JP2008164376A - Method and device for calculating load generated on tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To calculate a load generated on a tire, when an object is pressed against the tire. <P>SOLUTION: In a tire model in which a plurality of spring elements E<SB>i</SB>are arranged radially from the tire center, a displacement increment δ<SB>i</SB>' of the spring element E<SB>i</SB>due to the envelope effect, when a projection is pressed against the tire is expressed by the equation: δ<SB>i</SB>'=L(p)(ξ<SB>i</SB>-δ<SB>i</SB>), where p represents the pressing amount of the projection or plate; ξ<SB>i</SB>represents the displacement amount of each spring element E<SB>i</SB>when the plate is pressed against the tire model; δ<SB>i</SB>represents the displacement amount of each spring element E<SB>i</SB>, when the projection is pressed against the tire model assuming that there is no envelope effect; and L(p) represents a function of p. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for modeling a tire using a spring element.

In general, when a tire climbs over a protrusion such as a curb on the road while the vehicle is running, the outer periphery of the tire does not deform in close contact with the protrusion, but deforms so as to wrap around the protrusion and climbs over the protrusion. Such tire characteristics are referred to as envelope characteristics. The analysis of the envelope characteristics is very important when evaluating the performance of the tire. Therefore, various techniques for observing and analyzing envelope characteristics are known. For example, Patent Document 1 discloses a tire installation tread observation device that can observe envelope characteristics during actual vehicle travel.
JP 2004-340860 A Japanese Patent Laid-Open No. 11-201874 JP 2004-85297 A JP 2000-241309 A

  However, in the above-mentioned Patent Document 1, it is possible to observe the envelope characteristics when the tire goes over the protrusion from the photographed image, but it is not possible to evaluate the reaction force generated in the tire when it goes over the protrusion.

  This invention is made | formed in view of such a condition, The objective is to provide the technique which calculates the tire generation | occurrence | production load when an object is pressed with respect to a tire.

According to an aspect of the present invention, in a tire model in which a plurality of spring elements E _i are arranged radially from the tire center, the displacement increase amount δ _i ′ of the spring element E _i due to the envelope effect when the protrusion is pressed against the tire is expressed by the following equation: Δ _i ′ = L (p) (ξ _i −δ _i ). Where p represents the pressing amount of the protrusion or the flat plate, ξ _i represents the displacement amount of each spring element E _i when the flat plate is pressed against the tire model, and δ _i represents the protrusion when it is assumed that there is no envelope effect. It represents the amount of displacement of the spring element E _i when pressed against the tire model, L (p) represents a function by p.

According to this aspect, in the tire model, the correction formula for obtaining the displacement increase amount δ _i ′ of the spring element E _i in consideration of the envelope effect is expressed by the displacement amount ξ _i of the spring element when pressing the flat plate and the spring when pressing the protrusion. The function is expressed as a function including a difference term (ξ _i −δ _i ) with respect to the displacement amount δ _{i of the} element. In this equation, when a flat plate is pressed, ξ _i = δ _i , so δ _i ′ = 0. Therefore, the displacement increase amount due to the envelope effect is not calculated when the flat plate is pressed. Therefore, it is possible to obtain the tire generated load using the same radial spring model regardless of whether the flat plate or the protrusion is pressed.

Another aspect of the present invention is a method of calculating a tire generated load generated in a tire when an object is pressed against the tire using a tire model in which a plurality of spring elements E _i are arranged radially from the tire center. In this method, δ _i ′ = L (p) (ξ _i −δ _i ) (provided that the displacement increase amount δ _i ′ of the spring element E _i taking into account the envelope effect when the protrusion is pressed against the tire) , P represents the pressing amount of the protrusion or the flat plate, ξ _i represents the displacement amount of each spring element E _i when the flat plate is pressed against the tire model, and δ _i represents the protrusion when the envelope effect is assumed to be absent. It represents the amount of displacement of the spring element E _i when pressed against the model, L (p) is generated in the tire when pressing the steps of preparing a representative) functions p, a flat plate by a predetermined pressing amount to the tire The process of measuring the tire generated load at the time of flat plate pressing, the process of determining the spring constant of the spring element in the tire model based on the tire generated load at the time of flat plate pressing, and pressing the protrusion by a predetermined pressing amount on the tire The process of measuring the tire generated load at the time of pressing the protrusion generated on the tire when it is squeezed, and the sum of the displacement increase amount δ _i ′ and the displacement amount δ _i obtained using the above formula (δ _i + δ _i ′) ) Is substituted into the tire model, the process of identifying L (p) so that the result obtained by equalizing the tire-generated load at the time of pressing the protrusion, and using the identified L (p), the tire And calculating a tire generation load at the time of pressing a protrusion or a plate according to a model.

  According to this aspect, it is possible to calculate the tire generated load using the same tire model regardless of whether the object pressed against the tire is a flat plate or a protrusion.

Yet another aspect of the present invention is a method for calculating a tire generated load generated in a tire when an object is pressed against the tire using a tire model in which a plurality of spring elements E _i are arranged radially from the tire center. . In this method, δ _i ′ = L (p) (ξ _i −δ _i ) (provided that the displacement increase amount δ _i ′ of the spring element E _i taking into account the envelope effect when the protrusion is pressed against the tire) , P represents the pressing amount of the protrusion or the flat plate, ξ _i represents the displacement amount of each spring element E _i when the flat plate is pressed against the tire model, and δ _i represents the protrusion when the envelope effect is assumed to be absent. It represents the amount of displacement of the spring element E _i when pressed against the model, L (p) is generated in the tire when pressing the steps of preparing a representative) functions p, a flat plate by a predetermined pressing amount to the tire F _flat = M (ξ _all ), which is a relational expression between the process of measuring the _flat plate pressing tire generated load F _flat and the _flat plate pressing tire generated load F _flat and the total displacement amount ξ _all of the spring element E _i The process of seeking , A process of measuring the projection pushing when the tire generating force F _Curb generated in the tire when pressed against a predetermined pushing amount by the projection in the tire, the total displacement Sigma] [Delta] _i of the spring element when the pressing projections, the envelope process of obtaining a _'sum of (Σδ _{i +} Σδ _i' sum Sigma] [Delta] _i of the displacement increment in the spring element by effect) is the result obtained by substituting the equation _{F flat '= M (Σδ i} + Σδ i') And the process of identifying L (p) so that F _flat ′ = F _curb, and using the identified L (p), the tire generation load at the time of pressing the protrusion or the flat plate is calculated according to the tire model Process.

  According to this aspect, it is possible to determine the correction function L (p) for obtaining the displacement increase amount due to the envelope effect without calculating the spring constant of the spring element. Further, it is possible to calculate the tire generated load using the same tire model regardless of whether the object pressed against the tire is a flat plate or a protrusion.

  It should be noted that a representation of the present invention by a method, apparatus, system, recording medium, computer program, a permutation of those representations, a permutation of the processing order of the present invention, etc. are also effective as an aspect of the present invention. is there.

  According to the present invention, a tire generated load when an object is pressed against a tire can be calculated with high accuracy.

Embodiment 1 FIG.
FIG. 1 shows a radial spring model for calculating a load generated on a tire by a reaction force from a road surface when the tire is deformed. The radial spring model is a model for numerical calculation in which a plurality of spring elements extending in the tire radial direction with one end placed at the center O of the tire and the other end placed on the outer periphery B of the tire are arranged equiangularly around the center O. . In FIG. 1, (n + 1) spring elements E _i (i = 0 to n) are shown around the center O. In this radial spring model, when the deformation of the tire outer periphery B is input as the displacement of each spring element E _i, a reaction force f _i is generated in each spring element. The reaction force f _i to synthesize at the center O, it is possible to obtain the tire vertical load F caused the central axis of the tire by the reaction force from the road surface.

  As shown in FIG. 2, the case where the protrusion A is pressed against the tire T will be considered. This corresponds to, for example, a case where a tire rides on a curb on a road while the vehicle is running. As shown in the figure, when the protrusion A is pressed against the tire T, the outer periphery of the tire is not deformed along the oblique side of the chevron of the protrusion A, and the apex of the protrusion A is in contact with the outer periphery of the tire T, but away from the apex. Accordingly, the outer periphery of the tire moves away from the oblique side of the protrusion A. That is, the tie and the outer periphery are as shown by the curve C in the figure. Thus, when the protrusion is pressed against the tire, the deformation of the outer periphery of the tire so that it does not contact the oblique side of the protrusion and wraps the protrusion is referred to as “envelope effect”.

  Due to the envelope effect, the radial spring model shown in FIG. 1 cannot accurately calculate the reaction force when the protrusion is pressed. This will be described with reference to FIG.

  FIG. 3 shows a state in which the protrusion A is pressed against the outer periphery B of the radial spring model. Due to the protrusion A, the outer periphery B of the tire draws an envelope curve as indicated by “C” in the figure. The depth at which the tip of the protrusion A has entered most from the tire outer periphery B is referred to as “push-in amount” in this specification. In FIG. 3, the pushing amount is represented by “p”.

In radial spring model, the spring element E ₀ is assumed to be arranged in a vertical direction. Further, the displacement amount of the spring element E _i when it is assumed that there is no envelope effect and the outer periphery of the tire is in close contact with the oblique side of the protrusion A is represented by δ _i . From this definition, the displacement amount δ ₀ of the spring element E ₀ is equal to the pushing amount p. That is, δ ₀ = p.

Under this premise, when the pushing amount p of the protrusion A is given, the displacement amount δ of the spring element E _i is obtained by obtaining the intersection of the radial straight line connecting the tire center O and the tire outer periphery B and the oblique side of the protrusion A. _i can be determined geometrically. However, when considering the envelope effect, spring elements E _1, E _2, the displacement amount of ... is [delta] ₁ in FIG. 3 ', [delta] _2', but would increase by an amount indicated by ..., This cannot be determined geometrically.

Therefore, in the conventional radial spring model, the following correction calculation is performed in order to obtain the displacement increase amount δ _i ′ of the spring element due to the envelope effect.
σ _i ′ = {(σ _i−1 + σ _i−1 ′) −σ _i } / f (p) (i ≧ 1) (1)
Here, p is a pressing amount, and f (p) is a function obtained from a test in which a protrusion is pressed by p on a real tire. In Formula (1), the displacement increase amount by an envelope effect is expressed using the difference of the displacement amount of an adjacent spring element. If the sum (δ _i + δ _i ′) of this displacement increase amount δ _i ′ and the displacement amount δ _i when there is no envelope effect is given as the displacement of the spring element E _i , the resultant force of the reaction force of each spring element is obtained. The tire vertical load when the envelope effect is taken into consideration can be calculated.

Here, consider a case where a flat plate is pressed against the outer periphery B of the radial spring model. FIG. 4 shows this state. As shown in the figure, when the flat plate D is pressed against the tire, it is not necessary to consider the envelope effect, and the tire outer periphery B is in contact with the upper surface of the flat plate D almost entirely. The displacement amount of each spring element E _i when the flat plate D is pressed is represented by ξ _i . If the pushing amount of the flat plate D is expressed as p as in the case of the protrusion A, ξ ₀ = p from the definition. Geometric Given pushing amount p of flat plate D, a radial straight line connecting the tire center O and the tire outer peripheral B, by obtaining the intersection point of the upper surface of the plate D, and the displacement amount xi] _i of each spring element E _i Can be obtained.

Substituting the displacement xi] ₀ to? ₂ of the spring element _E 0 to E ₂ represented in FIG. 4 in the formula (1), the molecule of formula (1) does not become zero. Therefore, δ ₁ ′ and δ ₂ ′ are not 0. That is, when trying to obtain the tire vertical load when pressing the flat plate using a radial spring model that takes into account the envelope effect using equation (1), the displacement amount δ _i ′ due to the envelope effect that is originally unnecessary is calculated. Therefore, the tire up-down load with respect to the tire outer peripheral shape different from the actual is calculated.

  Therefore, in the present embodiment, a radial spring model is provided that can accurately calculate the tire vertical load both when pressing the flat plate and when pressing the protrusion.

FIG. 5 shows a state in which the protrusion A is pressed against the outer periphery B of the radial spring model when it is assumed that there is no envelope effect. In Figure 5, the spring element _{E 0,} E 1, the displacement amount [delta] ₀ of _{E 2,} δ _1, δ ₂ are shown.

Figure 6 is a diagram showing a state in which taking into consideration the envelope effect to correct the displacement of the spring element E _i. For the spring element E ₀ , δ ₀ = p. For the spring element E ₁ , the length δ ₁ ′ between the hypotenuse of the protrusion A and the envelope curve C is the amount of displacement to be corrected. For the spring element E ₂ , δ ₂ ′ is the displacement amount to be corrected.

In the present embodiment, an increase δ _i ′ of the displacement amount of the spring element generated by the envelope effect is expressed as follows.
δ _i ′ = L (p) (ξ _i −δ _i ) (i = 0 to n) (2)
Here, L (p) is the protrusion pressing amount p and tire vertical and results of the relationship between measured load F, wherein the displacement increment [delta] _{i 'and} envelope effect calculated in (2) using a real tire This is a correction function for matching the tire vertical load calculated by giving the sum (δ _i + δ _i ′) of the displacement amount δ _i when there is no displacement as the displacement of the spring element E _i .

In equation (2), the equation for the displacement increment [delta] _{i 'by} the envelope effect, include the difference term between the displacement amount [delta] _i during the pressing projection and the displacement amount xi] _i during the pressing flat (xi] _i - [delta _i) I tried to make it. As a result, ξ _i = δ _i at the time of flat plate pressing, so δ _i ′ = 0 from equation (2). In other words, using Equation (2), a radial spring model is created in which the amount of increase in the displacement of the spring element due to the envelope effect is zero when the flat plate is pressed, and the amount of increase in the displacement of the spring element due to the envelope effect is appropriately calculated when the projection is pressed. Can do.

  Next, a process for determining the correction function L (p) will be described.

FIG. 7 is a flowchart showing a process for determining the correction function L (p) according to an embodiment of the present invention.
First, the tire vertical load F _flat generated on the center axis of the tire when the flat plate D is pressed against the actual tire by various pressing amounts p is measured (S10). Hereinafter, this test is referred to as a “flat plate pressing test”. From the result of the flat plate pressing test, the relationship between the pressing amount p and the tire vertical load F _flat is obtained as follows.
F _flat = H (p) (3)
H is a function of p.

Next, a tire vertical load F _flat 'calculated when the flat plate D is pressed by the pressing amount p in the radial spring model will be considered. The tire vertical load F _flat ′ is a resultant force of the forces f ₀ , f ₁ , f ₂ ,... Generated in the spring elements E ₀ , E ₁ , E ₂ ,. Therefore, assuming that the spring coefficient K is the same for all spring elements, the following relationship is established (S12).
F _flat '= K (a ₀ ξ ₀ + a ₁ ξ ₁ + a ₂ ξ ₂ +...) (4)
Here, a _i is a coefficient determined from the angle between the tire vertical direction and the longitudinal direction of the spring element E _i .

Since the positional relationship of the spring elements E ₁ , E ₂ ,... In the radial spring model is determined in advance, the values of the displacement amounts ξ ₁ , ξ ₂ ,. Further, in order to calculate the tire vertical load at the time of flat plate pressing with the radial spring model, F _flat and F _flat 'must be equal. Therefore, the spring coefficient K is determined so that F _flat = F _flat 'with respect to the pressing amount p (S14). For example, an optimal spring constant K is determined using a known method such as a least square method so that F _flat ′ gives the best approximation for each p.

Next, a case where the projection A is pressed against the tire by the same pressing amount p as the flat plate D will be considered. First, the tire vertical load _Fcurb generated on the center axis of the tire when the protrusion A is pressed against the actual tire by various pressing amounts p is measured (S16). Hereinafter, this test is referred to as a “projection pressing test”. From the result of the protrusion pressing test, the relationship between the pressing amount p and the tire vertical load _Fcurb is obtained as follows.
_Fcurb = J (p) (5)
J is a function of p.

When the projection A is pressed against the radial spring model, the displacement amounts δ ₀ , δ ₁ , δ ₂ when there is no envelope effect of each spring element E ₀ , E ₁ , E ₂ ,. , ... are uniquely determined. Furthermore, when the displacement increase amount δ _i ′ = L (p) (ξ _i −δ _i ) when the above-described envelope effect is taken into consideration, the tire vertical load F _curb ′ with respect to the pressing amount p is expressed by the following equation: (S18).
_{F curb '= K {a 0} (δ 0 + δ 0') + a 1 (δ 1 + δ 1 ') + a 2 (δ 2 + δ 2') + ···} ··· (6)
Here, K and a _i are the same as those described in the above equation (4).

Of the displacement increase amount δ ′ = L (p) (ξ _i −δ _i ), ξ _i and δ _i are known, and therefore, by solving F _curb = F _curb ′ for each value of p, the displacement increase amount δ A correction function L (p) for obtaining _i ′ can be determined (S20).

As a result, the tire vertical load F _flat can be expressed by the following equation regardless of whether the object to be pressed is a flat plate or a protrusion.
F _flat = K {a ₀ (δ ₀ + δ ₀ ′) + a ₁ (δ ₁ + δ ₁ ′) + a ₂ (δ ₂ + δ ₂ ′) +..., Δ _i ′ = L (p) (ξ _i − δ _i ) (7)
When the pressing projections may be input the deformation amount [delta] _i of each spring element the above equation, when pressing the flat plate, Substituting the deformation amount xi] _i during pressing flat the [delta] _i of equation (7) That's fine. In the latter case, since δ _i ′ = 0, the envelope effect is not considered.

Embodiment 2. FIG.
FIG. 8 is a flowchart illustrating a process for determining the correction function L (p) according to another embodiment of the present invention.

First, as in the first embodiment, the relationship between the pressing amount p of the flat plate and the tire vertical load F _flat is obtained from the result of the flat plate pressing test as shown in the following equation (S30).
F _flat = H (p) (8)
H is a function of p.

When the pressing amount p is determined spring element E _i displacement xi] _{0 of,} xi] _1, xi] _2, since ... are uniquely determined, the sum of the displacement of the spring element E _i at the time of pressing a flat plate (hereinafter, "total Σξ _i (where i = 0 to n) is also uniquely determined. When Σξ _i = ξ _all , ξ _all is a function of p,
_{F flat = M (ξ all)} ··· (9)
Can be obtained (S32). Equation (9) represents the relationship between the tire vertical load F _flat and the total displacement amount ξ _all of the spring element E _i .

Subsequently, as in the first embodiment, the relationship between the protrusion pressing amount p and the tire vertical load _Fcurb is obtained from the result of the protrusion pressing test as shown in the following equation (S34).
_Fcurb = J (p) (10)

When the projection A is pressed against the radial spring model, the displacement amounts δ ₀ , δ ₁ , δ ₂ ,... When there is no envelope effect of each spring element E ₀ , E ₁ , E ₂ ,.・ Is uniquely determined. Therefore, the total displacement amount Σδ _i of each spring element when the projection A is pressed and the total sum Σδ _i ′ of the displacement increase amount of each spring element due to the envelope effect are also uniquely determined. Substituting these sums (Σδ _i + Σδ _i ′) into an equation representing the relationship between the total displacement amount and the tire vertical load in equation (9) yields the following equation (S36).
F _flat '= M (Σδ _i + Σδ _i ') (11)

Of the displacement increase amount δ ′ = L (p) (ξ _i −δ _i ), ξ _i and δ _i are already known. Therefore, by solving F _flat ′ = F _curb for each value of p, the displacement increase amount δ A correction function L (p) for obtaining _i ′ can be determined (S38).

  Thus, according to the second embodiment, it is possible to determine the correction function L (p) for obtaining the displacement increase amount due to the envelope effect without calculating the spring constant K of the spring element.

  FIG. 9 is a graph showing a calculation result of the tire vertical load F with respect to the pressing amount p when the radial spring model according to the embodiment is used. The horizontal axis represents the pressing amount p of the flat plate or the protrusion, and the vertical axis represents the tire vertical load F. Also, the black dots represent experimental values, and the solid line represents the calculation results using the radial spring model. As shown in the figure, it can be seen that a calculation result equivalent to the experimental value can be obtained when either the flat plate or the protrusion is pressed.

  FIG. 10 is a functional block diagram showing a configuration of the tire vertical load calculation device 10 according to the embodiment. Each block shown here can be realized in terms of hardware by elements and electric circuits such as a CPU and memory of a computer, and in terms of software by a computer program or the like. It is drawn as a functional block to be realized. Therefore, those skilled in the art will understand that these functional blocks can be realized in various forms by a combination of hardware and software.

The model storage unit 12 stores a radial spring model that employs δ _i ′ = L (p) (ξ _i −δ _i ) as a calculation formula for obtaining a displacement increase amount considering the envelope effect.
The data input unit 18 receives input of measurement results when a flat plate pressing test and a protrusion pressing test are performed using real tires. The data storage unit 16 stores those data.
The model calculation unit 14 performs calculation using a radial spring model.
The identification unit 20 identifies the correction function L (p) so as to approximate the measurement result stored in the data storage unit 16 using the process of either the first or second embodiment.
The modified model storage unit 22 stores a radial spring model using the identified correction function L (p) in consideration of the envelope effect.
The tire load calculation unit 24 calculates the tire vertical load with respect to a given pressing amount for both the flat plate and the protrusion using the radial spring model in the correction model storage unit 22.

As described above, according to the present invention, in the radial spring model, the correction equation for obtaining the displacement increase amount δ _i ′ of the spring element E _i considering the envelope effect is expressed as δ _i ′ = L (p) ( as ξ _i -δ _i), expressed as a function including the difference term (ξ _i -δ _i) the displacement xi] _i and the displacement [delta] _i of the spring element during the pressing protrusion of the spring elements during the pressing flat I did it. In this equation, when a flat plate is pressed, ξ _i = δ _i , so δ _i ′ = 0. Therefore, the displacement increase amount due to the envelope effect is not calculated when the flat plate is pressed. Therefore, the tire vertical load can be obtained using the same radial spring model regardless of whether the flat plate or the protrusion is pressed. In other words, there is no need to use a different radial spring model depending on which of the flat plate or protrusion is pressed.

  The present invention has been described based on some embodiments. These embodiments are merely examples, and modifications such as arbitrary combinations of the embodiments, each component of the embodiments, and any combination of the processing processes are also within the scope of the present invention. It will be understood by those skilled in the art.

  The present invention is not limited to the above-described embodiments, and various modifications such as design changes can be added based on the knowledge of those skilled in the art. The configuration shown in each drawing is for explaining an example, and can be appropriately changed as long as the configuration can achieve the same function.

  In the embodiment, the tire vertical load at the time of pressing the flat plate or the protrusion is obtained, but it goes without saying that the same radial spring model can be used when obtaining other physical quantities.

  The method of the present invention can also be applied to a model in which each element constituting the radial spring model includes a spring element and a damper element in parallel.

  Embodiment 1 or 2 described above can also be applied to a three-dimensional radial spring model. FIG. 11 shows an example of such a three-dimensional tire model. A plurality of the two-dimensional radial spring models M of the embodiment are arranged on the same central axis at an appropriate interval 1 over the tire width. By doing so, it is possible to calculate the tire vertical load generated in the tire when the three-dimensional protrusion on the road surface passes.

It is a figure which shows the radial spring model for calculating the load which generate | occur | produces on a tire by the reaction force from a road surface. FIG. 4 is a diagram showing a state where a protrusion A is pressed against a tire T. It is a figure which shows a mode that the protrusion A was pressed on the outer periphery B of a radial spring model. It is a figure which shows a mode that the flat plate D was pressed on the outer periphery B of a radial spring model. It is a figure which shows a mode that the processus | protrusion A was pressed on the outer periphery B of a radial spring model when it assumed that there was no envelope effect. Is a diagram showing a state of correcting the displacement of the spring element E _i in consideration of the envelope effect. It is a flowchart which shows the determination process of the correction function L (p) based on one Embodiment of this invention. It is a flowchart which shows the determination process of the correction function L (p) based on another embodiment of this invention. It is a graph showing the calculation result of the tire up-and-down load F with respect to the pressing amount p when using the radial spring model according to the embodiment. It is a functional block diagram which shows the structure of the tire up-and-down load calculation apparatus according to embodiment. It is a figure which shows an example of a three-dimensional tire model.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Tire vertical load calculation apparatus, 12 Model storage part, 14 Model calculation part, 16 Data storage part, 18 Data input part, 20 Identification part, 22 Correction model storage part, 24 Tire load calculation part

Claims (4)

In a tire model in which a plurality of spring elements E _i are arranged radially from the tire center, a method of expressing the displacement increase amount δ _i ′ of the spring element E _i due to the envelope effect at the time of pressing the protrusion on the tire as follows:
δ _i ′ = L (p) (ξ _i −δ _i )
Where p represents the pressing amount of the protrusion or the flat plate, ξ _i represents the displacement amount of each spring element E _i when the flat plate is pressed against the tire model, and δ _i represents the protrusion when it is assumed that there is no envelope effect. The displacement amount of each spring element E _i when pressed against the tire model is represented, and L (p) represents a function of p. Using a tire model in which a plurality of spring elements E _i are arranged radially from the tire center, a method of calculating a tire generated load generated in the tire when an object is pressed against the tire,
Δ _i ′ = L (p) (ξ _i −δ _i ) (where p is the protrusion) as a calculation formula for obtaining the displacement increase amount δ _i ′ of the spring element E _i considering the envelope effect when the protrusion is pressed against the tire Or, it represents the pressing amount of the flat plate, ξ _i represents the displacement amount of each spring element E _i when the flat plate is pressed against the tire model, and δ _i pressed the protrusion against the tire model when it was assumed that there was no envelope effect. Representing the amount of displacement of each spring element E _i when L (p) represents the function of p),
A process of measuring a tire generated load at the time of pressing the flat plate generated on the tire when the flat plate is pressed against the tire by a predetermined pressing amount;
A process of determining a spring constant of a spring element in the tire model based on the tire generation load at the time of pressing the flat plate;
A process of measuring tire generated load at the time of pressing the protrusion generated on the tire when the protrusion is pressed against the tire by a predetermined pressing amount;
The calculation formula results obtained displacement increment obtained [delta] _{i 'the} sum of the amount of displacement _{δ i (δ i + δ i} ' a) by substituting the tire model with the tire load generated when pressing the protrusion The process of identifying L (p) to be equal to
Using the identified L (p) to calculate the tire generated load when the protrusion or flat plate is pressed according to the tire model;
A tire generated load calculation method comprising: Using a tire model in which a plurality of spring elements E _i are arranged radially from the tire center, a method of calculating a tire generated load generated in the tire when an object is pressed against the tire,
Δ _i ′ = L (p) (ξ _i −δ _i ) (where p is the protrusion) as a calculation formula for obtaining the displacement increase amount δ _i ′ of the spring element E _i considering the envelope effect when the protrusion is pressed against the tire Or, it represents the pressing amount of the flat plate, ξ _i represents the displacement amount of each spring element E _i when the flat plate is pressed against the tire model, and δ _i pressed the protrusion against the tire model when it was assumed that there was no envelope effect. Representing the amount of displacement of each spring element E _i when L (p) represents the function of p),
A process of measuring a tire generated load F _flat at the time of pressing the flat plate generated on the tire when the flat plate is pressed against the tire by a predetermined pressing amount;
A process of obtaining F _flat = M (ξ _all ), which is a relational expression between the tire generated load F _flat at the time of pressing the flat plate and the total displacement amount ξ _all of the spring element E _i ;
A process of measuring a tire generated load _Fcurb at the time of pressing the protrusion generated on the tire when the protrusion is pressed against the tire by a predetermined pressing amount;
The total displacement of Sigma] [Delta] _i of the spring element when the pressing projections, _'sum of (Σδ _{i +} Σδ _i' the sum Sigma] [Delta] _i displacement increment of the spring element according to the envelope effect) were substituted into the equation results and process of obtaining the _{F flat '= M (Σδ i} + Σδ i') is,
Identifying L (p) such that F _flat ′ = F _curb ,
Using the identified L (p) to calculate the tire generated load when the protrusion or flat plate is pressed according to the tire model;
A tire generated load calculation method comprising: A tire model in which a plurality of spring elements E _i are arranged radially from the tire center, and δ _i ′ = is a calculation formula for obtaining a displacement increase amount δ _i ′ considering an envelope effect when a protrusion or a flat plate is pressed against the tire. L (p) (ξ _i −δ _i ) (where p represents the pressing amount of the projection or the flat plate, ξ _i represents the displacement amount of each spring element E _i when the flat plate is pressed against the tire model, and δ _i Represents a displacement amount of each spring element E _i when the protrusion is pressed against the tire model when there is no envelope effect, and L (p) represents a function of p). A storage unit;
A data input unit that accepts input of real tire data, which is a result of measuring the tire generated load at the time of flat plate pressing and the tire generated load at the time of pressing against various pressing amounts;
An identification unit for identifying L (p) from a comparison between the result calculated using the tire model and the actual tire data;
A load calculation unit that calculates a displacement increase amount δ _i ′ of the spring element E _i using the identified L (p), and calculates a tire generation load for a given pressing amount p of the flat plate or the projection;
A tire generated load calculating device comprising:

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