JPH0632150B2 - Furnace temperature monitor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a furnace temperature monitor device for a reflow furnace that conveys an object to be heated into a furnace by a conveyor to cure an adhesive, solder, and the like. It is a thing.

[Prior Art] Generally, an in-furnace temperature monitoring device of a reflow furnace that conveys an object to be heated into a furnace by a conveyor to cure an adhesive, solder, etc. is operated under preset control conditions and The heating object is heated in a predetermined heating pattern. For example, when soldering components mounted on a printed circuit board using cream solder, the area, thickness, material of the printed circuit board, the number or area of the components,
The heating means is controlled and the convey speed of the conveyor is controlled based on the melting point of the solder so that the solder is heated in a predetermined heating pattern. By the way, when setting the control conditions so that a predetermined heating pattern is obtained, it is necessary to actually measure the temperature inside the reflow furnace to obtain the temperature distribution and monitor whether the predetermined heating pattern is obtained. was there. Conventionally, as shown in FIG. 9 (a), the furnace temperature monitoring device conventionally used in such a case is carried by a conveyor 2 that carries the heated object 1 into the reflow furnace A, and the heated object 1 The measurement unit 20 is configured to measure the temperature of a main part of the measurement unit and store the measurement data in the storage unit, and the monitor unit 21 that reads out the measurement data from the storage unit in the measurement unit 20 and prints (or displays) the measurement data. Was configured. The heating means is formed by a plurality of heaters H arranged above and below along the conveying direction of the conveyor 2, and the ultraviolet lamp U is provided in the preceding stage of the heating means.
V is provided, and a halogen lamp HL is provided at the subsequent stage.

[Problems to be Solved by the Invention] However, in such a conventional example. After the circuit section 20b of the measurement unit 20 is housed in the heat insulation case 20a and passed through the reflow furnace A, the circuit section 20b of the measurement unit 20 is taken out from the heat insulation case 20a as shown in FIG. Since it is necessary to connect to the unit 21 with a connector and read out and print out (or display) the data, the monitoring work is troublesome, and the temperature inside the reflow furnace cannot be monitored in real time. There was a problem that the waiting time became long.

Therefore, as shown in FIG. 1, a battery B that measures the temperature of the main part of the object to be heated 1 and transmits a radio wave in which a carrier wave is modulated by the measurement data from the transmitting antenna 5 projecting from the heat insulating case 4 is used. The built-in data transmitter 4 is connected to the heated object 1
In addition, a data receiver 7 is provided which conveys on the conveyor 2 and is stretched above the conveyor 2 in the furnace along the conveying direction to amplify and demodulate the output of the reception antenna 6 that receives the above-mentioned radio waves and output a data signal. A wireless furnace temperature monitoring device has been considered. However, even with such a wireless furnace temperature monitoring device, the reflow furnace A
Since the data transmitter 3 which has passed through once has a high temperature, as shown in FIG. 10, in order to prevent the deterioration of the circuit 3a and the built-in battery B housed in the heat insulating case 4, the data transmitter 3 shown in FIG. As shown, body 4a and cover 4b
It is necessary to open the cover 4b of the heat insulating case 4 while it is hot to air-cool the circuit 3a and the battery B, and there is a problem that the air-cooling operation is troublesome.

The circuit 3a of the data transmitter 3 is driven by a built-in battery B made of a secondary battery (for example, Ni / Cd), and is a power source made of a slide switch provided in the heat insulating case 4 after use. It is necessary to turn off the switch 10 ', but since the power switch 10' is provided in the heat insulating case 4, it is necessary to open the cover 4b of the heat insulating case 4 in order to turn off the power switch 10 '. There was a problem that power-off operation was also troublesome.

The present invention has been made in view of the above points, and an object thereof is to easily monitor the furnace temperature and to monitor the furnace temperature in real time. An object of the present invention is to provide a furnace temperature monitoring device capable of weakening transmitted radio waves to prevent radio wave interference to other electronic devices and easily performing air cooling operation and power shutoff operation.

[Means for Solving the Problems] A furnace temperature monitoring device of the present invention measures a temperature of a main part of an object to be heated and a transmitting antenna provided with a radio wave in which a carrier wave is modulated by measurement data, protruding from an insulating case. A data transmitter with a built-in battery is sent back from the belt conveyor along with the object to be heated and is stretched above the conveyor in the furnace along the transport direction to receive the above radio waves. In a furnace temperature monitoring device equipped with a data receiver for outputting a signal, a switch operating hole is provided in the heat insulating case of the data transmitter, and a blocking piece that doubles as an operating piece of a power switch is provided in the inner opening of the switch operating hole. Forced cooling means that automatically drives the cooling fan and forcibly cools when the data transmitter is placed on the cooling tray provided in the data receiver. At the same time, the operation protrusion provided on the cooling tray is inserted into the operation hole so that the power switch is turned off via the closing piece.

[Operation] The present invention is configured as described above, and measures the temperature of the main part of the object to be heated and transmits the radio wave in which the carrier wave is modulated by the measurement data from the transmitting antenna protruding from the heat insulating case. A data transmitter with a built-in battery is carried into the reflow furnace by a belt conveyor together with an object to be heated, and the output of the receiving antenna that receives the radio waves stretched above the conveyor in the furnace along the carrying direction is amplified and demodulated. It is equipped with a data receiver that outputs a data signal by simply monitoring the furnace temperature in real time, and it is possible to monitor the furnace temperature in real time and weaken the radio waves transmitted from the data transmitter. Therefore, it is possible to prevent radio wave interference to other electronic devices.

In addition, a switch operating hole is provided in the heat insulating case of the data transmitter, and a closing piece that also serves as an operating piece of the power switch is elastically contacted with the inner opening of the switch operating hole to cool the data transmitter provided in the data receiver. When the tray is placed on the tray, the cooling fan is automatically driven to forcibly cool the cooling tray, and the operation protrusion projecting on the cooling tray is inserted into the operation hole, so that the operation is performed through the blocking piece. Since the power switch is turned off, it is possible to perform the cooling operation by the cooling fan and the power switch off operation by simply placing the data transmitter at the predetermined position on the cooling tray, and to easily perform the air cooling device and the power cutoff operation. It has become.

[Embodiment] FIGS. 1 to 5 show an embodiment of the present invention, in which the temperature of a main part of the object 1 to be heated is conveyed along with the object 1 to be heated in a reflow furnace A by a conveyor 2. In addition, the radio wave which modulated the carrier wave with the measurement data (F2 of 150MHz)
Data transmitter 3 with a built-in battery for transmitting D) from a transmitting antenna 5 projecting from heat insulating case 4 and conveyor 2 in the furnace
It is formed by a receiving antenna 6 which is stretched upward along the transport direction and which receives the radio wave, and a data receiver 7 which amplifies and demodulates the output of the receiving antenna 6 and outputs measurement data. Here, in the embodiment, the data transmitter 3 uses the thermocouples TC ₁ to TC ₄ to measure the temperature of the main part of the heated object 1 (0 to 300 ° C., resolution 1 ° C., sampling time 0). .2 sec) is transmitted by radio waves radiated through the transmission antenna 5, and the data transmitter 3
Are driven by a battery housed in the heat insulating case 4. The heat insulating case 4 for accommodating the circuit portion 3a of the data transmitter 3 and the battery B is formed of a heat insulating plate whose surface is made of stainless steel and backed with bakelite in order to avoid a temperature rise due to the heating means. On one side, the transmission antenna 5 is exposed and the thermocouple T
C _{1 to} TC ₄ have been derived. The extraction portions of the thermocouples TC ₁ to TC ₄ and the transmission antenna 5 from the heat insulating case 4 are
It has an insulated and insulated drawer structure that is sandwiched by mica. On the other hand, the receiving antenna 6 stretched in the furnace is supported by a heat resistant insulator having a heat resistant temperature of 1300 ° C. The measurement data output from the data receiver 7 is processed by the data processing circuit 8 and printed out by the plotter 9. CRT display device (not shown)
Is displayed.

Further, a switch operating hole 11 is provided in the heat insulating case 4 of the data transmitter 3, and a closing piece 12 made of a heat insulating material which also serves as an operating piece of the power switch 10 is elastically contacted with an inner opening of the switch operating hole 11 ( For example, it is urged outward by a spring). On the other hand, the data receiver 7 is provided with a cooling tray 13 on which the data receiver 3 is placed, and the fact that the data transmitter 3 is placed on the cooling tray 13 is detected by a sensor 15 which is a proximity sensor. Forced cooling means for detecting and automatically driving the cooling fan 16 provided on the side surface of the data receiver 7 to force cooling is provided. At the same time, the operation protrusion 14 provided on the cooling tray 13 is inserted into the operation hole 11 to turn off the power switch 10 which is a micro switch attached to the printed circuit board P via the blocking piece 12. It is supposed to be done.

The operation of the embodiment will be specifically described below. Now
The data transmitter 3 is placed on the printed circuit board which is the object to be heated 1 and passes through the furnace. During the passage through the furnace, the data transmitter 3 is printed at regular intervals (0.2 sec). Are measured by the thermocouples TC ₁ to TC ₄ and the measurement data obtained by A / D converting the measurement signal is transmitted from the transmission antenna 4 by radio waves using a carrier wave of a predetermined frequency (15 MHz). ing. This radio wave is received by a receiving antenna 6 stretched above the conveyor 2, and is amplified and demodulated by a data receiver 7 to obtain measurement data. This measurement data is processed by the data processing circuit and the heating pattern is displayed in real time by printout or CRT display. As described above, in the present invention, the heating pattern can be actually measured only by carrying the data transmitter 3 by the conveyor 2 and passing it through the furnace.
The furnace temperature can be easily monitored and the temperature inside the furnace can be monitored in real time.
In addition, since the receiving antenna 6 is stretched along the conveyance path of the object to be heated 1, the weak radio wave to the extent that the radio wave emitted from the transmitting antenna 5 does not interfere with other electronic devices.
(Electric field strength at 3m away is less than 500μV / m)
Even in this case, the data transmission between the data transmitter 3 and the data receiver 7 can be surely performed.

Further, the heat insulating case 4 of the data transmitter 3 is provided with a switch operating hole 11, and an inward opening of the switch operating hole 11 is provided with a closing piece 12 made of a heat insulating material (hemitt plate) which also serves as an operating piece of the power switch 10. It is elastically contacted as shown in FIG. 4 (a), so that it is possible to secure the heat insulating property in a normal use state (during transportation in the reflow furnace A). On the other hand, when the data transmitter 3 is placed on the cooling tray 13 provided in the data transmitter 7 as shown in FIG. 5, the operation protrusion 14 protruding from the cooling tray 13 is shown in FIG. 4 (b). As shown, the power switch 1 is inserted into the operation hole 11 and the push button of the power switch 10 is pressed through the blocking piece 12.
0 is turned off (however, the normally-closed contact is used), and the power-off operation can be easily performed without removing the cover 4b of the heat insulating case 4.

Further, by placing the data transmitter 3 at a predetermined position on the cooling tray 13, the sensor 15 detects this and the forced cooling means operates to cool by the cooling fan 16, so that the air cooling operation can be easily performed. It has become.

FIG. 6 shows another embodiment in which the data processing circuit 8 of the above embodiment is realized by the CPU 7c of the data receiver 7 to simplify the system configuration. 8 is not necessary, and is directly connected to the plotter 9 so that data from the data transmitter 3 can be plotted (temperature distribution chart) in real time.
In the figure, 7a is a receiving unit for receiving a wireless signal from the data transmitter 3 via the antenna 6, 7b is an I / O circuit for inputting / outputting data of the CPU 7c, 7d is a memory, and 7e is a display unit. The display section 7e formed of digit number display elements has a thermocouple number (first digit) and a temperature (2 to 4).
The digit) is appropriately displayed. The seventh
The figure shows a power supply circuit. The transmitter electronic circuit 3a of the data transmitter 3 is supplied with power from a battery B in which a plurality of battery units are connected in parallel via a normally closed power switch 10. ing. Further, FIG. 8 is an example of temperature data showing the temperature distribution in the furnace printed out by the plotter 9.

[Advantages of the Invention] The present invention is configured as described above, and measures the temperature of the main part of the object to be heated and transmits the radio wave in which the carrier wave is modulated by the measurement data from the transmitting antenna protruding from the heat insulating case. A data transmitter with a built-in battery is conveyed along with the object to be heated into the reflow furnace by a belt conveyor and is stretched above the conveyor in the furnace along the conveying direction to amplify and demodulate the reception antenna output that receives the radio waves. It is equipped with a data receiver that outputs a data signal by simply monitoring the furnace temperature in real time, and it is possible to monitor the furnace temperature in real time and weaken the radio waves transmitted from the data transmitter. Therefore, there is an effect that it is possible to prevent radio wave interference to other electronic devices.

In addition, a switch operating hole is provided in the heat insulating case of the data transmitter, and a closing piece that also serves as an operating piece of the power switch is elastically contacted with the inner opening of the switch operating hole to cool the data transmitter provided in the data receiver. When the tray is placed on the tray, the cooling fan is automatically driven to forcibly cool the cooling tray, and the operation protrusion projecting on the cooling tray is inserted into the operation hole, so that the operation is performed through the blocking piece. Since the power switch is turned off, the cooling fan and the power switch can be turned off by simply placing the data transmitter at a predetermined position on the cooling tray, and the air cooling operation and the power cutoff operation can be easily performed. effective.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, FIG. 2 is a configuration diagram of main parts of the same, FIG. 3 is a perspective view of main parts of the same, and FIGS. 4 (a) and 4 (b).
Is a cross-sectional view of an essential part showing the same operation, FIG. 5 is a side view of an essential part of the same, FIG. 6 is a block circuit diagram of an essential part of another embodiment, and FIG.
FIG. 8 is a circuit diagram of a main part of the same as above, FIG. 8 is an operation explanatory diagram of the same as above, FIG. 9 (a) is a schematic configuration diagram of a conventional example, FIG. FIG. 11 is a cross-sectional view of a main part of a wireless furnace temperature monitoring device according to the present invention, and FIG. 11 is a top view of the same part. A is a reflow furnace, 1 is an object to be heated, 2 is a conveyor, 3 is a data transmitter, 4 is an insulating case, 5 is a transmission antenna, and 6
Is a receiving antenna, 7 is a data receiver, 10 is a power switch, 11 is a switch operating hole, 12 is a closing piece, 13 is a cooling tray, 14 is an operating protrusion, 15 is a sensor, and 16 is a cooling fan.

Claims (1)

[Claims] 1. A transmitting antenna, which is carried in a reflow furnace together with an object to be heated by a conveyor, measures the temperature of a main part of the object to be heated, and modulates a carrier wave with the measured data to project a radio wave into an adiabatic case. A data transmitter with a built-in battery to transmit from, a reception antenna that is installed above the conveyor in the furnace along the transport direction to receive the above radio waves, data reception that amplifies and demodulates the output of the reception antenna and outputs a data signal. In the furnace temperature monitoring device consisting of a reactor, a switch operating hole is provided in the heat insulating case of the data transmitter, and a closing piece that also serves as an operating piece of the power switch is elastically contacted with the inner opening of the switch operating hole to transmit the data. When the device is placed on the cooling tray provided in the data receiver, the cooling fan is automatically driven to forcibly cool the device and the cooling device is installed. Furnace temperature monitoring device through the closure piece by operating projection protruding from the tray is inserted into the operation hole, characterized in that as the power switch is turned off.