WO2024166729A1

WO2024166729A1 - Analysis method, analysis device, and analysis program

Info

Publication number: WO2024166729A1
Application number: PCT/JP2024/002650
Authority: WO
Inventors: 秀雅伊藤; 洋介川井; 克信菊池; 和夫長澤; 大海橋本
Original assignee: 日本発條株式会社
Priority date: 2023-02-06
Filing date: 2024-01-29
Publication date: 2024-08-15

Abstract

The present invention obtains an analysis method, an analysis device, and an analysis program with which it is possible to carry out sewing simulation analysis for members being sewn in a calculation state that is stabilized by preventing the members being sewn from being turned up.　This analysis method involves carrying out a simulation of sewing steps, the analysis method comprising: a first step for folding seam allowances (46) in the same direction at respective prescribed seal allowance widths (D), the seam allowances (46) respectively being part of an end section (45A) of a first member being sewn (44A) and an end section (45B) of a second member being sewn (44B); a second step for securing the seam allowances (46) in the folded state; and a third step for securing together end sections (47A, 47B) of the first member being sewn (44A) and the second member being sewn (44B), in a manner corresponding to final stitching, in the state where the seam allowances are secured (46).

Description

Analysis method, analysis device, and analysis program

This disclosure relates to an analysis method, an analysis device, and an analysis program.

Patent Publication No. 6180675 discloses that a simulation sheet simulating the sewing process of a product such as an automobile seat trim can be used to determine whether or not wrinkles occur during sewing, and what causes wrinkles when they do occur. It also discloses that the joining position of the first and second fabrics, the seam width, and the sewing pitch can be specified so that the change in stiffness of the fabric around the sewing line caused by folding the seam can be expressed, and that the seam can be folded by applying loads in opposite directions to the sewing line and the edges of the first and second fabrics on the side of the sewing line.

In the invention described in Patent Document 1, the first and second fabrics are joined by a spring element, and then the seam is folded. However, if the first and second fabrics are joined first, there is a risk that the ends of the seam will collide and turn up. If the seam turns up, the calculation state of the analysis may become unstable.

The present disclosure takes into consideration the above facts and aims to provide an analysis method, analysis device, and analysis program that can perform sewing simulation analysis of a sewn material under stable calculation conditions by preventing the sewn material from turning over.

The analysis method of the first aspect of the present disclosure includes a first step of folding the seam at the end of a first sewn member and the end of a second sewn member in the same direction with a predetermined seam width, a second step of fixing the seam in the folded state, and a third step of fixing the ends of the first sewn member and the second sewn member with the fixed seam to each other in a manner equivalent to a lock stitch, and performs a simulation of the sewing process.

In the analysis method of the first aspect of the present disclosure, the seam allowance is folded in the first step, and the folded seam allowance is fixed in the second step. Furthermore, in the third step, the ends of the first sewn member and the second sewn member with the seam allowance fixed are fixed together in a manner equivalent to a lock stitch. Therefore, since the seam allowance is folded and fixed first during sewing, it is possible to prevent the sewn member from turning over when the ends of the first sewn member and the second sewn member are fixed together in a manner equivalent to a lock stitch. By preventing the sewn member from turning over in this way, a sewing simulation analysis of the sewn member can be performed under stable calculation conditions.

The analysis method of the second aspect of the present disclosure is the same as that of the first aspect, and the second step fixes the first sewn member and the second sewn member at a location that is a predetermined distance away from each end of the first sewn member and the second sewn member in a folded state.

In the analysis method of the second aspect of the present disclosure, the first sewn material and the second sewn material are fixed at points that are a predetermined distance away from each end of the material when the seam is folded. Therefore, the points that will become stitches when the sewn material is actually sewn are fixed, which further improves the analysis accuracy of the sewing simulation.

The analysis method of the third aspect of the present disclosure is a method in which, in the configuration of the first or second aspect, at least one of the fixing in the second step and the fixing in the third step is performed by compressing a spring element.

In the analysis method of the third aspect of the present disclosure, the sewn material can be fixed by compressing the spring element, so that fixation equivalent to actual sewing can be easily achieved in the sewing simulation.

The analysis method of the fourth aspect of the present disclosure is any one of the first to third aspects, in which the first sewn member and the second sewn member are the surface of a seat.

In the analysis method of the fourth aspect of the present disclosure, the first sewn member and the second sewn member are the seat skin, and therefore curling of the seat skin can be prevented. Preventing curling of the seat skin in this way allows a simulation analysis of the sewing process of the seat skin to be performed in a stable calculation state.

The analysis method of the fifth aspect of the present disclosure is the same as that of the fourth aspect, except that the seat is a vehicle seat.

In the analysis method of the fifth aspect of the present disclosure, the first sewn member and the second sewn member are the upholstery of the vehicle seat, and therefore, it is possible to prevent the upholstery of the vehicle seat from turning over. By preventing the upholstery of the vehicle seat from turning over in this way, it is possible to perform a simulation analysis of the sewing process of the upholstery of the vehicle seat in a stable calculation state.

The analysis device of the sixth aspect of the present disclosure includes a first process unit that folds the seam at a predetermined seam width in the same direction at the end of a first sewn member and the end of a second sewn member, a second process unit that fixes the seam in the folded state, and a third process unit that fixes the ends of the first sewn member and the second sewn member together with the fixed seam in a manner equivalent to a lock stitch, and performs a simulation of the sewing process.

In the analysis device of the sixth aspect of the present disclosure, the seam allowance is folded in the first process section, and the folded seam allowance is fixed in the second process section. Furthermore, in the third process section, the ends of the first sewn member and the second sewn member with the seam allowance fixed are fixed together in a manner equivalent to a lock stitch. Therefore, since the seam allowance is folded and fixed first during sewing, it is possible to prevent the sewn member from turning over when the ends of the first sewn member and the second sewn member are fixed together in a manner equivalent to a lock stitch. By preventing the sewn member from turning over in this way, a sewing simulation analysis of the sewn member can be performed in a stable calculation state.

The analysis program of the seventh aspect of the present disclosure causes a computer to function as a first process unit that folds the seam at the end of a first sewn member and the end of a second sewn member in the same direction with a predetermined seam width, a second process unit that fixes the seam in the folded state, and a third process unit that fixes the ends of the first sewn member and the second sewn member together with the fixed seam in a manner equivalent to a lock stitch, and performs a simulation of the sewing process.

In the analysis program of the seventh aspect of the present disclosure, the computer functions as a first process unit that folds the seam allowance and a second process unit that fixes the seam allowance in the folded state. The computer also functions as a third process unit that fixes the ends of the first sewn member and the second sewn member with the seam allowance fixed together in a manner equivalent to a lock stitch. Therefore, since the seam allowance is folded and fixed first during sewing, it is possible to prevent the sewn member from turning over when the ends of the first sewn member and the second sewn member are fixed together in a manner equivalent to a lock stitch. By preventing the sewn member from turning over in this way, a sewing simulation analysis of the sewn member can be performed in a stable calculation state.

As described above, the analysis method, analysis device, and analysis program disclosed herein have the excellent effect of preventing the sewn material from turning over, thereby enabling sewing simulation analysis of the sewn material to be performed under stable calculation conditions.

1 is a block diagram showing a hardware configuration of an analysis system including an analysis device according to an embodiment of the present disclosure. 1 is a block diagram showing a functional configuration of an analysis device according to an embodiment of the present disclosure. 1 is a simplified perspective view showing a cushion sheet according to an embodiment of the present disclosure, as viewed obliquely from above; FIG. 11 is an explanatory diagram for explaining stitches. FIG. 11 is an explanatory diagram for explaining stitches. 1A to 1C are diagrams for explaining a sewing method according to an embodiment of the present disclosure. FIG. 6 is a diagram showing an analysis result of a model generated by the sewing method of FIG. 5 . 1 is a flowchart illustrating an example of a series of processes of an analysis method according to an embodiment of the present disclosure. 1A to 1C are diagrams for explaining a conventional sewing method. FIG. 9 is a diagram showing an analysis result of a model generated by the conventional sewing method of FIG. 8 .

Below, an analysis system 10 including an analysis device 20 according to one embodiment of the present disclosure will be described with reference to the attached drawings. FIG. 1 is a block diagram showing the hardware configuration of the analysis system 10 including the analysis device 20. As shown in FIG. 1, the analysis system 10 of this embodiment includes the analysis device 20, a display unit 30, and an input unit 32.

As shown in FIG. 1, the analysis device 20 includes a CPU (Central Processing Unit: processor) 20A, a ROM (Read Only Memory) 20B, a RAM (Random Access Memory) 20C, storage 20D, a communication interface (communication I/F) 20E, and an input/output interface (input/output I/F) 20F. Each component is connected to each other so that they can communicate with each other via a bus 20G.

CPU 20A is a central processing unit that executes various programs and controls each part. That is, CPU 20A reads programs from ROM 20B or storage 20D, and executes the programs using RAM 20C as a working area. CPU 20A controls each of the above components and performs various calculation processes according to the programs recorded in ROM 20B or storage 20D.

ROM 20B stores various programs and various data. RAM 20C temporarily stores programs or data as a working area. Storage 20D is configured with a HDD (Hard Disk Drive) or SSD (Solid State Drive) and stores various programs including an operating system and various data. In this embodiment, ROM 20B or storage 20D stores an analysis program for performing analysis processing, and various data such as analysis conditions.

The communication I/F 20E is an interface that allows the analysis device 20 to communicate with a server and other devices (not shown), and uses standards such as Ethernet (registered trademark), LTE, FDDI, and Wi-Fi (registered trademark).

The input/output I/F 20F is connected to a display unit 30 and an input unit 32. The display unit 30 is configured, for example, as a liquid crystal display, and displays the analysis model and analysis results. The display unit 30 may be configured as a touch panel and may also be used as the input unit 32. The input unit 32 is equipped with a mouse, keyboard, etc., and is used to input various settings by the user, such as analysis conditions.

Analysis device 20 uses the above hardware resources to realize various functions. The functional configuration realized by analysis device 20 will be described with reference to FIG. 2. FIG. 2 is a block diagram showing the functional configuration of analysis device 20.

As shown in FIG. 2, the analysis device 20 is configured to include, as its functional components, a first process unit 22, a second process unit 24, a third process unit 26, and an analysis unit 28. Each functional component is realized by the CPU 20A reading and executing an analysis program stored in the ROM 20B or storage 20D.

First, the cushion seat 40 used as the analysis model in this embodiment will be described. The cushion seat 40 is an analysis model of a member of a vehicle seat (not shown) that supports the buttocks and thighs of a seated occupant. Figure 3 is a simplified perspective view of the cushion seat 40 as viewed diagonally from above. Note that in the following figures, the arrow FR indicates the front side of the seat, the arrow UP indicates the upper side of the seat, and the arrow W indicates the width direction of the seat.

As shown in FIG. 3, the cushion sheet 40 includes a cushion pad 41 and a skin 44 as analytical models. Although not shown, the cushion sheet 40 also includes a cushion frame as an analytical model of the skeletal members. The cushion sheet 40 includes a cushion frame covered with a cushion pad 41, which is, for example, a cushioning material. The surface of the cushion pad 41 is covered with a skin 44. The cushion pad 41 covered with the skin 44 is the component on which the occupant sits.

As shown in FIG. 3, in this embodiment, the skin 44 is constructed by sewing together multiple skin pieces. Note that "sewing" in the analytical model does not actually mean sewing together with thread, but rather, as an example, means arranging spring elements between the mesh nodes of two analytical models and fixing them at a fixed interval by shrinking the spring elements. In this embodiment, the skin 44 comprises upper skin 44A and side skin 44B on each of the left and right sides, a front skin 44C, and a rear skin 44D as skin pieces. FIGS. 4A and 4B are explanatory diagrams for explaining stitches. In this embodiment, "stitches" refer to the seams that appear on the surface of the skin.

Now, the actual sewing method will be described. Specifically, as shown in FIG. 4A, as an example, two actual (not analytical model) skin pieces 145 are sewn at the position of the lockstitch sewing line 142 with seam allowance width D from the end 145A. At this time, the portion of seam allowance width D including the end 145A is made into the seam allowance 146. Next, as shown in FIG. 4B, the two seams 146 are folded so as to be fixed at a fixed interval to the skin piece 145 from the position of the lockstitch sewing line 142 so that they are positioned on the back surface of the skin 144. In this state, the seam allowance 146 and one skin piece 45 are sewn together at a predetermined position inside from the end 145A to form a stitch 150.

FIG. 8 is a diagram for explaining a conventional sewing method, and FIG. 9 is a diagram showing the analysis results of a model generated by the conventional sewing method of FIG. 8. In FIG. 8, the skin 244 is shown in thick lines for convenience, but in reality, a cross-sectional view is shown. As shown in FIG. 8, in a sewing method for the upper skin 244A and the side skin 244B, as an example, conventionally, in the analytical model, the upper skin 244A and the side skin 244B are fixed at the position of the lockstitch sewing line 242 at a seam width D from the end 245A and the end 245B, as in the actual sewing method described above. In this case, "fixing" is intended to simulate sewing by arranging multiple spring elements at predetermined intervals between the end 245A of the rising skin 244A and the end 245B of the upper end skin 244B, and compressing the spring elements.

In this way, when the upper skin 244A and the side skin 244B are fixed in a manner equivalent to a lock stitch, analysis reveals that, for example, the seam allowance 246A of the upper skin 244A and the seam allowance 246B of the side skin 244B collide, causing the seam allowance 246A to turn up as shown in the dotted circle indicated by arrow A, as shown in the lower diagram of Figure 8. In other words, as shown in Figure 9, a turn-up 248 of the skin 244 occurs between the upper skin 244A and the side skin 244B.

Therefore, in this embodiment, stitches are sewn first. FIG. 5 is a diagram for explaining the sewing method of this embodiment, and FIG. 6 is a diagram showing the analysis result of the model generated by the sewing method of FIG. 5. In FIG. 5, the skin 44 is shown in a thick line for convenience, but in reality, a cross-sectional view is shown. As shown in the upper diagram of FIG. 5, in this embodiment, the first process unit 22 of FIG. 2 first performs the first process of folding the seams 46A and 46B at the end 45A of the upper skin 44A and the end 45B of the side skin 44B with the seam width D in the same direction, i.e., toward the back surface of the skin 44. Specifically, the first process unit 22 folds the seams 46A and 46B by applying a load from the front surface side of the skin 44 at the end 45A and 46B sides of the seams 46A and 46B. At this time, the first process unit 22 applies the load with the position of the lock stitch sewing line 42 set as the fulcrum.

Next, as shown in the lower diagram of Figure 5, the second process unit 24 of Figure 2 performs the second process of fixing the seam allowances 46A and 46B in the folded state to the upper skin 44A and the side skin 44B, respectively. Specifically, the second process unit 24 fixes the seam allowances 46A and 46B at locations that are a predetermined distance F away from the respective ends 45A and 45B of the upper skin 44A and the side skin 44B in the folded state. In this embodiment, the position where the stitch 150 appears in the actual sewing shown in Figure 4 as described above is set as the fixed position 50.

In this embodiment, as an example, multiple spring elements are arranged at regular intervals in the depth direction of the page between the upper skin 44A and the seam 46A, and between the side skin 44B and the seam 46B, and these spring elements are fixed by contracting them. This "fixing" simulates sewing.

Next, as shown in the lower diagram of Figure 5, the third process unit 26 in Figure 2 performs the third process of fixing the end 47A of the upper skin 44A and the end 47B of the side skin 44B in a state where the seams 46A, 46B are respectively fixed, in a manner equivalent to a lock stitch. In this embodiment, as an example, a number of spring elements are arranged at predetermined intervals between the end 47A and the end 47B in the depth direction of the page, and the fixing is performed by compressing the spring elements. Note that this "fixing" simulates a lock stitch.

In this manner, in this embodiment, the seam allowances 46A and 46B in the folded state are first fixed to the upper skin 44A and the side skin 44B, respectively, at the fixing position 50, and then the upper skin 44A and the side skin 44B are fixed in a manner equivalent to a lock stitch, and the sewing process is simulated. Then, as shown in the circle R indicated by the dashed line in Figure 6, the analysis results show that no turning up of the skin 44 occurs between the upper skin 44A and the side skin 44B.

Returning to FIG. 2, the analysis unit 28 performs CAE analysis. Specifically, the analysis unit 28 is configured with known analysis software, for example, LS-DYNA. Specifically, as an example, the analysis software is stored in storage 20D, and the analysis unit 28 performs the analysis by executing the analysis software stored in storage 20D.

Next, a series of processes executed in the analysis device 20 will be described with reference to the flowchart shown in FIG. 7. The analysis process executed in the analysis device 20 is performed by the CPU 20A reading out an analysis program from the ROM 20B or storage 20D, expanding it in the RAM 20C, and executing it.

As shown in FIG. 7, first, in step S11, the analysis unit 28 starts analyzing the cover 44 of the cushion sheet 40 of the vehicle seat. In step S12, the first process unit 22 folds the seams 46A, 46B at the end 45A of the upper cover 44A and the end 45B of the side cover 44B with the seam width D in the same direction, i.e., toward the back surface of the cover 44.

Next, in step S13, the second process unit 24 fixes the seams 46A and 46B in the folded state to the upper skin 44A and the side skin 44B, respectively. Next, in step S14, the third process unit 26 fixes the end 47A of the upper skin 44A and the end 47B of the side skin 44B, with the seams 46A and 46B fixed, in a manner equivalent to a lock stitch.

Next, in step S15, the CPU 20A determines whether the analysis of the cushion sheet 40 by the analysis unit 28 has been completed. If the CPU 20A determines in step S15 that the analysis has not been completed (step S15; NO), the CPU 20A transitions to step S15, where the analysis unit 28 continues to analyze the cushion sheet 40.

On the other hand, if the CPU 20A determines in step S15 that the analysis has ended (step S15; YES), the CPU 20A ends the analysis by the analysis unit 28. Note that in this embodiment, as an example, the CPU 20A determines that the analysis has ended when the analysis result by the analysis unit 28 has been output. Note that, as an example, after the CPU 20A ends the analysis by the analysis unit 28, it causes the analysis result by the analysis unit 28 to be displayed on the display unit 30.

Next, the effects of this embodiment will be explained.

In the analysis method according to this embodiment, the seams 46A, 46B are folded in the first step, and the seams 46A, 46B are fixed in the folded state in the second step. In addition, in the third step, the end 47A of the upper skin 44A and the end 47B of the side skin 44B are fixed in a state equivalent to a lock stitch with the seams 46A, 46B fixed. Therefore, since the seams 46A, 46B are folded and fixed first when sewing, it is possible to prevent the skin 44 from turning over when the end 47A of the upper skin 44A and the end 47B of the side skin 44B are fixed in a state equivalent to a lock stitch. By preventing the skin 44 from turning over in this way, it is possible to perform a sewing simulation analysis of the skin 44 in a stable calculation state.

In addition, in the analysis method according to this embodiment, the seams 46A, 46B are fixed at a predetermined distance F from the end 47A of the upper skin 44A and the end 47B of the side skin 44B when the seams 46A, 46B are folded. Therefore, the fixed position 50 that will become the stitch 150 when the skin 144 is actually sewn is fixed, so the analysis accuracy of the sewing simulation can be further improved.

In addition, in the analysis method according to this embodiment, the skin 44 can be fixed by compressing the spring element, so that fixation equivalent to actual sewing can be easily achieved in the sewing simulation.

In addition, in the analysis method according to this embodiment, since the upper skin 44A and the side skin 44B are the seat skin 44, it is possible to prevent the seat skin 44 from turning over. By preventing the seat skin 44 from turning over in this way, it is possible to perform a simulation analysis of the sewing process of the seat skin 44 in a stable calculation state.

In addition, in the analysis method according to this embodiment, since the upper skin 44A and the side skin 44B are the skin 44 of the vehicle seat, it is possible to prevent the skin 44 of the vehicle seat from turning over. By preventing the skin 44 of the vehicle seat from turning over in this way, it is possible to perform a simulation analysis of the sewing process of the skin 44 of the vehicle seat in a stable calculation state.

[Supplementary explanation of the embodiment]
In the above embodiment, the cushion seat 40 of a vehicle seat is taken as an example of a target for simulating a sewing process, but the present disclosure is not limited thereto. For example, the present disclosure may be applied to a back seat of a vehicle seat, or to a seat of a vehicle other than a vehicle. In addition, the present disclosure is not limited to a seat, and may be applied when simulating a sewing process of clothing, kimono, etc.

In addition, in the above embodiment, spring elements are used for "fixing" in the second process section 24 and the third process section 26, but the present disclosure is not limited to this. For example, "fixing", i.e., sewing, may be simulated by simply setting the distance between the two sewn members to be fixed to "0 (zero)." Furthermore, this "fixing" method may be applied to only one of the second process section 24 and the third process section 26, or to both.

Furthermore, the processes executed by the CPU 20A shown in FIG. 1 after reading the software (program) in the above embodiment may be executed by various processors other than the CPU. Examples of processors in this case include PLDs (Programmable Logic Devices) such as FPGAs (Field-Programmable Gate Arrays) whose circuit configuration can be changed after manufacture, and dedicated electric circuits such as ASICs (Application Specific Integrated Circuits), which are processors with circuit configurations designed exclusively to execute specific processes. Furthermore, each process may be executed by one of these various processors, or may be executed by a combination of two or more processors of the same or different types (for example, multiple FPGAs, or a combination of a CPU and an FPGA, etc.). Moreover, the hardware structure of these various processors is, more specifically, an electric circuit that combines circuit elements such as semiconductor elements.

Furthermore, each program described in this embodiment may be provided in a form recorded on a recording medium such as a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), or a USB (Universal Serial Bus) memory. The programs may also be provided in a form downloaded from an external device via a network.

The above describes one example of the present disclosure, but the present disclosure is not limited to the above, and can of course be implemented in various other modifications without departing from the spirit of the disclosure.

In addition, the disclosure of Japanese Patent Application No. 2023-016455, filed on February 6, 2023, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

A first step of folding a seam width in the same direction at an end of a first sewn material and an end of a second sewn material, each of which has a predetermined seam width;
A second step of fixing the seam allowance in the folded state;
a third step of fastening ends of the first sewn member and the second sewn member together in a manner equivalent to a lock stitch while the seam allowance is fixed;
The present invention provides an analysis method for simulating a sewing process.
The analysis method according to claim 1, wherein the second step fixes the first sewn member and the second sewn member at a location that is a predetermined distance away from each end of the first sewn member and the second sewn member in a folded state.
The analysis method according to claim 1, wherein at least one of the fixing in the second step and the fixing in the third step is performed by compressing a spring element.
The analysis method according to claim 1, wherein the first sewn member and the second sewn member are the surface of a seat.
The analysis method according to claim 4, wherein the seat is a vehicle seat.
a first process section for folding a seam width in the same direction at an end of a first sewn material and an end of a second sewn material, the seam width being a predetermined seam width;
A second process section that fixes the seam in a folded state;
a third process section for fixing ends of the first sewn member and the second sewn member together in a manner equivalent to a lock stitch while the seam allowance is fixed;
This is an analysis device that is equipped with an analyzer and performs a simulation of the sewing process.
Computer,
a first process section for folding a seam width in the same direction at an end of a first sewn material and an end of a second sewn material, the seam width being a predetermined seam width;
A second process section that fixes the seam in a folded state;
and an analysis program that functions as a third process unit that fixes the ends of the first sewn material and the second sewn material together in a manner equivalent to a lockstitch while the seam allowance is fixed, and that performs a simulation of the sewing process.