JP2004139974A - Wiring design assisting method of wire-like structure, its device and its program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method, its device and its program to design the optimum cabling and configuration easily without depending on expertise of a designer. <P>SOLUTION: By providing a finite-element method with information regarding the constrained condition, material characteristics, and shape characteristics of a wire-like structure, the shape 35 of the wire-like structure is outputted which is predicted when forcible change is carried out so that the wire-like structure satisfies the constrained condition, the material characteristics, and the shape characteristics. Thus, by utilizing the finite-element method, without depending on the expertise of the designer, the predicted shape of the wire-like structure with always stable precision can be obtained. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a wiring design support method for a wire-like structure composed of a plurality of wire rods, an apparatus for the same, and a program therefor, and in particular, an optimal wiring design for a wire harness wired to a vehicle as a wire-like structure. The present invention relates to a method, an apparatus, and a program for supporting.

Usually, in a vehicle or the like, a plurality of electrical components are mounted, and as these wire members, a plurality of electric wires and communication lines are bundled by a binding member such as an insulation lock or a protective member such as a tape. Connected with a wire harness. As shown in FIG. 1, the wire harness 1 has connectors 2 a, 2 b, 2 c, and 2 d connected to electrical components and the like at each end. In addition, various clips 3a, 3b, 3c, and 3d are attached to the middle portion, and a branch point 4 is further provided. In addition, since each branch line of the wire harness 1 which comprises from each edge part to the branch point 4 is fundamentally different in the number and kind of each constituent line material, the thickness of each branch line, length, elasticity Also, the rigidity and the like are various. Conventionally, the wiring design of such a wire harness is often performed mainly by the intuition and experience of the designer.

Here, documents cited in the present specification are shown below.
B. "Matrix Finite Element Method" by Nath, published by Brain Book Publishing Co., Ltd., August 10, 1978, p. 7-15

The wire harness designed as described above is designed so that the coordinates of the fixed point to which the connector etc. are attached are temporarily satisfied, and each part of the wire harness has rigidity against bending and torsion, etc. It was difficult. That is, assembling as designed is often difficult or unrealistic. Therefore, in order to design the optimal wiring of the wiring harness, a high level of skill is required or a great deal of time is wasted due to trial and error.

Therefore, in view of the above-mentioned present situation, the present invention regards the wire-like structure as an elastic body and an elastic-plastic body and applies the finite element method, so that the optimum wiring can be easily made without depending on the skill level of the designer. It is an object of the present invention to provide a method for enabling design of a shape, an apparatus thereof, and a program thereof.

The wiring design support method for a wire-like structure according to claim 1, which has been made to solve the above-mentioned problem, is such that a wire-like structure composed of a plurality of wire rods is kept linear in a circular cross section. Considering an elastic body in which a plurality of beam elements are combined, using the finite element method, predicting and outputting the shape of the wire-like structure that satisfies a predetermined condition, and optimally wiring the wire-like structure A method for supporting design, wherein the wire-like structure is configured so as to satisfy the condition by applying information on the shape characteristics, material characteristics and constraint conditions of the wire-like structure as the predetermined condition to the finite element method. A predicted shape when the object is forcibly displaced is calculated, and the calculation result is output.

In addition, the wiring design support method for a wire-like structure according to claim 2, which has been made to solve the above-mentioned problems, maintains the linearity of a wire-like structure composed of a plurality of wire rods in a circular cross section. The wire-like structure is optimized by predicting and outputting the shape of the wire-like structure that satisfies a predetermined condition by using a finite element method, assuming that a plurality of beam elements are combined. The wire-like structure is supported on the basis of a predetermined bending radius of the wire-like structure set as an initial value, a restraint position, and a restraint direction with respect to the wire-like structure at the restraint position. The initial shape of the structure is calculated, conditions for the shape characteristics, material characteristics and constraint conditions of the wire-like structure are given to the initial shape, and the given shape is obtained using the finite element method. The calculated predicted shape when the wiring structure is forcibly displaced so as to satisfy the condition, and outputs the calculation result, characterized in that.

A wiring design support method for a wire-like structure according to claim 3, which is made to solve the above-described problem, is the wiring design support method according to claim 1 or 2, wherein the output predicted shape is Giving information on the change of the shape characteristic, the material characteristic and the constraint condition, and using the finite element method, recalculating the predicted shape when the wire-like structure is forcibly shifted, The calculation result is output again so that the optimum shape of the wire-like structure can be verified.

Moreover, the wiring design support method of the wire-like structure according to claim 4 made to solve the above-mentioned problem is the wiring design support method of the wire-like structure according to any one of claims 1 to 3. The wire-like structure is a wire harness wired to a vehicle, and the constraint condition is a coordinate of each vertex of the plurality of beam elements and a degree of freedom at each vertex, and the shape characteristic is the wire-like structure A cross-sectional area and a length of a beam element of a structure, and the material characteristics are a cross-sectional secondary moment, a cross-sectional secondary pole moment, a density, a longitudinal elastic modulus, and a transverse elastic modulus of the beam element, To do.

In addition, the wiring design support device for a wire-like structure according to claim 5, which has been made to solve the above-described problem, maintains the linearity of a wire-like structure composed of a plurality of wire rods in a circular cross section. The wire-like structure is optimized by predicting and outputting the shape of the wire-like structure that satisfies a predetermined condition by using a finite element method, assuming that a plurality of beam elements are combined. An apparatus for supporting a simple wiring design, wherein setting means for setting information on the shape characteristics, material characteristics and constraint conditions of the wire-like structure as the predetermined conditions, and applying the predetermined conditions to the finite element method. And calculating means for calculating a predicted shape when the wire-like structure is forcibly displaced so as to satisfy this condition, and output means for outputting the predicted shape calculated by the calculating means. The features.

In addition, the wiring design support device for a wire-like structure according to claim 6, which has been made to solve the above-described problem, maintains the linearity of a wire-like structure composed of a plurality of wire rods in a circular cross section. The wire-like structure is optimized by predicting and outputting the shape of the wire-like structure that satisfies a predetermined condition by using a finite element method, assuming that a plurality of beam elements are combined. An apparatus for supporting a simple wiring design, based on a predetermined bending radius of the wire-like structure set as an initial value, a restraint position, and a restraint direction with respect to the wire-like structure at the restraint position. A first calculating means for calculating an initial shape of the structure; a setting means for setting conditions relating to the shape characteristics, material characteristics and constraint conditions of the wire-like structure for the initial shape; Using a limit element method, a second calculation unit that calculates a predicted shape when the wire-like structure is forcibly shifted so as to satisfy the set condition is calculated by the second calculation unit. Output means for outputting the predicted shape.

The wire design support device for a wire-like structure according to claim 7, which has been made to solve the above problem, is the wiring design support device for a wire-like structure according to claim 5 or 6, wherein the output means For the predicted shape output in step 4, when giving the information on the change of the shape property, the material property and the constraint condition, when the wire-like structure is forcibly shifted using the finite element method Further, it is further characterized by further comprising verification means for recalculating the predicted shape and causing the output means to output the calculated result again to enable verification of the optimum shape of the wire-like structure.

The wiring design support program for a wire-like structure according to claim 8, which has been made in order to solve the above-mentioned problems, maintains the linearity of a wire-like structure composed of a plurality of wire rods in a circular cross section. The wire-like structure is optimized by predicting and outputting the shape of the wire-like structure that satisfies a predetermined condition by using a finite element method, assuming that a plurality of beam elements are combined. In order to support proper wiring design, a computer applies setting means for setting information on the shape characteristics, material characteristics and constraint conditions of the wire-like structure as the predetermined conditions, and applies the predetermined conditions to the finite element method. Calculating means for calculating a predicted shape when the wire-like structure is forcibly displaced so as to satisfy this condition, and output means for outputting the predicted shape calculated by the calculating means Function as, and wherein the.

In addition, a wiring design support program for a wire-like structure according to claim 9, which has been made to solve the above-mentioned problems, is a linear cross-section of a wire-like structure composed of a plurality of wire rods and maintains linearity. The wire-like structure is optimized by predicting and outputting the shape of the wire-like structure that satisfies a predetermined condition by using a finite element method, assuming that a plurality of beam elements are combined. In order to support an appropriate wiring design, a computer is used to determine the wire based on a predetermined bending radius of the wire-like structure set as an initial value, a restraint position, and a restraint direction with respect to the wire-like structure at the restraint position. A first calculating means for calculating an initial shape of the like structure, and a setting for setting conditions relating to the shape characteristics, material properties and constraint conditions of the wire-like structure for the initial shape; Means, using the finite element method, second calculation means for calculating a predicted shape when the wire-like structure is forcibly shifted so as to satisfy the set condition, calculated by the second calculation means Functioning as output means for outputting the predicted shape.

According to the invention of claim 1, claim 5 and claim 8, the finite element method is provided with information on the shape characteristics, material characteristics and restraint conditions of the wire-like structure, and the wire-like structure has these shape characteristics, The shape of the wire-like structure that is predicted when it is forcibly shifted to satisfy the material properties and constraint conditions is output.

Further, according to the inventions of claim 2, claim 6 and claim 9, first, the initial shape is calculated based on the restraining position, restraining direction and predetermined bending radius of the wire-like structure set as the initial value. The In addition, the initial shape is given information on the shape characteristics, material properties and restraint conditions of the wire-like structure, and the wire-like structure is forced to be changed to satisfy these shape characteristics, material properties and restraint conditions. The shape of the wire-like structure predicted at the time of output is output.

Further, according to the inventions of claim 3 and claim 7, the output predicted shape is given information on the change of the shape characteristic, material characteristic and constraint condition, and the finite element method is used. The predicted shape when the structure is forcibly shifted is calculated again, and the calculation result is output again, so that the optimum shape of the wire-like structure can be verified.

According to the invention of claim 4, the constraint condition is the coordinates of a plurality of nodes and the degree of freedom of constraint at each node, the shape characteristic is the cross-sectional area and length of each of the plurality of beam elements, and the material characteristics Is a cross-sectional secondary moment, a cross-sectional secondary pole moment, a density, a longitudinal elastic modulus, and a transverse elastic modulus of each of the plurality of beam elements.

According to the invention of claim 1, claim 5 and claim 8, the finite element method is provided with information on the shape characteristics, material characteristics and restraint conditions of the wire-like structure, and the wire-like structure has these shape characteristics, The shape of the wire-like structure that is predicted when it is forcibly shifted to satisfy the material properties and constraint conditions is output. By using the finite element method in this way, it is possible to always obtain a predicted shape of the wire-like structure with stable accuracy without depending on the skill level of the designer. Therefore, the optimal wiring design of the wire-like structure can be easily and accurately performed.

Further, according to the inventions of claim 2, claim 6 and claim 9, first, the initial shape is calculated based on the restraining position, restraining direction and predetermined bending radius of the wire-like structure set as the initial value. Thus, an approximate wire-like structure can be obtained immediately. In addition, the initial shape is given information on the shape characteristics, material properties and restraint conditions of the wire-like structure, and the wire-like structure is forced to be changed to satisfy these shape characteristics, material properties and restraint conditions. Since the shape of the wire-like structure predicted at the time is output, it is possible to always obtain the predicted shape of the wire-like structure with stable accuracy without depending on the skill level of the designer. Therefore, the optimal wiring design of the wire-like structure can be performed more easily and accurately.

Further, according to the inventions of claim 3 and claim 7, the output predicted shape is given information on the change of the shape characteristic, material characteristic and constraint condition, and the finite element method is used. The predicted shape when the structure is forcibly changed is calculated again, and the result of the calculation is output again, so that the optimal shape of the wire-like structure can be verified. Can be designed more accurately.

According to the invention of claim 4, the constraint condition is the coordinates of a plurality of nodes and the degree of freedom of constraint at each node, the shape characteristic is the cross-sectional area and length of each of the plurality of beam elements, and the material characteristics Is the secondary moment of section, secondary moment of section, density, longitudinal elastic modulus and transverse elastic modulus of each of the plurality of beam elements, all of which can be obtained in advance from the wire harness wired to the vehicle. Therefore, it is possible to examine a realistic and accurate route that assumes actual assembly work.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the overall shape of a wire harness as a wire-like structure to be designed and a typical support member will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram schematically showing the overall shape of a wire harness to be designed in an embodiment of the present invention. FIG. 2 is a diagram illustrating a relationship between a typical support member that supports the wire harness and a degree of freedom of restraint. As will be described later, the present embodiment supports the design by outputting a predicted shape by simulation for a wire harness as shown here.

The wire harness 1 to be designed in this embodiment has connectors 2a, 2b, 2c, and 2d connected to electrical components (not shown) at both ends as described above, and various clips 3a, 3b, 3c, and 3d are attached, and a branch point 4 is provided. Since each branch line of the wire harness 1 basically has a different number and type of constituent wire members, the thickness, length, elasticity, rigidity, and the like of each branch line are also different.

Each of the connectors 2a, 2b, 2c, and 2d is detachably fixed at a predetermined position according to the fixing position and the mounting direction of the mating connector on the electrical component side, and completely restrains the end of the wire harness. Each of the clips 3a, 3b, 3c, and 3d is completely or rotationally restricted at a predetermined position of the wire harness at a predetermined position such as a housing or a stay of the electrical component.

Here, I will explain the clip. The clip basically includes a long hole clip and a round hole clip. The round hole clip is also called a rotary clip, and is composed of a pedestal portion that holds the wire harness and a support leg that is inserted into a round hole-shaped attachment hole provided in a stay or the like. The round hole clip is rotatable around the Z axis (perpendicular to the attachment site).

On the other hand, the long hole clip is also called a fixed clip, and is composed of a pedestal portion that holds the wire harness and a support leg that is inserted into a long hole shaped mounting hole provided in a stay or the like. The cross-sectional shape of the support leg is a long hole shape that is substantially the same as the mounting hole. The long hole clip cannot rotate around the Z axis.

Furthermore, the long hole clip and the round hole clip include a corrugated long hole clip and a corrugated round hole clip that can rotate around the X axis (longitudinal direction of the wire harness). FIG. 2 shows the degree of freedom of restraint in each axial direction and around each axis of each clip.

2, the X axis, the Y axis, and the Z axis correspond to three orthogonal axes in the right-hand local coordinate system at each node (also referred to as a node) on the wire harness. For example, the Z axis coincides with the clip axis, but these determination methods can be appropriately changed depending on the function to be used. In the figure, the degree of freedom of constraint at the branch point is also shown for reference. In addition, although not shown here, the nodes on the wire harness arbitrarily set other than the constraint points are basically completely free. As described later, such a degree of freedom of constraint is set for each node prior to calculation of the predicted path, reaction force, and the like.

Next, with reference to FIG. 3 to FIG. 6, the assumption conditions, the theory used, and the basic formula used in this embodiment will be described. FIG. 3 (A) is a diagram showing the appearance of the wire harness, FIG. 3 (B) is a diagram showing a state where the wire harness of FIG. 3 (A) is discretized, and FIG. It is the figure which represented the wire harness of FIG. 3 (A) with the beam element and the node. FIG. 4 is a diagram for explaining the degree of freedom in the wire harness represented by beam elements and nodes. FIG. 5A is a diagram illustrating the wire harness with three beam elements, and FIG. 5B is a diagram illustrating a state in which the three beam elements in FIG. 5A are coupled. FIG. 6A is a diagram showing a state of measuring the cross-sectional secondary moment and the longitudinal elastic modulus, and FIG. 6B is a diagram showing a state of measuring the cross-sectional secondary moment and the longitudinal elastic modulus. is there.

First, in the present embodiment, the following assumptions are made when the finite element method is used for designing a wire harness.
(1). The wire harness is assumed to be an elastic body.
(2). Assume that the wire harness is a combination of beam elements.
(3). Assume that each beam element is linear.
(4). Assume that the cross section of the wire harness is circular.
In this embodiment, by making such an assumption, it is possible to apply the finite element method to the wire harness, which has not been made conventionally.

In this embodiment, first, the wire harness is discretized. That is, as shown in FIG. 3A, the wire harness 1 in which a plurality of electric wires 11 are bundled by a protective member such as a tape 12 can be regarded as a continuous body. Next, as shown in FIG. 3B, such a wire harness 1 is divided (discretized) into several beam elements C1, C2, C3,. That is, since the wire harness is like a single rope, it can be considered that a finite number of beam elements are connected.

Therefore, as shown in FIG. 3C, the wire harness can be represented as a plurality of beam elements C1, C2, C3,... Coupled by a plurality of nodes N1, N2, N3,. The characteristic values required for the beam elements are as follows.
Length l (see Fig. 3 (B))
Cross section A (See Fig. 3 (B))
Sectional secondary moment I
Cross section secondary pole moment J
Density ρ
Longitudinal elastic modulus E
Transverse elastic modulus G
As will be described later, in this specification, the length l and the cross-sectional area A are the shape characteristics, and the cross-sectional secondary moment I, the cross-sectional secondary pole moment J, the density ρ, the longitudinal elastic modulus E, and the transverse elastic modulus G are the materials. It is characteristic.

As shown in FIG. 4, each beam element C (C1, C2, C3,...) Has two nodes α and β. In the three-dimensional space, the node α has three translation components and three rotation components, and thus has a total of six degrees of freedom. The same applies to the node β. Therefore, the beam element C has 12 degrees of freedom.

In the figure,
F _xi : Force of the i-th element in the xi-axis direction F _yi : Force of the i-th element in the yi-axis direction F _zi : Force of the i-th element in the zi-axis direction M _xi : Moment of the i-th element around the xi axis M _yi : Moment about the yi axis of the i-th element M _zi : Moment about the zi-axis of the i-th element U _xi : Displacement of the i-th element in the xi-axis direction U _yi : Displacement of the i-th element in the yi-axis direction U _zi : i _Xi : displacement of the i-th element in the zi-axis direction θ _xi : angular displacement of the i-th element in the xi-axis direction θ _yi : angular displacement of the i-th element in the yi-axis direction θ _zi : angular displacement of the i-th element in the zi-axis direction α And β is the right node.

By the way, it is known that the displacement of a structure due to a static force that does not vibrate satisfies the hook law expressed by the following formula (1) within an elastic range.
Kx = F (1)
Here, K: spring constant, x: displacement, F: force.

Also, it is known that Hook's law is similarly established for the beam element C shown in FIG. However, since the beam element C has 12 degrees of freedom as described above, the relationship between force and displacement is expressed by a matrix of 12 rows and 12 columns and a vector of 12 rows, as shown in the following equation (2). Can be expressed.

Here, the conformance condition and the balance condition will be described. Here, for the sake of simplicity, as shown in FIG. 5A, the wire harness is represented by three beam elements C1, C2, and C3. In this case, the displacements of the node 1β of the beam element C1 and the node 2α of the beam element C2 are equal, and the forces applied to these nodes are also balanced. Similarly, the displacements of the node 2β of the beam element C2 and the node 3α of the beam element C3 are also equal, and the forces applied to these nodes are also balanced. Therefore, the beam elements C1 and C2 and the beam elements C2 and C3 can be coupled as shown in FIG. 5B by satisfying the condition of the balance between the continuity of the displacement and the force.

In the figure,
F _xi : Force of the i-th element in the xi-axis direction F _yi : Force of the i-th element in the yi-axis direction F _zi : Force of the i-th element in the zi-axis direction M _xi : Moment of the i-th element around the xi axis M _yi : Moment about the yi axis of the i-th element M _zi : Moment about the zi-axis of the i-th element U _xi : Displacement of the i-th element in the xi-axis direction U _yi : Displacement of the i-th element in the yi-axis direction U _zi : i The displacement of the number element in the zi-axis direction θ _xi : The angular displacement of the i-th element in the xi-axis direction θ _yi : The angular displacement of the i-th element in the yi-axis direction θ _zi : The angular displacement of the i-th element in the zi-axis direction
i = 1α, 1β, 2α, 2β, 3α, 3β.

Then, when the continuity of the displacement and the balance of force in the beam elements C1, C2, and C3 shown in FIG. 5B are shown in the same form as the above equation (2), the following equation (3) is obtained. Become.

Here, the matrixes M1, M2 and M3 of 12 rows and 12 columns in the formula (3) are the same as those shown in the formula (2). However, the portions M12 and M23 where the matrices M1, M2 and M3 are overlapped are the components of each matrix added together.

Note that four or more beam elements can be handled in the same manner. In this manner, a mathematical model of a wire harness that is divided into an arbitrary number of beam elements can be created.

By the way, when the above formula (3) is simply expressed,
[K] {x} = {F} (4)
It becomes.
Therefore, for example, assuming that the clip is attached to each node and the force applied to the clip is determined in advance, the path, that is, the wire harness is obtained by obtaining the displacement vector {x} based on the above equation (4). Can be calculated. Conversely, if the path is determined, the force vector {F} at each node can be calculated. Based on such a basic concept, in the present embodiment, the predicted path and strain, stress, reaction force, moment, etc. of the wire harness are calculated. The unknowns in the displacement vector {x} and the force vector {F} can be determined by using a known Newton-Raphson method, arc length method, or the like.

The general matrix finite element method as described above is also shown in Non-Patent Document 1, for example.

Here, in the present embodiment, an example of how to obtain each characteristic value necessary for the beam element will be described below. First, the length l, the cross-sectional area A, and the density ρ can be obtained by simple calculation after a target wire harness is created and measured using a caliper, a measure, a weight scale, or the like.

The longitudinal elastic modulus E can be expressed by the following equation (5) when the measurement method shown in FIG.
^{E = FL 3 / 3XI ... (} 5)
Moreover, since the wire harness is assumed to have a circular cross section as described above, the cross sectional secondary moment I can be expressed by the following equation (6).
^{I = πD 4/64 ... (} 6)
Therefore,
E = 64FL ³ / 3XπD ⁴ (7)
It becomes.
In this measurement,
E = (F / X) × (64L ³ / 3πD ⁴ )
And the relationship between F and x may be measured.

On the other hand, the transverse elastic modulus G can be expressed by the following equation (8) when the measurement method shown in FIG.
G = (TL / θJ) × 2 (8)
The cross-section secondary pole moment J can be expressed by the following equation (9) because the wire harness is assumed to have a circular cross section.
^{J = πD 4/32 ... (} 9)
The twisting force is
T = FS (10)
It becomes.
Therefore,
G = (32FSL / θπD ⁴ ) × 2 = (F / θ) (32SL / πD ⁴ ) × 2 (11)
Therefore, the relationship between F and θ may be measured.

The above measurement method is an example, and each value may be obtained by a method other than the above measurement example. Alternatively, a representative wire harness may be measured in advance and stored in a database, and this may be used as appropriate.

Next, a hardware configuration according to this embodiment that calculates and outputs the shape of the wire harness according to the processing procedure described later using the above theory and basic formula will be described. FIG. 7 is a block configuration diagram showing a hardware configuration according to the present embodiment.

As shown in FIG. 7, in this embodiment, the microcomputer 21, the input device 22, the display device 23, the printing device 24, the storage device 25, the communication interface 26, and the read / write device 27 are configured. A computer is used. The microcomputer 21 includes a CPU 21a (central processing unit), a ROM 21b that stores a boot program and the like, and a RAM 21c that temporarily stores various processing results. The input device 22 is a keyboard, mouse or the like for inputting the above values, the display device 23 is an LCD or CRT for displaying the processing results, and the printing device 24 is a printer for printing the processing results.

The storage device 25 is an installed wiring design support program 29a and a hard disk drive for storing the processing results of the program 29a. The communication interface 26 is connected to an external device using, for example, the Internet or a LAN line. A modem board for data communication. The read / write device 27 reads a wiring design support program 29a (corresponding to claims 8 and 9) according to the present invention stored in a recording medium 29 such as a CD-ROM or DVD-ROM, or this wiring design support program. This is a device for writing the calculation result by 29a into the recording medium 29. Each of these components is connected via an internal bus 28.

The microcomputer 21 installs the wiring design support program 29a read by the read / write device 27 in the storage device 25. When the power is turned on, the microcomputer 21 is activated in accordance with the boot program stored in the ROM 21b and starts up the installed wiring design support program 29a. The microcomputer 21 performs processing related to the wiring design support of the present invention according to the wiring design support program 29a, outputs the processing result from the display device 23 and the printing device 24, and stores the processing result in the storage device 25 and the recording device. It is stored in the medium 29. The wiring design support program 29a can be installed in another personal computer or the like having the above basic configuration. After installation, the computer is made to function as a wiring design support device (corresponding to claims 5, 6 and 7). . The wiring design support program 29a may be provided not only via the recording medium 29 but also via a communication line such as the Internet or a LAN.

Furthermore, the processing procedure according to the present embodiment will be described with reference to FIGS. FIG. 8 is a flowchart illustrating a processing procedure according to the present embodiment performed using the hardware configuration illustrated in FIG. 7. FIG. 9A to FIG. 9D are diagrams illustrating output results in the course of each process shown in FIG.

First, an initial shape is calculated in step S2 based on the initial value set in step S1 shown in FIG. 8, and the calculated initial shape 33 is output in step S3 as shown in FIG. 9B. The As initial values for obtaining this initial shape 33, for example, as shown in FIG. 9A, restraint positions 31a and 31z to which connectors at both ends of the wire harness to be designed are attached, restraint directions 32a and 32z, and The minimum bending radius or the like of this wire harness is used, and the initial shape 33 that is a curve having a bending radius larger than the minimum bending radius or the like passes through the constraint position in the constraint direction. You may make it also use the coordinate of a clip to attach, a restraint direction, etc. Note that the minimum bending radius is a value that depends on the material characteristics of the wire harness, and it may be assumed that the normal bending force of the operator who performs the assembly work of the wire harness cannot be bent to the minimum bending radius. Therefore, it is more practical to obtain the initial shape 33 by using a bending radius that can be bent with the normal force of the operator, rather than the minimum bending radius. The bending radius is slightly larger than the minimum bending radius depending on the material characteristics, and can be obtained in advance by a test or the like for each typical wire harness. The “bending radius” in the claims includes both a bending radius depending on the material characteristics and the operator's force. Further, the restraining direction is a specific direction in which the direction in which the wire harness extends from the restraining position is restricted or restrained by the support member. The method for obtaining the initial shape 33 is not limited to such a method, and other methods may be used. The shape calculation process is performed by the microcomputer 21, and the input device 22 is used to set the initial value, and the display device 23 is used to output the initial shape. Also in the subsequent processing, the shape calculation processing is performed by the microcomputer 21, the input device 22 is used for setting each value, and the display device 23 is used for outputting the calculation result. Step S2 and related hardware correspond to the first calculation means in the claims.

Next, in step S4, the nodes 31a to 31z as shown in FIG. 9C are assigned to the output initial shape 33, and the nodes 31a to 31z are forcibly displaced. Each constraint condition is set. As the constraint condition, a constraint type (complete constraint, rotational constraint, complete freedom, etc.) as shown in FIG. 2 for each node 31a to 31z, local coordinates, and the like are set. These constraint conditions correspond to the displacement destination. As each of the nodes 31a to 31z, a part to which a support member such as a connector or a clip is attached is assigned. In addition, as shown in FIG. 2, support member names such as connectors and clips may be used for setting the constraint type. Each value set here relates to each element in the displacement vector {x} in the above equation (3).

At the same time, in step S4, the shape characteristics and material characteristics of the predicted wire harness are also set. The length l and the cross-sectional area A are set as the shape characteristics, and the secondary moment I, the secondary cross-pole moment J, the density ρ, the longitudinal elastic modulus E, and the transverse elastic modulus G are set as the material characteristics. . For these, values measured or calculated in advance as described above are used. The value set here relates to each element in the stiffness matrix [K] in the above equation (3). Step S4 and related hardware correspond to the setting means in the claims.

When the setting of each value is completed, the process proceeds to step S5, and the currently displayed path shape is deleted. Next, in step S6, a finite element method is applied to calculate a new predicted shape. That is, in step S6, each value set in step S4 is applied to the above equation (3), and each unknown in the above equation (3) is calculated. Specifically, when the unknown number of the displacement vector {x} in Equation (3) is calculated, a new predicted shape of the wire harness is obtained. Step S5 and related hardware correspond to the calculation means and the second calculation means in the claims.

Next, in step S7, as shown in FIG. 9D, the calculated new predicted shape 35 is displayed. It should be noted that the nodes 31b ', 31c', 31d ', and 31e' of the new predicted shape 35 shown in FIG. 9D are respectively connected to the nodes 31b, 31c, 31c in the initial shape 33 shown in FIG. It corresponds to 31d and 31e. Here, the positions of the nodes 31a and 31z are not moved, and the other nodes are forcibly displaced. Step S7 and related hardware correspond to output means of claims. The output of the claims is not limited to the display by the display device 23, and includes printing by the printing device 24 and the like.

Next, in step S8, it is determined whether or not the set value has been changed. For example, as shown in FIG. 9E, if it is determined that the new predicted shape 35 interferes with the obstacle 36 caused by various electrical components or stays as a result of the forced displacement, for example, a new The bending radius, the position to be forcibly displaced, and the like are reset using the input device 22 and the like. The elements to be reset and changed are not limited to these, and may be other elements in the formula (3). If it is determined that the set value has been changed, the process returns to step S5 to calculate the next new predicted shape (Y in step S8).

When returning to step S5 to step S7, the next new predicted shape is calculated and displayed. Such a verification process is repeated, and for example, a predicted shape 37 that satisfies the given condition is displayed while avoiding the obstacle 36 as shown in FIG. When a predicted shape that satisfies the predetermined set value is obtained, the series of processes is terminated (N in step S8). Steps S8 and S5 to S7 correspond to verification means in claims.

Thus, according to the present embodiment, the predicted shape of a wire-like structure such as a wire harness with stable accuracy can always be acquired without depending on the skill level of the designer. Therefore, the optimal wiring design of the wire-like structure can be easily and accurately performed. In particular, according to the present embodiment, the present invention can be applied to a wire harness that changes thickness and rigidity, and a wire harness having a branch point, which has conventionally been difficult to design accurately. In addition, the present embodiment has a great influence on the path shape of the wire harness, and is also useful when considering the optimum path shape by arbitrarily changing the constraint point, the constraint direction, etc., which are the main points of the design. .

It should be noted that the method and apparatus of the present invention are not limited to a wire harness wired in a vehicle, but can be similarly applied to a wire-like structure wired indoors.

It is a figure which shows roughly the whole shape of the wire harness used as design object in embodiment of this invention. It is a figure which shows the relationship between the typical support member which supports a wire harness, and a restraint freedom degree. FIG. 3 (A) is a diagram showing the appearance of the wire harness, FIG. 3 (B) is a diagram showing a state where the wire harness of FIG. 3 (A) is discretized, and FIG. It is the figure which represented the wire harness of FIG. 3 (A) with the beam element and the node. It is a figure for demonstrating the freedom degree in the wire harness represented with the beam element and the node. FIG. 5A is a diagram illustrating the wire harness with three beam elements, and FIG. 5B is a diagram illustrating a state in which the three beam elements in FIG. 5A are coupled. FIG. 6A is a diagram illustrating a state in which the cross-sectional secondary moment and the longitudinal elastic modulus are measured, and FIG. 6B is a diagram illustrating a state in which the cross-sectional secondary moment and the longitudinal elastic modulus are measured. It is a block block diagram which shows an example of the hardware constitutions concerning this embodiment. It is a flowchart which shows the process sequence which concerns on this embodiment. FIG. 9A to FIG. 9F are diagrams illustrating output results in the course of each process shown in FIG.

Explanation of symbols

1 Wire harness (wire-like structure)
2a, 2b, 2c, 2d connector 3a, 3b, 3c, 3d clip 4 branch point 21 microcomputer 22 input device 23 display device 24 printing device 25 storage device 26 communication interface 27 read / write device 28 internal bus C1 to C7 beam element N1 N8 nodes

Claims (9)

A wire-like structure composed of a plurality of wire rods is regarded as an elastic body in which a plurality of beam elements having a circular cross-section and maintained linearity are used, and a finite element method is used to satisfy a predetermined condition. By predicting and outputting the shape of the wire-like structure, the method supports the optimal wiring design of the wire-like structure,
Prediction when the wire-like structure is forcibly displaced so as to satisfy this condition by applying information about the shape characteristics, material characteristics and constraint conditions of the wire-like structure as the predetermined condition to the finite element method. Calculate the shape and output this calculation result.
A wiring design support method for a wire-like structure. A wire-like structure composed of a plurality of wire rods is regarded as an elastic body in which a plurality of beam elements having a circular cross-section and maintained linearity are used, and a finite element method is used to satisfy a predetermined condition. By predicting and outputting the shape of the wire-like structure, the method supports the optimal wiring design of the wire-like structure,
Based on a predetermined bending radius of the wire-like structure set as an initial value, a restraining position, and a restraining direction with respect to the wire-like structure at the restraining position, an initial shape of the wire-like structure is calculated, and this initial shape is calculated. Gives the conditions regarding the shape characteristics, material characteristics and constraint conditions of the wire-like structure to the shape, and forcibly shifts the wire-like structure to satisfy the given conditions using the finite element method. Calculate the predicted shape at the time of output, and output this calculation result,
A wiring design support method for a wire-like structure. In the wiring design support method according to claim 1 or 2,
For the predicted shape that is output, information on the change in the shape property, the material property, and the constraint condition is given, and the wire-like structure is forcibly shifted using the finite element method Recalculate the shape and output the calculation result again, making it possible to verify the optimal shape of the wire-like structure,
A wiring design support method for a wire-like structure. In the wiring design support method of the wire-like structure according to any one of claims 1 to 3,
The wire-like structure is a wire harness wired to a vehicle,
The constraint condition is the coordinates of each vertex of the plurality of beam elements and the degree of freedom at each vertex,
The shape characteristic is a cross-sectional area and a length of a beam element of the wire-like structure, and
The material properties are a cross-sectional secondary moment, a cross-sectional secondary moment, a density, a longitudinal elastic modulus, and a transverse elastic modulus of the beam element.
A wiring design support method for a wire-like structure. A wire-like structure composed of a plurality of wire rods is regarded as an elastic body in which a plurality of beam elements having a circular cross-section and maintained linearity are used, and a finite element method is used to satisfy a predetermined condition. By predicting and outputting the shape of the wire-like structure, the device supports the optimal wiring design of the wire-like structure,
Setting means for setting information on the shape characteristics, material characteristics, and constraint conditions of the wire-like structure as the predetermined conditions;
Applying the predetermined condition to the finite element method, calculating means for calculating a predicted shape when the wire-like structure is forcibly displaced so as to satisfy this condition;
Output means for outputting the predicted shape calculated by the calculation means;
A wiring design support device for a wire-like structure characterized by comprising: A wire-like structure composed of a plurality of wire rods is regarded as an elastic body in which a plurality of beam elements having a circular cross-section and maintained linearity are used, and a finite element method is used to satisfy a predetermined condition. By predicting and outputting the shape of the wire-like structure, the device supports the optimal wiring design of the wire-like structure,
A first calculation for calculating an initial shape of the wire-like structure based on a predetermined bending radius of the wire-like structure set as an initial value, a restraining position, and a restraining direction with respect to the wire-like structure at the restraining position. Means,
Setting means for setting conditions regarding the shape characteristics, material characteristics, and constraint conditions of the wire-like structure with respect to the initial shape;
Using the finite element method, a second calculation means for calculating a predicted shape when the wire-like structure is forcibly shifted so as to satisfy the set condition;
Output means for outputting the predicted shape calculated by the second calculation means;
A wiring design support device for a wire-like structure characterized by comprising: In the wiring design support device for the wire-like structure according to claim 5 or 6,
For the predicted shape output by the output means, information on the change of the shape property, the material property and the constraint condition is given, and the wire-like structure is forcibly shifted using the finite element method. Recalculating the predicted shape at the time of letting it, and outputting the calculation result again to the output means, a verification means that makes it possible to verify the optimal shape of the wire-like structure,
A wiring design support device for a wire-like structure, further comprising: A wire-like structure composed of a plurality of wire rods is regarded as an elastic body in which a plurality of beam elements having a circular cross-section and maintained linearity are used, and a finite element method is used to satisfy a predetermined condition. In order to support optimal wiring design of the wire-like structure by predicting and outputting the shape of the wire-like structure,
Setting means for setting information on the shape characteristics, material characteristics and restraint conditions of the wire-like structure as the predetermined condition;
Applying the predetermined condition to the finite element method, calculating means for calculating a predicted shape when the wire-like structure is forcibly displaced so as to satisfy this condition,
Function as output means for outputting the predicted shape calculated by the calculation means;
A wiring design support program for wire-like structures. A wire-like structure composed of a plurality of wire rods is regarded as an elastic body in which a plurality of beam elements having a circular cross-section and maintained linearity are used, and a finite element method is used to satisfy a predetermined condition. In order to support optimal wiring design of the wire-like structure by predicting and outputting the shape of the wire-like structure,
A first calculation for calculating an initial shape of the wire-like structure based on a predetermined bending radius of the wire-like structure set as an initial value, a restraining position, and a restraining direction with respect to the wire-like structure at the restraining position. means,
Setting means for setting conditions regarding the shape characteristics, material characteristics and constraint conditions of the wire-like structure with respect to the initial shape;
Using the finite element method, a second calculation means for calculating a predicted shape when the wire-like structure is forcibly shifted so as to satisfy the set condition;
Function as output means for outputting the predicted shape calculated by the second calculation means;
A wiring design support program for wire-like structures.

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