Press-fit terminals

Abstract

To provide a press-fit terminal capable of obtaining excellent conductive performance while presenting sufficient holding power and further capable of suppressing an increase of an insertion force into a through hole even in that case.SOLUTION: The present invention relates to a press-fit terminal 1 to be inserted into a through hole of a substrate. The press-fit terminal comprises a pair of elastic piece parts 20 holding an eyehole 10 therebetween. In each of the pair of elastic piece parts 20, an outer edge straight part 21 extending in an axial direction of the through hole is formed at an outer edge side to be pressure-welded by the through hole, and an inner edge straight part 22 extending in the axial direction is formed at an inner edge side opposed to the eyehole 10. The inner edge straight part 22 is disposed more eccentrically to a terminal tip end side than the outer edge straight part 21.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a press-fit terminal. [Background technology]

[0002] In recent years, solderless press-fit terminals have been used in a wide range of applications, including automotive applications. Press-fit terminals utilize the elastic deformation of a pair of elastic pieces that face each other across an eye hole to maintain a press-fit state in a through-hole provided in a wiring board of an electronic device and to establish a conductive connection with an electrode film on the inner surface of the through-hole (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-225701 Summary of the Invention [Problem to be solved by the invention]

[0004] Press-fit terminals are required to have sufficient holding force and excellent electrical conductivity when pressed into through-holes, but it is undesirable for this to require a large force when inserting the press-fit terminal into the through-hole.

[0005] The present invention aims to provide a press-fit terminal that exhibits sufficient holding power while providing excellent conductive performance, and that can suppress an increase in insertion force into a through-hole even in this case. [Means for solving the problem]

[0006] According to one aspect of the present invention, A press-fit terminal inserted into a through hole in a substrate, A pair of elastic pieces sandwiching the eye holes are provided, Each of the pair of elastic pieces has an outer edge straight portion formed on an outer edge side that is pressed against the through hole and that extends along the axial direction of the through hole, and an inner edge straight portion formed on an inner edge side that faces the eye hole and that extends along the axial direction, the inner straight edge portion is disposed closer to the terminal tip end than the outer straight edge portion, The forming length of the outer edge straight portion is longer than the forming length of the inner edge straight portion. Ku, Each of the pair of elastic pieces is formed with a base-side inner edge curved portion that connects the inner edge straight portion to an edge of the eye hole on the terminal base side, and a tip-side inner edge curved portion that connects the inner edge straight portion to an edge of the eye hole on the terminal tip side, The radius of the curved inner edge portion on the base side is smaller than the radius of the curved inner edge portion on the tip side, The width of the curved inner edge portion on the base side is larger than the width of the curved inner edge portion on the tip side. Press-fit terminals are provided. [Effects of the Invention]

[0007] According to the present invention, it is possible to obtain excellent conductive performance while exerting sufficient holding force, and even in this case, it is possible to suppress an increase in the insertion force into the through-hole. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a specific example of the overall configuration of a press-fit terminal according to an embodiment of the present invention; [Figure 2] 1A and 1B are explanatory views showing a specific example of a main configuration of a press-fit terminal according to an embodiment of the present invention, in which (a) is a plan view and (b) is a cross-sectional view taken along the line AA in (a). [Figure 3] 1A and 1B are explanatory diagrams showing a specific example of a usage mode of a press-fit terminal according to an embodiment of the present invention, in which FIG. 1A shows the state when inserted into a through-hole, and FIG. 1B shows the state after insertion into the through-hole. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a press-fit terminal according to one embodiment of the present invention will be described with reference to the drawings.

[0010] (1) Overall structure of press-fit terminal First, the overall configuration of the press-fit terminal according to this embodiment will be briefly described. FIG. 1 is a perspective view showing a specific example of the overall configuration of a press-fit terminal.

[0011] The press-fit terminal 1 is used by being inserted into a through-hole formed in a wiring board (hereinafter simply referred to as "board") of an electronic device (not shown). To this end, the press-fit terminal 1 includes at least an eye hole 10 formed as a through-hole and a pair of elastic pieces 20 facing each other across the eye hole 10. The press-fit terminal 1 is configured to maintain the press-fit state in the through-hole and to establish a conductive connection with an electrode film on the inner surface of the through-hole by utilizing elastic deformation of the elastic pieces 20 that bend in a direction narrowing the eye hole 10.

[0012] Such a press-fit terminal 1 is formed, for example, by pressing a conductive metal material (e.g., copper or a copper alloy) and may be subjected to a surface treatment such as tin plating. As described above, the press-fit terminal 1 includes at least the eye hole 10 and the pair of elastic pieces 20, but other components are not particularly limited, and various configurations may be applied.

[0013] (2) Main components of press-fit terminals Next, the configuration of the eye hole 10 and the pair of elastic pieces 20 as the main configuration of the press-fit terminal 1 according to this embodiment will be described in more detail. FIG. 2 is an explanatory diagram showing a specific example of the main configuration of a press-fit terminal.

[0014] 2(a), in the press-fit terminal 1 according to this embodiment, the elastic piece portion 20 is formed so that the outer edge side that is pressed into the through-hole bulges toward the through-hole, and the apex of this bulging shape has an outer edge straight portion 21. The outer edge straight portion 21 is a linear portion that extends along the axial direction of the through-hole (i.e., the insertion / removal direction of the press-fit terminal 1). In other words, each of the pair of elastic piece portions 20 has an outer edge straight portion 21 formed on the outer edge side that is pressed into the through-hole, extending along the axial direction of the through-hole.

[0015] Additionally, elastic piece portion 20 is configured to have inner edge straight portion 22 on the inner edge side facing eye hole 10 to correspond to outer edge straight portion 21. Inner edge straight portion 22 is a linear portion extending parallel to (including a state that can be considered parallel to) outer edge straight portion 21. In other words, each of the pair of elastic piece portions 20 has inner edge straight portion 22 formed on the inner edge side facing eye hole 10, extending along the axial direction of the through hole.

[0016] The outer edge straight portion 21 and the inner edge straight portion 22 are arranged to be offset from each other in the insertion / removal direction of the press-fit terminal 1 (i.e., the longitudinal direction of the press-fit terminal 1). Specifically, the inner edge straight portion 22 is arranged closer to the tip end of the terminal than the outer edge straight portion 21. Here, the term "terminal tip side" refers to the tip side of the press-fit terminal 1 when the press-fit terminal 1 is inserted into the through-hole. The side opposite to the terminal tip side, i.e., the base side of the press-fit terminal 1 when the press-fit terminal 1 is inserted into the through-hole, will be referred to as the "terminal base side" hereinafter. Being positioned to one side toward the terminal tip means that, in the longitudinal direction of the press-fit terminal 1, the position of the midpoint of the formed length a of the outer edge straight portion 21 does not coincide with the position of the midpoint of the formed length b of the inner edge straight portion 22, and the midpoint of the formed length b of the inner edge straight portion 22 is closer to the terminal tip, and as a result, the edge of the inner edge straight portion 22 on the terminal base side is positioned closer to the terminal tip than the edge of the outer edge straight portion 21 on the terminal base side.

[0017] As described above, in the press-fit terminal 1 according to this embodiment, the inner edge straight portion 22 is positioned closer to the terminal tip than the outer edge straight portion 21. This allows the forming width c on the terminal base side of each of the pair of elastic piece portions 20 to be larger than the forming width d on the terminal tip side. In other words, by increasing the forming width c, it is possible to increase the spring constant of the elastic piece portion 20 on the terminal base side while suppressing an increase in the spring constant on the terminal tip side.

[0018] Furthermore, the fact that the inner edge straight portion 22 is positioned closer to the terminal tip than the outer edge straight portion 21 also affects the spring length of the elastic piece portion 20 when it elastically deforms. For example, the distance between the terminal base edge 11 of the eye hole 10 and the terminal tip edge 12 is considered to be the total spring length of the elastic piece portion 20 when it elastically deforms. In this case, the inner edge straight portion 22 is positioned closer to the terminal tip than the outer edge straight portion 21, so that the tip-side spring length e of the elastic piece portion 20, which is determined by the distance between the midpoint of the formed length a of the outer edge straight portion 21 and the terminal tip-side edge 11 of the eye hole 10, can be made longer than the base-side spring length f of the elastic piece portion 20, which is determined by the distance between the midpoint of the formed length a of the outer edge straight portion 21 and the terminal base-side edge 12 of the eye hole 10. Specifically, for example, the tip-side spring length e can be set to be 120% or more of the base-side spring length f.

[0019] As described above, in the press-fit terminal 1 according to this embodiment, the tip-side spring length e is greater than the base-side spring length f. This makes it possible to increase the spring constant of the base side of the terminal while suppressing the increase in the spring constant of the tip side of the terminal due to the difference between the tip-side spring length e and the base-side spring length f for each of the pair of elastic pieces 20. In particular, if the tip-side spring length e is 120% or more of the base-side spring length f, the difference in the spring constants of the respective springs can be made apparent. Furthermore, the angle formed by the outer edges of the pair of elastic pieces 20 can be made smaller at the tip of the terminal than at the base of the terminal due to the difference between the spring lengths e and f. Specifically, for example, angle g can be set to 30° or less while satisfying angle g < angle h. In this way, by reducing angle g at the tip of the terminal, it is possible to reduce the load when inserting the press-fit terminal 1 into a through-hole.

[0020] On the inner edge sides of the pair of elastic pieces 20 (i.e., the sides facing the eye hole 10), a root-side inner edge curved portion 23 is formed on the terminal root side of the inner edge straight portion 22, connecting the inner edge straight portion 22 with the terminal root-side edge 11 of the eye hole 10. On the other hand, on the terminal tip side of the inner edge straight portion 22, a tip-side inner edge curved portion 24 is formed, connecting the inner edge straight portion 22 with the terminal tip-side edge 12 of the eye hole 10. In other words, in addition to the inner edge straight portion 22, the root-side inner edge curved portion 23 and the tip-side inner edge curved portion 24 are formed on the inner edge side of the elastic piece 20.

[0021] Both the base-side inner edge curved portion 23 and the tip-side inner edge curved portion 24 are arc-shaped curved portions, but in the press-fit terminal 1 according to this embodiment, the radius r1 of the base-side inner edge curved portion 23 is smaller than the radius r2 of the tip-side inner edge curved portion 24. In other words, the base-side inner edge curved portion 23 has a tighter curve (curvature), while the tip-side inner edge curved portion 24 has a gentler curve.

[0022] Thus, in the press-fit terminal 1 according to this embodiment, the inner-edge straight portion 22 is positioned closer to the terminal tip than the outer-edge straight portion 21, and the radius r1 of the base-side inner-edge curved portion 23 is smaller than the radius r2 of the tip-side inner-edge curved portion 24. This makes it possible to make the width c of each of the pair of elastic pieces 20 on the base side larger than the width d on the tip side of the terminal even more pronounced.

[0023] Furthermore, in the press-fit terminal 1 according to this embodiment, the inner-edge straight portion 22 is disposed so as to be interposed between the root-side inner-edge curved portion 23 and the tip-side inner-edge curved portion 24. In this manner, even when the root-side inner-edge curved portion 23 and the tip-side inner-edge curved portion 24 are curved in an arc shape, the presence of the inner-edge straight portion 22 allows the root-side inner-edge curved portion 23 and the tip-side inner-edge curved portion 24 to be continuous without creating ridges or steps between them, by positioning the inner-edge straight portion 22 on a tangent thereto. In other words, it is possible to prevent the elastic piece portion 20 from having locations (ridges, steps, etc.) where stress concentration may occur when the elastic piece portion 20 is elastically deformed.

[0024] Meanwhile, outer edge straight portions 21 are disposed at the tops of the bulging shapes on the outer edge sides of the pair of elastic pieces 20. Therefore, when the press-fit terminal 1 is inserted into a through-hole in a circuit board, the outer edge straight portions 21 come into contact with the electrode film on the inner circumferential surface of the through-hole. This increases the contact area with the electrode film on the inner circumferential surface of the through-hole compared to a case in which the outer edge straight portions 21 are absent and the elastic pieces are curved in an arc shape. This reduces the contact pressure with the electrode film and also reduces the electrical resistance between the electrode film and the press-fit terminal. Furthermore, even if an external force acts in a direction that tilts the press-fit terminal 1 inserted into a through-hole, the press-fit terminal 1 can withstand the external force.

[0025] However, it is desirable to reduce the formation length a of the outer edge straight portion 21 while ensuring sufficient area for the outer edge straight portion 21. Specifically, the formation length a of the outer edge straight portion 21 is, for example, 0.1 mm to 0.5 mm, preferably 0.3 mm ± 0.1 mm. A formation length a of 0.1 mm or greater ensures sufficient area for the outer edge straight portion 21, thereby achieving the effects of the outer edge straight portion 21 described above. Furthermore, a formation length a of 0.5 mm or less allows the entire outer edge straight portion 21 to contact the electrode film on the inner surface of the through hole without being affected by changes in the thickness of the substrate containing the through hole. In other words, changes in the substrate thickness can be prevented from affecting the contact pressure of the elastic piece 20 on the inner surface of the through hole.

[0026] The formation length a of the outer edge straight portion 21 may be determined taking into account the contact pressure with the electrode film. For example, the contact pressure of the outer edge straight portion 21 with the electrode film is expected to have a range of allowable pressure to prevent damage to the electrode film, depending on the material and surface treatment of the elastic piece portion 20, the material and surface treatment of the electrode film on the inner surface of the through-hole, and other factors. Therefore, the formation length a, which determines the contact area between the outer edge straight portion 21 and the electrode film, can be determined so that the contact pressure does not deviate from this pressure range. Even in this case, the formation length a of the outer edge straight portion 21 is preferably within a range of, for example, 0.1 mm to 0.5 mm.

[0027] 2(b), in the press-fit terminal 1 according to this embodiment, the elastic piece 20 has R-shaped portions 25 at the corners of the cross-sectional shape of the outer edge straight portion 21, at least over the entire forming length a of the outer edge straight portion 21. Therefore, each pair of elastic pieces 20 has an R-shaped portion 25 at each of the four corners of the cross-sectional shape. The R-shaped portions 25 are formed so that the corners of the cross-sectional shape of the outer edge straight portion 21 are curved in an arc. It is conceivable that the radius of the arc portions of the R-shaped portions 25 is the same at all four corners, but this is not necessarily limited to this.

[0028] The radius of the arc portion of the R-shaped portion 25 at each of the four corners must satisfy the following conditions. Forming radius of R-shaped portion 25 / hole diameter of board through hole ≥ 0.17 Therefore, for example, when the diameter of the through-hole is 1.0 mm, the above condition is met if the radius of the R-shaped portion 25 is 0.17 mm or more.

[0029] In this way, in the press-fit terminal 1 according to this embodiment, the rounded portions 25 are provided at the corners of the cross-sectional shape of the outer edge straight portion 21, and therefore it is possible to reduce the load on the inner peripheral surface of the through-hole when the press-fit terminal 1 is inserted into the through-hole of the circuit board, compared to a case in which the rounded portions 25 are not provided. In particular, if the rounded portions 25 are configured so that the ratio of the radius of the rounded portions 25 to the diameter of the through-hole of the circuit board is equal to or greater than 0.17, it is possible to reliably reduce the load on the inner peripheral surface of the through-hole, regardless of the diameter of the through-hole.

[0030] (3) How to use press-fit terminals Next, a description will be given of how the press-fit terminal 1 according to this embodiment is used. FIG. 3 is an explanatory diagram showing a specific example of a usage mode of the press-fit terminal.

[0031] The press-fit terminal 1 is used by being inserted into a through-hole 2a of a substrate 2. As shown in Fig. 3(a), the press-fit terminal 1 is inserted into the through-hole 2a by inserting the terminal tip side into the through-hole 2a (see the arrow in the figure).

[0032] At this time, the pair of elastic pieces 20 of the press-fit terminal 1 are not elastically deformed (i.e., the width between the outer edges of the pair of elastic pieces 20 is greater than the diameter of the through-hole 2a). Therefore, when the press-fit terminal 1 is inserted into the through-hole 2a, the portion of the elastic piece 20 closer to the terminal tip than the outer edge straight portion 21 first contacts the inner circumferential surface of the through-hole 2a. The angle g formed by the outer edges of the portion closer to the terminal tip than the outer edge straight portion 21 is smaller, thereby reducing the load (insertion force) during insertion. Furthermore, the portion closer to the terminal tip than the outer edge straight portion 21 constitutes the tip-side spring length e. Since the tip-side spring length e is large, an increase in the spring constant is suppressed, which also reduces the load (insertion force) during insertion. In other words, the press-fit terminal 1 according to this embodiment can suppress an increase in the insertion force into the through-hole 2a.

[0033] Then, as the press-fit terminal 1 continues to be press-fitted into the through-hole 2a, the pair of elastic pieces 20 of the press-fit terminal 1 elastically deform in a direction that narrows the eye hole 10.

[0034] 3(b), when the press-fit terminal 1 is pressed into the terminal block 1 to a predetermined depth, the reaction force generated by the elastic deformation of the pair of elastic pieces 20 causes the straight outer edge portions 21 of the elastic pieces 20 to come into contact with the electrode film on the inner circumferential surface of the through-hole 2a. Since the straight outer edge portions 21 are in contact, the contact pressure of the elastic pieces 20 with the electrode film can be reduced compared to when the straight outer edge portions 21 are not present and the outer edges of the elastic pieces are curved in an arc shape. This prevents the elastic pieces 20 from damaging the electrode film. Furthermore, the reduced electrical resistance between the elastic pieces 20 and the electrode film results in excellent electrical conductivity.

[0035] When the press-fit terminal 1 is inserted to a predetermined depth, the outer edge straight portion 21 is in contact with the inner peripheral surface of the through-hole 2a, which increases the resistance to external forces, even if an external force acts in a direction that tilts the press-fit terminal 1. In other words, the press-fit terminal 1 can maintain a good retention state when pressed into the through-hole 2a.

[0036] When press-fitted into the through-hole 2a, the press-fit terminal 1 exerts a holding force by utilizing the elastic deformation of the pair of elastic pieces 20. At this time, the outer edge straight portion 21 and the inner edge straight portion 22 are offset, which makes it possible to suppress an increase in the spring constant at the tip side of the terminal while increasing the spring constant at the base side of the terminal, thereby enabling the exertion of a necessary and sufficient holding force. In other words, the press-fit terminal 1 according to this embodiment is able to suppress an increase in the insertion force into the through-hole 2a, while still exerting a sufficient holding force when press-fitted into the through-hole 2a.

[0037] Furthermore, because the corners of the cross-sectional shape of the outer edge straight portion 21 are provided with R-shaped portions 25, when the connector is press-fitted into the through hole 2a, the R-shaped portions 25 come into contact with the inner peripheral surface of the through hole 2a. This prevents the corner apexes from coming into contact, as would occur if there were no R-shaped portions 25, and reduces the load on the inner peripheral surface of the through hole 2a. Furthermore, in addition to reducing the load, electrical resistance can also be reduced compared to when the corner apexes come into contact, resulting in superior electrical conductivity.

[0038] Furthermore, the outer edge straight portion 21 that contacts the inner circumferential surface of the through-hole 2a is formed so that its formation length a falls within a predetermined dimensional range, such as 0.1 mm to 0.5 mm. This allows the entire outer edge straight portion 21 to contact the electrode film on the inner circumferential surface of the through-hole 2a, regardless of the thickness of the substrate 2 that contains the through-hole 2a (regardless of the thickness). In other words, sufficient holding power and excellent conductivity can be achieved without being affected by the thickness of the substrate 2 that contains the through-hole 2a.

[0039] (4) Effects Obtained by the Present Embodiment According to this embodiment, one or more of the following effects can be obtained.

[0040] (a) In the press-fit terminal 1 according to this embodiment, a pair of elastic pieces 20 sandwiching the eye hole 10 each have an outer edge straight portion 21 and an inner edge straight portion 22, with the inner edge straight portion 22 positioned closer to the terminal tip than the outer edge straight portion 21. The offset between the outer edge straight portion 21 and the inner edge straight portion 22 increases the rigidity of the base end of the terminal compared to the tip end. More specifically, it is possible to increase the spring constant of the base end while suppressing an increase in the spring constant of the tip end. Therefore, after inserting the press-fit terminal 1 into the through hole 2a, the press-fit terminal 1 can exert a necessary and sufficient holding force. Moreover, the contact of the outer edge straight portion 21 reduces the electrical resistance between the elastic pieces 20 and the electrode film, thereby achieving excellent electrical conductivity. Furthermore, it is possible to suppress an increase in insertion force during insertion into the through hole 2a. In other words, the press-fit terminal 1 of this embodiment provides sufficient holding force after insertion into the through-hole 2a while providing excellent conductive performance, and even in this case, it is possible to suppress an increase in the insertion force into the through-hole 2a.

[0041] (b) The press-fit terminal 1 according to this embodiment is configured such that the tip-side spring length e is greater than the base-side spring length f due to the offset arrangement of the outer edge straight portion 21 and the inner edge straight portion 22. By making the tip-side spring length e greater than the base-side spring length f, it is possible to increase the spring constant at the base of the terminal while suppressing an increase in the spring constant at the tip of the terminal, and it is also possible to make the angle g at the tip of the terminal smaller than the angle h at the base of the terminal. Therefore, after insertion into the through-hole 2a, sufficient retention force is exerted and excellent conductive performance is obtained, which is also very preferable in suppressing an increase in the insertion force into the through-hole 2a.

[0042] (c) In addition to the offset arrangement of the outer-edge straight portion 21 and the inner-edge straight portion 22, the press-fit terminal 1 according to this embodiment is configured so that the radius r1 of the base-side inner curved portion 23 is smaller than the radius r2 of the tip-side inner curved portion 24. By making the radius r1 smaller than the radius r2, it is possible to further increase the rigidity of the base side of the terminal compared to the tip side of the terminal. Therefore, after insertion into the through-hole 2a, sufficient retention force is exerted and excellent conductive performance is obtained, which is extremely preferable in terms of suppressing an increase in the insertion force into the through-hole 2a.

[0043] (d) As explained in this embodiment, if the formation length a of the outer edge straight portion 21 is 0.1 mm or more and 0.5 mm or less, it is possible to make the entire outer edge straight portion 21 contact the electrode film on the inner surface of the through hole 2a without being affected by the thickness of the substrate 2 having the through hole 2a, thereby achieving sufficient holding power and excellent conductive performance.

[0044] (e) As explained in this embodiment, if the corners of the cross-sectional shape of the outer edge straight portion 21 are provided with rounded portions 25, and the radius of the rounded portions 25 is configured to be equal to or greater than 0.17, it is possible to reliably reduce the load on the inner surface of the through-hole 2a into which the press-fit terminal 1 is inserted, regardless of the diameter of the through-hole 2a. This is therefore highly desirable in terms of achieving sufficient holding force and excellent electrical conductivity after insertion into the through-hole 2a.

[0045] (5) Modifications, etc. Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments and can be modified as appropriate without departing from the spirit of the present invention.

[0046] In the above-described embodiment, there are some parts where specific dimensional values ​​etc. are given as explanations, but the present invention is not necessarily limited to these dimensional values ​​etc., and they may be changed as appropriate as necessary.

[0047] Furthermore, in the above-described embodiment, the press-fit terminal 1 is considered to be used for electrical connection with a circuit board of an in-vehicle electronic device, but this is not necessarily limited to this and can be applied to a wide range of uses. [Explanation of symbols]

[0048] 1...press-fit terminal, 2...substrate, 2a...through hole, 10...eye hole, 11, 12...edge, 20...elastic piece portion, 21...outer edge straight portion, 22...inner edge straight portion, 23...base side inner edge curved portion, 24...tip side inner edge curved portion, 25...R-shaped portion

Claims

1. A press-fit terminal inserted into a through hole in a substrate, A pair of elastic pieces sandwiching the eye holes are provided, Each of the pair of elastic pieces has an outer edge straight portion formed on an outer edge side that is pressed against the through hole and that extends along the axial direction of the through hole, and an inner edge straight portion formed on an inner edge side that faces the eye hole and that extends along the axial direction, the inner straight edge portion is disposed closer to the terminal tip end than the outer straight edge portion, a forming length of the outer edge straight portion is longer than a forming length of the inner edge straight portion; Each of the pair of elastic pieces is formed with a base-side inner edge curved portion that connects the inner edge straight portion to an edge of the eye hole on the terminal base side, and a tip-side inner edge curved portion that connects the inner edge straight portion to an edge of the eye hole on the terminal tip side, The radius of the curved inner edge portion on the base side is smaller than the radius of the curved inner edge portion on the tip side, The width of the curved inner edge portion on the base side is larger than the width of the curved inner edge portion on the tip side. Press-fit terminals.

2. The spring length of the elastic piece portion on the tip side, which is determined by the distance between the midpoint of the formed length of the outer edge straight portion and the edge of the eyehole on the terminal tip side, is configured to be greater than the spring length of the elastic piece portion on the base side, which is determined by the distance between the midpoint and the edge of the eyehole on the terminal base side. The press-fit terminal according to claim 1 .

3. The formed length of the outer edge straight portion is 0.1 mm or more and 0.5 mm or less. The press-fit terminal according to claim 1 or 2.

4. The outer edge straight portion has rounded corners at least over the entire formed length of the outer edge straight portion, The radius of the R-shaped portion / the diameter of the through-hole is set to 0.17 or more. The press-fit terminal according to any one of claims 1 to 3.

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