JP2000326933A - Heat sealing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temperature control which can quickly cope with an uncontrolled state for a temperature control means and to prevent a secondary malfunction by a method wherein a time-out error processing is executed when a control signal from the temperature control means for controlling the temperature for a heat sealing member is not outputted within a specified period of time. SOLUTION: A counter means 30 for executing a time-out error processing counts the time until output of a control signal from a temperature control means and outputs the counted result, then the counted time is compared with a specified duration of time, and when the control signal is not outputted within the specified duration of time, an error signal is outputted and a time-out error is indicated. With the error signal transmitted to a CPU 15, the CPU 15 gives a warning or the like. For the specified duration of time, a period of time which passes at a heat sealing apparatus with no control signal being outputted and is allowed to be considered as not being the state of no-signal resulting from a normal temperature fluctuation at a heat sealing member 12 is set. Therefore, an uncontrolled state can be sensed in a real time, being synchronized with the control signal from the temperature control means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sealing apparatus for a heat-sealing packaging sheet of a packaging machine for packaging, for example, a medicine.

[0002]

2. Description of the Related Art Generally, in a heat sealing apparatus of a packaging machine for packaging medicines, etc., medicines are packed using a heat-fusible packaging sheet. As this type of heat sealing device, for example, a device described in Japanese Patent Application Laid-Open No. H8-230832 is known.

In such a heat sealing apparatus, a heat roller or the like for heat-sealing the packaging sheet 101 is used. FIG. 6 is an explanatory view schematically showing a main part of a conventional heat sealing device, and shows only one heat roller 102 of a heat roller pair.

[0004] The heat roller 102 is a roller pair having a heating source therein, and its surface is heated to a uniform temperature state (horizontal heating body 103, vertical heating body 104, axial heating body 105). In this state, the packaging sheet 101 in which the medicine and the like (not shown) are put in from the chute 111 and put into a packaged state, and the heat roller 102 itself is rotated by the rotating mechanism 11.
While being rotated and fed by 2 and 113, it is configured to seal one package 102a for each rotation.

For this reason, the heat roller 102 is used only when the portion 101b of the packaging sheet 101 to be welded comes to a position where it is sandwiched between the pair of heat rollers.
02 so that it can contact the surface,
The other surface portion is cut away except for a portion to be contacted by the portion 101b to be welded, so that a non-contact surface 106 is formed. Then, a sewing machine blade 134 for forming a perforation on the sealed packaging sheet is provided on a surface portion of the roller that should come into contact with the packaging sheet 101b.

[0006]

A conventional heat sealing apparatus of this kind is characterized in that the surface of the heat roller is affected by differences in the local environment of the installation location and seasonal or temporal differences in the time when the heat sealing apparatus is operated. Is not always quantitatively grasped with respect to the supplied current, and causes a considerable difference in temperature.

Therefore, when the heat sealing device is shipped, while it is adjusted so that a predetermined current can be supplied,
At the time of delivery, the person in charge or the user must make fine adjustments according to the respective circumstances, which is very troublesome. Therefore, while detecting the surface temperature of the heat roller 10, the surface temperature is maintained in a predetermined temperature range. The present applicant has proposed a heat sealing apparatus capable of performing heat fusion of a packaging sheet by using the present invention (Japanese Patent Application No. 11-131647).

As shown in FIG. 7, one example of the configuration of such a heat sealing device is a surface temperature detecting means for detecting the surface temperature of the heat sealing member of the packaging machine, and a temperature control for controlling the temperature of the heat sealing member. And a detection control circuit 14 and the like related to both means.

The heat sealing apparatus of this configuration has a configuration in which the surface temperature is measured, the surface temperature is maintained in a predetermined range, and the packaging sheet 20 is heat-sealed. Two systems of abnormality detecting means for detecting an abnormal state of disconnection are provided respectively, and when a disconnection detection signal e _C or a short detection signal e _S is obtained corresponding to the abnormal state of the thermistor TH provided as the surface temperature detecting means, a heat source is generated. A circuit breaker SB is provided on the input path of the heat source EH to stop the input to the heat source EH, and receives the disconnection detection signal e _C or the short detection signal e _S to shut off the circuit breaker SB.

The heat sealing apparatus can perform a predetermined heat sealing without wasting power consumption without monitoring the surface temperature of the heat sealing member.
It is possible to detect an abnormal state of the above, and to provide an excellent effect that abnormal heating and the like can be prevented.

However, when the thermistor TH is detached from the heat roller 10 or when the heat source EH is disconnected, the surface temperature detecting means detects a signal derived from a normal temperature control range in the heat sealing device. When the temperature control means cannot generate a control signal (hereinafter, referred to as “non-control state”), the thermistor TH cannot measure the surface temperature of the heat roller 10, However, there is a problem that the detection of the uncontrolled state may not be performed.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a heat sealing apparatus capable of temperature control that can promptly respond to a non-control state in a temperature control unit.

[0013]

According to a first aspect of the present invention, there is provided a heat sealing device, comprising: a heat sealing member; and a surface temperature detecting device for detecting a surface temperature of the heat sealing member. Means, and a temperature control means for controlling the temperature of the heat-sealing member, wherein the surface temperature is maintained in a predetermined range, and the packaging sheet is heat-sealed by the heat-sealing member. When the control signal e _C by the temperature control means is not issued during the predetermined period P, timeout error processing is performed.

According to the above-described configuration, when the temperature control means enters the non-control state, this can be detected and it can be clearly indicated that a countermeasure should be taken.

According to the heat sealing apparatus of the second aspect of the present invention, the counter means 30 is provided, and a part of the output of the control signal e _C is used as a reset signal for the counter means 30. Means 30
After receiving the reset signal, timing is started, and a predetermined period P
If the control signal e _C is not input to the counter means 30 during this period, the timeout error processing is performed, so that the non-control state can be detected in synchronization with the control signal e _C.

According to the third aspect of the present invention, the surface temperature detecting means is a thermistor TH, and the temperature control means is a first comparator CM1 and a first comparator CM1.
The first constant-voltage power supply comprises a constant-voltage power supply and a relay SR, and the first constant-voltage power supply is set to a heat generation reference voltage V ₀ set to maintain the surface temperature of the heat roller pair 10 in the predetermined range. Output and the heating reference voltage V
_The relay SR is opened / closed by the output of the first comparator CM1 based on a comparison with _0, and the input to the heat source EH of the heat roller pair 10 is controlled.
Since the output is used as the control signal e _C , the non-control state can be defined by the presence or absence of the first comparator output.

According to the heat sealing apparatus of the fourth aspect of the present invention, since the counter means 30 is constituted by the reference clock signal generating means 31, the counter 32, and the digital comparing means 33, the reliability of timekeeping is improved. High in nature.

According to the heat sealing apparatus of the fifth aspect of the present invention, there is provided abnormality detecting means for stopping the input to the heat source of the heat fusing member in response to the abnormal state of the surface temperature detecting means. Therefore, an abnormal state such as short circuit or disconnection in the detection range of the surface temperature detecting means is detected.

According to the heat sealing apparatus of the present invention, since the abnormality detecting means is provided in a plurality of systems, abnormal states such as short circuit and disconnection in the detection range of the surface temperature detecting means can be separately determined. Detect.

[0020]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a heat sealing apparatus 50 according to the present invention. For example, a contact-type thermistor TH is provided as a surface temperature detecting means for performing a time-out error process for an uncontrolled state of the temperature control means. A configuration of a main part of a heat sealing device 50 provided with a time counter means (hereinafter, referred to as “counter means”) is conceptually shown.
As the sheet heating member 12 (12a and 12b) as the heat-sealing member of the heat sealing device 50, an example will be described in which each roller of the roller pair 10 has a built-in heat source EH.

FIG. 1 shows a heat roller 10 similar to FIG.
Only one of “a” is illustrated, and portions other than those related to the measurement and control of the surface temperature are shown simply or omitted. FIG. 2 is a schematic block diagram showing a specific circuit configuration of a surface temperature detecting unit, a temperature controlling unit, and an abnormality detecting unit for obtaining a signal e _C for performing a timeout error process according to the present embodiment. is there.

First, as shown in FIG. 1, the heat sealing device 50 is provided with a surface temperature detecting means for detecting the surface temperature of the heat roller 10, a temperature control means, and a detection control circuit 14 relating to both means. The surface temperature is measured, and the surface temperature is maintained in a predetermined range so that the packaging sheet 20 is heat-sealed.

A part of an output of a comparator CM1 to be described later is taken out of the temperature control means, and is input to the counter means 30 shown in FIG. 3 to perform a timeout error process. The configuration other than the counter means shown in the present embodiment is similar to that of the related art in that the heat roller pair 10 incorporating the heat source EH, a frame (not shown) for fixing the heat roller pair 10, and the rotation of the heat roller. Drive unit 13 involved, control device 1 for overall heat sealing device
5, a power supply 16 for generating heat from the heat roller, a transport device (not shown) for supplying the packaging sheet 20 to the pair of heat rollers 10, and the like. Hereinafter, the configuration that is not particularly described is the same as the conventional configuration.

Hereinafter, the heat roller pair 10, the surface temperature detecting means, and the temperature controlling means, which are main components of the heat sealing apparatus of the present embodiment, will be described.
The counter means 30 will be described. In the following description, the heat roller pair 10 describes one roller 10a, but also corresponds to the roller 10b.

First, the heat roller pair 10 has the same shape and structure as the conventional one, for example, about 20Φ × 60
As described above, a column made of an iron material having a size of about L has a shape in which a non-contact surface is formed by cutting a surface portion other than a sheet heating body portion for heat welding of a packaging sheet.

The heat roller pair 10 contains a heat source EH inside, and the heat source EH is, for example, 50 W
Electric resistance heating with a nichrome wire of about 100 W
The control of the exothermic temperature is easy and preferable. According to the roller-shaped heat-sealing member, a steady operation without intermittent stop can be performed, and the surface temperature can be easily stabilized because the heat roller is kept in contact with the packaging sheet.

Next, the surface temperature detecting means is a heat roller 1
A thermistor TH having a shape in which a temperature sensor is coated with thin glass and covered with a resin tape or the like, for example.
Is used. As will be described later, the thermistor TH can obtain an electrical signal that is accurate and highly sensitive to temperature, and is controlled by ordinary circuit elements together with a control circuit such as a heat source EH to control the heat roller 10a. The surface temperature can be adjusted to the fusing conditions of the packaging sheet 20, and the size is small, the failure is small, and the apparatus cost is low.

In the thermistor TH, the heat-sensitive portion is formed from the surface of the sheet heating body 12 of the heat roller 10a.
The sheet heater 12 is attached to the surface of the sheet heater 12 such that an appropriate pressure is applied so that the temperature can be sensed. The mounting position is preferably as close as possible to the heat source, for example, the surface of the sheet heating member 12 or the surface or side surface of the heat roller 10a. Has been shown as an example of being attached to a position opposite to a contacting portion.

The appropriate pressure in this case is thermistor TH
From the position close to the heat roller 10a.
0a, and is set by adjusting the pressure to a small pressure that does not hinder the rotation of the heat roller 10a and fixing the heat roller 10a. In this case, the thin glass plate has abrasion resistance, and the thin glass plate and the heat roller 10a made of an iron material are used.
Since the abrasion does not continue to progress when they are foldable with each other, it is possible to obtain a state where the temperature sensing unit is less worn and a stable foldable state can be obtained. Therefore, the thermistor TH has few failures and has a long life.

In addition to the thermistor TH, a platinum resistance temperature detector, a thermocouple, or the like may be attached to the heat roller 10a as a thermistor as a contact-type surface temperature detecting means as in the case of the thermistor, or a non-contact type. May be provided. According to these contact surface temperature measuring means, the surface temperature of the heat roller 10a can be accurately detected,
The heat source can be controlled so that the surface temperature exactly matches the fusion condition of the packaging sheet.

By the way, the packaging sheet 20 is provided by applying a thin coating of a synthetic resin such as polyethylene or a metal such as aluminum on the surface of a normal paper material such as glassine paper or cellophane polyethylene paper. It is provided with heat fusion property. Depending on the type of the material of the coating and the setting length of the welding time, the conditions for the thermal fusion slightly differ, but they can be fused to each other generally at 50 to 300 degrees Celsius. Therefore, the surface temperature of the heat roller 10a can be set so as to be suitable for each material in the range of 50 to 300 degrees Celsius.

Next, the temperature control means will be described. The temperature control means includes a first comparator (first comparator) CM1, a first constant voltage power supply (first constant voltage power supply), and a relay. Heat roller 10 described above
In order to maintain the surface temperature of a in a predetermined range, a target value of the temperature to be controlled is determined as a target temperature, and a signal voltage obtained by the surface temperature detecting means (thermistor) at this target temperature is defined as a heat generation reference voltage V _0. Set.

Then, the heat generation reference voltage V ₀ is compared with a signal voltage generated by detecting the surface temperature of the heat roller 10a by the surface temperature detecting means in the first comparator CM1, and a comparator output e _C obtained as a result is obtained. depending on, so as to open and close the relay SR, the heat source E of the heat roller 10a in accordance with the set value of the heating reference voltage V ₀
Control the input to H.

[0035] The first constant voltage power supply, the voltage is set by the resistance means r _A to the constant voltage source CVS to equal the heating reference voltage V _0. As described above, since the predetermined temperature range can be maintained by the ordinary circuit elements, the predetermined temperature range can be arbitrarily determined and precisely controlled.

In this embodiment, the relay SR
Is composed of semiconductor relays (solid state relays) such as photo MOS relays, so that relay operation is performed without contact, and it is small, has almost no failures, has high reliability, and has low power consumption. Can be downsized, and the running cost is small.

Since the surface temperature of the heat roller 10a is maintained within a predetermined range by forming the heat sealing device as described above, the heat source EH
It is not necessary to adjust manually and empirically while monitoring the current etc. of the packaging sheet at all, and it is possible to perform predetermined heat welding on the packaging sheet and heat seal the packaging sheet,
There is an excellent advantage that there is no problem of packaging, there is no waste of power consumption, and there is no need to monitor the heat sealing state of the wrapping paper or the current value of the heat source.

Next, the counter means 30 for performing a timeout error process according to the present invention will be described.
The counter means 30 measures and outputs the time until the control signal e _C is issued, compares it with a predetermined period P described later, and outputs the error signal S _err when there is no control signal by the predetermined period P. Issue and specify a timeout error. By sending this error signal S _err to the CPU,
The CPU presents an alarm or the like. The predetermined period P sets a time period in which the control signal e _C can be considered not to be a non-signal state due to a normal temperature change in the heat sealing member when the control signal e _C has not been issued in the heat sealing device. I do. Therefore, the length of the predetermined period P can be changed in consideration of the temperature to be set, the processing quantity, the occurrence probability of the uncontrolled state, and the like.

FIG. 3 shows the configuration of the counter means 30. In the present embodiment, the counter means 30
It comprises a reference clock signal generating means 31 for generating a reference clock signal of 1 Hz, a counter 32 capable of timing processing, and a digital comparator 33 for setting a predetermined period P and comparing with a counter output.

As the reference clock signal generating means 31 and the counter 32, well-known ones can be used. The digital comparator 33 has a setting switch that can digitally set a predetermined period P by a digital setting switch 34, and the predetermined period P is set in advance.

The counter 32 updates the count value every second in accordance with the clock signal of the reference clock signal generating means 31, resets the count value when receiving the signal e _C , and starts counting again. Restart from 0. Then, the counter 32 sends the count value as a digital signal to the digital comparator 33, and the digital comparator 33 compares the count value with a set value indicating a predetermined period P. The determination is made and an error signal S _err is issued.

Therefore, if the reset is not performed for a long time, the count value of the digital signal becomes the same as the set value of the digital comparator 33, and the time-out occurs.

As described above, the use of the signal e _C , that is, the non-control state of the temperature control means can be defined by the presence or absence of the output of the first comparator, and the time-out error processing is performed. A non-control state can be detected in an automatic manner, and a non-control state can be detected in real time. Therefore, the countermeasure can be taken, and the time reliability of the timeout error processing is high. Since the first comparator CM1 and the like use general-purpose circuit elements,
The operation reliability is high and the device cost is low.

Further, as in the present embodiment, the counter means 30 is provided with a reference clock signal generating means 31 and a counter 3.
2 and the digital comparator 33, the reliability of timekeeping is high and the reliability of the entire heat sealing device is high by using general-purpose circuit elements with excellent accuracy. As described above, the non-control state of the temperature control means can be detected, and the fact that a countermeasure should be taken can be clearly indicated by the CPU. Therefore, the countermeasure can be taken promptly and the occurrence of the secondary trouble can be prevented.

Embodiment 2 In this embodiment, the reference clock signal generating means 31 and the counter 3 in the counter means of the first embodiment are used.
2 and the digital comparator 33, the respective functions are programmed using a computer and configured to control timeout error processing. This computer may be mounted on the CPU, the reference clock signal generating means uses a reference clock of the computer, and the time measurement by the counter and the comparison with the set value are performed on a computer program. Other configurations are the same as those of the first embodiment.

With such a configuration in which the timeout error processing is performed by the computer program, the control circuit and the like of the heat sealing device are multifunctional, and even when a plurality of heat rollers are driven, unified control by the CPU can be achieved. Suitable configuration is possible. By such programming, it can be used for the same device as the heat sealing device according to the present invention or another device for performing the same type of temperature control.

Third Embodiment This embodiment is different from the first or second embodiment in that the normal setting range of the surface temperature detecting means such as short-circuit and disconnection of the thermistor TH serving as the surface temperature detecting means. In order to detect each of the abnormal conditions that can be detected by the above, two systems of abnormality detecting means are provided, and a circuit breaker SB is provided in the input path of the heat source EH, and the thermistor TH receives the disconnection detection signal e _C or the short detection signal e _S. In this case, the circuit breaker SB is shut off in response to the abnormal state of the above, and the input to the heat source EH is stopped. Other configurations are the same as those of the first or second embodiment.

FIG. 4 is a block diagram of a main part of a heat seal device provided with two such abnormality detecting means. In the first embodiment, the comparator (first comparator CM1), the resistance means r _A and the constant voltage power supply CVS (first
A constant-voltage power supply is provided, and a heat generation reference voltage V ₀ is set.

On the other hand, in the third embodiment,
Further, the second and third comparators CM2 and CM3
There soon as it is connected to the output line of the temperature detection means, the constant-voltage power supply CVS resistor means as a shared remains one r _B and r _C by the second and third voltage (exothermic reference voltage V Embodiment 1 Vn and _Vm are set ( _{where 0} is the first voltage), and this setting results in a connection equivalent to providing the second and third constant-voltage power supplies. The second and third voltage V _n and V _m, is determined corresponding to the next virtual temperature value of the abnormal state will be described.

In this way, the abnormality detection means provided in the two systems comprises the second and third comparators CM2 and CM3.
And the constant voltage power supply CVS and the second and third constant voltages V _n
And constituted by a V _m. Thermistor T described above
In order to detect an abnormal state in the range where H can normally be detected,
A virtual temperature value in each case to be recognized as an abnormal state when a short circuit or disconnection occurs is determined as an abnormal set value.

When the thermistor TH reaches this abnormal state, the signal voltage at which the surface temperature detecting means detects and outputs this abnormal state and the signal voltage of the surface temperature detecting means in the normal operating state are determined. The output signal voltage is compared with the second and third comparators CM2 and CM3, respectively, and the comparator outputs obtained at this time are sent to the circuit breaker SB as a disconnection detection signal e _C and a short detection signal e _S , respectively. Controls to stop the input to the heat source EH. At this time, without providing a circuit breaker, the detection signal e _C and the short detection signal e _S
May be sent to the CPU, and the input to the heat source EH may be stopped by other means.

The constant voltage power supply CVS is shared, and is provided with three resistance means r _A to r 3 so as to be equal to the signal voltages V _n and V _m corresponding to the heat generation reference voltage V ₀ and the abnormal set value, respectively. The voltage is set using r _C. This will be described how the setting procedure of how to configure Specifically respectively by resistance means r _A ~r _C according to the abnormal setting value short or disconnection of.

That is, the resistance means r_BIs the second comparator
The thermistor disconnects so that CM2 is used for disconnection detection.
Then, the voltage at point S reaches the upper limit.
Voltage slightly lower than the upper limit of the output of the voltage power supply CVS
Set. On the other hand, resistance means r _CIs the third comparator C
Just as M3 is for short detection, the thermistor TH
When the short circuit occurs, the voltage at point S becomes almost 0.
From the lower limit of the output of the voltage power supply CVS to a slightly larger voltage
Set.

As described above, since the constant voltage power supply CVS is used in common and the abnormal setting value is set by the resistance means r _{A to} r _C , the power supply cost can be reduced and, for example, a variable resistor can be used. There is an advantage that an easy-to-operate means such as adjustment of a variable knob in a simple resistance means can be used.

It should be noted that the abnormality detection means may be provided in only one system, or may be provided in three or more systems. Further, the heat generation reference voltage V
_A plurality of target temperatures can be set in consideration of the difference in the material and thickness of the packaging sheet, the number of welding processes, and the like, by setting a plurality of _zeros, thereby further improving the convenience.

As described above, since the abnormality detecting means is provided,
An abnormal state can be detected immediately, and measures can be taken. In addition, if a plurality of systems are provided, each of a plurality of types of abnormal states can be separately detected, and each of them can be properly dealt with.

When a plurality of temperature detecting means and abnormality detecting means are provided, they may be provided separately for each roller of the heat roller pair 10 so as to eliminate the temperature difference.

In this embodiment, the circuit breaker S
Since B is composed of light emitting diodes, thyristors, etc., which are semiconductor switches, it can be miniaturized with no contacts, high reliability and low power consumption, so the driving device of the heat sealing device can be miniaturized and running cost can be reduced. Also have small advantages.

As described above, since the abnormality detecting means and the circuit breaker are provided, the abnormal state is immediately detected and the input to the heat source is stopped to prevent abnormal heating or the like, and to prevent secondary damage. And the like, and if a plurality of systems are provided, each of a plurality of types of abnormal states can be separately detected, and each of them can be properly dealt with.

Embodiment 4 In this embodiment, as shown in FIG. 6, a heat-sealing member of a heat-sealing device has a flat surface in conformity with the shape of a portion where the packaging sheets are heat-sealed to each other. In this configuration, the packaging sheet 20 is heat-sealed using the heat equalizer 40 formed in the above-described manner, the surface temperature of the heat equalizer 40 is detected and measured, and the input to the heat source EH is controlled. Other configurations can be the same as any of the first to third embodiments. FIG. 6 shows only the positional relationship between the heat equalizer 40 and the packaging sheet 20 and only the position where a thermistor TH, which is a contact-type temperature detector, is attached as a surface temperature detector.

With the structure in which the heat equalizer 40 is brought into contact with the packaging sheet 20 in a plane as described above, the efficiency of heat transfer to the packaging sheet 20 can be improved, and the adhesion of the sealing portion of the packaging sheet 20 can be improved. Good.

As is clear from the above description, the heat sealing device according to the present invention is not limited to chemicals and the like, but can also be configured to seal food with a packaging sheet or the like.
The same operational effects as those described in the first to fourth embodiments are obtained.

[0063]

According to the heat sealing apparatus of the present invention, when the control signal from the temperature control means is not issued during the predetermined period P, the time-out error processing is performed. At this time, this can be detected and it can be clearly indicated that a countermeasure should be taken, so that a non-control state can be detected quickly and a countermeasure can be taken, so that a secondary problem can be prevented.

Counter means can be provided for time-out error processing, and a part of the output of the control signal is used as a reset signal for the counter means. When there is no input, the timeout error processing is performed, so that the non-control state can be detected in synchronization with the control signal, a countermeasure can be taken in real time, and the time reliability of the timeout error processing is high.

The surface temperature detecting means is a thermistor, and the temperature controlling means is a first comparator and a first comparator.
The relay comprises a constant voltage power supply and a relay SR, and the relay is opened and closed by a first comparator output based on a comparison between the output of the thermistor and a heat generation reference voltage, and the input to the heat source of the heat roller pair is controlled. Since the comparator output can be used as the control signal, the non-control state can be defined by the presence or absence of the first comparator output. Therefore, since general-purpose circuit elements are used, the reliability of operation is high and the device cost is low.

Since the counter means can be constituted by a reference clock signal generating means, a counter, and a digital comparing means, the reliability of timekeeping is high. Therefore, the reliability of the heat sealing device is high.

Since there can be provided an abnormality detecting means for stopping the input to the heat source of the heat sealing member in response to an abnormal state of the surface temperature detecting means, a short circuit or a disconnection in the detection range of the surface temperature detecting means can be provided. Abnormal state can be detected, and the abnormal state can be quickly detected and countermeasures can be taken, so that secondary problems can be prevented. By providing a plurality of the abnormality detecting means, it is possible to separately detect an abnormal state such as a short circuit and a disconnection in the detection range of the surface temperature detecting means.

[Brief description of the drawings]

FIG. 1 is an explanatory view conceptually showing a main part of a heat sealing device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a part related to detection and control in the heat sealing device according to the first embodiment of the present invention.

FIG. 3 is a block diagram of a counting unit according to the first embodiment of the present invention.

FIG. 4 is a block diagram of a part related to detection and control in a heat sealing device according to a third embodiment of the present invention.

FIG. 5 is a perspective view of a main part of a heat sealing device according to a fourth embodiment of the present invention.

FIG. 6 is an explanatory view conceptually showing a main part of a conventional heat sealing device.

FIG. 7 is an explanatory view conceptually showing a main part of a conventional heat sealing device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Heat roller pair, 12 ... Sheet heating body, 20 ... Packaging sheet, 30 ... Counter means, TH ... Thermistor, E
H: heat source, SR: semiconductor relay, SB: semiconductor switch

Claims (6)

[Claims] A heat-fusing member; a surface temperature detecting means for detecting a surface temperature of the heat-fusing member; and a temperature control means for controlling a temperature of the heat-fusing member. A heat sealing device in which a packaging sheet is heat-sealed by the heat-sealing member while being maintained in a predetermined range, wherein a control signal (e _C ) by the temperature control means is not issued during a predetermined period (P). A heat sealing device wherein a timeout error process is performed. 2. A counter means (30) is provided, and a part of the output of the control signal (e _C ) is supplied to the counter means (30).
The counter means (30) starts measuring time after receiving the reset signal, and the counter means (30) sends the control signal (e _C ) to the counter means (30) during a predetermined period (P). The heat seal device according to claim 1, wherein a timeout error process is performed when there is no input. 3. The device according to claim 1, wherein said surface temperature detecting means is a thermistor (T
H) and the temperature control means is a first comparator (CM
1), a first constant voltage power supply, and a relay (SR). The first reference voltage (V ₀ ) is set to a heat generation reference voltage (V ₀ ) set to maintain the surface temperature of the heat roller pair (10) within the predetermined range. A constant voltage power supply is set, and a first comparator based on a comparison between the output of the thermistor (TH) and the heating reference voltage (V ₀ )
The (CM1) output opens and closes the relay (SR) to control the input to the heat source (EH) of the heat roller pair (10),
The output of the first comparator (CM1) is the control signal
3. The heat sealing device according to claim 2, which is used as (e _C ). 4. The heat sealing device according to claim 2, wherein said counter means (30) comprises a reference clock signal generating means (31), a counter (32), and a digital comparing means (33). 5. The heat sealing apparatus according to claim 1, further comprising abnormality detecting means for stopping input to a heat source of the heat sealing member in response to an abnormal state of the surface temperature detecting means. 6. The heat sealing device according to claim 5, wherein a plurality of the abnormality detecting means are provided.