JP6850168B2 - Estimator of resistance value of crimping part of electric wire with terminal - Google Patents

Description

The present invention relates to an estimation method for estimating a crimping portion resistance value, which is an electrical resistance value at a crimping portion of an electric wire with terminals whose terminals are crimped to a conductor core wire of the electric wire, and an estimation device for performing such estimation.

Conventionally, from the viewpoint of improving the electrical characteristics of an electric wire with a terminal, the magnitude of the voltage drop (in other words, the electric resistance value at the crimped portion) that occurs at the crimped portion where the terminal is crimped to the conductor core wire of the electric wire is evaluated. Various proposals have been made regarding the method of doing so. It is considered that the voltage drop in the crimping portion is mainly caused by the contact resistance (electrical resistance existing near the interface between the two conductors) at the position where the conductor core wire and the terminal are in contact with each other.

For example, in one of the conventional evaluation methods (hereinafter referred to as "conventional method"), a sample (actual) of a wire with a terminal is actually manufactured, and a four-terminal measurement method (for energization and current measurement of a measurement target) is performed. By making the circuit for measuring the voltage drop in the measurement target and the circuit for measuring the voltage drop in the measurement target separate circuits, the measurement method for measuring the electric resistance value of the measurement target while eliminating the electric resistance of the circuit itself) is used. The electric resistance value at the crimping portion between the conductor core wire and the terminal is measured (actually measured) (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2009-175062

In the above-mentioned conventional method, the electric resistance value of the crimping portion of the electric wire with a terminal (actual) is actually measured. Therefore, for example, when evaluating a wide variety of samples in the development stage of a wire with a terminal, if a conventional method is used, a large number of prototypes are actually manufactured and then the electric resistance value of the crimping portion is measured (actual measurement). ) Will be repeated. As a result, in the conventional method, the manufacturing cost of the mold for manufacturing the prototype and the evaluation man-hours for the actual measurement become large, and the evaluation cost of the electric wire with a terminal may increase. Therefore, there is a demand for a method capable of evaluating the electric resistance value at the crimping portion of the electric wire with a terminal while reducing the evaluation cost as much as possible.

The present invention has been made in view of the above circumstances, and an object of the present invention is to evaluate an electric resistance value (hereinafter referred to as "crimping portion resistance value") in a crimping portion of an electric wire with a terminal at the lowest possible cost. and to provide an estimation device, the crimping portion resistance to.

Further, in order to achieve the above-mentioned object, the "device for estimating the resistance value of the crimping portion of the electric wire with a terminal" according to the present invention is characterized by the following (1).
( 1 )
It is an estimation device that estimates the resistance value of the crimping part, which is the electrical resistance value at the crimping part of the electric wire with terminals whose terminals are crimped to the conductor core wire of the electric wire, by simulation.
A first calculation unit that simulates the process of crimping the terminal to the conductor core wire,
Of the locations where the conductor core wire and the terminal are in contact after the process, the oxide film formed on the surface of the conductor core wire is destroyed through the process, so that the base material of the conductor core wire and the terminal are destroyed. The second calculation unit that identifies the adhesion point where the terminals are adhered,
A third calculation unit that estimates the electric resistance value when an electric current is generated between the conductor core wire and the terminal via the adhesion portion as the crimping portion resistance value is provided.
It must be a device for estimating the resistance value of the crimping part of an electric wire with terminals.

According to the estimation device having the configuration of ( 1 ) above, instead of manufacturing a sample (actual) of a wire with a terminal as in the conventional method, the crimping process is performed based on a simulation of the process of crimping a terminal to a conductor core wire. The location where the oxide film of the conductor core wire is destroyed and the base material of the conductor core wire and the terminal are adhered (adhesion location) is specified. Then, the electric resistance value when a current flows through the adhesion portion (in other words, the electric resistance value due to the contact resistance at the adhesion portion) is estimated as the pressure-bonding portion resistance value. Therefore, unlike the conventional method, it is not necessary to prepare a mold for each prototype, and the evaluation can be completed under simulation, so that the evaluation man-hours can be reduced.

Further, for example, when an aluminum-based electric wire is used, a portion that actually contributes to energization (adhesion portion; simply in contact) is taken into consideration in consideration of the insulating property of the oxide film (aluminum oxide) formed on the surface of the conductor core wire. (Usually narrower than the existing part) is specified, and the electric resistance value when electricity flows through this adhesion part is estimated as the pressure-bonding part resistance value. Therefore, even when an electric wire whose conductor core wire is made of aluminum or an aluminum alloy (hereinafter, referred to as " aluminum-based electric wire " for convenience) is used, the resistance value of the crimping portion can be estimated accurately.

Therefore, the estimation device having this configuration can evaluate the electric resistance value (crimping portion resistance value) in the crimping portion of the electric wire with a terminal at the lowest possible cost. Further, even when an aluminum-based electric wire is used, the resistance value of the crimping portion is estimated with high accuracy.

The present invention can provide an estimation device, the crimping portion resistance to be evaluated at a low cost as possible electric resistance value (crimp portion resistance value) at the compression bonding portion of the wire with terminals.

The present invention has been briefly described above. Further, the details of the present invention will be further clarified by reading through the embodiments described below (hereinafter referred to as "embodiments") with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a hardware configuration of a crimping portion resistance value estimation device for an electric wire with a terminal according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an outline of a method for manufacturing an electric wire with a terminal whose crimping portion resistance value is estimated by the estimation device shown in FIG. 1, and FIG. 2A is a diagram showing an end of the electric wire before crimping the terminal. 2 (b) is a perspective view of an end portion of an electric wire after crimping a terminal. FIG. 3 is a schematic view (a view of the end portion of the electric wire viewed from the side) for explaining the contact portion and the adhesion portion between the conductor core wire and the terminal after crimping the terminal. FIG. 4 is a flowchart showing a processing flow of a program executed by the estimation device shown in FIG. 1 to estimate the pressure-bonding portion resistance value. FIG. 5 is a schematic diagram showing an example of contact points and adhesion points estimated in the program shown in the flowchart of FIG. FIG. 6 is a diagram illustrating an example of utilization of a method of estimating the resistance value of the crimping portion of the electric wire with a terminal using the estimation device shown in FIG. 1, and FIG. 6A is a diagram showing the height of the crimping portion of the electric wire with a terminal. It is a graph which shows an example of the relationship between (crimp height) and a crimping portion resistance value, and FIG. 6B is a cross-sectional view of a crimping portion of an electric wire with a terminal for explaining crimp height.

<Crimping part resistance value estimation device>
Hereinafter, the estimation device 10 according to the embodiment of the present invention will be described with reference to the drawings. The estimation device 10 has an electric resistance value (crimping portion resistance shown in FIG. 6A) at the crimping portion of the terminald electric wire (terminal attached electric wire WT shown in FIG. 2B) in which the terminal is crimped to the conductor core wire of the electric wire. It is a device that estimates the value R) by simulation.

First, the outline of the hardware configuration of the estimation device 10 will be briefly described with reference to FIG. As shown in FIG. 1, the estimation device 10 includes a CPU 11, a memory 12, an input unit 13, a display unit 14, and an HDD 15.

The CPU 11 is a so-called microprocessor, and controls the estimation device 10 by executing various programs including a program executed for estimating the pressure-bonding portion resistance value (details will be described later with reference to FIG. 4). It is designed to do. The memory 12 is a volatile storage area, and is used as a work area for various programs to be executed.

The input unit 13 is an input device including a mouse and a keyboard, and receives input from a user who uses the estimation device 10. The display unit 14 is an output device such as a display, and sequentially displays input information from the input unit 13, a program execution status, an estimation result of a crimping unit resistance value, and the like.

The HDD 15 is a so-called non-volatile storage area, and includes various programs including a program (see FIG. 4) executed to estimate the resistance value of the crimping portion, and various data (tables, maps, etc.) used when executing the program. ) Is stored and stored.

<Structure of electric wire with terminal>
Hereinafter, the electric wire WT with a terminal will be described as an example of a target for which the crimping portion resistance value is estimated by the estimation device 10 with reference to FIG. As shown in FIG. 2, the electric wire WT with a terminal includes an electric wire 20 and a terminal 30.

As shown in FIG. 2A, the electric wire 20 is configured to cover the outer periphery of the core wire bundle 22 in which a plurality of conductor core wires 21 are bundled with an insulating coating 23. In this example, the conductor core wire 21 is a non-plated wire made of aluminum or an aluminum alloy. In other words, the electric wire 20 is a so-called aluminum-based electric wire (aluminum electric wire or aluminum alloy electric wire).

The terminal 30 has an electrical connection portion 31 and a crimp connection portion 32. The terminal 30 is formed by pressing a metal plate made of a conductive metal material such as copper or a copper alloy, for example. In this example, the thickness of the terminal 30 is substantially the same at every location.

The electrical connection portion 31 has a flat plate-shaped connection plate portion 33, and a connection hole 33a is formed in the connection plate portion 33. The connection plate portion 33 is electrically connected to the terminal block, for example, by inserting a fastening bolt into the connection hole 33a and fastening the connecting bolt to the terminal block of the connecting device.

The crimping connection portion 32 has a conductor crimping portion 34 and an outer cover crimping portion 35 in this order from the electrical connection portion 31 side. The conductor crimping portion 34 has a base portion 36 and a pair of conductor crimping pieces 37 formed on both sides of the base portion 36. A core wire bundle 22 is placed on the base portion 36. The conductor crimping piece 37 extends from the base portion 36 so as to sandwich the core wire bundle 22. Serrations (unevenness, not shown) are formed on the inner wall surface of the conductor crimping portion 34. The conductor crimping portion 34 crimps the core wire bundle 22 of the electric wire 20 by bending (crimping) the pair of conductor crimping pieces 37 inward. As a result, the terminal 30 is electrically connected to the core wire bundle 22 of the electric wire 20.

The outer cover crimping portion 35 has a base portion 38 and a pair of outer cover crimping pieces 39 formed on both sides of the base portion 38. The base portion 38 of the outer cover crimping portion 35 extends from the base portion 36 of the conductor crimping portion 34. The insulating coating 23 of the electric wire 20 is placed on the base portion 38. The outer cover crimping piece 39 extends from the base portion 38 so as to sandwich the insulating coating 23 portion of the electric wire 20. The outer cover crimping portion 35 crimps and fixes the portion of the insulating coating 23 of the electric wire 20 by bending (crimping) the pair of outer cover crimping pieces 39 inward.

More specifically, the terminald electric wire WT (actual) is manufactured according to the following procedure.

First, as shown in FIG. 2A, the insulating coating 23 at the end of the electric wire 20 is peeled off, and the core wire bundle 22 in which the conductor core wires 21 are bundled is exposed by a predetermined length. The predetermined length of the core wire bundle 22 to be exposed may be a length sufficient for crimping the terminal 30.

Next, the terminal 30 is crimped to the core wire bundle 22 as shown in FIG. 2B using a terminal crimping machine (a general device provided with a crimping mechanism using an anvil and a crimper. Not shown). Specifically, the terminal 30 is placed on the support surface of the anvil (not shown) of the terminal crimping machine, and the end of the electric wire 20 is arranged on the terminal 30, and the crimper is arranged above the anvil (not shown). Omitted) is lowered. Then, the conductor crimping piece 37 is pressed in the direction close to each other by the arch groove of the crimper to be curved inward, and the conductor crimping portion 34 is sandwiched between the anvil and the crimper and pressed (tightened) against the core wire bundle 22. By these processes, the electric wire WT with a terminal as shown in FIG. 2B is manufactured.

In the electric wire WT with terminals, as shown in FIG. 6B described later, the base portion 36 of the conductor crimping portion 34 and the conductor crimping piece 37 are crimped to the core wire bundle 22, and the conductor crimping portion 34 (that is, the terminal 30) is crimped. It will be electrically connected (conducted) to the core wire bundle 22. Before crimping the terminals, the core wire bundle 22 may be ultrasonically bonded, and the terminal 30 may be crimped to the core wire bundle 22 that has been ultrasonically bonded.

In the electric wire WT with terminals, the portion contributing to the crimping of the terminal 30 (the core wire bundle 22 (conductor core wire 21) of the electric wire 20 and the conductor crimping portion 34 (= base portion 36 + conductor crimping piece 37) of the terminal 30) The portion including the portion) is referred to as a "crimping portion 40" for convenience.

The outer cover crimping piece 39 of the terminal 30 is also crimped by the outer cover anvil and crimper (not shown) provided in the terminal crimping machine. As a result, the outer cover crimping portion 35 of the terminal 30 crimps and fixes the insulating coating 23 of the electric wire 20.

By the way, from the viewpoint of improving the electrical characteristics of the electric wire WT with terminals, it is important to evaluate the magnitude of the voltage drop (electrical resistance value in the crimping portion 40) that occurs in the crimping portion 40 after crimping the terminals. Hereinafter, the electric resistance value in the crimping portion 40 is referred to as a “crimping portion resistance value”. Specifically, the resistance value of the crimping portion is such that the core wire bundle 22 (conductor core wire 21) of the electric wire 20 and the conductor crimping portion 34 (= base portion 36 + conductor crimping piece 37) of the terminal 30 come into contact (or adhere) with each other. It can also be said to be the value of the contact resistance (electrical resistance existing near the interface between the two conductors) at the present location.

<Estimation method of crimp resistance value>
Hereinafter, a method of estimating the pressure-bonding portion resistance value by the estimation device 10 will be described with reference to FIGS. 3 to 6 in particular.

In order to estimate the resistance value of the crimping portion, a place where energization can occur between the core wire bundle 22 of the electric wire 20 and the conductor crimping portion 34 of the terminal 30 (in other words, the contact between the core wire bundle 22 and the conductor crimping portion 34). It is necessary to specify location A). In FIG. 3, the contact point A is schematically illustrated (see the shaded area).

Here, when the electric wire 20 is an aluminum-based electric wire, an oxide film (aluminum oxide. Al ₂ O ₃ ) is usually formed on the surface of the core wire bundle 22 (conductor core wire 21). Since this oxide film has high insulating properties, it hinders energization between the core wire bundle 22 (base material of the conductor core wire 21) and the terminal 30. Therefore, when an aluminum-based electric wire such as a terminal-equipped electric wire WT is used, in order to accurately estimate the resistance value of the crimping portion, it actually contributes to energization among the contact points A between the core wire bundle 22 and the conductor crimping portion 34. It is preferable to specify the portion to be attached (adhesion portion B). Specifically, at the adhesion portion B, the oxide film formed on the surface of the core wire bundle 22 is destroyed through the crimping process, and the base material of the conductor core wire 21 and the conductor crimping portion 34 are adhered to each other. It is a place. In FIG. 3, the adhesion portion B is also schematically illustrated (see the intersecting shaded areas).

The estimation device 10 is adapted to specify the adhesion point B in addition to the contact point A (or instead of the contact point A if the specification of the contact point A can be omitted). Then, the estimation device 10 estimates the electric resistance value (electrical resistance value due to the contact resistance) when electricity flows through the adhesion portion B as the crimping portion resistance value R.

Specifically, the CPU 11 of the estimation device 10 estimates the pressure-bonding portion resistance value R by executing the routine (program) shown in the flowchart in FIG. This program is stored in HDD 15 (see FIG. 1). The processing of this program is started when the user inputs an instruction to start the estimation processing of the crimping portion resistance value R to the input unit 13.

When the processing of this program is started, data regarding various specifications such as the shape and material of the core wire bundle 22 of the electric wire 20 is input to the CPU 11 in step S1 of FIG. The input shape of the core wire bundle 22 is divided into meshes. This input is performed via the input unit 13.

Next, in step S2, data regarding various specifications such as the shape and material of the terminal 30 are input to the CPU 11. The input shape of the terminal 30 is divided into meshes. This input is also performed via the input unit 13.

Next, in step S3, a simulation of a crimping process (crimping simulation) of crimping the terminal 30 to the conductor core wire 21 (core wire bundle 22) of the electric wire 20 is executed. In the crimping simulation, the core wire bundle is based on various data input by executing steps S1 and S2 and various data related to the terminal crimping machine stored in advance in the HDD 15 (including the shape and material of the anvil and crimper). The deformation behavior and the pressing state of the crimping portion 40 in the process of crimping the conductor crimping portion 34 to 22 are simulated in chronological order for each of the divided minute regions, for example.

By executing this crimping simulation, the shape and pressing state (contact state) of the crimping portion 40 after the crimping process is completed are estimated, and in the process of the crimping process, the core wire bundle 22 and the conductor crimping portion 34 are brought together. The relative movement amount (relative slip amount) when moving relatively while maintaining the contact state can also be estimated. This crimping simulation can be realized, for example, by using a well-known finite element method (FEM) or the like.

Next, in step S4, the contact point A (see FIG. 3) after the crimping process is completed is specified based on the result of the crimping simulation. Specifically, the contact point A can be specified as a place where the conductor crimping portion 34 is pressed against the core wire bundle 22 (the contact pressure becomes a positive value) after the crimping process is completed.

Next, in step S5, the adhesion portion B (see FIG. 3) after the completion of the crimping process is specified based on the result of the crimping simulation. Specifically, the adhesion portion B is a state in which the core wire bundle 22 and the conductor crimping portion 34 are in contact with each other in the process of the crimping process among the contact portions A specified in step S4 (a state in which the contact pressure is positive). It can be specified as a place where the relative movement amount (relative slip amount) relatively moved while maintaining the above threshold value is equal to or higher than a predetermined threshold value.

Here, the reason why the portion where the relative movement amount is equal to or more than the threshold value is specified as the adhesion portion B is that when the core wire bundle 22 and the conductor crimping portion 34 are relatively moved while maintaining the contact state in the process of the crimping process. The oxide film (aluminum oxide) formed on the surface of the core wire bundle 22 (conductor core wire 21) is destroyed by friction between the core wire bundle 22 and the conductor crimping portion 34, and the base material of the conductor core wire 21 and the conductor crimping portion 34 This is because it is considered that adhesion between them occurs. The threshold value used in this case can be appropriately determined by conducting various experiments or the like in advance.

FIG. 5 is a schematic view showing an example of the contact portion A and the adhesion portion B specified by steps S4 and S5. In FIG. 5, the region surrounded by the alternate long and short dash line corresponds to the crimping portion 40 (the portion where the conductor crimping portion 34 is crimped to the core wire bundle 22) in FIG. In FIG. 5, the contact portion A is shown in light gray, and the adhesion portion B is shown in dark gray. As shown in FIG. 5, in this example, the adhesion portion B corresponds to a part of the contact portion A, and the area of the adhesion portion B is smaller (narrower) than the area of the contact portion A. It is considered that the ring-shaped adhesion portion B in the central region of the crimping portion 40 is caused by serrations (unevenness) formed on the inner wall surface of the conductor crimping portion 34.

Next, in step S6, the area S of the adhesion portion B specified in step S5 is calculated. This area S can be calculated as the sum of the areas of the minute regions specified as the adhesion points B.

Next, in step S7, the pressure-bonding portion resistance value R is estimated based on the area S of the adhesion portion B calculated in step S6. The crimping portion resistance value R is calculated by numerically calculating the energizing current and the voltage drop according to the area S by the CPU 11. In this example, the pressure-bonding portion resistance value R is calculated to decrease in inverse proportion as the area S increases. When the process of step S7 is completed, the process of this program ends.

By the above processing, the crimping portion resistance value R in the crimping portion 40 is estimated based on the simulation of the crimping process of the electric wire WT with terminals.

<Practical example>
Hereinafter, an example in which the above-mentioned estimation device 10 and the estimation method are put into practical use will be described with reference to FIG.

In FIG. 6A, the process (crimping simulation) shown in FIG. 4 is repeated while changing the height of the crimping portion 40 (crimp height CH shown in FIG. 6B) after the crimping process of the electric wire WT with terminals is completed. An example of "the relationship between the crimp height CH and the crimping portion resistance value R" obtained by the execution is shown.

The crimp height CH in the crimping simulation can be changed by changing the relative positions of the anvil and the crimp among various data related to the terminal crimping machine stored in advance in the HDD 15. The larger the crimp height CH, the smaller the degree of crimping of the crimping portion 40 after the completion of the crimping treatment (low compression), and the smaller the crimp height CH, the smaller the degree of crimping of the crimping portion 40 after the completion of the crimping treatment. It will be large (high compression).

In the example shown in FIG. 6A, the estimated crimp resistance value R (vertical axis of the graph) is relatively less than the reference value Rth in the range where the crimp height CH (horizontal axis of the graph) is equal to or less than the predetermined value CHth. It changes at a small and almost constant value, starts to rise when the crimp height CH approaches the predetermined value CHth, reaches the reference value Rth when the crimp height CH is the predetermined value CHth, and the crimp height CH exceeds the predetermined value CHth. It has become a relatively large value that exceeds the reference value Rth.

Therefore, for example, the reference value Rth is determined based on the electrical characteristics required for the electric wire WT with terminals, and the crimping portion resistance value R calculated (estimated) by using the estimation method by the estimation device 10 determines this reference value Rth. It is conceivable to set the specifications of the electric wire 20 and the terminal 30 and the specifications of the terminal crimping machine (not shown) so as not to exceed the specifications. If the electric wire WT (actual) with terminals is actually manufactured according to the specifications set in this way, the required electrical is required without manufacturing a large number of samples (prototypes) as in the conventional method described above. It is possible to manufacture an electric wire WT with a terminal that satisfies the characteristics. The estimation device 10 and the estimation method can be put into practical use in this way, for example.

By the way, the transition of the crimping portion resistance value R shown in FIG. 6A can be explained by the fact that the area S of the adhesion portion B becomes small (or large) when the crimp height CH is large (or small). In a normal terminal crimping machine, the thickness of the crimping portion 40 (crimp height CH) changes significantly before and after crimping, but the width of the crimping portion 40 does not substantially change. Therefore, the thickness of the crimping portion 40 (crimp height CH) is very important in evaluating the crimping portion resistance value R. Therefore, in the example shown in FIG. 6A, only the thickness of the crimping portion 40 (crimp height CH) is examined, and the width of the crimping portion 40 is not examined.

According to a comparative test or the like conducted by the inventor using an actual electric wire with a terminal (actual), the estimation result of the crimping portion resistance value R by the estimation device 10 shown in FIG. It has been confirmed that the measurement results (relationship between the crimp height CH and the crimping portion resistance value R) using the electric wire (actual) are in agreement with each other to a practically sufficient degree.

<Action / effect>
As described above, according to the estimation device 10 and the estimation method (see the flowchart of FIG. 4) according to the embodiment of the present invention, instead of manufacturing the sample (actual) of the electric wire with a terminal as in the conventional method, the electric wire 20 A simulation was performed in which the conductor crimping portion 34 of the terminal 30 was crimped to the core wire bundle 22 of the above, and it was formed on the surface of the core wire bundle 22 among the contact points A (see FIG. 3) between the core wire bundle 22 and the conductor crimping portion 34. By breaking the oxide film through the crimping process, the adhesion portion B where the base material of the conductor core wire 21 and the conductor crimping portion 34 are adhered is specified. Then, the electric resistance value (contact resistance value) when the adhesion portion B is energized is estimated as the crimping portion resistance value R.

As a result, unlike the conventional method, it is not necessary to prepare a mold for each prototype, and the evaluation can be completed under simulation, so that the evaluation man-hours can be reduced. _{Further, even when an aluminum-based electric wire in which an oxide film (aluminum oxide. Al 2} O ₃ ) is easily formed on the surface is used as the core wire bundle 22 (conductor core wire 21), the pressure-bonding portion resistance value R is estimated accurately. obtain.

Therefore, according to the estimation device 10 and the above-mentioned estimation method (FIG. 4), the electric resistance value (crimping portion resistance value R) in the crimping portion 40 of the electric wire WT with a terminal can be evaluated at the lowest possible cost. Further, even when an aluminum-based electric wire is used, the pressure-bonding portion resistance value R can be estimated accurately.

<Other aspects>
The present invention is not limited to each of the above embodiments, and various modifications can be adopted within the scope of the present invention. For example, the present invention is not limited to the above-described embodiment, and can be appropriately modified, improved, and the like. In addition, the material, shape, size, number, arrangement location, etc. of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

For example, the estimation device 10 and the estimation method according to the above embodiment actually contribute to energization after considering the insulating property of the oxide film (aluminum oxide) formed on the surface of the conductor core wire 21 (core wire bundle 22). A portion (adhesion portion B) is specified, and the electric resistance value (contact resistance value) when energization is generated through the adhesion portion B is estimated as the crimping portion resistance value R.

However, as the electric wire 20, it is not necessary to consider the insulating property of the oxide film formed on the surface of the conductor core wire 21 (for example, an electric wire having a conductor core wire 21 made of copper or a copper alloy, so-called copper electric wire). When used, only the contact point A may be specified, and the electric resistance value (contact resistance value) when energization occurs through the contact point A may be estimated as the crimping portion resistance value R. In this case, in the flowchart shown in FIG. 4, the estimation method may be configured so that step S5 is omitted and the area S of the contact portion A is calculated instead of the adhesion portion B in step S6.

Further, in the above embodiment, the adhesion portion B is determined by the magnitude of the relative movement amount (relative slip amount) between the conductor core wire 21 (core wire bundle 22) and the terminal 30 (conductor crimping portion 34) based on the crimping simulation. It is designed to be specified (estimated) (step S6 in FIG. 4). However, the adhesion portion B can be specified (estimated) by a method different from this method.

Specifically, for example, the depth of the wear mark caused by the friction between the conductor core wire 21 and the terminal 30 is calculated based on the crimping simulation, and the adhesion portion B is specified (estimated) based on the magnitude of the depth of the wear mark. ) May. Further, for example, the adhesion portion B may be specified (estimated) by the magnitude of the deformation (distortion) generated in the conductor core wire 21. Furthermore, we actually manufacture, disassemble, and analyze several samples of electric wires with terminals (prototypes with different specifications), measure the area of the adhesion point for each specification and each degree of compression, and measure the area of the adhesion point. An actually measured value (graph or the like) may be used to identify (estimate) the adhesion portion B of the terminal-attached electric wire having specific specifications.

In addition, in the above embodiment, the area S of the adhesion portion B of the electric wire WT with a terminal is internally calculated. However, if necessary, the adhesion portion B of the electric wire WT with a terminal is visualized by mapping the adhesion portion B on the image of the conductor core wire 21 (core wire bundle 22) after crimping and displaying it on the display unit 14. You may.

Here, the features of the embodiments of the "method for estimating the crimping portion resistance value of the electric wire with terminals" and the "apparatus for estimating the crimping portion resistance value of the electric wire with terminals" according to the present invention described above are as follows (1) to (4), respectively. ) Is briefly summarized and listed.
(1)
The crimping portion resistance value (R), which is the electrical resistance value at the crimping portion (40) of the terminald electric wire (WT) in which the terminal (30) is crimped to the conductor core wire (21) of the electric wire (20), is estimated by simulation. The estimation method (Fig. 4)
The first step (S3 in FIG. 4) of simulating the crimping process of crimping the terminal (30) to the conductor core wire (21), and
A second step (S4, S5 in FIG. 4) of identifying a contact portion (A) in which the conductor core wire and the terminal are in contact after the crimping process is performed.
A third step (S6, FIG. 4) of estimating the electric resistance value when an electric current is generated between the conductor core wire and the terminal via the contact portion (A) as the crimping portion resistance value (R). S7) and, including,
A method for estimating the resistance value of the crimping part of an electric wire with a terminal.
(2)
In the estimation method described in (1) above,
The conductor core wire (21)
Consists of aluminum or aluminum alloy
The second step (S4, S5 in FIG. 4)
Of the contact points (A), the oxide film formed on the surface of the conductor core wire (21) is destroyed through the crimping process, and the base material of the conductor core wire and the terminal (30) adhere to each other. This is a step (S5) for identifying the adhesion location (B).
The third step (S6, S7 in FIG. 4)
This is a step (S7) of estimating the electric resistance value when the energization occurs through the adhesion portion (B) as the crimping portion resistance value (R).
How to estimate the resistance value of the crimped part of a wire with a terminal.
(3)
In the estimation method described in (2) above,
The second step is
A location where the relative movement amount when the conductor core wire (21) and the terminal (30) are in contact with each other in the crimping process and the conductor core wire and the terminal move relative to each other is equal to or greater than a predetermined threshold value. Is a step (S5 in FIG. 4) for identifying the adhesion portion (B).
A method for estimating the resistance value of the crimping part of an electric wire with a terminal.
(4)
The crimping portion resistance value (R), which is the electrical resistance value at the crimping portion (40) of the terminald electric wire (WT) in which the terminal (30) is crimped to the conductor core wire (21) of the electric wire (20), is estimated by simulation. The estimation device (10)
The first calculation unit (11, S3 in FIG. 4) that simulates the crimping process of crimping the terminal (30) to the conductor core wire (21), and
Of the locations where the conductor core wire (21) and the terminal (30) are in contact with each other after the crimping process, the oxide film formed on the surface of the conductor core wire is destroyed and destroyed through the crimping process. The second calculation unit (11, S4 and S5 in FIG. 4) for specifying the adhesion portion (B) where the base material of the conductor core wire and the terminal are adhered to each other.
The third arithmetic unit (11, FIG. 3) estimates the electric resistance value when an electric current is generated between the conductor core wire and the terminal via the adhesion portion (B) as the crimping portion resistance value (R). 4 with S6, S7),
A device for estimating the resistance value of the crimping part of an electric wire with a terminal.

Electric wire with WT terminal 10 Estimator 20 Electric wire 21 Conductor core wire 22 Core wire bundle 30 Terminal 40 Crimping part

Claims (1)

It is an estimation device that estimates the resistance value of the crimping part, which is the electrical resistance value at the crimping part of the electric wire with terminals whose terminals are crimped to the conductor core wire of the electric wire, by simulation.
The first calculation unit that simulates the crimping process of crimping the terminal to the conductor core wire,
Of the locations where the conductor core wire and the terminal are in contact after the crimping process, the oxide film formed on the surface of the conductor core wire is destroyed through the crimping process and becomes a base material of the conductor core wire. A second calculation unit that identifies the adhesion location where the terminals are adhered, and
A third calculation unit that estimates the electric resistance value when an electric current is generated between the conductor core wire and the terminal via the adhesion portion as the crimping portion resistance value is provided.
A device for estimating the resistance value of the crimping part of an electric wire with a terminal.

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