CN214407552U - Glue leakage detection sensor and detector applying same - Google Patents

Abstract

The utility model provides a leak and glue detection sensor, sets up in the hourglass position of awaiting measuring and glues, its characterized in that: the glue leakage detection sensor comprises a first conductive part, a second conductive part and an insulating layer which is arranged between the first conductive part and the second conductive part and realizes mutual electrical isolation, and a glue leakage accommodating cavity which can change a capacitance value between the pressurized first conductive part and the pressurized second conductive part is formed at the glue leakage part to be detected. The utility model has the advantages that: the structure is simple, the manufacturing cost is low, the installation and the use are convenient, and the factor of being interfered by the outside is small; the control circuit adopts the latest capacitance digital conversion integrated chip to replace the traditional capacitance digital conversion circuit, thereby simplifying the circuit structure, improving the precision, having strong anti-interference capability and ensuring the requirements of the precision and the accuracy of the detection.

Description

Glue leakage detection sensor and detector applying same

Technical Field

The utility model relates to a leak and glue detection sensor, especially a can be applied to the sensor that the injection molding machine leaks to glue and detects and use the detector that has this sensor.

Background

In the prior art, in the injection molding process of an injection molding machine, plastic is ejected from a gap of an injection nozzle or a bearing seat under the condition of high speed and high pressure due to various reasons (such as deformation of a mold, blockage of a flow passage, overlarge back pressure or mismatching of the injection nozzle and the mold, and the like), so that rubber materials cannot be injected into a mold cavity or overflow to generate rubber leakage; once glue leakage occurs, the glue solution can be adhered to a plastic machine, a mold, a product or a hot runner assembly, if the glue solution is not found in time, the leaked glue solution is more and more, not only can a heating cable and a temperature measuring system on the plastic machine heating assembly or the hot runner assembly be damaged, but also the problems of material loss, equipment damage and the like can be easily caused, moreover, the glue solution adhered to the equipment is extremely difficult to clean, the whole injection molding machine head, the heating system or the hot runner system can be scrapped due to excessive glue leakage, the plastic machine heating system or the hot runner system can only be replaced again, the workload is huge, the time and the labor are wasted, and the money is wasted.

Therefore, for the problem of glue leakage, various glue leakage detection devices are adopted to detect the glue leakage phenomenon at present, and if the glue leakage is found, a user is informed of cleaning in time. The existing china utility model "an intelligent glue leakage detector that uses on injection molding machine" as patent number ZL201920859164.8 discloses such glue leakage detector, its structure includes casing down, go up the casing, connect quick-witted line and power lamp, the utility model discloses when the injection molding machine leaks glue, and only use first capillary connecting pipe to detect, when the glue that spills enters into in the middle of the first capillary connecting pipe tip, make first air pump inhale the unable discharge of the air of first breather pipe and first capillary connecting pipe, the atmospheric pressure increases, the first baroceptor department response of connecting in first breather pipe department, and pass the information of response to microprocessor department and handle, when the pressure value reaches or surpassed first baroceptor's setting value, at this moment, microprocessor starts the scintillation alarm and sends out the police dispatch newspaper, the suggestion staff, and in time inspect and adjust this injection molding machine. However, the structure of the leakage detector in the patent is complex, and the small holes in the capillary connecting pipe are easy to block, thereby affecting the detection precision and the use reliability.

And as for patent invention with application number 201910703152.0, namely a temperature control alarm device for glue leakage detection and a practical novel patent with patent number ZL201921958638.0, a nozzle leakage detection mechanism for an injection molding machine is characterized in that the nozzle leakage detection mechanism for the injection molding machine is used for carrying out online detection on the injection molding machine through a temperature sensor, when the nozzle leakage of the injection molding machine occurs, the injection molding machine automatically stops working, and meanwhile, an audible and visual electric alarm gives an alarm. However, the accuracy of the detection result obtained by the temperature detection method is easily affected by the ambient temperature, the deviation of the detection result is large, and the requirement of the temperature detection method on the installation position is high.

In summary, the existing glue leakage detection method and equipment still have the above problems, and further improvement and perfection are to be made.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the first technical problem that a simple structure and reliable hourglass of testing result are glued and are provided and detect sensor to above-mentioned prior art current situation.

The utility model discloses the second technical problem that will solve is to above-mentioned prior art current situation and provides an use and has above-mentioned hourglass to glue the detection sensor and detect the higher detector of precision.

The utility model provides a technical scheme that above-mentioned first technical problem adopted does: the utility model provides a leak and glue detection sensor, sets up in the hourglass position of awaiting measuring and glues, its characterized in that: the glue leakage detection sensor comprises a first conductive part, a second conductive part and an insulating layer which is arranged between the first conductive part and the second conductive part and realizes mutual electrical isolation, and a glue leakage accommodating cavity which can accommodate leaked glue solution and change a capacitance value between the first conductive part and the second conductive part after voltage is applied is formed at the part to be detected where glue leakage is to be detected.

The glue leakage part to be detected is a nozzle, and for convenience of installation, preferably, the first conductive part is a first conductive cylinder piece sleeved outside the nozzle, the second conductive part is a second conductive cylinder piece sleeved outside the first conductive part, the insulating layer is filled between the first conductive cylinder piece and the second conductive cylinder piece, an annular cavity is formed between the first conductive cylinder piece and the nozzle, the cavity is a glue leakage accommodating cavity, and the second conductive cylinder piece is connected with the nozzle in an equipotential manner. The conductive part is designed into a barrel shape, so that the nozzle can be conveniently and directly sleeved for use, and the structure is simple and the manufacture is simple.

In order to facilitate the installation and the positioning of the sensor, as further preferable, a base is further formed at the bottom of the nozzle, the nozzle and the base are integrally formed, the cross section of the nozzle is in an inverted T shape, the diameter of the second conductive cylinder piece is matched with that of the base, the bottom of the second conductive cylinder piece is in direct contact with the base, and the bottom of the first conductive cylinder piece is suspended in the air in the base. The diameter of the second conductive cylinder piece is designed to be matched with the diameter of the base, so that the sensor can be directly limited on the base on one hand, and the equipotential connection between the second conductive cylinder piece and the base can be realized on the other hand.

The part is glued for leaking by the hot runner flow distribution plate and the die carrier die cavity of constituteing in order to save space, conveniently detects simultaneously, as preferred, first conductive part is first conductive pole piece, the second conductive part is hot runner flow distribution plate or die carrier, one side of insulating piece attached in on the lateral wall of hot runner flow distribution plate and/or the inside wall of die carrier, the opposite side of this insulating piece is attached with first conductive part, the die cavity of constituteing by hot runner flow distribution plate and die carrier is promptly leak and glue the holding chamber.

In order to improve the precision and reliability of detection, it is further preferable that one or two or more hot runner nozzles are arranged on the hot runner manifold, and at least one first conducting pole piece with an insulating sheet is arranged on the side wall of the hot runner manifold and/or the inner side wall of the mold base.

The utility model provides a technical scheme that above-mentioned second technical problem adopted does: the utility model provides a leak and glue detector which characterized in that: the glue leakage detector comprises a glue leakage detection sensor, and a control circuit which is electrically connected with the glue leakage detection sensor and used for acquiring, analyzing and processing information of the glue leakage sensor, wherein the control circuit comprises a first electrode socket which can be connected with a first conductive part and a second electrode socket which is connected with a second conductive part, the glue leakage detection sensor further comprises a first lead which is connected with the first electrode socket and the first conductive part, and a second lead which is connected with the second electrode socket and the second conductive part.

The control circuit comprises

The power supply circuit provides power supply voltage of the whole control circuit;

the capacitance digital conversion circuit is provided with a signal receiving end and a signal output end and is used for converting continuous capacitance signal data into data which can be read by digital equipment;

the signal conditioning circuit is provided with an input end and an output end, the signal conditioning circuit carries out filtering amplification processing on the collected signals from the glue leakage detection sensor to enable the collected signals to be suitable for analog-to-digital conversion, the input end comprises a first electrode socket and a second electrode socket, and the output end is connected with a signal receiving end of the capacitance-to-digital conversion circuit;

the alarm circuit controls the alarm output of the acousto-optic and electronic equipment; and

the main control circuit is used for processing circuit information of each functional module and comprises a digital signal acquisition end, a power input end and a trigger end, wherein the digital signal acquisition end is connected with a signal output end of the capacitance digital conversion circuit, the power input end is connected with the power circuit, and the trigger end is connected with the alarm circuit.

Preferably, the capacitance-to-digital conversion circuit is a capacitance-to-digital conversion integrated chip with the model number of FDC2212, FDC2112, FDC2214 or FDC 2114. The capacitive digital conversion integrated chip (FDC2212 or FDC2112 or FDC2214 or FDC2114) has the advantages of simple and reliable peripheral circuit, strong anti-interference capability and high conversion precision.

For convenience of observation, it is further preferable that the control circuit further includes a display circuit capable of setting parameters and displaying contents, and the main control circuit further includes a display control terminal connected to the display circuit.

Compared with the prior art, the utility model has the advantages of: the sensor realizes the glue leakage detection by adopting a capacitance principle, has simple integral structure, lower manufacturing cost, convenient installation and use and small factor of external interference; secondly, the sensor is matched with a control circuit, so that the precision and the reliability of a detection result can be effectively improved, the glue leakage amount can be controlled according to actual needs, an alarm is sent to remind a user when a set threshold value is exceeded, the timeliness is strong, and the detection result is accurate; in addition, the latest capacitance-to-digital conversion integrated chip is adopted in the control circuit to replace the traditional capacitance-to-digital conversion circuit, so that the circuit structure is simplified, the precision is improved, the anti-interference capability is strong, and the requirements on the precision and the accuracy of detection are met.

Drawings

Fig. 1 is the utility model provides a leak and glue detection sensor three-dimensional cross-sectional view.

Fig. 2 is the utility model provides a leak and glue detection sensor spatial structure sketch map.

Fig. 3 is a cross-sectional view of a use state of the first glue leakage detection sensor according to the present invention.

Fig. 4 is a usage status diagram of the glue leakage detection sensor according to the first embodiment of the present invention.

Fig. 5 is a schematic block diagram of a control circuit of the glue leakage detector according to the first embodiment of the present invention.

Fig. 6 is a diagram showing a state of the glue leakage detecting sensor according to the second embodiment of the present invention.

Fig. 7 is a second usage state diagram of a glue leakage detection sensor according to a second embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments.

The utility model relates to a leak and glue detection sensor and use detector that has this sensor, this leak and glue detection sensor sets up in the hourglass position of awaiting measuring to glue, leak and glue detection sensor including first conductive part, second conductive part and set up between first conductive part and second conductive part and realize the insulating layer of mutual electrical isolation, and, the hourglass that the position shaping of gluing of awaiting measuring has the glue solution that can hold and spill and make the capacitance value between the first conductive part after the energizing and the second conductive part change (the medium changes between two conductive parts) and leak gluey holding chamber.

The glue leakage detection sensor can be used for various injection molding machine extruders, hot runner mold systems or other systems with glue leakage and liquid substances needing to be detected, the specific shape of the glue leakage detection sensor can be adjusted adaptively according to different glue leakage detection positions (different shapes and sizes), the specific structural shape and the installation mode of the glue leakage detection sensor are different, and the following embodiments are specifically referred.

In the first embodiment, as shown in fig. 1 to 5:

the embodiment is applied to an injection molding machine extruder, a to-be-tested glue leakage part is a cylindrical nozzle 1 (injection molding nozzle/nozzle), a base 2 is formed at the bottom of the nozzle 1, the nozzle 1 and the base 2 are integrally formed, the cross section of the to-be-tested glue leakage part is in an inverted T shape, a first conductive part is a first conductive cylinder sheet 31 sleeved outside the nozzle 1, a second conductive part is a second conductive cylinder sheet 32 sleeved outside the first conductive part, a cylindrical insulating layer 33 is filled between the first conductive cylinder sheet 31 and the second conductive cylinder sheet 32, for convenience of installation, the first conductive cylinder sheet 31, the insulating layer 33 and the second conductive cylinder sheet 32 of the embodiment are sequentially attached from inside to outside and rolled into a cylindrical shape, an annular cavity 4 is formed between the first conductive cylinder sheet 31 and the nozzle 1, and the cavity 4 is a glue leakage accommodating cavity, and refer to fig. 3 and 4;

in order to facilitate the installation and positioning of the sensor, the diameter of the second conductive cylinder piece 32 is matched with the diameter of the base 2, the bottom of the second conductive cylinder piece 32 is directly contacted with the base 2, and the bottom of the first conductive cylinder piece 31 is suspended in the base 2, namely the bottom of the first conductive cylinder piece 31 is not contacted with the base 2; the diameter of the second conductive cylinder piece 32 is designed to match the diameter of the base 2, so that the sensor can be directly limited on the base 2 on one hand, and the equipotential connection between the second conductive cylinder piece 32 and the base 2 (the base 2 and the nozzle 1) can be realized on the other hand.

The sensor of this embodiment can directly overlap when using on nozzle 1, simple structure, simple manufacture, and the drum diameter size of sensor can be adjusted according to 2 external diameters of base of nozzle 1 size, and the drum height of sensor is less than the jet 11 of nozzle 1.

As shown in fig. 4, the glue leakage detecting apparatus for applying the glue leakage detecting sensor of the present embodiment includes a glue leakage detecting sensor and a control circuit electrically connected to the glue leakage detecting sensor, the control circuit is integrated on a circuit board 7 and is used for collecting, analyzing and processing information of the glue leakage detecting sensor, wherein the control circuit includes a first electrode socket 51 and a second electrode socket 52, and the glue leakage detecting sensor further includes a first wire 61 and a second wire 62; then, the first conductive cylinder 31 is connected to the first electrode socket 51 through the first wire 61, the second conductive cylinder 32 is connected to the second electrode socket 52 through the second wire 62, and after the power is turned on, a certain voltage value is always maintained between the first conductive cylinder 31 and the second conductive cylinder 32.

The functional block diagram of the control circuit of this embodiment is shown in fig. 5, and specifically includes

A power supply circuit a1 for supplying a power supply voltage of the entire control circuit;

the capacitance digital conversion circuit b1 adopts a capacitance digital conversion integrated chip U with the model number of FDC2212 or FDC2112 or FDC2214 or FDC2114, and the capacitance digital conversion circuit b1 is provided with a signal receiving end and a signal output end and is used for converting continuous capacitance signal data into data which can be read by digital equipment; in the present embodiment, a capacitance-to-digital conversion integrated chip of the type FDC2212 is used, and a specific connection manner of a peripheral circuit is shown in a dashed line frame in fig. 5;

a signal conditioning circuit c1 having an input terminal c11 and an output terminal, wherein the signal conditioning circuit c1 filters and amplifies the collected signal from the glue leakage detection sensor to make it suitable for analog/digital conversion, and the input terminal c11 comprises a first electrode socket 51(P1) and a second electrode socket 52(P2), and the output terminal is connected with the signal receiving terminal of the capacitance digital conversion circuit b 1;

the alarm circuit d1 controls the alarm output of the acousto-optic device, and can adopt alarm devices such as LED lamps or alarms to realize the alarm output;

the display circuit e1 can set parameters and display contents, and a nixie tube display screen is adopted, so that a user can conveniently observe parameter changes;

the main control circuit (singlechip) f1 is used for processing circuit information of each functional module, and the main control circuit comprises a display control end, a digital signal acquisition end, a power input end and a trigger end, wherein the display control end is connected with the display circuit, the digital signal acquisition end is connected with the power input end of the signal output end of the capacitor digital conversion circuit b1, which is connected with the power circuit a1, and the trigger end is connected with the alarm circuit d 1.

The capacitance digital conversion circuit b1 of this embodiment has adopted the newest capacitance digital conversion integrated chip, compares in traditional digital conversion circuit, and this integrated chip has that peripheral circuit is simple reliable, the interference killing feature is strong, the high advantage of conversion precision, and this integrated chip still leaves sensor spare channel interface, can connect the convenience and connect other sensor spare circuit g1 and use.

The functional modules (the power circuit a1, the signal conditioning circuit c1, the alarm circuit d1, the display circuit and the main control circuit) of the control circuit can be implemented by the existing functional circuits in the prior art, and the specific circuit structure belongs to the prior art and is not described herein.

The working principle of the glue leakage detector of the embodiment is as follows:

installing a glue leakage detection sensor on the nozzle 1 to ensure that the second conductive cylinder piece 32 is contacted with the base 2, and connecting the first conductive cylinder piece 31 with a first electrode socket 51 of a control circuit through a first lead 61; the second conductive barrel 32 controls the second electrode socket 52 of the circuit via a second lead 62;

after the power is switched on, the second conductive cylinder piece 32, the base 2 and the nozzle 1 are connected into a first electrode of a capacitor in an equipotential manner, the first conductive cylinder piece 31 becomes a second electrode of the capacitor, the first conductive cylinder piece 31 is isolated from the second conductive cylinder piece 32 through the insulating layer 33, when the power is started, a medium between the first conductive cylinder piece 31 and the two poles of the nozzle 1 is air, namely an initial capacitance value, when leaking glue flows out, the leaking glue medium can be filled in a cavity 4 (namely a glue leakage accommodating cavity) between the first conductive cylinder piece 31 and the nozzle 1, the medium between the two electrodes changes, the capacitance value changes, when the capacitance value changes to reach a set threshold value, the alarm device is started, and the warning of glue leakage is prompted.

Example two, as shown in fig. 6 and 7:

the application scenario of this embodiment is a hot runner mold, considering that the space near the hot runner nozzle is limited, and the cylindrical sensor in the first embodiment cannot be directly sleeved outside the hot runner nozzle, and the to-be-tested glue leakage position of this embodiment is set in the cavity 9 formed by the hot runner manifold 71 and the mold frame 72, so the first conductive part of this embodiment is set as the first conductive sheet 81, the second conductive part is directly replaced by the hot runner manifold 71 and/or the mold frame 72 (the hot runner manifold 71 and the mold frame 72 are in contact with each other, and have the same potential therebetween), the insulating layer adopts an insulating sheet 82 adapted to the size of the first conductive sheet 81, one side of the insulating sheet 82 can be directly attached to the side wall of the hot runner manifold 71 or the inner side wall of the mold frame 72, a first conductive part is attached to the other side of the insulating sheet 82, and a cavity 9 formed by the hot runner manifold 71 and the mold frame 72 is a leaking glue accommodating cavity.

As shown in fig. 6, the application scenario is that one side of the insulating sheet 82 is attached to the sidewall of the hot runner manifold 71, and as shown in fig. 7, one side of the insulating sheet 82 is attached to the inner sidewall of the mold frame 72; in either case, the first conductive portion is disposed on the other side of the insulating sheet 82, the second conductive portion is replaced by the hot runner manifold 71 or the mold frame 72, and the first conductive pole piece 81 and the hot runner manifold 71 (or the mold frame 72) are connected to the first electrode socket 51 and the second electrode socket 52 of the control circuit via wires, respectively.

In practical applications, one or more hot runner nozzles 73 are usually disposed on the hot runner manifold 71, the shape of the mold cavity 9 may be various, and during installation, in order to improve the accuracy and reliability of detection, at least one or more first conductive pole pieces 81 with an insulating sheet 82 may be disposed on the side wall of the hot runner manifold 71 and/or the inner side wall of the mold frame 72, specifically, 6 first conductive pole pieces 81 with an insulating sheet 82 in the present embodiment are respectively distributed at different positions (on the side wall of the hot runner manifold 71 and/or the inner side wall of the mold frame 72) in the mold cavity 9, so as to ensure the sensitivity and reliability of detection.

The working principle of the glue leakage detector using the glue leakage detection sensor of the present embodiment is the same as that of the first embodiment, and the principle of the control circuit used is also the same, which is not described herein again.

After the power is switched on, the first conducting pole piece 81 is a first electrode of a capacitor, the hot runner flow distribution plate 71 and/or the die carrier 72 is a second electrode of the capacitor, in an initial state, the cavity 9 (namely, the glue leakage accommodating cavity) is filled with air and is an initial capacitance value, after glue leakage flows out and enters the cavity 9, a medium between the two electrodes changes, the capacitance value changes, and when the capacitance value changes and reaches a set threshold value, the alarm device is started to prompt glue leakage and warn.

The glue leakage detection method realized by adopting the glue leakage detectors of the first embodiment and the second embodiment comprises the following steps:

the method comprises the following steps that firstly, a glue leakage detection sensor is arranged at a glue leakage position to be detected, and a first conductive part and a second conductive part of the glue leakage detection sensor are respectively connected to a first electrode socket and a second electrode socket of a control circuit through leads;

step two, starting a control circuit, detecting whether a capacitance value C between the first conductive part and the second conductive part changes, and if so, executing the next step; if not, continuing to execute the step;

step three, judging whether the capacitance change value delta C between the first conductive part and the second conductive part exceeds a set capacitance change threshold Ct, if so, executing the next step; if not, executing the step five;

fourthly, the control circuit gives an alarm to prompt the glue leakage fault and stop the equipment;

step five, the equipment keeps the original working state and returns to the step three.

Claims (9)

1. The utility model provides a leak and glue detection sensor, sets up in the hourglass position of awaiting measuring and glues, its characterized in that: the glue leakage detection sensor comprises a first conductive part, a second conductive part and an insulating layer which is arranged between the first conductive part and the second conductive part and realizes mutual electrical isolation, and a glue leakage accommodating cavity which can accommodate leaked glue solution and change a capacitance value between the first conductive part and the second conductive part after voltage is applied is formed at the part to be detected where glue leakage is to be detected.

2. The missing glue detection sensor according to claim 1, characterized by: the glue leakage detection device is characterized in that the glue leakage part to be detected is a nozzle (1), the first conductive part is a first conductive cylinder piece (31) sleeved outside the nozzle (1), the second conductive part is a second conductive cylinder piece (32) sleeved outside the first conductive part, an insulating layer is filled between the first conductive cylinder piece (31) and the second conductive cylinder piece (32), an annular cavity (4) is formed between the first conductive cylinder piece (31) and the nozzle (1), the cavity (4) is a glue leakage accommodating cavity, and the second conductive cylinder piece (32) is connected with the nozzle (1) in an equipotential mode.

3. The missing glue detection sensor according to claim 2, characterized in that: the nozzle is characterized in that a base (2) is further formed at the bottom of the nozzle (1), the nozzle (1) and the base (2) are integrally formed, the cross section of the nozzle is in an inverted T shape, the diameter of the second conductive cylinder piece (32) is matched with that of the base (2), the bottom of the second conductive cylinder piece (32) is in direct contact with the base (2), and the bottom of the first conductive cylinder piece (31) is suspended in the base (2).

4. The missing glue detection sensor according to claim 1, characterized by: await measuring leaking the die cavity (9) that gluey position is constituteed by hot runner flow distribution plate (71) and die carrier (72), first conductive part is first conductive pole piece (81), the second conductive part is hot runner flow distribution plate (71) and/or die carrier (72), the insulating layer adopts insulating piece (82) with first conductive pole piece (81) size looks adaptation, one side of insulating piece (82) attached in on the lateral wall of hot runner flow distribution plate (71) and/or the inside wall of die carrier (72), the opposite side of this insulating piece (82) is attached with first conductive part, and die cavity (9) of constituteing by hot runner flow distribution plate (71) and die carrier (72) are promptly leak and glue holding chamber.

5. The missing glue detection sensor according to claim 4, characterized in that: the hot runner flow distribution plate (71) is provided with one or two or more hot runner nozzles (1), and at least one first conductive pole piece (81) with an insulating sheet (82) is arranged on the side wall of the hot runner flow distribution plate (71) and/or the inner side wall of the mould base (72).

6. The utility model provides a leak and glue detector which characterized in that: the glue leakage detector comprises the glue leakage detection sensor as claimed in claim 1, and further comprises a control circuit which is electrically connected with the glue leakage detection sensor and used for collecting, analyzing and processing information of the glue leakage sensor, wherein the control circuit comprises a first electrode socket (51) which can be connected with the first conductive part and a second electrode socket (52) which is connected with the second conductive part, the glue leakage detection sensor further comprises a first lead which is connected with the first electrode socket (51) and the first conductive part, and a second lead which is connected with the second electrode socket (52) and the second conductive part.

7. The missing glue detector of claim 6, characterised in that: the control circuit comprises

A power supply circuit (a1) that supplies a power supply voltage of the entire control circuit;

a capacitance-to-digital conversion circuit (b1) having a signal receiving terminal and a signal output terminal for converting continuous capacitance signal data into data readable by a digital device;

a signal conditioning circuit (c1) having an input terminal and an output terminal, wherein the signal conditioning circuit (c1) filters and amplifies the collected signal from the glue leakage detection sensor to make the signal suitable for analog/digital conversion, and the input terminal comprises the first electrode socket (51) and the second electrode socket (52), and the output terminal is connected with the signal receiving terminal of the capacitance digital conversion circuit (b 1);

an alarm circuit (d1) for controlling the alarm output of the acousto-optic device; and

master control circuit (f1) for handle each functional module circuit information, this master control circuit (f1) is including having digital signal collection end, power input and trigger end, digital signal collection end is connected the signal output part of electric capacity digital conversion circuit (b1), power input connects power supply circuit (a1), alarm circuit (d1) is connected to the trigger end.

8. The missing glue detector of claim 7, characterised in that: the capacitance digital conversion circuit (b1) is a capacitance digital conversion integrated chip with the model number of FDC2212 or FDC2112 or FDC2214 or FDC 2114.

9. The missing glue detector of claim 7, characterised in that: the control circuit also comprises a display circuit (e1) capable of setting parameters and displaying content, and the main control circuit (f1) also comprises a display control end which is connected with the display circuit (e 1).

Images