed against the protrusion 27 formed on the inner wall 20b of the female terminal 2 by the pressure from the leaf spring 4, and ultimately engages with the female terminal 2. Therefore, even if an external force due to vibration is applied to the protrusion 27 serving as a contact portion, the reaction force against the leaf spring 4 and the frictional force against the male terminal 30 can suppress contact sliding in any direction of vibration, thereby maintaining the engaged state of the male terminal 30. Furthermore, the pressure from the leaf spring 4 keeps the male terminal 30 pressed against the protrusion 27, maintaining contact, thereby maintaining electrical continuity between the male terminal 30 and the female terminal 2, as indicated by the white arrow in FIG. 6 . In the above example, there are four protrusions 27 in total: two front protrusions 27a and two rear protrusions 27b.

[0034] Next, let us consider a state in which the female terminal 2 and the male terminal structure 3 are connected to each other in the terminal connection structure 1. We will focus on the portion of the female terminal 2 where the multiple elastic portions 31 press against the outer wall portion 20a of the female terminal 2, i.e., the connection portion on the outside of the female terminal 2. As the female terminal 2 inserts into the male terminal 30, each elastic portion 31 presses against the outer wall portion 20a of the female terminal 2 in a direction toward the second center axis AX2, ultimately holding the female terminal 2 from the outer wall portion 20a side. Therefore, even if an external force due to vibration is applied to a portion of the elastic portion 31 serving as a contact portion, the reaction force against that portion and the frictional force against the outer wall portion 20a of the female terminal 2 suppress contact sliding in any direction of vibration, thereby maintaining the holding state of the female terminal 2. Furthermore, the female terminal 2 continues to contact a portion of the elastic portion 31 due to the pressure from the elastic portion 31, thereby maintaining electrical continuity between each elastic portion 31 and the female terminal 2, as indicated by the outline arrows in FIG. 6 . In the above example, there are eight elastic portions 31 in total.

[0035] Here, as a comparative example, it is assumed that a female terminal equivalent to the above-exemplified female terminal 2 exists, and also that a male terminal consisting only of the above-exemplified male terminal 30 exists. In this case, the female terminal and the male terminal contact each other only at the contact portion corresponding to the protrusion 27 in the above-exemplified case. Therefore, in a terminal connection structure having such a female terminal and a male terminal, if a larger current is used, there is a concern that heat generated when current is passed through the few contact portions will be concentrated, resulting in excessive heat generation, and as a result, it may be impossible to use the structure in an actual vehicle.

[0036] In contrast, in the terminal connection structure 1 according to the present embodiment, a male terminal structure 3 including a male terminal 30 and multiple elastic portions 31 is connected to a female terminal 2. In other words, in the terminal connection structure 1, a first conductive circuit including the male terminal 30 that is electrically connected to the female terminal 2 via the protrusion 27 and a second conductive circuit that is electrically connected to the female terminal 2 via a portion of the elastic portion 31 serving as a contact portion exist in parallel. Therefore, compared to the configuration of the comparative example equivalent to the first conductive circuit, the terminal connection structure 1 increases the number of conductive circuits by the amount of the second conductive circuit, thereby reducing the current flow per contact portion and, as a result, reducing the amount of heat generated per contact portion. For example, because the amount of heat generated is proportional to the square of the current, the amount of heat generated in the protrusion 27 or one of the multiple elastic portions 31 in the terminal connection structure 1 can theoretically be reduced to one-ninth of the value when only the first conductive circuit is present. In the above example, there are four protrusions 27 that form the first conductive circuit, and eight elastic portions 31 that form the second conductive circuit, so there are a total of 12 contact points in the entire terminal connection structure 1. In other words, according to this example, a second conductive circuit including eight contact points has been added to the comparative example, which can be considered to have only the first conductive circuit.

[0037] As described above, according to this embodiment, it is possible to provide a terminal connection structure 1 that suppresses contact sliding between the female terminal 2 and the male terminal 30 while suppressing the amount of heat generated at each contact point.

[0038] Furthermore, in the terminal connection structure 1, the elastic portion 31 may be rod-shaped. Furthermore, one end of the elastic portion 31 may be an open end portion 31c that forms an opening through which the female terminal 2 is inserted.

[0039] According to this terminal connection structure 1, the open end portions 31c can be regarded as contact portions with the female terminals 2, and the elastic portions 31 can be set to a simpler and more compact shape.

[0040] Furthermore, in the terminal connection structure 1, when the male terminal 30 is not inserted into the female terminal 2, the inner diameter D2 of the opening including the open end 31c of each elastic portion 31 may be smaller than the diameter D1 of the outer wall portion 20a of the female terminal 2.

[0041] As the male terminal 30 is inserted into the female terminal 2, the open end 31c that contacts the first open end 22 of the female terminal 2 then moves away from the second center axis AX2 along the shape of the outer wall portion 20a of the female terminal 2, deforming each elastic portion 31. After the male terminal 30 is inserted into the female terminal 2, that is, when the connection between the female terminal 2 and the male terminal structure 3 is complete, the deformed state of the elastic portion 31 is maintained, and the elastic portion 31 continues to press against the female terminal 2. Therefore, according to this terminal connection structure 1, the open end 31c of each of the multiple elastic portions 31 can be kept in stable contact with the female terminal 2.

[0042] Although one embodiment has been described above, the embodiment is not limited to this, and various modifications are possible within the scope of the gist of the embodiment. [Explanation of symbols]

[0043] 1 terminal connection structure 2 female terminals 3 Male terminal structure 4 Leaf spring part 20b Inner wall 27 Protrusion 30 male terminal 31 Elastic part 31c open end AX2 2nd center axis D1 Diameter of the outer wall of the female terminal D2 Inner diameter of opening including open end

Claims

1. a cylindrical female terminal having an inner wall portion on which a protrusion is formed; a male terminal structure including a pin-shaped male terminal to be inserted into the female terminal, and a plurality of elastic parts arranged cylindrically around a central axis of the male terminal, each of which presses an outer wall of the female terminal into which the male terminal is inserted in a direction toward the central axis of the male terminal; a leaf spring portion that is held by the inner wall portion of the female terminal and presses the male terminal inserted into the female terminal against the protruding portion; A terminal connection structure comprising:

2. The elastic portion is rod-shaped, The terminal connection structure according to claim 1 , wherein one end of the elastic portion is an open end portion that forms an opening through which the female terminal is inserted.

3. 3. The terminal connection structure according to claim 2, wherein when the male terminal is not inserted into the female terminal, the inner diameter of the opening including the open end of each of the elastic portions is smaller than the diameter of the outer wall portion of the female terminal.

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