JP2955201B2 - Ski material selection method with low temperature dependence of camber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for selecting a ski material having a small temperature dependency of a camber, and more particularly to a ski having a plurality of materials different in a width direction and a thickness direction laminated thereon. to predict the amount (camber), about the material selection how the ski so as to select a temperature less dependent on material.

[0002]

2. Description of the Related Art It is important to predict the amount of warpage due to a temperature change in a long plate structure composed of a plurality of materials, such as a ski or a snowboard, which slides on snow. If the amount of warpage due to temperature change is large, the work environment (press machine temperature, mold shape for manufacturing skis) must be adjusted between summer and winter to maintain a constant camber at the ski production site. It needs to be changed according to the season. In addition, since the temperature difference between a store and a ski resort is 50 ° C. or more, the shape of a camber or the like of the same ski is different due to a change in temperature.

FIGS. 17 to 19 are views for explaining the cross-sectional structure and warpage of a ski. In general, techniques for eliminating ski warpage are often made by trial and error based on experience and intuition. As shown in FIG. 17A, a laminate having a constant cross section in the length direction is formed as shown in FIG.
When warpage occurs in the width direction,
When the cross section has a complicated structure as shown in FIG. 18A, or when the cross section has a different cross section in the length direction as shown in FIG. ) And the warp in the length direction as shown in FIG. 19B are still under examination.

[0004]

In the case of a ski, there are two types of warpage, one in the width direction and the other in the length direction. The former is considered a countermeasure as a concave tendency (a warp occurs in the width direction and the ski is curved in a concave shape), but the latter technology for controlling the warpage in the longitudinal direction is not yet considered. .

[0005] It is another object of the present invention predicts the warping of the ski, is to provide a material selection how to select the material of the temperature dependence is small ski camber.

[0006]

The invention according to claim 1 is
This is a method for selecting a material having low temperature dependence of a ski in which a plurality of materials having different widths and thicknesses are accumulated, and is obtained when one arbitrary cross section in the longitudinal direction of the ski is extracted.
In one cross-sectional shape and lamination configuration,
The sum of the axial forces around the neutral axis satisfies zero (formula (1))
And the sum of the bending moments around the neutral axis is zero (No.
(2)) to select a material so that satisfactory simultaneously.

(Equation 2)

According to a second aspect of the present invention, there is provided a method for selecting a material having low temperature dependence of a ski in which a plurality of materials different in a width direction and a thickness direction are laminated. A first step for inputting reference values of rigidity and curvature, a temperature change width, and a material division width, and a second step of selecting a material name of a material registered in advance and its physical property value . A third step of determining the material combination of the laminated structure based on the step 2 and the input cross-sectional information and division width, and determining the physical property value of the determined material with the selected physical property value ;
Step and the radius of curvature is determined for each cross section of the determined laminated configuration, and if the determined curvature value is within the reference value of the input curvature, the curvature value is output, and the determined physical property value is input. Calculates the neutral axis for each cross section based on the obtained cross section information, calculates the bending stiffness based on the calculated neutral axis for each cross section, and if the obtained stiffness value is within the reference value of the input stiffness value. And a fourth step of outputting the stiffness value.

[0008] In the invention according to claim 3, the fourth aspect of the second aspect is provided .
If the obtained curvature value is outside the reference value of the inputted curvature, the process waits until a new lamination structure is determined.

In the invention according to claim 4 , the fourth aspect of claim 2 is provided .
If the obtained stiffness value is outside the reference value of the input stiffness value, the step waits until a new lamination configuration is determined.

The invention according to claim 5 further includes a step of displaying the calculated curvature value and rigidity value.

[0011]

The present invention relates to a method for selecting a material having a low temperature dependency of a ski in which a plurality of materials having different widths and thicknesses are accumulated.
In one cross-sectional shape and lamination structure obtained when one is extracted, the sum of the axial forces around the neutral axis of the cross section satisfies zero according to a predetermined equation, and the sum of the bending moments around the neutral axis is zero according to the predetermined equation. The material is selected so as to satisfy at the same time. In addition, the material selection of the ski according to the present invention
The method is based on the input of the cross-sectional area in the width direction of the ski, the reference value of the bending stiffness and the curvature, the temperature change width, and the division width of the material. Is determined, the physical property value of the determined material is determined by the selected physical property value, the radius of curvature is determined for each cross section of the determined laminated structure, and the obtained curvature value is within the reference value of the input curvature. If so, output the curvature value, calculate the neutral axis for each cross section based on the determined physical property values and the input cross-sectional information, and calculate the bending rigidity based on the calculated neutral axis for each cross section. If the obtained stiffness value is within the reference value of the input stiffness value, the stiffness value is output.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the principle of the present invention will be described. The above-described laminated structure shown in FIG. 18 is used to determine the widthwise warpage of the ski. In the laminated structure shown in FIG. 18 (a), when viewed from the cross-sectional direction, the cross-section has a complicated configuration, and the warpage of the laminated plate is obtained when the material configuration in the length direction is the same. . In order to determine the warpage of the ski in the length direction, the laminated structure shown in FIG. 19A is used. This laminated structure has a constant cross section when viewed from the longitudinal direction, and determines the warpage of the laminated plate when the material composition in the width direction is different. In order to predict the amount of warpage in the width direction as shown in FIG. 18, the sectional shape (width, thickness) and the physical properties (Young's modulus,
Linear expansion coefficient) is required. The amount of warpage is represented by a radius of curvature (or curvature), and is obtained by solving the following boundary conditions.

The sum of the axial forces around the neutral axis is 0 ... The sum of the bending moments around the neutral axis is 0 ... The above equations can be expressed by the following equations (1) and (2).

[0014]

(Equation 3)

In order to predict the warpage deformation in the longitudinal direction as shown in FIG. 19B, the boundary condition is solved in the same manner as in FIG. 18, but the material composition is different in the cross-sectional direction. The physical properties are averaged for each layer viewed from the vertical direction. Further, as shown in FIG. 1, the material properties used are not the width direction but the length direction. In FIG. 1, the axial stress σ is expressed by the following equation (3).

[0016]

(Equation 4)

The above equations (1) and (2) are expressed by the following equations (4) and (5).

[0018]

(Equation 5)

The radius of curvature R and the neutral axis H can be obtained from the above equation (4) = equation (5).

A lamination structure of skis which simultaneously satisfies the desired amount of warpage deformation and bending rigidity EI (E: Young's modulus, I: second moment of area) is determined. The amount of warpage can be calculated in both the cross section direction and the length direction, and the bending rigidity EI can be calculated only in the cross section direction. It is possible to register in advance the minimum required laminated member as a ski, and this is important in reducing the number of selected laminated configurations.

FIG. 3 is a diagram for explaining the cross section information of the ski, FIG. 4 is a diagram for explaining the division width of the ski, and FIG. 5 is a diagram for explaining a combination of materials of the lamination structure. FIG. 5A shows a seven-layer structure, and FIG.
(B) shows an eight-layer configuration. FIG. 6 is a diagram for explaining a neutral axis, FIG. 7 is a diagram showing an example of a calculation result displayed on a display, and FIGS. 8 to 10 illustrate an operation of one embodiment of the present invention. It is a flowchart for the.

Next, the operation of optimizing the ski structure will be described in more detail with reference to FIGS. In step (abbreviated as SP in the drawing) SP1, as shown in FIG.
Number of layers NUM, number of subdivisions in width direction SUB, total length LENG of plate
Is input from the keyboard 2. In step SP2, the upper and lower limits of the bending rigidity EI and the curvature are input from the keyboard 2 as design reference values. The flexural rigidity EI varies depending on the type of ski, but is generally 10 ⁷ <
A value of EI <10 ⁸ is set, 10 ⁷ is the lower limit,
10 ⁸ is the upper limit. The amount of warpage deformation is defined by curvature, and a value of 0 <curvature <2 × 10 ⁻⁵ is set, where 0 is the lower limit and 2 × 10 ⁻⁵ is the upper limit.

In step SP3, a temperature gradient is inputted by the keyboard 2. Initial setting value is 50 ° C, for example.
(Room temperature 30 ° C.) and the value of the ski resort −20 ° C. In step SP4, material property values registered in the database memory 4 shown in FIG. 2 are read. Data is registered in the database memory 4 in the order of linear expansion coefficient, Young's modulus, plate thickness, and material name. To confirm the version of the database, the version *. * Is attached. Step SP5
In FIG. 4, the type and name of the material used in the optimization program are selected from the material property values read in step SP4, and in step SP6, the division width is not optimized. The division width is input in advance.

In the example shown in FIG. 4, the width of the central portion is 60
mm, and two vertical columns on both sides are set to 1.5 mm.
In step SP7, the plate thickness is optimized. The plate thickness is defined for the portion where the fixed frame is formed in advance, and the other plate thicknesses are optimized. Step SP8
In, the calculation of the combination of the lamination configurations is performed. FIG.
In the case of the seven-layer configuration shown in (a), the lowermost layer 11 and the uppermost layer 12 are fixed frames, ABS and ultra-high molecular weight polyethylene (PE) are allocated as materials, and the second layer 22 and the third layer 23. Is assigned to the core material. The first layer 2
Steel is assigned to the right end of 1 as a fixed frame, and ABS is assigned to the right end of the second layer 22 and the third layer 23 as a fixed frame. In the case of the eight-layer configuration shown in FIG.
One of the second to fourth layers 22 to 24 becomes a core material.

Physical property values are determined corresponding to the material numbers of the laminated structure determined in step SP8 described above. Step SP8
At this stage, only the material number is determined, and it is necessary to convert the material number into the material property used for calculation. In step SP10, an area that is not optimized is set in advance. In this optimization problem, Fig. 5 (a),
As shown in (b), the shaded area is the fixed area.

In the case of optimizing, since the sheet thickness varies depending on the material used, every time the stacking order is changed, the sheet thickness is replaced in step SP11. Step SP12
, The physical properties converted in step SP9 are defined again as an array at the lamination position determined in step SP8.

In step SP13, a radius of curvature is calculated. If the sum of the axial forces around the neutral axis is 0, and if the sum of the bending moments around the neutral axis is 0, no warpage occurs. Therefore, this boundary condition is calculated by using the above-mentioned equations (1) to (5). It is obtained by performing an operation. And step S
In P14, the calculated curvature is equal to the value in the aforementioned step SP2.
It is determined whether or not it is within the range of the upper and lower limits set in the above. If it is not within the range of the upper and lower limits, the process returns to step SP8 and the calculation of the combination of the lamination configurations is performed again. And
In step SP15, a neutral axis is calculated for each section as shown in FIG. This neutral axis can be obtained according to the following equation (6).

[0028]

(Equation 6)

In step SP16, the bending stiffness EI for each section is determined using the following equations (7) to (9).

[0030]

(Equation 7)

At this time, the neutral axis for each section calculated in step SP15 is used. Then, in step SP17, the bending rigidity EI is set in step SP2.
It is determined whether or not the bending stiffness entered in the above is within the range of the upper and lower limit values. If not, the process returns to step SP8 to recalculate the combination of the lamination configurations. If the bending stiffness EI is within the upper and lower limit values, in step SP18, FIG.
The calculation result is displayed as shown in. That is, as shown in FIG. 7, the name of the material to be used, the lamination order, the curvature, the neutral axis, the amount of warpage, and the bending rigidity EI are displayed on the display 5. Then, in step SP19, it is determined whether both the calculated curvature and bending stiffness EI are included in the range of the optimum solution, and only when both are included, the data is stored in a file in step SP20. The data to be stored are the names of the materials used, the stacking order, and the calculation results (curvature, position of the neutral axis, amount of warpage deformation, bending stiffness EI).

FIG. 11 is a diagram showing experimental results and analysis results of one embodiment of the present invention, and FIGS.
FIG. 16 is a view showing a cross-sectional structure of the plates 11 to 14 and their materials and dimensions shown in FIG. 16, and FIG. 16 is a view showing a list of physical properties for analyzing ski thermal deformation.

As shown in FIG. 11, the plates 11 to 14
FIG. 1A is a sectional structure shown in FIGS.
The materials and dimensions shown in FIGS. 2 (b) to 15 (b) were used, and the analysis results of one embodiment of the present invention and experimental values were compared. As a result, the analysis values and the experimental values are almost the same except for the plate 12. Since the position of the neutral axis of the plate 12 is different from that of the other, it is considered that the amount of warpage is increased. When only the amount of warpage is considered, the structures of the plates 11 and 14 are considered to be optimal.

[0034]

As described above, according to the present invention, materials are selected so that the total of the axial forces around the neutral axis of the ski is zero and the total of the bending moments around the neutral axis is zero. Thereby, a ski having less temperature dependence of the camber can be configured. Therefore, skis can be produced in the same working environment throughout the year, and the same shape can be maintained at the store and the ski resort.

[Brief description of the drawings]

FIG. 1 is a sectional view of a ski for explaining the principle of the present invention.

FIG. 2 is a block diagram of a processing device for executing an embodiment of the present invention.

FIG. 3 is a diagram for explaining cross section information of a ski.

FIG. 4 is a view for explaining a division width of a ski.

FIG. 5 is a diagram for explaining a combination of materials of a laminated structure.

FIG. 6 is a diagram for explaining a neutral shaft.

FIG. 7 is a diagram showing an example of a calculation result displayed on a display device 5;

FIG. 8 is a diagram showing a flowchart for explaining the operation of one embodiment of the present invention.

FIG. 9 is a diagram showing a flowchart similarly.

FIG. 10 is a diagram showing a flowchart similarly.

FIG. 11 is a diagram showing an experimental result and an analytical result of one embodiment of the present invention.

FIG. 12 is a diagram showing a cross-sectional structure of the plate 11 shown in FIG. 11, and its materials and dimensions.

FIG. 13 is a diagram showing a cross-sectional structure of the plate 12, its material and dimensions.

FIG. 14 is a diagram showing a cross-sectional structure of a plate 13, its material and dimensions.

FIG. 15 is a diagram showing a cross-sectional structure of a plate 14, its material and dimensions.

FIG. 16 is a view showing a list of physical properties for ski thermal deformation analysis.

FIG. 17 is a diagram for explaining the warpage of a laminate having a constant cross section in the length direction.

FIG. 18 is a diagram for explaining the warpage of the laminated board when the cross section has a complicated structure.

FIG. 19 is a diagram for explaining warpage of a laminated plate having different cross-sectional structures in the length direction.

[Explanation of symbols]

 1 CPU 2 Keyboard 3 Program memory 4 Database memory 5 Display

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Masaaki Okuyama 1-12-13 Minami Kohoku, Suminoe-ku, Osaka-shi, Osaka Mitsuno Co., Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) A63C 5 / 12

Claims (5)

(57) [Claims] 1. A method for selecting a material having a low temperature dependency of a ski in which a plurality of materials different in a width direction and a thickness direction are accumulated, wherein one arbitrary cross section in the longitudinal direction of the ski is extracted. In one obtained cross-sectional shape and laminated configuration, the sum of the axial forces around the neutral axis of the cross-section is zero (formula (1)).
And selecting the material so that the sum of the bending moments about the neutral axis satisfies zero (formula (2)) at the same time. (Equation 1) 2. A temperature less dependent on material selection side in the width direction and the ski formed by laminating a plurality of materials different in thickness direction
A first step for inputting cross-sectional information of the ski in the width direction, reference values of bending stiffness and curvature, temperature change width, and material division width, which are registered in advance. A second step of selecting a material name of the material and its physical property value; determining a material combination of the lamination configuration based on the cross-sectional information and the division width input in the first step ; A third step of determining a value by the physical property value selected in the second step , and the third step
Obtains a curvature radius for each cross section of the in determined lamination structure,
If the obtained curvature value is within the reference value of the curvature input in the first step, the curvature value is output, and for each cross section based on the determined physical property values and the input cross section information. The neutral axis is calculated, and the bending stiffness is calculated based on the calculated neutral axis for each cross section.
A ski material selection method , comprising: a fourth step of outputting a stiffness value if the stiffness value is within a reference value of the stiffness value input in the first step . 3. The method according to claim 2, wherein the fourth step waits until a new lamination configuration is determined if the obtained curvature value is outside the reference value of the inputted curvature. Material selection method for skis described in 1. 4. The method according to claim 4, wherein the fourth step waits until a new lamination configuration is determined if the obtained stiffness value is outside the reference value of the input stiffness value. 2. The method for selecting a ski material according to 2. 5. The ski material selection according to claim 2, further comprising display means for displaying the curvature value and the stiffness value calculated in the fourth step .
How .