Apparatus for estimating the thickness of centrifugal cast tubes, method for estimating the thickness of centrifugal cast tubes, method for manufacturing centrifugal cast tubes, centrifugal cast tubes, and apparatus for manufacturing centrifugal cast tubes

Abstract

In centrifugal casting, this invention provides a configuration that enables accurate, non-contact estimation of tube thickness even when the surface temperature is high after centrifugal casting. [Solution] The pipe thickness estimation device 1 estimates the pipe thickness of a centrifugal cast pipe W cast by centrifugal casting based on the outer surface temperature of the centrifugal cast pipe W. The pipe thickness estimation device 1 includes an outer surface temperature related information acquisition unit 11 that acquires outer surface temperature related information related to the outer surface temperature of the centrifugal cast pipe W, and a pipe thickness estimation unit 12 that estimates the pipe thickness of the centrifugal cast pipe W based on the outer surface temperature related information using a pipe thickness estimation model in which the relationship between the outer surface temperature related information and the pipe thickness is defined for each axial region of the centrifugal cast pipe W.

Description

Technical Field

[0001] The present invention relates to a pipe thickness estimation device for a centrifugally cast pipe, a pipe thickness estimation method for a centrifugally cast pipe, a manufacturing method for a centrifugally cast pipe, a centrifugally cast pipe, and a manufacturing apparatus for a centrifugally cast pipe.

Background Art

[0002] Techniques for casting pipes by centrifugal casting are known. In this centrifugal casting, a pipe is cast by forming molten metal into a ring shape by centrifugal force within a mold. In a pipe cast by centrifugal casting, variation in pipe thickness in the axial direction is likely to occur depending on the casting conditions, so management of the pipe thickness is important.

[0003] Devices for measuring the pipe thickness for the purpose of pipe thickness management are known. For example, Patent Document 1 discloses a pipe thickness measuring device including a traveling unit that travels along the stretching direction, a transmitting unit that sends ultrasonic waves toward the inner surface of a metal pipe, a receiving unit that receives reflected waves reflected by the inner surface, and a measuring unit mounted on the traveling unit. The measuring unit can travel along a metal pipe even if the metal pipe includes bends. Therefore, the pipe thickness measuring device can quickly measure the pipe thickness even for a metal pipe including bends.

[0004] Also, as a method for measuring the pipe thickness non - contact, for example, Patent Document 2 discloses a hot - thickness measurement method in which a temperature difference between an average temperature in the wall thickness direction and an outer surface temperature is calculated from a steel pipe temperature distribution model, the calculated value is added to the measured value of an outer surface thermometer of the steel pipe to estimate the average temperature in the wall thickness direction of the steel pipe, and the average ultrasonic velocity in the wall thickness direction is corrected from the estimated average temperature to perform a calculation of the wall thickness.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] In the pipe thickness measuring device disclosed in Patent Document 1, the measuring unit is brought into contact with the top of the metal pipe, making it impossible to measure the pipe thickness when the surface temperature of the pipe is high after centrifugal casting. In contrast, the hot wall thickness measuring method disclosed in Patent Document 2 can measure the pipe thickness even when the surface temperature of the pipe is high after centrifugal casting.

[0007] However, in the hot wall thickness measurement method described in Patent Document 2, the steel pipe temperature distribution model used to calculate the temperature difference between the average temperature in the wall thickness direction and the outer surface temperature is the same regardless of the position in the axial direction of the steel pipe. Therefore, if the relationship between the temperature difference and the wall thickness of the steel pipe differs depending on the position in the axial direction due to the pipe manufacturing conditions, etc., it may not be possible to estimate the wall thickness accurately.

[0008] Centrifugal casting tubes are cast in an annular shape by relatively moving the mold and the molten metal supply unit that supplies molten metal into the mold in the axial direction. As a result, variations in tube thickness in the axial direction are likely to occur depending on the relative movement speed and the amount of molten metal supplied. Therefore, it is desirable to accurately estimate the tube thickness of centrifugal casting tubes by taking into account the changes in tube thickness in the axial direction.

[0009] The objective of the present invention is to realize a configuration that allows for accurate, non-contact estimation of the tube thickness in centrifugal cast tubes, even when the surface temperature is high after centrifugal casting. [Means for solving the problem]

[0010] A centrifugal casting tube thickness estimation device according to one embodiment of the present invention is a centrifugal casting tube thickness estimation device that estimates the tube thickness of a centrifugal casting tube cast by centrifugal casting based on the outer surface temperature of the centrifugal casting tube. The tube thickness estimation device includes an outer surface temperature related information acquisition unit that acquires outer surface temperature related information related to the outer surface temperature of the centrifugal casting tube, and a tube thickness estimation unit that estimates the tube thickness of the centrifugal casting tube based on the outer surface temperature related information using a tube thickness estimation model in which the relationship between the outer surface temperature related information and the tube thickness is defined for each axial region of the centrifugal casting tube (first configuration).

[0011] This allows for accurate estimation of the pipe thickness for each axial region of the centrifugal cast pipe based on external temperature-related information related to the external surface temperature of the centrifugal cast pipe. Therefore, even when the surface temperature of the centrifugal cast pipe is high after centrifugal casting, the pipe thickness can be accurately estimated without contact.

[0012] In the first configuration described above, the pipe thickness estimation model is configured to define the relationship between the outer surface temperature-related information and the pipe thickness for each region determined according to the relative axial movement speed between the mold used for centrifugal casting and the molten metal supply unit that supplies molten metal to the mold (second configuration).

[0013] In centrifugal casting, the thickness of the centrifugal casting tube changes depending on the relative axial movement speed between the mold and the molten metal supply unit that supplies molten metal to the mold. Therefore, in the tube thickness estimation model, by defining the relationship between external surface temperature-related information and tube thickness for each axial region determined by the relative axial movement speed between the mold and the molten metal supply unit, the tube thickness can be estimated for each axial region. Thus, the tube thickness of the centrifugal casting tube can be estimated accurately in the axial direction.

[0014] In the first configuration described above, the outer surface temperature-related information acquisition unit has an infrared radiation measurement unit that measures the amount of infrared radiation on the outer surface of the centrifugal casting tube. The tube thickness estimation unit uses the tube thickness estimation model to estimate the tube thickness based on the amount of change in the amount of infrared radiation measured by the infrared radiation measurement unit over time (third configuration).

[0015] This allows the thickness of the centrifugal cast tube to be estimated based on the time-dependent change in the amount of infrared radiation on the outer surface of the centrifugal cast tube. Therefore, even when the centrifugal cast tube is in a high-temperature state immediately after casting, the amount of infrared radiation on the outer surface of the centrifugal cast tube can be measured, and the thickness of the centrifugal cast tube can be estimated from the measurement results. Consequently, since the thickness of the centrifugal cast tube can be estimated quickly and easily after casting, the production efficiency of the centrifugal cast tube can be improved by reflecting the estimated thickness of the centrifugal cast tube in the casting conditions.

[0016] A method for estimating the pipe thickness of a centrifugal cast pipe according to one embodiment of the present invention is a method for estimating the pipe thickness of a centrifugal cast pipe cast by centrifugal casting from the outer surface temperature of the centrifugal cast pipe. This pipe thickness estimation method comprises: an outer surface temperature related information acquisition step of acquiring outer surface temperature related information related to the outer surface temperature of the centrifugal cast pipe; and a pipe thickness estimation step of estimating the pipe thickness of the centrifugal cast pipe based on the outer surface temperature related information acquired in the outer surface temperature related information acquisition step, using a pipe thickness estimation model in which the relationship between the outer surface temperature related information and the pipe thickness is defined for each axial region of the centrifugal cast pipe (first method).

[0017] This allows for accurate estimation of the tube thickness for each axial region of the centrifugal cast tube based on external temperature-related information. Therefore, even when the surface temperature is high after centrifugal casting, the tube thickness can be accurately estimated non-contactually in centrifugal cast tubes.

[0018] A method for manufacturing a centrifugal cast tube according to one embodiment of the present invention comprises: a centrifugal casting step of casting the centrifugal cast tube by centrifugal casting; an outer surface temperature-related information acquisition step of acquiring outer surface temperature-related information related to the outer surface temperature of the centrifugal cast tube; a pipe thickness estimation step of estimating the pipe thickness of the centrifugal cast tube based on the outer surface temperature-related information acquired in the outer surface temperature-related information acquisition step, using a pipe thickness estimation model in which the relationship between the outer surface temperature-related information and the pipe thickness is defined for each axial region of the centrifugal cast tube; and a centrifugal casting condition adjustment step of adjusting the conditions of the centrifugal casting based on the pipe thickness estimated in the pipe thickness estimation step (second method).

[0019] This allows the centrifugal casting conditions to be adjusted based on the estimated pipe thickness for each axial region of the centrifugal cast pipe, derived from the outer surface temperature-related information obtained by centrifugal casting. Therefore, if the estimated pipe thickness is larger or smaller than the appropriate range, the centrifugal casting conditions can be adjusted so that the pipe thickness is within the appropriate range, and the centrifugal cast pipe can be cast. Thus, centrifugal cast pipes with a pipe thickness within the appropriate range can be manufactured.

[0020] In the second method described above, the centrifugal casting condition adjustment step adjusts the relative axial movement speed between the mold used for centrifugal casting and the molten metal supply unit that supplies molten metal to the mold, based on the pipe thickness estimated in the pipe thickness estimation step (third method).

[0021] By adjusting the relative axial movement speed between the mold used in centrifugal casting and the molten metal supply unit that supplies molten metal to the mold, the thickness of the centrifugal casting tube can be easily changed. Therefore, based on the tube thickness estimated in the tube thickness estimation step, a centrifugal casting tube with a tube thickness within an appropriate range can be easily cast.

[0022] In the second method described above, the centrifugal casting condition adjustment step adjusts the amount of molten metal supplied during centrifugal casting based on the pipe thickness estimated in the pipe thickness estimation step (fourth method).

[0023] As a result, based on the estimated pipe thickness, the molten metal supply amount can be adjusted, so that the pipe thickness of the centrifugally cast pipe can be accurately adjusted.

[0024] The centrifugally cast pipe according to an embodiment of the present invention is a centrifugally cast pipe cast by centrifugal casting by any one of the second to fourth manufacturing methods (the fourth configuration).

[0025] As a result, a centrifugally cast pipe in which the pipe thickness is accurately estimated in a state where the surface temperature after centrifugal casting is high and the centrifugal casting conditions are adjusted based on the estimated pipe thickness is obtained. Therefore, a centrifugally cast pipe with high dimensional accuracy of the pipe thickness and efficiently manufactured can be obtained.

[0026] The manufacturing apparatus for a centrifugally cast pipe according to an embodiment of the present invention includes a centrifugal casting unit that casts the centrifugally cast pipe by centrifugal casting, an outer surface temperature related information acquisition unit that acquires outer surface temperature related information related to the outer surface temperature of the centrifugally cast pipe, and a pipe thickness estimation unit that estimates the pipe thickness of the centrifugally cast pipe based on the outer surface temperature related information acquired by the outer surface temperature related information acquisition unit using a pipe thickness estimation model in which the relationship between the outer surface temperature related information and the pipe thickness is defined for each region in the axial direction of the centrifugally cast pipe, and a centrifugal casting condition adjustment unit that adjusts the centrifugal casting conditions based on the pipe thickness estimated by the pipe thickness estimation unit (the fifth configuration).

[0027] As a result, based on the pipe thickness estimated for each region in the axial direction of the centrifugally cast pipe from the outer surface temperature related information related to the outer surface temperature of the centrifugally cast pipe obtained by centrifugal casting, the centrifugal casting conditions can be adjusted. Therefore, when the estimated pipe thickness is larger or smaller than the appropriate range, the centrifugal casting conditions can be adjusted so that the pipe thickness is within the appropriate range, and the centrifugally cast pipe can be cast. Therefore, a centrifugally cast pipe having a pipe thickness within the appropriate range can be manufactured.

Effects of the Invention

[0028] A centrifugal casting tube thickness estimation device according to one embodiment of the present invention has a tube thickness estimation unit that estimates the tube thickness of the centrifugal casting tube based on the external temperature-related information, using a tube thickness estimation model in which the relationship between external temperature-related information and tube thickness is defined for each axial region of the centrifugal casting tube. .

[0029] This makes it possible to realize a configuration in which the pipe thickness can be accurately estimated non-contact, even when the surface temperature is high after centrifugal casting of a centrifugal cast pipe. [Brief explanation of the drawing]

[0030] [Figure 1] Figure 1 shows a schematic configuration of the pipe thickness estimation device according to Embodiment 1. [Figure 2] Figure 2 shows a schematic configuration of a centrifugal casting tube manufacturing apparatus. [Figure 3] Figure 3 shows the change in the movement speed of the trolley when centrifugal casting the centrifugal casting tube W of this embodiment. [Figure 4] Figure 4 shows an example of a pipe thickness estimation model at the initial and final stages of trolley movement. [Figure 5] Figure 5 shows an example of a pipe thickness estimation model during the middle phase of trolley movement. [Figure 6] Figure 6 is a flowchart showing the method for estimating the pipe thickness of centrifugal cast pipes. [Figure 7] Figure 7 shows a schematic configuration of the manufacturing apparatus for centrifugal casting tubes W according to Embodiment 2. [Figure 8] Figure 8 schematically shows an example of the relationship between the pipe thickness of a centrifugal cast pipe estimated by the pipe thickness estimation unit and the target pipe thickness. [Figure 9] Figure 9 is a flowchart showing the method for manufacturing centrifugal casting tubes. [Modes for carrying out the invention]

[0031] The following describes each embodiment with reference to the drawings. In each drawing, the same parts are denoted by the same reference numerals, and the description of those parts will not be repeated. Note that the dimensions of the components in each drawing do not faithfully represent the dimensions of the actual components or the dimensional ratios of each component.

[0032] In the following explanation, the axial direction refers to the direction in which the axis P of the centrifugal casting tube W extends. The radial direction refers to the direction perpendicular to the axis P of the centrifugal casting tube W, i.e., the radial direction of the centrifugal casting tube W.

[0033] Furthermore, in the following explanation, the expressions "fix," "connect," and "attach" (hereinafter referred to as "fixing, etc.") include not only cases where components are directly fixed to each other, but also cases where they are fixed to each other via other components. In other words, in the following explanation, the expressions "fixing, etc." include both direct and indirect fixing of components to each other.

[0034] [Embodiment 1] Figure 1 shows a schematic configuration of a pipe thickness estimation device 1 according to Embodiment 1 of the present invention. The pipe thickness estimation device 1 is a device that estimates the pipe thickness of a centrifugal cast pipe W cast by centrifugal casting based on external temperature-related information related to the external temperature of the centrifugal cast pipe W.

[0035] (Centrifugal casting tube) First, the centrifugal casting of centrifugal casting tubes W will be explained using Figure 2. Figure 2 is a diagram showing the schematic configuration of the centrifugal casting tube W manufacturing apparatus 100. As shown in Figure 2, the centrifugal casting tube W manufacturing apparatus 100 has a trolley 101 that can move along the axis P, a mold 102 supported on the trolley 101, and a molten metal supply unit 111 that supplies molten metal into the mold 102. In Figure 2, for explanatory purposes, the configuration of the centrifugal casting tube W manufacturing apparatus 100 is schematically shown, and the mold 102 is shown in cross-section.

[0036] The mold 102 has a casting space 102a inside for casting the centrifugal casting tube W. The casting space 102a is partitioned inside the mold 102 by the inner surface of the mold 102, which has a shape corresponding to the outer shape of the centrifugal casting tube W. The mold 102 is supported by a trolley 101 so as to be rotatable about an axis P.

[0037] The molten metal supply unit 111 supplies molten metal into the casting space 102a of the mold 102. The molten metal supply unit 111 has a molten metal inlet 112 and a supply pipe section 113. The molten metal inlet 112 is connected to one end of the tubular supply pipe section 113. The molten metal inlet 112 is configured to allow molten metal flowing in from the molten metal storage section 121, which contains the molten metal, to flow into the supply pipe section 113 (see the solid arrow in Figure 2). The supply pipe section 113 is configured to extend from the molten metal inlet 112 into the casting space 102a of the mold 102. At the other end of the supply pipe section 113, there is a supply port (not shown) for supplying the molten metal flowing inside into the casting space 102a of the mold 102.

[0038] In the example shown in Figure 2, the mold 102 rotates around axis P relative to the trolley 101, and the trolley 101 moves it away from the molten metal supply section 111 along axis P, starting from a state where the other end of the supply pipe section 113 is positioned on the other end of the mold 102 (the receiving end of the centrifugal casting pipe W) (see the white arrow in Figure 2).

[0039] As a result, the molten metal supplied onto the inner surface of the mold 102 that partitions the casting space 102a is uniformly extended circumferentially on the inner surface of the mold 102 by centrifugal force due to rotation around the axis P of the mold 102, forming a tubular shape. Furthermore, as the mold 102 is moved axially by the trolley 101, the molten metal is supplied axially onto the inner surface of the mold 102 and forms an annular shape extending axially. Thus, a tubular centrifugal casting tube W is cast by the mold 102. The centrifugal casting tube W cast by the mold 102 is removed from inside the mold 102.

[0040] (Pipe thickness estimation device) As shown in Figure 1, the pipe thickness estimation device 1 is a device that can estimate the pipe thickness of a centrifugal cast pipe W, which has been cast as described above, without contact, even when the surface temperature is high after centrifugal casting. The pipe thickness estimation device 1 has an outer surface temperature related information acquisition unit 11 that acquires the outer surface temperature related information and a pipe thickness estimation unit 12 that estimates the pipe thickness of the centrifugal cast pipe W.

[0041] The external temperature-related information acquisition unit 11 acquires external temperature-related information related to the external temperature of the centrifugal casting tube W. The external temperature-related information acquisition unit 11 measures, for example, the amount of infrared radiation emitted from the external surface of the centrifugal casting tube W as the external temperature-related information. In this case, the external temperature-related information acquisition unit 11 has an infrared radiation amount measurement unit 21. The infrared radiation amount measurement unit 21 is, for example, an infrared camera or a hyperspectral camera.

[0042] Furthermore, the external temperature-related information acquisition unit 11 may detect physical quantities other than infrared radiation if it is capable of acquiring external temperature-related information related to the external temperature of the centrifugal casting tube W. The external temperature-related information acquisition unit 11 may, for example, have a radiation thermometer.

[0043] The external temperature-related information acquisition unit 11 may be configured to be movable in the circumferential direction relative to the centrifugal casting tube W. This allows the external temperature-related information acquisition unit 11 to acquire external temperature-related information related to the external temperature of the centrifugal casting tube W over the entire circumference of the centrifugal casting tube W.

[0044] The external temperature-related information acquisition unit 11 may be configured to be movable in the axial direction relative to the centrifugal casting tube W. This allows the external temperature-related information acquisition unit 11 to acquire external temperature-related information related to the external temperature of the centrifugal casting tube W along the entire axial direction of the centrifugal casting tube W.

[0045] The centrifugal casting tube W may be supported by a support device configured to be circumferentially rotatable with respect to the outer surface temperature-related information acquisition unit 11. Alternatively, the centrifugal casting tube W may be supported by a support device configured to be axially movable with respect to the outer surface temperature-related information acquisition unit 11.

[0046] The external temperature-related information acquisition unit 11 outputs the acquired external temperature-related information to the pipe thickness estimation unit 12. If the external temperature-related information acquisition unit 11 has an infrared radiation amount measurement unit 21, the infrared radiation amount measurement unit 21 outputs the measured infrared radiation amount as external temperature-related information to the pipe thickness estimation unit 12.

[0047] The pipe thickness estimation unit 12 estimates the pipe thickness of the centrifugal cast pipe W based on the external temperature-related information output from the external temperature-related information acquisition unit 11, using a pipe thickness estimation model. If the external temperature-related information output from the external temperature-related information acquisition unit 11 is related to the amount of infrared radiation emitted from the external surface of the centrifugal cast pipe W, the pipe thickness estimation unit 12 calculates the ratio of the infrared radiation amounts of two wavelengths and uses the change in this ratio over time as the change in the amount of infrared radiation over time. This cancels out the effect of the emissivity of the external surface of the centrifugal cast pipe W, and allows for accurate determination of the change in the amount of infrared radiation on the external surface.

[0048] Furthermore, if the pipe thickness estimation unit 12 can estimate the pipe thickness of the centrifugal cast pipe W based on the temperature change of the outer surface of the centrifugal cast pipe W, it may use values ​​related to the temperature conversion other than the ratio of infrared radiation amounts to estimate the pipe thickness of the centrifugal cast pipe W.

[0049] The aforementioned pipe thickness estimation model is a model in which the relationship between external surface temperature-related information and pipe thickness is defined for each axial region of the centrifugal cast pipe W. Specifically, in the pipe thickness estimation model, the relationship between the change over time in the amount of infrared radiation emitted from the external surface of the centrifugal cast pipe W and the pipe thickness is defined for each axial region of the centrifugal cast pipe W.

[0050] When the thickness of the centrifugal casting tube W is large, the change over time of the amount of infrared radiation emitted from the outer surface of the centrifugal casting tube W is small, and when the thickness of the centrifugal casting tube W is small, the change over time of the amount of infrared radiation is large. The tube thickness estimation model is a model that reflects these characteristics. The tube thickness estimation model may be a relational expression that defines the relationship between the change over time of the amount of infrared radiation and the thickness of the centrifugal casting tube W, or it may be a table data or the like.

[0051] Figure 3 shows the change in the movement speed of the trolley 101 when centrifugal casting the centrifugal casting tube W of this embodiment. As shown in Figure 3, when centrifugal casting the centrifugal casting tube W, the movement speed of the trolley 101 of the manufacturing apparatus 100 is not constant, and the movement speed of the trolley 101 at the beginning and end of its movement is relatively slower than the movement speed of the trolley 101 in the middle of its movement.

[0052] The initial, middle, and final stages of movement are determined by dividing the movement range of the trolley 101 according to the movement speed of the trolley 101. In this embodiment, the initial stage of movement is the period when the speed of the trolley 101 is increasing from zero. The middle stage of movement is the period when the speed of the trolley 101 is constant. The final stage of movement is the period when the speed of the trolley 101 is decreasing. When the centrifugal casting tube W is divided into axial regions, the initial, middle, and final stages of movement correspond to the respective axial regions of the centrifugal casting tube W during centrifugal casting.

[0053] Because the supply rate of molten metal during centrifugal casting of the centrifugal casting tube W changes according to the axial position, the relationship between the surface temperature and thickness of the centrifugal casting tube W after centrifugal casting also changes according to the axial direction. The aforementioned pipe thickness estimation model includes a model in which the relationship between the change in infrared radiation over time and the pipe thickness differs depending on the axial position where the supply rate of molten metal changes during centrifugal casting of the centrifugal casting pipe W. As a result, the pipe thickness estimation model can accurately estimate the pipe thickness of the centrifugal casting pipe W in the axial direction from the change in infrared radiation over time on the outer surface of the centrifugal casting pipe W, taking into account that the supply rate of molten metal changes in the axial direction during centrifugal casting of the centrifugal casting pipe W.

[0054] Figure 4 shows an example of a pipe thickness estimation model at the beginning and end of the movement of the trolley 101. Figure 5 shows an example of a pipe thickness estimation model at the middle of the movement of the trolley 101. As shown in Figures 4 and 5, the relationship between the change in infrared radiation over time and the pipe thickness differs between the pipe thickness estimation model at the beginning and end of the movement of the trolley 101 and the pipe thickness estimation model at the middle of the movement of the trolley 101. Specifically, in the examples shown in Figures 4 and 5, the pipe thickness changes linearly with respect to the change in infrared radiation over time, but the slope of the change is different. The change in infrared radiation over time refers to the amount of change (decrease or increase) of infrared radiation per unit time.

[0055] Furthermore, the pipe thickness estimation model for the initial and final stages of movement of the trolley 101 and the pipe thickness estimation model for the middle stage of movement of the trolley 101 may differ in parameters other than the slope, as long as the relationship between the change in infrared radiation over time and the pipe thickness is different. The pipe thickness estimation model may not have a linear relationship in relation to the change in infrared radiation over time, but rather a curvilinear relationship, or the relationship between the change in infrared radiation over time and the pipe thickness may be expressed by a polynomial.

[0056] Furthermore, the relationship between the change in infrared radiation over time and the pipe thickness may differ between the pipe thickness estimation model at the beginning of the trolley 101's movement and the pipe thickness estimation model at the end of the trolley 101's movement. The relationship between the change in infrared radiation over time and the pipe thickness may be the same between the pipe thickness estimation model at the beginning of the trolley 101's movement and the pipe thickness estimation model at the middle of the trolley 101's movement. The relationship between the change in infrared radiation over time and the pipe thickness may be the same between the pipe thickness estimation model at the middle of the trolley 101's movement and the pipe thickness estimation model at the end of the trolley 101's movement.

[0057] The centrifugal casting tube thickness estimation device 1 according to this embodiment is a centrifugal casting tube thickness estimation device that estimates the tube thickness of a centrifugal casting tube W cast by centrifugal casting based on the outer surface temperature of the centrifugal casting tube W. The tube thickness estimation device 1 includes an outer surface temperature related information acquisition unit 11 that acquires outer surface temperature related information related to the outer surface temperature of the centrifugal casting tube W, and a tube thickness estimation unit 12 that estimates the tube thickness of the centrifugal casting tube W based on the outer surface temperature related information using a tube thickness estimation model in which the relationship between the outer surface temperature related information and the tube thickness is defined for each axial region of the centrifugal casting tube W.

[0058] This allows for accurate estimation of the tube thickness for each axial region of the centrifugal cast tube W based on external temperature-related information related to the external surface temperature of the centrifugal cast tube W. Therefore, even when the surface temperature of the centrifugal cast tube W is high after centrifugal casting, the tube thickness can be accurately estimated non-contact.

[0059] The pipe thickness estimation model is configured to define the relationship between the outer surface temperature-related information and the pipe thickness for each region, which is determined according to the relative axial movement speed between the mold 102 used in centrifugal casting and the molten metal supply unit 111 that supplies molten metal to the mold 102.

[0060] In centrifugal casting, the thickness of the centrifugal casting tube W changes depending on the relative axial movement speed between the mold 102 and the molten metal supply unit 111 that supplies molten metal to the mold 102. Therefore, in the tube thickness estimation model, by defining the relationship between external temperature-related information and tube thickness for each axial region determined by the relative axial movement speed between the mold 102 and the molten metal supply unit 111, the tube thickness can be estimated for each axial region. Thus, the tube thickness of the centrifugal casting tube W can be estimated accurately in the axial direction.

[0061] The external temperature-related information acquisition unit 11 includes an infrared radiation measurement unit 21 that measures the amount of infrared radiation on the outer surface of the centrifugal casting tube W. The tube thickness estimation unit 12 uses the tube thickness estimation model to estimate the tube thickness based on the amount of change in the amount of infrared radiation measured by the infrared radiation measurement unit 21 over time.

[0062] This allows the thickness of a centrifugal cast tube W to be estimated based on the time-dependent change in the amount of infrared radiation on the outer surface of the centrifugal cast tube W. Therefore, even when the centrifugal cast tube W is in a high-temperature state immediately after casting, the amount of infrared radiation on the outer surface of the centrifugal cast tube W can be measured, and the thickness of the centrifugal cast tube W can be estimated from the measurement results. Consequently, since the thickness of the centrifugal cast tube W can be estimated quickly and easily after casting, the estimated thickness of the centrifugal cast tube W can be reflected in the casting conditions, thereby reducing the number of centrifugal cast tubes W whose thickness is outside the appropriate range and improving the production efficiency of the centrifugal cast tube W.

[0063] (Method for estimating the thickness of centrifugal cast tubes) Next, the method for estimating the pipe thickness of a centrifugal cast pipe W using the pipe thickness estimation device 1 having the above-described configuration will be explained with reference to Figure 6. Figure 6 is a flowchart showing the method for estimating the pipe thickness of a centrifugal cast pipe W.

[0064] First, the centrifugal casting tube W is formed by centrifugal casting using the manufacturing apparatus 100 (Step SA1). Then, the centrifugal casting tube W is removed from the mold 102 of the manufacturing apparatus 100 (Step SA2).

[0065] Next, in step SA3, the outer surface temperature-related information acquisition unit 11 of the pipe thickness estimation device 1 acquires outer surface temperature-related information related to the temperature of the outer surface of the centrifugal casting pipe W. For example, the outer surface temperature-related information acquisition unit 11 measures the amount of infrared radiation emitted from the outer surface of the centrifugal casting pipe W as the outer surface temperature-related information. The outer surface temperature-related information acquisition unit 11 outputs the acquired outer surface temperature-related information to the pipe thickness estimation unit 12 of the pipe thickness estimation device 1.

[0066] In the following step SA4, the pipe thickness estimation unit 12 of the pipe thickness estimation device 1 estimates the pipe thickness of the centrifugal cast pipe W using the pipe thickness estimation model and based on the external temperature-related information acquired by the external temperature-related information acquisition unit 11. After that, this flow ends.

[0067] Here, step SA3 corresponds to the step of acquiring external temperature-related information, and step SA4 corresponds to the step of estimating pipe thickness.

[0068] The pipe thickness estimation method according to this embodiment is a method for estimating the pipe thickness of a centrifugal cast pipe W cast by centrifugal casting from the outer surface temperature of the centrifugal cast pipe W. This pipe thickness estimation method comprises an outer surface temperature related information acquisition step SA3 in which outer surface temperature related information related to the outer surface temperature of the centrifugal cast pipe W is acquired, and a pipe thickness estimation step SA4 in which the pipe thickness of the centrifugal cast pipe W is estimated based on the outer surface temperature related information acquired in the outer surface temperature related information acquisition step SA3, using a pipe thickness estimation model in which the relationship between the outer surface temperature related information and the pipe thickness is defined for each axial region of the centrifugal cast pipe W.

[0069] This allows for accurate estimation of the tube thickness for each axial region of the centrifugal cast tube W based on external temperature-related information related to the external surface temperature of the centrifugal cast tube W. Therefore, even when the surface temperature of the centrifugal cast tube W is high after centrifugal casting, the tube thickness can be accurately estimated non-contact.

[0070] [Embodiment 2] Figure 7 shows a schematic configuration of the centrifugal casting tube W manufacturing apparatus 200 according to Embodiment 2. When centrifugal casting tubes W are cast by centrifugal casting, the centrifugal casting tube W manufacturing apparatus 200 changes the casting conditions based on the tube thickness of the centrifugal casting tube W estimated by the tube thickness estimation unit 12, and performs centrifugal casting. This makes it possible to centrifugal cast a centrifugal casting tube W with an appropriate tube thickness. In the following description, components similar to those in Embodiment 1 are denoted by the same reference numerals and their description is omitted.

[0071] The centrifugal casting pipe W manufacturing apparatus 200 includes a centrifugal casting section 210, an external surface temperature-related information acquisition section 11, a pipe thickness estimation section 12, and a centrifugal casting condition adjustment section 220.

[0072] The centrifugal casting unit 210 includes a trolley 201, a mold 202, and a molten metal supply unit 211. The configurations of the trolley 201, mold 202, and molten metal supply unit 211 are the same as those of the manufacturing apparatus 100 in Embodiment 1, except that the casting conditions can be changed by the centrifugal casting condition adjustment unit 220, as will be described later. Therefore, a detailed explanation of the configurations will be omitted.

[0073] The outer surface temperature-related information acquisition unit 11 and the pipe thickness estimation unit 12 are the same as the outer surface temperature-related information acquisition unit 11 and the pipe thickness estimation unit 12 in the pipe thickness estimation device 1 of Embodiment 1. In other words, the manufacturing apparatus 200 of centrifugal casting pipe W according to this embodiment includes the pipe thickness estimation device 1 of Embodiment 1.

[0074] The centrifugal casting condition adjustment unit 220 adjusts the casting conditions for the centrifugal casting tube W in the centrifugal casting unit 210 based on the tube thickness of the centrifugal casting tube W estimated by the tube thickness estimation unit 12. Figure 8 is a schematic diagram showing an example of the relationship between the tube thickness of the centrifugal casting tube W estimated by the tube thickness estimation unit 12 and the appropriate range of tube thickness. As shown in Figure 8, if the estimated tube thickness (estimated value in Figure 8, indicated by a white circle in Figure 8) is smaller than the appropriate range, the centrifugal casting condition adjustment unit 220 adjusts the casting conditions for the centrifugal casting tube W so that the tube thickness of the centrifugal casting tube W cast by centrifugal casting approaches the appropriate range (see the white arrow in Figure 8).

[0075] Specifically, the centrifugal casting condition adjustment unit 220 adjusts, for example, the axial movement speed of the trolley 201 of the centrifugal casting unit 210, that is, the relative axial movement speed between the mold 202 and the molten metal supply unit 211, based on the estimated pipe thickness. For example, if the estimated pipe thickness is greater than the appropriate pipe thickness range, the centrifugal casting condition adjustment unit 220 increases the relative movement speed. On the other hand, for example, if the estimated pipe thickness is smaller than the appropriate pipe thickness range, the centrifugal casting condition adjustment unit 220 decreases the relative movement speed.

[0076] The centrifugal casting condition adjustment unit 220 may, for example, adjust the amount of molten metal supplied by the molten metal supply unit 211 of the centrifugal casting unit 210 based on the estimated pipe thickness. For example, if the estimated pipe thickness is greater than the appropriate pipe thickness range, the centrifugal casting condition adjustment unit 220 will reduce the amount of molten metal supplied. On the other hand, if the estimated pipe thickness is smaller than the appropriate pipe thickness range, the centrifugal casting condition adjustment unit 220 will increase the amount of molten metal supplied. The adjustment of the amount of molten metal supplied can be achieved by changing the inclination angular velocity of the molten metal storage unit 121 or by changing the amount of molten metal supplied into the molten metal storage unit 121.

[0077] Furthermore, the centrifugal casting condition adjustment unit 220 may adjust the time it takes for the molten metal to flow through the molten metal supply unit 211 by adjusting the viscosity of the molten metal and the amount of molten metal supplied. In addition, the centrifugal casting condition adjustment unit 220 may adjust the rotation speed of the mold 201.

[0078] By adjusting the centrifugal casting conditions using the centrifugal casting condition adjustment unit 220 as described above, the thickness of the centrifugal casting tube W cast by the centrifugal casting unit 210 can be easily changed. Therefore, the thickness of the centrifugal casting tube W can be easily controlled to an appropriate range. The centrifugal casting condition adjustment unit 220 may also adjust both the relative axial movement speed between the mold 202 and the molten metal supply unit 211, and the amount of molten metal supplied by the molten metal supply unit 211.

[0079] The centrifugal casting pipe W manufacturing apparatus 200 according to this embodiment includes: a centrifugal casting unit 210 that casts the centrifugal casting pipe W by centrifugal casting; an outer surface temperature-related information acquisition unit 11 that acquires outer surface temperature-related information related to the outer surface temperature of the centrifugal casting pipe W; a pipe thickness estimation unit 12 that estimates the pipe thickness of the centrifugal casting pipe W based on the outer surface temperature-related information acquired by the outer surface temperature-related information acquisition unit 11, using a pipe thickness estimation model in which the relationship between the outer surface temperature-related information and the pipe thickness is defined for each axial region of the centrifugal casting pipe W; and a centrifugal casting condition adjustment unit 220 that adjusts the conditions of the centrifugal casting based on the pipe thickness estimated by the pipe thickness estimation unit 12.

[0080] This allows the centrifugal casting conditions to be adjusted based on the estimated pipe thickness for each axial region of the centrifugal cast pipe W, derived from the outer surface temperature-related information obtained by centrifugal casting. Therefore, if the estimated pipe thickness is larger or smaller than the appropriate range, the centrifugal casting conditions can be adjusted so that the pipe thickness is within the appropriate range, and the centrifugal cast pipe W can be cast. Thus, a centrifugal cast pipe W having a pipe thickness within the appropriate range can be manufactured.

[0081] (Method of manufacturing centrifugal cast tubes) A method for manufacturing a centrifugal casting tube W using the manufacturing apparatus 200 having the above-described configuration will be explained with reference to Figure 9. Figure 9 is a flowchart showing the method for manufacturing a centrifugal casting tube W. In Figure 9, steps SA1 to SA4 are the same as steps SA1 to SA4 in the flowchart shown in Figure 6 in Embodiment 1.

[0082] As shown in Figure 9, after centrifugal casting of the centrifugal casting tube W (step SA1), the centrifugal casting tube W is removed from the mold 202 (step SA2). Subsequently, the outer surface temperature-related information acquisition unit 11 acquires outer surface temperature-related information of the centrifugal casting tube W (step SA3). Next, the tube thickness estimation unit 12 estimates the tube thickness of the centrifugal casting tube W based on the outer surface temperature-related information using a tube thickness estimation model (step SA4).

[0083] Subsequently, in step SB5, the centrifugal casting condition adjustment unit 220 determines whether the pipe thickness of the centrifugal casting tube W, estimated by the pipe thickness estimation unit 12, is within the appropriate range. If, in step SB5, the estimated pipe thickness is determined to be within the appropriate range (YES in step SB5), there is no need to change the casting conditions of the centrifugal casting tube W, and the flow ends there (END). On the other hand, if, in step SB5, the estimated pipe thickness is determined to be outside the appropriate range (NO in step SB5), the process proceeds to step SB6, where the centrifugal casting condition adjustment unit 220 adjusts the casting conditions of the centrifugal casting tube W so that the pipe thickness of the centrifugal casting tube W is within the appropriate range. After that, this flow ends (END).

[0084] In the flowchart shown in Figure 9, the flow may be restarted from step SA1 after step SB6.

[0085] Here, step SA1 corresponds to the centrifugal casting step, step SA3 corresponds to the external surface temperature related information acquisition step, step SA4 corresponds to the pipe thickness estimation step, and steps SB5 and SB6 correspond to the centrifugal casting condition adjustment steps.

[0086] The method for manufacturing a centrifugal cast tube according to this embodiment includes: a centrifugal casting step SA1 for casting a centrifugal cast tube W by centrifugal casting; an outer surface temperature-related information acquisition step SA3 for acquiring outer surface temperature-related information related to the outer surface temperature of the centrifugal cast tube W; a tube thickness estimation step SA4 for estimating the tube thickness of the centrifugal cast tube W based on the outer surface temperature-related information acquired in the outer surface temperature-related information acquisition step SA3, using a tube thickness estimation model in which the relationship between the outer surface temperature-related information and the tube thickness is defined for each axial region of the centrifugal cast tube W; and centrifugal casting condition adjustment steps SB5 and SB6 for adjusting the conditions of the centrifugal casting based on the tube thickness estimated in the tube thickness estimation step SA4.

[0087] This allows the centrifugal casting conditions to be adjusted based on the estimated pipe thickness for each axial region of the centrifugal cast pipe W, derived from the outer surface temperature-related information obtained by centrifugal casting. Therefore, if the estimated pipe thickness is larger or smaller than the appropriate range, the centrifugal casting conditions can be adjusted so that the pipe thickness is within the appropriate range, and the centrifugal cast pipe W can be cast. Thus, a centrifugal cast pipe W having a pipe thickness within the appropriate range can be manufactured.

[0088] The centrifugal casting condition adjustment steps SB5 and SB6 adjust the relative axial movement speed between the mold 202 used for centrifugal casting and the molten metal supply unit 211 that supplies molten metal to the mold 202, based on the pipe thickness estimated in the pipe thickness estimation step SA4.

[0089] The thickness of the centrifugal casting tube W can be easily changed by adjusting the relative axial movement speed between the mold 202 used in centrifugal casting and the molten metal supply unit 211 that supplies molten metal to the mold 202. Therefore, based on the tube thickness estimated in the tube thickness estimation step SA4, a centrifugal casting tube W having a tube thickness within an appropriate range can be easily cast.

[0090] The centrifugal casting condition adjustment steps SB5 and SB6 adjust the amount of molten metal supplied during centrifugal casting based on the pipe thickness estimated in the pipe thickness estimation step SA4.

[0091] This allows the molten metal supply rate to be adjusted based on the estimated pipe thickness, thus enabling precise adjustment of the pipe thickness of the centrifugal casting pipe W.

[0092] (Other embodiments) Although embodiments of the present invention have been described above, the embodiments described above are merely examples for carrying out the present invention. Therefore, the invention is not limited to the embodiments described above, and it is possible to carry out the invention by appropriately modifying the embodiments described above without departing from the spirit of the invention.

[0093] In each of the above embodiments, the centrifugal casting tube manufacturing apparatus 100, 200 has trolleys 101, 201 that can move along the axis P while rotatably supporting the molds 102, 202 around the axis P. However, in the centrifugal casting tube manufacturing apparatus, the molten metal supply unit may be configured to move along the axis P. In this case, the trolleys may be fixed so as not to move along the axis P.

[0094] In each of the embodiments described above, the molten metal supply section 111, 211 has a supply pipe section 113 and a molten metal inlet section 112. However, the molten metal supply section may have any configuration as long as it has a configuration that allows it to supply molten metal into the casting space of the mold and manufacture a centrifugal casting tube.

[0095] In each of the embodiments described above, the pipe thickness estimation model defines the relationship between the change in the amount of infrared radiation emitted from the outer surface of the centrifugal cast pipe W over time and the pipe thickness for each axial region of the centrifugal cast pipe W. The axial region is divided according to the movement speed of the trolley 101 (initial, middle, and final stages of movement). However, the axial region may be divided according to parameters other than the movement speed of the trolley. [Industrial applicability]

[0096] This invention can be used in a pipe thickness estimation device for estimating the pipe thickness of centrifugal cast pipes. [Explanation of Symbols]

[0097] 1 Pipe thickness estimation device 11 External surface temperature related information acquisition unit 12 Pipe thickness estimation section 21 Infrared Quantity Measurement Unit Manufacturing equipment for 100 and 200 centrifugal casting tubes 101, 201 bogies 102, 202 molds 102a Casting space 111, 211 Molten metal supply section 112 Molten metal inlet 113 Supply pipe section 121 Molten metal containment section 210 Centrifugal Casting Section 220 Centrifugal casting condition adjustment unit W Centrifugal Casting Tube P axis

Claims

1. A centrifugal casting tube thickness estimation device for estimating the tube thickness of a centrifugal casting tube based on the outer surface temperature of the centrifugal casting tube, An outer temperature-related information acquisition unit that acquires outer temperature-related information related to the outer surface temperature of the centrifugal casting tube, A pipe thickness estimation unit estimates the pipe thickness of the centrifugal cast pipe based on the external temperature-related information, using a pipe thickness estimation model in which the relationship between the external temperature-related information and the pipe thickness is defined for each axial region of the centrifugal cast pipe. Having, A device for estimating the thickness of centrifugal-cast tubes.

2. In the pipe thickness estimation device for centrifugal casting pipes according to claim 1, The pipe thickness estimation model is configured to define the relationship between the outer surface temperature-related information and the pipe thickness for each region determined by the relative axial movement speed between the mold used in centrifugal casting and the molten metal supply unit that supplies molten metal to the mold. A device for estimating the thickness of centrifugal-cast tubes.

3. In the pipe thickness estimation device for centrifugal casting pipes according to claim 1, The external surface temperature-related information acquisition unit includes an infrared radiation measurement unit that measures the amount of infrared radiation on the outer surface of the centrifugal casting tube. The pipe thickness estimation unit estimates the pipe thickness based on the time change in the amount of infrared radiation measured by the infrared radiation measurement unit, using the pipe thickness estimation model. A device for estimating the thickness of centrifugal-cast tubes.

4. A method for estimating the thickness of a centrifugal cast tube, which is cast by centrifugal casting, from the outer surface temperature of the centrifugal cast tube, An external temperature-related information acquisition step for acquiring external temperature-related information related to the external temperature of the centrifugal casting tube, The system includes a pipe thickness estimation step which estimates the pipe thickness of the centrifugal cast pipe based on the external temperature-related information obtained in the external temperature-related information acquisition step, using a pipe thickness estimation model in which the relationship between the external temperature-related information and the pipe thickness is defined for each axial region of the centrifugal cast pipe. A method for estimating the thickness of centrifugal-cast pipes.

5. A method for manufacturing centrifugal cast tubes, A centrifugal casting step in which the centrifugal casting tube is cast by centrifugal casting, An external temperature-related information acquisition step for acquiring external temperature-related information related to the external temperature of the centrifugal casting tube, A pipe thickness estimation step in which the pipe thickness of the centrifugal cast pipe is estimated based on the external temperature-related information obtained in the external temperature-related information acquisition step, using a pipe thickness estimation model in which the relationship between the external temperature-related information and the pipe thickness is defined for each axial region of the centrifugal cast pipe, A centrifugal casting condition adjustment step, in which the conditions of the centrifugal casting are adjusted based on the pipe thickness estimated in the pipe thickness estimation step, Having, A method for manufacturing centrifugal cast tubes.

6. In the method for manufacturing a centrifugal cast tube according to claim 5, The centrifugal casting condition adjustment step adjusts the relative axial movement speed between the mold used for centrifugal casting and the molten metal supply unit that supplies molten metal to the mold, based on the pipe thickness estimated in the pipe thickness estimation step. A method for manufacturing centrifugal cast tubes.

7. In the method for manufacturing a centrifugal cast tube according to claim 5, The centrifugal casting condition adjustment step adjusts the amount of molten metal supplied during centrifugal casting based on the pipe thickness estimated in the pipe thickness estimation step. A method for manufacturing centrifugal cast tubes.

8. A centrifugal cast tube cast by centrifugal casting according to any one of the manufacturing methods of claims 5 to 7.

9. A manufacturing apparatus for centrifugal casting tubes, A centrifugal casting section for casting the centrifugal casting tube by centrifugal casting, An outer temperature-related information acquisition unit that acquires outer temperature-related information related to the outer surface temperature of the centrifugal casting tube, A pipe thickness estimation unit estimates the pipe thickness of the centrifugal cast tube based on the external temperature-related information acquired by the external temperature-related information acquisition unit, using a pipe thickness estimation model in which the relationship between the external temperature-related information and the pipe thickness is defined for each axial region of the centrifugal cast tube. A centrifugal casting condition adjustment unit adjusts the conditions of centrifugal casting based on the pipe thickness estimated by the pipe thickness estimation unit, Having, Manufacturing equipment for centrifugal casting tubes.

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