JP7428883B2 - Method and device for estimating rubber flow characteristics - Google Patents

Description

The present invention relates to a method and apparatus for estimating the flow characteristics of rubber, and more particularly to a method and apparatus capable of estimating the flow characteristics of rubber during vulcanization with higher accuracy.

When manufacturing rubber products such as tires, a molded article made of unvulcanized rubber is vulcanized in a mold. Alternatively, unvulcanized rubber may be injected into a mold to produce rubber products. The unvulcanized rubber flows within the mold and is shaped into a predetermined shape by the mold. If unvulcanized rubber does not flow sufficiently, it may not be possible to mold it into a predetermined shape, which greatly affects the quality of the rubber product. This flow characteristic also affects the vulcanization time, ie, the productivity of the rubber product.

Therefore, the behavior of unvulcanized rubber during vulcanization is simulated. In this simulation, index data indicating the flow characteristics of the rubber is required, and viscosity is used as a typical index data. Elements of rubber viscosity can be broadly divided into basic viscosity elements, which are affected by shear rate and temperature, and thermosetting elements, which are affected by thermal history (vulcanization temperature and vulcanization time). A capillary viscometer (capillary rheometer) is known as a general method for determining basic viscosity factors. A flat plate rotational viscometer (curastometer) is known as a general method for determining thermosetting elements.

When calculating the overall viscosity by combining the basic viscosity element and thermosetting element determined by the above method and using it for simulating the behavior of vulcanized rubber, the actual behavior of unvulcanized rubber and the simulation results It is difficult to achieve a sufficiently high level of consistency. This is because the basic viscosity element and the thermosetting element are determined using different methods (different conditions), and variations (inconsistency) occur due to the differences in the methods.

As a method for measuring the viscosity of unvulcanized rubber, it is possible to measure the viscosity of unvulcanized rubber by filling a flow channel with a certain cross-sectional shape with unvulcanized rubber, and measuring the detected pressure and flow rate in the flow channel. A method of calculating viscosity based on the tip position and detection speed of sulfur rubber has been proposed (see Patent Document 1). However, this method does not separately grasp the basic viscosity element and thermosetting element of the unvulcanized rubber. Therefore, there is room for improvement in estimating the flow characteristics of unvulcanized rubber during vulcanization with higher accuracy.

JP 2019-27959 Publication

An object of the present invention is to provide a method and apparatus that can estimate the flow characteristics of rubber during vulcanization with higher accuracy.

In order to achieve the above object, the rubber flow characteristic estimation method of the present invention estimates the basic viscosity element and thermosetting element of the viscosity during vulcanization of a target rubber in which a vulcanizing agent is blended with unvulcanized rubber. A flow characteristic estimating device comprising a predetermined flow path having a constant cross-sectional shape, a flow path heating means for heating the flow path to a predetermined temperature, the target rubber having a predetermined viscosity at a set specified temperature, and the target rubber. Comparison rubbers prepared in a formulation in which the vulcanizing agent is excluded from the rubber and prepared to have a viscosity equivalent to the predetermined viscosity at the specified temperature are individually injected into the flow path under the same conditions to fill the flow path. an injection means for causing the rubber to flow in the flow path, a flow rate detection unit that acquires flow rate data in the flow path of each of the rubbers, and a tip position detection unit that acquires data on changes in the tip position of each of the rubbers in the flow path over time. a pressure difference detection unit that acquires pressure difference data between two detection positions spaced apart in the longitudinal direction of the flow path of each of the rubber; a calculation unit that receives input, and the calculation unit calculates the shear rate dependence of the viscosity as the basic viscosity element of the target rubber based on the flow rate data and the pressure difference data; The viscosity at the same tip position of each of the rubbers in the flow path is calculated based on the data, the temporal change data, and the pressure difference data, and the calculated viscosity at the same tip position of each of the rubbers is calculated. The present invention is characterized in that the thermal history dependence of the viscosity is calculated as the thermosetting element of the target rubber based on the comparison.

The rubber flow characteristic estimating device of the present invention is a rubber flow characteristic estimating device that estimates the basic viscosity factor and thermosetting factor of the viscosity during vulcanization of a target rubber in which a vulcanizing agent is blended with unvulcanized rubber. a predetermined flow path having a constant cross-sectional shape; a flow path heating means for heating the flow path to a predetermined temperature; Comparative rubbers prepared in a formulation in which the viscosity is the same as the predetermined viscosity at the specified temperature are individually injected into the flow path under the same conditions, and the flow paths are filled with the comparative rubbers, and the rubbers are flowed while being filled in the flow path. a flow rate detection unit that acquires flow rate data in the flow path of each of the rubbers; a tip position detection unit that acquires time-varying data of a tip position of each of the rubbers in the flow path; a pressure difference detection unit that acquires pressure difference data between two detection positions spaced apart in the longitudinal direction of the flow path; and a calculation unit to which the flow rate data, the temporal change data, and the pressure difference data are input. The calculation unit calculates the shear rate dependence of the viscosity as the basic viscosity element of the target rubber based on the flow rate data and the pressure difference data, and the flow rate data, the temporal change data, and The viscosity at the same tip position of each of the rubbers in the flow path is calculated based on the pressure difference data, and based on the comparison of the calculated viscosity, the viscosity of the thermosetting element of the target rubber is calculated. The present invention is characterized by a configuration in which the thermal history dependence of viscosity is calculated.

According to the present invention, each of the target rubber and the comparative rubber is individually injected into the heated flow channel under the same conditions, and the rubbers obtained by flowing the filled state are provided in the flow channel. Flow rate data and tip position change data over time, and pressure difference data between two detection positions spaced apart in the longitudinal direction of the flow path of each of the rubbers are used. Using this flow rate data and pressure difference data, the shear rate dependence of viscosity can be calculated as a basic viscosity element of the target rubber. Further, based on a comparison of the viscosity at the same tip position of each of the rubbers in the flow path calculated using the flow rate data, temporal change data, and pressure difference data, the target rubber is determined as a thermosetting element of the target rubber. The thermal history dependence of rubber viscosity can be calculated. In this way, the basic viscosity element and thermosetting element of the viscosity of the target rubber can be determined by one method under the same conditions. Therefore, in order to prevent the problem that the calculation results vary (inconsistency) due to the difference in the method of understanding each element, such as when the basic viscosity element and the thermosetting element are determined using different methods. becomes advantageous. Therefore, by understanding the basic viscosity element and thermosetting element according to the present invention, it becomes possible to estimate the flow characteristics of the target rubber during vulcanization with higher accuracy.

FIG. 2 is an explanatory diagram illustrating the rubber flow characteristic estimating device of the present invention with a cylinder and a flow path in cross section. FIG. 2 is an explanatory diagram illustrating a state in which rubber is injected into the channel of FIG. 1; FIG. 2 is a graph diagram illustrating changes over time in the position of the tip of rubber injected into a flow path. FIG. 2 is a graph diagram illustrating the relationship between the shear rate and viscosity of rubber injected into a flow path. FIG. 3 is a graph diagram illustrating a change in viscosity over time at a tip position of rubber injected into a flow path. FIG. 2 is a graph diagram illustrating the relationship between the tip position and viscosity of rubber injected into a flow path. FIG. 3 is a graph diagram illustrating the relationship between the tip position of the rubber injected into the flow path and the viscosity increase ratio. FIG. 2 is a graph diagram illustrating a change over time in the viscosity increase rate at the tip of the rubber injected into the flow path.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method and apparatus for estimating rubber flow characteristics of the present invention will be described below based on the embodiments shown in the drawings.

The present invention estimates the flow characteristics during the vulcanization process of target rubber R1, which is an unvulcanized rubber mixed with a vulcanizing agent. In order to estimate the viscosity of the target rubber R1, which is an index indicating the flow characteristics, with higher accuracy, this viscosity is calculated using the above-mentioned basic viscosity element MA (shear rate dependence) and thermosetting element MB (thermal history dependence). Differentiate and understand. One of the characteristics of the present invention is that it uses the target rubber R1 and an unvulcanized rubber R2 (hereinafter referred to as comparative rubber R2) that is a mixture of the target rubber R1 and excluding the vulcanizing agent.

As a preparatory work, a target rubber R1 and a comparison rubber R2 having the same predetermined viscosity at a set specified temperature are prepared. This specified temperature is a temperature at which the crosslinking reaction of the target rubber R1 is not promoted, and may be set to, for example, about 10° C. to 50° C. or room temperature.

The target rubber R1 is manufactured by blending various compounding agents including a vulcanizing agent with raw rubber and kneading the mixture to obtain a predetermined viscosity. Comparative rubber R2 is produced by blending and kneading various compounding agents except for the vulcanizing agent from the compounding of target rubber R1 to give a predetermined viscosity. Since the target rubber R1 and the comparative rubber R2 cannot have exactly the same viscosity, it is sufficient that they have the same viscosity. Equivalent viscosity means that the viscosity (Pa·s) of the comparative rubber R2 is approximately ±1% of the viscosity (Pa·s) of the target rubber R1. At this time, the viscosity of the target rubber R1 and the comparative rubber R2 may be confirmed using a general viscometer such as a capillary rheometer.

If the blending ratio of the vulcanizing agent in the target rubber R1 is small and the influence on the viscosity can be ignored, then the comparative rubber R2 is produced with a formulation in which only the vulcanizing agent is simply excluded from the formulation of the target rubber R1. If the blending ratio of the vulcanizing agent in target rubber R1 is relatively large and its influence on viscosity cannot be ignored, for example, vulcanization may be The amount of the remaining compounding ingredients of the target rubber R1 excluding the compounding agent is adjusted. This makes the target rubber R1 and the comparative rubber R2 have the same viscosity. The difference between the target rubber R1 and the comparative rubber R2 is essentially only the presence or absence of a vulcanizing agent.

Since the target rubber R1, which is a plastic body, contains a vulcanizing agent, heating causes a crosslinking reaction and transforms it into an elastic body. Comparative rubber R2 does not contain a vulcanizing agent, so even when heated, no crosslinking reaction occurs and it remains a plastic body.

The unvulcanized rubber flow characteristic estimating device 1 (hereinafter referred to as estimating device 1) of the present invention illustrated in FIGS. 1 and 2 includes a predetermined flow path 2 having a constant cross-sectional shape, a flow path heating means 2a, An injection means 3 for injecting the rubber R (target rubber R1 and comparison rubber R2) into the flow path 2, a flow rate detection section 9 for acquiring rubber flow rate Q data in the flow path 2, a pressure sensor 7, and a calculation section 10. It is equipped with In this embodiment, the estimation device 1 further includes two temperature sensors 8a and 8b. Detection data from the flow rate detection section 9, the pressure sensor 7, and the temperature sensors 8a and 8b is input to the calculation section 10.

The flow path 2 may be formed in a pipe or a metal piece such as a mold. The cross-sectional shape of the flow path 2 may be a polygon such as a circle, an ellipse, a triangle, a square, or a pentagon, but a circular cross-section that is generally used in actual manufacturing processes is preferable. The cross-sectional area of this channel 2 is substantially constant and extends straight over its entire length. Although the channel 2 may extend in a curved manner, it is preferably straight.

The channel heating means 2a heats the channel 2 to a predetermined temperature. For example, a heater that covers the flow path 2 is used as the flow path heating means 2a. The flow path 2 is heated by the flow path heating means 2a to a predetermined temperature at which the crosslinking reaction of the target rubber R1 is promoted, and this predetermined temperature is, for example, an arbitrary temperature between 100° C. and 250° C.

The injection means 3 injects the rubber R into the channel 2 and causes it to flow in a filled state. As the injection means 3, for example, a rubber extruder or injection machine can be used. In this embodiment, the injection means 3 includes a cylindrical cylinder 4 in which the rubber R is accommodated, a plunger 5a disposed inside the cylinder 4, and a drive mechanism 5c that moves the plunger 5a in the injection direction of the rubber R. An extruder is used. The inner circumferential surface of the cylindrical portion of the cylinder 4 having a constant inner diameter and the outer circumferential surface of the cylindrical portion having a constant outer diameter of the plunger 5a face each other with almost no gap. The injection means 3 further includes a temperature adjustment section 5b that adjusts the temperature of the rubber R, and a control section 6 that controls the operation of the temperature adjustment section 5b and the drive mechanism 5c. The degree of heating by the channel heating means 2a is also controlled by the control unit 6.

In this embodiment, the plunger 5a serves as an injection moving part that moves in the injection direction of the rubber R and injects the rubber R into the flow path 2. The amount of movement of the plunger 5a per unit time in the injection direction of the rubber R is detected by the flow rate detection section 9, and this detection data is input to the calculation section 10.

The pressure sensor 7 detects pressure at a detection position arranged in the flow path 2 . The detection position of the pressure sensor 7 is set at a position where the rubber R flows stably.

The temperature sensors 8a and 8b detect the temperature of the rubber R at their respective detection positions. This embodiment includes a temperature sensor 8a that detects the temperature of the rubber R inside the cylinder 4, and a temperature sensor 8b that detects the temperature of the flow path 2 (the temperature of the rubber R in the flow path 2).

A computer or the like can be used as the calculation unit 10. The calculation unit 10 compares the detection data (sensed temperature) by the temperature sensors 8a and 8b with a preset target temperature, and transmits the comparison result to the control unit 6. The control unit 6 controls the heating by the temperature adjustment unit 5b and the flow path heating means 2a so that there is no difference between the detected temperature and the target temperature. In addition to the various data described above, the calculation unit 10 includes the cross-sectional area of the plunger 5a (inner cross-sectional area of the cylinder 4), the cross-sectional area of the flow path 2, the length of the flow path 2, and the pressure sensor in the flow path 2. Known data such as detection positions of temperature sensors 7 and temperature sensors 8b and 8c are input.

When the calculation unit 10 calculates the viscosity μ of the rubber R, the following equation (1) is used. This equation (1) is a calculation equation for the pressure loss of Newtonian fluid in a circular pipe flow path.
Pressure loss △P=(8・μ・Q・L)/(πr ⁴ )...(1)
Here, ΔP is the pressure difference at the distance L between the channels 2, Q is the flow rate of the rubber R in the channels 2, and r is the radius of the channels 2. Since the pressure at the tip position of the rubber R in the flow path 2 becomes zero, the pressure difference ΔP between the detection position of the pressure sensor 7 and the tip position of the rubber R becomes detection data (detected pressure) by the pressure sensor 7, The separation distance between the tip position of the rubber R and the detection position of the pressure sensor 7 can be set to L.
Note that equation (1) is a calculation equation that is applied to a circular pipe flow path, but if the cross-sectional shape of the flow path 2 is other than circular, equation (1) is used with an arrangement.

Next, a procedure for grasping the basic viscosity element MA (viscosity dependence on shear rate) and thermosetting requirement MB (viscosity dependence on thermal history) of the target rubber R1 will be explained.

The following measurements are performed individually on each of the target rubber R1 and the comparative rubber R2 under the same conditions. Since either rubber R1 or R2 may be measured first, in this embodiment, the target rubber R1 and the comparative rubber R2 will be described as rubber R, respectively.

As illustrated in FIG. 1, rubber R is stored in the cylinder 4 of the injection means 3. At this time, the rubber R is heated by the temperature control section 5b. The flow path 2 is heated to a predetermined temperature by the flow path heating means 2a.

Next, as illustrated in FIG. 2, the plunger 5a is moved forward to inject the rubber R from the cylinder 4 into the flow path 2. The cylinder 4 and the flow path 2 are continuous, and the rubber R flows without interruption between the cylinder 4 and the flow path 2, filling the flow path 2. That is, the rubbers R1 and R2 are each injected into the flow path 2 under the same conditions and pass through the detection position of the pressure sensor 7. The pressure at the detection position of the flowing rubber R is detected by the pressure sensor 7.

The amount of movement of the plunger 5a per unit time detected by the flow rate detection section 9 is input to the calculation section 10. Further, detection data from the pressure sensor 7 is input to the calculation section 10 . The calculation unit 10 performs calculation processing using input data and known data input in advance.

The basic viscosity element MA (shear rate dependence of viscosity) of the target rubber R1 is calculated by the following calculation.

Since the rubber R can be regarded as an incompressible fluid, the flow rate Q of the rubber R is the volume of the section in which the plunger 5a moves within the cylinder 4 per unit time. Since the cross-sectional area of the plunger 5a is known, the calculation unit 10 calculates the flow rate Q of the rubber R in the flow path 2 based on the amount of movement of the plunger 5a per unit time and the cross-sectional area of the plunger 5a. be done. That is, the flow rate detection section 9 acquires the flow rate Q data.

The position of the tip of the rubber R in the flow path 2 can be calculated based on the flow rate Q. The volume of the section in which the plunger 5a moves per unit time inside the cylinder 4 (flow rate Q) is the same as the volume that the rubber R moves in the flow path 2 per unit time. Since the cross-sectional area of the flow path 2 is known, the calculation unit 10 calculates the tip position of the rubber R in the flow path 2 based on the flow rate Q and the cross-sectional area of the flow path 2.

As a result, data on changes over time in the tip positions of the respective rubbers R1 and R2 in the flow path 2 illustrated in FIG. 3 is obtained. The solid line shows the data for the target rubber R1, and the broken line shows the data for the comparison rubber R2. Although the tip positions of the respective rubbers R1 and R2 are initially the same, the fluidity of the target rubber R1 decreases as it is vulcanized. At the time of elapsed time t, the tip position of the target rubber R1 becomes almost unchanged at X1, and the tip position of the comparison rubber becomes X2, which is advanced from X1.

Detection data from the pressure sensor 7 and the flow rate detection section 9 is used to obtain data on changes over time in the tip positions of the respective rubbers R1 and R2 in the flow path 2. Therefore, the pressure sensor 7 and the flow rate detection section 9 function as a tip position detection section that obtains data on changes in the tip position of the rubber R over time.

Furthermore, since the tip position of the rubber R flowing in the flow path 2 is known and the detection position of the pressure sensor 7 in the flow path 2 is known, the separation distance L between the tip position of the rubber R and the detection position of the pressure sensor 7 is known. It also becomes clear. Since the pressure at the tip of the rubber R is zero, the calculation unit 10 acquires the detection data (detected pressure) of the pressure sensor 7 as pressure difference data between this separation distance L.

Detection data from the pressure sensor 7 and the flow rate detection section 9 is used to obtain pressure difference data between two detection positions spaced apart in the longitudinal direction of the flow path 2 of each rubber R1, R2. Therefore, the pressure sensor 7 and the flow rate detection section 9 also function as a pressure difference detection section that acquires pressure difference data of the rubber R.

This acquired pressure difference data is substituted as △P in equation (1), and the calculated flow rate Q, separation distance L, and radius r of flow path 2 are substituted into equation (1), so that the viscosity μ is Calculated. At this time, the shear rate y of the rubber R relative to the flow path 2 is y=4Q/(πr ³ ), so the relationship between the viscosity μ and the shear rate y illustrated in FIG. 4 can be understood.

The dependence of the viscosity μ on the shear rate y (shear stress) is the same regardless of the presence or absence of vulcanization if the viscosity is the same, so the target rubber R1 and the comparative rubber R2 can be represented by the same line segment. That is, the data measured using the comparative rubber R2 can be regarded as the data of the target rubber R1. In this way, as the basic viscosity element MA of the target rubber R1, the viscosity change rate depending on the shear rate y of the target rubber R1, which is shown in FIG. 4 showing the shear rate dependence of viscosity, is calculated. Since the relationship shown in FIG. 4 changes depending on the temperature, it is preferable to obtain the relationship at a plurality of different temperatures of the rubber R.

The thermosetting element MB (thermal history dependence of viscosity) is calculated by the following calculation.

Using the data on changes over time of the tip position illustrated in FIG. 3 and the viscosity μ calculated as described above, calculating the data on changes over time in the viscosity μ of each rubber R1 and R2 results in the results illustrated in FIG. 5. . The solid line shows the data for the target rubber R1, and the broken line shows the data for the comparison rubber R2. The viscosity μ of each of the rubbers R1 and R2 is initially the same, but as the target rubber R1 is vulcanized, it increases rapidly at a certain point in time. At the time of elapsed time t, the viscosity of the target rubber R1 becomes μ1, and the viscosity of the comparative rubber R2 becomes μ2, which is lower than μ1.

The data in FIG. 5 is a comparison of the viscosity μ of the respective rubbers R1 and R2 over the same elapsed time. However, at the same elapsed time, the tip positions of the respective rubbers R1 and R2 are different. Therefore, when the viscosity μ at the tip position of each rubber R1 and R2 is calculated using the data on changes over time of the tip position illustrated in FIG. 3 and the viscosity μ calculated as described above, the result shown in FIG. 6 is obtained. . The solid line shows the data for the target rubber R1, and the broken line shows the data for the comparison rubber R2. The viscosity μ at the tip of each of the rubbers R1 and R2 is initially the same, but when the target rubber R1 is vulcanized and the tip reaches a certain position, it increases rapidly. When the respective rubbers R1 and R2 are at the same tip position X, the viscosity of the target rubber R1 is μ1, and the viscosity of the comparative rubber R2 is μ2, which is lower than μ1.

Here, the viscosity μ of the comparative rubber R2 does not change over time due to the influence of vulcanization, that is, it does not harden due to heat. Therefore, based on the data of the comparative rubber R2 in FIG. Rewriting the data results in the result illustrated in FIG. In FIG. 7, the data of the viscosity μ of the comparative rubber R2 is set as 1, and the vertical axis is expressed as the viscosity increase ratio with respect to the viscosity of the comparative rubber R1. When the respective rubbers R1 and R2 are at the same tip position X, the viscosity increase ratio of the target rubber R1 is μ1/μ2, and the viscosity increase ratio of the comparison rubber R2 is μ2/μ2, so it is always 1.

If the data in FIG. 7 is rewritten with the horizontal axis as the elapsed time, it becomes the data shown in FIG. 8. In FIG. 8, the viscosity increase rate of the target rubber R1 increases rapidly at a certain point in time, and the viscosity increase rate of the comparative rubber R2 remains 1 times without changing over time. In this way, as the thermosetting element MB at the viscosity μ of the target rubber R1, the viscosity change rate depending on the thermal history of the target rubber R1, which is shown in FIG. 8 showing the thermal history dependence of viscosity, is calculated. Since the relationship shown in FIG. 8 changes depending on the vulcanization temperature, it is preferable to obtain the relationship at a plurality of different temperatures of the rubber R (temperature of the flow path 2).

As described above, in the present invention, the basic viscosity element MA and thermosetting element MB of the viscosity of the target rubber R1 can be determined by one method under the same conditions. Since the basic viscosity element MA and thermosetting element MB are not determined using separate methods, there is a problem that the calculation results vary (inconsistency) due to the difference in the method of determining the respective elements MA and MB. Prevented. Therefore, by understanding the basic viscosity element MA and the thermosetting element MB, the flow characteristics of the target rubber R1 during vulcanization can be estimated with higher accuracy.

When simulating the behavior of the target rubber R1 during the vulcanization process, the above-described calculated basic viscosity element MA and thermosetting element MB are used as index data (viscosity) indicating the flow characteristics of the target rubber R1. These basic viscosity element MA and thermosetting element MB are applied to a simulation model, and the simulation model is caused to flow in a mold using a computer to confirm its behavior. The basic viscosity element MA and thermosetting element MB are used to manufacture various rubber products such as tires, hoses, fenders, and conveyor belts, rubber members that make up these rubber products, and rubber manufacturing equipment members such as bladders. It can be used to simulate the behavior of unvulcanized rubber during processing.

1 Flow characteristic estimation device 2 Flow path 2a Flow path heating means 3 Injection means 4 Cylinder 5a Plunger 5b Temperature adjustment section 5c Drive mechanism 6 Control section 7 Pressure sensors 8a, 8b Temperature sensor 9 Flow rate detection section 10 Calculation section R1 Target rubber R2 comparison rubber

Claims (3)

A rubber flow characteristic estimation method for estimating the basic viscosity element and thermosetting element of the viscosity during vulcanization of a target rubber in which a vulcanizing agent is blended with unvulcanized rubber, the method comprising:
Prepare the target rubber having a predetermined viscosity at a predetermined temperature, and a comparative rubber prepared by excluding the vulcanizing agent from the target rubber to have a viscosity equivalent to the predetermined viscosity at the predetermined temperature. The target rubber and the comparison rubber are each individually injected into a predetermined heated flow path with a constant cross-sectional shape under the same conditions, and the filled state is made to flow, and the flow rate data of each of the rubbers in the flow path is obtained. and time-dependent change data of the tip position, and pressure difference data between two detection positions spaced apart in the longitudinal direction of the flow path of each of the rubbers, and use the flow rate data and the pressure difference data. By calculating the shear rate dependence of the viscosity as the basic viscosity element of the target rubber, and using the flow rate data, the temporal change data, and the pressure difference data, each in the flow path can be calculated. A rubber characterized in that the viscosity at the same tip position of the rubber is calculated, and the thermal history dependence of the viscosity as the thermosetting element of the target rubber is calculated based on a comparison of the calculated viscosity. A method for estimating flow characteristics. The pressure difference data of each of the rubbers is determined by the detection data of a pressure sensor at one detection position through which each of the rubbers arranged in the flow path passes, and the pressure difference data of each of the rubbers at the time of acquisition of this detection data. 2. The rubber fluidity estimation method according to claim 1, wherein the rubber fluidity estimation method is obtained using a pressure at a tip position in a flow path. A rubber flow characteristic estimating device for estimating the basic viscosity element and thermosetting element of the viscosity during vulcanization of a target rubber in which a vulcanizing agent is blended with unvulcanized rubber,
A predetermined flow path having a constant cross-sectional shape, a flow path heating means for heating the flow path to a predetermined temperature, the target rubber having a predetermined viscosity at the set specified temperature, and the vulcanizing agent being removed from the target rubber. Injecting means for individually injecting comparative rubbers prepared to have a viscosity equivalent to the predetermined viscosity at the specified temperature into the flow path under the same conditions and flowing while filling the flow path; a flow rate detection unit that acquires flow rate data in the flow path of each of the rubbers; a tip position detection unit that acquires data on changes over time in the tip position of each of the rubbers in the flow path; A pressure difference detection section that acquires pressure difference data between two detection positions spaced apart in the longitudinal direction of the path, and a calculation section into which the flow rate data, the temporal change data, and the pressure difference data are input. ,
Based on the flow rate data and the pressure difference data, the calculation unit calculates the shear rate dependence of the viscosity as the basic viscosity element of the target rubber, and the flow rate data, the temporal change data, and the pressure difference data. The viscosity at the same tip position of each of the rubbers in the flow path is calculated based on, and based on the comparison of the calculated viscosity, the thermal history of the viscosity as the thermosetting element of the target rubber is calculated. A rubber flow characteristic estimating device characterized by having a configuration in which dependence is calculated.

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