JP2019189921A - Estimation device, estimation method and estimation program - Google Patents

Abstract

To estimate a size of graphite crystal in flaky graphite cast iron effectively.SOLUTION: An acquisition unit 12 acquiring an eutectic cell size of flaky graphite cast iron, and a graphite size estimation unit 13 estimating the size of the graphite of the flaky graphite cast iron bigger when the acquired eutectic cell size is big.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to an estimation apparatus, an estimation method, and an estimation program, and more particularly, to a technique for estimating a graphite dimension of cast iron.

  Cast iron is widely used as a material for automobile parts such as engines and industrial machines. Cast iron is roughly classified into flake graphite cast iron and spheroidal graphite cast iron. The structure and mechanical properties of flake graphite cast iron and spheroidal graphite cast iron can be predicted by obtaining the cooling rate of each part during casting by casting analysis (see, for example, Patent Documents 1 and 2).

JP, 2015-112673, A JP 2013-082003 A

  By the way, in flake graphite cast iron castings (hereinafter also simply referred to as flake graphite cast iron), graphite crystals that are carbon crystals are flakes, and the size (size) of the graphite crystals is flake graphite cast iron. It is thought to greatly affect the fatigue limit characteristics of the steel. According to the above casting analysis, the structure and mechanical properties of flake graphite cast iron can be predicted, but the graphite dimensions cannot be grasped, and as a result, the fatigue limit cannot be estimated. .

  The technology of the present disclosure has been made in view of the above problems, and an object thereof is to effectively estimate the size of graphite crystals of flake graphite cast iron.

The estimation apparatus of the present disclosure includes an acquisition unit that acquires a eutectic cell size of flake graphite cast iron,
And a graphite size estimation unit that estimates a larger size of the graphite of the flake graphite cast iron as the acquired eutectic cell size becomes larger.

  Moreover, it is preferable that the estimation apparatus of this indication is further provided with the fatigue limit estimation part which estimates the fatigue limit of the flake graphite cast iron high, so that the estimated dimension of the graphite becomes small.

  The estimation method of the present disclosure includes a step of acquiring a eutectic cell size of flake graphite cast iron, and a step of estimating a size of graphite of the flake graphite cast iron as the acquired eutectic cell size increases. It is characterized by having.

  Moreover, it is preferable that the estimation method of this indication further has the step which estimates the fatigue limit of the flake graphite cast iron high, so that the estimated dimension of the graphite becomes small.

  An estimation program according to the present disclosure includes a computer, an acquisition unit that acquires a eutectic cell size of flake graphite cast iron, and a graphite that estimates a size of graphite of the flake graphite cast iron as the acquired eutectic cell size increases. It is made to function as a dimension estimation part.

  In addition, it is preferable that the estimation program of the present disclosure further causes the computer to function as a fatigue limit estimation unit that estimates the fatigue limit of the flake graphite cast iron to be higher as the estimated size of the graphite becomes smaller.

  According to the technique of the present disclosure, the size of the graphite crystal of flake graphite cast iron can be estimated effectively.

It is a typical functional block diagram which shows the estimation apparatus which concerns on this embodiment. It is a schematic diagram which shows an example of the graphite dimension map which concerns on this embodiment. It is a schematic diagram which shows an example of the fatigue limit map which concerns on this embodiment. It is a conceptual diagram explaining the maximum dimension of the graphite crystal of flake graphite cast iron. It is a flowchart explaining the flow of the estimation process which concerns on this embodiment.

  Hereinafter, an estimation device, an estimation method, and an estimation program according to the present embodiment will be described with reference to the accompanying drawings. The same parts are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  FIG. 1 is a schematic functional block diagram showing an estimation apparatus 10 according to this embodiment.

  The estimation device 10 is an information processing device such as a computer, and includes a CPU (Central Processing Unit), a memory, an auxiliary storage device, and the like connected by a bus, and executes an estimation program. Moreover, the estimation apparatus 10 functions as an apparatus provided with the eutectic cell size calculation part 11, the acquisition part 12, the graphite dimension estimation part 13, the fatigue limit estimation part 14, and the memory | storage part 15 by execution of an estimation program. The estimation program may be recorded on a computer-readable recording medium. The computer-readable recording medium is a storage device such as a magneto-optical disk, a portable medium such as a USB or a CD-ROM, or a hard disk built in a computer system. The estimation program may be transmitted via a telecommunication line.

  The input unit 30 is, for example, a keyboard connected to the estimation device 10 and inputs various information, instructions, and the like to the estimation device 10. The display unit 40 is a display connected to the estimation device 10, for example, and displays an output result from the estimation device 10, an input content from the input unit 30 to the estimation device 10, and the like.

  The eutectic cell size calculation unit 11 calculates the size of the eutectic cell of flake graphite cast iron (hereinafter, eutectic cell size S). In general, the eutectic cell size S of flake graphite cast iron is determined by the casting conditions of the flake graphite cast iron casting, such as the amount of the core material of the molten metal, the solidification time, and the cooling rate. The eutectic cell size calculation unit 11 calculates the eutectic cell size S based on a model formula or a map including these casting conditions as input values. Each numerical value such as the casting conditions may be input from the input unit 30 by the operator. In the illustrated example, the eutectic cell size calculation unit 11 is shown as a part of functional elements of the estimation device 10, but may be provided in hardware separate from the estimation device 10.

  The acquisition unit 12 acquires the eutectic cell size S calculated by the eutectic cell size calculation unit 11 and outputs it to the graphite size estimation unit 13 and the storage unit 15. The storage unit 15 stores the eutectic cell size S input from the acquisition unit 12. The storage unit 15 stores a graphite dimension map M1 (see FIG. 2) and a fatigue limit map M2 (see FIG. 3), which will be described later.

  Based on the eutectic cell size S and the graphite size map M1 (see FIG. 2) input from the acquisition unit 12, the graphite size estimation unit 13 determines the maximum graphite size D (for example, FIG. The maximum diameter of the graphite crystal 100 of the flake graphite cast iron shown) is estimated.

  Specifically, in the graphite dimension map M1, eutectic obtained by measuring a plurality of flake graphite cast iron specimens prepared in advance under different casting conditions with a microscope (for example, an optical microscope or an electron microscope). The relationship between the cell size S and the maximum graphite dimension D is defined. In the graphite dimension map M1, the maximum graphite dimension D increases as the eutectic cell size S increases. In other words, the linear approximation curve L1 of each plot of measured values is set in a curved shape that protrudes upward. . The graphite dimension estimation unit 13 estimates the maximum graphite dimension D by referring to the graphite dimension map M1 based on the eutectic cell size S input from the acquisition unit 12. The maximum graphite dimension D estimated by the graphite dimension estimation unit 13 is output to the fatigue limit estimation unit 14 and the storage unit 15. The eutectic cell size S used for estimating the maximum graphite dimension D is the value stored in the storage unit 15 without directly using the value input from the eutectic cell size calculation unit 11 to the acquisition unit 12. Alternatively, an input value input from the input unit 30 to the acquisition unit 12 by the operator may be used. The graphite dimension map M1 does not necessarily need to be graphed, and may be stored as numerical data.

  The fatigue limit estimator 14 estimates the fatigue limit of flake graphite cast iron based on the maximum graphite dimension D calculated by the graphite dimension estimator 13 and the fatigue limit map M2 (see FIG. 3).

  Specifically, in the fatigue limit map M2, the maximum graphite dimension D and the fatigue limit (for example, flake graphite cast iron obtained in advance using a testing machine (for example, a rotary bending fatigue testing machine, a tensile compression fatigue testing machine, etc.) In addition, a relationship with a stress value that does not lead to fatigue failure even when a repeated stress having a constant amplitude is applied to the specimen and the load is repeated a predetermined number of times is defined. In the fatigue limit map M2, the fatigue limit increases as the maximum graphite dimension D decreases. In other words, the linear approximation curve L2 of each plot of measured values is set in a curved shape that protrudes downward. The fatigue limit estimation unit 14 estimates the fatigue limit by referring to the fatigue limit map M2 based on the maximum graphite dimension D estimated by the graphite dimension estimation unit 13. The fatigue limit estimated by the fatigue limit estimation unit 14 is output to the storage unit 15 and the display unit 40. Note that the fatigue limit map M2 is not necessarily graphed, and may be stored as numerical data.

  Next, the flow of the estimation process according to the present embodiment will be described based on FIG.

  In step S100, the eutectic cell size S calculated by the eutectic cell size calculation unit 11 is acquired. Next, in step S110, the maximum graphite dimension D of the graphite crystal of flake graphite cast iron is estimated by referring to the graphite dimension map M1 based on the acquired eutectic cell size S. Finally, in step S120, the fatigue limit of flake graphite cast iron is estimated by referring to the fatigue limit map M2 based on the maximum graphite dimension D estimated and calculated in step S110.

  According to this embodiment described in detail above, the relationship between the eutectic cell size S and the maximum graphite dimension D of the graphite crystal of flake graphite cast iron is determined in advance in the graphite dimension map M1 through experiments and the like. The maximum graphite dimension D of the graphite crystal of flake graphite cast iron is estimated by referring to M1 based on the eutectic cell size S obtained from the casting conditions of the flake graphite cast iron casting. This makes it possible to easily and effectively grasp the maximum size of the graphite crystal of flake graphite cast iron, which has been difficult to measure by conventional casting analysis.

  In addition, the relationship between the maximum graphite dimension D of the graphite crystal of flake graphite cast iron and the fatigue limit is determined in advance in the fatigue limit map M2 through experiments or the like, and this fatigue limit map M2 is based on the estimated maximum graphite dimension D. By referencing, the fatigue limit of flake graphite cast iron can be estimated easily and effectively. This makes it possible to grasp the fatigue limit of flake graphite cast iron in a short time and extremely easily, without conducting a long-time test that requires labor, such as a fatigue fracture test for determining the number of repetitions until fracture for each different stress amplitude. Is possible. Moreover, when flake graphite cast iron is used, for example as materials, such as automobile parts, such as an engine, and an industrial machine, those lifetimes can be grasped correctly.

  It should be noted that the present disclosure is not limited to the above-described embodiment, and can be appropriately modified and implemented without departing from the spirit of the present disclosure.

  For example, in the above-described embodiment, the functional elements such as the eutectic cell size calculation unit 11, the graphite size estimation unit 13, the fatigue limit estimation unit 14, and the like have been described as being included in the estimation device 10 that is an integral hardware. Any one of these may be provided in separate hardware.

DESCRIPTION OF SYMBOLS 10 Estimation apparatus 11 Eutectic cell size calculation part 12 Acquisition part 13 Graphite dimension estimation part 14 Fatigue limit estimation part 15 Memory | storage part

Claims (6)

An acquisition unit for acquiring a eutectic cell size of flake graphite cast iron;
An estimation apparatus comprising: a graphite size estimation unit that estimates a larger size of graphite of the flake graphite cast iron as the acquired eutectic cell size becomes larger. The estimation apparatus according to claim 1, further comprising a fatigue limit estimation unit that estimates a higher fatigue limit of the flake graphite cast iron as the estimated size of the graphite becomes smaller. Obtaining a eutectic cell size of flake graphite cast iron;
Estimating the size of the graphite of the flake graphite cast iron as the acquired eutectic cell size becomes larger. The estimation method according to claim 3, further comprising estimating a fatigue limit of the flake graphite cast iron as the estimated size of the graphite becomes smaller. The acquisition unit to acquire the eutectic cell size of flake graphite cast iron,
An estimation program that functions as a graphite size estimation unit that estimates a larger size of graphite of the flake graphite cast iron as the acquired eutectic cell size becomes larger. The estimation program according to claim 5, further causing the computer to function as a fatigue limit estimation unit that estimates a higher fatigue limit of the flake graphite cast iron as the estimated size of the graphite becomes smaller.

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