JPWO2013065583A1 - Aluminum alloy plate for terminals, terminal fittings, and terminal connection structure for electric wires - Google Patents

Abstract

Provided are an aluminum alloy plate for a terminal from which a terminal fitting that is difficult to relieve stress, a terminal fitting that is difficult to relieve stress, and a terminal connection structure for an electric wire including the terminal fitting. The terminal fittings are Si: 0.6 to 1.5%, Mg: 0.7 to 1.3%, Cu: 0.5 to 1.2%, Mn: 0.5 to 1.1%, Fe: 0.02 to 0.4%, Cr: 0.01 to 0.3%, Zn : 0.005 to 0.5%, Ti: 0.01 to 0.2%, Zr: 0.05 to 0.2%, and the balance is made of an aluminum alloy composed of Al and inevitable impurities. This terminal fitting is, for example, a wire barrel portion 110 to which a conductor 210 of an aluminum-based electric wire is connected, and a fitting portion (female fitting) that extends from the wire barrel portion 110 and is electrically connected to another terminal fitting. A mating portion 130 or a male fitting portion 140). Since this terminal fitting is made of an aluminum alloy having a specific composition, it has a high yield strength and is difficult to relieve stress even at high temperatures.

Description

  The present invention relates to an aluminum alloy plate for a terminal used as a material for a terminal fitting, a terminal fitting formed from the aluminum alloy plate and attached to an aluminum base electric wire, and a terminal connection structure of an electric wire provided with the terminal fitting. is there. In particular, the present invention relates to an aluminum alloy plate for terminals from which a terminal metal fitting that is difficult to relax stress is obtained.

  Conventionally, electric wires of mobile devices such as automobiles and airplanes and industrial devices such as robots have been used by removing the insulating layer at the ends thereof to expose the conductor and attaching terminal fittings to the exposed portions. There are various types of terminal fittings. For example, in a form in which the terminal fittings are connected to each other, as an electrical connection portion for electrically connecting both terminal fittings, a female terminal fitting 100F having a female fitting portion 130 as shown in FIG. There is a male terminal fitting 100M having a fitting portion 140.

  Each of the female terminal fitting 100F and the male terminal fitting 100M shown in FIG. 1 is a crimp type wire barrel portion (crimping portion) that crimps and connects the conductor 210 as a conductor connecting portion that connects the conductor 210 included in the electric wire 200. Contains 110. In the example shown in FIG. 1, the wire barrel portion 110 includes a pair of crimping pieces as shown in FIG. 1 (A), and the crimping pieces are folded and compressed so as to wrap the conductor 210 as shown in FIG. 1 (B). .

  The female terminal fitting 100F includes a cylindrical female fitting part 130 extending on one side of the wire barrel part 110, and includes elastic pieces 131 and 132 arranged to face each other inside the cylindrical body (FIG. 1 (A) ). In the male terminal fitting 100M, a rod-shaped male fitting portion 140 is extended on one side of the wire barrel portion 110. As shown in FIG. 1 (B), when the rod-shaped male fitting portion 140 is inserted into the cylindrical body of the female fitting portion 130, the male fitting portion 140 is firmly held by the urging force of the elastic pieces 131 and 132. Both terminal fittings 100F and 100M are electrically connected. In FIG. 1, only the female fitting part 130 is shown in cross section for easy understanding.

  Copper-based materials such as copper and copper alloys, which are excellent in conductivity, are mainly used as constituent materials for electric wire conductors and terminal fittings. In recent years, to reduce the weight of electric wires, it has been studied to use aluminum or aluminum alloy (hereinafter referred to as Al alloy etc.) whose specific gravity is about 1/3 of copper as a constituent material of conductors and terminal fittings ( Patent Document 1).

  Patent Document 1 discloses a terminal fitting in which an aluminum-based molded body having a conductor crimping portion and an iron-based molded body having a fitting portion provided with a spring contact portion (elastic piece) are combined. This terminal metal fitting is provided with an elastic piece made of an iron-based material that is generally higher in strength and harder to sag than an Al alloy or the like, so that high contact pressure (spring load) can be secured and high over a long period of time. Contact pressure can be maintained.

Japanese Patent No. 3984539

  When dissimilar metals are combined, contact corrosion (battery corrosion) of dissimilar metals can occur. By performing anticorrosion treatment such as resin coating, battery corrosion can be reduced or prevented, but productivity is lowered due to an increase in the number of processes.

  On the other hand, if a metal fitting made of an aluminum alloy is used as a terminal fitting attached to an aluminum-based electric wire whose conductor is made of an Al alloy or the like, contact corrosion of dissimilar metals cannot occur and the above-described anticorrosion treatment is unnecessary. it can. However, mechanical properties desired for terminal fittings made of an aluminum alloy and compositions that satisfy the properties have not been sufficiently studied.

  For example, in the above-described crimp type terminal fitting, it is desired that the crimping force with respect to the conductor of the electric wire is large and difficult to decrease over a long period of time. However, since aluminum generally tends to undergo creep deformation, the crimping force decreases due to stress relaxation, and the crimping part may not be able to sufficiently hold the conductor. In addition, in an aluminum-based electric wire, the conductor is also easily creep-deformed compared to a copper-based electric wire. If the conductor and the terminal metal fitting cannot be sufficiently contacted due to stress relaxation, problems such as an increase in contact resistance occur. Therefore, it is desired to develop an aluminum alloy in which the connection state between a conductor made of an Al alloy or the like and a terminal fitting made of an aluminum alloy does not loosen with time. In particular, in terminal fittings for automobiles and the like, the operating temperature is as high as over 100 ° C. Therefore, a terminal fitting that is difficult to relieve stress by heat during use and has excellent heat resistance is desired.

  In addition, in a terminal fitting having an elastic piece as shown in FIG. 1, it is desired that the contact pressure (spring load) is sufficiently high in the connection between the terminal fittings and is maintained for a long time. In a terminal fitting having a rod-like fitting portion as shown in FIG. 1, the repulsive force against the urging force by the elastic piece is sufficiently high and the repulsive force is maintained for a long time in the connection between the terminal fittings. Is also desired. When the contact pressure and the repulsive force decrease due to the stress relaxation, problems such as the elastic piece and the fitting portion of another terminal fitting being unable to sufficiently contact or the connection resistance increasing may occur. Therefore, it is desired to develop an aluminum alloy in which the connection state between terminal fittings made of an aluminum alloy is less likely to loosen with time.

  Here, as a manufacturing method of the terminal metal fitting, a material plate is punched into a predetermined shape and subjected to press working. In this case, when the thickness of the material plate is increased to some extent, the above-described pressure-bonding force, contact pressure, and repulsive force can be increased. However, when the plate thickness is increased, distortion during plastic working such as press working becomes large and cracking is likely to occur, leading to a decrease in productivity of the terminal fitting. Further, if a material plate having a large plate thickness is used, the terminal fitting is increased in size, which is not preferable for applications that require a reduction in size (for example, automotive applications).

  Then, one of the objectives of this invention is providing the aluminum alloy plate for terminals from which the terminal metal fitting which is hard to relieve stress is obtained. Another object of the present invention is to provide a terminal fitting made of an aluminum alloy and less susceptible to stress relaxation. Furthermore, the other object of this invention is to provide the terminal connection structure of the electric wire which provides the said terminal metal fitting.

  The present invention achieves the above object by specifying the composition of the aluminum alloy. The aluminum alloy plate for terminals of the present invention is used as a material for a terminal fitting to be crimped to an aluminum base wire, and is composed of the following aluminum alloys. This aluminum alloy is, by mass, Si: 0.6% to 1.5%, Mg: 0.7% to 1.3%, Cu: 0.5% to 1.2%, Mn: 0.5% to 1.1%, Fe: 0.02% or more 0.4% or less, Cr: 0.01% to 0.3%, Zn: 0.005% to 0.5%, Ti: 0.01% to 0.2%, Zr: 0.05% to 0.2%, the balance from Al and inevitable impurities Become. In addition, an aluminum base electric wire means the electric wire in which the said conductor was comprised from aluminum or aluminum alloy.

  The aluminum alloy sheet of the present invention has a low stress relaxation rate and is difficult to relax, as shown in test examples described later, and is excellent in stress relaxation characteristics at high temperatures. In addition, the aluminum alloy plate of the present invention is excellent in mechanical properties at room temperature and has high proof stress as shown in test examples described later. By using such an aluminum alloy plate of the present invention as a material, a terminal fitting capable of maintaining a high pressure bonding force, a high contact pressure, and a high repulsive force can be manufactured. Moreover, since it has high proof stress, even when the thickness of the aluminum alloy plate of the present invention is reduced, a terminal fitting having high crimping force, high contact pressure, and high repulsive force can be manufactured. Therefore, the aluminum alloy plate of the present invention can contribute to miniaturization of the terminal fitting. Furthermore, by reducing the thickness of the aluminum alloy plate of the present invention, it is easy to perform various processes such as plastic processing such as cutting and pressing in the manufacture of terminal fittings, and contribute to the improvement of terminal fitting productivity. Can do.

  The terminal fitting of the present invention is a terminal fitting including a crimping portion for crimping a conductor of an aluminum-based electric wire and an electrical connection portion that extends from the crimping portion and is electrically connected to another connection target. And an aluminum alloy having a specific composition as described above.

  The terminal metal fittings manufactured from the aluminum alloy plate of the present invention and the terminal metal fittings of the present invention (hereinafter referred to as the terminal metal fittings of the present invention) are aluminum having a specific composition excellent in stress relaxation characteristics at high temperatures and yield strength at room temperature. Since it is made of an alloy, a sufficiently high crimping force can be obtained, and the crimping force hardly decreases even at high temperatures, and a high crimping force can be maintained. Moreover, in the terminal metal fitting etc. of this invention which provides the above-mentioned elastic piece, while being able to obtain a sufficiently high contact pressure, it is difficult for the contact pressure to decrease even at high temperatures, and a high contact pressure can be maintained. . On the other hand, the terminal fitting of the present invention having the above-described rod-shaped fitting portion provides a sufficiently high repulsive force, and the repulsive force does not easily decrease even at high temperatures, and has a high repulsive force over a long period of time. Can be maintained. Therefore, the terminal metal fittings of the present invention are less likely to relieve stress over time, and it is difficult to loosen the connection state with the aluminum base wire and the connection state between the terminal metal fittings over a long period of time, thereby constructing a low resistance connection structure. it can. Moreover, even when the terminal fitting of the present invention is made of a relatively thin aluminum alloy plate, a high pressure-bonding force, a high contact pressure, and a high repulsive force can be realized, and it is small.

  The terminal connection structure for an electric wire according to the present invention includes an electric wire having a conductor and a terminal fitting attached to an end of the conductor. The electric wire is an aluminum-based electric wire in which the conductor is made of aluminum or an aluminum alloy. And the said terminal metal fitting is a terminal metal fitting of this invention comprised from the aluminum alloy of the said specific composition.

  The terminal connection structure of the electric wire of the present invention can maintain low resistance for a long period of time by including the terminal fitting of the present invention that is difficult to relieve stress. In addition, since the terminal connection structure of the electric wire of the present invention has the same main component of the conductor of the electric wire and the terminal fitting, contact corrosion of dissimilar metals cannot occur, and it is necessary to perform a special treatment for battery corrosion. And excellent productivity.

  As one form of this invention, the said aluminum alloy further includes the form which contains Sr: 0.005% or more and 0.05% or less by the mass%.

  By containing Sr, the above form is further excellent in stress relaxation characteristics at high temperature and yield strength at room temperature.

  One form of the aluminum alloy plate for terminals of the present invention is a form having a 0.2% proof stress at room temperature of 200 MPa or more.

  Since the above-mentioned form has sufficiently high yield strength, for example, even when the thickness is reduced, it is possible to manufacture a terminal fitting that can obtain a high crimping force, a high contact pressure, and a high repulsive force.

  As one form of the aluminum alloy plate for terminals of the present invention, a form in which the stress relaxation rate at 120 ° C. is 50% or less can be mentioned.

  Since the stress relaxation rate is sufficiently small and the heat resistance is excellent even at a high temperature exceeding 100 ° C., the above form can be suitably used as a material for a terminal fitting used in a high temperature environment. Moreover, the terminal metal fitting formed from the aluminum alloy plate of the said form is hard to relieve stress even if it is high temperature.

  As one form of the terminal fitting of the present invention, there is provided an elastic piece in which the electrical connecting portion is fitted and electrically connected to another terminal fitting, and the fitting portion is disposed oppositely. Form.

  The above-mentioned form comprising an elastic piece composed of an aluminum alloy having the above-mentioned specific composition can express a sufficiently high contact pressure with respect to the fitting portion of another terminal fitting, and is difficult to relieve stress. High contact pressure can be maintained over a long period of time.

  The form used for a motor vehicle is mentioned as one form of the terminal metal fitting of this invention and the terminal connection structure of the electric wire of this invention.

  The terminal fitting of the present invention and the terminal connection structure of the electric wire of the present invention can be used for various applications. However, the main component of the conductor of the electric wire and the terminal fitting is aluminum. It can be suitably used. Moreover, by providing the terminal fitting of the present invention having excellent stress relaxation characteristics at high temperatures as described above, it can be suitably used for automobiles whose operating temperature is about 120 ° C to 150 ° C.

  The aluminum alloy plate for terminals of the present invention is excellent in stress relaxation characteristics at high temperature and yield strength at room temperature. In the terminal fitting of the present invention and the terminal connection structure of the electric wire of the present invention, it is difficult for the terminal fitting to relieve stress, and the connection state with the conductor and the connection state between the terminal fittings can be firmly maintained for a long time.

It is a schematic block diagram of a female terminal metal fitting and a male terminal metal fitting, (A) is before fitting of both terminal metal fittings, (B) shows the state which fitted the fitting part of both terminal metal fittings.

  Hereinafter, the present invention will be described in more detail. First, the composition of the aluminum alloy constituting the aluminum alloy plate and the terminal fitting, which is a feature of the present invention, will be described. The element content indicates a mass ratio (%).

[Aluminum alloy]
·composition
(Si: 0.6% to 1.5%)
Si partially dissolves in the matrix (Al) together with Mg, strengthening the aluminum alloy. In addition, Si forms aging precipitates during artificial aging, improves the mechanical properties such as strength of aluminum alloy, and obtains the mechanical properties desired for terminal fittings (especially stress relaxation properties and yield strength). Contribute. By containing Si in an amount of 0.6% or more, an aluminum alloy plate or a terminal fitting having excellent stress relaxation characteristics and proof stress can be obtained by appropriately expressing the effects of solid solution strengthening and age hardening. By making the Si content 1.5% or less, the workability from cast material to a plate with a desired thickness (mainly rollability) and the formability from material plate to terminal fitting (mainly press workability) are hindered. In addition, it is possible to suppress the formation of coarse crystallized substances and precipitates that are the starting points of cracks, and contribute to increasing the strength and proof stress of the plate and terminal fitting. A more preferable Si content is 0.8% or more and 1.4% or less. By being in this range, it is easier to obtain a plate or a terminal fitting having excellent proof stress.

(Mg: 0.7% to 1.3%)
Mg solidifies and strengthens an aluminum alloy, and at the time of artificial aging, forms an aging precipitate that contributes to improving the strength together with Si, and contributes to obtaining the above-mentioned mechanical properties desired for the terminal fitting. By containing 0.7% or more of Mg, sufficient solid solution strengthening and age hardening can be achieved, and by setting the upper limit to 1.3%, coarse crystallized substances and precipitates that are the starting points of cracks as described above The formation of objects can be suppressed. A more preferable Mg content is 0.8% or more and 1.3% or less, and by being within this range, it is easier to obtain a plate or a terminal fitting having excellent proof stress.

(Cu: 0.5% to 1.2%)
Cu, together with Mg and Si, contributes to improving strength and proof stress. Containing 0.5% or more of Cu makes it easy to obtain this effect and excellent heat resistance. By setting the upper limit to 1.2%, it is easy to ensure the moldability to the terminal fitting. A more preferable Cu content is 0.7% or more and 1.2% or less, and within this range, it is difficult to relieve stress even at a high temperature, and it is easier to obtain a plate and a terminal fitting having excellent proof stress.

(Mn: 0.5% to 1.1%)
Mn partially dissolves in the matrix and strengthens the aluminum alloy by solid solution. Further, Mn forms Al—Mn-based dispersed particles, can refine crystal grains of the alloy structure, and can improve stress relaxation characteristics, yield strength, strength, formability, corrosion resistance, heat resistance, and the like. By containing 0.5% or more of Mn, solid stress strengthening makes it easy to obtain stress-reducing characteristics and plates and terminal fittings with proof stress. By setting the upper limit to 1.1%, coarse crystallization that becomes the starting point of cracking It is possible to suppress the formation of objects and precipitates, and contribute to increasing the strength and proof stress of the plate and terminal fitting. A more preferable Mn content is 0.6% or more and 1.1% or less, and within this range, it is difficult to relieve stress even at high temperatures, and it is easier to obtain a plate and a terminal fitting having excellent proof stress.

(Fe: 0.02% to 0.4%)
Fe contributes to the promotion of the fine effect by the crystal refining agent containing Ti at the time of casting in the presence of a group 2 element of the periodic table (for example, Mg or Sr). Containing 0.02% or more of Fe effectively contributes to refinement of aluminum alloy crystal grains, and by setting the upper limit to 0.4%, Fe-based crystallized substances are generated at grain boundaries in the alloy structure. This can suppress a decrease in plastic workability of the aluminum alloy. A more preferable Fe content is 0.05% or more and 0.3% or less, and within this range, it is easier to obtain a plate or a terminal fitting having excellent proof stress.

(Cr: 0.01% to 0.3%)
Since Cr forms dispersed particles in the same manner as Mn, it has the effect of preventing the crystal grains of the aluminum alloy from becoming coarse during heat treatment and making the crystal grains finer. The refinement of crystal grains contributes to the improvement of the yield strength and strength of the plate and the formability of the terminal fitting. Cr also has an effect of improving corrosion resistance and heat resistance. Containing 0.01% or more of Cr makes it difficult to relieve stress even at high temperatures, making it easy to obtain high-yield and high-strength plates and terminal fittings, and setting the upper limit to 0.3% can increase the size of crystal grains. It is possible to suppress the crystal grain refinement effect appropriately. A more preferable Cr content is 0.02% or more and 0.25% or less, and by being in this range, it is easy to obtain a plate or a terminal metal fitting that is particularly excellent in heat resistance and difficult to relieve stress even at high temperatures.

(Zn: 0.005% to 0.5%)
Zn dissolves in the matrix and contributes to the improvement of the yield strength of the aluminum alloy. By containing Zn in an amount of 0.005% or more, the effect of improving the yield strength can be appropriately exhibited, and by setting the upper limit value to 0.5%, appropriate corrosion resistance can be ensured. The more preferable Zn content is 0.05% or more and 0.25% or less. By being in this range, it is difficult to relieve stress even at high temperatures, and it is easier to obtain a plate and terminal fitting with excellent proof stress. It is easy to ensure the toughness required for molding, and it is easy to obtain plates and terminal fittings that are excellent in workability and corrosion resistance.

(Ti: 0.01% to 0.2%)
Ti has the effect of reducing the crystal structure of the cast material, reducing the ratio of columnar crystals in the cast material, and increasing the ratio of equiaxed crystals. Therefore, the rolling property of a cast material and the moldability to a terminal metal fitting can be improved by containing Ti. In addition, the refinement of the crystal structure makes it difficult for wrinkles to occur during plastic processing, and a plastic work material (terminal fitting) with less wrinkles and excellent surface properties can be obtained. By containing 0.01% or more of Ti, the effect of refining crystal grains can be easily obtained, and the higher the content of Ti, the more effective the refining of crystal grains and the reduction of wrinkles associated with miniaturization. However, the above-mentioned effect tends to be saturated when the Ti content is about 0.2%, and since the formation of coarse intermetallic compounds can be suppressed by not containing Ti excessively, the upper limit is set to 0.2%. A more preferable Ti content is 0.01% or more and 0.1% or less. By being in this range, it is easier to obtain a plate or a terminal fitting having excellent proof stress. Incidentally, B from the fact that the same crystalline structure and Ti has the effect of improving to strength and yield strength fine, it may be mixed in the melt Ti as TiB _2. In the present invention, the content of B in a mass ratio of about 50 ppm or less is allowed.

(Zr: 0.05% to 0.2%)
Zr is an element necessary for improving the heat resistance of the aluminum alloy. Zr, like Mn and Cr, forms Al-Zr-based dispersed particles, prevents coarsening of the crystal grains of the aluminum alloy during heat treatment, and has the effect of making the crystal grains fine. As described above, the miniaturization of the plate contributes to the improvement of the yield strength and strength of the plate and the moldability to the terminal fitting. By containing 0.05% or more of Zr, the effect of improving heat resistance, proof stress, strength and plastic workability can be sufficiently obtained, and by setting the upper limit to 0.2%, coarsening of crystal grains can be effectively suppressed. . The preferable Zr content is 0.1% or more and 0.2% or less, and within this range, it is difficult to relieve stress even at high temperatures, and it is easier to obtain a plate or terminal fitting having excellent proof stress.

(Sr: 0.005% to 0.05%)
Sr also has a function of refining the crystal structure of the cast material, and by refining the crystal, as described above, it contributes to improving the yield strength and strength of the plate and the formability to the terminal fitting. In particular, when Sr is contained in the presence of Zr, the yield strength and strength can be improved without embrittlement of the aluminum alloy. By containing 0.005% or more of Sr, it is easy to improve the yield strength and strength, and by setting the upper limit to 0.05%, the embrittlement of the aluminum alloy is effectively suppressed, and the plates and terminals with excellent yield strength and strength. A bracket is obtained. A more preferable Sr content is 0.005% or more and 0.03% or less, and within this range, it is difficult to relieve stress even at high temperatures, and it is easier to obtain a plate or terminal fitting having excellent proof stress. In particular, when the Sr content is 0.005% or more and 0.03% or less, and the ratio Zr / Sr of Zr content to Sr content is 3 or more and 50 or less, the embrittlement suppression and mechanical properties of the aluminum alloy are achieved. Can be effectively improved.

[Aluminum alloy plate]
-Thickness The thickness of the aluminum alloy plate of the present invention or the plate constituting the terminal fitting of the present invention can be selected as appropriate. For example, in automobile applications, it is about 0.1 mm to 0.5 mm. The thinner the thickness, the better the moldability and the smaller and lighter the terminal fitting. The thicker the thickness, the better the crimping force, contact pressure, and repulsion of the terminal fitting. Can do. Manufacturing conditions (for example, degree of processing such as reduction ratio) may be adjusted so as to obtain a desired thickness. The thickness of the plate which comprises the terminal metal fitting manufactured from the aluminum alloy plate of this invention substantially maintains the thickness of the aluminum alloy plate of this invention, and both thickness is substantially equal.

-Shape The aluminum alloy plate of the present invention is typically a rectangular sheet material cut to a predetermined length. In addition, the coil material which wound up the elongate board, the cut material cut | disconnected by the shape of the desired terminal metal fitting, etc. are mentioned.

・ Mechanical properties
(Stress relaxation rate)
The aluminum alloy plate of the present invention is difficult to relieve stress even at a high temperature exceeding 100 ° C. As a specific form, although depending on the composition and manufacturing conditions (heat treatment temperature, degree of processing, etc.), for example, a form in which the stress relaxation rate at 120 ° C. satisfies 50% or less can be mentioned. The lower the stress relaxation rate, the more difficult it is to relax, that is, the stress is less likely to be released even at high temperatures, and sufficient stress (crimping force, contact pressure, repulsive force) can be expressed, 40% or less, 30% or less, especially 20% The following is more preferable.

(0.2% proof stress / tensile strength)
The aluminum alloy plate of the present invention has high yield strength. As a specific form, although depending on the composition and manufacturing conditions (heat treatment temperature, degree of processing, etc.), for example, a form in which the 0.2% proof stress at room temperature satisfies 200 MPa or more can be mentioned. The higher the 0.2% proof stress, the harder the permanent deformation, the less difficult the connection between the conductor and the terminal fitting and the connection between the terminal fittings, 250 MPa or more, 300 MPa or more, particularly 400 MPa or more is preferable. Since the proof stress is high, the residual load is high with time and it is easy to maintain a high stress over a long period of time. The higher the 0.2% proof stress, the higher the tensile strength. For example, the tensile strength at room temperature is 250 MPa or more, further 300 MPa or more, particularly 400 MPa or more, especially 500 MPa or more.

(Elongation)
The aluminum alloy plate of the present invention has high proof stress and high strength as described above, and also has excellent toughness due to crystal refinement as described above. For example, a mode in which the elongation satisfies 1% or more, further 2% or more, particularly 5% or more can be mentioned. Since it is excellent in plastic workability by being excellent in toughness as described above, the aluminum alloy plate of the present invention is subjected to plastic processing such as press processing, and the male terminal fitting 100M and the female terminal fitting 100F as shown in FIG. Such a complicated-shaped terminal fitting can be accurately formed.

(conductivity)
Although the aluminum alloy sheet of the present invention depends on the composition and production conditions (heat treatment temperature, degree of processing, etc.), a form in which the electrical conductivity satisfies 35% IACS or more, further 40% IACS or more, particularly 45% IACS or more can be mentioned. . Since the electrical conductivity is high, it can be suitably used as a material for the terminal fitting.

  In addition, the terminal metal fitting manufactured from the aluminum alloy plate of the present invention and the terminal metal fitting of the present invention made of the specific aluminum alloy described above are mechanical properties (0.2% proof stress, stress relaxation rate, Properties such as tensile strength and elongation) and conductivity are substantially maintained.

Production method The production of the aluminum alloy plate of the present invention can be performed in accordance with a production method of a plate made of a 6000 series alloy (Al-Mg-Si alloy). For example, it can be produced by a process such as melting / casting → hot working / cold working → cold rolling → various heat treatment (typically solution treatment or aging treatment).

  More specifically, pure aluminum and a specific element are prepared and melted as raw materials to produce a molten aluminum alloy having a specific composition and cast. For casting, either continuous casting such as a twin roll method or a belt-and-wheel method, or batch casting can be used. Continuous casting can be rapidly solidified, can easily produce long materials, and can be suitably used for mass production of plates.

  The hot working performed on the cast material is typically hot rolling. In particular, when hot rolling is performed continuously after continuous casting, the heat accumulated in the cast material can be used for easy hot rolling and energy efficiency, and when using a batch casting method Compared to the above, the productivity of (cast) rolled material is excellent. The cast rolled material can be performed using, for example, a belt-and-wheel casting machine and a rolling machine connected to the casting machine. An example of such an apparatus is a Properti type continuous casting and rolling mill. An example of cold working is cold rolling. If the homogenization treatment is performed on the cast material before processing, the workability of subsequent processing can be improved. Examples of the homogenization treatment conditions include a temperature of about 500 ° C. to 600 ° C. and a holding time of about 0.5 hours to 50 hours.

  In cold rolling, the rolling reduction and the number of passes can be appropriately selected so that an aluminum alloy sheet having a desired thickness can be obtained. When an intermediate heat treatment (softening treatment) is appropriately performed before cold rolling, during cold rolling, or during the above-described cold working, the workability can be improved. The intermediate heat treatment conditions include a temperature of about 300 ° C. to 500 ° C. and a holding time of about 0.1 hours to 10 hours. The total rolling reduction of the cold rolling performed from the final intermediate heat treatment to the solution treatment is, for example, about 30% to 90%.

  As the heat treatment performed after the cold rolling, for example, a known process such as a T6 process, a T7 process, a T8 process, or a T9 process can be used. As processing conditions, known conditions can be used. For example, in the T6 treatment, the solution treatment is about 510 ° C. to 550 ° C., the aging treatment is about 160 ° C. to 180 ° C., and about 5 hours to 30 hours. In the T6 treatment, the aging treatment temperature can be increased to 200 ° C. or more and 250 ° C. or less to obtain the T7 treatment. In the T8 treatment, solution treatment and cold working (here, cold rolling) are sequentially performed, and then an aging treatment is further performed. In the T9 treatment, solution treatment and aging treatment are sequentially performed, and then cold working (here, cold rolling) is further performed. By the cold working, it is possible to improve the yield strength and strength by work hardening of the material. The specific conditions of the T8 treatment and T9 treatment are, for example, the cold treatment after the solution treatment in the T8 treatment, for the solution treatment and the aging treatment, as in the above-mentioned T6 treatment, cold working is exemplified. The total rolling reduction of cold rolling after aging treatment in rolling or T9 treatment is about 5% to 50%. In the T8 treatment, if cold working is performed after the preliminary aging treatment is performed after the solution treatment, the proof stress and strength after the final aging treatment performed after the cold working can be easily controlled. Specific conditions for the pre-aging treatment include about 70 to 120 ° C. and about 1 to 15 hours.

[Terminal bracket]
The terminal fitting of the present invention is a crimping type including a crimping portion as a wire barrel portion to which a conductor is connected. Examples of the crimping part include a pair of crimping pieces and a crimping cylinder. More specifically, there is a form having a U-shaped cross section and a bottom portion on which the conductor of the electric wire is disposed and a pair of crimping pieces standing on the bottom portion and sandwiching the conductor. The wire barrel portion is connected to the conductor by bending and compressing the crimping piece so as to wrap the conductor. The crimping cylinder has a hole into which the conductor is inserted. By inserting a conductor into the hole and compressing in this state, the wire barrel portion is connected to the conductor.

  An electrical connection portion serving as a connection location with another connection target extends to one side of the above-described crimping portion and is connected to another terminal metal fitting or electronic device that is the connection target. In the form in which the terminal fittings are connected to each other, examples of the electrical connection portion include a rod-shaped male fitting portion 140 and a female fitting portion 130 having elastic pieces 131 and 132 as shown in FIG. There is also a female fitting part which has only one elastic piece. In male terminal fittings that have rod-shaped male fittings, the male fittings are made of the above-described aluminum alloy that excels in stress relaxation characteristics and heat resistance, making it difficult to relieve stress even at high temperatures. . In the female terminal fitting having a female fitting portion having at least one elastic piece, the female fitting portion is made of the above-described aluminum alloy having excellent stress relaxation characteristics and heat resistance. It is difficult to relieve stress. In a form in which the fastening member such as a bolt is connected to another terminal fitting or an electronic device, the electrical connection part may be a fastening part including a through hole or a U-shaped piece through which the fastening member is inserted. Or there exists a flat plate member etc. which are inserted in the fitting hole provided in the connection object for an electrical connection part.

  In addition, as shown in FIG. 1, the terminal fitting of the present invention can be configured to include an insulation barrel portion 120 that crimps the insulating layer 220 of the electric wire 200 on the other side of the crimp portion. The terminal fitting of the present invention can appropriately utilize the shape of a known crimping type terminal fitting including a crimping portion and an electrical connection portion.

  In addition, the terminal fitting of the present invention can be configured to include a Sn plating layer (not shown) on at least a part of its surface. In particular, if the Sn plating layer is provided in the contact area (for example, the contact point between the fitting parts) in the electrical connection part, the soft Sn is deformed so that the terminal fitting and another connection object are sufficiently adhered to each other. Thus, a low resistance connection structure can be constructed.

-Manufacturing method The terminal metal fitting of this invention makes the aluminum alloy plate of this invention which consists of an aluminum alloy of the above-mentioned specific composition into a raw material board, this board is stamped into a predetermined shape, and press processing is carried out so that it may become a predetermined shape. It can be manufactured by applying plastic working.

  In the case of applying the Sn plating layer, Sn plating is performed at any one of the stage of the material plate, the stage of the blank piece punched into a predetermined shape, and the stage of the pressed molded body. For the Sn plating, for example, a wet plating method such as a displacement plating method or an electroplating method, a vacuum plating method such as a plasma sputtering method, or the like can be used. When Sn plating is applied to an aluminum alloy, generally, zinc plating is performed to form a Zn layer, and then Sn plating is performed. If a Sn plating layer is formed directly on a material plate using displacement plating or vacuum plating, the Zn layer may elute due to contact corrosion of dissimilar metals, and the Sn plating layer above the Zn layer may disappear. There is no Sn plating layer over a long period of time.

[Wire terminal connection structure]
-Electric wire The electric wire to which the terminal metal fitting of the present invention is attached is an aluminum-based electric wire including a conductor and an insulating layer provided on the outer periphery of the conductor, and the conductor is made of aluminum or an aluminum alloy (Al alloy or the like). That is, the terminal connection structure of the electric wire of the present invention is a connection structure composed of the same kind of metal (aluminum), which is a connection structure between a terminal fitting made of an aluminum alloy having a specific composition and a conductor made of an Al alloy or the like. There is substantially no battery corrosion between the conductor and the terminal fitting.

(conductor)
The aluminum alloy constituting the conductor contains, for example, 0.005% by mass or more and 5.0% by mass or less of one or more elements selected from Fe, Mg, Si, Cu, Zn, Ni, Mn, Ag, Cr and Zr in total. In addition, a material whose balance is made of Al and impurities is mentioned. The preferred content of each element is mass%, Fe: 0.005% to 2.2%, Mg: 0.05% to 1.0%, Mn, Ni, Zr, Zn, Cr, and Ag: 0.005% to 0.2% in total Cu: 0.05% to 0.5%, Si: 0.04% to 1.0%. These additive elements can be contained alone or in combination of two or more. In addition to the above additive elements, Ti and B can be contained in a range of 500 ppm or less (mass ratio). As an alloy containing the above additive elements, for example, Al-Fe alloy, Al-Fe-Mg alloy, Al-Fe-Mg-Si alloy, Al-Fe-Si alloy, Al-Fe-Mg- (Mn, Ni, Zr, Ag (at least one kind) alloy, Al-Fe-Cu alloy, Al-Fe-Cu- (at least one kind of Mg, Si) alloy, Al-Mg-Si-Cu alloy and the like. A known aluminum alloy wire can be used as the wire constituting the conductor.

  The wire constituting the conductor may be a single wire, a stranded wire obtained by twisting a plurality of strands, or a compressed wire obtained by compressing a stranded wire. The wire diameter of the wire constituting the conductor (in the case of a stranded wire, the wire diameter of the strand before twisting) can be appropriately selected depending on the application. For example, a wire having a wire diameter of 0.2 mm to 1.5 mm can be mentioned.

  The wire that constitutes the conductor (strand in the case of stranded wire) has at least one tensile strength of 110 MPa to 200 MPa, 0.2% proof stress of 40 MPa or more, elongation of 10% or more, and conductivity of 58% IACS or more The one that satisfies In particular, a wire with an elongation of 10% or more has excellent impact resistance, and is difficult to break when attaching a terminal fitting to another terminal fitting, connector, electronic device, or the like.

(Insulation layer)
Examples of the constituent material of the insulating layer include various insulating materials such as polyvinyl chloride (PVC), halogen-free resin compositions based on polyolefin resins, and flame retardant compositions. The thickness of the insulating layer can be appropriately selected in consideration of a desired insulating strength.

(Wire manufacturing method)
The conductor can be manufactured, for example, by a process of casting → hot rolling (→ homogenization treatment in the case of billet cast material) → cold wire drawing (→ softening treatment, twisting / compression, as appropriate). it can. By forming an insulating layer on this conductor, an aluminum-based electric wire can be manufactured.

-Manufacturing method of the terminal connection structure of an electric wire The insulating layer is peeled off at the end portion of the electric wire to expose the conductor, and the exposed portion is arranged and connected to the crimping portion of the terminal fitting of the present invention described above. For example, in a form including a crimping piece, a conductor is disposed at the bottom of the crimping part, and the crimping piece is bent and further compressed so as to wrap the conductor. At this time, the compression state is adjusted so that the crimp height (C / H) becomes a predetermined size (height). Through the above steps, the terminal connection structure of the electric wire of the present invention and the electric wire with terminal in which the terminal fitting of the present invention is attached to the end portion of the aluminum base electric wire can be manufactured.

[Test Example 1]
Aluminum alloy plates of various compositions were manufactured and the characteristics were investigated.

  In this test, an aluminum alloy plate having the composition shown in Table 1 was manufactured in the steps of melting / casting → hot working / cold working → intermediate heat treatment → cold rolling → heat treatment. More specifically, a melt of pure aluminum was prepared, and an additive element shown in Table 1 was added to the melt to prepare an aluminum alloy melt. The molten metal was appropriately subjected to degassing treatment and foreign matter removal treatment, and then the molten metal was poured into a mold to produce an ingot. The obtained ingot was appropriately subjected to homogenization treatment, and then subjected to hot working (here hot rolling) / cold working (here cold rolling). During the cold working, an intermediate heat treatment (here, softening treatment at 400 ° C. × 1 hr) was performed as necessary to produce a cold worked material having a thickness of 0.5 mm. The obtained cold-worked material was subjected to an intermediate heat treatment (here, 400 ° C. × 1 hr softening treatment) and then cold-rolled to produce a rolled material having a thickness of 0.25 mm or 0.3 mm. Table 2 shows the processing conditions after cold rolling applied to a rolled material having a thickness of 0.25 mm or 0.3 mm.

  In alloy Nos. (I), (III), and (IV), the T6 treatment was performed at a solution temperature of 510 ° C, 530 ° C, or 550 ° C, and an aging temperature of 175 ° C. In Alloy No. (I), the T7 treatment was performed at a solution temperature of 510 ° C. or 550 ° C. and an aging temperature of 200 ° C., 220 ° C., or 250 ° C. By performing each heat treatment, a heat treated material (aluminum alloy plate) having a thickness of 0.25 mm was obtained. In the alloy Nos. (I) and (II), the T9 treatment was performed in order after heat treatment (solution treatment and aging) under the conditions shown in Table 2, followed by cold rolling (rolling ratio: 20%), and a thickness of 0.25. mm rolled material (aluminum alloy plate) was obtained. Alloy No. (II) was subjected to T6 treatment under the conditions shown in Table 2 to obtain a heat treated material (aluminum alloy plate) having a thickness of 0.25 mm. In alloy No. (II), T8 treatment was performed under the conditions shown in Table 2 (however, the order was solution treatment → preliminary aging → cold rolling (thickness 0.25 mm) → final aging) and heat treatment material with a thickness of 0.25 mm. (Aluminum alloy plate) was obtained.

  For comparison, a copper alloy plate (brass type 1 C2600-EH, thickness 0.25 mm, commercially available) used as a material for conventional copper-based terminal fittings was prepared.

  The room temperature characteristics (tensile strength, 0.2% proof stress, elongation, electrical conductivity) and stress relaxation characteristics at high temperatures of the prepared aluminum alloy sheet having a thickness of 0.25 mm and the prepared copper alloy sheet were investigated. The results are shown in Table 3.

  Tensile strength (MPa), 0.2% proof stress (MPa), and elongation (%) were all measured according to JIS Z 2241 (2011). The conductivity (% IACS) was calculated from the electrical resistance measured by the four probe method. The conductivity of the copper alloy plate of sample No. 100 is a catalog value (shown in parentheses in Table 3).

For stress relaxation characteristics, calculate the stress relaxation rate based on the provisions of JIS B 2712 (2006) (ρ = ((W ₀ -W) / W ₀ ) × 100, ρ is the stress relaxation rate (%), W ₀ is The initial test load (N), W represents the test load after relaxation (N), and this stress relaxation rate is evaluated. Here, a test piece having a thickness of 0.25 mm and a width of 10 mm was prepared for each sample, and the gauge distance was 30 mm, the test temperature was 120 ° C., the test time was 1000 hours, and the load application method was A method. The initial test load W ₀ is 75% to 80% of the maximum tensile stress generated when the test piece is elastically bent and deformed, and 0.2% proof stress of each sample (0.2% proof stress shown in the room temperature characteristics shown in Table 2). Was set to be. After applying an initial test load set on the test piece at room temperature, the temperature was raised to 120 ° C. and the load was measured over time. Table 3 shows the residual load (N) and stress relaxation rate (%) after 1000 hours.

  As shown in Table 3, it can be seen that an aluminum alloy sheet having a specific composition has a low stress relaxation rate at a high temperature of 120 ° C. and is excellent in stress relaxation characteristics at a high temperature. Further, it can be seen that an aluminum alloy plate having a specific composition has a high 0.2% proof stress even if it is a thin plate of 0.25 mm, and has an excellent proof stress of 200 MPa or more depending on the sample. Compared to sample No. 100 made of copper alloy, sample No. 100 has a 0.2% proof stress at room temperature, but the stress relaxation rate at high temperature exceeds 60%. On the other hand, samples No.1 to No.13 made of aluminum alloy with a specific composition have a 0.2% proof stress at room temperature equivalent to or lower than that of sample No.100, but the stress relaxation rate at high temperature is low, 50% or less. It is. In particular, samples No. 1, No. 3, No. 7, and No. 9 have a very low stress relaxation rate of 13% or less, and No. 7 is 10% or less. Therefore, it can be said that these samples No. 1 to No. 13 can have a residual load equivalent to, or equal to or higher than that of the sample No. 100 made of copper alloy.

  As described above, the aluminum alloy plate having a specific composition has a smaller stress relaxation rate than Sample No. 100 made of brass. Therefore, when the terminal piece including the elastic piece in the fitting portion is configured by the aluminum alloy plate, for example, like the female terminal metal fitting 100F shown in FIG. 1, the elastic piece is necessary for electrical connection. It is expected that the proof stress required to generate the contact pressure (contact pressure before stress relaxation) may be smaller than that of the copper alloy plate.

  From the result of the stress relaxation characteristics of sample No. 100 made of copper alloy, the proof stress necessary for the stress relaxation rate at 120 ° C. to be 0% is calculated to be about 202 MPa. When the proof stress necessary to generate the contact pressure required after stress relaxation is 202 MPa, the proof stress required to generate the contact pressure required before stress relaxation is No. 100 made of brass. The sample No. 3 made of a specific aluminum alloy is about 233 MPa, and the sample No. 8 is about 405 MPa. Thus, in the aluminum alloy plate having a specific composition, the proof stress necessary for generating the contact pressure required before stress relaxation is smaller than that of the brass sample No. 100, and the above prediction is correct. It is supported.

  In addition, as shown in Table 3, Samples No. 1 to No. 13 made of an aluminum alloy having a specific composition are found to have sufficiently high tensile strength, elongation, and conductivity. In addition, even with the same composition as shown in Table 3, characteristics such as stress relaxation rate, 0.2% proof stress, tensile strength, elongation, and conductivity are further improved by changing the heat treatment conditions after cold rolling. I understand that I can do it. As shown in Table 3, it can be seen that when Sr is further contained, the proof stress and strength are improved while maintaining high elongation. For example, comparing sample No. 1 and sample Nos. 12 and 13, sample Nos. 12 and 13 containing Sr have improved 0.2% proof stress and tensile strength without substantially reducing the elongation. I understand that In addition, when comparing sample No. 12 and sample No. 13 containing Zr and Sr, sample No. 13 having a large mass ratio of Zr / Sr has higher 0.2% proof stress and tensile strength. It can be seen that the elongation is not substantially reduced. Furthermore, when Sr is contained, if Sr is contained in the range where Zr / Sr is 3 or more and 50 or less in terms of mass ratio, it is possible to improve the yield strength and strength while suppressing the brittleness of the aluminum alloy as described above. It can be said that it can be planned.

  From the above results, it was confirmed that an aluminum alloy plate having a specific composition is difficult to relieve stress, particularly difficult to relieve stress even at high temperatures, and has excellent proof stress.

[Test Example 2]
A terminal fitting was produced using the aluminum alloy plate produced in Test Example 1, and this terminal fitting was attached to an aluminum-based electric wire to produce an electric wire with a terminal, and the corrosion resistance was examined.

  Here, as the terminal fitting made of an aluminum alloy, the female terminal fitting 100F shown in FIG. 1 was produced, and Sn plating was applied only to the contact region (the surface of the elastic piece). As a comparison, a copper alloy terminal fitting was produced. Specifically, a copper alloy plate similar to sample No. 100 of Test Example 1 was prepared, and prepared by applying Sn plating to the entire surface of this copper alloy plate, using this Sn plated copper alloy plate, A female terminal fitting 100F shown in FIG. 1 was produced.

  Prepare an aluminum-based electric wire with a conductor made of an aluminum alloy and an insulating layer, peel off the insulating layer at the end of the electric wire to expose the conductor, and place the conductor on the wire barrel of each terminal fitting Was placed and compressed to produce a terminal-attached electric wire (wire end connection structure). A known aluminum base wire was used.

A corrosion test was performed on each of the manufactured electric wires with terminals. Here, the corrosion test was conducted under the following conditions so that the influence of contact corrosion of different metals could be easily understood. NaCl is dissolved in ultrapure water to make a neutral aqueous solution with a concentration of 26% by mass. Place silica (SiO ₂ ) powder with an average particle size of about 100 μm on the filter paper, drop the prepared neutral aqueous solution from above the silica powder, then place it in a constant temperature bath heated to 150 ° C. and dry it. to obtain a powder NaCl adheres (Cl ^- adhesion amount: 35,000 ppm). The obtained powder is sprinkled evenly on the electric wires with terminals of each sample. Here, the above-mentioned powder was sprinkled so that a part of the sample could be visually confirmed (thickness of 1 mm or less). The electric wire with terminal of each sample sprinkled with the powder is put in a constant temperature and humidity chamber set at 60 ° C. and 95% RH and held for 6 days (144 hours). After 6 days, remove the sample from the constant temperature and humidity chamber, cut the vicinity of the wire barrel, and observe this cross section. Residual rate of conductor (%) = {(remaining conductor area) / (pre-test area) Wire conductor area)} × 100. Corrosion resistance is evaluated by this residual ratio. The area of the conductor can be easily obtained by subjecting the cross-sectional photograph to image processing. It can be said that the higher the residual ratio, the higher the corrosion resistance.

  As a result, all the samples having terminal fittings made of an aluminum alloy had a residual ratio of 95% or more and were excellent in corrosion resistance. A sample provided with a terminal fitting made of a copper alloy prepared for comparison had a remaining rate of less than 95%. The reason for this is considered to be that the conductor made of an aluminum alloy was eluted due to battery corrosion.

  From this test, by using a terminal fitting made of an aluminum alloy having a specific composition for a conductor made of an aluminum alloy, contact corrosion of dissimilar metals cannot occur, and an electric wire with a terminal excellent in corrosion resistance can be obtained. confirmed. Moreover, it can be said that the use of this terminal fitting eliminates the need for a special anticorrosion treatment for preventing contact corrosion of dissimilar metals on the electric wire with terminal.

[effect]
As shown in the test results described above, an aluminum alloy plate made of an aluminum alloy having a specific composition is excellent in stress relaxation characteristics at high temperatures and has a high yield strength. Therefore, by using this aluminum alloy plate as a material for the terminal metal fitting, the obtained terminal metal fitting is difficult to relieve stress even at a high temperature, and the pressure-bonding force is hardly reduced. Further, when the terminal fitting includes an elastic piece, the urging force of the elastic piece is unlikely to decrease, and when the terminal fitting includes a rod-shaped fitting portion, the repulsive force of the fitting portion decreases. It is hard to do. Therefore, this terminal fitting is less likely to loosen the connection state with a conductor made of an Al alloy or the like or between the terminal fittings, and can maintain a strong connection state for a long period of time. Furthermore, a conductor, a crimping | compression-bonding part, and an electrical-connection part fully contact | adhere, and it can be set as a low-resistance connection structure over a long period of time. In addition, since this aluminum alloy plate is excellent in yield strength, it is difficult to relieve stress even when the thickness is reduced. Therefore, by using a thin aluminum plate as the material for the terminal fitting, it is possible to reduce the size and weight of the terminal fitting. Furthermore, when a terminal fitting made of an aluminum alloy having the above specific composition is attached to an aluminum-based electric wire, battery corrosion cannot occur between the terminal fitting and the conductor of the electric wire. Without this, it is possible to construct a low resistance connection structure.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention. For example, the composition of the aluminum alloy, the thickness of the aluminum alloy plate, the shape of the terminal fitting, and the like can be changed as appropriate.

  The terminal fitting of the present invention and the terminal connection structure of the electric wire of the present invention can be suitably used for, for example, constituent members of wiring structures such as mobile devices such as automobiles and airplanes, and industrial devices such as robots. In particular, the terminal fitting of the present invention and the terminal connection structure of the electric wire of the present invention are lightweight because the main component is aluminum, and thus can be suitably used as a constituent member of an automobile wire harness. The aluminum alloy plate for terminals of the present invention can be suitably used as the material for the terminal fitting of the present invention.

100F Female terminal fitting 100M Male terminal fitting 110 Wire barrel
120 Insulation barrel part 130 Female fitting part 140 Male fitting part
131,132 Elastic piece
200 Electric wire 210 Conductor 220 Insulation layer

Claims (9)

An aluminum alloy plate for a terminal used as a material for a terminal fitting to be crimped to an aluminum base wire,
% By mass
Si: 0.6% to 1.5%,
Mg: 0.7% or more and 1.3% or less,
Cu: 0.5% to 1.2%,
Mn: 0.5% to 1.1%,
Fe: 0.02% to 0.4%,
Cr: 0.01% or more and 0.3% or less,
Zn: 0.005% or more and 0.5% or less,
Ti: 0.01% or more and 0.2% or less,
Zr: An aluminum alloy plate for terminals containing 0.05% or more and 0.2% or less, the balance being made of an aluminum alloy made of Al and inevitable impurities.   2. The aluminum alloy sheet for terminals according to claim 1, wherein the aluminum alloy contains Sr: 0.005% or more and 0.05% or less by mass%.   3. The aluminum alloy plate for terminals according to claim 1, wherein the 0.2% proof stress at room temperature is 200 MPa or more.   The aluminum alloy sheet for terminals according to any one of claims 1 to 3, wherein a stress relaxation rate at 120 ° C is 50% or less. A terminal fitting comprising a crimping portion for crimping a conductor of an aluminum-based electric wire, and an electrical connection portion that extends to the crimping portion and is electrically connected to another connection object,
% By mass
Si: 0.6% to 1.5%,
Mg: 0.7% or more and 1.3% or less,
Cu: 0.5% to 1.2%,
Mn: 0.5% to 1.1%,
Fe: 0.02% to 0.4%,
Cr: 0.01% or more and 0.3% or less,
Zn: 0.005% or more and 0.5% or less,
Ti: 0.01% or more and 0.2% or less,
Zr: A terminal fitting made of an aluminum alloy containing 0.05% or more and 0.2% or less, the balance being Al and inevitable impurities.   6. The terminal fitting according to claim 5, wherein the aluminum alloy contains, by mass%, Sr: 0.005% or more and 0.05% or less. The electrical connection portion is a fitting portion that is electrically connected to another terminal fitting,
7. The terminal fitting according to claim 5, wherein the fitting portion includes elastic pieces arranged to face each other. An aluminum based electric wire comprising a conductor composed of aluminum or an aluminum alloy;
An end connection structure for an electric wire comprising the terminal fitting according to any one of claims 5 to 7, which is attached to an end of the conductor.   The electric wire terminal connection structure according to claim 8, which is used in an automobile.

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