Terminal connection module

Abstract

To further enhance the wear resistance between terminals while enhancing the holding force of a terminal when the terminal is clamped by a clamping member.SOLUTION: A connection module 10 of a terminal includes a first terminal 20 including a first terminal connection portion 24, a second terminal 30 including a second terminal connection portion 34, and a clamping member 40 for clamping the first terminal connection portion 24 and the second terminal connection portion 34 while the first terminal connection portion and the second terminal connection portion overlap each other. The first terminal connecting portion has a first terminal contact surface 25 and a first receiving surface 26 that contacts the clamping member. The second terminal connection portion has a second terminal contact surface 35 and a second receiving surface 36 that contacts the clamping member. The clamping member 40 has a first clamping surface 43 and a second clamping surface 45. The maximum friction coefficient between the first terminal contact surface and the second terminal contact surface is smaller than at least one of the maximum friction coefficient between the first receiving surface and the first clamping surface and the maximum friction coefficient between the second receiving surface and the second clamping surface.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a connection module for a terminal and a terminal. [Background technology]

[0002] Patent document 1 discloses a connector that includes a plate-shaped connection terminal, a spring portion, an insertion port into which the mating terminal is inserted, and a housing that holds the spring portion, and in which the mating terminal and the connection terminal inserted into the insertion port are clamped by the spring portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-097055 Summary of the Invention [Problem to be solved by the invention]

[0004] In a configuration in which a terminal and a mating terminal are sandwiched by a spring portion, it is desired to improve the holding force of the terminal or the mating terminal while further increasing the wear resistance between the terminal and the mating terminal.

[0005] Therefore, an object of the present disclosure is to improve the holding force of the terminals when the terminals are clamped by a clamping member, while further increasing the wear resistance between the terminals. [Means for solving the problem]

[0006] The terminal connection module of the present disclosure comprises a first terminal including a first terminal connection portion, a second terminal including a second terminal connection portion, and a clamping member that clamps the first terminal connection portion and the second terminal connection portion in an overlapping state, wherein the first terminal connection portion has a first terminal contact surface that contacts the second terminal connection portion and a first receiving surface that is located opposite the first terminal contact surface and contacts the clamping member, the second terminal connection portion has a second terminal contact surface that contacts the first terminal connection portion and a second receiving surface that is located opposite the second terminal contact surface and contacts the clamping member, the clamping member has a first clamping surface that contacts the first receiving surface and a second clamping surface that contacts the second receiving surface, and the maximum coefficient of friction between the first terminal contact surface and the second terminal contact surface is smaller than at least one of the maximum coefficient of friction between the first receiving surface and the first clamping surface and the maximum coefficient of friction between the second receiving surface and the second clamping surface.

[0007] The terminal of the present disclosure is a terminal having a terminal connection portion, the terminal connection portion including a terminal contact surface that contacts the mating terminal, and a receiving surface that is located opposite the terminal contact surface and receives a force pressing the terminal contact surface against the mating terminal, the terminal contact surface and the receiving surface having plating layers made of different materials. [Effects of the Invention]

[0008] According to the present disclosure, when terminals are clamped by a clamping member, the holding force of the terminals can be improved and the wear resistance between the terminals can be further increased. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an exploded perspective view showing a terminal connection module according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing a terminal connection module. [Figure 3] FIG. 3 is a diagram showing the change in the friction coefficient with respect to the sliding distance in Experimental Example 1. [Figure 4] FIG. 4 is a diagram showing the change in the friction coefficient with respect to the sliding distance in Experimental Example 2. [Figure 5] FIG. 5 is a diagram showing the change in the friction coefficient with respect to the sliding distance in Experimental Example 3. [Figure 6] FIG. 6 is a diagram showing the change in the friction coefficient with respect to the sliding distance in Experimental Example 4. [Figure 7] FIG. 7 is a diagram showing the change in the friction coefficient with respect to the sliding distance in Experimental Example 5. [Figure 8] FIG. 8 is a diagram showing the change in the friction coefficient with respect to the sliding distance in Experimental Example 6. [Figure 9] FIG. 9 is a diagram showing the change in the friction coefficient with respect to the sliding distance in Experimental Example 7. [Figure 10] FIG. 10 is a graph showing the relationship between the purity of the silver plating layer and the maximum coefficient of friction. [Figure 11] FIG. 11 is a diagram showing the presence or absence of plating cracks in Experimental Examples 10, 11, and 12. [Figure 12] FIG. 12 is a diagram showing the state of cracks that occurred in the silver plating layer in Experimental Example 10. [Figure 13] FIG. 13 is a diagram showing the change in the friction coefficient with respect to the sliding distance in Experimental Example 13. [Figure 14] FIG. 14 is a diagram showing the change in the friction coefficient with respect to the sliding distance in Experimental Example 14. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Description of the embodiments of the present disclosure] First, embodiments of the present disclosure will be listed and described.

[0011] The terminal connection module of the present disclosure is as follows.

[0012] (1) A terminal connection module comprising: a first terminal including a first terminal connection portion; a second terminal including a second terminal connection portion; and a clamping member that clamps the first terminal connection portion and the second terminal connection portion in an overlapping state, wherein the first terminal connection portion has a first terminal contact surface that contacts the second terminal connection portion and a first receiving surface that is located on the opposite side of the first terminal contact surface and contacts the clamping member, the second terminal connection portion has a second terminal contact surface that contacts the first terminal connection portion and a second receiving surface that is located on the opposite side of the second terminal contact surface and contacts the clamping member, the clamping member has a first clamping surface that contacts the first receiving surface and a second clamping surface that contacts the second receiving surface, and the maximum coefficient of friction between the first terminal contact surface and the second terminal contact surface is smaller than at least one of the maximum coefficient of friction between the first receiving surface and the first clamping surface and the maximum coefficient of friction between the second receiving surface and the second clamping surface.

[0013] In this terminal connection module, the maximum coefficient of friction between the first terminal contact surface and the second terminal contact surface is relatively small, making it difficult for wear to occur between the first terminal contact surface and the second terminal contact surface due to micro-sliding caused by insertion / removal of the first or second terminal, thermal cycling, etc. This improves wear resistance between the first terminal contact surface and the second terminal contact surface. Furthermore, the maximum coefficient of friction between at least one of the first receiving surface and the first clamping surface and the second receiving surface and the second clamping surface is relatively large, improving the holding force of at least one of the first terminal and the second terminal. This improves the wear resistance between the first terminal and the second terminal in a terminal connection module in which the first terminal and the second terminal are clamped by a clamping member while improving the holding force of at least one of the first terminal and the second terminal.

[0014] (2) In a terminal connection module of (1), the maximum coefficient of friction between the first terminal contact surface and the second terminal contact surface may be smaller than both the maximum coefficient of friction between the first receiving surface and the first clamping surface and the maximum coefficient of friction between the second receiving surface and the second clamping surface.

[0015] This increases the holding force of both the first terminal and the second terminal.

[0016] (3) A connection module for the terminal of (1) or (2), wherein at least one surface of the first receiving surface and the second receiving surface has a high friction coefficient plating layer, and the high friction coefficient plating layer may be a plating layer that increases the maximum friction coefficient with respect to the first clamping surface or the second clamping surface compared to when the high friction coefficient plating layer is not present.

[0017] In this case, the high friction coefficient plating layer can increase the maximum friction coefficient at least one of between the first receiving surface and the first clamping surface and between the second receiving surface and the second clamping surface.

[0018] (4) A connection module for the terminal of (3), wherein the clamping member is a clip made of stainless steel, at least one of the first clamping surface and the second clamping surface is a surface on which the stainless steel is exposed, the high friction coefficient plating layer is a tin plating layer, and the stainless steel and the tin plating layer may be in direct contact at least between the first receiving surface and the first clamping surface and between the second receiving surface and the second clamping surface.

[0019] In this way, the stainless steel and the tin-plated layer are in direct contact with each other, thereby increasing the maximum coefficient of friction at least between the first receiving surface and the first clamping surface and between the second receiving surface and the second clamping surface.

[0020] (5) A connection module of any one of the terminals of (1) to (4), wherein the first terminal contact surface and the second terminal contact surface each have a low-friction coefficient plating layer, the low-friction coefficient plating layer being a plating layer that reduces the maximum coefficient of friction between the first terminal contact surface and the second terminal contact surface compared to when the low-friction coefficient plating layer is not present, and the low-friction coefficient plating layers may be in direct contact with each other between the first terminal contact surface and the second terminal contact surface.

[0021] This results in the low friction coefficient plating layers being in direct contact with each other between the first terminal contact surface and the second terminal contact surface, thereby reducing the maximum friction coefficient between the first terminal contact surface and the second terminal contact surface.

[0022] (6) In the terminal connection module of (5), the low friction coefficient plating layer may be a silver plating layer having a purity of 95.0 mass percent or more and less than 99.0 mass percent.

[0023] In this way, by having silver plating layers with a purity of 95.0 mass percent or more and less than 99.0 mass percent directly contact each other between the first terminal contact surface and the second terminal contact surface, it is possible to reduce the maximum coefficient of friction between the first terminal contact surface and the second terminal contact surface while suppressing plating cracks.

[0024] (7) In the terminal connection module of any one of (1) to (6), oil may be interposed between the first terminal contact surface and the second terminal contact surface.

[0025] In this case, the oil can reduce the maximum coefficient of friction between the first terminal contact surface and the second terminal contact surface.

[0026] The terminals of the present disclosure are as follows:

[0027] (8) A terminal having a terminal connection portion, the terminal connection portion including a terminal contact surface that contacts the mating terminal and a receiving surface located on the opposite side of the terminal contact surface and that receives a force pressing the terminal contact surface against the mating terminal, the terminal contact surface and the receiving surface having plating layers made of different materials.

[0028] In this case, since the terminal contact surface and the receiving surface have plating layers made of different materials, it is easier to make the maximum coefficient of friction between the terminal contact surface and the opposing terminal smaller than the maximum coefficient of friction between the receiving surface and the member pressing the receiving surface.

[0029] (9) In the terminal of (8), the terminal contact surface may have a silver plating layer with a purity of 95.0 mass percent or more and less than 99.0 mass percent, and the receiving surface may have a tin plating layer.

[0030] In this case, it is easy to make the maximum coefficient of friction between the terminal contact surface and the mating terminal smaller than the maximum coefficient of friction between the receiving surface and the member pressing the receiving surface, while suppressing plating cracks in the silver plating layer.

[0031] [Details of the embodiments of the present disclosure] Specific examples of the terminal connection module and terminal of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0032] [Embodiment] The terminal connection module and the terminal according to the embodiment will be described below. Fig. 1 is an exploded perspective view showing the terminal connection module 10. Fig. 2 is a cross-sectional view showing the terminal connection module 10.

[0033] <Overall configuration of the terminal connection module> The terminal connection module 10 includes a first terminal 20, a second terminal 30, and a clamping member 40. The terminal connection module 10 is used, for example, as a component that electrically connects electrical components in a vehicle.

[0034] The first terminal 20 includes a first terminal connection portion 24. The first terminal 20 is formed, for example, by pressing a metal plate.

[0035] In this embodiment, it is assumed that the first terminal 20 is a terminal to be connected to an end of an electric wire 18. The electric wire 18 is, for example, a covered electric wire including a core wire 18a and a covering 18b that covers the core wire 18a. The core wire 18a is exposed at the end of the electric wire 18.

[0036] The first terminal 20 includes a wire connection portion 22 continuous with the first terminal connection portion 24. The wire connection portion 22 is a portion that is connected to the core wire 18a exposed at the end of the electric wire 18. In this embodiment, the wire connection portion 22 is formed in a plate shape. The core wire 18a at the end of the electric wire 18 is welded, soldered, or the like to the wire connection portion 22, whereby the core wire 18a is fixed to and electrically connected to the wire connection portion 22. The wire connection portion 22 may be configured to have a crimping piece that is crimped to the core wire 18a.

[0037] It is not essential that the first terminal 20 is a terminal that is connected to the electric wire 18. The first terminal 20 may be directly screwed, soldered, or the like to a circuit in the electric component.

[0038] The first terminal connection portion 24 is formed in a plate shape. More specifically, the first terminal connection portion 24 is formed in a rectangular plate shape that is long in one direction. The first terminal connection portion 24 has a first terminal contact surface 25 and a first receiving surface 26. One main surface of the first terminal connection portion 24 is the first terminal contact surface 25. The main surface of the first terminal connection portion 24 opposite the first terminal contact surface 25 is the first receiving surface 26. In other words, the first terminal contact surface 25 and the first receiving surface 26 are surfaces that face opposite each other in the thickness direction of the first terminal connection portion 24.

[0039] The first terminal contact surface 25 faces the second terminal connection portion 34 and is a surface that comes into contact with the second terminal connection portion 34. The first receiving surface 26 faces the clamping member 40 and is a surface that receives the clamping force of the clamping member 40.

[0040] In this embodiment, the first terminal connection portion 24 has a contact portion 25P. While the number of contact portions 25P is not particularly limited, in this embodiment, multiple (here, two) contact portions 25P are formed at intervals in the longitudinal direction of the first terminal connection portion 24. The contact portion 25P is a portion of the first terminal connection portion 24 that partially protrudes toward the first terminal contact surface 25. Therefore, the contact portion 25P is observed as a partially protruding portion from the first terminal contact surface 25 side, and as a partially recessed portion from the first receiving surface 26. The most protruding portion of the contact portion 25P may be formed flat. This increases the contact area between the contact portion 25P and the second terminal connection portion 34. The shape of the contact portion 25P is not particularly limited, and may be, for example, rectangular, elongated, elliptical, or the like. The contact portion 25P may have an outer peripheral surface that slopes inward toward the most protruding portion. This allows the second terminal connecting portion 34 to slide easily on the outer circumferential surface of the contact portion 25P and be guided onto the contact portion 25P.

[0041] The most protruding portion of the contact portion 25P of the first terminal connection portion 24 can come into contact with the second terminal connection portion 34. This makes it possible to destroy the oxide film on the terminal surface, improve contact pressure, etc. Note that it is not essential that the contact portion 25P be formed on the first terminal connection portion 24.

[0042] The second terminal 30 includes a second terminal connection portion 34. The second terminal 30 is formed, for example, by pressing a metal plate.

[0043] The second terminal 30 is, for example, a terminal to be connected to the end of an electric wire, similar to the first terminal 20. The electric wire connection portion of the second terminal 30 is omitted. The second terminal 30 does not necessarily have to be a terminal to be connected to an electric wire, and may be a terminal to be connected to a circuit in an electric component.

[0044] The second terminal connection portion 34 is formed in a plate shape. More specifically, the second terminal connection portion 34 is formed in a rectangular plate shape that is long in one direction. The second terminal connection portion 34 has a second terminal contact surface 35 and a second receiving surface 36. One main surface of the second terminal connection portion 34 is the second terminal contact surface 35. The main surface of the second terminal connection portion 34 opposite the second terminal contact surface 35 is the second receiving surface 36. In other words, the second terminal contact surface 35 and the second receiving surface 36 are surfaces that face opposite each other in the thickness direction of the second terminal connection portion 34.

[0045] The second terminal contact surface 35 faces the first terminal connection portion 24 and is a surface that comes into contact with the first terminal connection portion 24. The second receiving surface 36 faces the clamping member 40 and is a surface that receives the clamping force of the clamping member 40.

[0046] In this embodiment, both sides of the second terminal connection portion 34 2nd terminal contact surface 35 The second receiving surface 36 is formed as a flat surface. Similar to the first terminal connecting portion 24, the second terminal connecting portion 34 may have a contact portion that protrudes toward the first terminal connecting portion 24 side.

[0047] The clamping member 40 is a member that clamps the first terminal connection portion 24 and the second terminal connection portion 34 in an overlapping state. The clamping member 40 is formed, for example, by pressing a metal plate. The clamping member 40 may be a member called a clip.

[0048] More specifically, the clamping member 40 includes a first clamping piece 42 , a second clamping piece 44 , and a connecting piece 46 .

[0049] The first clamping piece 42 is formed in a plate shape, more specifically, in a rectangular plate shape that is long in one direction. The first clamping piece 42 has a first clamping surface 43 that faces the first receiving surface 26, and this first clamping surface 43 contacts the first receiving surface 26.

[0050] In this embodiment, the first clamping piece 42 has a first pressing portion 42P. The first pressing portion 42P is formed by protruding a portion of the first clamping piece 42 inward. The first pressing portion 42P protrudes in an elongated dome shape, and its most protruding portion has a gently spheric shape that is close to a flat surface. The shape of the first pressing portion 42P is arbitrary. It is not essential that the first pressing portion 42P be formed.

[0051] The second clamping piece 44 is formed in a plate shape, more specifically, in a rectangular plate shape that is long in one direction. The second clamping piece 44 has a second clamping surface 45 that faces the second receiving surface 36, and this second clamping surface 45 contacts the second receiving surface 36.

[0052] In this embodiment, the second clamping piece 44 has a second pressing portion 44P. The second pressing portion 44P is formed by protruding a portion of the second clamping piece 44 inward. The second pressing portion 44P protrudes in an elongated dome shape, and its most protruding portion has a gently spheroidal shape that is close to a flat surface. The shape of the second pressing portion 44P is arbitrary. It is not essential that the second pressing portion 44P be formed.

[0053] The leading edges of the first clamping piece 42 and the second clamping piece 44 opposite the portion where the connecting piece 46 is connected are formed as guide edges 42g, 44g that slope outward away from each other. The guide edges 42g, 44g make it possible to easily guide the first terminal connecting portion 24 and the second terminal connecting portion 34 between the first clamping piece 42 and the second clamping piece 44.

[0054] The connecting piece 46 is connected to the base ends of the first clamping piece 42 and the second clamping piece 44, and connects the first clamping piece 42 and the second clamping piece 44 in a parallel state with a gap between them. In other words, the first clamping piece 42, the connecting piece 46, and the second clamping piece 44 are connected to form a U-shape.

[0055] The distance between the first clamping piece 42 and the second clamping piece 44 can be changed by utilizing the connection point to the connecting piece 46 and the elastic deformation of the connecting piece 46.

[0056] Furthermore, the minimum distance between the first clamping piece 42 and the second clamping piece 44 is smaller than the sum of the thicknesses of the first terminal connection portion 24 and the second terminal connection portion 34. Therefore, by elastically deforming the clamping member 40 to widen the distance between the first clamping piece 42 and the second clamping piece 44, the overlapping body of the first terminal contact surface 25 and the second terminal connection portion 34 can be positioned between the first clamping piece 42 and the second clamping piece 44. In this state, the elastic force of the clamping member 40 returning to its original shape causes the first clamping surface 43 to press against the first receiving surface 26, and the second clamping surface 45 to press against the second receiving surface 36. This presses the first terminal connection portion 24 and the second terminal connection portion 34 toward each other, allowing the first terminal contact surface 25 and the second terminal contact surface 35 to come into contact with each other while being pressed against each other. This allows electrical continuity to be established between the first terminal 20 and the second terminal 30.

[0057] It is not essential that the clamping member 40 has the above-described configuration. The clamping member does not necessarily have to be conductive, and may be formed of, for example, resin or a combination of resin and metal.

[0058] <Contact points on the terminal connection module> The first terminal 20 and the second terminal 30 are parts through which electricity flows, and therefore may be made of a material with excellent conductivity. For example, the first terminal 20 and the second terminal 30 may be made of copper or a copper alloy.

[0059] The first terminal contact surface 25 and the second terminal contact surface 35 of the first terminal 20 and the second terminal 30 are surfaces that contact each other to establish electrical continuity. Therefore, to prevent oxidation of the first terminal contact surface 25 and the second terminal contact surface 35 and maintain a good electrical connection between the first terminal contact surface 25 and the second terminal contact surface 35, the first terminal contact surface 25 and the second terminal contact surface 35 are expected to have a plating layer. Examples of such a plating layer include a silver plating layer and a tin plating layer. Meanwhile, the first receiving surface 26 and the second receiving surface 36 are surfaces that receive the force from the clamping member 40, and maintaining a good electrical connection between the first terminal contact surface 25 and the second terminal contact surface 35 and the clamping member 40 is not particularly important. Therefore, the base material forming the first terminal 20 and the second terminal 30 is exposed on the first receiving surface 26 and the second receiving surface 36. Therefore, the first receiving surface 26 and the second receiving surface 36 are expected to be surfaces on which copper or a copper alloy is exposed.

[0060] Furthermore, clamping member 40 may be formed from a material with excellent spring properties in order to maintain a clamped state between first terminal 20 and second terminal 30. For example, clamping member 40 may be formed from stainless steel (including, for example, stainless steel classified as SUS in the JIS standard), particularly stainless steel for springs.

[0061] In this case, the contact points between the first terminal contact surface 25 and the second terminal contact surface 35 (hereinafter sometimes referred to as "inter-terminal contact points") are contact points between the silver plating layers. The contact points between the first receiving surface 26 and the first clamping surface 43 and the contact points between the second receiving surface 36 and the second clamping surface 45 (hereinafter the contact points between the terminals 20, 30 and the clamping member 40 are referred to as "clamping contact points") are contact points between the copper or copper alloy surface and the stainless steel surface.

[0062] The inventors of the present application have discovered that, based on assumed examples of contact points, it is difficult to simultaneously increase the holding force of the clamping member 40 around the first terminal 20 or the second terminal 30 and increase the wear resistance between the first terminal 20 and the second terminal 30.

[0063] The reason is as follows: With the surface material according to the above assumed example, the maximum coefficient of friction at the contact points between the terminals is greater than the maximum coefficient of friction at the pinch contact points.

[0064] Contact points between terminals are required to have wear resistance that can withstand wear caused by insertion and removal of terminals and by fricative wear due to thermal cycling, etc. If the maximum coefficient of friction is large, wear is more likely to occur due to fricative wear caused by insertion and removal of terminals and by fricative wear due to thermal cycling, etc., and wear resistance tends to decrease. For this reason, it is preferable to reduce the maximum coefficient of friction at contact points between terminals in order to increase wear resistance.

[0065] The clamping contact points are required to have a holding performance that can withstand force or vibration in the insertion / removal direction of the terminals 20, 30 so that they do not move. If the maximum friction coefficient is small, the terminals 20, 30 tend to move easily between the clamping members 40, which tends to reduce the holding performance. For this reason, it is preferable to increase the maximum friction coefficient at the clamping contact points in order to improve the holding performance.

[0066] In the above assumed example, it was found that the maximum coefficient of friction at the contact points between the terminals was greater than the maximum coefficient of friction at the pinch contact points, which contradicts the requirement for the maximum coefficient of friction that is considered to be preferable.

[0067] Therefore, the inventors of the present application have realized that it is sufficient to make the maximum friction coefficient μa between the first terminal contact surface 25 and the second terminal contact surface 35 smaller than at least one of the maximum friction coefficient μb1 between the first receiving surface 26 and the first clamping surface 43 and the maximum friction coefficient μb2 between the second receiving surface 36 and the second clamping surface 45, and preferably to make the maximum friction coefficient μa smaller than both the maximum friction coefficient μb1 and the maximum friction coefficient μb2.

[0068] Here, the maximum coefficient of friction between the first member and the second member may be, for example, the maximum value of the coefficient of friction measured when the second member is pulled against the first member while applying a constant load. The maximum value may be, for example, the maximum value within a sliding distance range of 15 mm or less. The coefficient of friction may be measured, for example, by a method conforming to the Japan Copper and Brass Association Technical Standard (JCBA T311:2002).

[0069] As an example of how to achieve the above, it is conceivable to configure the first terminal contact surface 25 and the second terminal contact surface 35 to have low-friction coefficient plating layers 25F, 35F, respectively. These low-friction coefficient plating layers 25F, 35F are plating layers that reduce the maximum friction coefficient μa between the first terminal contact surface 25 and the second terminal contact surface 35 compared to when the low-friction coefficient plating layers 25F, 35F are not present. It is also conceivable to configure the low-friction coefficient plating layers 25F, 35F to be in direct contact with each other between the first terminal contact surface 25 and the second terminal contact surface 35.

[0070] An example of the low-friction coefficient plating layer 25F, 35F may be a silver plating layer with a purity of 95.0 mass percent or more and less than 99.0 mass percent. This is because a silver plating layer with a silver purity of less than 95.0 mass percent is brittle and prone to plating cracks. It is particularly likely that plating cracks are likely to occur when forming the contact portion 25P. If plating cracks occur, the underlying plating or base material may be exposed, potentially increasing the contact resistance at the contact point between the terminals. Furthermore, when the silver purity exceeds 99.0 mass percent, the maximum friction coefficient μa tends to increase. A silver plating layer with a purity of 95.0 mass percent or more and less than 99.0 mass percent may contain organic compounds, sulfur (S)-containing substances, and additive elements in addition to silver.

[0071] In order to reduce the maximum coefficient of friction μa at the contact points between the terminals, oil 60 may be interposed between the first terminal contact surface 25 and the second terminal contact surface 35 (see the two-dot chain line in FIG. 2). The lubricating properties of oil 60 can reduce the maximum coefficient of friction μa at the contact points between the terminals.

[0072] This reduces the maximum friction coefficient μa at the contact points between the terminals, thereby improving the wear resistance.

[0073] In addition to or instead of the above-described configuration for reducing the maximum friction coefficient μa at the contact points between the terminals, it is possible to configure at least one of the first receiving surface 26 and the second receiving surface 36 to have a high friction coefficient plating layer 26F, 36F. This high friction coefficient plating layer 26F, 36F provides a higher friction coefficient than when there is no high friction coefficient plating layer. First clamping surface 43 Alternatively, it is a plating layer that increases the maximum coefficient of friction with respect to the second clamping surface 45 .

[0074] More specifically, for example, it is conceivable that the clamping member 40 is a clip made of stainless steel, at least one of the first clamping surface 43 and the second clamping surface 45 is a surface where the stainless steel is exposed, and the high friction coefficient plating layers 26F, 36F are tin plating layers. It is also conceivable that the stainless steel and the tin plating layer are in direct contact at least or both between the first receiving surface 26 and the first clamping surface 43 and between the second receiving surface 36 and the second clamping surface 45.

[0075] A plating layer that increases the maximum coefficient of friction may be formed on the clamping surfaces 43 and 45 of the clamping member 40.

[0076] This increases the maximum friction coefficients μb1 and μb2 at the clamping contact points, thereby increasing the holding force of the terminals 20 and 30.

[0077] For example, by using a silver plating layer with a purity of 95.0 mass percent or more and less than 99.0 mass percent as the low friction coefficient plating layers 25F, 35F so that the silver plating layers of that purity come into contact with each other at the contact points between the terminals, and by using a tin plating layer as the high friction coefficient plating layers 26F, 36F so that the tin plating layer comes into contact with the stainless steel surface at the clamping contact points, the maximum friction coefficient μa at the contact points between the terminals can easily be made smaller than the maximum friction coefficients μb1, μb2 at the clamping contact points.

[0078] <Effects, etc.> In the terminal connection module 10 configured as described above, the maximum friction coefficient μa between the first terminal contact surface 25 and the second terminal contact surface 35 is relatively small, making it difficult for wear to occur between the first terminal contact surface 25 and the second terminal contact surface 35 due to slight sliding caused by insertion / removal of the first terminal 20 or the second terminal 30 or thermal cycling. This improves the wear resistance between the first terminal contact surface 25 and the second terminal contact surface 35. Furthermore, at least one of the maximum friction coefficient μb1 between the first receiving surface 26 and the first clamping surface 43 and the maximum friction coefficient μb2 between the second receiving surface 36 and the second clamping surface 45 is relatively large, improving the holding force of the clamping member 40 to hold at least one of the first terminal 20 and the second terminal 30. This makes it difficult for the first terminal 20 or the second terminal 30 to come off the clamping member 40. Furthermore, increasing the maximum friction coefficients μb1 and μb2 also contributes to making it more difficult for the first terminal 20 and the second terminal 30 to move, which also helps improve wear resistance. This makes it possible to further improve wear resistance between the first terminal 20 and the second terminal 30 in the terminal-connecting module 10 in which the first terminal 20 and the second terminal 30 are clamped by the clamping member 40, while increasing the holding force of at least one of the first terminal 20 and the second terminal 30.

[0079] In particular, by making both the maximum friction coefficients μb1 and μb2 larger than the maximum friction coefficient μa, both the first terminal 20 and the second terminal 30 are less likely to come off the clamping member 40.

[0080] For example, by providing the high friction coefficient plating layer 26F, 36F on at least one surface of the first receiving surface 26 and the second receiving surface 36, the maximum friction coefficient μb1 or the maximum friction coefficient μb2 can be increased.

[0081] A tin plating layer is used as the high friction coefficient plating layers 26F, 36F, and by making the surface of the stainless steel, which is the base material of the clamping member 40, directly contact the tin plating layer, which is the high friction coefficient plating layer 26F, 36F, at least in one of the areas between the first receiving surface 26 and the first clamping surface 43 and the area between the second receiving surface 36 and the second clamping surface 45, the maximum friction coefficient μb1 or the maximum friction coefficient μb2 can be increased.

[0082] Furthermore, for example, the first terminal contact surface 25 and the second terminal contact surface 35 have low friction coefficient plating layers 25F and 35F, respectively, so that the maximum friction coefficient μa can be reduced.

[0083] By using a silver plating layer with a purity of 95.0 mass percent or more and less than 99.0 mass percent as the low friction coefficient plating layers 25F, 35F, it is possible to reduce the maximum friction coefficient μa while suppressing plating cracks in the low friction coefficient plating layers 25F, 35F.

[0084] Furthermore, regardless of whether the low friction coefficient plating layers 25F, 35F are present or not, the maximum friction coefficient μa can be reduced by interposing oil 60 between the first terminal contact surface 25 and the second terminal contact surface 35.

[0085] Furthermore, in a configuration in which the terminal 20 (or 30) includes a terminal contact surface 25 (or 35) and a receiving surface 26 (or 36), by configuring the terminal contact surface 25 (or 35) and the receiving surface 26 (or 36) to have plating layers of different materials (for example, a combination of a low friction coefficient plating layer 25F and a high friction coefficient plating layer 26F), it is easier to make the maximum friction coefficient μa between the terminal contact surface 25 (or 35) and the mating terminal 30 (or 20) smaller than the maximum friction coefficient μb1 (or μb2) between the receiving surface 26 (or 36) and the clamping member 40 that presses the receiving surface.

[0086] In this case, as described above, if the terminal contact surface 25 (or 35) has a silver plating layer with a purity of 95.0 mass percent or more and less than 99.0 mass percent, and the receiving surface 26 (or 36) has a tin plating layer, it is easier to make the maximum friction coefficient μa smaller than the maximum friction coefficient μb1 (or μb2).

[0087] The configurations described in the above embodiment and modifications can be combined as appropriate as long as they are not mutually contradictory.

[0088] [Experimental Example] <Experimental example regarding pinch contact points> In Experimental Examples 1 and 2, the coefficient of friction between stainless steel and a copper plate was measured. In Experimental Example 1, the copper plate was formed into the same shape as the second terminal 30. In Experimental Example 2, the copper plate was formed into the same shape as the first terminal 20. The change in the coefficient of friction versus the sliding distance in Experimental Example 1 is shown in Figure 3. The change in the coefficient of friction versus the sliding distance in Experimental Example 2 is shown in Figure 4. Note that each curve in Figure 3 shows the measurement results for multiple samples. Figure 3 also shows a legend indicating the correspondence between each curve and the sample number (n1, n2, n3). The legends will be omitted in the following figures.

[0089] In the case of Figure 3, the maximum friction coefficient was approximately 0.36, and in the case of Figure 4, the maximum friction coefficient was approximately 0.29. Figures 3 and 4 show that the maximum friction coefficient between the stainless steel and the copper plate is a relatively small value. Furthermore, Figures 3 and 4 show that the shape of the copper plate, that is, whether a contact portion 25P is provided as in first terminal 20 or not as in second terminal 30, does not have a significant effect on the friction coefficient.

[0090] Therefore, when copper is exposed on the first receiving surface 26 and the second receiving surface 36, and stainless steel is exposed on the first clamping surface 43 and the second clamping surface 45, the maximum friction coefficients μb1 and μb2 are small, and it is predicted that the holding force of the first terminal 20 and the second terminal 30 will be small.

[0091] Note that the maximum friction coefficient originally means the maximum value of the friction coefficient between specific objects. In the description of this experimental example, in order to evaluate the maximum friction coefficient between objects with specific physical properties, if the friction coefficient is measured multiple times, the maximum value of the multiple measurement results is regarded as the maximum friction coefficient.

[0092] In Experimental Example 3, the coefficient of friction between stainless steel and a copper plate having a tin-plated layer was measured. The change in the coefficient of friction with respect to the sliding distance in Experimental Example 3 is shown in FIG.

[0093] As can be seen from Figure 5, the maximum coefficient of friction between stainless steel and a copper plate having a tin-plated layer is approximately 0.6. Therefore, if a tin-plated layer is formed on the first receiving surface 26 and the second receiving surface 36 and stainless steel is exposed on the first clamping surface 43 and the second clamping surface 45, the maximum coefficients of friction μb1 and μb2 will be large, and it is predicted that the holding force of the terminals 20 and 30 can be improved. Therefore, it has been found that a tin-plated layer can be used as an example of the high-friction coefficient plating layers 26F and 36F.

[0094] <Example of experiment regarding contact points between terminals> In Experimental Example 4, the coefficient of friction between two copper plates having a tin-plated layer was measured. In Experimental Example 5, the coefficient of friction between copper plates having a silver-plated layer with a silver purity of 99 mass percent or more was measured. In Experimental Examples 4 and 5, one copper plate was formed into the same shape as the first terminal 20, and the other copper plate was formed into the same shape as the second terminal 30. The change in the coefficient of friction with respect to the sliding distance in Experimental Example 4 is shown in Figure 6. The change in the coefficient of friction with respect to the sliding distance in Experimental Example 5 is shown in Figure 7.

[0095] As can be seen from Figure 6, the maximum friction coefficient between two copper plates with tin-plated layers was approximately 0.82. As can be seen from Figure 7, the maximum friction coefficient between copper plates with silver-plated layers with a purity of 99 mass percent or more was approximately 1.00.

[0096] Therefore, when a tin-plated layer is formed on the first terminal contact surface 25 and the second terminal contact surface 35, and when a silver-plated layer with a purity of 99 mass percent or more is formed, it is predicted that the maximum friction coefficient μa will become large, resulting in reduced wear resistance.

[0097] In Experimental Example 6, the coefficient of friction between copper plates having a silver-plated layer with a silver purity of 97.6 mass percent was measured. One copper plate was formed into the same shape as first terminal 20, and the other copper plate was formed into the same shape as second terminal 30. The change in the coefficient of friction with respect to the sliding distance in Experimental Example 6 is shown in Figure 8.

[0098] As can be seen from Figure 8, the maximum friction coefficient between the copper plates having a silver-plated layer with a silver purity of 97.6 mass percent was a small value of 0.43.

[0099] Therefore, when a silver plating layer with a silver purity of 97.6 mass percent is formed on the first terminal contact surface 25 and the second terminal contact surface 35, it is predicted that the maximum friction coefficient μa will be small and the wear resistance will be improved. Therefore, it was found that a silver plating layer with a purity of 97.6 mass percent can be used as an example of the low-friction coefficient plating layers 25F, 35F.

[0100] In Experimental Example 7, the coefficient of friction between copper plates having a silver-plated layer with a silver purity of 99.6 mass percent was measured. The change in the coefficient of friction with respect to the sliding distance in Experimental Example 7 is shown in FIG.

[0101] As can be seen from FIG. 9, the maximum coefficient of friction between the copper plates having a silver-plated layer with a silver purity of 99.6 mass percent was 1.00.

[0102] In Experimental Example 8, the coefficient of friction between copper plates having a silver-plated layer with a silver purity of 98.8 mass percent was measured, and the maximum coefficient of friction was determined. In Experimental Example 9, the coefficient of friction between copper plates having a silver-plated layer with a silver purity of 99.9 mass percent was measured, and the maximum coefficient of friction was determined.

[0103] Figure 10 shows the maximum friction coefficient as a function of silver purity. It can be seen from the figure that the maximum friction coefficient decreases when the silver purity is less than 99 mass percent, and increases sharply when the silver purity exceeds 99 mass percent. Therefore, it was found that if the silver purity is less than 99 mass percent, the maximum friction coefficient between the copper plate and the silver plating layer can be reduced, and the silver can be used as the low-friction-coefficient plating layers 25F and 35F.

[0104] For example, when a tin plating layer is used as the high-friction-coefficient plating layer 26F, 36F, the maximum friction coefficient is 0.60, and when a silver plating with a silver purity of less than 99% is used as the low-friction-coefficient plating layer 25F, 35F, the maximum friction coefficient is clearly smaller than 0.60. Therefore, such a combination of plating layers is suitable as an example in which the maximum friction coefficient μa is smaller than at least one, and preferably both, of the maximum friction coefficients μb1, μb2.

[0105] Furthermore, in Experimental Examples 10, 11, and 12, copper plates already coated with a silver plating layer were processed to form contact portion 25P, and the occurrence of plating cracks was observed. In Experimental Example 10, a silver plating layer with a purity of 96.7 mass percent was formed, in Experimental Example 11, a silver plating layer with a purity of 97.6 mass percent was formed, and in Experimental Example 12, a silver plating layer with a purity of 98.5 mass percent was formed. The presence or absence of plating cracks for Experimental Examples 10, 11, and 12 is shown in Figure 11.

[0106] In this case, a micrograph of the surface of the test piece in Experimental Example 10 (silver purity 96.7 mass percent) is shown in Figure 12. As shown in the figure, in Experimental Example 10 (silver purity 96.7 mass percent), numerous fine cracks were observed on the surface of the silver plating layer.

[0107] In contrast, in the cases of Experimental Example 11 (silver purity 97.6 mass %) and Experimental Example 12 (silver purity 98.5 mass %), no plating cracks were observed.

[0108] Therefore, it was found that if the purity of silver is 97 mass percent or more, plating cracks are less likely to occur even when processed to form contact portions 25P, etc., and it is suitable for use as low friction coefficient plating layers 25F, 35F.

[0109] In Experimental Example 13, the friction coefficient was measured when oil was interposed between the tin-plated layers in Experimental Example 4. In Experimental Example 14, the friction coefficient was measured when oil was interposed between the silver-plated layers in Experimental Example 5. The change in friction coefficient with respect to the sliding distance in Experimental Example 13 is shown in Figure 13. The change in friction coefficient with respect to the sliding distance in Experimental Example 14 is shown in Figure 14. In Experimental Example 13, the maximum friction coefficient was approximately 0.59. In Experimental Example 14, the maximum friction coefficient was approximately 0.58.

[0110] For this reason, it was found that the maximum friction coefficient μa can be reduced when oil is interposed between the first terminal contact surface 25 and the second terminal contact surface 35, compared to when no oil is present. Therefore, depending on the values ​​of the maximum friction coefficients μb1 and μb2, by interposing oil between the first terminal contact surface 25 and the second terminal contact surface 35, the maximum friction coefficient μa can be reduced below the maximum friction coefficients μb1 and μb2. [Explanation of symbols]

[0111] 10 Connection Modules 18 Electric wire 18a core wire 18b Covering 20 1st terminal 22 Wire connection 24 First terminal connection part 25 1st terminal contact surface 25F low friction coefficient plating layer 25P contact part 26 First receiving surface 26F high friction coefficient plating layer 30 2nd terminal 34 Second terminal connection part 35 2nd terminal contact surface 35F low friction coefficient plating layer 36 Second receiving surface 36F high friction coefficient plating layer 40 Clamping member 42 1st clamping piece 42P First pressing part 42g, 44g guide edge 43 First clamping surface 44 Second clamping piece 44P Second pressing part 45 Second clamping surface 46 Connecting piece 60 oil

Claims

1. a first terminal including a first terminal connection portion; a second terminal including a second terminal connection portion; a clamping member that clamps the first terminal connection portion and the second terminal connection portion in an overlapping state; Equipped with the first terminal connection portion has a first terminal contact surface that contacts the second terminal connection portion and a first receiving surface that is located on the opposite side to the first terminal contact surface and contacts the clamping member, the second terminal connection portion has a second terminal contact surface that contacts the first terminal connection portion and a second receiving surface that is located on the opposite side to the second terminal contact surface and contacts the clamping member, the clamping member has a first clamping surface in contact with the first receiving surface and a second clamping surface in contact with the second receiving surface, A terminal connection module, wherein the maximum coefficient of friction between the first terminal contact surface and the second terminal contact surface is smaller than at least one of the maximum coefficient of friction between the first receiving surface and the first clamping surface and the maximum coefficient of friction between the second receiving surface and the second clamping surface.

2. 2. The terminal connection module according to claim 1, A terminal connection module, wherein the maximum coefficient of friction between the first terminal contact surface and the second terminal contact surface is smaller than both the maximum coefficient of friction between the first receiving surface and the first clamping surface and the maximum coefficient of friction between the second receiving surface and the second clamping surface.

3. 3. The terminal connection module according to claim 1, At least one surface of the first receiving surface and the second receiving surface has a high friction coefficient plating layer, A terminal connection module, wherein the high friction coefficient plating layer is a plating layer that increases the maximum coefficient of friction with the first clamping surface or the second clamping surface compared to when the high friction coefficient plating layer is not present.

4. 4. The terminal connection module according to claim 3, the clamping member is a clip made of stainless steel, At least one of the first clamping surface and the second clamping surface is a surface on which the stainless steel is exposed, the high friction coefficient plating layer is a tin plating layer, A terminal connection module in which the stainless steel and the tin plating layer are in direct contact at least between the first receiving surface and the first clamping surface and between the second receiving surface and the second clamping surface.

5. A terminal connection module according to any one of claims 1 to 4, each of the first terminal contact surface and the second terminal contact surface has a low friction coefficient plating layer; the low-friction-coefficient plating layer is a plating layer that reduces a maximum coefficient of friction between the first terminal contact surface and the second terminal contact surface compared to when the low-friction-coefficient plating layer is not present, A terminal connection module, wherein the low friction coefficient plating layers are in direct contact with each other between the first terminal contact surface and the second terminal contact surface.

6. 6. A terminal connection module according to claim 5, A terminal connection module, wherein the low friction coefficient plating layer is a silver plating layer with a purity of 95.0 mass percent or more and less than 99.0 mass percent.

7. A terminal connection module according to any one of claims 1 to 6, A terminal connection module, wherein oil is interposed between the first terminal contact surface and the second terminal contact surface.

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