WO2009104762A1

WO2009104762A1 - Compression performance coefficient calculating apparatus, contact performance coefficient calculating apparatus, compression performance coefficient calculating method, and contact performance coefficient calculating method

Info

Publication number: WO2009104762A1
Application number: PCT/JP2009/053085
Authority: WO
Inventors: 直樹角田
Original assignee: 矢崎総業株式会社
Priority date: 2008-02-20
Filing date: 2009-02-20
Publication date: 2009-08-27

Abstract

Disclosed is a compression performance calculating apparatus that can provide such support that anybody can perform the connection design for the terminal fixtures and the core wires easily in a short period of time without depending on the experience of the designer by calculating the contact performance coefficient corresponding to the contact resistance derived from simulations. The displacement of each node that constitutes a core wire model (3m) and a crimping piece model (2m) after a core wire is crimped with a crimping piece is calculated by the finite element method. A node (N_s) in contact with the crimping piece (2m) is extracted from the nodes on the profile of the core wire model (3m) based on the calculated displacement of each node. Then, distance L_k+1 between the extracted node N_s and the node N_k+1 adjacent to the node N_s among the nodes on the profile of the core wire model 3m, and distance L_k _- ₁ between the extracted node N_s and the node N_k _- ₁ adjacent to the extracted node among the nodes on the profile of the core wire model 3m are calculated. Half of the sum of distance L_k+1 and distance L_k _- ₁ is calculated as the contact length L_k of the extracted node N_s. The sum of the contact lengths L_k derived for all the extracted nodes N_s is calculated. The value calculated by dividing the sum of the volume resistivity of the core wire and the volume resistivity of the crimping piece by 8 times the sum of contact lengths L_k is found as the compression performance coefficient.

Description

Crimping performance coefficient calculation apparatus, contact performance coefficient calculation apparatus, crimping performance coefficient calculation method, and contact performance coefficient calculation method

The present invention relates to a crimping coefficient calculation device and a crimping performance coefficient calculation method, and in particular, calculates a crimping performance coefficient according to contact resistance between a crimping piece provided on a terminal fitting and a core wire crimped to the crimping piece. The present invention relates to a crimping performance coefficient calculation device and a crimping performance coefficient calculation method.

In addition, the present invention relates to a contact performance coefficient calculation device and a contact performance coefficient calculation method, and in particular, a contact performance coefficient according to a contact resistance between a caulking piece provided on a terminal fitting and a core wire caulked on the caulking piece. The present invention relates to a contact performance coefficient calculation device and a contact performance coefficient calculation method to be calculated.

Conventionally, as a method of electrically connecting a core wire of a conductive wire and a terminal fitting, for example, there is a method of crimping and crimping a core wire with a caulking piece provided on the terminal fitting (for example, Patent Documents 1 to 3). ). A terminal fitting used for this crimp connection is generally configured as shown in FIG. As shown in the figure, the terminal fitting 1 includes a caulking piece 2. Then, the crimping piece 2 and the core wire 3 of the terminal fitting 1 described above are sandwiched between the crimper 4 (upper mold) and the anvil 5 (lower mold) as shown in FIGS. 14B and 14C, and then the pressure is applied. In addition, the core wire 3 is crimped and crimped by the caulking piece 2, and the terminal fitting 1 and the core wire 3 are electrically and mechanically connected as shown in FIG.

By the way, the relationship between the crimp height C / H after crimping (see FIG. 14D) and the fixing force F or contact resistance R between the terminal fitting 1 and the core wire 3 after crimping is shown in FIG. It becomes like this. As shown in the figure, since the fixing force F has a non-linear characteristic that is convex upward with respect to the crimp height C / H, the crimp height C / H can be used for a certain range. Will exist. Similarly, there is a contact resistance R that can be used with respect to the crimp height C / H. From the relationship between the fixing force F having such a non-linear characteristic and the contact resistance R, the range of the crimp height C / H that can be used for both the fixing force F and the contact resistance R (“optimal crimp height shown in FIG. 15”). ") Will be limited.

Therefore, conventionally, for example, when designing a new connection, the terminal fitting 1, the core wire 3, the crimper 4 or the anvil 5 are designed. Then, after actually performing the crimping connection using the designed terminal fitting 1, core wire 3, crimper 4 or anvil 5, etc., the fixing force F, the contact resistance R, etc. are measured to obtain the optimum fixing force. F and evaluation of whether or not the contact resistance R is obtained are executed. If not obtained, the terminal fitting 1, the core wire 3, the crimper 4 or the anvil 5 is newly designed, and then the above is repeated.

By the way, it is known that the contact resistance R described above increases when left in a low temperature environment or a high temperature environment. Therefore, the measurement of the contact resistance R has been performed after, for example, a cold collision test in which a low temperature environment of −40 ° C. and a high temperature environment of + 120 ° C. are alternately repeated 1000 times. If one cycle of the low temperature environment and the high temperature environment requires 2 hours, 2000 hours are required until the contact resistance R is measured. That is, in the conventional connection design of the terminal fitting 1 to the core wire 3, it is necessary to obtain an appropriate one by repeatedly performing the cut-and-try process as described above: design → actual connection → cooling collision test → evaluation (measurement). For this reason, if the person who has little design experience performs the connection design described above, there is a problem that a lot of time is wasted until the desired product is obtained, and the design period becomes longer and the design cost increases. there were.
JP 2007-173215 A JP 2006-351451 A Japanese Patent Laid-Open No. 10-50449

Therefore, the present invention pays attention to the problems as described above so that anyone can easily and quickly perform the connection design between the terminal fitting and the core wire without being influenced by the experience of the designer. It is an object of the present invention to provide a crimping performance coefficient calculation device and a crimping performance coefficient calculation method for calculating a crimping performance coefficient according to contact resistance by simulation so that they can be supported.

In addition, the present invention is based on simulation so that anyone can easily and quickly perform the connection design between the terminal fitting and the core wire without being influenced by the experience of the designer. It is an object of the present invention to provide a contact performance coefficient calculation device and a contact performance coefficient calculation method for calculating a contact performance coefficient according to contact resistance.

In addition, the inventor of the present invention has repeatedly studied to obtain a crimping performance coefficient calculation device and a crimping performance coefficient calculation method for calculating the crimping performance coefficient according to the contact resistance by simulation without being influenced by the experience of the designer. The inventors have found that the crimping performance coefficient R _CL shown in the following formulas (1) and (2) is a value corresponding to the contact resistance R, and have completed the present invention.

Note that ρ1 is the volume resistivity of the core wire, and ρ2 is the volume resistivity of the core wire. Further, as shown in FIG. 4 (B), L _{k + 1} is the caulking piece model 2m among the nodes on the contour of the core wire model 3m after crimping (after caulking) obtained by executing the finite element method. Of the nodes on the contour of the node N _SK that touches the node N _SK and the node N _{k + 1} adjacent to the node N _SK among the nodes on the contour of the core wire model 3m, L _k-1 is the node N _SK This is the distance from the node N _k-1 adjacent to the node N _SK among the nodes. n is the total number of nodes N _SK contacting the crimping pieces model 2m of sections on the contour of the core wire model 3m.

That is, the present invention is a crimping performance coefficient calculation device that calculates a crimping performance coefficient according to contact resistance between a crimping piece provided on a terminal fitting and a core wire crimped on the crimping piece, and a plurality of the core wires are provided. A core wire model acquisition means for acquiring a core wire model divided into elements, a crimped piece model acquisition means for acquiring a caulking piece model obtained by dividing the caulking piece into a plurality of elements, and sandwiched between an upper mold and a lower mold The core wire model after caulking the caulking piece and the deformation calculating means for calculating the displacement of each knot constituting the caulking piece model by a finite element method, and the displacement of each knot calculated by the deformation calculating means From the nodes on the outline of the core model after caulking, a node extracting means for extracting a node that contacts the caulking piece model, the nodes extracted by the node extracting means and the caulking First distance calculating means for obtaining a first distance between one of a pair of nodes adjacent to the node extracted by the node extracting means among the nodes on the contour of the core model after the core model; A second distance between the node extracted by the extracting unit and the other of the pair of nodes adjacent to the node extracted by the node extracting unit among the nodes on the outline of the core model after the caulking is obtained. A second distance calculating means; a contact length calculating means for obtaining 1/2 of the sum of the first distance and the second distance as a contact length of the node extracted by the node extracting means; Sum total calculating means for obtaining the sum of the contact lengths obtained for all the nodes extracted by the extracting means, and the sum of the volume resistivity of the core wire and the volume resistivity of the caulking piece was obtained by the sum calculating means. The value obtained by dividing the sum by 8 times is the crimping performance coefficient. , A crimp performance coefficient calculating means for calculating Te is crimped performance coefficient calculation device equipped with.

Further, the present invention is a crimping performance coefficient calculation method for calculating a crimping performance coefficient according to a contact resistance between a crimping piece provided on a terminal fitting and a core wire crimped on the crimping piece, wherein the core wire includes a plurality of core wires. A core wire model divided into elements and a caulking piece model obtained by dividing the caulking piece into a plurality of elements; and the core wire model after caulking the core wire between the upper die and the lower die. And a step of calculating the displacement of each node constituting the crimped piece model by a finite element method, and the crimped piece model among the nodes on the outline of the core model after the crimping from the calculated displacement of each node A node that contacts the extracted node and one of a pair of nodes adjacent to the extracted node among the extracted nodes and the nodes on the contour of the core model after the caulking. 1 distance And obtaining a second distance between the extracted node and the other of the pair of nodes adjacent to the extracted node among the nodes on the contour of the core model after caulking. And calculating the half of the sum of the first distance and the second distance as the contact length of the extracted nodes, and the contact lengths calculated for all the extracted nodes. A step of obtaining a sum, a step of calculating a value obtained by dividing the sum of the volume resistivity of the core wire and the volume resistivity of the caulking piece by 8 times the sum obtained by the sum calculation means, as the crimping performance coefficient, Is a method of calculating the crimping performance coefficient by sequentially performing.

Further, the inventor has repeatedly studied to obtain a contact performance coefficient calculation device and a contact performance coefficient calculation method for calculating a contact performance coefficient according to contact resistance by simulation without being influenced by the experience of the designer. The inventors have found that the contact performance coefficient CC shown in the following formulas (3) and (2) is a value corresponding to the contact resistance R, and have completed the present invention.

As shown in FIG. 11B, _PSK is a node that contacts the crimped piece model 2m among the nodes on the contour of the core wire model 3m after crimping (after crimping) obtained by executing the finite element method. N _SK is the force acting on the caulking piece model 2m. L k _{+ 1} sections N _SK, and a distance between the node N _{k + 1} adjacent to the inner section N _SK sections on the contour of the core wire model 3m, L _k-1 sections N _SK and the core wire model 3m This is the distance from the node N _k-1 adjacent to the node N _SK among the nodes on the contour of the. n is the total number of nodes N _SK contacting the crimping pieces model 2m of sections on the contour of the core wire model 3m.

That is, the present invention is a contact performance coefficient calculation device for calculating a contact performance coefficient according to the contact resistance between a caulking piece provided on a terminal fitting and a caulking piece caulked to the caulking piece, wherein the core wire includes a plurality of elements. A core wire model acquisition means for acquiring a core wire model divided into a plurality of elements, a caulking piece model acquisition means for acquiring a caulking piece model obtained by dividing the caulking piece into a plurality of elements, and the core wire sandwiched between an upper die and a lower die Deformation calculating means for calculating the displacement and the force acting on each node constituting the core model and the caulking piece model after the caulking piece by the finite element method, and the deformation calculating means A node extracting means for extracting a node in contact with the caulking piece model from the nodes on the contour of the core model after the caulking from the displacement of each node, and the node extracting means First distance calculation for obtaining a first distance between one of the pair of nodes adjacent to the node extracted by the node extraction means among the nodes on the contour of the core model after caulking Means between the node extracted by the node extracting unit and the other of the pair of nodes adjacent to the node extracted by the node extracting unit among the nodes on the contour of the core model after the caulking A second distance calculation means for obtaining a distance of 2, and a contact length calculation for obtaining a contact length of a node extracted by the node extraction means as ½ of the sum of the first distance and the second distance A total sum of values obtained by multiplying the force acting on the caulking piece model by the means and the contact length obtained for all the nodes extracted by the node extracting means and the nodes extracted by the node extracting means; Obtain the reciprocal of the sum as the contact performance coefficient The contact performance coefficient calculating means, the contact performance coefficient calculation device equipped with.

Further, the present invention is a contact performance coefficient calculation method for calculating a contact performance coefficient according to contact resistance between a caulking piece provided on a terminal fitting and a caulking piece caulked to the caulking piece, wherein the core wire includes a plurality of elements. A core line model divided into a plurality of elements and a caulking piece model obtained by dividing the caulking piece into a plurality of elements, and the core wire model after caulking the core wire with the caulking pieces sandwiched between an upper mold and a lower mold, and Calculating a displacement of each node constituting the crimped piece model and a force acting on each node by a finite element method, and a node on the contour of the core model after the crimping from the calculated displacement of each node One of a pair of nodes adjacent to the extracted node out of the extracted nodes and the nodes on the outline of the core model after caulking. When A first distance between the extracted node and the other of the pair of nodes adjacent to the extracted node among the nodes on the contour of the core model after the caulking A step of obtaining a distance of 2, a step of obtaining ½ of a sum of the first distance and the second distance as a contact length of the extracted nodes, and obtaining all of the extracted nodes. Calculating a contact performance coefficient by sequentially calculating a sum of values obtained by multiplying the contact length and a force acting on the caulking piece model by the extracted node, and obtaining a reciprocal of the sum as the contact performance coefficient. Is the method.

As described above, according to the present invention, since the crimping performance coefficient corresponding to the contact resistance can be calculated by simulation, it is possible to determine the connection design between the terminal fitting and the core wire regardless of the designer's experience. It is possible to support so that it can be performed easily and in a short time.

In addition, according to the present invention, since the contact performance coefficient corresponding to the contact resistance can be calculated by simulation, anyone can easily design the connection between the terminal fitting and the core wire without being influenced by the experience of the designer. In addition, it is possible to assist so that it can be performed in a short time.

It is a block diagram which shows one Embodiment of the crimping performance coefficient calculation apparatus which implemented the crimping performance coefficient calculation method of this invention. It is a flowchart which shows the analysis simulation process procedure of CPU shown in FIG. It is explanatory drawing for demonstrating the deformation | transformation calculation process shown in FIG. It is explanatory drawing for demonstrating contact resistance. (A) is explanatory drawing for demonstrating the deformation | transformation calculation process result shown in FIG. 2, (B) is an enlarged view of the X section of (A). 4 is a table showing the types of core wires, terminal fittings and crimping molds, order of contact resistance, and order of crimping performance coefficients corresponding to sample products (1) to (5). 6 is a graph showing contact resistance and crimping performance coefficient of sample products (1) to (5) corresponding to the conductor compressibility. It is a block diagram which shows one Embodiment of the contact performance coefficient calculation apparatus which implemented the contact performance coefficient calculation method of this invention. It is a flowchart which shows the analysis simulation process procedure of CPU shown in FIG. It is explanatory drawing for demonstrating the deformation | transformation calculation process shown in FIG. (A) is explanatory drawing for demonstrating the deformation | transformation calculation process result shown in FIG. 9, (B) is an enlarged view of the X section of (A). 7 is a table showing the types of core wires, terminal fittings and crimping dies, order of contact resistance, and order of contact performance coefficient corresponding to sample products (1) to (5). 7 is a graph showing contact resistance and contact performance coefficient of sample products (1) to (5) corresponding to conductor compressibility. It is a graph which shows. (A) is a side view which shows the shape of the terminal metal fitting used for crimping connection, (B) is a figure which shows the shape of the anvil and crimper used for crimping work, (C) is a terminal metal fitting and a core wire. It is a figure which shows the state in the time of a crimping | compression-bonding operation | work, (D) is a figure which shows the state after crimping | bonding of a terminal metal fitting and a core wire. It is a graph which shows the relationship between crimp height at the time of crimping | bonding connection, sticking force, and contact resistance.

Explanation of symbols

1 Terminal fitting 2 Caulking piece 3 Core wire 4 Crimper (upper mold)
5 Anvil (bottom)
6 Crimping performance coefficient calculating device 106 Contact performance coefficient calculating device 10,110 CPU
L _{k + 1} distance (first distance)
L _k-1 distance (second distance)
N nodes N _S node N _Sk clause

Hereinafter, the crimping performance coefficient calculation device and the crimping performance coefficient calculation method of the present invention will be described based on the drawings. The crimping performance coefficient calculation device 6 shown in FIG. 1 is composed of, for example, a personal computer. When the terminal fitting 1 and the core wire 3 are crimped and connected, the terminal fitting 1 to the core wire 3 prior to the actual crimping connection. This is a device for calculating a crimping performance coefficient R _CL corresponding to the contact resistance R between the two.

As shown in the figure, the crimping performance coefficient calculation device 6 includes an input device 7, a display device 8, and a microcomputer 9. The input device 7 is composed of operation means such as a keyboard and a mouse, for example, and includes information on the shape of the crimping piece 2, the core wire 3, the crimper 4 and the anvil 5 of the terminal fitting 1 described in the prior art, and the crimping piece 2 and This is a device for inputting material property information which is a stress-strain property of the material of the core wire 3. As the shape information, for example, CAD data of the caulking piece 2, the core wire 3, the crimper 4, and the anvil 5 created by CAD can be considered.

The display device 8 is a device for displaying, for example, the calculated crimping performance coefficient _RCL . The microcomputer 9 is a read-only memory that stores a central processing unit (hereinafter referred to as CPU) 10 that controls the entire crimping performance coefficient calculation device 6 and performs various processes according to a processing program, and a program for processing performed by the CPU 10. A ROM 11 and a RAM 12 which is a readable / writable memory having a work area used in various processing steps in the CPU 10 and a data storage area for storing various data are included.

Next, the operation of the crimping performance coefficient calculation device 6 having the above-described configuration will be described below with reference to FIGS. First, when an analysis simulation process start operation is performed by the input device 7, the CPU 10 starts the analysis simulation process. First, the CPU 10 displays on the display device 8 an input screen for inputting the shape information of the crimping piece 2, the core wire 3, the crimper 4 and the anvil 5 of the terminal fitting 1 and the material characteristic information of the crimping piece 2 and the core wire 3. An input process for display is performed (step S1 in FIG. 2).

The user operates the operation means such as the keyboard and mouse of the input device 7 in accordance with the display on the display device 8 to input the shape information and material property information. The shape information and material characteristics according to the types A, B, C,... Of the terminal fitting 1, the types A, B, C,... Of the core wire 3, and the types A, B, C,. Information may be recorded in the ROM 11 in advance, and the user may be allowed to input the shape information and material information by selecting the types of the terminal fitting 1, the core wire 3, the crimper type crimper 4 and the anvil 5. .

Thereafter, the CPU 10 performs a finite element model conversion process (step S2). In the finite element model conversion processing, as shown in FIG. 3A, the CPU 10 converts the crimped piece 2 and the core wire 3 input by the input processing into a crimped piece model 2m and a core wire model 3m, each of which is divided into a plurality of elements. To do. In this finite element model conversion process, the CPU 10 functions as a core wire model acquisition unit and a caulking piece model acquisition unit.

Next, the CPU 10 performs a deformation calculation process (step S3). In the deformation calculation process, as shown in FIGS. 3B to 3D, the CPU 10 crimps the core wire 3 with the caulking piece 2 with the crimper 4 sandwiched between the crimper 4 and the anvil 5 using the finite element method. And the displacement of each node N which comprises the core wire model 3m and the caulking piece model 2m after releasing the anvil 5 and unloading the load applied to the caulking piece 2 and the core wire 3 is calculated. In this deformation calculation process, the CPU 10 functions as a deformation calculation unit.

When the crimper 4 and the anvil 5 are brought close to each other and the crimping piece 2 is caulked and then the crimper 4 and the anvil 5 are released to remove the load applied to the caulking piece 2 and the core wire 3, the caulking piece 2 and the core wire 3 are spring-backed. This causes an elastic recovery phenomenon called. Therefore, the displacement calculation process can calculate the displacement of each node N constituting the core model 3m and the caulking piece model 2m after the spring back.

Thereafter, the CPU 10 executes steps S4 to S6 to obtain a later-described crimping performance coefficient R _CL corresponding to the contact resistance R between the crimping piece 2 and the core wire 3 from the displacement of each node N obtained by the deformation calculation process. . The contact resistance R is the sum of the concentrated resistance Rc and the film resistance Rf as shown in the following formula (4).
R = Rc + Rf (4)

As shown in FIG. 5, if the crimping piece 2 and the core wire 3 are in contact at a plurality of contact surfaces S ₁ , S ₂ ... Having radii a ₁ , a ₂ . Can be obtained by the following equations (5) and (6), respectively.

In addition, ρ1 is the volume resistivity of the core wire 3, and ρ2 is the volume resistivity of the caulking piece 2.

Here, ρf is the volume resistivity of the metal film 13 (FIG. 5), and d is the thickness of the metal film 13 (assuming constant).

The thickness d of the metal film 13 is very thin. Therefore, the film resistance Rf is considered to be close to zero. Therefore, as is apparent from the equations (5) and (6), the contact resistance R increases as the sum of the volume resistivity ρ1 of the core wire 3 and the volume resistivity ρ2 of the caulking piece 2 increases. Further, the contact resistance R decreases as the contact area between the caulking piece 2 and the core wire 3 increases. Therefore, the CPU 10 executes the following steps S4 and S5 to obtain the contact length between the caulking piece 2 and the core wire 3 on the cross section as shown in FIG. 3 as a value corresponding to the contact area.

That is, the CPU 10 functions as a node extracting means, and the node N that contacts the caulking piece model 2m among the nodes N on the contour of the core model 3m after the spring back from the displacement of each node N calculated by the deformation calculation process described above. A node extraction process for extracting _S is performed (step S4). The results are shown in FIG. As shown in the figure, as a result of the clause extraction process, for example, the total number of n nodes N _S are extracted. Incidentally, P _S in FIG. 5 (A) force acting on the node N _S on the core wire model 3m extracted in step S4, i.e., the crimping pieces model 2m from node N _S on the core wire model 3m extracted in step S4 The contact pressure acting on is shown. Then, CPU 10 has the first distance calculating unit, the second distance calculating means, serves as a contact length calculating unit, a crimping piece 2 and the core wire 3 after the spring-back at each node N _S extracted by clause extraction process The contact length calculation process for obtaining the contact length is performed (step S5). As shown in FIG. 5 (B), the caulking piece model 2m and the core wire model 3m are in contact with each other at a point (node), but the present inventor actually made an arbitrary node N _Sk extracted in step S4. Therefore, it is assumed that the contact is made with the contact length L _k shown by the following formula (2).
L _k = (L _{k + 1} + L _k-1 ) / 2 (2)

Note that L _{k + 1} is the distance (first distance) between any extracted node N _Sk and node N _{k + 1} . The node N _{k + 1} is _one of a pair of nodes N _{k + 1} and N _k−1 adjacent to the node N _Sk among the nodes N on the outline of the core wire model 3m. L _k-1 is a distance (second distance) between the extracted arbitrary nodes N _Sk and N _k-1 . The node N _k-1 is the other of the pair of nodes N _{k + 1} and N _k-1 adjacent to the node N _Sk among the nodes N on the outline of the core wire model 3m.

Next, the CPU 10 functions as a crimping performance coefficient calculation unit, and as shown in the following equation (1), the contact length L _k obtained for all the nodes N _S extracted in step S4, that is, the total number of nodes _NS. Crimping performance obtained by dividing the sum of the volume resistivity ρ1 of the core wire 3 and the volume resistivity ρ2 of the caulking piece 2 by 8 times the sum of the contact lengths L _k as the crimping performance coefficient R _CL After performing the coefficient calculation process (step S6), the calculated crimping performance coefficient R _CL is displayed on the display device 8 (step 7), and the analysis simulation process is terminated.

As is apparent from the equation (1), the crimping performance coefficient R _CL is a coefficient that increases as (ρ1 + ρ2) increases as in the case of the contact resistance R. The crimping performance coefficient R _CL is a coefficient that decreases as the contact length (area) L _k between the crimping piece 2 and the core wire 3 increases. That is, the present inventor assumed that the crimping performance coefficient R _CL shown in the above formula (1) would be a value corresponding to the contact resistance R.

Next, the inventor of the present invention uses the crimping performance coefficient R _CL calculated using the product of the present invention described above for the sample products (1) to (5) shown in FIG. 6, and the sample product (1) shown in FIG. A comparison was made with the contact resistance R measured after actually making a prototype of (5) to (5) and executing the cold collision test. The results are shown in FIG. Sample product (1) is a product in which core wire 3 is crimped with crimping piece 2 of terminal metal fitting 1 using type A core wire 3, type A terminal metal fitting 1, type A crimping type (crimper 4, anvil 5). It is. Similarly, the sample product (2) is of type A core wire 3, type B terminal fitting 1, type A crimping type, and the sample product (3) is type A core wire 3, type A terminal fitting 1, type B Crimp type, sample product (4) is type A core wire 3, type C terminal fitting 1, type A crimp type, sample product (5) is type A core wire 3, type A terminal fitting 1, type C Each of the crimping molds is used to crimp the core wire 3 with the crimping piece 2 of the terminal fitting 1.

As shown in FIG. 7, the contact resistance R according to the measured conductor compression ratio% (= crimp height) is the sample product (4), sample product (3), sample product (2), sample product ( 1) The sample product (5) increases in this order. Therefore, as the performance of the actually measured product, the sample product (4) is the best, and the sample product (3), the sample product (2), the sample product (1), and the sample product (5) become worse in this order.

In contrast, the crimping performance coefficient R _CL corresponding to the conductor compression ratio%, which is a simulation value, is also the sample product (4), sample product (3), sample product (2), sample product (1), sample product ( Increase in the order of 5). Therefore, similarly to the actual measurement product, the sample product (4) is the best from the crimping performance coefficient R _CL which is a simulation value, and the sample product (3), sample product (2), sample product (1), sample product ( It turns out that it gets worse in the order of 5). That is, it was found that the crimping performance coefficient R _CL shown in the equation (1) is a value corresponding to the contact resistance R.

According to the crimping performance coefficient calculation device 6 described above, a plurality of samples can be obtained by calculating the crimping performance coefficient R _CL which is a simulation value without actually making a plurality of sample products and actually measuring the contact resistance R. The magnitude of the contact resistance R of the product can be compared. For this reason, it can support that anyone can perform the connection design of the terminal metal fitting 1 and the core wire 3 easily and in a short time without being influenced by a designer's experience.

According to the above-described embodiment, the finite element model conversion process for converting the caulking piece 2 and the core wire 3 input by the input process into the caulking piece model 2m and the core wire model 3m, respectively, is provided. It is not limited to. For example, the caulking piece model 2m corresponding to the types A, B, C... Of the terminal fitting 1 and the core wire model 3m corresponding to the types A, B, C. By selecting the type of 1 and the core wire 3, the caulking piece model 2m and the core wire model 3m may be input by input processing. In this case, it is not necessary to perform a finite element model conversion process.

Next, the contact performance coefficient calculation device and the contact performance coefficient calculation method of the present invention will be described with reference to the drawings. The contact performance coefficient calculation device 106 shown in FIG. 8 is constituted by, for example, a personal computer, and when the terminal fitting 1 and the core wire 3 are connected by crimping, the terminal fitting 1-core wire 3 prior to the actual crimping connection. This is a device for calculating a contact performance coefficient CC according to the contact resistance R between the two.

As shown in the figure, the contact performance coefficient calculation device 106 includes an input device 107, a display device 108, and a microcomputer 9. The input device 107 is composed of operation means such as a keyboard and a mouse, for example, and includes information on the shape of the crimping piece 2, the core wire 3, the crimper 4 and the anvil 5 of the terminal fitting 1 and the material of the crimping piece 2 and the core wire 3. This is a device for inputting material property information which is a stress-strain property. As the shape information, for example, CAD data of the caulking piece 2, the core wire 3, the crimper 4, and the anvil 5 created by CAD can be considered.

The display device 108 is a device for displaying, for example, the calculated contact performance coefficient. The microcomputer 109 is a read-only memory that stores a central processing unit (hereinafter referred to as CPU) 110 that controls the entire contact performance coefficient calculation device 106 and performs various processes according to a processing program, and a program for processing performed by the CPU 110. A ROM 111 and a RAM 112 which is a readable / writable memory having a work area used in various processing steps in the CPU 110 and a data storage area for storing various data are included.

Next, the operation of the contact performance coefficient calculating apparatus 106 having the above-described configuration will be described below with reference to FIGS. First, when an analysis simulation process start operation is performed by the input device 107, the CPU 110 starts the analysis simulation process. First, the CPU 110 displays on the display device 108 an input screen for inputting the shape information of the caulking piece 2, the core wire 3, the crimper 4 and the anvil 5 of the terminal fitting 1 and the material characteristic information of the caulking piece 2 and the core wire 3. An input process for display is performed (step S1 in FIG. 9).

The user operates the operation means such as the keyboard and mouse of the input device 107 according to the display on the display device 108 to input the shape information and material property information. The shape information and material characteristics according to the types A, B, C,... Of the terminal fitting 1, the types A, B, C,... Of the core wire 3, and the types A, B, C,. Information may be recorded in the ROM 111 in advance, and the shape information and material information may be input by allowing the user to select the types of the terminal fitting 1, the core wire 3, the crimping crimper 4 and the anvil 5. .

Thereafter, the CPU 110 performs a finite element model conversion process (step S2). In the finite element model conversion processing, as shown in FIG. 10A, the CPU 110 converts the crimped piece 2 and the core wire 3 input by the input processing into a crimped piece model 2m and a core wire model 3m, which are each divided into a plurality of elements. To do. In this finite element model conversion process, the CPU 110 functions as a core wire model acquisition unit and a caulking piece model acquisition unit.

Next, the CPU 110 performs deformation calculation processing (step S3). In the deformation calculation process, as shown in FIGS. 10B to 10D, the CPU 110 crimps the core wire 3 with the crimping piece 2 with the crimper 4 sandwiched between the crimper 4 and the anvil 5 using the finite element method. The displacement of each node N constituting the core wire model 3m and the caulking piece model 2m after the load applied to the caulking piece 2 and the core wire 3 is released by separating the anvil 5 and the force P acting on each node N are calculated. To do. In this deformation calculation process, the CPU 110 functions as a deformation calculation unit.

When the crimper 4 and the anvil 5 are brought close to each other and the crimping piece 2 is caulked and then the crimper 4 and the anvil 5 are released to remove the load applied to the caulking piece 2 and the core wire 3, the caulking piece 2 and the core wire 3 are spring-backed. This causes an elastic recovery phenomenon called. Therefore, the deformation calculation process can calculate the displacement of each node N and the force P acting on each node N constituting the core model 3m and the caulking piece model 2m after the spring back.

Thereafter, the CPU 110 executes steps S4 to S6 according to the contact resistance R between the caulking piece 2 and the core wire 3 from the displacement of each node N obtained by the deformation calculation process and the force P acting on each node N. A contact performance coefficient CC described later is obtained. The contact resistance R decreases as the contact area and contact pressure between the caulking piece 2 and the core wire 3 increase. Therefore, the CPU 110 executes the following steps S4 and S5 to obtain the contact length between the caulking piece 2 and the core wire 3 on the cross section as shown in FIG. 10 as a value corresponding to the contact area.

That is, the CPU 110 functions as a node extracting means, and the node that contacts the caulking piece model 2m of the nodes N on the contour of the core model 3m after the spring back from the displacement of each node N calculated by the deformation calculation process described above. performing clause extraction process for extracting the N _S (step S4). The results are shown in FIG. As shown in the figure, as a result of the clause extraction process, for example, the total number of n nodes N _S are extracted. Incidentally, P _S is the force acting on the node N _S on the core wire model 3m extracted in step S4 in FIG. 11 (A), the words, the caulking pieces 2 model from node N _S on the core wire model 3m extracted in step S4 The contact pressure acting on is shown. Next, CPU 110 is the first distance calculating unit, the second distance calculating means, and functions as a contact length calculating unit, crimping piece 2 and the core wire 3 after the spring-back at each node N _S extracted by clause extraction process The contact length calculation process for obtaining the contact length is performed (step S5). As shown in FIG. 11 (B), the caulking piece model 2m and the core wire model 3m are in contact with each other at a point (node), but the present inventor actually made an arbitrary node N _Sk extracted in step S4. Therefore, it is assumed that the contact is made with the contact length L _k shown by the following formula (2).
L _k = (L _{k + 1} + L _k-1 ) / 2 (2)

Next, the CPU 110 functions as a contact performance coefficient calculation unit, and as shown in the following formula (3), the contact length L obtained for all the nodes N _S extracted in step S4, that is, a total of n nodes NS. _k and a node N _S extracted in step S4 is the total sum of values obtained by multiplying the contact pressure P _SK acting on crimping pieces model 2m, it obtains the reciprocal of the sum as the contact performance coefficient CC contact performance coefficient calculation process (Step S6), the calculated contact performance coefficient CC is displayed on the display device 108 (Step 7), and the analysis simulation process is terminated.

As is clear from the equation (3), the contact performance coefficient CC decreases as the contact length (area) L _k between the caulking piece 2 and the core wire 3 and the contact pressure P _Sk increase as in the case of the contact resistance R. Is a coefficient. That is, the present inventor assumed that the contact performance coefficient CC shown in the above formula (3) would be a value corresponding to the contact resistance R.

Next, the inventor of the present invention uses the contact performance coefficient CC calculated using the product of the present invention described above for the sample products (1) to (5) shown in FIG. 12, and the sample products (1) to (5) shown in FIG. Comparison was made with the contact resistance R measured after actually making a prototype of (5) and executing the thermal collision test. The results are shown in FIG. Sample product (1) is a product in which core wire 3 is crimped with crimping piece 2 of terminal metal fitting 1 using type A core wire 3, type A terminal metal fitting 1, type A crimping type (crimper 4, anvil 5). It is. Similarly, the sample product (2) is of type A core wire 3, type B terminal fitting 1, type A crimping type, and the sample product (3) is type A core wire 3, type A terminal fitting 1, type B Crimp type, sample product (4) is type A core wire 3, type C terminal fitting 1, type A crimp type, sample product (5) is type A core wire 3, type A terminal fitting 1, type C Each of the crimping molds is used to crimp the core wire 3 with the crimping piece 2 of the terminal fitting 1.

As shown in FIG. 13, the contact resistance R corresponding to the measured conductor compression ratio% (= crimp height) is the sample product (4), sample product (3), sample product (2), sample product ( 1) The sample product (5) increases in this order. Therefore, as the performance of the actually measured product, the sample product (4) is the best, and the sample product (3), the sample product (2), the sample product (1), and the sample product (5) become worse in this order.

In contrast, the contact performance coefficient CC corresponding to the conductor compression ratio%, which is a simulation value, is also the sample product (4), sample product (3), sample product (2), sample product (1), sample product (5). ) In order. Therefore, similarly to the actual measurement product, the sample product (4) is the best from the contact performance coefficient CC that is a simulation value, and the sample product (3), the sample product (2), the sample product (1), and the sample product (5) It turns out that it gets worse in the order of). That is, it was found that the contact performance coefficient CC shown in Equation (3) is a value corresponding to the contact resistance R.

According to the contact performance coefficient calculation device 106 described above, a plurality of sample products can be obtained by calculating the contact performance coefficient CC, which is a simulation value, without actually making a plurality of sample products and actually measuring the contact resistance R. The magnitude of the contact resistance R can be compared. For this reason, it can support that anyone can perform the connection design of the terminal metal fitting 1 and the core wire 3 easily and in a short time without being influenced by a designer's experience.

Further, the above-described embodiments are merely representative forms of the present invention, and the present invention is not limited to the embodiments. That is, various modifications can be made without departing from the scope of the present invention.

This application is based on the Japanese patent application filed on February 20, 2008 (Japanese Patent Application No. 2008-038208) and the Japanese patent application filed on February 20, 2008 (Japanese Patent Application No. 2008-038209), and its contents Is incorporated herein by reference.

According to the present invention, since the crimping performance coefficient and the contact performance coefficient corresponding to the contact resistance can be calculated by simulation, anyone can design the connection between the terminal fitting and the core wire without being influenced by the designer's experience. Can be supported easily and in a short time.

Claims

A crimping performance coefficient calculating device for calculating a crimping performance coefficient according to a contact resistance between a crimping piece provided on a terminal fitting and a core wire crimped on the crimping piece,
A core wire model acquisition means for acquiring a core wire model obtained by dividing the core wire into a plurality of elements;
A caulking piece model obtaining means for obtaining a caulking piece model obtained by dividing the caulking piece into a plurality of elements;
Deformation calculation means for calculating displacement of each node constituting the core wire model and the caulking piece model after caulking the core wire with the caulking piece sandwiched between an upper die and a lower die; and
A node extracting unit that extracts a node that contacts the caulking piece model from the nodes on the outline of the core model after the caulking from the displacement of each node calculated by the deformation calculating unit;
A first distance between the node extracted by the node extraction unit and one of a pair of nodes adjacent to the node extracted by the node extraction unit among the nodes on the outline of the core model after the caulking First distance calculating means for obtaining
A second distance between the node extracted by the node extraction unit and the other of the pair of nodes adjacent to the node extracted by the node extraction unit among the nodes on the outline of the core model after the caulking Second distance calculating means for obtaining
Contact length calculating means for obtaining 1/2 of the sum of the first distance and the second distance as the contact length of the node extracted by the node extracting means;
A sum total calculating means for calculating a sum of the contact lengths obtained for all the nodes extracted by the node extracting means;
A crimping performance coefficient calculating unit that calculates a value obtained by dividing the sum of the volume resistivity of the core wire and the volume resistivity of the caulking piece by 8 times the total obtained by the total calculating unit, as the crimping performance coefficient;
A crimping performance coefficient calculation device comprising:
A crimping performance coefficient calculation method for calculating a crimping performance coefficient according to a contact resistance between a crimping piece provided on a terminal fitting and a core wire crimped on the crimping piece,
Obtaining a core wire model obtained by dividing the core wire into a plurality of elements and a caulking piece model obtained by dividing the caulking pieces into a plurality of elements;
Calculating the displacement of each node constituting the core wire model and the caulking piece model after the caulking piece is caulked between the upper die and the lower die by the finite element method; and
Extracting a node that contacts the caulking piece model from nodes on the outline of the core model after the caulking from the calculated displacement of each node;
Obtaining a first distance between the extracted node and one of a pair of nodes adjacent to the extracted node among the nodes on the contour of the core model after caulking;
Obtaining a second distance between the extracted node and the other of the pair of nodes adjacent to the extracted node among the nodes on the outline of the core model after the caulking;
Obtaining 1/2 of the sum of the first distance and the second distance as the contact length of the extracted node;
Determining the sum of the contact lengths determined for all the extracted nodes;
Calculating the value obtained by dividing the sum of the volume resistivity of the core wire and the volume resistivity of the caulking piece by 8 times the total obtained by the total calculation means as the crimping performance coefficient;
Are sequentially performed.
A contact performance coefficient calculation device that calculates a contact performance coefficient according to a contact resistance between a caulking piece provided on a terminal fitting and a core wire caulked on the caulking piece,
A core wire model acquisition means for acquiring a core wire model obtained by dividing the core wire into a plurality of elements;
A caulking piece model obtaining means for obtaining a caulking piece model obtained by dividing the caulking piece into a plurality of elements;
The core wire model after the core wire is caulked by the caulking piece sandwiched between the upper die and the lower die, the displacement of each node constituting the caulking piece model and the force acting on each node are calculated by the finite element method. Deformation calculation means;
A node extracting unit that extracts a node that contacts the caulking piece model from the nodes on the outline of the core model after the caulking from the displacement of each node calculated by the deformation calculating unit;
A first distance between the node extracted by the node extraction unit and one of a pair of nodes adjacent to the node extracted by the node extraction unit among the nodes on the outline of the core model after the caulking First distance calculating means for obtaining
A second distance between the node extracted by the node extraction unit and the other of the pair of nodes adjacent to the node extracted by the node extraction unit among the nodes on the outline of the core model after the caulking Second distance calculating means for obtaining
Contact length calculating means for obtaining 1/2 of the sum of the first distance and the second distance as the contact length of the node extracted by the node extracting means;
The sum of values obtained by multiplying the contact lengths obtained for all the nodes extracted by the node extracting means and the force that the nodes extracted by the node extracting means act on the caulking piece model is obtained. Contact performance coefficient calculating means for obtaining the reciprocal as the contact performance coefficient;
A contact performance coefficient calculation device comprising:
A contact performance coefficient calculation method for calculating a contact performance coefficient according to contact resistance between a crimped piece provided on a terminal fitting and a core wire crimped on the crimped piece,
Obtaining a core wire model obtained by dividing the core wire into a plurality of elements and a caulking piece model obtained by dividing the caulking pieces into a plurality of elements;
The core wire model after the core wire is caulked by the caulking piece sandwiched between the upper die and the lower die, the displacement of each node constituting the caulking piece model and the force acting on each node are calculated by the finite element method. Process,
Extracting a node that contacts the caulking piece model from nodes on the outline of the core model after the caulking from the calculated displacement of each node;
Obtaining a first distance between the extracted node and one of a pair of nodes adjacent to the extracted node among the nodes on the contour of the core model after caulking;
Obtaining a second distance between the extracted node and the other of the pair of nodes adjacent to the extracted node among the nodes on the outline of the core model after the caulking;
Obtaining 1/2 of the sum of the first distance and the second distance as the contact length of the extracted node;
The sum of values obtained by multiplying the contact lengths obtained for all the extracted nodes by the force acting on the caulking piece model by the extracted nodes is obtained, and the reciprocal of the sum is obtained as the contact performance coefficient. Process,
The contact performance coefficient calculation method characterized by performing sequentially.