JP7740927B2 - Female terminals, connectors, wires with terminals, wires with connectors, and wire harnesses - Google Patents

Description

This invention relates to female terminals, connectors, electric wires with terminals, electric wires with connectors, and wire harnesses for electrical circuits through which large currents flow.

Conventionally, electrical equipment has formed electrical circuits by connecting electric devices and power supplies via wire harnesses. The wire harness and electric device, as well as the wire harness and power supply, are connected to each other via connectors attached to each.

For example, the connector shown in Patent Document 1 has a female terminal housed in a connector housing. The female terminal has a terminal body formed by a base and a spring member, and when the connector housings are mated, a male terminal is inserted into the female terminal. At this time, it is important to press an arm spring, which is part of the spring member, against the male terminal to ensure reliable contact.

Japanese Patent Application Laid-Open No. 2009-245701

In electrical circuits such as those in automobile drivetrains, where large currents flow, it is conceivable to weld the base and spring member together to ensure good conductivity. However, if the welding heat from welding the base and spring member together reaches the base of the arm spring, the temperature at the base can rise, changing the metal structure and potentially reducing the pressing force of the arm spring. This could ultimately lead to unstable conductivity.

The purpose of this invention is to provide a female terminal, connector, electric wire with terminal, electric wire with connector, and wire harness that can prevent a decrease in the pressing force of the arm spring and thereby stabilize conductivity.

This invention relates to a female terminal in which a terminal body is provided by a base portion connected to an electric wire and a spring member attached to the base portion, the base portion having a pair of side walls spaced a predetermined distance apart so that a male terminal can be inserted, the spring member having a longitudinal plate attached to at least one of the side walls and an arm spring extending from the longitudinal plate toward the other side wall, the side walls and the longitudinal plate being welded to form a weld, the region formed around the weld where the metal structure has changed due to the welding heat being a heat-affected zone, the boundary between the longitudinal plate and the arm spring extending from the longitudinal plate being the base point of the arm spring that abuts or is close to the inner surface of the side wall, and the base point of the arm spring that abuts or is close to the inner surface of the side wall being positioned away from the heat-affected zone.

In this specification, the term "heat-affected zone" refers to the area where changes in the metal structure occur due to welding heat. Furthermore, the term "base point of the arm spring" refers to the boundary between the base plate and the arm spring extending from the base plate.

The present invention also includes a connector having the aforementioned female terminal and a connector housing that accommodates the female terminal, as well as a terminal-attached electric wire having the aforementioned female terminal and the electric wire connected to the base portion of the female terminal.

Furthermore, this invention includes a connector-equipped electric wire that includes the aforementioned terminal-equipped electric wire and a connector housing that accommodates the terminal-equipped electric wire, as well as a wire harness that includes at least one of the terminal-equipped electric wire and the connector-equipped electric wire.

In the present invention, the outermost point on one side of the heat-affected zone refers to the point on the outer edge of the heat-affected zone that is closest to the leading edge of the side wall. Similarly, the outermost point on the other side refers to the point that is farthest from the leading edge of the side wall. Furthermore, the leading edge side refers to the direction toward the leading edge of the side wall, and the opposite leading edge side refers to the direction away from the leading edge of the side wall.

According to this invention, it is possible to prevent the pressing force of the arm spring from decreasing, and in turn to stabilize the conductivity.
Specifically, in the female terminals and the like according to the present invention, the base portion of the arm spring, which is the boundary between the longitudinal plate and the arm spring extending from the longitudinal plate, is located on the inner surface of the side wall, away from the heat-affected zone, which is the region formed around the weld where the metallurgical structure is changed by the welding heat, and is abutted against or adjacent to the longitudinal plate. This configuration allows the welding heat to be largely dissipated before reaching the base portion of the arm spring. This suppresses the temperature rise at the base portion and prevents changes in the metallurgical structure at this base portion. This prevents a decrease in the pressing force of the arm spring, thereby stabilizing conductivity.

The terminal has a longitudinal plate that is disposed along the inner surface of the side wall, and the inner surface of the side wall and the longitudinal plate are welded obliquely from the terminal opening to form the welded portion. The base portion of the arm spring is disposed in contact with or close to the inner surface of the side wall at a position closer to the tip surface of the side wall than the outermost point on one side of a heat-affected region formed around the welded portion, or closer to the opposite tip surface of the side wall than the outermost point on the other side of the heat-affected region.

This configuration allows a certain distance to be maintained between the heat-affected zone and the base of the arm spring, allowing the welding heat to dissipate significantly before reaching the base of the arm spring. This suppresses the temperature rise at the base and prevents changes to the metal structure at the base. This prevents a decrease in the pressing force of the arm spring and ultimately stabilizes conductivity.

Explaining in more detail, the heat-affected zone is formed in a roughly bell shape that widens on the inner side of the side wall and gradually narrows as the welding heat is transmitted from the inner surface of the side wall in the depth direction (penetration direction) and dissipates to the surrounding area. Therefore, if the base point of the arm spring is positioned in contact with or close to the inner surface of the side wall at a position closer to the tip surface of the side wall than the outermost point (upper end point) on one side of the heat-affected zone, or closer to the opposite tip surface of the side wall than the outermost point (lower end point) on the other side of the heat-affected zone, a certain distance can be maintained from the outer edge of the heat-affected zone.

In particular, welding the inner surface of the side wall to the base plate can be performed at an angle from the terminal opening using a laser welder due to the narrow gap between the opposing side walls. This transfers welding heat obliquely to the inner surface of the side wall and also to the area between the formed heat-affected zone and the inner surface. Therefore, even slight increases or decreases in the amount of heat generated during welding can easily change the width of the heat-affected zone. Therefore, the relative positional relationship between the heat-affected zone and the base point of the arm spring in the lateral direction (height direction of the female terminal) is important. Therefore, if the base point of the arm spring is placed in contact with or adjacent to the inner surface of the side wall at a position closer to the tip surface of the side wall than the outermost point (upper end point) on one side of the heat-affected zone, or closer to the opposite tip surface of the side wall than the outermost point (lower end point) on the other side of the heat-affected zone, this reliably suppresses temperature increases at the base point and prevents changes to the metal structure at this base point. This prevents a decrease in the pressing force of the arm spring and ultimately stabilizes conductivity.

In another aspect of the present invention, the hardness of the base portion of the arm spring may be 80% or more of the hardness of the base material.
In the present invention, the hardness refers to the hardness measured by an indentation test method, typically the so-called Vickers hardness test.

This invention ensures that the required pressing force of the arm spring is secured. Furthermore, by confirming that the hardness at the base point is 80 percent or more of the hardness of the base material, it can be assumed that the pressing force of the arm spring is secured, making testing related to pressing force easier. Furthermore, because the hardness of the base point, which has a significant impact on the pressing force of the arm spring, is measured, a high degree of reliability can be obtained in estimating the test results (whether the pressing force of the arm spring is secured or not).

In another aspect of the present invention, the hardness of the contact portion of the arm spring may be 90% or more of the hardness of the base material.
The hardness in the present invention also means the hardness measured by an indentation test method, typically the so-called Vickers hardness test.

This invention ensures that the required pressing force of the arm spring is secured. Furthermore, by confirming that the hardness of the contact point is 90% or more of the base material hardness, it can be assumed that the pressing force of the arm spring is secured, making testing of the pressing force easier. Furthermore, because the hardness of the contact point is measured even if work hardening occurs at the base point of the arm spring due to bending, highly reliable estimations of the test results (whether the pressing force of the arm spring is secured) can be made.

In one aspect of the present invention, the side wall may have a longitudinally extending plate disposed along the tip end surface thereof, the tip end surface of the side wall and the longitudinally extending plate may be welded to form the welded portion, and the base portion of the arm spring may be disposed in contact with or adjacent to a position on the inner surface of the side wall that is closer to the tip end surface of the side wall than the deepest point of a heat-affected zone formed around the welded portion.

In the present invention, the deepest point of the heat-affected zone refers to the point on the outer edge of the heat-affected zone that is located farthest from the tip end face of the side wall. Also, the opposite side to the tip end face refers to the direction away from the tip end face of the side wall.

This invention allows a certain distance to be maintained between the heat-affected zone and the base of the arm spring, allowing the welding heat to dissipate significantly before reaching the base of the arm spring. This suppresses the temperature rise at the base and prevents changes to the metal structure at the base. This prevents a decrease in the pressing force of the arm spring and ultimately stabilizes conductivity.

More specifically, the heat-affected zone is formed in a generally bell-shaped configuration that widens toward the tip end of the side wall and gradually narrows because the welding heat is transmitted from the tip end of the side wall in the depth direction (penetration direction) and dissipates to the surrounding area. Therefore, if the base point of the arm spring is placed in contact with or close to a position on the inner surface of the side wall opposite the tip end of the side wall from the deepest point of the heat-affected zone, a certain distance can be maintained from the outer edge of the heat-affected zone.

In particular, a laser welding machine, capable of achieving fine welding, is used to weld the tip surface of the side wall and the base plate because the weldable area is narrow. When welding is performed using a laser welding machine, the welding heat is more easily transmitted in the depth direction (the height direction of the female terminal) than in the lateral direction (the width direction of the female terminal). Therefore, the relative positional relationship between the heat-affected zone and the base point of the arm spring in the depth direction (the height direction of the female terminal) is important. Therefore, if the base point of the arm spring is abutted or positioned on the inner surface of the side wall, opposite the tip surface of the side wall from the deepest point of the heat-affected zone, the temperature rise at the base point can be reliably suppressed and the metal structure at this base point can be prevented from changing. This prevents a decrease in the pressing force of the arm spring and ultimately stabilizes conductivity.

In another aspect of the present invention, the side wall may have a longitudinally extending plate disposed along the outer surface thereof, the outer surface of the side wall and the longitudinally extending plate being welded to form the welded portion, and the base portion of the arm spring may be positioned in contact with or close to the inner surface of the side wall at a position closer to the tip surface of the side wall than the outermost point on one side of a heat-affected zone formed around the welded portion, or closer to the opposite tip surface of the side wall than the outermost point on the other side of the heat-affected zone.

In the present invention, the outermost point on one side of the heat-affected zone refers to the point on the outer edge of the heat-affected zone that is closest to the leading edge of the side wall. The outermost point on the other side refers to the point that is farthest from the leading edge of the side wall. Furthermore, the leading edge side refers to the direction toward the leading edge of the side wall, and the opposite leading edge side refers to the direction away from the leading edge of the side wall.

This invention allows a certain distance to be maintained between the heat-affected zone and the base of the arm spring, allowing the welding heat to dissipate significantly before reaching the base of the arm spring. This suppresses the temperature rise at the base and prevents changes to the metal structure at the base. This prevents a decrease in the pressing force of the arm spring and ultimately stabilizes conductivity.

More specifically, the heat-affected zone is formed in a generally bell-shaped configuration that widens toward the outer surface of the side wall and gradually narrows because the welding heat is transmitted from the outer surface of the side wall in the depth direction (penetration direction) and dissipates to the periphery. Therefore, if the base point of the arm spring is placed in contact with or close to the inner surface of the side wall at a position closer to the tip surface of the side wall than the outermost point (upper end point) on one side of the heat-affected zone or closer to the opposite tip surface of the side wall than the outermost point (lower end point) on the other side of the heat-affected zone, a certain distance can be maintained from the outer edge of the heat-affected zone.

In particular, because the weldable area between the outer surface of the side wall and the base plate is large, ultrasonic welding or arc welding can be used in addition to laser welding. When welding is performed using an arc welding machine, welding heat is more easily transmitted laterally (in the height direction of the female terminal) than in the depth direction (in the width direction of the female terminal). Therefore, the relative position of the heat-affected zone and the base point of the arm spring in the lateral direction (in the height direction of the female terminal) is important. Therefore, if the base point of the arm spring is abutted against or adjacent to the inner surface of the side wall at a position closer to the tip surface of the side wall than the outermost point (upper end point) on one side of the heat-affected zone or closer to the opposite tip surface of the side wall than the outermost point (lower end point) on the other side of the heat-affected zone, the temperature rise at the base point can be reliably suppressed and the metal structure at this base point can be prevented from changing. This prevents a decrease in the pressing force of the arm spring and ultimately stabilizes conductivity.

FIG. FIG. FIG. Side view of a female terminal. Front view of the female terminal. FIG. 7 is a cross-sectional view taken along the line AA in FIG. 6. 7 is a cross-sectional view taken along the line BB in FIG. 6 and a cross-sectional view taken along the line CC in FIG. 6. FIG. FIG. 10 is an enlarged cross-sectional view of a male terminal inserted inside a female terminal. Assembly instructions for female terminals. FIG. 10 is an enlarged cross-sectional view of a female terminal according to another embodiment. FIG. 10 is an enlarged cross-sectional view of a female terminal according to another embodiment. FIG. 10 is an enlarged cross-sectional view of a female terminal according to another embodiment. FIG. 10 is an enlarged cross-sectional view of a female terminal according to another embodiment.

An embodiment of the present invention will be described in detail with reference to the drawings.
Fig. 1 is an overall perspective view showing a connector 1. In Fig. 1, a connector housing 4 that accommodates female terminals 10 is shown by a broken line.

Figure 2 is an exploded perspective view of the female terminal 10. Figure 3 is a perspective view of the female terminal 10. Figure 4 is a side view of the female terminal 10, Figure 5 is a front view of the female terminal 10, and Figure 6 is a plan view of the female terminal 10. Figure 7 is a cross-sectional view taken along the line A-A in Figure 6, and Figure 8 is a cross-sectional view taken along the line B-B and C-C in Figure 6. Figure 9 is an enlarged cross-sectional view of the female terminal 10, and Figure 10 is an enlarged cross-sectional view of the female terminal 10 with the male terminal 5 inserted inside.

As shown in Figure 1, the connector 1 is attached to the tip of the electric wires 3 that make up the wire harness 2. The connector 1 has two female terminals 10 housed in parallel in the connector housing 4.

The wire harness 2 is composed of multiple bundled electric wires 3. Each electric wire 3 has an electric conductor core 3a covered with an insulating coating 3b, and the exposed core 3a at its tip is connected to the base 20 of the female terminal 10.

The connector housing 4 has a wire insertion section 41 through which the wire 3 is inserted, and a terminal accommodating section 42 that accommodates the female terminal 10. The accommodating space 4S that accommodates the female terminal 10 has a roughly rectangular opening, and the protruding portion of the connector housing that accommodates the male terminal 5 (see Figure 10) fits into this opening. At this time, the male terminal 5 is inserted inside the female terminal 10, and the terminals are electrically connected to each other.

As shown in Figures 2 to 10, the female terminal 10 is composed of a wire connection portion 11 and a terminal connection portion 12. The wire connection portion 11 and the terminal connection portion 12 are arranged in series on an extension of the wire 3. In this application, this direction will be described as the longitudinal direction L. Furthermore, the direction parallel to the insertion direction of the male terminal 5 (see Figure 10) will be described as the height direction H, and the direction perpendicular to the longitudinal direction L and the height direction H will be described as the width direction W.

The wire connection portion 11 is provided with a connection plate 111 that is perpendicular to the width direction W. The upper and lower ends of the connection plate 111 are bent to form guide pieces 112. Each guide piece 112 serves to prevent the core wire 3a connected to the connection plate 111 from spreading.

The terminal connection portion 12 is provided with a terminal body 13 that is electrically connected to the male terminal 5 (see Figure 10). In the female terminal 10 according to this embodiment, the terminal body 13 is composed of a base portion 20 that is integrally formed with the electric wire connection portion 11, and a spring member 30 that is attached to the base portion 20. The base portion 20 and spring member 30 will be described in detail below.

The base portion 20 has a pair of side walls 21 spaced a predetermined distance apart, allowing the male terminals 5 to be inserted. More specifically, the base portion 20 has a pair of side walls 21 spaced a predetermined distance apart, each perpendicular to the width direction W. The base portion 20 also has a bottom wall 22 connecting the lower ends of the side walls 21. Therefore, the base portion 20 is generally U-shaped when viewed in the longitudinal direction L (see Figure 4).

In addition, one side wall 21 of the base portion 20 is formed by extending the connecting plate 111 in the longitudinal direction L. The other side wall 21 is formed by folding back the plate material (the base material of the base portion 20) on the side where the guide piece 112 is formed. As a result, the base portion 20 has a substantially rectangular shape when viewed from the height direction H (see Figure 6). In this way, by forming the other side wall 21 of the base portion 20 on the side where the guide piece 112 is formed, the female terminal 10 is made more compact.

Furthermore, the upper guide piece 112 of the base part 20 is formed by bending the upper end of the connecting plate 111, and a notch 11a is provided to prevent the side wall 21 from being distorted when forming the guide piece 112. Similarly, the lower guide piece 112 of the base part 20 is formed by bending the lower end of the connecting plate 111, and a notch 11b is provided to prevent the side wall 21 from being distorted when forming the guide piece 112. Furthermore, a portion of the spring member 30 is exposed at the notch 11b, allowing the spring member 30 to be pushed out from below and removed (see Figures 5 and 7).

In addition, the base portion 20 is formed by cutting out and bending a conductive plate material such as a copper alloy or aluminum alloy. The surface of the base portion 20 is not plated, but this is not a limitation. Therefore, the surface may be plated with silver plating, tin plating, or other plating to improve conductivity. Alternatively, the base portion 20 may be partially plated. A partially plated portion may, for example, be one surface of the wire connection portion 11 or the terminal connection portion 12 plated. Alternatively, only the wire connection portion 11 or only the terminal connection portion 12 may be plated.

The spring member 30 has an inner plate 31 that fits along the inner surface 21a of the side wall 21 when fitted between a pair of side walls 21. It also has an outer plate 32 that fits along the outer surface 21b of the side wall 21. It also has a flange plate 33 that connects the upper ends of the inner plate 31 and outer plate 32. It also has a bottom plate 34 that connects the lower ends of each inner plate 31. Therefore, the spring member 30 is generally M-shaped when viewed from the longitudinal direction L (see Figure 4).

The inner plate 31 on one side of the spring member 30 extends in the longitudinal direction L along the opening edge of the side wall 21, and six arm springs 35 extend from this inner plate 31 toward the opposing side wall 21 (see Figure 7). These arm springs 35 all have the same shape; specifically, when viewed from the longitudinal direction L, they extend diagonally downward toward the opposing side wall 21, and are partially folded back, including their leading edges (see Figure 8).

The arm spring 35 provided on one inner plate 31 extends from the lower edge of the inner plate 31 along the opening edge of the side wall 21, and the boundary with this inner plate 31 serves as the base point 35b of the arm spring 35 (see Figure 8). In the female terminal 10 according to this embodiment, the base point 35b of the arm spring 35 always abuts against the inner surface 21a of the side wall 21. The reaction force from the side wall 21 acts on the arm spring 35 via the base point 35b, allowing the contact point 35c of the arm spring 35 to be pressed against the male terminal 5 (see arrow F in Figure 10).

Furthermore, the inner plate 31 on the other side of the spring member 30 also extends in the longitudinal direction L along the opening edge of the side wall 21, and six arm springs 35 extend from this inner plate 31 toward the opposing side wall 21 (see Figure 7). These arm springs 35 all have the same shape; specifically, when viewed from the longitudinal direction L, they extend diagonally downward toward the opposing side wall 21, and are partially folded back, including their leading edges (see Figure 8).

The arm spring 35 provided on the other inner plate 31 also extends from the lower edge of the inner plate 31 along the opening edge of the side wall 21, and the boundary portion with this inner plate 31 serves as the base point 35b of the arm spring 35 (see Figure 8). In the female terminal 10 according to this embodiment, the base point 35b of the arm spring 35 always abuts against the inner surface 21a of the side wall 21. Because the reaction force from the side wall 21 acts on the arm spring 35 via the base point 35b, it is possible to press the contact point 35c of the arm spring 35 against the male terminal 5 (see arrow F in Figure 10).

In addition, the spring member 30 has the flange plate 33 in surface contact with the tip surface 21c of the side wall 21. A predetermined portion of this surface contact in the width direction W is welded along the longitudinal direction L. Therefore, a linear weld 36 is formed on the flange plate 33 along the longitudinal direction L (see Figures 6 to 10). The weld 36 refers to a solidified metal portion 36m where a portion of the side wall 21 or flange plate 33 melts and then cools and solidifies. A heat-affected zone 36h is formed around the weld 36, where the welding heat has caused a change in the base material structure. The center line C of the weld 36 is perpendicular to the tip surface 21c of the side wall 21 and the flange plate 33, as they are welded perpendicular to these.

Furthermore, in the female terminal 10 according to this embodiment, the base point 35b of the arm spring 35 abuts against the inner surface 21a of the side wall 21 at a position spaced from the heat-affected zone 36h. Specifically, the base point 35b of the arm spring 35 abuts against a position on the opposite side of the tip surface of the side wall 21 (see arrow A in Figures 9 and 10) from the deepest point Pe of the heat-affected zone 36h. This configuration can be said to be configured such that, if D1 is the length from the tip surface 21c of the side wall 21 to the deepest point Pe, which is the farthest point in the depth direction (downward: the penetration direction along the center line C of the weld 36) on the outer edge of the heat-affected zone 36h, and D2 is the length from the tip surface 21c of the side wall 21 to the abutment point Pc where the base point 35b of the arm spring 35 abuts, then D1 < D2.

As shown in Figure 11, the assembly of the female terminal 10 according to this embodiment is completed through the following steps: The spring member 30 is fitted between the pair of side walls 21 of the base portion 20 (see Figure 11(a)), the tip surface 21c of the side wall 21 is welded to the flange plate 33 that is in surface contact with this tip surface 21c (see Figure 11(b)), and the hardness of the base portion 35b of the arm spring 35 is measured to complete the assembly (see Figure 11(c)). Of course, the hardness measurement process may be performed for each specified number of units (each production lot).

The hardness of the base point 35b of the arm spring 35 is measured to confirm that the hardness of the base point 35b of the arm spring 35 is 80% or more of the hardness of the base material. In other words, this is to confirm that the hardness of the base point 35b of the arm spring 35 is 80% or more of the hardness (base material hardness) of the base material. This requirement is imposed because it makes inspection easy and ensures that the pressing force of the arm spring 35 is appropriately secured.

In this regard, the hardness of the contact portion 35c of the arm spring 35 may also be measured. This is done to confirm that the hardness of the contact portion 35c of the arm spring 35 is 90% or more of the hardness of the base material. In other words, this is to confirm that the hardness of the contact portion 35c of the arm spring 35 is 90% or more of the hardness in the base material state (base material hardness). This requirement is imposed because it makes inspection easy and ensures that the pressing force of the arm spring 35 is properly secured. In particular, it has the advantage that inspection can be performed without any changes even if the base portion 35b of the arm spring 35 has undergone work hardening due to bending.

Next, we will explain the female terminal 10 according to the second embodiment. Figure 12 is an enlarged cross-sectional view of the female terminal 10 according to the second embodiment. This female terminal 10 has the same structure as the female terminal 10 described above, except for the position where the welded portion 36 is provided.

In the female terminal 10 according to this embodiment, the spring member 30 has the outer plate 32 in surface contact with the outer surface 21b of the side wall 21. A predetermined portion of this surface contact in the height direction H is welded along the longitudinal direction L. Therefore, a linear weld 36 is formed on the outer plate 32 along the longitudinal direction L. As mentioned above, the weld 36 refers to a solidified metal portion 36m formed when a portion of the side wall 21 or outer plate 32 melts and then cools and solidifies. A heat-affected zone 36h is formed around the weld 36, where the welding heat has caused a change in the base material structure. The center line C of the weld 36 is perpendicular to the outer surface 21b of the side wall 21 and the outer plate 32, as they are welded perpendicular to these.

In the female terminal 10 according to this embodiment, the base point 35b of the arm spring 35 also abuts the inner surface 21a of the side wall 21 at a position spaced from the heat-affected region 36h. Specifically, the base point 35b of the arm spring 35 abuts at a position closer to the side wall 21's distal end than the lower end point Pd of the heat-affected region 36h (see arrow A in FIG. 12). This configuration can be said to be configured such that D1 < D2 holds true, where D1 is the length from the distal end surface 21c of the side wall 21 to the lower end point Pd, which is the farthest point in the depth direction (downward) on the outer edge of the heat-affected region 36h, and D2 is the length from the distal end surface 21c of the side wall 21 to the contact point Pc where the base point 35b of the arm spring 35 abuts.

In the female terminal 10 according to this embodiment, the base point 35b of the arm spring 35 abuts on the inner surface 21a of the side wall 21 at a position closer to the distal end of the side wall 21 than the lower end point Pd of the heat-affected zone 36h (see arrow A in FIG. 12). However, the base point 35b of the arm spring 35 may also abut at a position closer to the distal end of the side wall 21 than the upper end point Pu of the heat-affected zone 36h. Even with this configuration, it is believed that the same effect can be achieved. Furthermore, in the female terminal 10 according to this embodiment, the base point 35b of the arm spring 35 abuts on the inner surface 21a of the side wall 21. However, the base point 35b may also be positioned close to the inner surface 21a (with a slight gap between the base point 35b and the inner surface 21a).

Next, we will explain the female terminal 10 according to the third embodiment. Figure 13 is an enlarged cross-sectional view of the female terminal 10 according to the third embodiment. This female terminal 10 has the same structure as the female terminal 10 described above, except for the position where the welded portion 36 is provided.

In the female terminal 10 according to this embodiment, the spring member 30 is in surface contact with the inner surface 21a of the side wall 21, and the inner plate 31 is welded along the longitudinal direction L at a predetermined portion of the height direction H of this surface contact area. Therefore, a linear weld 36 is formed on the inner plate 31 along the longitudinal direction L. As mentioned above, the weld 36 refers to a solidified metal portion 36m formed when a portion of the side wall 21 or inner plate 31 melts and then cools and solidifies. A heat-affected zone 36h is formed around the weld 36, where the welding heat has caused a change in the base material structure. The center line C of the weld 36 is inclined relative to the inner surface 21a of the side wall 21 and the inner plate 31, as the weld is welded at an angle to these.

In the female terminal 10 according to this embodiment, the base point 35b of the arm spring 35 also abuts the inner surface 21a of the side wall 21 at a position spaced from the heat-affected region 36h. Specifically, the base point 35b of the arm spring 35 abuts at a position closer to the distal end of the side wall 21 than the lower end point Pd of the heat-affected region 36h (see arrow A in FIG. 13). This configuration can be said to be configured such that D1 < D2 holds true, where D1 is the length from the distal end surface 21c of the side wall 21 to the lower end point Pd, which is the farthest point in the depth direction (downward) on the outer edge of the heat-affected region 36h, and D2 is the length from the distal end surface 21c of the side wall 21 to the contact point Pc where the base point 35b of the arm spring 35 abuts.

In the female terminal 10 according to this embodiment, the base point 35b of the arm spring 35 abuts on the inner surface 21a of the side wall 21 at a position closer to the distal end of the side wall 21 than the lower end point Pd of the heat-affected zone 36h (see arrow A in FIG. 13). However, the base point 35b of the arm spring 35 may also abut at a position closer to the distal end of the side wall 21 than the upper end point Pu of the heat-affected zone 36h. Even with this configuration, it is believed that the same effect can be achieved. Furthermore, in the female terminal 10 according to this embodiment, the base point 35b of the arm spring 35 abuts on the inner surface 21a of the side wall 21. However, the base point 35b may also be positioned close to the inner surface 21a (with a slight gap between the base point 35b and the inner surface 21a).

As described above, the female terminal 10 according to each of the above-described embodiments has a terminal body 13 formed by a base portion 20 connected to the electric wire 3 and a spring member 30 attached to the base portion 20. The base portion 20 has a pair of side walls 21 spaced a predetermined distance apart to allow insertion of the male terminal 5, and the spring member 30 has an extension plate (inner plate 31) attached to at least one side wall 21 and an arm spring 35 extending from the extension plate (inner plate 31) toward the other side wall 21. The side wall 21 and the extension plate (e.g., flange plate 33) are welded to form a weld 36, and the base portion 35b of the arm spring 35 abuts against the inner surface 21a of the side wall 21 at a position spaced from a heat-affected zone 36h formed around the weld 36.

Such a female terminal 10 prevents the pressing force of the arm spring 35 from decreasing, thereby stabilizing conductivity.
More specifically, in the female terminal 10 according to the present invention, the base point 35b of the arm spring 35 abuts on the inner surface 21a of the sidewall 21 at a position spaced from the heat-affected zone 36h formed around the weld 36. This configuration allows the welding heat to be largely dissipated before reaching the base point 35b of the arm spring 35. This suppresses the temperature rise at the base point 35b and prevents changes to the metal structure at the base point 35b. This prevents a decrease in the pressing force of the arm spring 35, thereby stabilizing conductivity.

The female terminal 10 according to the first embodiment has a flange 33 provided along the tip surface 21c of the side wall 21, and the tip surface 21c of the side wall 21 and the flange 33 are welded to form a weld 36. The base point 35b of the arm spring 35 abuts the inner surface 21a of the side wall 21 at a position on the opposite side of the tip surface of the side wall 21 (see arrow A in Figures 9 and 10) from the deepest point Pe of the heat-affected zone 36h formed around the weld 36.

With this type of female terminal 10, a certain distance can be maintained from the heat-affected zone 36h to the base point 35b of the arm spring 35, allowing the welding heat to dissipate significantly before reaching the base point 35b of the arm spring 35. This prevents the temperature from rising at the base point 35b and prevents changes to the metal structure at this base point 35b. This prevents a decrease in the pressing force of the arm spring 35, thereby stabilizing conductivity.

Explaining in more detail, the heat-affected zone 36h is formed in a roughly bell shape that widens toward the tip surface 21c of the side wall 21 and gradually narrows as the welding heat is transmitted from the tip surface 21c of the side wall 21 in the depth direction (penetration direction) and dissipates to the surrounding area. Therefore, if the base point portion 35b of the arm spring 35 abuts on the inner surface 21a of the side wall 21 at a position on the opposite tip surface side of the side wall 21 (see arrow A in Figures 9 and 10) from the deepest point Pe of the heat-affected zone 36h, a certain distance can be maintained from the outer edge of the heat-affected zone 36h.

In particular, a laser welder is used to weld the tip surface 21c of the side wall 21 to the flange plate 33, as the weldable area is narrow. When welding is performed using a laser welder, welding heat is more easily transferred in the depth direction (height direction H of the female terminal 10) than in the lateral direction (width direction W of the female terminal 10). This means that the depth of the heat-affected zone 36h is easily affected by slight increases or decreases in the amount of heat during welding, making the relative positional relationship between the heat-affected zone 36h and the base point 35b of the arm spring 35 in the depth direction (height direction H of the female terminal 10) important. Therefore, if the base point 35b of the arm spring 35 is in contact with the inner surface 21a of the side wall 21 at a position closer to the distal end of the side wall 21 than the deepest point Pe of the heat-affected zone 36h (see arrow A in Figures 9 and 10), it is possible to reliably suppress the temperature rise at the base point 35b and prevent changes to the metal structure at this base point 35b. This prevents a decrease in the pressing force of the arm spring 35, and ultimately stabilizes conductivity.

The base point 35b of the arm spring 35 may not abut but may be positioned close to the inner surface 21a of the side wall 21 (with the base point 35b positioned with a slight gap from the inner surface 21a). Even with this configuration, it is possible to prevent a decrease in the pressing force of the arm spring 35, thereby stabilizing conductivity.

The female terminal 10 according to the second embodiment has an outer plate 32 that is provided along the outer surface 21b of the side wall 21, and the outer surface 21b of the side wall 21 and the outer plate 32 are welded to form a weld 36. The base point 35b of the arm spring 35 abuts the inner surface 21a of the side wall 21 at a position closer to the distal end of the side wall 21 than the lower end point Pd of the heat-affected zone 36h formed around the weld 36 (see arrow A in Figure 12).

With this type of female terminal 10, a certain distance can be maintained from the heat-affected zone 36h to the base point 35b of the arm spring 35, allowing the welding heat to dissipate significantly before reaching the base point 35b of the arm spring 35. This prevents the temperature from rising at the base point 35b and prevents changes to the metal structure at this base point 35b. This prevents a decrease in the pressing force of the arm spring 35, thereby stabilizing conductivity.

Explaining in more detail, the heat-affected zone 36h is formed in a roughly bell shape that widens toward the outer surface 21b of the side wall 21 and gradually narrows as the welding heat is transmitted from the outer surface 21b of the side wall 21 in the depth direction (penetration direction) and dissipates to the surrounding area. Therefore, if the base point 35b of the arm spring 35 abuts on the inner surface 21a of the side wall 21 at a position closer to the tip surface of the side wall 21 than the lower end point Pd of the heat-affected zone 36h (see arrow A in Figure 12), a certain distance can be maintained from the outer edge of the heat-affected zone 36h.

In particular, because the weldable area between the outer surface 21b of the side wall 21 and the outer plate 32 is large, an ultrasonic welding machine or arc welding machine can be used in addition to a laser welding machine. When welding is performed using an arc welding machine, the welding heat is more easily transferred laterally (in the height direction H of the female terminal 10) than in the depth direction (in the width direction W of the female terminal 10). This means that the width of the heat-affected zone 36h is easily changed by slight increases or decreases in the amount of heat during welding, and the relative positional relationship between the heat-affected zone 36h and the base point 35b of the arm spring 35 in the horizontal direction (in the height direction H of the female terminal 10) is important. Therefore, if the base point 35b of the arm spring 35 is in contact with the inner surface 21a of the side wall 21 at a position closer to the distal end of the side wall 21 than the lower end point Pd of the heat-affected zone 36h (see arrow A in Figure 12), it is possible to reliably suppress the temperature rise at the base point 35b and prevent changes to the metal structure at this base point 35b. This prevents a decrease in the pressing force of the arm spring 35, and ultimately stabilizes conductivity.

The base point 35b of the arm spring 35 may abut on the inner surface 21a of the side wall 21 at a position closer to the tip surface of the side wall 21 than the upper end point Pu of the heat-affected zone 36h. Alternatively, the base point 35b of the arm spring 35 may not abut, but may be positioned close to the inner surface 21a of the side wall 21 (with the base point 35b positioned with a slight gap from the inner surface 21a). Even with this configuration, it is possible to prevent a decrease in the pressing force of the arm spring 35, thereby stabilizing conductivity.

The female terminal 10 according to the third embodiment has an inner plate 31 that is provided along the inner surface 21a of the side wall 21, and the inner surface 21a of the side wall 21 and the inner plate 31 are welded together at an angle from the terminal opening to form a weld 36. The base point 35b of the arm spring 35 abuts the inner surface 21a of the side wall 21 at a position closer to the distal end of the side wall 21 than the lower end point Pd of the heat-affected zone 36h formed around the weld 36 (see arrow A in Figure 13).

With this type of female terminal 10, a certain distance can be maintained from the heat-affected zone 36h to the base point 35b of the arm spring 35, allowing the welding heat to dissipate significantly before reaching the base point 35b of the arm spring 35. This prevents the temperature from rising at the base point 35b and prevents changes to the metal structure at this base point 35b. This prevents a decrease in the pressing force of the arm spring 35, thereby stabilizing conductivity.

Explaining in more detail, the heat-affected zone 36h is formed in a roughly bell shape that widens toward the inner surface 21a of the side wall 21 and gradually narrows as the welding heat is transmitted from the inner surface 21a of the side wall 21 in the depth direction (penetration direction) and dissipates to the surrounding area. Therefore, if the base point 35b of the arm spring 35 abuts on the inner surface 21a of the side wall 21 at a position closer to the tip surface of the side wall 21 than the lower end point Pd of the heat-affected zone 36h (see arrow A in Figure 13), a certain distance can be maintained from the outer edge of the heat-affected zone 36h.

In particular, welding the inner surface 21a of the side wall 21 to the inner plate 31 can be performed at an angle from the terminal opening using a laser welder due to the narrow gap between the opposing side walls 21. This causes welding heat to be transferred obliquely to the inner surface 21a of the side wall 21, as well as to the area between the formed heat-affected zone 36h and the inner surface 21a (area R in Figure 13). Therefore, slight increases or decreases in the amount of heat during welding can easily change the width of the heat-affected zone 36h, making the relative positional relationship between the heat-affected zone 36h and the base point 35b of the arm spring 35 in the lateral direction (height direction H of the female terminal 10) important. Therefore, if the base point 35b of the arm spring 35 is in contact with the inner surface 21a of the side wall 21 at a position closer to the distal end of the side wall 21 than the lower end point Pd of the heat-affected zone 36h (see arrow A in Figure 13), it is possible to reliably suppress the temperature rise at the base point 35b and prevent changes to the metal structure at this base point 35b. This prevents a decrease in the pressing force of the arm spring 35, and ultimately stabilizes conductivity.

The base point 35b of the arm spring 35 may abut on the inner surface 21a of the side wall 21 at a position closer to the tip surface of the side wall 21 than the upper end point Pu of the heat-affected zone 36h. Alternatively, the base point 35b of the arm spring 35 may not abut, but may be positioned close to the inner surface 21a of the side wall 21 (with the base point 35b positioned with a slight gap from the inner surface 21a). Even with this configuration, it is possible to prevent a decrease in the pressing force of the arm spring 35, thereby stabilizing conductivity.

Furthermore, in the female terminal 10 according to the first to third embodiments, the hardness of the base portion 35b of the arm spring 35 is 80% or more of the hardness of the base material. This is calculated based on measurements taken before and after welding. Alternatively, it is calculated based on measurements taken of the spring member 30 in its base material state and measurements taken after welding.

This type of female terminal 10 ensures the necessary pressing force for the arm spring 35. Furthermore, by verifying that the hardness of the base point 35b is 80 percent or more of the base material hardness, it can be assumed that the pressing force of the arm spring 35 is ensured, making testing related to pressing force easier. Furthermore, because the hardness of the base point 35b, which has a significant impact on the pressing force of the arm spring 35, is measured, highly reliable estimations of the test results (whether the pressing force of the arm spring 35 is ensured) can be made.

Furthermore, in the female terminal 10 according to the first to third embodiments, the hardness of the contact portion 35c of the arm spring 35 is 90% or more of the base material hardness. This is also calculated based on measurements taken before and after welding. Alternatively, it is calculated based on measurements of the spring member 30 in its base material state and measurements taken after welding.

This type of female terminal 10 ensures the necessary pressing force for the arm spring 35. Furthermore, by verifying that the hardness of the contact portion 35c is 90 percent or more of the base material hardness, it can be assumed that the pressing force of the arm spring 35 is ensured, making testing of the pressing force easier. Furthermore, because the hardness of the contact portion 35c is measured even if work hardening occurs in the base portion 35b of the arm spring 35 due to bending, highly reliable estimations of the test results (whether the pressing force of the arm spring 35 is ensured) can be made.

In the female terminal 10 according to each embodiment, the side wall 21 and the supporting plates (inner plate 31, outer plate 32, and flange plate 33) are welded using a fiber laser welding machine, but welding may also be performed using an arc welding machine or the like. Welding may also be performed using a welding machine capable of ultrasonic welding, resistance welding, friction welding, or other types of welding. Furthermore, brazing and soldering are also included in the concept of welding.

In correspondence between the configuration of this invention and the above-described embodiment, the connector of this invention corresponds to the connector 1,
Similarly,
The wire harness corresponds to wire harness 2,
The wire corresponds to wire 3,
The connector housing corresponds to the connector housing 4,
The male terminal corresponds to the male terminal 5,
The female terminal corresponds to the female terminal 10,
The terminal body corresponds to the terminal body 13,
The base portion corresponds to the base portion 20,
The side wall corresponds to the side wall 21,
The inner surface corresponds to the inner surface 21a,
The outer surface corresponds to the outer surface 21b.
The tip surface corresponds to tip surface 21c,
The spring member corresponds to the spring member 30,
The contact plates correspond to the inner plate 31, the outer plate 32, and the flange plate 33.
The arm spring corresponds to arm spring 35,
The base point corresponds to the base point 35b.
The contact portion corresponds to the contact portion 35c,
The weld corresponds to weld 36;
The metal solidification section corresponds to the metal solidification section 36m;
The heat affected area corresponds to heat affected area 36h,
The deepest point of the heat affected zone corresponds to the deepest point Pe,
The outermost point on one side of the heat affected zone corresponds to the upper end point Pu,
The outermost point on the other side of the heat affected area corresponds to the bottom point Pd.
The present invention is not limited to the configurations of the above-described embodiments, and many other embodiments can be obtained.

For example, the female terminal 10 according to the first embodiment has a flange plate 33 welded to the tip surface 21c of the side wall 21, the female terminal 10 according to the second embodiment has an outer plate 32 welded to the outer surface 21b of the side wall 21, and the female terminal 10 according to the third embodiment has an inner plate 31 welded to the inner surface 21a of the side wall 21. However, as shown in FIG. 14(a), welding may be performed at the flange plate 33 and at the outer plate 32. Alternatively, as shown in FIG. 14(b), welding may be performed at the flange plate 33 and at the inner plate 31. Of course, other combinations are also possible. Furthermore, each weld 36 may be composed of multiple lines or multiple welded locations.

In addition, in the female terminal 10 according to the first to third embodiments, the arm spring 35 extends from the lower edge of the inner plate 31 along the opening edge of the side wall 21, and the boundary between this inner plate 31 and the arm spring 35 is the base point 35b of the arm spring 35. However, as shown in FIG. 15(a), if a convex portion 31t is formed on the inner plate 31 and the arm spring 35 functions with the abutment point Pc between the side wall 21 and the convex portion 31t as the base point, this convex portion 31t becomes the base point 35b of the arm spring 35. Alternatively, as shown in FIG. 15(b), if a convex portion 21t is formed on the side wall 21 and the arm spring 35 functions with the abutment point Pc between the convex portion 21t and the inner plate 31 as the base point, the portion where this convex portion 21t abuts becomes the base point 35b of the arm spring 35.

Finally, the present invention includes a connector 1 (see Figure 1) equipped with the aforementioned female terminal 10 and a connector housing 4 that accommodates the female terminal 10, as well as a terminal-attached electric wire 6 (see Figure 1) equipped with the aforementioned female terminal 10 and an electric wire 3 connected to the base portion 20 of the female terminal 10.

Furthermore, the present invention includes a connector-equipped electric wire 7 (see Figure 1) that includes the aforementioned terminal-equipped electric wire 6 and a connector housing 4 that accommodates the terminal-equipped electric wire 6, as well as a wire harness 2 (see Figure 1) that includes at least one of the terminal-equipped electric wire 6 and the connector-equipped electric wire 7.

These devices also achieve the same effects as the female terminal 10 of the present invention. That is, they can suppress temperature increases at the base point 35b and prevent changes to the metal structure at this base point 35b. This prevents a decrease in the pressing force of the arm spring 35, thereby stabilizing conductivity.

DESCRIPTION OF SYMBOLS 1...connector 2...wire harness 3...electric wire 4...connector housing 5...male terminal 6...electric wire with terminal 7...electric wire with connector 10...female terminal 13...terminal body 20...base portion 21...side wall 21a...inner surface 21b...outer surface 21c...tip surface 30...spring member 31...inner plate 32...outer plate 33...flange plate 35...arm spring 35b...base point portion 35c of arm spring...contact portion 36 of arm spring...welded portion 36m...metal solidified portion 36h...heat-affected zone Pe...deepest point Pu...upper end point Pd...lower end point

Claims (7)

a base portion connected to the electric wire;
a terminal body is provided by the spring member attached to the base portion,
The base portion has a pair of side walls arranged at a predetermined interval into which the male terminal can be inserted,
The spring member has a longitudinal plate provided along at least one of the side walls, and an arm spring extending from the longitudinal plate toward the other side wall and in an oblique direction from a tip end surface of the side wall toward an opposite tip end surface thereof,
The side wall has an installation plate provided along an inner surface thereof,
The inner surface of the side wall and the longitudinal plate are welded obliquely toward the opposite tip surface and toward the outer surface to form a welded portion,
A region formed around the welded portion and in which a change in the metal structure occurs due to welding heat is defined as a heat-affected region,
The heat-affected zone is formed in a generally bell-shaped shape that is wide on the side of the tip surface and gradually narrows in a depth direction from the tip surface,
a boundary portion between the longitudinal plate and the arm spring extending from the longitudinal plate as a base point portion of the arm spring that abuts against or is close to an inner surface of the side wall;
a base point of the arm spring that is in contact with or close to the inner surface of the side wall is disposed at a position spaced apart from the heat-affected region ;
The base point of the arm spring is disposed in contact with or close to a position on the inner surface of the side wall that is closer to the distal end surface of the side wall than the outermost point of the heat-affected region on the distal end surface side of the side wall.
Female terminal. 2. The female terminal according to claim 1 , wherein the hardness of the base portion of the arm spring is 80% or more of the hardness of the base material. 3. The female terminal according to claim 1 , wherein the hardness of the contact portion of the arm spring is 90% or more of the hardness of the base material. The female terminal according to any one of claims 1 to 3 ,
a connector housing that accommodates the female terminals. The female terminal according to any one of claims 1 to 3 ,
and the electric wire connected to the base portion of the female terminal. The electric wire with terminal according to claim 5 ;
and a connector housing that accommodates the terminal-attached electric wire. A wire harness comprising at least one of the electric wire with terminal according to claim 5 and the electric wire with connector according to claim 6.