JP3627231B2 - Method and apparatus for detecting high-frequency induction heating degree of thermoplastic resin - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a detection method and a detection apparatus for a high frequency induction heating degree of a thermoplastic resin.
[0002]
[Prior art]
Some automobile interiors, such as door trims, are decorated with a carpet or fabric attached to the surface of a core material (molding material) of a thermoplastic resin. There is a method of joining the core material and the carpet by an adhesive, tackering, or the like. However, according to this method, it is necessary to apply an adhesive, crimp, and tacker the end. Therefore, there was a problem that the number of assembly processes was large.
[0003]
In view of this, the present applicant has proposed a technique for joining a fabric to a thermoplastic resin by high-frequency induction heating in Japanese Patent Application Laid-Open No. 4-103338, and in Japanese Patent Application No. 9-202467, a fusion horn. We have proposed a technique that captures the timing at which the anchor effect that occurs in the thermoplastic resin occurs by monitoring the electromotive force of the detection coil wound around. According to the technique for capturing the timing at which the anchor effect occurs, the electromotive force generated in the detection coil of the fusion horn is monitored, and a predetermined time has elapsed from the rapid increase as the timing at which the anchor effect occurs. For this reason, since the rapid increase in the electromotive force of the detection coil is used as a reference, it is necessary to obtain a relatively stable electromotive force from the detection coil except for this “rapid increase”.
[0004]
[Problems to be solved by the invention]
However, according to the technique for capturing the timing at which the anchor effect occurs disclosed in the above-mentioned Japanese Patent Application No. 9-202467, the high-frequency power induced in the detection coil wound around the fusion horn is not stable. In addition to the “rapid increase” of the electromotive force caused by the detection coil to be monitored, a sudden increase or decrease caused by instability of the high-frequency generation source occurs, so the “rapid increase” is erroneously detected. There is a risk. Specifically, for example, the strength of the high-frequency power accompanying the fluctuation of the power supply voltage of the high-frequency generation source that may occur when the power supply environment such as the factory premises is not good is a factor.
[0005]
This power supply voltage fluctuation of the high frequency generation source can be solved by interposing an automatic voltage regulator on the primary power supply side of the high frequency generation source to stabilize the primary side power supply voltage, but the power consumption of the high frequency generation source is extremely large. Need an automatic voltage regulator with high power specifications. Therefore, there arises a new problem that it is inevitable that the equipment cost is greatly increased.
[0006]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a thermoplastic resin that can detect the heating state of the thermoplastic resin regardless of the presence or absence of power supply voltage fluctuation of the high-frequency generation source. An object of the present invention is to provide a detection method and a detection apparatus for high-frequency induction heating.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, in the method for detecting the high frequency induction heating degree of the thermoplastic resin according to claim 1, the fusion horn around which the detection coil is wound and the high frequency generating coil are overlapped with each other, Method for detecting high-frequency induction heating degree of thermoplastic resin in high-frequency fusion in which this thermoplastic resin and fusion-bonding material are fused by the fusion horn disposed by interposing a fusion material and heated by high-frequency induction so When the thermoplastic resin melts, the fusion horn and the high frequency generating coil rapidly approach each other, so that the high frequency induction voltage of the detection coil rapidly rises to detect the melting of the thermoplastic resin. To detect the heating state of the thermoplastic resin A method for detecting a high-frequency induction heating degree of a thermoplastic resin,
With respect to the initial voltage value of the power supply voltage at a time that is back by the time until the strength of the high frequency power due to the fluctuation of the power supply voltage driving the high frequency oscillator connected to the high frequency generating coil appears as the fluctuation of the high frequency induction voltage of the detection coil The amount of fluctuation is obtained, and the correction value based on the amount of fluctuation is subtracted from the high-frequency induction voltage value induced from the high-frequency generation coil to the detection coil, thereby correcting the high-frequency induction voltage value, and the corrected high-frequency induction voltage A technical feature is to detect the heating state of the thermoplastic resin based on the value.
[0010]
In order to achieve the above object, in the detection device for the high frequency induction heating degree of the thermoplastic resin according to claim 2, the fusion horn around which the detection coil is wound and the high frequency generating coil are overlapped with each other, An apparatus for detecting a high frequency induction heating degree of a thermoplastic resin in a high frequency fusion in which the thermoplastic resin and a material to be fused are fused by the fusion horn disposed by interposing a fusion material and heated by high frequency induction. so When the thermoplastic resin melts, the fusion horn and the high frequency generating coil rapidly approach each other, so that the high frequency induction voltage of the detection coil rapidly rises to detect the melting of the thermoplastic resin. To detect the heating state of the thermoplastic resin A detection device for high-frequency induction heating degree of thermoplastic resin,
A first detector for detecting a driving power supply voltage of a high-frequency oscillator connected to the high-frequency generating coil;
A second detector for detecting a high-frequency induced voltage induced from the high-frequency generating coil to the detection coil;
An arithmetic unit for correcting the high-frequency induced voltage based on the drive power supply voltage,
The arithmetic unit is configured to output the power supply voltage at a time that is traced back by a time until the fluctuation of the driving power supply voltage detected by the first detector appears as the fluctuation of the high-frequency induction voltage detected by the second detector. Is obtained by subtracting a correction value based on the fluctuation amount from the high-frequency induction voltage value detected by the second detector, thereby correcting the corrected high-frequency induction voltage value. The present invention is characterized by detecting the heating state of the thermoplastic resin based on the high frequency induction voltage value.
[0011]
Claims 3 In the detection apparatus of the high frequency induction heating degree of the thermoplastic resin of claim 2 The detection apparatus for the high-frequency induction heating degree of the thermoplastic resin described above is characterized in that a third detector that detects an output voltage of the high-frequency generating coil is provided instead of the first detector.
[0012]
In the first aspect of the present invention, the power supply voltage for driving the high frequency oscillator connected to the high frequency generating coil Obtain the amount of fluctuation for the initial voltage value of the power supply voltage at the time before the time until the strength of the high-frequency power due to the fluctuation appears as the fluctuation of the high-frequency induction voltage of the detection coil. The high frequency induction voltage value is corrected by subtracting from the high frequency induction voltage value induced in the detection coil, and the heating state of the thermoplastic resin is detected based on the corrected high frequency induction voltage value. To do. As a result, even if the high-frequency power level changes due to the power supply voltage fluctuation of the high-frequency oscillator, it is based on the fluctuation amount of the power supply voltage. Go back by the phase delay time of the high-frequency induced voltage relative to the power supply voltage The high frequency induction voltage value of the detection coil can be corrected.
[0015]
Claim 2 In the invention, the first detector for detecting the driving power supply voltage of the high-frequency oscillator connected to the high-frequency generating coil and the high-frequency induced voltage induced from the high-frequency generating coil to the detection coil wound around the fusion horn are detected. A second detector; and an arithmetic unit that corrects a high-frequency induced voltage based on a drive power supply voltage of the high-frequency oscillator. The arithmetic unit calculates the initial voltage value of the power supply voltage at a time that is traced back until the fluctuation of the driving power supply voltage detected by the first detector appears as the fluctuation of the high-frequency induction voltage detected by the second detector. Is obtained by subtracting a correction value based on the fluctuation amount from the high-frequency induction voltage value detected by the second detector, thereby correcting the high-frequency induction voltage value. Detects the heating state of thermoplastic resin based on The That is, based on the driving power supply voltage of the high frequency oscillator detected by the first detector, the high frequency induction voltage of the detection coil detected by the second detector is corrected by the arithmetic unit. As a result, even if the high-frequency power level changes due to the power supply voltage fluctuation of the high-frequency oscillator, it is based on the fluctuation amount of the power supply voltage. Go back by the phase delay time of the high-frequency induced voltage relative to the power supply voltage The high frequency induction voltage value of the detection coil can be corrected.
[0016]
Claim 3 In the invention, the third detector for detecting the output voltage of the high frequency generating coil, the second detector for detecting the high frequency induced voltage induced in the detection coil wound around the fusion horn from the high frequency generating coil, And an arithmetic unit that corrects the high-frequency induced voltage based on the drive power supply voltage of the high-frequency oscillator. That is, based on the output voltage of the high frequency generating coil detected by the third detector, the high frequency induction voltage of the detecting coil detected by the second detector is corrected by the arithmetic unit. Thus, even if the high-frequency power of the high-frequency oscillator is changed due to fluctuations in the power supply voltage or other factors, the high-frequency induced voltage value of the detection coil can be corrected based on the output voltage of the high-frequency generating coil.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a detection method and a detection apparatus for a high frequency induction heating degree of a thermoplastic resin according to the present invention will be described with reference to FIGS.
First, the configuration of a high-frequency fusion apparatus (hereinafter referred to as “fusion apparatus”) to which an embodiment of the present invention is applied will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, this fusion apparatus includes a pressing die 30 configured to match the shape of the door trim, and a pressing die (not shown) formed in accordance with the shape of the pressing die 30. The pressing mold (not shown) is provided with a horn for high frequency fusion (hereinafter referred to as “fusion horn”) 40, which will be described later. A “high frequency coil”) 32 is provided.
[0018]
A carpet 10 is placed on the pressing mold 30, and a thermoplastic polypropylene resin (hereinafter “PP resin”) 20 that forms a door trim is placed on the carpet 10 with a nonwoven fabric 18 interposed therebetween. The carpet 10 is made of a base cloth 14 on which nylon hair 12 is planted, and a thermoplastic polyethylene resin (hereinafter referred to as “PE resin”) disposed on the back side of the base cloth 14 to prevent the nylon hair 12 from being removed. It consists of PE backing 16.
For convenience of illustration, only a part of the pressing die 30 or the like is shown, but the pressing die 30 or the like has a curved surface formed three-dimensionally according to the shape of the door trim, and a plurality of sets of high-frequency waves are formed along the curved surface. A coil 32 and a fusion horn 40 are provided.
[0019]
The fusion horn 40 has a cylindrical shape, and is formed of a magnetic material (for example, iron) so that heat can be generated by eddy current when a high frequency is applied by the high frequency coil 32. The front end of the fusion horn 40 is provided with a mountain-shaped protrusion, and a recess having an arc-shaped vertical cross section from the front end of the protrusion toward the periphery of the front end. The tip portion of the fusion horn 40 formed in this way is heated by high-frequency power, so that the PP resin 20 pressed against the fusion horn 40 and the carpet 10 are fused.
[0020]
The stopper 50 has a ring shape surrounding the outer periphery of the fusion horn 40, and is formed of a ceramic material having a low magnetic constant so that an eddy current does not easily occur even when a high frequency is applied. This stopper 50 is provided in order to prevent the PP resin 20 melted by the fusion horn 40 from flowing out, and a ring-shaped recess is formed from the periphery of the lower end toward the center of the lower end. By forming the lower end portion of the stopper 50 in this way, the molten PP resin is stored in the concave portion of the stopper 50 to prevent leakage to the outside, and the molten resin is used for fusion with the carpet 10. It has become. The stopper 50 also serves as a coil bobbin for winding a pickup coil 52 described below.
[0021]
The pickup coil 52 is wound around the outer periphery of the stopper 50, and both ends thereof are electrically connected to the rectifier 54. That is, the high frequency emitted from the high frequency coil 32 is detected by high frequency induction, and can be extracted as a pickup coil voltage by the rectifier 54. The pickup coil voltage taken out by the rectifier 54 is the high frequency power to be induced. of Since it is output as an analog value that changes continuously depending on the strength, it is converted into a digital value that changes stepwise by an A / D converter 56 described later. As a result, the strength of the high-frequency power is converted into a data format that can be taken into the sequencer 60 that performs predetermined arithmetic processing.
[0022]
The high-frequency coil 32 is made of a high-power winding material having a relatively large wire diameter, and both ends thereof are electrically connected to the high-frequency oscillator 33. That is, the high frequency power applied by the high frequency oscillator 33 can be induced as high frequency energy in the fusion horn 40 positioned opposite to the carpet 10 and the PP resin 20.
[0023]
The high frequency oscillator 33 is a device that converts AC power supplied from the primary power supply 34 into high frequency energy of a predetermined frequency and supplies the high frequency coil 32 with the AC power. Therefore, the high frequency power that can be supplied to the high frequency coil 32 is easily affected by voltage fluctuations of the primary power supply 34. For example, in a factory premises where a fusion apparatus is installed, when another machine or the like that requires high power is started, the load of the primary power supply 34 greatly fluctuates with the start-up, so the voltage of the primary power supply 34 is so-called. “Fluctuation” or “momentary interruption” may occur. In such an unfavorable power supply environment, the output fluctuation of the high-frequency power of the high-frequency oscillator 33 caused by the voltage fluctuation of the primary power supply 34 occurs. Therefore, the pickup coil 52 that detects the strength of the high-frequency power and outputs it as a pickup coil voltage. This also affects the high frequency induction voltage.
[0024]
Therefore, the rectifier 36 is electrically connected to the primary power supply 34 and the voltage of the primary power supply 34 is taken out, and information on the amount of power supply voltage fluctuation accompanying load fluctuation or the like is taken into the sequencer 60. An accurate pickup coil voltage can be obtained by correcting the pickup coil voltage induced in the pickup coil 52 described above based on the fetched fluctuation amount information by a predetermined algorithm described later. Further, the power supply voltage taken out by the rectifier 36 is also output as an analog value that continuously changes in the same manner as the pickup coil voltage described above, and therefore is stepwise by an A / D converter 38 described later. Converted to a changing digital value. As a result, the strength of the high-frequency power is converted into a data format that can be taken into the sequencer 60 that performs predetermined arithmetic processing.
[0025]
In this embodiment, the information of the power supply voltage fluctuation amount due to the load fluctuation or the like is taken into the sequencer 60 by taking out the voltage of the primary power supply 34 from the rectifier 36 connected to the primary power supply 34, but the output side of the high frequency oscillator 33 Information on the output voltage fluctuation amount of the high-frequency oscillator 33 taken out from the rectifier as the second detector electrically connected to may be taken into the sequencer 60. As a result, the output fluctuation of the high-frequency oscillator 33 can be directly detected, so that not only the output fluctuation of the high-frequency oscillator 33 due to the voltage fluctuation of the primary power supply 34 but also the output fluctuation due to other factors is also the output voltage of the high-frequency oscillator 33. Based on this, the pickup coil voltage of the pickup coil 52 can be corrected.
[0026]
The primary power supply 34 is an AC power supply device that can supply AC power to the high-frequency oscillator 33, and its on / off control, that is, on / off control, can be operated remotely via an interface (not shown). As a result, the sequencer 60 described later also performs on / off control of the primary power supply 34 via the on / off control interface.
[0027]
The A / D converters 38 and 56 are devices that convert analog signals into digital signals. That is, the A / D converter 38 outputs the voltage signal of the primary power supply 34 output as an analog signal from the rectifier 36, and the A / D converter 56 outputs the pickup coil voltage of the pickup coil 52 output as an analog signal from the rectifier 54. Are converted into digital signals of several tens of bits according to a predetermined sampling process, and output to the sequencer 60. The power supply voltage information and the pickup coil voltage information output as the digital signal are used by the sequencer 60 for detection processing of the high frequency induction heating degree described later.
[0028]
Next, the configuration of the sequencer 60 that performs correction processing and fusion control processing described later based on the above-described pickup coil voltage and power supply voltage will be described with reference to FIG.
The sequencer 60 mainly includes a display unit 62, an operation unit 64, a CPU 66a, a memory 66b, an external storage device 66c, and interfaces 66d and 66e. The CPU 66a is a so-called central processing unit, and performs predetermined calculation processing, various control processing, and the like while receiving support from the display unit 62, the operation unit 64, the memory 66b, the external storage device 66c, and the like. The memory 66b is connected to the CPU 66a via a system bus, and is used for storing a predetermined control program, a work area, and the like. The external storage device 66c stores a program for controlling the fusing device, a program for performing a pickup coil voltage correction process described later, data, and the like, and these programs are loaded into the memory 66b as necessary. Further, a display unit 62, an operation unit 64, and an external storage device 66c are connected to the interface 66d, and control data exchange with the CPU 66a. On the other hand, the above-described A / D converters 38 and 56 and the on / off control interface of the primary power supply 34 are connected to the interface 66e. The pickup coil voltage information and the power supply voltage information sent from the A / D converters 38 and 56 are sequentially transferred to the CPU 66a, and the on / off signal of the primary power supply 34 output from the CPU 66a is supplied to the on / off control interface of the primary power supply 34. Is being sent to.
[0029]
Subsequently, a process of fusing thermoplastic resin by the above-described fusing apparatus will be described with reference to FIG. First, a high frequency is applied to the high frequency coil 32 by the high frequency oscillator 33 to heat the fusion horn 40. When the heated fusion horn 40 is pressed against the PP resin 20, the PP resin 20 is pressed against the back side of the carpet 10 by the tip of the fusion horn 40. The PE backing 16 of the carpet 10 is heated and melted. As a result, the carpet 10 is fused to the PP resin 20, that is, the door trim. Then, after a predetermined time has elapsed, the power supply to the high-frequency coil 32 is stopped by turning off the power supply of the high-frequency oscillator 33, the fusion horn 40 is cooled, and then the fusion horn 40 is pulled out from the fusion location. This completes the fusion process. Since the PP resin 20 and the PE backing 16 fused in this manner are intricately combined with each other at the joint, an anchor effect is generated, and this anchor effect can firmly fuse the carpet 10 to the door trim. It becomes possible.
[0030]
Here, the process of fusing the thermoplastic resin by the above-described fusing device can be explained as follows based on the change with time of the pickup coil voltage detected by the pickup coil 52 shown in FIG. In FIG. 3 (A), the solid line shows the high-frequency induction voltage of the fusion horn 40 in real time, that is, the waveform of the pickup coil voltage of the pickup coil 52, and the chain line shows the waveform with a delay of DT. FIG. 3B is an explanatory diagram showing an enlarged portion F of FIG. 3A.
[0031]
First, at time C1, high frequency power is applied to the high frequency coil 32 by the high frequency oscillator 33 shown in FIG. 1, and heating of the fusion horn 40 is started. By applying the high frequency power, the temperature of the fusion horn 40 is increased, the pickup coil voltage is gradually increased (time C1 to C2), and the PP resin 20 starts to melt, so that the fusion horn 40 is slightly moved to the high frequency coil 32 side. Get closer to. Then, since the high frequency power that can be received by the fused horn 40 is increased by the amount close to the high frequency coil 32, the pickup coil voltage further increases (time C2 to A). Then, since the PP resin 20 is completely melted, the fusion horn 40 rapidly approaches the high frequency coil 32, so that the pickup coil voltage also rises rapidly (time A to D). At time B after a lapse of a predetermined time from time A when the pickup coil voltage suddenly increased, the application of high-frequency power is stopped, that is, the time from time A to time B is controlled. Thereby, since the temperature control of the fusion horn 40 can be performed, the temperature of the fusion horn 40 is controlled so as to exhibit the optimum anchor effect, that is, the highest fusion force.
[0032]
Further, a description will be given of whether or not the PP resin 20 described above has completely melted and the fusion horn 40 has rapidly approached the high-frequency coil 32, that is, whether or not the pickup coil voltage has risen rapidly.
Whether or not the pickup coil voltage has rapidly increased is determined based on the difference between the real-time pickup coil voltage indicated by the solid line in FIG. 3A and the pickup coil voltage provided with the delay indicated by the chain line. Is called. That is, when the pickup coil voltage is gradually rising as indicated at time G in FIG. 3B, the difference between the real-time pickup coil voltage value and the delayed pickup coil voltage value is small. On the other hand, when the pickup coil voltage rapidly rises, the difference between the real-time pickup coil voltage value indicated at time H and the pickup coil voltage value given the delay becomes a large value. A sudden rise in the pickup coil voltage is determined based on the difference.
[0033]
However, when the measured waveform of the pickup coil voltage PV actually detected by the pickup coil 52 is observed, as shown in FIG. 5B, the original “rapid increase of the pickup coil voltage (time AD)” (FIG. 5 ( In addition to the symbol [alpha] in B), a similar sharp rise in the pickup coil voltage (signs [beta] and [gamma] in FIG. 5B) can be confirmed at a plurality of locations. As described above, this is because, for example, the high frequency power of the high frequency oscillator 33 caused by the “fluctuation” of the voltage VPS of the primary power supply 34 that may occur when the power supply environment such as the factory premises where the fusion apparatus is installed is not good. This is due to output fluctuations. Therefore, it is difficult to distinguish between “similar pickup coil voltage sudden increase” and “original pickup coil voltage sudden increase (time A to D)” indicated by symbols β and γ in FIG. 5B. There is a risk of erroneous operation such as erroneous detection. Therefore, correction processing for the pickup coil voltage described below is necessary.
[0034]
The correction process for the pickup coil voltage will be described with reference to FIGS.
The pickup coil voltage correction process shown in FIG. 4 is performed by the sequencer 60 described above. First, in step S10, the setting value of the basic correction data is captured. That is, the phase delay time PDT and the correction coefficient K of the pickup coil voltage are read from the external storage device 66c or the operation unit 64 shown in FIG. Here, the phase delay time PDT means a time until the strength of the high frequency power due to the fluctuation of the power supply voltage of the high frequency oscillator 33 appears as the fluctuation of the pickup coil voltage of the pickup coil 52, and the pickup is traced back by this phase delay time. This is correction basic data for correcting the coil voltage. The correction coefficient K is a constant used for absorbing the difference in the ratio of the fluctuation ranges when correcting the fluctuation of the pickup coil voltage based on the fluctuation of the power supply voltage. For example, the phase delay time PDT is set to 0.2 seconds, and the correction coefficient K is set to 0.4.
[0035]
In step 12, the initial value VPS (0) of the power supply voltage of Capture is performed. That is, the current voltage information of the primary power source 34 shown in FIG. 2 is read into the sequencer 60 via the rectifier 36 and the A / D converter 38. The initial value VPS (0) of the power supply voltage is a reference value for obtaining the fluctuation range of the power supply voltage, and is used in the correction calculation in step 16 described later. Steps up to step 12 correspond to so-called initial setting, and reading of the actual pickup coil voltage and the correction thereof are repeated in the following steps 14 and 16.
[0036]
In step S14, the power supply voltage VPS (T) and the pickup coil voltage PV (T) are read. That is, at an arbitrary time T, the voltage information of the primary power supply 34 and the pickup coil voltage information of the pickup coil 52 are read via the A / D converter 38, the A / D converter 56, etc., respectively, and once the operation of the memory 66b is performed. Store in an area or the like. In step S16, the power supply voltage VPS obtained by subtracting the initial value VPS (0) of the power supply voltage from the power supply voltage VPS at the time (T-PDT) that goes back from the time T by the phase delay time, that is, the fluctuation range of the power supply voltage is obtained. The pickup coil correction voltage V (T) is calculated by subtracting the fluctuation width of the power supply voltage multiplied by the correction coefficient K from the pickup coil voltage PV at time T.
[0037]
According to the correction processing of the pickup coil voltage described above, the fused horn is based on the voltage fluctuation (VPS (T-PDT) −VPS (0)) of the primary power supply 34 that drives the high-frequency oscillator 33 connected to the high-frequency coil 32. The pickup coil voltage PV (T) of the pickup coil 52 wound around 40 is corrected to obtain a pickup coil correction voltage V (T). As a result, as shown in FIG. 5A, even if “fluctuation” or the like is included in the voltage VPS of the primary power supply 34, a good pickup coil voltage V that is not affected by the “fluctuation” or the like is obtained. Can do. Therefore, even if the power supply environment such as the factory premises where the above-described fusion bonding apparatus is installed is not good, the original “pickup of pickup coil voltage (time A to D)” (FIG. 5A) The code X) inside can be accurately captured. That is, the heating state of the thermoplastic resin can be accurately detected regardless of whether or not the voltage of the primary power supply 34 of the high-frequency oscillator 33 is varied.
[0038]
Next, a fusion control process by the fusion apparatus to which the above-described pickup coil voltage correction process is applied will be described with reference to FIGS.
As shown in FIG. 6, first, in step S110, the elapsed time is set to T and the voltage at time T is set to V, and in the next step S112, a data processing variable is defined. Here, for example, 0.2 seconds is set as the delay time (delay time) DT, and a predetermined time is set as the determination invalid time Cut Time. The invalid determination time here refers to a predetermined time from when the power is turned on (time C1) to when the pickup coil voltage suddenly rises (time A) shown in FIG. 3A. During this time, the pickup coil voltage suddenly rises. Since it does not occur, the detection is paused. Further, for example, 1V is set as the power-up detection threshold value Slant1. This value is used to determine the slope of the pickup coil voltage generated when the primary power supply 34 is turned on from time C1 to time C2 in FIG. 3 (A), and the primary power supply 34 is detected based on this slope. Furthermore, a resin intersection start detection voltage threshold value Volt is set. This value is for detecting a sharp rise in the pickup coil voltage from time A to time D in FIG. In addition, a peak generation voltage error DV is set. This value is for removing the noise component contained in the pickup coil voltage by software by detecting it through the pickup coil 52. Further, the resin crossing acceleration time JT is set. This value is the time from time D to time B in FIG. 3 (A), and is intended to exhibit high fusing power by crossing the resin by continuing high-frequency heating to the fusing horn 40. is there.
[0039]
Next, in step S113, the setting value of the basic correction data described above is captured. That is, the phase delay time PDT and the correction coefficient K of the pickup coil voltage are read from the external storage device 66c or the operation unit 64 shown in FIG. The phase delay time PDT and the correction coefficient K here are as described above. For example, the phase delay time PDT is set to 0.2 seconds and the correction coefficient K is set to 0.4.
[0040]
Subsequently, an initial data value is set in step S114. Here, the maximum voltage Peak Volt is set to 0, the maximum voltage generation time Peak Time is set to 0, and the elapsed time T is set to 0, that is, reset. Then, the energization of the high-frequency oscillator 33 is started by turning on the primary power source 34 shown in FIG. 1 (S116), whereby heating of the fusion horn 40 is started by the high frequency emitted from the high-frequency coil 32. Next, the timer T starts counting (S118), and the start time is set to T (S120). Thereafter, whether or not the value obtained by subtracting the pickup coil voltage V (T-DT) giving the delay time from the current pickup coil voltage V (T) is less than the power supply rise detection threshold value Slant 1 set in step S112 described above. Is determined (S122). Then, until the subtraction value is less than Slant1, that is, until it is confirmed that the primary power source 34 is turned on (Yes in S122), the process returns to step S120 and the start time is reset to T. On the other hand, if the subtraction value exceeds Slant1 and it is confirmed that the primary power supply 34 is turned on (No in S122), the initial value of the power supply voltage by the primary power supply 34 is fetched in step S123.
[0041]
In step S123, as described above, the power supply voltage of the primary power supply 34 serving as the reference value for the correction calculation is captured as the initial value VPS (0). In this way, by measuring the voltage of the primary power supply 34 after being turned on, a voltage that is not affected by the voltage fluctuation due to the power supply load fluctuation accompanying the energization of the high-frequency oscillator 33 can be obtained as the initial value VPS (0). it can. Therefore, the correction calculation described above can be performed more accurately. After taking in the power supply voltage as the initial value VPS (0), it waits until the judgment invalid time Cut Time elapses (S124).
[0042]
When the determination invalid time Cut Time of the predetermined time has elapsed (No in S124), detection of a sudden rise in the pickup coil voltage shown in FIG.
Note that the pickup coil correction voltage V (T) used for detection or calculation in the following steps is corrected in advance by the pickup coil voltage correction subroutine shown in FIG. That is, in step S150 of FIG. 7 corresponding to step S14 shown in FIG. 4, the power supply voltage VPS (T) and the pickup coil voltage PV (T) are read. Further, in step S152 of FIG. 7 corresponding to step S16 shown in FIG. 4, the initial value VPS (0) of the power supply voltage is subtracted from the power supply voltage VPS at the time (T-PDT) that goes back from the time T by the phase delay time. That is, the fluctuation range of the power supply voltage is obtained, and the pickup coil correction voltage V (T) is calculated by subtracting the fluctuation width of the power supply voltage multiplied by the correction coefficient K from the pickup coil voltage PV at time T. The pickup coil correction voltage V (T) calculated in this way is obtained by the pickup coil voltage correction subroutine in steps S125 and S129.
[0043]
In step S126, it is determined whether or not the value obtained by subtracting the delayed pickup coil correction voltage V (T-DT) from the current pickup coil correction voltage V (T) exceeds the measured maximum voltage Peak Volt. . Here, when the subtraction value exceeds the maximum voltage Peak Volt (S126 is Yes), this subtraction value is set as the maximum voltage value (S128). That is, the largest value among the differences between the current pickup coil correction voltage V (T) and the delayed pickup coil correction voltage V (T-TD) is set as the maximum voltage Peak Volt.
[0044]
Next, in step S130, a value obtained by subtracting the pickup coil correction voltage V (T-TD), which is delayed from the current pickup coil correction voltage V (T), and the peak generation voltage error DV for removing the noise described above. Is determined to exceed the maximum voltage Peak Volt. Here, when the subtraction value exceeds the maximum voltage Peak Volt (S130 is Yes), the time Peak Time when the maximum voltage occurs is set to the current time T (S132). That is, the maximum voltage generation time Peak Time is set so as not to be affected by an error due to noise.
[0045]
In step S134, the measured maximum voltage Peak Volt detects the sudden rise in the pickup coil correction voltage from time A to time D in FIG. It is determined whether or not the value is less than Volt. Here, if the detected maximum voltage Peak Volt is less than the resin crossing start detection voltage threshold value Volt, that is, before the pickup coil correction voltage suddenly increases (Yes in S134), the process returns to Step S125 and returns to the maximum voltage Peak Volt. Continue detection. On the other hand, when the detected maximum voltage Peak Voltage is equal to or greater than the resin crossing start detection voltage threshold value Volt, that is, when the pickup coil correction voltage has risen rapidly (No in S134), the time Peak Time when the maximum voltage is generated from the current time T. It is determined whether the value obtained by subtracting is less than the resin crossing acceleration time JT set in step S112 described above (S136). Here, when the resin crossing acceleration time JT has elapsed, that is, when the high-frequency heating to the fusion horn 40 shown in FIG. 1 is continued from time D to time B shown in FIG. 3A (No in S136), the high-frequency oscillator 33 Is terminated (S138), and all the processes are completed.
[0046]
As described above, according to the present embodiment, the fused horn is based on the voltage fluctuation (VPS (T-PDT) −VPS (0)) of the primary power source 34 that drives the high-frequency oscillator 33 connected to the high-frequency coil 32. The pickup coil voltage PV (T) of the pickup coil 52 wound around 40 is corrected to obtain a pickup coil correction voltage V (T). For this reason, even if the voltage VPS of the primary power supply 34 includes “fluctuation” or the like, a good pickup coil voltage V that is not affected by the “fluctuation” or the like can be obtained. Thereby, even when the power supply environment such as the factory premises where the fusion apparatus is installed is not good, the heating state of the thermoplastic resin is accurately determined regardless of the voltage fluctuation of the primary power supply 34 of the high-frequency oscillator 33. There is an effect that can be detected. Therefore, since it is possible to appropriately manage the temperature of the fusion horn 40 even in an unfavorable power supply environment, there is an effect that can enable the optimum anchor effect, that is, the high frequency fusion of the thermoplastic resin that exhibits the highest fusion force. .
[0047]
Further, according to the present embodiment, the sequencer 60 corrects the pickup coil voltage of the pickup coil 52 detected by the rectifier 54 based on the voltage of the primary power supply 34 detected by the rectifier 36. For this reason, even if the output of the high-frequency oscillator 33 is increased or decreased due to “fluctuation” of the primary power supply 34, the pickup coil voltage value of the pickup coil 52 is corrected based on the voltage fluctuation of the primary power supply 34 that is the fluctuation factor of the high-frequency output. can do. Accordingly, there is an effect that the heating state of the predetermined thermoplastic resin can be accurately detected regardless of the voltage fluctuation of the primary power supply 34 of the high frequency oscillator 33. Therefore, even under an unfavorable power supply environment, the temperature of the fusion horn 40 can be appropriately controlled, so that there is an effect capable of enabling high-frequency fusion of a thermoplastic resin that exhibits the highest fusion force.
[0048]
Furthermore, according to the present embodiment, the sequencer 60 corrects the pickup coil voltage of the pickup coil 52 detected by the rectifier 54 based on the voltage of the primary power supply 34 of the high-frequency oscillator 33 detected by the rectifier 36 in the fusion apparatus. For this reason, even if the output of the high-frequency oscillator 33 is increased or decreased due to “fluctuation” of the primary power supply 34, the pickup coil voltage value of the pickup coil 52 is corrected based on the voltage fluctuation of the primary power supply 34 that is the fluctuation factor of the high-frequency output. can do. Accordingly, there is an effect that the heating state of the predetermined thermoplastic resin can be accurately detected regardless of the voltage fluctuation of the primary power supply 34 of the high frequency oscillator 33. Therefore, since the appropriate temperature control of the fusion horn 40 can be performed even in an unfavorable power supply environment, an optimum anchor effect, that is, an effect capable of providing a thermoplastic resin high-frequency fusion apparatus that exhibits the highest fusion force is provided. is there.
[0049]
In the present embodiment, two or more thermoplastic resins (for example, PP resin 20 and carpet 10) can be fused, and other materials to be fused (for example, brushed materials and cloth materials) other than the thermoplastic resin and the thermoplastic resin. ) Can be fused.
[0050]
【The invention's effect】
In the first aspect of the present invention, the power supply voltage for driving the high frequency oscillator connected to the high frequency generating coil Obtain the amount of fluctuation for the initial voltage value of the power supply voltage at the time before the time until the strength of the high-frequency power due to the fluctuation appears as the fluctuation of the high-frequency induction voltage of the detection coil. The high frequency induction voltage value is corrected by subtracting from the high frequency induction voltage value induced in the detection coil, and the heating state of the thermoplastic resin is detected based on the corrected high frequency induction voltage value. To do. As a result, even if the high-frequency power level changes due to the power supply voltage fluctuation of the high-frequency oscillator, it is based on the fluctuation amount of the power supply voltage. Go back by the phase delay time of the high-frequency induced voltage relative to the power supply voltage The high frequency induction voltage value of the detection coil can be corrected. Therefore, there is an effect that the heating state of the thermoplastic resin can be detected regardless of the presence or absence of the power supply voltage fluctuation of the high frequency generation source.
[0053]
Claim 2 In the invention, the first detector for detecting the driving power supply voltage of the high-frequency oscillator connected to the high-frequency generating coil and the high-frequency induced voltage induced from the high-frequency generating coil to the detection coil wound around the fusion horn are detected. A second detector; and an arithmetic unit that corrects a high-frequency induced voltage based on a drive power supply voltage of the high-frequency oscillator. The arithmetic unit calculates the initial voltage value of the power supply voltage at a time that is traced back until the fluctuation of the driving power supply voltage detected by the first detector appears as the fluctuation of the high-frequency induction voltage detected by the second detector. Is obtained by subtracting a correction value based on the fluctuation amount from the high-frequency induction voltage value detected by the second detector, thereby correcting the high-frequency induction voltage value. Detects the heating state of thermoplastic resin based on The That is, based on the driving power supply voltage of the high frequency oscillator detected by the first detector, the high frequency induction voltage of the detection coil detected by the second detector is corrected by the arithmetic unit. As a result, even if the high-frequency power level changes due to the power supply voltage fluctuation of the high-frequency oscillator, it is based on the fluctuation amount of the power supply voltage. Go back by the phase delay time of the high-frequency induced voltage relative to the power supply voltage The high frequency induction voltage value of the detection coil can be corrected. Therefore, there is an effect that the heating state of the thermoplastic resin can be detected regardless of the presence or absence of the power supply voltage fluctuation of the high frequency generation source. Therefore, there is an effect that a predetermined high-frequency induction heating degree can be detected regardless of whether or not the power supply voltage of the high-frequency generation source varies.
[0054]
Claim 3 In this invention, based on the output voltage of the high frequency generating coil detected by the third detector, the high frequency induced voltage of the detecting coil detected by the second detector is corrected by the arithmetic unit. Thus, even if the high-frequency power of the high-frequency oscillator is changed due to fluctuations in the power supply voltage or other factors, the high-frequency induced voltage value of the detection coil can be corrected based on the output voltage of the high-frequency generating coil. Therefore, a predetermined high-frequency induction heating degree can be detected regardless of the presence or absence of the high-frequency power of the high-frequency oscillator due to not only the power supply voltage fluctuation of the high-frequency generation source but also other external or internal factors. effective.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view showing the configuration of a fusion apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a schematic configuration of a sequencer of the fusion apparatus according to the present embodiment.
FIG. 3 (A) is a characteristic diagram showing a pickup coil voltage detected by the fusion apparatus of the present embodiment, and FIG. 3 (B) is an enlarged view of a portion F in FIG. 3 (A). FIG.
FIG. 4 is a flowchart showing a pickup coil voltage correction process according to the present embodiment.
FIG. 5A is a characteristic diagram showing the pickup coil voltage after the correction processing of the pickup coil voltage according to the present embodiment, and FIG. 5B is a characteristic diagram showing the pickup coil voltage before the correction processing. It is.
FIG. 6 is a flowchart showing a fusion control process by the fusion apparatus of the present embodiment.
7 is a flowchart showing a subroutine of the fusion control process shown in FIG.
[Explanation of symbols]
10 Carpet (thermoplastic resin)
16 PE backing (thermoplastic resin)
20 PP resin (thermoplastic resin)
30 Pressing type
32 High frequency coil (High frequency generating coil)
33 high frequency oscillator
34 Primary power supply
36 Rectifier (first detector)
40 fused horn
52 Pickup coil (detection coil)
54 Rectifier (second detector)
60 Sequencer (arithmetic unit)

Claims (3)

A fusion horn around which a detection coil is wound and a high-frequency generating coil are disposed with a thermoplastic resin and a material to be fused superimposed on each other, and this heat is generated by the fusion horn heated by high-frequency induction. In the method of detecting the high frequency induction heating degree of the thermoplastic resin in the high frequency fusion for fusing the plastic resin and the material to be fused, when the thermoplastic resin is melted, the fusion horn and the high frequency generating coil are rapidly approached. By detecting the melting state of the thermoplastic resin and detecting the heating state of the thermoplastic resin based on the rapid increase in the high-frequency induction voltage of the detection coil, the detection method of the high-frequency induction heating degree of the thermoplastic resin There,
With respect to the initial voltage value of the power supply voltage at a time that is back by the time until the strength of the high frequency power due to the fluctuation of the power supply voltage driving the high frequency oscillator connected to the high frequency generating coil appears as the fluctuation of the high frequency induction voltage of the detection coil The amount of fluctuation is obtained, and the correction value based on the amount of fluctuation is subtracted from the high-frequency induction voltage value induced from the high-frequency generation coil to the detection coil, thereby correcting the high-frequency induction voltage value, and the corrected high-frequency induction voltage A method for detecting a high-frequency induction heating degree of a thermoplastic resin, wherein the heating state of the thermoplastic resin is detected based on a value. A fusion horn around which a detection coil is wound and a high-frequency generating coil are arranged with a thermoplastic resin and a material to be fused that are superposed on each other, and this heat is generated by the fusion horn heated by high-frequency induction. A detector for detecting the high frequency induction heating degree of the thermoplastic resin in the high frequency fusion for fusing the plastic resin and the material to be fused. When the thermoplastic resin is melted, the fusion horn and the high frequency generating coil are rapidly approached. By detecting the melting state of the thermoplastic resin and detecting the heating state of the thermoplastic resin based on the rapid increase of the high-frequency induction voltage of the detection coil , There,
A first detector for detecting a driving power supply voltage of a high-frequency oscillator connected to the high-frequency generating coil;
A second detector for detecting a high-frequency induced voltage induced from the high-frequency generating coil to the detection coil;
An arithmetic unit that corrects the high-frequency induced voltage based on the drive power supply voltage,
The arithmetic unit is configured to supply the power supply voltage at a time that is traced back until the fluctuation of the drive power supply voltage detected by the first detector appears as the fluctuation of the high-frequency induction voltage detected by the second detector. Is obtained by subtracting a correction value based on the fluctuation amount from the high-frequency induction voltage value detected by the second detector, thereby correcting the corrected high-frequency induction voltage value. An apparatus for detecting a high-frequency induction heating degree of a thermoplastic resin, wherein the heating state of the thermoplastic resin is detected based on the high-frequency induction voltage value. The high-frequency induction heating degree detection apparatus for a thermoplastic resin according to claim 2, further comprising a third detector for detecting an output voltage of the high-frequency generating coil instead of the first detector. A detection device for high-frequency induction heating degree of thermoplastic resin.

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