JPH03295183A - Heating device for adhesive - Google Patents

Abstract

PURPOSE:To easily detect the open circuit of a heater by providing an open circuit detecting means 1-4 which stops the energization of the heater for a preset period, then energize it, and detects the open circuit of the heater based on the temperature change of an adhesive. CONSTITUTION:A coating head 1 is constituted of a container holding a heated adhesive, and a heater 2 heating the container and a thermistor 3 measuring the temperature of the adhesive are provided. A temperature adjusting controller measures the temperature of the coating head 1 based on the signal from the thermistor 3 and controls the temperature of the adhesive by feedback control based on the measured result so that the temperature becomes a preset value. The heater 2 and a temperature measurement section used for the temperature control of the adhesive are used as they are, the heating by the heater 2 is stopped for a fixed period during the detection of the open circuit, then the heater 2 is energized, the temperature change is detected, and the presence of the open circuit of the heater 2 is detected based on the temperature change.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an adhesive heating device used in an electronic component mounting machine, etc., for heating an adhesive applied to a mounting portion of an electronic component on a mounting surface. be.

[Prior Art] In recent years, adhesive applicators are required to have performance comparable to that of electronic component mounting machines due to faster mounting speeds and higher precision. FIG. 5 is a diagram showing a coating head 1 used as a main part of a conventional adhesive coating device. The coating head 1 consists of a container that holds heated adhesive, and is provided with a heater 2 that heats the container and a thermistor 3 that measures the temperature of the adhesive.

In the conventional temperature control device, the output of the thermistor 3 is connected to a temperature adjustment controller (not shown). The temperature adjustment controller adjusts the coating head 1 based on the signal from the thermistor 3.
The temperature of the adhesive is controlled by measuring the temperature of the adhesive and performing feedback control based on the measurement result so that the temperature becomes a predetermined value.

[Problem to be solved by the invention]

2. Description of the Related Art In recent years, in devices for mounting electronic components, it has become necessary to drive adhesive applicators at high speeds as mounting speeds have increased. However, in the conventional adhesive applicator, since the heater portion of the heater 2 and the lead wire are rotated at high speed (not shown in FIG. 5), the heater wire is easily broken. Furthermore, even if the heater wire is broken, the disconnection state cannot be detected, and the temperature of the adhesive decreases, causing the adhesive to soften by 1 or more, resulting in poor coating.

The present invention has been made in view of the problems of the adhesive heating device used in the conventional adhesive applicator, and a technical problem is to easily detect disconnection of the heater. .

[Means to solve the problem]

As shown in FIG. 1, the present invention includes an adhesive container 10 that holds an adhesive, and a heater 1 that heats the adhesive in the adhesive container.
1, a temperature measuring means 12 that includes a temperature sensor provided in an adhesive container and measures the temperature of the adhesive, and a temperature control means 1 that controls power supply to the heater and maintains the adhesive temperature at a predetermined value.
3, the adhesive heating device has a disconnection detection means 14 that detects a disconnection of the heater based on a temperature change of the adhesive by stopping energization to the heater for a predetermined period of time, and then turning on the current. This is a characteristic feature.

(Function) According to the present invention having such features, the heater and temperature measurement unit used for adhesive temperature control are used as they are, and when a disconnection is detected, overheating by the heater is stopped for a certain period of time, and then the power supply to the heater is stopped. The system detects temperature changes and detects whether there is a disconnection based on the temperature changes.

〔Example〕

Next, an adhesive coating device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a block diagram showing the configuration of a temperature control device used in an adhesive coating device in an embodiment of the present invention.

In this figure, the coating head 1 is an adhesive container 10 containing adhesive, and the configuration of the heater 2 that heats the coating head 1 and the thermistor 3 that is the temperature measuring means 12 that detects the temperature is the same as the conventional example described above. The same is true. In this embodiment, the output of the thermistor 3 is given to the signal processing section 22 of the temperature adjustment controller 21. Signal processing section 22
is for amplifying and linearizing the signal obtained from the thermistor and converting it into a digital value, and its output is given to the CPU 24 via the interface circuit 23. A memory 25 and a display section 26 are connected to the CPU 24 . The CPU 24 fulfills the function of the temperature control means 13 that controls the adhesive in the coating head 1 to a predetermined temperature, and also performs a process of detecting heater disconnection, as will be described later.

The output of the CPU 24 is configured to be outputted to the outside via the output section 27 and to drive the heater 2.

Next, the operation of the temperature adjustment controller 21 having a disconnection detection function will be explained using a flowchart. FIG. 3 is a flowchart showing the operation of the temperature adjustment controller 21 according to an embodiment of the present invention. In this figure, when the operation starts, temperature control processing is first performed for a certain period of time (routine 31). In the temperature control process, first, a timer for a certain period of time is turned on, a manipulated variable is calculated based on the temperature input from the signal processing section 22, and the heater 2 is driven. By performing this process until time-up, temperature control is performed for a certain period of time. The process then proceeds to step 32, where the set temperature at that time is compared with the dark value temperature that is considered abnormal.

If there is an abnormality in the temperature, the heater may be disconnected or the temperature may fluctuate due to disturbance, so the same process is executed again. That is, the routine advances from step 33 to routine 34, where, like routine 31, temperature control is performed for a fixed period of time. The process then proceeds to step 35, where the temperature is again compared with the dark value temperature, and the presence or absence of an abnormality is checked (step 36). If there is no abnormality here, it is determined that the abnormality is not due to heater disconnection, but rather a temperature change due to disturbance, and the process returns to routine 31 to repeat the same process. If it is determined in step 36 that there is an abnormality, the process proceeds to step 37, where a disconnection process is performed, for example, a disconnection is displayed on the display unit 26, and the operation is stopped. Here CPU2
4 achieves the function of the disconnection detection means 14 which detects disconnection of the heater 2 by stopping energization to the heater 2 and then energizing it in the flowchart shown in FIG.

In this way, it is possible to prevent wire breakage while adjusting the temperature. Furthermore, by double checking the temperature effect due to disturbance and the temperature effect due to heater disconnection, it is possible to reliably check whether there is a heater disconnection.

Next, an adhesive heating device according to a second embodiment of the present invention will be described with reference to a flowchart.

This embodiment has the same hardware configuration as the first embodiment described above, but the disconnection detection function is performed by different processing. In this embodiment, the % deviation width above the set temperature is defined as a settling zone. When the operation starts, temperature control is first performed in routine 41. The process then proceeds to step 42 to check whether a stable state has been reached. If the stable state has not been reached, the process returns to routine 41 and repeats the same process until the stable state is reached, and if the stable state is reached, the process advances to step 43 to determine whether or not it is stable within the settling zone. If the temperature is stable outside the settling zone, use the following procedure to check for heater burnout. That is, in step 44, it is checked whether the disconnection determination is the second time, and if it is determined to be disconnected the second time, the process advances to step 45 and T is
The output is turned off for 1 second to stop heating by the heater 2. When the output stop period ends, the process proceeds to step 46 to measure the temperature change Δt1 while the output is turned off. Further, when this is completed, the process proceeds to step 47, where the output is turned on for 12 seconds and the coating head 1 is heated by the heater 2. Then, the process proceeds to step 48 and the subsequent temperature t
Measure 2. Further, the process proceeds to step 49, where the temperature due to the temperature drop when no heating is performed for T2 seconds is predicted from the temperature drop of Δt1 and set as the temperature t1. The process then proceeds to step 50, where temperatures t1 and t2 are compared.

If the expected temperature t1 is lower, there is a possibility of wire breakage, so the process returns to routine 41 and repeats the same process.

If the temperature t2 is high, there is no possibility of heater breakage, so it is determined that there is no heater breakage (step 51), and the process ends. When returning to routine 41, temperature control is performed again for a certain period of time, and if the temperature is stabilized outside the settling zone, similar processing is performed from step 43 to step 44--.

If the disconnection is determined twice, the process proceeds from step 44 to step 52, where disconnection processing is performed such as displaying on the display unit 26, and a signal indicating that the heater is disconnected is output to the outside (step 5).
3) Finish the process.

If it is determined in step 43 that the temperature is stabilized in the settling zone, the process proceeds to routine 54, where temperature control is performed for a fixed period of time in the same manner as routine 41. And when it is finished, Step 7 55
The process proceeds to step 55) to check whether it is within the settling band. If it is within the settling band, the process proceeds to step 51. If it is not within the settling band, the process returns to step 44 and repeats the same process. In this way, it will be stable for a certain period of time in the settling zone,
Even if the temperature subsequently decreases, it is possible to determine whether there is a disconnection.

Here, the CPU 24 achieves the function of the disconnection detection means 14 that detects a disconnection based on a temperature change by stopping the supply of electricity to the heater for a predetermined period of time in the flowchart shown in FIG. 4, and then turning on the heater.

[Effects of the Invention] As described above in detail, according to the present invention, the heater that heats the adhesive container is turned on and off, and disconnection of the heater is detected based on a change in the output from the temperature measuring means. Therefore, when a wire breakage occurs, it is possible to immediately detect the presence or absence of a wire breakage.
The necessary processing can be performed. Therefore, it is possible to prevent the adhesive from decreasing in temperature or becoming soft, resulting in poor coating.

[Brief explanation of the drawing]

Figure 1 is a professional diagram showing the functional configuration of the present invention;
The figure is a block diagram showing the configuration of an adhesive applicator according to an embodiment of the present invention, FIGS. 3 and 4 are flowcharts showing the operation of the temperature adjustment controller according to this embodiment, and FIG. FIG. 2 is a perspective view showing a coating head, which is a main component. 1-----1 application head 2.11--heater 3 thermistor 10-----1 adhesive container
12 Temperature measuring means 13---1 Temperature controlling means 14
---Disconnection detection means 21-----Temperature adjustment controller 24-111--CPU.

Claims (1)

[Claims] (1) An adhesive container that holds an adhesive, a heater that heats the adhesive in the adhesive container, and a temperature sensor provided in the adhesive container, and that measures the temperature of the adhesive. In an adhesive heating device having a measuring means and a temperature control means for controlling energization to the heater to maintain the adhesive temperature at a predetermined value, the adhesive is heated by stopping the energization to the heater for a predetermined period of time and then energizing the heater. An adhesive heating device comprising a disconnection detection means for detecting disconnection of the heater based on a temperature change of the adhesive.