JPWO2019186869A1 - Temperature control device and temperature control method - Google Patents

Abstract

Feedback is given to the target temperature setting unit 133 in which the target temperature of each of the plurality of temperature control zones 111 to 114 is set, and the master zone based on the measurement temperature of the master zone and the target temperature set in the target temperature setting unit 133. With the temperature control unit 131, which calculates the operation amount to be controlled and calculates the operation amount for feedback control of the slave zone based on the measured temperature of the slave zone and the target temperature calculated to follow the temperature rise of the master zone. , Among a plurality of temperature control zones 111 to 114, the temperature control zone having the largest difference between the target temperature and the measured temperature is determined, the temperature control zone having the largest difference is set as the master zone, and the other temperature control zones are set. The master zone is automatically set by providing the master / slave setting unit 132 that sets the temperature in the slave zone.

Description

The present invention relates to a temperature control device and a temperature control method in which temperature rise is synchronously controlled.

In reflow furnaces and heat treatment equipment that have multiple temperature control zones, heaters are designed according to the characteristics such as heat capacity in each temperature control zone, but in actual temperature control, each temperature control zone is the target temperature. In many cases, there will be variations in the time to reach.
In the temperature control zone where the target temperature is reached early, it is necessary to maintain the target temperature until the other temperature control zones reach the target temperature, which causes problems such as wasteful power consumption.
In response to such a problem, Patent Document 1 describes the temperature control zone (master) in which the time required to reach the target temperature is the slowest so that the temperature rise completion times of a plurality of temperature control zones can be synchronized. A temperature control method for calculating a corrected temperature target value for another temperature control zone (slave section) using the measured value arrival rate of the section) is disclosed.
Further, Patent Document 2 discloses a technique capable of automatically setting a master section and a slave section.

Japanese Unexamined Patent Publication No. 2005-35090 Japanese Unexamined Patent Publication No. 2010-89432

According to Patent Document 1, even when the target temperatures of a plurality of temperature control zones are different, the temperature rise completion time can be synchronized, which is very useful, but a master section and a slave section are set (optimal as a master section). It took a lot of time and effort to select a suitable temperature control zone.
On the other hand, according to Patent Document 2, the optimum temperature control zone as the master section is automatically updated. Therefore, in Patent Document 1, "processing and labor for selecting the optimum temperature control zone for the master section". Can be omitted.
However, since the method of Patent Document 2 determines the master section based on the "target temperature arrival rate", there is a problem that an appropriate master section cannot be automatically set at the start of temperature control. ..
That is, since the "target temperature arrival rate" in Patent Document 2 is the achievement rate from the initial state to the target temperature, "target temperature arrival rate = zero" in any temperature control zone at the start of temperature control. Therefore, it is not possible to automatically determine an appropriate temperature control zone as the master section.

In view of the above points, the present invention follows the master zone whose feedback is controlled based on the set target temperature and the temperature rise of the master zone in order to synchronize the temperature rise completion times of the plurality of temperature control zones. It is an object of the present invention to provide a temperature control device capable of automatically setting the master zone and the slave zone in temperature control having a slave zone that is feedback-controlled based on the target temperature calculated so as to be performed. ..

(Structure 1)
A target temperature setting unit in which each target temperature of a plurality of temperature control zones is set, and an operation amount for feedback control of the master zone based on the measured temperature of the master zone and the target temperature set in the target temperature setting unit. Is provided, and a temperature control unit for calculating the operation amount for feedback control of the slave zone based on the measured temperature of the slave zone and the target temperature calculated to follow the temperature rise of the master zone. This is a temperature control device that synchronizes the temperature rise completion time of the plurality of temperature control zones, and among the plurality of temperature control zones, the temperature control zone having the largest difference between the target temperature and the measured temperature is determined. A temperature control device including a master / slave setting unit that sets a temperature control zone having the largest difference as a master zone and sets other temperature control zones as slave zones.

(Structure 2)
The temperature according to the configuration 1, wherein the master zone and slave zone setting process in the master / slave setting unit is performed every time any of the plurality of temperature control zones rises by a predetermined temperature or every predetermined time. Control device.

(Structure 3)
In the master zone and slave zone setting process in the master / slave setting unit, when there is a slave zone in which the difference between the target temperature and the measured temperature is larger than the difference between the target temperature and the measured temperature of the master zone by a predetermined value or more. The temperature control device according to configuration 2, wherein this is set as a master zone.

(Structure 4)
The target temperature of each of the plurality of temperature control zones is set, the operation amount for feedback control of the master zone based on the measured temperature of the master zone and the set target temperature is calculated, and the slave zone is set as the slave zone. A temperature control method that synchronizes the temperature rise completion times of a plurality of temperature control zones by calculating the operation amount for feedback control based on the measurement temperature and the target temperature calculated to follow the temperature rise of the master zone. Among the plurality of temperature control zones, the temperature control zone having the largest difference between the target temperature and the measured temperature is determined, the temperature control zone having the largest difference is set as the master zone, and the other temperature controls are controlled. A temperature control method characterized by setting a zone as a slave zone.

According to the temperature control device of the present invention, the temperature control zone having the largest difference between the target temperature and the measured temperature is determined and set as the master zone. Therefore, an appropriate master zone including the start of temperature control is used. Can be set automatically.

A block diagram showing an outline of the configuration of a reflow furnace according to an embodiment of the present invention. A flowchart showing an outline of processing according to the present invention in the reflow furnace (temperature control device) of the embodiment. Explanatory drawing which shows the concept of a temperature rise state in an embodiment

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. The following embodiment is an embodiment of the present invention, and does not limit the present invention to the scope thereof. The description will be omitted or simplified for devices having the same configuration and the same processing content as the conventional device.

FIG. 1 is a block diagram showing an outline of the configuration of a reflow furnace according to an embodiment of the present invention.
Reflow furnace 1 of the present embodiment is to perform soldering of the printed circuit board PCB, a plurality of heating zones (temperature control _zone) has a 11 1 to 11 _4, each heating zone ₁₁ 1 to 11 ₄ a heater (not specifically shown) and a temperature sensor ₁₂ 1 to 12 ₄ is provided.
Reflow furnace 1, the measured temperature of each heating zone ₁₁ 1 to 11 ₄ provided with a temperature controller 13 for controlling the temperature of each heating zone obtained from the temperature sensor ₁₂ 1 to 12 _{4 11} 1 to 11 ₄ Feedback control is performed using. In the present invention, the feedback control is not limited to a specific control method, and various control methods such as PID control can be used.

Temperature controller 13, in order to synchronize the heating completion time of each heating zone ₁₁ 1 to 11 _4, the heating zones ₁₁ 1 to 11 ₄ master zone one of the master to the others as slaves zone Each heating zone is feedback-controlled by the slave method.
The “master / slave method” means, for example, that the heating zone in which the time to reach the target temperature is the slowest is the master zone, the other heating zones are the slave zones, and the master zone is the measured temperature PV of the master zone. _The operation amount MV _m is calculated based on _m and the set target temperature SV _m to perform feedback control, and for each slave zone, the measured temperature PV _{s of the} slave zone and the temperature rise of the master zone are followed. The operation amount MV _s is calculated based on the target temperature SV _s ′ calculated in 1 (different from the target temperature SV _s set as the target temperature of the zone), and feedback control is performed.
Specifically, for example, the control method is as described in Patent Document 1, but the present invention relates to the setting of the master zone and the slave zone, and the master zone and the slave zone are determined after the master zone and the slave zone are determined. -As the slave type temperature control method, various control methods can be used in addition to those shown in Patent Document 1.

The temperature control device 13 includes a temperature control unit 131 that calculates each operation amount MV for feedback control of each heating zone by the master / slave method, and a master / slave setting unit 132 that sets the master zone and the slave zone. , the target temperature setting unit 133 each target temperature of each heating zone 11 ₁ to 11 ₄ is set, an output unit 134 that drives the heaters based on the manipulated variable MV calculated by the temperature controller 131, the a temperature measuring unit 135 for measuring the temperature of each heating zone ₁₁ 1 to 11 ₄ based on a signal from the temperature sensor ₁₂ 1 to 12 _4, and a.

Master-slave setting section 132, among the heating zones ₁₁ 1 to 11 _4, (a target temperature of each heating zone is set in the target temperature setting unit 133 ₁₁ 1 to 11 ₄₎ the target temperature SV and the measured temperature PV The heating zone having the largest difference is determined, the heating zone having the largest difference is set as the master zone, and the other heating zones are set as the slave zones.
As a result, an appropriate master zone can be automatically set including the start of temperature control.

Next, the processing operation of the reflow furnace 1 (temperature control device 13) having the above configuration will be described with reference to FIG. FIG. 2 is a flowchart showing an outline of processing according to the present invention in the reflow furnace 1 (temperature control device 13).
When the temperature control is started, first, it calculates the respective target temperature _SV 1 _{~ 4} of the heating zones ₁₁ 1 to 11 ₄ the difference between the measured temperature _PV 1 _{~ 4} (step 201). Target temperature _SV 1 _{~ 4} is a value set in the target temperature setting unit 133, the measured temperature _PV 1 _{~ 4} are values obtained based on the signals from the temperature sensors ₁₂ 1 to 12 _4.

In the following step 202, a process of determining whether or not the master zone has been set is performed. Here, since the master zone is not set immediately after the start of temperature control, the determination in step 202 is NO, and the process proceeds to step 203.
At step 203, compared to the target temperature SV of the respective heating zones 11 ₁ to 11 ₄ which has been calculated in step 201 the difference between the measured temperature PV, set the heating zone which is the largest difference as a master zone, otherwise Is set in the slave zone. If there are a plurality of items having the maximum difference between the target temperature SV and the measured temperature PV, one of the corresponding heating zones is selected. The selection may be made by any method, such as one that follows a preset priority, for example, one that determines in ascending order of IDs assigned to each heating zone, or one that randomly selects.

For each heating zone 11 ₁ to 11 _4, after the setting of the master-slave is, at the master-slave mode, starts the temperature control of the heating zone (step 204). As described above, the control can be any control method other than the method described in Patent Document 1.

In the loop processing of steps 205 to 206 following step 204 (after starting the temperature control), the temperature of the master zone is monitored (step 205) and it is determined whether the control is completed (step 206).
The end of control is an end based on a preset setting, an end based on an instruction from a user, or the like, and if this is the case, the process ends (step 206: Yes → end).
The monitoring of the temperature of the master zone detects that the temperature of the master zone has risen by 1 ° C. If the temperature of the master zone rises by 1 ° C., the process returns to step 201 (step 205: Yes → step 201).

The process of step 201 is the same as described above, but in the determination in step 202, since the master has already been set, the process proceeds to step 207 (step 202: Yes → step 207).
In step 207, it is determined whether or not there is a heating zone in which the difference between the measurement temperature SV and the measurement temperature PV is larger than the difference between the target temperature SV and the measurement temperature PV in the master zone by 1 ° C. or more.
If there is a heating zone having a difference of 1 ° C. or more from the difference between the target temperature SV of the master zone and the measurement temperature PV, the heating zone is set as a new master zone and the previous master zone is set as the slave zone. The process is performed (step 207: Yes → step 208). On the other hand, if there is no heating zone having a difference of 1 ° C. or more larger than the difference between the target temperature SV of the master zone and the measurement temperature PV, the master zone is not updated (step 208 is skipped).
If there are a plurality of heating zones having a difference of 1 ° C. or more larger than the difference between the target temperature SV of the master zone and the measured temperature PV, the one having the largest difference between the target temperature SV and the measured temperature PV is selected. To do. Further, when there are a plurality of items having the maximum difference between the target temperature SV and the measured temperature PV, one of them is selected. The selection may be made by any method, such as one that follows a preset priority, for example, one that determines in ascending order of IDs assigned to each heating zone, or one that randomly selects.

After the master zone update process of steps 207 to 208 is completed, the process proceeds to step 204, and the process described above is repeated thereafter.
As a result, every time the master zone rises by 1 ° C., the master zone is updated (automatic setting).

FIG. 3 is an explanatory diagram illustrating an example of a transition of temperature rise in the reflow furnace 1 (temperature control device 13). Here, for the sake of simplicity, there are two heating zones 1 and 2. Further, an example is taken in which the target temperatures of the heating zones 1 and 2 are the same.
Immediately after the start of temperature control, the temperature of the heating zone 2 is lower, so the difference between the target temperature SV and the measured temperature PV is large. Therefore, the heating zone 2 is set as the master zone and the heating zone 1 is set as the slave zone. (FIGS. 2 steps 201-203).
After that, the temperature rises faster in the heating zone 2 (master) and becomes higher than that in the heating zone 1 (slave). As a result, the difference between the target temperature SV and the measured temperature PV is that of the heating zone 1 (slave). When the temperature rises by 1 ° C. or more, the heating zone 1 becomes the master zone and the heating zone 2 becomes the slave zone at that stage (steps 207 to 208 in FIG. 2).

As described above, according to the reflow furnace 1 (temperature control device 13) of the present embodiment, the temperature control zone having the largest difference between the target temperature and the measured temperature is determined and set as the master zone. An appropriate master zone can be set automatically, including when the temperature control is started.
It is preferable that the master zone is the “temperature control zone in which the time to reach the target temperature is the slowest”, but this cannot be automatically and accurately determined at the start of temperature control. Therefore, in the reflow furnace 1 (temperature control device 13) of the present embodiment, the temperature control zone having the largest difference between the target temperature and the measured temperature is automatically set as the master zone. The "temperature control zone with the largest difference between the target temperature and the measured temperature" is not necessarily the "temperature control zone with the slowest time to reach the target temperature", but the difference between the target temperature and the measured temperature is large. This means that it takes time to reach the target temperature, and an appropriate master zone can be automatically set with a certain degree of validity.

Further, according to the reflow furnace 1 (temperature control device 13) of the present embodiment, the master zone is updated every time the master zone rises by 1 ° C. Therefore, the master zone is set at the start of temperature control. Even if it is not optimal, the master zone setting is optimized as the temperature rises.
In this embodiment, the master zone is updated every time the master zone rises by 1 ° C. However, the monitoring temperature is not limited to the rise of 1 ° C, and is appropriately determined according to the design concept. A predetermined value may be used. The monitoring target may be any temperature control zone other than the master zone. Further, instead of monitoring the temperature of the temperature control zone such as the master zone, the master zone may be updated at a predetermined timing (for example, at predetermined time intervals).

Further, according to the reflow furnace 1 (temperature control device 13) of the present embodiment, when there is a slave zone in which the difference between the target temperature and the measured temperature is 1 ° C. or more larger than the difference between the target temperature and the measured temperature in the master zone. In addition, since this is updated as the master zone, it is possible to prevent a decrease in efficiency due to frequent update of the master zone.
In this embodiment, when there is a slave zone having a difference of 1 ° C. or more larger than the difference between the target temperature of the master zone and the measured temperature, the update process is performed as an example, but the difference is 1 ° C. It is not limited to the above, and a predetermined value appropriately determined according to the design concept may be used.

Although the reflow furnace is taken as an example in the present embodiment, the temperature control device and the temperature control method of the present invention can be used not only for the reflow furnace but also for a device or system having a plurality of temperature control zones. it can.

1. 1. .. .. Reflow furnace 11 _{1 to} 11 ₄ . .. .. Heating zone (temperature control zone)
12 _{1 to} 12 ₄ . .. .. Temperature sensor 13. .. .. Temperature control device 131. .. .. Temperature control unit 132. .. .. Master / slave setting unit 133. .. .. Target temperature setting unit 134. .. .. Output unit 135. .. .. Temperature measuring unit

Claims (4)

A target temperature setting unit that sets the target temperature for each of the multiple temperature control zones,
The operation amount for feedback control of the master zone based on the measured temperature of the master zone and the target temperature set in the target temperature setting unit is calculated, and the slave zone is set to the measured temperature of the slave zone and the temperature rise of the master zone. A temperature control unit that calculates the operation amount for feedback control based on the target temperature calculated to follow
It is a temperature control device that synchronizes the temperature rise completion time of the plurality of temperature control zones by providing the above.
Among the plurality of temperature control zones, the temperature control zone having the largest difference between the target temperature and the measured temperature is determined, the temperature control zone having the largest difference is set as the master zone, and the other temperature control zones are the slave zones. A temperature control device including a master / slave setting unit to be set to. The first aspect of the present invention, wherein the master zone and the slave zone setting process in the master / slave setting unit is performed every time any of the plurality of temperature control zones rises by a predetermined temperature or every predetermined time. Temperature control device. In the master zone and slave zone setting process in the master / slave setting unit, when there is a slave zone in which the difference between the target temperature and the measured temperature is larger than the difference between the target temperature and the measured temperature of the master zone by a predetermined value or more. The temperature control device according to claim 2, wherein this is set as a master zone. The target temperature of each of the plurality of temperature control zones is set, the operation amount for feedback control of the master zone based on the measured temperature of the master zone and the set target temperature is calculated, and the slave zone is set as the slave zone. A temperature control method that synchronizes the temperature rise completion times of a plurality of temperature control zones by calculating the operation amount for feedback control based on the measurement temperature and the target temperature calculated to follow the temperature rise of the master zone. And
Among the plurality of temperature control zones, the temperature control zone having the largest difference between the target temperature and the measured temperature is determined, the temperature control zone having the largest difference is set as the master zone, and the other temperature control zones are the slave zones. A temperature control method characterized by setting to.

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