JP7348832B2 - Method and device for calculating sipe length of pneumatic tires - Google Patents

Description

The present invention relates to a method and device for calculating the sipe length of a pneumatic tire.

Fine grooves called sipes are formed in the tread of a pneumatic tire. A plurality of sipes are generally formed in order to adjust tire performance such as traction performance and on-ice performance. In adjusting tire performance, the shape and number of multiple sipes are adjusted, and the total length of multiple sipes is adjusted. Therefore, in order to efficiently adjust tire performance, a method is required that can easily calculate the total length of a plurality of sipes.

However, the number of sipes is enormous, and it is inefficient to visually recognize and count each one. Therefore, it is preferable to automatically calculate the length of the sipe by computer calculation. Methods for calculating the dimensions of specific elements using computer calculations have been in existence for a long time. For example, Patent Document 1 discloses a method for measuring the mounting position of outfitting parts. In this method, predetermined dimensions of the outfitting parts assembly position are automatically displayed.

Japanese Patent Application Publication No. 2012-252577

The method of Patent Document 1 targets a predetermined dimension of an outfitting part assembly position, but there is room for improvement when targeting a sipe of a pneumatic tire. That is, the method of Patent Document 1 has room for improvement in efficiently calculating the total length of a huge number of sipes.

An object of the present invention is to efficiently calculate the total value of the lengths of a plurality of sipes in a method and device for calculating the sipe length of a pneumatic tire.

A first aspect of the present invention is a method for calculating the sipe length of a pneumatic tire using a computer, the method comprising: acquiring CAD data of a pneumatic tire; displaying the acquired CAD data; receiving identification of an extraction region in the CAD data, extracting sipes in the extraction region and adding them to an active list, and calculating a total length of all the sipes in the active list. Provides a method for calculating the sipe length of a tire.

According to this method, an arbitrary extraction region can be specified and the total value of the lengths of a plurality of sipes in the specified extraction region can be efficiently calculated. In particular, since an active list is adopted, it is possible to easily distinguish between sipes for which the total length value is calculated and sipes for which the total length is calculated.

The sipes added to the active list may be identifiably displayed.

According to this method, it is possible to easily recognize which sipes have been added to the active list. The method of displaying the sipes in an identifiable manner is not particularly limited, but may include, for example, changing the line color, line type, or line thickness for displaying the sipes added to the active list.

The extraction area may be specified by defining a rectangular area.

According to this method, the extraction area can be identified easily and visually.

The pneumatic tire may have a land portion defined by a plurality of grooves, and the extraction region may be identified by selecting the land portion.

According to this method, the total length of the sipes can be calculated for each land area. Sipes are formed on the surface of pneumatic tires because they are used to adjust tire performance such as traction performance and on-ice performance. In other words, it is formed not within the groove but on the land surface. Therefore, it is possible to easily calculate how much a specific land area contributes to tire performance.

The identification of the extraction area and the addition of the sipe to the active list may be performed additively.

According to this method, the extraction area can be identified and added to the active list not only once, but can be added as many times as necessary. This enables continuous evaluation and improves work efficiency.

The calculated total length of the sipes may include the total length of the sipes.

According to this method, the total amount of sipes formed on the surface of the pneumatic tire can be easily calculated.

The calculated total length of the sipes may include a total value of tire width direction components of the sipes.

According to this method, the total value of the tire width direction components of the sipes can be easily calculated. The tire width direction component of the sipes contributes to the braking performance of the pneumatic tire, and therefore, the evaluation can be easily performed.

The calculated total length of the sipes may include a total value of circumferential components of the sipes.

According to this method, the total value of the tire circumferential direction components of the sipes can be easily calculated. The tire circumferential direction component of the sipes contributes to the cornering performance of the pneumatic tire, so the evaluation can be easily performed.

A second aspect of the present invention includes an output unit that displays CAD data of a pneumatic tire, an extraction area specifying unit that accepts specification of an extraction area in the CAD data displayed on the output unit, and a sipe in the extraction area. Provided is a sipe length calculation device for a pneumatic tire, comprising a sipe extraction unit that extracts and adds the sipe length to an active list, and a calculation unit that calculates a total value of the lengths of all the sipes in the active list. .

The sipe extraction unit may display the sipes added to the active list in an identifiable manner on the output unit.

The extraction area specifying unit may specify the extraction area by defining a rectangular area.

The pneumatic tire may have a land portion defined by a plurality of grooves, and the extraction area specifying unit may specify the extraction area by selecting the land portion.

The calculation device further includes a storage unit that stores the active list, and the extraction area specifying unit specifies the extraction area and the Sipe extraction unit adds the Sipe to the active list in the storage unit. may be configured to be performed additively with respect to the active list of .

The total length of the sipes calculated by the calculation unit may include the total length of the sipes.

The total value of the lengths of the sipes calculated by the calculation unit may include the total value of the tire width direction components of the sipes.

The total value of the lengths of the sipes calculated by the calculation unit may include the total value of tire circumferential direction components of the sipes.

According to the present invention, in the method and device for calculating the sipe length of a pneumatic tire, it is possible to efficiently calculate the total value of the sipe lengths.

A developed view of the tread portion of a pneumatic tire. FIG. 2 is an enlarged view of the extraction area in FIG. 1. FIG. 1 is a block diagram of a pneumatic tire sipe length calculation device according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing an example of a method for calculating sipe length. 1 is a flowchart showing a method for calculating the sipe length of a pneumatic tire according to an embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The pneumatic tire sipe length calculation device (hereinafter also simply referred to as calculation device) of the present embodiment calculates an arbitrary extraction area 2 in CAD (Computer Aided Design) data of a pneumatic tire 1 as shown in FIG. is specified, and the total value of the lengths of the plurality of sipes 3 in the specified extraction area 2 is calculated.

FIG. 1 is a developed view showing a tread portion 4 of a pneumatic tire 1. As shown in FIG. Although not shown, this pneumatic tire has a structure in which a carcass is stretched between a pair of bead cores, reinforced by a belt wrapped around the outer circumferential side of the middle part of the carcass, and a tread portion 4 is provided on the outer diameter side of the tire. . FIG. 2 is an enlarged view of the extraction area 2 in FIG.

In the following description, the left-right direction in FIGS. 1 and 2 will be referred to as the tire width direction TW. Moreover, in FIGS. 1 and 2, the vertical direction is referred to as the tire circumferential direction TC. Further, in FIGS. 1 and 2, a tire equator line Ce indicating the center of the tire width direction TW is shown.

A tread pattern is formed in the tread portion 4 of the pneumatic tire 1 by a plurality of groove portions 5. Specifically, land portions 6 of various shapes are defined by the plurality of groove portions 5 .

A plurality of sipes 3 are formed in the land portion 6 by cutting. The term sipe used here refers to something that has a thickness (dimension in the direction perpendicular to the longitudinal direction of the groove) that closes the groove when it makes contact with the ground. For example, the thickness of the groove is set to 1.5 mm or less. has been done.

Each of the plurality of sipes 3 extends in various directions such as the tire width direction, the tire circumferential direction, or a direction inclined therefrom. Each of the plurality of sipes 3 includes a straight portion 3a and a wavy portion 3b. However, the shape of the plurality of sipes 3 is not particularly limited.

FIG. 3 shows a calculation device 10 according to an embodiment of the present invention.

The calculation device 10 of this embodiment includes a storage section 11, an output section 12, an extraction area specifying section 13, and a control section 14.

The storage unit 11 records necessary data such as CAD data of the pneumatic tire 1 as shown in FIG. 1, a program operated by the control unit 14, and an active list 11a to be described later. The storage unit 11 includes a hard disk device, a magneto-optical disk device, a non-volatile memory such as a flash memory (a read-only storage medium such as a CD-ROM), and a volatile memory such as a RAM (Random Access Memory). It may be configured by memory or a combination thereof.

The output unit 12 is a unit that displays the CAD data of the pneumatic tire 1 stored in the storage unit 11 and the processing results of the control unit 14, and is configured with, for example, a liquid crystal display, an organic EL display, a plasma display, or the like. obtain. Furthermore, in addition to the CAD data of the pneumatic tire 1 stored in the storage unit 11, data input separately may be directly displayed on the output unit 12.

The extraction area specifying unit 13 is an input device that accepts specification of the extraction area 2 (see FIG. 1) on the CAD data displayed on the output unit 12, and may be configured by, for example, a keyboard, a mouse, a touch panel, or the like. Further, the output unit 12 and the extraction area specifying unit 13 may be integrally configured by a touch panel display.

The extraction area 2 indicates an area in the tread portion 4 from which a plurality of sipes 3 are extracted, as shown in FIG. In this embodiment, the extraction area specifying unit 13 can specify the extraction area 2 as a rectangular area. Thereby, the extraction area 2 can be identified easily and visually. Alternatively, when specifying the extraction area 2 by the extraction area specifying unit 13, an arbitrary area such as a circular area or a polygonal area may be specified. Further, the land portion 6 may be selected as the extraction region 2. Thereby, the total value of the lengths of the plurality of sipes 3 can be calculated for each land portion 6. The sipes 3 are formed on the surface of the pneumatic tire 1 because they are used to adjust tire performance such as traction performance and on-ice performance. In other words, it is formed not within the groove portion 5 but on the surface of the land portion 6 . Therefore, it is possible to easily calculate how much a specific land portion 6 contributes to tire performance.

The control section 14 includes a Sipe extraction section 14a and a calculation section 14b. These are realized through cooperation between a processor, which is a hardware resource, and a program, which is software, recorded in the storage unit 11 and the like.

The sipe extraction unit 14a extracts the sipe 3 within the extraction area 2 and adds it to the active list 11a. At this time, the active list 11a in the storage unit 11 is read out, and the newly extracted Sipe 3 is added to the active list 11a. The active list is a list that stores selected sipes 3. For example, in this embodiment, a number is attached to each of the plurality of sipes 3, and the number is stored in the active list 11a. However, if the extraction area 2 is specified such that one sipe 3 straddles the inside and outside of the extraction area 2, only a part of one sipe 3 may be stored in the active list 11a. In that case, information specifying part of the sipe 3 is also stored in the active list 11a at the same time. The information specifying a part of the sipe 3 may be based on coordinate information, for example, as described later. Note that the form of the active list 11a may be other than those described above, and is not particularly limited.

The extraction of the sipe 3 by the sipe extraction unit 14a is performed based on attribute information previously given to the sipe 3 on the CAD data. For example, on the CAD data as shown in FIG. 1, attribute information such as a specific line type, line color, or line thickness, which can be distinguished from other elements, is given to the sipe 3 in advance. The Sipe extraction unit 14a extracts Sipe 3 by distinguishing it from other elements based on the attribute information.

The Sipe 3 added to the active list 11a by the Sipe extraction unit 14a is displayed in an identifiable manner on the output unit 12. In this embodiment, in FIG. 1, the plurality of sipes 3 added to the active list 11a are displayed with thicker lines than the other sipes 3. Alternatively, it may be displayed in an identifiable manner by changing the line color or line type.

The calculation unit 14b calculates the total length of all the sipes 3 in the active list 11a. The length of each of the plurality of sipes 3 calculated in this embodiment includes a total length value, a tire width direction component value, and a tire circumferential direction component value. Therefore, the calculation unit 14b calculates the total length of the plurality of sipes 3, the total value of the tire width direction components of the plurality of sipes 3, and the total value of the tire circumferential direction components of the plurality of sipes 3, and the output unit 12 will be displayed. Alternatively, any one or two of the total length of the plurality of sipes 3, the total value of the tire width direction components of the plurality of sipes 3, and the total value of the tire circumferential direction components of the plurality of sipes 3. It may be calculated and displayed on the output unit 12.

With reference to FIG. 4, a method for calculating each component of the length of the sipe 3 in the calculation unit 14b will be described. The illustrated sipe 3 has straight portions 3a at both ends and a wavy portion 3b at the center, and extends in the tire width direction from point P1 to point P6 while waving in the tire circumferential direction. In the illustrated Sipe 3, inflection points P2, P3, P4, and P5 of the wavy portion 3b are the peaks of each wave.

The calculation unit 14b calculates each component of the length of the sipe 3 based on the coordinates of the points P1 to P6. For example, in the example of FIG. 4, the tire width direction TW is the X direction, the tire circumferential direction TC is the Y direction, the coordinates of point P1 (0,0), the coordinates of point P2 (2,1), and the coordinates of point P3. (4, -1), the coordinates of point P4 (6,1), the coordinates of point P5 (8, -1), and the coordinates of point P6 (10,0). When calculating each component of the length of the sipe 3, the total moving distance of each component when moving on the sipe 3 from point P1 toward point P6 is calculated.

The value of the tire width direction component of Sipe 3 is the tire width direction component between points P1 and P2 (=2), the tire width direction component between points P2 and P3 (=2), and the tire width direction component between points P3 and P4. As the sum of the tire width direction component between points P4 and P5 (=2), the tire width direction component between points P5 and P6 (=2), It is calculated as 10.

The value of the tire circumferential direction component of Sipe 3 is the tire circumferential direction component between point P1 and point P2 (=1), the tire circumferential direction component between point P2 and point P3 (=2), and the tire circumferential direction component between point P3 and point P4. As the sum of the tire circumferential direction component between points P4 and P5 (=2), the tire circumferential direction component between points P5 and P6 (=1), It is calculated as 8.

The value of the total length of the sipe 3 is calculated as the total moving distance when moving on the sipe 3 from the point P1 to the point P6. The total movement distance may be calculated by, for example, approximating the sum of straight-line distances between adjacent points. That is, the straight line distance between point P1 and point P2 (=√5), the straight line distance between point P2 and point P3 (=2√2), and the straight line distance between point P3 and point P4 (=2√2) The sum of the straight-line distance between points P4 and P5 (=2√2) and the straight-line distance between points P5 and P6 (=√5) may be calculated as 2√5+6√2. . In this case, it is not considered whether the adjacent points are curved or straight, but this degree of error is allowed.

In FIG. 4, as an example, the sipes 3 are shown extending in the tire width direction from point P1 to point P6 while undulating in the tire circumferential direction. Although this is just an example, the method of calculating the value of the total length of Sipe 3, the value of the component in the tire width direction of Sipe 3, and the value of the component in the tire circumferential direction of Sipe 3 is as follows. It can be applied to any sipe by detecting the crest of the wave. Note that the peak of each wave of the wavy portion 3b of the sipe 3 may be detected by the sipe extraction unit 14a. This is also an example of how to calculate the length of Sipe 3 using the apex of each wave above, and the length of Sipe 3 can be calculated more accurately using a known method other than the above. It's okay.

In the calculation unit 14b, the lengths of the sipes 3 calculated as described above are totaled and displayed on the output unit 12 as the total length of the sipes 3. In this embodiment, the total length of the sipes 3, the total value of the tire width direction components of the sipes 3, and the total value of the tire circumferential direction components of the sipes 3 are calculated and displayed on the output unit 12.

Further, the extraction area specifying unit 13 may specify the extraction area 2 and the Sipe extracting unit 14a may add the Sipe 3 to the active list 11a in an additive manner. That is, after repeating the identification of the extraction area 2 and the extraction of the sipes 3 to increase the number of sipes 3 added to the active list 11a, the lengths of all the sipes 3 in the active list 11a are determined at the user's desired timing. The calculation unit 14b may calculate the total value of .

Referring to FIG. 5, a method for a user to calculate the sipe length (total length of sipes 3) of the pneumatic tire 1 using the calculation device 10 such as a computer having the above configuration will be described below.

When the method is executed, first, CAD data of the pneumatic tire 1 is acquired (step S1). The CAD data may be acquired from the storage unit 11 as described above. Further, the CAD data may be two-dimensional data or three-dimensional data. The acquired CAD data is displayed on the output unit 12 (step S2). Then, the user refers to the displayed CAD data and uses the extraction area specifying section 13 to specify the extraction area 2 as a rectangular area or the like (step S3). When the extraction area 2 is specified, the sipe extraction unit 14a extracts the sipe 3 within the extraction area 2 and adds it to the active list 11a (step S4). At this time, the Sipe 3 added to the active list 11a is displayed on the output unit 12 in an identifiable manner. Therefore, the user can easily recognize which Sipe 3 has been added to the active list 11a. If the identification of the extraction area 2 is not completed (N: step S5), the identification of the extraction area 2 (step S3) and the extraction of the sipe 3 (step S4) are repeated. When all the extraction regions 2 are specified (Y: step S5), the user causes the calculation unit 14b to calculate the total value of the sipe lengths (step S6). The calculated total value of sipe lengths is displayed on the output unit 12 (step S7).

According to this embodiment, an arbitrary extraction region 2 can be specified, and the total value of the lengths of the plurality of sipes 3 in the specified extraction region 2 can be efficiently calculated. In particular, since the active list 11a is employed, it is possible to easily distinguish between the sipes 3 for which the total length value is calculated and the other sipes 3.

In addition, identifying the extraction area 2 and adding it to the active list 11a is not completed only once, but can be added and executed as many times as necessary, making continuous evaluation possible and improving work efficiency. can.

Moreover, in this embodiment, three types of values (total length, tire width direction component, and tire circumferential direction component) are calculated as the length of the sipe 3. Since the total length of the plurality of sipes 3 is calculated, the total amount of the sipes 3 formed on the surface of the pneumatic tire 1 can be easily calculated. Since the total value of the tire width direction components of the plurality of sipes 3 is calculated, it is possible to easily evaluate the braking performance, etc. of the pneumatic tire. Since the total value of the tire circumferential direction components of the plurality of sipes 3 is calculated, the cornering performance and the like of the pneumatic tire 1 can be easily evaluated.

Although specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and can be implemented with various changes within the scope of the present invention.

1 Pneumatic tire 2 Extraction area 3 Sipe 3a Straight part 3b Wavy part 4 Tread part 5 Groove part 6 Land part 10 Calculation device 11 Storage part 11a Active list 12 Output part 13 Extraction area identification part 14 Control part 14a Sipe extraction part 14b Calculation part

Claims (16)

A method of calculating the sipe length of a pneumatic tire using a computer,
Obtain CAD data for pneumatic tires,
Displaying the acquired CAD data,
Accepting identification of an extraction area in the displayed CAD data,
extracting the sipes within the extraction area and adding them to the active list;
A method for calculating a sipe length of a pneumatic tire, the method comprising: calculating a total value of lengths of all the sipes in the active list. The method for calculating the sipe length of a pneumatic tire according to claim 1, wherein the sipes added to the active list are displayed in an identifiable manner. The method for calculating the sipe length of a pneumatic tire according to claim 1 or 2, wherein the extraction area is specified by defining a rectangular area. The pneumatic tire has a land portion defined by a plurality of grooves,
The method for calculating the sipe length of a pneumatic tire according to claim 1 or 2, wherein the extraction area is specified by selecting the land area. The method for calculating the sipe length of a pneumatic tire according to any one of claims 1 to 4, wherein the identification of the extraction area and the addition of the sipe to the active list are performed additively. The method for calculating the sipe length of a pneumatic tire according to any one of claims 1 to 5, wherein the calculated total value of the length of the sipe includes a total value of the total length of the sipe. The method for calculating the sipe length of a pneumatic tire according to any one of claims 1 to 6, wherein the calculated total length of the sipes includes a total value of components of the sipes in the tire width direction. . The method for calculating the sipe length of a pneumatic tire according to any one of claims 1 to 7, wherein the calculated total value of the length of the sipe includes a total value of the tire circumferential direction components of the sipe. . an output section that displays CAD data of the pneumatic tire;
an extraction area identification unit that accepts identification of an extraction area in the CAD data displayed on an output unit;
a sipe extraction unit that extracts sipes within the extraction area and adds them to an active list;
A calculation device for calculating the sipe length of a pneumatic tire, comprising: a calculation unit that calculates a total value of the lengths of all the sipes in the active list. The pneumatic tire sipe length calculation device according to claim 9, wherein the sipe extraction unit displays the sipes added to the active list in an identifiable manner on the output unit. The pneumatic tire sipe length calculation device according to claim 9 or 10, wherein the extraction area specifying unit specifies the extraction area by defining a rectangular area. The pneumatic tire has a land portion defined by a plurality of grooves,
The pneumatic tire sipe length calculation device according to claim 9 or 10, wherein the extraction area specifying unit specifies the extraction area by selecting the land area. further comprising a storage unit that stores the active list,
The identification of the extraction area by the extraction area identification unit and the addition of the sipe to the active list by the Sipe extraction unit are configured to be performed additively with respect to the active list in the storage unit. The device for calculating the sipe length of a pneumatic tire according to any one of claims 9 to 12. The calculation of the sipe length of the pneumatic tire according to any one of claims 9 to 13, wherein the total value of the lengths of the sipes calculated by the calculation unit includes the total value of the total lengths of the sipes. Device. The sipe of the pneumatic tire according to any one of claims 9 to 14, wherein the total length of the sipes calculated by the calculation unit includes a total value of tire width direction components of the sipes. Length calculation device. The pneumatic tire sipe according to any one of claims 9 to 15, wherein the total length of the sipes calculated by the calculation unit includes a total value of tire circumferential direction components of the sipes. Length calculation device.

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