JP2023085676A - Heat calculation program and heat treatment device - Google Patents

Abstract

To provide a heat calculation program and a heat treatment device capable of suppressing a deterioration in calculation accuracy of a heat calculation even if the number of objects increases when analyzing a state of a heated object including an aggregation of the objects.SOLUTION: A computer executes: a calculation step of calculating an amount of heat transfer between objects using a physical quantity indicating heat transfer characteristics of the objects, and calculating a temperature distribution in a space by solving a heat transfer equation including the amount of heat transfer, with respect to a heat transfer model describing heat transfer in the space in which the object to be heated, including an aggregation of the objects, is arranged; and an update step of updating the physical quantity as a manipulated variable of feedback control or feedforward control regarding a temperature using the calculated temperature distribution.SELECTED DRAWING: Figure 3

Description

The present invention relates to a heat calculation program and a heat treatment apparatus that perform heat calculation based on a heat transfer model that describes heat transfer in space.

2. Description of the Related Art Conventionally, there has been known an analysis technique for performing thermal calculation using computer simulation. For example, Patent Literature 1 discloses a technique for optimally designing a heat treatment furnace using analysis that takes into account radiant heat. Specifically, the document describes that the pitch of the semiconductor wafers is determined so that the in-plane temperature of the semiconductor wafers becomes substantially uniform under the condition that the semiconductor wafers are arranged in multiple stages at regular intervals. there is

JP-A-9-080613

On the other hand, in the case of general heat treatment of mechanical parts, unlike wafers in the semiconductor manufacturing process, parts having various surface conditions such as polished surfaces, ground surfaces, and black scale surfaces can coexist. Therefore, if the calculation is performed assuming that the surface state of the object is uniform, an error may occur in the calculation result of the amount of heat transfer due to radiation. In particular, when analyzing the state of an object to be heated including an aggregate of objects, as the number of objects increases, the number of combinations in which heat exchange is performed increases, so calculation errors become apparent accordingly.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems. An object of the present invention is to provide a heat calculation program and a heat treatment apparatus capable of suppressing deterioration in calculation accuracy.

The heat calculation program in the first aspect of the present invention relates to a heat transfer model describing heat transfer in a space in which an object to be heated including an assembly of objects is arranged, using physical quantities indicating heat transfer characteristics of the object a calculation step of calculating the heat transfer amount between the objects and calculating the temperature distribution in the space by solving a heat transfer equation including the heat transfer amount; and an update step of updating the physical quantity as the manipulated variable of feedforward control.

In the heat calculation program according to the second aspect of the present invention, in the updating step, the operation of the feedback control is performed based on the relationship between the target value of temperature at a specific position in the space and the calculated temperature distribution. Update the physical quantity as a quantity.

In the thermal calculation program according to the third aspect of the present invention, the update step updates the physical quantity as the manipulated variable of the feedforward control according to the surface area of the object or the energy absorption rate of the surface.

In the heat calculation program according to the fourth aspect of the present invention, the heat transfer model describes a state in which a heater is arranged outside the object to be heated and the object to be heated is heated by heat generated from the heater, In the calculating step, a temporal change in temperature from the start of heating by the heater until reaching the target temperature is obtained for each of the objects.

In the heat calculation program according to the fifth aspect of the present invention, the computer obtains the arrival time until the two or more objects in the aggregate of objects reach the target temperature, respectively, and the two or more A determination step of determining a control time associated with heating or cooling the object to be heated using the arrival time is further performed.

A heat treatment apparatus according to a sixth aspect of the present invention is a heat treatment apparatus comprising an apparatus main body for heat-treating an object to be treated, and a controller for controlling the apparatus main body, wherein the apparatus main body a heat insulating wall provided to surround an object to be heated including an aggregate of objects; With respect to a heat transfer model that describes heat transfer in the heating chamber in which objects are arranged, a physical quantity indicating heat transfer characteristics of the objects is used to calculate the amount of heat transfer between the objects, and a heat transfer model that includes the amount of heat transfer is calculated. Calculate the temperature distribution in the heating chamber by solving the equation, update the physical quantity as the manipulated variable of feedback control or feedforward control using the calculated temperature distribution, and obtain by sequential calculation A control time for heating in the heating chamber is determined from the change in the temperature distribution over time, and the control time is used to control the heating of the heater.

ADVANTAGE OF THE INVENTION According to this invention, when analyzing the state of the to-be-heated object containing the aggregate|assembly of an object, even when the number of objects increases, it can suppress the fall of the calculation accuracy of thermal calculation.

1 is a schematic cross-sectional view of a vacuum carburizing furnace as a heat treatment apparatus in one embodiment of the present invention; FIG. 2 is a flow chart showing an example of temperature control operation by the controller of FIG. 1; FIG. 3 is a detailed flowchart relating to a control time calculation method shown in step SP10 of FIG. 2; FIG. It is a figure which shows an example of the heat-transfer model which is analysis object. 2 is a diagram showing an example of a model setting screen displayed on the operation panel of FIG. 1; FIG. FIG. 4 is a diagram showing temperature characteristics of emissivity in different surface states; It is a figure which shows an example of the determination method of soaking holding time. FIG. 8A is a diagram showing an example of temperature change of a part whose surface is polished. FIG. 8B is a diagram showing an example of temperature change of a part with a rusted surface.

Embodiments of the present invention will be described below with reference to the accompanying drawings. In order to facilitate understanding of the description, the same constituent elements in each drawing are denoted by the same reference numerals as much as possible, and overlapping descriptions are omitted.

[Overall configuration of heat treatment apparatus 10]
FIG. 1 is a schematic cross-sectional view of a heat treatment apparatus 10 according to one embodiment of the present invention. The heat treatment apparatus 10 includes a vacuum carburizing furnace 12 (corresponding to "apparatus body"), a controller 14 (corresponding to "computer"), a heating power source 16, and temperature sensors 18, 19, and 20. be.

The vacuum carburizing furnace 12 is a device for performing vacuum carburizing with a hydrocarbon gas under high temperature and reduced pressure. The vacuum carburizing furnace 12 includes a furnace body 22 that accommodates a work W (corresponding to an “object to be treated” or “to-be-heated”) and a frame body 24 attached inside the furnace body 22 . Inside the frame 24, a relatively large hollow rectangular parallelepiped heat insulating member 26, a relatively small hollow rectangular parallelepiped heat insulating member 28, and a plurality of heat insulating members 30 for connecting the heat insulating member 26 to the heat insulating member 28. and is provided. The heat insulating members 26, 28, 30 are made of a heat insulating material such as ceramic fiberboard, for example. A space layer 32 functioning as a heat insulating layer is formed by providing the two heat insulating members 26 and 28 with a space therebetween.

A carburizing chamber 36 for performing vacuum carburizing is formed inside the furnace body 22 by being surrounded by the hollow heat insulating member 30 . A hearth 38 is provided in the furnace body 22 so as to extend inwardly of the carburizing chamber 36 from the bottom thereof. A work W is placed on the upper end of the hearth 38 .

A plurality of radiator tubes 40 (corresponding to “heaters”) are attached to the upper portion of the furnace body 22 so as to extend inwardly of the carburizing chamber 36 . Each radiator pipe 40 is provided at a position that widely covers the range from the upper end to the lower end of the carburizing chamber 36 . Thereby, the space formed by the carburizing chamber 36 can be heated substantially uniformly. The inside of the carburizing chamber 36 is set to a high temperature exceeding 900° C., for example.

A plurality of gas introduction nozzles 44 are provided at the upper and side portions of the furnace body 22 so as to face the positions of the workpieces W. As shown in FIG. The surface of the work W can be carburized by introducing a hydrocarbon gas from a gas supply mechanism (not shown) into the carburizing chamber 36 through the gas introduction nozzle 44 .

An exhaust pipe 46 that communicates the carburizing chamber 36 with the outside of the vacuum carburizing furnace 12 is provided in the lower portion of the furnace body 22 . The pressure in the carburizing chamber 36 can be adjusted by operating a vacuum pump (not shown) to exhaust the gas from the exhaust port 48 .

The controller 14 is a computer having a processor 50 , a memory 52 and an operation panel 54 and controlling the operation of each part of the vacuum carburizing furnace 12 . The controller 14 reads and executes programs and data stored in the memory 52 to [1] control the supply of hydrocarbon gas into the carburizing chamber 36 and [2] adjust the pressure in the carburizing chamber 36. Pressure control and [3] heating control for heating the interior of the carburizing chamber 36 are performed synchronously or in parallel. A flow rate sensor, a pressure sensor (none of which are shown), and temperature sensors 18-20 are connected to the controller 14 to control these operations.

Processor 50 obtains temperature signals from temperature sensors 18 and 19 and uses the measured temperatures to calculate an estimate of the temperature in carburizing chamber 36 and the temperature of workpiece W. The processor 50 determines setting conditions (hereinafter also referred to as “heat treatment conditions”) regarding the heat treatment of the work W based on the estimated values calculated by itself. The processor 50 obtains a temperature signal from the temperature sensor 20 and turns on/off the heating power source 16 to control the heating of each radiator tube 40 .

Here, the temperature sensor 18 is provided at a position contacting the upper portion of the furnace body 22, and the temperature sensor 19 is provided at a position around the vacuum carburizing furnace 12, respectively. The temperature sensor 20 is provided to extend inwardly of the carburizing chamber 36 from the upper portion of the furnace body 22 . The temperature sensor 20 comprises, for example, a heat-resistant thermocouple so as to withstand the high temperatures within the carburizing chamber 36 .

The memory 52 stores setting conditions (that is, heat treatment conditions) relating to the heat treatment of the workpiece W and information relating to a heat transfer model describing heat transfer in the furnace body 22 (hereinafter also referred to as “model information”). The model information includes [1] "shape information" regarding the shape of model elements, [2] "arrangement information" regarding the arrangement of model elements, [3] "temperature information" regarding temperature constraint conditions, or [4] It includes "physical property information" related to the physical properties of model elements.

The physical property information described above includes various information on changes in the surface area of the object or the energy absorption rate of the surface, specifically, the type of material, the surface state, the radiation index, and the like. The "surface condition" includes surface roughness, surface color, degree of oxidation progress, film thickness, surface temperature, and the like. The surface state may be expressed qualitatively or quantitatively. Specific examples of the former include a polished surface, a shot surface, presence or absence of rust, and the like. Specific examples of the latter include arithmetic mean roughness, maximum height, and coating thickness.

The "radiation index" mentioned above is used to correct a physical quantity that indicates the heat transfer characteristics of an object. This "physical quantity" includes, for example, emissivity, emissivity, heat transfer coefficient, thermal radiation coefficient, heat flux, and the like. The "radiation index" is used to express an intermediate state between the surface state before heat treatment (hereinafter referred to as first surface state) and the surface state after heat treatment (hereinafter referred to as second surface state). For example, if the radiation index η is defined in the range [0, 1], η=0 corresponds to the first surface state and η=1 corresponds to the second surface state.

The operation panel 54 is an input/output device for an operator to operate. The operation panel 54 includes, for example, a touch panel display, hardware switches, speakers, and the like. Thereby, the operation panel 54 can display a model setting screen 80 (FIG. 5) for setting a thermal structure model.

[Operation of controller 14]
<1. Temperature control operation>
The heat treatment apparatus 10 in this embodiment is configured as described above. Subsequently, the operation of the heat treatment apparatus 10, more specifically, the temperature control by the controller 14 will be described in detail with reference to the flowchart of FIG.

At step SP10 in FIG. 2, the controller 14 calculates various control times included in the heat treatment conditions. Here, the “control time” is the time related to the control of each step that constitutes a series of heat treatments. "Soaking time" until the temperature is changed, or [3] "heating time" which is the sum of the heating time and the soaking time.

At step SP12, the controller 14 sets heat treatment conditions including the control time calculated at step SP10.

At step SP14, the controller 14 starts the temperature control operation for the radiator tube 40 as the heat treatment starts.

In step SP16, the controller 14 performs a series of temperature control operations (for example, feedback control or feedforward control regarding temperature) on the heat sink 40 according to the heat treatment conditions set in step SP12. By this operation, a temperature raising process, a soaking process, a carburizing process, a diffusion process, a furnace cooling process, a quenching soaking process, and an oil cooling process are sequentially performed.

<2. Control Time Calculation Operation>
Next, the method of calculating the control time in step SP10 of FIG. 2 will be described with reference to the detailed flowchart of FIG.

At step SP20 in FIG. 3, the controller 14 acquires model information including a radiation index. Specifically, the controller 14 acquires model information indicating a heat transfer model to be analyzed through reading of three-dimensional CAD (Computer Aided Design) data and input operation by an operator.

FIG. 4 is a diagram showing an example of a heat transfer model to be analyzed, and more specifically corresponds to a plan view of the inside of the carburizing chamber 36 shown in FIG. 1 as viewed from above. The carburizing chamber 36 is provided with a temperature sensor 20, a hearth 38, a work W on the hearth 38, and a plurality of heat radiation pipes 40 arranged side by side along both sides of the work W. . The workpiece W is made up of a metal part 60 (corresponding to an "object") or a group of parts 62 (corresponding to an "aggregate of objects") housed in a container (not shown). It should be noted that the hatched radiator tube 40 indicates that it is arranged at the position closest to the temperature sensor 20 .

FIG. 5 is a diagram showing an example of a model setting screen 80 displayed on the operation panel 54 of FIG. Via the model setting screen 80, the operator can input model information including the above-described shape information, arrangement information, physical property information, and temperature information. For example, when the [Physical properties] tab 82 is selected, on the model setting screen 80, user controls 84 and 85 regarding the update setting of the radiation index, user controls 86 to 90 regarding the radiation of the work W, and [Cancel]. A button 92 labeled and a button 94 labeled "Save" are respectively arranged.

A user control 84 is provided so as to be able to select ON/OFF of feedback control (FF control) regarding the radiation index. A user control 85 is provided so as to be able to select ON/OFF of feedback control (FB control) regarding the radiation index. Note that user controls 86-90 are active only when "ON" is selected in user control 84. FIG.

A user control 86 is provided to allow selection of the type of material for the part 60 (here, "steel"). A user control 87 is provided so that the surface state of the component 60 before heat treatment (here, "state A") can be selected. A user control 88 is provided so that the surface state of the component 60 after heat treatment (here, "state B") can be selected. A user control 89 is provided to select the method of setting the radiation index (either fixed or variable; here "fixed"). A user control 90 is provided to allow entry of a radiation index value (0-100%; here "50%").

The controller 14 ends the display of the model setting screen 80 when the touch operation of the [Cancel] button 92 is accepted. On the other hand, when the controller 14 accepts the touch operation of the [Save] button 94, the controller 14 acquires the values most recently input to the model setting screen 80, and stores them in the memory 52 of FIG. 1 as model information.

At step SP22 in FIG. 3, the controller 14 determines a heat transfer model to be analyzed based on the model information acquired at step SP20. In determining the heat transfer model, controller 14 uses the radiation index to determine an initial value for the emissivity of component 60 .

At step SP24 in FIG. 3, the controller 14 sets a point in time to be calculated (hereinafter also referred to as a "sampling point"). If the initial state is defined as t=0, the first sampling point is set to t=Δt.

At step SP26, the controller 14 builds a heat conduction equation for each model element at the sampling time (t=Δt) set at step SP24. In order to calculate the amount of heat transferred by radiation (that is, heat flux), for example, the Discrete Beam Method (DBM) is used. This "discretized beam method" is a method of tracing a radiation beam, calculating each shape factor, and using this shape factor to determine the amount of heat transfer.

In step SP28, the controller 14 simultaneously or coupled solves the heat conduction equation constructed in step SP26. As a result, the temperature (that is, temperature distribution) at each position at the first sampling point (t=Δt) is obtained.

At step SP30, the controller 14 confirms whether or not the temperature distribution obtained at step SP28 satisfies the end condition of the repeated calculation. This "end condition" is, for example, that the temperatures of n (1<n≦N) out of the N parts 60 match or sufficiently approach the target temperature. Since the end condition is not satisfied at the time of the first sampling (step SP30: NO), the process proceeds to step SP32.

In step SP32, the controller 14 uses the temperature distribution calculated in step SP28 to update the manipulated variable (here, the radiation index) of the temperature control. This control may be [1] feedback control, [2] feedforward control, or [3] both feedback control and feedforward control.

(1. Feedback control)
The controller 14 calculates a feedback term (FB term) based on the relationship between the temperature target value at a specific position in the carburizing chamber 36 and the calculated temperature distribution, and multiplies the gain value to update the radiation index. Perform feedback control. The "specific position" is desirably a position where the target temperature value is known, for example, the position of the temperature sensor 20 provided in the carburizing chamber 36 or a position in the vicinity thereof. On the other hand, as the temperature output value, the temperature at any position on the temperature distribution can be selected. As a radiation index update rule. Proportional control (P control), integral control (I control), derivative control (D control), or a combination thereof is used.

(2. Feedforward control)
The controller 14 calculates a feedforward term (FF term) according to the surface area of the object or the energy absorption rate of the surface, multiplies the gain value, and performs feedforward control to update the radiation index. This update amount may be determined, for example, according to a predetermined temperature characteristic of emissivity.

FIG. 6 is a diagram showing temperature characteristics of emissivity in different surface states. The horizontal axis of the graph indicates temperature (unit: °C), and the vertical axis of the graph indicates emissivity (unit: dimensionless). As understood from this figure, the emissivity increases as the temperature rises in all of the states A, B, and C. However, the emissivity tends to change depending on the surface state, and for an arbitrary temperature T, a magnitude relationship of ε _A (T)<ε _B (T)<ε _C (T) is established. Here, ε _A (T), ε _B (T), and ε _C (T) correspond to the emissivity of states A, B, and C at temperature T, respectively.

Here, when the radiation index is defined as η (0≦η≦1), the corrected emissivity ε(T) is obtained according to the following equation (1).

Returning to step SP24 in FIG. 2, the controller 14 updates the sampling time. This sets the second sampling point to t=2Δt. Thereafter, the controller 14 repeatedly executes steps SP24 to SP32 to obtain the temperature distribution at each sampling time point (t=mΔt; m is a natural number). In addition, when the setting method of the radiation index is "variable", the controller 14 may dynamically change the radiation index η each time the sampling time is updated. For example, by gradually increasing the value of η as the heat treatment progresses, it is possible to further improve the calculation accuracy of the amount of heat transfer.

If the temperature distribution becomes more uniform with the passage of time and the end condition described above is satisfied (step SP30: YES), the controller 14 proceeds to step SP34 instead of step SP32.

In step SP34, the controller 14 determines the control time, which is part of the heat treatment conditions, using the temporal change in temperature distribution obtained by repeatedly executing step SP28.

FIG. 7 is a diagram showing an example of a method for determining the soaking holding time. The horizontal axis of the graph indicates elapsed time (unit: minutes), and the vertical axis of the graph indicates temperature (unit: °C). Three curves indicate the temperature at different positions P1, P2, P3 within the workpiece W. FIG. As can be understood from the drawing contents of FIG. 4, the degree of heat transfer varies depending on the position in the workpiece W, so the curves have different shapes. When the arrival times to the target temperatures at the positions P1, P2, and P3 are defined as t1, t2, and t3, respectively, the magnitude relationship of t1<t2<t3 is satisfied. In this case, the maximum value of the difference (t3-t1) can be calculated as the soaking holding time.

FIG. 8A is a diagram showing an example of temperature change of the component 60 whose surface is polished. FIG. 8B is a diagram showing an example of temperature change of the part 60 with a rusted surface. The horizontal axis of the graph indicates the elapsed time (unit: minutes), and the vertical axis of the graph indicates [1] temperature (unit: °C) or [2] output rate of the radiator tube 40 (unit: %). The curve indicated by the solid line corresponds to the measured temperature value (that is, the target value) at the position of the temperature sensor 20 . Two curves indicated by a short dashed line and a dashed line correspond to calculated temperatures at two different points.

As can be understood from FIG. 8A, the temperature rise time is set to a short value because the time required to reach the set target temperature is relatively short. However, since the variation in temperature rise depending on the position of the workpiece W is relatively large, the soaking holding time is set to a large value. Further, as can be understood from FIG. 8B, the time required to reach the set target temperature is relatively long, so the heating time is set to a large value. However, since variations in temperature rise depending on the position of the workpiece W are relatively small, the soaking holding time is set to a small value. Thus, a soaking holding time suitable for the surface state of the component 60 can be obtained.

As described above, the controller 14 ends the control time calculation operation (flow chart in FIG. 3). In this manner, by appropriately selecting the soaking holding time so that the end point is reached at the timing when the workpiece W is soaked, it is possible to achieve both the quality and efficiency of the heat treatment.

[Summary of embodiment]
As described above, in the thermal calculation program and method in this embodiment, one or more computers (here, the controller 14) control an assembly (here, the part group 62) of objects (here, the parts 60) Part A calculation step (SP26, SP28 in FIG. 3) of calculating the temperature distribution in the carburizing chamber 36 by calculating the amount of heat transfer between 60 and solving the heat transfer equation including the amount of heat transfer, and calculating the calculated temperature distribution. is used to execute an update step (SP32) for updating physical quantities as manipulated variables for feedback control or feedforward control relating to temperature.

In this way, by updating the physical quantity that indicates the heat transfer characteristics of the component 60 as the manipulated variable for feedback control or feedforward control, the amount of heat transfer due to radiation is reduced compared to the case where the physical quantity is unchanged. Calculation errors are smaller. As a result, when analyzing the state of the workpiece W including the part group 62, even if the number of the parts 60 increases, it is possible to suppress the deterioration of the calculation accuracy of the heat calculation.

Further, in the updating step, the physical quantity as the manipulated variable for feedback control may be updated based on the relationship between the target temperature value at a specific position in the carburizing chamber 36 and the calculated temperature distribution. In addition to this or separately, in the updating step, the physical quantity as the manipulated variable of the feedforward control may be updated according to the surface area of the object or the energy absorption rate of the surface.

Further, when the heat transfer model describes a state in which a heater is arranged outside the workpiece W and the workpiece W is heated by the heat generated from the heater, in the calculation step, from the start of heating until the target temperature is reached, may be obtained for each part 60.

In addition, the controller 14 obtains the arrival times for two or more parts 60 of the parts group 62 to reach the target temperature, and uses the two or more arrival times to be involved in the heating or cooling of the workpiece W. A determination step (SP34 in FIG. 3) of determining the control time may also be performed.

Further, when the physical quantity is the emissivity, and the component 60 changes from the first surface state to the second surface state through heating, the updating step includes the emissivity in the first surface state and the emissivity in the second surface state. Feedforward control may be performed to update the emissivity to an intermediate value between. Also, in the calculating step, the amount of heat transfer between the parts 60 may be calculated using the discretized beam method.

Further, the heat treatment apparatus 10 in this embodiment includes an apparatus main body (in this case, the vacuum carburizing furnace 12 ) for heat-treating the workpiece W, and a controller 14 for controlling the vacuum carburizing furnace 12 . The vacuum carburizing furnace 12 is formed by a heat insulating wall (here, heat insulating members 26, 28, 30) provided so as to surround a work W including an assembly of objects (here, a part group 62), and a heat insulating wall. and a heater (here, heat radiation tube 40) for heating the inside of the heating chamber (here, carburizing chamber 36).

Then, the controller 14 uses the physical quantity indicating the heat transfer characteristics of the parts 60 with respect to the heat transfer model that describes the heat transfer in the carburizing chamber 36 in which the work W including the part group 62 is arranged, to determine the heat transfer between the parts 60. Calculate the temperature distribution in the carburizing chamber 36 by solving a heat transfer equation including the amount of heat transfer, and use the calculated temperature distribution as a manipulated variable for feedback control or feedforward control regarding temperature The physical quantity is updated, the control time related to the heating in the carburizing chamber 36 is determined from the time change of the temperature distribution obtained by the sequential calculation, and the heat radiation tube 40 is controlled using the control time. By configuring in this way, when heat-treating the workpiece W including the part group 62, it is possible to set the control time suitable for the number of parts 60 and the packing style, and it is possible to achieve both quality and efficiency of heat treatment. become.

[Modification]
It goes without saying that the present invention is not limited to the above-described embodiments, and can be freely modified without departing from the gist of the present invention. Alternatively, each configuration may be arbitrarily combined as long as there is no technical contradiction.

In the above-described embodiment, a case has been described in which the controller 14 that constitutes a part of the heat treatment apparatus 10 executes the heat calculation program, but the configuration of the apparatus is not limited to this. For example, a general-purpose computer independent of the vacuum carburizing furnace 12 may execute a heat calculation program for computer simulation purposes.

DESCRIPTION OF SYMBOLS 10... Heat treatment apparatus, 12... Vacuum carburizing furnace, 14... Controller (computer), 36... Carburizing chamber (heating chamber), 40... Radiation tube (heater), 50... Processor, 52... Memory, 60... Parts (objects) , 62... Parts group (collection of objects), W... Work (object to be heated, object to be processed)

Claims (6)

With respect to a heat transfer model describing heat transfer in a space in which objects to be heated including an assembly of objects are arranged, a physical quantity indicating heat transfer characteristics of the objects is used to calculate an amount of heat transfer between the objects, a calculating step of calculating the temperature distribution in the space by solving a heat transfer equation including the amount of heat transfer;
an updating step of using the calculated temperature distribution to update the physical quantity as a manipulated variable for feedback control or feedforward control relating to temperature;
A heat calculation program characterized by causing a computer to execute In the updating step, the physical quantity as the manipulated variable of the feedback control is updated based on a relationship between a target temperature value at a specific position in the space and the calculated temperature distribution. The thermal calculation program according to claim 1. 3. The thermal calculation program according to claim 1, wherein in the updating step, the physical quantity as the manipulated variable of the feedforward control is updated according to the surface area of the object or the energy absorption rate of the surface. . The heat transfer model describes a state in which a heater is arranged outside the object to be heated and the object to be heated is heated by heat generated from the heater,
2. The thermal calculation program according to claim 1, wherein in said calculating step, a change in temperature over time from the start of heating by said heater until reaching a target temperature is obtained for each of said objects. The computer obtains the arrival times for two or more objects in the assembly of objects to reach the target temperature, and uses the two or more arrival times to heat the object to be heated or 5. The heat calculation program according to claim 4, further causing a determination step of determining a control time related to cooling to be executed. A heat treatment apparatus comprising: a device body for heat-treating an object to be processed; and a controller for controlling the device body,
The device main body is
a heat insulating wall provided so as to surround an object to be heated including an aggregate of objects as the object to be processed;
a heater that heats the inside of the heating chamber formed by the heat insulating wall;
with
The controller is
With respect to a heat transfer model describing heat transfer in the heating chamber in which an object to be heated including an assembly of objects is arranged, a physical quantity indicating the heat transfer characteristics of the objects is used to calculate the amount of heat transfer between the objects, calculating the temperature distribution in the heating chamber by solving a heat transfer equation including the amount of heat transfer;
using the calculated temperature distribution to update the physical quantity as a manipulated variable for feedback control or feedforward control relating to temperature;
A heat treatment apparatus, wherein a control time related to heating in the heating chamber is determined from a time change of the temperature distribution obtained by sequential calculation, and heating control of the heater is performed using the control time.

Images